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Biomedical subjects

Y Yukiyama

Publications and source records attributed to Y Yukiyama.

At least 19 recordsLinked to original sources
PubMed1994

[Relationship between occupational factors and medical indicators related to arteriosclerotic diseases].

The relationship between occupational factors and indicators related to arteriosclerotic diseases which include blood pressure, total cholesterol, triglyceride, HDL-cholesterol, body mass index, and HMS (Hitachi mental health scale) score. The study subjects were 7226 male electric company employees (40 to 59 years old). Records of annual health examinations were reviewed, and those of 3553 blue-color workers and 1860 white-color workers were used for analyses. The main results were as follows: Work style (overtime work and frequency of business trips) was strongly related to life style. Overtime work and walking time from home to the workplace did not relate to indicators of arteriosclerotic diseases. However, frequency of business trips, working posture and job category were related to most of the indicators. Smoking and frequency of drinking were strongly related to the indicators in both blue-color and white-color workers. In both blue-color and white-color workers, HMS score was not related to work style, but related strongly to psychological factors. In white-color workers, HMS were also related to life style. In addition, this study suggests that a cohort study about the progress of arteriosclerotic diseases in middle-aged workers is necessary, and that more accurate information on work style should be obtained for further investigation.

Adult↗
PubMed1990

Restriction fragment length polymorphism of complement C4 in Japanese patients with rheumatoid arthritis and normal Japanese.

Restriction fragment length polymorphism (RFLP) of the two genes for complement C4A and C4B was studied in 56 Japanese patients with rheumatoid arthritis (RA) and 161 normal individuals. HindIII digestion revealed six common patterns, from which the segregation of three common RFLP-types were deduced; 32-15 kb, 32-25 kb, and 32-20-13-6.5 kb. The last type showed positive associations with C4B5 and HLA-DR4. In the RA patients, an increase of this type was found as well as a decrease of the 32-15 kb/32-25-15 kb heterozygotes.

Arthritis, Rheumatoid↗
PubMed1990

Lack of gene deletion for complement C4A deficiency in Japanese patients with systemic lupus erythematosus.

The frequency of C4A gene deletion was studied in Japanese patients with systemic lupus erythematosus (SLE) and was compared with healthy controls. DNA preparations were extracted from peripheral blood leukocytes from 59 patients with SLE and from 166 healthy persons, and digested by restriction enzymes. They were hybridized with C4 complementary DNA by the Southern blotting method and the deletion of C4A gene was judged from restriction fragment length polymorphism. At the same time phenotypic C4A deficiency (C4AQ0) was measured. Our results showed that the frequency of phenotypic C4A deficiency was 44.1% in Japanese patients with SLE and this value was comparable with that (43.2%) in Caucasian patients. On the other hand the deletion of C4A gene was not found in Japanese patients with SLE (0%), or in healthy controls (0.6%). Our results indicate that C4AQ0 may contribute to the pathogenesis of SLE beyond the ethnical differences but Japanese patients with SLE have a different genetic background from Caucasian patients with the C4A gene deleted.

Alleles↗
PubMed1990

[Complement activation by killed polyvalent bacterial vaccine on the pleurodesis].

Broncasma Berna (B.B.) prepared from killed polyvalent bacterial vaccine is used as a pleural irritant for pleurodesis on patients with spontaneous pneumothorax. The effects of B.B. on the complement system in vivo after injections into pleural spaces were investigated. Five patients with spontaneous pneumothorax underwent intrapleural injections of B.B. Increased body temperatures with positive C-reactive proteins and increased polymorphonuclear leukocyte counts in peripheral blood were observed in all patients. Serum levels of complement components (Clq, Cls, C4, C3 and B), hemolytic activity of complement (CH50) and plasma levels of C3a were gradually elevated after intrapleural injections of B.B. Analysis of pleural fluids from 4 patients showed that levels of C3a and C5a were increased compared with plasma levels, and an accumulation of polymorphonuclear leukocytes were observed. These findings suggest that intrapleural injections of B.B. activate the complement system and cause inflammatory reactions accompanied by an increase of C3a and C5a and an accumulation of polymorphonuclear leukocytes. Such inflammatory reactions might inversely induce the synthesis of complement components and promote the migration of polymorphonuclear leukocytes from bone marrow. The deposit of fibrin during these inflammatory processes might contribute to the development of pleurodesis. These inflammatory reactions might be mediated through the activation of the classical complement pathway by B.B.

Adult↗
PubMed1987

Quantification of the complement receptor function on polymorphonuclear leukocytes: its significance in patients with systemic lupus erythematosus.

The function of complement receptors (CR1) on polymorphonuclear leukocytes (PMN) was assessed by C3b mediated binding of immune complexes (IC) to PMN. The binding of IC to CR1 on PMN depends on the activation of the classical complement pathway and was inhibited by the antibody to CR1 or C3b. CR1 function of PMN from patients with systemic lupus erythematosus was reduced compared with those from normal controls or patients with rheumatoid arthritis.

Antibodies, Monoclonal↗
PubMed1986

Interaction between immune complexes and C3b receptors on erythrocytes.

We studied the interaction between immune complexes (IC) and C3b receptors (CR1) on erythrocytes (E) and showed that activation of the classical complement pathway is essential for the binding of IC to CR1, that C3b inactivator (I) and beta 1H (H) are essential for the release of IC from CR1, that CR1 retain the capacity to bind IC after repeated binding and release of IC, and that on the other hand, IC lose the capacity to bind to CR1 after repeated binding and release. These results suggest a dynamic in vivo interaction between IC and CR1 on E which are supposed to transport IC to the reticuloendothelial system. CR1 on E, with a help of I and H, might make IC less harmful to the tissues in the process of releasing IC from E.

Antigen-Antibody Complex↗
PubMed1985

In vitro biological effects of volcanic ash from Mount Sakurajima.

Mount Sakurajima in the south of the Kyushu Island of Japan erupts hundreds of times a year and continuously emits large amounts of ash. More than a million people live under this ash plume, and there is considerable concern about the possible effects of this on their health. We have studied the physicochemical characteristics and in vitro effects of airborne ash collected at 8 km from the crater. More than 30% of the ash was found to be SiO2 (w/w) with most of the particles within the respirable size range. The ash did not inhibit the colony formation of V79-4 cells and failed to activate complement or generate chemotactic factor activity in samples of fresh human serum. It was minimally active in causing the release of lysosomal enzymes from human neutrophile, and did not cause arachidonic acid release from macrophage-like cells. These results were in accord with our epidemiological study, in which very low prevalences of nonspecific respiratory disease were demonstrated even at the area with highest ash exposure.

Air Pollutants↗
PubMed1985

The change in C3b receptors on erythrocytes from patients with systemic lupus erythematosus.

A deficiency of C3b receptors (CR1) on erythrocytes from patients with systemic lupus erythematosus (SLE) has already been reported and assumed to be one of the causes of the impaired immune complex clearing function found in these patients. In the present study, we developed a functional assay to quantify the amount of CR1 on human erythrocytes. Sample erythrocytes were reacted with tetanus toxoid-anti-tetanus toxoid immune complexes (IC) in the presence of complement. The amount of CR1 was expressed as the amount of IC bound to sample erythrocytes. Determination of CR1 showed a decrease in erythrocytes from patients with SLE, rheumatoid arthritis and other connective tissue diseases. The activity of CR1 in erythrocytes from patients with SLE changed in parallel with complement activity and also reflected the clinical status of two of three patients. These results imply that the reduction of CR1 found in SLE patients might be cause not only by hereditary factors but by unknown factors that influence the amount or function of CR1.

Adult↗
PubMed1984

Further study on a BF silent allele.

A family was found which indicated the existence of a silent allele (BF*QO) at the locus for complement factor B. Three generations with eight members were studied. Four individuals were considered to be heterozygous for B deficiency because of unusual segregation patterns of the BF electrophoretic variants and low levels of B. Haplotype study on the other HLA-linked markers supported the presumption. No unusual products were detected by immunoblotting after sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE).

Alleles↗
PubMed1984

An immunochemical method for assessing the function of the alternative complement pathway.

Activation of the alternative pathway of human complement (C) by soluble C activators resulted in a decrease of C9 antigen, measured by single radial immunodiffusion, concomitant with a decrease of C9 hemolytic activity. In the presence of ethylene glycol bis-(beta-aminoethylether)-tetraacetic acid (EGTA) and Mg2+, this decrease of C9 antigen in the presence of soluble activators such as dinitrophenylated bovine serum albumin depends mainly on the activation of the alternative C pathway. Therefore, an assay system to express the total activity of the alternative C pathway in human serum - the C9 depletion test (C9DT) -, was devised. C9DT showed significantly lower values for patients with systemic lupus erythematosus and rheumatoid arthritis than for control patients.

Antigens↗
PubMed1984

Role of protease--protease-inhibitor complexes in inflammation.

Neutrophils accumulate and release proteolytic enzymes at the site of acute inflammation. These proteases cause tissue damage but are inactivated by protease-inhibitors which have been thought to finish their activity. We paid attention to these protease--protease-inhibitor complexes and examined their roles. Trypsin was used as a proteolytic enzyme and was mixed with an excess of purified alpha 1-antitrypsin (alpha 1AT). The trypsin-alpha 1AT complex was separated from native alpha 1AT by column chromatography. Then the complex was incubated with human neutrophils and lysosomal enzyme release was examined. Significant enzyme release was observed when neutrophils were incubated with the complex, but the amount of enzyme release from the cells was not obvious when neutrophils were incubated with alpha 1AT or trypsin alone. The amount of lysosomal enzyme release was proportional to the amount of the complex added. Further study revealed that the complex did not have much influence on neutrophil chemotaxis or superoxide radical generation, but could activate complement by the classical pathway. These facts indicate that protease--protease-inhibitor complexes play a role in prolonging inflammation.

Adult↗