Biomedical subjects
Publications and source records attributed to J Walser.
Internal gall bladder fistulas with a hollow viscus following dislocation of a gallstone into the intestine represent one of the late sequelae of cholelithiasis. We report the case of a 78-year-old patient, who suffered from a cholecystogastric fistula with consecutive stone transmigration into the stomach.
We have described a 49-year-old man with chronic granulomatous disease. The diagnosis was established by a deficiency of NBT dye reduction by neutrophils, in addition to impairment in 14C-1-glucose utilization, 125I-iodination of zymosan, chemiluminescence, superoxide radical generation, and bactericidal activity toward S aureus. This adult patient exhibits many characteristics of chronic granulomatous disease of childhood but of less severity, which may explain his unusually long survival. It is thus important to consider the diagnosis of chronic granulomatous disease not only in children but also in adult patients having the characteristic pattern of recurrent infections.
Six cases of hyperplastic gastric polyps are described that, in the region of the eroded head, revealed strikingly atypical mesenchymal cells. These disseminated cells with marked nuclear pleomorphism and also atypical mitotic figures, undergoing direct transition to typical granulation tissue, are considered to be particularly activated mesenchymal cells. In a single case in which only excisional biopsy was performed, these cells were found to persist over a lengthy period, while in endoscopic-biopsy follow-ups of the polypectomized cases, these cells were subsequently no longer detectable. In four of the cases, the polyp was located in the region of the cardia, so that a traumatic factor may possibly be considered as having some causal relevance. In particular when biopsy excisions are performed, the differential diagnosis of this polyp with its endoscopic and histologic appearance of a tumor-like lesion, from epithelial and mesenchymal malignancies, as also from neural tumors, can be difficult.
Electrophysiological experiments were done to investigate the effect o p-nitrophenyl diazonium fluoroborate (p-NPD) on motor endplates of the frog's m. cutaneus pectoris. The compound has no direct depolarizing effect on the postsynaptic membrane and stabilizes it irreversibly when added to the bath. Longtime iontophoretical applications of p-NPD produce a biphasic effect: initially a potentiation of the depolarizations due to acetylcholine (ACh) (both iontophoretically applied and presynaptically liberated), and subsequently an inhibition of the response to ACh. When the acetylcholinesterase (AChE) is inactivated previously, only the inhibiting effect of the compound is demonstrable. The association constant of p-NPD to purified AChE and to membrane fragments of electroplax was determined by biochemical methods. The compound's affinity to the AChE was found to be about 20 times greater than to the acetylcholine receptor (AChR). Iontophoretical application of p-NPD to cholinergic neurons in the hippocampal cortex of the cat also produced the characteristic biphasic effect on ACh-induced activity of these investigated neurons. The results suggest that the biphasic effect depends on the capacity of p-NPD to combine with both the AChE and the AChR. The AChE is first inhibited with low concentrations thereby potentiating the ACh response. At higher concentrations the AChR's are progressively inhibited too, thereby diminishing the excitability of the postsynaptic membrane up to a complete block.
Lymphocyte-mediated immune responsiveness to mumps virus was studied with use of a 51chromium (51Cr)-release microassay of lymphocytotoxicity to target cells persistently infected with mumps virus. The release of 51Cr from immune cells was found to be virus-specific and reproducible and correlated well with the presence of antibody but not with the magnitude of antibody levels. Delayed-type skin hypersensitivity and specific immune release of 51Cr did not correlate well, which suggests that the two events may be mediated by different populations of cells.
The effect of the antitumor antibiotic illudin S on bacterial macromolecular synthesis was investigated. Illudin S was found to be inhibitory to in vivo deoxyribonucleic acid (DNA) synthesis from thymidine. Ribonucleic acid (RNA) synthesis was inhibited only at a concentration of illudin S 10 times that which inhibited DNA synthesis. The rate of protein synthesis remained the same except for a brief initial inhibition. When thymidine triphosphate was used for in vitro DNA synthesis, inhibition by illudin S did not occur, as tested with partially purified DNA polymerase II from Escherichia coli pol A(1) (-), with E. coli DNA-dependent RNA polymerase, with E. coli pol A(1) (-) spheroplasts, and with frozen and thawed Bacillus subtilis cells. A protein fraction isolated from B. subtilis capable of forming thymidine mono-, di-, and triphosphates from thymidine was not inhibited by illudin S. Furthermore, (14)C-illudin S taken up by B. subtilis cells was reisolated unchanged, making an intracellular activation of illudin S unlikely. Therefore, an attractive hypothesis is that illudin S inhibits DNA synthesis from thymidine which does not proceed through deoxyribonucleoside triphosphates, the generally accepted substrates for DNA synthesis.
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