Biomedical subjects

H Yanagawa

Publications and source records attributed to H Yanagawa.

At least 73 records · Page 4Linked to original sources

PubMed1999

Incidence rate of Creutzfeldt-Jakob disease in Japan.

BACKGROUND: The objective of this study is to clarify the incidence rate of Creutzfeldt-Jakob disease (CJD) during the last decade in Japan. METHODS: A nationwide mail survey was conducted in all hospitals with a minimum bed capacity of 100 and having at least one of three departments: neurology, psychiatry, and neuropathology. The survey required the patient's sex, date of birth, date of diagnosis, diagnostic criteria, medical history and CJD incidence in the family. RESULTS: From 493 hospitals throughout the country, 821 patients with CJD were reported from January 1985 through March 1996. The annual incidence rate was 0.49 per million population for males and 0.68 for females. The age-specific incidence rate was highest among those 70-79 years of age, followed by the 60-69, and 50-59 age groups. The incidence and mortality increased during the observed period; however, the incidence rate among younger generations did not rise. CONCLUSION: A nationwide incidence survey of CJD in Japan revealed the incidence and distribution of the disease over the recent decade. It was found that the incidence and mortality rates had increased during the observed period.

Adolescent↗

PubMed1999

Changes in epidemic patterns of Kawasaki disease in Japan.

OBJECTIVE: Clustering of cases of Kawasaki disease throughout Japan was noted three times during the period before 1986. During the ensuing 10 years, however, no nationwide epidemic has been recognized. The purpose of this study is to test the hypothesis that local outbreaks have persisted after 1987. METHOD: The data on 56 980 patients reported from 1987 through 1996 were classified according to the area of residence. The time trend of the incidence rate was compared by year and by quarter of the year (January to March, April to June, July to September and October to December) in 10 geographical areas in Japan. RESULTS: No nationwide outbreaks have been noted since 1987 in Japan, but the existence of local outbreaks of various magnitudes was recognized as occurring in different periods in certain areas. The incidence rates were continuously high in Area 1 between 1987 and 1988 and in Area 4 between 1995 and 1996. In Area 9 local outbreaks were noted on three separate occasions (from 1987 to the first half of 1988, between 1990 and 1991 and from the second half of 1992 to 1993). No clusterings were witnessed in other areas during the 10-year period. CONCLUSION: The current annual number of patients ranges from 5000 to 6000, and local epidemics occur in various areas. The current epidemiologic patterns support the infection theory for the etiology of this disease.

Cluster Analysis↗

PubMed1999

[Building aging level indices based on ability to perform personal care and household management activities].

Defining aging as deterioration of the ability required for the activities of daily living with increasing age, we developed a formula for estimating the age of aging. In 1994 and 1995, a questionnaire survey was conducted for 11,592 individuals (4,885 men, mean age 61.6, standard deviation 14.6; and 6,677 women, mean age 63.2, standard deviation 14.8) who were members of 7 cohorts (5 community-based cohorts and 2 cohorts of examiners at a health-promotion center). The questionnaire included three groups of questions related to medical treatment, aging-related symptoms, and personal care (ADL; Activities of Daily Living) and household management (IADL: Instrumental ADL). Multiple regression analysis was made by sex and age group (over 65 years old, under 65 years old) using age as a dependent variable and the three question categories as explanatory variables. Using multiple regression analysis by question category, five items were abstracted from each of the three groups, so that a total of 15 items were abstracted from all questions. Five items were then abstracted from the 15 by multiple regression analysis, and the predicted aging age for an individual is estimated using this statistical model from the results of the questionnaire survey. The predicted aging age is significantly associated with age (r = 0.40-0.49, p = 0.0001). The difference between the predicted aging age and age is greater among the older or younger people. The expected predicted aging age is estimated using regression analysis of the predicted aging age on age. Aging level indices by sex and age groups were determined by the difference between the expected predicted aging age and age. We are planning to carry out an epidemiological study on the risk factor for aging using the aging level indices in seven cohorts.

Activities of Daily Living↗

PubMed1999

[Chronological trend of the incidence rate of Creutzfeldt-Jakob disease in Japan].

OBJECTIVE: The purpose of this study was to find whether the number of incidents of Creutzfeldt-Jakob disease has increased during the last decade in Japan. METHODS: The chronological trend was observed by examining the data from a nationwide epidemiologic survey conducted by a special committee sponsored by the Ministry of Health and Welfare of Japan in May 1996. The subjects of the survey were patients with Creutzfeldt-Jakob disease who had been diagnosed between January 1985 and May 1996. Although the number of patients reported each year increased continually during the 11-year 5-month period, there were two issues that remained to cast doubt on the accuracy of this apparently obvious chronological trend: (1) the existence of hospitals that did not respond to the survey, and (2) the existence of hospitals where no information was available before a specific time during the observation period. To make up for the incomplete data, the following two methods were proposed: (1) for those hospitals where the precise annual incidence was not known, the average annual incidence for those years when the information was available should be used to make up for the missing data and (2) when a hospital did not have the information for certain years, it would be considered to be a nonrespondent for those years; the response rate should be calculated year-by-year; then the total number of patients should be obtained by the reported number of patients divided by the response rate. The first method underestimates the annual trend if a trend does exist. To evaluate the trend mathematically, linear regression and quadratic regression models were used, in which the independent variable was the calendar year, the dependent variable, the number of patients. RESULTS: With either method, a trend for increases in incidence was noted. Statistical significance was obtained for the increasing trend in each model. It was found that the quadratic regression model was a better fit than the linear model. CONCLUSION: The incidence of Creutzfeldt-Jakob disease in Japan has increased during the last decade.

Creutzfeldt-Jakob Syndrome↗

PubMed1999

Process and current status of the epidemiologic studies on cedar pollinosis in Japan.

This paper reviews the present situation and future aspects of epidemiologic studies on Japanese cedar pollinosis. Increase of allergic rhinitis patients is observed in both the Patient Survey and the Reports on the Surveys of Social Medical Care Insurance Services, however, these surveys are conducted when cedar pollens do not pollute the air. Many have reported on the prevalence of pollinosis in limited areas but only a few nationwide epidemiologic surveys have been conducted. Most of the studies were conducted at special medical facilities such as university hospitals. There is a high possibility that patients who visit the specific facilities do not exactly represent the actual number of patients and epidemiologic pictures of pollinosis in Japan. The rapid advances in laboratory test methods may change the diagnostic criteria and increase the number of reported patients. Therefore, the prevalence of Japanese cedar pollinosis in Japan has not been determined yet. Determination of the prevalence of cedar pollinosis and description of the epidemiologic pictures constitute the essential steps toward the control of this clinical entity. Thus it is necessary to conduct an epidemiologic survey on Japanese representative samples with a standardized survey form with clear and concise diagnostic criteria.

Allergens↗

PubMed1999

Association between health-related knowledge and the awareness of blood pressure readings. Japan Lifestyle Monitoring Study Group.

This study aims to evaluate the relationships between awareness of blood pressure testing and health-related knowledge. Among 9 blocks in Japan, one or two areas were selected and a questionnaire survey including physical activity, nutrient intake, drinking habits, smoking habits, medical history, annual frequency of blood pressure testing, subjective sense of wellness, and health related knowledge was conducted. Respondents' sex and age were adjusted as potential confounding factors and the association between possession of health-related knowledge and awareness of blood pressure testing were examined by using a multiple logistic regression model. Among the 1,834 effective responses, 263 (14.3%) answered that they could state their blood pressure levels. These individuals tended to have a greater health-related knowledge. Even after adjusting for other potential confounders (smoking habits, medical history, annual frequency of blood pressure testing, and subjective sense of wellness) health-related knowledge were significantly related to blood pressure awareness.

Adult↗

PubMed1999

[Relationship between breast milk and atopic dermatitis in children].

OBJECTIVE: To determine whether or not dioxins and furans in breast milk have a role in the prevalence of atopic dermatitis among children. METHODS: The target population of the study was all children participating in health check-up program for 3-year-old children in Tochigi Prefecture in September and October 1997. Using a questionnaire, information on nutrition in infants (breast milk only, bottled milk only, or mixed), parity, mothers' age at birth, and a history of atopic dermatitis was obtained. Besides, data on potential confounding factors were obtained. RESULTS: Questionnaires from 2,968 children (85.3% of those who were to participate in the programs, and 90.2% of children who participated them) were analyzed. The risk of atopic dermatitis was higher among children with breast milk (odds ratio [OR] = 1.37 with 95% confidence interval [CI] 1.02-1.83) and those with mixed nutrition (OR = 1.21, 95% CI: 0.94-1.57) in comparison with children with only bottled milk. Mothers' age at birth (OR for those who were more than 30 years or older in comparison with those who were younger than 30 years = 1.27; 95% CI, 1.01-1.62) and those with second or later parity orders (OR = 1.32, 95% CI; 1.04-1.67) were also risk factors of the dermatitis after the adjustment for some potential confounding factors. CONCLUSION: Breast milk elevates the risk of atopic dermatitis slightly; the risk is, however, higher in children in second or later parity orders. If the PCDDs and PCDFs in breast milk cause the dermatitis, this would contradict the assumed metabolism of these chemicals in human bodies.

Adult↗

PubMed1998

Therapeutic efficacy of mouse-human chimeric anti-ganglioside GM2 monoclonal antibody against multiple organ micrometastases of human lung cancer in NK cell-depleted SCID mice.

The development of distant metastases to multiple organs is a critical problem in the treatment of human lung cancer. In this study, we evaluated the therapeutic efficacy of a mouse-human chimeric anti-ganglioside GM2 (GM2) monoclonal antibody (MAb), KM966 against metastasis formation of GM2-positive human lung cancer cells inoculated intravenously (i.v.) into natural killer (NK) cell-depleted severe combined immunodeficient (SCID) mice. GM2-positive human small cell lung cancer (SCLC), SBC-3 cells (1 x 10(6)), injected through a tail vein into NK cell-depleted SCID mice, formed large number of metastatic colonies in the liver, kidneys and lymph nodes by 42 days after inoculation (day 42). KM966, but not control MAb, given on days 2 and 7, almost completely inhibited metastasis formation of SBC-3 cells in the liver, kidneys and lymph nodes in a dose-dependent fashion. Moreover, treatment with KM966 at advanced stages of metastasis (even from day 28) significantly suppressed multiple organ metastases of SBC-3 cells. The anti-metastatic effect of KM966 in vivo was mainly due to an antibody-dependent cell-mediated cytotoxicity (ADCC) reaction mediated by macrophages of the SCID mice. Our findings suggest that the mouse-human chimeric anti-GM2 MAb, KM966 may be useful for eradicating multiple organ micrometastases of lung cancer in humans.

Animals↗

PubMed1998

Origins of globular structure in proteins.

Since natural proteins are the products of a long evolutionary process, the structural properties of present-day proteins should depend not only on physico-chemical constraints, but also on evolutionary constraints. Here we propose a model for protein evolution, in which membranes play a key role as a scaffold for supporting the gradual evolution from flexible polypeptides to well-folded proteins. We suggest that the folding process of present-day globular proteins is a relic of this putative evolutionary process. To test the hypothesis that membranes once acted as a cradle for the folding of globular proteins, extensive research on membrane proteins and the interactions of globular proteins with membranes will be required.

Cell Membrane↗

PubMed1998

Characterization of random-sequence proteins displayed on the surface of Escherichia coli RNase HI.

In a previous study, random-sequence proteins of 120-130 amino acid residues were inserted into the surface loop region of the enzyme, Escherichia coli RNase HI [Doi et al. (1997) FEBS Lett. 402, 177-1801. Here we established that the RNase H activity of the insertion mutants is correlated with their secondary structure contents evaluated by circular dichroism measurement at 222 nm. The random-sequence insert of a mutant enzyme possessing relatively high RNase H activity was detached from the RNase HI scaffold, and its characterization indicated that the random-sequence protein maintains its secondary structure after separation from the scaffold. Thus, the structural features of random-sequence proteins were suggested to be monitored by measuring the activity of the scaffold enzyme into which these proteins have been inserted.

Amino Acid Sequence↗

PubMed1998

Protein anatomy: C-tail region of human tau protein as a crucial structural element in Alzheimer's paired helical filament formation in vitro.

Tau is a microtubule-associated protein in mammalian brain. In Alzheimer's disease, this protein is present in the somatodendritic compartment of certain nerve cells, where it forms a portion of paired helical filament, the major constituent of the neurofibrillary tangle. For clarification of the mechanism of this formation, recombinant human tau and its fragments (N-terminal half, C-terminal half, and 4-repeats) expressed in Escherichia coli were prepared, eight peptide fragments (C-tails 1-8) of the C-tail region were synthesized, and the conformation and capacity for aggregation essential for filamentous structure formation in vitro were examined. Recombinant full-length tau, the N-terminal half, 4-repeats, and the C-terminal half did not form filamentous structures in aqueous solution after standing at 20 degrees C. Peptides corresponding to the C-tail region of tau, C-tail 5, C-tail 7, and C-tail 8, produced the paired filament or single straight filament in acidic solution. The rate of filament formation by each peptide was followed by circular dichroism, which showed the C-tails to have predominantly random coil structures immediately following dissolution in aqueous solution and be gradually converted to the beta-sheet structure. The kinetics of aggregation were characterized by a delay period during which the solution remained clear, followed by a nucleation event which led to a growth phase, whose negative peak intensity at 218 nm in circular dichroism increased due to filamentous structure formation. This delay was eliminated by seeding supersaturated solution of preformed filaments. C-tails interacted with recombinant full-length tau to form definite single straight filament. The C-tail region of tau is thus shown indispensable to the formation of paired helical filament and nucleation to reduce the rate of paired helical filament formation in amyloidogenesis in vitro. These findings may provide some clarification of the pathogenesis of Alzheimer's disease.

Alzheimer Disease↗

PubMed1998

Screening of conformationally constrained random polypeptide libraries displayed on a protein scaffold.

The selection of novel proteins or enzymes from random protein libraries has come to be a major objective in current biology, and these enzymes should prove useful in various biological and biomedical fields. New technologies such as in vitro selection of proteins in cell-free systems have high potential to realize evolutionary molecular engineering of proteins. This review highlights an application of insertional mutagenesis of proteins to evolutionary molecular engineering. Random sequence proteins are inserted into the surface of a host enzyme which serves as a scaffold to display random protein libraries. Constraints on random polypeptide conformations owing to the proximity of N- and C-termini on the scaffold would result in greater screening efficiency of libraries. The scaffold enzyme is also used as a probe for monitoring the hill climbing of random sequence proteins on a fitness landscape and navigating rapid protein folding in the sequence space.

Animals↗

PubMed1998

Generation of killer activity by interleukin-12 of mononuclear cells in malignant pleural effusions due to lung cancer.

In the present study, we examined the ability of interleukin (IL)-12 to generate an antitumor effect in the tumor-growing site. Mononuclear cells (MNC) were obtained from 12 malignant pleural effusions due to lung cancer in the tumor-growing site. Non-major-histocompatibility-complex-restricted killer activity, examined by 4-h 51Cr release assay against Daudi lymphoma cells as well as various lung cancer cell lines (H69 and PC-9), and in vitro production of interferon gamma (IFNgamma), measured by enzyme immunoassay, were investigated as mediators of antitumor effects of host cells activated by IL-12. IL-12 induced killer activity of MNC in pleural effusions (pleural MNC) dose-dependently. Moreover, pleural MNC produced a signficant amount of IFNgamma in response to IL- 12. The killer activities of IL-12-activated blood MNC were higher than those of pleural MNC. The supernatants of pleural effusions of these untreated patients suppressed killer induction by IL-12 of blood MNC of healthy volunteers. These observations suggest that MNC present at the site of growing tumors may act as effector cells against lung cancer in the presence of IL-12.

Cell Separation↗

PubMed1998

Comparative analysis of interleukin 15 and interleukin 2 for induction of killer activity and of type 2 cytokine production by mononuclear cells from lung cancer patients.

Interleukin (IL) 15 is a novel cytokine with IL-2-like activity. In this study, we examined the effect of IL-15 on induction of non major histocompatibility complex (MHC)-restricted killer activity and of type 2 cytokine production by peripheral blood and pleural mononuclear cells (MNCs), from 34 lung cancer patients and 20 control subjects. IL-15 induced significant killer activity in blood MNCs from lung cancer patients as well as control subjects against a small-cell lung cancer cell line (SBC-3). Effective killer induction by IL-15 was observed even in blood MNCs and pleural MNCs from the site of tumour growth in advanced lung cancer patients. IL-12 had an additive effect with a suboptimal dose of IL-15 in induction of killer activity. In the case of MNCs from lung cancer patients, IL-10 production was more prominent when cells were incubated with IL-2 than with IL-15. IL-5 production was observed in MNCs from lung cancer patients stimulated with IL-2, but not with IL-15. These observations suggest that IL-15, by virtue of its lesser induction of type 2 cytokine, may be a better candidate than IL-2 for lung cancer immunotherapy.

Adult↗

PubMed1998

Lower level of serum potassium and higher level of C-reactive protein as an independent risk factor for giant aneurysms in Kawasaki disease.

Giant aneurysms are the most serious issue of patients with Kawasaki disease (KD). To clarify risk factors for these giant aneurysms, we conducted a matched case-control study. Among the patients reported in nationwide surveys, 117 patients with giant aneurysms had an unequivocal new diagnosis and presented at the treatment center within 9 d of illness. We obtained clinical information on admission of about 69 patients (case) from the treatment centers. One control was selected for each case, an age- and sex-matched patient without coronary involvement, reported from the same treatment center at about the same time as the case, and we obtained the same clinical information about controls. Fourteen variables were analysed with a conditional logistic regression model: body temperature, hematocrit, hemoglobin, numbers of leukocyte and platelets, concentrations of serum albumin, globulin, total cholesterol, sodium, potassium and chloride, erythrocyte sedimentation rate, C-reactive protein and alanine aminotransferase activity. After adjustment for age, duration of illness before admission and use of intravenous gamma globulin therapy, C-reactive protein [odds ratio (OR)=1.142, 95% confidence interval (CI) 1.054-1.237], alanine aminotransferase activity (OR=1.008, 95% CI 1.002-1.014), serum sodium concentration (OR=0.877, 95% CI 0.770-0.999) and serum potassium concentration (OR=0.319, 95% CI 0.124-0.822) were significantly related to the risk for giant aneurysms. Further analyses with these four explanatory variables revealed that C-reactive protein (OR=1.159, 95% CI 1.022-1.315) and serum potassium concentration (OR=0.222, 95% CI 0.052-0.948) met the significant level. Thus, the values for serum C-reactive protein and potassium are independent risk factors for the development of the giant aneurysms of Kawasaki disease.

Age Distribution↗

PubMed1998

Mortality among patients with a history of Kawasaki disease: the third look. The Kawasaki Disease Follow-up Group.

BACKGROUND: Long-term prognosis of Kawasaki disease is still unclear. METHODS: In a cohort study, 6576 patients with Kawasaki disease were observed from their first medical encounter because of the disease through the end of 1994, or until death. Standardized mortality ratios (SMR) with 95% confidence intervals (CI) were calculated with vital statistics data of Japan used for the control. RESULTS: Of 6576 patients who met the eligibility criteria, 6550 (99.6%) were followed through either the end of the study or the date of death. Twenty patients (14 male, 6 female subjects) died during the study period; an overall SMR of 1.35 (95% CI 0.82-2.08) was calculated. The SMR was 1.45 (95% CI 0.79-2.44) for male subjects and 1.15 (95% CI 0.42-2.52) for female subjects. During the acute phase of the disease (the first 2 months after the first visit to hospital), the SMR was higher, particularly in male subjects (SMR 10.13, 95% CI 3.72-22.08). After the acute phase, however, both boys and girls had low SMR. Nine of the 20 deaths were caused by Kawasaki disease; there were three deaths as a result of congenital heart diseases and two subjects died of malignant neoplasms of lymphatic or hematopoietic tissues. CONCLUSIONS: Although the mortality rate among those with a history of Kawasaki disease was elevated in Japan, many of the deaths that caused the elevation occurred during the acute phase of the disease. The mortality rate was not increased after the acute phase of the disease.

Adolescent↗

PubMed1998

Cardiac sequelae of Kawasaki disease among recurrent cases.

OBJECTIVE: This study was undertaken to clarify whether cardiac sequelae due to Kawasaki disease are more frequent among recurrent cases than initial onset cases. STUDY DESIGN: A cross sectional study using data from nationwide surveys of Kawasaki disease in Japan was conducted. A total of 33,976 patients reported were divided into two groups: initial onset cases (32,923 patients) and recurrent cases (1053 patients). Proportions of cardiac sequelae such as coronary aneurysms/dilatation, coronary stenosis/narrowing, myocardial infarction, and valvular lesions were compared between the two groups. RESULTS: The proportions of patients with the sequelae were significantly more common among recurrent cases. In men 25.5% of the recurrent cases had the sequelae in comparison with 14.9% for initial onset cases, and in women 16.1% of recurrent cases had the sequelae compared with 9.8% of initial onset cases. Giant coronary aneurysms were twice as likely in men in whom the disease was recurring than in initial onset cases, and 1.5 times more likely in women in whom the disease was recurring than in initial onset cases. CONCLUSION: Cardiac sequelae of Kawasaki disease are more likely to appear on recurrent case patients.

Child↗

PubMed1998

[Characteristics of medical institutions visited by patients with intractable diseases--analyses of patients receiving financial aid for treatment].

The Research Committee of Epidemiology of Intractable Diseases (Ministry of Health and Welfare, Japan) conducted a nationwide survey of 34 intractable diseases. Each of 47 prefectural governments reported information on all patients with the diseases who received financial aid for the disease from April 1992 to March 1993. Information collected on each patient included the identification number, sex, age, the code of the municipality where the patient lived, and the medical institution and department where the patient was being treated. Out of 247, 726 patients whose information was reported by prefectural governments, we analysed data of 208,945 patients whose medical institutions were reported. The results can be summarized as follows: 1) Aged patients and children who were less than ten years old tended to visit medical institutions located in their neighborhoods and be treated in small hospitals or clinics. 2) The proportion of patients who visited hospitals with 200 beds or more was 77 percent. 3) Patients with the diseases resulting in physical disabilities such as SMON and malignant rheumatoid arthritis tended to visit clinics. Patients with skin diseases as pemphigus, epidermolysis bullosa and pustular psoriasis tended to be treated in university hospitals. 4) Many patients living in prefectures near large cities such as Tokyo and Ishikawa visited medical institutions in the large cities. 5) The proportion of patients who visited university hospitals decreased during the eight years from 1984 to 1992. However, a quarter of these patients visited university hospitals.

Adolescent↗