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Biomedical subjects

K Wakai

Publications and source records attributed to K Wakai.

At least 55 records · Page 3Linked to original sources
PubMed1999

A simple food frequency questionnaire for Japanese diet--Part II. Reproducibility and validity for nutrient intakes.

A self-administered 97-item simple food frequency questionnaire (FFQ), without portion size questions for most items, was completed twice at an one-year interval by 88 men and women in central Japan to evaluate its reproducibility. This FFQ was further validated by referring to four 4-day weighed dietary records (DRs) which were performed at 3-month intervals. Mean energy and 18 nutrient intakes measured by the first and the second FFQs were quite similar to those measured by the DRs. In our reproducibility study, Pearson and intraclass correlation coefficients, adjusted for energy intake, sex and age, ranged from 0.48 to 0.82 (median = 0.67). In the validation study, adjusted and de-attenuated correlation coefficients between the second FFQ and the DRs ranged from 0.42 for iron to 0.83 for calcium (median = 0.61). The proportion of subjects classified by the FFQ into the same or adjacent quintiles defined by the DRs was between 65.9% and 83.0% (median = 69.9%). These findings essentially suggested that our FFQ is well reproducible and sufficiently valid, and therefore, reasonably useful for nutritional epidemiological studies for Japanese diets, particularly for those of Tokai Area.

Adult↗
PubMed1999

[Evidence-based medicine and 'The Cochrane Collaboration'].

In Evidence-Based Medicine (EBM), a clinical decision is based neither on pathophysiological theories nor personal experience but on the results derived from scientifically designed clinical epidemiological studies (i.e., evidence). EBM is used in various clinical applications, such as therapy, diagnosis, and prognosis prediction. The process includes (1) asking a clinical question consisting of the three elements of "patient", "exposure", and "outcome"; (2) searching for the best evidence using MEDLINE or Cochrane Library; (3) appraising critically the validity of the method and the magnitude and probability of the result; and finally (4) applying the evidence of the patient. In actual clinical practice, clinical expertise and patient preferences should be as much regarded as research evidence. 'The Cochrane Collaboration' supplies systematic reviews of clinical trials carried out all over the world to its consumers. Its fruit, 'The Cochrane Library (CD-ROM),' is a highly valuable resource. 'The Cochrane Collaboration' serves as the infrastructure for EBM. EBM, which was originally developed for the individual patient care, can also be applicable to community- or workplace-healthcare and policy making by governments. Thus, EBM is both a philosophy and a method to provide people with the most appropriate medical practice.

Databases as Topic↗
PubMed1999

[Intra- and inter-individual variations in diets of the middle-aged and the elderly].

This study was conducted to examine intra- and inter-individual variations in diets of the middle-aged and the elderly (40 years or older, 46 men and 42 women). The coefficients of variations for intakes of nutrients and food groups were computed from four 4-day weighed dietary records performed at 3-month intervals from June 1996. The results were as follows: a) The highest intra-individual variation (%) for nutrient intake was observed in retinol (men 293.5, women 283.8) and the lowest in carbohydrate (men 17.7, women 22.1). b) The highest inter-individual variation (%) was found in retinol (58.2) in men, and in carotene (56.7) in women. The lowest inter-individual variation (%) was observed in magnesium (17.0) in men, and in carbohydrate (14.4) in women. c) Nuts and seeds showed the highest intra-individual variation (%) for food group intake (men 291.5, women 391.8), while rice presented the lowest (men 30.5, women 38.9). d) The highest inter-individual variation for food group intake (%) was seen in milk and dairy products (111.7) in men and in alcoholic beverages (162.3) in women. The lowest inter-individual variation was observed in potatoes and starches (20.7) in men and in pulses (26.0) in women. e) The number of days necessary to estimate true average nutrient intake was much longer for such vitamins as retinol and carotene (over 50 days) than for macronutrients (3-5 days) except for fat. More than one year was required to estimate intake of nuts and seeds in both sexes and alcoholic beverages or seaweeds in women, whereas only 9-15 days for intake of rice. In conclusion, energy, protein and carbohydrate can be estimated by short-period dietary recalls or records, since their intra-individual variations were relatively small. On the other hand, many days, were found to be required to estimate usual dietary intake of such vitamins as retinol or carotene and that of each food group except for rice. It would therefore be very difficult to estimate usual intake of these nutrients and food groups by short-period dietary recalls or records.

Diet↗
PubMed1999

[Sudden death of clinically unknown origin. An overview of postmortem examinations in Japan].

To elucidate the possible causes of sudden unexpected deaths (SUD) in Japan, we over-viewed autopsy findings described in the Annual of the Pathological Autopsy Cases in Japan, Vol. 35-37, 1992-1994. A total of 313 cases of SUD of clinically unknown origin (age > = 5 year) were found among the 95,142 autopsy cases listed in the above compilation. The direct causes of death, if identified, were described with their incidences. When the direct cause was undetermined, the most dominant pathological finding was listed. The difference in age between identified and unidentified groups was also studied. In 225 (72%) out of 313 SUD, direct causes of death were clarified as follows: cardiovascular diseases in 140 (acute myocardial infarction in 75), pulmonary diseases in 32, cerebrovascular diseases in 17, and gastrointestinal or hepatic disease in 17 cases. Even among 88 cases whose direct causes of death were unclear, 55 had cardiovascular abnormalities including myocardial hypertrophy and ischemic changes. No life-threatening abnormalities were found in 23 SUD cases, most of whom were men in their forties or younger. This study indicates that autopsy is helpful to reveal the cause of SUD. It also suggests cardiovascular diseases are the leading causes of SUD of clinically unknown origin.

Autopsy↗
PubMed1999

hOGG1 Ser326Cys polymorphism and lung cancer susceptibility.

The human homologue of the yeast OGG1 gene, hOGG1, has been cloned, and its genetic structure has been determined. Several polymorphisms in the hOGG1 gene were detected in the Japanese populations, and among them, the Ser-Cys polymorphism at codon 326 has been shown to have a functional difference in complementation of mutant Escherichia coli that is defective in the repair of 8-hydroxyguanine. Activity in the repair of 8-hydroxyguanine is greater in hOGG1-Ser326 protein than in hOGG1(326) protein. Because many environmental carcinogens produce 8-hydroxyguanine residue and mismatching to this modified base potentially causes oncogenic mutations, the capacity to repair these lesions can be involved in cancer susceptibility in human beings. We, therefore, examined allele distributions of the Ser326Cys polymorphism in a case-control study of male lung cancer in Okinawa. The analyses based on 241 cases and 197 hospital controls disclosed the following findings. (a) Those with the Cys/Cys genotype were at an increased risk of squamous cell carcinoma and nonadenocarcinoma compared to those with the Ser/Cys and those with the Ser/Ser genotypes combined. The odds ratios adjusted for age and smoking history were 3.01 (95% confidence interval, 1.33-6.83) and 2.18 (95% confidence interval, 1.05-4.54), respectively. (b) The odds ratios for other histological subtypes of lung cancer or those in total were not significant. Those for Cys/Cys or Ser/Cys genotype against Ser/Ser did not reach statistical significance in any cell type. (c) The distributions of this polymorphism varied for different populations (Chinese, Japanese, Micronesians, Melanesians, Hungarians, and Australian Caucasians), with much less prevalence of Cys allele in the latter three populations. Although our sample size was limited, these results indicate that the Ser326Cys variant may be related to squamous cell lung cancer susceptibility. The Cys/Cys genotype appears to be more susceptible to squamous cell carcinoma, although the risk is less than that previously reported to be associated with the CYP1A1 gene. Further studies are needed to assess the importance of the interpopulation variation to cancer susceptibility.

Adult↗
PubMed1998

Possible factors affecting response to intravesical bacillus Calmette-Guérin (Tokyo 172 strain) therapy for carcinoma in situ of the bladder: a multivariate analysis.

To evaluate clinicopathological factors affecting response to intravesical instillation therapy with the bacillus Calmette-Guérin (BCG) Tokyo 172 strain for carcinoma in situ (CIS) of the bladder, we reviewed data for 84 patients treated between 1985 and 1996. Median follow-up was 56 months. The patients comprised three groups: primary (only the in situ lesion, 31 patients), subsequent (found after treatment of a gross neoplasm, 20), and concomitant (found together with a gross neoplasm, 33). A complete response was found in 62 (74%) of the 84 patients. Intravesical BCG therapy eradicated tumour cells in 74% of the primary group, 70% of the subsequent group, and 76% of the concomitant group. Multivariate logistic regression analysis revealed that the presence of gross haematuria and patient age were significantly associated with a complete response to the intravesical BCG therapy (p<0.05). On the other hand, gender, irritative bladder symptoms, type of extent of CIS, histological grade of CIS, BCG dose, and number of times BCG was given did not exert any significant influence. The 5-year recurrence rate was 33% for the 62 patients for whom a complete response was once achieved. Patients aged 60 or older had a higher probability of recurrence than those less than 60 years of age (p<0.05). Disease progression was found in 13% of the 84 patients and total cystectomy was performed in 19%. The present finding that patient age is related to the response to intravesical BCG therapy may point to a role for the reduced host immunocompetence in elderly individuals.

Administration, Intravesical↗
PubMed1998

Estimated number of patients with chronic renal failure but not with end-stage renal disease in Japan: comparisons between two estimation methods.

We estimated the number of patients with chronic renal failure (CRF) but not with end-stage renal disease (ESRD) in Japan by two methods: a nationwide survey and an estimation using incidence rates of ESRD among CRF patients as well as the number of incident ESRD. The former estimated the number of patients with CRF but not with ESRD as 154,000 (95% confidence interval 139,000-168,000), while so did the latter as 142,000 (133,000-150,000). It follows that the number of CRF patients including ESRD could amount to more than 300,000, which would give a substantial impact on public health in Japan. Despite some own methodological issues in estimation, the two estimates were reasonably in good agreement: supporting their methodological validity in estimation, since sources of errors appeared to be quite independent of each other.

Adult↗
PubMed1998

Descriptive epidemiology of pancreatic cancer in Japan.

This paper aimed to explore descriptive epidemiological features of pancreatic cancer in Japan, by examining secular trends in mortality (1950-1995) and incidence rates (1975-1991), and also to discuss background factors possibly ascribable to the recent variation in mortality and incidence rates. The age-adjusted mortality rate (adjusted by the 1985 model population) has increased by approximately 9-fold in both males (from 1.4 to 12.5 per 100,000 population) and females (from 0.8 to 6.8 per 100,000 population) between 1950 and 1995. But it began to level off in both sexes since 1985. The age-adjusted incidence rate has remained plateau in both sexes, but likely showed a downward trend since 1988 in females. The older age groups showed the most steep increasing gradient in both age-specific mortality and incidence rates in both sexes, whereas a little or no apparent increase was observed in young age groups. Diagnostic improvement and increased cigarette consumption were believed to be the two major factors contributing to the increased mortality and incidence rates in Japan, but further epidemiological studies will be required to clarify possible background factors for the recent levelling-off of the mortality and incidence rates.

Adult↗
PubMed1998

Association of Ile462Val (Exon 7) polymorphism of cytochrome P450 IA1 with lung cancer in the Asian population: further evidence from a case-control study in Okinawa.

Okinawa, a group of islands that lie between the East China Sea and the Pacific Ocean, 2000 km south of the Japanese main islands, has a different profile of diseases, ethnicities, and cultures than does the rest of Japan. We examined an Ile462Val polymorphism (CYP1A1*2 allele) of cytochrome P450 IA1 in a hospital-based case-control study of lung cancer patients (247 cases and 185 controls) in Okinawa to ascertain the association of this variant with lung cancer. In addition, the distribution of this genotype was studied in populations from different areas of Japan, including Tokyo (n = 69) and Iwate (northern part of Japan; n = 81), as well as in a Chinese group from the Jiangsu province (n = 39) and in an Australian Caucasian group (n = 146). Genotype frequency in controls was not significantly different from area to area in Japan. In Okinawa, however, the genotype encoding Val/Val was associated with a significantly higher risk of lung cancer (odds ratio = 3.32, P = 0.013), especially of squamous cell carcinoma and small cell carcinoma (odds ratio = 4.85 and 9.35, respectively). The Val-encoding allele was less frequent in the Chinese population and was rare in Australian Caucasians. Thus, this study gives support to the value of the cytochrome P450 IA1 Ile462Val polymorphism as a practical high-risk marker of lung cancer in populations, especially those in southeast Asia, in which this variant is more common.

Adult↗
PubMed1998

Newly developed diabetic retinopathy and its preceding changes in biological markers.

To disclose the chronological changes prior to the manifestation of diabetic retinopathy (DR), we analyzed the time course of biological markers among apparently healthy diabetic subjects in a case-control study of 21,579 adults who had undergone comprehensive health examinations for > or = 10 years. We identified 54 cases who had newly developed DR, and selected 108 adults without fundus abnormalities, matching them for sex, age, and fasting plasma glucose (FPG) at the onset of the patient group's retinopathy as a referent group from the same population. In a multivariate analysis, a high average FPG (> 175 mg/dl) and a final-year FPG reduction (< -3%) were significantly associated with a 5.4 (95% CI, 1.8-15.7)- and 5.0 (95% CI, 1.0-24.7)-fold increased risk of DR, respectively. Thus, we surmised that sustained hyperglycemia and a subsequent drop in FPG might promote retinopathy in non-insulin dependent diabetes mellitus.

Biomarkers↗
PubMed1997

Multivariate evaluation of prognostic determinants for renal cell carcinomas which are metastatic at initial diagnosis.

To clarify the relative importance of clinicopathological factors potentially affecting the survival of individuals initially diagnosed as having metastatic renal cell carcinoma (RCC), univariate and multivariate analyses using Cox's proportional hazards model were performed for 111 RCC patients who were admitted to four hospitals in Nagoya, Japan, between 1978 and 1993. Survival time was calculated from the date of diagnosis to the date of death or the end of May, 1995. Nineteen factors (17 clinically applicable before treatment and 2 histological in nature) were included for assessment. Univariate analysis revealed that 10 of the total 19 factors were significantly associated with patient survival. Multivariate analysis found 7 factors to be statistically significant determinants. Survival was further evaluated by categorizing the patients into three groups according to the number of the 7 factors. These groups showed clearly different survivals (log-rank test, p < 0.0001), confirming the importance of the 7 factors as definite determinants. They should therefore prove to be of advantage for classifying metastatic RCC patients when designing clinical prospective studies of immunotherapy and chemotherapy.

Adult↗
PubMed1997

Epidemiological features of moyamoya disease in Japan: findings from a nationwide survey.

To estimate an annual number of patients treated for Moyamoya disease in Japan and to describe the clinico-epidemiological features, a nationwide epidemiological survey was conducted in 1995. The study consisted of two questionnaires, which were distributed to departments randomly selected, of neurosurgery, neurology and pediatrics in hospitals throughout Japan. The first questionnaire inquired the number of the patients treated in 1994 and the second one detailed clinico-epidemiological information of each patient reported. Following major epidemiological findings emerged from the study: (a) The total annual number of patients treated for Moyamoya disease was estimated as 3900 (95% confidence interval (CI) 3500-4400) in Japan 1994, with the prevalence and incidence rates of 3.16 and 0.35 per 100,000 population, respectively; (b) the sex ratio (females to males) of the patients was 1.8; (c) the peak of age distribution of the patients was observed in 10-14 years old and a smaller peak in their forties; (d) the age at onset was under 10 years old in 47.8% of the patients, but some had developed the disease at the age of 25-49 years; (e) family history of Moyamoya disease was found in 10.0% of the patients; and (f) about 75% of the patients had normal activity of daily life or working ability even before treatment. The present findings were quite comparable with those obtained in the previous nationwide epidemiological survey in 1990.

Adolescent↗
PubMed1997

The current status of the treatment for hemorrhagic type moyamoya disease based on a 1995 nationwide survey in Japan.

The optimal treatment regimen for hemorrhagic type Moyamoya disease has yet to be clearly established. Furthermore, it remains unclear as to whether or not bypass surgery can help prevent future intracranial hemorrhaging in Moyamoya patients. In Japan, several treatment options, such as conservative, medical, and surgical intervention, have been employed for the treatment of hemorrhagic type of Moyamoya disease. In this study, 282 hemispheres with hemorrhagic onset were analyzed based on a 1995 nationwide survey by the Research Committee on Spontaneous Occlusion of the Circle of Willis (Moyamoya Disease) of the Ministry of Health and Welfare Japan to clarify the current status of treatment for hemorrhagic type Moyamoya disease. Questionnaires were distributed to the departments of neurology, neurosurgery, and pediatrics all over Japan asking about both treatment and rebleeding. As a result, 12.5% of the affected hemispheres were treated conservatively while 32.3% were medically treated. Ventricular drainage and/or hematoma removal was performed in 15.8%, and revascularization surgery in 38.3% of all hemorrhagic sides. Among the revascularization procedures used, 45.7% of the hemispheres underwent single indirect bypass surgery, such as EDAS while 22.2% of them received a direct (superficial temporal artery--middle cerebral artery: STA-MCA) bypass surgery. A combination of direct and indirect bypass surgery or a combination of different kinds of indirect procedures comprised 32.1%. Forty-nine out of 282 hemorrhagic hemispheres demonstrated rebleeding. An intracranial hemorrhage occurred in 15 hemispheres with ischemic onset even though nine of them had undergone bypass surgery prior to hemorrhaging. Nearly 18% of the patients with hemorrhagic type disease experienced rebleeding regardless of the treatment modalities. Based on these findings, there remains no clearly superior treatment plan for hemorrhagic Moyamoya disease to prevent rebleeding at this time. However, the selection of patients, treatment modalities, and the timing of the surgery might all play an important role in controlling rebleeding. The final outcome of the patients are therefore mainly considered to correlate with the initial severity of the clinical features.

Cerebral Hemorrhage↗
PubMed1997

Risk factors for sudden deafness: a case-control study.

In order to investigate risk factors for idiopathic sudden sensorineural hearing loss (sudden deafness), a case-control study was done in 109 patients with sudden deafness who visited our hospital between 1992 and 1994, with 109 controls matched to each patient by gender and age. Odds ratio (OR) and 95% confidence interval (CI) for smoking habits, drinking habits, dietary habits, environmental noise, past history of disease, sleeping hours, appetite, fatigue, incidence of common cold were obtained. Fatigue (OR: 3.28; 95% CI: 1.36-7.90) and loss of appetite (OR: 8:00; 95% CI: 1.00-64.0) elevated the risk for sudden deafness. Those who ate many fresh vegetables were at a decreased risk (OR: 0.48; 95% CI: 0.24-0.96 for light-colored vegetables, OR: 0.55; 95% CI: 0.30-1.02 for green-yellow vegetables). Personal histories of hypertension and thyroid disease, and susceptibility to colds appeared to be positively associated with the risk (0.05 < P < 0.10). Smoking habits, drinking habits and environmental noise had no significant association with sudden deafness. These results suggested that environmental factors, including diet, may be importantly involved in the genesis of sudden deafness.

Adolescent↗
PubMed1997

Estimated prevalence and incidence of adult Still's disease: findings by a nationwide epidemiological survey in Japan.

To estimate prevalence and incidence of adult Still's disease in Japan, and to describe the epidemiological features of the patients, a nationwide epidemiological survey was conducted in 1994. The study consisted of two questionnaires which were distributed to the heads of the relevant departments, randomly sampled, in hospitals throughout Japan. Following major epidemiological findings emerged from the study: (a) The total annual number of patients treated for adult Still's disease was estimated as 1,100 in 1993 in Japan. The estimated crude prevalence among those aged 16 years or older were calculated as 0.73 and 1.47 per 100,000 population for males and females, respectively, with the corresponding crude incidence rate of 0.22 and 0.34. (b) The sex ratio (female to male) of the reported patients was 2.1. This female predominance might be specific to Japan, though additional surveys in other countries will be warranted. The mean age of the patients was 38.1 years, and female patients tended to be older than male ones; 50% of the female patients aged 40 years or older, while so did only 28% of the male patients.

Adolescent↗
PubMed1997

Smoking habits, local brand cigarettes and lung cancer risk in Okinawa, Japan.

To disclose the association between smoking habits and lung cancer in Okinawa, Japan, we analyzed the data from a case-control study conducted from 1988 to 1991. The analysis, based on 333 cases and 666 age-, sex- and residence-matched population controls, provided the following major findings. (a) The odds ratios (ORs) for current smokers relative to nonsmokers were much greater for squamous cell carcinoma than for adenocarcinoma. The OR was 9.82 for squamous cell carcinoma and 2.18 for adenocarcinoma in males, 28.2 and 1.14, correspondingly, in females. (b) Males who quit smoking for 20 years or more demonstrated no elevated lung cancer risk. (c) Among male current smokers, the more the number of cigarettes smoked per day, the higher the lung cancer risk for both cell types, but particularly for squamous cell carcinoma. In contrast, deep smoke inhalation significantly increased the risk for adenocarcinoma in particular. (d) Okinawan brand cigarettes were more strongly associated with the risk, compared with other brand ones. This finding might partly explain the higher frequency of lung cancer in males with the relatively lower smoking rate in Okinawa.

Adenocarcinoma↗
PubMed1996

Epidemiology of diseases of unknown etiology, specified as "intractable diseases".

In Japan, epidemiological studies on intractable diseases have been undertaken and greatly promoted for more than 20 years by the Research Committee on Epidemiology of Intractable Diseases, with the financial supports from the Ministry of Health and Welfare of Japan. In this paper, chronological history of development of the Research Committee and some scientific accomplishments by the recent Research Committee (1993-1995) were summarized, mainly focusing on descriptive, analytical and other epidemiological studies. Hoped is that the readers are to be acquainted with the recent research activities by the Research Committee and seek for possible international collaborations in epidemiological studies on intractable diseases.

Epidemiologic Methods↗