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E Shibata

Publications and source records attributed to E Shibata.

69 records · Page 4Linked to original sources
PubMed1989

Effects of chronic n-hexane exposure on nervous system-specific and muscle-specific proteins.

Two kinds of nervous system-specific and muscle-specific proteins, enolase and S-100 protein, were quantitatively determined in peripheral nerves and skeletal muscles of rats chronically exposed to a neurotoxic solvent - n-hexane. Three groups of animals were exposed to n-hexane vapor at three different solvent concentrations (500 ppm, 1200 ppm, 3000 ppm) for 12 h/day, 7 days/week for 16 weeks. The body weight gain and motor nerve conduction velocity (MCV) in exposure groups show progressively concentration-dependent decreases compared to control values. Histopathological examination also demonstrates the degeneration of peripheral nerves in 3000 ppm- and 1200 ppm-exposed rats. The significant decrease in the amount of S-100 protein in peripheral nerves was observed not only in the high level exposure groups (3000 ppm and 1200 ppm), but also in the lowest level group (500 ppm), although the MCV and morphological examination remained unchanged at this level. In addition, the muscle-specific S-100 protein in 3000 ppm exposed rats' soleus also displayed a significant reduction. In contrast to this, however, enolase isozymes were not significantly changed by either dosage level in both nervous tissue and skeletal muscle. The experiment suggests that beta- and alpha-S-100 proteins which are specifically localized in nervous system and muscles, respectively, are more vulnerable than enolase isozymes under treatment with n-hexane, and may possibly serve as a specific indicator to evaluate the neurotoxic effects. Further research would be worthwhile to elucidate the role of the specific S-100 protein in evaluating the neurologic damage induced by various industrial chemicals.

Animals↗
PubMed1988

Asbestos fibers in human pulmonary and extrapulmonary tissues.

The association between asbestos fibers in human lung tissues and those in other extrapulmonary organs was studied by analysing three autopsied cases, one of whom had a high pulmonary asbestos burden, one an intermediate burden, and one a low burden. The amount, types and sizes of asbestos fibers in the tissues of lung, liver, spleen, pancreas, kidney, and gastrointestinal tract were identified and measured by transmission electron microscopy equipped with an energy dispersive X-ray analyser. The following results were obtained: 1) The concentrations of asbestos fibers in extrapulmonary organs tended to increase with that in lung tissues. 2) The types of fibers identified in lungs were approximately consistent with those in other organs. 3) A relatively large range of fiber length was observed in both lungs and other organs. The findings extend and support previous light microscopic studies comparing asbestos bodies in various organs, and may imply that persons with high levels of asbestos in their lungs are also likely to have the same types and high levels of asbestos in their other tissues.

Aged↗
PubMed1983

Properties of the strongly immobilized signal observed in spin-labeled erythrocytes.

A strongly immobilized signal from fatty acid spin labels was observed in human erythrocytes treated with oxidizing agents such as glutaraldehyde, hydrogen peroxide, phenylhydrazine and copper-ortho-phenanthroline. This signal was also observed in freshly prepared ghosts treated with potassium superoxide and in old erythrocyte ghosts. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of these samples demonstrated the diffuse, nondiscrete bands of high molecular weight due to the cross-linking of membrane proteins. The temperature and pH dependences of the outer hyperfine splitting of this signal were very similar to those of bovine serum albumin. We propose that the strongly immobilized signal reflects the interaction of the lipids with the cross-linked products of membrane proteins.

Adult↗
PubMed1981

Autonomic transmitter actions on cardiac pacemaker tissue: a brief review.

Application of the voltage clamp technique to cardiac primary pacemaker tissue has yielded sufficiently detailed information that a qualitative model of the pacemaker response can now be formulated. One important difference between the generation of spontaneous activity in sinus tissue, and in the Purkinje fiber, appears to be the involvement of the slow inward current, Isi, in the sinus pacemaker depolarization. The voltage clamp results also demonstrate the importance of the Isi in the chronotropic responses of pacemaker tissue. Epinephrine has been shown to increase Isi in rabbit sinoatrial node, and there is indirect evidence that acetylcholine may reduce Isi in reptilian sinus venosus. Additional, more quantitative data are essential, however, before cardiac primary pacemaker activity and its modulation by the autonomic transmitters can be fully understood.

Acetylcholine↗
PubMedDate not supplied

Metabolic acidosis and renal tubular injury due to pure toluene inhalation.

A 22-y-old woman was hospitalized for muscle weakness of her lower extremities after she sniffed approximately 6 l of pure toluene during the month prior to admission. The examinations on serum and urine revealed mixed hyperchloremic and high anion gap metabolic acidosis accompanied by impaired urinary acidification. Histopathological changes of the kidney were patchy areas of tubular injury. Acidosis normalized on the fourth day of admission, but both proximal and distal tubular dysfunction persisted. These findings indicate that toluene is a tubular toxin and may contribute to the development of distal renal tubular acidosis.

Acidosis↗
PubMedDate not supplied

[Positive skin test and age]

OBJECTIVE: To evaluate positive responses to skin tests for immediate hypersensitivity to allergens in children with asthma and rhinitis at different ages. METHOD: We observed positive skin test reactivity in prick tests using fifteen allergens of same origin (total dust and Dermatophagoides sp.; Dermatophagoides pteronyssinus; Dermatophagoides farinae; Blomia tropicalis; Penicillium sp; Alternaria alternata; Cladosporium herbarium; Aspergillus fumigatus; Bermuda grass; forage grass; dog and cat epithelia; feathers; Blatella germanica and wool). We placed 713 selected patients into different age groups - Group I: 6 to 11 months; Group II: 1 to 3 years and 11 months; Group III: 4 to 8 years and 11 months; and Group IV: 9 to 15 years. We used the chi-square test for statistical analysis. RESULTS: The total significant differences between these groups were: I to II = 5; II to III = 5; II to IV = 5; III to IV = 6; I to III = 10; and I to IV = 10. CONCLUSION: Skin test reactivity is acquired progressively with age, and can be observed as early as at 12 months. Reactivity is significantly more positive from the age of 4 on.

Journal Article↗