The benefits of fish consumption

In 2004, The UK government advice stated that consumers should increase fish consumption to two portions a week, one of which should be oil‐rich fish. However, survey data show that this advice has not been acted upon by most members of the public. In addition, limited data on consumer attitudes highlight barriers to increased fish consumption, such as concerns about buying and cooking fish, perceptions that fish is expensive, and worries that fish meals may not be eaten by all family members. The ‘two‐a‐week’ message is underpinned by strong scientific evidence for heart health, while weaker emerging evidence associates certain nutrients found in fish with a lower risk of immune dysfunction, normal brain development in infants, insulin sensitivity and maintenance of cognitive function in later life. Clearly, further refinement of the two‐a‐week message is needed to ensure that greater numbers of people respond. Ideas include determining appropriate portion sizes for babies and children, increasing awareness of the broad range of fish and shellfish species, highlighting sustainable sources of fish, and reassuring consumers that frozen and prepared fish products count towards the two‐a‐week target. Further work is also needed to address barriers to consumption, particularly among teenagers and younger adults, who have the lowest intakes.     

Relation between methylmercury exposure and plasma paraoxonase activity in inuit adults from Nunavik

Background: Methylmercury (MeHg) exposure has been linked to an increased risk of coronary heart disease (CHD). Paraoxonase 1 (PON1), an enzyme located in the high-density–lipoprotein (HDL) fraction of blood lipids, may protect against CHD by metabolizing toxic oxidized lipids associated with low-density liproprotein and HDL. MeHg has been shown to inhibit PON1 activity in vitro, but this effect has not been studied in human populations.Objectives: This study was conducted to determine whether blood mercury levels are linked to decreased plasma PON1 activities in Inuit people who are highly exposed to MeHg through their seafood-based diet.Methods: We measured plasma PON1 activity using a fluorogenic substrate and blood concentrations of mercury and selenium by inductively coupled plasma mass spectrometry in 896 Inuit adults. Sociodemographic, anthropometric, clinical, dietary, and lifestyle variables as well as PON1 gene variants (rs705379, rs662, rs854560) were considered as possible confounders or modifiers of the mercury–PON1 relation in multivariate analyses.Results: In a multiple regression model adjusted for age, HDL cholesterol levels, omega-3 fatty acid content of erythrocyte membranes, and PON1 variants, blood mercury concentrations were inversely associated with PON1 activities [β-coefficient = –0.063; 95% confidence interval (CI), –0.091 to –0.035; p < 0.001], whereas blood selenium concentrations were positively associated with PON1 activities (β-coefficient = 0.067; 95% CI, 0.045–0.088; p < 0.001). We found no interaction between blood mercury levels and PON1 genotypes.Conclusions: Our results suggest that MeHg exposure exerts an inhibitory effect on PON1 activity, which seems to be offset by selenium intake.     

Effect of intravenous omega-3 fatty acid infusion and hemodialysis on fatty acid composition of free fatty acids and phospholipids in patients with end-stage renal disease

Background: Patients treated with hemodialysis (HD) have been reported to have decreased levels of ω‐3 polyunsaturated fatty acids (PUFAs) in plasma and cells. The aim of this study was to investigate the effect of ω‐3 PUFAs administered intravenously during HD, as well as the effect of HD treatment, on the fatty acid composition of plasma free fatty acids (FFAs), plasma phospholipids, and platelet phospholipids. Methods: Forty‐four HD patients were randomized to groups receiving either a single dose of a lipid emulsion containing 4.1 g of ω‐3 PUFAs or placebo (saline) administered intravenously during HD. Blood was drawn immediately before (baseline) and after (4 hours) HD and before the next HD session (48 hours). Fatty acid composition was measured using gas chromatography. Results: The increase in ω‐3 FFAs was greater in the ω‐3 PUFA group compared with the placebo group, whereas the increase in total FFAs was similar between the 2 groups. In the ω‐3 PUFA group, ω‐3 PUFAs in plasma phospholipids were higher after 48 hours than at baseline, and in platelet phospholipids, ω‐3 PUFAs increased after 4 hours. In the placebo group, no changes were observed in ω‐3 PUFAs in plasma and platelet phospholipids. Conclusions: Intravenous ω‐3 PUFAs administered during HD caused a transient selective increase in ω‐3 FFA concentration. Furthermore, ω‐3 PUFAs were rapidly incorporated into platelets, and the content of ω‐3 PUFAs in plasma phospholipids increased after 48 hours.     

Nutrition Support and Infections Associated With Hepatic Resection and Liver Transplantation in Patients With Chronic Liver Disease

Malnutrition is common in liver cirrhotic patients who will undergo liver resection or liver transplantation. A precise evaluation of their nutrition status is thus difficult because of the presence of ascites and the edema caused by their impaired protein synthesis. Both perioperative enteral and parenteral nutrition have benefits in reducing the morbidity and mortality of liver surgery, and in general, oral nutrition supplements are recommended. Branched‐chain amino acids (BCAAs) promote protein and glycogen synthesis and regulate immune system function. Synbiotics, a combination of pro‐ and prebiotics, is reported to enhance immune responses. Oral nutrition support with BCAAs, synbiotics, and an immune‐enhancing diet have a beneficial effect on preventing the perioperative infections associated with hepatic resection or liver transplantation.     

The Role of the ω‐3 Fatty Acid DHA in the Human Life Cycle

Dietary consumption of the essential fatty acids linoleic acid (LA; ω‐6) and α‐linolenic acid (ALA; ω‐3) is necessary for human growth and development. In the past 150 years, the average Western diet has changed dramatically such that humans today consume a much higher proportion of ω‐6 fatty acids relative to ω‐3 fatty acids than ever before. The importance of ω‐3 fatty acids in human development has been well established in fetal and neonatal development, with brain and retinal tissues highly dependent on ω‐3 fatty acids, specifically docosahexaenoic acid (DHA) for membrane fluidity and signal transduction. In childhood, ω‐3s have been shown to contribute to ongoing cognitive development and may be involved in metabolic programming of bone turnover and adipogenesis. ω‐3s may also play important roles in adult neurophysiology and disease prevention.     

The Effects of Paraquat and Superoxide Dismutase on Pulmonary Vascular Permeability and Edema in Mice

Intraperitoneal administration of 50 mg/kg paraquat dichloride to mice significantly increased pulmonary vascular permeability at 24 and 48 hr, as measured by ¹²⁵I-albumin content of alveolar lavage. Lung edema, measured by lung weight as percent body weight, was significantly increased 48 hr after paraquat treatment. Intravenous administration of four doses of superoxidase dismutase at 12-hr intervals (i.e., one before and three after paraquat treatment) failed to inhibit paraquat-induced increased pulmonary vascular permeability and pulmonary edema. Superoxide dismutase treatment also failed to reduce mortality and had no significant effect on the death time course in animals challenged with paraquat. The results of this study suggest that acute toxic effects of paraquat, such as increased pulmonary vascular permeability and pulmonary edema, may not be mediated through the generation of superoxide anion.     

蛴螬与蛴螬滴眼液的成分研究

对Ｈｏｌｏｔｒｉｃｈｉａ ｄｉｏｍｐｈａｌｉａ Ｂａｔｅｓ（蛴螬）的水浸液、乙醇提取液、石油醚提取液进行了成分分析,结果表明蛴螬中含有氨基酸、多肽或蛋白质、糖类、生物碱、有机酸盐、甾体化合物等成分。对蛴螬滴眼液氨基酸成分分析表明,其中谷氨酸、甘氨酸含量最高,约占水解氨基酸总量的４０．３３％,推测谷氨酸、甘氨酸可能是其治疗白内障、角膜翳的有效成分之一。蛴螬的成分研究国内外文献均未见报道。     

邻苯二甲酸酯类化合物与自然流产的研究进展

邻苯二甲酸酯类化合物（phthalic acid esters,PAEs）作为工业用增塑剂,广泛应用于各种生产、生活用品。其特点是产量大、用途广、毒性隐匿,现已成为一类最为普遍的威胁人类健康的环境污染物。作为内分泌干扰物,PAEs可以通过多种途径进入人体并蓄积,干扰机体内分泌,对女性生殖健康产生重要的影响。研究发现,PAEs可能是通过过氧化物酶体增殖物激活型受体γ（PPARγ）影响胎盘的形成及滋养细胞的侵蚀性,从而导致了自然流产的发生。     

The effect of growth hormone treatment alone or growth hormone with supplemental zinc on growth rate,serum, and urine zinc and copper concentrations and hair zinc concentration in patients with growth hormone deficiency.

Previous studies suggest that growth hormone (GH) may increase daily zinc requirements to meet the demand of growing bone and to replace increased urinary losses. We tested the hypothesis that zinc or copper availability might be limiting factors in the response of children receiving GH replacement. Ten patients with GH deficiency were followed for GH-induced changes in urine and serum zinc and copper during acute (0.3 IU/kg/day × 5 days) and chronic GH treatment (0.1 IU/kg/tiw). Zinc was measured in hair collected every 3 months. Zinc sulfate (220 mg/day) was given to half the patients during the second year of treatment. There was no evidence of zinc or copper deficiency, and zinc supplements did not venhance growth response to GH during the second year of treatment. We conclude that GH treatment in children does not alter serum or urine zinc or copper or hair zinc, and zinc supplementation does not improve growth in children with GH deficiency.     

Role of cytochrome P4502E1 in alcoholic liver disease pathogenesis

The intragastric tube feeding model is ideal for the study of the role of dietary factors and the effect of drugs on experimental alcoholic liver disease (ALD), since the model allows us to study the effect of a single variable in the diet on the pathology of liver where the blood alcohol level (BAL) is maintained over 150 mg%. By varying the dietary fatty acid composition we showed that the pathology was worsened by increasing linoleic acid or polyunsaturated fatty acids (PUFAs) in the diet where cytochrome P4502E1 (CYP2E1) was increased posttranslationally by high BAL. Concomitant with the increase in CYP2E1 there was evidence for an increase in lipid peroxidation (LP) by microsomes. Protein adducts of the products of LP were increased in the blood. Isoniazid (INH) enhanced this process and the pathology of ALD when INH was fed at therapeutic levels with ethanol. Preliminary studies show that diallyl sulfide, which inhibits and destroys liver CYP2E1 selectively, also modified the pathologic effects of ethanol. Thus we postulate that CYP2E1 induction plays a central role in the pathogenesis of ALD.