Differences in sensitivity between magnetic motor-evoked potentials and somatosensory-evoked potentials in experimental spinal cord lesions.

STUDY DESIGN: Graded posterior spinal cord compression and partial sectioning of the spinal cord were performed, and magnetically induced descending spinal cord potentials were recorded. OBJECTIVES: To compare the sensitivity of transcranial magnetic motor-evoked potentials in the spinal cord and other spinal cord evoked potentials to spinal cord lesions. SUMMARY OF BACKGROUND DATA: Somatosensory-evoked potentials have been the standard technique for monitoring spinal cord function during spinal surgery. These potentials, however, do not necessarily reflect descending motor tract function. Transcranial electric or magnetic stimulation for motor-evoked potentials is a more direct measure of motor tract function. However, more research on magnetic motor-evoked potentials is needed. METHODS: Fifteen adult cats were used. Graded posterior spinal cord compression was performed at L2 in 10 cats, and partial sectioning of the spinal cord was performed at L2 in five cats. The location sequence of lesioning was dorsal column section, dorsal 1/2 section, dorsal 2/3 section, and total spinal cord section. Magnetic motor-evoked potentials were recorded by epidural catheter electrodes placed above at, and below the lesion. Electric motor evoked potentials and spinal and cortical somatosensory-evoked potentials were recorded serially for a comparison of their sensitivity to spinal cord dysfunction. RESULTS: In posterior spinal cord compression, N1 amplitude of magnetic motor-evoked potentials at and below the lesion decreased after 1 minute of compression with a 70 g weight, and N1 and N2 amplitude disappeared after 1 minute of compression with a 100 to 120-g weight. Electric motor-evoked potentials changed at amplitudes comparable with those shown by magnetic motor-evoked potentials. Spinal somatosensory-evoked potentials showed the most sensitive changes to spinal cord posterior compression and disappeared after 1 minute of compression with 80 g Cortical somatosensory-evoked potentials in five cats were not sensitive enough for spinal cord posterior compression injury and did not disappear even after 1 minute of compression with 120 g. In magnetic motor-evoked potentials, after dorsal hemisectioning of the spinal cord only N3 disappeared; N1 and N2 disappeared after ventral spinal cord sectioning in spinal somatosensory-evoked potentials, amplitudes decreased after dorsal column sectioning, and all negative peaks disappeared after dorsal hemisectioning of the spinal cord. CONCLUSIONS: Posterior compression injuries are diagnosed more easily with spinal somatosensory-evoked potentials. Motor-evoked potentials were slightly less sensitive, but they were significantly more useful in diagnosing posterior compression injuries than were cortical somatosensory-evoked potentials.

The effect of the platelet derived wound healing formula and the nerve growth factor on the experimentally injured spinal cord.

The main purpose of this study is to investigate the effect of platelet derived wound healing formula (PDWHF) and nerve growth factor (NGF) in the treatment of experimental spinal cord injury. PDWHF is a conglomerate of growth factors which include platelet derived growth factor (PDGF), platelet derived angiogenesis factor (PDAF), transforming growth factor-beta (TGF beta) and platelet factor IV (PF4). Complete spinal cord transection was performed at T12 in rats and the treatment of the spinal cord injury was achieved by filling the dead space with type 1 collagen gel impregnated with PDWHF, or with 2.5S-NGF. Controls were treated with only type 1 collagen gel. Animals were sacrificed at 1, 2 or 3 months. Histopathologically, tissue autolysis and cavity formation by phagocytosis expanded 1-3 mm into the cord stumps and the volume of cavitation was less in the two treated groups. In the NGF group, a greater number of surviving nerve cells were observed in this region. Most of the control animals formed only thin, short axonal bundles, however, increased axonal regrowth was noted in animals treated with trophic factors, especially in the NGF group. The NGF group formed thick axonal bundles and abundant neuroma. Increased angiogenesis was observed in the collagen gel matrix and the injured spinal cord parenchyma, in the PDWHF group. Recent studies have shown that mammalian adult CNS possesses the ability for structural and/or functional plasticity following injury under appropriate circumstances. In this in vivo study, exogenous NGF appeared to induce axomal outgrowth and nerve cell survival. PDWHF produced notable angiogenesis which seemed to improve the extracellular microenvironment. This may be important for the delivery of exogenous trophic factors, nutrients and for the changes of extracellular matrices to support nerve cells and axons.

A case of Fabry's disease with granulomatous interstitial nephritis.

A 15-year-old boy with proteinuria and hematuria is reviewed in this study. He was first found to have urinary abnormalities at the age of 13 years, and his renal function was exacerbated for a short duration. Renal biopsy was performed to make a histological diagnosis and to establish adequate therapy. Light microscopy showed marked tubulointerstitial inflammation with granulomatous changes, and electron microscopy revealed that numerous osmiophilic inclusions were present in podocytes, mesangial cells, and endothelial cells of the glomeruli and in epithelial cells of the tubules. The alpha-galactosidase activity of lymphocytes from the patient was measured, and the results of this assay indicated that the patient's lymphocytes had a low level of alpha-galactosidase activity. Therefore, the patient was diagnosed as having Fabry's disease with renal dysfunction. This study demonstrated that the onset age of renal insufficiency in Fabry's disease may be earlier than that described previously, and that when granulomatous interstitial nephritis is developed, renal function may deteriorate progressively.

Application of polyvinyl alcohol hydrogel membrane as anti-adhesive interposition after spinal surgery.

STUDY DESIGN: Three inflammatory and adhesive changes inside the spinal canal were analyzed histopathologically in cats. OBJECTIVE: To investigate the usefulness of a polyvinyl alcohol hydrogel sheet as an interposition over the dura to prevent inflammatory and adhesive reaction after laminectomy. SUMMARY OF BACKGROUND DATA: A major concern after laminectomy is scar tissue formation that may result in extradural compression or make subsequent surgery to the same area difficult and hazardous. METHODS: Wide laminectomy was performed at L5 in 30 adult cats. The dura was covered with a polyvinyl alcohol hydrogel sheet, free fat graft, or without interposition as a control. Animals were killed at 3 or 12 weeks. RESULTS: In the control group, adhesion of the exposed dura was apparent. Thick, fibrous connective tissue was observed between the dura and the paravertebral muscles. In the fat graft group, the dura was separated from the scar tissue by living grafted fat. However, the dura was adherent to the grafted fat and fibroblasts migrated into the interstitial space. In the polyvinyl alcohol hydrogel group, only a thin synovium-like layer was formed around the polyvinyl alcohol hydrogel sheet. CONCLUSIONS: Polyvinyl alcohol hydrogel is made of water and alcohol, and has been shown to be nontoxic to tissues. This is permeable to low molecular weight, but impermeable to large cells such as fibroblasts. Thus, the polyvinyl alcohol hydrogel sheet prevents migration of inflammatory cells and subsequently reduces intraspinal canal scar tissue formation and adhesive reaction. Other beneficial properties are extreme elasticity and low friction, which eliminate mechanical reaction to the spinal cord. The polyvinyl alcohol hydrogel sheet is believed to be useful in eliminating scar tissue formation and does not interfere with the dynamic gliding movement of the spinal cord and nerve roots.

[A case of focal encephalitis with psychological symptoms similar to chorea minor].

We reported a patient with choreic movements, emotional lability, and compulsive-obsessive behavior that developed 4 weeks after onset of fever and lasted for several years. There was no evidence of streptococcal infection or rheumatic fever. T2-weighted MRI showed hyperintense lesions in the bilateral caudate nuclei and putamina. A diagnosis of focal encephalitis was made according to initial fever, convulsion, and CSF pleocytosis. Treatments with haloperidol and prednisolone were effective in some degree. The neurobehavioral syndrome as well as the involuntary movements in this patient can be attributed to the striatal damage, which may disrupt the basal ganglia-limbic-frontal lobe tracts. A symptomatic similarity between the syndrome in this patient and chorea minor suggests a striatal damage in chorea minor, where the causative lesions remain unknown.

X-linked elements associated with negative segregation distortion in the SD system of Drosophila melanogaster.

Three elements, M1, M2 and M3, found in a special X chromosome, supp-X(SD), modify the degree and direction of segregation distortion in the SD system of Drosophila melanogaster. The first element, M1, is located between the y and the cv loci, probably close to the y locus. The second element, M2, is located near the cv locus and the third element, M3, is located between the y and the car loci. The M1 element appears to cause a relatively small amount of reduction in the rate of recovery of the SD-72, but not the cn bw, chromosome from SD-72/cn bw males, when raised at 27.5 degrees. The M2 and the M3 elements cause considerable decrease in the recovery rate of the SD-72 chromosome, whereas they increase the recovery rate of the cn bw chromosome. The amount of decrease is nearly the same as the amount of increase for each element. Some type of "switch" mechanism in the directions of distortion is suggested for each of these two elements and their effects appear to be approximately additive.

Temperature sensitivity of negative segregation distortion in Drosophila melanogaster.

Previous work has shown that the direction of segregation distortion in the SD (Segregation Distorter) system in Drosophila melanogaster can sometimes be reversed, but this was found only with rather weak distorters and the effect was not large. The present study reports large negative segregation distortion in a strong distorter, SD-72 chromosome. In the presence of a specific X chromosome, supp-X(SD), the proportion, k, of SD-72 chromosomes recovered from the SD-72/cn bw males ranges from 0.99 at 20 degrees to 0.11 at 28.5 degrees, whereas with a standard-X chromosome, k ranges from 0.99 to 0.95 for the same temperature range. The temperature-sensitive period is during spermiogenesis. Using a mating system in which the sperm supply is nearly exhausted, it was shown that the negative distortion at high temperatures is due to an absolute reduction in the number of SD-72 chromosomes and an absolute increase in the number of cn bw chromosomes recovered. After adjusting for non-SD-related temperature effects, the amount of decrease in the number of SD-72 progeny is nearly the same as the amount of increase in the number of cn bw progeny, suggesting that the dysfunction switches from a spermatid carrying one homolog to one carrying the other. Negative distortion requires a radical revision of current hypotheses for the mechanism of segregation distortion and a possible modification of the current model is suggested, based on differential recovery of dysfunction in the two homologs during spermiogenesis.

Electrophysiologic evaluation of intermittent sacral nerve dysfunction in lumbar spinal canal stenosis.

Intermittent sacral nerve dysfunction, induced by walking in lumbar spinal canal stenosis, may cause symptoms including hyperesthesia and pain in perineum, urinary bladder incontinence, and penile erection. However, it is difficult to objectively document these symptoms. Evoked external urethral sphincter potentials by conus medullaris stimulation were measured both before walking and after walking in five patients who complained of sexual organ or urinary dysfunction during walking, and were compared with simultaneously induced sacral nerve symptoms. These potentials were also measured during surgery. Sacral nerve symptoms were reproduced by walking 80-350 meters (average 177.5 m). These potentials disappeared in one patient and were decreased in four patients at the time when the claudicant symptoms disabled the patient during walking. The amplitude subsequently recovered in keeping with relief of those symptoms during rest. Monitoring of these potentials during surgery showed an increase of amplitude shortly after the decompression procedure of the cauda equina. In conclusion, this measuring method was valuable as an objective evaluation of intermittent sacral nerve dysfunction in lumbar spinal canal stenosis.

[An acute axonal form of Guillain-Barré syndrome with autoantibody against ganglioside GD1b--a case report].

We reported a 3-year-old boy of an acute axonal form of Guillain-Barré syndrome (GBS) with autoantibody against GD1b ganglioside. A week after an episode of upper respiratory infection, he was hospitalized with a weakness in the lower extremities. Neurological examination revealed facial weakness, restricted extra-ocular movement, hyporeflexia and tetraparesis without any sensory impairment. CSF protein was elevated with normal cell count after the first week of symptoms. Electrophysiological studies demonstrated normal motor nerve conduction velocity and low M potential amplitude. He had been on a respirator for two months. Although he received plasmapheresis in the acute phase, sixteen month after the onset he continued to have distally dominant limb weakness with wasting. Thin-layer chromatogram with immunostaining revealed that serum IgG from this patient reacted with GD1b, but did not react with GM1. Enzyme-linked immunosorbent assay showed that anti-GD1b titer (IgG) decreased concurrently with the clinical improvement. There have been several reports of an acute axonal form of GBS with antibody to GM1. GD1b, as well as GM1, seems to be a target pathogenic antigen in motor axon disorders.

In vivo angiogenesis by platelet-derived wound-healing formula in injured spinal cord.

In vivo angiogenesis was investigated using platelet-derived wound-healing formula (PDWHF) in the injured cat spinal cord. Twenty-two gauge teflon sheaths, which had been coated with PDWHF-Hydron or only with Hydron, were inserted into the spinal cords of cats and the injured cats were maintained for 3 weeks. Selection of PDWHF-Hydron or Hydron was double blinded. The PDWHF-Hydron group showed notable neovascularization as well as dilation around the injury site, and this was statistically significant when compared to the control group. PDWHF seems to play a role in the healing processes of spinal cord injury and may have important interactions with other growth factors and in particular neurogenic growth factor.

Immunohistochemical identification of muscle fiber types in normal and degenerated muscles.

Myosin ATPase reactions are generally used to differentiate between muscle fibers. However, those reactions have disadvantages including the need for delicate pH control and preincubation under non-physiological pH. Furthermore enzyme activity is only an indirect reflection of myofilament characteristics. In this study, an immunohistochemical method with anti-slow and anti-fast myosin heavy chain antibodies was used to observe: 1) whether muscle fiber types could be distinguished in degenerated muscles, 2) immunoreactivity of type 2C fibers in denervated muscles, and 3) discrepancies in structural disorders. Thirty one muscle biopsies which included neurogenic, myogenic, and control muscles were examined. Muscle fiber types were recognized in normal and in severely degenerated muscles. Type 2C muscle fibers were not necessarily constantly immunoreactive to both anti-slow and anti-fast myosin antibodies. In some targetoid fibers sites with absence of myosin ATPase activity had the same or rather higher immunoreactivity. Some muscle fibers undergoing fiber-type transformation showed discrepancies in reactivity between enzyme- and immuno-reactivity. This immunohistochemical method is capable of observing changes of muscle fibers during denervation, reinnervation, and also sports activity.

Open total dislocation of the talus with extrusion (missing talus): report of two cases.

Two different methods of treatment for open dislocation of the extruded talus without soft tissue attachments (missing talus) were examined. In case 1, a 20-year-old man sustained an open total dislocation of the talus due to a motorcycle accident. The missing talus was found within 3 hr and replaced after thorough washing and debridement. Weightbearing was permitted at 20 weeks; however, the density of the talar body increased in the x-ray and nonweightbearing status was resumed. Reexamination at 2 1/2 years revealed that there was joint space narrowing on the x-ray and decreased pain with ambulation; the patient had returned to his job. In case 2, a 26-year-old man sustained an open total dislocation of the talus with a severe crush wound and impaired circulation to the foot. After thorough washing and debridement of the wound, the calcaneus and distal end of the tibia were aligned. The missing talus was found 3 days later, but not replaced. Weightbearing was allowed on the affected foot at 2 months; however, the patient felt pain at the joint surfaces and arthrodesis was consequently performed. At 2 1/2 years, the patient had a 4.0-cm leg length discrepancy in the involved extremity, but felt no pain when walking. Although reduction of the talus is ideal to preserve function and length of the extremity, several complications can occur. A review of literature on open total dislocation of the talus with extrusion was performed.

Gly145 to Arg substitution in HBs antigen of immune escape mutant of hepatitis B virus.

A Japanese child born to an HBeAg-positive carrier mother received anti-HBs immunoglobulins and a plasma-derived HBs vaccine with a poor anti-HBs-antibody response. The child, who is now 3 years old, is presently suffering from chronic hepatitis with unusual serological findings that are positive for HBsAg, anti-HBs and HBeAg, since being infected with a measles virus at 12 months of age. The nucleotide sequences of the S region of HBV DNA obtained from the patient, the mother and an HBeAg-positive brother were completely identical except for one nucleotide at position 587 (mother and brother: guanosine, patient: adenosine), giving an amino acid change: Gly - greater than Arg at position 145 of the major HBs protein.

The effect of growth factor formula (platelet derived wound healing formula) in experimental spinal cord injuries.

The main purpose of this study was to investigate the usefulness of platelet derived wound healing formula (PDWHF) in the treatment of experimentally induced spinal cord injuries in cats. The injury model in ten adult cats consisted of the placement of three 22-gauge Teflon catheter sheaths into the spinal cord at the L2 level. Treatment consisted of coating these sheaths with PDWHF in Hydron. Three animals were used as controls. In the 7 remaining cats, treatment was double blinded. Cats were sacrificed at 3 weeks after injury and injured spinal cord segments were excised for histologic evaluation. Electrophysiologic and clinical motor function were evaluated throughout a period of observation. Evoked potentials in both the treated and control groups indicated incomplete spinal cord lesions due to insertion of the needles. There did not appear to be any significant improvement or difference in the evoked response and clinical function as a result of treatment with PDWHF. The histological findings in the PDWHF-treated group showed significant new vessel formation as well as dilation and around the injury site. This neovascularization, both qualitative and quantitative, was noted in the treatment group. This information, with a limited injury and very simple delivery system for growth factor, would suggest there is definite neovascularization occurring as a result of this treatment and this may be useful in the subsequent wound healing response such as axonal growth and scar tissue formation.

Long-term morphology of spastic or flaccid muscles in spinal cord-transected rabbits.

Despite difficulty in long-term maintenance of spinalized rabbits, muscular pathologic changes in chronic spinalized rabbits could be observed for a period of four weeks. Rabbits were prepared by spinal cord transection at T10 (spastic paralysis) or by spinal cord removal below L7 (flaccid paralysis). Spastic preparations showed hind-limb spasticity and reflex incontinence one to two days after operation. Hypertrophic fibers began to appear in spastic muscles after two weeks. This hypertrophy, thought to be caused by phasic repetitive contraction, was verified by electron microscopy to be different from normal exercise hypertrophy. Flaccid preparations maintained hind-limb flaccidity and overflow incontinence. In flaccid muscle, marked muscle fiber necrosis indicated rapid atrophy. Spinal deformity and joint contracture inactivate spinalized rabbits, and cause pressure sores. However, feeding assistance and avoidance of complications make long-term maintenance possible.

Negative segregation distortion in the SD system of Drosophila melanogaster: a challenge to the concept of differential sensitivity of Rsp alleles.

Current models of segregation distortion based on previous experimental results predict that, in the Sd heterozygous Rspi/Rsps male, the chromosome carrying the sensitive Rsps allele is distorted or transmitted in a frequency smaller than that of the expected Mendelian 0.5 relative to the chromosome carrying the insensitive Rspi allele. The present study presents a case where this does not occur, that is, when the genotype of the males is supp-X(SD)/Y; Sd E(SD)Rspi M(SD)+/Sd+ E(SD)+ Rsps M(SD)+ where supp-X(SD) is an X chromosome carrying a strong suppressor or suppressors of SD activity and SD+ E(SD)+ Rsps M(SD)+ is the standard cn bw chromosome. Following the "inseminated female transfer" procedure, young males of the above genotype carrying the standard-X instead of the supp-X(SD) chromosome show k values for the SD chromosome (frequencies of the SD chromosome recovered among progeny) of about 0.75, but with the supp-X(SD) chromosome, the k values are reduced to 0.36-0.41. Several possibilities other than the mechanism of segregation distortion to explain the reduced k values are ruled out. The occurrence of "negative segregation distortion" is clearly demonstrated, where the chromosome carrying the Rspi allele is distorted but the chromosome with the Rsps allele is not. This result requires a major modification of the current models or even a new model for the mechanism of segregation distortion to accommodate Rsp allele sensitivity or insensitivity. The present study also shows that males of the genotype, Sd Rspss M(SD)+/Sd+ Rspss M(SD), are almost completely sterile, but their fertility is considerably increased when SD activity is suppressed by the presence of the supp-X(SD) chromosome. This result suggests that the amount of the Sd product is not limited with respect to the interacting sites available, that is, the amount is large enough to interact with both of the Rspss alleles.

Selection at the ABO locus in the Japanese population.

Hiraizumi et al. (1973b) concluded that maternal-fetal ABO incompatibility effect upon the frequency of prenatal deaths was totally absent in two modern Japanese cities, Ohdate and Akita. However, they found a significant heterogeneity in the frequency of prenatal deaths among 16 mating types and suggested that the viability of A-bearing fetuses was higher than that of others, hence the frequency of prenatal deaths decreased with the increasing probability of producing A-bearing fetuses. Further analyses were performed in the present study and the above suggestion was confirmed. Then, the average numbers of prenatal deaths and pregnancies per couple were analyzed separately for their relationships with the probability of producing an A-bearing fetus. The results were found to be consistent with the model that the average numbers of prenatal losses per couple are approximately the same between two groups of matings, one producing and the other not producing A-bearing fetuses, but such losses occur more frequently for the A-bearing fetuses than others at the very early stage of pregnancy such that wives may not recognize such losses. Although the stages of losses are different between A-bearing and other fetuses, the net losses are nearly the same between them, so that such losses will not be reflected in the segregation frequencies among children, as shown by Hiraizumi et al. (1973a).