iMRS 2000 - PEMF Publications
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PEMF Publications

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1201

Transient pulsed radio emission from a magnetar

Anomalous X-ray pulsars (AXPs) are slowly rotating neutron stars with very bright and highly variable X-ray emission that are believed to be powered by ultra-strong magnetic fields of >10(14) G, according to the 'magnetar' model. The radio pulsations that have been observed from more than 1,700 neutron stars with weaker magnetic fields have never been detected from any of the dozen known magnetars. The X-ray pulsar XTE J1810-197 was revealed (in 2003) as the first AXP with transient emission when its luminosity increased 100-fold from the quiescent level; a coincident radio source of unknown origin was detected one year later. Here we show that XTE J1810-197 emits bright, narrow, highly linearly polarized radio pulses, observed at every rotation, thereby establishing that magnetars can be radio pulsars. There is no evidence of radio emission before the 2003 X-ray outburst (unlike ordinary pulsars, which emit radio pulses all the time), and the flux varies from day to day. The flux at all radio frequencies is approximately equal--and at >20 GHz XTE J1810-197 is currently the brightest neutron star known. These observations link magnetars to ordinary radio pulsars, rule out alternative accretion models for AXPs, and provide a new window into the coronae of magnetars.

1202

Transient radical pairs studied by time-resolved EPR

Photogenerated short-lived radical pairs (RP) are common in biological photoprocesses such as photosynthesis and enzymatic DNA repair. They can be favorably probed by time-resolved electron paramagnetic resonance (EPR) methods with adequate time resolution. Two EPR techniques have proven to be particularly useful to extract information on the working states of photoinduced biological processes that is only difficult or sometimes even impossible to obtain by other types of spectroscopy. Firstly, transient EPR yields crucial information on the chemical nature and the geometry of the individual RP halves in a doublet-spin pair generated by a short laser pulse. This time-resolved method is applicable in all magnetic field/microwave frequency regimes that are used for continuous-wave EPR, and is nowadays routinely utilized with a time resolution reaching about 10 ns. Secondly, a pulsed EPR method named out-of-phase electron spin echo envelope modulation (OOP-ESEEM) is increasingly becoming popular. By this pulsed technique, the mutual spin-spin interaction between the RP halves in a doublet-spin pair manifests itself as an echo modulation detected as a function of the microwave-pulse spacing of a two-pulse echo sequence subsequent to a laser pulse. From the dipolar coupling, the distance between the radicals is readily derived. Since the spin-spin interaction parameters are typically not observable by transient EPR, the two techniques complement each other favorably. Both EPR methods have recently been applied to a variety of light-induced RPs in photobiology. This review summarizes the results obtained from such studies in the fields of plant and bacterial photosynthesis and DNA repair mediated by the enzyme DNA photolyase.

1203

Translational free random walk of spins in the presence of a parabolic magnetic field

The free random walk approach has been used to analyze the attenuation of the NMR signal due to spin dephasing in the presence of a constant and pulsed parabolic magnetic field. The spin echo sequence was chosen to examine the attenuation of the NMR signal resulting from self-diffusion. In the framework of the gaussian approach, the long-time limit calculations predict more pronounced diffusion weighting for the parabolic field than for linear magnetic field. Analytical results were obtained and compared with those from other approaches based on a variety of different of approximations.

1204

Treatment of an adult with neglected congenital pseudoarthrosis of the tibia with acute fracture: a case report

Treatment of congenital pseudoarthrosis of the tibia is very difficult. Numerous surgical procedures have been used including bone grafting, fixation, pulsed electromagnetic field, vascularized fibular bone grafting and lengthening devices. Previous studies, often reporting unsatisfactory results, are limited to children and adolescents. In adults, the following factors need to be considered: leg length discrepancy, leg deformity, soft tissue problems, lack of potential for growth and difficulties in healing. We reported a case of untreated congenital pseudoarthrosis of the tibia with fracture in a 32-year-old man. Conventional treatments used included excision of the pseudoarthrosis, correction of the deformity, intramedullary fixation, bone grafting and soft tissue transplantation for lengthening and coverage. These procedures led to good bony union and a satisfactory outcome.

1205

Treatment of chronic varicose ulcers with pulsed electromagnetic fields: a controlled pilot study

To evaluate the efficacy of pulsed electromagnetic fields (PEMF) in healing of chronic varicose ulcers, 19 patients with this condition were included in a double-blind controlled clinical trial. All patients received standard ulcer therapy throughout the duration of the study and were randomly divided into two groups to receive either active or inactive PEMF therapy. Active therapy was provided by the use of a pait of helmholtz coils on a twice weekly basis over a five week period and inactive therapy was provided on an identical regimen with identical coils wound so that no magnetic field was produced when an electric current was passed through them. The clinician and patients were unable to distinguish the active or inactive coils. No statistically relevant difference was noted between the two groups in the healing rates of the ulcer, change in the lower leg girth, pain or infection rates. However there was a trend in favour of a decrease in ulcer size and lower leg girth in the group treated with active PEMF. As PEMF is a novel treatment for chronic varicose ulcers, more work needs to be done to establish treatment parameters and its usefulness in the treatment of this condition.

1206

Treatment of congenital and infantile pseudarthrosis of the tibia with pulsing electromagnetic fields

The management of congenital and infantile pseudarthrosis of the tibia poses difficult problems because of the variability in the type and prognosis of the lesion and varied response to surgical treatment. Whatever the severity of the lesion, the use of pulsed electromagnetic fields can be expected to improve the prognosis for union by a factor of at least 20 per cent. In a very few patients, usually those with pseudarthrosis presenting later in life, pulsed electromagnetic fields alone together with plaster immobilization may be sufficient to produce union. In some, partially successful previous surgery may be made completely successful by subsequent application of pulsed electromagnetic fields. In patients with a fair or good prognosis as regards the type of lesion, a combination of surgery and pulsed electromagnetic treatment, some period of which may also be given before surgical treatment, gives a moderately high rate of success. In the three groups already described, the overall success rate is likely to be more than 70 per cent. In lesions with a poor prognosis, or after multiple surgical procedures in an older child, a combination of very adequate further surgery and pulsed electromagnetic fields can produce union in perhaps 30 per cent of cases, but it is unwise to commence any treatment if the limb is already unacceptably short, if there is gross wasting of the limb with evidence of inadequate vascular supply, and/or if the joints of the foot and ankle are stiff and associated with deformity. In such cases, the procedure of choice is amputation.

1207

Treatment of delayed union and nonunion of the tibia by pulsed electromagnetic fields. A retrospective follow-up

The results of a clinical follow-up of 57 tibial lesions treated with pulsed electromagnetic fields at least six months after the primary lesion occurred proved that this noninvasive method can be a valuable alternative to other commonly accepted modes of therapy. The overall success rate was 75% but could be improved to 81% when the proper indications were met.

1208

Treatment of delayed unions and nonunions of the proximal fifth metatarsal with pulsed electromagnetic fields

Nine delayed unions and nonunion of the proximal fifth metatarsal were treated with pulsed electromagnetic fields (PEMF). All fractures healed in a mean time of 4 months (range 2-8 months). Those fractures treated with both pulsed electromagnetic fields and a nonweightbearing cast healed in a mean time of 3 months (range 2-4 months). The average duration of follow-up was 39 months (range 24-60 months). There were no refractures. When compared with reported healing times and morbidity for conventional casting, medullary curettage with inlay bone, and closed axial intramedullary screw fixation, pulsed electromagnetic fields provided an effective alternative for the treatment of delayed unions and nonunion of the proximal fifth metatarsal.

1209

Treatment of delayed- and non-union of fractures using pulsed electromagnetic fields

A prospective series of 32 consecutive patients, with 33 long-bone fractures suffering from delayed- or non-union were treated by pulsed electromagnetic fields (PEMF) or by PEMF with surgery. The management regime for the PEMF treatment was simpler and less rigid than that reported by Bassett et al. and our stimulation waveform was also different. Nineteen fractures (100%) treated with surgery and PEMF united within nine months of the commencement of PEMF treatment. Fourteen fractures were treated with PEMF alone. Twelve (86%) united within ten months and two failed to unite. The results of this study suggest that the stimulating waveform is less critical than is claimed by Bassett et al. and that a simpler and easier management regime for PEMF treatment can be just as effective. Alternatively PEMF may have no effect on fracture healing.

1210

Treatment of knee osteoarthritis with pulsed electromagnetic fields: a randomized, double-blind, placebo-controlled study

This study was unable to demonstrate reduction in pain, BUT able to REDUCE STIFFNESS in patients 65 and older.

1211

Treatment of knee osteoarthritis with pulsed electromagnetic fields: a randomized, double-blind, placebo-controlled study

OBJECTIVE: The investigation aimed at determining the effectiveness of pulsed electromagnetic fields (PEMF) in the treatment of osteoarthritis (OA) of the knee by conducting a randomized, double-blind, placebo-controlled clinical trial. DESIGN: The trial consisted of 2h daily treatment 5 days per week for 6 weeks in 83 patients with knee OA. Patient evaluations were done at baseline and after 2 and 6 weeks of treatment. A follow-up evaluation was done 6 weeks after treatment. Activities of daily living (ADL), pain and stiffness were evaluated using the Western Ontario and McMaster Universities (WOMAC) questionnaire. RESULTS: Within group analysis revealed a significant improvement in ADL, stiffness and pain in the PEMF-treated group at all evaluations. In the control group there was no effect on ADL after 2 weeks and a weak significance was seen after 6 and 12 weeks. Significant effects were seen on pain at all evaluations and on stiffness after 6 and 12 weeks. Between group analysis did not reveal significant improvements over time. Analysis of ADL score for the PEMF-treated group revealed a significant correlation between less improvement and increasing age. Analysis of patients <65 years using between group analysis revealed a significant improvement for stiffness on treated knee after 2 weeks, but this effect was not observed for ADL and pain. CONCLUSIONS: Applying between group analysis we were unable to demonstrate a beneficial symptomatic effect of PEMF in the treatment of knee OA in all patients. However, in patients <65 years of age there is significant and beneficial effect of treatment related to stiffness.

1214

Treatment of nonunion using pulsed electromagnetic fields: a retrospective follow-up study

Pulsed electromagnetic fields (PEMF) are a useful means of treating cases of fracture nonunion. In 67.7% of nonunions with a disability time of at least 24 months, complete consolidation was obtained. This success rate is increased to 76.6% if we exclude nonunion, that presented contraindications for treatment with PEMF. The disability time had no effect on the success rate. Lesions of the humerus and atrophic nonunion had an unfavorable prognosis.

1215

Treatment of nonunited scaphoid fractures by pulsed electromagnetic field and cast

Thirty-five of 44 nonunited scaphoid fractures that were at least 6 months old healed in a mean time of 4.3 months during pulsed electromagnetic field (PEMF) treatment using external coils and a thumb spica cast. The mean time from the onset of the fracture to treatment was 40 months. No concurrent operation was performed. Follow-up time averaged 8.4 months. Eight of nine fractures with avascular necrosis healed. Five of eight fractures in the proximal third healed. Twelve (75%) of 16 patients treated in short-arm thumb spica casts and PEMF healed versus 22 (92%) of 24 patients treated initially in long-arm thumb spica casts and PEMF. We have found PEMF to be a reliable alternative method of treating nonunited scaphoid fractures. Because of the low risk, simplicity of use, and reliability, we recommend its consideration in the treatment of undisplaced, nonunited fractures without carpal instability less than 5 years after the injury. Treatment should initially begin with a long-arm cast.

1216

Treatment of nonuniting osteotomies with pulsating electromagnetic fields. A controlled animal experiment

To evaluate treatment of nonunions or pseudarthrosis in humans by pulsating electromagnetic fields (PEMF), the authors tested the method in four- to six-year-old beagle dogs with midshaft osteotomies of both ulnae. This type of osteotomy in dogs leads to nonunion. After surgery one foreleg of each dog was stimulated for an average of 25 days; the second foreleg served as a control. Subsequently all ulnae were harvested, radiographs were obtained, and the stiffness of the callus was mechanically tested. Thus, the reputed efficiency is not confirmed by controlled experiments on dogs. The stimulated bones were neither radiologically nor mechanically superior to the controls.

1217

Treatment of Parkinson's disease with magnetic fields reduces the requirement for antiparkinsonian medications

Recently, I reported that extracranial treatment with picoTesla range magnetic fields (MF) is an effective, safe, and revolutionary modality in the management of Parkinsonism including those patients manifesting levodopa-induced motor complications. This treatment, which has emerged as a potentially more advantageous modality than pharmacologic therapy, also produces improvements in nonmotor aspects of the disease including mood, cognitive functions, sleep, pain, appetite, autonomic functions, and sexual behavior, which are usually minimally, if at all, ameliorated by long term therapy with levodopa or anticholinergic agents. The present communication concerns a 69 year old Parkinsonian patient who, following a series of two treatments with extracranial picoTesla range MF on two separate days, improved to the point where he was able to discontinue most of his antiparkinsonian medications for a period of two weeks without experiencing deterioration in symptoms. On the third week he began to develop recurrence of symptoms and resumed taking his regular medications. At the end of the fourth week the patient received a series of four magnetic treatments on four successive days after he completely discontinued his antiparkinsonian medications. During this period he experienced a remarkable improvement in motor disability as well as in cognitive functions (i.e., visuospatial performance), mood, sleep, appetite, bowel functions and resolution of pain in the lower extremity. This report attests to the antiparkinsonian efficacy of picoTesla range MF and suggests that this treatment, when applied on a regular basis, may reduce the requirement for antiparkinsonian medications. This observation, when confirmed in a larger cohort of patients, may carry important implications for the therapy of Parkinsonism as it may offer an alternative treatment for patients who develop levodopa failure or experience intolerable side effects from dopaminergic medication. The observation that magnetic treatment improved the patient's symptoms while being off dopaminergic therapy supports the role of nondopaminergic mechanisms in the pathophysiology of Parkinsonism.

1218

Treatment of scaphoid nonunion with casting and pulsed electromagnetic fields: a study continuation

This article presents a continuation of a study of the treatment of scaphoid nonunion with pulsed electromagnetic fields (PEMF) and cast immobilization. Fifty-four patients were reviewed. The overall success rate for healing has decreased since the previous review from 80% to 69%. Proximal pole fractures healed in 50%. Success in nonunions with associated radiographic evidence of avascular necrosis decreased from 89% to 73%. Although we believe that the indications for use of PEMF have not changed significantly, this study suggests that a successful outcome with PEMF and casting is less likely than previously reported. We believe that until additional clinical studies have further defined the indications, treatment protocol, and efficacy of this method PEMF treatment should be a secondary alternative to bone-grafting procedures.

1219

Treatment of spasticity with repetitive magnetic stimulation; a double-blind placebo-controlled study.

The effect of repetitive magnetic stimulation on spasticity was evaluated in 38 patients with multiple sclerosis in a double-blind placebo-controlled study. One group was treated with repetitive magnetic stimulation (n = 21) and the other group with sham stimulation (n = 17). Both groups were treated twice daily for 7 consecutive days. Primary end-points of the study were changes in the patients self-score, in clinical spasticity score, and in the stretch reflex threshold. The self-score of ease of daily day activities improved by 22% (P = 0.007) after treatment and by 29% (P = 0.004) after sham stimulation. The clinical spasticity score improved -3.3 +/- 4.7 arbitrary unit (AU) in treated patients and 0.7 +/- 2.5 AU in sham stimulation (P = 0.003). The stretch reflex threshold increased 4.3 +/- 7.5 deg/s in treated patients and -3.8 +/- 9.7 deg/s in sham stimulation (P = 0.001). The data presented in this study supports the idea that repetitive magnetic stimulation has an antispastic effect in multiple sclerosis. Future studies should clarify the optimal treatment regimen.

1222

Treatment of therapeutically resistant non-unions with bone grafts and pulsing electromagnetic fields

This study reviews the cases of eighty-three adults with ununited fractures who were treated concomitantly with bone-grafting and pulsed electromagnetic fields. An average of 1.5 years had elapsed since fracture and the use of this combined approach. Nearly one-third of the patients had a history of infection, and an average of 2.4 prior operations had failed to produce bone union. Thirty-eight patients who were initially treated with grafts and pulsed electromagnetic fields for ununited fractures with wide gaps, synovial pseudarthrosis, and malalignment achieved a rate of successful healing of 87 per cent. Forty-five patients who had initially been treated unsuccessfully with pulsing electromagnetic fields alone had bone-grafting and were re-treated with pulsing electromagnetic fields. Ninety-three per cent of these fractures healed. The residual failure rate after two therapeutic attempts, one of which was operative, was 1.5 per cent. The median time to union for both groups of patients was four months.

1225

Treatment of ununited tibial fractures: a comparison of surgery and pulsed electromagnetic fields (PEMF)

The use of pulsed electromagnetic fields (PEMF) is gaining acceptance for the treatment of ununited fractures. The results of 44 articles published in the English language literature have been compiled to assess the effectiveness of PEMF vs surgical therapy. For ununited tibial fractures, 81% of reported cases healed with PEMF vs 82% with surgery. After multiple failed surgeries, the success rate of PEMF is reported to be greater than with surgery; this discrepancy increases with additional numbers of prior surgeries. In infected nonunions, the results of surgical treatment decreased by 21% and were less than the results utilizing PEMF (69% vs 81%). In open fractures, surgical healing exceeded PEMF (89% vs 78%), whereas in closed injuries PEMF cases healed more frequently (85% vs 79%). In general, PEMF treatment of ununited fractures has proved to be more successful than noninvasive traditional management and at least as effective as surgical therapies. Given the costs and potential dangers of surgery, PEMF should be considered an effective alternative. Experience supports its role as a successful method of treatment for ununited fractures of the tibia.

1226

Treatment of whiplash-associated disorders--part I: Non-invasive interventions

BACKGROUND: A whiplash-associated disorder (WAD) is an injury due to an acceleration-deceleration mechanism at the neck. WAD represents a very common and costly condition, both economically and socially. In 1995, the Quebec Task Force published a report that contained evidence-based recommendations regarding the treatment of WAD based on studies completed before 1993 and consensus-based recommendations. OBJECTIVE: The objective of the present article--the first installment of a two-part series on interventions for WAD--is to provide a systematic review of the literature published between January 1993 and July 2003 on noninvasive interventions for WAD using meta-analytical techniques. METHODS OF THE REVIEW: Three medical literature databases were searched for identification of all studies on the treatment of WAD. Randomized controlled trials (RCTs) and epidemiological studies were categorized by treatment modality and analyzed by outcome measure. The methodological quality of the RCTs was assessed. When possible, pooled analyses of the RCTs were completed for meta-analyses of the data. The results of all the studies were compiled and systematically reviewed. RESULTS: Studies were categorized as exercise alone, multimodal intervention with exercise, mobilization, strength training, pulsed magnetic field treatment and chiropractic manipulation. A total of eight RCTs and 10 non-RCTs were evaluated. The mean score of methodological quality of the RCTs was five out of 10. Pooled analyses were completed across all treatment modalities and outcome measures. The outcomes of each study were summarized in tables. CONCLUSIONS: There exists consistent evidence (published in two RCTs) in support of mobilization as an effective noninvasive intervention for acute WAD. Two RCTs also reported consistent evidence that exercise alone does not improve range of motion in patients with acute WAD. One RCT reported improvements in pain and range of motion in patients with WAD of undefined duration who underwent pulsed electromagnetic field treatment. Conflicting evidence in two RCTs exists regarding the effectiveness of multimodal intervention with exercise. Limited evidence, in the form of three non-RCTs, exists in support of chiropractic manipulation. Future research should be directed toward clarifying the role of exercise and manipulation in the treatment of WAD, and supporting or refuting the benefit of pulsed electromagnetic field treatment. Mobilization is recommended for the treatment of pain and compromised cervical range of motion in the acute WAD patient.

1227

Treatment of whiplash-associated disorders--part II: Medical and surgical interventions

BACKGROUND: Whiplash-associated disorder (WAD) is a term used to describe injury due to an acceleration-deceleration mechanism at the neck. In 1995, the Quebec Task Force published a report that contained evidence-based recommendations regarding the treatment of WAD based on studies completed before 1993 and consensus-based recommendations. OBJECTIVE: The objective of the present article--the second installment of a two part review on WAD--is to provide a systematic review of the literature published between January 1993 and July 2003 on medical and surgical interventions for WAD using meta-analytical techniques. METHODS OF THE REVIEW: Three medical literature databases were searched for identification of all clinical trials on the treatment of WAD. Randomized controlled trials (RCTs) and epidemiological studies were categorized by treatment modality and analyzed by outcome measures. The methodological quality of the RCTs was assessed. When possible, pooled analyses of the RCTs were completed for meta-analyses of the data. The results of all the studies were compiled and systematically reviewed. RESULTS: The studies were categorized as medical or surgical interventions. A total of five RCTs and six non-RCTs were evaluated. The mean methodological quality of the RCTs was 7.3 among studies on medical interventions and 7.5 for studies on surgical intervention. Pooled analyses were completed across all treatment modalities and outcome measures. The outcomes of each study were summarized in tables. CONCLUSIONS: While several quality RCTs and epidemiological studies have been published since 1993 on medical and surgical interventions, the cumulative evidence is lacking. Moderate evidence exists in support of radiofrequency neurotomy. Evidence for steroid injections, botulinum treatments, carpal tunnel decompression and cervical discectomy is conflicting or unclear. Future research is required to clarify the utility of radiofrequency neurotomy and pulsed electromagnetic field treatment for WAD.

1228

Treatment with AC pulsed electromagnetic fields improves olfactory function in Parkinson's disease

Olfactory dysfunction is a common symptom of Parkinson's disease (PD). It may manifest in the early stages of the disease and infrequently may even antedate the onset of motor symptoms. The cause of olfactory dysfunction in PD remains unknown. Pathological changes characteristic of PD (i.e., Lewy bodies) have been demonstrated in the olfactory bulb which contains a large population of dopaminergic neurons involved in olfactory information processing. Since dopaminergic drugs do not affect olfactory threshold in PD patients, it has been suggested that olfactory dysfunction in these patients is not dependent on dopamine deficiency. I present two fully medicated Parkinsonian patients with long standing history of olfactory dysfunction in whom recovery of smell occurred during therapeutic transcranial application of AC pulsed electromagnetic fields (EMFs) in the picotesla flux density. In both patients improvement of smell during administration of EMFs occurred in conjunction with recurrent episodes of yawning. The temporal association between recovery of smell and yawning behavior is remarkable since yawning is mediated by activation of a subpopulation of striatal and limbic postsynaptic dopamine D2 receptors induced by increased synaptic dopamine release. A high density of dopamine D2 receptors is present in the olfactory bulb and tract. Degeneration of olfactory dopaminergic neurons may lead to upregulation (i.e., supersensitivity) of postsynaptic dopamine D2 receptors. Presumably, small amounts of dopamine released into the synapses of the olfactory bulb during magnetic stimulation may cause activation of these supersensitive receptors resulting in enhanced sense of smell. Interestingly, in both patients enhancement of smell perception occurred only during administration of EMFs of 7 Hz frequency implying that the release of dopamine and activation of dopamine D2 receptors in the olfactory bulb was partly frequency dependent. In fact, weak magnetic fields have been found to cause interaction with biological systems only within narrow frequency ranges (i.e., frequency windows) and the existence of such frequency ranges has been explained on the basis of the cyclotron resonance model.

1229

Treatment with AC pulsed electromagnetic fields improves the response to levodopa in Parkinson's disease

A 52-year-old fully medicated Parkinsonian patient with severe disability became asymptomatic in the weeks after he received twice weekly transcranial treatments with AC pulsed electromagnetic fields of picoTesla flux density. This gentleman experienced significant enhancements in his response to standard Sinemet medication. visit study concludes that intermittent applications of AC pulsed EMFs of pictesla flux denisty reverse the course of chronic progressive Parkinson's disease.

1230

Treatment with AC pulsed electromagnetic fields improves the response to levodopa in Parkinson's disease

A 52 year old fully medicated Parkinsonian patient with severe disability (stage 4 on the Hoehn & Yahr disability scale) became asymptomatic 10 weeks after he received twice weekly transcranial treatments with AC pulsed electromagnetic fields (EMFs) of picotesla flux density. Prior to treatment with EMFs, his medication (Sinemet CR) was about 50% effective and he experienced end-of-dose deterioration and diurnal-related decline in the drug's efficacy. For instance, while his morning medication was 90% effective, his afternoon medication was only 50% effective and his evening dose was only 30% effective. Ten weeks after introduction of treatment with EMFs, there was 40% improvement in his response to standard Sinemet medication with minimal change in its efficacy during the course of the day or evening. These findings demonstrate that intermittent, AC pulsed applications of picotesla flux density EMFs improve Parkinsonian symptoms in part by enhancing the patient's response to levodopa. This effect may be related to an increase in the capacity of striatal DA neurons to synthesize, store and release DA derived from exogenously supplied levodopa as well as to increased serotonin (5-HT) transmission which has been shown to enhance the response of PD patients to levodopa. Since decline in the response to levodopa is a phenomenon associated with progression of the disease, this case suggests that intermittent applications of AC pulsed EMFs of picotesla flux density reverse the course of chronic progressive PD.

1231

Treatment with AC pulsed electromagnetic fields normalizes the latency of the visual evoked response in a multiple sclerosis patient with optic atrophy

Visual evoked response (VER) studies have been utilized as supportive information for the diagnosis of multiple sclerosis (MS) and may be useful in objectively monitoring the effects of various therapeutic modalities. Delayed latency of the VER, which reflects slowed impulse transmission in the optic pathways, is the most characteristic abnormality associated with the disease. Brief transcranial applications of AC pulsed electromagnetic fields (EMFs) in the picotesla flux density are efficacious in the symptomatic treatment of MS and may also reestablish impulse transmission in the optic pathways. A 36 year old man developed an attack of right sided optic neuritis at the age of 30. On presentation he had blurring of vision with reduced acuity on the right and fundoscopic examination revealed pallor of the optic disc. A checkerboard pattern reversal VER showed a delayed latency to right eye stimulation (P100 = 132 ms; normal range: 95-115 ms). After he received two successive applications of AC pulsed EMFs of 7.5 picotesla flux density each of 20 minutes duration administered transcranially, there was a dramatic improvement in vision and the VER latency reverted to normal (P100= 107 ms). The rapid improvement in vision coupled with the normalization of the VER latency despite the presence of optic atrophy, which reflects chronic demyelination of the optic nerve, cannot be explained on the basis of partial or full reformation of myelin. It is proposed that in MS synaptic neurotransmitter deficiency is associated with the visual impairment and delayed VER latency following optic neuritis and that the recovery of the VER latency by treatment with pulsed EMFs is related to enhancement of synaptic neurotransmitter functions in the retina and central optic pathways. Recovery of the VER latency in MS patients may have important implications with respect to the treatment of visual impairment and prevention of visual loss. Specifically, repeated pulsed applications of EMFs may maintain impulse transmission in the optic nerve and thus potentially sustain its viability.

1232

Treatment with electromagnetic field alters the clinical course of chronic progressive multiple sclerosis--a case report

It is estimated that 10-20% of patients with multiple sclerosis (MS) have a chronic progressive (CP) course characterized by an insidious of neurological deficits followed by steady progression of disability in the absence of symptomatic remission. No therapeutic modality has shown specific efficacy in the treatment of patients with CP MS and there are no data to indicate that any pharmacologic or other modality alters the clinical course of CP MS. Treatment with picotesla electromagnetic fields (EMFs) is a highly effective modality for the symptomatic management of MS including the chronic progressive form. In addition, this treatment also appears to alter the natural course of the disease in CP patients. A 36 year-old man experienced, at the age of 31, insidious weakness in the legs and several months later developed difficulties with balance with ataxia of gait. His gait abnormality progressed slowly over the following years and at the age of 35 he was severely disabled with spastic paraparesis and ataxia using a rolling walker for ambulation and a scooter for longer distances. In particular, his disability had progressed rapidly over the six months preceding the initiation of treatment with EMFs. He as classified have CP MS and his prognosis was considered extremely unfavorable due to the degree of cerebellar and pyramidal tract involvement and the rapid course of deterioration. In July 1995 the patient began experimental treatment with EMFs. While receiving three treatment sessions a week over 12 months he experienced improvement in cerebellar functions such as gait, balance and tremor as well as bowel and bladder functions, mood, sleep and cognitive function and resolution of diplopia, blurring of vision, dysarthria, paresthesias in the hands, and fatigue. Most remarkably, there was no further progression of the disease during the course of magnetic therapy. This case illustrated that treatment with EMFs, in addition to producing symptomatic improvement, also reverses the clinical course of CP MS.

1233

Treatment with electromagnetic fields improves dual-task performance (talking while walking) in multiple sclerosis

Multiple sclerosis (MS) is associated with an increased risk of falling resulting from visual disturbances, difficulties with gait and balance, apraxia of gait and peripheral neuropathy. These factors often interact synergistically to compromise the patient's gait stability. It has long been recognized that walking involves a cognitive component and that simultaneous cognitive and motor operations (dual-task) such as talking while walking may interfere with normal ambulation. Talking while walking reflects an example of a dual-task which is frequently impaired in MS patients. Impaired dual-task performance during walking may compromise the patient's gait and explain why in some circumstances, MS patients unexpectedly lose their balance and fall. Frontal lobe dysfunction, which commonly occurs in MS patients, may disrupt dual-task performance and increase the risk of falling in these patients. This report concerns a 36 old man with remitting-progressive MS with an EDSS score of 5.5 who experienced marked increase in spasticity in the legs and trunk and worsening of his gait and balance, occasionally resulting in falling, when talking while walking. His gait and balance improved dramatically after he received two successive transcranial treatments, each of 45 minutes, with AC pulsed electromagnetic fields (EMFs) of 7.5 picotesla flux density. Simultaneously, there was improvement in dual-task performance to the extent that talking while walking did not adversely affect his ambulation. In addition, neuropsychological testing revealed an almost 5-fold increase in word output on the Thurstone's Word-Fluency Test, which is sensitive to frontal lobe dysfunction. It is suggested that facilitation of dual-task performance during ambulation contributes to the overall improvement of gait and balance observed in MS patients receiving transcranial treatment with AC pulsed EMFs.

1234

Treatment with electromagnetic fields reverses the long-term clinical course of a patient with chronic progressive multiple sclerosis

It is estimated that 10-20% of patients with multiple sclerosis (MS) have a chronic progressive (CP) course characterized by an insidious onset of neurological deficits followed by steady progression of disability in the absence of symptomatic remission. To date no therapeutic modality has proven effective in reversing the clinical course of CP MS although there are indications that prolonged treatment with picotesla electromagnetic fields (EMFs) alters the clinical course of patients with CP MS. A 40 year-old woman presented in December of 1992 with CP MS with symptoms of spastic paraplegia, loss of trunk control, marked weakness of the upper limbs with loss of fine and gross motor hand functions, severe fatigue, cognitive deficits, mental depression, and autonomic dysfunction with neurogenic bladder and bowel incontinence. Her symptoms began at the age of 18 with weakness of the right leg and fatigue with long distance walking and over the ensuing years she experienced steady deterioration of functions. In 1985 she became wheelchair dependent and it was anticipated that within 1-2 years she would become functionally quadriplegic. In December of 1992 she began experimental treatment with EMFs. While receiving regularly weekly transcortical treatments with AC pulsed EMFs in the picotesla range intensity she experienced during the first year improvement in mental functions, return of strength in the upper extremities, and recovery of trunk control. During the second year she experienced the return of more hip functions and recovery of motor functions began in her legs. For the first time in years she can now initiate dorsiflexion of her ankles and actively extend her knees voluntarily. Over the past year she started to show signs of redevelopment of reciprocal gait. Presently, with enough function restored in her legs, she is learning to walk with a walker and is able to stand unassisted and maintain her balance for a few minutes. She also regained about 80% of functions in the upper limbs and hands. Most remarkably, there was no further progression of the disease during the 4 years course of magnetic therapy. This patient's clinical recovery cannot be explained on the basis of a spontaneous remission. It is suggested that pulsed applications of picotesla EMFs affect the neurobiological and immunological mechanisms underlying the pathogenesis of CP MS.

1235

Treatment with weak electromagnetic fields attenuates carbohydrate craving in a patients with multiple sclerosis

Pharmacological studies have implicated serotonergic (5-HT) neurons in the regulation of food intake and food preference. It has been shown that the urge to consume carbohydrate rich foods is regulated by 5-HT activity and that carbohydrate craving is triggered by 5-HT deficiency in the medical hypothalamus. Ingestion of carbohydrate foods stimulates insulin secretion which accelerates the uptake of tryptophan, the precursor of 5-HT and melatonin, into the brain and pineal gland, respectively. Thus, carbohydrate craving might be considered a form of "self medication" aimed at correcting an underlying dysfunction of cerebral 5-HT and pineal melatonin functions. A 51 year old woman with remitting-progressive MS experienced carbohydrate craving during childhood and adolescence and again in temporal association with the onset of her first neurological symptoms at the age of 45. Carbohydrate craving, which resembled the pattern observed in patients with seasonal affective disorder (SAD), was attenuated by a series of extracranial AC pulsed applications of picotesla (10(-12) Tesla) flux intensity electromagnetic fields (EMFs). It is suggested that AC pulsed EMFs applications activated retinal mechanisms which, through functional interactions with the medial hypothalamus, initiated an increased release of 5-HT and resynchronization of melatonin secretion ultimately leading to a decrease in carbohydrate craving. The occurrence of carbohydrate craving in early life may have increased the patient's vulnerability to viral infection given the importance of 5-HT and melatonin in immunomodulation and the regulation of the integrity of the blood brain barrier. The recurrence of this craving in temporal relation to the onset of neurological symptoms suggests that 5-HT deficiency and impaired pineal melatonin functions are linked to the timing of onset of the clinical symptoms of the disease. The report supports the role of experimental factors in the pathophysiology of MS.

1237

Treatment with weak electromagnetic fields improves fatigue associated with multiple sclerosis

It is estimated that 75-90% of patients with multiple sclerosis (MS) experience fatigue at some point during the course of the disease and that in about half of these patients, subjective fatigue is a primary complaint. In the majority of patients fatigue is present throughout the course of the day being most prominent in the mid to late afternoon. Sleepiness is not prominent, but patients report that rest may attenuate fatigability. The pathophysiology of the fatigue of MS remains unknown. Delayed impulse conduction in demyelinated zones may render transmission in the brainstem reticular formation less effective. In addition, the observation that rest may restore energy and that administration of pemoline and amantadine, which increase the synthesis and release of monoamines, often improve the fatigue of MS suggest that depletion of neurotransmitter stores in damaged neurons may contribute significantly to the development of fatigue in these patients. The present report concerns three MS patients who experienced over several years continuous and debilitating fatigue throughout the course of the day. Fatigue was exacerbated by increased physical activity and was not improved by rest. After receiving a course of treatments with picotesla flux electromagnetic fields (EMFs), which were applied extracranially, all patients experienced improvement in fatigue. Remarkably, patients noted that several months after initiation of treatment with EMFs they were able to recover, after a short period of rest, from fatigue which followed increased physical activity. These observations suggest that replenishment of monoamine stores in neurons damaged by demyelination in the brainstem reticular formation by periodic applications of picotesla flux intensity EMFs may lead to more effective impulse conduction and thus to improvement in fatigue including rapid recovery of fatigue after rest.

1238

Treatment with weak electromagnetic fields restores dream recall in a parkinsonian patient

Absent or markedly reduced REM sleep with cessation of dream recall has been documented in numerous neurological disorders associated with subcortical dementia including Parkinson's disease, progressive supranuclear palsy and Huntington's chorea. This report concerns a 69 year old Parkinsonian patient who experienced complete cessation of dreaming since the onset of motor disability 13 years ago. Long term treatment with levodopa and dopamine (DA) receptor agonists (bromocriptine and pergolide mesylate) did not affect dream recall. However, dreaming was restored after the patient received three treatment sessions with AC pulsed picotesla range electromagnetic fields (EMFs) applied extracranially over three successive days. Six months later, during which time the patient received 3 additional treatment sessions with EMFs, he reported dreaming vividly with intense colored visual imagery almost every night with some of the dreams having sexual content. In addition, he began to experience hypnagogic imagery prior to the onset of sleep. Cessation of dream recall has been associated with right hemispheric dysfunction and its restoration by treatment with EMFs points to right hemispheric activation, which is supported by improvement in this patient's visual memory known to be subserved by the right temporal lobe. Moreover, since DA neurons activate REM sleep mechanisms and facilitate dream recall, it appears that application of EMFs enhanced DA activity in the mesolimbic system which has been implicated in dream recall. Also, since administration of pineal melatonin has been reported to induce vivid dreams with intense colored visual imagery in normal subjects and narcoleptic patients, it is suggested that enhanced nocturnal melatonin secretion was associated with restoration of dream recall in this patient. These findings demonstrate that unlike chronic levodopa therapy, intermittent pulsed applications of AC picotesla EMFs may induce in Parkinsonism reactivation of reticular-limbic-pineal systems involved in the generation of dreaming.

1239

Tumoricidal cells increased by pulsating magnetic field

Repeated applications of pulsed magnetic fields (right-angle waves, 50 Hz = 135 Gauss, 2 Hz = 262 Gauss) significantly enhanced the number and the tumoricidal activity of nonparenchymal liver cells. The transplantable mouse leukemia L1210 used as a tumor model was not significantly influenced, either directly or during Cyclophosphamide treatment.

1240

Tunneling-induced spin alignment at low and zero field

The transfer of rotational to spin angular momentum of CH3 groups according to the Haupt effect is shown to be independent of magnetic field strength, including zero field. Haupt enhanced pulsed nuclear resonance signals of gamma-picoline have been observed at fields below 50 mT with a sensitivity enhancement of more than 3 orders of magnitude over thermally polarized experiments.

1241

Two-element dielectric antenna serially excited by optical wavelength multiplexing

A single pulsed laser beam containing multiple wavelengths (wavelength multiplexing) is employed to activate two semiconductor antennas in series. The dielectric nature of the semiconductors permits serial cascading of the antenna elements. Recently observed nonlinear characteristics of the radiated field as a function of the free carrier accelerating (bias) voltage are used to minimize the small interactions between elements. We demonstrate that the temporal electromagnetic radiation distribution of two serial antennas is sensitive to the three-dimensional pattern of the optical excitation source. One can, in turn, vary this distribution continuously by optical means to reconfigure the array.

1242

Type testing of the Siemens Plessey electronic personal dosemeter

This paper presents the results of a laboratory assessment of the performance of a new type of personal dosimeter, the Electronic Personal Dosemeter made by Siemens Plessey Controls Limited. Twenty pre-production dosimeters and a reader were purchased by Ontario Hydro for the assessment. Tests were performed on radiological performance, including reproducibility, accuracy, linearity, detection threshold, energy response, angular response, neutron response, and response time. There were also tests on the effects of a variety of environmental factors, such as temperature, humidity, pulsed magnetic and electric fields, low- and high-frequency electromagnetic fields, light exposure, drop impact, vibration, and splashing. Other characteristics that were tested were alarm volume, clip force, and battery life. The test results were compared with the relevant requirements of three standards: an Ontario Hydro standard for personal alarming dosimeters, an International Electrotechnical Commission draft standard for direct reading personal dose monitors, and an International Electrotechnical Commission standard for thermoluminescence dosimetry systems for personal monitoring. In general, the performance of the Electronic Personal Dosemeter was found to be quite acceptable: it met most of the relevant requirements of the three standards. However, the following deficiencies were found: slow response time; sensitivity to high-frequency electromagnetic fields; poor resistance to dropping; and an alarm that was not loud enough. In addition, the response of the electronic personal dosimeter to low-energy beta rays may be too low for some applications. Problems were experienced with the reliability of operation of the pre-production dosimeters used in these tests.

1243

Ultrafast high resolution separation of large DNA fragments by pulsed-field capillary electrophoresis

Pulsed-field capillary electrophoresis (PFCE) in buffers containing ultradilute polymer solutions is used to separate long chain dsDNA in less than 4 min. Separations are shown to work with chain lengths below 10 kbp and greater than 1.5 Mbp. Several pulse protocols have been examined. If running time is to be minimized, a field inversion with higher peak amplitude in the forward direction than in the reverse, but with equal pulse durations, provides the best resolution. Other protocols can provide higher resolution, but only with longer running times.

1244

Ultrashort electric pulse induced changes in cellular dielectric properties

The interaction of nanosecond duration pulsed electric fields (nsPEFs) with biological cells, and the models describing this behavior, depend critically on the electrical properties of the cells being pulsed. Here, we used time domain dielectric spectroscopy to measure the dielectric properties of Jurkat cells, a malignant human T-cell line, before and after exposure to five 10ns, 150kV/cm electrical pulses. The cytoplasm and nucleoplasm conductivities decreased dramatically following pulsing, corresponding to previously observed rises in cell suspension conductivity. This suggests that electropermeabilization occurred, resulting in ion transport from the cell's interior to the exterior. A delayed decrease in cell membrane conductivity after the nsPEFs possibly suggests long-term ion channel damage or use dependence due to repeated membrane charging and discharging. This data could be used in models describing the phenomena at work.

1245

Ultrastructural study of hyaluronic acid before and after the use of a pulsed electromagnetic field, electrorydesis, in the treatment of wrinkles

BACKGROUND. Treatment of wrinkles has become an increasing problem for dermatologists. Hyaluronic acid is a component of the family of glycosaminoglycans (GAGS, substances known for their property of retaining water), that significantly decreases with aging and in wrinkles. A new technique that uses a specific pulsed electromagnetic field, electrorydesis, has been introduced in the treatment of wrinkles associated with aging. The treatment is based on the reported in vitro effects of specific electromagnetic fields on fibroblast cultures (e.g., an increase in DNA synthesis and in the production of collagen and presumably also of GAGS). METHODS. The in vivo effects of the electromagnetic field on aged skin (3 subjects aged 50, 56 and 60 years), with particular focus on the ultrastructural modifications and GAGS amount before and after the treatment, were evaluated by electron microscope. RESULTS. The ultrastructural study (tissue stained with alcian blue) showed after treatment a significant increase (p < 0.005) of the electron-dense granules (corresponding to hyaluronic acid), located in collagen elastic fibers, and in the soluble matrix. This presumably leads to subsequent edema that was clinically evident after the treatment. CONCLUSIONS. These data suggest that the increased levels of GAGS and the subsequent edema of the dermis could explain at least in part the clinical changes observed after electrorydesis treatment (e.g., swelling and "disappearance" of the wrinkle).

1246

Ultrawideband radiation and pentylenetetrazol-induced convulsions in rats

New non-ionizing pulsed systems using ultrawideband (UWB) require safety assessment before they can be used by either military or civilian communities. The development of directed energy weaponry intended for use against electronically vulnerable targets, as well as ground-probing radar systems, have used fast-rise-time high-peak-power electromagnetic pulses characteristic of UWB emitters. It has been postulated that these ultrashort pulses might produce electromagnetic transients resulting in tissue damage. Several challenges to this notion have been posed, however. One report found that rats exposed to UWB after receiving a convulsant drug tended toward longer latency to the onset of convulsions than the no-exposure group. Although not statistically significant, the presence of this trend prompted the present study. An ED99 dose of the convulsant pentylenetetrazol (PTZ) or saline was given just before UWB or sham exposure and resultant seizure activity was recorded. The data from the current study show no effect of UWB exposure on PTZ-induced seizure activity, thereby not supporting the tissue damage concerns, at least for the exposure parameters used here.

1247

United States' trends and regional variations in lumbar spine surgery: 1992-2003.

STUDY DESIGN: Repeated cross-sectional analysis using national Medicare data from the Dartmouth Atlas Project. OBJECTIVE: To describe recent trends and geographic variation in population-based rates of lumbar fusion spine surgery. SUMMARY OF BACKGROUND DATA: Lumbar fusion rates have increased dramatically during the 1980s and even more so in the 1990s. The most rapid increase appeared to follow the approval of a new surgical implant device. METHODS: Medicare claims and enrollment data were used to calculate age, sex, and race-adjusted rates of lumbar laminectomy/discectomy and lumbar fusion for fee-for-service Medicare beneficiaries over age 65 in each of the 306 US Hospital Referral Regions between 1992 and 2003. RESULTS: Lumbar fusion rates have increased steadily since 1992 (0.3 per 1000 enrollees in 1992 to 1.1 per 1000 enrollees in 2003). Regional rates of lumbar discectomy, laminectomy, and fusion in 1992-1993 were highly correlated to rates of discectomy, laminectomy (R2 = 0.44), and fusion (R2 = 0.28) in 2002-2003. There was a nearly 8-fold variation in regional rates of lumbar discectomy and laminectomy in 2002 and 2003. In the case of lumbar fusion, there was nearly a 20-fold range in rates among Medicare enrollees in 2002 and 2003. This represents the largest coefficient of variation seen with any surgical procedure. Medicare spending for inpatient back surgery more than doubled over the decade. Spending for lumbar fusion increased more than 500%, from 75 million dollars to 482 million dollars. In 1992, lumbar fusion represented 14% of total spending for back surgery; by 2003, lumbar fusion accounted for 47% of spending. CONCLUSIONS: The rate of specific procedures within a region or "surgical signature" is remarkably stable over time. However, there has been a marked increase in rates of fusion, and a coincident shift and increase in cost. Rates of back surgery were not correlated with the per-capita supply of orthopedic and neurosurgeons.

1248

Unraveling near-field origin of electromagnetic waves scattered from silver nanorod arrays using pseudo-spectral time-domain calculation

In this study, we report the investigation of both near- and far-field electromagnetic characteristics of two-dimensional silver nanorod arrays embedded in anodic aluminum oxide with the use of a high-accuracy three-dimensional Legendre pseudospectral time-domain scheme. The simulated far-field scattering spectra agree with the experimental observations. We show that enhanced electric field is created between adjacent nanorods and, most importantly, far-field scattered light wave is mainly contributed from surface magnetic field, instead of the surface enhanced electric field. The identified near-field to far-field connection produces an important implication in the development of efficient surface-enhanced Raman scattering substrates.

1249

Update on extracorporeal magnetic innervation (EXMI) therapy for stress urinary incontinence

Pulsed magnetic technology has been developed for pelvic floor muscle strengthening for the treatment of urinary incontinence. This report includes an update of the prospective multicenter study of extracorporeal magnetic innervation (ExMI) therapy for stress incontinence and a discussion of the possible mechanisms of action. Issues of patient selection for ExMI therapy will also be discussed. One hundred and eleven women with demonstrable stress urinary incontinence were studied. The mean age was 55 +/- 13 years, and the mean duration of symptoms was 11 years. Ninety-seven completed ExMI therapy and analysis. Evaluation before treatment included bladder diaries, dynamic pad weight test, urodynamics, and a quality-of-life survey. For treatment the patients were seated fully clothed in a Neocontrol chair with a magnetic field therapy head in the seat. Treatment sessions were for 20 minutes, twice a week, for 6 weeks. After ExMI therapy, all of the measures were repeated at 8 weeks, including the dynamic pad weight testing and quality-of-life survey. At 6 months, further data were added, including repeat bladder diary, pad use, and quality-of-life survey. Forty-seven women completed 6 months of follow-up; of the 47, 13 patients were completely dry (28%) and 25 used no pad or less than 1 pad per day (53%). Pad use was reduced in 33 patients (70%). The median number of pads was reduced from 2.16 to 1 per day (Wilcoxon signed rank test, P <0.005). The frequency of leak episodes was reduced from 3.0 to 1.7 at 6 months (Wilcoxon signed rank test, P = 0.004). Detrusor instability was demonstrated in 10 before and 6 after ExMI (P <0.05). ExMI offers an alternative approach for the treatment of urinary incontinence. ExMI therapy is effective for both stress and urge incontinence. The best results are achieved in those patients who use no more than 3 pads a day and have had no prior continence surgery.

1250

Use of a static magnetic field to promote recovery after peripheral nerve injury

OBJECT: While pulsed electromagnetic stimulation has been shown to enhance peripheral nerve regeneration, the effect of a static magnetic field on nerve repair is less clear. The aim of this study was to establish what effect an imposed exogenous static magnetic field has on peripheral nerve regeneration after transection and repair. METHODS: Three groups of six adult sheep were used. The first group acted as normal controls. In the second group, the median nerve was divided and immediately repaired by entubulation within a "controlled-release" biodegradable glass tube. In the third group, small magnets were applied to the sides of the biodegradable glass tubes before the median nerve was repaired using these magnetic tubes. The sheep were allowed to recover and were reexamined 10 months later. The animals underwent comprehensive morphometric (cross-sectional morphometry and measurement of internodal lengths), electrophysiological (determinations of stimulated jitter, maximum conduction velocity, refractory period, and F waves), and isometric tension (isometric twitch and tetanic tension) assessments. CONCLUSIONS: Exogenously applied static electromagnetic fields do not enhance peripheral nerve regeneration.

1251

Use of electromagnetic fields in a spinal fusion. A rabbit model

STUDY DESIGN: The biomechanical and histologic characteristics of posterolateral spinal fusion in a rabbit model with and without the application of a pulsed electromagnetic field were analyzed in a prospective, randomized trial. In addition, fusion rate with and without a pulsed electromagnetic field in this model was assessed by biomechanical testing, radiographs, and manual palpation. OBJECTIVES: To evaluate the influence of a pulsed electromagnetic field on the spinal fusion rate and biomechanical characteristics in a rabbit model. SUMMARY OF BACKGROUND DATA: Previous studies performed to assess the benefits of a pulsed electromagnetic field in spinal fusion have been complicated by the use of instrumentation, and the animal models used do not have a pseudarthrosis rate comparable to that seen in humans. In contrast, the posterolateral intertransverse process fusion in the rabbit is uncomplicated by the use of instrumentation and has been shown to have a pseudarthrosis rate similar to that found in humans (5-35%). METHODS: Ten New Zealand white rabbits each were randomly assigned to undergo spinal fusion using either 1) autologous bone with electromagnetic fields, or 2) autologous bone without electromagnetic fields. A specially designed plastic constraint was used to focus the pulsed electromagnetic field over the rabbits' lumbar spine 4 hours per day. Animals were killed at 6 weeks for biomechanical and histologic testing. RESULTS: The rate of pseudarthrosis, as evaluated radiographically and manually in a blinded fashion, decreased from 40% to 20% with the pulsed electromagnetic field, but this decrease in the nonunion rate was not statistically significant given the number of animals per group. Biomechanical analysis of the fusion mass showed that a pulsed electromagnetic field resulted in statistically significant increases in stiffness (35%), area under the load-displacement curve (37%), and load to failure of the fusion mass (42%). Qualitative histologic assessment showed increased bone formation in those fusions exposed to a pulsed electromagnetic field. CONCLUSIONS: This study demonstrates the reproducibility of a rabbit fusion model, and the ability of a pulsed electromagnetic field to induce a statistically significant increase in stiffness, area under the load-displacement curve, and load to failure of the fusion mass. This investigation provides a basis for continued evaluation of biologic enhancement of spinal arthrodesis with the use of a pulsed electromagnetic field.

1252

Use of physical forces in bone healing

During the past two decades, a number of physical modalities have been approved for the management of nonunions and delayed unions. Implantable direct current stimulation is effective in managing established nonunions of the extremities and as an adjuvant in achieving spinal fusion. Pulsed electromagnetic fields and capacitive coupling induce fields through the soft tissue, resulting in low-magnitude voltage and currents at the fracture site. Pulsed electromagnetic fields may be as effective as surgery in managing extremity nonunions. Capacitive coupling appears to be effective both in extremity nonunions and lumbar fusions. Low-intensity ultrasound has been used to speed normal fracture healing and manage delayed unions. It has recently been approved for the management of nonunions. Despite the different mechanisms for stimulating bone healing, all signals result in increased intracellular calcium, thereby leading to bone formation.

1253

Use of pulsed electromagnetic fields in Perthes disease: report of a pilot study

A pilot study of pulsed electromagnetic fields (PEMFs) in the treatment of 10 older children with unilateral Perthes disease of the hip is reported. Patients were allowed to walk using crutches, with the affected hip splinted by the Birmingham containment orthosis during the day. For 10 h during the night the affected hip was exposed to PEMFs delivered via a pair of coils, mounted anterior and posterior to the hip joint on a plastic abduction orthosis. Splintage time of this group was compared with that of 72 patients selected at random from a historical control group of 200 patients. The 72 patients and the 10 children were assigned to early or late groups depending on the radiologic evolution of the disease when treatment commenced. The group of 10 children showed an overall reduction of time in all splintage of 32% in early cases (to 12.8 months) and 18% in late cases (to 13.5 months). No untoward effects were detected during the 2 years that these children have been under observation. In view of the apparent safety of PEMFs and their effects in this limited population of older patients with advanced Perthes disease, a double-blind study in younger patients with earlier lesions seems to be justified.

1254

Use of pulsed electromagnetic fields in treatment of loosened cemented hip prostheses

RCT on PEMFs showed 53% success but a 90% relapse rate at 3 years, even with maintenance therapy of 1 hour of PEMF per day. In this study of 37 patients, PEMFs only served to delay an inevitable revision hip surgery. A Stimetics 3000 device was used (BGS Medical, Englewood, Colorado).

1255

Use of pulsed electromagnetic fields in treatment of loosened cemented hip prostheses. A double-blind trial

A double-blind trial of pulsed electromagnetic fields (PEMFs) for loosened cemented hip prostheses was conducted at two centers. Of the 40 patients who enrolled, 37 met entry criteria and were available for analysis. All patients completed six months of treatment (either active or control units). Success was determined clinically by a Harris hip score greater than or equal to 80 points (or an increase of ten points if initially greater than or equal to 70 points). Ten of the 19 active units were successes (53%), whereas two of the 18 controls (11%) exhibited a placebo effect, a statistically significant and clinically relevant result. A 60% relapse rate among the active successes was seen at 14 months poststimulation, and despite maintenance therapy of one hour per day, the relapse rate increased to 90% at three years. These data suggest that for loosened cemented hip prostheses, use of PEMFs is a treatment option only to delay revision hip surgery.

1256

Utilization of extremely low frequency magnetic fields in chronic disease; five years experience: three case reports

Using the Seqex device and ion cyclotronic resonance, 3 patients (2 with MS, 1 with COPD) received 2 thirty-minute applications per week for 12 sessions. In all three cases, adding electromagnetic therapy to pharmacological treatment improves the quality of life. The authors consider these to be very good results.

1257

Various effects on transposition activity and survival of Escherichia coli cells due to different ELF-MF signals

Previous assays with weak sinusoidal magnetic fields (SMF) have shown that bacteria that had been exposed to a 50 Hz magnetic field (0.1-1 mT) gave colonies with significantly lower transposition activity as compared to sham-exposed bacteria. These experiments have now been extended by using a pulsed-square wave magnetic field (PMF) and, unexpectedly, it was found that bacteria exposed to PMF showed a higher transposition activity compared to the controls. The increase of the transposition activity was positively correlated with the intensity of the magnetic fields (linear dose-effect relation). This phenomenon was not affected by any bacterial cell proliferation, since no significant difference was observed in number and size of PMF-exposed and sham-exposed colonies. In addition, the cell viability of E. coli was significantly higher than that of the controls when exposed to SMF, and lower than that of the controls when exposed to PMF. Under our experimental conditions it was shown that exposure to PMF stimulates the transposition activity and reduces cell viability of bacteria, whereas exposure to SMF reduces the transposition mobility and enhances cell viability. These results suggest that the biological effects of magnetic fields may critically depend on the physical characteristics of the magnetic signal, in particular the wave shape.

1258

Vascular reactions during electrical stimulation. Vital microscopy of the hamster cheek pouch and the rabbit tibia

Vital microscopy during electrical stimulation was performed in the hamster cheek pouch and the rabbit tibia. Stimulation with DC of 5,20 or 50 microA or AC of 20 microA was demonstrated to cause macromolecular capillary leakage as evidenced by FITC-dextran fluorescence and histological demonstration of extravasated white blood cells. It was further demonstrated that the vascular leakage was blocked by administration of indomethacin. Pulsed electromagnetical fields did not visibly affect the vascular permeability within 3 h. As the same DC electrical stimulator has been demonstrated to increase the osteogenic capacity in similar titanium implants in the rabbit tibia, it is suggested that the observation of macromolecular leakage may predict a positive osteogenic response.

1259

Velocity distributions remotely measured with a single-sided NMR sensor

The pulsed field gradient nuclear magnetic resonance (PFG NMR) method has proved to be a powerful non-invasive technique to measure molecular displacement in various systems. It has been largely implemented with conventional NMR magnets where the volume for housing the flow setup is restricted. In this work we present the first approach to measure velocity distributions ex situ implementing a pulsed field gradient sequence on a single-sided NMR sensor. The open geometry of these sensors provides access to NMR measurements of a large number of applications previously excluded by the geometry of conventional closed magnets. Both, the distortions to the displacement encoding observed when implementing a PFG sequence in the presence of strongly inhomogeneous B0 and B1 fields, and the performance of the modifications proposed to eliminate these distortions are shown by means of numerical simulations. An alternating stimulated spin-echo PFG sequence implemented to remotely measure velocity distributions was combined with a multi-echo acquisition scheme to significantly increase the sensitivity of the method. The technique was implemented to measure the velocity propagator in a fluid undergoing laminar flow and good agreement with the theoretical result is observed.

1260

Velocity imaging by ex situ NMR

A pulsed field gradient stimulated spin-echo NMR sequence is combined with imaging methods to spatially resolve velocity distributions and to measure 2D velocity maps ex situ. The implementation of these techniques in open sensors provides a powerful non-invasive tool to measure molecular displacement in a large number of applications inaccessible to conventional closed magnets. The method is implemented on an open tomograph that provides 3D spatial localization by combining slice selection in the presence of a uniform static magnetic field gradient along the depth direction with pulsed field gradients along the two lateral directions. Different pipe geometries are used to demonstrate that the sequence performs well even in the extremely inhomogeneous B0 and B1 fields of these sensors.

1261

Very different responses to electromagnetic fields in binary ionic liquid-water solutions

The thermal and nonthermal effects of electromagnetic fields in the microwave to far-infrared frequency on binary mixtures of dimethylimidazolium hexafluorophosphate salts and water have been investigated by means of nonequilibrium molecular dynamics simulation. Significant alterations in dipole alignment, thermal response, and molecular mobility were found vis-a-vis zero-field conditions for mixtures of varying composition. Results indicate that ionic liquids respond most significantly to frequencies much lower than that of water in terms of both heating and nonthermal responses of dipole alignment and molecular mobility, and this was rationalized in terms of dipole moment magnitudes, rotational inertia, and translational field response.

1262

Viability of cancer cells exposed to pulsed electric fields: the role of pulse charge

The goal of this study was to collect a comprehensive set of data that related lethal effects of electric fields to the duration of the pulse. Electric pulses of different strengths and durations were applied to a suspension of HEp-2 cells (epidermoid carcinoma of the human larynx) using a six-needle electrode array connected through an autoswitcher to a square wave generator. Pulse durations varied from 50 micros to 16 ms and the ranges of electric field were adjusted for each duration to capture cell viabilities between 0% and 100%. After pulsation, cells were incubated for 44 h at 37 degrees C, and their viability was measured spectrophotometrically using an XTT assay. For each pulse duration (d), viability data were used to determine the electric field that killed half of the cells (E50). When plotted on logarithmic axes, E50 vs. d was a straight line, leading to a hyperbolic relationship: E50=const/d. This relationship suggests that the total charge delivered by the pulse is the decisive factor in killing HEp-2 cells.

1263

Visual responses of the human superior colliculus: a high-resolution functional magnetic resonance imaging study

The superior colliculus (SC) is a multimodal laminar structure located on the roof of the brain stem. The SC is a key structure in a distributed network of areas that mediate saccadic eye movements and shifts of attention across the visual field and has been extensively studied in nonhuman primates. In humans, it has proven difficult to study the SC with functional MRI (fMRI) because of its small size, deep location, and proximity to pulsating vascular structures. Here, we performed a series of high-resolution fMRI studies at 3 T to investigate basic visual response properties of the SC. The retinotopic organization of the SC was determined using the traveling wave method with flickering checkerboard stimuli presented at different polar angles and eccentricities. SC activations were confined to stimulation of the contralateral hemifield. Although a detailed retinotopic map was not observed, across subjects, the upper and lower visual fields were represented medially and laterally, respectively. Responses were dominantly evoked by stimuli presented along the horizontal meridian of the visual field. We also measured the sensitivity of the SC to luminance contrast, which has not been previously reported in primates. SC responses were nearly saturated by low contrast stimuli and showed only small response modulation with higher contrast stimuli, indicating high sensitivity to stimulus contrast. Responsiveness to stimulus motion in the SC was shown by robust activations evoked by moving versus static dot stimuli that could not be attributed to eye movements. The responses to contrast and motion stimuli were compared with those in the human lateral geniculate nucleus. Our results provide first insights into basic visual responses of the human SC and show the feasibility of studying subcortical structures using high-resolution fMRI.

1264

Visualization and classification in biomedical terahertz pulsed imaging

'Visualization' in imaging is the process of extracting useful information from raw data in such a way that meaningful physical contrasts are developed. 'Classification' is the subsequent process of defining parameter ranges which allow us to identify elements of images such as different tissues or different objects. In this paper, we explore techniques for visualization and classification in terahertz pulsed imaging (TPI) for biomedical applications. For archived (formalin-fixed, alcohol-dehydrated and paraffin-mounted) test samples, we investigate both time- and frequency-domain methods based on bright- and dark-field TPI. Successful tissue classification is demonstrated.

1265

Wave propagation in media having negative permittivity and permeability

Wave propagation in a double negative (DNG) medium, i.e., a medium having negative permittivity and negative permeability, is studied both analytically and numerically. The choices of the square root that leads to the index of refraction and the wave impedance in a DNG medium are determined by imposing analyticity in the complex frequency domain, and the corresponding wave properties associated with each choice are presented. These monochromatic concepts are then tested critically via a one-dimensional finite difference time domain (FDTD) simulation of the propagation of a causal, pulsed plane wave in a matched, lossy Drude model DNG medium. The causal responses of different spectral regimes of the medium with positive or negative refractive indices are studied by varying the carrier frequency of narrowband pulse excitations. The smooth transition of the phenomena associated with a DNG medium from its early-time nondispersive behavior to its late-time monochromatic response is explored with wideband pulse excitations. These FDTD results show conclusively that the square root choice leading to a negative index of refraction and positive wave impedance is the correct one, and that this choice is consistent with the overall causality of the response. An analytical, exact frequency domain solution to the scattering of a wave from a DNG slab is also given and is used to characterize several physical effects. This solution is independent of the choice of the square roots for the index of refraction and the wave impedance, and thus avoids any controversy that may arise in connection with the signs of these constituents. The DNG slab solution is used to critically examine the perfect lens concept suggested recently by Pendry. It is shown that the perfect lens effect exists only under the special case of a DNG medium with epsilon(omega)=mu(omega)=-1 that is both lossless and nondispersive. Otherwise, the closed form solutions for the field structure reveal that the DNG slab converts an incident spherical wave into a localized beam field whose parameters depend on the values of epsilon and mu. This beam field is characterized with a paraxial approximation of the exact DNG slab solution. These monochromatic concepts are again explored numerically via a causal two-dimensional FDTD simulation of the scattering of a pulsed cylindrical wave by a matched, lossy Drude model DNG slab. These FDTD results demonstrate conclusively that the monochromatic electromagnetic power flow through the DNG slab is channeled into beams rather then being focused and, hence, the Pendry perfect lens effect is not realizable with any realistic metamaterial.

1266

Weak electromagnetic fields attenuate tremor in multiple sclerosis

It has been estimated that about 75% of patients diagnosed with multiple sclerosis (MS) have tremor which can be exceedingly disabling. The most common tremor observed in patients with MS is a cerebellar intention tremor ('kinetic tremor') although postural tremor ('static tremor') is also common and often extremely incapacitating. Currently there is no effective medical treatment for the tremor of MS which, in some severe cases, may be abolished by stereotactic thalamotomy. It was reported recently that extracranial application of brief AC pulsed electromagnetic fields (EMFs) in the picotesla (pT) range produced improvement in motor and cognitive functions in patients with MS. The present communication concerns three MS patients with a chronic progressive course of the disease (mean age: 39.3 +/- 8.3 years; mean duration of illness: 11.3 +/- 3.2 years) in whom brief external applications of pulsed EMFs of 7.5 pT intensity reduced intention and postural tremors resulting in significant functional improvement. The report suggests that these extremely low intensity EMFs are beneficial also in the treatment of tremors in MS and that this treatment may serve as an alternative method to stereotactic thalamotomy in the management of tremor in MS. The mechanisms by which EMFs attenuate the tremors of MS are complex and are thought to involve augmentation of GABA and serotonin (5-HT) neurotransmission in the cerebellum and its outflow tracts.

1267

Weak electromagnetic fields improve body image perception in patients with multiple sclerosis

Neuropsychological studies have demonstrated that multiple sclerosis (MS) is associated with various cognitive deficits and it has been suggested that it be considered a form of subcortical dementia. It is now recognized that visuoperceptive and visuomotor deficits commonly occur in MS patients particularly in those with chronic progressive course of the disease. The Human Figure Drawing Test has been employed in the assessment of generalized intellectual deterioration and specifically in the evaluation of visuoperceptive, visuospatial and visuoconstructional abilities in brain injured patients. I have demonstrated recently, on the basis of various drawing test, the external application of electromagnetic fields (EMFs) in the picotesla (pT) range intensity improved visuoperceptive and visuospatial functions in patients with MS. In the present communication I present five MS patients who were administered the Human Figure Drawing Test before and after a series of treatments with EMFs. Prior to application of EMFs four of these patients' drawings showed distortions, poor perspectives, impoverished facial expression, and lack of attention to details suggesting poor body image perception related to right posterior hemispheric dysfunction. In response to the administration of EMFs the group demonstrated improvement in motor disability which was associated with a striking improvement in the drawing particularly the drawings of the face the perception of which is localized to the right parietal lobe. These findings demonstrate that treatment with pT EMFs improves body image perception in MS patients thus corroborating previous observations which demonstrated this treatment modality to exert beneficial effects on cognitive functions in patients with MS.

1268

Weak electromagnetic fields increase the amplitude of the pattern reversal VEP response in patients with multiple sclerosis

Visual evoked potential (VEP) studies are widely used for the diagnosis of multiple sclerosis (MS) and are also useful in monitoring the effects of various therapeutic modalities in the disease. Brief, extracerebral applications of picotesla (pT) range flux intensity electromagnetic fields (EMFs) of low frequency have been shown efficacious in the treatment of motor and cognitive symptoms in MS implying that this treatment modality improves action potential transmission in demyelinating pathways. This report documents three MS patients with a remitting-progressive course in whom two successive brief extracerebral applications of pT range EMFs caused an immediate increase (and normalization) of the amplitudes of the visual evoked response in the eye previously affected by optic neuritis. However, the pretreatment prolonged latencies of the evoked responses remained essentially unchanged after the administration of EMFs. Since the latency of the VEP reflects the degree of conduction velocity and the amplitude the degree of conduction block in demyelinating optic pathways, the report demonstrates that extracerebral applications of these EMFs may rapidly reverse conduction block in demyelinating fibers. Reversal of the conduction block, which is though to be related to changes in axonal Na+ and K+ channels and synaptic neurotransmitter release, accounts for the immediate improvement of vision and other neurological deficits observed in MS patients following exposure to these EMFs.

1270

Weak electromagnetic fields restore dream recall in patients with multiple sclerosis

It is now well established that dreaming is a phenomenon associated with REM sleep and that we dream far more than we can recall. Loss of dream recall has been reported in association with cerebral lesions of different sites with predilection to the posterior cerebral hemispheres. Multiple sclerosis (MS) is a chronic neurological disorder characterised by the presence of diffuse pathological lesions affecting cortical, subcortical, and brainstem areas which are implicated in the generation and maintenance of REM sleep as well as dream recall. Although MS is associated with a high incidence of sleep disturbances, little is known about the frequency of dreaming and particularly dream recall in these patients and their association with such features as the course of the disease, extent of neurological deficits, rate of progression, sites of demyelinating plaques on MRI scan, and recovery. In my experience morning dream recall and probably dreaming activity become infrequent with the onset and/or during periods of exacerbation of the disease. The present communication concerns four selected MS patients who experienced alterations in dream content and loss of morning dream recall during the course of the disease. In all patients dream recall was restored, along with improvement in neurological symptoms, following the external application of a series of treatments with weak electromagnetic fields (EMFs). These findings suggest that in MS morning dream recall may decline and cease to occur during the course of the disease. Recurrence of dream recall may be a marker of clinical recovery which can be used to assess neurologic improvement in patients undergoing treatment with experimental treatment modalities.

1271

Weak electromagnetic fields reverse visuospatial hemi-inattention in Parkinson's disease

Drawing tasks, both free and copied, have achieved a central position in neuropsychological testing of patients with unilateral cerebral dysfunction by virtue of their sensitivity to different kinds of organic brain disorders and their ability to provide information on lateralized brain damage. In the drawings of patients with right hemispheric damage, visuospatial neglect is revealed by the omission of details on the side of the drawing contralateral to the hemispheric lesion. Patients with unilateral cerebral damage, particularly those with left hemispheric damage, also demonstrate a tendency to place their drawings on the side of the page ipsilateral to the cerebral lesion, a phenomenon which has been termed visuospatial hemi-inattention. It has been reported previously that brief external application of alternating pulsed electromagnetic fields (EMFs) in the picotesla (pT) range intensity improved visuoperceptive and visuospatial functions and reversed neglect in Parkinsonian patients. The present communication concerns four fully medicated elderly nondemented Parkinsonian patients (mean age: 74.7 +/- 4.6 yrs; mean duration of illness: 7.7 +/- 5.2 yrs) in whom application of these EMFs produced reversal of visuospatial hemi-inattention related to left hemispheric dysfunction. These findings support prior observations demonstrating that pT EMFs may bring about reversal of certain cognitive deficits in Parkinsonian patients.

1272

Weak low frequency electromagnetic fields and chick embryogenesis: failure to reproduce positive findings

Fertilised chicken eggs were incubated for 48 hours while exposed to pulsed trains of magnetic fields having a duration of 0-5 ms, a rise time of 42 microsecond, and a pulse repetition rate of 100 at a magnetic field flux density of 1 microT. Some eggs were exposed to 1,552 rad X-rays as a positive control. After exposure the embryos were scored blind for a variety of morphological features. X-irradiated eggs displayed highly significant and repeatable anatomical alterations. There were no differences between magnetic field-exposed, sham-exposed and control eggs.

1273

Weak magnetic fields antagonize the effects of melatonin on blood glucose levels in Parkinson's disease

Treatment with picoTesla magnetic fields recently has been reported to attenuate symptoms of Parkinson's disease (PD). The mechanisms by which weak magnetic fields ameliorate Parkinsonian symptoms are unknown. There is evidence that the pineal gland is a "magnetosensor" in the brain since in experimental animals exposure to external magnetic fields alters the firing rate of pineal cells and induces inhibition of melatonin secretion. Hence, the clinical effects of weak magnetic fields in PD likewise may involve the mediation of the pineal gland. Animal data indicate that the pineal gland is involved in the regulation of glucose metabolism and that exogenous administration of melatonin induces an hyperglycemic effect. To investigate the hypothesis that the pineal gland mediates the therapeutic properties of weak magnetic fields in PD, I studied the effects of orally administered melatonin (3.0 mg) followed by a 6 minute application of low intensity external weak magnetic fields (7.5 picoTesla) on blood glucose levels in two Parkinsonian patients. In both patients melatonin challenge produced a moderate hyperglycemic effect which was reversed by subsequent stimulation with weak magnetic fields. These findings support the hypothesis that weak magnetic fields inhibit melatonin secretion and that the antiParkinsonian properties of weak magnetic fields are mediated partially via the inhibition of melatonin secretion. Furthermore, these data suggest that melatonin receptor antagonists could be beneficial as an adjunctive treatment in PD and highlight the importance of the pineal-hypothalamic axis in the pathophysiology of the disease as well as in the mechanisms of action of antiParkinsonian drugs.

1275

Weak magnetic fields in the treatment of Parkinson's disease with the "on-off" phenomenon

Application of external weak magnetic fields recently has been reported to be efficacious in the treatment of a 62-year-old patient with idiopathic Parkinson's disease (PD) complicated by levodopa-induced fluctuations in motor response ("on-off"). I report an additional case of a 67-year-old man with idiopathic PD and levodopa-related motor fluctuations who likewise experienced marked and sustained improvement in Parkinsonian symptoms and amelioration of "on-off" symptoms following the application of external weak magnetic fields. Based on these observations it is concluded that artificial weak magnetic fields may be beneficial for the treatment of PD complicated by levodopa-related "on-off" phenomenon. Furthermore, since in experimental animals external magnetic fields alter the secretion of melatonin, which in turn has been shown to regulate striatal and mesolimbic dopamine-mediated behaviors, it is proposed that the antiParkinsonian effects of weak magnetic fields are mediated via the pineal gland.

1276

Weak, but complex pulsed magnetic fields may reduce depression following traumatic brain injury

Many patients who display psychological depression following a traumatic brain injury do not respond completely to antidepressant drugs. We hypothesized that this type of depression is strongly correlated with subclinical, complex partial seizure-activity within the hippocampal-amygdaloid region that continues for months to years after apparent neurological and behavioral "recovery." Four depressed patients who had sustained traumatic brain injuries and who exhibited mild to moderate brain impairment according to standardized tests received 30 min. of weak (1 microT) burst-firing magnetic fields across the temporal lobes once per week for 5 weeks. There was a significant improvement of depression and reduction of phobias while physical symptoms and other complaints were not changed.

1277

What have we learned about the evidence-informed management of chronic low back pain?

in a summary of evidence for the efficacy of various treatment categories for chronic low back pain, including spine surgery, it was found that there is insufficient evidence on the efficacy of spine surgery for chronic low back pain.

1278

Whole-body exposure to 2.45 GHz electromagnetic fields does not alter 12-arm radial-maze with reduced access to spatial cues in rats

Lai et al. [Lai H, Horita A, Guy AW. Microwave irradiation affects radial-arm maze performance in the rat. Bioelectromagnetics 1994;15(2):95-104] reported that exposure of rats to pulsed 2.45 GHz microwaves altered maze performance. Their maze was bordered by 20 cm high opaque walls. Using a maze test based on unrestrained access to spatial cues (no walls), we could not replicate this result [Cassel JC, Cosquer B, Galani R, Kuster N. Whole-body exposure to 2.45 GHz electromagnetic fields does not alter radial-maze performance in rats. Behav Brain Res 2004;155:37-43]. Here, we attempted another replication using a maze apparatus bordered by 30 cm high opaque walls. Performance of exposed rats was normal. These results show that microwave exposure as used herein does not alter spatial working memory, when access to spatial cues is reduced.

1279

Whole-body exposure to 2.45 GHz electromagnetic fields does not alter radial-maze performance in rats

Mobile communication is based on utilization of electromagnetic fields (EMFs) in the frequency range of 0.3-300 GHz. Human and animal studies suggest that EMFs, which are in the 0.1 MHz-300 GHz range, might interfere with cognitive processes. In 1994, a report by Lai et al. [Bioelectromagnetics 15 (1994) 95-104] showed that whole-body exposure of rats to pulsed 2.45 GHz microwaves (2 micros pulse width, 500 pps, and specific absorption rate [SAR] 0.6 W/kg) for 45 min resulted in altered spatial working memory assessed in a 12-arm radial-maze task. Surprisingly, there has been only one attempt to replicate this experiment so far [Bioelectromagnetics 25 (2004) 49-57]; confirmation of the Lai et al. experiment failed. In the present study, rats were tested in a 12-arm radial-maze subsequently to a daily exposure to 2.45 GHz microwaves (2 micros pulse width, 500 pps, and SAR 0.6 W/kg) for 45 min. The performance of exposed rats was comparable to that found in sham-exposed or in naive rats (no contact with the exposure system). Regarding the methodological details provided by Lai et al. on their testing protocol, our results might suggest that the microwave-induced behavioral alterations measured by these authors might have had more to do with factors liable to performance bias than with spatial working memory per se.

1280

Whole-brain 3D perfusion MRI at 3.0 T using CASL with a separate labeling coil

A variety of continuous and pulsed arterial spin labeling (ASL) perfusion MRI techniques have been demonstrated in recent years. One of the reasons these methods are still not routinely used is the limited extent of the imaging region. Of the ASL methods proposed to date, continuous ASL (CASL) with a separate labeling coil is particularly attractive for whole-brain studies at high fields. This approach can provide an increased signal-to-noise ratio (SNR) in perfusion images because there are no magnetization transfer (MT) effects, and lessen concerns regarding RF power deposition at high field because it uses a local labeling coil. In this work, we demonstrate CASL whole-brain quantitative perfusion imaging at 3.0 T using a combination of strategies: 3D volume acquisition, background tissue signal suppression, and a separate labeling coil. The results show that this approach can be used to acquire perfusion images in all brain regions with good sensitivity. Further, it is shown that the method can be performed safely on humans without exceeding the current RF power deposition limits. The current method can be extended to higher fields, and further improved by the use of multiple receiver coils and parallel imaging techniques to reduce scan time or provide increased resolution.

1281

Why do electromagnetic pulses enhance bone growth?

The excitation probability of substrate molecules involved in the production of growth factors influencing the division of chondrocytes in the growth layer of bone under the influence of pulsed electromagnetic fields is studied theoretically in a quantum mechanical model calculation. In this model matrix elements and anti-bonding energy levels are assumed known and the dynamics of the interaction with pulsed electromagnetic fields is derived. The derivation makes it clear that continuous pulsing or large driving currents can overwhelm local diffusive transport to the growth plane resulting in a loss of its enhancement properties. Optimal locations within a pair of Helmholtz coils for enhancement of bone growth are also investigated and found to be close to the coils. The work presented here is believed to be the first derivation in a model calculation of a physical basis for the effects of pulsed electromagnetic fields on bone growth and fusion.

1282

X-ray diffractometer combining synchrotron radiation and pulsed magnetic fields up to 40 T

A synchrotron X-ray diffractometer incorporating a pulsed field magnet for high fields up to 40 T has been developed and a detailed description of this instrument is reported. The pulsed field magnet is composed of two coaxial coils with a gap of 3 mm at the mid-plane for passage of the X-rays. The pixel detector PILATUS 100K is used to store the diffracted X-rays. As a test of this instrument, X-ray diffraction by a powder sample of the antiferromagnet CoO is measured below the Neel temperature. A field-dependent lattice distortion of CoO due to magnetostriction is observed up to 38 T.

1283

XAS and XMCD under high magnetic field and low temperature on the energy-dispersive beamline of the ESRF

The present paper demonstrates the feasibility of X-ray absorption spectroscopy (XAS) and X-ray magnetic circular dichroism (XMCD) under high magnetic fields up to 26 T and low temperatures down to 5 K on the ID24 energy-dispersive XAS beamline of the ESRF. The pulsed magnetic field set-up, entirely developed at the ESRF, is described as well as the beamline set-up, the synchronization and the measurement procedure. It allows field strengths up to 30 T. Finally, as an example, we report a recent XMCD study at the Re L2 and L3 absorption edges of the double perovskite Sr2CrReO(6).

1284

Yawning and stretching induced by transcranial application of AC pulsed electromagnetic fields in Parkinson's disease

Yawning is considered a brainstem regulated behavior which is associated with changes in arousal and activity levels. Yawning and stretching are dopamine (DA) mediated behaviors and pharmacological studies indicate that these behaviors are associated with increased DA release coupled with stimulation of postsynaptic DA-D2 receptors. Despite their relation to the dopaminergic system, yawning and stretching are poorly documented in untreated or treated patients with Parkinson's disease (PD). A 49 year old fully medicated female patient with juvenile onset PD is presented in whom recurrent episodes of yawning and stretching developed during transcranial administration of AC pulsed electromagnetic fields (EM Fs) of picotesla flux density. These episodes have not been observed previously in this or other patients during treatment with levodopa or DA receptor agonists or in unmedicated PD patients during treatment with AC pulsed EMFs. It is suggested that yawning and stretching behavior resulted in this patient from a synergistic interaction between EMFs and DA derived from levodopa supplementation with EMFs possibly facilitating the release of DA and simultaneously activating postsynaptic DA-D2 receptors in the nigrostriatal dopaminergic pathways. In addition, it is postulated that the release of ACTH/MSH peptides from peptidergic neurons in the brain upon stimulation of the DA-D2 receptors reinforced the yawning and stretching behavior.

1285

Yawning and stretching--a behavioral syndrome associated with transcranial application of electromagnetic fields in multiple sclerosis

Intracerebral administration of adrenocorticotropic hormone (ACTH) elicits in experimental animals a yawning stretching behavior which is believed to reflect an arousal response mediated through the septohippocampal cholinergic neurons. A surge in plasma ACTH levels at night and just prior to awakening from sleep is also associated in humans with yawning and stretching behavior. Recurrent episodes of uncontrollable yawning and body stretching, identical to those observed upon awakening from physiological sleep, occur in a subset of patients with multiple sclerosis (MS) during transcranial therapeutic application of AC pulsed electromagnetic fields of picotesla flux density. This behavioral response has been observed exclusively in young female patients who are fully ambulatory with a relapsing remitting course of the disease who also demonstrate a distinctly favorable therapeutic response to magnetic stimulation. ACTH is employed for the treatment of MS due to its immunomodulatory effects and a surge in its release in response to AC pulsed magnetic stimulation could explain some of the mechanism by which these fields improve symptoms of the disease.

1286

Zero- to low-field MRI with averaging of concomitant gradient fields

Magnetic resonance imaging (MRI) encounters fundamental limits in circumstances in which the static magnetic field is not sufficiently strong to truncate unwanted, so-called concomitant components of the gradient field. This limitation affects the attainable optimal image fidelity and resolution most prominently in low-field imaging. In this article, we introduce the use of pulsed magnetic-field averaging toward relaxing these constraints. It is found that the image of an object can be retrieved by pulsed low fields in the presence of the full spatial variation of the imaging encoding gradient field even in the absence of the typical uniform high-field time-independent contribution. In addition, error-compensation schemes can be introduced through the application of symmetrized pulse sequences. Such schemes substantially mitigate artifacts related to evolution in strong magnetic-field gradients, magnetic fields that vary in direction and orientation, and imperfections of the applied field pulses.

1287

Zero-field remote detection of NMR with a microfabricated atomic magnetometer

We demonstrate remote detection of nuclear magnetic resonance (NMR) with a microchip sensor consisting of a microfluidic channel and a microfabricated vapor cell (the heart of an atomic magnetometer). Detection occurs at zero magnetic field, which allows operation of the magnetometer in the spin-exchange relaxation-free (SERF) regime and increases the proximity of sensor and sample by eliminating the need for a solenoid to create a leading field. We achieve pulsed NMR linewidths of 26 Hz, limited, we believe, by the residence time and flow dispersion in the encoding region. In a fully optimized system, we estimate that for 1 s of integration, 7 x 10(13) protons in a volume of 1 mm(3), prepolarized in a 10-kG field, can be detected with a signal-to-noise ratio of approximately 3. This level of sensitivity is competitive with that demonstrated by microcoils in 100-kG magnetic fields, without requiring superconducting magnets.

1289

[A comprehensive approach to designing of magnetotherapy techniques based on the Atos device]

The paper determines how to apply a comprehensive approach to designing magnetic therapeutical techniques based on concomitant exposures to two or more physical factors. It shows the advantages of the running pattern of a magnetic field and photostimuli in terms of optimization of physiotherapeutical exposures. An Atos apparatus with an Amblio-1 attachment is used as an example to demonstrate how to apply the comprehensive approach for ophthalmology.

1291

[Accumulation of calcium ions in myocardial sarcoplasmic reticulum of restrained rats exposed to the pulsed electromagnetic field]

Alteration in the velocity of Ca++ accumulation was investigated in myocardial homogenates from restrained rats which were chronically (1 and 2 months) exposed to the impulse electromagnetic field with frequency 1 Hz and magnetic induction 6-24 mT. The fall of the studied variable by 33% was observed in a month while restoration of the velocity of Ca++ transport was shown after two months of exposure. The results are discussed in terms of the organism adaptation to physico-chemical and physiological impacts.

1292

[Action of gentamycin against a background of magnetotherapy of the anterior chamber in a traumatic infected erosion of the cornea]

Fifteen patients with surface infections of the cornea due to a foreign body in one eye were treated with magnetophoresis and gentamicin before and after removal of the foreign bodies. The lower eyelid was turned back and a cotton tampon impregnated with 1 ml of a 0.3 per cent aqueous solution of gentamicin was applied. After that the tube of the alternating magneto was placed before the eyelids. The magnetic field (50 oersted, 50 Hz) was applied for 9 minutes. Such a treatment promoted suppression of the eye inflammatory reaction and accelerated corneal epithelization.

1293

[Adaptogenic potentialities of dynamic magnetotherapy in the treatment and prevention of ENT pathology in ailing children]

Efficacy of dynamic magnetotherapy (in transcranial and adrenal variants) for treatment of ENT pathology and prevention of its exacerbations is demonstrated in 126 ailing children. Mechanism of action of this magnetotherapy is due to formation of adequate adaptation reactions raising resistance to pathogens.

1294

[Algal inactivation and removal by pulsed magnetic field with varying frequency]

The paper studied the algal inactivation and removal by pulsed magnetic field with varying frequency. The results indicated that algae could be inactivated and killed by the magnetic treatment for the circulating water sample. When the accumulated resident time reached 6 minutes, the algae became to die with the mortality of 94%. If the resident time were 10 minutes, the algal mortality would be more than 96%. The treated algae didn't grow within 120 hours, which indicated that the "magnetic memory time" can reach 120 hours. For the static sample in magnetic field, the inhibition effect became to do the work after 1 hour. Different treatment methods brought about different results. It was more propitious to inactivate the algae for circulating sample.

1295

[Amplipulse-magnetotherapy and iodine-bromine waters in combined treatment of patients with chronic nonspecific salpingo-oophoritis]

Amplipulse-magnetotherapy was used as monotherapy and in combined treatment of 110 patients with chronic nonspecific salpingo-oophoritis (CNSO). Clinical assessment shows that transcerebral amplipulse-megnetotherapy (TAMT) has a positive effects on the course of CNSO, reproductive system and psychoemotional status of the patients. The addition of physical and balneological factors to TAMT enhances and prolongs neurotropic, endocrine, analgetic and anti-inflammatory effects of TAMT.

1297

[Analgesic effect induced by stimulation of rats brain with strong pulsed magnetic field: a preliminary study]

The Objective of this study was to determine whether stimulation on the brain of SD rats with strong pulsed magnetic field could produce analgesic effect. A stimulator of CADWELL (MES-10) was adopted in the study. The pain index used was the Tail Flick Latency (TFL) of rats. The stimulation parameters were: (1) the intensity percent (20%) and stimulation duration (7 min); (2) the intensity percent (30%) and stimulation duration (3 min). The results showed that the mean Acquired TFL change was 23% (P < 0.01) for the 20% intensity group, and 26% (P < 0.01) for the 30% intensity group. CONCLUSION: These data indicate that the new method for analgesia is effective, and compared with other approaches to stimulation analgesia, this one is non-invasive, easy to operate, and less causative of discomfort.

1298

[Analgesic physical therapy. Present clinical data]

Analgesic electrotherapy is now based on more consistent scientific data; the biological action of the electric current, of the electromagnetic radiations and of the mechanical vibrations is better approached. But the randomized control trials still provide contradictory results concerning the analgesic efficiency of the cryotherapy, the TENS, the pulsed electro-magnetic fields, the ultrasound and laser therapy, the shock waves; iontophoresis, short waves, microwaves, infrasound vibrations are very few investigated. The analgesic electrotherapy cannot be recommended nor prohibited; physical agents represent only therapeutic options. On the basis of the scientific data and of their personal experience, the therapists can use them. More controlled clinical investigations of higher methodological levels are still required.

1300

[Application of variable magnetic fields in medicine--15 years experience]

The results of 15-year own experimental and clinical research on application of variable magnetic fields in medicine were presented. In experimental studies analgesic effect (related to endogenous opioid system and nitrogen oxide activity) and regenerative effect of variable magnetic fields with therapeutical parameters was observed. The influence of this fields on enzymatic and hormonal activity, free oxygen radicals, carbohydrates, protein and lipid metabolism, dielectric and rheological properties of blood as well as behavioural reactions and activity of central dopamine receptor in experimental animals was proved. In clinical studies high therapeutic efficacy of magnetotherapy and magnetostimulation in the treatment of osteoarthrosis, abnormal ossification, osteoporosis, nasosinusitis, multiple sclerosis, Parkinson's disease, spastic paresis, diabetic polyneuropathy and retinopathy, vegetative neurosis, peptic ulcers, colon irritable and trophic ulcers was confirmed.

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