Ming-Jer Shieh

Daily intake of TBT, Cu, Zn, Cd and As for fishermen in Taiwan

The consumption of contaminated seafood has been reported as an important route of human exposure to metals in Taiwan. We consider the concentrations of TBT, Cu, Zn, Cd, As, and the consumption of oysters of Taiwanese to be the important information related to public health in Taiwan. Therefore, the aim of this study was to evaluate the public health risks associated with TBT, Cu, Zn, Cd and As from shellfish for the general population and fishermen of Taiwan. In general, TBT concentrations in various oysters ranging from 0.32 to 1.51 microg/g dry wt. varied with sampling locations. The highest TBT, Cu, and Zn geometric mean (GM) concentrations in oysters of 1.51, 1180 and 1567 microg/g dry wt. were obtained from the Hsiangshan coastal area. The values of oyster consumption for fishermen were 94.1 and 250 g/day for typically and maximally exposed individuals, respectively. In particular, the highest intake (250 g/day) from fishermen was almost two times greater than that of the general population (139 g/day). The THQ (target hazard quotient) values of Hsiangshans fishermen are 3.87 and 20.50 for TBT and Cu for maximally exposed individuals are higher than other oyster culture areas. It is interesting that those consuming oysters from Hsiangshan, Lukang, Taishi caused abnormally high THQs of TBT and other metals (100% over 1.0), and TBT was attributed to only 3-21% of the total THQs in different fishermen of Taiwan. Our results suggest that current environmental levels of TBT and other metals are associated with a significant potential threat to human health for fishermen resident in coastal areas of Taiwan.

Pharmacokinetic model of daily selenium intake from contaminated seafood in Taiwan

Contaminated seafood has been reported as an important source of human exposure to metals in Taiwan. Seafood represents a non-negligible source of selenium in the human diet. This study was designed to determine the concentration of selenium in different types of seafood and predict the concentration of selenium in the blood of Taiwanese using a one-compartment steady-state pharmacokinetic (PK) model. Samples involved three subgroups, including fish, crustaceans and bivalve molluscs. Quantitative analysis for selenium was performed using an ICP-AES (Perkin Elmer) instrument. Selenium concentrations in seafood ranged from 0.63 to 2.01 microg/g wet wt. The highest selenium concentration found in fish was 2.01+/-0.36 microg/g wet wt in Salmo salar Linnaeus. In general, selenium concentration increased in the order of bivalve molluscs<crustacean<fish. The daily selenium intakes resulting from a high-seafood diet and an average diet were 145.2 and 60.2 microg/day, respectively. Daily selenium intake from seafood alone is higher than the US recommended daily allowance (RDA) of 55 microg/day and the World Health Organization (WHO) normative requirement of 40 microg/day. From PK model estimates, the concentrations of selenium in the blood of a typical seafood consumer and a high-seafood consumer were approximately 93 and 224 microg/l based on daily seafood intake of 60.2 and 145.2 microg/day, respectively.

Leptin, Superoxide Dismutase, and Weight Loss: Initial Leptin Predicts Weight Loss

Objective: Our goal was to study how plasma leptin concentration, superoxide dismutase (SOD) activity, and weight loss are related in obese adults.

Effects of different ratios of monounsaturated and polyunsaturated fatty acids to saturated fatty acids on regulating body fat deposition in hamsters.

OBJECTIVE Effects of monounsaturated fatty acid (MUFA) and polyunsaturated fatty acid consumption on regulating body fat accumulation and body weight gain are controversial between animal and human studies. METHODS We designed a 2 x 2 factorial study, with two levels of MUFAs (60% and 30%) and two levels of polyunsaturated-to-saturated fatty acid (P/S) ratio (5 and 3) to prepare four kinds of experimental oils consisting of 60% MUFAs with a high or low P/S ratio (HMHR or HMLR, respectively) or 30% MUFAs with a high or low P/S ratio (LMHR or LMLR, respectively). Thirty-two male golden Syrian hamsters were randomly divided into four groups and fed the experimental diets containing 15% (w/w) fat for 12 wk. RESULTS No difference was observed in the mean daily food intake. Hamsters fed the LMLR diet had increased weight gain, epididymal and retroperitoneal white adipose tissues, plasma non-esterified fatty acids, insulin, hepatic acetyl coenzyme A carboxylase and malic enzyme activities, and mRNA expressions of peroxisome proliferator-activated receptor-alpha and sterol regulatory element-binding protein-1c among all groups (P < 0.05). Hamsters fed the HMHR diet had lower plasma insulin levels and hepatic acetyl coenzyme A carboxylase activities among groups (P < 0.05) and elevated hepatic acyl coenzyme A oxidase and carnitine palmitoyltransferase-I activities compared with those fed the LMLR diet (P < 0.05). CONCLUSION Hamsters fed the LMLR diet had increased weight gain and body fat accumulation, whereas the HMHR diet appeared to be beneficial in preventing white adipose tissue accumulation by decreasing plasma insulin levels and increasing hepatic lipolytic enzyme activities involved in beta-oxidation.

Effects of β-carotene, vitamin C and E on antioxidant status in hyperlipidemic smokers

Smoking can accelerate the consumption of the stored antioxidant vitamins and increase the oxidative stress in the hyperlipidemic patients. The study investigated the effects of combined beta-carotene, vitamin C, and vitamin E on plasma antioxidant levels, erythrocyte antioxidative enzyme activities, and LDL lipid peroxides. Male hyperlipidemic smokers (35-78 years old) were randomly divided into two antioxidant supplemented groups: intervention 1 (I1, n = 22) (15 mg beta-carotene/day, 500 mg vitamin C/day, and 400 mg alpha-tocopherol equivalent/day) and intervention 2 (I2, n = 20) (30 mg beta-carotene/day, 1000 mg vitamin C/day, and 800 mg alpha-tocopherol equivalent/day). After 6-week supplementation, plasma beta-carotene, vitamin C, vitamin E, and erythrocyte glutathione levels increased significantly by 200%, 98%, 129%, and 39%, respectively, in the I1 group, and by 209%, 216%, 197%, and 32%, respectively, in the I2 group. Plasma Fe(+2) concentrations and Fe(+2)/Fe(+3) decreased significantly in both groups. Except erythrocyte glutathione peroxidase activity in the I1 group, erythrocyte catalase, glutathione peroxidase, and superoxide dismutase activities increased significantly in both groups. Lipid peroxides in LDL decreased significantly by 56% and 72% in the I1 and I2 groups, respectively. However, the levels of plasma iron, erythrocyte glutathione, and LDL lipid peroxides, and the activities of erythrocyte antioxidative enzymes did not differ between two groups. In conclusion, combined antioxidant supplements increased plasma antioxidant levels and antioxidative enzyme activities, and lowered LDL lipid peroxides in male hyperlipidemic smokers. Higher dosage of the supplements did not have an additive effect.

Effect of dietary casein and soy protein on plasma lipids in a streptozotocin-induced diabetes model in hamsters

While it is known that soy protein diet depresses serum cholesterol relative to a casein diet in hypercholesterolemic humans and a variety of animal species, the effect of soy protein on diabetes mellitus-induced hyperlipidemia has not been studied. We investigated the effect of soy protein and casein on the levels of plasma glucose and lipids in hamsters with streptozotocin-induced diabetes. Thirty-one hamsters were divided into control and diabetic groups. Diabetes was induced by introperitoneal injection of streptozotocin. Control and diabetic hamsters were further assigned to two subgroups, respectively. One subgroup was fed with casein and the other with soy protein isolate. The basal composition of the diets was identical, except for the difference in protein source. After 4 weeks of the test diet, plasma concentrations of glucose, triglyceride (TG), and nonesterified fatty acids (NEFA) were significantly higher in diabetic groups than in the control groups. The plasma levels of glucose, TG, and total cholesterol were significantly lower in the diabetic soy protein group than in the diabetic casein group. The plasma total cholesterol level in the diabetic soy protein group was similar to those of the control subgroups. No significant differences in plasma glucose, TG, cholesterol or NEFA concentrations were observed between the two control subgroups. The malondialdehyde level in the livers, as well as the erythrocyte glutathione peroxidase and superoxide dismutase activities did not differ between control and diabetic groups, nor were there differences between the casein and soy protein groups. These findings suggest that soy protein also exerts hypocholesterolemic effects in this diabetic model system, and had favorable effects on lowering plasma glucose and TG. The soy protein diet did not affect lipid peroxide production or the erythrocyte antioxidant enzyme activities indicated that the antioxidant system was not changed under the present experimental condition.

The characteristics of dietary pattern between hypercholesterolemic and control subjects

Abstract This study investigated the dietary selected nutrient intake of cholesterol, fat and crude fiber in a hypercholesterolemic group(TC≧240mg/dl,N=23),borderline hypercholesterolemic group (200≦ TC