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Biomedical subjects

R Nakamura

Publications and source records attributed to R Nakamura.

At least 307 records · Page 17Linked to original sources
PubMed1989

Effects of porcine pancreastatin on postprandial pancreatic exocrine secretion and endocrine functions in the conscious rat.

The inhibitory effect of a newly discovered polypeptide, pancreastatin, on postprandial pancreatic exocrine secretions and endocrine functions was examined in the conscious rat with a chronic external bile, pancreatic and gastric fistula. The infusion of 100 and 200 pmol/kg/h of pancreastatin significantly inhibited meal-stimulated pancreatic secretion of fluid and protein but not bicarbonate in a dose-dependent manner. The infusion of 100 and 200 pmol/kg/h of pancreastatin increased plasma pancreastatin concentrations (mean +/- SE) up to 133.5 +/- 15.9 and 209.8 +/- 14.5 pM, respectively. However, the same doses of pancreastatin failed to inhibit postprandial insulin and gastrin releases and did not affect blood glucose levels. It is suggested that pancreastatin may be an inhibitor of postprandial pancreatic exocrine secretion. However, the doses used in the present study may not have been high enough to affect endocrine functions.

Animals↗
PubMed1989

Characteristics of the fastest isometric knee extension in patients with spinocerebellar degenerations.

The force output of the knee extensor muscles and its time course were measured in nine patients with spinocerebellar degenerations and age-matched 10 normal subjects during the fastest and strongest isometric contraction. The time from the rise of tension to its maximum, FTmax, was definitely long in the SCD compared to the normal group, whereas the peak tension was not different between the two groups. FTmax of the SCD group was not related to the rate of tension development and the maximum tension nor to the degree of ataxia, suggesting that the prolongation of FTmax was a characteristic feature of cerebellar lesions.

Adult↗
PubMed1989

Loss of reaction time specificity for movement direction in Parkinson's disease.

Electromyographic (EMG) reaction times (RTs) of the right biceps brachii muscle and its integrated EMG (iEMG) from the onset until 50 msec after the start of activities for elbow flexion and forearm supination in the condition with or without warning signal were examined in seven patients with Parkinson's disease and seven age- and sex-matched normal subjects. In the control group RT of forearm supination with warning tended to be faster than that of elbow flexion and the reverse occurred without warning, and iEMG of forearm supination were significantly small compared to those of elbow flexion in each condition. In the Parkinson group both RT and iEMG of elbow flexion were nearly the same as that of forearm supination regardless the presence or absence of warning signal, indicating the loss of RT and iEMG specificity for the two direction of movement in Parkinson's disease.

Electromyography↗
PubMed1989

Differences in stimulatory effects between rat pancreatic secretory trypsin inhibitor-61 and -56 on rat pancreas.

Two types of pancreatic secretory trypsin inhibitors (PSTIs) were recently purified from rat pancreatic juice. One consisted of 61 (PSTI-61) and the other of 56 (PSTI-56) amino acid residues. PSTI-61 has been reported to elicit cholecystokinin (CCK) release when injected into the duodenum. Since no information has been available about the action of PSTI-56 on CCK release, the two PSTIs were compared for their stimulatory effect on CCK release and pancreatic exocrine secretions in conscious rats after intraduodenal administration. Rats were prepared with bile and pancreatic fistulae and with two duodenal cannulae. Pancreatic juice was excluded from the duodenum for 48 h prior to the experiment because rat PSTIs were trypsin sensitive. PSTI-61 significantly stimulated pancreatic secretions and increased plasma CCK concentrations from 3.6 to 6.5 pM, whereas PSTI-56 had no effect on either CCK release or pancreatic secretions. It is suggested that the action as a regulator for CCK release and pancreatic secretions is possessed only by PSTI-61, but not by PSTI-56.

Amino Acid Sequence↗
PubMed1989

[Age related changes in the walking cycle during fastest walking in healthy male subjects].

Velocity, step length and walking rate during fastest walking were measured together with maximum torque (MVC) in the left knee extension for 81 healthy males with aged from 22 to 79 years. Velocity and step length showed an accelerated decline from the sixties, while walking rate decreased with age linearly. Multiple regression analysis with age, height, weight and MVC as independent variables and velocity, step length and walking rate as dependent variables indicated that (1) walking velocity was significantly related to age, MCV and weight, (2) step length to MVC and weight, and (3) walking rate to age.

Adult↗
PubMed1989

Interactions between bile and pancreatic juice diversions on cholecystokinin release and pancreas in conscious rats.

Pancreatic exocrine secretion in the conscious rat is regulated by proteases secreted by the pancreas, and cholecystokinin (CCK) is known to be involved in its mechanism. It has also been reported that the absence of either pancreatic juice or bile in the duodenum could stimulate pancreatic secretion. Therefore, differences in CCK release responding to the exclusion of bile, pancreatic juice (PJ), or both bile and pancreatic juice (BPJ) from the intestine were examined by using a bioassay for cholecystokinin. Plasma CCK levels were increased by all three treatments compared with the basal value, the order of their effects being BPJ greater than PJ greater than bile diversion, and CCK concentrations produced by BPJ diversion were much greater than can be explained as simply summed effect of exclusions of bile and PJ. Pancreatic exocrine secretions were significantly increased by PJ and BPJ diversions, but the effect of bile diversion on the pancreas was not statistically significant. An additional infusion of CR-1409 (0.1 mg/rat), one of CCK receptor antagonists, inhibited exocrine function stimulated by BPJ diversion. We conclude (i) BPJ diversion is the strongest endogenous stimulant on CCK release; (ii) the potentiation between bile and PJ diversions is induced on CCK release; (iii) pancreatic protein secretion during BPJ diversion is mainly modulated by CCK.

Animals↗
PubMed1989

[Effect of pancreastatin on pancreatic exocrine secretion in vivo and in vitro].

The effects of pancreastatin on pancreatic exocrine secretion were examined both in vivo and in vitro in rats. Pancreastatin inhibited pancreatic fluid and protein outputs stimulated by the exclusion of pancreatic juice from the intestine with the intraduodenal infusion of Trasylol but did not inhibit bicarbonate output stimulated by HCl in vivo in conscious rats. However, pancreastatin did not affect amylase release from dispersed acini or Ca concentration in acinar cells. Therefore, it is concluded that pancreastatin inhibits pancreatic exocrine secretion but the effect is indirect.

Amylases↗
PubMed1989

[Long-term post-treatment observation of a case with orthodontic treatment using occipito-mental anchorage only].

Occipito-mental anchorage (OMA) was used in a skeletal class III case with maxillary retrognathism. Long term observation of the patient post treatment revealed the following: 1. The facial profile was improved gradually until the end of treatment: but by 5 years after treatment, it had become slightly worse. 2. Improvement was seen in the maxillomandible relationship owing to the continuous slight advancement of the maxilla and the inhibition of the advancement of the mandible. And this relationship also showed long-term stability after treatment. Hardly any rotation of the mandible was found during the treatment. But clockwise rotation of the palatal plane during treatment and counterclockwise rotation after treatment were observed. 3. Regarding dental changes, labial inclination of upper incisors and lingual inclination of lower incisors owing to the improvement of overjet were seen during treatment. But they reverted to almost the same inclinations seen at the first examination by 5 years after treatment.

Child↗
PubMed1989

[Basal plasma cholecystokinin levels in digestive diseases--comparison between CCK-8 like bioactivity by bioassay and CCK immunoreactivity by radioimmunoassay].

Basal plasma cholecystokinin levels were measured by a bioassay using dispersed rat pancreatic acini in various digestive diseases and compared with corresponding values by CCK-8 specific radioimmunoassay. The mean basal level in healthy volunteers was 0.40 +/- 0.06 pM. The basal level in liver cirrhosis was significantly elevated to 0.92 +/- 0.14 pM. The patients with cholestasis, that is, primary biliary cirrhosis and obstructive jaundice due to choledocholithiasis, bile duct cancer or lymph node metastasis , had markedly increased basal plasma CCK-8 like bioactivities from 1.88 pM to more than 25 pM. These CCK bioactivities were not correlative with CCK immunoreactivities. It was concluded not only that basal plasma CCK in patients with bile flow disturbance were truly increased, but also that interfering substances of the bioassay might appear in the plasma of these patients.

Adult↗
PubMed1989

[Postoperative pyuria after TUR-P: the study of postoperative pyuria by using NFLX].

The postoperative duration of pyuria was studied in 35 patients who underwent transurethral resection of the prostate (TUR-P). The average postoperative duration of pyuria was 58.0 +/- 23.6 days. The age over 70 years, preoperative indwelling of urethral catheter and the preoperative urinary tract infection did not make the duration of pyuria longer. The volume of resected prostatic tissue over 20 g and the existence of diabetes mellitus make it significantly longer. It is effective and safe to use a low-dose antibacterial agent such as NFLX which has a broad spectrum and hardly develops bacterial resistance after TUR-P. It is suggested unnecessary to change the anti-bacterial agent even when pyuria continues.

Aged↗
PubMed1989

[The effects on upper first molars by the face-bow construction. Consideration of utilizing the strain gauge method and the computer method of structural analysis].

The present study was undertaken for the purpose of detecting the influence on upper first molars by the dynamic behavior originated in face-bow construction. Tests were made at occipital pull and cervical pull face-bows utilizing strain gauge method and the computer method of structural analysis. As for the occipital pull face-bow, a short outer-bow 35 mm frontward of a tube was bent 30 degrees upward and be pulled in that direction. As for the cervical pull face-bow, a medium outer-bow flash to tube, parallel to the inner-bow was pulled from 20 degrees downward. These two types of face-bows were divided into 4 types, those with loops at the back end (WL) and to those without loops (NL). In the strain gauge method, the force and moment to tubes was measured and compared with the values obtained from theoretical analysis. And in the structural analysis, the data of deflection was compared with each other. Those results indicated that 1. face-bow shows a different force to the molars and a different phase of deflection, according to the difference of it's force concentrative section. 2. the larger the deflection, the larger the deviation of forces on molars from theoretical values. 3. the way of setting loops against the direction of pull alters the phase of deflection of face-bow and the force on molars. 4. existance of loops at inner-bow affects as follows: (1) Reduction of moment of each type of face-bow. (2) Reduction of vertical force at occipital pull face-bow and it's increase at cervical pull face-bow. (3) Resistance for deflection of face-bows in the case of tractive force for closing loops.

Dental Stress Analysis↗
PubMed1988

Bioactivity of synthetic human pancreastatin on exocrine pancreas.

A biological activities of synthetic human pancreastatin (1-52) and its C-terminal fragment (24-52) were evaluated for the first time in the conscious rats. Both pancreastatins inhibited CCK-stimulated pancreatic secretion in a range of 20-200 pmol/kg/h with the same potency, indicating that the C-terminal portion of this peptide has a full biological activity. The relative molar potency of this substance compared to that of porcine pancreastatin was equivalent. This study suggests that human pancreastatin has the same biological activity as that of porcine, and plays a biological action in the exocrine pancreas.

Animals↗
PubMed1988

Prenatal detection of fetal thymidine kinase activity in maternal plasma: normal values and clinical application in postterm pregnancy.

Deoxythymidine kinase is present in human cells in two forms: the cytosolar form (fetal thymidine kinase) and the mitochondrial form (adult thymidine kinase). The activity of thymidine kinase isozymes in plasma of preterm and term newborns has been previously reported to be related to gestational age, and fetal thymidine kinase activity was reported to be undetectable after the thirty-ninth week of gestation. Our purpose was to determine if similar changes in the activity levels of the thymidine kinase isozymes could be demonstrated in late third trimester maternal plasma. A cross-sectional sample of 35 patients was studied from week 34 of pregnancy to delivery. Significant differences between fetal and adult thymidine kinase activity patterns were observed. Adult thymidine kinase activity remained relatively constant throughout the evaluation interval, while fetal thymidine kinase activity decreased with advancing gestational age. Regression analysis of gestational age by neonatal examination (GAPED) and fetal thymidine kinase revealed a linear relationship (fetal thymidine kinase = 0.380 - 0.00745 GAPED; R2 = 0.2944; standard estimate of error = 0.0350; p less than 0.0008). Comparison of fetal thymidine kinase activity in term and postterm pregnancy plasma revealed a significant difference (p less than 0.0159). Our findings indicate that deoxythymidine kinase activity can be measured in maternal plasma, may relate to the fetoplacental growth rate, and may be useful in differentiating between term and postterm gestations.

Embryonic and Fetal Development↗
PubMed1988

Effect of endocrine treatment on prostatic blood flow in patients with prostatic adenocarcinoma.

Prostatic blood flow in 19 patients with prostatic adenocarcinoma was measured by the hydrogen gas clearance method before and during endocrine treatment. Prostatic volume was reduced to 70 per cent of the pre-treatment volume by 3 months after the beginning of treatment. Prostatic blood flow was remarkably depressed in patients who had never had any treatment of the prostatic carcinoma (22.2 +/- 8.3 ml. per minute per 100 gm.), while prostatic blood flow increased significantly after endocrine treatment (56.3 +/- 21.8 ml. per minute per 100 gm.). It was likely that prostatic blood flow increased as the prostate volume decreased. Final histology of serial prostatic biopsy specimens after endocrine treatment, revealed distinct deterioration of tumor cells and slight stromal hyperplasia compared to the initial pre-treatment biopsy. The stromal-epithelial ratio, which was calculated by computer-assisted image analysis, was markedly increased after endocrine treatment. Our study indicated that endocrine treatment caused a growth-inhibitory effect that was accompanied by increased blood flow in the prostatic carcinoma.

Adenocarcinoma↗