Clear cell lymphoma: a clinicopathological study of four cases

Four cases of clear cell lymphoma were studied by means of light and electron microscopy, enzyme-histochemistry, and E- and EAC-rosette formation. On light microscopic examination the tumors were seen to be composed mainly of round, oval, or slight irregular cells with water-clear, abundant cytoplasm. The neoplastic cells has round, oval, or convoluted nuclei with fine, evenly dispersed chromatin and one or more small but distinct nucleoli. On electron microscopic examination the clear cell lymphoma were characterized by lymphoid cells with striking electron lucent cytoplasm with few organelles. According to E-rosette test and enzyme-histochemical findings, the investigators proposed that the clear cell lymphoma may be derived from T-cell lineages. Differentiated diagnoses of clear cell lymphoma from B-immunoblastic sarcoma, pleomorphic cell lymphoma, clear cell sarcoma, and clear carcinomas derived from lung, ovary, or kidney were discussed.

Histochemistry and electron microscopy in the diagnosis of small mucous cells in carcinoma of the stomach

One hundred and two cases of poorly differentiated adenocarcinoma were obtained from 71 surgical and 31 biopsy specimens of the stomach. These tumours produced both intracellular and extracellular mucins, which were demonstrated to be neutral mucins, N-acetyl sialomucins, sulphomucins and O-acetyl sialomucins. The majority of tumours (85.3%) secreted two or more kinds of mucins simultaneously, but only a small proportion (14.7%) produced a single kind of mucin. Ultrastructurally, three types of mucin granules were identified; these differed in shape and density. Tumour cells containing intracellular mucins or mucin granules were designated as mucous cancer cells and further subdivided into small, large and goblet mucous cells; tumour cells having neither mucins nor glandular differentiation were designated as undifferentiated cancer cells. These histochemical distinctions, supported by the electron microscopical observations, may be useful to demonstrate early malignant foci in gastric biopsies.

Response of the wild type and low xanthine dehydrogenase strains of Drosophila melanogaster to adenine resistance selection

Survival rates of two Drosophila melanogaster strains, the Oregon R Wild Type (WT), and a mutant that was Low Xanthine Dehydrogenase (LXD), grown for six generations in control and in adenine-supplemented media, were determined. Although adenine was toxic to both strains, it was less toxic to the LXD strain. Uric acid levels indicated that WT Drosophila melanogaster was less able to metabolize adenine through the detoxification pathway. Male flies of both strains appeared to be more susceptible to adenine toxicity than were female. The results demonstrate that the adenine resistant strain may possess an enzyme pattern to minimize the toxic effect of adenine.

T-cell lymphoma: a morphological, histochemical and immunological study of nine Chinese cases

Nine cases of T-cell lymphoma presenting in the Guizhou province of China between 1982 and 1984 are reviewed. Seven of the patients were male; seven patients have died, the mean survival period being 22 months. The clinical features resembled those reported in Japanese cases, but skin lesions were absent. Histologically three cases were classified as of lymphoblastic type, three as pleomorphic cell type, two as clear cell type and one as immunoblastic-lymphadenopathy-like T-cell type.

Genetic analysis of the nitrogen fixation system in Klebsiella pneumoniae

Fine structure mapping of nif mutations of Klebsiella pneumoniae was accomplished by means of Pl-transductional crosses and the plasmid R144 drd mediated conjugations. The physical distance between nif mutations based on the percentage of co-transduction with hisD of the nif mutations was estimated. The maximal distance between two mutations was calculated about 3 Kb, and the average distance between different nif mutations was about 1 to 2 Kb. So no "silent region" was shown within the nif cluster nearby the histidine operon. Several hisD-unlinked nif mutants were isolated and investigated genetically and biochemically. They all differed from the glutamineless mutants, one of these mutants was tentatively assigned as a sort of N-assimilation mutant with little activity of glutamate synthetase. It differed from the known N-assimilation mutants in its absence of nitrogenase activity. Since the wild type hisD-linked nif genes carried by the plasmid RP4 failed to complement the defects of the hisD-unlinked nif genes in the recipient cells but they were effective to facilitate E. coli in acquiring the ability to fix nitrogen, which indicates that the hisD-unlinked nif genes necessary for the functioning of the hisD-linked nif genes are present in E. coli.