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Biomedical subjects

T Yamano

Publications and source records attributed to T Yamano.

At least 109 records · Page 6Linked to original sources
PubMed1993

Serological study of Japanese encephalitis in Nepal.

Antibodies against Japanese encephalitis virus (JEV) were examined in 356 serum samples from individuals visiting Tribhuvan University Teaching Hospital using neutralization test. A total of 13.2% (47/356) seropositivity was observed. Antibody positivity against both Nakayama-NIH and Beijing-1 strains was seen in 7.9% subjects. Infection by Nakayama-NIH strain alone was seen to be 4.2% while 1.1% of study populations were found to be infected only by Beijing-1 strain. High antibody titer was observed in the 20-40 years age-group and did not increase with age. Seropositivity was more common in zone-A (Tarai) area compared to zone-B (Hills) and zone-C (Mountains). Spectrum of antigenicity of JEV in zone-A as shown by neutralization test was identical to Indian isolates (strains). Difference in seropositivity was observed against Nakayama-NIH and Beijing-1 strain in zone-B and C indicating recent spread of JEV in these areas.

Adolescent↗
PubMed1993

[Studies on urinary apolipoprotein H in diabetics].

In order to elucidate the diagnostic significance of urinary apolipoprotein H (apo H), known as beta 2-glycoprotein I, urinary apo H levels were measured by a non-competitive enzyme immunoassay in diabetics without hypertension and Albustix-positive proteinuria. The relationships between urinary apo H levels and urinary albumin (Alb) levels as well as clinical profiles in diabetics were investigated. The mean urinary apo H level in 45 diabetics was 264.2 +/- 189.5 micrograms/g.cr, and significantly higher than that in 41 healthy subjects (120.6 +/- 84.8 micrograms/g.cr, p < 0.01). Diabetics were classified into three groups based on urinary Alb levels; 17 group I patients with normoalbuminuria (U-Alb < 15mg/g.cr), 12 group II patients, whose urinary Alb levels were in between normo- and microalbuminuria (15 < or = U-Alb < 30mg/g.cr) and 16 group III patients with microalbuminuria (30 < U-Alb < or = 300mg/g.cr). The mean urinary apo H level in group I patients, who were regarded as without nephropathy, was 199.2 +/- 109.0 micrograms/g.cr, significantly higher than that in normal subjects (p < 0.01). The mean urinary apo H levels in group II and III were 271.4 +/- 177.1 and 327.8 +/- 246.1 micrograms/g.cr, respectively. These values were also higher than in normal subjects (both of p < 0.01). Urinary apo H levels correlated positively with urinary levels of glycosaminoglycan (r = 0.382, n = 45, p < 0.01), which was regarded as an indicator of the anion loss from glomerular basement membrane to urine, and with urinary N-acetyl-beta-D-glucosaminidase activities (r = 0.378, n = 37, p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

Hepatotoxicity of trichlorfon and dichlorvos in isolated rat hepatocytes.

Hepatotoxicity of organophosphorus insecticides, trichlorofon and dichlorvos, a dechlorinated form of the former, was examined in isolated hepatocytes from untreated control and phenobarbital-pretreated (80 mg/kg, i.p., for 3 days) rats. These compounds produced toxic effects on hepatocytes as evidenced by malondialdehyde production and lactate dehydrogenase leakage in a dose-dependent manner up to the concentration of 2 mM, dichlorvos being more toxic than trichlorfon. Hepatocytes from phenobarbital-pretreated rats were more sensitive to these organophosphates than those from control rats. Dichloroacetaldehyde and dichloroacetic acid, metabolites of dichlorvos, did not injure hepatocytes. The toxic effects of dichlorvos on hepatocytes were enhanced by increasing oxygen concentration during the incubation, or by addition of glycolytic substrates (pyruvate, lactate or fructose) to the incubation mixtures. On the other hand, addition of antioxidants (diethyldithiocarbamate or N,N'-diphenyl-p-phenylenediamine), or cytochrome P-450 inhibitors (SKF-525A or metyrapone) to the incubation mixtures attenuated malondialdehyde production caused by dichlorvos and protected cells from death. Addition of dichlorvos to the incubation mixtures of hepatic microsomes stimulated lipid peroxidation in the presence of NADPH, which was inhibited by further addition of superoxide dismutase but not catalase. These results suggest that hepatotoxicity of trichlorfon and dichlorvos are related to their peroxidative property in microsomes which is accelerated by oxygen.

Animals↗
PubMed1992

Comparative teratogenicity of di-n-butyltin diacetate with n-butyltin trichloride in rats.

Teratological tests were conducted on di-n-butyltin diacetate (DBTA), and n-butyltin trichloride (MBTC). Pregnant Wistar rats were treated orally with DBTA at doses of 0, 1.7, 5.0, 10.0, and 15.0 mg/kg/day or with MBTC at doses of 0, 50, 100, 200, and 400 mg/kg/day during days 7-17 of gestation. Cesarean sections were performed on day 20 of gestation. Thymic atrophy of the pregnant rats was observed in a dose-dependent manner by DBTA treatment. The incidence of dead or resorbed fetuses and total resorption fetuses increased at the highest dose of DBTA. The incidence of fetuses with external malformations, such as cleft mandible, cleft lower lip, ankyloglossia (tongue-tie) and schistoglossia (cleft tongue), increased in a dose-dependent manner by DBTA treatment. The incidence of fetuses with skeletal malformations such as anomaly of mandibular fixation, fused ribs, fused cervical vertebral arches and fused thoracic vertebral arches also increased at 10.0 and 15.0 mg/kg. However, MBTC, one of the main metabolites of di-n-butyltin, failed to show any evidence of tetatogenic activity at any doses tested. The results indicate that DBTA has potent teratogenic effects on rat fetuses, and DBTA is different from MBTC with respect to teratogenic effects.

Animals↗
PubMed1992

Role of gastric glutathione in smoke flavouring-induced gastric injury in rats.

Some commercial liquid smoke flavourings have been shown to induce acute gastric mucosal injury in rats when given orally as a large single dose. The present study was carried out to examine the mechanism of action in rats of two selected smoke flavourings containing about 10% total acids as acetic acid. These flavourings and 10% acetic acid decreased the concentration of glutathione (GSH) in the glandular stomach. The decrease in gastric GSH was coupled with smoke flavouring-induced gastric injury. Pretreatment with N-ethylmaleimide, a GSH depletor, enhanced acetic acid-induced gastric injury. Pretreatment with cysteine, a sulphhydryl compound, protected rats against smoke flavouring-induced gastric injury. Aqueous fractions of the smoke flavourings, after removal of non-polar compounds and acidic organic compounds (including acetic acid) by diethyl ether extraction, decreased the gastric GSH concentration considerably and had a marked reactivity in vitro with GSH, but these fractions by themselves showed no ability to induce gastric injury. Addition of 10% acetic acid to these aqueous fractions caused greater gastric injury than 10% acetic acid alone, which suggests that these aqueous fractions contain the (unidentified) compound(s) that facilitate acetic acid-induced gastric injury. These findings indicate that gastric endogenous and exogenous sulphhydryls play an important part in gastric cytoprotection.

Acetates↗
PubMed1992

Cervical cord birth injury and subsequent development of syringomyelia: a case report.

A 2830 g full-term baby, born by breech delivery, exhibited weak crying and sucking and severe hypotonia of the extremities after birth. Magnetic resonance imaging (MRI) showed marked thinning of the cervical cord at the level of C4 and C5. This lesion evolved into focal syringomyelia by the fourth month after birth. In this patient, MRI was useful in detecting the initial spinal cord injury, which appeared as marked thinning, and the subsequent syringomyelia as well. The role of birth trauma in cervical spinal cord injuries is discussed.

Birth Injuries↗
PubMed1992

[Urinary N-acetyl-beta-D-glucosaminidase and gamma-glutamyl-transpeptidase activities for evaluation of renal disturbance in patients with multiple myeloma].

The activities of N-acetyl-beta-D-glucosaminidase (NAG), gamma-glutamyl-transpeptidase (gamma-GTP) and NAG isoenzyme were measured in the urine of 20 patients with multiple myeloma (IgG/IgA type/Bense Jones type; 15/1/4 cases) and 25 healthy controls to evaluate these activities as indicators of renal disturbance in multiple myeloma. NAG isoenzyme fractions in urine were measured by agarose electrophoresis-m-cresol sulfonphthaleinyl-NAG reaction. Mean urinary NAG activity in the patients with myeloma was significantly higher than that in the controls (20.1 +/- 3.3 vs 4.3 +/- 0.3U/g. cr; p < 0.001). Urinary NAG activity in these patients correlated positively with the dose (mg/g. cr) of urinary protein (r = 0.755; p < 0.01), most of which were considered to be light chain protein, but not with creatinine clearance. Each urinary NAG isoenzyme fraction (NAG-1, -2, -3) was higher in the patients than that in the controls, and especially NAG-2 fraction (A form) showed a highly positive correlation with the dose of urinary protein. Urinary gamma-GTP activity in the patients did not differ from that in the controls, but urinary NAG/gamma-GTP ratio was higher in the patients, and reversely correlated with creatinine clearance (r = -0.721; p < 0.01). It is suggested that the elevation of urinary NAG activity results from the damage of lysosome in proximal tubular cells by urinary light chain protein and its degradation products. Therefore, urinary NAG activity may be a good index for proximal tubular disturbance, and NAG/gamma-GTP ratio may be an index for the extensive damage of nephrons in addition to the damage of tubular cells in multiple myeloma.

Acetylglucosaminidase↗
PubMed1991

Immunochemical relationship of D-amino acid oxidases in various tissues and animals.

1. By means of an enzyme immunoassay, the contents of D-amino acid oxidase (DAO) were determined in kidney, liver, cerebellum and lung of hog, but the oxidase was not detectable in heart or cerebrum. 2. The oxidases in kidney, liver and cerebellum of hog were indistinguishable as regards immunoreactivity toward anti-hog kidney DAO antibody, specific activity and molecular weight. 3. The oxidases in rat and dog kidneys immunochemically cross-reacted with anti-hog DAO antibody. 4. The overall structure of the hog oxidase was more similar to that of the dog enzyme than that of the rat, while the structure around the catalytic site of the hog oxidase was more similar to that of the rat oxidase than that of the dog enzyme. 5. On immunoblot analysis, two forms of the oxidase were detected in extracts of hog, rat and dog kidneys.

Animals↗
PubMed1991

Teratogenicity study of tri-n-butyltin acetate in rats by oral administration.

A teratological test was carried out on tri-n-butyltin acetate (TBTA) used as a biocide and anti-fouling agent. Pregnant Wistar rats were treated orally with TBTA at dose levels of 0, 1, 2, 4, 8, and 16 mg/kg from days 7-17 of gestation. Cesarean sections were performed on day 20 of gestation. In pregnant rats, salivation and depression of body weight gain and food intake were observed at a late stage of pregnancy at the highest dose level of TBTA. Atrophy of the thymus was also observed in a dose-dependent manner on day 20 of gestation. In the fetuses, treatment with the highest dose level increased embryonic and fetal deaths, increased the incidence of fetuses with cleft palate, cervical rib and/or rudimentary lumbar rib, and decreased the body weights of fetuses.

Abnormalities, Drug-Induced↗
PubMed1991

Effects of triphenyltin acetate on pregnancy in rats by oral administration.

A teratological test was carried out on triphenyltin acetate (TPTA) used as a fungicide and antifouling agent. Pregnant Wistar rats were treated orally with TPTA at dose levels of 0, 1.5, 3.0, 6.0, 9.0 and 12.0 mg/kg/d during days 7-17 of gestation. Cesarean sections were performed on day 20 of gestation. In the pregnant rats, 2 of 13 and 2 of 12 dams died at 9.0 and 12.0 mg/kg, respectively. Vaginal bleeding, bloody mouth and nose, somnolence and depression of body weight gain and food intake were observed at 9.0 and 12.0 mg/kg at late stages of pregnancy. No statistically significant reductions in maternal thymus and spleen weights were observed on day 20 of gestation. Increase in embryonic and fetal deaths and in dams with total resorption of fetuses were observed at doses of more than 6.0 mg/kg. The doses of TPTA in this experiment, however, induced no teratogenic effects in rats.

Abnormalities, Drug-Induced↗
PubMed1991

Formation of an ipsilateral corticospinal tract after ablation of cerebral cortex in neonatal rat.

The formation of an aberrant ipsilateral corticospinal tract after unilateral cerebral cortical ablation during the neonatal period has been confirmed in the rat. The tract was chronologically studied using the antegrade horseradish peroxidase (HRP) tracing method. An aberrant ipsilateral tract is not observed 3 days after the operation. However, ipsilateral HRP positive fibers become apparent on day 7 and progressively more prominent until day 14. These results suggest that the ipsilateral corticospinal tract is composed of collateral axons originating from pyramidal neurons in the healthy ipsilateral cerebral cortex. These results also indicate that, when cerebral cortex has the damage during early postnatal life, the remaining cortical neurons which have been freed from the damage show considerable plasticity in terms of the collateral axons.

Animals↗
PubMed1991

Congenital hydrocephalus in suckling hamsters caused by transplacental infection with parainfluenza virus type 3.

The possible occurrence of congenital hydrocephalus by viral infection of the mother was examined by inoculating pregnant hamsters intravenously with parainfluenza virus type 3 (PIV-3). We could produce congenital hydrocephalus in littermates born to a mother which had been inoculated into the left cervical vein on the 14th day of pregnancy. This result may indicate that the virus could pass through the placenta to arrive at the fetus, and infect the central nervous system.

Animals↗
PubMed1991

Seroepidemiological study of herpes viruses in Nepal.

The antibody positive rates among Nepalese, in a community, to herpes simplex virus (HSV), varicella-zoster virus (VZV) and cytomegalovirus (CMV) were studied. Immune adherence hemagglutination test (for VZV) and complement fixation test (for HSV and CMV) were used to measure the antibodies. An 80% positive rate of anti-HSV antibodies was found in early childhood (1-4 years) that further increased with age (96.1% positive in greater than 15 years age). Only 25% of children 1-4 years old showed antibodies to VZV but the number of positives increased rapidly with age (82.9% in greater than 15 years age). Antibody against CMV was positive in all the subjects studied.

Adolescent↗