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Biomedical subjects

S Hosoda

Publications and source records attributed to S Hosoda.

At least 19 recordsLinked to original sources
PubMed1992

[Aplastic anemia successfully treated with erythropoietin and rhG-CSF].

A 32 year-old female admitted to our hospital with pancytopenia. The hematological data on admission were: RBC: 247 x 10(4)/microliters, Hb: 8.8 g/dl, Plts: 13,000/microliters, WBC: 2,500/microliters. Bone marrow aspirate and biopsied specimen showed marked hypocellularity without infiltration of abnormal cells. A diagnosis of aplastic anemia was made. Neither high-dose methyl-prednisolone pulse therapy nor anti-lymphocyte globulin were effective. With combination of oxymetholone (30 mg/day), recombinant erythropoietin (rHuEpo; 12,000 U/day, three times a week) and recombinant granulocyte-colony simulating factor (rHuG-CSF; 33 micrograms/day) for 3 months, remarkable improvements of hematological data were obtained. Her hemoglobin level reached 11.4 g/dl, and platelets count 49,000/microliters. However, 4 weeks after the withdrawal of erythropoietin and G-CSF administrations, her platelet count fell to 12,000/microliters. It was suggested that combination therapy with erythropoietin and G-CSF were effective for aplastic anemia.

Adult↗
PubMed1979

Effects on induction of tyrosine aminotransferase in fetal mouse liver in vitro of prednisolone, insulin and thyroxine.

The hormonal requirements for formation of tyrosine aminotransferase (EC 2.6.1.5) in fetal mouse liver were investigated in organ culture using chemically defined medium. The hormones tested were insulin, thyroxine and prednisolone. Prednisolone alone resulted in a two-fold increase in tyrosine amino-transferase activity in explanted liver in hormone-free medium on day 6, and its effect was dose dependent, but neither insulin nor thyroxine alone induced the enzyme. Addition of prednisolone plus thyroxine and prednisolone plus insulin increased the enzyme activity 1.4- and 1.3-fold, respectively, over that of explants with prednisolone alone. These three hormones together had the greatest effect, causing induction of 1.5-fold more activity than that with prednisolone plus insulin or plus thyroxine. The three hormones were not all needed continuously during the culture period: prednisolone and insulin were required during the early part of cultivation and thyroxine during the later part. The effects of these hormones were blocked by actinomycin D or puromycin, suggesting that these hormones increase de novo synthesis of tyrosine aminotransferase. Phase-contrast microscopy showed that prednisolone stimulated liver epithelial cell outgrowth, probably acting with insulin.

Animals↗
PubMed1979

Precocious differentiation of chick embryo pancreas in vitro. Roles of prednisolone, insulin and L-thyroxine.

The hormonal requirement for functional differentiation of chick embryo pancreas were investigated by using organ cultures in chemically defined medium. The hormones tested were prednisolone, insulin and thyroxine, and the parameters examined were alpha-amylase (EC 3.2.1.1) and chymotrypsinogen (EC 3.4.4.5) activities, and the ultrastructure of the tissues. Addition of prednisolone alone to explants from 14-day-old chicken embryo pancreas for 3 days increased the activities of amylase and chymotrypsinogen in the tissues by 3.4- and 6.6-fold, respectively, those of tissues before cultivation. Neither thyroxine or insulin alone, nor both hormones together affected pancreatic exocrine differentiation. Thyroxine enhanced the effect of prednisolone on both enzymes, but insulin did not. When the explants were cultured in the medium containing all three hormones, maximum enzyme activities were observed; amylase or chymotrypsinogen activity being 7- or 18-fold, respectively, that of tissues before cultivation. But these three hormones were not simultaneously necessary. Morphological differentiation was also observed in explants cultuvated in medium containing these three hormones. These results suggest that glucocorticoids are essential for normal differentiation of chick pancreas during the late fetal period, possibly with insulin and thyroxine, and also support the idea that pancreatic enzymes are controlled separately.

Amylases↗
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

Effects of hormones on differentiation of parotid glands of suckling mice in vitro.

The hormonal requirements for functional differentiation of mouse parotid glands were investigated using organ cultures in chemically defined medium. The hormones tested were insulin, thyroxine and prednisolone, and the parameters examined were alpha-amylase activity and the ultrastructure of the tissue. It is found that most of the amylase in the cultures (80%) was released into the culture medium after 5 days of cultivation. Prednisolone (5 . 10(-3) mg/ml) alone resulted in a 3--4-fold increase in specific activity of amylase (total amylase activity in the medium and culture) over that in its absence, but neither insulin nor thyroxine alone induced the enzyme. Prednisolone plus thyroxine (over 1 . 10(-7) mg/ml) or insulin (over 1 . 10(-3) unit/ml) induced markedly the enzyme, amylase specific activity being as much as 4- or 6-fold that with prednisolone alone. Moreover the enzyme specific activity was dependent on the prednisolone concentration (5 . 10(-7) - 5 . 10(-3) mg/ml) in the presence of thyroxine (1 . 10(-2) mg/ml) or insulin (1 . 10(-2) unit/ml). Morphological differentiation was also observed in explants cultivated in medium containing prednisolone plus thyroxine or insulin. These results suggest that besides glucocorticoids, insulin and thyroxine are involved in increase in amylase activity in mouse parotid glands during the late suckling period.

Amylases↗
PubMed1978

Precocious induction of pepsinogen in the stomach of suckling mice by hormones.

Effects of hormones on pepsinogen activity in mouse stomach were investigated by enzyme assay and electron microscopy. Administration of hydrocortisone alone to mice on days 5--10 increased the enzyme activity in the stomach to as much as 4.5-fold that of untreated mice and the increase was dose dependent. Thyroxine also evoked precocious differentiation of the stomach. The effects of thyroxine and hydrocortisone were additive. Injections of insulin had little effect when given alone, or in combination with other hormones. Injection of hydrocortisone alone or plus thyroxine also caused morphological differentiation of the chief cells in the stomach mucosa. Administration of thyroxine to mice on days 15--20 induced as much enzyme activity as that induced by hydrocortisone, but neither of these hormones had any effect when injected after day 23. These results suggest that besides hydrocortisone, thyroxine is also involved in differentiation of the stomach in mice for the first 20 days after birth and that the normal increase of pepsinogen activity in the stomach of mice during the late suckling period is brought about by serum glucocorticoids, possibly with thyroxine.

Age Factors↗
PubMed1978

Changes in cyclic nucleotides of rat thyroid by chronic administration of LATS and TSH.

The effects of LATS and TSH on the cyclic nucleotide content and enzymatic activity in rat thyroid was observed during the continuous administration of LATS or TSH for 6 days. Serum T4 and T3 levels were increased significantly compared with the saline controls. The cyclic nucleotide (cAMP and cGMP) levels and enzyme activities per wet weight of tissue were determined. The thyroid weight in both the LATS and TSH groups increased approximately two-fold, but cAMP and cGMP content per wet weight did not significantly change. Neither cyclic nucleotide showed any significant change in plasma. The cAMP-PDE activity in the thyroid significantly increased in both the LATS and TSH groups, but the cGMP-PDE activity was unchanged. Neither was cyclic nucleotide-PDE activity changed in the plasma. The ATPase activity in the thyroid increased markedly in both the LATS and TSH groups, while 5'-nucleotidase activity did not change. These data suggest that LATS and TSH appear to have a stimulatory effect on the metabolism of cAMP, but do not affect the metabolism of cGMP.

Adenosine Triphosphatases↗