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Biomedical subjects

K Asakawa

Publications and source records attributed to K Asakawa.

64 records · Page 4Linked to original sources
PubMed1983

Short-term study of biosynthesized hGH in man.

Daily injection of 8IU of methionyl human growth hormone (met-hGH), produced by recombinant DNA technology, was performed in healthy young volunteers. Daily injections for four days did not cause any significant change in the results of physical examination, electrocardiogram, blood count or urinalysis. Non-esterified fatty acid levels increased significantly at 4 hours after the first injection of met-hGH in a manner similar to pituitary human growth hormone (pit-hGH). Both hGHs caused a significant increase in serum somatomedin A during the four daily injections. Plasma hGH reached peak levels at 3-4 hours after im injection of met-hGH and 4-6 hours after pit-hGH. The levels were 19.5 +/- 1.6 and 21.3 +/- 2.8 ng/ml, respectively. After iv one bolus administration of 4IU hGH to two volunteers, plasma hGH reached peak levels at 5 minutes at mean levels of 292 ng/ml after met-hGH and 293 ng/ml after pit-hGH. The half life of the two hGHs was 17.2 and 17.1 minutes, respectively, according to the disappearance curve measured after iv administration.

Adult↗
PubMed1983

Insulin stimulation of somatomedin A production in monolayer cultures of rat hepatocytes.

The effect of insulin on the generation of somatomedin by a monolayer culture of rat hepatocytes was investigated. Release of somatomedin into the medium of cultured hepatocytes was observed for at least three days, as determined by a radioreceptor assay for somatomedin A. The addition of 1-100 micrograms/ml insulin to the medium caused dose-related increases in somatomedin A in the conditioned medium for up to three days. The conditioned medium also stimulated DNA synthesis in human fibroblasts. To investigate hormone degradation by hepatocytes, labelled somatomedin A or insulin was added to the medium and the degradation was examined by trichloroacetic acid (TCA) precipitation, and gel chromatography. Although [125I]somatomedin A was slightly degraded even after 24 h of incubation, [125I]insulin was degraded within 6 h and the TCA precipitation at 24 h was 15% only. This degradation of hormones was inhibited by 1 mM bacitracin. Insulin stimulation of somatomedin production was significantly increased to 131.2% as compared with cultures without bacitracin. The molecular size of the somatomedin released into the medium was greater than that of purified somatomedin, suggesting that this somatomedin is bound to carrier proteins.

Animals↗
PubMed1982

Effect of GH and insulin on the generation of somatomedin by perfused rat liver.

The release of somatomedin from perfused livers of normal and hypophysectomized (hypox) rats has been studied. Somatomedin was determined by the radioreceptor assay for somatomedin A. The release of somatomedin in the perfusates of normal livers was observed during the initial 30 minutes and maintained during the second and third 30 minutes of recirculation. The addition of insulin at a concentration of 10 mU/ml to the perfusates caused a significant increase in the release of somatomedin in the 1st, 2nd and 3rd 30-minutes recirculatory perfusates. The addition of human growth hormone (25 micrograms/ml) and/or insulin (1 mU/ml) to the perfusates caused a significant increase in somatomedin after 120 minutes of recirculation. Hypox rats released amounts of somatomedin in perfusates similar to those of normal rats. The effect of insulin on the release of somatomedin was greater in hypox rats than that observed in normal rats. The molecular size of the somatomedin released in the perfusate was greater than that of purified somatomedin, suggesting that this somatomedin is bound to carrier proteins.

Animals↗
PubMed1982

Effects of glucocorticoid on body growth and serum levels of somatomedin A in the rat.

Serum levels of somatomedin A, as measured by radioreceptor assay, and body weight gain were 86.5 +/- 9.2% and 166.9 +/- 7.8% (N = 5) of the initial values, respectively, after 18 days administration of 2.5 mg cortisone acetate (CA). These values were significantly lower than those for saline treated rats (P less than 0.005). Reduced serum somatomedin A and body growth rate were partially restored after halting the injection of CA. Combined administration of daily doses of 100 micrograms hGH with CA did not prevent the decrease in somatomedin activity in treated rats. This observation suggests that GH plays a minor (or no) role in the fall of serum somatomedin A in CA-treated rats. From these data we conclude that glucocorticoids reduce serum somatomedin by inhibiting the effect of GH on the generation of somatomedin.

Animals↗
PubMed1981

Effect of food and GH on the binding of 125I-somatomedin A to the membranes of rat lung and kidney.

Studies were undertaken to examine the relationship between serum levels of somatomedin A and its binding sites in the lung and kidney of rats. After three days of fasting, serum levels of somatomedin A decreased, accompanied by increases of 17.5% and 21.4% in binding to the plasma membranes from lung and kidney, respectively. After two days of refeeding, this binding decreased with the increase in the serum level of somatomedin A. There was observed a negative correlation between the serum level of somatomedin A and the percentage of labelled somatomedin A bound to the membranes. These observations suggest that somatomedin down-regulates its own receptor under these conditions. A similar regulatory mechanism was not observed with either hypophysectomized- or GH-treated rats.

Animals↗
PubMedDate not supplied

Effects of insulin-like growth factor-1 on Short bowel syndrome without ileocecal valve in rats.

Insulin-like growth factor-1 (IGF-1) can promote enterocyte proliferation which may be beneficial to postoperative conditions after massive small bowel resection (SBR) including the ileocecal valve (ICV). Wistar rats were subjected to SBR including or preserving ICV and continuously received IGF-1 or saline alone. Nutritional status, enterocyte proliferation, liver damage and hepatic IGF-1 mRNA levels were analyzed. Body weights, serum levels of total protein and transferrin, and enterocyte proliferation were significantly lower after SBR including ICV than preserving it. IGF-1 mRNA levels in the liver were decreased after SBR, especially after SBR including ICV. However, IGF-1 therapy significantly attenuated those decreased levels after SBR including ICV. Furthermore, IGF-1 significantly decreased serum liver transaminase levels which were increased after SBR including ICV. Continuous administration of IGF-1 may be available as a supplemented therapy for short bowel syndrome without ICV.

Animals↗
PubMedDate not supplied

Comparison of urine cytology between the ileal conduit and Indiana pouch.

OBJECTIVE: To compare the cytomorphologic features of urine obtained from two different kinds of urinary diversions constructed after total bladder resection. STUDY DESIGN: The smears of urine from 11 ileal conduits and 6 Indiana pouches were evaluated. All patients underwent total bladder resection due to transitional cell carcinoma (TCC) or other kinds of cancer before urine diversion. RESULTS: The cytologic features of Indiana pouch urine include degenerated, small, round cells without columnar cells derived from intestinal epithelium. In ileal conduit urine, well-preserved columnar cells and degenerated, small, round cells were frequently observed. The columnar cells in ileal conduit urine exhibited cytologic features that should be distinguished from TCC cells. CONCLUSION: The method of reconstructing the urinary tract is important in urine cytology from urine diversions because the cytomorphologic features of urine are different between the two kinds of urinary diversions. Since columnar cells in ileal conduit urine might lead to misdiagnosis as TCC, special consideration is required to examine ileal conduit urine.

History, 16th Century↗