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Biomedical subjects

K Ozasa

Publications and source records attributed to K Ozasa.

At least 19 recordsLinked to original sources
PubMed2005

The relationship between 24-hour blood pressure readings, subcortical ischemic lesions and vascular dementia.

BACKGROUND: Twenty-four-hour blood pressure (BP) readings have been found to correlate with hypertensive target organ damage. Lacunar infarcts (LI) and white matter lesions (WML) probably represent manifestations of cerebral hypertensive target organ damage. This study was conducted to better delineate the relationships between 24-hour BP measurements, LI/WML and small vessel disease cognitive impairment/vascular dementia (CI/VD). METHODS: Two hundred patients with first-time symptomatic LI were examined with 24-hour BP monitoring. The degree of nocturnal BP dip, (daytime BP - nighttime BP)/daytime BP, was categorized into three groups: dippers (>0.1), nondippers (0-0.1) and reverse dippers (<0). WML were subdivided into periventricular hyperintensities (PVH) and subcortical hyperintensities. RESULTS: The breakdown of patients was: 50% nondippers, 27.5% reverse dippers and 22.5% dippers. Forty-one patients (20.5%) were found to have CI and dementia. Male sex (OR 3.35; 95% CI 1.20-9.34), advanced PVH (OR 14.42; 95% CI 5.62-36.98) and absence of a dipping status (nondipper: OR 12.62; 95% CI 1.37-115.95; reverse dipper: OR 11.95; 95% CI 1.27-112.11) were independently associated with CIVD after multivariate analysis. High nighttime systolic BP (OR 3.93; 95% CI 1.38-11.17), high daytime (OR 2.06; 95% CI 1.03-4.04) and nighttime diastolic BP (OR 2.48; 95% CI 1.13-5.45) and absence of a dipping status (nondipper: OR 2.7; 95% CI 1.03-7.05; reverse dipper: OR 3.78; 95% CI 1.38-10.34) were significantly associated with PVH. CONCLUSIONS: High prevalence of a nondipping status was found in the LI cohort. A nondipping status appears to be directly associated with CIVD independent of PVH. This study indicates the need for further studies to investigate whether or not controlling nighttime BP will help reduce the risk for CI/VD development.

Aged↗
PubMed2005

Trends of delays in tuberculosis case finding in Japan and associated factors.

SETTING: Nationwide tuberculosis (TB) registry in Japan, 1987-2002. OBJECTIVE: To clarify the trends of patient's delay (PD), doctor's delay (DD) and total delay (TD), their relation and factors associated with the delays. DESIGN: Longitudinal study on trends in delays. Among patients with symptomatic smear-positive pulmonary TB, those with long PD (> or =2 months), DD (> or =1 month) and TD (> or =3 months) were analysed. RESULTS: Long PD rates increased until around 1997, whereas long DD rates decreased markedly from 1995 to 1999. Long TD rates increased until 1997, and decreased slightly thereafter. Men aged 30-59 years had higher rates of long PD, and the long PD rates increased through the 16-year observation period. Day labourers receiving or applying for welfare benefit had the highest rate of long TD, 46.5% during 1995-2002. Teachers and medical doctors showed the greatest increase in long TD rates through the period. CONCLUSION: Long TD was influenced more by PD than DD, and showed an upward trend. However, the long TD rate has declined slightly owing to the recent reduction in long DD. The reduction in DD since 1995 occurred immediately after the introduction of new technology in bacteriological examinations.

Adolescent↗
PubMed2002

Twenty-four-hour blood pressure and MRI as predictive factors for different outcomes in patients with lacunar infarct.

BACKGROUND AND PURPOSE: A long-term follow-up study was conducted in patients with lacunar infarct to assess how 24-hour blood pressure monitoring values and MRI findings, in particular lacunar infarcts and diffuse white matter lesions, can predict subsequent development of dementia and vascular events, which include cerebrovascular and cardiovascular events. METHODS: One hundred seventy-seven patients were tracked for a mean of 8.9 years of follow-up. Documented events comprise the development of dementia and the occurrence of vascular events. The predictors for developing dementia and vascular events were separately evaluated by Cox proportional hazards analysis. RESULTS: Twenty-six patients developed dementia (0.17/100 patient-years). Male sex (relative risk [RR], 4.2; 95% CI, 1.2 to 14.7), cognitive impairment (RR, 3.0; 95% CI, 1.0 to 8.5), confluent DWML (moderate: RR, 7.1; 95% CI, 1.6 to 31.5; severe: RR, 35.8; 95% CI, 7.2 to 177.3), and nondipping status (RR, 7.1; 95% CI, 2.2 to 22.0) were independent predictors for dementia. Forty-six patients suffered from vascular events (3.11/100 patient-years). Diabetes mellitus (RR, 5.7; 95% CI, 2.7 to 11.9), multiple lacunae (moderate: RR, 6.4; 95% CI, 2.5 to 15.8; severe: RR, 8.5; 95% CI, 3.1 to 23.3), and high 24-hour systolic blood pressure (>145 mm Hg versus <130 mm Hg) (RR, 10.3; 95% CI, 1.3 to 81.3) were independent predictors for vascular events. CONCLUSIONS: Predictors for developing dementia and vascular events appear to differ. Male sex, confluent diffuse white matter lesions, and nondipping status were independent predictors for subsequent development of dementia, while diabetes mellitus, multiple lacunae, and high 24-hour systolic blood pressure were independent predictors for vascular events.

Aged↗
PubMed2001

High-resolution elemental mapping of titanium oxide/aluminium oxide multilayer by spectrum-imaging.

A spectrum-imaging technique based on scanning transmission electron microscopy combined with an electron energy-loss spectroscopy has been applied for the multilayer of amorphous titanium oxide and aluminium oxide layers on silicon substrate. We demonstrate the high-resolution elemental mapping and discuss the advantage of this method compared to an energy-filtering transmission electron microscopy. The main advantage is the absence of chromatic broadening, which allows the use of a large collection angle to acquire spectrum-image data and a wide energy window to integrate the core-loss signals. This suggests that the spatial resolution of elemental maps is mainly determined by the size of the electron probe.

Journal Article↗
PubMed2001

Decrease in risk of lung cancer death in males after smoking cessation by age at quitting: findings from the JACC study.

To evaluate the impact of smoking cessation in individuals and populations, we examined the decrease in risk of lung cancer death in male ex-smokers by age at quitting in the Japan Collaborative Cohort Study for Evaluation of Cancer Risk Sponsored by Monbusho (JACC Study), which was initiated from 1988 to 1990 in Japan. For simplicity, subjects were limited to male non-smokers, and former / current smokers who started smoking at ages 18 - 22, and 33654 men aged 40 - 79 years were included. We modeled the mortality rates in non-smokers and current smokers, and compared the rates in ex-smokers with those expected from the model if they had continued smoking. During the mean follow-up of 8.0 years, 341 men died from lung cancer. The mortality rate ratio for current smokers, compared to non-smokers, was 5.16, and those for ex-smokers who had quit smoking 0 - 4, 5 - 9, 10 - 14, 15 - 19 and > or = 20 years before were 4.84, 3.19, 2.03, 1.29 and 0.99, respectively. The functions of 3.20 x 10(-7) x (age)(4.5) and 1.96 x 10(-5) x (age - 29.6)(4.5) fitted the observed mortality rates (per 100000 person-years) in non-smokers and continuing smokers, respectively. A greater decrease in lung cancer mortality was estimated among those who quit smoking at younger ages. Stopping smoking earlier in life appears preferable to keep the individual risk low. The absolute rate, however, substantially decreased after smoking cessation even in those who quit at ages 60 - 69, reflecting the high mortality rate among continuing smokers in the elderly.

Adult↗
PubMed2001

Dietary habits and risk of lung cancer death in a large-scale cohort study (JACC Study) in Japan by sex and smoking habit.

Lung cancer has increased and is the leading cause of cancer death among Japanese males. The associations of dietary habits with the risk of lung cancer death were evaluated by sex and smoking habits in this study. In the Japan Collaborative Cohort (JACC) Study, a cohort established in 1988 - 90 and consisting of 42 940 males and 55 308 females was observed for lung cancer deaths up to the end of 1997. During the observation period, 446 males and 126 females died of lung cancer. A self-administered food frequency questionnaire was used as the baseline survey. Hazard ratios for dietary factors were calculated by Cox's proportional hazards model. Among males, a high intake of ham and sausages, cheese, green-leafy vegetables, oranges, and other fruits significantly and dose-dependently decreased the risk of lung cancer death. Among females, a high intake of miso-soup, ham and sausages, and liver significantly and almost dose-dependently increased the risk. Vegetables and fruits rich in antioxidative and carcinogenic agents reduced the risk of lung cancer deaths among male smokers more than among female nonsmokers. The results among female nonsmokers were partially consistent with the hypothesis that high fat consumption increases the risk of lung cancer, especially that of adenocarcinoma.

Adult↗
PubMed2001

Unique place of Kampo (Japanese traditional medicine) in complementary and alternative medicine: a survey of doctors belonging to the regional medical association in Japan.

Although there are various kinds of complementary and alternative medicine (CAM) therapies, it is conjectured that medical doctors consider individual CAM therapies to be heterogeneous in nature. Therefore, to investigate the relationship among Kampo (Japanese traditional medicine) and other CAM, a survey using a structured, self-administered questionnaire was performed for 540 randomly selected doctors of the Kyoto Medical Association (KMA). The results showed that some form of CAM was practiced by 73% of the KMA doctors. The most common CAM practice was Kampo, which corresponded to 96.1% of CAM-practicing doctors. A smaller percentage of doctors practiced other forms of alternative medicine. Kampo was best known by doctors among other CAM therapies. Almost all doctors believed in the effectiveness of Kampo. Doctors who believed in the effectiveness of Kampo tended to believe that other CAM therapies were also effective. Cluster analysis revealed that Kampo was distant from the other CAM. It was concluded that Kampo was most frequently practiced and most believed by doctors in Japan among CAM therapies. Since Kampo was independent of other CAM therapies, Kampo's place in CAM therapies was very unique in Japan.

Adult↗
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↗
PubMed2001

[Meta-analysis of pharmacotherapies for allergic rhinitis].

We performed meta-analysis using the data in literatures of the clinical study related to pharmacotherapies for allergic rhinitis in Japan as evidences. We extracted double-blind studies which used first-generation antihistamines, early-stage second-generation antihistamines, late-stage second-generation antihistamines and arachidonic acid metabolite-receptor antagonists as investigational drugs. In meta-analysis of first-generation antihistamines and early-stage second-generation antihistamines, significant differences between them were detected in final overall improvement and usefulness. In meta-analysis of early-stage second-generation antihistamines and late-stage second-generation antihistamines, significant differences between them were detected in usefulness and sleepiness as an adverse effect. In meta-analysis of late-stage second-generation antihistamines and arachidonic acid metabolite-receptor antagonists, significant differences between them were detected in final overall improvement and usefulness. These results indicate a historical trend in the development of drugs including measures to deal with sleepiness as an adverse effect. The arachidonic acid metabolite antagonists appeared to be promising among the oral drugs for allergic rhinitis, although data related to the arachidonic acid metabolite antagonists are still few and further collection of them is necessary.

Arachidonic Acids↗
PubMed2000

Exposure to Japanese cedar pollen in early life and subsequent sensitization to Japanese cedar pollen.

The effect of exposure to Japanese cedar pollen (JCP) in early life on subsequent sensitization to it was evaluated. Specific IgE antibody to JCP was examined in 440-504 school children in a rural town each year during 1995-98. The amount of dispersed pollen measured by a Durham sampler widely ranged from 165 to 5941 grains/cm2/year during this period. The amount had been measured during the period of 1982-91 in which these children were born, and it also widely ranged from 148 to 8566 grains/cm2/year. Children born during November to January, who were exposed to JCP within 6 months of age, increased at the risk of sensitization to JCP, especially severe sensitization, relative to those born in the other months. Age-adjusted prevalence rate ratio (RR) of having a JCP-IgE > or = 15 U/ml (control; < 0.35 U/ml) for children born in December to February relative to children born in the other months was 1.74 (95% confidence interval; 1.06-2.87, examined in 1998), and for those born in November to January was 1.57 (95% CI; 1.00-2.46, examined in 1997). The risk of sensitization to JCP was low for those born in May to July (RR = 0.42, 95% CI; 0.19-0.93, examined in 1998). There was also a strong correlation between the amount of the dispersed pollen during the period of 2-6 months after birth and the prevalence of sensitization to JCP.

Adolescent↗
PubMed1999

Helicobacter pylori infection and atrophic gastritis: a nested case-control study in a rural town in Japan.

A seroepidemiologic, nested case-control study was conducted to evaluate the risk for atrophic gastritis associated with Helicobacter pylori infection. Atrophic gastritis was diagnosed on the basis of serum pepsinogen levels: pepsinogen I level < or = 70 ng/ml and pepsinogen I/pepsinogen II ratio < or = 3.0. Cases were 23 men and 39 women who were not diagnosed with atrophic gastritis in 1987, but who were diagnosed with the condition in 1992. Controls were the 120 men and 282 women who did not meet the serologic criteria for atrophic gastritis in either time period. Neither cases nor controls had a history of upper gastrointestinal operations. Helicobacter pylori infection at the initial survey was associated with a significantly increased risk of atrophic gastritis incidence for both sexes combined (odds ratio = 3.72; 95% confidence interval, 1.78-7.79; P = 0.0005). Cigarette smoking and consumption of alcohol and green-yellow vegetables were not associated with incidence of atrophic gastritis.

Adult↗
PubMed1997

Hypermethylation in the retinoblastoma gene is associated with unilateral, sporadic retinoblastoma.

We previously reported 9 unilateral, sporadic retinoblastomas with hypermethylation in the 5' region of the RB gene, and we found that CpG methylation in the RB promoter inhibits the binding of the retinoblastoma binding factor 1 (RBF-1) and the activating transcription factor (ATF)-like factors, thereby resulting in a considerable reduction in RB promoter activity. In this study, we screened for hypermethylation in 121 additional cases of retinoblastoma, and found 5 tumors with hypermethylation, including 4 unilateral, sporadic tumors, and one hereditary tumor. The hereditary tumor had a germline deletion of one allele, and the hypermethylation was an acquired, epigenetic change in the other allele. Another tumor had hypermethylation restricted to approximately 800 base pairs in the RB promoter region including the essential RBF-1 and ATF sites. The frequency of hypermethylation in unilateral, sporadic tumors was 9.3% combining our previous and present examinations (13 among 140), whereas the frequency was 1.0% in bilateral hereditary tumors (one among 101). The statistical analyses using the chi-square test indicated significant correlation between hypermethylation and unilateral, sporadic tumors (p < 0.05). These results suggest that hypermethylation in the RB gene is always an acquired, epigenetic change and causes about 9% of unilateral, sporadic tumors.

Blotting, Southern↗
PubMed1997

Helicobacter pylori infection and gastric cancer. A nested case-control study in a rural area of Japan.

We conducted a seroepidemiological nested case-control study to determine the association of gastric cancer with Helicobacter pylori infection and atrophic gastritis. A cohort of 2858 participants in an annual multiphasic health check-up were followed for eight years. Data for 45 gastric cancer cases and 225 sex-, age-, and address-matched control subjects were analyzed. Helicobacter pylori infection was determined by IgG antibodies, and atrophic gastritis was diagnosed by both serum pepsinogen I level (< or = 70 ng/ml) and the pepsinogen I/II ratio (< or = 3.0). Univariate analysis showed that Helicobacter pylori and atrophic gastritis were significantly associated with gastric cancer. In a multivariate analysis, atrophic gastritis was associated with significantly increased risk of cancer (odds ratio, 3.38; 95% confidence interval, 1.54-7.42); however, Helicobacter pylori was not associated with cancer (odds ratio, 1.84; 95% confidence interval, 0.59-5.72). These results suggest that Helicobacter pylori infection alone is not directly associated with gastric carcinogenesis but has an indirect relation to gastric cancer through the development of atrophic gastritis.

Adult↗
PubMed1997

Helicobacter pylori infection and atrophic gastritis. A case-control study in a rural town of Japan.

We enrolled five hundred twenty-one patients with atrophic gastritis and 769 controls in a case-control study of atrophic gastritis and Helicobacter pylori infection and lifestyle factors. The participants had no history of upper gastrointestinal surgery. They were selected from 1,395 adult (35 years or older) residents of a rural town in Kyoto prefecture who participated in an annual health examination in 1987. Atrophic gastritis was diagnosed on the basis of serum pepsinogen levels: pepsinogen I levels (< or = 70 ng/ml) and pepsinogen I/pepsinogen II ratios (< or = 3.0). The presence of immunoglobulin G antibodies to H. pylori indicated H. pylori infection. At the time of the health examination, participants were interviewed about daily lifestyle habits such as use of cigarettes and alcoholic beverages and consumption of green-yellow vegetables. Unconditional logistic regression analysis indicated that H. pylori infection was associated with a significantly increased risk for atrophic gastritis for all participants (odds ratio, 8.17; 95% confidence interval, 5.63-11.84); for men (odds ratio, 10.91; 95% CI, 5.25-22.67); and for women (odds ratio, 7.28; 95% CI, 4.72-11.22). We found no statistically significant relations between lifestyle factors and atrophic gastritis.

Adult↗
PubMed1997

Validity of self-reported passive smoking evaluated by comparison with smokers in the same household.

Validity of self-reported passive smoking among nonsmokers was evaluated by comparing it with data from smokers in the same household. Eight hundred and ninety-four males and 990 females responded to a lifestyle survey for a cohort study. Subjects consisted of all members aged 20 years or older in each household. One hundred and thirty-six males and 692 females nonsmokers within this group were examined for self-reported passive smoking. It should be noted that guests' smoking was also considered because the question about passive smoking included that when guests visited although guests' smoking could not be evaluated. Four percent of nonsmokers who reported passive smoking almost every day lived in households without smokers. This value was considered a misclassification of negative passive smoking as positive unless these subjects were visited by smoking guests almost every day. Eight percent of nonsmokers who reported no passive smoking had a spouse who smoked and 18% of these subjects also had other smokers in the same household. The misclassification rate for positive passive smoking as negative was thought to be 8% or higher although it was possible that the smoking spouse smoked only outside the home and that household members may live in different structures at the same site. The validity was thought to be fair in comparison with similar previous studies in Western countries.

Adult↗
PubMed1997

[An epidemiological study on an outbreak of Escherichia coli O157:H7 infection].

We conducted an epidemiological study on an outbreak of Escherichia coli (E. coli) O157:H7 to reveal the food vehicle for E. coli O157:H7. An approach of descriptive and analytical epidemiology was conducted on the basis of a case definition, that is workers reported the onset of diarrhea in between July 15 and July 22, 1996. There were 47 workers including five patients who had stool cultures that yielded E. coli O157:H7. A case-control study of all workers who dined at the company cafeteria during the 8 days probable exposure period was conducted using cafeteria computer records. Eating in the cafeteria on July 11 or 12 was associated with illness. Further case-control study using a self-administered questionnaire revealed that eating radish sprout salad on July 11 was the only food item slightly associated with diarrhea. Since the epidemiological study could reveal the cause of the outbreak of E. coli O157:H7, it should be used more and properly in collaboration with epidemiologists.

Case-Control Studies↗
PubMed1997

[Association of participation in health checkups with medical service utilization in a rural town].

Association of participation in health checkups in 1983-94 with medical service utilization in 1989-94 was studied. The study subjects consisted of 1,198 males and 1,247 females aged 30 years or over, who were members of the National Health Insurance in a rural town in Kyoto prefecture. One hundred and four males and 95 females died during 1989-94. Cumulative death rates were higher among both males and females with less participation in checkups than among those with higher participation, however, there was no difference seen for medical service utilization. Regarding subjects alive in 1994, both males and females who participated frequently in checking in 1983-88 also visited medical facilities more frequently and had higher medical costs in 1989-94 than those with less frequent participation. Similar analysis for checkups in 1989-94, showed that only females had that tendency. Among participants in checkups in 1989-94, there were smaller numbers of hypertensives, current smokers, and current drinkers than among non-participants, therefore, the participants are thought to have decreased their risk for chronic diseases. In conclusion, frequent participation in health checkups are thought to increase medical utilization even with a lower prevalence or risk of chronic diseases.

Adult↗