Effect of dietary seal and fish oils on triacylglycerol metabolism in rats

Eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids were distributed mainly in the sn-1 and 3 positions of seal oil triacylglycerol and in the sn-2 position of fish oil triacylglycerol. Seal oil or fish oil-rich fats having constant polyunsaturated/monounsaturated/saturated fatty acids and n-6/n-3 polyunsaturated fatty acid (PUFA) ratios were fed to rats for 3 wk. Control rats were fed on a fat containing linoleic acid as the sole PUFA. Seal oil more effectively lowered serum and liver triacylglycerol concentrations than fish oil. The activities of fatty acid synthase (FAS), glucose-6-phosphate dehydrogenase (G6PDH) and hepatic triacylglycerol lipase (HTGL) were significantly lower in the seal oil group than in the control group, whereas the activity of HTGL was significantly lower and the hepatic peroxisomal beta-oxidation and activity of lipoprotein lipase (LPL) in adipose tissue were significantly higher in the fish oil group than in the control group. These observations suggest that the predominant hypotriacylglycerolemic effect of seal oil is caused by the suppression of fatty acid synthesis.     

Effect of dietary seal and fish oils on lipid metabolism in hamsters

Eicosapentaenoic and docosahexaenoic acids were distributed mainly in the sn-1 and 3 positions of seal oil triacylglycerols and in the sn-2 position of fish oil triacylglycerols. Seal oil-rich or fish oil-rich fats having constant polyunsaturated (PUFAs)/monounsaturated/saturated fatty acids and n-6/n-3 PUFAs ratios were fed to hamsters for 3 weeks. The control fat contained linoleic acid as the sole PUFA. The concentration of triacylglycerols in the liver was significantly lower in the fish oil group than in the control group. Phospholipid concentration in serum was lower and that in the liver was higher in the seal oil group compared with the fish oil group. The activities of fatty acid synthase (FAS), glucose-6-phosphate dehydrogenase (G6PDH), and the malic enzyme were significantly lower in both the fish and seal oil groups than in the control group. Dietary seal oil more effectively reduced arachidonic acid content in liver phosphatidylcholine and phosphatidylethanolamine and serum phosphatidylcholine than fish oil. These results showed that different intramolecular distribution of n-3 PUFAs influenced glycerolipid metabolism and arachidonic acid content in serum and liver phospholipids of hamsters.     

Toxicity of five shale oils to fish and aquatic invertebrates

The chemical composition and toxicity of three shale crude oils (Tosco, Paraho, and Geokinetics), a hydrotreated oil (Paraho HDT), and a refined shale oil (Paraho JP-4) were assessed to determine the potential hazards to native fish species and food chain organisms posed by accidental spills of such materials. Colorado squawfish (Ptychocheilus lucius), fathead minnow (Pimephales promelas), cutthroat trout (Salmo clarki), and colonies of aquatic invertebrates were exposed to the watersoluble fractions of the shale oils for 96 hr to determine concentrations lethal to 50% of the exposed organisms (LC-50). The behavior of surviving fish was also measured to determine the sublethal influences of exposure. The composition of the five water-soluble fractions was similar to that of the crude and refined shale oils from which they were made. Hydrotreated and refined oils contained fewer aromatic compounds than the crude shale oils. The cutthroat trout, a species endemic to oil shale regions, was less tolerant of shale oil exposure than the other species tested; the LC-50 concentrations were 1.8 mg/L Geokinetics, 2.1 mg/L Tosco, and 1.3 mg/L Paraho. Exposure to concentrations of one-half to one-eighth those causing mortality reduced the swimming capacity of squawfish and significantly impaired their ability to capture prey. The number of invertebrate taxa, species, and organisms colonizing plate samplers declined with increasing oil concentration. The generaBaetis andIsoperla were most sensitive to shale oil exposure; significant mortality occurred at the lowest concentration (0.5–0.7 mg/L) tested for each shale oil.     

Long-term fish toxicity test using the zebrafish: Effect of group formation and temporary separation by sex on spawning

Bulletin of Environmental Contamination and Toxicology -     

ApoE genotype, cardiovascular risk and responsiveness to dietary fat manipulation

Cardiovascular risk is determined by the complex interactions between genetic and environmental factors. The apoE genotype represents the most-widely-studied single nucleotide polymorphism in relation to CVD risk, with >3600 publications cited in PubMed. Although originally described as a mediator of lipoprotein metabolism, the lipoprotein-independent functions of apoE are being increasingly recognised, with limited data available on the potential impact of genotype on these metabolic processes. Furthermore, although meta-analyses suggest that apoE4 carriers may have a 40-50% increased CVD risk, the associations reported in individual studies are highly heterogeneous and it is recognised that environmental factors such as smoking status and dietary fat composition influence genotype-phenotype associations. However, information is often derived from observational studies or small intervention trials in which retrospective genotyping of the cohort results in small group sizes in the rarer E2 and E4 subgroups. Either larger well-standardised intervention trials or smaller trials with prospective recruitment according to apoE genotype are needed to fully establish the impact of diet on genotype-CVD associations and to establish the potential of dietary strategies such as reduced total fat, saturated fat, or increased antioxidant intakes to counteract the increased CVD burden in apoE4 carriers.     

Public health guidance on cardiovascular benefits and risks related to fish consumption

Historically, concerns with fish consumption have addressed risks from contaminants (e.g., methylmercury (MeHg), and PCBs). More recently public health concerns have widened in appreciation of the specific benefits of fish consumption such as those arising from polyunsaturated fatty acids (PUFAs) in fish oil. Fish contains varying levels of PUFAs and MeHg. Since both address the same health outcomes (in opposite directions) and occur together in fish, great care must be exercised in providing public health guidance. Mozaffarian and Rimm in a recent article (JAMA. 2006, 296:1885–99) have made a strong case for the beneficial effects of PUFAs in reducing the risk of coronary heart disease, but at the same time, have also broadly discounted the increased risks of coronary heart disease posed by MeHg in fish, stating that "... among adults... the benefits of fish intake exceed the potential risks." This conclusion appears to be based on an inaccurate and insufficiently critical analysis of the literature. This literature is re-examined in light of their conclusions, and the available and appropriate public health options are considered.     

Differential responses to selenomethionine supplementation by sex and genotype in healthy adults

A year-long intervention trial was conducted to characterise the responses of multiple biomarkers of Se status in healthy American adults to supplemental selenomethionine (SeMet) and to identify factors affecting those responses. A total of 261 men and women were randomised to four doses of Se (0, 50, 100 or 200 μg/d as L-SeMet) for 12 months. Responses of several biomarkers of Se status (plasma Se, serum selenoprotein P (SEPP1), plasma glutathione peroxidase activity (GPX3), buccal cell Se, urinary Se) were determined relative to genotype of four selenoproteins (GPX1, GPX3, SEPP1, selenoprotein 15), dietary Se intake and parameters of single-carbon metabolism. Results showed that supplemental SeMet did not affect GPX3 activity or SEPP1 concentration, but produced significant, dose-dependent increases in the Se contents of plasma, urine and buccal cells, each of which plateaued by 9-12 months and was linearly related to effective Se dose (μg/d per kg0·75). The increase in urinary Se excretion was greater for women than men, and for individuals of the GPX1 679 T/T genotype than for those of the GPX1 679 C/C genotype. It is concluded that the most responsive Se-biomarkers in this non-deficient cohort were those related to body Se pools: plasma, buccal cell and urinary Se concentrations. Changes in plasma Se resulted from increases in its non-specific component and were affected by both sex and GPX1 genotype. In a cohort of relatively high Se status, the Se intake (as SeMet) required to support plasma Se concentration at a target level (Se(pl-target)) is: Se(in) = [(Se(pl - target) - Se(pl))/(18.2ng d kg?.??/ml per mu g)] .     

微小RNA作为生物标志物在心血管疾病的研究进展

微小RNA(micro RNA)是一类长18～24个核苷酸高度保守的非编码RNA分子,调节基因转录后表达。大量研究显示micro RNA通过调节增殖、凋亡、分化和代谢等生物学进程参与多种危险因素诱导的心脏血管损伤。此外,循环micro RNA作为新的心血管领域生物标志物被深入研究。Micro RNA在危险因素诱导心血管损伤早期过程的多种调控功能预示micro RNA在心血管疾病诊断、预测方面具有广泛的应用前景。然而,在micro RNA作为心血管损伤诊断和预后分析的生物标志物及靶向治疗策略应用于临床之前,尚有许多问题亟待解决,仍需大量深入和系统的研究。     

Using the nucleolar biomarker and the micronucleus test on in vivo fish fin cells

This study was aimed at developing the nucleolar biomarker and the micronucleus test on in vivo fish fin cells for assessing water cytotoxicity and genotoxicity. Both biomarkers can be used either jointly or separately on fins of the same fish during the experiment. For studying the nucleolar characteristics, small pieces of the fin edge were cut several times during 30-180 min of fish exposure. For micronucleus testing, the fin tissue regenerating after its cutting was investigated after 2-5 days of fish incubation. Effects of copper (0.1 and 2.5 mg/L), cadmium (0.005 and 1.0 mg/L) ions and chloral hydrate (400 and 800 mg/L) solutions were studied on cells of common carp (Cyprinus carpio L.), crucian carp (Carassius auratus gibelio Bloch.), and Mozambique tilapia (Tilapia (Sautherodon) mossambica) using a set of nucleolar characteristics (the number of nucleoli per cell, the size of a single nucleolus, and the percentage of cells with heteromorphic paired nucleoli) and the frequencies of cells with micronuclei and double nuclei. Substantial changes in parameters of nucleolar activity of fin cells were found to be caused by cadmium and copper impact. In comparison to blood cells, gill and fin cells were more sensitive as demonstrated by their nuclear damages after the chloral hydrate influence. Fin cells were useful to determine periodically cytotoxic and genotoxic effects of organic and inorganic substances in the same individual fish without any disruption of its physiological functions.     

苯接触的易感性生物标志物研究进展

苯是工业生产中重要的生产原料和有机溶剂,油漆、制鞋、制药等行业都使用苯。苯的长期接触可引起白细胞减少、骨髓抑制,严重时可致白血病。但在同一工作环境中,并非所有工人都发生苯中毒,即个体对苯毒性的易感性存在差异,这种易感性差异主要是由基因的多态性造成的。基因的多态性是生物进化早期基因突变造成的,能稳定遗传,可改变基因的表达水平和基因功能,与疾病相关。因此确定敏感的、特异的易感性生物标志物对预防和控制苯中毒、保护接触苯人群的健康具有重要意义。苯中毒易感性生物标志物的研究较多,本文着重从苯代谢酶基因多态性、细胞…     

苯接触人群的生物标志物研究进展

苯是应用广泛的化工原料.接触苯可引起急、慢性苯中毒,甚至白血病.研究苯接触人群的生物标志物在了解苯致病机制、接触苯人群的健康筛查等方面有重要价值,下面就国内外关于苯接触人群的生物标志物的研究进行综述. 1 苯的接触标志物 接触标志物是指进入机体内的外源性物质、代谢产物和它们与靶分子交互作用的产物.苯进入人体后多储留在脂肪组织内,在肝脏氧化成苯环氧化物,环氧化物与谷胱甘肽结合,形成苯巯基尿酸(S-PMA),其半减期为12.8 h[1].PACI等[2]利用高效液相色谱-串联质谱联用(HPLC/MS/MS)对S-PMA进行了研究,得到了尿S-PMA与苯的时间加权平均浓度直线相关,且不受性别、年龄、吸烟习惯的影响.     

Effect of tributyltin on the chemiluminescent response of phagocytes from three species of estuarine fish

The effect ofin vitro exposure to tributyltin (TBT) on the chemiluminescent (CL) responses of kidney macrophages was examined in oyster toadfish (Opsanus tau), hogchoker (Trinectes maculatus) and Atlantic croaker (Micropogonias undulatus). Phagocytic activity was evaluated using a luminol-amplified chemiluminescent (CL) assay with zymosan as the stimulus. Following brief exposure to selected doses of TBT, the CL response of toadfish and hogchoker phagocytes was found to be significantly decreased at 400 g/L TBT, while the croaker phagocytic activity was significantly decreased at 40 g/L TBT. With 18 hrexposure to TBT, the effect on the CL response was noticeable at lower doses (40 g/L TBT for toadfish and 4 g/L TBT for hogchoker).     

Extraction, processing, and stabilization of health-promoting fish oils

Fish oil is known to be an important source of highly unsaturated n-3 polyunsaturated fatty acids (PUFA) such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which play an important role in the prevention of different human diseases. Fortification of foods with such fatty acids is, thus, increasingly recommended. A growing public awareness about the benefits and the limited dietary sources of PUFA has created a substantial interest in the production of PUFA concentrate. Thus, ecofriendly extraction and purification techniques, exhibiting higher yield and minimum degradation of the nutrient, are of prime focus among the researchers. Due to the presence of these highly unsaturated PUFA, fish oil is highly prone to oxidation, leading to the production of off-odors and off-flavors. Presently, synthetic antioxidants have been replaced by natural ones for stabilizing the fish oil against oxidation. This article reviews major research and patents that have been published on fish oil extraction, purification and its stability.     

High-performance liquid chromatographic determination of vitamin D3 in fish liver oils and eel body oils

Identification and determination of vitamin D3 (or D2) and 25-OH-D3 in fish liver oils and eel body oils were carried out. By co-chromatography on HPLC, UV spectra and/or GC-MS, vitamin D3 was identified in naturally occurring fish liver oils and eel body oils, whereas a drop of fish liver oil contained supplemented vitamin D2. 25-OH-D3 was identified only in skipjack liver oil. The HPLC method proposed in a previous report (Takeuchi, A. et al. (1984): J. Nutr. Sci. Vitaminol., 30, 11-25) was confirmed to also be useful for determination of vitamin D3 (or D2) in fish liver oils and eel body oils. The assayed values of vitamin D3 in skipjack and tuna liver oils were 57,760 and 16,200 IU/g, respectively, which were much higher than those in cod and pollack liver oils. The assayed values of vitamin D3 in eel body oils were very low (16-43 IU/g) and showed no appreciable change despite differences in the farming conditions. Determination of 25-OH-D3 in skipjack oil was performed by using HPLC, and the assayed value was 1.8 micrograms/g. This was about 1/800 lower than that of vitamin D3.