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Biomedical subjects

T Suda

Publications and source records attributed to T Suda.

At least 973 records · Page 54Linked to original sources
PubMed1978

beta-Endorphin is not detectable in plasma from normal human subjects.

beta-Endorphin is not detectable in plasma from normal human subjects when measured under baseline conditions or after the subjects have received vasopressin, an agent that elevates beta-lipotropin and adrenocorticotropic hormone (ACTH). Significant amounts of beta-endorphin are present in plasma of patients with endocrine disorders associated with increased ACTH and beta-lipotropin production. Highly purified, natural beta-lipotropin is not peripherally converted to beta-endorphin in vivo in normal subjects.

Addison Disease↗
PubMed1978

Prognostic aspects of aplastic anemia in pregnancy. Experience on six cases and review of the literature.

Our resent experience on six cases of aplastic anemia complicated with pregnancy is described. In addition, 43 similar cases were collected from the literature and reviewed to analyze some prognostic aspects of this relatively rare but potentially serious complication. Clinical and hematological data were treated to extract some clinically meaningful factors in relation to the success and failure of pregnancy. Among initial hematological parameters, no significant difference was found between successful and unsuccessful cases with an exception of hemoglobin concentration. The patients diagnosed as aplastic anemia prior to conception demonstrated an better outcome of pregnancy as well as survival rate of mother when compared with those diagnosed during pregnancy. Mortality has apparently improved after the late 1950's. Success rate of pregnancy before 1958 was 21%, while it was 67% and 71% in the era of 1959-1969 and after 1970, respectively. However, hemorrhage and infection remained to be two major causes of maternal death in both eras. Based on these observations, the currently recommendable attitude to this complication is discussed.

Adult↗
PubMed1978

Comparative studies on the 25-hydroxylations of cholecalciferol and 1 alpha-hydroxycholecalfierol in perfused rat liver.

The 25-hydroxylations of [(3)H]cholecalciferol and 1alpha-hydroxy[(3)H]cholecalciferol in perfused rat liver were compared. Results showed that about twice as much 1alpha(OH)D(3) (1alpha-hydroxycholecalciferol) was incorporated into the liver as cholecalciferol. 25-Hydroxy[(3)H]cholecalciferol and 1alpha-25-dihydroxy[(3)H]cholecalciferol were not incorporated significantly. Livers isolated from vitamin D-deficient rats formed the 25-hydroxy derivatives of cholecalciferol and 1alpha(OH)D(3) respectively linearly with time for at least 120min. The rate of 1alpha,25(OH)(2)D(3) (1alpha,25-dihydroxycholecalciferol) production increased exactly 10-fold on successive 10-fold increases in the dose of 1alpha(OH)D(3), suggesting that hepatic 25-hydroxylation of 1alpha(OH)D(3) is not under metabolic control. On the other hand, the rate of conversion of cholecalciferol into 25(OH)D(3) (25-hydroxycholecalciferol) did not increase linearly with increase in the amount of cholecalciferol in the perfusate. The 25-hydroxylation of cholecalciferol seemed to proceed at a similar rate to that of 1alpha(OH)D(3) at doses of less than 1nmol, but with doses of more than 2.5nmol, the conversion of cholecalciferol into 25(OH)D(3) became much less efficient, though the linear relation between the amounts of substrate and product was maintained. A reciprocal plot of data on the 25-hydroxylation of cholecalciferol gave two K(m) values of about 5.6nm and 1.0mum, whereas that for the 25-hydroxylation of 1alpha(OH)D(3) gave a single K(m) value of about 2.0mum. These results suggest that there are two modes of 25-hydroxylation of cholecalciferol in the liver, which seem to be closely related to the mechanism of control of 25(OH)D(3) production by the liver.

Animals↗
PubMed1978

An estimation of the parathyroid hormone secretion rate in vitamin D deficient rats.

In an attempt to define the rate of endogenous secretion of parathyroid hormone in vitamin D deficiency, graded amounts of hormone were infused constantly into vitamin D deficient and vitamin D fed acutely thyroparathyroidectomized rats in a perfusion balance study. The dose of hormone needed to compensate for acute thyroparathyroidectomy was estimated. Serum levels of calcium and phosphorus, renal clearances of phosphorus and urinary excretion of cyclic AMP, each determined 16 hr after the surgery, were employed as parameters of the hormone effect. It was concluded that, in the condition of the perfusion balance study, the secretion rate of parathyroid hormone was 5.1-8.6 USP u/hr in the vitamin D deficient animals compared with 0.81-0.84 USP u/hr in the control.

Animals↗
PubMed1978

beta-Lipotropin is the major opioid-like peptide of human pituitary and rat pars distalis: lack of significant beta-endorphin.

beta-Lipotropin is the predominant opioid peptide of the human pituitary and rat pars distalis and is present in concentrations essentially equimolar with corticotropin. When freshly, obtained nonfrozen rat anterior pituitaries were homogenized with 0.2 M HCl, approximately 98% of the immunoreactivity detected utilizing an antiserum that crossreacts equally with beta-lipotropin and beta-endorphin coeluted with 125I-labeled human beta-lipotropin upon molecular sieve chromatography. The remainder of the activity eluted with synthetic human beta-endorphin. Similar results were obtained for human pituitary. HCl homogenization of thawed tissue or homogenization of fresh tissue with acetic acid yielded substantially greater concentrations of beta-endorphin and decreased concentrations of beta-lipotropin. In human subjects, acute anterior pituitary stimulation using either insulin-induced hypoglycemia or vasopressin administration was associated with increased plasma beta-lipotropin and corticotropin levels. At the time of peak concentrations, no significant levels of beta-endorphin were detectable. These data indicate the lack of significant amounts of beta-endorphin in human pituitary. Additionally, there appears to be no specific intrapituitary conversion of beta-lipotropin to beta-endorphin.

Adrenocorticotropic Hormone↗
PubMed1978

Erythroblast kinetics in pernicious anaemia, erythroleukaemia and sideroblastic anaemia.

DNA synthesis time (Ts) and 3H-thymidine labelling index (TLI) of erythroblasts have been determined in 25 patients with various types of haematologic disorders using in vitro double labelling method. No remarkable differences in both Ts and TLI were noted between haematologically normal subjects and patients with increased effective erythropoiesis (haemolytic anaemias), suggesting that the cell cycle time is not principally altered under the augmented erythropoiesis. In pernicious anaemia, Ts of basophilic erythroblasts was significantly shortened and TLI was elevated above normal. Normalization of erythropoiesis by vitamin B12 was associated with a transient increase of TLI in polychromatic erythroblasts, which was interpreted to reflect prevention of intramedullary premature death of basophilic megaloblasts. Erythroleukaemia showed a markedly prolonged Ts and lowered TLI indicating the presence of cells with prolonged cell cycle time. These findings contrasted to that of pernicious anaemia despite certain morphological as well as functional similarities. In idiopathic sideroblastic anaemia, prolongation of Ts was observed to a similar extent as erythroleukaemia, while TLI remained almost normal. In 2 cases with suspected erythroleukaemia presenting an intermediate clinical picture between erythroleukaemia and sideroblastic anaemia, Ts of basophilic erythroblasts was found to be prolonged along with modestly lowered TLI.

Anemia, Pernicious↗
PubMed1978

Developmental changes in the enzymatic capacity for reduction and oxidation of alpha-ketoadipate in rat liver, heart, kidney, and brain.

alpha-Ketoadipate, an intermediate common to lysine and tryptophan metabolism, is a substrate for both alpha-ketoadipate reductase (alpha-KAR) and alpha-ketoadipate dehydrogenase (alpha-KADH). A comparison was made of the activities of these two enzymes in liver, heart, kidney, and brain of rats during the period from 5 days before birth to 56 days after birth. In general, both enzymes increased in activity during development in all tissues tested; however, different patterns of increase were observed (Figs. 1 and 2). The ratio of alpha-KADH to alpha-KAR (on the basis of activity/g tissue) did not change significantly in liver until day 10 and then increased 6.6-fold (from 0.08 to 0.53) in the period from day 10 to day 28. For other tissues the ratios increased 5.5-fold in hearts (from 0.2 to 1.1), 12-fold in kidney (from 0.2 to 2.4), and 5.3-fold in brain (from 0.3 to 1.6) during the period from day -5 to day 56. These results suggest that alpha-KAR has a major role in the metabolism of lysine and tryptophan during development.

Adipates↗