Myelination in cerebellar slice cultures: development of a system amenable to biochemical analysis

Myelin deposition and maintenance are critical to proper function of the mammalian nervous system. Previous investigations of myelination in the central nervous system (CNS) were hampered by the lack of an in vitro system that can faithfully reproduce in vivo events yet is amenable to biochemical investigation. We have developed a procedure, based on organotypic cultures, which permits efficient preparation of large numbers of cerebellar slice cultures that can be easily manipulated. Cultures have been examined to document myelination biochemically (by incorporation of [35S]sulfate into sulfolipids), immunohistochemically (by labeling the myelin components myelin basic protein and galactocerebroside), and morphologically (by both light and electron microscopy). We tested the effects of biologically active peptides and antibodies on myelination in the thin slices. The results indicate that the cultures provide an in vitro system that can be used to examine specific cellular events that occur during CNS myelination.     

Ultrasound in the management of acute pancreatitis

Thirty-eight patients have been examined by ultrasound when symptoms or sign suggested the development of a pseudocyst following an attack of proven acute pancreatitis. Pseudocyst was diagnosed in 23 of the 38 cases. Five patients had multilocular cysts, four of which were shown to be communicating. Laparotomy was carried out on 14 of the 23 patients and surgical drainage was performed in 12 cases. The remaining nine cases were monitored and showed steady regression. Small cysts arising in the head of pancreas may give rise to recurrent or persistent pancreatitis and may be demonstrated pre-operatively by ultrasound but not readily by other means. A further 12 patients showed an area of irregular absorption of ultrasound interpreted as an inflammatory mass. Monitoring of these cases showed progressive resolution without cyst formation. Three of these cases subsequently required laparotomy-one developed an abscess and one necrosis of the body and tail of pancreas while a third developed severe pancreatic fibrosis of the area identified by ultrasound. The ability to distinguish between pseudocysts and inflammatory masses and to demonstrate communication between multiple cysts is of considerable value in pre-operative diagnosis.     

Bioplast fibrin buttons for liver biopsy and partial hepatic resection

Absorbable buttons made from fibrin (Bioplast buttons) have been used to facilitate liver biopsy or to control haemorrhage from the liver in 3 dogs and 14 patients. The buttons are easy to use, effective, and readily absorbed.     

The hypotensive effect of fusaric acid: the results of long-term administration of fusaric acid in elderly hypertensive patients

The hypotensive effect of fusaric acid calcium salt (Calcium salt of 5-butylpicolinic acid) was examined clinically in 10 elderly hypertensive patients by the long-term administration of this agent and the following results were obtained. 1) The means of the systolic and/or diastolic blood pressures of each patient were significantly lower during the first year of the trial period than those during the one year's control period in all patients. 2) The means of the systolic and/or diastolic blood pressures of each patient were significantly lower during the second year of the trial period than those during the one year's control period in whom administration of fusaric acid calcium salt was continued throughout two years. A significant reduction of the systolic blood pressure was observed in 3 out of 6 patients and that of the diastolic blood pressure was observed in 5 out of 6 patients. 3) Comparison was made between the means of the systolic and diastolic blood pressures during the one year's control period and those during the six month's placebo period after two year's administration of fusaric acid calcium salt. During the placebo period, both systolic and diastolic blood pressures showed a tendency of returning to the levels during the control period confirming the hypotensive effect of this agent. 4) Laboratory findings after one year's administration of fusaric acid calcium salt showed no adverse effect of this agent.     

Stable chronic disease: a behavioral model

A three-year study was undertaken in the general medical clinic of a private community hospital, to assess the health behavior, health status, and profile of function of stable chronic disease was developed and tested. It was shown that these patients used a disproportionate amount of health care services. Half of the group was treated by a nurse practitioner/physician team and half by a house officer/preceptor team. Patients in both groups behaved similarly. These patients: 1) made frequent demands for outpatient services but did not need more than average hospital care; 2) tended to have problems of socio-economic indigency; 3) were likely to have hypertension, obesity, arthritis, and functional disease; 4) were chiefly women; 5) required special visits 9 percent of the time, usually for exacerbations of illness or intercurrent health problems; 6) made greater demands if they had functional complaints as a primary or secondary health problem; and 7) viewed their health more positively and functioned at a higher level if they were over 65 years of age. It was also found that the nurse practitioner, working in consultation with a physician, was able to provide high-quality health care.     

Glycine receptors in the retinas of normal and spastic mutant mice

PURPOSE: Spastic mutant mice have abnormal gait and righting behavior, and the responses of their retinal ganglion cells have recently been shown to be abnormal. The former defects have been linked to a reduction of glycine-receptor density in the spinal cord of spastic mutants, but the cause of the retinal defects has not yet been determined. The authors thus tested for reduced glycine-receptor density in the mutant retina by comparing the levels of glycine receptors in the retinas of spastic mutant mice with those found in normal mice. METHODS: Indirect immunofluorescence histochemistry was employed, using monoclonal antibodies directed against the alpha- and beta-subunits of the receptor and against the 93-kd cytoplasmic receptor-associated protein, gephyrin. RESULTS: In normal mice, all glycine-receptor antibodies labeled two laminae of the inner plexiform layer (IPL): a broad band in the distal third of the IPL and a narrow band in the middle of the IPL. Lighter labeling was also seen in the outer plexiform layer with these antibodies. In spastic mutant mice, the glycine-receptor labeling of the IPL was reduced markedly. However, the overall structure of the spastic mutant retina was not disrupted because the distribution and intensity of both a presynaptic marker (synaptophysin) and a marker for the rod bipolar cell (protein kinase C) in the mutant retina were indistinguishable from those in normal retinas. CONCLUSIONS: The glycine-receptor distribution in normal mice was consistent with that previously reported for the rat and with the distribution of glycine responsiveness of dissociated rodent bipolar cells. The reduced levels of glycine receptors in spastic mice help explain the abnormal ganglion cell responses in the spastic mutant.