Correction of the QT interval in children.

We evaluated the usefulness of 11 formulas for correcting the QT interval in children, including the square root, cubic root, logarithmic, linear, exponential, and inverse formulas using the Mean-squared residual (MSR) values and Akaike Information Criterion (AIC) in 8,086 first-graders, 9,989 seventh-graders, and 5,786 tenth-graders. The subjects were divided into six groups according to age and sex. MSR and AIC values were lowest in all of the groups for the exponential formula (eQTc) and Fridericia's formula (fQTc). We then evaluated the relative usefulness of these two formulas by determining the optimal value for parameter k using the following exponential model: eQTc = (QT interval)/(RR interval)k. The best-fit value for k was different for each group. However, the tentative abnormal eQTc and fQTc values, determined by statistical analysis, were equivalent in all groups when 0.31 was used as the exponential parameter k. These results suggest that the exponential formula and Fridericia's formula are equally useful for screening for QT prolongation.

Influence of left ventricular filling profile during preceding control beats on pulse pressure during ventricular premature contractions.

We investigated whether the left ventricular filling profile, defined as the early to late diastolic left ventricular filling volume ratio, during the preceding control beats actually affects the pulse pressure during a ventricular premature contraction (PVC). Twenty patients underwent invasive electrophysiological study for sinus bradycardia. VPCs with various coupling intervals were induced by right ventricular electrical stimulation, and the mitral filling flow velocity by pulsed Doppler echocardiography, the femoral arterial pressure curve and the electrocardiogram were simultaneously recorded. The early to late diastolic velocity-time integral ratio (Ei/Ai ratio) of the mitral filling flow velocity during the control beats which preceded the VPC was measured as an index characterizing left ventricular filling profile. The coupling interval of each VPC and the extrasystolic beat pulse pressure were measured. The ratio of the extrasystolic beat pulse pressure to the control beat pulse pressure was expressed in % (% extrasystolic beat pulse pressure). The correlation between the coupling interval and the % extrasystolic beat pulse pressure was investigated. Coupling intervals of 0.80, 0.70, 0.60, 0.50, and 0.45 s were used. At a coupling interval of 0.80 or 0.45 s, the % extrasystolic beat pulse pressure showed no significant correlation with the Ei/Ai ratio. In contrast, the % extrasystolic beat pulse pressure with coupling intervals of 0.70, 0.60, and 0.50 s showed a significant positive correlation with the Ei/Ai ratio (r = 0.67, 0.74, and 0.66, P < 0.01, respectively). In addition to the prematurity and the site of origin of the VPCs, the left ventricular filling profile during the preceding control beats may significantly affect the height of the pulse pressure during extrasystoles with medium length coupling intervals.

[The effect of Habu toxoid--from the view point of public health center].

In order to clarify the effect of Habu Toxoid, serum sampling was performed with from July 1990 to February 1991, on 503 vaccinated subjects living in Amami Islands by staff of Naze health center. Sera were analyzed by Enzyme Linked Immunosorbent Assay (ELISA) for levels of serum antitoxin to venom, both anti-Hemorrhagic Factor 1 (anti-HR1) and anti-Hemorrhagic Factor 2 (anti-HR2). Information on vaccinated subjects-age, sex, occupation, vaccination date, frequency, period and interval of vaccinations, years after final vaccination and past history of Habu bites-was obtained and analyzed with relation to serum antitoxin levels. The following results were obtained: 1) Serum antitoxin levels, both anti-HR1 and anti-HR2, of the Habu bitten group (N = 47) were significantly higher than that of the unbitten group (N = 456). This finding suggests that crude Habu venom injected by bites elevated the levels. Regardless of past history of Habu bites, levels of antibody to HR2 was significantly lower than that to HR1. 2) Among the unbitten group, detection of antitoxin was related to subjects' attributes. Production of antitoxin was related to being male, high frequency of vaccinations, long period of vaccinations and short period after final vaccination. 3) Among the unbitten group, anti-HR2 was found in high levels with the following factors: high frequency of vaccinations and short period after final vaccination. However among the well-vaccinated group (N = 153), differences in antitoxin levels by vaccination frequency were not recognized.(ABSTRACT TRUNCATED AT 250 WORDS)

Two-dimensional echocardiographic assessment of papillary muscle contractility in patients with prior myocardial infarction.

OBJECTIVES: This study was performed to assess the length and contractile performance of human left ventricular papillary muscles and to determine the relation between papillary muscle dysfunction and mitral regurgitation. BACKGROUND: Assessment of human papillary muscle contractility remains a clinical challenge. METHODS: Two-dimensional echocardiographic examinations were performed in 16 normal subjects and 31 patients with prior myocardial infarction. Apical echocardiograms were used to obtain long-axis views of the anterior and posterior papillary muscles. The end-systolic and end-diastolic lengths of the papillary muscles were measured and fractional shortening was calculated. RESULTS: Fractional shortening in normal subjects was 27 +/- 8% for the anterior papillary muscle and 30 +/- 8% for the posterior papillary muscle. In patients with prior myocardial infarction, a significant decrease in fractional shortening was observed in proportion to the severity of left ventricular wall motion abnormalities at the site of papillary muscle implantation. Moderate or severe mitral regurgitation was significantly more frequent in patients with combined anterior and posterior papillary muscle dysfunction than in those with isolated anterior or posterior dysfunction or with normal function of both papillary muscles (p < 0.05). CONCLUSIONS: Two-dimensional echocardiography is useful for demonstrating abnormal contractility of human left ventricular papillary muscles. Papillary muscle contractility should be analyzed in each case to elucidate the mechanism of mitral regurgitation in patients with papillary muscle dysfunction.

Exponential correction of QT interval to minimize the effect of the heart rate in children.

The exponential correction of the QT interval (eQTc) was studied using 12,543 resting electrocardiograms obtained in children (first and seventh graders) who were screened for heart disease in Kagoshima City. The values of eQTc to minimize the effect of the RR interval were estimated using following exponential model, eQTc = (QT interval)/(RR interval)--k. The parameter k = 0.31 was found to be the most useful exponent. The distribution of eQTc values showed a hiatus or break at probability points near p < 0.001 or p < 0.0005. Tentative criteria for an abnormally long eQTc were selected using these points and the following convenient data: 0.430 and 0.435 for the male and female first graders, and 0.440 and 0.445 for the male and female seventh graders, increased by 0.005, respectively. Abnormal values must ultimately be selected using data on patients with the long QT syndrome; however, our findings suggest that the exponential correction of the QT interval may be useful in large-scale screening programs for detecting a QT prolongation in young school children.

[Mercury in the environs of Kagoshima Bay].

Mercury contents of samples of sea water and fish from Kagoshima Bay, sediments in rivers, and the surface soil from the area surrounding a waste incinerator in the city of Kagoshima were measured to search for the source of mercury in Kagoshima Bay. The results obtained were as follows: 1) Mercury contents of sea water samples at 26 stations in Kagoshima Bay ranged from 6.3 to 19.7 ng/l. When the 26 stations were classified into four areas, the entrance, the middle and the interior of the Bay, and the water around the Sakurajima area, mercury contents of the samples from the last area were significantly higher than either at the entrance or in the interior of the Bay. 2) Mercury contents in the cardinal fish, Apogon notatus, were significantly higher than those in either the dragonet, Callionymus lunatus, or the sillaginoid, Sillago japonica. Mercury contents of fish from the Ushine coast station, the innermost part of the Bay, were significantly higher than those from the other collecting stations. Moreover, significantly interactions between the species of fish and the sampling stations were detected, and mercury contents of cardinal fish from Ushine coast station were 6.7-fold higher than those from the sampling station at the mouth of the Shinkawa river. 3) River sediments obtained 1 km from the mouth of each river contained from 4 to 96 micrograms/kg of mercury. Mercury contents of the river sediments from the Wada river were higher than those from the other rivers examined.(ABSTRACT TRUNCATED AT 250 WORDS)

[Seasonal variation of mortality from cerebro-cardiovascular diseases--effect of ambient temperature on death].

A study to clarify the relationship between seasonal variations in mortality from cerebro-cardiovascular diseases and ambient temperature (maximum/minimum temperature and daily range) was performed using time series analysis, and the role of ambient temperature as an associated factor in cerebro-cardiovascular disease caused death was discussed. The following results were obtained: 1) The seasonality factor associated with the monthly variation for mortality was of greater magnitude for heart diseases more than for cerebral diseases. There was a tendency for mortality from cardiac diseases to decline gradually from February/March to July/August, and to increase in October/November, with a maximum peak in the curve of seasonal variation observed in January/February. 2) The seasonal factor associated with maximum/minimum temperature and daily temperature range showed a stable variation in magnitude from January to December, with temperatures displaying a single peak in August. Daily temperature range was lowest during summer and highest during the late fall, winter or early spring. 3) A statistically significant negative correlation was seen between mortality from cerebro-cardiovascular diseases and seasonality and temperature, while a positive correlation was seen between mortality and daily temperature range, suggesting that low environmental temperatures may operate indirectly as a factor that affects cerebro-cardiovascular disease mortality.

[Concordance of risk factors for cerebro-cardiovascular diseases among spouses].

The present study was carried out to clarify the concordance or similarity of risk factors among 298 spouse pairs in a random sample who lived in Mizobe town of Kagoshima Prefecture. A sample of 298 spouse pairs was surveyed by using the house-to-house interviewing method and was classified into three groups by the marriage duration. The following results were obtained. 1) Statistically significant partial correlation coefficients were demonstrated among the spouses for blood pressure in the present study. However, they were smaller than among spouses in remote islands, this fact suggested that there was no higher spouse concordance in this surveyed area than in remote island areas, and also that there might be a difference in the shared environment of spouse pairs and the genetic effect on blood pressure between the former area and the latter. 2) In regard to the intake of salt in miso soup and the ratio of sodium to potassium (Na/K), an increasing gradient of partial correlation coefficients for the risk factors among the spouses was observed with increasing marriage duration, suggesting that the intake might be caused by the shared environment on the basis of a similar dietary pattern for the spouse pairs.

[Relationship between serum fatty acid composition and life style and/or health status in a rural population in Kagoshima].

Serum fatty acid compositions of 232 subjects (97 men and 135 women) living in a rural area of Kagoshima, were analyzed by gas-chromatography. Subjects were classified by sex into three groups (Group I, II and III) by cluster analysis according to concentrations of selected serum fatty acids. Dietary habits obtained through an interview and variable data related to health status presented by biochemical and biophysical measurements, were studied in relation to serum fatty acids of the three groups. The results are summarized as follows: 1) No significant differences in specific serum fatty acids were observed among the three groups for each sex, but males and females were characterized by the concentrations and compositions of omega-3 and omega-6 polyunsaturated acids, respectively. 2) Differences in urinary Na/K ratio among the groups were significant for males but no significant differences in urinary Na or K were observed between groups for either males or females. 3) For males or females significant differences in systolic blood pressure were seen between groups. Significant differences in distolic blood pressure were seen for female. Furthermore, the distribution among the three categories of blood pressure as defined by WHO, was significantly different among the groups for each sex. 4) Comparison of frequency distributions for dietary habits, showed that amount of salt and fruits consumed, and drinking habits for each sex, smoking habits among males, and the frequency of use of foods using fat or oil by females were significantly different. The amount of shellfish and vegetable consumed for either males or females was not significantly different among the three groups.(ABSTRACT TRUNCATED AT 250 WORDS)

[An analysis of industrial accidents in the working field with a particular emphasis on repeated accidents].

The present study is based on an analysis of routinely submitted reports of occupational accidents experienced by the workers of industrial enterprises under the jurisdiction of Kagoshima Labor Standard Office during a 5-year period 1983 to 1987. Officially notified injuries serious enough to keep employees away from their job for work at least 4 days were utilized in this study. Data was classified so as to give an observed frequency distribution for workers having any specified number of accidents. Also, the accident rate which is an indicator of the risk of accident was compared among different occupations, between age groups and between the sexes. Results obtained are as follows; 1) For the combined total of 6,324 accident cases for 8 types of occupation (Construction, Transportation, Mining & Quarrying, Forestry, Food manufacture, Lumber & Woodcraft, Manufacturing industry and Other business), the number of those who had at least one accident was 6,098, of which 5,837 were injured only once, 208 twice, 21 three times and 2 four times. When occupation type was fixed, however, the number of workers having one, two, three and four times of accidents were 5,895, 182, 19 and 2, respectively. This suggests that some workers are likely to have experienced repeated accidents in more than one type of occupation.(ABSTRACT TRUNCATED AT 250 WORDS)

Pattern of medical care services utilization in Fiji.

The present study was designed to analyze sociodemographic and health related factors that influence the utilization of medical care services in Fiji by using the method of discriminant function. Some sociodemographic and health related independent variables had significant effects on the two patterns of modern and traditional medical services utilization. Discriminant function coefficients for sex, age and race are large enough to suggest the importance of discriminating between two patterns of medical care utilization. This suggests that traditional medical service is coexistent with modern medicine in Fiji and might play an extremely important role in providing health care for rural communities in the same way as modern medicine.

[Health effects of volcanic air pollution--an analysis of the national health insurance].

Using the national health insurance bills covering the one-year period from January through December 1987, the morbidity figures for respiratory diseases, conjunctivitis and dermatitis were compared among four local districts; Ushine, Kaikata, Kunugibaru and Shinjo, in the city of Tarumizu. The former two districts are 10 km south-east of Mt. Sakurajima supposedly experience higher volcanic ash exposure compared to the latter two located 10 to 15 km from this volcano. Results obtained are as follows; 1) Age-adjusted rates of patients' consultations and existing patients were apparently higher in the Ushine and Kaikata districts than in the Kunugibaru and Shinjo districts for non-infectious or infectious respiratory diseases and the common cold. For the rates of other diagnostic categories of disease, i.e., rhinitis, other respiratory diseases, conjunctivitis and dermatitis, a difference between the district was not clearly noted. These figures are suggestive of an association of volcanic air pollution with an increased number of outpatient consultations for respiratory problems. 2) Variations of monthly clinical consultations for patients with diagnoses of non-infectious or infectious respiratory diseases and the common cold showed a seasonality, being highest in winter and lowest in summer, while another seasonality, highest in summer and lowest in winter, was proved in the variation of monthly clinical consultations for patients with dermatitis. Few or no stable seasonalities were shown in the variations of monthly clinical consultations for patients with the other diseases, studied, rhinitis, other respiratory diseases and conjunctivitis. In addition, the variations in the monthly averages of sulfur dioxide concentrations showed a stable seasonality with the highest peak in winter and the lowest in summer but there was no stable seasonality in the monthly variations of total suspended particles at the place in Arimura for which air pollution data were available. These facts suggest that in the area exposed to volcanic air pollution, the seasonal variation in the number of monthly clinical consultations for respiratory problems is partly modified by the exposure levels of sulfur dioxide rather than total suspended particles, although no adjustments were made for climatologic factors. 3) A few patients diagnosed as having "pneumoconiosis" were found in the Ushine and Kaikata districts. However, it is difficult to interpret these cases without information about occupational and other risk factors for the development of pneumoconiosis.

[Mercury concentration in gray hair].

Scalp hair sample were collected from 20 gray-haired males and 7 gray-haired females. Two hair samples, one each of dark hair and gray hair, obtained from each individual were selectively analysed for organic and inorganic mercury concentrations. The following finding were made: 1) In both sexes, total and organic mercury concentrations were significantly higher in gray hair than in dark hair but no difference was observed between dark hair and gray hair for the concentration of inorganic mercury. 2) For males, no significant differences between dark hair and gray hair were found for total, organic or inorganic mercury concentrations. On the other hand, gray hair had significantly higher levels of total, organic and inorganic mercury concentrations than dark hair in females. 3) When comparison was made between the sexes, total, organic and inorganic mercury concentrations were significantly higher in males than in females for dark hair. For gray hair, however, significantly higher levels of total and organic mercury concentrations, but not of inorganic mercury concentrations, were found in males. 4) The proportion of inorganic mercury to total mercury was higher in females than in males for both dark and gray hair. It was also higher in gray hair than in dark hair for females.

An epidemiological study of the occurrence of habu snake bite on the Amami Islands, Japan.

This study was carried out in order to estimate the risk of habu snake bite on the Amami Islands in relation to meteorological and human behavioural factors. A time-series analysis of the seasonal variation of habu snake bite was also carried out in order to clarify the possible mechanism of the epidemiological features of habu bite. It was found that the risk of habu bite has been decreasing over a long period of time on both the islands of Amamioshima and Tokunoshima. In general, the risk is higher on Tokunoshima for males and on Amamioshima it is higher for females. There was a significant positive correlation between risk and time spent in the sugar cane fields. Analysis of annual cumulative risk revealed that the inhabitants of Tokunoshima were more likely to be bitten by the habu than those of Amamioshima. The probable explanation for this was the difference between the two islands in the size of cultivated area or the proportion of the labour force engaged in primary industry. Seasonal variation of habu bite showed a maximum occurrence in June. This seasonality was probably caused by the effects of climate on the activities of both humans and habu snakes. Meteorological conditions were investigated by multiple regression analysis for causal effects on the seasonal variation in the occurrence of habu bite; as a result, temperature and humidity were presumed to have an important influence. These facts supplied the most probable explanation for the highest incidence of habu bite being in June rather than in August--the hottest season--on the Amami Islands.