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Biomedical subjects

H Tamura

Publications and source records attributed to H Tamura.

At least 433 records · Page 24Linked to original sources
PubMed1986

Cell features and patterns in fine-needle aspirates of hepatocellular carcinoma.

The values of the cytologic features of individual cells and cellular patterns in aspirated materials in the diagnosis of 49 hepatocellular carcinomas (HCC) were investigated. Excellent cytologic specimens were obtained by percutaneous aspiration biopsy with a heparinized fine 22-gauge needle. In the well-differentiated type of HCC, a correct diagnosis of malignancy was difficult from the cytologic features of individual cells because of their resemblance to normal hepatocytes. In contrast, in moderately differentiated and poorly differentiated types of HCC, a correct diagnosis of malignancy was easily made from the features of individual cells, but there was little or no cytologic evidence of the hepatic origin of the cells. Comparison of histologic and cytologic findings in aspirated materials obtained from the same patients showed that the cellular patterns seen in cytologic specimens faithfully reflected the histologic structures of HCC. Various characteristic cellular patterns were recognized only in specimens obtained from patients with HCC, but not in those from patients with benign liver diseases. These cellular patterns were very useful not only for diagnosis of malignancy, but also for identification of the hepatic origin of cells. A combination of the features of individual cells and of characteristic cellular patterns raised the diagnostic rates for well-, moderately, and poorly differentiated types of HCC to 90.5%, 100%, and 100%, respectively.

Adult↗
PubMed1986

Accumulation of cells with 4N DNA content at nonpermissive temperature in rat embryo diploid cells transformed by tsA mutant of simian virus 40.

Primary rat embryo cells were transformed by a tsA mutant (tsA640) of simian virus 40 (SV40). Proliferation of all four independent diploid transformants was suppressed at a nonpermissive temperature (40.3 degrees C), being accompanied by a marked increase in the fraction of cells with a 4N DNA content (a 4N peak in the flow cytofluorogram). However, in this case, the fraction of cells with a 2N DNA content (a 2N peak in the flow cytofluorogram) was preserved. Both effects (suppression of proliferation and increase in the 4N peak) diminished when transformed cells were superinfected with wild-type SV40. The increased 4N peak was preserved, albeit not completely, for at least 24 hours, when cells were further incubated in the presence of hydroxyurea at the nonpermissive temperature. On the other hand, the preserved 2N peak all but disappeared within 24 hours, when cells were further incubated in the presence of colcemid at the nonpermissive temperature. These results suggest that the thermolabile large T antigen of SV40 directly or indirectly induces an accumulation of cells with a 4N DNA content, at the nonpermissive temperature, by prolonging the G2 (and/or late S) period.

Animals↗
PubMed1986

Clearance of endotoxin from blood of rabbits injected with staphylococcal toxic shock syndrome toxin-1.

This study was undertaken to examine some of the properties of staphylococcal toxic shock syndrome toxin 1 (TSST-1) with regard to the clearance of endotoxin from blood. The concentration of endotoxin in blood was measured by using a chromogenic limulus test and modified perchloric acid method. When TSST-1, which produces fever in rabbits, was injected (100 ng/ml or 100 micrograms/ml per kg) intravenously (i.v.) into the animals, no measurable level of endotoxin was detected in the blood. In control animals, which were given 5 micrograms of endotoxin per ml per kg i.v., endotoxin could be detected in the blood at rapidly declining levels. These results suggested that TSST-1 might not lead bacterial endotoxin from other body sites into the blood. When the animals were given TSST-1 (1 to 100 ng/ml per kg) i.v. and then endotoxin (5 micrograms/ml per kg) i.v. 4 h later, endotoxin was detected in the blood at a high level, depending on the dose of TSST-1 injected. These results showed that TSST-1 inhibited the clearance of endotoxin in the blood; this clearance is thought to be mainly done by the reticuloendothelial system. In the animals given TSST-1 (100 ng/ml per kg) and endotoxin (5 micrograms/ml per kg) simultaneously, the endotoxin level in the blood was found to be higher than that in control animals given endotoxin only but lower than that in the animals given TSST-1 and then endotoxin at the same doses.

Animals↗
PubMed1986

Endotoxin-inactivating activity in normal and pathological human blood samples.

The endotoxin-specific chromogenic test revealed that plasma endotoxin-inactivating activity was markedly diminished by endotoxemia, but not by fungemia or by dialysis with cellulose membranes, suggesting that fungal polysaccharides and other nonendotoxic, Limulus-reactive materials do not consume endotoxin-inactivating factors in the blood. There was a close negative correlation between plasma endotoxin concentration and endotoxin-inactivating activity. The specificity of the test was improved by fractionating amebocyte lysate and using only the factors that constitute the endotoxin-sensitive coagulation pathway of the horseshoe crab. This test was able to differentiate endotoxemia from fungemia and from contamination with other nonendotoxic, Limulus-reactive materials.

Endotoxins↗
PubMed1986

Na+-K+ regulation in cultured vascular smooth muscle cell of the spontaneously hypertensive rat.

Na+-K+ passive transport and activity of the Na+ pump were examined in serially passed cultured vascular smooth muscle cells originating from spontaneously hypertensive (SH), Wistar-Kyoto (WKY), and Wistar (W) rats. Measurements included 22Na+ and 86Rb+ (K+ analogue) uptake and washout rate constants as well as intracellular Na+ and K+ levels. The aforementioned variables were studied in cells subjected to either 2 mM Ca2+ or Ca2+-deficient media. In 2 mM Ca2+ medium, SH rat cells demonstrated the highest exchange (uptake and washout) rate constants for Na+ and Rb+ (K+) among cells of the three rat strains. At this extracellular Ca2+ concentration, the Na+ pump activity of SH rat cells was higher than that of WKY rat cells and was not different from that of W rat cells. Incubation in Ca2+-deficient medium resulted in increased magnitudes of Rb+ washout and Na+ uptake rate constants in all cell preparations associated with elevated intracellular Na+ concentrations and augmented activity of the Na+ pump. Under this condition, cells derived from SH rats showed the highest Na+ uptake and Rb+ washout rate constants associated with the highest Na+ pump activity. The increase in intracellular Na+ level in Ca2+-deficient medium was the highest in SH rat cells. These findings show that innate membrane defects and the response of the Na+ pump to these abnormalities can be demonstrated in in vitro-grown vascular smooth muscle cells of the SH rat.

Animals↗
PubMed1986

Ouabain binding to cultured vascular smooth muscle cells of the spontaneously hypertensive rat.

The binding of ouabain and K+ to the Na+ pump were analyzed in serially passed cultured vascular smooth muscle cells (VSMCs) originating from spontaneously hypertensive (SH), Wistar-Kyoto (WKY), and American Wistar (W) rats. Our techniques have utilized analyses of displacement of [3H]ouabain by both unlabeled ouabain and K+ from specific binding sites on the VSMCs. We have found that each of the VSMC preparations from the three rat strains appeared to demonstrate one population of specific ouabain receptors (Na+ pumps); the number of Na+ pump units (mean +/- SE, expressed as 10(5) units/cell; number of observations indicated in parentheses) of both the SH and WKY rats was significantly lower than the number of Na+ pump units of W rat VSMCs [SH: 3.00 +/- 0.02 (231), WKY: 2.87 +/- 0.05 (245), and W: 3.62 +/- 0.04 (225)]; the equilibrium dissociation constant values (microM) for ouabain in VSMCs of SH and WKY rats were similar but were significantly higher than that of VSMCs derived from W rats [SH: 4.69 +/- 0.09 (231), WKY: 4.57 +/- 0.12 (245), and W: 3.69 +/- 0.17 (225)]; and among the VSMCs originating from the three rat strains, the apparent equilibrium dissociation constant value for K+ (mM) was the lowest in those of the SH rat [1.04 +/- 0.003 (143), compared with VSMCs of the WKY rat [1.54 +/- 0.006 (135)] and W rat [1.19 +/- 0.003 (136)]. Our previous studies have demonstrated increased passive Na+ and K+ transport rate constants of SH rat VSMCs compared with either W or WKY rat cells. These findings suggest the possibility of higher permeabilities of the SH cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

Bumetanide-sensitive sodium-22 transport in vascular smooth muscle cell of the spontaneously hypertensive rat.

The effect of bumetanide, a known probe of Na+, K+ cotransport, on 22Na+ uptake and washout was examined in serially passed cultured vascular smooth muscle cells of spontaneously hypertensive rats (SHR), Wistar-Kyoto rats (WKY), and Wistar rats. In Ca2+-deficient medium, the drug exerted the greatest effect on 22Na+ washout in vascular smooth muscle cells from SHR and the least effect on cells from WKY. The respective mean values for the apparent bumetanide-sensitive 22Na+ washout rate constants (Ke; X 10(-2)/min) were 7.2, 4.3, and 1.7 for cells from SHR, WKY, and Wistar rats. In both 1 mM Ca2+ and Ca2+-deficient medium, in the presence of 1 mM ouabain, vascular smooth muscle cells from SHR had the highest plateau phase of 22Na+ uptake among the three cell preparations. All cells exhibited higher 22Na+ uptake in Ca2+-deficient medium than in 1 mM Ca2+ medium. Under this condition, bumetanide caused an additional rise in steady state 22Na+ uptake that was most pronounced in cells from SHR (21.3% versus 16.6% for Wistar rats and 4.8% for WKY). This finding indicates that a quantitatively greater inhibition of washout than of the uptake component of the bumetanide-sensitive 22Na+ transport occurs in Ca2+-deficient medium. It is concluded that, in Ca2+-deficient medium, the bumetanide-sensitive 22Na+ washout is higher in vascular smooth muscle cells of SHR than in those of normotensive controls and that this phenomenon reflects a higher Na+ turnover in vascular smooth muscle cell in the hypertensive rat strain.

Animals↗
PubMed1986

Detection of a new antigen associated with chicken thrombocytes on Marek's disease lymphoblastoid cell line.

A monoclonal antibody, 2C12, produced against MDCC-MSB1 cells, reacted with several cell lines derived from Marek's disease (MD), including MDCC-MSB1 cells, normal chicken thrombocytes, and MD tumor cells. It did not react with cell lines derived from avian leukosis or reticuloendotheliosis, cells from normal chicken thymus and bursa, chicken kidney cells and quail fibroblast cultures inoculated with MD virus, or with erythrocytes from 1-day-old and adult chickens, cow, sheep, and horse. Anti-thrombocyte serum prepared in a rabbit reacted with thrombocytes and MDCC-MSB1 cells. The specificities of antibody 2C12 and anti-thrombocyte serum against MDCC-MSB1 cells and thrombocytes were confirmed by cross-absorption, blocking, and double-membrane fluorescent antibody tests. The existence of a polypeptide with an apparent molecular weight of 103,000, common to both MDCC-MSB1 cells and thrombocytes, was demonstrated by Western blotting analyses.

Animals↗
PubMed1986

Studies on improvement of pharmaceutical preparations prescribed in hospitals. V. Nifedipine hollow type suppository.

Nifedipine is a calcium antagonist used for the treatment of hypertension and angina pectoris. However, commercial nifedipine preparations are only available in forms suitable for oral administration, e.g. soft capsules and tablets. Therefore, we developed a suppository form in which the drug was incorporated into a hollow type suppository. The suppository preparation was administered to humans for evaluation of the clinical and commercial usefulness. It was as fast-acting as the soft capsule, but the blood concentration of nifedipine immediately after administration was lower than that seen with the soft capsule. It was considered to be superior to the soft capsule and similar to the tablet in terms of its long-acting effect. Thus, the hollow type suppository form of nifedipine should have useful clinical applications.

Adult↗
PubMed1986

[Studies on Campylobacter and Salmonella in feces of pregnant women and newborn infants].

Fecal cultures from five thousand four hundred and twenty-seven pregnant women, who were delivered at Osaka National Hospital from January 1, 1980 to December 31, 1984, were examined to detect intestinal Campylobacter and Salmonella during 30 and 36 gestational weeks. In addition, the feces of newborn infants were cultured three days after delivery to check for the presence of Campylobacter and Salmonella. During pregnancy, Campylobacter was detected in the feces of 116 women (2.14%), and Salmonella in 99 cases (1.82%). By administering antibiotics to the affected cases, the number of women whose fecal cultures were positive for Campylobacter and Salmonella at the time of delivery was reduced to 8 and 15, respectively. Neonatal fecal cultures revealed that Salmonella infection occurred in two among fifteen (13.33%) and Campylobacter infection in three among eleven (27.27%) infants whose mothers had been affected. These findings suggest the importance of adequate management for these bacterial infections during pregnancy and the perinatal period to prevent danger to the newborn.

Campylobacter fetus↗