Oral exposure of PBDE-47 in fish: toxicokinetics and reproductive effects in Japanese Medaka (Oryzias latipes) and fathead minnows (Pimephales promelas)

The toxicokinetics of 2,2,4,4-tetrabromodiphenyl ether (PBDE-47) was studied in the Japanese Medaka (Oryzias latipes) after a single oral exposure followed by termination at specific time points. The effects of repeated oral exposure to PBDE-47 on reproductive performance was assessed using a pair breeding experimental design with fathead minnows (Pimephales promelas) given daily PBDE-47 exposures for 25 days, during which fecundity was measured as an indicator of reproductive performance. Medaka and fathead minnows were orally exposed to PBDE-47 by bioencapsulation in brine shrimp, Artemia sp. In the medaka studies, measurable levels of PBDE-47 were detected in the carcass within 0.25 h with peak levels occurring at 8 h. The body levels of PBDE-47 slowly declined and were still 25% of peak levels at 624 h after dosing. Assimilation of the bioencapsulated dose was at least 80% and may well approach 100%. The PBDE-47 concentration-time profile was fitted to a one-compartment clearance-volume toxicokinetic model and the model-predicted value for elimination half-life was determined to be 281 h and the first-order absorption rate constant was Ka = 0.26 hr(-1). In the fathead minnow study, egg laying in the PBDE-treated breeding pairs stopped after 10 days. The condition factor of PBDE-treated males was significantly reduced (P <0.011) compared with control males, whereas no significant difference was observed in females. Histological examination revealed a greater than 50% reduction in mature sperm in PBDE-47 exposed minnows compared to controls. Collectively, these results suggest PBDE-47 is selectively toxic to sexually mature male fathead minnows.     

Influence of an inhibitor of monoaminooxidase (nialamide) on the serum levels, urinary excretion and plasma clearance of urea, uric acid and creatinine in adult and growing rats

Serum levels, urinary excretion and plasma clearance of urea, uric acid and creatinine were studied in adult (230 g) and growing (75 g) rats under the influence of nialamide (an IMAO) administered in daily doses of 20 mg/100 g diet during 15 or 30 days in adults and 10 mg/100 g diet during 15 days in growing rats. A pair feeding design was used in both ages. Serum levels of urea rose in adult rats fed nialamide for 30 days while urinary excretion decreased. No change in serum levels were noted in growing rats although urinary excretion showed a net increase. Serum uric acid levels were increased in adult female rats given nialamide for 30 days, while urinary excretion fell in both sexes. Growing rats showed a drop in urinary excretion of uric acid. Serum creatinine levels were unchanged in adult and growing rats after treatment with nialamide, although a marked increase was recorded in urinary excretion in both groups.     

Influence of an inhibitor of monoaminooxidase (nialamide) on the absorption and retention of nitrogen in adult rats

A study was made on adult rats (170 g) of the effect of nialamide (20 mg/100 g of diet), an inhibitor of monoaminooxidase, administered for 15 or 30 days (short or long-term, respectively), with food intake controlled (pair fed), on the absorption and retention of nitrogen, and on the nitrogen content in the liver, the gastronemio and longissimus dorsi muscles and in the small intestine. Nialamide administered for a time which can be considered prolonged (30 days) negatively affects absorption of alimentary protein, while metabolic utilization is reduced when the drug is administered both in the short and the long term. Proteic catabolism is less marked in male rats, due to the hormonal anabolizant situation in this sex. Nitrogen content under the effect of nialamide showed no significant variation in the gastronemio muscle or in the small intestine. There is a clear reduction in the longissimus dorsi muscle and an increase in the liver of those animals of both sexes treated with the drug, with the exception of male rats given nialamide in the long term.     

Cloning and in vitro expression and characterization of the androgen receptor and isolation of estrogen receptor alpha from the fathead Minnow (Pimephales promelas)

In vitro screening assays designed to identify hormone mimics or antagonists typically use mammalian (rat, human) estrogen (ER) and androgen receptors (AR). Although we know that the amino acid sequences of steroid receptors in nonmammalian vertebrates are not identical to the mammalian receptors, a great deal of uncertainty exists as to whether these differences affect interactions of potential endocrine-disrupting chemicals (EDC) with the receptors. This leads to substantial uncertainty with respect to the utility of mammalian-based screening assays to predict possible effects of EDCs in nonmammalian wildlife. This paper describes preparation of a cDNA library from a small fish model commonly used in ecological risk assessments, the fathead minnow (Pimphales promelas). The cDNA library was subsequently used to isolate and sequence both AR and ERalpha. In addition, the fathead minnow (fh)AR was expressed and characterized with respect to function using saturation and competitive binding assays in COS monkey kidney cells. Saturation experiments along with subsequent Scatchard analysis determined that the Kd of the fhAR for the potent synthetic androgen R1881 was 1.8 nM, which is comparable to that for the human AR in the same assay system. In COS whole cell competitive binding assays, potent androgens such as dihydrotestosterone and 11-ketotestosterone were also shown to be high affinity ligands for the fhAR. We also report affinity of the receptor for a number of environmental contaminants including the AR agonists androstenedione and 17a- and 17beta-trenbolone;AR antagonists such as p,p'-DDE, linuron, and vinclozolin; and the ER agonist 17beta-estradiol. Future plans include comparison of binding affinities of the fhAR to those of the human AR, also expressed in COS cells, using a range of EDCs.     

Spatial variation in hepatic levels and patterns of PCBs and PCDD/Fs among young-of-the-year and adult Atlantic tomcod (Microgadus tomcod) in the Hudson River estuary

Full congener-specific polychorinated biphenyl (PCB) and partial-congener-specific polychorinated dibenzo-p-dioxin/furan (PCDD/F) analyses were performed on livers from young-of-the-year (YOY) and adult Atlantic tomcod from the Hudson River estuary including multiple sites along the main-stem Hudson River and Newark Bay/Hackensack River, NJ, and from a reference river, the Miramichi River, NB. Highest hepatic burdens of PCBs were found in fish collected in the main-stem Hudson River between river miles (RM) 37 and 50 and in Newark Bay/Hackensack River. By far, the highest concentrations of PCDD/Fs were seen in fish from Newark Bay/Hackensack River. The di- to tetrachlorinated biphenyls dominated the PCB composition in YOY tomcod, whereas the penta- to nonachlorinated biphenyls predominated in adults with particular prevalence of the 2,4,5-substituted diortho congeners. Overall, using a direct mixing model an aroclor composition of approximate 1:1:1, A1242:A1254:A1260, was calculated from the hepatic PCB profiles in YOY tomcod. A linear increase in A1242 characteristics with river mile was seen in YOY collected between RM 0 and RM 80, which was likely due to the well-characterized A1242 source from the former capacitor manufacturing plants located upriver. However, tomcod caught upstream of RM 80 exhibited a PCB pattern with decreasing A1242 characteristics, and it was hypothesized that this was due to the increased depuration or decreased uptake of low chlorinated (log K(OW) < 6) congeners upon entry of the fish into freshwater from brackish water. The most abundant tetra-octa PCDD/F chlorohomologue in tomcod collected from the main stem of the Hudson River was TCDF, whereas 2,3,7,8-TCDD was the major congener detected in tomcod from Newark Bay/Hackensack River, which showed elevated total PCDD/F levels compared to tomcod from the main-stem Hudson River.     

Equine seminal plasma reduces sperm binding to polymorphonuclear neutrophils (PMNs) and improves the fertility of fresh semen inseminated into inflamed uteri

Seminal plasma (SP) is known to have immunosuppressive properties in several species. Equine SP has been reported to reduce or inhibit chemotaxis, phagocytosis and complement activity in vitro. The type and amount of the SP component that suppresses sperm-polymorphonuclear neutrophil (PMN) binding in vitro was determined, and the effect of such suppression on the fertility of mares inseminated in the presence of uterine inflammation, was analyzed. Sperm cells were suspended in either SP, semen extender or a mixture of both, and each was mixed with PMN-rich uterine secretions collected at 12 h after artificial insemination (AI). SP reduced binding between spermatozoa and PMNs significantly (P < 0.05). Fertile spermatozoa were suspended in SP or semen extender and used to inseminate mares 12 h after the induction of uterine inflammation. The pregnancy rate was normal (77%) when spermatozoa were suspended in SP, but was dramatically reduced to only 5% when spermatozoa were suspended in extender. The proteins from SP, blood plasma (BP) and a skim-milk-based semen extender (skim milk extender, SME) were precipitated by ammonium sulfate, resuspended in PBS and dialyzed. The effect of the precipitated proteins on sperm-PMN binding was compared with fresh, untreated SP. Both fresh SP, and isolated SP proteins reduced sperm-PMN binding (P < 0.001). Conversely, proteins isolated from either BP or SME did not reduce sperm-PMN binding. The different concentrations of SP proteins used showed a dose-dependent suppression of sperm-PMN binding. Concentrations of 1 mg/ml SP protein significantly reduced sperm-PMN binding and 6 mg/ml reduced the binding to a level similar to that observed with fresh whole SP (P < 0.001). Finally, SP protein digested with proteinase K resulted in the complete loss of SP suppressive activity confirming that the effective component is a proteinaceous substance.     

Combined effect of cold atmospheric plasma,intrinsic and extrinsic factors on the microbial behavior in/on (food) model systems during storage

Microbial decontamination by means of cold atmospheric plasma (CAP) offers great potential for treatment of heat-sensitive food products, extending their storage life. CAP is created by applying a high voltage to a gas stream, resulting in microbial inactivation according to different mechanisms. This paper thoroughly assesses the influence of CAP on the storage life of food model systems inoculated with Salmonella Typhimurium. (Food) model systems, with varying intrinsic factors (pH, salt concentration, and food (micro)structure), are treated for 5 min using a dielectric barrier discharge reactor generating a helium‑oxygen plasma. Following treatment, the impact of extrinsic factors is evaluated by storage at 8 °C or 20 °C. During storage, cell densities are determined. Data are fitted with predictive (growth or inactivation) models. As additional experiments indicate that the CAP treatment itself has a limited or even negligible effect on the properties of the model system (pH, a_w, (micro)structure), the microbial behavior of CAP treated samples during storage can be attributed to the treatment. CAP treatment can result in microbial reductions up to 2.7 log₁₀ and prolongs storage, however its rate of success is dependent on both extrinsic and intrinsic factors. An important factor is the storage temperature, as recovery of CAP treated cells proves more difficult when stored at 8 °C. At 20 °C, cell growth is merely slowed down. Additionally, at pH 5.5, 6% (w/v) NaCl, osmotic stress is induced on the microorganisms, which results in low cell recovery or further inactivation. The influence of the food (model) structure on the storage behavior is insignificant.Industrial relevanceAlthough being a very promising technology, most studies regarding the use of cold atmospheric plasma (CAP) for food decontamination focus on the inactivation of a target microorganism, in relation to a specific food product. Fundamental knowledge on this non-thermal technology, including its impact on the storage life, is lacking. This study investigates the effect of CAP on the microbial behavior during storage. By performing tests on model systems, for a variation of intrinsic and extrinsic factors, this work renders information on the suitability of this novel technology regarding treatment of a broad spectrum of food products. Moreover, this study demonstrates the limited impact of CAP on the food (model) properties, enhancing the suitability of the technology to be implemented in the food industry.     

The effect of milk polar lipids separated from butter serum on the lipid levels in the liver and the plasma of obese-model mouse (KK-A)

The effect of lipid concentrated-butter serum (LC-BS) on the plasma and hepatic cholesterol and triacylglycerol levels of obese-model mouse (KK-A^y) was evaluated. The same analysis was done on the main lipid fractions from LC-BS, namely, ceramide rich fraction (Ceramide-fr), phosphatidylethanolamine (PE) rich fraction (PE-fr), and sphingomyelin (SPM) rich fraction (SPM-fr). Plasma cholesterol of mice fed LC-BS and Ceramide-fr was significantly (P < 0.05) lower than that of the control. Hepatic total cholesterol and triacylglycerol levels was also reduced significantly by Ceramide-fr feeding (P < 0.05). Although there was no significant difference in the fatty acid composition of all dietary lipids, significant decrease (P < 0.05) in content of 18:1n-9 was found in the liver lipids of the mice fed Ceramide-fr containing diet. The level of 16:1n-7 and 18:1n-7 was also reduced by Ceramide-fr feeding. This result suggests the down-regulation of stearoyl-CoA desaturase-1 (SCD1) by milk ceramides, which would be related to the decrease in triacylglycerol and cholesterol levels in the liver and in the plasma.     

Effect of chronic administration of 7alpha-methyl-19-nortestosterone on serum testosterone,number of spermatozoa and fertility in adult male bonnet monkeys (Macaca radiata)

Hormonal approaches to male contraception that are based on the suppression of LH secretion require androgen replacement treatment to maintain sexual behaviour and secondary sexual characteristics. Androgen supplementation not only involves large and frequent doses of testosterone esters but also results in undesirable effects on the prostate gland. In an attempt to avoid such problems, a synthetic androgen, 7alpha-methyl-19-nortestosterone (MENT), which is much more potent than testosterone, has been developed. In the present study, MENT was administered at different doses (25, 50, 100, 300 and 1000 microg day(-1)) either alone or in combination with oestradiol via Silastic implants for a specified period to adult male bonnet monkeys (Macaca radiata). Blood and semen samples were collected at specific intervals and analysed for serum testosterone and seminal parameters, respectively. The results of the present study clearly indicate that administration of MENT at all doses tested results in suppression of the nocturnal surge of testosterone (by day 3), as well as a decrease in the number of spermatozoa (by day 45). Co-administration of oestradiol resulted in a reduction in the dose of MENT required to suppress the nocturnal surge. None of the male bonnet monkeys treated with MENT were able to impregnate females, clearly demonstrating the efficacy of MENT in blocking fertility in male bonnet monkeys.     

Effects of a black rice extract (Oryza sativa L. indica) on cholesterol levels and plasma lipid parameters in Wistar Kyoto rats

This study was designed to evaluate the efficacy of an anthocyanin pigmented rice (e.g. black rice) to mitigate the onset of hypercholesterolemia in rats-fed atherogenic diets. Male Wistar (n = 10/group) rats were fed with atherogenic diets containing 0.5% cholesterol in the presence and in the absence of bile salt (e.g. 0.05% cholic acid) along with a standardized black rice extract (BRE) (e.g. 3%, w/w). All animals were individually housed in stainless steel cages and fed with the experimental diets during a 12-h period for 10 weeks. Body weights of rats were measured every week of the experiment. After 10 weeks fed on experimental diets, rats were sacrificed and plasma total cholesterol, HDL and LDL cholesterol and triacylglycerols were measured immediately. The total cholesterol (TC) content in the liver, heart and aorta, and the concentration of triacylglycerol (TAG) were measured after lipid extraction using Folch method. Rats fed with 0.5% cholesterol containing diets which also included bile salt exhibited a considerably more severe hypercholesterolemia than counterparts fed diets containing only 0.5% cholesterol. The inclusion of the BRE in diets significantly (p < 0.05) decreased the level of TC, LDL–TC and TAG in plasma of rats-fed control diets that either contained or were absent in bile salt (p < 0.05). There were no differences in HDL-level. Liver crude lipids and total cholesterol levels were also significantly (p < 0.05) decreased in experimental groups relative to the control group in both experiments. Thus, supplementation of atherogenic experimental diets with BRE effectively decreased lipid levels in hypercholesterolemic rats. In lieu of the mixture of bioactive components present in BRE, it is possible that more than one mechanism underlying this reduction in lipids is involved.     

Deletion of MCD 4 involved in glycosylphosphatidylinositol (GPI) anchor synthesis leads to an increase in beta-1,6-glucan level and a decrease in GPI-anchored protein and mannan levels in the cell wall of Saccharomyces cerevisiae

Most proteins involved in the synthesis of the GPI core structure of Saccharomyces cerevisiae are essential for growth. To explore the relationship between the GPI anchor structure and beta-1,6-glucan synthesis, we screened deletion mutants in genes involved in GPI synthesis for osmotic remedial growth. Heterozygous diploid strains were dissected on medium with osmotic support and slow growth of the mcd 4 deletion mutant was observed. The mcd 4 mutant showed abnormal morphology and cell aggregation, and was hypersensitive to SDS, hygromycin B and K1 killer toxin. Incorporation of GPI cell wall proteins was examined using a GPI-Flo 1 fusion protein. The result suggested that the mcd 4 deletion causes a decrease in GPI cell wall proteins levels. The mutation also caused a decrease in mannan levels and an increase in alkali-insoluble beta-1,6-glucan and chitin levels in the cell wall.     

Acute-phase inter-alpha-trypsin inhibitor heavy chain 4 (ITIH4) levels in serum and milk of cows with subclinical mastitis caused by Streptococcus species and coagulase-negative Staphylococcus species

The aim of the study was to investigate the concentrations of acute-phase inter-α-trypsin inhibitor heavy chain 4 (ITIH4) in serum and milk of cows with subclinical mastitis caused by Streptococcus spp. (STR) and coagulase-negative Staphylococcus spp. (CNS) and healthy cows. The blood and milk samples were obtained from 60 mid-lactation, multiparous Holstein-Friesian cows from 7 herds in the Lublin region of Poland. In the milk samples from 40 cows with subclinical mastitis, Streptococcus spp. and CNS were isolated. The ITIH4 was significantly higher in serum of cows with subclinical mastitis caused both by STR and CNS compared with healthy cows. One hundred percent of animals infected with Streptococcus spp. and 89% of animals infected with Staphylococcus spp. showed ITIH4 concentration in sera higher than 0.5 mg/mL. The concentration of ITIH4 in milk also was significantly higher in cows with subclinical mastitis caused by Streptococcus spp. and Staphylococcus spp. compared with the control group. Seventy percent of cows infected by STR and CNS showed ITIH4 concentration in milk higher than 2.5 μg/mL. Milk ITIH4 concentration higher than 5 µg/mL was found in 55% of animals infected with Streptococcus spp. and in 40% of animals infected with Staphylococcus spp. No statistically significant differences were observed in ITIH4 concentrations both in serum and in milk between the studied unhealthy animal groups. These results suggest that ITIH4 may be used in the future as a novel diagnostic marker in serum and in milk of subclinical mastitis in cows.     

Total mercury levels in muscle tissue of swordfish (Xiphias gladius) and bluefin tuna (Thunnus thynnus) from the Mediterranean Sea (Italy).

This study was carried out to determine the current levels of total mercury in the muscle tissue of swordfish (Xiphias gladius) and bluefin tuna (Thunnus thynnus) caught in the Mediterranean Sea with the purpose of ascertaining whether the concentrations exceeded the maximum level fixed by the European Commission Decision. In addition, specimens of each species were divided into different ranges of weight to investigate the influence of size on mercury accumulation in order to provide data upon which commercial fishing strategies and marketing of swordfish and bluefin tuna may be based. Higher mean levels of total mercury were found in bluefin tuna (1.02 microg g(-1) wet wt) than in swordfish (0.49 microg g(-1) wet wt). In 4.3% of swordfish and in 44.3% of bluefin tuna analyzed, total mercury concentrations exceeded the maximum level fixed by the European Commission Decision (Hg = 1 microg g(-1) wet wt). Besides, for bluefin tuna the total mercury level variability observed, due to size, suggests that there should be greater regulatory control by the authorities.     

Expression and purification of the recombinant mustard trypsin inhibitor 2 (MTI2) in Escherichia coli

The mustard trypsin inhibitor 2, MTI2, was expressed in Escherichia coli. A specific procedure for its production and purification is described. The recombinant protein was recovered by protein extraction from the insoluble fraction, then renatured and purified by ion exchange and gel filtration chromatography. Finally, the inhibitory activity against trypsin was also determined.     

Physiological and molecular study on the anti-obesity effects of pineapple (Ananas comosus) juice in male Wistar rat

Food Science and Biotechnology - The present study was performed to assess anti-obesity effects of raw pineapple juice in high fat diet (HFD)-induced fatness. Based on food type, rats were divided...     

刺葡萄成年植株移栽当年结果试验

刺葡萄属山葡萄种群,因其耐高温、高湿、低光照和高抗病性,在南方作为经济和园林作物已有多年的品种选育和栽培历史。为了检验刺葡萄品种在种植地的适应性、变异性及快速成园,移栽成年植株是可选之法。但通常情况下,大树移栽后当年挂不了果,主要是由于移栽后大树根系发育不健全,营养供给不上,树体较弱,需要一定时间适应当地的气候和土壤,而且由于树体本身抗性下降,病虫害发生严重,所以实现当年挂果必须克服树体本身的生理障碍。本文主要就刺葡萄大树移栽实现当年挂果的可行性进行探讨。     

Comparative study of the influence of an inhibitor of monoaminooxidase (nialamide) on the calcium and phosphorus metabolism in slow and fast-growing rats

Nialamide was supplied to slow-growing animals in doses of 20 mg/100 g of diet for 15 or 30 days. The dose for fast-growing animals was 10 mg/100 g of diet. The digestive utilization of calcium and phosphorus decreases significantly when adult slow-growing rats receive the drug for 30 days. This fall is already important in fast-growing rats when they receive nialamide for only 15 days. In the same way the falls in the retention of calcium and phosphorus in adult rats are only evident when the period of treatment is through 30 days, even females being in negative balance of phosphorus. The amount of calcium retained decreases significantly in fast-growing rats and so does phosphorus impressively after only 15 days of treatment.