Biomedical subjects

Shigeru Yamamoto

Publications and source records attributed to Shigeru Yamamoto.

At least 19 recordsLinked to original sources

PubMed2006

Association of estrogen receptor alpha gene polymorphisms and lifestyle factors with calcaneal quantitative ultrasound and osteoporosis in postmenopausal Vietnamese women.

Genetic and lifestyle factors are important in the pathogenesis of osteoporosis. We investigated the relationships of PvuII and XbaI polymorphisms of the estrogen receptor alpha (ER-alpha) gene, lifestyle factors with speed of sound at the calcaneus (calcaneal SOS) and osteoporosis in a population-based study of 140 healthy postmenopausal women. By an analysis of covariates, women with higher copies of P or X alleles had higher calcaneal SOS compared with others (P=0.012, PP vs. pp; P=0.045, Xx vs. xx). Women with lower copies of px or higher copies of PX haplotypes had higher calcaneal SOS compared with others (P=0.021, 0 px vs. 2 px; P=0.011, 1 PX vs. 0 PX). The px and PX haplotypes, age and years since menopause were found to be independent predictors of calcaneal SOS in multiple linear regression models. Using logistic regression, we found an increased osteoporosis risk with evidence for a px haplotype dose effect (OR=2.82, 95% CI=1.50-5.31, P=0.001) and for a PX haplotype dose effect (OR=0.42, 95% CI=0.19-0.93, P=0.033). An increased educational level was associated with a reduced risk of osteoporosis (P=0.035 in the model with px, P=0.044 in the model with PX). In conclusion, the present study suggests that PvuII and XbaI polymorphims of the ER-alpha gene, age, years since menopause and educational level are associated with bone density, as assessed by calcaneal SOS, and osteoporosis in postmenopausal Vietnamese women.

Aged↗

PubMed2006

Zinc nutrition in healthy subjects and patients with taste impairment from the view point of zinc ingestion, serum zinc concentration and angiotensin converting enzyme activity.

OBJECTIVE: To estimate the zinc nutrition in healthy subjects and patients with taste impairment. Dietary zinc intake, zinc concentration in the serum and the ratio of apo/holo-activities of angiotensin converting enzyme (ACE), a zinc dependent enzyme in the serum (ACE ratio) were used as indices. SUBJECTS: Healthy paramedical volunteers from a local hospital and patients with taste impairment seen in the Department of Otolaryngology, Tokushima University Hospital. MEASUREMENTS: Dietary zinc intake was estimated with the food frequency questionnaire (FFQ). Zinc concentration in the serum was measured by means of atomic absorption spectrometry. The ACE activity in the serum was measured spectrophotometrically as the activity of holo-ACE, which contains zinc and shows full ACE activity. The activity of apo-ACE, which dose not contain zinc, was determined as the increase of its activity over that of the initial holo-ACE activity after the addition of zinc to the serum in vitro. ACE ratio was used as a more sensitive indicator of zinc nutrition than measuring zinc concentration in the serum. RESULTS: There were no differences in dietary intake of zinc after adjusting for energy and zinc concentration in the serum between patients and age-adjusted healthy subjects. The ACE ratio in patients with taste impairment was significantly higher than that in age-adjusted healthy subjects (P<0.05). CONCLUSION: Our date demonstrate that zinc deficiency is a predominant factor underlying taste impairment and we hypothesize that patients with taste impairment may have malabsorption of dietary zinc.

Adult↗

PubMed2006

Deletion polymorphisms in the promoter region of Fcgamma receptor IIB is not associated with antigen-specific IgG2a and IgG2b antibody responses in NC/Nga mice.

Fcgamma receptor (R) IIB, a low-affinity FcR for IgG, inhibits B cell Ag R (BCR)-mediated activation when these two receptors are cross-linked by Ag and IgG-containing immune complexs (ICs). We found deletion polymorphisms in the promoter region of fcgr2b in NC/Nga mice, a model for human atopic dermatitis. NC/Nga mice produced significantly higher levels of ovalbumin (OVA)-specific IgG, IgG2a and IgG2b than did BALB/c mice. Analysis of (BALB/c x NC/Nga)F1 x BALB/c or (BALB/c x NC/Nga) F1 x NC/Nga backcross mice revealed that deletion polymorphisms of fcgr2b in NC/Nga mice does not directly regulate hyper OVA-specific IgG2a and IgG2b Ab responses.

Animals↗

PubMed2006

Defect of oral tolerance in NC/Nga mice.

The NC/Nga mouse is a model animal for human atopic dermatitis. In this study, we investigated oral tolerance induction in NC/Nga mice. In BALB/c mice, oral administration of ovalbumin (OVA) resulted in suppression of both OVA-specific T and B cell responses induced by OVA immunization. In NC/Nga mice, OVA-induced antigen (Ag) -specific T and B cell responses were significantly less than those in BALB/c mice. Furthermore, oral administration of OVA did not suppress OVA-specific immunoresponses in NC/Nga mice. We further examined antibody (Ab) response against food Ag by feeding mice an experimental diet that contained OVA or casein as a protein source. The level of serum OVA or casein-specific IgG was significantly higher in NC/Nga mice than in BALB/c mice. These results indicate that NC/Nga mice have a defect in the induction of oral tolerance. NC/Nga mice can therefore be used as a model for investigating the mechanism of oral tolerance.

Administration, Oral↗

PubMed2006

Low resting energy expenditure in middle-aged and elderly hemodialysis patients with poor nutritional status.

Due to high resting energy expenditure (REE) in maintenance hemodialysis patients, an increase in energy intake is usually recommended to improve their nutritional status. However, some patients appear to have poor appetite and low energy intake. In such patients low energy metabolism is expected. We hypothesized that in maintenance hemodialysis patients there are two types of the energy metabolism, high and low. This study was aimed at finding the energy metabolism in maintenance hemodialysis patients, especially in those with poor nutritional status. Subjects were hemodialysis out-patients (34 males and 20 females, mean age 59.1+/-10.7 y). REE was measured by an indirect calorimeter. Protein intake was obtained from normalized protein catabolic rate (nPCR), and physical activity level (PAL) was obtained by time study. Nutritional status assessed by serum albumin concentration was poor (3.7+/-0.2 g/dL) in spite of the adequate protein intake (1.1+/-0.3 g/kg per day). Only 11% of the subjects had appropriate serum albumin concentration. Mean REE was 24.6 kcal/kg per day which was lower than that of healthy Japanese (26.5 kcal/kg per day). REE and PAL positively correlated with serum albumin concentration (p<0.01). The results suggest that maintenance hemodialysis patients with poor nutritional status may have low REE.

Adult↗

PubMed2006

Favorable effects of tea on reducing the cognitive deficits and brain morphological changes in senescence-accelerated mice.

The present study was carried out to explore the effects of oolong and green teas on improving the memory deficits and brain pathological changes in senescence accelerated-prone mice P8 (SAMP8). Six-month-old mice were supplied with oolong tea, green tea or water as the sole drinking fluid for 16 wk. The memory ability of mice was evaluated by passive and active avoidance tests, while the extent of the brain degeneration was measured by the spongiosis grades and the lipofuscin percentage in the hippocampus. The total grading score and serum biochemical levels were also measured. The results indicated that the mice supplemented with the oolong and green tea drinks reversed the cognitive impairment, lessened the spongy degeneration and lipofuscin, and increased the serum Trolox equivalent antioxidant capacity more than the control group. The total grading score of the oolong tea group was lower than that of the control group in male mice, whereas it did not differ among female groups. No differentiations in the concentrations of total cholesterol. triglyceride, glucose, iron or hemoglobin were observed among three drink groups. In conclusion, oolong and green teas could reduce the deteriorations of cognitive ability, brain degenerative changes and aging process in SAMP8, probably through the potent antioxidative activity of the tea.

Aging↗

PubMed2006

Genistein suppresses development of spontaneous atopic-like dermatitis in NC/Nga mice.

In this study, we examined the effect of genistein on the severity of dermatitis and level of serum IgE in NC/Nga (NC) mice. NC mice housed in conventional conditions develop spontaneous atopic-like dermatitis; however, oral administration of 20 mg/kg genistein suppresses the development of dermatitis. We also investigated the levels of serum IgE in genistein-treated NC mice and found that the levels were the same as those in control NC mice. We further investigated in vitro IFN-gamma and IL-4 production from spleen cells upon stimulation with anti-CD3 and anti-CD28 mAbs. IFN-gamma production level in NC mice that received 20 mg/kg genistein was significantly lower than that in control NC mice. In contrast, the production level of IL-4 in genistein-treated mice was not significantly different from that in control mice but tended to increase in a dose-dependent manner.

Animals↗

PubMed2006

Genistein enhances antigen-specific cytokine production in female DO11.10 transgenic mice.

Genistein is a phytoestrogen contained at high levels in soy products and has been shown to regulate immunoresponse. In this study, we evaluated the effects of genistein on the production of cytokines from antigen (Ag)-specific T cells using DO11.10 transgenic mice because the direct effect of genistein on Ag-specific cytokine production has not been elucidated. The oral administration of 20 mg/kg genistein increased IFN-gamma and IL-4 production from DO11.10+ T cells in response to ovalbumin (OVA)323-339 peptide in female DO11.10 mice. Analysis of intracellular cytokine synthesis revealed that the percentages of cytokine-producing cells in the control and genistein-treated groups were not different, indicating that increased cytokine production occurred at the single-cell level. In contrast to the female mice, genistein did not increase cytokine production in male mice, suggesting that the effect of genistein on cytokine production is gender-dependent.

Animals↗

PubMed2006

Protein deficiency impairs DNA vaccine-induced antigen-specific T cell but not B cell response in C57BL/6 mice.

DNA vaccination is a simple method to induce antigen (Ag)-specific immunoresponse and has many potential advantages over other vaccines. Although people who need to receive vaccines often suffer undernutrition, there has been no study on a how nutritional status affects the immunoresponse induced by DNA vaccination. The aim of this study was to determine the relationship between protein deficiency and DNA vaccine-induced immunoresponses. C57BL/6 mice were fed a 5% or 20% casein diet for 30 d. The mice were immunized with an ovalubumin (OVA)-expression plasmid by the gene gun-based method three times at 10-d intervals. Body weight and serum albumin concentration in protein-deficient mice were significantly lower than those in mice fed the 20% casein diet (p<0.01, p<0.05). The percentage of OVA-specific CD8+ T cells was significantly decreased in the 5% casein group compared to that in the 20% casein group (p<0.05). Furthermore, CD4+ T cells from mice fed the low-protein diet showed lower interleukin (IL)-2 production than did those from the 20% group. In contrast to the T-cell function, protein deficiency did not affect OVA-specific Ab responses (p>0.05). These results suggest that protein deficiency impairs the induction of Ag-specific T-cell but not B-cell response in DNA-immunized mice. Our observation indicates that, in addition to development of an effective of DNA vaccine, the management of nutritional state is important for the prevention of infectious disease by DNA vaccination.

Animals↗

PubMed2006

A community-based picture of type 2 diabetes mellitus in Vietnam.

There has been a significant increase in the prevalence of type 2 diabetes mellitus (T2DM) in Vietnam. We found that Vietnamese with T2DM had a normal body mass index (BMI), but high levels of total body fat and abdominal fat. Based on published reports together with our own findings, we believe that a sedentary lifestyle and an abundance of starchy foods and also Western style energy-rich foods are factors associated with disease. The staple food of the Vietnamese is still polished-rice which has high glycemic index values. In addition, a Westernized diet, and the chronic consumption of high-glycemic index foods together with a sedentary lifestyle result in insulin resistance and diabetes. The average BMI of T2DM patients is or= 0.90). We therefore, tentatively suggest a BMI of 23 kg/m(2) together with a WHR of 0.90 for males and 0.85 for females as new cutoff values for the risk of T2DM in Vietnamese. These findings have important implications for primary prevention because they indicate that screening and intervention should focus on high-risk populations.

Body Mass Index↗

PubMed2005

Determining the prevalence of osteoporosis and related factors using quantitative ultrasound in Vietnamese adult women.

In 2003, the authors conducted a population-based, cross-sectional survey to determine the prevalence of osteoporosis and related factors in Vietnamese adult women by using quantitative ultrasound at the heel bone (calcaneus). A total of 2,232 adult women aged > or =20 years, living in Hanoi City, and free of illnesses affecting bone metabolism were randomly selected to participate in the study. Subjects' bone mass was assessed by speed of sound at the calcaneus, referred to as quantitative ultrasound measurement. The T-score threshold, defined as < or =-1.8, was used to identify subjects with osteoporosis. The crude prevalence of osteoporosis in Hanoi City was 15.4%; after adjustment for age, it was 9.0%. Among premenopausal women, the crude prevalence of osteoporosis was higher in the urban areas compared with the rural areas. By contrast, postmenopausal women in the rural areas had a higher prevalence of osteoporosis. Multiple logistic regression analysis revealed that factors associated with low speed of sound were age, menopause, educational level, lifelong occupation, recreational weight-bearing exercise, number of births, and height. Results suggest that osteoporosis is a noteworthy problem in Vietnam, and intervention strategies should be considered to control it, especially in high-risk populations.

Adult↗

PubMed2005

Outcome following surgery for primary lung cancer with interlobar pleural invasion.

PURPOSE: To determine whether interlobar pleural invasion into the adjacent lobe (interlobar P3) should be assessed as T3 according to the tumor-node metastasis classification. METHODS: Surgically treated patients with primary lung cancer (n = 322) were analyzed. RESULTS: Tumors with interlobar P3 had a significantly lower incidence of mass screening detection, a higher occurrence rate of squamous cell carcinoma, and a larger tumor diameter than tumors without interlobar P3. The lymph node metastatic rate did not differ between the patients with and without interlobar P3. The 5-year survival rate of patients with interlobar P3 was 63% and the rates of other patients were 56% with T1 disease, 57% with T2, 31% with T3, and 19% with T4. The survival rate for patients with interlobar P3 was higher than for those with T3 without interlobar P3 (P < 0.05). The 5-year survival rate of the patients with interlobar P3 was lower in adenocarcinoma (39%) than in squamous cell carcinoma (69%, P < 0.01). The results were similar when the analysis was restricted to patients without lymph node metastasis. In adenocarcinoma, the survival rate for interlobar P3 was between the rates for T2 (53%) and T3 (13%) without interlobar P3, whereas in squamous cell carcinoma, the survival rate for interlobar P3 was between the rates for T1 (88%) and T2 (54%) without interlobar P3. CONCLUSION: Tumors with interlobar P3 should be classified as T2 only in squamous cell carcinoma.

Aged↗

PubMed2005

The metabolic syndrome: prevalence and risk factors in the urban population of Ho Chi Minh City.

The purpose of this study was to determine the prevalence of metabolic syndrome (MeS) and its risk factors in urban population of Ho Chi Minh City. A cross-sectional study was conducted in urban areas of Ho Chi Minh City with 611 participants. The demographic, socio-economic details, anthropometric indexes and blood pressure were recorded. A fasting blood sample was collected for the analyses of glucose, total cholesterol, triglycerides, high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C). MeS was defined by presence of three or more of the following components: abdominal obesity, hypertriglyceridemia, low HDL-cholesterolemia, high blood pressure and high fasting plasma glucose. The crude prevalence of MeS was 18.5% (95% CI: 15.5-21.9). After age, sex standardization, this prevalence was 12.0% (95% CI: 10.9-13.2). The prevalence increased with age and sedentary work. Subjects with MeS had significantly higher body fat percentage than that of normal subjects. Metabolic syndrome showed a positive association with age, body fat percentage and sedentary occupation. This first study on MeS showed that 12% adults in urban areas of Ho Chi Minh City had metabolic syndrome. It suggests that MeS is becoming a noteworthy health problem in Vietnam and to the early detection and appropriate intervention as well as healthy lifestyle education programs need to be established.

Adult↗

PubMed2005

Anthropometric characteristics, dietary patterns and risk of type 2 diabetes mellitus in Vietnam.

OBJECTIVE: To determine the impact of anthropometric characteristics and dietary patterns on Type 2 diabetes mellitus in Vietnam. METHODS: Data from 144 subjects (9m/39f newly diagnosed diabetics; 18m/78f control subjects) were analyzed in this case-control study. Height, weight, waist and hip circumferences and percent body fat were measured. Dietary intakes were assessed by 24-hour recall on three non-consecutive weekdays. Fasting blood samples were collected for the analysis of plasma glucose, fructosamine, protein and lipid concentrations. RESULTS: Although the body mass index (BMI, kg/m(2)) was similar between diabetic and control subjects, diabetic subjects had significantly greater percent body fat (31.1 +/- 5.8% vs. 27.7 +/- 6.2%) and waist-hip ratios (WHR, 0.91 +/- 0.07 vs. 0.86 +/- 0.08). Diabetic subjects had higher intakes of protein (p < 0.01), especially animal protein (p < 0.001), and consumed more meat (p < 0.01) than control subjects. Percent body fat and WHR were positively associated with diabetes (odds ratios [OR] 1.53 [95%CI 1.29-1.79] and 1.09 [95% CI 0.89-1.58], respectively) as were protein intake (OR 1.21 [95% CI 1.12-1.31]) and animal protein intake (OR 1.18 [95% CI 1.10-1.26]). CONCLUSIONS: This study indicates that percent body fat and WHR are risk factors associated with diabetes even when the BMI is normal. Evolving dietary patterns with increasingly more protein and meat consumption may also contribute to the deterioration of glucose metabolism among Vietnamese people.

Adipose Tissue↗

PubMed2005

Reproducibility and validity of a food frequency questionnaire among Vietnamese in Ho Chi Minh City.

OBJECTIVE: Our objective was to assess the reproducibility and validity of a food frequency questionnaire (FFQ) among individuals living in Ho Chi Minh City, Vietnam. METHODS: A total of 116 food items in our FFQ were selected by ranking food items according to their contribution to the population intake of nutrients, based on multiple 24-hour recalls (24HRs) from 144 participants in July 2001. The FFQ was validated by using three 24HRs for 118 men and women in Ho Chi Minh City, Vietnam in August 2002. The reproducibility of the FFQ was assessed by repeated administration at 7 +/- 3.4 days. RESULTS: The reproducibility study showed that Spearman correlation coefficients, adjusted for energy intake, ranged from 0.47 to 0.72, and that weighted kappa values ranged from 0.42 for lipid to 0.65 for potassium. In the validation study, correlation coefficients, adjusted for energy intake, between the FFQ and the 24HRs ranged from 0.16 (calcium) to 0.45 (retinol). The proportion of subjects classified by the FFQ into the same third as determined by the 24HRs was between 42% and 62%. CONCLUSIONS: This food frequency questionnaire measured the usual intake of major nutrients for Vietnamese adults living in Ho Chi Minh City and its urban area, where dietary patterns are similar to those of the Vietnamese population.

Adult↗

PubMed2005

Breast sentinel lymph node navigation with three-dimensional interstitial multidetector-row computed tomographic lymphography.

OBJECTIVE: Three-dimensional multidetector-row computed tomographic lymphography (3D MDCT-LG) with interstitial injection of a widely available nonionic monometric contrast medium iopamidol was used for navigation of breast sentinel lymph node (SLN) biopsy. METHODS: 3D MDCT-LG was obtained after massage of the interstitially injection sites of a total of 4-5 mL undiluted iopamidol at periareolar and peritumoral areas in 68 consecutive patients with early-stage breast cancer, using a 4 detector-row CT scanner. Drainage lymphatic patterns and SLN anatomy were assessed on 3D MDCT-LG images. 3D MDCT-LG-navigated SLN biopsy with combined use of blue dye was followed by backup axillary lymph node dissection to evaluate accuracy of SLN biopsy. RESULTS: The 3D MDCT-LG images clearly localized primary SLNs by visualizing the direct connection between these nodes and their afferent lymphatic vessels on detailed anatomy of the surrounding structures in all patients. Drainage lymphatic pathways on these images were classified into 4 patterns: single route/single SLN (39 cases, 57%), multiple routes/multiple SLNs (10 cases, 15%), single route/multiple SLNs (9 cases, 13%), and multiple routes/single SLN (10 cases, 15%). Under 3D MDCT-LG navigation, SLNs was found at the accurate location in all patients. With backup axillary lymph node dissection, metastasis was found in 14 (20%) patients, and 8 of these patients had metastasis only in the preoperatively identified SLNs. In other 5 positive patients, metastasis was found both in the SLN and non-SLNs. However, micrometastasis eventually was found only in non-SLN in an elderly patient. Overall, the sensitivity, false-negative rate, and accuracy of 3D CT-L-navigated SLN biopsy were 92% (13/14 patients), 7% (1/14 patients), and 98% (67/68 patients), respectively. CONCLUSIONS: Topographic 3D interstitial MDCT-LG can be a widely available and reliable navigator for breast SLN biopsy.

Adult↗

PubMed2005

Postprandial blood glucose and insulin responses to pre-germinated brown rice in healthy subjects.

Effects of pre-germinated brown rice (PGBR) on postprandial blood glucose and insulin concentrations were compared with brown rice (BR) and white rice (WR) in two studies. In the first study, we investigated the time course of postprandial blood glucose and insulin concentrations after ingesting 25% (W/V) glucose solution, PGBR, BR or WR in 19 healthy young subjects. In the second study, dose-dependent effect of PGBR on the time course of postprandial blood glucose concentrations was compared among 4 different mixtures of PGBR and WR in 13 healthy young subjects. They were solely PGBR, 2/3 PGBR (PGBR: WR = 2 : 1), 1/3 PGBR (PGBR : WR = 1 : 2) and solely WR. Each sample was studied on a different day. The samples were selected randomly by the subjects. All the rice samples contained 50 g of available carbohydrates. The previous day the subjects ate the assigned dinner by 9:00 pm and then were allowed only water until the examination. The next morning, they ingested each test rice sample with 150 ml of water in 5-10 min. Blood was collected into capillary tubes from finger at 0, 30, 60, 90 and 120 min after the ingestion. The incremental areas under the curve (IAUC) of blood glucose concentrations (IAUC-Glc) for 120 min after the administration of PGBR and BR were lower than those after WR. In contrast the IAUC-Glc of BR and PGBR were not different (Study 1). The higher the ratio of PGBR/WR, the lower the glycemic index became (Study 2). These results suggest that intake of PGBR instead of WR is effective for the control of postprandial blood glucose concentration without increasing the insulin secretion.

Adult↗

PubMed2005

Overweight is associated with allergy in school children of Taiwan and Vietnam but not Japan.

We collected information concerning diagnosed allergy from 2027 school children in Japan, Taiwan and Vietnam. Children were classified according to the age and sex-specific body mass index (BMI) per-age as indicator of weight status. Logistic regression was performed to examine the relationship between percentiles of BMI-per-age and allergy. Compared with children at the lowest percentile group Taiwanese children at > 85th percentile group showed a tendency toward higher risk of allergy (OR = 1.79, 95% CI 0.98 to 3.27; p = 0.060). When children with rhino-conjunctivitis were excluded from the analysis the association reached statistical significance (OR = 2.89, 95% CI 1.08 to 7.75; p = 0.035). Vietnamese children at > 85th percentile group showed a significantly higher risk of allergy (OR = 2.34, 95% CI 1.06 to 5.17; p = 0.035). This association was not observed when children with atopic dermatitis or food allergy were excluded from the analysis, although a tendency toward increased risk of allergy at BMI-per-age > 85th percentile remained. Our study sample of Japanese school children showed no association between being overweight and allergy.

Adolescent↗