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1.
Manipulated Mouse Embryos as Bioassay System for Water Quality Control   总被引:1,自引:0,他引:1  
Mouse pronuclear stage embryos with intact slit zona pellucida (manipulated) were cultured in vitro until the hatched blastocyst stage in simplex optimized medium with higher K+ concentration (KSOM) prepared with three different water types: tap, deionized reverse osmosis (D‐O) water and Milli‐Q system (M‐Q) water. The culture media were supplemented with or without protein and ethylenediaminetetraacetic acid (EDTA, disodium salt). The rates of hatched blastocysts were significantly affected (p < 0.01) by micromanipulation, protein supplement and water source. The water source has no influence (p > 0.05) on development in EDTA‐supplemented protein‐free culture media, whereas in EDTA‐ and protein‐free culture media, the water quality significantly (p < 0.001) affected the rates of development, with higher rates in media prepared with M‐Q water. The micromanipulated embryos showed higher sensitivity to the water quality (p < 0.01). It worth mentioning that the rates of hatched blastocysts in protein‐free culture media were very low (0–7.5%). Furthermore, the three different water types were analysed by measuring the electrical conductivity, inorganic ions, total organic carbon and endotoxins to evaluate the purity. M‐Q water showed the lowest levels of inorganic ion, total organic carbon and endotoxin concentrations. We concluded that manipulated mouse embryos are good system to evaluate the quality of water used in biological system.  相似文献   
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To assess the effect of the angiotensin‐converting enzyme (ACE) inhibition on the efficiency of the fixed‐time artificial insemination (TAI), 69 goats were divided randomly into two groups: enalapril (n = 35) and control (n = 34). In the experiment, all animals underwent the protocol of fixed‐time artificial insemination for 12 days. Enalapril group received enalapril maleate dissolved in saline (Enalapril, Lab Teuto Ltda) subcutaneously at the following doses: 0.2 mg/kg/day in D0‐D2; 0.3 mg/kg/day in D3‐D6 and 0.4 mg/kg/day in D7‐D11. The control group received the corresponding volume of 0.9% saline solution. We performed a single insemination 36 hr after sponge removal using frozen semen from two adult male goats with recognized fertility. The ultrasound pregnancy diagnosis was 30 days after the artificial insemination (AI). There was significant increase in pregnancy rates and twinning as well as a decrease in foetal loss in animals receiving enalapril (p < .01). The use of ACE inhibitors during the TAI protocol was shown to be a promising alternative to increase the efficiency of such reproductive biotechnology.  相似文献   
4.
It is known that active peroxidase isozymes exist in mature wood of Norway spruce (Picea abies L. Karst.) and that they remain active for years and are found even in the heartwood (in Scots pine), where all cellular activity has ceased. This peroxidase activity was utilised in the impregnation of wood blocks with a natural monolignol, coniferyl alcohol and hydrogen peroxide. The hypothesis was that the internal wood peroxidases would oxidise the added monolignol and bind it stably into the cell wall matrix, which could hinder fungal decay. Since coniferyl alcohol is not very soluble in water, the impregnation was done under vacuum with an acetone–water solution containing 10% coniferyl alcohol and 0.4 mM H2O2 at room temperature (ca. 0.02 g of coniferyl alcohol was added to 1 g of wood). After impregnation, dimers of coniferyl alcohol and free coniferyl alcohol were found in acetone extracts with GC–MS analysis. Penetration of coniferyl alcohol and non-extractable reaction products were studied from the wood blocks with FTIR PAS technique. The wood samples treated were also subjected to a fungal decay test with Coriolus versicolor. This treatment hindered fungal decay in a 60-day experiment and led to a dry weight loss of 8.8% in comparison with 19.9% in the control. The reactions of coniferyl alcohol and H2O2 in the presence of peroxidases are discussed as well as the use of monolignols to increase wood decay resistance.  相似文献   
5.

Background

The aims of this study were to investigate the prevalence of Campylobacter species in Swedish dogs, to identify the species of the Campylobacter isolates and to genotype the C. jejuni isolates. Young and healthy dogs were targeted and the sampling was performed at 11 veterinary clinics throughout Sweden from October 2011 to October 2012. Faecal swab samples were collected and sent to the laboratory at the National Veterinary Institute (SVA) for isolation of Campylobacter, speciation and genotyping.

Results

Campylobacter spp. were isolated from 67 of the 180 sampled dogs which yields an overall prevalence of 37%. The most prevalent species of Campylobacter among the participating dogs was C. upsaliensis with 52 of the 67 identified isolates. A lower prevalence was observed for C. jejuni with seven identified isolates and one isolate was identified as C. helveticus. Multi-locus sequence typing (MLST) was carried out on the seven C. jejuni isolates and all sequence types that were found are also commonly found in humans. The dogs were divided into three age groups; 1) under 12 months, 2) 12 to 23 months and 3) 24 months and older. The highest prevalence was found in the two younger age groups. Dogs shedding C. jejuni were between 3–12 months of age while dogs shedding C. upsaliensis were found in all ages.

Conclusions

The present investigation finds that Campylobacter spp. known to cause campylobacteriosis in humans are present in Swedish dogs. The results suggest an age predisposition where dogs under 2 years of age are more likely to shed Campylobacter spp. than older dogs. The most commonly isolated species was C. upsaliensis followed by C. jejuni, which was only detected in dogs up to 12 months of age. All C. jejuni isolates identified in the present study were of the same MLST types that have previously been described both in humans and in animals. The awareness of the Campylobacter risk of healthy young dogs may be an important way to reduce the transmission from dogs to infants, young children and immunocompromised adults.  相似文献   
6.
The aim of this study was to evaluate the reproductive performance of three parities of gilts treated or not treated with gonadotropin to induce puberty. Sixty gilts received 600 IU of equine chorionic gonadotropin (eCG) followed by 2.5 mg of porcine luteinizing hormone (LH) 72 h later. Fifty‐nine other gilts were exposed only to a mature boar for 15 min twice daily. Artificial insemination (AI) was performed at 0, 12 and 24 h after the detection of oestrus, and gestation was confirmed by ultrasound after 35 days. Sows were inseminated at the first post‐weaning oestrus. The total numbers of piglets born, piglets born alive, stillborn, mummified foetuses, as well as pregnancy and farrowing rates were evaluated for each of the three parities. Culling rates, farrowing intervals and weaning‐to‐oestrous intervals (WEI) were also analysed. Mean age at puberty and oestrous manifestation were not significantly different between treatments (p = 0.0639; 179.20 ± 17.52 compared with 173.96 ± 16.94, 91.66% compared with 94.92%) across the experimental period. However, females that underwent puberty induction showed modest increases both in the number of total pigs born and in the number of piglets born alive. In conclusion, puberty induction through exogenous gonadotropin administration in field conditions did not induce a more concentrated first oestrous manifestation, but trended to a modest increase in the number of pigs born alive in the first parity and a reduced culling rate during the first gestation.  相似文献   
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Rotaviruses are important human and animal pathogens with high impact on public health and livestock industry. There is little evidence about the cross-species pathogenicity and extra-intestinal infections of animal and human reassortant rotaviruses, particularly based on all 11 genotyping data. In this study, the bovine triple reassortant KJ56-1 strain harboring two bovine-like genome segments, eight porcine-like genome segments, and one human-like genome segment was used to evaluate the cross-species pathogenicity in its parent species, calves and piglets, and to determine its abilities of causing viremia and extra-intestinal tropisms in piglets. The KJ56-1 strain isolated from a calf diarrhea fecal sample replicated without causing diarrhea and severe intestinal pathology in calves. However, piglets inoculated with this strain showed persistent severe diarrhea and marked intestinal pathology. By SYBR Green real-time RT-PCR, viral RNA was detected in the sera, mesenteric lymph node, lung, liver, choroid plexus, and cerebrospinal fluid in the experimental piglets. An immunofluorescence assay confirmed viral replication in these extra-intestinal organs and tissues. These results indicated that the bovine triple reassortant KJ56-1 strain was virulent to piglets but not to calves. Our data also demonstrated that the reassortant rotaviruses had the ability to spread to the bloodstream from the gut, enter and amplify in the mesenteric lymph node, and disseminate to the extra-intestinal organs and tissues.  相似文献   
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10.
Timely onset of postpartum ovarian activity is vital for optimal reproductive performance of dairy cows. Much depends upon genetic constitution of an animal although several factors interplay to govern the onset of postpartum ovarian activity. South Asian zebu cattle have much longer service period when compared with other exotic or crossbred cattle reared in the same Asian environment, which suggests differences in their genetic makeup. However, the cows with same genetic configuration expressed better reproductive potential when reared under different environment, such as in Brazil and Mexico, which suggests the role of extrinsic factors such as management, nutrition, environment and disease conditions. Better management of animals (provision of proper shade, water and housing, efficient oestrous detection and timely insemination), good quality nutrition supplemented with appropriate minerals and vitamins, prevention of diseases (vaccination, deworming, suitable therapeutic interventions) and application of biotechnology have helped in improving postpartum ovarian activity and, therefore, reproductive performance of zebu cattle in Asia. No comprehensive study appears to have been carried out on the various aspects of reproduction in zebu cattle reared under South Asian socio-agro-climatic conditions. This paper is a modest effort to collect what ever information available and to critically review the postpartum ovarian activity in zebu cattle with special reference to the effect of the various managemental practices and pharmacological interventions.  相似文献   
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