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Biomedical subjects

S Horiguchi

Publications and source records attributed to S Horiguchi.

At least 145 records · Page 8Linked to original sources

Alterations of lipids of the erythrocyte membranes in workers exposed to lead.

Changes in lipids (cholesterol and phospholipids) of the erythrocyte membrane were studied and several laboratory examinations were performed with 25 male workers employed in a scrap lead refining factory using as controls 38 male railway construction workers. The examinations included measurements of erythrocyte count, hematocrit, mean corpuscular volume (MCV), blood and urine lead concentrations, urine coproporphyrin and delta-aminolevulinic acid, membrane cholesterol (CHO) and phospholipids (PL), total and free CHO in plasma, and lecithin cholesterol acyltransferase (LCAT) activity in plasma. The results were: 1) Membrane CHO (P less than 0.01) and CHO: PL ratio (P less than 0.05) of lead workers were higher than those of the controls. But no significant difference was observed in membrane PL between both groups. 2) Membrane phosphatidyl choline was higher (P less than 0.05) and lysophosphatidyl choline was lower (P less than 0.05) in lead workers compared with controls. But no significant difference was observed in membrane sphingomyelin, phosphatidyl serine, and phosphatidyl ethanolamine between both groups. 3) Free CHO in plasma was higher (P less than 0.05) in lead workers compared with controls. But no significant difference was observed in total CHO in plasma, erythrocyte count, hematocrit, MCV, and LCAT activity between both groups.

Adult↗

Relationships between osmotic fragility of red blood cells and various hematologic data in workers exposed to lead.

This paper describes relationships between osmotic fragility (OF) of red blood cells and various hematologic data in 32 male workers exposed to lead and 30 controls. The examination included measurements of OF determined by the coil planet centrifuge system, red blood cell (RBC) count, hematocrit, hemoglobin, mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), water of RBC, sodium and potassium of RBC, blood and urine lead, urine coproporphyrin, and urine delta-aminolevulinic acid. The results were: 1) OF was lower in lead workers at all three hemolytic points compared with the controls (P less than 0.05). 2) A difference in hemolysis pattern between the two groups was observed (P less than 0.05). 3) A close relationship was observed in both groups between OF and MCV (P less than 0.05), although the results were contrasting. Also a close relationship was observed in lead workers between OF and hematocrit, OF and hemoglobin, OF and MCH, and OF and intracellular potassium (P less than 0.05) but not in the controls. In the controls a close relationship was found between OF and RBC (P less than 0.05) but this was not observed in the lead workers. No significant relationship was observed in either group between OF and MCHC, OF and intracellular sodium, and OF and intracellular water. 4) No difference in RBC, hematocrit, hemoglobin, MCV, MCH, MCHC, and intracellular water, sodium and potassium was observed between both groups.

Adult↗

Mechanism of increased osmotic resistance of red cells in workers exposed to lead.

In order to clarify the mechanism of the increased osmotic resistance of red blood cells in lead workers 19 men employed in a lead refining factory and 18 control male workers employed in railway construction were examined for red cell count, haematocrit, MCV, blood and urine lead concentrations, urine coproporphyrin and delta-aminolevulinic acid, osmotic resistance of red cells, lecithin-cholesterol acyltransferase (LCAT) activity in serum, and cholesterol content and cholesterol-to-phospholipid ratio of the red cell membrane. The results were: (1) The osmotic resistance of the red cells (p less than 0.05), cholesterol content of the red cell membrane, blood and urine lead, urine coproporphyrin, and urine delta-ALA concentrations (p less than 0.01) were higher in the lead workers than in the controls. (2) In the lead workers close relationships were observed between the osmotic resistance and the blood lead concentration (r = -0.515, p less than 0.05), osmotic resistance and LCAT activity (r = 0.596, p less than 0.01), and osmotic resistance and cholesterol of the red cell membrane (r = -0.492, p less than 0.05).

Adult↗

An increase in the Na+/K+-ATPase activity of erythrocyte membranes in workers employed in a lead refining factory.

To clarify the relationship between erythrocyte Na+/K+-ATPase activity and haematological findings, several clinical laboratory examinations were performed on 31 male workers employed in a scrap lead refining factory and, as controls, 50 male workers employed in railway construction. The results were: (1) Values for erythrocyte Na+/K+-ATPase activity, blood and urine lead, urine delta-aminolaevulinic acid, and urine coproporphyrin of lead workers were significantly higher than those of the controls (p less than 0.01). (2) A strongly positive relationship between blood lead and erythrocyte Na/K-ATPase activity was observed in lead workers (r = 0.473, p less than 0.01). (3) A strongly negative relationship between Na+/K+-ATPase activity and intracellular sodium was observed in both groups (lead workers; r = -0.601, p less than 0.01: controls; r = 0.595, p less than 0.01).

Adult↗

Effect of lead in vitro on water metabolism and osmotic fragility of human erythrocytes.

The addition of lead to normal human blood was previously found to cause a decrease in erythrocyte osmotic fragility in vitro. The mechanism of the decreased osmotic fragility caused by lead has not been completely clarified, but the following hypothesis has been proposed. Lead causes a leakage of water from erythrocytes, thus more water can enter the cell before haemolysis occurs. There has been no report, however, of the direct measurement of the intracellular water content of erythrocytes treated with lead. This study has tried to clarify the relation between intracellular water and the osmotic fragility of lead-treated erythrocytes in vitro. The results showed that 0.05 microM/ml of lead decreased the osmotic fragility, the intracellular water content, and intracellular potassium and mean corpuscular volume, increased the plasma water content and trapped water content, and contracted the erythrocyte shape. These changes corresponded well with each other, and close coincidence of the osmotic fragility and the intracellular water content was also observed.

Body Water↗

[Studies on industrial styrene poisoning (Part XIII). Experimental studies on the damage on the mucosal membrane of respiratory tracts of rats exposed to styrene-contemporary observations of the changes in ciliary function and fine structures].

Styrene is known to have an irritating effect on the tracheal mucosa, but there are few reports that have demonstrated it histologically. We carried out styrene-exposure experiments on rats, and made observations on morphological changes of the trachea with an electron-microscope. Observations on its functional aspects were also made by estimation of the ciliary movement per minute. The present study has revealed a considerable damaging effect of styrene on the tracheal mucosa, which we presented in this report in the hope that it could be used as an index in settling the maximum permissible concentration of styrene for the future.

Animals↗

[Experimental studies on the acute toxicity of tetrahydrofuran in animals].

The toxicity of tetrahydrofuran (THF), an important solvent in chemical industries, was studied by experiments on mice and rats. Acute toxicity was studied by intraperitoneally injecting 20% THF solution in various doses and by causing THF of various concentrations to be inhaled. Toxic symptoms appearing during the experimental period were observed. The results are as follows: 1. Acute toxic dose of THF. LD50 was estimated to be 2,500 mg/kg in mice with intraperitoneal administration of 20% THF-olive oil solution and 1,900 mg/kg in mice and 2,900 mg/kg in rats with intraperitoneal administration of 20% THF-0.9% NaCl solution. LC50 was estimated to be 21,000 ppm in rats when THF was inhaled for three hours. 2. Acute toxicity by inhalation of THF for three ours. Rats exposed to 100 to 200 ppm of THF showed no significant effects, except for slight local irritant symptoms such as redness of the nose and eyelids. Almost all rats exposed to over 5,000 ppm of THF displayed marked local irritant symptoms such as edema or opacity of the cornea, salivation and discharge or bleeding in nasal mucosa. A cataleptoid posture, coma and clonic muscle spasms indicating irritant symptoms of the central nervous system were also observed.

Animals↗

[Experimental studies on the toxicity of tetrahydrofuran administered to animals by repeated inhalation].

The toxicity of tetrahydrofuran (THF) was evaluated by repeated inhalation experiments on rats. The animals were separated into a control group and groups exposed to 100, 200, 1,000 or 5,000 ppm THF for 4 hours a day, 5 days a week over a 12-week period. No significant differences appeared between the groups exposed to 100 ppm as well as 200 ppm and the control group, except for slight local irritant symptoms of the mucosa. The group exposed to 1,000 ppm showed an effect on the liver function according to the results by serum chemistry test. In the group exposed to 5,000 ppm, marked local irritant symptoms and morphological damage of the respiratory mucous membrane were found upon histological examinations. Also significant differences were noted between this group and the control group in white blood cell counts, blood sugar values and liver functions by hematological and serum chemistry tests.

Administration, Intranasal↗

[Effects of lead on the protein of erythrocyte membranes].

In order to study the effects of lead in the circulating peripheral blood on the erythrocyte membrane, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of protein in the erythrocyte membrane was performed in 28 men exposed to lead in a scrap lead refining factory and 18 men working in railway construction as the controls. Furthermore, in order to corroborate the effects in vitro experiments by SDS-PAGE of protein in the mixture of human erythrocyte membranes with added lead were performed. 1) In the lead workers compared with the controls, SDS-PAGE of protein in the erythrocyte membrane showed that relative concentrations of bands 1, 2, 3 and 4.1 were significantly decreased while those of bands 2.3, 6 and 7 were significantly increased. 2) SDS-PAGE of protein in the in vitro experiment showed that the relative concentrations of bands 1, 2, 3, 4.1 and 4.2 were decreased while those of bands 2.3, 4.5, 5, 6 and 7 were increased. Therefore, these results show the same trends as those of the in vivo experiments. 3) For the lead workers, the correlation coefficients between blood lead and bands 2, 2.3 and 3 were r = -0.414 (p less than 0.05), r = 0.545 (p less than 0.01) and r = -0.509 (p less than 0.01), respectively. Also a higher coefficient of correlation (r = -0.777, p less than 0.001) was found between bands 2 and 2.3. 4) As the molecular weight of substances showing bands 2 and 2.3 were 220700 and 133800, respectively, according to PAGE using molecular weight markers, band 2.3 is considered to be due to a cleavage product from that of band 2. From these results, we summarized as follows. Lead combined with erythrocyte membrane decreases the band 3 penetrating lipid bilayer, and that causes the decrease of membrane transportation. On the other hand, the variation of band 2 and 4.1 influences the spectrin-actin network. This is considered to be one of the reasons that MCV is decreased.

Adult↗

Improvement in the atomic absorption determination of lead in blood.

A simple, precise and accurate analysis for lead in blood and tissue was developed using spectrophotometry after extraction with HCl, H3PO4, KI and methyl isobutyl ketone. The results were similar to those obtained by anodic stripping voltammetry. The method is simple, requires only four reagents, does not need pH adjustment for lead extraction, saves time and is suitable for analyzing a large number of specimens.

Humans↗

Studies on osmotic fragility of red blood cells determined with a coil planet centrifuge for workers occupationally exposed to lead.

In order to clarify the relationship between lead exposure level and osmotic fragility of red blood cells determined by the coil planet centrifuge method, several clinical laboratory examinations were performed on 27 male workers employed in a scrap lead refining factory using as controls 40 male workers employed in railway construction. The examinations included measurement of red blood cell and reticulocyte counts, hematocrit, MCV, blood and urine lead concentrations, urine coproporphyrin, and urine delta-aminolevulinic acid. The results were: 1. Osmotic fragility of red blood cells was lower in lead workers at all three hemolytic points compared with the controls. Significant difference was observed in hemolysis of the maximum point (P less than 0.05). 2. The red blood cell and reticulocyte counts, hematocrit value and MCV of the lead workers were not significantly different from those of the controls. Values for blood and urine lead, coproporphyrin, and delta-aminolevulinic acid of the lead workers were much higher than those of the controls (P less than 0.01). 3. In lead workers, close relationships between the osmotic fragility and these laboratory findings were observed: blood lead, r = -0.572, P less than 0.01; coproporphyrin, r = -0.608, P less than 0.01; delta-aminolevulinic acid, r = -0.559, P less than 0.01; urine lead, r = -0.453, P less than 0.05.

Adult↗