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Biomedical subjects

H Ochiai

Publications and source records attributed to H Ochiai.

At least 163 records · Page 9Linked to original sources
PubMed1992

Comparisons of several dosages of a GnRH analog with the standard dose of hCG in the treatment of follicular cysts in dairy cows.

Two experiments were carried out to examine therapeutic effect of a gonadotropin-releasing hormone analog, buserelin, on ovarian follicular cysts in dairy cows. Follicular cysts were diagnosed by palpation per rectum as well as by milk progesterone assay. Luteinization of the follicular cysts following treatment was judged by an increase in milk progesterone. In Experiment 1, 35 cows were diagnosed to have follicular cysts on the basis of palpations and low milk progesterone concentrations 1 week before treatment. Another 19 cows which were clinically diagnosed with follicular cysts but showed high milk progesterone levels before treatment were excluded. Sixty-two percent (11/18) of cows with follicular cysts treated with 20 microg of buserelin and 82% (14/17) of cows treated with 10,000 IU of human chorionic gonadotropin (hCG) showed luteinization of follicular cysts within 4 to 5 days after the treatments. The percentage of cows conceiving within 100 days after treatment and the average interval in days between treatment and conception were 44% and 42+/-18 (SD) days for the buserelin-treated cows and 47% and 42+/-18 days for the hCG-treated cows. In Experiment 2, the effects of treatment doses (6, 10, 20 and 30 microg of buserelin and 10,000 IU of hCG) on follicular cysts were compared using 103 cows. An additional 23 cows which were clinically diagnosed as having follicular cysts and which were given treatment showed a high milk progesterone concentration on the day of treatment and were therefore excluded. Fifty to 64% of the cows responded with luteinization of follicular cysts after treatment. There was no significant difference in response among cows given either the different dosages of buserelin or the hCG. However, the percentage of the total number of cows that conceived after a single or a repeated treatment with 6 microg buserelin was lower than that of cows after a single or a repeated treatment with 10 microg buserelin (P<0.05). An increase in the dose of buserelin from 10 to 30 microg did not improve the therapeutic effect of the drug. Thus, it is concluded that a single intramuscular injection of buserelin at a dose of 10 microg or higher is as effective as 10,000 IU hCG, and is, therefore, recommended for the treatment of ovarian follicular cysts in cows.

Journal Article↗
PubMed1992

Comparison of antiviral assay methods using cell-free and cell-associated varicella-zoster virus.

Assay methods for varicella-zoster virus (VZV) susceptibility to acyclovir (ACV) of VZV were compared by using cell-free (CF) and cell-associated (CA) virus of 6 x plaque-purified VZV. The 50% effective doses (ED50) of ACV, as required to reduce virus plaque formation by 50%, were about 8 times higher for CA virus than for CF virus. Also, the ED50 of 1-beta-D-arabinofuranosyl-(E)-5-(2-bromovinyl)uracil (BVaraU) for CA-VZV was higher than for CF-VZV, and fresh clinical isolates of VZV gave higher ACV ED50 values than CF virus. CA virus prepared at various times after CF virus infection showed a gradual increase of the ACV ED50 with time, ranging from the ED50 for CF virus to that for CA virus.

Acyclovir↗
PubMed1992

Murine cytomegalovirus DNA polymerase: purification, characterization and role in the antiviral activity of acyclovir.

Murine cytomegalovirus (MCMV) neither induces a viral thymidine kinase (TK) nor enhances the activity of a cellular TK. Nevertheless, MCMV is highly susceptible to 9-(2-hydroxyethoxymethyl)guanine (acyclovir, ACV). The cellular TK is neither responsible for phosphorylation of ACV nor its anti-MCMV activity. This is clear from the findings that little ACV triphosphate is formed in MCMV-infected mouse embryo fibroblasts (MEF) and that the replication of MCMV is inhibited equally well by ACV in TK+ and TK- cells. Even if trace amounts of ACV triphosphate would be formed by enzymes other than TK, and ACV triphosphate would be responsible for the anti-MCMV activity of ACV, then the MCMV DNA polymerase ought to be highly sensitive to ACV triphosphate. To examine this possibility, the MCMV DNA polymerase was partially purified and characterized. The apparent Ki value of the MCMV DNA polymerase for ACV triphosphate indicates that the sensitivity of the MCMV DNA polymerase to ACV triphosphate is equivalent to that of the HSV DNA polymerase. Therefore, the trace amounts of ACV triphosphate that are formed in MCMV-infected MEF seem to be insufficient to inhibit MCMV DNA polymerase and may not play a key role in the anti-MCMV activity of ACV.

Acyclovir↗
PubMed1992

GABAergic innervation of serotonergic neurons in the dorsal raphe nucleus of the rat studied by electron microscopy double immunostaining.

A double immunocytochemical method combining the preembedding PAP technique and the postembedding immunogold technique was used to examine interactions between GABAergic and serotonergic neurons in the same tissue sections of the dorsal raphe nucleus of the rat. A large number of immunogold stained GABAergic axon terminals were found to be presynaptic to strongly PAP immunostained serotonergic perikarya and dendrites. The types of synapses were mostly symmetrical although a few asymmetrical ones were also found. No axo-axonic synapse between the GABAergic axon terminals and the serotonergic neuronal profiles was found. These results suggest that GABAergic neurons could modulate serotonergic neurons in the dorsal raphe nucleus through synaptic relations.

Animals↗
PubMed1992

Effects of polyethylene glycol conjugated superoxide dismutase on coxsackievirus B3 myocarditis in mice.

OBJECTIVE: The aim was to examine the role of oxygen derived free radicals in the development of myocarditis by investigating the effects of polyethylene glycol conjugated superoxide dismutase (PEG-SOD), a potent scavenger of oxygen free radicals, upon coxsackievirus B3 (CB3) myocarditis. METHODS: Two week old male C3H/He mice were inoculated intraperitoneally with 10(3) plaque forming units of CB3. PEG-SOD, 1 x 10(3), 5 x 10(3), 1 x 10(4), and 1 x 10(5) U.kg-1 x d-1, was given subcutaneously daily on days 0 to 14. Treated groups were compared to the infected control. RESULTS: The survival rate of the 1 x 10(5) U.kg-1 x d-1 PEG-SOD group was lower than that of the infected control group (40% v 78%, p < 0.01). The survival rates of the other treated groups did not differ significantly from the infected control. The myocardial calcification score in the 1 x 10(5) U.kg-1 x d-1 PEG-SOD group was higher than in the infected control group on d 7, when myocardial virus titres did not differ significantly among the five groups. The scores for myocardial cellular infiltration and myocardial necrosis in the 1 x 10(3) and the 5 x 10(3) U.kg-1 x d-1 PEG-SOD groups were significantly lower than in the infected control on d 14, when myocardial viruses were not detected in the five groups. However, the myocardial necrosis and myocardial calcification scores in the 1 x 10(5) U.kg-1 x d-1 PEG-SOD group were higher than in the infected control. CONCLUSIONS: The improvement of cardiac pathology in the 1 x 10(3) and the 5 x 10(3) U.kg-1 x d-1 PEG-SOD groups seems to have resulted not from the reduction in myocardial virus titres but from inhibition of generation of oxygen free radicals. The mechanism of the impaired survival and aggravation of cardiac pathology in the 1 x 10(5) U.kg-1 x d-1 PEG-SOD group is unknown. The results suggest that oxygen free radicals may be involved in the pathogenesis and development of CB3 myocarditis and that appropriate dosages of PEG-SOD have therapeutic potential for clinical CB3 myocarditis, although caution must be paid to the treatment window.

Animals↗
PubMed1992

Processing of hepatitis B virus surface antigen expressed by recombinant Oka varicella vaccine virus.

We have constructed a recombinant Oka varicella vaccine virus expressing hepatitis B virus (HBV) surface antigen (HBsAg). HBsAg was synthesized as 26K and 30K proteins in infected cells and secreted into the culture supernatant as 30K and 35K proteins. Inhibitors and glycosidase treatments, and pulse-chase labelling experiments, revealed the glycosylation process of HBsAg. The latter was synthesized as a non-glycosylated 26K protein and subjected to N-linked glycosylation to form a 30K protein with high mannose glycans. Three species of dimers composed of 26K and 30K subunits were then formed with disulphide bonds. Both subunits of the dimers were further subjected to O-linked glycosylation and conversion from high mannose glycans to complex glycans followed by sialylation. Three species of dimers composed of 30K and 35K subunits were secreted into the culture supernatant as HBsAg particles. HBsAg was synthesized, glycosylated with both N- and O-linked glycans, sialylated, and then secreted into the culture supernatant within 1 h. These modifications of HBsAg by glycans might stabilize its structure and enhance its immunogenicity as a live HBV vaccine.

Electrophoresis, Polyacrylamide Gel↗
PubMed1992

Study on proteoglycans having low-sulfated chondroitin 4-sulfate in human urine and serum.

State analysis of low-sulfated chondroitin 4-sulfate (LSC) in human urine and serum was performed by the use of high performance liquid chromatography and Western blot analysis. It was revealed that the most amount of LSC in urine is present as urinary trypsin inhibitor and a small amount (about 10% of total LSC) is as an LSC chain. The LSC in serum is mainly present as a proteoglycan such as inter-alpha-trypsin inhibitor (ITI), with a molecular weight of 212 kDa, but a small amount of LSC-proteoglycans having molecular weights of 128 and 38 kDa were also observed on SDS-PAGE. Those two compounds may be fragments of ITI, or one of the compounds (128 kDa) may be pre-alpha-trypsin inhibitor which was found by Enghild et al. (J. Biol. Chem., 264, 15975 (1989)).

Blotting, Western↗
PubMed1992

Pituitary metastasis of thyroid follicular adenocarcinoma--case report.

A rare case of pituitary metastasis of thyroid follicular adenocarcinoma occurred in a 62-year-old female manifesting as left retro-orbital pain and diplopia. Computed tomography and magnetic resonance imaging revealed a tumor in the pituitary fossa extending to the left cavernous sinus, sphenoid sinus, and prepontine cistern, destroying the upper portion of the clivus. An asymptomatic thyroid mass, probably malignant, was also found. She also had an incidental small meningioma in the posterior fossa. The pituitary tumor was partially removed, and the thyroid and posterior fossa tumors were totally removed in two operations. Both pituitary and thyroid tumors were verified to be follicular adenocarcinoma. Postoperatively, she developed panhypopituitarism for which cortisol and thyroxine replacement therapy was necessary. Three years after first therapy, she was alive but her symptoms did not improve.

Adenocarcinoma↗
PubMed1992

The effects of FK-506, a novel and potent immunosuppressant, upon murine Coxsackievirus B3 myocarditis.

To test the therapeutic efficacy of immunosuppression with FK-506 upon coxsackievirus B3 myocarditis, C3H/He mice were inoculated with coxsackievirus B3, and the effects of FK-506 were compared to those of cyclosporine. FK-506 (2.5 mg/kg/day) or cyclosporine (25 mg/kg/day) was administered s.c. daily on days 0 to 14 (experiment I) and on days 14 to 28 (experiment II). In experiment I, the survival rate of the FK-506 or cyclosporine-treated group was significantly lower compared with that of the untreated, control group. However, the score of myocardial cellular infiltration in both treated groups was lower compared to the control. On day 14, myocardial virus was not detected in the control group, but was present in both treated groups. Serum neutralizing antibody titers on day 14 in FK-506 group were lower than in the control group. In experiment II, survival rate did not differ significantly among the three groups. Serum-neutralizing antibody titers on day 21 in FK-506 group were lower than in the control. Histologically, marked cellular depletion in the thymus and spleen was evident in FK-506 groups; in cyclosporine groups, it was only evident in the thymus. Thus, FK-506 induced immunosuppression in coxsackievirus B3 myocarditis, associated with a high mortality, notwithstanding the reduction of myocardial cellular infiltration in the acute stage when immune mechanisms play a role in the pathogenesis of the disease. With respect to the dosage, the immunosuppressive action of FK-506 in vivo is at least 10-fold stronger compared to that of cyclosporine.

Animals↗
PubMed1991

Augmentation of murine lymphokine-activated killer cell cytotoxicity by beta-cyclodextrin-benzaldehyde.

We investigated the effect of beta-cyclodextrin-benzaldehyde (CDBA) on lymphokine-activated killer (LAK) cell activity of spleen cells from normal or RCT(+)H-2(+)-sarcoma-bearing C3H/He mice. CDBA augmented the induction of LAK cytotoxicity in vitro against RCT(+)H-2+ tumor cells by IL-2, whereas the culture with CDBA alone did not. In a LAK cytotoxicity assay in vitro, the augmentative effect of CDBA was strongly exerted against spleen cells originating from 2-week-tumor-bearing mice, rather than those from normal mice or mice that had born tumors for 5 weeks. Such an augmentative effect was not observed against other tumor cells (YAC-1, D-6, Colon-26 and EL-4 cells) non-specifically. When the intravenous adoptive transfer of LAK cells was carried out in the mice, LAK cells from tumor-bearing mice induced by combined culture with interleukin-2 (IL-2) and CDBA markedly inhibited the pulmonary metastases of RCT(+)H-2+ tumor, while neither LAK cells from the same tumor-bearing mice induced by only IL-2 nor those from normal mice inhibited the pulmonary metastasis. The majority of LAK cells induced either by IL-2 plus CDBA or by IL-2 alone were found to be Thy1.2+ and asialoGM1+ cells by flow-cytometric analysis, but no obvious phenotypical difference was observed between them. However, the most significant effect of CDBA might be the maintenance of the Lyt-2+ cell level in the spleen cells from tumor-bearing mice. These results suggested that the costimulation of spleen cells with IL-2 and CDBA might induce cytotoxic T cells specific for syngeneic tumor cells.

Animals↗
PubMed1991

Influence of trifluoperazine on the late stage of influenza virus infection in MDCK cells.

We investigated the influence of the anticalmodulin drug, trifluoperazine (TFP) on influenza virus growth in MDCK cells. The inhibitory effect of TFP on virus growth was observed even when TFP was added at a late stage of infection. This inhibitory effect was concentration-dependent in the concentration range of 20-35 microM. At 35 microM, TFP caused a complete alteration in the distribution pattern of hemagglutinin (HA), concomitant with a decrease in the appearance of HA on the cell surface. After removal of the drug, the HA gradually began to show a normal distribution pattern and reappeared on the cell surface. The time course of rearrangement of HA was in accord with that of the recovery of cell supernatant infectivity. Scanning electron microscopic study revealed that the drug did not cause accumulation of the progeny viruses on the cell surface. The drug effect on the virus growth was reversed by the simultaneous presence of purified calmodulin (CaM). These data suggest that TFP acts as a reversible inhibitor of influenza virus morphogenesis, but not budding, by disturbing cellular CaM and/or CaM-dependent functions.

Animals↗
PubMed1991

Glucosylation of Steviol and Steviol-Glucosides in Extracts from Stevia rebaudiana Bertoni.

To evaluate and characterize stevioside biosynthetic pathway in Stevia rebaudiana Bertoni cv Houten, two enzyme fractions that catalyze glucosylation of steviol (ent-13-hydroxy kaur-16-en-19-oic acid) and steviol-glucosides (steviol-13-O-glucopyranoside, steviolbioside and stevioside), utilizing UDP-glucose as the glucose donor, were prepared from the soluble extracts of S. rebaudiana leaves. Enzyme fraction I, passed through DEAE-Toyopearl equilibrated with 50 millimolar K-phosphate pH 7.5, catalyzed the glucosylation to steviol and 19-O-methylsteviol, but not to iso-steviol and 13-O-methylsteviol, indicating that 13-hydroxyl group of the steviol skeleton is glucosylated first from UDP-glucose to produce steviol-13-O-glucopyranoside. Enzyme fraction II, eluted from the DEAE-Toyopearl column with 0.15 molar KCI, catalyzed the glucose transfer from UDP-glucose to steviol-13-O-glucopyranoside, steviolbioside and stevioside, but not to rubusoside (13, 19-di-O-glucopyranoside) and rebaudioside A. The reaction products glucosylated from steviol-13-O-glucopyranoside, steviolbioside and stevioside were identified to be steviolbioside, stevioside and rebaudioside A, respectively. These results indicate that in the steviol-glucoside biosynthetic pathway, steviol-13-O-glucopyranoside produced from the steviol glucosylation is successively glucosylated to steviolbioside, then to stevioside producing rebaudioside A.

Journal Article↗
PubMed1991

Immunological mechanisms in experimental coxsackievirus B3 myocarditis in mice.

To address unresolved questions, experimental models of viral myocarditis may be of great value. In this study, immunological mechanisms of myocardial damage in coxsackievirus B3 myocarditis in mice were investigated. The results showed that susceptibility to viral infection is primarily determined by the genetic background of the host, that the severity of myocarditis depends not upon B cells but upon T cells, and that antigen-specific T cells play a pivotal role in the pathogenesis of acute coxsackievirus B3 myocarditis.

Acute Disease↗
PubMed1991

Immunocytochemical localization of synaptophysin (protein p38) and synapsin I in nerve terminals of rat neurohypophysis.

Synaptophysin and synapsin I, the synaptic vesicle-associated proteins, were demonstrated immunocytochemically in nerve terminals of the neurohypophysis of rats. Although both are associated with microvesicles 50-60 nm in diameter, they are not localized on or around the large neurosecretory granules nor the clear vacuoles, 100-200 nm in diameter. These findings strongly suggest that the microvesicles in the nerve terminal of the neurohypophysis are, for the most part, not the structures involved in the retrieval of the limiting membranes of the released neurosecretory granules, but rather typical synaptic vesicles. The clear vacuoles, which are negative for synaptophysin and synapsin I, are considered to be related to the retrieval of the limiting membranes of the released neurosecretory granules.

Animals↗
PubMed1991

Role of lymphocytes in collagen induced arthritis.

We investigated the time related changes of lymphocyte subsets in the blood, regional lymph node and thymus during the development of collagen induced arthritis in mice. Flow cytometric analysis showed that Lyt2+ T, but not L3T4+ T cells in the blood or regional lymph node, was significantly reduced throughout the observation. The number of Lyt2+ T cells was decreased in lymph nodes of collagen immunized vs adjuvant controls while B cells were increased and L3T4+ T cells were not different. These might act as a potential factor for the onset of collagen induced arthritis. The reduction of Lyt2+ cells was not influenced by thymic T cell maturation; it is conceivable that the main immune organ is the regional lymph node.

Animals↗
PubMed1991

[Antitumor activity of T-506, a novel synthetic FUDR derivative, on murine colon cancer and its hepatic metastasis].

T-506 is a novel synthetic FUDR derivative which releases FUDR slowly in vivo. We studied antitumor activity of T-506 by i.v. injection against mouse colon cancer, colon 26. When T-506 was administrated to mice daily, from day 1 through day 10, or every 3 days, on days 1, 4, 7, and 11, after s.c. inoculation of the tumor, the survival period was expanded significantly. The subcutaneous tumor growth was also inhibited according to the dose levels. Then, we compared the therapeutic effects on the experimental hepatic metastasis of colon 26 between T-506, 5'-DFUR and UFT at each maximal tolerable dose; that is, T-506 (0.074 m mole/kg/day; i.v. on days 1, 4, 7, and 10), 5'-DFUR (1.0 m mole/kg/day; P. O. from day 1 to 7), UFT (0.1 m mole/kg/day; P. O. from day 1 to 7). T-506 and 5'-DFUR suppressed completely the metastases of 5 of 6 (83.3%) mice and 6 of 7 (85.7%), respectively. UFT did not show a significant inhibitory effect. However, since the loss of body weight was more marked in T-506 than in the other two drugs, the side effect was thought to be a serious problem. These data suggested that if the side effect could be overcome, T-506 would be useful clinically for the treatment of gastrointestinal cancers or hepatic metastases.

Animals↗