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Biomedical subjects

T Oishi

Publications and source records attributed to T Oishi.

At least 163 records · Page 9Linked to original sources
PubMed1983

Variations in the photoperiodic cloacal response of Japanese quail: association with testes weight and feather color.

The size of the cloacal gland was found to be a reliable indicator of testicular activity of Japanese quail. Six experiments were performed to examine the effects of alternating long and short photoperiod on the size of the cloacal gland of male Japanese quail. Three types of photoperiodic cloacal responses were distinguished. Type I birds became refractory to short photoperiods after they had experienced 5 weeks or more of short days. They maintained large cloacal glands under subsequent condition of alternating long and short photoperiod. Type II birds were intermediate types I and III birds did not become refractory to short photoperiods after experiencing 5 weeks or more of short days. The cloacal glands responded to conditions of alternating long and short photoperiods with increases or decreases in size. Feather color on the throat was found to correspond to the type of cloacal response. Type I birds had brick-red throat feathers. Type II birds had white feathers intermingled with brick-red feathers. Type III had white throat feathers. The percentages of types I, II, and III observed in the experimental population was 67, 18, and 15%, respectively. Type III birds were used to study the effects of blinding on the cloacal response to short photoperiod. Five out of eight blinded type III birds did not lose the responsiveness to short photoperiod. These results are consistent with the view that extraocular photoreceptors participate in the photoperiodic gonadal response of Japanese quail.

Aging↗
PubMed1983

Genetic relationship among several pig populations in East Asia analysed by blood groups and serum protein polymorphisms.

The gene frequencies were calculated to investigate genetic variation apparent in blood group and serum protein systems in Asian native pigs. The results revealed that gene frequencies were generally similar in the nine pig populations, except in some systems. Differences of gene frequencies were recognized in HpY and Cpc detected on Taoyuan pigs of Taiwan and Ohmini pigs of Japan, respectively. TfC and AmC alleles were found in eight pig populations except Ohmini pigs. The overall genetic distances were calculated by gene frequencies of 13 loci and it was observed that Taoyuan pigs are closer to Ohmini pigs than to Short-ear pigs of Taiwan and other East Asian native pigs. However, the genetic distances between Asian native pigs and European or American breeds were larger than those among East Asian native pig populations.

Animals↗
PubMed1982

Effect of tyrosine on brain catecholamine turnover in reserpine-treated rats.

The injection of reserpine [2.5 mg/kg, intraperitoneally (i.p.)] increased brain concentration of tyrosine and of the major catecholamine metabolites, 3-methoxy-4-hydroxy-phenylethylene--glycol-sulfate (MHPG-SO4) in the rat. In reserpine-treated animals, tyrosine administration (200 mg/kg, i.p.) caused further increases in brain tyrosine, DOPAC, and HVA, but not in brain MHPG-SO4. The increases in DOPAC and HVA levels were observed in a dopaminergic brain region (the corpus striatum) and a noradrenergic region (the cerebellum). These results support previous observations that catecholamine synthesis and release in both dopaminergic and noradrenergic neurons can depend in part upon brain tyrosine levels.

Animals↗
PubMed1980

Genetic polymorphism of erythrocyte esterase-D in pigs.

The erythrocyte esterase-D (Es-D) of four European-American pig breeds, two Taiwan native pigs (Taoyuan and Short ear breeds), Philippine native pig and wild boar populations (Sus scrofa riukiuanus) in Japan was investigated by using starch gel electrophoresis. Analysis of parentage records of the pigs revealed that the phenotypic variation of erythrocyte esterase-D was controlled by two codominant alleles Es-DA and Es-DB. The allele Es-DB was mostly found in three European-American pig breeds, Landrace (0.100), Hampshire (0.135) and Duroc (0.102). All of the wild boar populations were monomorphic for allele Es-DA.

Alleles↗
PubMed1980

Relative potency in acute and chronic suppressive effects of prednisolone and betamethasone on the hypothalamic-pituitary-adrenal axis in man.

The relative potency in the hypothalamic-pituitary-adrenal (HPA) suppression of both prednisolone and betamethasone was examined in an acute study with normal volunteers and in a chronic study with glucocorticoid-treated patients. Circadian rhythm of plasma cortisol was studied after a single dose administration of 5 to 30 mg prednisolone or 0.5 to 3.0 mg betamethasone at 8:00 hr. Morning-rise of plasma cortisol occurred on the morning after the administration of 30 mg or less prednisolone but no morning rise was noted after the administration of 1.0 mg or more betamethasone. Plasma ACTH was slightly elevated on the morning after 30 mg prednisolone administration but showed low levels throughout the night after 3.0 mg betamethasone administration. Plasma cortisol responsiveness to ACTH was examined in patients before and during therapy with either prednisolone or betamethasone. The basal cortisol level was not suppressed and the responsiveness to ACTH remained nearly normal during long-term 5 mg prednisolone therapy, but these were completely suppressed during long-term 5 mg betamethasone therapy. The responsiveness to ACTH was nearly normal in patients receiving alternate-day therapy with prednisolone in such large doses as 50 or 60 mg every other day, but was completely suppressed in patients receiving 1.0 mg betamethasone every other day. The relative potency of betamethasone in acute and chronic suppressive effects on the HPA system seems to be much stronger than that of prednisolone in equivalent doses with comparable anti-inflammatory effects. It is also suggested that the alternate-day therapy with such long-acting steroids as betamethasone are useless in preventing HPA suppression.

Adrenocorticotropic Hormone↗
PubMed1979

Development and genetic differences of complement activity in rabbits.

The ontogeny of haemolytic complement in rabbit serum and the genetic differences of the activity in five strains of adult rabbits were investigated by single radial haemolysis in gel and a microtiter method with purified complement components and the appropriate haemolytic intermediate cells. The haemolytic complement activity was found as early as the 15th day of foetal life, and increased with age reaching approximately adult level by the 120th day of life. Marked strain differences in both total haemolytic activity and C3 levels of adult rabbit sera were observed. The repeatability of haemolytic activity for an individual serum taken at different times was higher than that for C3 level was observed. An inherited complement deficiency, due to the lack of C6, was found in a strain of Angora rabbits. The genetic studies confirmed that this complement defect was transmitted as an autosomal recessive trait.

Aging↗