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Biomedical subjects

C Ohta

Publications and source records attributed to C Ohta.

17 recordsLinked to original sources
PubMed1992

Correlation between increased susceptibility to primary Toxoplasma gondii infection and depressed production of gamma interferon in pregnant mice.

To explore a possible mechanism of pregnancy-associated suppression of T cell-mediated immunity to Toxoplasma gondii, acquired resistance and gamma interferone (IFN-gamma) production in pregnant mice were compared with those in virgin mice after infection with the S-273 strain of this protozoan parasite. The 50% lethal dose of this strain was less than 200 tachyzoites for pregnant mice and 2,800 organisms for virgin controls. Toxoplasma-induced production of both IFN-alpha and IFN-gamma in the bloodstream of pregnant mice was significantly depressed as compared with that in virgin controls. The administration of recombinant murine IFN-gamma (rMuIFN-gamma) resulted in a significant decrease of mortality and parasitic growth in the organs of pregnant mice infected with a lethal dose of S-273 strain tachyzoites. Thus, the impairment of T cell-mediated immune responses was evident in pregnant mice from the impaired IFN-gamma-generating capacity and poor survival rate after primary infection with Toxoplasma. When mice with chronic Toxoplasma infection were injected with specific antigen, the resultant production of IFN-gamma was also significantly suppressed during pregnancy. However, there was no direct correlation between the serum levels of IFN-gamma and susceptibility to reinfection, since the mortality rate of chronically infected pregnant mice after the challenge with the high virulent RH strain was not significantly higher than that of virgin controls.

Animals↗
PubMed1992

Antibody responses of swine to type A influenza viruses in the most recent several years.

A serological survey was conducted on 4,080 swine sera collected for the years 1985-90. The swine sera positive to A/New Jersey/8/76 (swine type H1N1) strain were observed in annual (10-20%) and monthly (20-40%) incidences during the observation period except for occasional months. Antibodies to recent human H1N1 viruses in swine were recognized in relation to the human H1N1 influenza epidemics. Antibody responses of swine to human H3N2 strains appeared irrespective of human epidemics with the virus in the years 1985-87. However, in 1988 almost no antibodies to three human H3N2 isolates of 1983-88 were observed for this year except a few months though the human epidemic occurred in the area. Although in 1989-90 many swine had antibodies to the three strains in the percentage of 3 to 35, no antibody to the latest isolate, A/Hokkaido/20/89 (H3N2), was found for almost all the months of both years. These findings differed markedly from the possible relationship between the prevalence of H3N2 virus-antibodies in swine and the human influenza epidemics, which were described previously in many reports including our studies.

Animals↗
PubMed1991

Efficacy of colostral immunoglobulins for therapeutic and preventive treatments of calf diarrhea.

Pooled colostral milk samples were collected from apparently healthy Holstein cows. Immunoglobulin (Ig) was partially purified from the colostral milk and concentrated by freeze drying. The Ig powders had neutralizing antibody titers of 1:6,250 to 1:31,250 against bovine rotavirus (RV), and reacted with four RV proteins of VP2, VP4, VP6, and VP7. No therapeutic effect of Ig powder showed on clinically serious diarrhea with RV in dairy and beef calves. However, the Ig powder had a preventive effect on the diarrhea in beef calves when it was given soon after calving.

Animals↗
PubMed1990

Epizootiological and virological studies of foal diarrhea associated with serotype 3 rotavirus.

Epizootiological and virological studies were conducted on foal diarrhea occurring in 3 foal-raising locations in a light horse farm from March to July, 1987. At the first location, although 27 (75%) of 36 foals had developed diarrhea, the isolation rate of rotavirus (RV) was low (5/14 feces, 36%). Many of the foals had the disease as early as 23 days after birth. At the second and third locations, 21 (27%) of 78 foals and 41 (76%) of 54 foals were affected with diarrhea. Isolation rates of RV were 90% (20/22 feces) and 100% (26/26 feces), respectively. The diseased cases were observed throughout the short period from June to early July and on foals aged from 63 to 65 days. These findings suggested the importance of RV as a causal agent of foal diarrhea at the latter location, RV and/or other agents at the former location. All the 3 strains of RV represented from each location were identified as serotype 3 by plaque reduction neutralization test against the antiserums of serotypes 1 to 6 of RV. However, the 3 strains showed low cross-reactivity with antiserum of the serotype 3 of the equine RV.

Age Factors↗
PubMed1990

Effects of cyclosporin A on susceptibility and interferon-generating capacity in mice infected with Toxoplasma gondii.

Cyclosporin A (Cs-A), a potent immunosuppressant, was administered to mice to evaluate the role of T lymphocytes for the development of a protective immunity to an obligate intracellular protozoan parasite, Toxoplasma gondii. Although daily administration of various amounts of Cs-A for 7 days enhanced the host susceptibility at all doses employed, a dose-dependent manner of Cs-A treatment was not observed as far as the dosage regimens applied here are concerned; mice died at the same rate (40%) among the groups receiving various amounts of Cs-A. Cs-A treatment had a differential effect on the course of disease depending on how it was given in relation to infection. All mice receiving 50 mg of Cs-A per kg per day for 10 days from the beginning of infection eventually died of toxoplasmosis. Cs-A did not suppress the production of intereferon(IFN)-alpha/beta that was induced shortly after the infection, whereas it reduced greatly the ability of Toxoplasma-infected mice to produce IFN-gamma induced by stimulation with Toxoplasma lysate antigen (TLA). Moreover, the decrease in IFN-gamma production correlated with an increase in the parasitic growth in the peritoneal cavities of Cs-A-treated mice. These results suggest that the immunosuppressive effect of Cs-A on the primary Toxoplasma infection in mice is expressed by inhibiting the development of effector T cells responsible for the production of IFN-gamma.

Animals↗
PubMed1990

[T gamma lymphoma with CD3+ CD4- CD8- WT31- and TcR gamma delta].

An 18 years old female was admitted to hospital due to pancytopenia on May 25, 1987 and found to have petechiae, mild hepatomegaly and severe splenomegaly. The bone marrow was found to contain 12% of blast cells. Splenectomy was performed followed by CHOP therapy. In September, 1987 the peripheral blood was found to contain tumor cells, which turned out to be resistant to various combination chemotherapies. The patient died on August 21, 1988. The phenotype of tumor cells in this case was CD2+ CD7+ CD3+ CD4- CD8- WT31-. Genetic analysis detected rearrangement of the beta and gamma chain of TcR but not transcription or translation of the beta chain of TcR, while the antibodies of delta TCS 1 and TcR delta 1 to the delta chain of TcR were positive. From this fact, the present case was considered to be the malignant counterpart of normal CD3+ WT31- double negative T cells. The reactivity of this tumor cells to IL-2 and IL-1 beta suggested the association of the IL-2R beta chain.

Adolescent↗
PubMed1990

[Clinical analysis on thrombotic thrombocytopenic purpura and hemolytic uremic syndrome, with plasma level of cytokine].

We studied 10 patients with thrombotic thrombocytopenic purpura (TTP) and 5 patients with hemolytic uremic syndrome (HUS). Common cold symptoms were observed in 2 with TTP and 3 with HUS, and SLE was noted or suspected in 3 with TTP, and the onset was after operation in on with TTP and one with HUS. All TTP patients had coma and high fever. Renal failure was noted in 3 with TTP and their prognosis was poor. Seven patients with TTP and 4 patients with HUS survived. Autoantibody was highly positive in TTP but slightly positive in HUS. High molecular weight multimer of von Willebrand factor was decreased in 3 of 6 with TTP, platelet aggregating factor was positive in 4 of 6 with TTP, and microthrombus was observed in 7 of 8 with TTP. Tumor necrosis factor was increased in 5 of 9 with TTP and HUS, Interleukin-1 beta was increased in all TTP and HUS patients, and soluble interleukin 2 receptor and interferon alpha were also increased. Although plasma exchange was generally effective, some patients required combination therapy with steroids. We speculated that an autoimmune mechanism was involved in the on onset of TTP.

Adolescent↗
PubMed1989

[New method for preventing spinal headache (prophylactic blood patch method)].

After spinal anesthesia, early ambulation frequently caused spinal headache. If the patient was discharged on the day of the operation, spinal headache occurred very frequently. With epidural anesthesia, if the dura was erroneously punctured with the needle, headache often occurred. In order to prevent spinal headache, we tried the Blood Patch Method during operation (Prophylactic Blood Patch Method). Epidural catheterization and spinal tap were simultaneously performed. The epidural catheter was threaded 3 cm cephalad in the epidural space. Five ml Venous blood of the patient was injected through the epidural catheter (Blood Patch Method). Epidural puncture was performed one spinal segment cephalad (A Method) or one spinal segment cauded (B Method) from the site of spinal puncture. The prophylactic Blood Patch Method was very effective in preventing spinal headache after the dural puncture. Especially B Method, in which blood was injected near the dural pore, was much more effective than A Method.

Anesthesia, Obstetrical↗
PubMed1987

[Single-agent trial with epirubicin in hematological malignancies].

Twelve patients with hematological malignancies were treated with epirubicin and ten patients were evaluable. One out of our four patients with ALL, who had a previous therapy of anthracycline, achieved a partial remission (PR: 25%). In two patients with AML, remission was not obtained. Of four patients with NHL, one with B-cell lymphoma achieved complete remission (CR) and one with ATLL partial remission (CR + PR: 50%). Stomatitis was observed as a major side effect in three patients with acute leukemia and in one with NHL. In conclusion, our trial seems to show the efficacy of epirubicin in lymphoid malignancies.

Acute Disease↗
PubMed1987

[Combined clinical effect of amikacin and cefoxitin in patients with severe infections complicated by hematological diseases].

A clinical investigation was made on the concurrent use of amikacin (AMK) and cefoxitin (CFX) against complicated infections with hematological disorders. The results obtained were summarized as follows: Eleven patients were treated with AMK and CFX. Clinical responses were excellent in 2 (18%), good in 4 (36%), fair in 1 (9%), and poor in 4 (36%), with an efficacy rate of 64%. No significant side effects requiring cessation of the treatment were observed.

Adolescent↗
PubMed1985

[Suture material in vaginal hysterectomy].

In order to find the best suture material to use for vaginal hysterectomies, we examined the tensile strength, stretchability and contractibilty of suture materials such as silk, chromic and plain catgut, and dexon under both wet and dry conditions. We also observed the incidence of postoperative hemorrhage, granulation and healing of the vaginal stump. Under dry conditions, the tensile strength, stretchability and contractibility was greatest in No. 3 plain catgut. (plain catgut greater than chromic catgut greater than dexon or silk) Under wet conditions, the tensile strength was not so changed, but the stretchability of catgut and silk was increased and that of dexon was low and unchanged. The contractibility of all types of suture material was increased. Silk had low tensile strength, was not absorbable and became an infectious foreign body. Dexon had low stretchability and tended to result in postoperative hemorrhage. Chromic catgut was frequently found to cause infectious granulation and postoperative hemorrhage in the vaginal stump. Plain catgut was easily absorbed and had the greatest tensile strength and stretchability. Plain catgut was considered to be the most suitable suture material for vaginal hysterectomy.

Biomechanical Phenomena↗