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Biomedical subjects

N Yoshida

Publications and source records attributed to N Yoshida.

At least 631 records · Page 35Linked to original sources
PubMed1979

Effect of actinomycin D on the expression of herpes simplex virus-common surface antigen in cells transformed by herpes simplex virus type 2.

Using rabbit antiserum hyperimmune to herpes simplex virus (HSV) type 1, the expression of HSV-common surface antigen(s) was studied by indirect immunofluorescence tests in cells transformed by HSV type 2 and in derived tumor cells. The following results were obtained. (i) Antiserum to HSV type 1 reacted specifically with surface antigen present on the plasma membrane of both HSV type 2-infected and HSV type 2-transformed hamster cells. (ii) The expression of this antigen was enhanced in the absence of active protein synthesis in transformed cells, but not in tumor cells, after culture for 3 to 5 h at 37 degrees C. (iii) This enhancement of expression was maintained for 20 h in the presence of actinomycin D, but this prolonged expression required active protein synthesis. (iv) The enhancing effect observed in the presence of actinomycin D continued for some time after removal of the drug, for example, for 20 h after 5 h of treatment with 2 microgram/ml of actinomycin D per ml. Actinomycin D had no detectable effect on antigen expression in tumor cells. (v) The protease inhibitor antipain inhibited the actinomycin D-enhanced expression without causing significant cell damage but did not modify the transient enhanced expression of antigen when cells were seeded in the absence of actinomycin D. These results indicate that in transformed cells antigen expression can be enhanced in at least two ways.

Antigens, Surface↗
PubMed1979

Measurement of plasma renin concentration using exogenous human renin substrate in normal subjects: correlation with plasma renin concentration and plasma aldosterone concentration.

Measurement of plasma renin concentration (PRC) was done in normal subjects at rest and under acute stimulation of renin release under unrestricted sodium intake. Concurrent measurements of plasma renin activity (PRA) and plasma aldosterone concentration (PA) were carried out. The mean values of PRC at rest and after stimulation of renin release were 12.8 +/- 1.3 (SEM) and 21.7 +/- 4.4 (SEM) ng AT I/ml/h, respectively. These corresponded to renin contents of 3.4 +/- 0.34 (SEM) X 10(-5) Goldblatt units and 5.8 +/- 0.36 (SEM) respectively. The mean percent increase of PRC (82.1 +/- 19.3 (SEM)) %) was almost indentical to that of PA (81.5 +/- 16.4 (SEM) %), but differed from that of PRA (269 +/- 83.1 (SEM) %). A very high correlation between concurrent PRC and PA (r = 0.92, P less than 0.001) was found in normal subjects at rest and under acute stimulation of renin release. A good correlation between PRC and PRA (r = 0.85, P less than 0.001) was also observed. However, a higher correlation between percent increases of PRC and PA (r = 0.92, P less than 0.001) than that of PRA and PA (r = 0.80, 0.01 less than P less than 0.005) was found. Results show that PRA is a good index of the renin content in plasma in normal subjects at rest and PRC reflects actual renin concentration in plasma at rest as well as under stimulation of renin release.

Adult↗
PubMed1979

Response of urinary noradrenaline excretion to reserpine administration in normal and hypertensive subjects.

Reserpine was administered in purpose to determine the "Noradrenaline store" in sympathetic nerve endings. The marked increase of urinary noradrenaline excretion was observed by reserpine 0.4 mg/day administration. Total amount of noradrenaline in urine for first three days of 0.4 mg/day of reserpine administration was considered as a good indicators of "Noradrenaline store". There was no difference of "Noradrenaline store" between normal and hypertensive subjects. The increase % of urinary noradrenaline was higher in labile hypertension than in established hypertension as well as in normal subjects. Though the relationship between "Noradrenaline store" or the increase % of noradrenaline and sympathetic nerve activity was not clear, it is suspected that the releasable noradrenaline in sympathetic nerve granule was higher in labile hypertension than in established hypertension or normal subjects.

Adult↗
PubMed1979

Cyclic adenosine 3',5'-monophosphate levels in response to norepinephrine in rectum of postnatal rats.

Age-related changes in cyclic adenosine 3',5'-monophosphate levels in response to norepinephrine (NE) in the rectum of postnatal rats and the localization of cyclic AMP in the rectum were studied. During the first 2 weeks after birth, the basal levels of cyclic AMP were high, NE responses to cyclic AMP contents were minimal and thereafter, the basal cyclic AMP levels rapidly declined, while NE response significantly increased compared to those seen in tissues from adult rats. Furthermore, cyclic AMP immunofluorescence was visualized in smooth muscle and postganglionic neurons of the myenteric plexus. NE application produced an increase of cyclic AMP immunofluorescence in smooth muscle. These results indicate that NE response to cyclic AMP levels in rat rectum is age-dependent and suggest that the majority of beta-adrenoceptors associated with cyclic AMP generating system are localized in the smooth muscle of rat rectum.

Adrenergic beta-Antagonists↗
PubMed1979

Adrenergic innervation and cyclic adenosine 3':5'-monophosphate levels in response to norepinephrine in stomach of postnatal rats.

Changes in receptor function, innervation and cyclic adenosine 3':5'-monophosphate (cAMP) levels in response to norepinephrine were investigated in the stomach of postnatal developing rats. We found that although the beta adrenergic receptor function and responsiveness of cAMP-generating system to norepinephrine are present in the early postnatal stage (3-day-old), these systems are not fully developed at birth and that increase in sensitivity comes with age. Adrenergic innervation is present at birth in Auerbach's plexus but not in smooth muscle, during the 1st postnatal week. Direct adrenergic innervation to smooth muscle appears 1 week after birth and matures during the first 4 weeks. This maturation of direct adrenergic innervation runs in parallel with the increased sensitivity of beta receptors and is accompanied by an elevated responsiveness of the cAMP-generating system to norepinephrine.

Acetylcholine↗
PubMed1979

Transplantable argyrophilic gastric carcinoid of Mastomys natalensis secreting both histamine and serotonin.

A transplantable strain of gastric carcinoids of Mastomys (Praomys) natalensis secreted not only histamine but also serotonin [5-hydroxytryptamine (5-HT)]. Mastomys bearing growing transplants excreted 11.3 times more histamine and 4.4 times more 5-hydroxyindole-3-acetic acid (5-HIAA) in the urine than did Mastomys in which transplanted tumors did not grow. Mastomys that developed primary gastric carcinoids also excreted 3.9 times more histamine than did those free from primary tumors, but the difference in urinary excretion of 5-HIAA was not significant in both groups. All transplantable carcinoids contained definite amounts of both histamine and serotonin, whereas the primary gastric carcinoids contained only histamine. We also confirmed that the histamine and 5-HIAA excreted in urine increased as the size of transplanted tumors enlarged. 5-HT was histochemically demonstrated in a small number of carcinoid cells of the transplanted tumors but not in primary carcinoids.

Animals↗
PubMed1978

Distribution of cold-insoluble globulin in plasma and tissues.

Cold-insoluble globulin is normally present in plasma and serum at concentrations of 27.52 +/- 4.60 and 23.46 +/- 5.18 mg/dl, respectively (means +/- SD). The concentration of CIg in blood samples was significantly decreased in DIC syndromes (14.69 +/- 6.55 mg/dl; p less than 0.001). A strong, positive correlation was found with AT-III (r = 0.68) and a less striking one with Plg. Although alpha 2-PI was shown to be significantly decreased in DIC syndromes (p less than 0.001), a weak, inverse correlation was found between CIg and alpha 2-PI (r = -0.29). Immunologically cross-reactive substances were found to be widely distributed in association with the cells and tissues of mesenchymal origin, including fibroblasts, adipose cells, smooth muscle cells, and basement membranes. The glomerular basement membrane was an exception and is currently believed to be of different origin. In the kidney, fluorescence was found in the mesangium. Cold-insoluble globulin is also present as a component of cryofibrinogen that forms a solid gel at low temperatures. Sodium dodecyl sulfate polyacrylamide gel electrophoresis revealed that CIg in this fraction was rather homogeneous. Although closely migrating doublets were occasionally seen in the 440,000-dalton region on gels of unreduced samples, monomeric derivatives with a molecular weight of 220,000 or less, which have been claimed to occur in circulating plasma, were not observed. Thus, intact dimeric CIg appears to be the form of the molecule that complexes with fibrinogen. Cold-insoluble globulin is the fraction that was shown to exist as an independent entity from fibrinogen at an ambient temperature by immunoelectrophoresis and ultracentrifugation. However, very rapid formation of highly polymerized complexes in the sol phase at low temperatures was manifested by the finding of a sharp increase in light-scattering intensity using the technique of quasielastic light scattering. A control study on a mixture of normal CIg and fibrinogen disclosed no appreciable change in the temperature range between 37 and 8.5 degrees C. A comparative study on a mixture of cryofibrinogen-derived CIg and normal fibrinogen revealed an intermediate light-scattering pattern. After 2 hr at 8 degrees C, this mixture reached a state of equilibrium, where no further polymerization occurred. The secondary structures of normal and cryofibrinogen-derived CIg, determined by circular dichroism, showed no appreciable difference. A noteworthy finding was the almost complete absence of alpha-helices and a relatively high proportion of beta-structure in both forms of CIg. Amino termini of the fibrinogen moiety of cryofibrinogen were found to consist of alanine, tyrosine, and a small quantity of aspartic acid, consistent with the NH2 terminal moiety composition of normal fibrinogen but not of soluble fibrin monomer complex.

Amino Acids↗
PubMed1978

Ureotelism and ammonotelism in trypanosomatids.

According to their genera, trypanosomatids excrete urea, ammonia, or both. Species of Herpetomonas and Trypanosoma are ammonotelic. Species of Leishmania, Leptomonas, Crithidia, and Blastocrithidia can be ureotelic, ammonotelic, or both, depending on growth media composition.

Ammonia↗