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Biomedical subjects

A Kawamoto

Publications and source records attributed to A Kawamoto.

At least 55 records · Page 3Linked to original sources
PubMed1994

Three year follow up study of national influenza vaccination practices in Japan.

STUDY OBJECTIVE: To evaluate new national influenza vaccination practices which were started in 1987 under a revised law in Japan. DESIGN: This was a three year, nonrandomised cohort study with information collected by questionnaire between 1989 and 1991. SETTING: Eight primary schools in the city of Yonago, Tottori, Japan. These schools were selected from 23 schools in the city. PARTICIPANTS: Altogether 4251 pupils (1355 boys and 2896 girls) in years 1-4 of the eight primary schools were included in this study, and followed up. Three years later, data for 1619 pupils (768 boys and 851 girls) were obtained and analysed. MAIN RESULTS: The one-winter seasonal incidence rates of influenza-like disease were 13.4%, 29.9%, and 10.3% in 1989, 1990, and 1991 respectively. The incidence rate of influenza-like disease in fully vaccinated pupils was significantly lower than that in unvaccinated pupils in 1990, but not in 1989 or 1991. Stepwise multiple regression analysis showed that the incidence of influenza-like disease had a statistical relationship with the frequency of vaccination and the school year (R2 was 0.0148). Standardised parameters of the frequency of vaccination and the school frequency of vaccination and the school year were -0.089 and -0.080 respectively. CONCLUSIONS: The preventive effects of influenza vaccine are not strong. There must be some unknown factors that affect the incidence of influenza. This vaccine is useful for pupils in the early school years who seem to have less resistance. All pupils should not be inoculated with the vaccine to reduce influenza transmission in the community or school.

Child↗
PubMed1994

[Normal ranges of blood urea nitrogen and serum creatinine levels in the community-dwelling elderly subjects aged 70 years or over--correlation between age and renal function].

To estimate normal ranges of blood urea nitrogen (BUN) and serum creatinine (Cr) levels in the aged, we measured BUN and Cr levels in 332 cases of apparent-healthy elderly subjects (male, 152; female, 180) aged 70 years or more. We measured the variables also in 315 cases of sex-matched young control subjects (male, 139; female, 176). This study was a part of the Kahoku Longitudinal Aging Study (KLAS) that aims to reveal the comprehensive functions in the aged. We calculated the mean and the standard deviation (SD) in each group, and excluded subjects with values beyond twice the SD-line. We defined the normal range as range within the single SD-line of the remainder. The estimated normal range of BUN was 14-23 mg/dl both in male and female elderly subjects, and that of Cr was 0.9-1.3 mg/dl in male and was 0.7-1.1 mg/dl in female. The mean BUN level in the elderly subjects was significantly higher than that in the control young subjects. The mean Cr level in the elderly subjects was slightly higher than that in the control subjects. Significant positive correlation was found between BUN levels and age in male elderly subjects. Although Cr levels did not correlate with age in elderly subjects, Cr levels divided by body surface area significantly correlated with age. We concluded that the normal range of BUN and Cr levels differed between young and elderly subjects, and that the decline in renal function correlated with age after the seventh decade.

Adult↗
PubMed1994

[Longitudinal change in independence in the elderly--Kahoku Longitudinal Aging Study (KLAS)].

A community based study named Kahoku Longitudinal Aging Study (KLAS) was conducted since 1990 for the purpose of evaluating the comprehensive geriatric functional assessment (CGA) and preventing a decline in CGA in the community-dwelling elderly population. It was carried out in a Japanese rural town, in which 32% of the population was over 65 years of age. This study included a questionnaire about activity of daily living (ADL), information-related physical function, mental (cognitive and affective) and social functional domains. In addition to subjective informative instruments, various types of objective assessment such as quantitative neuro-behavioral function tests and medical examinations were performed. Subjects were all the eligible elderly aged over 65 years in the community. Although the ratio of subjects who were independent in ADL decreased with advancing age in both 1991 and 1993, the ratio of the independent elderly in ADL became significant higher (74%) in 1993 than in 1991 (71%). Scores on 2 kinds of neurobehavioral function tests in the 159 subjects aged over 75 years who attended the examination every year showed a significant and slight decrease during two years. However, some test indices significantly improved during the 2 years. These results suggested that age-related dependency in ADL and some kind of neurobehavioral functions might be prevented, in part, by health promoting education and improvement of life style.

Activities of Daily Living↗
PubMed1994

Pathophysiology and end-organ damage in elderly hypertensives.

PATHOPHYSIOLOGY OF HYPERTENSION: Blood pressure increases with advancing age in most developed countries. The pathophysiology of elderly hypertension is characterized by changes in the structure and function of the cardiovascular system. Changes in arterial structure lead to a decrease in aortic compliance, which augments the aortic pressure component generated by the wave reflection mechanism. The age-related increase in the reflected-wave component of arterial pressure may contribute, at least in part, to the age-related rise in systolic blood pressure. Disproportionately elevated systolic blood pressure in the elderly may account for the progressive increase in left ventricular mass with advancing age. In addition to the changes in vascular and cardiac structures, the haemodynamic function of elderly hypertensives is characterized by increased peripheral resistance as well as reduced cardiac output, renal blood flow and intravascular volume. In contrast to younger hypertensives, the sympathetic and renin-angiotensin systems may not be major factors in the genesis of high peripheral resistance in this patient group. END-ORGAN DAMAGE: The most important end-organ damage in elderly hypertensives is left ventricular hypertrophy with or without coronary heart disease, cerebrovascular disease or renal impairment. Furthermore, this end-organ damage is frequently asymptomatic (silent). The prevalence of silent cerebrovascular disease in particular is surprisingly high in this elderly population. Asymptomatic cerebrovascular disease has been shown to be associated with various cardiovascular risk factors, and depressed neurobehavioural function. Diurnal blood pressure variations appear to be related to end-organ damage. The presence of occult end-organ damage and co-existing diseases common in elderly hypertensives has important clinical implications in the management of this disorder.

Aged↗
PubMed1993

Accuracy of a continuous blood pressure monitor based on arterial tonometry.

A validation study of the continuous noninvasive tonometric blood pressure monitor called JENTOW was performed in 20 normotensive subjects and 10 hypertensive patients. Tonometric and intra-arterial blood pressures were simultaneously recorded at supine rest and during a Valsalva maneuver and tilting test. The results of the strict evaluation of the instrument's capacity for reproducing intra-arterial blood pressure were as follows: 1) The overall frequency response of the transcutaneous blood pressure-monitoring system based on arterial tonometry was flat, with negligible delay to intra-arterial blood pressure in the range of 0-5 Hz. 2) The largest discrepancy between intra-arterial and tonometric pressure waveforms was found at the early systolic phase; except for this phase, the tonometric waveform was almost equal to the intra-arterial waveform. 3) The beat-to-beat variability of tonometric pressure corresponded to that of intra-arterial pressure almost perfectly in the physiologically significant frequency range of 0-0.5 Hz. 4) During resting conditions, the averages of the systolic and diastolic values measured tonometrically corresponded well to those measured intra-arterially. 5) The changes in the between-method discrepancy of blood pressure values during the Valsalva maneuver were statistically significant but small (< 5 mm Hg). 6) No significant effect of postural tilting was found on the between-method discrepancy. We conclude that this method is clinically acceptable and reliable except for its limited capacity for recording the higher frequency intra-arterial waveform and for responding to the relatively rapid and large transient changes in blood pressure.

Adult↗
PubMed1992

Incidental brain lesions on magnetic resonance imaging and neurobehavioral functions in the apparently healthy elderly.

BACKGROUND AND PURPOSE: Controversies exist whether incidental neuroradiological brain lesions in the elderly are associated with depressed neuropsychological function. To address this important issue in a cross-sectional study, we related brain lesions on magnetic resonance imaging to a variety of cognitive and neurobehavioral function tests in an independent, normal elderly population. METHODS: We studied 73 independent asymptomatic elderly individuals (mean +/- SD age 70 +/- 6 years) to determine the relations between degree of brain atrophy, location and number of "lacunes," and grade of periventricular hyperintense lesions with a variety of cognitive and neurobehavioral function scores. RESULTS: We found that severity of neuroradiological changes increased while neuropsychological function scores declined with age. After adjustment for the effect of age, advanced periventricular hyperintensities, but not brain atrophy or patchy "lacunar" lesions, were associated with declines in all neuropsychological functions tested. CONCLUSION: We conclude that incidental advanced periventricular diffuse or patchy white matter changes may play a role in the development of cognitive and neurobehavioral impairments in apparently normal elderly persons.

Aged↗
PubMed1992

Mechanism of antioxidant action of pueraria glycoside (PG)-1 (an isoflavonoid) and mangiferin (a xanthonoid).

The antioxidant activities of pueraria glycoside (PG)-1 (isoflavonoid) and mangiferin (xanthonoid) were studied and compared with PG-3 and daidzein (isoflavonoids) and with wogonin (flavonoid). PG-1 and mangiferin rapidly scavenged 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, and inhibited lipid peroxidation which was initiated enzymatically by reduced nicotinamide adenine dinucleotide phosphate (NADPH) or non-enzymatically by ascorbic acid or Fenton's reagent (H2O2 + Fe2+) in rat liver microsomes. Wogonin inhibited the enzymatically induced lipid peroxidation but had no scavenging effect on DPPH radical or on the non-enzymatic peroxidation. PG-3 and daidzein did not show any of these effects. Formation of Fe2+ by NADPH-dependent cytochrome P-450 reductase was inhibited by wogonin, but not by PG-1 or mangiferin. PG-1 and mangiferin had no effect on terminating radical chain reaction during the lipid peroxidation in the enzymatic system of microsomes or in the linoleic acid hydroperoxide-induced peroxidation system. These results suggest that PG-1 and mangiferin have an antioxidant activity, probably due to their ability to scavenge free radicals involved in initiation of lipid peroxidation. In contrast, wogonin may affect NADPH-dependent cytochrome P-450 reductase action, since it inhibited only the enzymatically induced lipid peroxidation.

Animals↗
PubMed1992

[Evaluation of subjective happiness in the elderly using a visual analogue scale of happiness in correlation with depression scale].

A Visual analogue scale of happiness (VAS-H) was applied to elderly population in a community to evaluate their subjective quality of life. The study population consisted of 313 elderly people aged over 75. Using a 20 cm visual analogue scale (VAS), VAS-H was measured by asking subjects to place a single vertical mark on a horizontal line at a point corresponding to their current subjective degree of happiness judged from health condition and psycho-social background as a whole; The VAS-H was anchored on the left and with the words "-100%; unhappiest" and on the right end with the words "+100%; happiest". The scores of VAS-H (%) were obtained by multiplying the distance (cm) from the zero point to the vertical line by 10. To determine the characteristics of VAS from the standpoint of the quality of life, we compared VAS with scores of two kinds of established depression scale, because the mood which was assessed by these scale was supposed to be an important factor of the quality of life. The results of the simultaneously assessed Geriatric Depression Scale (GDS), and Zung's depression scale (SDS) which was obtained 1 year before for the same subjects were compared with that of VAS-H. The score of VAS-H had a significantly negative correlation with both GDS and SDS. In conclusion, VAS-H was a simple and useful method to evaluate degree of subjective happiness which was one factor of quality of life in the elderly people.

Aged↗
PubMed1992

[Evaluation of subjective happiness in the elderly using a visual analogue scale of happiness to analyze the effect of life style and neurobehavioral function on subjective happiness].

The effects of activity of daily living (ADL), physical conditions, social environmental factors and neurobehavioral functions on subjective happiness were investigated in 313 elderly subjects. The degree of subjective happiness was measured using visual analogue scale of happiness (VAS-H). There was significant relationship between VAS-H and ADL. The VAS-H score had weak but significant correlation with physical conditions and neurobehavioral functions. The social environmental factors, especially economical conditions, family relationships and group behavior had a significant correlation with VAS-H. In conclusion, in apparent healthy elderly people, the subjective degree of happiness was not related to ADLs, but to social environment and information physical conditions.

Activities of Daily Living↗
PubMed1992

Diurnal blood pressure variations and silent cerebrovascular damage in elderly patients with hypertension.

OBJECTIVE: To examine the effect of diurnal blood pressure changes upon cerebrovascular damage in elderly patients with hypertension. DESIGN: Fifty-four asymptomatic hypertensive and 34 normotensive elderly subjects underwent both 24-h non-invasive ambulatory blood pressure monitoring and brain magnetic resonance imaging. METHODS. Diurnal variation was defined as a difference of greater than or equal to 10 mmHg between mean awake and asleep systolic blood pressure. Hypertensives were thus classified as dippers or non-dippers. Low intense foci (lacunae) and advanced periventricular hyperintensity were identified as silent cerebrovascular damage. RESULTS: In the hypertensive group, lacunae were correlated more closely with mean asleep systolic blood pressure than with mean awake systolic blood pressure. Age, awake blood pressure, predicted whole blood viscosity, lipid profiles or quantity of sleep did not differ between the hypertensive dippers or non-dippers. The non-dippers, however, showed significantly higher grades of cerebrovascular damage as well as cardiac hypertrophy by electrocardiography than the dippers, whose results were similar to those of normotensives in this regard. CONCLUSIONS: An absent or lower nocturnal blood pressure fall in elderly hypertensives is associated with silent cerebrovascular damage. In contrast, the presence of a nocturnal fall could prevent the development of hypertensive vascular damage.

Aged↗
PubMed1991

Lipid peroxide makes rabbit platelet hyperaggregable to agonists through phospholipase A2 activation.

Treatment of rabbit platelets with tert-butyl hydroperoxide and Fe2+ caused increasing arachidonic acid release, lysophosphatidylcholine formation, and aggregation with increasing concentrations of Fe2+. A combination of tert-butyl hydroperoxide and a low concentration of Fe2+, which by itself causes slight or no such activation, elicited synergistic release of arachidonic acid and aggregation under stimulation with a suboptimal concentration of collagen or arachidonic acid as an agonist. These responses were inhibited by pretreatment of the platelets with vitamin E or mepacrine in a concentration-dependent manner, but not by uric acid. The arachidonic acid release was dependent on the presence of Ca2+ in the medium. Synergistic formation of lysophosphatidylcholine, but not diacylglycerol, was also observed under this condition. The aggregation was also inhibited by indomethacin, a cyclooxygenase inhibitor. Cyclooxygenase activity was not affected by the oxidative treatment. These results suggest that lipid peroxide formed in membranes causes phospholipase A2 to become hypersusceptible to the agonist used, making the platelets hyperaggregable.

Animals↗