Comparison of Ehrlichia muris strains isolated from wild mice and ticks and serologic survey of humans and animals with E. muris as antigen. (1/201)

In metropolitan Tokyo, the Ehrlichia muris seropositivity rate of 24 wild mice was 63% in Hinohara Village, but in the surrounding areas, it was 0 to 5%. This finding suggests that the reservoir of E. muris is focal. Among the 15 seropositive mice, ehrlichiae were isolated from 9 Apodemus speciosus mice and 1 A. argenteus mouse, respectively. Five ehrlichial isolates were obtained from 10 ticks (Haemaphysalis flava) collected in Asuke Town, Aichi Prefecture, where the E. muris type strain had been isolated. These new isolates were compared with the E. muris type strain. The mouse virulence and ultrastructure of the new isolates were similar to those of the type strain, and all of them were cross-reactive with each other, as well as with the type strain, by indirect immunofluorescent-antibody test. The levels of similarity of the base sequences of the 16S rRNA gene of one of the A. speciosus isolates and one of the tick isolates to that of the E. muris type strain were 99.79 and 99.93%, respectively. We suggest that all of these isolates are E. muris; that E. muris is not limited to Eothenomys kageus but infects other species of mice; and that E. muris is present at locations other than Aichi Prefecture. It appears that H. flava is a potential vector of E. muris. Twenty (1%) of 1803 humans from metropolitan Tokyo were found to be seropositive for E. muris antibodies. A serological survey revealed that exposure to E. muris or organisms antigenically cross-reactive to E. muris occurred among dogs, wild mice, monkeys, bears, deer, and wild boars in Gifu Prefecture, nearby prefectures, and Nagoya City, central Japan. However, human beings and Rattus norvegicus rats in this area were seronegative. These results indicate broader geographic distribution of and human and animal species exposure to E. muris or related Ehrlichia spp. in Japan.  (+info)

Disease patterns of the homeless in Tokyo. (2/201)

In recent years, homelessness has been recognized as a growing urban social problem in various countries throughout the world. The health problems of the homeless are considerable. The purpose of this study was to elicit, with sociodemographic profiles, the disease patterns among Tokyo's homeless. The subjects were 1,938 men who stayed at a welfare institution from 1992 to 1996. Diagnosed diseases/injuries and sociodemographic profiles were analyzed. The disease patterns of the homeless were compared to those of the male general population. Of the subjects, 8.3% were admitted to the hospital; 64.0% received outpatient care. Their observed morbidity rates by disease category were greater than those of the male general population in both Japan and Tokyo. Comorbidity of alcoholic psychosis/alcohol-dependent syndrome to both liver disease and pulmonary tuberculosis were greater than the average (P < .01). Construction work brought a higher risk of pulmonary tuberculosis (odds ratio = 2.0) and dorsopathies (odds ratio = 1.4) than did other jobs (P < .05). Disease patterns among the homeless in Tokyo were characterized by alcoholic psychosis/alcohol-dependence syndrome; liver disease; pulmonary tuberculosis; diabetes mellitus; fractures, dislocations, sprains, strains; hypertension; and cerebrovascular disease. Although the sociodemographic backgrounds of Tokyo's homeless have become more diverse, the principal occupation of the homeless was unskilled daily construction work, which underlay the characteristics of their disease patterns.  (+info)

Determination of abundance and biovolume of bacteria in sediments by dual staining with 4',6-diamidino-2-phenylindole and acridine orange: relationship to dispersion treatment and sediment characteristics. (3/201)

We measured the abundance and biovolume of bacteria in intertidal sediments from Tokyo Bay, Japan, by using a dual-staining technique (4',6-diamidino-2-phenylindole and acridine orange) and several dispersion techniques (ultrasonic cleaner, ultrasonic sonicator, and tissue homogenizer). Dual staining reduced serious background fluorescence, particularly when used for silt-, clay-, and detritus-rich sediments, and allowed us to distinguish bacteria from other objects during both counting and sizing. Within the studied samples, the number of bacterial cells ranged from 0.20 x 10(9) to 3. 54 x 10(9) g of wet sediment(-1). With the cleaner and sonicator treatments, the bacterial numbers for all of the sites initially increased with dispersion time and then became constant. For the homogenizer treatments, the highest bacterial numbers were observed with the shortest (0.5- to 2-min) treatments, and the counts then declined steeply as the homogenization time increased, indicating that cell destruction occurred. The cleaner treatment had the possibility of insufficient dispersion of bacteria for fine-grain sediments. Within the studied samples, the bacterial biovolume ranged from 0.07 to 0.22 microm(3). With the cleaner and sonicator treatments, the biovolume peaked during the shorter dispersion time. This pattern was caused not by cell destruction but by the incremental portion of dispersed small cells. We concluded that with the cleaner and sonicator treatments, the longer dispersion time reflected the real size spectrum and was preferable for accurate estimation of mean bacterial biovolumes.  (+info)

Temperature and air pollution as risk factors for heat stroke in Tokyo, July and August 1980-1995. (4/201)

Heat stroke is associated with prolonged exposures to high air temperatures that usually occur in the summer months of July and August in Tokyo, Japan. Also during July and August, residents of Tokyo are often exposed simultaneously to high concentrations of air pollutants. To assess the impacts of these combined exposures, daily numbers of heat stroke emergency transport cases/million residents for Tokyo were stratified by gender and three groups: 0-14, 15-64; and > 65 years of age, for the months of July and August in 1980-1995. A regression model was constructed using daily maximum temperature (Tmax) and daily average concentrations of NO2 and O3 as model covariates. Classification indices were added to make it possible to compare the expected number of heat stroke cases by age and gender. Lag times of 1-4 days in Tmax and air quality covariates and terms to account for interactions between pairs of model covariates were also included as additional risk factors. Generalized linear models (GLMs), assuming a Poisson error structure for heat stroke emergency transport cases, were used to determine which covariates were significant risk factors for heat stroke for the three age groups of males and females. Same-day Tmax and concentrations of NO2 were the most significant risk factors for heat stroke in all age groups of males and females. The number of heat stroke emergency transport cases/million residents was greater in males than in females in the same age groups. The smallest number of heat stroke emergency transport cases/million residents occurred for females 0-14 years of age and the greatest number of heat stroke emergency transport cases/million residents occurred for males > 65 years of age.  (+info)

High incidence of acute myositis with type A influenza virus infection in the elderly. (5/201)

We describe six elderly cases of acute myositis with type A influenza virus infection (Sydney) during the 1998-1999 outbreak. All six cases suffered from myalgia or muscle weakness especially in the lower extremities and the serum creatine kinase (CK) values were elevated above 1,000 IU/l without MB isoenzymes or electrocardiogram abnormalities. There have been a few case reports of acute myositis associated with influenza virus infection in the elderly. However, we noticed a high incidence of acute myositis among elderly patients with type A influenza virus infection. This complication may occur more commonly in elderly patients than has previously been thought.  (+info)

Characterization of Staphylococcus aureus coagulase type VII isolates from staphylococcal food poisoning outbreaks (1980-1995) in Tokyo, Japan, by pulsed-field gel electrophoresis. (6/201)

Staphylococcus aureus coagulase type VII strains have been the strains most frequently isolated from staphylococcal food poisoning outbreaks in Tokyo, Japan. We applied pulsed-field gel electrophoresis (PFGE) of chromosomal DNA digested with SmaI to characterize 129 coagulase type VII strains. These were isolated from 129 cases occurring in outbreaks in 35 districts during a 16-year period (1980-1995). The 129 outbreak strains were classified into three types, designated A (n = 115), B (n = 10), and C (n = 4). Types A and C were further divided into 33 (A1 to A33) and 4 (C1 to C4) subtypes, respectively. Strains of the same subtypes were isolated from food poisoning cases in the same districts at time intervals of 1 or 2 to 5 years. PFGE typing appears to be a useful method for subdividing strains of S. aureus coagulase type VII. A combination of coagulase typing and PFGE typing would provide more detailed information than the former method alone in epidemiologic investigations of staphylococcal food poisoning.  (+info)

Association of school absence with air pollution in areas around arterial roads. (7/201)

Association of school absence with air pollution from suspended particulate matter (SPM) and nitrogen dioxide was analyzed in areas around arterial roads for five years, from 1993 to 1997. The prevalence of absence was calculated using the data for school absence in two schools around arterial roads, one of which is near a crossing (Sch.A), and the other is adjacent to an arterial road (Sch.B). Although the results from annual correlation analyses did not indicate common findings for five years or in the two schools, the prevalence of absence correlated positively with SPM, nitrogen dioxide, or relative humidity, and negatively with atmospheric temperature. As the results from multiple regression analyses, atmospheric temperature in Sch.A was adopted as the optimum explanatory variable, whereas SPM and relative humidity were considered in Sch.B. Odds ratios for the prevalence of absence to SPM were elevated and were significant in Sch.B, when using a quintile method. The other odds ratios for the air pollutants were not significant, but exceeded 1. When the data were classified by day of the week, significant associations of the prevalence of absence were observed with atmospheric temperature in Sch.A and with SPM in Sch.B. The slope of the regressive equations by day of the week became steeper with the day in Sch.B. SPM was weakly associated with the prevalence of absence in Sch.A and was closely associated in Sch.B according to the optimum variables selected from the multiple regression analyses by day of the week.  (+info)

Survey of dental treatments for pediatric patients referred to the pediatric dental clinic of a dental school hospital. (8/201)

This survey was conducted to clarify which dental treatments in children are regarded as difficult by general dentistry practitioners. The subjects were 615 children who first visited Tokyo Dental College Chiba Hospital from January 1995 to August 1999 with reference letters. There were 615 children in the study; 571 (92.8%) came from Chiba City where our hospital is located and the 11 regions surrounding Chiba City. The prime reasons for referral in the order of frequency were treatments of dental caries, malalignment/malocclusion, traumatized teeth, supernumerary teeth, retarded eruption/impacted teeth, abnormal direction of erupted teeth, congenitally missing teeth, prolonged retention of deciduous teeth, and abnormal frenulum. Patients with dental caries or traumatized teeth in the deciduous dentition period and those with malalignment/malocclusion, supernumerary teeth, or retarded eruption/impacted teeth in the mixed dentition period were often referred to medical organizations specializing in pediatric dentistry because of the difficulties in controlling the patients' behavior and in providing adequate treatment. The information about pediatric dental treatments considered difficult by general dentists revealed by this survey appears to be useful and needs to be incorporated in the programs for clinical training of undergraduate students and education of postgraduate students.  (+info)