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Biomedical subjects

M Sakamoto

Publications and source records attributed to M Sakamoto.

At least 667 records · Page 37Linked to original sources
PubMed1987

Serum lysyl oxidase activity in patients with various liver diseases.

Serum lysyl oxidase activity was examined in patients with various liver diseases. The activity of the enzyme was detected mainly in the serum fraction of the supernatant 80% saturated with (NH4)2SO4, and its molecular weight was estimated to be about 30,000 by Sephadex G-150 column filtration. Mean serum lysyl oxidase activity in 18 healthy controls was 129 +/- 50 (+/- SEM) cpm/ml and was significantly increased in patients with acute hepatitis, chronic active hepatitis, alcoholic liver disease and primary biliary cirrhosis, but not in those with chronic inactive hepatitis or liver cirrhosis. Serum lysyl oxidase activity was not correlated with the histological grade of hepatic fibrosis, but appeared to reflect active hepatic fibrogenesis in patients with liver diseases.

Adult↗
PubMed1987

Dynamic characteristics of saccadic eye movements in the albino rat.

Using the magnetic search coil technique it was shown that the rat made saccadic eye movements spontaneously. Most saccades were horizontal. Although their amplitude was usually less than 10 degrees (deg.), the peak velocity could reach 400 deg/s. The peak velocity increased as a linear function of the amplitude at a rate comparable to that in the monkey and higher than in other species. Only a weak correlation between saccade and neck electromyogram (EMG) activity was observed.

Animals↗
PubMed1987

Promotion of hepatocarcinogenesis by suxibuzone in rats initiated with 3'-methyl-4-dimethylaminoazobenzene.

Among phenylbutazone (PZ) and its related compounds, suxibuzone (SUX) caused the most extensive decrease in pyruvate kinase (PK) activity with lower toxicity. Therefore, we studied the effect of SUX on rat hepatocarcinogenesis to confirm our assumption that an agent which causes a prolonged decrease in PK activity in rat liver promotes hepatocarcinogenesis. For initiation rats were fed a diet containing 0.06% 3'-methyl-4-dimethylaminoazobenzene (3'-Me-DAB) for 4 weeks. At the end of 53 weeks of the experiment the incidences of liver tumors were 14.3 and 70.0% in the rats fed basal diet and in the rats fed 0.5% SUX diet, respectively, after the initiation. No tumors were observed in rats fed the SUX diet without the initiation. The result shows that SUX promotes hepatocarcinogenesis and supports the above assumption.

Administration, Oral↗
PubMed1987

Affinity purification and characterization of serine hydroxymethyltransferases from rat liver.

A rapid and simple method was developed for the purification of serine hydroxymethyltransferases [EC 2.1.2.1]. The procedure involved ammonium sulfate precipitation, DEAE-cellulose column chromatography and affinity chromatography on an L-adsorbent. Through this procedure the cytosolic enzyme (s-SHMT) was purified 1,650-fold, and the mitochondrial enzyme (m-SHMT) 1,730-fold, with a yield of more than 30% in both cases. Both preparations gave a single band with a Mr of 54,000 on SDS-PAGE. The native enzymes both contained 4 mol of pyridoxal phosphate/mol of enzyme, and showed a Mr value of 220,000 on gel filtration, indicating a tetrameric structure. Several other properties of the enzymes were also studied.

Animals↗
PubMed1987

Secretory form of atrial natriuretic polypeptide as cardiac hormone in humans and rats.

To elucidate the secretory form of atrial natriuretic polypeptide from the atrium, the molecular form of atrial natriuretic polypeptide in the perfusate from the isolated beating rat heart and in plasma taken at the coronary sinus of 10 patients during cardiac catheterization has been investigated using high performance gel permeation chromatography and reverse phase high performance liquid chromatography coupled with radioimmunoassay for atrial natriuretic polypeptide. Atrial natriuretic polypeptide in the perfusate from the rat heart showed a single peak eluting at the position of a low molecular weight form of atrial natriuretic polypeptide, without any detectable amounts of atrial natriuretic polypeptide with high molecular weights. The major component of atrial natriuretic polypeptide in the rat heart perfusate co-migrated with rat alpha-atrial natriuretic polypeptide in reverse phase high performance liquid chromatography. In 9 out of 10 patients atrial natriuretic polypeptide in plasma taken at the coronary sinus revealed a single peak of atrial natriuretic polypeptide emerging at the position of human alpha-atrial natriuretic polypeptide in gel filtration. Only one plasma sample had a small quantity of high molecular weight forms with the predominant low molecular weight form of atrial natriuretic polypeptide. The major component of atrial natriuretic polypeptide in the plasma extract from the coronary sinus was identified with human alpha-atrial natriuretic polypeptide. These results indicate that alpha-ANP, a 28-amino acid polypeptide, is secreted as a cardiac hormone into the coronary blood stream from the atrium.

Animals↗
PubMed1987

Clinical use of CA 125 and its combination assay with other tumor marker in patients with ovarian carcinoma.

The serum levels of CA 125 and CA 19-9 were determined by an immunoradiometric assay employing the monoclonal antibody OC 125 and anti-CA 19-9 antibody in 88 patients with ovarian carcinoma. When a cut-off value of CA 125 was set below 35 U/ml in the control group, serum elevated levels of CA 125 were found in 86.7% of the patients with surgically demonstrable ovarian serous cystadenocarcinoma, in 100% (4/4 cases) of clear-cell carcinoma, in 50% (2/4 cases) of endometrioid carcinoma, in 100% (5/5 cases) of undifferentiated carcinoma, and in 80% of the recurrent cases. Using a cut-off value of 37 U/ml, serum elevated levels of CA 19-9 were detected in 68.2% of mucinous cystadenocarcinoma, in 28.9% of serous cystadenocarcinoma, in 75% (3/4 cases) of metastatic ovarian carcinoma, and in 37.5% of the recurrent cases. A statistical analysis of the combination assay using CA 125, CA 19-9, tissue polypeptide antigen (TPA), immunosuppressive acidic protein (IAP), ferritin and CEA was carried out by multivariate method (discriminatory analysis) in 45 patients with ovarian carcinoma and 50 healthy subjects. As a result before treatment, positive rates of a single tumor marker were 79.7% with CA 125, 42.7% with CA-19-9, 73.1% with IAP, 61.7% with TPA, 64.3% with ferritin and 25.4% with CEA, respectively. A combination assay of these markers was useful for detecting identification of ovarian carcinoma, by which it gave a higher accuracy of ovarian cancer detection.

Adenocarcinoma↗
PubMed1987

Use of indwelling double-curved ureteral stents and problems after stenting.

Indwelling double-curved ureteral stents were placed in 19 patients for 28 months. We used these stents to bypass ureteral obstruction and as adjunct surgery of upper urinary tract troubles. There were 5 cases with stent problems such as stone formation and spontaneous breakage. The duration of stenting with problems was longer than that without problems with statistical significance.

Adult↗
PubMed1987

Familial apoceruloplasmin deficiency associated with blepharospasm and retinal degeneration.

A 52-year-old woman had a newly recognized disorder of familial hypoceruloplasminemia, blepharospasm, retinal degeneration, and high-density areas in CT of the basal ganglia and liver scan. Immunofixation electrophoresis disclosed apoceruloplasmin deficiency. Kinetic, x-ray analysis, and histochemical study showed accumulation of iron in liver and brain, but not of copper. Intestinal copper absorption was reduced, but liver uptake was increased. Ceruloplasmin is involved in iron metabolism, and the findings suggest that hypoceruloplasminemia due to lack of apoceruloplasmin was causally linked to the iron deposition in basal ganglia and other organs, leading to blepharospasm and retinal degeneration.

Apoproteins↗
PubMed1987

Central actions of atrial natriuretic polypeptides in spontaneously hypertensive and normotensive rats.

The effects of intracerebroventricular (i.c.v.) administration of ANP on blood pressure and intakes of water and salt were examined, using conscious, unrestrained normotensive Wistar rats and spontaneously hypertensive rats (SHR). In normotensive rats, i.c.v. administration of alpha-rat ANP (alpha-rANP), alpha-human ANP (alpha-hANP), alpha-rANP (4-28) and alpha-rANP (5-28) at the dose of 1.5 nmol significantly attenuated water intake induced by i.c.v. injection of 0.1 nmol of angiotensin II (AII). Centrally administered alpha-hANP (5 micrograms) also attenuated AII-induced pressor response. Centrally injected alpha-hANP (1 microgram) produced a greater reduction of water intake after 24-hour water deprivation in SHR compared to control Wistar Kyoto rats (WKY). Central infusion of alpha-hANP for 1 week also reduced the salt appetite of SHR, as shown by two bottle preference test with 0.3 M NaCl solution and tap water, while it had no effect on drinking behavior of WKY. These results suggest the central antagonistic relationship of the ANP and renin-angiotensin systems and the possible involvement of brain ANP in the pathophysiology of genetically hypertensive rats.

Angiotensin II↗
PubMed1987

Ontogeny of atrial natriuretic polypeptide in the human heart.

To elucidate the developmental changes of atrial natriuretic polypeptide in the human heart, we studied alpha-human atrial natriuretic polypeptide (alpha-hANP)-like immunoreactivity (alpha-hANP-LI) in the extracts from the hearts of three foetuses of 10, 14 and 22 weeks' gestation, a 1-day-old premature infant of 33 weeks' gestation, and two adults, alpha-hANP-LI levels in the atria of the three foetuses of 10, 14 and 22 weeks' gestation and the premature infant (31.4, 12.2, 9.25 and 15.3 nmol/g, respectively) were comparable to those in two adult atria (16.9 and 13.6 nmol/g). The ventricles also contained alpha-hANP-LI (0.763----0.0818 nmol/g with descending values with increasing gestational age) in the three foetuses and the premature infant although it was undetectable (less than 0.0162 nmol/g) in two adult ventricles. The highest alpha-hANP-LI concentration was observed in the auricles in all the hearts except in the premature infant. The concentration in the right auricle was higher than in the left during foetal life, whereas that in the left was the higher one after birth. High performance gel permeation chromatography coupled with radioimmunoassay revealed that alpha-hANP-LI in the atria and apexes of the foetuses and the premature infant consisted of gamma-hANP, beta-hANP and alpha-hANP, with gamma-hANP being the predominant form. Essentially similar gel filtration patterns were observed in the two adult atria. These results indicate that: ANP appears in human heart tissue early in foetal life; cardiac ventricles also contain ANP in the foetus, and there is probably no difference in posttranslational processing of the precursor molecule in foetal and adult hearts.

Aged↗
PubMed1987

Atrial natriuretic polypeptide during exercise in healthy man.

The plasma concentration of atrial natriuretic polypeptide was measured in eight healthy men during two grades of exercise performed in the supine position on a bicycle ergometer. The plasma concentration of atrial natriuretic polypeptide slightly increased during the first exercise test with 20% of the maximal oxygen uptake and it approximately doubled during the second exercise with 40% of the maximal oxygen uptake (from 15.5 +/- 5.5 (mean +/- SD) pmol/l to 31.8 +/- 10.7 pmol/l). The increase in the plasma level of atrial natriuretic polypeptide in the second exercise was significantly greater than that in the first one. The plasma norepinephrine level and plasma renin activity showed significant increases during the second exercise test. Heart rate and systolic blood pressure also increased in response to the graded exercise. The increase in the plasma concentration of atrial natriuretic polypeptide during exercise was significantly correlated with the increase in heart rate, systolic blood pressure, and the plasma norepinephrine concentration (r = 0.75, r = 0.71 and r = 0.51, respectively). These results indicate that the plasma concentration of atrial natriuretic polypeptide increases in response to the intensity of a workload, and suggest that exercise is a useful test to evaluate the releasing function of atrial natriuretic polypeptide in the heart.

Adult↗
PubMed1987

[The analysis of prognostic factors on postsurgical pyuria of benign prostatic hypertrophy].

The outcome of postsurgical pyuria in benign prostatic hypertrophy was studied in 87 patients, and the factors that might affect the outcome were determined. No significant differences were found between operation method and duration until normalization of pyuria, which was 75.5 +/- 46.0 days for transurethral resection of the prostate, 72.7 +/- 30.6 days for suprapubic prostatectomy and 69.3 +/- 32.7 days for retropubic prostatectomy. Prognostic factors were statistically analyzed preoperatively, at operation, and postoperatively. The definite prognostic factors were preoperative diabetes mellitus, preoperative pyuria, preoperative bacteriuria, and postoperative hypoproteinemia. The probable prognostic factors were old-age, preoperative indwelling catheters, heavy prostate tissue, postoperative bacteriuria, postoperative anemia and postoperative complications.

Aged↗
PubMed1987

Atrial natriuretic polypeptide in brain--implication of central cardiovascular control.

Biologically active peptides isolated in the peripheral organs often distribute in the central nervous system and vice versa. Accumulating evidence supports the concept that the effects of centrally active peptides are often, although not always, complementary to their peripheral actions. Atrial natriuretic polypeptide (ANP) is one of these biologically active peptides. Evidence presented here indicates that ANP is involved in the cardiovascular control as a neuropeptide in the central nervous system as well as a circulating hormone in the periphery.

Animals↗