Green tea consumption and cognitive function: a cross-sectional study from the Tsurugaya Project 1

BACKGROUND: Although considerable experimental and animal evidence shows that green tea may possess potent activities of neuroprotection, neurorescue, and amyloid precursor protein processing that may lead to cognitive enhancement, no human data are available. OBJECTIVE: The objective was to examine the association between green tea consumption and cognitive function in humans. DESIGN: We analyzed cross-sectional data from a community-based Comprehensive Geriatric Assessment (CGA) conducted in 2002. The subjects were 1003 Japanese subjects aged > or =70 y. They completed a self-administered questionnaire that included questions about the frequency of green tea consumption. We evaluated cognitive function by using the Mini-Mental State Examination with cutoffs of <28, <26, and <24 and calculated multivariate-adjusted odds ratios (ORs) of cognitive impairment. RESULTS: Higher consumption of green tea was associated with a lower prevalence of cognitive impairment. At the <26 cutoff, after adjustment for potential confounders, the ORs for the cognitive impairment associated with different frequencies of green tea consumption were 1.00 (reference) for < or =3 cups/wk, 0.62 (95% CI: 0.33, 1.19) for 4-6 cups/wk or 1 cup/d, and 0.46 (95% CI: 0.30, 0.72) for > or =2 cups/d (P for trend = 0.0006). Corresponding ORs were 1.00 (reference), 0.60 (95% CI: 0.35, 1.02), and 0.87 (95% CI: 0.55, 1.38) (P for trend = 0.33) for black or oolong tea and 1.00 (reference), 1.16 (95% CI: 0.78, 1.73), and 1.03 (95% CI: 0.59, 1.80) (P for trend = 0.70) for coffee. The results were essentially the same at cutoffs of <28 and <24. CONCLUSION: A higher consumption of green tea is associated with a lower prevalence of cognitive impairment in humans.     

Initial Experience with Computed Tomography and Fluoroscopically Guided Placement of Push-Type Gastrostomy Tubes Using a Rupture-Free Balloon Catheter

The purpose of this study was to evaluate the safety and feasibility of percutaneous radiologic gastrostomy placement of push-type gastrostomy tubes using a rupture-free balloon (RFB) catheter under computed tomography (CT) and fluoroscopic guidance. A total of 35 patients (23 men and 12 women; age range 57–93 years [mean 71.7]) underwent percutaneous CT and fluoroscopically guided gastrostomy placement of a push-type gastrostomy tube using an RFB catheter between April 2005 and July 2008. Technical success, procedure duration, and complications were analyzed. Percutaneous radiologic gastrostomy placement was considered technically successful in all patients. The median procedure time was 39 ± 13 (SD) min (range 24–78). The average follow-up time interval was 103 days (range 7–812). No major complications related to the procedure were encountered. No tubes failed because of blockage, and neither tube dislodgement nor intraperitoneal leakage occurred during the follow-up period. The investigators conclude that percutaneous CT and fluoroscopically guided gastrostomy placement with push-type tubes using an RFB catheter is a safe and effective means of gastric feeding when performed by radiologists.     

Identification of osteoblast-specific monoclonal antibodies

Summary A series of four antibodies against rat osteoblasts have been produced using the hybridoma technique. After bone cells isolated from newborn rat calvariae by a sequential digestion procedure were cultured for 3 days, the cells were trypsinized and further maintained in rotation cultures overnight. Out of the cultured bone cells alkaline phosphatase-positive cells were sorted by flow cytometry and used as immunogens. The clones secreting the antibodies were selected on the basis of the abilities of these antibodies to bind to the bone cells but not to fibroblasts from neonatal rat head skins, in an enzyme-linked immunosorbent assay. Clones of two hybridomas, designated AOB-1 and AOB-2, were used to characterize the antigenic determinant(s) in osteogenic cells. The antibody showed the reactivity with isolated alkaline phosphatase-positive cells, osteogenic tissue cells in newborn rat calvaria, and mandibula, but not with the cells in head skin, lung, kidney, liver, or stomach as determined by immunofluorescence study. Western blot analysis has identified the antigenic determinants possessing apparent molecular weights of 210,000, 110,000, 65,000, 58,000, 40,000, 36,000, 32,000, 28,000, 25,000, 17,000, and 15,000 of osteoblast-rich monolayer cultured cells. According to the cell surface detection with biotin-avidin protein blotting technique, these fractions appear to be present as components of the cell surface of the osteoblast.     

Association of a mast cell chymase gene variant with HDL cholesterol, but not with blood pressure in the Ohasama study.

Two enzymes, chymase and angiotensin converting enzyme (ACE), are involved in the production of angiotensin II. Our previous study revealed the male-specific effect of the ACE DD genotype on the risk for hypertension, but the genetic role of chymase remains unclear. In the present study, we report the results of an association study involving 1,046 subjects recruited from a general population in Ohasama, a rural community in the northern part of Japan. In addition to casual blood pressure (casual BP) measurement, home BP measurements were obtained from all participants. There were no differences in either home or casual BP values according to G3255A polymorphism of the mast cell chymase gene (MCC). HDL cholesterol level was significantly higher among carriers of the A3255 allele (p<0.04). After adjustment for confounding factors, the A3255 allele was still shown to have an effect on HDL cholesterol metabolism (p<0.03). Multiple regression analysis showed that MCC polymorphism was significantly and independently related to serum HDL cholesterol level. In conclusion, G3255A polymorphism of MCC is not directly associated with blood pressure but may modulate the prevalence of hypertensive complications via alteration of lipid metabolism.     

Quantitative carbohydrate analyses of the tectorial and otoconial membranes of the guinea pig.

Carbohydrate composition of the tectorial membrane (TM) and the otoconial membrane (OM) of the guinea pig was analyzed after hydrolysis, using high-performance anion-exchange chromatography and pulsed amperometric detection. Both of the tissues were highly glycosylated; the carbohydrate content being 24-42% of protein. GlcN, Gal, Glc and Man were found to be the major component sugars of TM, whereas little GalN was found. Fuc and NANA were also present, but NGNA was not detectable. After digestion with thermolysin for solubilization, OM was separated into two fractions: insoluble mineral particles of the otoconia (OM-ppt) and a soluble fraction from the gelatinous layer (OM-sup). These two fractions showed distinct carbohydrate composition from each other. Further analyses using glycosidases revealed that TM contained asialyl and monosialyl but little di-, tri- and tetrasialyl N-glycosides, and OM-sup did not seem to be susceptible to endo-beta-galactosidase, which is known to cleave some N-acetyl-polylactosamine and keratan sulfate. Based on these analyses, it can be suggested that most of the carbohydrates in TM are likely to be asialyl and monosialyl N-glycosides. N-Glycosides may be predominant in the otoconia as well, and a polymer structure consisting of GlcN(Ac) and Gal other than N-acetyl-polylactosamine may exist in the gelatinous layer of OM. O-Glycosylation of the usual type appeared to be minor in all the fractions.     

No effect of the Trp64Arg variant of the beta3-adrenergic receptor gene on weight loss by diet and exercise intervention among Japanese adults

Controversy remains as to whether the presence of the tryptophan-to-arginine (Trp64Arg) variant of the β₃-adrenergic receptor gene impedes the magnitude of body weight loss by diet and exercise intervention. The objectives of the present study were to compare the changes in body weight between carriers and noncarriers of the Trp64Arg variant before and after 6 months of diet and exercise interventions for weight loss. A total of 37 middle-aged Japanese individuals (12 carriers and 25 noncarriers of the Trp64Arg variant) participated in the study. There were no significant differences in body weight between the 2 groups at the baseline. There were significant reductions in body weight both in carriers and noncarriers, but no significant differences between the 2 groups with respect to changes in these variables. The weight changes were −2.52 kg (95% confidence interval [CI], −3.56 to −1.48) among carriers and −1.89 kg (95% CI, −2.65 to −1.13) among noncarriers, and the change in the variant carrier group minus the change in the variant noncarrier group was −0.47 (95% CI, −1.97 to 1.02). These results suggest that the presence of the Trp64Arg variant of the β₃-adrenergic receptor gene may not play a major role as a hindrance to weight reduction.     

Relation of blood pressure and all-cause mortality in 180,000 Japanese participants: pooled analysis of 13 cohort studies

Hypertension is a leading cause of death because of cardiovascular disease and predominantly affects total mortality. To reduce avoidable deaths from hypertension, we need to collect blood pressure data and assess their impact on total mortality. To examine this issue, a meta-analysis of 13 cohort studies was conducted in Japan. Poisson regression was used for estimating all-cause mortality rates and ratios. In the model, blood pressure data were treated as continuous (10-mm Hg increase) and categorical (every 10 mm Hg) according to recommendations of the Seventh Joint National Committee on Prevention, Detection, Evaluation, and Treatment of Hypertension. Potential confounders included body mass index, smoking, drinking, and cohort. The impact of hypertension was measured by the population-attributable fraction. After excluding participants with cardiovascular disease history, 176 389 participants were examined in the analysis. Adjusted mortality rates became larger as the blood pressure increased, and these were more distinct in younger men and women. Hazard ratios also showed the same trends, and these trends were more apparent in younger men (hazard ratio [unit: 10-mm Hg increase] aged 40 to 49 years: systolic blood pressure 1.37 (range: 1.15 to 1.62); diastolic blood pressure 1.46 [range: 1.05 to 2.03]) than older ones (hazard ratio: aged 80 to 89 years: systolic blood pressure 1.09 [range: 1.05 to 1.13]and diastolic blood pressure 1.12 [range: 1.03 to 1.22]). Population-attributable fraction of hypertension was approximately 20% when the normal category was used as a reference level and was 10% when we included the prehypertension group in the reference level. In conclusion, high blood pressure raised the risk of total mortality, and this trend was higher in the younger Japanese population.