Simultaneous Bio-reduction of Nitrate,Perchlorate, Selenate,Chromate, Arsenate,and Dibromochloropropane Using a Hydrogen-based Membrane Biofilm Reactor

We tested the hypothesis that the H₂-based membrane biofilm reactor (MBfR) is capable of reducing multiple oxidized contaminants, a common situation for groundwater contamination. We conducted bench-scale experiments with three groundwater samples collected from California’s San Joaquin Valley and on two synthetic groundwaters containing selenate and chromate. The actual groundwater sources had nitrate levels exceeding 10 mg-N l⁻¹ and different combinations of anthropogenic perchlorate + chlorate, arsenate, and dibromochloropropane (DBCP). For all actual groundwaters, the MBfR reduced nitrate to less than 0.01 mg-N l⁻¹. Present in two groundwaters, perchlorate + chlorate was reduced to below the California Notification Level, 6 μg-ClO₄ l⁻¹. As(V) was substantially reduced to As(III) for two groundwaters samples, which had influent As(V) concentrations from 3 to 8.8 μg-As l⁻¹. DBCP, present in one groundwater at 1.4 μg l⁻¹, was reduced to below its detection limit of 0.01 μg l⁻¹, which is well below California’s 0.2 μg l⁻¹ MCL for DBCP. For the synthetic groundwaters, two MBfRs initially reduced Se(VI) or Cr(VI) stably to Se° or Cr(III). When we switched the influent oxidized contaminants, the new oxidized contaminant was reduced immediately, and its reduction soon was approximately the same or greater than it had been reduced in its original MBfR. These results support that the H₂-based MBfR can reduce multiple oxidized contaminants simultaneously.     

Meat Eating by Wild Chimpanzees (<Emphasis Type="Italic">Pan troglodytes schweinfurthii</Emphasis>): Effects of Prey Age on Carcass Consumption Sequence

Despite the fact that many primates consume vertebrate prey, surprisingly little is known about the nutritional benefits of eating meat for members of this diverse order. Although chimpanzees (Pan troglodytes) primarily eat plant source foods, especially fruit, they consume vertebrate prey with excitement, attesting to its nutritional value. Meat is a concentrated source of macro- and micronutrients; however, a carcass is not a uniform package. For example, the mammalian brain has considerably higher fat content than lean muscle tissue. The brain both has great caloric value and contains high concentrations of long-chain polyunsaturated fatty acids, which are critical for normal brain function. It thus represents a large, nutrient-dense source of energy and essential nutrients that should be highly valued. We filmed consumption of 29 arboreal monkeys by chimpanzees at Gombe National Park, Tanzania, and recorded the order in which general regions of the body were consumed. Overall, the head was significantly more likely to be targeted first than either the torso (including viscera) or appendages. This result was driven by subadult prey, 91% of which were eaten head-first, probably because their skulls were relatively easy for chimpanzees to break with a single bite. Possessors of adult prey (with robust skulls) often first selected the viscera, probably to harvest the fat-rich liver, thus maximizing immediate return in the face of the threat of harassment or theft. This has important implications for our understanding of the nutritional benefits of meat eating among primates, and highlights the need for future studies that measure the nutritional content of specific tissues and examine which are preferentially consumed or shared.     

Dietary n-6- or n-3-rich vegetable fats and α-tocopheryl acetate: effects on fatty acid composition and stability of rabbit plasma, liver and meat

We supplemented diets with α-tocopheryl acetate (100 mg/kg) and replaced beef tallow (BT) in feeds with increasing doses of n-6- or n-3-rich vegetable fat sources (linseed and sunflower oil), and studied the effects on the fatty acid (FA) composition, the α-tocopherol (αT) content and the oxidative stability of rabbit plasma and liver. These effects were compared with those observed in a previous study in rabbit meat. As in meat, the content of saturated, monounsaturated and trans FA in plasma and liver mainly reflected feed FA profile, except stearic acid in liver, which increased as feeds contained higher doses of vegetable fat, which could be related to an inhibition of the activity of the stearoyl-CoA-desaturase. As linseed oil increased in feeds, the n-6/n-3 FA ratio was decreased in plasma and liver as a result of the incorporation of FA from diets and also, due to the different performance and selectivity of desaturase enzymes. However, an increase in the dose of vegetable fat in feeds led to a significant reduction in the αT content of plasma and liver, which was greater when the fat source was linseed oil. Increasing the dose of vegetable fat in feeds also led to an increase in the susceptibility to oxidation (lipid hydroperoxide (LHP) value) of rabbit plasma, liver and meat and on the thiobarbituric acid (TBA) values of meat. Although the dietary supplementation with α-tocopheryl acetate increased the αT content in plasma and liver, it did not modify significantly their TBA or LHP values. In meat however, both TBA and LHP values were reduced by the dietary supplementation with α-tocopheryl acetate. The plasma αT content reflected the αT content in tissues, and correlated negatively with tissue oxidability. From the studied diets, those containing 1.5% linseed oil plus 1.5% BT and 100 mg of α-tocopheryl acetate/kg most improved the FA composition and the oxidative stability of rabbit tissues.     

Isolation and characterization of lipid-protein complexes present in commercial albumin preparations

Most commercially available albumin preparations examined by us contain phospholipids, cholesterol and apolipoprotein impurities. As these albumin preparations are frequently used in large amounts in systems involving lipoprotein metabolism these impurities may reach remarkable levels to introduce exogenous effects in these studies. We have studied in detail tow bovine albumin preparations differing in their content of these contaminants. Using preparative ultracentrifugation, we have isolated from both albumins a lipid protein complex at a buoyant density of d = 1.063-1.21 g/ml with a chemical composition resembling plasma high density lipoproteins. This complex when further characterized proved also to have a similar apoprotein composition to bovine plasma high density lipoproteins. Electron microscopic study of this complex revealed discoidal particles closely resembling nascent high density lipoproteins recovered from rat liver or lymph. The similarity of these lipid-protein complexes to high density lipoproteins, accounts for some reported effects caused by commercially available albumin preparations on cholesterol excretion from cells in tissue culture and their ability to act as acceptors for surface remnants released upon VLDL catabolism in vitro.     

Lipids in monogastric animal meat.

Meat from monogastric animals, essentially pigs and poultry, is from afar the most consumed of all meats. Meat products from every species have their own characteristics. For a long time, pig meat has been presented as a fatty meat because of the importance of subcutaneous adipose tissue. Actually, when the visible fat is separated, this meat is rather poor in lipids: pieces eaten as fresh meat and without transformation, such as roasts, contain less then 2% total lipids. Poultry meat has always had a reputation of leanness because of its low content in intramuscular lipids. In addition, adipose tissues, localised in the abdominal cavity, are easily separable. The progress in genetics and a better knowledge of dietary needs has allowed to improve growth performances, to increase muscle weight and, in the pig, to strongly decrease carcass adiposity. However, strong contradictions appear between transformers and nutritionists, especially concerning the pig: the former wish to have meat with adipose tissues containing a high percentage of saturated fatty acids and the latter wish meat with more unsaturated fatty acids. The consumer, however, regrets the pigs of yesteryear or the poultry bred on farmyard that had tastier meat. At the same time, however, they request meat with a low fat content, which is paradoxical.     

Modulation of DNA modification (I-compound) levels in rat liver and kidney by dietary carbohydrate, protein, fat, vitamin, and mineral content.

I-compounds are DNA modifications detected by 32P-postlabeling that increase with age in rodents without known carcinogen exposure. Diet type (natural ingredient versus purified) greatly influences patterns and levels of I-compounds. To test the hypothesis that I-compound formation is affected, also, by dietary macro- and micronutrients, effects of carbohydrate, protein, fat, vitamin, and mineral content on rat liver and kidney I-compounds were determined. Female Sprague-Dawley rats were fed basic or modified AIN-76A purified diets for 3-6 months. High protein (HP) diet (50%, w/w) increased I-compound levels in liver but not kidney. High carbohydrate (HC) diet (78%) produced a significant increase in the polar as well as total I-compound levels in both tissues. High fat diets (20%) elicited significantly lower levels of liver I-compounds than HC, HP, and basic diets. There were few significant differences between high polyunsaturated (safflower oil) and saturated fat (lard) diet groups. No qualitative differences in I-compound profiles were observed in either tissue. In rats fed basic diet supplemented with vitamins and/or minerals, increased vitamin content reduced the levels of polar I-compounds in liver. No extra diet-induced adducts were observed; all effects were of a quantitative nature. These data provide direct evidence that nutrients significantly influence I-compound levels and support the hypothesis that normal metabolism of nutrients leads to the production of small amounts of DNA-reactive electrophiles. These observations suggest a novel mechanism where nutrient composition of the diet may play a role in development of neoplasia and other adverse health effects.     

Effects of raw and diluted municipal sewage effluent with micronutrient foliar sprays on the growth and nutrient concentration of foxtail millet in southeast Iran

In this study, the effect of irrigation with raw or diluted municipal sewage effluent accompanied by foliar micronutrient fertilizer sprays was examined on the growth, dry matter accumulation, grain yield, and mineral nutrients in foxtail millet plants. The experimental design was a split plot with three irrigation sources: raw sewage, 50% diluted sewage, and well water comprising the main treatments, and four combinations of Mn and Zn foliar sprays as sub-treatments that were applied with four replications. The experiment was conducted in 2009 at the Zabol University research farm in Zabol, south Iran. The applied municipal sewage effluent contained higher levels of micronutrients and macronutrients and exhibited greater degrees of electrical conductivity compared to well water. Because of the small scale of industrial activities in Zabol, the amount of heavy metals in the sewage was negligible (below the limits set for irrigation water in agricultural lands); these contaminants would not be severely detrimental to crop growth. The experimental results indicated that irrigation of plants with raw or diluted sewage stimulates the measured growth and productivity parameters of foxtail millet plants. The concentrations of micronutrients and macronutrients were also positively affected. These stimulations were attributed to the presence of high levels of such essential nutrients as N, P, and organic matter in wastewater. Supplied in sewage water alone, Mn and Zn were not able to raise the productivity of millet to the level obtained using fertilizers at the recommended values; this by itself indicated that additional nutrients from fertilizers are required to obtain higher levels of millet productivity with sewage farming. Despite the differences in nutrient concentrations among the different irrigation water sources, the micronutrient foliar sprays did not affect the concentrations of micronutrients and macronutrients in foxtail millet plants. These results suggested that municipal sewage effluent could be utilized efficiently as an important source of water, and that the nutrients used in growing foxtail millet with sewage water irrigation did not have any significant harmful effect on crop productivity. In contrast, the nutrients proved beneficial to soil fertility and millet productivity and quality.     

The formation and occurrence of polynuclear aromatic hydrocarbons associated with food

Polynuclear aromatic hydrocarbons are common contaminants of processed food, usually at trace levels. These hydrocarbons are products of combustion and pyrolysis, and are present in petroleum and coal, and in products derived from them. Most polynuclear aromatic hydrocarbons are not carcinogenic, but some of them are, and a few are potent inducers of skin and lung tumors in mice. Their carcinogenic properties have not been fully explored, but they seem to be less potent by ingestion or inhalation, and they are known as a group to produce cancer in humans. The most effective carcinogens among them are those with 5 or 6 fused rings, and these tend to be less prevalent in mixtures than the 3- and 4-ring hydrocarbons, most of which are not carcinogenic. Sophisticated analytical methods, using solvent extraction and chromatography have been developed to detect and measure polynuclear aromatic hydrocarbons at levels of 1 in 10(9) (1 part per billion) or less, and these have been applied to the measurement of individual compounds in foods, as well as in products of combustion and pyrolysis. Wood smoke and smoked foods contain the carcinogenic benzo[a]pyrene at levels of 1 ppb, and other hydrocarbons; liquid smoke has lower levels. Crude vegetable oils have higher concentrations, but purified 'deodorized' oils have benzo[a]pyrene levels near 1 ppb. Sausages cooked over burning logs had as much as 200 ppb benzo[a]pyrene. Charcoal-broiled steaks and ground meat had benzo[a]pyrene concentrations up to 50 micrograms/kg, while less fatty pork and chicken had lower concentrations (up to 10 micrograms/kg). It was probable that the rendered fat dripped on to the hot charcoal and pyrolyzed to form quantities of polynuclear aromatic hydrocarbons, which rose with the smoke to deposit on the meat. Therefore, oven cooking or cooking with a heat source above the meat, or segregation of the meat from the smoke resulted in food containing negligible amounts of polynuclear aromatic hydrocarbons. Modifications of cookings practices accordingly would greatly reduce exposure to this group of carcinogens.     

Oxidized oils and dietary zinc and α-tocopheryl acetate supplementation: effects on rabbit plasma, liver and meat fatty acid composition and meat Zn, Cu, Fe and Se content

The effects of the addition of heated oils to feeds (3%, w/w) and the dietary supplementation with α-tocopheryl acetate (TA; 100 mg/kg) and Zn (200 mg/kg) on rabbit tissue fatty acid (FA) composition and on the Zn, Cu, Fe and Se content in meat were assessed. Heating unrefined sunflower oil (SO) at 55°C for 245 h increased its content in primary oxidation products and reduced its α-tocopherol content. However, this did not significantly affect tissue FA composition. Heating SO at 140°C for 31 h increased its content in secondary oxidation products and in some FA isomers as c9,t11-CLA and di-trans CLA. This led to increases in di-trans CLA in liver and in t9,c12-18:2 in meat. The c9,t11-CLA was the most incorporated CLA isomer in tissues. The dietary supplementation with α-TA did not affect the FA composition of plasma, liver or meat. The cooking of vacuum-packed rabbit meat at 78°C for 5 min reduced significantly but slightly its polyunsaturated FA content. The dietary supplementation with Zn did not modify the content of Zn, Fe or Se in meat, but it reduced its Cu content. On the other hand, it increased the content of some FAs in meat when SO heated at 140°C for 31 h was added to feeds.     

Selenium and Zinc Concentrations in Kidney,Liver And Muscle of Cattle from Different Parts of Norway

Cattle slaughtered in four different parts of Norway have been examined with respect to selenium and zinc content in kidney, liver and muscle. Highest selenium concentrations were found in kidney and lowest in muscle. In spite of extensive use of standardized concentrates, geographic differences were detected with regard to selenium tissue levels, animals from the southeastern inland region having the lowest levels. According to other workers, this region has low-selenium humus soils, and selenium responsive diseases among young ruminants have been of considerable importance, especially when concentrates had not been given during winter feeding. The recorded tissue selenium levels are compared to other workers’ proposals for normal values. All animals examined in this study seem to be well within healthy limits. Kidney, liver and muscle from cattle are good sources of selenium with respect to human nutrition. As far as zinc concentrations are concerned, muscle has the highest and kidney the lowest levels. Geographic differences were found, and individuals from the midland and northern coastal regions have the highest zinc tissue levels. Cattle from the northern coastal region seems to have especially high zinc concentrations in the organs.     

Beta-carotene breakdown products may impair mitochondrial functions--potential side effects of high-dose beta-carotene supplementation

Beta-carotene (BC) and other carotenoids are mainly considered as belonging to the group of micronutrients. As they are contained in fruit and vegetables and thus part of human diet, a regular low-dose intake from natural sources is normally assured. In the last decade high-dose supplementation with synthetic carotenoids has been used successfully in the treatment of diseases believed to be associated with oxidative stress. However, in a few clinical studies harmful effects have been observed as well, e.g., a higher incidence of lung cancer after BC was given in high doses to smokers. Our studies aim at shedding light on the causal mechanisms of the known side effects that we have investigated. Possibilities of preventing them are discussed. Obviously, on certain conditions of high-dose carotenoid supplementation, both the antioxidant and prooxidant reactions may arise. Carotenoid breakdown products (CBP) including very reactive aldehydes and epoxides are formed during oxidative attack in the course of antioxidative action. Carotenoid breakdown products inhibit state 3 respiration of isolated rat liver mitochondria at concentrations between 0.5 and 20 microM. In vivo stimulated neutrophils might represent an important source for the generation of CBP, and the lung might be a critical organ in CBP formation. The inhibition of mitochondrial state 3 respiration by CBP is accompanied by a reduced content of protein sulfhydryl groups, decreasing glutathione levels and redox state, and also elevated accumulation of malondialdehyde. Changes in mitochondrial membrane potential favour functional deterioration of the adenine nucleotide translocator (ANT). The findings reflect a basic mechanism of the side effects of BC supplementation in circumstances of severe oxidative stress induced by CBP representing a class of lipid oxidation products. We are striving for safe conditions of carotenoid supplementation in order to protect patients in need of this kind of medical treatment from possible side effects, such as unwanted prooxidative reactions.     

Radioimmunoassay for human type VI collagen and its application to tissue and body fluids

A liquid phase radioimmunoassay (RIA) was developed for pepsin-solubilized human type VI collagen, allowing quantitative analysis of this protein down to a concentration of 3 ng/ml. No cross-reactivity was observed with human collagens type I, III, IV (triple helical portion and 7-S domain), and V, nor with laminin fragment Pl and plasma fibronectin. Significant amounts of closely related antigenic material were detected in serum, bile, ascites, and mesenchymal cell culture media. Type VI collagen could be completely solubilized from several tissues by a repeated pepsin digest, and its content as determined by RIA was found to be less than 0.1% of total collagen (55-70 micrograms/g protein). In fibrotic liver tissue type VI collagen was elevated up to 10-fold (620 micrograms/g protein) when compared to normal liver. Sera of patients with fibrotic liver disease, however, revealed antigen levels usually below the narrow normal range of 22 +/- 7.8 ng/ml (mean +/- 2.5 SD). We conclude that, although type VI collagen represents a minor fraction of the interstitial collagens, its comparatively high serum levels point to a considerable turnover in the normal individual. Our data suggest that in fibrosis as exemplified in fibrotic liver disease, the metabolism of this collagen is down-regulated, while at the same time, it accumulates in the interstitial matrix.     

Plasma Somatostatin-like immunoreactivity in chemically sympathectomized dogs

The present study was designed to determine the role of the adrenergic nerves upon basal and postprandial gastric and pancreatic SLI release. In 19 chemically sympathectomized dogs peripheral venous plasma SLI levels in the basal and postprandial state were significantly below those of 30 controls for the first 135 min after the ingestion of a fat-protein meal. To determine the origin of this reduction, the SLI release from fundus, antrum and pancreas was studied in anesthetized dogs during the gastric phase of a meal at either pH 7 or pH 2. In response to a liver meal at pH 7 fundic, antral and pancreatic vein SLI levels were below the control and the rise in inferior vena cava SLI was abolished. In response to a liver meat at pH 2, the rise in antral and pancreatic vein SLI as clearly reduced in the sympathectomized dogs, while the decrease in fundic SLI was not influenced. The data demonstrate that adrenergic innervation plays a role in basal and postprandial SLI release from the stomach and pancreas.     

Pigs' aggressive temperament affects pre-slaughter mixing aggression, stress and meat quality

Pre-slaughter stress has a negative impact on animal welfare and on meat quality. Aggressive behaviour when pigs are mixed together for transportation to, or on arrival at, the abattoir is an important factor in pre-slaughter stress. Aggressiveness of pigs varies between individuals in the population, and this study investigated its effects on stress and meat quality at slaughter. We mixed pigs at a young age to identify individuals of high (H) or low (L) aggressive temperament using the previously validated approach of lesion scoring. To contrast extremes of social stress single-sex groups of eight pigs were mixed according to their aggressiveness in HH, HL or LL combinations or left unmixed (U) prior to transport and slaughter (n = 271). Each treatment was replicated in at least two groups in each of four slaughter batches. Mixing per se had little effect, but mixed groups composed of aggressive pigs (HH) had more carcass skin lesions and higher levels of plasma cortisol at slaughter and had loin muscle samples with higher pH at 24 h, and lower redness (a*) and yellowness (b*) compared to the other treatments. Females had higher levels of plasma cortisol at slaughter, a more rapid decline in pH post-slaughter and greater lean content of meat. Lactate and creatine kinase (CK) levels and meat pH were affected by the interaction of sex and treatment. Genetic factors, dam and sire line composition, and halothane locus (ryanodine receptor 1, RYR1) genotype, also affected a number of production and meat quality parameters as expected. Additionally, 'commercially normal' levels of social stress were studied in four further slaughter batches with no manipulation of group composition (n = 313). In these pigs, the proportion of unfamiliar pigs and group size of lairage groups explained limited variation in lesion scores at slaughter, but earlier aggressiveness did not. High numbers of skin lesions on the carcass were associated with high levels of cortisol and lactate and low glucose at slaughter, but not with meat quality measures. When stress and meat quality measures were compared for all pigs, high lactate was associated with low early pH and high drip loss, while high cortisol and CK were associated with high pH at 24 h and changes in meat colour. In conclusion, mixing pigs of above average aggressiveness resulted in greater aggression and stress, and changes in meat quality parameters, consistent with the effects of pre-slaughter stress on muscle chemistry.     

Chromatographic and related techniques for the determination of aromatic heterocyclic amines in foods

Some 20 years ago, Japanese scientists discovered a new group of highly toxic compounds, classified as heterocyclic aromatic amines, from broiled and grilled meat and fish products. Numerous studies have shown that most HAs are mutagenic and carcinogenic, and the safety of HA-containing foods has become a concern for the public. To date, more than 20 different mutagenic and/or carcinogenic heterocyclic amines have been identified in foods. This paper reviews the analysis of foods for HAs with 145 references. We survey some of the numerous methods available for the chromatographic analysis of heterocyclic amines and highlight the recent advances. We discuss chromatographic and related techniques, including capillary electrophoresis, and their coupling to mass spectrometry for the determination of these contaminants in foods. In addition, the review summarises data on the content of HAs in various cooked foods.     

Altered hepatic retinyl ester concentration and acyl composition in response to alcohol consumption

Retinoids (vitamin A and its metabolites) are essential micronutrients that regulate many cellular processes. Greater than 70% of the body's retinoid reserves are stored in the liver as retinyl ester (RE). Chronic alcohol consumption induces depletion of hepatic retinoid stores, and the extent of this has been correlated with advancing stages of alcoholic liver disease. The goal of this study was to analyze the mechanisms responsible for depletion of hepatic RE stores by alcohol consumption. A change in the fatty-acyl composition of RE in alcohol-fed mice was observed within two weeks after the start of alcohol consumption. Specifically, alcohol-feeding was associated with a significant decline in hepatic retinyl palmitate levels; however, total RE levels were maintained by a compensatory increase in levels of usually minor RE species, particularly retinyl oleate. Our data suggests that alcohol feeding initially stimulates a futile cycle of RE hydrolysis and synthesis, and that the change in RE acyl composition is associated with a change in the acyl composition of hepatic phosphatidylcholine. The alcohol-induced change in RE acyl composition was specific to the liver, and was not seen in lung or white adipose tissue. This shift in hepatic RE fatty acyl composition is a sensitive indicator of alcohol consumption and may be an early biomarker for events associated with the development of alcoholic liver disease.     

Reproducibility of erythrocyte polyamine measurements and correlation with plasma micronutrients in an antioxidant vitamin intervention study

Erythrocyte polyamine measurements have been previously investigated as candidate biomarkers for hyperproliferation and recently as a potential intermediate endpoint in clinical chemoprevention trials with difluoromethylornithine, an inhibitor of polyamine biosynthesis. This study was performed to determine the reproducibility of erythrocyte polyamine measurements and their possible correlation with plasma micronutrients in seven healthy adults in an antioxidant vitamin intervention study. As part of this cross-over intervention study, three subjects took β-carotene (31.4 mg/day) plus D-α-tocopherol acetate (720 IU/day) supplements during the first 3 months and four subjects took the supplements during the second 3 months. Heparinized blood samples were collected at baseline and every month over total 6 months for simultaneous determination of erythrocyte polyamines and plasma micronutrients by the high-performance liquid chromatographic method. For all the measures of erythrocyte polyamines the intraindividual variation was smaller than that between subjects, and three or four measurements required to accurately characterize long-term erythrocyte polyamines for an individual. The intra-class correlations were moderately high for all erythrocyte polyamine measurements, indicating a good reproducibility for intra-individual erythrocyte polyamine measurements. Based on monthly values, significant inverse correlations were found between erythrocyte spermidine and the plasma levels of retinol (r = -0.50) and lutein (r = -0.52). There were also significant inverse associations between erythrocyte spermine and plasma levels of α-tocopherol (r = -0.29), lutein (r = -0.44), lycopene (r = -0.29), β-cryptoxanthin (r = -0.30), and total carotenoids (r = -0.29). The effects of supplementation upon the associations between erythrocyte polyamines and plasma nutrient levels were additionally addressed. The results indicate an acceptable longitudinal reproducibility of erythrocyte polyamine measurements, support the hypothesis that erythrocyte polyamine measurements may be correlated with plasma levels of certain nutrients, and suggest a further biomarker application in cancer prevention trials involving dietary modifications or specific relevant micronutrients. © 1996 Wiley-Liss, Inc.     

Vitamins/minerals and genomic stability in humans

Recommended dietary allowances (RDAs) of micronutrients have been traditionally derived as those levels necessary to prevent symptoms of deficiency diseases. There is increasing evidence that higher levels of many such micronutrients may be necessary for various DNA maintenance reactions, and that the current RDAs for some micronutrients may be inadequate to protect against genomic instability. Supplementation of a normal diet, with either vitamins and/or minerals or with isolated plant polyphenols, is becoming increasingly common in most Western populations. However, there is no clear agreement as to how much supplementation should occur, if at all, and genotypic differences are not accounted for. The 14 mini-reviews in this special issue summarise the role of specific micronutrients in various aspects of DNA maintenance: DNA synthesis, DNA repair, DNA methylation, gene mutation, chromosome breakage, chromosome segregation, gene expression, oxidative stress, necrosis and apoptosis. Evidence has been collated from mammalian and human experiments, both using in vitro cultures and in vivo approaches. Authors were asked to critically assess the strength of evidence as to whether the micronutrient can affect genomic stability in humans at realistic intake levels, and to estimate optimal dietary ranges where possible. Information on further research necessary is also documented. These reviews are an essential step towards a definition of RDAs designed to maintain genomic stability.     

Effects of Ag Nanoparticles on Growth and Fat Body Proteins in Silkworms (<Emphasis Type="Italic">Bombyx mori</Emphasis>)

This growing interest in the cultivation of Japanese quince Chaenomeles japonica L. results from the potentially beneficial properties of its fruit. Fresh fruits are very firm and too acidic to eat raw, but their bioactive components, distinctive aroma, and high amount of dietary fiber make the fruits well suited for industrial processing. However, not all the properties of the fruit have been investigated. For example, there are no comprehensive reports about the mineral content or potentially harmful effects on liver metabolism. Hence, the purpose of our study was to examine fresh Japanese quince fruit in terms of (1) ascorbic acid, oxalate, fiber, macro- and micronutrients, dry matter, extract, total acidity, antioxidant activity, and phenolic compound levels; and (2) the effect of its extract on in vitro hepatocyte metabolism, measured by the concentration of lipid peroxides (LPO) and reactive oxygen species (ROS) and the severity of apoptosis and necrosis. The fruit of C. japonica had high levels of macro- and microelements, ascorbic acid, phenolic compounds, fiber, and low oxalate levels. Our analysis of macro- and microelements showed that the average content of Fe was 0.516 mg/g, Cu 0.146 mg/g, Zn 0.546 mg/g, Mg 16.729 mg/g, and Ca 22.920 mg/g of fresh fruit. A characteristic feature of the fresh fruit of C. japonica is a high level of polyphenols, which—combined with a high content of vitamin C—affect their high antioxidant potential. In the tested hepatocyte cultures incubated with extract of the Japanese quince, we observed a significant decrease in the concentration of lipid peroxides compared to the control. There were also no signs of increased formation of ROS in the mitochondria of hepatocytes incubated with the extract of quince. Malondialdehyde was strongly negatively correlated with the concentration of Japanese quince extract, which indicates the hepatoprotective properties of Japanese quince. In addition, our analysis of confocal microscopy images showed that the hepatocytes incubated with the extract of Japanese quince at any concentration did not show any signs of apoptosis or necrosis. The aqueous extract of quince fruit has antioxidative and antiapoptotic hepatocytes, thus exerting a hepatoprotective effect.