PAPIMI

Detlavs et al., "Experimental study of the effects of radiofrequency electromagnetic fields on animals with soft tissue wounds,

Bassett et al, "Augmentation of Bone Repair by Inductively Coupled Electromagnetic Fields," 134 Science 575 (May, 1974).

This article describes describing the enhancement of the repair of canine osteotomies by the application of low frequency, pulsing electromagnetic fields produced by air-gap, rectangular coils to induce dynamic, orthogonal voltage fields in bone and soft tissue.

Pulses of 1 millisecond duration with a 1 hertz frequency and of 150 microsecond duration with a 65 hertz frequency were used,

and resulted in augmented bone repair.

Results of this study found that exposure to constant magnetic fields improved healing in rats with experimentally induced spinal cord injury, and in human patients suffering from spinal cord trauma as well.

E.V. Tkach,Characteristics of the Effect of a Constant Electromagnetic Field on Reparative Processes in Spinal Cord Injuries,

This study found that exposure to pulsed electromagnetic fields following focal cerebral ischemia provided significant protection against neuronal damage, in rabbits.

G. Grant, Protection Against Focal Cerebral Ischemia Following Exposure to a Pulsed Electromagnetic Field, Bioelectromagnetics, 15(3), 1994, p. 205-216.

Results of this controlled study showed that low-frequency pulsed electromagnetic fields produced significant beneficial cutaneous wound healing effects in rats.

O. Patino, Pulsed Electromagnetic Fields in Experimental Cutaneous Wound Healing in Rats, Journal of Burn Care Rehabil, 17(6 PT 1),

This study examined the effects of low-frequency magnetic fields coupled with conventional therapies in rats suffering from inflammatory lung disease. Results showed that rats receiving the magnetic fields experienced significant reductions in lung abscesses and associated symptoms, and similar beneficial effects were seen among a group of 165 human patients receiving comparable treatment.

L.V. Iashchenko, "Low-Frequency Magnetic Fields in the Combined Therapy of Inflammatory Lung Diseases,

This controlled study found that exposure to pulsed electromagnetic fields enhanced the speed and degree of peripheral nerve regeneration twofold in rats with experimentally severed sciatic nerves.

H. Ito C.A. Bassett, Effect of Weak, Pulsing Electromagnetic Fields on Neural Regeneration in the Rat,

Results of this controlled study demonstrated that treatment with 15 minutes per day of pulsed electromagnetic fields enhanced recovery time of experimentally-injured nerves in rats.

A.R. Raji R.E. Bowden,

Effects of High-peak Pulsed Electromagnetic Field on the Degeneration and Regeneration of the Common Peroneal Nerve in Rats,

Journal of Bone Joint Surg, 65(4),August 1983, p. 478-492.

Results of this study indicated that the use of pulsed electromagnetic fields on experimentally divided and sutured nerves in rats sped up regeneration of damaged nerves and the time ittook for limb use to be recovered.

A.M. Raji, An Experimental Study of the Effects of Pulsed Electromagnetic Field (Diapulse) on Nerve Repair,

Osteoporosis (rats)

This study examined the effects of pulsed electromagnetic fields on postmenopausal osteoporosis in 10-month-old female rats.

Results showed that EMF treatment for one hour per day for 4 months with a 30-gauss maximum pulse reduced bone mass loss to within 10 percent,while a 70-gauss maximum pulse reduced bone mass loss entirely.

M. Hinsenkamp, Preliminary Results in Electromagnetic Field Treatment of Osteonecrosis,

Osteoporosis (rats)

This study examined the effects of long-term pulsing electromagnetic fields in the form of repetitive pulse burst waves over a period of 6 months in osteoporotic rats. Results showed increased bone volume and formation activity.

S. Mishima, The Effect of Long-term Pulsing Electromagnetic Field Stimulation on Experimental Osteoporosis of Rats,

Results from several recent studies conducted the author are reviewed. Conclusions are that pulsed electromagnetic fields exhibit protective effects against necrosis from acute ischemia in rats, cerebral infarcts in rabbits, and myocardium infarcts in rats.

R. Cadossi, "Protective Effect of Electromagnetic Field Exposure on Acute Soft Tissue Ischaemic Injury,"

Second World Congress for Electricity and Magnetism in Biology and Medicine,8-13 June 1997, Bologna, Italy.

Three hours of exposure to a 50-Hz magnetic field in this study revealed that experimentally induced inflammation and suppressed arthritis in rats was significantly inhibited as a result.

Y. Mizushima, et al., "Effects of Magnetic Field on Inflammation," Experientia, 31(12),

Synovitis

This study examined the effects of magnetic fields on synovitis in rats. Results showed that the placement of a 3800-gauss magnet on the bottom of the cage significantly suppressed inflammation associated with the condition, relative to controls.

A. Weinberger, Treatment of Experimental Inflammatory Synovitis with Continuous Magnetic Field,

Pasquinelli P, Petrini M, Mattii L, Galimberti S, Saviozzi M, Malvaldi G (1993) Biological effects of PEMF (pulsing EMF): an attempt to modify cell resistance to anticancer agents. J Environ Pathol Toxicol Oncol Oct;12(4):193-197. CRESAM, Pisa, Italy.

PEMF effects modify the multidrug resistance (MDR) of cells in vitro and in vivo. The murine leukemic doxorubicin-resistant cell line, P388/Dx, subjected to PEMF irradiation in vitro, showed a significant difference in thymidine incorporation when the concentration of doxorubicin reached a level of 1 ug/mL, which corresponds to the inhibition dose 50 (ID50). The human lymphoblastic leukemia vinblastine-resistant cell line, CEM/VLB100, also showed a significant modification under the same experimental conditions at the in vitro ID50 corresponding to a vinblastine concentration of 100 ng/mL. BDF1 mice transplanted with P388/Dx cells also lived longer when doxorubicin was injected ip in fractionated doses, while being subjected to PEMF irradiation. PMID: 8189374, UI: 94246562

[Radioprotective effect of weak ultra-low frequency alternating magnetic field in adrenalectomized mice - Article in Russian]. Radiats Biol Radioecol Jan;38(1):110-115. Simferopol State Univ, Krym, Ukraine. PMID: 9606412, UI: 98269257

Stashkov AM, Gorokhov IE (1998) [Modification of radiosensitivity of mice by combination of alternating magnetic field and fractionated irradiation with small daily doses over many days - Article in Russian]. Radiats Biol Radioecol Jan;38(1):116-120. Simferopol State Univ, Krym, Ukraine. Everyday before radiation combination of weak magnetic field and fractioned radioactive irradiation in dose of 0.5 Gy up to total doses of 6.0-8.0 Gy increased surviving of mice by 34-53% and prolonged the life-time by 50%. It also decreased the rate of accumulation of damaged systems, extended average time of death and the value of dose changing factor, and reduced the gradient of damaged systems. PMID: 9606413, UI: 98269258

Correction of lipid metabolism

Temur'iants NA, Evstaf'eva EV, Makeev VB (1985) [Correction of lipid metabolism in rats with limited mobility by an alternating magnetic field of infra-low frequency - Article in Russian]. Biofizika Mar;30(2):313-316. The effect of changing magnetic field at the frequency of 8 Hz and intensity at 4.1 A/M on rats lipid metabolism state in the exposition of continuous hypokinesia was investigated. It was found that changing magnetic field of such parameters greatly restricted the development of hyperlipidemia of rats with a low level of mobile activity. PMID: 3986233, UI: 85175202

Dindar H, Zeybek N, Yucesan S, Barlas M, Yurtaslani Z, Yazgan E, Konkan R, Ozguner IF, Gokcora IH (1993)

Augmentation of mucosal adaptation following small-bowel resection by EMF stimulation in rats.

Tokai J Exp Clin Med Jun;18(1-2):39-47. Dept of Pediatric Surgery, School of Med, Ankara Univ, Turkiye.

Survival after massive resection of the small intestine is often possible due to substantial hyperplasia of the mucosal surface in the remaining small intestine. While nutrients provide the major stimulus for hyperplasia in the clinical setting, the availability of drugs to augment this process would have obvious therapeutic implications. EMF stimulation of connective tissue and skin increased the DNA and messenger RNA and protein synthesis in experimental studies. We evaluated the ability of EMF stimulation to augment mucosal hyperplasia after massive small bowel resection in the rat. 2 groups of 10 Wistar rats (250 g), were subjected to 70% jejunoileal resection. Group 1 received EMF stimulation for 10 d at a dosage of 43.2 Gauss; group 2 received no stimulation. After 14 d, segmental evaluation of mucosal mass in the remaining small intestine was determined by measuring mucosal protein, and disaccharidase levels, as well as intestinal length and circumference.

EMF stimulation seemed to augment mucosal adaptation after massive small bowel resection in the proximal and distal small intestine of rats. PMID: 7940605, UI: 95026918

Dindar H, Renda N, Barlas M, Akinay A, Yazgan E, Tincer T, Cakmak M, Konkan R, Gokcora IH, Yucesan S (1993) The effect of EMF stimulation on corticosteroids-inhibited intestinal wound healing. Tokai J Exp Clin Med Jun;18(1-2):49-55. Dept of Pediatric Surgery, School of Med, Ankara Univ, Turkiye.

EMF stimulation has been used successfully in the clinical setting to promote healing of ununited fractures.

In a few studies, EMF stimulation enhanced soft tissue healing. To investigate the effect of EMF stimulation on intestinal wound healing in normal rats and in those treated with corticosteroids, 80 Wistar rats received twice-daily injections of either saline dexamethasone (0.1 mg/kg/d) for 2 wk. Animals then underwent creation of single-layer, inverting small intestine anastomoses. All injections were continued postoperatively. Animals were grouped as intestinal anastomoses; intestinal anastomoses plus EMF stimulation; intestinal anastomoses plus dexamethasone; and intestinal anastomoses plus dexamethasone plus EMF. On postoperative d 7 and 14, the anastomosed intestines were removed and the tensile strength (TS) and hydroxyproline (OH-P) contents measured. EMF stimulation significantly increased intestinal wound healing in normal animals by d 7 and 14. Corticosteroids significantly impaired the healing of the small intestine anastomoses, with decreased TS and OH-P contents after wk 1 and 2.

However, EMF stimulation significantly reversed this inhibitory effect. PMID: 7940606, UI: 95026919

[Effect of an alternating magnetic field on the development of carrageenan paw edema in the rat - Article in German].

Mizushima Y, Akaoka I, Nishida Y (1975) Effects of magnetic field on inflammation.

The effects of a 50 Hz magnetic field on experimentally-induced inflammation in rats were studied. Carrageenan edema was inhibited significantly by exposure to magnetic field for 3 h. Adjuvant-induced arthritis in rats was also suppressed by the magnetic field.

Lin Y, Nishimura R, Nozaki K, Sasaki N, Kadosawa T, Goto N, Date M, Takeuchi A (1992) Effects of pulsing EMFs on the ligament healing in rabbits. J Vet Med Sci Oct;54(5):1017-1022. Dept of Veterinary Surgery, Faculty of Agriculture, Univ of Tokyo, Japan.

Effects of PEMFs on ligament healing were investigated using 80 rabbits. All animals received square resection (4 x 4 mm) of both patellar ligaments in full thickness at their center. They were divided into 4 groups of 20 rabbits each and stimulated with different EM intensity of 0 (control), 2, 10, and 50 Gauss (G) for 6 hr daily. Pulse frequency and pulse width were 10 Hz and 25 us, respectively. After PEMF stimulations for 1, 2, 3 and 4 wk, 5 animals of each group were euthanized. The regenerated tissue at the lesion was studied histologically and biomechanically. PEMF-stimulated tissue showed an earlier increase in capillaries and fibroblasts and more matured, prominent longitudinal orientation of collagen fibers than those of control groups. Among the rabbits given EM stimulation, those stimulated at 50 G revealed the earliest ligament healing. Tensile strength of regenerated ligament tissues of any PEMFs groups increased significantly at 1 and 2 wk after operation, however, at 3 and 4 wk after operation, there were no significant differences between groups. Among these values, those of 50 G group were the highest consistently during most of the experimental period. PEMFs enhanced the earlier stage of ligament healings and 50 G seemed to be the most effective among the 3 field intensities used. This promoting effect may potentiate the earlier recovery of the function after the ligament injury. PMID: 1420550, UI: 93042251

Kanje M, Rusovan A, Sisken B, Lundborg G (1993) Pretreatment of rats with pulsed EMFs enhances regeneration of the sciatic nerve. Bioelectromagnetics 14(4):353-359. Dept of Animal Physiology, Univ of Lund, Sweden.

Regeneration of the sciatic nerve was studied in rats pretreated in a PEMF. The rats were exposed between a pair of Helmholtz coils at a pulse repetition rate of 2 pps at a field density of 60 or 300 uT. The PEMF treatment was then discontinued. After an interval of recovery, regeneration of the sciatic nerve was initiated by a crush lesion. Regeneration of sensory fibers was measured by the "pinch test" after an additional 3-6 d. A variety of PEMF pretreatments including 4 h/d for 1-4 d or exposure for 15 m/d during 2 d resulted in an increased regeneration distance, measured 3 d after the crush lesion. This effect was found even after a 14-d recovery period. In contrast, pretreatment for 4 h/d for 2 d at 60 uT did not affect the regeneration distance. PEMF pretreatment conditioned the rat sciatic nerve in a manner similar to that which occurs after a crush lesion, which shows that PEMF affects the neuronal cell body. However, the mechanism of this effect remains obscure. PMID: 8216387, UI: 94030101

Nerve regeneration

Meissl G (1979) [Nerve regeneration by means of the effect of an intermittent EMF: Experimental study on a rabbit - Article in German]. Handchirurgie 11(1):31-35.

An experiment on healing of transected nerves of rabbits was carried out. Under microsurgical techniques continuity of the nerve was reestablished by end-to-end coaptation without creating a defect, so only the elasticity of the nerve tissue had to be overcome, and by nerve grafting. In both cases treatment with intermittent high frequency magnetic field was applied continuously. Histologic studies revealed that the scar at the suture site matured more quickly than usually and that distal to the site of transection the normal calibre of regenerated axons was reached within a shorter time than previously. PMID: 393577, UI: 80113931

Orgel MG, O'Brien WJ, Murray HM (1984) Pulsing EMF therapy in nerve regeneration: an experimental study in the cat.

A multidisciplinary approach to the study of peripheral nerve regeneration in the cat has been presented. The purpose of this work has been to determine if PEMF therapy can enhance peripheral nerve regeneration after injury. In equal groups of animals, two types of PEMF treatment were compared with untreated controls. All animals underwent quantitative electrophysiologic and morphologic assessment at the area of injury. Also, muscle fiber sizing in the periphery and retrograde labeling of anterior horn motoneurons with horseradish peroxidase were studied. There were no statistical differences between the groups in electrophysiologic or morphologic parameters. However, in animals treated with a pulse-burst EMF there was a statistically significant improvement in the labeling and localization of anterior horn cells in the CNS. Pulse-burst EM radiation can increase the numbers of motor neurons that reestablish appropriate connections to the periphery after nerve injury. It remains to be seen if this improved spinal cord organization can translate to improved peripheral functional return. PMID: 6695016, UI: 84119896

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Wilson DH, Jagadeesh P (1976) Experimental regeneration in peripheral nerves and the spinal cord in lab animals exposed to a pulsed EMF. Paraplegia May;14(1):12-20.

Peripheral nerve section and suture was performed in 132 rats. Postoperatively 50% of the rats were exposed to a PEMF daily and 50% were kept as controls. Nerve conduction studies, histology and nerve fibre counts all showed an increased rate of regeneration in EMF-treated rats. Preliminary results from a similar controlled study of spinal cord regeneration after hemicordotomy in cats show that PEMF therapy had induced nerve fibre regeneration across the region of the scar in cats killed 3 mo after the hemicordotomy. PMID: 180476, UI: 76221416

Zienowicz RJ, Thomas BA, Kurtz WH, Orgel MG (1991) A multivariate approach to the treatment of peripheral nerve transection injury: the role of EMF therapy. Plast Reconstr Surg Jan;87(1):122-129. Univ of Massachusetts Med School, Berkshire Med Ctr, Pittsfield.

A multivariate approach to the treatment of peripheral nerve transection injury has been used in rats. Phase 1, a pilot study, (48 rats, 8 groups) examined variables associated with the method and timing of surgical repair, the arrest of wallerian degeneration, and the role of PEMF therapy in functional recovery. Phase 2 (90 rats, 6 groups) then studied the timing and duration of PEMF therapy as the only variable in larger groups of rats. Phase 1 showed that a vein-graft conduit did not improve functional recovery compared with standard epineurial repair. Also, delayed repair compared favorably with immediate repair. The use of chlorpromazine to inhibit the toxic effects of calcium influx seemed to enhance early functional recovery, and the combination of delayed nerve repair and PEMF therapy seemed to consistently improve function. Phase 2 gave the first published evidence for statistically improved ambulation in animals treated with delayed surgical repair and prolonged PEMF therapy. We postulate that future treatment of nerve transection injuries will involve a combined treatment regimen consisting of the immediate arrest of wallerian degeneration, delayed surgery, and PEMF therapy. PMID: 1984256, UI: 91074893

Temur'iants NA, Mikhailov AV (1985) [Effect of weak alternating ultra-low frequency magnetic fields on the development of the hypercoagulation syndrome in immobilized rats - Article in Russian]. Biofizika Nov;30(6):1046-1049.

The experimental results are given concerning the effect of variable magnetic field (VMF) with the frequency of 8 Hz and intensity 4 A/m on some parameters of rat haemocoagulation system under standard mobile regime as well as under prolonged hypokinesia. It is stated that repeated daily exposition of VMF causes hypocoagulational blood shift in intact animals. Under the effect of simultaneous VMF and hypokinesia the correction of hypercoagulational shift induced by animal hypokinesia was found. The highest VMF effect was seen in prolonged experiments. The ability of VMF with the given parameters to limit the development of rat blood hypercoagulation under hypokinesia was discussed.

Grant G, Cadossi R, Steinberg G (1994) Protection against focal cerebral ischemia following exposure to a pulsed EMF.

Bioelectromagnetics 15(3):205-216. Dept of Neurosurgery, Stanford Univ, California 94305.

There is evidence that EM stimulation may accelerate the healing of tissue damage after ischemia. We studied the effects of low frequency PEMF exposure on cerebral injury in a rabbit model of transient focal ischemia (2 h occlusion followed by 4 h of reperfusion). PEMF exposure (280 V, 75 Hz, IGEA Stimulator) was initiated 10 min after the onset of ischemia and continued throughout reperfusion (6 exposed, 6 controls). MRI and histology were used to measure the degree of ischemic injury. Exposure to PEMF attenuated cortical ischemia edema on MRI at the most anterior coronal level by 65% (p<.001). On histology, PEMF exposure reduced ischemic neuronal damage in this same cortical area by 69% (p<.01) and by 43% (p<.05) in the striatum. Exposure to a PEMF of short duration may have implications for the treatment of acute stroke. PMID: 8074737, UI: 94354894

Gorczynska E (1988) Fibrinolytical processes in rabbits activated by the magnetic field.

J Hyg Epidemiol Microbiol Immunol 32(4):391-396. Dept of Biochemistry, Academy of Agriculture, Szczecin, Poland.

Rabbits were exposed to a constant magnetic field of 0.005 T, 0.1 T and 0.3 T induction for 1 h/d for 28 d. The magnetic field increased the rate of fibrinolysis. A decrease in fibrinogen concentration, an increase in the level of fibrinogen degradation products and a considerably shorter time of fibrinolysis in plasma were all noted. The magnitude of these processes was proportional to duration of exposure to the magnetic field in action. These date confirms the similar effect seen in other mammalians (guinea pigs, rats). Thus, the application of a static magnetic field of intensity as low as 0.005 T to increase a fibrinolysis in the thrombotic therapy seems to be justified.

Bellossi A, Desplaces A (1991) Effect of a 9 mT pulsed magnetic field on C3H/Bi female mice with mammary carcinoma: A comparison between the 12 Hz and the 460 Hz frequencies. In Vivo Jan;5(1):39-40. Laboratoire de Biophysique, Faculte de Medecine, Rennes, France.

In a previous experiment, the exposure of tumoral C3H/Bi female mice to a 9 mT, 460 Hz pulsed magnetic field led to an increase in the length of survival in the late period of the disease; this might be due to a hampered metastatic process. In the present study 27 controls and 52 exposed mice were treated with the same protocol (a 10-m exposure, 3 non-consecutive d/wk, from 2-3 wk after the tumors appeared until death) but with a 12 Hz PMF. In this experiment the 12 Hz PMF seemed to increase length of survival times in the early period of the disease. PMID: 1932623, UI: 92032693