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Biomedical subjects

M Kasuya

Publications and source records attributed to M Kasuya.

At least 37 records · Page 2Linked to original sources

Preliminary study on serum levels of 1,25-dihydroxyvitamin D and 25-hydroxyvitamin D in cadmium-induced renal tubular dysfunction.

Serum 1,25-dihydroxyvitamin D [1,25(OH)2D] and 25-hydroxyvitamin D [25(OH)D] were measured in 7 women living in a cadmium-polluted area in Toyama, Japan. Despite the fact that these subjects had severe proximal renal tubular dysfunction showing increased fractional excretion of beta 2-microglobulin (FE beta 2-m) ranging from 9.7-49.1% with a mean of 30.7%, the levels of serum 1,25(OH)2D, which is produced in the proximal tubules, were within the normal range in 6 subjects. Significant correlations were found between 1,25(OH)2D and creatinine clearance (r = 0.802, P less than 0.05), and FE beta 2-m (r = -0.829, P less than 0.05), respectively. These results suggest that renal production of 1,25(OH)2D decreases with progression of cadmium-induced renal tubular dysfunction.

25-Hydroxyvitamin D 2↗

An ecological study on air pollution: changes in annual ring growth of the Japanese cedar and prevalence of respiratory symptoms in schoolchildren in Japanese rural districts.

The effect of air pollution caused by oil-fired electricity-generating stations on the annual ring growth of the Japanese cedar (Cryptomeria japonica, D. Don) and prevalence of respiratory symptoms in schoolchildren were investigated. By retrospective analysis the annual ring growth has been demonstrated to show good agreement with the general trend in air pollution. In addition it was found to be related to the prevalence of respiratory symptoms. The reduction in annual ring growth and increase in the prevalence of respiratory symptoms followed a deterioration in air pollution. Following upgrading of the power station and an improvement in air pollution, the annual ring growth and prevalence of respiratory symptoms showed opposite changes, respectively. Concerning the latter, the prevalence of wheezing and respiratory symptoms associated with school absence in schoolchildren with a positive skin test to house dust extract showed a closer correlation with the annual ring growth when compared with those who had never had a positive skin test.

Adolescent↗

[Evaluation of qualitative and quantitative tests for proteinuria and glucosuria as screening tests for cadmium-induced renal tubular dysfunction].

To evaluate the screening tests for cadmium-induced renal tubular dysfunction, qualitative and quantitative tests for urinary protein and glucose have been done in 146 urine samples obtained from subjects who had lived in the cadmium-polluted Jinzu River basin in Toyama Prefecture, Japan. The subjects consisted of 66 men and 80 women aged 55 to 71 years with beta 2-microglobulinuria exceeding 1,000 micrograms/g creatinine. The results obtained from this study were as follows; 1) The positive reaction (above 1+) for protein by the dipstick method was seen in 19.7% of men and 20.0% of women, and for glucose using Tes-tape in 48.5% of men and 33.8% of women. 2) The geometric means of protein and glucose concentrations in urine were 16.4 mg/dl and 12.7 mg/dl in men, and 14.2 mg/dl and 6.8 mg/dl in women, respectively. 3) The criteria of the primary screening in the health survey system for the residents in cadmium-contaminated areas conducted by the Japan Environment Agency were a proteinuria level exceeding 10 mg/dl and a glucosuria above (+/-) with Tes-tape. Nearly all subjects with urinary beta 2-microglobulin exceeding 30 mg/g creatinine were screened by these criteria in both sexes, whereas only 52.9% of men and 30.0% of women who had urinary beta 2-microglobulin between 10 to 30 mg/g creatinine could be screened in this manner. These results indicate that semiquantitative tests are insufficient as initial tests for screening cadmium-induced renal tubular dysfunction.

Cadmium Poisoning↗

Changes in lens proteins induced at the early stage of cataractogenesis in cac (Nakano) mice.

Changes in lens proteins induced at the early stages of cataractogenesis in cac (Nakano) mice were investigated by two-dimensional gel electrophoresis (2D-PAGE). The 2D-PAGE profile of lens proteins in 21-day-old cac mice differed from that in 27-day-old normal mice, even though the appearance of 'pin-head' nuclear opacity (26-day-old) had not yet been observed in the lenses. Especially noticeable were great differences in the polypeptides associated with the alpha- and beta- crystallin subfractions, the appearances of which corresponded to an increase in a ratio of the amounts of Na+ to that of K+ in the lenses of defective mice. No dramatic decrease in the gamma-crystallin fraction was observed until the mature cataract stage.

Animals↗

Urinary trehalase activity as an indicator of kidney injury due to environmental cadmium exposure.

One hundred and seventy-eight subjects, patients with Itai-itai disease and their family members, aged 12-87 years living in a cadmium (Cd)-polluted area in the Jinzu River basin (Cd-exposed group) and 176 controls (control group) were examined. In the Cd-exposed group urinary trehalase increased with increasing age, urinary beta 2-microglobulin (beta 2-m) and retinol-binding protein. Although urinary cadmium was higher in the Cd-exposed group, no particular correlation was found between urinary trehalase and urinary cadmium. Seventeen men and 11 women showed raised urinary trehalase activities despite normal values of urinary beta 2-m (less than 300 micrograms/g.creatinine), suggesting that urinary trehalase increases earlier than urinary beta 2-m. In 19 patients with Itai-itai disease included in the Cd-exposed group, urinary trehalase decreased with decreasing reciprocal of serum creatinine, suggesting that urinary trehalase decreases in the most advanced cases of chronic cadmium nephropathy due to reduced tubular cell mass.

Adolescent↗

Elevation of urinary trehalase activity in patients of itai-itai disease.

The elevation of urinary trehalase activity in patients of itai-itai disease was examined. Urinary trehalase was correlated with tubular reabsorption of phosphorus (%TRP): the lower the trehalase activity, the worse was %TRP. Furthermore, this activity was inversely correlated with urinary glucose and urinary total protein. In itai-itai disease, the excretion of beta 2-microglobulin seems to be maximal, and urinary trehalase activity was low in the latter stages of the disease. It is inferred that itai-itai disease produces extremely severe tubular damage as well as glomerular dysfunction.

Aged↗

Severity of tubular brush border damage in cadmium-polluted area (Jinzu river basin): clinical role of urinary trehalase.

Urinary trehalase activity and leucine aminopeptidase activity were parabolically correlated with urinary beta 2-microglobulin, and these enzymes were observed to be biphasic in relation to urinary beta 2-microglobulin when the study populations included patients of Itai-itai disease and inhabitants of a cadmium-polluted area. Furthermore, urinary trehalase activity was parabolically correlated with urinary total protein and urinary glucose. From these results, it is inferred that by measuring both urinary trehalase and urinary beta 2-microglobulin, one can elucidate the degree of tubular damage.

Aged↗

Comparison of the effects of the new anxiolytic suriclone and benzodiazepines on motor function and electroencephalogram.

(6-(7-Chloro-1,8-naphthyridin-2-yl)-7-oxo-2,3,6,7-tetrahydro-5H- 1,4- dithiino[2,3-c]pyrrol-5-yl)-4-methyl-1-piperazinecarboxylate (suriclone, RP 31264), a new anxiolytic, produced behavioral effects similar to those of diazepam and lorazepam, had a protective effect against electroshock convulsion and potentiated the sleeping effect of hexobarbital in mice. It inhibited crossed extensor reflexes in chicks and augmented the dorsal root reflex potential, the increase of which is considered to be an index of increased GABAergic presynaptic inhibition. Suriclone produced high-amplitude slow waves in the amygdala and cerebral cortex and desynchronization of theta waves in the hippocampus in rat electroencephalogram (EEG). These observations were quantitatively confirmed by power spectrum analysis of EEG. The mechanisms of action of suriclone on the CNS are discussed in relation to those of benzodiazepines.

Animals↗

The actions of ivermectin on cultured chick spinal cord neurons.

The effects of ivermectin (IVM) on cultured chick spinal neurons sensitive to GABA agonists were investigated. IVM caused a change of membrane potential which was associated with an increase in membrane conductance, apparently reversed at about -40 mV and weakened by repetitive application. Furthermore, this agent did not have any effects on either the actions of GABA agonists on neurons or [3H]GABA efflux from those cells. These results suggest that IVM increases membrane conductance through sites which are different from GABA recognition sites.

Animals↗