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Biomedical subjects

S Kusumi

Publications and source records attributed to S Kusumi.

11 recordsLinked to original sources
PubMed2000

Prevalence of anti-hepatitis C virus antibody and chronic liver disease among atomic bomb survivors.

To investigate whether exposure to atomic bomb radiation altered the prevalence of hepatitis C virus (HCV) infection or accelerated the progress toward chronic hepatitis after HCV infection, the seropositivity of antibody to hepatitis C virus (anti-HCV) was determined for 6,121 participants in the Adult Health Study of atomic bomb survivors in Hiroshima and Nagasaki. The seropositivity of anti-HCV antibody was 2.5 times higher among those with a history of blood transfusion and 1.2 times higher among those with a family history of liver disease, whereas acupuncture showed no association with anti-HCV. Although the prevalence of anti-HCV was lower for survivors with positive dose estimates than for those with 0 dose (relative prevalence 0.84, P = 0.022), there was no evidence of a smooth dose-response relationship. However, these data suggested that the radiation dose response for chronic liver disease among HCV antibody-positive survivors may be greater than that among HCV antibody-negative survivors (slope ratio 20). In conclusion, no dose-response relationship was found between anti-HCV positivity and radiation dose; a possible increase in the radiation dose response of chronic liver disease among anti-HCV-positive individuals was found. Thus radiation exposure may accelerate the progress of chronic liver disease associated with hepatitis C virus infection.

Aged↗
PubMed1999

Plasma fibrinogen and its correlates in elderly Japanese men living in Japan and Hawaii.

Plasma fibrinogen levels were determined using comparable methods for 329 Japanese men in Hiroshima Japan, and 3571 Japanese-American men in Honolulu Hawaii, aged 71-93 years. The age-adjusted mean fibrinogen level in Japanese-American men (307 mg/dl) was significantly higher (p<0.0001) than in native Japanese men (270 mg/dl). In multiple linear regression models, the fibrinogen level was associated significantly and positively with white blood cell count (WBC) and total cholesterol, and inversely with HDL cholesterol and hematocrit in both study samples. The strongest association with fibrinogen was shown for WBC, and this association was not mediated through cigarette smoking. The observed difference in fibrinogen levels could not be fully explained by WBC, total and HDL cholesterol, triglyceride, hematocrit, body mass index, and diabetes. Some unmeasured environmental or lifestyle variables such as diet and physical activity may be partly responsible for the observed difference in fibrinogen levels between native Japanese men and Japanese-American men in Hawaii.

Aged↗
PubMed1994

Cancer incidence in atomic bomb survivors. Part III. Leukemia, lymphoma and multiple myeloma, 1950-1987.

This paper presents an analysis of data on the incidence of leukemia, lymphoma and myeloma in the Life Span Study cohort of atomic bomb survivors during the period from late 1950 through the end of 1987 (93,696 survivors accounting for 2,778,000 person-years). These analyses add 9 additional years of follow-up for leukemia and 12 for myeloma to that in the last comprehensive reports on these diseases. This is the first analysis of the lymphoma incidence data in the cohort. Using both the Leukemia Registry and the Hiroshima and Nagasaki tumor registries, a total of 290 leukemia, 229 lymphoma and 73 myeloma cases were identified. The primary analyses were restricted to first primary tumors diagnosed among residents of the cities or surrounding areas with Dosimetry System 1986 dose estimates between 0 and 4 Gy kerma (231 leukemias, 208 lymphomas and 62 myelomas). Analyses focused on time-dependent models for the excess absolute risk. Separate analyses were carried out for acute lymphocytic leukemia (ALL), acute myelogenous leukemia (AML), chronic myelocytic leukemia (CML) and adult T-cell leukemia (ATL). There were few cases of chronic lymphocytic leukemia in this population. There was strong evidence of radiation-induced risks for all subtypes except ATL, and there were significant subtype differences with respect to the effects of age at exposure and sex and in the temporal pattern of risk. The AML dose-response function was nonlinear, whereas there was no evidence against linearity for the other subtypes. When averaged over the follow-up period, the excess absolute risk (EAR) estimates (in cases per 10(4) PY Sv) for the leukemia subtypes were 0.6, 1.1 and 0.9 for ALL, AML and CML, respectively. The corresponding estimated average excess relative risks at 1 Sv are 9.1, 3.3 and 6.2 respectively. There was some evidence of an increased risk of lymphoma in males (EAR = 0.6 cases per 10(4) PY Sv) but no evidence of any excess in females. There was no evidence of an excess risk for multiple myeloma in our standard analyses.

Adolescent↗
PubMed1991

Autocrine and/or paracrine mechanism operate during the growth of human bone marrow fibroblasts.

The growth of human marrow fibroblasts was studied at various plating cell densities. The growth rate of fibroblasts cultured with human plasma derived serum (PDS) increased depending on the cell density plated, whereas fibroblasts cultured with human serum proliferated almost independent of the cell density. Conditioned medium obtained from the culture with PDS at high cell density enhanced the growth of fibroblasts plated at low density, as well as that of fibroblast colony forming cells. Characterization of this conditioned medium showed heat unstable and acid stable peptide factor(s) with high molecular weight (approximately 10(6)) may be responsible for this activity. These results suggest that autocrine and/or paracrine mechanism can operate during the proliferation of marrow fibroblasts, a process thought to be involved in the progression of marrow fibrosis.

Adult↗
PubMed1991

Does heparin inhibit renin activity?

Although heparin was reported in the 1960s to inhibit renin activity, this has not always been confirmed by other investigators. Hence, we re-examined whether heparin really inhibits renin or not. Renin activities were determined by radioimmunoassay of angiotensin I generated at pH 7.4. (i) No significant difference was found between the two kinds of plasma samples obtained with heparin and with EDTA as anticoagulant, in ARC (renin activity with addition of sheep renin substrate), TRC (ARC after activation of inactive renin by trypsin), or PRA (plasma renin activity without additional substrate). (ii) Even in higher concentrations of heparin up to 500 U/mL, neither PRA, ARC, nor TRC of plasma was affected significantly. (iii) Heparin, in concentrations up to 500 U/mL, exerted no significant effect on TRC of the media of human vascular smooth muscle cell culture. In conclusion, heparin does not exert any significant inhibitory effect on human renin nor does it affect activation of inactive renin by trypsin in the range of concentration of practical use, under the conditions employed in this study.

Edetic Acid↗
PubMed1990

Fibroblast colony-forming cells with high sensitivity to serum mitogen(s) exist in bone marrow of patients with chronic myelocytic leukemia.

Marrow fibroblast colony formation was studied in patients with myeloproliferative disorders, using human serum or platelet-derived growth factor plus plasma-derived serum as growth-stimulating factors. Colony numbers negatively correlated with the patient's age, but were not different from those of controls. However, both maximum and average cell numbers per colony were significantly increased in patients with chronic myelocytic leukemia (CML) as compared to controls. These results suggest that fibroblast colony-forming cells with high sensitivity to human serum mitogen(s) exist in a CML bone marrow. These may possibly be involved in one of the mechanism concerned with promoting fibrosis in this disease.

Adult↗
PubMed1989

[Relationships between patterns of dyad relations and its change and mutual understanding of psychological traits].

The link between dyad friendship pattern and properties of mutual understanding was explored using the seventh graders as subjects. In Study 1, 42 mutual (MP) and 47 unilateral (UP) friendship pairs were selected. Each partner in each pair was asked to choose five dispositional traits which deemed to describe properly (1) self, (2) partner, and (3) self perceived by partner respectively from 30 traits. Five kinds of criteria to delineate mutual understanding were devised. MP, as opposed to UP, showed greater mutual understanding and recognized not only partners' attractive traits but receiving desirable estimation from partners. MP were also aware of sharing weak points. In Study 2, conducted four-months after Study 1, stable pairs (20 maintained mutual, MM) and vacillating ones (six growing mutual, GM; 11 decayed mutual, DM) were selected. For each of these pairs, the degree of fluctuations in mutual understanding was analyzed. Results showed DM became to see partner as having negative traits, besides to assume receiving negative evaluation from the partner, while MM sustained high degree of mutual understanding.

Adolescent↗
PubMed1989

[Thrombotic thrombocytopenic purpura which was effectively treated by plasma exchange therapy--involvement of vWF and endothelial cell injury].

A 49-year-old man with a one-week history of general fatigue and several other symptoms, including hematuria, numbness of the mouth, anemia and thrombocytopenia, was admitted because of an episode of convulsions and unconsciousness after blood transfusion. A diagnosis of thrombotic thrombocytopenic purpura (TTP) was then made, and treatment with steroids, anti-platelet agents, transfusion of fresh frozen plasma was started. However, since no improvement was seen, on the third day of admission, treatment with plasma exchange was instituted (total plasma exchange volume was 18.1 iota), and his clinical and hematological conditions improved markedly. Since then, he has been in a remission state for about three years. Laboratory examinations during the acute phase showed increase of vWf: Ag, decrease of RCof/vWf: Ag, increase of vWf large multimers and a high endothelial cell injury activity by the patient's serum. In the next day following the plasma exchange therapy, RCof/vWf: Ag improved, but not to the normal range. One and a half years later, while in the remission phase, the vWf multimers and endothelial cell injury activity normalized. Thus, these findings show further evidence on the involvement of endothelial cell injury and vWf in the pathogenesis of TTP.

Endothelium, Vascular↗
PubMed1979

Metabolic activation of 3-amino-5H-pyrido[4,3-b]indole, a highly mutagenic principle in tryptophan pyrolysate, by rat liver enzymes.

3-Amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2), a mutagenic principle in tryptophan pyrolysates, binds to DNA after metabolic activation by rat liver enzymes. The enzymes for activation of Trp-P-2 were found in both microsomes and the cytosol. The reaction required NADPH and ATP, metabolic and was inhibited by 7,8-benzoflavone. Considerable binding was observed with only microsomes as enzyme source, but further addition of cytosol enhanced the binding, enhancement depending on the amount of cytosol added. Inducers for microsomal mixed-function oxidases induced activating enzyme(s) for Trp-P-2, 3-methylcholanthrene being most effective, followed by polychlorinated biphenyls and then phenobarbital.

Animals↗