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Biomedical subjects

Y Nakazawa

Publications and source records attributed to Y Nakazawa.

At least 163 records · Page 9Linked to original sources
PubMed1988

[A case of primary carcinoid tumor of the testis].

A case of a primary carcinoid tumor of the testis which occurred in a 57-year-old man is reported. The patient was treated by orchiectomy, and no clinical features of a carcinoid syndrome had been noted. The tumor measured 4.0 X 3.2 X 2.0 cm in size and was yellowish in color. Histochemically, the tumor cells were composed in part of argentaffin and in part of argyrophil. Immunohistochemically, the argentaffin tumor cells were positive for neuron-specific-enolase. No tumor cells were positive, however, for neurofilaments, vimentin, keratin, desmin, GFAP, S-100 protein, ACTH, and somatostatin. Electronmicroscopy revealed numerous neurosecretory granules. Tumorous tissue presented a histomorphology of a pure carcinoid tumor composed of parts of argentaffin and argyrophil.

Carcinoid Tumor↗
PubMed1988

Motility of the sphincter of Oddi and pancreatic main ductal pressure in patients with alcoholic, gallstone-associated, and idiopathic chronic pancreatitis.

We endoscopically measured pressures of the pancreatic duct (PP) and the sphincter of Oddi (SO) in patients with alcoholic (ALCP, n = 10), gallstone-associated (GSCP, n = 7), and idiopathic chronic pancreatitis (ICP, n = 21), and in 20 controls. The PP was significantly higher in the patients with ALCP (55.7 +/- 28.9 mm Hg), GSCP (33.6 +/- 16.2 mm Hg), or ICP (44.5 +/- 25.8 mm Hg) than in the controls (16.2 +/- 8.7 mm Hg), but there was no significant difference between ALCP, GSCP, and ICP. There was no significant difference between control subjects and ICP in the motility of SO. In ICP, there was no correlation between the PP and the motility of SO. In ALCP and GSCP, the frequencies of the papillary sphincter waves were significantly higher than in normal subjects, and there were correlations between the PP and the motility of SO. These data suggest that increased pancreatic ductal pressure in GSCP with papillitis or ALCP may be due in part to papillary dysfunction, but not in ICP.

Alcoholism↗
PubMed1987

Role of acetaldehyde in ethanol-induced increase in the activity of phosphatidate phosphatase in rat liver.

The effect of ethanol on the activity of phosphatidate phosphatase was studied in rat liver using membrane-bound phosphatidate and phosphatidate emulsion as substrate. A single large dose of ethanol (5 g/kg body wt) caused an increase in the enzyme activity measured with membrane-bound phosphatidate after an approximate 2-hr lag period in both cytosolic and microsomal fraction and the increase was approximately 2.2- and 1.8-fold that in control rats at 5 hr in cytosol and microsomes, respectively. A similar time-course of the increase was obtained with phosphatidate emulsion as substrate. These ethanol-induced increases in the activity of cytosolic and microsomal phosphatidate phosphatase were blocked by the pretreatment of rats with actinomycin D. The ethanol-induced rise in the activity of cytosolic and microsomal phosphatidate phosphatase measured with membrane-bound phosphatidate was abolished when rats were injected with pyrazole prior to ethanol administration. On the other hand, pretreatment with cyanamide enhanced the increase in cytosolic activity produced by a suboptimal dose of ethanol (1 g/kg), while microsomal activity was not affected by the same treatment, suggesting that acetaldehyde may be selectively involved in the ethanol-induced increase in the activity of cytosolic phosphatidate phosphatase. This hypothesis was supported by a finding that administration of paraldehyde, a cyclic trimer of acetaldehyde, produced an increase (35%) in cytosolic activity, but not in microsomal activity.

Acetaldehyde↗
PubMed1987

The effect of carbon tetrachloride on the enzymatic hydrolysis of cellular triacylglycerol in adult rat hepatocytes in primary monolayer culture.

The effect of carbon tetrachloride on the intracellular hydrolysis of triacylglycerol and on the activity of acid triacylglycerol lipase was investigated with primary cultured rat hepatocytes. It was found that the concentration of the precursors in the medium did not affect the time course of the synthesis, secretion and the hydrolysis of triacylglycerol, and that carbon tetrachloride significantly suppressed the hydrolysis of intracellular triacylglycerol and the activity of acid triacylglycerol lipase with a concomitant accumulation of triacylglycerol. The results indicate a possibility that the triacylglycerol accumulation in the cultured rat hepatocytes caused by carbon tetrachloride might be mediated by the suppression of lysosomal acid triacylglycerol lipase activity in addition to the suppression of the secretion of triacylglycerol.

Animals↗
PubMed1987

Cerebral atrophy and slow wave sleep of abstinent chronic alcoholics.

Although a considerable decrease of slow wave sleep (SWS) has been observed in abstinent chronic alcoholics, the under-lying mechanism is still obscure. In the present study CT scans and polysomnographic recording were repeatedly conducted in nine chronic alcoholics. SWS was remarkably reduced in all the patients, but it was slightly restored in six patients on the 6th month after abstinence. On the other hand, enlargement was observed in the cortical sulci, cerebral fissures and ventricles in these patients. The enlargement of the cortical sulci was improved in five patients, and four of the patients showed increase of SWS. Although enlargement of the cerebral fissures and ventricles was improved in a few patients, in most of the patients who showed improvement in the cortical sulci SWS was increased. The results indicate that the decrease in SWS in abstinent alcoholics may have resulted from the atrophy of the cerebral cortex.

Adult↗
PubMed1987

Effects of medroxyprogesterone acetate on sleep of healthy young male adults.

The effects of a single 100 mg dose of medroxyprogesterone acetate (MPA) on human sleep were investigated using healthy young male adults. After a baseline night recording, two consecutive MPA nights and the following two withdrawal nights were recorded. The total sleep time was reduced after the 2nd MPA night and the decrease was significant on the 1st withdrawal night. The time of intrasleep awakening increased after the 2nd MPA night. Stage 1 sleep increased significantly on the 2nd MPA and 1st withdrawal nights. Stage 4 sleep decreased and the sleep latency gradually increased after the MPA administration. REM sleep reduced slightly on the 1st withdrawal night. These results indicate that MPA has a mild arousal action on human sleep and that the action may be pronounced a few days after administration of MPA.

Adult↗
PubMed1987

[Right ventricular function in patients with chronic obstructive pulmonary disease measured by krypton-81m].

Right ventricular function was assessed at rest and during exercise in patients with chronic obstructive pulmonary disease (COPD). Right ventricular ejection fraction (RVEF) was measured by first-pass radionuclide angiography using ultrashort-lived radionuclide krypton-81m. The half-life of this nuclide is only 13 sec, and it is completely expired from the lungs. These properties allow measurement of RVEF without correcting for background activity. In 30 patients with cardiac or pulmonary disease, RVEF was first measured by krypton-81 m scintigraphy (Kr-RVEF), then by technetium-99m (Tc-RVEF), without changing the patients' positions. In eight of the 30 cases, right ventricular cineangiography (RVG) was performed within 72 hrs after the radionuclide study, and RVEF was measured according to the Chapman's rule (RVG-RVEF). Kr-RVEF correlated significantly with Tc-RVEF (r = 0.87), and also with RVG-RVEF (r = 0.80). In 10 patients with stable COPD, who had severe hypoxemia (PaO2 less than or equal to 60 mmHg) and pulmonary hypertension [mean pulmonary arterial pressure (mean PAP) greater than or equal to 20 mmHg], and in seven normal control subjects, radionuclide angiographic and hemodynamic monitoring were performed at rest and during supine ergometer exercise. Kr-RVEF at rest was 47.6 +/- 5.4% (mean +/- SD) in patients with COPD and was 54.1 +/- 4.8% in normal subjects. Kr-RVEF during exercise was 51.8 +/- 7.3% in the patients, and 62.3 +/- 3.2% in the normal subjects. Hemodynamically, mean PAP and pulmonary vascular resistance (PVR) increased significantly during exercise, but the RV end-diastolic volume index (RVEDVI) did not change. There was inverse correlation between Kr-RVEF and mean PAP (r = -0.51) or PVR (r = -0.47) as an index of RV afterload. However, there was no correlation between Kr-RVEF and RVEDVI as an expression of RV preload. These findings suggest that a poor response by RVEF during exercise in patients with COPD is associated with elevation of afterload. Thus, right ventricular imaging techniques using the ultrashort-lived nuclide krypton-81 m allow noninvasive, serial and accurate assessments of right ventricular function in patients with COPD.

Aged↗
PubMed1987

[A case report of condyloma acuminata of the urethra].

A 29-year-old man noted a wart around the external urethral orifice. The lesion was diagnosed as condyloma acuminata and he had the tumor excised and circumcision on September 10, 1985. He complained of urethral bleeding on December 21, 1985. Physical and endoscopic examination revealed papillo-granular condyloma acuminata at the distal urethra. He received transurethral fulguration on January 17, 1986 and intraurethral instillation of 5-fluorouracil cream weekly. The lesions were successfully treated.

Adult↗
PubMed1986

In vitro effects of chlorpromazine on glycerol-3-phosphate acyl transferase and 1-acylglycerol-3-phosphate acyltransferase in rat liver microsomes.

The in vitro effect of chlorpromazine on rat liver glycerol-3-phosphate acyltransferase and 1-acylglycerol-3-phosphate acyltransferase was studied. Chlorpromazine decreased glycerol-3-phosphate acyltransferase activity in a concentration-dependent manner. The inhibition was competitive with respect to palmitoyl-CoA, while non-competitive with respect to sn-glycerol-3-phosphate. Ki was determined to be approximately 0.15 mM with respect to both palmitoyl-CoA and sn-glycerol-3-phosphate. From these results, together with the inhibitory effect of amphiphilic anions and neutral detergents on the enzyme demonstrated by others, it was proposed that the hydrophobic moiety of chlorpromazine competes with acyl-CoA. The activity of 1-acylglycerol-3-phosphate acyltransferase was inhibited by excess of 1-acyl-sn-glycerol-3-phosphate. In the acceptor concentration range where the substrate inhibition was observed, chlorpromazine showed stimulatory effect on the enzyme activity. At lower concentrations of the acceptor, however, chlorpromazine produced marked inhibition of the enzyme activity. From the kinetic analysis, the inhibition was found to be uncompetitive with respect to acyl-CoA. It was found that the enzyme was more susceptible to the inhibitory action of chlorpromazine with unsaturated acyl-CoAs than with the saturated species, raising the possibility that chlorpromazine alters the molecular species composition of phosphatidic acid produced by the acylation reaction.

1-Acylglycerol-3-Phosphate O-Acyltransferase↗
PubMed1986

Changes in cytochrome P450 molecular species in rat liver in chloroform intoxication.

The effect of CHCl3 on the composition of hepatic microsomal cytochrome P450 species was compared with that of CCl4 in rats pretreated with phenobarbital (PB) or 3-methylcholanthrene (3MC). The administration of CHCl3 hardly affected cytochrome P450 content in non-treated rat liver, but caused a similar degree of depletion in the content as observed after CCl4 administration in PB-pretreated rats. In the pretreatment with 3MC, the administration of CHCl3 brought about a marked decrease in the content to 24% of control after 12 hr, while CCl4 reduced the content only to one-half of control. It was demonstrated by SDS-polyacrylamide gel electrophoresis and Whatman DE-52 anion-exchange chromatography that 3MC-induced P450 species decreased with CHCl3, while it was affected little by CCl4 treatment. The activity of benzo[a]pyrene hydroxylase was altered together with the change in the content of cytochrome P450 species. The administration of CHCl3 to PB-pretreated rats caused the depletion in PB-induced P450. These findings indicate that cytochrome P450 species induced with 3MC as well as PB are highly susceptible to CHCl3 intoxication, whereas the administration of CCl4 depletes the PB-induced species without affecting the 3MC-induced species.

Animals↗
PubMed1986

Circadian rhythm of REM sleep of chronic alcoholics during alcohol withdrawal.

Sleep structures were polygraphically investigated during the alcohol withdrawal periods of six male alcoholics. Polygraphic recordings were taken 10 days, 1 month and 3 months after hospitalization. Total sleep time was almost equal among the three recording nights for each patient. Stages 3 and 4 sleep were remarkably reduced on all the recording nights. REM sleep time was normal throughout the study. REM latency decreased in many patients on the 10th day, and gradually increased on the following nights. A very important change was observed in the distribution of REM sleep. Maximal duration was noted in the first REM episode on the 10th day in four of the six. On the second recording night the second REM episode was the longest in five of the six subjects. On the last recording night many patients exhibited a normal distribution of REM sleep. These findings which suggest that the acrophase of REM sleep is advanced by several hours for a few months after alcohol withdrawal have also been observed in patients with endogenous depression. Although our patients did not show any depressive symptoms during the study, one of them developed a severely depressive state after he began to drink alcohol thereafter.

Adult↗
PubMed1986

Carbon tetrachloride and trichloroethylene toxicities to rat hepatocytes in primary monolayer culture: its relationship to the level of cytochrome P-450.

The effects of carbon tetrachloride (CCl4) and trichloroethylene (TCE) on the synthesis and the secretion of triacylglycerols (TGs) in primary cultured rat hepatocytes were investigated in relation to the level of cellular cytochrome P-450 (P-450). Pretreatment of rats with phenobarbital (PB) and plating the hepatocytes in the presence of metyrapone attained a marked preservation of P-450 during the preparation of monolayer. CCl4 was able to cause the accumulation of cellular TG in the hepatocytes when the content of P-450 was retained at the level equivalent to that in the liver in vivo.

Animals↗
PubMed1986

Comparison of the effect of trihalomethanes on lipid metabolism in rat liver slice.

The effect of a series of trihalomethanes, CHCl3, CHBrCl2, CHBr2Cl, and CHBr3, on in vitro lipid metabolism was compared using rat liver slices. The incorporation of 32Pi and [3H]glycerol into phospholipid of liver slices was inhibited in the presence of trihalomethanes. The inhibitory effect followed the number of bromine atoms in the trihalomethane molecule in the initial period of incubation. CHBr3 markedly inhibited the incorporation of [3H]glycerol into triacylglycerol (TG); CHBr2Cl was less effective and the other two trihalomethanes were without effect. The activities of glycerophosphate acyltransferase, phosphatidate phosphatase and diacylglycerol acyltransferase were changed by the exposure to trihalomethanes. The effects of CHBr2Cl and CHBr3 were much more severe as compared to those of CHBrCl2 and CHCl3. The change in the enzyme activities could explain the alteration in the incorporation of [3H]glycerol into TG.

Animals↗