Search PubMed⌕ Search

Biomedical subjects

N Kawakami

Publications and source records attributed to N Kawakami.

At least 37 records · Page 2Linked to original sources
PubMed2000

Identification of a functional transposase of the Tol2 element, an Ac-like element from the Japanese medaka fish, and its transposition in the zebrafish germ lineage.

The Tol2 element of the medaka fish Oryzias latipes belongs to the hAT family of transposons (hobo/Ac/Tam3). We report here identification of a functional transposase of Tol2 that is capable of catalyzing its transposition in the germ line of zebrafish Danio rerio. A transcript produced from Tol2 encodes a putative transposase. Zebrafish fertilized eggs were coinjected with mRNA transcribed in vitro, using cDNA of the Tol2 transcript as a template and a plasmid DNA harboring a mutant Tol2, which had a deletion in the putative transposase gene but retained necessary cis sequences. The injected fish were raised to adulthood and mated to noninjected fish, and genomic DNA of the progeny fish were analyzed by PCR and Southern hybridization. Half of F(1) fish obtained from one of eight injected fish contained the Tol2 DNA in their genomes but not the vector portion. Among these F(1) fish, Tol2 insertions at four different loci were identified, and some F(1) fish carried two or three different Tol2 insertions, indicating that the germ line of the founder fish is highly mosaic. Sequencing analyses revealed that, in all cases, Tol2 was surrounded by zebrafish genomic sequences, and an 8-bp duplication was created at the target site, indicating that Tol2 was integrated in the zebrafish genome through transposition. This study identifies an autonomous member of a DNA-based transposable element from a vertebrate genome. The Tol2 transposon system should thus be used to develop novel transgenesis and insertional mutagenesis methods in zebrafish and possibly in other fishes.

Animals↗
PubMed2000

Activation of NADPH oxidase in Alzheimer's disease brains.

The present study is the first to show that superoxide (O(-)(2)) forming NADPH oxidase is activated in Alzheimer's disease (AD) brains by demonstrating the marked translocation of the cytosolic factors p47-phox and p67-phox to the membrane. In conjunction with a recent in vitro study showing that amyloid beta activates O(-)(2) forming NADPH oxidase in microglia, where these phox proteins are localized in this study, the present results suggest that, in AD, NADPH oxidase is activated in microglia, resulting in the formation of reactive oxygen species which can be toxic to neighboring neurons in AD.

Aged↗
PubMed2000

Quantum phase transitions in the shastry-sutherland model for SrCu2(BO3)(2)

We investigate quantum phase transitions in the frustrated antiferromagnetic Heisenberg model for SrCu2(BO3)(2) by using the series expansion method. It is found that a novel spin-gap phase, adiabatically connected to the plaquette-singlet phase, exists between the dimer and the magnetically ordered phases known thus far. When the ratio of the competing exchange couplings alpha( = J'/J) is varied, this spin-gap phase exhibits a first- (second-) order quantum phase transition to the dimer (the magnetically ordered) phase at the critical point alpha(c1) = 0.677(2) [ alpha(c2) = 0. 86(1)]. Our results shed light on some controversial arguments about the nature of quantum phase transitions in this model.

Journal Article↗
PubMed2000

Lumbopelvic lordosis and pelvic balance on repeated standing lateral radiographs of adult volunteers and untreated patients with constant low back pain.

STUDY DESIGN: Twenty volunteers and 20 patients with no prior spine surgery had two standing lateral radiographs taken, on the average, 66 months apart and 2 weeks apart, respectively. OBJECTIVES: To first determine the reliability of the measurement techniques used, and then the longitudinal variation between radiographs for the sagittal spinopelvic alignments measured in two stable populations, the one manifesting no back symptoms (volunteers) and the other showing no changes in symptoms (patients). Pelvic morphology also was assessed quantitatively, and significant correlations for the measurements were studied. SUMMARY OF BACKGROUND DATA: There are no published studies on longitudinal variation for measurements of sagittal spinal alignments in asymptomatic control subjects or untreated patients with stable back problems. It may be helpful to know not only how much variation in alignments can be expected between radiographs of the same individual, but also which measurements and measurement techniques offer the greatest clinical reliability and application. METHODS: Each patient in this study reported mechanical type low back pain that was constant in location and character as well as clinically consistent with symptomatic degenerative lumbar disc disease. Each patient and volunteer had 36-inch-long lateral radiographs taken of the entire thoracic and lumbar spine, which included the pelvis. After intervening periods of 1 to 4 weeks (patients) and 5 to 6 years (volunteers), a second radiograph was taken for comparison. Two observers made 24 different measurements on the radiographs including determinations for lumbopelvic lordosis, pelvic balance, and pelvic morphology using the pelvic radius technique. Reliabilities, longitudinal variations, and correlations for the measurements were compared. RESULTS: The most reliable measurements were for pelvic morphology, pelvic balance, and regional lumbopelvic lordosis by the pelvic radius technique. Pelvic morphology was the most constant measurement between individual radiographs. Pelvic morphology and total lumbosacral lordosis were dependent measurements that were complementary in determining total lumbopelvic lordosis. Lumbopelvic lordosis and pelvic balance also had strong correlation, whereas lumbosacral lordosis and pelvic balance were independent measurements. CONCLUSIONS: The pelvic radius technique is recommended for evaluating lordosis to the pelvis because this approach provided not only good measurement reliability on standing radiographs for lumbopelvic lordosis, but also determination of pelvic balance over the hips and the option to assess pelvic morphology quantitatively. Lumbopelvic lordosis and pelvic balance were strongly correlative. This finding, along with higher reliability and lower longitudinal variation on repeated radiographs, indicated greater clinical application for these specific measurements.

Adult↗
PubMed2000

Hypocholesterolemic effect of soymilk supplementation with usual diet in premenopausal normolipidemic Japanese women.

BACKGROUND: The hypocholesterolemic effect of soy protein concentrates on normolipidemic subjects still remains unclear. Our objective is to assess the effect of soymilk supplementation, a whole soy product, with usual diet on serum lipids in normolipidemic subjects. METHODS: We conducted a randomized controlled trial on 60 premenopausal normolipidemic Japanese women. After excluding 8 subjects whose initial serum concentration of total cholesterol or triacylglycerol was higher than 220 mg/dL (5.69 mmol/L) or 160 mg/dL (1.81 mmol/L), respectively, we encouraged the subjects in the soymilk-supplemented group (n = 27) to consume 400 mL (408 g) of commercial regular soymilk daily during two menstrual cycles. There were no significant differences in variables, including nutrient intake, between the soymilk-supplemented and control (n = 25) groups before the intervention. RESULTS: After the trial, we observed a significant decrease of 10.9 mg/dL, or 5.3%, in serum concentration of total cholesterol in the soymilk-supplemented group. During the intervention, nutrient intake assessment showed significant increases in nutrient densities of vitamin E, polyunsaturated fatty acids, isoflavones, and P/S ratio and decreases in total energy and nutrient densities of vitamin C and green tea in this group. A statistically significant decrease in serum total cholesterol could still be observed even after excluding the estimated hypocholesterolemic effects of soymilk's polyunsaturated fatty acids. CONCLUSIONS: Our results suggest the hypocholesterolemic effect of soymilk, a traditional whole soy product, in Asian countries in normolipidemic subjects.

Adult↗
PubMed2000

Rationality/antiemotionality personality and selected chronic diseases in a community population in Japan.

OBJECTIVE: To clarify the relationships of the rationality/antiemotionality (R/A) personality with past histories of seven chronic diseases and current smoking habits in a community population in Japan. METHODS: A questionnaire survey was conducted of all residents aged 35 years old or over (n = 37,287) in Takayama city, Gifu prefecture, Japan; the response rate was 90.3%. Data from 13,091 males and 14,061 females who completed all relevant questions were analyzed. The subjects were asked to complete an 11-item R/A personality scale developed by Grossarth-Maticek et al. (1985). Past histories of seven major chronic diseases and current smoking habit were also asked in the questionnaire. RESULTS: Among males, the R/A scale score was significantly lower in those who had stroke, diabetes or allergy than in those who did not. Among females, the R/A scale score was significantly lower in those who had stroke, allergy or stomach cancer than in those who did not. Among females, current smokers had significantly lower R/A scores than non-smokers. After controlling for age, smoking and drinking, the R/A score was significantly and negatively associated with stroke among males and females; it was significantly and negatively associated with diabetes and allergy among males. CONCLUSION: Our findings are contrary to those observed in Yugoslavia and West Germany, and suggest a cultural difference in the relationship between the R/A personality and disease occurrence.

Adult↗
PubMed2000

Temperature-dependent translational regulation of the ER omega-3 fatty acid desaturase gene in wheat root tips.

The proportion of alpha-linolenic acid (18:3) among the total fatty acids in root tissue increases as the growth temperature decreases. Endoplasmic reticulum omega-3 fatty acid desaturase is responsible for the production of most of the 18:3 in root tissue. In this study, the effect of temperature on expression of the TaFAD3 gene, which encodes endoplasmic reticulum omega-3 desaturase in wheat (Triticum aestivum L. cv. Chihoku), was analysed at the mRNA and protein levels. In wheat root tips grown at 30 and 10 degrees C, the proportions of 18:3 among total fatty acids were 22% and 55%, respectively. The level of TaFAD3 protein in microsomal preparations of the root tips grown at 10 degrees C was approximately 7.5 times higher than that of the root tips grown at 30 degrees C. The increased level of TaFAD3 protein at the lower temperature was accompanied by enhanced association of TaFAD3 mRNA with polyribosomes. In contrast, the level of TaFAD3 mRNA in root tips grown at 10 degrees C was slightly higher than in those grown at 30 degrees C. These results suggest that, in root tips, the increase in the 18:3 level at low temperature is achieved directly by an increase in the amount of TaFAD3 protein, and that temperature-dependent translational regulation of the TaFAD3 gene, rather than its transcriptional regulation, contributes to modulation of the TaFAD3 protein accumulation.

Endoplasmic Reticulum↗
PubMed2000

Decrease of suppressor-inducer (CD4+ CD45RA) T lymphocytes and increase of serum immunoglobulin G due to perceived job stress in Japanese nuclear electric power plant workers.

To clarify the effects of perceived job stress on the immune system, a cross-sectional study was conducted in 116 male Japanese workers of a nuclear electric power plant (age, 20 to 39; mean, 31 years). Perceived job stress, i.e., psychological job demand, job control, worksite social support, and job strain, was assessed by means of the Japanese version of the Job Content Questionnaire. The job strain score was calculated as the ratio of the job demand score to the job control score. Blood samples were taken from all workers, and numbers of T and natural killer cell subpopulations, B lymphocytes, total lymphocytes and white blood cells, and serum concentrations of immunoglobulins (IgG, IgM, IgA, IgE and IgD) in their blood were measured. The workers were divided into higher and lower strain groups according to their job strain scores. The number of CD4+ CD45RA+ T lymphocytes in the higher strain group having the job strain score of 0.5 or more (41 workers) was significantly smaller than that in the lower strain group having the score of less than 0.5 (75 workers). In contrast, the serum IgG concentration in the former group was significantly higher than that in the latter group (analysis of covariance with age and smoking as covariates). Also, the numbers of total CD4+ T and total T (CD3+) lymphocytes and of white blood cells in the former group were significantly smaller than those in the latter group. After controlling for age and smoking by the partial correlation coefficient in all 116 workers, the number of CD57+ CD16+ natural killer cells was inversely correlated with job demand and with job strain; the number of CD8+ T lymphocytes was positively correlated with worksite social support; and serum IgG and IgM concentrations were positively correlated with job strain. It is suggested that higher job strain decreases the number of CD4+ CD45RA+ T lymphocytes in male Japanese workers but increases serum IgG concentrations.

Adult↗
PubMed2000

Job strain, social support in the workplace, and haemoglobin A1c in Japanese men.

OBJECTIVES: To examine the association between job strain (defined in the model of job demands and job control) and social support at the workplace with levels of glycosylated haemoglobin A1c (HbA1c) METHODS: All male employees aged 40-60 in a manufacturing firm, Japan, were invited to take part in the study. A blood sample was taken from the participants and HbA1c (%) was measured. Job strain and social support at the workplace were assessed with the job content questionnaire (JCQ). After excluding those who had a history of diabetes mellitus or other chronic diseases, data from 268 male day workers were analyzed. RESULTS: Age adjusted average concentrations of HbA1c were significantly higher in the highest quartile group of job strain or the lowest quartile group of social support at the workplace (p<0.05). Multiple linear regression analysis indicated that job strain was significantly and positively related to HbA1c (p<0.05), whereas social support at the workplace was significantly and negatively related to HbA1c (p<0.05), both after controlling for other covariates. CONCLUSIONS: Greater job strain and lower social support at the workplace may be associated with increased concentrations of HbA1c. Increased blood glucose may be a physiological mediator between job strain or social support at the workplace and coronary heart disease.

Adult↗
PubMed2000

Inverse association of soy product intake with serum androgen and estrogen concentrations in Japanese men.

The cross-sectional relationships of soy product intake and serum testosterone, estrone, estradiol, sex hormone-binding globulin, and dihydrotestosterone were examined in 69 Japanese men. Soy product intake was estimated from a semiquantitative food frequency questionnaire. Serum estradiol concentration was significantly inversely correlated with soy product intake (r = -0.32, p = 0.009), and serum estrone concentration was nonsignificantly inversely correlated with soy product intake (r = -0.24, p = 0.05) after controlling for age, body mass index, smoking status, and ethanol intake. Total and free testosterone concentrations were inversely correlated with soy product intake after controlling for the covariates, but these correlations were of border line significance (r = -0.25, p = 0.05 and r = -0.25, p = 0.06, respectively). Similar correlations were observed for these hormones with isoflavone intake from soy products. The data suggest that soy product intake may be associated with the endogenous hormone levels in Japanese men.

Aged↗
PubMed2000

Total and monounsaturated fat intake and serum estrogen concentrations in premenopausal Japanese women.

The relationships between fat intake and serum estrone, estradiol, and sex hormone-binding globulin were examined cross-sectionally in 60 premenopausal Japanese women. Blood samples were collected on Day 11 of the menstrual cycle. Intake of fats, classified according to fat type, and other macro- and micronutrients was estimated on the basis of daily diet records from Day 2 through Day 10 of the cycle. Total fat intake was significantly correlated with serum estrone concentration (Spearman r = 0.30, p = 0.02) and marginally significantly correlated with serum estradiol concentration (r = 0.26, p = 0.05) after controlling for age, total energy, and number of days before the next menses. Monounsaturated fat intake was significantly correlated with serum estrone (r = 0.32, p = 0.02) and serum estradiol (r = 0.27, p = 0.045). These data suggest an effect of dietary fat on serum estrogen concentrations.

Adult↗
PubMed2000

Relationships between types of fat consumed and serum estrogen and androgen concentrations in Japanese men.

The relationships between types of fat consumed and serum concentrations of estrone, estradiol, total and free testosterone, dihydrotestosterone, and sex hormone-binding globulin were examined in 69 Japanese men aged 43-88 years. Diet was assessed by a semiquantitative food frequency questionnaire. Intake of saturated, monounsaturated, and polyunsaturated fats was inversely correlated with serum total testosterone after controlling for age, total energy, body mass index, alcohol intake, and smoking status, but the correlation was statistically significant only for polyunsaturated fat (r = -0.29, p = 0.02). Intakes of eicosapentanoic and docosahexaenoic acids, n-3 fatty acids from fish, were significantly inversely correlated with total testosterone (r = -0.25, p = 0.04 and r = -0.32, p = 0.01, respectively). Serum estrone, estradiol, and free testosterone were not significantly correlated with any type of fat studied. The correlations of total testosterone with n-3 fatty acids from fish remained significant after additional adjustment for the other categories of fat (r = -0.27, p = 0. 03 for eicosapentanoic acid and r = -0.32, p = 0.01 for docosahexaenoic acid), while the correlations with saturated and monounsaturated fats became nearly null after the adjustment.

Adult↗
PubMed2000

Phorbor myristate acetate induces NADPH oxidase activity of cytochalasin B-primed neutrophils through the protein kinase C-independent pathway.

We examined the effect of cytochalasin B (CB) or granulocyte colony stimulating factor (GCSF) on superoxide radical (O2-) production of neutrophils by phorbor myristate acetate (PMA)-stimulation. It was observed that O2- generation of intact and GCSF-treated neutrophils by PMA-stimulation showed a lag during the early stage, and was largely inhibited by 1-(5-isoquinoline-sulfonyl)-3-methyl-piperazine (200 microm) or GF109203X (GFX) (0.2 microM), but not by ethanol (1%) and wortmannin (100 nM). In contrast, O2- generation of CB-pretreated neutrophils by PMA-stimulation did not show a lag, but was less than that of intact cells, and was only minimally depressed by the above inhibitors, but was markedly depressed by the simultaneous addition of GFX and ethanol or GFX and wortmannin. Although translocation of p47phox and p67phox to the membrane fraction by PMA-stimulation of intact and GCSF-treated neutrophils occurred in parallel with O2- production, that of CB-treated neutrophils by PMA-stimulation was not always proportional to O2- production. These findings suggest that pretreatment of neutrophils with CB dramatically alters the PMA response of the cells; that is, the protein kinase C-dependent pathway is largely depressed, and a phospholipase D-dependent one for NADPH oxidase activation appears in CB-treated cells.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed2000

Evidence for the degradation of maleate moiety in chlorpheniramine maleate solution using a stability-indicating HPLC method.

The degradation phenomenon of maleate moiety of chlorpheniramine maleate in solution has been demonstrated by means of a peculiar ion-pair HPLC method developed by the authors, which permits the simultaneous determination of chlorpheniramine and maleate. A commercial cough drug containing chlorpheniramine maleate was dissolved in water with m-hydroxybenzoic acid as an internal standard, and then kept for several days at room temperature. It was recognized that the maleate content in the drug solution had gradually decreased, whereas chlorpheniramine content had not decreased. A simple solution of maleic acid was also kept for several days at room temperature, and it was also recognized that the maleate content in the solution preserved at the same concentration as the solution of the commercial cough drug had gradually decreased, and the percent of remaining maleate reached zero. The degraded peaks on HPLC chromatogram were not detected at all by UV detector, and the disappearance of maleate was ascertained by GC-MS. No detectable example of maleate of chlorpheniramine maleate in a commercial cough syrup has suggested that maleate moiety of chlorpheniramine maleate decomposed to carbon dioxide.

Chlorpheniramine↗
PubMed2000

[Job stress control at workplace: how to plan and conduct].

This review addressed that stress control activities at workplace could be classified into four categories: (1) improvement of work environment; (2) education/training; (3) health care for stress; (4) mental health service. Research has demonstrated that each of these activities is effective to some extent. The review also pointed out that stress control at workplace could be planned and conducted under occupational health systems, e.g., occupational safety & health management system. Then I proposed a possible effective strategy for planning and conducting stress control at workplace.

Health Education↗
PubMed2000

Does job stress affect injury due to labor accident in Japanese male and female blue-collar workers?

To clarify whether job stressors affecting injury due to labor accidents differ between Japanese male and female blue-collar workers, the Job Content Questionnaire (JCQ), assessing dimensions of job stressors based on the demand-control-support model, was applied to 139 blue-collar workers in a manufacturing factory. Of them, 24 male and 15 female workers suffered from injuries at work. In the female workers with the experience of work injury, the job demand score and job strain index (i.e., the ratio of job demand to job control) of the JCQ were significantly higher and the score of coworker support was significantly lower, than those in the female workers without the experience. High job demand (or, high job strain and low coworker support) was significantly related to work injury in all the female workers. Between the male workers with and without work injury, however, there was no significant difference in any job stressors. This pilot study suggests that high job strain (specifically, high job demand), as well as low coworker support, are important factors affecting work injury in Japanese female blue-collar workers. Further research with a large number of male blue-collar workers will be required to seek other factors that may be associated with work injury.

Accidents, Occupational↗
PubMed2000

Sleep problems in white-collar male workers in an electric equipment manufacturing company in Japan.

In order to clarify poor sleep habits and prevalence in sleep problems (disturbances) of healthy male white-collar workers and the relationship of these to age and job type, a total of 1,161 Japanese employees of an electric equipment manufacturing company (aged 23 to 59, mean 37 years) were surveyed by means of a mailed questionnaire. The workers were asked about eleven sleep habits. They were also divided into four groups according to age and job type: 23-29 (n = 226), 30-39 (n = 597), 40-49 (n = 225) and 50-59 (n = 113); managerial (n = 209), professional (n = 336), technical (n = 475) and clerical (n = 134). In this study, the sleep problems were defined as who had at least one of the following four poor sleep habits: 1) taking more than 30 minutes to fall asleep, 2) awakening during sleep (ADS) almost every day, 3) early morning awakening (EMA) almost every day, and 4) excessive daytime sleepiness (EDS) at work almost every day. Analyses showed that sleep problems were present in 26.0% of workers; the problems were most serious among workers aged 50 years and more (36.0%) which may be due to a significant increase in the prevalence rate of EMA. The results revealed that sleep problems are common in male white-collar daytime workers. The findings also suggest a need for increased attention to sleep problems in older workers and younger ones with EDS at work.

Adult↗