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Biomedical subjects

A Shimouchi

Publications and source records attributed to A Shimouchi.

At least 19 recordsLinked to original sources
PubMed2001

K(ATP) channels predominantly regulate conduit vessel tone in normoxic cat pulmonary arteries in vivo.

Through our investigations of the intact pulmonary circulation, we aimed to find out whether K(ATP) channels contribute to regulating basal vascular tone and to clarify which vascular segments dilate during K(ATP) channel activation under basal tone conditions. Using an X-ray television system on anesthetized cat lungs, we measured internal diameter (ID) responses to two K(ATP) channel inhibitors (glibenclamide and 4-morpholinecarboximidine-N-1-adamantyl-N'-cyclohexyl-hydrochloride (U-37883A)) and to an activator (levcromakalim) in normoxic pulmonary arteries. In conduit arteries (800-3000 microm ID), the inhibitors and activator induced larger ID constrictions (14-17%) and dilatations (29-32%), respectively. However, in resistance arteries (<500 microm), the constriction response was negligible and the dilatation response relatively small (5-10%). The data suggest that K(ATP) channels are active and capable of regulating basal vascular tone primarily within conduit pulmonary arteries even though these channels are present in all pulmonary arteries.

Adamantane↗
PubMed2001

Tuberculosis problems in the Asia-Pacific region.

Tuberculosis (TB) is the top killer of the productive age group in developing countries. More than half of cases in the world occur in Asia-Pacific region. The number of cases will increase in the next decades due to increase in urban poor population and HIV incidence, and poor access to health services and poor TB programme. The mainstay of effective strategy is to promote DOTS. DOTS population coverage is high, 58% in the Western Pacific Region but low; 29% in the southeast Asia region. Even among intermediate TB-burden countries in Asia, reduction of incidence has stagnated in recent years because of aging population, health problems in the urban poor population and influx of populations from high endemic areas. Indicators of successful TB programmes are high cure rate and low drug resistance rate. There is a strong correlation between the overall quality of TB control in the past and the current primary drug-resistant rate. To solve these problems, priority should be given to nationwide implementation of DOTS in high TB-burden countries with emphasis on ensuring availability of free anti-TB drugs and strengthening primary health care. General hospitals and private sector should be involved in control programmes to prevent drug resistant cases.

Antitubercular Agents↗
PubMed2001

Two-week, but not 1-week, hypoxic exposure enhances nitric oxide-mediated basal tone regulation in rat resistance pulmonary arteries.

We measured internal diameter (ID) changes in resistance and conduit pulmonary arteries of 1- and 2-week hypoxic rats and normoxic control rats in response to nitric oxide synthase (NOS) inhibitors in vivo. At 2 weeks of hypoxic exposure, the ID reduction as a result of NOS inhibition was enhanced within the resistance arteries, but not at 1 week of hypoxia.

Animals↗
PubMed2001

Gender difference in delays to diagnosis and health care seeking behaviour in a rural area of Nepal.

SETTING: Directly observed treatment for tuberculosis using a short-course regimen (DOTS) was introduced in a rural area of Nepal. All new patients assigned to DOTS from mid-December 1997 to mid-June 1999 were eligible for the study. OBJECTIVE: To examine delays in tuberculosis (TB) diagnosis and compare health care seeking behaviour between men and women. DESIGN: A cross-sectional analysis of patient interviews. RESULTS: Women were found to have a significantly longer total delay before diagnosis of tuberculosis (median 2.3 months for men, 3.3 months for women). When they visited traditional healers first, women had a significantly longer delay than men from the first visit to health care providers to diagnosis (median 1.5 months for men, 3.0 months for women). More women (35%) visited traditional healers before diagnosis than men (18%), and were more likely to receive more complicated charms from traditional healers. Men tended to visit the government medical establishment first if they knew that free TB treatment was available, but women did not. CONCLUSION: Women were more likely to visit and to believe in traditional healers; this might lead to the longer delays experienced before TB diagnosis.

Adolescent↗
PubMed2000

Improvement in exercise capacity with nitric oxide inhalation in patients with precapillary pulmonary hypertension.

BACKGROUND: Patients with precapillary pulmonary hypertension (PH) exhibit a poor exercise capacity due to an impaired vasodilatory response of their pulmonary arteries. By causing the pulmonary artery to dilate, inhaled nitric oxide (NO) may allow an increase in exercise capacity in patients with PH. METHODS AND RESULTS: On 2 separate days, 3 days apart, 14 patients with precapillary PH (10 primary PH, 4 residual PH after correction of an intracardiac shunt; age, 40+/-12 years; mean pulmonary artery pressure, 60+/-23 mm Hg) performed exercise, with and without inhalation of 20 ppm NO, on a cycle ergometer. The work rate was increased 15 W/min until their symptom-limited maximum, with breath-by-breath gas analysis. Patients were randomly and blindly selected to inhale NO on either their first or second test. Peak exercise load and anaerobic threshold tended to increase, but not significantly. Peak oxygen consumption (f1.gif" BORDER="0">O(2)) and Deltaf1.gif" BORDER="0">O(2)/DeltaW ratio increased significantly, by 18% and 22%, respectively (peak f1.gif" BORDER="0">O(2), 13.6+/-3.6 to 16.0+/-4. 1 mL. kg(-1). min(-1); Deltaf1.gif" BORDER="0">O(2)/DeltaW ratio, 5. 8+/-2.4 to 7.1+/-2.3 mL. kg(-1). min(-1). W(-1); both P<0.01). Peak f1.gif" BORDER="0">O(2) increased >10% in 12 of the 14 patients. However, respiratory quotient at peak exercise decreased from 1. 22+/-0.15 to 1.09+/-0.15 (P<0.01). CONCLUSIONS: Inhaled NO substantially increases oxygen consumption at the same workload during exercise. This finding supports the possibility of ambulatory NO inhalation therapy in patients with precapillary PH.

Administration, Inhalation↗
PubMed1999

Segmental differences in vasodilatation due to basal NO release in in vivo cat pulmonary vessels.

This study was conducted to examine segmental differences in vasodilatation caused by the basal release of nitric oxide (NO) in the serially connected pulmonary vessels and to estimate the relative contributions of endothelial and neuronal NO synthase (NOS), and inducible NOS to the vasodilatation. Using an X-ray TV system on in vivo cat lungs, we measured internal diameter (ID) changes in resistance (100-400 microm ID), small conduit (600-1000 microm) and large conduit (1200-1700 microm) arteries, and veins of the same size. Non-selective NOS inhibitors, L-NAME (30-50 mg/kg i.v.) and L-NMMA (40-60 mg/kg i.v.), decreased the ID of all vessels studied, although their D-isomers had no effect. The decrease was larger in conduit arteries than in resistance arteries, with maximum response of small conduit arteries (25 +/- 2%), while venous segments displayed relatively uniform response (10-12%). L-Arginine completely abolished the ID decrease but hexamethonium bromide and phentolamine had no effect. Selective inhibitors of inducible NOS, L-canavanine (100 mg/kg i.v.) and S-methylisothiourea (10 mg/kg i.v.) did not affect any of the vessels. The data suggest that basal release of NO chiefly derived from endothelial NOS serves to dilate cat pulmonary arteries and veins, particularly small conduit arteries.

Angiography↗
PubMed1999

Pulmonary microvascular responses to inhaled prostacyclin, nitric oxide, and their combination in anesthetized cats.

Using an X-ray television system on anesthetized cats, we directly measured internal diameter (ID) changes in identical small pulmonary vessels (100-1,100 microm ID) in response to inhalations of 25, 250, and 2,500 ng/kg/min aerosolized prostacyclin (PGI2), 4 and 34 ppm nitric oxide (NO), and the combination of aerosolized PGI2 and NO. We also compared ID changes during 250 ng/kg/min PGI2 inhalation both with and without an Nomega-nitro-L-arginine methyl ester (L-NAME, 30 mg/kg I.V.) pretreatment. In the arteries, inhaled PGI2 increased 100-900 microm vessel ID in a dose-dependent manner but caused no significant, or only slight, ID increases in the vessels larger than this. The greatest ID increase ( approximately 22%) was in the 100-500 microm arteries in response to 2,500 ng/kg/min PGI2 inhalation. PGI2 also increased the ID of the veins (6-12%), but the results were not dose related. NO inhalation also resulted in non-uniform ID response patterns similar to PGI2 with no significant, or only minimal, ID increases of the arteries >900 microm. The simultaneous inhalation of 2,500 ng/kg/min PGI2 and 34 ppm NO increased the arterial ID (maximum approximately 34%) more than either drug alone and to almost the same extent as brought about by injected papaverine (2 mg/kg), a smooth muscle relaxant. Inhaled PGI2 (250 ng/kg/min) decreased pulmonary arterial pressure and increased arterial ID to nearly the same extent with or without L-NAME pretreatment. These results indicate that inhaled PGI2 and inhaled NO locally dilate 100-900 microm pulmonary arteries in a dose-dependent manner and with a similar ID response pattern, and that the combination of these drugs produces a more enhanced vasodilator effect compared to their separate effects and induces the maximum dilated states. The data also suggest that inhaled PGI2 dilates these arteries directly, rather than via secondary release of endogenous NO.

Administration, Inhalation↗
PubMed1997

Vasodilator effects of adrenomedullin on small pulmonary arteries and veins in anaesthetized cats.

1. This study was conducted to determine adrenomedullin (AM) action sites in the pulmonary vascular bed and the relation between its vasodilator effects and vascular tone. Moreover, an examination was made into whether calcitonin gene-related peptide (CGRP) receptors mediate pulmonary vasodilatations induced by AM. To this end, we directly measured internal diameter (i.d.) changes in small pulmonary arteries and veins (100-1100 microns i.d.) by use of an X-ray television system on the in vivo cat lung. 2. Under control (resting vascular tone) conditions, AM injections into the left main pulmonary artery caused dose-related i.d. increases in both small arteries and veins. The mean i.d. increase of the 100-1100 microns arteries (4 +/- 1, 11 +/- 2, and 17 +/- 2% with 0.01, 0.1, and 1 nmol kg-1 AM, respectively) was significantly larger than that for the veins (1 +/- 1, 5 +/- 2, and 7 +/- 2% with 0.01, 0.1 and 1 nmol kg-1 AM, respectively) whatever the injected dose of AM. 3. When unilobar hypoxia (5% O2) had decreased the i.d. of the 100-1100 microns arteries and veins by 16 +/- 3 and 6 +/- 3%, respectively, AM (0.1 nmol kg-1) was able to induce significantly larger i.d. increases in the arteries (28 +/- 3%) and veins (11 +/- 3%) than those under control conditions. 4. The AM-induced i.d. response pattern in the serially connected pulmonary arteries was quite different from that induced by CGRP; AM caused a greater increase in smaller vessels (100-500 microns) than in larger vessels (500-1100 microns). In the case of CGRP, a greater increase was observed in the larger vessels. 5. CGRP8-37 (100 nmol kg-1, i.v., followed by a continuous infusion of 0.2 nmol kg-1 min-1) had no significant effect on the i.d. increase induced by AM (0.1 nmol kg-1) in any serial segments of the arteries and veins. 6. The results indicate that, in the cat, AM induces greater vasodilatation in small pulmonary arteries and lesser vasodilatation in small veins, the maximum dilatation being in the more peripheral arterial segment (100-500 microns). The vasodilator effect of AM was enhanced when vascular tone was elevated. The data suggest that the AM-induced pulmonary vasodilatation is not mediated by CGRP receptors but by its own specific receptor.

Adrenomedullin↗
PubMed1996

Inhaled nitric oxide: diameter response patterns in feline small pulmonary arteries and veins.

Using an X-ray television system on the in vivo cat lung, we directly measured internal diameter (ID) changes in the small pulmonary arteries and veins (100-1,100 microns ID) in response to 5, 15, and 40 ppm nitric oxide (NO) inhalations. We also measured to what extent 40 ppm NO inhalation can attenuate large ID constrictions at the different serial segments of the small vessels due to unilobar anoxic (0% O2) exposure. Under normoxic conditions, 5-40 ppm NO inhalations significantly increased the ID of both arteries and veins less than approximately 900 microns dose dependently but caused no significant, or only slight, ID increases in the vessels larger than this, if any at all. The ID increase in the serially connected arteries was nonuniform (4-18, 8-28, and 7-35% with 5, 15, and 40 ppm NO inhalations, respectively), whereas that for the veins was relatively uniform (4-9, 6-17, and 7-18% with 5, 15, and 40 ppm NO, respectively). The maximum ID increase occurred in the 200- to 500- and 200- to 700-microns arteries in response to 5-15 and 40 ppm NO, respectively. Unilobar anoxic exposure significantly decreased the ID of the 100- to 700-microns arteries and veins, but not the ID of the other-sized vessels. The ID decrease in the serially connected arteries was nonuniform (13-29%) but relatively uniform in the veins (8-12%). The maximum ID decrease occurred in the 200- to 300-microns arteries. However, adding 40 ppm NO to the lobe completely eradicated the ID decreases at all segments of the arteries and veins and, instead, caused significant ID increase (11-21%) in the arteries and (10-12%) in the veins. The data indicate that, according to dosage, 5-40 ppm NO inhalations cause selective dilation of approximately 100- to 900-microns pulmonary arteries and veins, particularly the 200- to 700-microns arteries. During anoxic exposure, the vasodilator effect of NO is preserved and can completely reverse the marked pulmonary vasoconstriction.

Administration, Inhalation↗
PubMed1996

[Incidence, risk factors relating to bacillary tuberculosis and secondary infections from registered patients in Hunai-Gun, Kyoto Prefecture].

To review how to strengthen tuberculosis program in Hunai-Gun, Kyoto Prefecture, the recent trend of incidence of tuberculosis and 148 index cases with pulmonary tuberculosis newly registered from 1987 to 1992 were analyzed regarding the mode of detection, conditions when consulting medical facilities, risk factors, bacteriological findings, and secondary infections among contacts. 1. The high crude incidence of tuberculosis in Hunai-Gun is explained by the high proportion (19.3%) of the elderly population of 65 years old and over in Hunai-Gun compared with the average (12.6%) in the Prefecture and the high tuberculosis incidence among age group of 70 years old and over in Hunai-Gun compared with the prefectural average. However, the reason of higher incidence of tuberculosis among the elderly in the district was not clear. 2. The proportion of bacillary as well as culture positive cases were higher among patients who were diagnosed by consulting medical facilities than those detected by regular health check. The proportion of bacillary cases without risk factors for tuberculosis among patients who were diagnosed at medical facilities was the highest among those newly attending medical facilities due to complaints related to tuberculosis (group A), followed by those patients regularly attending medical facilities for other diseases but consulting because of additional complaints related to tuberculosis (group B), and lowest among patients regularly attending medical facilities but detected by chance while being examined for other diseases (group C). The severer the diseases stage, the higher the proportion of bacillary cases, however, there were no difference in the proportion of bacillary cases among the above three groups including those with risk factors. It is explained by the fact that the ratio of patients with risk factors was high in group C, which masked the higher proportion of bacillary cases among patients with risk factors. 3. As future activities of public health center on tuberculosis control, it is important to give health education to those with risk factors on the fact that the progression of the disease is faster among them in addition to the increased risk of the disease onset, and advise them to attend regular health check and visit medical facilities when they have any symptom related to tuberculosis. 4. Considering the fact that the risk of secondary infection to contacts is higher among smear positive patients than bacilli negative patients, it is needed to examine all contacts of sputum smear positive patients thoroughly. In addition, it is advisable to follow-up contacts of smear negative but culture positive patients with the similar intensity with those for smear positive patients because their risk of secondary infection to contacts was also higher than bacilli negative patients although it was not statistically significant.

Adolescent↗
PubMed1996

[Cross sectional study of the relationship between bone density to diet and life style using ultrasound bone densitometry].

The relationship between bone density to diet and life style was investigated in pre- and postmenopausal women in Kyoto Prefecture in 1994 by a cross-sectional study. Bone densities of 453 women aged 30-86 years were measured by ultrasound bone densitometry. History of pregnancy and delivery, menstruation, medical history, bone and arthral symptoms, life style, food intake frequency, current and past intake of dairy products, and physical activity were examined by self-administered questionnaire. Analysis of covariance and multiple-regression analysis were performed to determine the relation between bone density and life style adjusted for age and obesity index among 151 premenopausal women (PRE), 244 postmenopausal but not sedentary (under 65 years of age) women (POST), and 58 sedentary (older than 65 years of age) women (SED). The results were as follows; 1) A marked age-related decline in bone density was observed at 45-55 years of age. The correlation coefficient between age and bone density was significant at -0.65 (p < 0.01). 2) Obesity index and bone density were positively correlated in each group. 3) Among the PRE group women, there was no relation between life style and bone density. Those who experienced bone fractures tended toward low bone density. Among the POST group, time since menopause, exercise, and current milk intake were significantly correlated with bone density. In the SED group, women with arthralgia showed significantly lower densities. 4) From multiple-regression analysis, age, obesity index, and milk intake during childhood were shown to be related to bone density in each group.

Adult↗
PubMed1995

Effectiveness of control programs for pneumonia among children in China and Fiji.

This article summarizes the implementation and efficacy of the World Health Organization's standard case management program for pediatric pneumonia in three counties in China and in the Western Division of Fiji. The information provided through this program was simple enough to be understood by parents and health care workers with a basic educational background. The program reduced mortality from pneumonia even when implemented through the existing health care system in a relatively poor county in China. The factors important in the success of the program included improved recognition of the signs of childhood pneumonia by parents, earlier presentation of children with these signs to health care facilities, availability of antimicrobial agents at the primary health care level, and rational decisions by health care workers about the use of these agents.

Anti-Bacterial Agents↗
PubMed1995

[Characteristics of smoking, drinking, dietary habits, and physical exercise in health behavioral models].

Various kinds of preventive health behaviors are promoted by health education. The extent of behavioral modification achieved, however, obviously differs from individual to individual according to habits, one of the reasons being the characteristics of various health habits are perceived differently. This cross-sectional study examined the association of indices representing health behavior models with smoking, drinking, dietary habits, and physical exercise. The indices and their meaning were as follows; health locus of control (HLC) and saliency of health are thought to cause the most active behavioral change, health norm relatively passive change, and vulnerability to illness the most passive change. The indices and lifestyle (health related practices) were surveyed by a self-administered questionnaire in a rural town in March 1994. The study sample consisted of 1,010 males and 1,055 females aged 20 years or older who responded to all questions related to the indices. Results are as follows: 1) Smoking and alcohol drinking were associated with vulnerability to illness, suggesting that people who quit smoking or alcohol drinking do so because of perception of their association with illness. Alcohol drinking seemed to have a higher magnitude of being associated with becoming ill or with fear of illness than smoking. 2) Consuming green-yellow vegetables and fresh fish, and physical fitness were associated with internal HLC, saliency of health, and health norm. These habits appeared to be easy to modify by active personal behavior choice. 3) Consuming milk, yogurt, boiled beans, tofu, oranges, and other fruits were associated with saliency of health. These habits seemed to relate to personal sense of being "healthy". 4) It seemed that younger people more likely changed their behavior by active self-management, while, older people changed due to their sense of value or norm. While it is important for health education to promote "self-management of health" by active behavioral change, certain habits are more resistant to change despite educational efforts possibly because of their characteristics in health behavioral models. For cases such as these, techniques promoting passive behavioral change should be considered.

Adult↗
PubMed1994

Diameter and flow velocity changes of feline small pulmonary vessels in response to sympathetic nerve stimulation.

Using an X-ray television system, we measured directly changes in the internal diameter (ID), flow velocity, and volume flow of the small pulmonary vessels (100-500 microns ID) in response to electrical sympathetic nerve stimulation (SNS) in anaesthetized cats before and after adrenergic receptor blockade. Flow velocity was obtained by measuring the distance that the leading edge of the contrast medium moved per 0.1 s in the small arteries. Volume flow was obtained from the product of flow velocity and cross-sectional area calculated from the ID of the small arteries. SNS was accomplished with 10- to 15-V square-wave pulses of 2-ms duration at 20-30 Hz for 20-s periods. In response to SNS, arterial ID decreased significantly by 8-13% in the 200- to 500-microns vessels but not in the 100- to 200-microns vessels. In the veins, on the other hand, there was no significant ID decrease in any of the 100- to 500-microns vessels. After alpha-receptor blockade (phentolamine, 2 mg/kg i.v.), there were significant ID increases (4-9%) in the 100- to 500-microns arteries in response to SNS, the maximum increases being in the 100- to 200-microns arteries. After beta-blockade (propranolol, 2 mg/kg i.v.), the ID decrease due to SNS in the 200- to 500-microns arteries was enhanced (24-27%) and, in addition, the 100- to 200-microns arteries exhibited a significant ID decrease (18%). Combined alpha- and beta-blockade completely abolished the ID decrease due to SNS. In the veins, on the other hand, no ID change occurred even after alpha- or beta-blockade.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Immunization coverage and infant mortality rate in developing countries.

We examined whether immunization coverage (IMC) is one of the predictors of infant mortality rate (IMR), as a single indicator representing the availability of primary health care (PHC) services in developing countries. Multiple regression analysis showed that partial correlation coefficients for IMR with immunization coverage (-0.224), logarithm of per capita GNP (-0.294), total fertility rate (0.269), and adult literacy rate (-0.325) were all statistically significant (p < 0.001) in 97 developing countries which make up more than 97% of the population in all the developing countries of the world. Multiple correlation coefficients of IMR with these four variables in 97 countries was 0.921. Thus, more than 80% of variation of IMR in developing countries were explained by the variation of the four variables. The study also showed that IMC was well correlated (simple correlation) with the four indicators of the availability of primary health care services; access to local care (0.730), care of pregnant women (0.603), delivery care (0.666), and infant care (0.553), all of which were statistically significant (p < 0.001) in the 48 developing countries which make up 42% of the population of all developing countries. Multiple correlation coefficients of these four variables was 0.787. About 60% of the variation of IMC will be explained by the variation of the four variables. Thus we conclude that immunization coverage is one of the main predictors of the infant mortality rate. It represents one of the health intervention components which can be used as a proxy indicator of the availability of PHC service in developing countries.

Adult↗