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Biomedical subjects

S Mizuno

Publications and source records attributed to S Mizuno.

At least 451 records · Page 25Linked to original sources
PubMed1988

[Prognostic significance of the nuclear DNA content of a small adenocarcinoma of the lung].

DNA ploidy has been determined by flow cytometry in 28 surgical specimens from patients with adenocarcinoma of the lung (tumor diameter, 3.0 cm or less), and the relationship between DNA ploidy and the clinical stage and survival also has been investigated. The cases were classified according to the DNA index (DI) into group A (DI 1.00 to 1.50), group B (DI 1.51 to 2.00) and group C (DI greater than 2.01). A close relationship was observed between the DI and the survival rates but not between the DI and the clinical stage. Tumor ploidy is considered to be one of the prognostic factors and may be useful in selecting adjuvant therapy.

Adenocarcinoma↗
PubMed1987

Tissue-specific and periodic changes in the nuclease sensitivity of the fibroin gene chromatin in the silkworm Bombyx mori.

Nuclei of substantial purity were isolated from the middle or posterior silk glands of the silkworm Bombyx mori larvae. Both the fibroin H- and L-chain gene sequences in the isolated nuclei from the posterior silk glands of the fifth instar larvae, where the genes are transcribed actively, are extremely sensitive to the digestion with DNaseI; on the other hand, these sequences in the middle silk gland nuclei from the same larvae, where the genes are not expressed, are markedly resistant to the digestion. The H-chain gene sequences in the posterior silk gland nuclei from the fifth instar larvae are also highly susceptible to the digestion with micrococcal nuclease, HinfI, and HhaI. The digestion products with micrococcal nuclease show a continuous size distribution. The H-chain gene sequences in the middle silk gland nuclei or the posterior silk gland nuclei from the fourth molting stage are cleaved partially into nucleosome dimer to oligomer sizes upon digestion with higher concentrations of micrococcal nuclease, suggesting that the inactive forms of the H-chain gene chromatin are constructed by folding of the chromatin fiber containing a regular array of nucleosomes. Hypersensitive sites to micrococcal nuclease are present near both ends of the second exon, a major body of the fibroin H-chain gene, in both the active and inactive forms of the chromatin. The DNaseI or micrococcal nuclease sensitivity of the H-chain gene chromatin in the posterior silk gland nuclei shows periodical changes corresponding to the intermolt-molt-intermolt cycle.

Animals↗
PubMed1987

Enhanced immunogenicity of the cultured rat fibrosarcoma KMT-17 by cultivation in a low concentration of fetal calf serum.

We examined in different culture conditions alterations in the tumorigenicity and immunogenicity of an A3 clone that had been derived from a rat fibrosarcoma KMT-17. When a fetal calf serum concentration in a culture medium was lowered from 10 to 1%, the tumorigenicity was diminished while the immunogenicity was enhanced in a reversible manner; this was accompanied by a reversible prolongation of the in vitro doubling time. These phenomena were not due to an increase in the quantities of the original tumor-associated antigen and/or of the rat major histocompatibility complex (RT1) but seemed to be due to the appearance of a unique antigen(s) that was detected by an antibody taken from rats immunized with A3 tumor cells cultured in the low fetal calf serum concentration; this antigen(s) may consist of glycoprotein and exist as a crypt antigen(s). These phenomena were measured by an absorption test and flow cytometric analysis. Our observations suggest that the in vitro culture condition of tumor cells, in particular their culturing in the low fetal calf serum concentration medium, modifies the surface of tumor cells and causes a diminishment in their tumorigenicity and an enhancement of their immunogenicity.

Animals↗
PubMed1987

Production of tumor growth-inhibiting protein by the neonatal mouse brain: dependence on intracellular glutamine metabolism.

We previously reported that the mouse brain at the neonatal stage but not at the adult stage secreted a carcinostatic factor of 62,000 Da, termed NBCF, which inhibited clonal growth and DNA synthesis of malignant cells preferentially over those of normal cells. In the present study, NBCF production by the neonatal mouse brain in culture was investigated. Addition of L-glutamine to the culture medium markedly promoted NBCF production in a concentration-dependent manner. The production seemed to be specific to glutamine, since no promotive effect was exerted by L-glutamic acid, its analogue DL-alpha-aminoadipic acid, L-aspargine, or L-aspartic acid or by other amino acids or vitamins. NBCF production was markedly reduced in culture medium either devoid of L-glutamine or containing 6-diazo-5-oxo-L-norleucine, a glutamine antagonist, or L-methionine sulfoximine, an inhibitor of glutamine synthetase. Thus NBCF production was promoted by extracellular supply, intracellular synthesis, and utilization of L-glutamine but was not affected by its deamidated form or homologue amino acids. On the other hand, NBCF production was completely repressed by addition of cycloheximide to the culture medium. The repressive effect was also exerted by actinomycin D although not completely, whereas cytosine beta-D-arabinofuranoside did not repress NBCF production. These results indicated that NBCF production by cultivation was independent of DNA replication but dependent mostly on a transcription stage and its following stages and partly on a translation stage from the preexisting mRNA to the protein.

Animals↗
PubMed1987

Nucleotide sequences and unusual electrophoretic behavior of the W chromosome-specific repeating DNA units of the domestic fowl, Gallus gallus domesticus.

Nucleotide sequences of three independently cloned repeating units of the W chromosome-specific repetitive DNA sequences ("XhoI family") of the chicken were determined. All three units are 717 bp long with XhoI sites at both ends. There are only 21 sites out of 717 bases where a single base change occurs in one of the three clones. Each of these repeating units consists of 34 tandem repeats of about 21 bp. Sequences of some members of these internal repeats are not well conserved, but the majority of the repeats are characterized by the presence of (A)3-5 and (T)3-5 clusters separated by 6-7 relatively G + C-rich base pairs. One striking feature of the cloned 717 bp repeating units is that they migrate unusually slowly on electrophoresis in polyacrylamide gels. The same feature is also shown by a genomic population of the 0.7 kb repeating units recovered from XhoI digests of the genomic DNA of the female chicken. This anomalous behavior is attributed to the occurrence of DNA curvatures because of the above sequence characteristics and partial recovery of the electrophoretic mobility in the presence of distamycin A. Another feature of the 717 bp repeating unit is the presence of 438 and 159 nucleotide-long open reading frames (ORFs) at each end of the unit. A possible function of the XhoI family sequences in the heterochromatization of the W chromosome and the significance of the ORFs are discussed.

Animals↗
PubMed1987

Unresponsiveness of both non-rearranged and rearranged c-myc to serum stimulation in a mouse plasmacytoma S194.

Expression of non-rearranged and rearranged c-myc in a mouse plasmacytoma cell line S194 cultured in different serum concentration or temperature was examined. Exponentially growing S194 cells expressed a high level of rearranged c-myc and a low level of non-rearranged c-myc mRNAs. The levels of the two c-myc mRNAs were nearly the same in the cells in which growth was suppressed by lowering serum concentrations or incubation temperature in culture medium. Furthermore, even when serum-deprived S194 cells resumed growth following serum restimulation, the induction of non-rearranged c-myc mRNA, observed in a mouse T-cell lymphoma cell line BW5147, was not demonstrated. In contrast to the unchanged c-myc expression, the level of N-ras mRNA was related to changes in cell growth rate induced by changes in serum concentration in S194 cells. These results suggest that not only the rearranged c-myc but also the non-rearranged c-myc is unresponsive to serum stimulation and temperature changes, even though cell growth rate is markedly changed.

Animals↗
PubMed1987

Further evidence for importance of the subunit combination of silk fibroin in its efficient secretion from the posterior silk gland cells.

A locus responsible for the Nd-s mutation of the silkworm, Bombyx mori, has been mapped very close to or within the fibroin light (L) chain gene on the 14th chromosome (Takei, F., K. Kimura, S. Mizuno, T. Yamamoto, and K. Shimura, 1984, Jpn. J. Genet., 59:307-313). A strain of B. mori carrying the homozygous Nd-sD mutation (Nd-sD/Nd-sD; Nd-sD is allelic to Nd-s) secretes less than 0.3% of fibroin into the lumen of the posterior silk gland compared with a strain carrying the homozygous wild-type alleles (+/+). The small amount of fibroin that is secreted in the Nd-sD/Nd-sD strain consists of the heavy (H) chain only and lacks the L chain, although the L chain mRNA and the proteins that are cross-reactable with the anti-L chain serum are present in the posterior silk gland cells. In the hybrid silkworm, Nd-sD/+, the H chain derived from either the Nd-sD or + allele forms disulfide linkage with the L chain derived from the + allele and these fibroins are secreted into the lumen with an equal efficiency, but the L chain derived from the Nd-sD allele remains in the cell unbound to the H chain. Some evidence suggesting structural abnormality of the L chain derived from the Nd-sD allele is presented. These results, together with the previous results on the effect of the H chain gene-linked Nd(2) mutation (Takei, F., F. Oyama, K. Kimura, A. Hyodo, S. Mizuno, and K. Shimura, 1984, J. Cell Biol., 99:2005-2010), strongly suggest that the H-L subunit combination of silk fibroin is important for its efficient secretion.

Alleles↗
PubMed1987

Determination of enolase isozymes in various adrenal gland tumours.

Enolase isozymes (alpha enolase and gamma enolase) in the extracts of adrenal tumours (phaeochromocytoma, adenoma of primary aldosteronism and Cushing's syndrome, and neurinoma) were determined by means of enzyme immunoassay systems. The mean +/- SEM, respectively, of alpha and gamma enolase levels were 2.5 +/- 0.37 microgram/mg protein and 3.2 +/- 0.69 micrograms/mg protein for 9 phaeochromocytomas, 15.2 +/- 3.1 microgram/mg protein and 0.65 +/- 0.18 microgram/mg protein for three adenomas with primary aldosteronism, 10.8 +/- 3.0 micrograms/mg protein and 0.23 +/- 0.02 micrograms/mg protein for five adenomas causing Cushing's syndrome, and 3.8 +/- 0.88 micrograms/mg protein and 0.30 +/- 0.15 micrograms/mg protein for three neurinomas. Thus, the gamma enolase concentration in the extract of phaeochromocytoma was higher than that of other adrenal tumours. The serum level of gamma enolase was determined in 36 patients with adrenal tumours and 26 normal controls by radioimmunoassay. The mean +/- SEM for gamma enolase level was 5.4 +/- 0.3 ng/ml in normal controls, 9.1 +/- 0.9 ng/ml for 10 patients with phaeochromocytoma, 6.3 +/- 0.3 ng/ml for 11 with primary aldosteronism, 5.5 +/- 0.4 ng/ml for 11 with Cushing's syndrome, and 5.1 +/- 0.7 ng/ml for four with neurinoma. Thus, patients with phaeochromocytoma had a significantly higher serum gamma enolase levels than did those with tumours derived from adrenal cortex and normal controls. In patients with phaeochromocytoma, serum gamma enolase levels showed a significant positive correlation with urinary adrenaline levels (P less than 0.05), and after resection the elevated level of gamma enolase fell significantly (P less than 0.05) and returned to normal.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenoma↗
PubMed1987

Multivariate evaluation of prognostic determinants in bladder cancer patients.

To clarify the relative importance of factors affecting the survival of patients with bladder cancer, a multivariate analysis by Cox's proportional hazards model was performed on 264 patients initially treated from 1973 to 1984 at Nagoya University Hospital. Clinicopathological data included in the analysis were sex, age, symptoms, interval from onset of symptoms to first consultation, smoking history and tumor characteristics (location, size, number, shape, histological grade and stage). The analysis revealed that stage is the most statistically significant determinant for survival, followed by size, irritative symptoms, age and grade in this order. The model composed of the above five determinants yielded hazard ratios of: 4.6 for stage (pT2-pT4 vs. pTa-pT1); 3.1 for size (greater than 3 vs. less than or equal to 3 cm); 2.5 for irritative bladder symptoms (present vs. absent); 2.7 for age (70 years or more vs. younger), and 2.1 for grade (high grade vs. low grade tumors). We conclude that these findings quantitatively confirm previous clinical impressions that accurate staging of the tumors is most important for improving the prognosis of bladder cancer patients, and that each of the above five determinants should be considered when planning an effective initial treatment regimen.

Adenocarcinoma↗
PubMed1987

A workplace-based case-control study of gastric ulcer among male municipal employees in Japan.

In order to detect risk factors of gastric ulcer among male workers in Japan, a workplace-based case-control study was conducted in a municipal government, using cases registered during 1981 to 1983 with individually matched controls. Statistically significant factors in univariate analysis were smoking, time interval from waking up to leaving home for job, meal time for supper, sleeping hours, anxiety, and gloomy feeling. Logistic analysis showed that among the above factors the significant relative risks were 11.9 (95% confidence interval: 1.6-89.4) for 1-9 cigarettes per day, 9.9 (2.6-37.7) for 10 cigarettes or more per day, and 5.3 (1.6-17.5) for gloomy feeling. These findings obtained among the male Japanese workers were almost consistent with those epidemiologic results in other developed countries that smoking and personality traits are major risk factors of gastric ulcer.

Adult↗
PubMed1987

Simple and rapid staining for detection of Entamoeba cysts and other protozoans with fluorochromes.

Three fluorochromes were applied to stain various parasitic protozoans. By double staining with 4',6-diamidino-2-phenylindole and propidium iodide, differentiation of the nuclei from the cytoplasm can easily be achieved within several seconds. The chromatoid bodies in Entamoeba cysts were stained bright red. Plasmodium yoelii at all stages except late trophozoites and young gametocytes was easily identified. In the oocysts of Cryptosporidium sp., the nuclei and cytoplasm of the sporozoites fluoresced bluish white and red, respectively, whereas the residual body appeared blue or green. The third fluorochrome, Calcofluor white M2R, was suitable for detecting the cysts of Entamoeba spp. and Chilomastix mesnili.

Entamoeba↗