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Biomedical subjects

H Ohta

Publications and source records attributed to H Ohta.

At least 613 records · Page 34Linked to original sources
PubMed1989

[Mechanism of the decrease in metacarpal bone mineral content due to oophorectomy].

In order to determine the pathogenesis and pathophysiology of post-oophorectomized osteopenia, we have investigated the bone mineral status and the serum levels of calcium regulating hormones in 250 females. The bone mineral status was measured in 250 [173 pre-menopausal females (controls) and 77 who received oophorectomy] females by microdensitometry in the metacarpal bone. Among these subjects, in some cases who were selected randomly, the serum levels of Alp, Ca, Pi, M-PTH, calcitonin (CT), bone gla protein (BGP), estrone, estradiol and delta 4-androstenedione, and the urinary excretion of Ca and hydroxyproline (OH-pro) as a function of the creatinine ratio were measured. The mineralization indices of bone such as GSmax, GSmin, and sigma GS/D in oophorectomized patients were significantly less than those in controls at ages up to 45 years. On the other hand, the index of periosteal bone resorption (MCI) in the oophorectomized group was less than that in controls at ages up to 50 years. Serum levels of Alp, Ca, Pi and BGP were higher in oophorectomized subjects than in controls. Despite these facts, the serum levels of calcium regulating hormones such as M-PTH and CT in these two groups were significantly different. Urinary Ca/cr and OH-pro/cr ratios were significantly higher in oophorectomized subjects at ages 40-44 than those in age matched controls. These data clearly indicate that oophorectomy causes high turn-over osteopenia.

Adult↗
PubMed1988

Cell type-specific expression of protein kinase C isozymes in the rabbit cerebellum.

Monoclonal antibodies raised against rabbit brain protein kinase C were classified into at least three types, MC-1a, MC-2a, and MC-3a, which selectively interact with hydroxyapatite column chromatographically resolved isozymes type I, II, and III of protein kinase C, respectively, determined on the basis of immunoblotting experiments. Immunoprecipitating analysis revealed that MC-1a, -2a, and -3a interacted with protein kinase C expressed in the brain and MC-2a and -3a, but MC-1a immunoprecipitated the protein kinase from rabbit spleen. Immunocytochemical localization of the protein kinase isozymes in the rabbit cerebellum and spleen was studied using these monoclonal antibodies. Staining with MC-1a was restricted to Purkinje cells of the rabbit cerebellum, and there was no reaction product in the Purkinje cells with either MC-2a or MC-3a. Cells in the granular layer of the cerebellum were labeled with MC-2a, and oligodendroglia in the white matter of the cerebellum was stained with MC-3a. The rabbit spleen contained no product reacting with MC-1a, but MC-2a and MC-3a reacted with lymphocytes in the mantle zone and the periarterial lymphatic sheath of the white pulp, respectively. These results suggest that expression of the protein kinase C isozyme in the rabbit cerebellum may depend on the cell type.

Animals↗
PubMed1988

Development of new immunoradiometric assay for CA 125 antigen using two monoclonal antibodies produced by immunizing lung cancer cells.

CA 125 is an antigen associated with non-mucinous epithelial ovarian cancer, which is defined by OC 125 antibody developed by immunizing ovarian cancer cells. We have produced two monoclonal antibodies, 130-22 and 145-9, by using the human lung adenocarcinoma cell line PC-9. Both 130-22 and 145-9 antibodies recognized CA 125 antigen. However, the binding sites seemed to be separate from those of OC 125. Testing by 9 immunoradiometric assays (IRMA), using different combinations of the 3 monoclonal antibodies 130-22, 145-9 and OC 125 demonstrated that the best standard curve for detecting CA 125 could be obtained by a "simultaneous sandwich" assay based on a mixture of 125I-labeled OC 125 and 130-22 or 145-9 coated beads. One-step IRMA, using 130-22 as a tracer and 145-9 as an immunoadsorbent, also showed good reproducibility and sensitivity for measuring CA 125. Antigens were detectable in the culture supernatants of PC-9 cells and 5 of 6 ovarian cancer and endometrial adenocarcinoma cells. These results indicate that one-step IRMA using 130-22 and 145-9 is useful for detecting CA 125 antigen.

Adenocarcinoma↗
PubMed1988

A case of unexpected gallium-67 uptake by sternum in non-Hodgkin's lymphoma with pleuritis.

A case of non-Hodgkin's lymphoma with pleural effusion was presented. Pleural effusion is not a common manifestation of this disease and 67Ga-citrate scintigraphy gave the clue for the diagnosis. The possibility of malignant lymphoma should be considered in cases with pleural effusion, and we showed that 67Ga-citrate scintigraphy can be useful in a case with pleural effusion of undetermined cause.

Adult↗
PubMed1988

Scintigraphic evaluation of two cases with alveolar soft part sarcoma.

Two cases of alveolar soft part sarcoma were examined with gallium-67 citrate (67Ga), technetium-99m-methylenediphosphate (99mTc-MDP) and technetium-99m(V)-dimercaptosuccinic acid (Tc(V)-DMS) to compare the sensitivity of these three radiopharmaceuticals. All scintigrams were positive with primary tumor, and images with Tc(V)-DMS were the best. Skull metastasis could be also detected by all agents, but scintigrams with lung metastases were negative. In scintigraphic evaluation of alveolar soft part sarcoma, Tc(V)-DMS may be a better agent than 67Ga or 99mTc-MDP.

Adult↗
PubMed1988

Endocrine profiles and embryo quality in superovulated Japanese Black cattle.

The relationships between plasma concentrations of progesterone (P4), estradiol-17beta (E2) and lutenizing hormone (LH) and embryo yield and quality were examined in 40 superovulated Japanese Black cattle. The results indicated that the ovarian function, especially the function of corpus luteum on the first treatment day, is an important factor for reliable superovulation in cattle. The levels of plasma E2 and LH at estrus were related to embryo yield and quality.

Journal Article↗
PubMed1988

Behavioral abnormalities and seizure susceptibility in rat after neonatal anoxia.

Wistar rat pups were exposed to 99.99%-nitrogen gas for 10 minutes at 4 days of age, and then their behavior and susceptibility to pentylentetrazol (PTZ) induced seizure were investigated at the ages of 28 and 56 days. Neonatal anoxic rats exhibited hyperactivity in the open field examination and motor coordination disturbance in the inclined screen test, hyperirritability to the startle response and high susceptibility to PTZ at the age of 28 days. However, these behavioral changes and high susceptibility to PTZ were improved with development and there were no longer significant difference from controls rats at 56 days of age except the wire maneuver test. These results suggested that neonatal total anoxia could produce transient dysfunction of the developing brain, including increased susceptibility to seizure and behavioral abnormalities.

Age Factors↗
PubMed1988

Immunocytochemical evidence for translocation of protein kinase C in human megakaryoblastic leukemic cells: synergistic effects of Ca2+ and activators of protein kinase C on the plasma membrane association.

Immunological analysis using monoclonal antibodies against subspecies of protein kinase C revealed the predominant expression of the isozyme, type II, in human megakaryoblastic leukemic cells. We investigated the effects of phorbol diester 12-O-tetradecanoyl phorbol-13-acetate (TPA), the Ca2+ ionophore ionomycin and synthetic diacylglycerol 1-oleoyl-2-acetylglycerol (OAG) on the immunocytochemical localization of protein kinase C in these cells. Indirect immunofluorescence techniques revealed the enzyme to be located in a diffuse cytosolic pattern, in the intact cells. When the cells were exposed to 100 nM TPA, the immunofluorescent staining was translocated from the cytoplasm to the plasma membrane. The translocation was protracted and staining on the membrane decreased in parallel with the Ca2+, phospholipid-dependent protein kinase activity. Treatment of the cells with 500 nM ionomycin caused an apparent translocation comparable with that seen with TPA, however, this translocation was transient and most of the cytosolic staining was within 60 min. We also found that 30 micrograms/ml OAG did not have significant effects on distribution of the staining, but rather acted synergistically on the translocation with the suboptimal concentration of 100 nM ionomycin. A similar synergism was also observed with 10 nM TPA and 100 nM ionomycin. These results obtained in situ provide evidence that intracellular Ca2+ and diacylglycerol regulate membrane binding of the enzyme in vivo.

Anti-Bacterial Agents↗
PubMed1988

Mechanism of the protective action of taurine against isoprenaline induced myocardial damage.

The effect of the sulphur amino acid, taurine, on the biochemical changes induced by a toxic dose of isoprenaline was examined in chick hearts. Isoprenaline treatment (80 and 240 mg.kg-1 subcutaneously twice a day for four days) caused a dose dependent increase in heart to body weight ratio. Isoprenaline administration induced a substantial accumulation of calcium and caused a profound decrease of adenosine triphosphate content and creatine phosphokinase activity in the myocardium. A pronounced increase in lipoperoxide and decrease in phospholipid and reduced glutathione concentrations were also seen. Oral administration of taurine (200 mg.kg-1 for seven days) partially protected against these changes induced by isoprenaline. It is suggested that the beneficial effect of taurine may be due in part to inhibition of lipoperoxide formation and calcium accumulation and to protection against the deterioration of membrane phospholipids.

Adenosine Triphosphate↗
PubMed1988

Gastric carcinoma metastatic to the breast diagnosed by mucosubstance histochemistry and electron microscopy.

Bilateral breast tumors with a histologically scirrhous pattern were conclusively diagnosed as gastric carcinoma metastatic to the breast using mucosubstance histochemistry and electron microscopy. The majority of the carcinoma cells gave histochemically positive reactions for galactose oxidase-Schiff, stable class III con A, and high-iron diamine-alcian blue (HID-AB). Also electron microscopically, numerous HID-positive mucus droplets (sulfomucin) were seen in the carcinoma cells. These findings invalidated the possibility that the carcinomas were primary breast cancer. The practical applications of distinctive patterns of mucus secretion are discussed.

Adenocarcinoma, Scirrhous↗
PubMed1988

Positive inotropic effects induced by carbachol in rat atria treated with islet-activating protein (IAP)--association with phosphatidylinositol breakdown.

1. To elucidate the functional consequences of phosphatidyl inositol (PI) breakdown produced by activation of the muscarinic receptor of the atrial muscle, and to clarify the subtypes of the muscarinic receptor involved, the effects of muscarinic agonists and antagonists on mechanical function were studied in atria isolated from rats given intravenous islet-activating protein (IAP; 50 micrograms kg-1 body weight) 48-72 h before the experiments. 2. The negative chronotropic and inotropic actions of carbachol (CCh) were attenuated and positive inotropic effects (62.5 +/- 5.8% above basal level) were observed with 10(-5) -10(-3) M CCh. Oxotremorine did not produce positive inotropic effects even in doses as high as 3 x 10(-4) M High doses of carbachol produced positive chronotropic effects, although the effects were weak. 3. Propranolol (10(-7) M) did not modify the positive inotropic effect of carbachol observed in IAP-treated atria, nor was there any change in the tissue cyclic AMP levels after carbachol. 4. High doses (10(-5)-10(-3) M) of carbachol produced PI breakdown in the absence and presence of IAP. Oxotremorine (3 x 10(-4) M) did not produce PI breakdown. In the presence of oxotremorine, the positive inotropic effects and PI breakdown by carbachol were abolished. 5. The positive inotropic effect of carbachol was readily antagonized by atropine but pirenzepine and gallamine exhibited only weak antagonist effects. 6. These results suggest that a muscarinic agonist such as carbachol can produce a positive inotropic effect in IAP-treated atria, in association with PI breakdown, through activation of a muscarinic receptor which shows some similarity to that previously identified in smooth muscles.

Animals↗
PubMed1988

Kinetic study of a change in intracellular ATP level associated with aerobic catabolism of ethanol by Streptococcus mutans.

Streptococcus mutans, a group of lactic acid bacteria and a normal inhabitant of the human oral cavity, generates ATP by substrate-level phosphorylation coupled to oxidation of ethanol (an end product of fermentation of sugars) into acetate in the presence of oxygen (K. Fukui, K. Kato, Kodama, H. Ohta, T. Shima moto, and T. Shimono, Proc. Jpn. Acad. 64B:13-16, 1988). Kinetic measurements were made of the cellular responses of S. mutans FA-1 to ethanol in comparison with those to glucose. In contrast to oxygen-independent acid production from glucose, oxygen was absolutely required for acid production from ethanol. Ethanol elicited a marked increase in the intracellular ATP concentration (ATPi) from a starved level to a steady level which was held constant as long as oxygen was present in the medium. Once oxygen was exhausted, ATPi returned to the starved level without delay. On the contrary, ATPi changes induced by glucose, which were independent of oxygen, followed a rather complicated time course before a steady level was established. Both the steady ATPi and the rate of accompanying oxygen consumption were functions of the ethanol concentration. These two parameters were linearly correlated, indicating that the unimolecular ATP turnover rate, which is independent of the rate of ATP generation in the steady state, can be calculated for cells energized by ethanol. The estimated turnover rate was 1.5 s-1 at 37 degrees C, which is comparable to that for other bacteria energized by glucose under nongrowing conditions.

Adenosine Triphosphate↗