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Biomedical subjects

R Nakamura

Publications and source records attributed to R Nakamura.

At least 523 records · Page 29Linked to original sources
PubMed1977

Reaction time in bimanual simultaneous motions.

Electromyographically determined reaction times (EMG-RTs) of the finger flexor and extensor of both forearms were measured for four different motions: inward (task 1), flexion of both wrists; outward (task 2), extension of both wrists; to the left (task 3), extension of the left wrist and flexion of the right; and to the right (task 4), flexion of the left and extension of the right. The EMG-RTs were shorter and synchronization errors in terms of left to right differences of EMG-RTs were smaller in tasks 1 and 2 than in tasks 3 and 4. Comparing the flexors and the extensors, the extent of prolongation of EMG-RTs in tasks 3 and 4 differed significantly on the left side, being larger in the flexor than in the extensor, but there was no difference in the extent of prolongation between the flexor and the extensor on the right. It was suggested that the timing of initiation of movements in simultaneous motions was primarily determined by the pattern of muscle coupling in both limbs, and not by the direction of movements. The steadiness of motor function and of the right hand in right-handed subjects was also discussed in regard to hand preference.

Adult↗
PubMed1976

Reconstruction of the mutilated hand.

The experience gained from the reconstruction of sixty-seven severely mutilated hands is applied to the analysis of the procedures of choice in three groups of injury.

Amputation, Surgical↗
PubMed1976

Quantitation of "acute-phase proteins" postoperatively. Value in detection and monitoring of complications.

Serial determinations of serum C-reactive protein are helpful in the detection and monitoring of postoperative complications associated with inflammation and/or tissue necrosis. The serum C-reactive protein level begins to increase within sex hours after operation, peaks on the second day, and by the third postoperative day begins to decrease toward the preoperative level. In cases with surgical complications involving inflammation, serum C-reactive protein levels remain elevated and do not show a decline on the third postoperative day. Serum levels of other "acute-phase proteins," such as alpha-1 acid glycoprotein, ceruloplasmin, alpha-1 antitrypsin, and haptoglobin, were found to increase in response to surgical procedures, but subsequent to the increase in C-reactive protein. These other proteins offer no additional information in monitoring the postoperative acutephase response,

Abscess↗
PubMed1976

The mechanism of low-renin hypertension: aldosterone response to sodium restriction and upright posture, angiotensin II, ACTH and potassium in patients with hypertension.

Plasma renin activity and aldosterone were measured simultaneously in 67 out-patients with essential hypertension. High aldosterone was more often in patients with high renin, and low levels of aldosterone were usual in those with low and normal renin. In order to study the mechanism by which aldosterone and renin acitvity are suppressed in low-renin hypertension, 25 patients (13 normal-renin hypertensives, 10 low-renin patients including 4 non-responders and two DOC excess hypertensives) were investigated as inpatients. Plasma renin activity, aldosterone and cortisol were determined by the following stimualtions with 3 days of sodium restriction and 2 hours of upright posture, angiotensin II infusion (at a dose which increased 20mmHg of diastolic blood pressure), ACTH administration (rapid i.m. injection of 0.25 mg of alpha 1-24 preparation) and potassium infusion (30 meq of potassium i.v.). Responses of aldosterone in normal-renin hypertensives to all stimulations were 3-5 fold increases from bases line values. Low-renin hypertensives except two of four non-responders showed the responses similar to those in normal-renin patients. The responses of two of the non-responders were similar to those in DOC excess hypertensives who showed reduced responses of aldosterone to some of these stimulations. Thus, it seems that low-renin hypertension is a clinical entity caused by a variety of mechanisms, and the mechanism by which low-renin hypertension is induced is not explained by one factor such as an unknown mineralocorticoid.

Adrenocorticotropic Hormone↗
PubMed1976

Preferred hand and steadiness of reaction time.

RT and its left/right difference of both biceps muscles were measured by electromyogram (EMG) in the bilateral simultaneous flexion of elbows using 11 left- and 13 right-handed subjects under four conditions which were combinations of two factors; warning signal; presence or absence of a fore-period, and position of limbs; elbow 90 degrees or 135 degrees. EMG-RT and its left/right difference were influenced by these factors. The effects of warning and position of limbs were not the same on the preferred and non-preferred hands. It was assumed that EMG-RTs of biceps in the preferred hand were less influenced by these experimental conditions.

Acoustic Stimulation↗
PubMed1976

Gonorrhea screening program in a women's hospital outpatient department: results and analysis of risk factors.

Endocervical cultures for Neisseria gonorrhoeae were taken from 4,285 new patients attending the emergency room and outpatient clinics at Women's Hospital, Los Angeles County-University of Southern California Medical Center. Of these, 144 (3.4%) were positive. Clinic-specific rates were: emergency room 9.0%, family planning clinic 2.3%, therapeutic abortion clinic 2.2%, and prenatal clinic 1.0%. An additional 70 return patients were cultured because of history, symptoms, or signs suggestive of gonorrhea; 14% of these "nonscreen" cultures were positive. Rates for the emergency room and nonscreen category were significantly greater than rates from the clinics. A questionnaire was used to determine patient characteristics in an attempt to identify a high-risk population. Variables of age, race, marital status, history of previous veneral disease or pelvic infection, number of sexual partners, and suspicion of venereal disease were significantly related to the incidence of positive cultures. Obstetrical history and symptoms of cramping or discharge were not related.

Abortion, Legal↗
PubMed1976

[A case of the A. Vertebralis sinistra direct arising from the arcus aorta (author's transl)].

A case of the left vertebral artery direct arising from the Arcus aorta, falling under C-type in ADACHI (1928), was encountered among the corpses dissected for practice in Hokkaido University, school of medicine. The Arcus aorta has four branches; Truncus brachiocephalicus, A. carotis communis sinistra, A. vertebralis sinistra, and A. subclavia sinistra. The A.vertebralis sinistra has passed through at first into Foramen transvwrsarium of the vertebra cervicales quintus (C5). The length of this artery between the origin of the Arcus aorta and the fifth cervicales was 120 mm. The other measurements of arteries were shown in table 1.

Aged↗
PubMed1975

[Effects of low salt plus upright posture, angiotensin II, ACTH, and potassium upon plasma renin activity, aldosterone, and cortisol (author's transl)].

In order to study the control system of plasma aldosterone in human, we examined the effects of low salt plus upright posture, angiotensin II, ACTH and potassium upon plasma renin activity, aldosterone and cortisol in five subjects who were supposed to be normal. All of the procedures, low salt diet with below 3 g of salt and 2 hr-upright posture, 0.25 mg of Cortrosyn, angiotensin infusion to increase 20mmHG of diastolic pressure for an hour, and 30 mEq of potassium infusion stimulated plasma aldosterone significantly. Furthermore, in each subject the degrees of response to each of these stimulations were almost same. In an old woman aged 68, responses to all of stimulations were significantly lower than those in other subjects. Plasma cortisol was significantly stimulated by ACTH, but slightly reduced by potassium infusion. From these results, it is certain that plasma aldosteron levels are easily affected by a small amount of changes in angiotensin, ACTH, potassium and sodium. However, responses of aldosterone to these changes seem to be decreased in old subjects.

Adrenocorticotropic Hormone↗
PubMed1975

Oestrogen hypertension in rats.

1. A large dose of oestrogen elevated the blood pressure in male Westar rats. 2. Plasma renin substrate and renin activity increased significantly but plasma renin concentration was unchanged. 3. The increase in blood pressure induced by oestrogen was significantly reduced by salt loading, plasma renin concentration was suppressed and the increase in plasma renin activity was reduced. 4. The increase in plasma renin activity induced by the increase of plasma renin substrate concentration may play a role in oestrogen-induced elevation of blood pressure.

Animals↗