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Biomedical subjects

T Ohashi

Publications and source records attributed to T Ohashi.

At least 307 records · Page 17Linked to original sources

Susceptibility of W/WV mice to murine cytomegalovirus infection.

The susceptibility of congenitally anemic W/WV mice to infection with murine cytomegalovirus (MCMV) was examined. W/WV mice showed a higher mortality rate and shorter survival time after MCMV infection than did their +/+ littermate mice. In addition, W/WV mice showed a lower plaque-forming unit (PFU) per 50% lethal dose (LD50) and produced higher titers of infectious virus in various organs. The mortality rate and survival time of W/WV mice which received a bone marrow graft 4 weeks before infection was completely restored to the level for +/+ mice, suggesting the importance of the cells of myeloid origin. Although natural killer (NK) activity of W/WV mice was comparable to that of +/+ mice before infection, marked reduction was observed after MCMV infection. Furthermore, OK-432 treatment failed to enhance NK activity of W/WV mice. Impaired NK response was also completely restored by bone marrow grafting 4 weeks before infection. The level of serum interferon (IFN) of infected or uninfected W/WV mice was comparable to that of +/+ mice. Therefore, impaired NK inducibility seems to be responsible, at least in part, for the high susceptibility of W/WV mice to MCMV infection.

Animals↗

Host-mediated antiviral activity of Lactobacillus casei against cytomegalovirus infection in mice.

The protective effect of heat-killed Lactobacillus casei (LC) against murine cytomegalovirus (MCMV) infection was examined. ICR mice treated once with LC 1 day or 2 days before challenge survived lethal infection, but untreated or Lactobacillus fermentum (LF)-treated mice did not. The protective effect was evidenced by an increase in plaque-forming units (PFU) per 50% lethal dose (LD50) and a decrease in titers of infectious viruses replicated in the target organs. This was further confirmed by severity of histopathological damage to the target organs, especially the liver. LC neither inactivated MCMV nor inhibited its replication in mouse embryonic fibroblasts (MEF). The spleen cells from LC-treated mice inhibited its replication in MEF on co-cultivation. Augmentation by LC of splenic natural killer (NK) cell activity correlated with survival of mice from otherwise lethal MCMV infection. Cytotoxic activity of peritoneal cells and level of serum interferon (IFN) were elevated after MCMV infection, but they were not associated with survival of mice nor with treatment of LC. The protective effect of LC was not clear in NK-deficient beige mutant (bgJ/bgJ) mice, when compared with that in their littermate (bgJ/+) mice. Poor protection of bgJ/bgJ mice by LC treatment correlated with failure to induce NK cell activity by LC treatment in the mutant mice. Thus, it is likely that LC protects mice from MCMV infection by augmentation of NK cell activity.

2',5'-Oligoadenylate Synthetase↗

[Clinical studies on the measurement of urinary tissue polypeptide antigen (TPA) levels using Prolifigen TPA kit "Daiichi"-II in urothelial cancers].

We have investigated the clinical significance of urinary tissue polypeptide antigen (TPA) as a tumor marker for urothelial cancers. Urinary TPA levels were determined by the immunoradiometric assay of Prolifigen TPA Kit "Daiichi"-II in 486 healthy controls and 1835 patients with various diseases including 526 with urothelial cancers and 140 with prostatic cancer. The mean value of urinary TPA was 199 +/- 213 (1SD)U/1 in 486 healthy controls. 95% of them having a level below 600 U/l. Therefore, 600 U/l was applied as a cut-off level. Positive rates of urothelial cancers and reactivated prostatic cancer were 57.6% (148 of 248 cases) and 45.5% (5 of 11 cases) respectively. On the other hand, the false positive rate of most urological benign diseases was only about 20% except for the acute stage of urinary tract infections and upper urinary tract stones with hydronephrosis. There was no significant difference in the positive rate between urinary TPA level and urinary cytology in urothelial cancers. The combination of both tests raised the positive rate to 73.1%. Therefore, urinary TPA may be useful in the monitoring of urothelial cancers, and the combination of urinary TPA and urinary cytology may increase the diagnostic accuracy.

Antigens, Neoplasm↗

Immunological and clinical effects of interferon-gamma on Crohn's disease.

Five patients with Crohn's disease (CD) confined to the small intestine were studied to determine whether intravenous administration of interferon (IFN)-gamma to normalize immunological imbalance produces clinical improvement. A daily dose of 12 million IU of IFN-gamma was intravenously infused for four weeks. Laboratory data, immunological responses, clinical and radiologic findings were evaluated after administration. Laboratory data showed no significant change after treatment. Immunological studies also failed to demonstrate any significant change except for a significant increase of natural killer (NK) cell activity after IFN-gamma infusion. Clinical assessment by Crohn's disease activity index as well as radiologic findings disclosed no definite improvement. This study suggests that enhancement of NK cell activity or augmentation of immunological imbalance induced by IFN-gamma does not play an important role in the pathogenesis of CD.

Adult↗

Long-lasting organic spasm of the near reflex.

A 57-year-old man was examined after head trauma and found to have long-lasting organic spasm of the near reflex lacking accommodative spasm. Convergence and miosis had been consistently observed for the follow-up period of one year and three months. Electrooculographical findings showed that there was no lateral rectus muscle palsy in either eye, and that his esotropia became intense in total darkness, compared with fixation on a visual target. Persistent convergence and miosis completely disappeared within 7 minutes after intravenous injections of benzodiazepine. Furthermore, he was able to make a normal near reflex when the spasm disappeared. The effect of benzodiazepine suggests that the disturbance of the GABAergic (gamma-aminobutyric acid) inhibitory system in the near reflex may be responsible for the occurrence of the spasm.

Benzodiazepines↗

Synergism between subthreshold concentrations of thrombin and 12-O-tetradecanoylphorbol 13-acetate in platelet activation.

A comparison was made between the time courses and interdependence of platelet aggregation, serotonin release, and cytosolic free Ca2+ concentration in the same sample of platelets loaded with [14C]-serotonin and Ca2+-sensitive photoprotein aequorin. In 100 micrograms/ml aspirin-treated platelets, neither 0.01 U/ml thrombin nor 50nM TPA, an active phorbol ester, induced significant aggregation, serotonin release, or a rise in the intracellular calcium concentration. However, when these two agents were added together, marked aggregation and release were observed without a change in the cytosolic free Ca2+ concentration. No correlation was observed between the extent of the synergistic effects and time of preincubation with TPA. Potentiatory effects of protein kinase C on receptor-mediated agonists need to be considered in platelet activation.

Blood Platelets↗

Potentiation of neutrophil function by recombinant DNA-produced interleukin 1a.

The effect of interleukin 1a (IL-1a) produced by E. coli-derived recombinant DNA was evaluated on various parameters of human neutrophil function. IL-1a alone stimulated neutrophil hydrogen peroxide production in a dose-dependent manner, but the rate was much lower than that of opsonized zymosan. IL-1a induced release of specific granule contents, but not azurophilic granule contents. Cytochalasin B did not augment the rate of release. IL-1a was chemotactic for neutrophils at the optimal concentrations of 0.1-10 ng/ml. Pretreatment of the neutrophils with IL-1a augmented neutrophil oxygen radical production induced by opsonized zymosan, and this synergistic effect was evident as early as 10 min after IL-1a was added to the neutrophil culture. Phagocytosis of opsonized particles by neutrophils, and degranulation induced by opsonized zymosan were also enhanced by IL-1a in a dose-dependent manner. The present results suggest that IL-1a is weak as a direct activator of neutrophil function and that IL-1a in vivo may augment the response of neutrophils to other stimulators such as foreign bodies.

Chemotaxis, Leukocyte↗

Effects of oestrogen and anti-oestrogen on the cells of the endosteal surface of male Japanese quail.

1. The endosteal cellular response occurring in the early stages of medullary bone formation was histologically examined in the femurs of male Japanese quail treated with oestrogen and antioestrogen. 2. The numbers of endosteal cells decreased, and preosteoblasts and osteoblasts increased, on the endosteal surface following oestrogen treatment. 3. After oestrogen and anti-oestrogen treatment the numbers of preosteoblasts and osteoblasts on the endosteal surface did not increase. However, endosteal cells slowly decreased in number and osteoclasts increased. 4. This study demonstrates that differentiation of osteoblasts is induced by oestrogen stimulation and suggests that osteoclasts occur by oestrogen inhibition on the endosteal surface.

Animals↗

A first case of complete remission of beta-interferon sensitive adult T-cell leukemia.

A case of complete remission of adult T-cell leukemia (ATL) induced by beta-interferon is reported. A 46-year-old male was diagnosed as ATL because of the increased number of ATL cells with deeply indented and lobulated nuclei in the peripheral blood, accompanied by elevated values of the lactic dehydrogenase, the alkaline phosphatase, and the calcium in the serum. The result of the cell surface marker analysis of peripheral blood lymphocytes was compatible with ATL and anti-ATL associated antibody (ATLA) was positive. The integration of proviral deoxyribonucleic acid (DNA) of human T-cell leukemia virus type I(HTLV-I) was proved in the peripheral blood lymphocytes using Southern blot hybridization. Since an ordinal chemotherapy was not so effective for this patient, he was treated with 1.8 X 10(7) units of recombinant beta-interferon (beta-IFN) per day for 7 days as one course. After 5 courses of treatment, a markedly favorable response was recognized, and he achieved complete remission. A lower dose of beta-IFN (9 X 10(6) units per day for 3 days as one course, one or two courses per month) has been continued and he has still been in a complete remission state for 10 months. It is concluded that beta-IFN should be used to treat ATL.

Blood Cells↗

Enhanced resistance of mice to bacterial infection induced by recombinant human interleukin-1a.

The effect of recombinant human interleukin-1a on the survival rate of Std-ddY male mice systemically infected with Pseudomonas aeruginosa 12 or Klebsiella pneumoniae P-5709 was evaluated. In P. aeruginosa infection, interleukin-1a given intramuscularly twice, 3 days and 1 day before inoculation of bacteria, most effectively protected animals from death due to infection. The effect was dose dependent, with a maximum survival rate of 92.5% at 10 micrograms per mouse, while only 8.3% of the control group survived until the end of the observation period. The 50% effective dose of interleukin-1a was 0.261 microgram per mouse. In K. pneumoniae infection, interleukin-1a given intramuscularly twice, simultaneously with and 1 day after the inoculation of bacteria, was most effective. The protective effect of interleukin-1a was again dose dependent and was generally more marked than in P. aeruginosa infection. The 50% effective dose was 0.034 microgram per mouse. In both infections, there was no significant increase in the survival rates of animals injected with human albumin or heat-inactivated interleukin-1a. These observations raise the possibility that human interleukin-1a could serve as a therapeutic tool for patients with bacterial infections.

Animals↗

Studies on the affinity and selectivity of tiquizium bromide (HSR-902), a novel spasmolytic agent, for muscarinic receptors.

The affinity and selectivity of a novel spasmolytic agent, tiquizium bromide (HSR-902), for muscarinic receptors were studied by the radioligand binding technique using 3H-quinuclidinyl benzilate. The parameters (Ki, nH) of HSR-902 obtained from competition experiments in cerebral cortex and heart muscarinic receptors showed that HSR-902 was an atropine-type, nonselective muscarinic antagonist. The affinity of HSR-902 toward the stomach and ileal muscarinic receptors was about 3-4 times more potent than atropine.

Animals↗