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Biomedical subjects

R Nakamura

Publications and source records attributed to R Nakamura.

At least 379 records · Page 21Linked to original sources
PubMed1985

Human IgE antibody to the carbohydrate-containing third domain of chicken ovomucoid.

Two kinds of the third domain, either with or without a carbohydrate chain, were prepared from chicken ovomucoid. The immunoreactivity of the domain preparations to human IgE antibody directed against ovomucoid was examined by using the sera from patients of egg allergy. About 30% of the serum antibody to ovomucoid reacted with the carbohydrate-containing domain, whereas little or no antibody with reactivity to the carbohydrate-free domain was detected, suggesting that the carbohydrate chain attached to the third domain played an important role in antigenic determinants of the carbohydrate-containing third domain against the human IgE antibody.

Animals↗
PubMed1985

The influence of oral contraceptives on the postmolar human chorionic gonadotropin regression curve.

This article reports a retrospective analysis of 149 evaluable cases of molar pregnancy managed at Women's Hospital, Los Angeles County/University of Southern California Medical Center, from January 1977, through June, 1983. In the 84 cases prior to 1981, the patients received estrogen-progestogen oral contraceptives after evacuation while the 55 patients seen after that used nonhormonal contraceptives. The frequency of abnormal regression of the serum beta-subunit of human chorionic gonadotropin in the two groups was not significantly different (22.6% in the hormonal contraception group versus 34.5% in the nonhormonal contraception group). The groups were compared for known and potential risk factors and were nearly identical with respect to patient age, parity, maternal blood type, and race. There were also no significant differences with respect to uterine size, preevacuation beta-subunit of human chorionic gonadotropin serum titer greater than 100,000 mIU/ml, and frequency of theca-lutein cysts. Gestational age was significantly shorter and the frequency of cases with a preevacuation beta-subunit of human chorionic gonadotropin serum titer greater than 250,000 mIU/ml significantly higher in the nonhormonal contraception group, indicating that the nonhormonal contraception group had a higher risk for abnormal human chorionic gonadotropin regression than the hormonal contraception group. We conclude that this study provides no evidence that the use of estrogen-progestogen oral contraceptives prior to human chorionic gonadotropin remission increases the risk for invasive mole or choriocarcinoma following molar pregnancy.

Adult↗
PubMed1985

Reaction time of patients with Parkinson's disease, with reference to asymmetry of neurological signs.

Electromyographic reaction times of the left and the right finger extensor muscles in extension movement of the wrist were examined in 42 patients with Parkinson's disease, and 20 normal subjects. Compared to the normal subjects and the patients with neurological signs confined to the right side, the patients with neurological signs on the left side or on both sides showed slowing of reaction times regardless of the side of responding hand. The patients with asymmetry of bilateral neurological signs showed slower RTs on the more affected side.

Electromyography↗
PubMed1985

Effect of antigastrin (SC-15396) on amylase release and 2-deoxyglucose uptake in mouse pancreatic acini.

The effects of antigastrin (SC-15396) on amylase release and 2-deoxyglucose uptake were studied in dispersed acini from mouse pancreas. Antigastrin at concentrations between 0.5 and 2 mM inhibited cholecystokinin (CCK)-stimulated amylase release and 2-deoxyglucose uptake in a dose-dependent fashion. Antigastrin at concentrations between 0.5 and 2 mM inhibited carbachol-stimulated amylase release and 2-deoxyglucose uptake as well. In addition, the drug (2 mM) inhibited bombesin-stimulated amylase release and 2-deoxyglucose uptake. In contrast, the stimulation of amylase release by Ca2+ ionophore A23187 was not inhibited by antigastrin. The results, therefore, suggest that antigastrin nonselectively inhibits the actions of these secretagogues probably at their receptor sites.

Amylases↗
PubMed1985

Motor time of the rectus femoris during passive movements.

Motor time (MT) of 10 normal subjects were examined in three conditions: 1) during passive flexion of the knee (PFLX), 2) during passive extension (PEXT), and without passive movement (STAT). Compared to STAT, MTs of PFLX and PEXT were significantly long. MT tended to be shorter, though insignificant statistically, in PFLX than in PEXT. In conclusion, passive movements are influential in changing the physical state of the muscle including both series-elastic and contractile components.

Adult↗
PubMed1985

Quantitative light and electron microscopical studies of the effect of vagotomy on parietal cells in rats.

As early as 3 days after truncal vagotomy, a decrease in the number of parietal cells per gland and the length of fundic glands of the stomach was observed in young Wistar rats. A decrease in the size of cells and the number of mitochondria per cell was also evident in the remaining parietal cells. These atrophic changes lasted nearly one month after the operation. A decrease in the cellular size and mitochondrial number in parietal cells was noted again in the rats sacrificed 12 months after the operation. Since the similar changes were also seen in the age-matched controls, the changes in older rats were interpreted as an aging phenomenon.

Age Factors↗
PubMed1985

Relationship of muscle strength for knee extension to walking capacity in patients with spastic hemiparesis.

Muscle strength for knee extension, both isokinetic and isometric, and walking capacity, maximum velocity and walking rate, were examined in 11 post-stroke hemiparetic patients. The degree of spasticity of the affected lower extremity was not related to the isokinetic and isometric torques, or to the walking capacity. Although both the isokinetic and isometric torques decreased on the affected side compared to the non-affected side, the rate of decrease was remarkable in isokinetic torque at fast velocities. The walking capacity was well correlated with isokinetic torque of the affected side at fast velocities but not isometric torques. These results suggest that reduction of muscle strength at rapid movements is an essential feature of spastic paresis and is primary cause of motor disabilities such as impaired locomotor function.

Adult↗
PubMed1985

Motor time of the rectus femoris under loading of different weights.

Motor time (MT) of the rectus femoris was measured for seven normal subjects during rapid extension of the knee joint at 60 degrees flexion in the sitting position with and without external loads on the leg. MT prolonged linearly with external load from 0 to 4 kg. Tangent of this linearity, the rate of tension development (RTD), was significantly different from one another of the subjects and was not related to MT without external load. RTD is a relevant index to assess an efficiency of rapid force generation of a muscle.

Adult↗
PubMed1985

EEG activation induced by facilitating position.

The effect of facilitating position of the lower extremity on EEG states was examined through topographical analysis of spectral power for each major frequency band in 8 healthy male subjects. Compared to neutral position, facilitating position of the left or right lower extremity produced significant changes in spectral power, especially in terms of non-specific increase at alpha band (8-12.8 Hz). These results provide further evidence of arousal shift induced by facilitating position, and suggest that EEG topography is a suitable indicator of monitoring the effect of facilitating position.

Adult↗
PubMed1985

Effect of islet transplantation on diabetes mellitus after subtotal pancreatectomy in rat: a quantitative analysis of islet tissue.

A reproducible model of diabetic state was produced by resecting more than 90% of the pancreatic tissue in Wistar strain male rats. Five rats with diabetic state after the resection received islet transplantation into the liver through the portal vein. All these five rats showed normoglycemia one week after the injection and it lasted about six months. A morphometric analysis using 1190 serial sections of the control rat pancreas showed that the islet distribution accorded satisfactorily with Weibull and gamma distribution, when an islet was regarded as a sphere in the three dimensional space. The estimated value of radius and number of the islets was 0.0155 mm and 131.2/mm3, respectively, whereas volume fractions of the islet tissue in the splenic and gastric segments, and parabiliary and duodenal segments were estimated at 1.45 and 0.98%, respectively. The mean half of the largest diameter of the isolated islets under dissecting microscope reached to 0.080 mm and 500 isolated islets account for about 14% of volume fraction in a whole pancreas. As the remnant pancreas possibly had approximately five percent of islet volume, the transplanted animal contained about 19% of islet volume as compared to the control animal. It could be concluded that transplantation of 500 islets controlled diabetes in the rat with subtotal pancreatectomy. But the transplanted rats eventually became diabetic about six months after the transplantation possibly because of insufficient volume of implanted islets.

Animals↗
PubMed1985

Effect of islet cell autograft from the highly scarred pancreas on pancreatectomized dogs.

Ligation and section of the main and accessory pancreatic ducts were performed in adult mongrel dogs. Four weeks after the procedure we carried out total pancreatectomy in six duct-ligated dogs, and an attempt was made to prepare the graft of islets from the highly scarred pancreas of the duct-ligated dogs by means of a newly developed collagenase perfusion method. We succeeded to normalize the high fasting glucose level which occurred after the total pancreatectomy in three of six dogs through the autotransplantation of the procured graft. However, insulin secretion was severely depressed in transplanted animals. Two of the three dogs showed high plasma glucose levels 15 and 20 weeks after the transplantation, respectively. Histological examination of the spleen revealed well preserved islets with good immunocytochemical insulin staining in one transplanted dog whose plasma glucose level was controlled for about five months. No pancreatic exocrine tissue was detected in the histological sections of the spleen in the transplanted dogs and in a transplanted control dog.

Animals↗
PubMed1985

Timing and rate of development of tension produced by the fast voluntary contraction of the rectus femoris muscle.

Tension produced by isometric contraction of the rectus femoris muscle for rapid knee extension was examined at different levels of force with five normal subjects, using an on-line method to measure the timing and the rate of development of tension. Tension began to rise about 50 msec. after onset of electromyographic activity of the rectus femoris muscle, increased most sharply at about 60 msec. after its rise, and attained maximum at about 100 msec. The rate of tension development was determined solely by the maximum tension from first 20 msec. up to 100 msec., while timing remained approximately constant regardless of the force. The result confirmed well a force-control hypothesis of maximal speed ballistic movement of a body segment that the motor centre controls the amplitude of force output when time to develop tension is invariant.

Adult↗