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Biomedical subjects

N Shimada

Publications and source records attributed to N Shimada.

At least 307 records · Page 17Linked to original sources

A sensitive and specific radioimmunoassay for 1-beta-D-arabino-furanosylcytosine.

In order to determine the blood level of 1-beta-D-arabinofuranosylcytosine (Ara-C), an antileukemic agent, a sensitive and specific radioimmunoassay (RIA) system using anti-Ara-C serum, [5-3H] Ara-C and a dextran-coated charcoal method has been developed. The anti-Ara-C serum obtained from a guinea pig was hardly cross-reactive with 1-beta-D-arabinofuranosyluracil (Ara-U), tetrahydrouridine (THU) and other Ara-C analogues. The RIA system for Ara-C could detect concentrations as low as 60 pg/ml in plasma. Average of the intra- and inter-assay variancies at 5, 10, 20 ng/ml were 4.3% and 5.6%, respectively. Ara-C in blood samples obtained from human patients who orally received N4-palmitoyl-1-beta-D-arabinofuranosyl-cytosine (PL-AC) was determined by the present RIA system.

Administration, Oral↗

Fatty liver and its fibrous changes found in simple obesity of children.

Of 299 obese children who visited our obesity clinics, 36 were found to have elevated levels of serum transaminases by routine laboratory examination. Liver biopsy was carried out in 11 children. Based on the criteria of Adler and Schaffner (1979), the biopsy specimens were studied histologically. As a result, fatty liver (Group I) was observed in three patients, fatty hepatitis (Group II) in two, fatty fibrosis (Group III) in five, and fatty cirrhosis (Group IV) in one. The duration of obesity, but not its degree, was considered to be related to the extent of fibrosis. Accordingly, we concluded that the fatty liver of simple obesity in children may progress to liver cirrhosis and that childhood obesity should be treated as early as possible.

Adolescent↗

[Cell kinetics and nuclear ploidy pattern in relation to the growth of gastric cancers as analyzed by DNA-RNA cytofluorometry].

We investigated the cell kinetics and nuclear ploidy pattern of human gastric cancers (12 early and 30 advanced cancers) using DNA-RNA cytofluorometry (NIKON SPM-RF1-D) with AO stain. The results showed that the gastric cancers studied could be divided into two main groups on the basis of ploidy pattern determined both by DNA and RNA contents: group I without, and group II with polyploidization. Cells having nuclear DNA contents between 2 n and 4 n were regarded as representing those in the S phase, and it was found that both groups had similar proliferative activity. In group I, cell proliferation without polyploidization seemed to be maintained during tumor growth regardless of the extent of invasion, and the fraction of 2 n cells was 72-94%, compared to 93-99% in control cells from the non-neoplastic gastric epithelium. In group II, however, the extent of polyploidization appeared to be increased in association with both the tumor growth and its invasion into deeper tissues; thus the fraction of 2 n cells was low, ranging from 12 to 79%. Especially, the fraction of 2 n cells in cancers with aneuploid-polyploidization was further decreased to 6-25%. Based on these results, it is hypothesized that, in the early stages of gastric cancers, the cell population may be composed mostly of diploid cells, but with both further tumor development and its invasion, the neoplastic cells may gradually differentiate into two distinct cell populations.

Adult↗