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Biomedical subjects

H Kitamura

Publications and source records attributed to H Kitamura.

At least 595 records · Page 33Linked to original sources
PubMed1977

The cold activation of the classical complement pathway: The cause of the differences between plasma and serum complement in liver cirrhosis.

The mechanism responsible for making the differences between plasma and serum complement (CH50) was studied on eight patients with hepatitis-B(s) antigen negative alcoholic liver cirrhosis. CH50 and C4 activities of the sera of all patients were equal to those of the corresponding EDTA-plasma, when sera wre separated after clotting the blood at 37 degrees C. CH50 and C4 activities of the sera, prepared at 21 degrees C or 4 degrees C, from four of eight patients were very low. When serum from one of these four patients was added to normal human serum, C4 activity of the serum mixture markedly decreased at 4 degrees C but not at 37 degrees C. The inactivation of C4 was prevented by adding EDTA or heparin to the serum mixture. These results indicated that very low complement in the sera, prepared at 21 degrees C or 4 degrees C, of the four cases were due to the cold activation of the classical complement pathway.

Cold Temperature↗
PubMed1976

Membrane fluidity change in erythrocytes induced by complement system.

The structural change in erythrocyte membranes induced by antibody and complement was studied using phospholipid spin-labels. Sheep erythrocytes were labeled with phosphatidylcholine spin-label and various intermediate cells (erythrocyte-antibody complex (EA), EA bound with complement components from C1 to C7 (EAC1-7), EAC1-8, and EAC1-9) were prepared. Electron spin resonance spectra of EA, EAC1-7, and EAC1-8 were very similar to that of the erythrocytes, while that of EAC1-9 was markedly different. The overall splitting value for the lysed EAC1-9 (53 G) was much smaller than that for the erythrocytes (57 G), indicating a marked fluidization around the phosphatidylcholine label. The unlysed EAC1-9 membranes contained a limited fraction of the fluidized area. When EA was reacted with complement in the presence of 36% bovine serum albumin, the membranes were fluidized similarly to the lysed EAC1-9, although the hemolysis was largely blocked. The membranes of unlysed EAC1-9 prepared in isotonic (ethylenedinitrilo)tetraacetic acid were also fluidized, but to somewhat smaller extent. The role of C9 in the modification of erythrocyte membranes was also demonstrated using Mg2+ ghosts, which were prepared by hypotonic hemolysis in the presence of Mg2+. The membranes of Mg2+ ghost of EAC1-7 were markedly fluidized when bound with C8 and C9, but not affected by binding of C8 only. The component C8 was found to give a latent effect on the membranes that caused irreversible fluidization upon osmotic shock. The terminal component thus creates a fluidized area in the erythrocyte membranes through which small ions and molecules may diffuse more easily and the resulting osmotic unbalance may finally cause hemolysis.

Animals↗
PubMed1976

Rhodopseudomonas sphaeroides forma sp. denitrificans, a denitrifying strain as a subspecies of Rhodopseudomonas sphaeroides.

From polluted water of a lagoon pond a new type of denitrifying photosynthetic purple bacteria was isolated. With respect to morphology, fine structure, photopigments, requirement for growth factors, the range of utilization of organic substrates for phototrophic growth and DNA base ratio, the denitrifying strains show the closest resemblance to Rhodopseudomonas sphaeroides and were therefore described as a subspecies named R. sphaeroides forma sp. denitrificans. The new isolates grow well with nitrate anaerobically in the dark accompanying the evolution of nitrogen gas. They cannot assimilate nitrate as the nitrogen source for growth.

Aerobiosis↗
PubMed1976

Necessity of the divalent cation in the reaction between EAC1-8hu and C9gp.

The reaction of EAC1-8hu and C9gp could not generate E* in 0.09 M EDTA solution. In 0.001 M EDTA solution, EAC1-8hu could not fix C9gp. But E* formation was observed in the buffer containing low concentration of divalent cations. Of the tested cations, Ca++ was most effective and its optimal concentration was 2 X 10(-7) M.

Animals↗
PubMed1976

Differences between plasma and serum complement in patients with chronic liver disease.

Of sixty patients with chronic liver disease, eight with cirrhosis or chronic hepatitis had very low serum CH50 but normal plasma CH50. The complement component profiles of these sera revealed markedly decreased C4 and C2 activities and normal C3T (C3-C9) activities. From these results, it is suggested that the early acting complement components had been non-specifically activated during blood coagulation in these patients. No difference between plasma and serum CH50 was found in patients with hepatitis B(s) antigen.

Adult↗
PubMed1975

Studies of tumor cell lines derived from patients with malignant melanoma.

Fourteen long-term human malignant melanoma cell lines established from biopsy specimens, malignant effusions and the peripheral blood are reported. Methods of culture, heterologous transplantation studies and characterization of these cell lines are presented. Several of these cell lines have retained the ability to produce pigment over a period of years, permitting bioassays at a subcellular level. Studies of cell lines grown with and without tyrosine and some of the theoretical uses of human melanoma cell lines are presented.

Animals↗