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Biomedical subjects

Y Nakazawa

Publications and source records attributed to Y Nakazawa.

At least 145 records · Page 8Linked to original sources
PubMed1991

[Laparoscopic laser cholecystectomy: a prospective analysis of 70 initial cases].

Laparoscopic cholecystectomy using Nd-YAG laser was performed in 70 consecutive patients with preoperatively symptomatic gallstones. Sixty-eight patients had successful completion of the laparoscopic cholecystectomy. Mean hospital stay was 7.8 days (range: 4-12), and a diet as well as physical walking was tolerated in all 68 patients by the next day following the procedure. Mean operating time was 216 minutes in the initial 10 cases, which improved significantly to 87 minutes in the latest 28 cases. The difference of operative time did not influence any difference on the postoperative course. Nineteen of 68 patients (27.9%) required postoperative pain medication (pentazocine 15 mg, i.m.). Two patients required conversion to open cholecystectomy because of a pin hole injury on the portal vein by laser quartz in the first case, and difficult dissection due to severe adhesion in the 46th case. There is a definite learning curve in this new modality. Laparoscopic cholecystectomy is a safe and effective procedure, significantly improving the quality of life of the patients with gallstones.

Adult↗
PubMed1990

Diacylglycerol generated in the phospholipid vesicles by phospholipase C is effectively utilized by diacylglycerol lipase in rat liver cytosol.

Diacylglycerol was generated in phosphatidylcholine vesicles by incubation with Clostridium welchii phospholipase C. Newly formed diacylglycerol was rapidly converted to monoacylglycerol and glycerol when rat liver cytosol fraction was present in the incubation mixture, suggesting the presence of di- and monoacylglycerol lipase activities in this subcellular fraction. On the other hand, 3H-labeled diacylglycerol co-emulsified with non-radioactive phosphatidylcholine was found to be a poor substrate for the diacylglycerol lipase. These results indicate that enzymatic generation of diacylglycerol provide a substrate having a suitable physical state for the expression of diacylglycerol lipase activity. It was also found that the rate of diacylglycerol hydrolysis was dependent upon the rate of diacylglycerol generation, but not upon the absolute concentration in the incubation mixture. When the rate of diacylglycerol hydrolysis was plotted against the rate of diacylglycerol generation, a saturation curve was obtained and the double-reciprocal plot gave a straight line. It is not known why a relationship similar to Michaelis-Menten type kinetics was obtained between the rate of diacylglycerol hydrolysis and diacylglycerol generation instead of diacylglycerol concentration, but it may be best explained by the following assumptions: (1) diacylglycerol molecules are generated at the surface of the lipid vesicles where they are readily accessible to diacylglycerol lipase; (2) soon after the generation, diacylglycerol molecules migrate into inside the vesicles where they are inaccessible to the enzyme; (3) the effective concentration of diacylglycerol, i.e., the concentration of diacylglycerol located in the surface layer of the vesicles is proportional to the rate of diacylglycerol generation.

Animals↗
PubMed1990

Platelet monoamine oxidase activity and personality traits in alcoholics and methamphetamine dependents.

Personality traits of alcoholics and methamphetamine dependents were examined by Karolinska scales of personality (KSP). The two groups differed with respect to Aggression, but, they were basically same in Impulsiveness. The biological marker platelet monoamine oxidase (MAO) activity showed a significant difference between the two groups. The low platelet MAO activity in alcoholics may suggest a certain biological basis to be involved in the etiology of dependence whereas the higher platelet MAO activity observed in methamphetamine dependents may reflect the prolonged use of methamphetamine and/or treatment with neuroleptics, or some biological basis.

Adult↗
PubMed1990

[Prognostic factor for prostate cancer. Gunma Urological Oncology Study Group].

The study of prognostic factors in patients with prostate cancer (Pca) may be of value in understanding the natural history of the disease and may also assist in planning and analyzing the results of clinical trials. Moreover some information through this study would be beneficial to assessing the prognosis and decision of better therapy form of individual patients. The significance of items studied was evaluated from the two view points, survival rate and Pca death rate. Stage, pathological differentiation and acid phosphatase were significantly related to them, in the category grade depending manner. Past history and complication, and age were also significantly related to them but higher category grade as a survival factor showed lower Pca death rates. ESR, gait disturbance and hematuria were related to only survival rate. Any significant relationship was not observed in serum testosterone, voiding disturbance and cancer-pain. Prognostic factors should be clinically used through the well understanding of each characteristics. This paper also showed that statistical significance not always provide a wide difference between categories compared.

Age Factors↗
PubMed1989

Rapid hydrolysis of diacylglycerol formed during phosphatidate phosphatase assay by lipase activities in rat liver cytosol and microsomes.

Side reactions which may affect the determination of phosphatidate phosphatase activity were investigated in rat liver cytosol and microsomes. Incubation of these subcellular fractions with either 14C-labeled phosphatidate bound to microsomal membranes (PAmb) or that coemulsified with microsomal lipids resulted in rapid formation of water-soluble products, most of which were identified as glycerol, in addition to diacylglycerol. Neither lysophosphatidate nor glycerol 3-phosphate accumulated under any of the conditions used and only a minute amount of activity catalyzing hydrolysis of glycerol 3-phosphate could be detected in cytosol and microsomes, suggesting that glycerol was not formed by the deacylation of phosphatidate to glycerol 3-phosphate and subsequent dephosphorylation. On the other hand, pretreatment of cytosol or microsomes with diisopropylfluorophosphate abolished the formation of water-soluble products, indicating that glycerol was formed from diacylglycerol, the product of the phosphatidate phosphatase reaction, by lipase-type activities. Rapid deacylation of diacylglycerol by these subcellular fractions was also observed with an emulsion of phosphatidate, which has been purified from the total lipid extract of PAmb as substrate. The rate of hydrolysis of diacylglycerol was maximum when the concentration of diacylglycerol was less than 20 microM with either cytosol or microsomes. The present results suggest that it is essential to characterize the reaction products before employing specific assay conditions for phosphatidate phosphatase. At least under the conditions we tested, reliable measurement of the enzyme activity in rat liver cytosol and microsomes can be achieved only by determining the release of Pi or that of water-soluble activity from 32P-labeled phosphatidate.

Animals↗
PubMed1989

Reflex regulation of the sphincter of Oddi by intrapancreatic ductal pressure in the Japanese monkey.

Japanese monkey has a common ampullary channel. By a continuous injection of sterile saline (1 mL/min) into the pancreatic main duct, the pancreatic main ductal pressure increased from 8.4 +/- 1.0 (mean +/- SD) to a plateau level (16-25 mmHg) in 5 Japanese monkeys. The frequency and amplitude of the slow wave in electromyography of the sphincter of Oddi (SO) were significantly decreased from 14 to 2/min and 0.06 to 0.04 mV (p less than 0.01), and the frequency of the spike component significantly decreased from 53 to 14/min (p less than 0.05). As soon as infusion of saline ceased, the electromyography recovered to the original level. The mean value of the minimum loading pressure affecting myoelectrical activities of the SO was 19.8 +/- 3.0 mmHg. When the pancreatic duct was obstructed at the head, there was no significant change in the SO myoelectrographic activities in spite of increased pancreatic ductal pressure by infusion. These findings suggest that a homeostatic mechanism of pancreatic ductal pressure exists when the activity of the SO is regulated by the distending pressure in the pancreatic ductal system. This reflex regulation seemed to be mediated by the distension of the ampullary duct itself.

Ampulla of Vater↗
PubMed1989

Improvement of right ventricular systolic performance by long-term domiciliary oxygen therapy in patients with chronic respiratory failure.

Eight patients with clinically stable chronic respiratory failure, hypoxemia (PaO2 less than or equal to 60 mmHg) and pulmonary hypertension (mean pulmonary arterial pressure greater than or equal to 20 mmHg) were allocated to long-term domiciliary oxygen therapy, and were followed for three months. Oxygen was supplied for from 15 to 18 hours daily from an oxygen concentrator at a flow rate sufficient to raise the PaO2 to 60 to 80 mmHg. We examined the effects of this therapy on right ventricular performance both at rest and during exercise in these patients. Hemodynamic data were obtained by right heart catheterization. Right ventricular ejection fractions (RVEF) were ascertained using first-pass quantitative radionuclide 81mKr angiocardiography. Thirty minutes of oxygen inhalation at rest had no significant effect on cardiac function, both before therapy (T0) and after 3 months of therapy (T1). The mean pulmonary arterial pressure and the pulmonary vascular resistance during exercise were not significantly different between T0 and T1. On the other hand, at T0, the RVEF tended to decrease from 51.6 +/- 4.9% (during oxygen inhalation at rest) to 48.7 +/- 7.9% (during exercise), whereas at T1 it significantly (p less than 0.05) increased from 48.8 +/- 6.8% (during oxygen inhalation at rest) to 54.2 +/- 8.2% (during exercise). Thus, while 3 months of long-term domiciliary oxygen therapy did not reduce the right ventricular afterload either at rest or during exercise, it was found to improve the right ventricular systolic performance during exercise. This suggested that long-term oxygen therapy could be useful in improving the quality of daily life of patients with chronic respiratory failure.

Aged↗
PubMed1989

[A shortened method for the assay with Centocor radioimmunoassay kit].

We have conducted a series of basic studies about Centocor's CA125 RIA Kit, especially for the conditions of the incubation. The standard curve and the outcome of recovery test gained through the standard method and the shortened method are quite decent. As for the incubation time, it took longer than 20 hours and 6-18 hours inthe standard method and shortened one respectively. As our conclusion, these results suggest that the shortened method can be adopted as a practical one as well as the standard method, provided that careful attention is paid to several peripheral conditions in the assay.

Antigens, Tumor-Associated, Carbohydrate↗
PubMed1988

Biorhythm of core temperature in depressive and non-depressive alcoholics.

Core temperature was longitudinally evaluated during the day- and nighttime in six non-depressive and in four depressive alcoholics who had been abstaining from alcoholic beverages. The least squares spectrum method was employed for detecting the periods and acrophase of the circadian rhythm of core temperature. Although normal periods were observed in all the patients throughout the study, an abnormal acrophase was found in many patients, especially in depressive alcoholics. On the 3rd and 4th days after alcohol withdrawal, all of the four depressive alcoholics showed a phase advance of the circadian rhythm, and three patients of the six non-depressive alcoholics exhibited an abnormal acrophase. On the 21st and 22nd days after alcohol withdrawal, a normal acrophase was observed in two patients of the four depressives and in four of the six non-depressives. The mean core temperature was higher in the depressives than in the non-depressives on the third and fourth days after alcohol withdrawal.

Adult↗
PubMed1988

Alteration of left ventricular geometry during preload reduction and afterload increment.

To ascertain whether or not left ventricular geometry changes during preload reduction and afterload increment, the shortening characteristics of small segments in the left ventricular free wall were examined using 4 pairs of ultrasonic crystals in 10 dogs. Three pairs of ultrasonic crystals were circumferentially implanted in the basal, the midventricular and the apical portion of the left ventricle. Another pair of crystals were longitudinally placed in the midventricle. In the control state, the shortening at the apex was largest of all segments. During preload reduction, the end-diastolic length decreased significantly in each segment. The percent shortening decreased significantly at the apical and the longitudinal segment, but it remained unchanged at the midventricular and the basal segment. During afterload increment, the end-diastolic length increased significantly, but the percent shortening remained unchanged in each segment. We concluded that left ventricular geometry was altered during preload reduction and that the apical part is more responsive to preload change than the other portion.

Animals↗
PubMed1988

Pressure of papillary sphincter zone and pancreatic main duct in patients with chronic pancreatitis in the early stage.

We measured pressures of the papillary sphincter zone and pancreatic main duct endoscopically in 20 control subjects and in 38 patients with chronic pancreatitis without papillary stenosis, including 19 cases believed to be in the early stages of chronic pancreatitis. There was no significant difference between control subjects and patients with chronic pancreatitis without papillary stenosis in the motility of the sphincter of Oddi. The pancreatic main ductal pressure was significantly higher in the patients in the early stage of chronic pancreatitis (35.7 +/- 9.1 mm Hg (mean +/- SD) in patients suspected of having chronic pancreatitis and 44.9 +/- 20.4 mm Hg in minimal-change chronic pancreatitis) than in the controls (16.2 +/- 8.7 mm Hg). The viscosity of pure pancreatic juice of patients with chronic pancreatitis (5.0 centi-Poise (cP] in the basal secretory phase was significantly higher than that of the controls (1.32 cP). These data suggest that endoscopic measurement of pancreatic ductal pressure is useful for diagnosis of the early stages of chronic pancreatitis.

Adult↗