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Biomedical subjects

H Sanada

Publications and source records attributed to H Sanada.

At least 127 records · Page 7Linked to original sources
PubMed1978

Changes in collagen cross-linking and lysyl oxidase by estrogen.

Dermal collagen solubility and lysyl oxidase activity of bones were measured in DDD mice of advancing age. Insoluble fractions of the dermal collagen increased more rapidly in females than in males after 5 weeks of age. Activity of the lysyl oxidase extracted from bones was higher in females than in males after 4 weeks of age. After sexual maturation, such sex differences were always observed in skin as well as in bone tissue. In other experimental animals, dermal collagen solubility was markedly decreased by estrogen treatment and lysyl oxidase was remarkably activated by estrogen in both skin and bone. Thus it is clear that estrogen stimulates the enzyme activity and accelerates the maturation of collagen and elastin in extracellular space.

Aging↗
PubMed1978

Effect of nicotinic acid on catecholamine synthesis in rat brain.

Effect of nicotinic acid on the formation of catecholamine has been studied. Norepinephrine and dopamine concentrations in brain were 30 per cent higher and brain catecholamine formation was 50 per cent higher in the nicotinic acid-supplemented rats than the nicotinic acid-deficient rats. However, these catecholamine levels of the nicotinic acid-deficient rats were recovered by the administration of nicotinic acid. The concentration of brain tyrosine was unaltered after administration of nicotinic acid to the nicotinic acid-deficient rats. Therefore, the changes catecholamine formation by the nicotinic acid supplementation were not due to the difference of tyrosine concentration in the brain which is the precursor for catecholamine biosynthesis. As the difference of catecholamine concentration between the nicotinic acid deficient and the nicotinic acid supplemented group was smaller than that of catecholamine formation of these groups, the turnover of catecholamine was supposed to be decreased in nicotinic acid deficiency.

Animals↗
PubMed1977

Vitamin B12 levels of cerebrospinal fluid in patients with a variety of neurological disorders.

The vitamin B12 levels of cerebrospinal fluid were assayed microbiologically (Lactobacillus leichmannii method) using samples from 44 patients with various neurological disorders, 4 patients with megaloblastic anemia and 34 controls. Twenty-seven controls that did not receive vitamin B12 showed a mean cerebrospinal fluid vitamin B12 level of 21.5 pg/ml (range: 0-60). No decrease in cerebrospinal fluid vitamin B12 level was seen in patients with subacute myelo-optico-neuropathy (SMON). High levels of cerebrospinal fluid vitamin B12 were observed only in the patients receiving long term administration of the vitamin. Intrathecal administration of vitamin B12 caused only a slight increase in serum vitamin B12 level after four hours. The existence of blood brain barrier for vitamin B12 was suggested.

Anemia, Megaloblastic↗
PubMed1977

Anemia in the elderly patients with special reference to folic acid status.

To investigate the role of folic acid deficiency in the pathogenesis of anemia in the elderly, hematological examinationa and assays of serum iron, vitamin B12 and folate were carried out on the 86 elderly patients admitted to a home for the aged. Means of red blood cell counts, hemoglobin levels and hematocrit were 385.3 x 10(4)/mm3, 12g/dl and 36%, respectively. These levels were lower than any other report in Japan. Anemia was detected in 23 out of 86 patients. Judging from mean corposcular volume and mean corposcular hemoglobin, most of them were normocytic and normochromic. Although low serum levels of iron and folate were rather frequently observed, the results on hematological examinations suggest that deficiency of these factors alone is not the cause of the anemia in the elderly patients. Rapid clearance of 5-methyl-tetrahydrofolic acid and increased excretion of formiminoglutamic acid after histidine loading were revealed in some of those who had subnormal serum folate levels. Therefore, supplementation of folic acid is recommended to those who had poor dietary intake.

Aged↗
PubMed1976

Role of ascorbic acid on tyrosine hydroxylase activity in the adrenal gland of guinea pig.

The decrease of tyrosine hydroxylase activity in adrenal homogenate in scurvy was recovered after the administration of ascorbic acid. The causes of the increase in the enzyme activity after the administration of ascorbic acid have been studied. 1. No significant elevation in the enzyme activity was observed after the administration of reserpine to the scortutic guinea pig. 2. A dose of metal chelating agent, alpha, alpha'-dipyridyl, prevented the ascorbic acid-induced or reserpine-induced increase in enzyme activity in the scorbutic and the non-scorbutic guinea pigs, respectively. 3. Tyrosine hydroxylase activity was partially recovered by the administration of FeSO4 to the scorbutic guinea pig. From these results, it became clear that the induction of tyrosine hydroxylase which was not observed in scurvy was due to the deficiency of Fe2+. These results suggested that ascorbic acid affected the induction of this enzyme via Fe2+.

2,2'-Dipyridyl↗
PubMed1976

Effect of catechol-thiol conjugates on tyrosinase-dependent tyrosine hydroxylation.

1. The tyrosinase reaction in the presence of a thiol compound was studied using mushroom tyrosinase (EC 1.10.3.1) with regard to catechol-thiol conjugates. 2. Although tyrosine hydroxylation of tyrosinase was extremely decreased in the presence of a thiol compound, the inhibitory effect was removed by the addition of a pyrocatechol-cysteine conjugate, S-(2,3-dihydroxyphenyl) cysteine, which was not oxidized by the enzyme. 3. The pyrocatechol-cysteine conjugate was also able to shorten the lag period of tyrosinase-dependent tyrosine hydroxylation. 4. The sigmoidal reaction curve of tyrosine hydroxylation observed in the presence of sulfhydryl compounds was found to be caused by the catechol-thiol conjugates, the final products of the enzyme reaction, which counteract the inhibitory effect of sulfhydryl compounds. 5. The pyrocatechol-cysteine conjugate, on the other hand, was shown to cause the decrease of the reaction rate of the enzyme during incubation.

Basidiomycota↗
PubMed1976

A case of smoldering acute leukemia: long survival duration of 3 years and 9 months after the diagnosis.

A typical case of smoldering acute leukemia has been followed up for long-standing course. This 73 year-old woman survived 3 years and 9 months after diagnosis of acute myelogenous leukemia. The hematological study on admission showed hypoplastic bone marrow with 51.6% of abnormal myeloblasts, although a few myeloblasts were seen in the peripheral blood. Intensive anti-leukemia chemotherapy was withheld during the whole course except on the terminal acute phase. Three episodes of pneumonia occurred and then, the proliferation of leukemic cells subsided concomitnantly after the exacerbation of infection. The direct and/or host-mediated anti-tumor effect by infectious organism was suggestive in this case. The labeling index with 3H-TdR of leukemic cells was 4.9%, suggesting the slow multiplication. Positive tuberculin reactivity and normal ratio of lymphocyte blastogenesis confirmed the preserved cellular immunity. These factors might be considered to be closely related with the smoldering course of this particular case.

Aged↗
PubMed1975

Regulation of tyrosine hydroxylase activity by prostaglandin E1 in guinea pig adrenal gland.

The action of prostaglandin E1 on tyrosine hydroxylase activity in adrenal slices of guinea pig was studied. The activity of tyrosine hydroxylase and was decreased by the incubation of adrenal slices with prostaglandin E1 at concentrations beyond 2 mug per ml for 2 hours. The activity of tyrosine hydroxylase was stimulated by dibutyryl adenosine 3',5'-monophosphate in slices of guinea pig adrenal glands. Incubation of adrenal slices wtth the combination of PGE1 and DBc-AMP lead to a tyrosine hydroxylase activity higher than that with PGE1 alone, but not as great as DBc-AMP alone. It was suggested that PGE1 inhibited the enzyme activity independently of the cyclic AMP level. Other prostaglandins such as PGA1 and PGB1 were deficient to the extent that the tyrosine hydroxylase activity was decreased. PGE1 inhibited the enzyme activity much to the same extent seen with protein synthesis inhibitors such as cycloheximide and actinomycin D. However, PGE1 did not influence the incorporation of L-leucine-14C into acid insoluble protein. The studies reported here showed that PGE1 inhibited the synthesis of tyrosine hydroxylase.

Adrenal Glands↗