Physiological characteristics of low threshold mechanoreceptor afferent units innervating frog skin

A total of ninety-three mechanoreceptor afferent units with fast conducting axons in the sciatic nerve innervating the plantar and lateral surface of the hind foot were isolated for electrophysiological recording in anaesthetized frogs (Rana catesbeiana). Sixty-three rapidly adapting (RA) units and thirty slowly adapting (SA) units were differentiated from each other mainly on the presence of an "off' response and a slope-locked "on' response to ramp stimulation in RA units and on the persistence of discharges of the SA units during steady pressure on the receptive field. RA units were subdivided into two subgroups; RA type I units and RA type II units. The RA type I units had small well-demarcated receptive fields in which the unit was uniformly sensitive, and low indentation amplitude and velocity thresholds. The RA type II units had receptive fields consisting of several sensitive spots, associated with skin warts in the warty skin, high indentation thresholds, and the fastest conduction velocities (mean 19.9+/-4.4 m/sec) among the three groups of the units studied. RA type I units showed U-shaped tuning curves with a best tuning frequency at around 2 Hz, while tuning curves of SA units were flat from 0.1 (the lowest frequency examined) to 1 Hz. RA type II units could only follow the first cycle of continuous sinusoidal stimulation at any frequency. The relation between the indentation velocity and amplitude of the ramp and the spike discharges was analysed quantitatively.

Periodic synchronous discharge and myoclonus in Creutzfeldt-Jakob disease: diagnostic application of jerk-locked averaging method

The technique of jerk-locked averaging was applied to two patients with pathologically proved Creutzfeldt-Jakob disease. Patient 1, whose brain contained numerous kuru plaques and severe cerebral white matter degeneration, did not show any periodic synchronous discharges in spite of frequently repeated EEG recordings. The technique of jerk-locked averaging, however, disclosed a negative sharp wave over the contralateral central area in close temporal association with myoclonus of an upper extremity. Patient 2 had classic periodic synchronous discharges on the EEG, and jerk-locked averaging delineated a fixed relationship in time and space between the periodic discharge and the myoclonus.

Onlay fundic patch method applied in spontaneous rupture of the esophagus: a case report

A successful attempt using the onlay fundic patch method for treatment of spontaneous rupture of the esophagus (SRE) was reported. A 38-year old male presented with left chest pain and a preoperative diagnosis of SRE was made. Surgery was performed 16 hours after the onset of symptoms and a 3 cm esophageal tear just above the level of the diaphragmatic hiatus was noted. The esophageal tear was repaired by the onlay fundic patch method through left thoracotomy and the postoperative course was uneventful and recovery was complete. A search of the literature has yielded only one case of SRE that was improved with onlay fundic patch by Thal and Hatafuku (1964) and this method is useful for the immediate and late repair of rupture of the esophagus.

Antagonistic effects of Bacillus natto and Streptococcus faecalis on growth of Candida albicans

The growth-inhibitory effects of Bacillus natto and Streptococcus faecalis on Canida albicans were investigated. When inoculated into the filtrate of a long-term culture of B. natto strain BN (BN), a stock culture of C. albicans RIMD 0301020 lost its viability completely, whereas C. albicans RIMD 0301011, a fresh isolate from a clinical source, did not. In continuous flow (CF) culture the growth of both strains of C. albicans was suppressed by mixed cultivation with BN. On the other hand, in classical batch culture BN did not suppress the growth of C. albicans. S. faecalis BIO-4R, a multi-drug resistant strain, was also antagonistic to C. albicans RIMD 0301011 but symbiotic with BN in CF culture. These findings suggest that BN in concert with S. faecalis BIO-4R may inhibit the growth of C. albicans in the intestinal tract.

De- and remyelination and onion bulb in cerebrotendinous xanthomatosis

In a case of cerebrotendinous xanthomatosis (CTX), confirmed biochemically and histologically quantitative histological studies of the biopsies sural nerve revealed significantly higher incidence of de- and remyelination and onion bulb than in controls. The density of total myelinated fibers fell within the range of controls, although the density of large myelinated fibers seemed to be slightly decreased. It was suggested that the preferential involvement of the myelin sheath and Schwann cell may exist in CTX.

Suppression of congenital nystagmus

Suppression of congenital nystagmus by eyelid closure was studied by electrooculography in four cases under various conditions in order to elucidate whether the suppression is caused by blocking of fixation or not. The nystagmus persisted in the light as well as in the dark provided that the eyes were kept open. Frenzel's glasses did not suppress the nystagmus except for one case in whom jerky nystagmus was attenuated. In the other cases, only voluntary lid closure suppressed the nystagmus. Passive lid closure while the patient attempted to keep eyes open did not suppress the nystagmus except in one case. Reflex eyelid closure by glabellar tap did not suppress the nystagmus in spite of the occurrence of Bell's phenomenon. Passive eyelid opening while the patient attempted to keep eyes closed, on the other hand, did not reproduce the nystagmus. The suppression of congenital nystagmus by lid closure, at least in some cases, seems to be related to the voluntary effort to keep eyes closed but not specifically to blocking of fixation.

Electroencephalographic studies myoclonus

Electroencephalographic studies were carried out in 30 patients with various kinds of myoclonus. It was confirmed that the technique of jerk-locked averaging with a backward averaging program was useful for detecting cortical spikes in association with the spontaneously occurring myoclonus, which are not recognized on the convential polygraph, and for evaluating the temporal and topographical relationship between the spike and the myoclonus. By this technique, cortical spikes were shown to precede the myoclonus of a contralateral upper extremity muscle by 7 to 15 ms ith progressive myoclonic epilepsy showed a high amplitude somatosensory evoked potential (SEP) in response to electrical stimulation of the median nerve. The N33 component of this high amplitude SEP was found to be similar to the myoclonus-related cortical spike in their wave form, time relationship and topographical distribution, suggesting an involvement of similar physiological mechanisms in the genesis of both phenomena. Myoclonus in these patients is compatible with "pyramidal" or "cortical loop reflex" type.

Somatosensory evoked potentials. Diagnostic criteria and abnormalities in cerebral lesions

In order to advance the practical application of measuring evoked cortical responses following electrical stimulation of the median nerve at the wrist (SEP) in clinical neurology, diagnostic criteria, consisting of the onset latency, peak latency and 2 indices of the first 3 negative components, and their left-and-right differences, were proposed and applied to 65 patients with cerebral lesions of various aetiologies. The criteria used were shown to be very useful in distinguishing between normal subjects and patients with cerebral lesions. The N1 and N2 components were related to the involvement of sensory pathways and were commonly associated with sensory impairment of all modalities or of deep proprioceptive and cortical modalities. The N3 component, on the other hand, was related to the presence of lesions and non-specific sites as well as non-specific symptomatology. SEP, judged by the present criteria, was shown to be useful as a complementary diagnostic aid in localizing the sites of lesions in sensory pathways and in evaluating sensory function, especially when used in combination with clinical symptomatology.

Evidence that the multi-drug-resistance of Streptococcus faecalis BIO-4R is not carried by a plasmid

The multi-drug-resistant strain Streptococcus faecalis BIO-4R was studied to see if it carried a plasmid responsible for antibiotic resistance. From results indicating that the antibiotic resistance of S. faecalis BIO-4R was not transferred to recipient bacteria, that the organism did not produce enzymes which inactivated antibiotics, and that the presence of covalently closed circular DNA was not demonstrated by dye-cesium chloride buoyant density gradient centrifugation, it was concluded that the organism did not carry such a plasmid. Studies on polyphenylalanine synthesis by cell-free extracts of the oganism showed that its ribosomes were resistant to chloramphenicol, tetracycline, streptomycin and kanamycin. These results, although rather indirectly, support the above notion that the multi-drug-resistance of S. faecalis BIO-4R is not mediated by a plasmid.

[Complications resulting from ventriculo-peritoneal shunt: an anticipatory comment-case report (author's transl)]

Case is 23 year-old man, Who was admitted to the University Hospital with a diagnosis of acoustic neurinoma as a manifestation of von Recklinghausen's disease. V-P shunt was performed because of the increased intracranial pressure and post-operative course was complicated by repeated bout of meningitis. Otherwise, postoperative course was uneventful till about 7 month after placement of V-P shunt when the proximal end of the shunt tube perforated into the lumen of the intestine and about 30 cm length of shunt tube emerged from anus. Subsequently the patient developed meningitis. Nowadays, the tendency was noted that ventriculo-peritoneal shunt is more frequently performed than ventriculoauricular shunt and so increased incidences of complications attributable to the position of the tip of the shunt tube in theperitoneal cavity is naturally anticipated. In this report, we discussed the mechanism of development of intestinal perforation, its prophylactic measures and the earty diagnosis. Number one factor which is attributed to the cause of intestinal perforation is a fact that any intra-peritoneal foreign body is potentially able to cause intestinal perforation. The second factor is the sharp tip of the peritoneal shunt tlbe which more easily cause intestinal perforation than otherwise. The third factor is the constant pressure at the same location of the intestinal wall over a long period of time which is applied by a peritoneal tip, which is considered to cause necrosis of the intestinal wall. The fourth factor is relatively poor general condition of the patient and secondary decrease in resistance of the intestinal wall against the foreign body. We therefore postulate for the prophylaxis and early diagnosis that we should often check the position of the tip of the shunt tube end should performed the radiological evaluation at the first sight of peritoneal irritation sign. The architecture and the location of the tip of the tube, the length and material of the tube seem to have intimate relation to the prophylaxis against intestinal perforation and these factors have to be evaluated in the future.

Regional cerebral blood flow in delayed brain swelling following x-irradiation of the right occipital lobe in the monkey

Four to 5 months after exposure of the right occipital lobe of the monkey to 3500 rads of X-irradiation there is a proliferative and degenerative lesion accompanied by a massive break in the blood-brain barrier. The resulting vasogenic edema causes gross swelling in the ipsilateral hemisphere, compression of the contralateral hemisphere with ventricular dilatation, and distortion of midline structures, which may result in herniation through the incisura and foramen magnum. The regional cerebral blood flow, determined by [14C]antipyrine method, at successive stages in the development and resolution of the delayed brain swelling shows a reduction of blood flow in white and gray matter, first regionally, then throughout the ipsilateral hemisphere and finally throughout the brain. This is accompanied by an increase in CSF pressure, CSF lactic dehydrogenase and total protein, and clinical signs of increased intracranial pressure. With resolution of CSF pressure, there is a return to baseline of CSF chemistry and partial resolution of the other parameters. The cerebral blood flow shows a greater recovery in gray than white matter, but there remains a diffuse depression suggesting a long-term impairment in cellular metabolism and/or blood flow regulatory mechanisms.

Medulloblastoma in two brothers

The occurrence of medulloblastoma in two brothers is presented. The striking similarities between two cases in the sex, age of onset of symptoms, clinical manifestations and histological findings suggested a possible role of heredity in the etiology of this tumor.

Action site of antagonists of vitamin B6 in the central nervous system of the frogs and cockroaches

Susceptibility to some antagonists of vitamin B6 was studied in frogs and cockroaches after operational intervention in their central nervous systems, and also in the intack frogs and cockroaches. Thiosemicarbazide, semicarbazide, isoniazide and penicillamine induced wild jumping behavior, and tonic or clonic convulsions in frogs, when the nervous parts posterior to the optic lobe inclusive remained intact. In frog, in which the nervous parts anterior to the diencephalon inclusive had been removed, no convulsions were induced by castrix or 4-deoxypyridoxine in large doses. In cockroaches excessive fluttering of wings and convulsions upon administration of thiosemicarbazide following severance of the central nerve cord between the subesophageal and prothoracic ganglions were induced. Castrix was not a convulsant in the intact frogs and cockroaches.

Haemagglutination inhibition assay of the common determinants and subspecificities of Australia antigen

Antigenic determinants of Australia antigen (AuAg) may be determined by haemagglutination inhibition with ease and high sensitivity. The reaction depends on the inhibitory effect of the test antigen-positive sample on the agglutination by specific antibody of glutaraldehyde-fixed sheep erythrocytes which have been tanned and coated with AuAg of different specificities. The standard monospecific antibody reactants are directed against one or other of the common antigens, a and Re, or against the subtypic determinants, d, y, w and r. Because it is more sensitive than conventional immunodiffusion or electrosyneresis, and more convenient than radio-immunoassay, haemagglutination inhibition is most suited to large-scale determinations of AuAg subtypes in samples of relatively low antigenic activity.