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Biomedical subjects

A Gunji

Publications and source records attributed to A Gunji.

At least 55 records · Page 3Linked to original sources
PubMed1997

Baroreflex during exercise in different postures before and after 20-days bed rest.

Vagal-cardiac baroreflex functions in young healthy humans (n=6) were investigated in four different conditions; supine rest, seated rest, supine and seated exercise (50 watts) before and after 20-day horizontal bed rest. By selectively stimulating carotid baroreceptors using a neck pressure and suction technique, the primary finding was that the baroreflex sensitivity tuation at which we observed a tendency for an attenuation (0.05<p<0.07) of baroreflex sensitivity. The range of decrease in heart rate during neck suction was diminished (p<0.05) after bed rest, but only during supine rest. In conclusion, an attenuation of carotid vagal baroreflex after inactivity was found to be dependent on posture, and was found only in supine rest. It was also concluded that an exaggerated exercise tachycardia found after bed rest is not due to an attenuation of vagal carotid baroreflex sensitivity in itself.

Adult↗
PubMed1997

Cardiovascular response to lower body negative pressure before and after 20 days horizontal bed rest.

To evaluate the effects of 20 days bed rest (BR) on cardiovascular system in normal subjects, left ventricular (LV) echocardiography and vascular ultrasound of the common carotid artery and abdominal aorta were performed during rest and a supine lower body negative pressure (LBNP) test in 14 healthy volunteers (mean age: 22 years) before and after BR. After BR, heart rates (HR) at rest and during LBNP (-40 mmHg) increased. In contrast, LV dimensions, stroke volume, and blood pressures decreased both at rest and during LBNP. Also LBNP tolerance time decreased after BR. Although resting cardiac output (CO) and abdominal aortic flow decreased after bed rest, CO and abdominal aortic flow were unchanged during LBNP comparing before and after BR. Common carotid artery flows both at rest and during LBNP showed no change after BR. LBNP did not increase HR before BR, but increased HR prominently after BR. In conclusion, LBNP tolerance time and LV size during LBNP decreased after BR, suggesting orthostatic intolerance due to a decreased blood volume. However, CO and flow in the abdominal aorta and common carotid artery during LBNP were similar before and after BR due to a compensatory increase after BR.

Adult↗
PubMed1997

Effects of the renin-angiotensin-aldosterone system on the cardiovascular system during 20-days bed rest.

Long term change of renin-angiotensin-aldosterone system (RAAS) induced by bed rest and its effects on cardiovascular system are still controversial. The purpose of this study was to obtain a general conclusion on these questions by analyzing our two 20-days horizontal bed rest experiments in past two years with 18 subjects. Plasma renin activity and aldosterone were consistently increased during the bed rest, but angiotensin II was increased only during the early days. Decrease in urinary sodium excretion and increase in urinary potassium excretion were observed during day 3-8 and day 7-12, respectively. Mean arterial pressure increased during day 3-8. Pulse pressure was returned to pre-bed rest level by day 10 after an initial decrease. All these results indicated an activated RAAS and its active effects on cardiovascular and overall fluid regulating systems during our horizontal bed rest studies. Direct effect of change in gravitational force on renal pressure-sensitive cells or effects related to physical inactivity may explain our results.

Adult↗
PubMed1997

Beta-blockade does not improve orthostatic intolerance induced by 20 days bed rest.

To assess if propranolol influences orthostatic intolerance induced by prolonged bed rest (BR), a lower body negative pressure test (LBNP) and left ventricular (LV) echocardiography before and during -40mmHg of LBNP were performed with and without intravenous propranolol administration (0.04mg/kg) in 9 healthy volunteers (mean age: 21 years) before and after 20 days BR. LBNP tolerance time (LBNP-T), endpoint heart rate(HR), and percentage changes from 0 to -40mmHg LBNP in HR, LV diastolic dimension(LVDd), stroke volume (SV), cardiac output (CO), and systemic vascular resistance(SVR) were measured. After BR, percentage changes in CO during LBNP was not altered by propranolol (-12+/-21% vs. -24+/-24%; with and without propranolol; p>0.05) because the effect on percentage changes in HR (18+/-11% vs. 26+/-12%; p<0.05) cancelled out the effects of percentage changes in LVDd (-9+/-6% vs. -15+/-10%; p<0.05) and percentage changes in SV (-26+/-16% vs. -39+/-22%; p<0.05). In addition, propranolol decreased end-point HR (85+/-15bpm vs. 119+/-l4bpm; p<0.05) and percentage changes in SVR (25+/-32% vs. 53+/-57%; p<0.05). As a result, LBNP-T after BR was unchanged by propranolol (8.8+/-3.3min vs. 10.8+/-5.0min; p>0.05). In conclusion, propranolol failed to change orthostatic intolerance induced by BR.

Adrenergic beta-Antagonists↗
PubMed1997

Prolonged bed rest impairs response of the small arteries to cold pressor test.

Cold pressor test (CPT) has been known to increase vascular resistance through adrenergic stimulation. To assess the effect of prolonged bed rest (BR) on sympathetic neural control, blood flow velocity of the proper palmar digital artery (resistance vessel) was measured in 10 healthy volunteers during a 90 seconds CPT by pulsed Doppler ultrasound using a 7.5 MHz linear transducer before and after 20 days BR. Blood flow velocity in the proper palmar digital artery decreased during the first half of the CPT both before and after BR, but decreases in peak flow velocity became less prominent (p<0.05) after BR (-48+/-20%) than before bed rest (-61+/-25%). The only subject whose lower body negative pressure tolerance time was prolonged after BR showed prominent decreases in peak flow velocity during the first half of the CPT after BR. Peak flow velocity returned to the pre-test value during the latter half of the CPT in 7 subjects before BR, but in only 2 subjects after BR (p<0.05). Thus, 20 days BR impairs the response of the small digital arteries to CPT, suggesting that a decrease in a adrenergic stimulation occurs after prolonged BR.

Adolescent↗
PubMed1997

Effect of bed rest immobilization on metabolic turnover of bone and bone mineral density.

Immobilization induces abnormal bone metabolism and severe decalcification of bone. To investigate the effect of middle-term immobilization on bone metabolism, we studied 10 young healthy males and females during bed rest for 20 days. Bone mineral density (BMD) rapidly decreased in both lumbar and metacarpal bones. No bone showed consistent BMD alterations, partial increase and partial decrease, and both lumbar and metacarpal bone showed similar rapid BMD change. Urinary excretion of pyridinoline tended to slightly increase by day 10, and to decline by day 20 (mean +/-SE: 34.2 +/-7.4, 26.3+/-4.6 nmol day-1, respectively). Neither alkaline phosphatase (isoform III) nor tartrate-resistant acid phosphatase, changed, suggesting that in the early stage of immobilization bone matrix in some part might increase or be resorbed without any activation of osteoblast or osteoclast, resulting in rapid calcification or decalcification, respectively.

Absorptiometry, Photon↗
PubMed1997

The effects of 20 days bed rest on serum lipids and lipoprotein concentrations in healthy young subjects.

The effects of 20 days bed rest (BR) on serum lipids and lipoprotein concentrations were investigated in 23 healthy young subjects (13 males and 10 females, aged 19 to 25 yr.). After 20 days BR, VO2max was reduced in both genders, but body composition did not change. The ratio of glucose area to insulin area during an oral glucose tolerance test decreased gradually throughout BR, which suggested a decrease in insulin sensitivity. Estimated changes in plasma volume from the beginning of BR were largest at day 3 of BR (-9.1% in females and -3.4% in males) and seemed to return the initial level at the end of BR in both genders. The increase in serum triglycerides and the decrease in high density lipoprotein (HDL) cholesterol, and apolipoprotein AI were observed in both genders during BR. In a smaller study of 4 males and 5 females, 20 days BR was associated with a decrease in HDL, cholesterol, a decrease in apolipoprotein AI and apolipoprotein AII, decrease in a plasma postheparin lipoprotein lipase activity and an increase in very low density lipoprotein triglyceride. Overall, the data suggested that the decrease in lipoprotein lipase activity and insulin sensitivity may contribute to the impairment in HDL metabolism.

Adult↗
PubMed1997

Effects of 20 days horizontal bed rest on kinesthesia during knee flexion and two-point discrimination in skin of young subjects.

Investigating the effect of 20 days bed rest (BR) on kinesthesia and two-point discrimination, 10 young volunteers participated in this study as subjects. Angle position sensation of right knee was measured in the prone position during flexion and extension monitored by a goniometer after two-point discrimination in skin was determined on the same lower leg. Flexed constant error was unchanged but directional constant error and absolute error were increased after BR (p<0.05). Two-point discrimination was unchanged after BR, which brought about a decline of the orientation of moving the joint indicated as over shooting of the angle during knee flexion, while it did not affect superficial sensation observed by two-point discrimination. Probably, an adjustment of deep sensation to the knee joint is lowered by the reduction in kinesthesia as well as the sensory disturbance during BR, which is independent on information from superficial sensation.

Adult↗
PubMed1997

Psychological stress induced by 20 days bed rest.

We investigated the changes of the psychological state during 20 days bed rest (BR) in 10 young participants,(5 males and 5 females, age; 19-24 yrs). Psychological assessment was accomplished by the following authorized 3 indices: 1) Zung's Self-rating Depression Scale, 2) Cornell Medical Index, and 3) Goldberg's General Health Questionnaire. Zung's Self-rating Depression Scale is a indicator for depression, and the other two indices were used for detecting signs of neurosis. The results from Zung's Self-rating Depression Scale and the General Health Questionnaire in this study indicated a tendency toward depression and neurosis developing during BR, respectively. The scores in the Cornell Medical Index did not change. Urinary excretion of 17-hydroxycorticosteroid increased significantly, indicating that BR immobilization induced an important psychological stress. We were unable to determine which factors caused the changes in psychological state during BR, immobilization insert or personal problems.

17-Hydroxycorticosteroids↗
PubMed1997

[Relationship between medical services utilization and preventive health behavior].

The purpose of this study was to examine the relationship between medical services utilization and preventive health behavior and to seek the factors affecting them. Subjects were 568 persons who were from 40 to 59 years old and lived in a community. Preventive health behaviors they actually performed and their interests in health were asked by questionnaire. Preventive health behaviors assessed included smoking behavior, drinking behavior, adequate hours of sleep, physical exercise, regularity of meals, and medical checkups. Medical services utilization, which included the number of visits to medical care providers, was measured by their medical claims during one year. Except for adequate hours of sleep, preventive health behaviors correlated positively with each other. A strong positive correlation was found between medical services utilization and medical checkups. However, correlations between medical services utilization and other preventive health behaviors were not statistically significant. Persons who performed preventive health behaviors and persons who utilized medical services scored higher in interest in health than persons who didn't. These results show that medical services utilization and preventive health behavior are strongly associated with interest in health, but are weakly correlated with each other.

Adult↗
PubMed1996

[Public health nurse staffing requirements for health examination of infants and children in municipalities of Japan].

In accordance with the Maternal and Child Health Service Act, public health centers and municipalities offer health education, health counseling, health examinations, and home visits for children and their mothers in their jurisdiction. On the basis of the new Maternal and Child Health Service Act, municipalities will have the responsibility to effectively promote health examination for three-year-old children beginning in 1997. To provide health examinations to infants and children, establishing a health personnel system, especially the public health nurse program, is extremely important. The purpose of this study is to determine fundamental facts concerning health manpower development among public health nurses in the municipalities, by reviewing research on health examinations for both infants and children. To determine personnel staffing requirements necessary for health examinations of infants and children in the municipalities of Japan, pertinent references were systematically reviewed. The main results are as follows; 1) The correlation coefficients between the total working hours of the public health nurse for MCH and the population per area and number of birth per year were significantly positive. 2) Total working hours for health examination of three-year-old children per 100 births per year, by the public health nurse were 143 hours, of which 79% were spent just for performing the examination itself. 3) Due to the lack of health personnel, rural towns and villages with small populations required public health nurses to be assisted by other staff, most often public health nurses from prefectural Health Centers. For example, in those areas with a population of less than 3,000, 43% of the total volume of work performed by public health nurses during the health examinations of three-year-old children required the assistance of prefectural public health nurses. 4) On the other hand, in those areas with populations more than 10,000, 88% of the total volume of work required to be performed by public health nurses during the health examinations for three-year-old children was covered by municipal public health nurses. 5) When the total number of working hours of the public health nurse for Maternal and Child Health was divided into the four parts of planning, implementation, evaluation and training, 86.7% of working hours were spent on implementation itself. 6) In those cities designated by the Government, the health personnel system was sufficient to carry out these health examinations. 7) It was found that in towns and villages with small populations, the health examinations for infants and children can be better carried out in combination with assistance by prefectural public health nurses. 8) The review of the findings suggests that it is important to clarify by further studies not only the relationship between the health manpower system and implementation of the health examination but also the relationship between this system and the effectiveness of the health examination in near future.

Adult↗
PubMed1996

[Medical services utilization of the elderly during the last six months of life].

The purpose of this study was to describe the characteristics of medical services utilization during the last six months of life. Subjects were 150 elderly who lived in a community and died in 1990. By each subject's medical claims during the last six months of life, the number of hospital days, the number of visits for ambulatory care, the number of physicians' and nurses' visits for home care, medical expenditure, and the utilization of medical care activities were measured as utilization variables. Subjects were classified into four subgroups by the combination of cancer and cerebrovascular disease. These diseases have an important impact on medical services utilization during the last six months of life. Utilization variables of each subgroup were compared. The findings were as follows; 1. During the last six months of life, hospital stays of cerebrovascular disease patients were for long periods, while cancer patients frequently and repeatedly changed the place of care between hospital and home. 2. The number of visits for ambulatory care and the number of medical care providers utilized by cancer patients were greater than that of cerebrovascular disease patients. Cerebrovascular disease patients whose stay at the hospital was short made greater use of physicians' and nurses' visit for home care. 3. The medical expenditure of cancer patients was higher than that of cerebrovascular disease patients, although the number of hospital days of cancer patients was less. 4. Most of the cancer patients utilized transfusion and urological treatment. These results suggest that the utilization of medical care activities of cancer patients was more intensive than that of cerebrovascular disease patients. However cancer patients made little use of resuscitation procedures.

Aged↗
PubMed1995

A study on indices of body fat distribution for screening for obesity.

In order to screen high risk obesity groups for coronary heart disease, the relationships between certain body fat distribution indices and coronary risk factors (CRFs) were analyzed. Body circumference at various measuring points and skinfold thickness were measured in 938 male clerical workers, and some indices of body fat distribution were calculated. The results are as follows: (1) The body mass index (BMI) showed the highest correlation with systolic blood pressure, and skinfold thickness showed a high correlation with serum total cholesterol (TC) and LDL-cholesterol. (2) In body fat distribution indices, the waist/stature ratio (WSR) showed the highest correlation with CRF measurements, especially with serum triglyceride (TG) and diastolic blood pressure (DBP). (3) WSR showed the highest sensitivity and specificity for screening for abnormal hypertension groups TG and TC. (4) There were significant differences in the mean value for all CRF measurements between the high WSR group (> = 0.49) and the low WSR group (< 0.49), and the rates for high CRF persons in the high WSR group were almost twice those of the low WSR group. These results show that WSR is useful for the screening for obesity to prevent coronary heart disease.

Adipose Tissue↗
PubMed1995

Activated renin-angiotensin-aldosterone system and its effects on cardiovascular system during 20-days horizontal bed rest.

Change in circulating blood volume by bed rest has been suggested to effect on many cardiovascular responses after bed rest including orthostatic intolerance and exercise performance. However, there is a lack of consensus on effect of renin-angiotensin-aldosterone system (RAAS) on baseline heart rate and blood pressure during bed rest, although RAAS is the most potent fluid regulating system. The purpose of this study was to clarify the effect of RAAS on changes in baseline cardiovascular system and urine excretion.

Aldosterone↗
PubMed1995

Effects of 20 days bed rest on mechanical efficiency during upright cycling and leg muscle mass in young males.

Delta efficiency defined as increase in work over the corresponding increase in energy liberation (delta work/delta energy) may be used to express the efficiency of working muscles under standard conditions where work is performed with similar changes in muscle length, identical pedal revolution frequencies, and contraction-to-relaxation ratios. The Delta efficiency is probably the most valid measure of the efficiency of muscular work, so it may be influenced by the difference in distribution and/or density of muscle fiber types in exercising muscles. It has been reported that after bed rest of 7-14 days, not only maximum oxygen uptake (VO2 max) but also oxygen uptake (VO2) at 3-min submaximal upright exercise decreased. However, the decrease might be apparent, and the mechanical efficiency might be unchanged. On the other hand, muscle mass of bicycling legs was decreased after continuous horizontal bed rest of 10 days and 20 days. Because the decreased muscle mass is probably related to decrease in the density of the slow twitch muscle fibers (ST-fiber), the decrease in submaximal VO2 during bicycle exercises after bed rest may result from a decrease in ST-fiber mass. Therefore, it could be hypothesized that the mechanical efficiency should increase during upright exercise because of the relative increase in amount of more efficient fast twitch muscle fibers (FT-fiber) than ST fibers in exercising muscles. The purpose of the present study was to investigate whether delta efficiency in working muscle is influenced by the decrease in muscle mass after 20 days horizontal bed rest in young males.

Adult↗
PubMed1995

[Personnel requirements for health examination for 6 month and 9 mont-old children in municipalities in Japan].

Based on the Maternal and Child Health Law, municipalities offer health education, health counseling, health examination, and home visitation service for children and their mothers. In order to determine the personnel staffing requirements for the health examinations of 6 and 9 month-old children conducted independently by municipalities in Japan in 1989, data from the questionnaire survey executed by the Ministry of Health and Welfare in 1990 was analyzed. Questionnaires were sent to all municipalities and there were 3,198 responses for a response rate of 97.9% Results showed that in 1989, 27.5% of the 3,198 municipalities were able to perform health examinations for 6 month-old children and 24.7% for 9 month-old children. In the case of those cities which had populations over 10,000 but under 20,000, about 30% were able to perform the health examinations for 6 and 9 month-old children independently. In those cities which had health Centers, the health personnel system most adequately supported these health examinations. Due to the lack of health personnel, rural towns and villages with small populations required public health nurses to be assisted by other staff, most often public health nurses from prefectural Health Centers. For example, in those areas with populations less than 3,000, about 42-45% of the total volume of the work required to be performed by public health nurses during the health examinations for 6 and 9 month-old children had to be covered by assistance from prefectural public health nurses.

Child Welfare↗
PubMed1995

[Health personnel staffing requirements for health examination for the age of 1 1/2 in municipalities in Japan].

Municipalities in Japan offer health education, health counseling, health examination, and home visit services for each development stage of children and for their mothers. In order to determine personnel staffing requirements for the health examination for the age of 1 1/2 as of 1989, data from a questionnaire survey in 1990 conducted by the Ministry of Health and Welfare, was analyzed. Questionnaires were sent to all municipalities and there were 3,198 responses for the response rate of 97.9%. Results showed that in 1989, 98.9% of the 3,012 municipalities were able to independently perform health examinations for 1 and half year old, and in only 0.9% these examination were performed by clinical hospitals. In the large cities designated by the Government, the health personnel system adequately supported these health examination. However due to lack of health personnel, rural towns and villages with small populations required public health nurses to be assisted by other staff, such as health workers or volunteers. And particularly they required help by public health nurses from prefectural Health Centers. For example, in those areas with populations less than 3,000, 53% of the total volume of the work required to be performed by public health nurses during the health examination had to be covered by assistance from prefectural public health nurses. While in cities with more than 300,000 population large numbers of health personnel were assigned to examinations of children, the large number of children processed resulted in inadequate time for each child/mother pair. Further study of quality levels of the examinations need to be performed.

Child Health Services↗