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Biomedical subjects

H Kurata

Publications and source records attributed to H Kurata.

At least 145 records · Page 8Linked to original sources
PubMed1989

Protection against influenza virus infection by a two-dose regimen of nasal vaccination using vaccines combined with cholera toxin B subunit.

The effectiveness of the two-dose regimen, composed of a primary intranasal inoculation of influenza A-type virus HA vaccine together with B subunit of cholera toxin (CTB) and the subsequent intranasal inoculation of vaccine alone 4 weeks later, was examined. In mice given a relatively high dose of virus A/PR/8/34 (PR-8, H1N1) HA vaccine (1.5 micrograms) both as a primary antigen with CTB (1 microgram) and as the second antigen, the secondary responses of both antiviral IgA antibodies in nasal wash and haemagglutination-inhibiting (HI) antibody in serum were much higher than those of primary responses and persisted for greater than 12 weeks after the second inoculation. Even in mice that received reduced amounts of a primary vaccine (0.03 microgram) [prepared from virus PR-8, A/Yamagata/120/86 (H1N1) or A/Fukuoka/C29/85 (H3N2)] together with reduced amounts of CTB (0.05 microgram), the subsequent inoculation of PR-8 vaccine produced both nasal IgA and serum HI antibodies and provided complete protection against homologous A-type virus (PR-8) infection. Moreover, the combination of the reduced amounts of heterologous A-type virus vaccine (A/Yamagata or A/Fukuoka) with CTB for primary inoculation and the secondary heterologous A-type virus vaccine [A/Yamagata, A/Kumamoto/37/79 (H1N1), or A/Fukuoka] resulted in high levels of cross-reactive IgA antibodies and partial cross-protection against PR-8 infection. On the other hand, a second inoculation of B/Ibaraki/2/85 vaccine failed to produce cross-reactive antibodies and to protect against PR-8 infection.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Intranasal↗
PubMed1989

Enhancement of protective antibody responses by cholera toxin B subunit inoculated intranasally with influenza vaccine.

Effects of the B subunit of cholera toxin (CTB) on the primary antibody responses to influenza virus A/PR/8/34 (PR-8) (H1N1) HA vaccine and on protection against viral challenge were investigated in Balb/c mice which were immunized intranasally with both the vaccine and CTB. The dose of CTB (greater than or equal to 1 microgram) inoculated with the vaccine (greater than or equal to 0.15 microgram) induced high responses of both antiviral IgA antibodies in the nasal wash and haemagglutinin-inhibiting (HI) antibody in the serum, enough to provide complete protection against viral challenge four weeks after immunization. High levels of antibody were maintained for more than 16 weeks after inoculation, affording complete protection during this interval. The inoculation of HA vaccine prepared from influenza viruses A/Yamagata/120/86 (H1N1) or A/Fukuoka/C29/85 (H3N2) together with CTB provided partial protection against PR-8 infection, with production of antiviral IgA antibodies which were cross-reactive to PR-8 antigens whereas immunization with CTB and HA vaccine prepared from a different type of influenza virus (B/Ibaraki/2/85) failed to protect against PR-8 infection. These results indicate that CTB can produce an augmented and persistent antibody response to PR-8 HA vaccine, which is cross-protective to other A-type virus infections. The mechanisms by which CTB enhances the protective antibody responses to the nasally inoculated vaccine were investigated. The ability of CTB to augment antibody responses was lost, either when CTB was inoculated via the intravenous or subcutaneous route, or when CTB was introduced into nasal site one day before or after the vaccine inoculation.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Intranasal↗
PubMed1989

Hematological studies on naturally occurring substances. II. Effects of animal crude drugs on blood coagulation and fibrinolysis systems.

The effects of 112 extracts prepared from 37 kinds of animal crude drugs and a dog's filaria were investigated on the blood coagulation and fibrinolysis systems in vitro. The plasma recalcification time method was employed for the assay of blood coagulation and fibrinolytic activity was tested by the fibrin plate method. It was found that the water extracts of Bombyx Batryticatus, Carpio Fel and Holotrichiae Vermiculus showed potent inhibitory effects on blood coagulation. The methanol extracts of Phocae Thstis et Penis, Scorpion and Tabanus were promotive effect, on the other hand. As regards the fibrinolysis system, the water extracts of Agkistrodon, Lumbricus, Hirudo, Scolopendra and Scorpion and the methanol extract of Hirudo showed a remarkable activity.

Animals↗
PubMed1989

[The effect of antileukemic chemotherapy on elderly patients with acute non-lymphocytic leukemia].

Thirty five elderly patients with acute non-lymphocytic leukemia were studied to examine the effects of antileukemic chemotherapy according to age group. Complete remissions were obtained in 5 of 10 patients (50%) age 60 to 69 years, in 5 of 14 (36%) age 70 to 79 years, but in 0 of 9 patients over 80 years. Three patients died before chemotherapy. The median survivals of these groups were 337,90 and 76 days, respectively. The median survival of the patients in whom complete remissions were achieved, was 700 days.

Aged↗
PubMed1989

Phosphoseryl-tRNA in Escherichia coli.

Two seryl-tRNAs, which were prepared from natural suppressor tRNA-rich fractions on a pattern of chromatography on Sephadex A-50, were phosphorylated by a tRNA kinase in Escherichia coli B. A part of phosphate on the tRNA was confirmed to be phosphoserine. Phosphoseryl-tRNA is universal in bacteria and vertebrates. Phosphoseryl-tRNA should be an intermediate from seryl-tRNA to selenocysteyl-tRNA.

Chromatography, Gel↗
PubMed1989

[Multivariate analysis of prognostic factors influencing survival in chronic myelogenous leukemia].

Prognostic significance of disease features obtained at the time of initial diagnosis was analyzed in 90 patients with chronic myelogenous leukemia (CML) in chronic phase. Median survival of this population was 45.9 months. Univariate analysis revealed that splenomegaly, bone marrow basophils, bone marrow blasts, peripheral blood blasts, and bone marrow eosinophils were significant prognostic factors for survival, and that peripheral blood leukocytes counts, hemoglobin concentration, performance status, age and lymphadenopathy were factors with border line significance. There were multiple interrelationship among these disease features. Multivariate regression analysis identified that age, hemoglobin concentration, and bone marrow blasts were independent primarily significant prognostic factors for survival. The Cox model generated with three variables of age, hemoglobin concentration, and percent blasts in bone marrow provided a useful representation of risk status in the population. A hazard function derived from the patients population segregated patients into three groups with significantly different survival patterns: A lower risk group, an intermediate group and a high risk group of patients with median survival of 57.8, 49.8 and 38.4 months respectively. Survival after CML blast crisis was short and overall median survival of 54 patients with CML blast crisis was 6.4 months. A sole prognostic factor for survival in blast crisis identified by multivariate analysis was blast cell type at CML blast crisis and patients with lymphoid phenotype had a good prognosis with median survival of 9.8 months. Median survival of myeloid crisis was 4.2 months. No other disease features were identified as significant prognostic factors in the present patient population.

Adult↗
PubMed1989

[Spleen and hematopoiesis].

In order to investigate the role of the human spleen on hematopoiesis, hematopoietic stem cells and stimulates were evaluated in fetal and adult spleens. BFU-E and CFU-C were existed in 20 weeks and 23 weeks fetal spleens (BFU-E 145 +/- 45/10(5) mononuclear cells, CFU-C 55 +/- 6/10(5) mononuclear cells). In adult spleen, a few stem cells were recognized, which may be contaminated from peripheral blood in sinus of the spleen. We tested conditioned media from adult spleen cells for the stimulative activity on the in vitro growth of BFU-E and CFU-C from bone marrow mononuclear cells. Spleen conditioned medium stimulated proliferation of these precursor cells. It seemed that PHA-stimulated spleen conditioned medium augmented BFU-E, whereas CFU-C growth was suppressed. Adult and fetal spleens were studied immunohistochemically using anti-G-CSF, GM- CSF and erythropoietin antibodies. The cells with G-CSF and GM-CSF were shown in fetal spleens. In adult spleens, however, only GM-CSF was detected.

Adult↗
PubMed1989

[Brachiocephalic arterial aplasia of the right aortic arch with subclavian steal syndrome].

A 44-year-old man was admitted to our hospital with complaint of weakness in his left upper extremity, vertigo, and diplopia. After aortic root injection of contrast medium, a right aortic arch was visualized. The left brachiocephalic artery was not found, however. An operation was performed through a midline sternotomy. The first branch of the aortic arch was the right common carotid artery, and the second branch was the right subclavian artery. The left brachiocephalic arterial aplasia was recognized. An E-PTFE graft was anastomosed proximally to the ascending aorta and distally to the junction of the left common carotid and left subclavian arteries. After the operation, some of the symptoms were improved and the others were removed.

Adult↗
PubMed1989

[A case of anterior communicating artery aneurysm with occlusion of the bilateral middle cerebral arteries].

A patient with ruptured anterior communicating artery aneurysm associated with occlusion of the bilateral middle cerebral arteries is presented. A 70-year-old woman was hospitalized for sudden onset of severe headache and vomiting. She was alert, and no neurological deficit was found. CT scan showed a subarachnoid hemorrhage. Cerebral angiogram demonstrated occlusion of the bilateral middle cerebral arteries and ruptured anterior communicating artery aneurysm. After operation, she fully recovered and was able to walk at the time of discharge. In aneurysmal formation, we know from the literatures that hemodynamic stress plays an important role. In this case, occlusion of the bilateral middle cerebral arteries caused hemodynamic stress on the anterior cerebral arteries and anterior communicating artery. It is suggested that this is a causative factor of aneurysmal formation under systemic hypertension.

Aged↗
PubMed1989

[Experimental and clinical studies on prevention of vascular prosthetic infection].

Since the treatment of infected vascular prosthetic graft is difficult, it is important to prevent graft infection. At the operation of aneurysmectomy, a part of aneurysmal wall was cultured. As a result, bacterial growth could be seen in 21 out of 58 cases (36%). In this experiment, expanded polytetrafluoroethylene (E-PTFE) graft was soaked in a solution of tobramycin (TOB) and tested for the prevention of graft infection. First, this E-PTFE graft with a TOB solution was tested for antithrombogenicity and patency rate, and secondly its effect of preventing graft infection was evaluated. 1. TOB had an effect of antithrombogenicity. 2. Patency rates of the E-PTFE graft with a TOB solution were as good as those of the graft soaked in a saline solution. 3. TOB concentration in the grafts was more than 100 micrograms/g after 6 hours from the implantation and more than MIC after 24 hours. 4. E-PTFE graft with a TOB solution had an effect of antibacteria. This study suggested that E-PTFE graft soaked in a TOB solution was effective to prevent graft infection.

Animals↗
PubMed1988

Protection against influenza virus infection by vaccine inoculated intranasally with cholera toxin B subunit.

Secretory IgA antibodies in mucosa are known to play an essential role in protection against various infectious agents. To enhance the induction of protective mucosal antibodies, influenza HA vaccine was inoculated intranasally into mice with the B subunit of cholera toxin (CTB), which is known to be an excellent mucosal self-adjuvanting molecule. This combination resulted in high levels of antiviral IgA antibodies in nasal secretions and enhanced serum haemagglutinin-inhibiting (HI) antibodies 4 weeks after inoculation, compared with the inoculation of vaccine alone which induced only a low level of HI serum antibodies and no local IgA antibodies. (Subcutaneous or intraperitoneal inoculation of the vaccine with CTB failed to induce detectable nasal antiviral IgA antibodies). Levels of nasal IgA and serum HI antibodies increased in a dose-dependent fashion with increasing nasal doses of both vaccine and CTB, and correlated with the degree of protection against viral challenge. A greater protective effect was seen with cholera toxin than with its B subunit. Moreover, a second administration of vaccine alone, 4 weeks after the inoculation of the vaccine with CTB, elevated the level of the antiviral IgA nasal antibodies to 10-100 times higher than that of the primary response. These results suggest that either CT or CTB could be used as a potent adjuvant to induce protective secretory antibodies by nasal vaccination against pathogens impinging on respiratory mucosa.

Adjuvants, Immunologic↗
PubMed1988

Effects of cholera toxin on delayed-type hypersensitivity to sheep red blood cells inoculated intranasally into mice.

The effects of cholera toxin (CT) on delayed-type hypersensitivity (DTH) to sheep red blood cells (SRBC) were studied in mice sensitized by intranasal administration of SRBC. CT (1 microgram/mouse), given intranasally together with SRBC (2 x 10(7)/mouse), induced a maximally enhanced DTH response, which reached its peak around 7 days after sensitization, and also induced an accelerated DTH response upon a second administration of SRBC 28 days later. The ability of CT to enhance the DTH to SRBC was lost, either when CT was administered via the intraperitoneal or subcutaneous route, or when CT was introduced into the nasal site from which a large proportion of the SRBC was discharged 2 days after SRBC administration. These results indicate that the cells that are located in the nasal site and participate in the earlier events of DTH response were most affected by CT. The following effects of CT on the earlier events, which occur within 24 hr after the intranasal administration of both CT and SRBC, appeared to be involved in the mechanisms by which CT enhances DTH to SRBC: (i) facilitation of the penetration of the antigen into the nasal tissue; (ii) reinforcement of the migration of immunocompetent cells from the blood to the nasal tissues; (iii) promotion of the ability of Ia-positive macrophages to present the antigenic determinants to T cells; (iv) facilitation of the differentiation of primed T cells to DTH-effector T cells.

Adjuvants, Immunologic↗
PubMed1986

Recent statistical survey of visceral aspergillosis in Japan, and experimental studies on the pathogenicity of Aspergillus fumigatus in rabbits.

A statistical survey of visceral aspergillosis in Japanese pathological autopsies (1972-1981) was carried out. It was found that the infection has increased remarkably in recent years, and the results obtained were briefly described. Pathogenicity of several strains of Aspergillus fumigatus in rabbits was studied on three occasions in the past 31 years. The pathogenicity appeared to be unchanged even after long subcultures for 13 years, while lowered pathogenicity was noted with long-term subcultures over 30 years. However, the lowered pathogenicity of the fungus seemed to be recovered by animal passage.

Age Factors↗