Effects of osmolality on water, electrolytes and VFAs absorption from the isolated ruminoreticulum in the cow

Effect of the osmolality on the absorption of water, electrolyte and VFAs from the isolated ruminoreticulum under normal feeding condition were investigated in a series of the study to evaluate the rumen as a potential site of absorption in oral fluid therapy of adult cattle. Thirty of 40 l of the test solutions with varying osmotic pressure (100, 200, 300 and 500 mosmol/L, pH 6.8) were prepared using different concentrations of electrolytes and VFAs. These were infused into the isolated and emptied ruminoreticulum, and the absorption rate of water and each components were studied for 3 hrs. Marked absorption of water was observed with solutions more hypotonic than rumen fluid, the extent of which was more extensive with less osmotic pressure; the absorption rate as high as 47.6% was obtained with a solution 100 mosmol in osmotic pressure. When hypertonic solution (500 mosmol/L) was infused, however, water was transported on the contrary from the blood to the rumen. Absorption rates of electrolytes such as Na, K and Cl were increased according to the elevation of osmolalities and their concentrations in the test solutions. VFAs were also absorbed in large quantities (23.9-74.5%) in any test solutions, though the absorption rates were significantly decreased with the elevation of osmolalities. These results may indicate that the ruminal wall has a high absorptive function for water, electrolytes and VFAs when the osmolalities and the concentration of solutes in the ruminal fluid are maintained within a certain range. Furthermore, it is thought that they may work as a rational support for a possible oral fluid therapy even in adult cows.     

The osmolality of caecal contents in piglets following weaning

Pigs weaned for five days had caecal contents with significantly lower osmolalities than those of unweaned animals of the same age. Supplementation of a standard weaning diet with therapeutic levels of oxytetracycline to suppress the normal large intestinal microbial flora did not significantly further reduce osmolarity of caecal contents after weaning. This observation suggests that microbial activity in the large intestine may not be sufficiently developed by five days after weaning to have a major influence on absorptive processes at that site. Incomplete development of the large intestinal microflora may be one more factor which acts to predispose the young pig to diarrhoea after weaning.     

Elimination of Salmonella spp. by lactic acid

The aim of the present study was to determine the elimination of Salmonella by different lactic acid concentrations in microbiological media and on turkey carcass elements. The average bacteria counts in the control samples without lactic acid were: 1.8 x 10(8), 1.1 x 10(8) and 2.3 x 10(8), for S. Enteritidis, S. Anatum and S. Typhimurium, respectively. The concentration of lactic acid of 0.1% in the agar media completely inhibited the growth of all Salmonella strains. At 0.05% lactic acid concentration, the bacteria count was 2 log cycles lower and at a 0.03% solution it was 1 log cycle lower than that in the respective control samples. However, the examined bacteria developed in the presence of 0.02% and 0.01% lactic acid concentrations and their counts fell into the same log brackets. An analysis of the experimental results obtained from turkey carcass elements immersed in the lactic acid solution showed that the Salmonella identification rate was determined by the bacteria inoculum spread over the turkey carcass surface. The contamination of 10(1) CFU of Salmonella spread onto the turkey carcass was completely eliminated by immersing the carcasses in 1% or 2% lactic acid solutions. The contamination of turkey carcass elements with 10(2) CFU of S. Enteritidis and their immersion in 2% lactic acid solution for 15 min resulted in the reduction of the number of samples with Salmonella compared to the number of control samples with Salmonella. At contaminations of 10(3) CFU on the carcass surfaces, the immersions in 1% and 2% lactic acid solutions did not reduce Salmonella counts.     

公牛精子在四种介质中的品质变化

６头荷斯坦成年公牛，每头采集３次精液，分别利用精子穿透试验和姬姆萨染色法，评定精子在发情母牛子宫颈粘液、ＶＢ１２、稀释液和解冻液等四种介质中的泳动速度、顶体完整车、畸形率以及精子有效存活时间的变化。结果表明，精子泳动速度在不同介质中的差异极显著，在宫颈粘液中显著高于其它介质，在ＶＢ１２中最低；不同介质中精子顶体完整率的差异不明显；畸形率在ＴＢ１２中显著低于解冻液；精子有效存活时间在稀释液和解冻液中显著高于ＶＢ１２中。不同公牛在四种介质中的反应亦有一定差异。     

A synthetic, selective culture medium for Pseudomonas aeruginosa

Selective and differentiating media consisting of simple chemical components have been developed, both in solid and in liquid form, for culturing Pseudomonas aeruginosa from foodstuffs. These media work on the basic principle that Gram-negative bacteria can utilize ammonia as inorganic nitrogen source. This principle has already been utilized for developing a culture medium for coliform bacteria (Szita and Biró, 1986; Szita et al., 1988). P. aeruginosa can produce the ammonia needed for its growth by decomposing acetamide. The liquid synthetic medium was compared with the nitrofurantoin broth and the solid one with cetrimide agar by parallel inoculation of 60 raw milk samples and 20 P. aeruginosa pure cultures. The main advantages of the synthetic media are their high selectivity, high sensitivity and rapidity. Owing to their advantageous properties, the new media can be recommended for replacing cetrimide agar and nitrofurantoin broth.     

Importance of oil overlay for production of porcine embryos in vitro

Technologies to edit the zygote genome have revolutionized biomedical research not only for the creation of animal models for the study of human disease but also for the generation of functional human cells and tissues through interspecies blastocyst complementation technology. The pig is the ideal species for these purposes due to its great similarity in anatomy and physiology to humans. Emerging biotechnologies require the use of oocytes and/or embryos of good quality, which might be obtained using in vitro production (IVP) techniques. However, the current porcine embryo IVP systems are still suboptimal and result in low monospermic fertilization and blastocyst formation rates and poor embryo quality. During recent years, intensive investigations have been performed to evaluate the influence of specific compounds on gametes and embryos and to avoid the use of undefined supplements (serum and serum derivate) in the incubation media. However, little consideration has been given to the use of the mineral oil (MO) to overlay incubation droplets, which, albeit being a routine component of the IVP systems, is a totally undefined and thus problematic product for the safety of gametes and embryos. In this review, we provide an overview on the advantages and disadvantages of using MO to cover the incubation media. We also review one important concern in IVP laboratories: the use of oils containing undetected contamination. Finally, we discuss the effects of different types of oils on the in vitro embryo production outcomes and the transfer of compounds from oil into the culture media.     

Development of Biofilter Devices for Nutrient Removal From Wastewater

Nutrient pollution still remains one of the greatest challenges to water quality contributing to harmful contaminations water sources,and costly impacts on the economy.This review considers the development of the biofilters,focusing on the design features that have the most influence on their technical and economic performance.Modern biofilters,based on SAF technology,are particularly suitable for sewage treatment works with throughput rates up to 1,000m~3/d.The main advantages of SAF plants include high quality effluent,low power usage and small footprint.A wide range of filter media are available for different designs,which could be configured for both aerobic and anaerobic treatment in BOD and/or ammonia reduction applications.The two most important parameters for filter media are their Specific Surface Area(SSA,m~2/m~3)and Void Fraction(percentage of void volume or porosity).However,due to the risk of clogging by suspended solids or excess sludge the media used for this application should be limited to about 500m~2/m~3.In tertiary treatment or river restoration applications where the influents tend lack any readily biodegradable substrates,SAF design provides the most appropriate choice for further development to produce effluents with very low nutrient levels.     

中国白兔血液和器官组织中硒含量的测定

选择40只中国白兔测定其血液和器官组织中硒的含量.分别将其血液、肝脏、肾脏、心脏和腿肌用硝酸和高氯酸消化使硒游离出来.在微酸性环境下,硒与2,3-二氨基萘(DAN)生成有较强荧光的物质,用环己烷萃取,在激发波长378nm、荧光波长518nm处测定其荧光强度,从而确定硒的含量.     

Reference blood chemical values in ostriches (Struthio camelus)

Reference blood chemical values were determined for 65 male and 61 female ostriches (Struthio camelus) 1 month to 72 months of age. Plasma values of glucose, total protein, triglycerides, cholesterol, uric acid, urea, bilirubin, creatinine, osmolality, electrolytes, and enzyme activity were determined. In general, differences in various values appeared mainly among age groups and less so between sexes. Older ostriches had lower plasma glucose values and enzyme activity than did younger ostriches. High plasma sodium and chloride concentrations in young ostriches correlated with high plasma osmolalities. Plasma calcium values were lower in laying ostriches. Uric acid concentrations were markedly higher than were urea concentrations in all ostriches.     

三硫钼酸钠对大鼠镉代谢的影响

补饲三硫钼酸钠,可以减少镉在生命器官内沉着,促进镉从粪、尿中排泄。在镉污染期,日粮中补饲硫钼酸钠,可使粪便镉排泄增多12.95％～33.66％,尿液镉排泄增多7.56％～21.66％,短期试验中显示增加更多。在粪中镉增多同时,钼浓度也增多,两者间呈正相关系（r=0.9596）。当停止镉污染以后,日粮中继续补饲I7ppm、10ppm、5ppm Mo的三硫钼酸钠,可使粪便镉排泄分别增加65.72％、10.18％和22.33％,尿液镉排泄分别增加109.17％、34.20％和50.36％,与未补钼的镉中毒大鼠相比,差异非常显著（P<0.01)。硫钼酸盐促进镉排泄的机理与它可使MT-Cd解离,使Cd转入分子量较大的蛋白质,因而有利于镉排泄有关。     

Onchocerca raillieti: Release from skin snips,maintenance in vitro and periodicity of microfilariae

Several media were tested for the release of Onchocerca raillieti microfilariae from skin snips and for their subsequent in vitro maintenance. Tyrode's solution containing 20% equine serum and antibiotics was the best medium tested, followed by phosphate buffered saline. Tyrode's solution alone or distilled water were poor media. A temperature 7–12°C lower than the host's body temperature favoured release of the microfilariae from skin snips. The microfilariae were best maintained at 4–10°C, when they remained alive for up to 5 days. O. raillieti microfilariae had an evening periodicity which could be related to a possible vector's peak of feeding activity.Part of this work was carried out when both authors were at the Department of Parasitology, Faculty of Veterinary Science, University of Khartoum, Khartoum North, Sudan.     

The structure of bovine secretory component

Bovine secretory component (SC) has been cleaved with trypsin into a series of fragments and their N-terminal amino acid sequences have been determined. The close homology with the known sequence of human SC has enabled the sequential order of the fragments to be deduced. The results indicate that bovine SC consists of a single glycosylated polypeptide chain (Mr 74,000) folded into five globular immunoglobulin-like domains. A protein (Mr 94,000) has been isolated from detergent solubilised bovine epithelial membranes from liver, intestine and mammary gland. This membrane protein is specific for the binding of J-chain linked IgM and IgA dimers. It can be proteolytically cleaved into a water soluble SC-like portion and a detergent soluble hydrophobic portion. Bovine SC is therefore most likely to be the extracellular part of an epithelial receptor which mediates the transport of IgA dimers to mucosal surfaces. The various tryptic fragments from bovine SC have been shown to differ in their relative binding affinities for IgM and IgA dimers. The results imply that the first three domains of bovine SC are most involved in binding and domains 4 and 5 play subsidiary roles. Computerized prediction and modelling methods have been used to deduce possible tertiary and quaternary structures for SC. There are good indications that the molecule has an elonaged "zig-zag" structure stabilized by longitudinal inter-domain contacts. A model of SC bound to IgA dimer is presented.     

Progress in the capture, manipulation, and delivery of medical media and its impact on education, clinical care, and research

In this article, advances in the application of medical media to education, clinical care, and research are explored and illustrated with examples, and their future potential is discussed. Impact is framed in terms of the Sloan Consortium's five pillars of quality education: access; student and faculty satisfaction; learning effectiveness; and cost effectiveness. (Hiltz SR, Zhang Y, Turoff M. Studies of effectiveness of learning networks. In Bourne J, Moore J, ed. Elements of Quality Online Education. Needham, MA: Sloan-Consortium, 2002:15-45). The alternatives for converting analog media (text, photos, graphics, sound, video, animations, radiographs) to digital media and direct digital capture are covered, as are options for storing, manipulating, retrieving, and sharing digital collections. Diagnostic imaging is given particular attention, clarifying the difference between computerized radiography and digital radiography and explaining the accepted standard (DICOM) and the advantages of Web PACS. Some novel research applications of medical media are presented.     

Comparative studies on enrichment and selective media for isolation of Salmonellae from faecal specimens.

Enrichment media (tetrathionate, selenite and Rapp ap ort broths) and selective media (desoxycholate citrate agar and brilliant green agar) were tested in different combinations to ascertain their capacity for isolation of salmonella bacteria. The material consisted of 299 samples of cattle faeces from two herds infected with salmonella (Table 1), and of 111 artificially contaminated samples of pig faeces (Table 3). The tetrathionate and selenite broths were equally useful for the material as a whole, whereas the results varied between different species of salmonella which is of great practical interest. The number of salmonella isolations was much lower when enrichment with Rappaport broth was used. The rate of salmonella isolations can often be increased by parallel enrichments with two different media. Of the selective agar media tested, brilliant green agar was superior to desoxycholate citrate agar.     

Bestimmung der osmotischen Resistenz von Eberspermien und deren Beziehungen zur Konservierungsfähigkeit von Samenproben

Contents Determination of the osmotic resistance of boar spermatozoa and the relations to sperm freezing and long storage The osmotic behaviour of fresh boar spermatozoa (482 ejaculates from 34 A.I. boars) was examined in a standard medium but with different osmotic pressures ranging from 150 mosm/kg till 500 mosm/kg. The percentage of spermatozoa with normal acrosomal ridge (NAR) was determined after incubation of 0.2 ml fresh semen in 3 ml of the osmotic test solutions at 39° C for 15 and 120 min. In the non-isotonic media % NAR decreased and could be quantified depending to incubation time and to the different osmolalities; NAR decreased strongest at 150 or 500 mosm/kg and after 120 min incubation time. Differences in % NAR were large between ejaculates and between boars but low within boars and statistically significant correlations had been found to % NAR and motility in froren/thawed semen samples or stored samples. Still higher correlations were found by calculation of an osmotic resistance test-value (ORT-value) which is defined as follows: ORT = 1/2 % NAR in isotonic medium/(after 15 min) +% NAR in 150 or 500 mosm/kg/(after 15 or 120 min) ORT-values can be calculated for hypotonic (150 mosm/kg) as well as for hypertonic (500 mosm/kg) test solutions and for 15 and 120 minutes incubation time. The hypotonic ORT-value for 120 min. is the most accurate; the values varied from 34 till 83 between ejaculates and from 44 till 76 between boars with a low variability within boars. Grouping of boars by their ORT-values in “good”, “moderate” and “poor” corresponded to a similar grouping of these boars by their semen quality (% NAR and motility) in preserved semen samples. Also a grouping of single ejaculates by their ORT-values corresponded to a similar qualitative classification of these ejaculates. ORT seems to become a good and practicable assessment test for the selection of boars suitable dor deep freezing or long storage of their spermatozoa. On the other hand preservation techniques too can be examined by ORT. But more investigations with this test must be done especially its relation to the fertilization capacity of semen samples with different ORT-values.     

The effect of different isolation procedures on canine leucocyte populations and on lectin-induced lymphocyte proliferation

Proliferation assays performed on peripheral blood mononuclear cells (PBMC) are commonly used in experimental and clinical immunology. A prerequisite for an in vitro assay is the ability to obtain relatively pure populations of mononuclear cells from whole blood, as contaminating polymorphonuclear cells may affect the proliferation of lymphocytes. Purification of canine leucocytes from whole blood is associated with difficulties in obtaining pure lymphocytes in high yields. The aim of this study was to optimize the lymphocyte purification from canine whole blood in terms of total cell recovery and purity, while not influencing the proliferation capacity of the isolated cells. To acquire optimal isolation of canine lymphocytes several density gradient media of different densities and osmolalities were examined. For optimal phagocyte removal, pre-treatment of whole blood with carbonyl iron/arabic gum and/or adherence to fibrinogen pre-coated polystyrene tissue flasks were examined. Lectin-induced proliferation was used as measurement of cell activity of the obtained cell fractions after the different separation procedures. Canine blood pre-treated with carbonyl iron/arabic gum followed by density gradient centrifugation with medium 'G' (density: 1.079 g/cm(3), osmolality: 256 mOsm) and adherence to pre-coated polystyrene tissue flask obtained the best PBMC cultures with a median lymphocyte purity of 88% and a median yield of recovered lymphocytes of 54%. This culture also resulted in the highest proliferation and subsequently the highest stimulation index upon lectin stimulation.     

A review of the factors affecting the survival of donkeys in semi-arid regions of sub-Saharan Africa

The large fluctuations seen in cattle populations during periods of drought in sub-Saharan Africa are not evident in the donkey population. Donkeys appear to have a survival advantage over cattle that is increasingly recognized by smallholder farmers in their selection of working animals. The donkey's survival advantages arise from both socioeconomic and biological factors. Socioeconomic factors include the maintenance of a low sustainable population of donkeys owing to their single-purpose role and their low social status. Also, because donkeys are not usually used as a meat animal and can provide a regular income as a working animal, they are not slaughtered in response to drought, as are cattle. Donkeys have a range of physiological and behavioural adaptations that individually provide small survival advantages over cattle but collectively may make a large difference to whether or not they survive drought. Donkeys have lower maintenance costs as a result of their size and spend less energy while foraging for food; lower energy costs result in a lower dry matter intake (DMI) requirement. In donkeys, low-quality diets are digested almost as efficiently as in ruminants and, because of a highly selective feeding strategy, the quality of diet obtained by donkeys in a given pasture is higher than that obtained by cattle. Lower energy costs of walking, longer foraging times per day and ability to tolerate thirst may allow donkeys to access more remote, under-utilized sources of forage that are inaccessible to cattle on rangeland. As donkeys become a more popular choice of working animal for farmers, specific management practices need to be devised that allow donkeys to fully maximize their natural survival advantages.     

Evaluation of microbial culture techniques for the isolation of Pythium insidiosum from equine tissues.

The purpose of this study was to evaluate the effects of sample handling, storage, and culture techniques on the isolation of Pythium insidiosum from infected equine tissues. Tissue and kunker samples obtained immediately posteuthanasia from a horse with subcutaneous pythiosis were used to assess the effects of sample type (kunkers vs. tissues), media type (selective vs. nonselective), storage technique, and storage time on P. insidiosum isolation rate. Overall, isolation rates were higher from fresh kunkers (94.6%) and stored kunkers (76.4%) than from fresh tissues (8.3%) or stored tissues (4.6%). Isolation of P. insidiosum also occurred more often on antibiotic-containing media than on nonselective media for both fresh and stored samples. For samples that were stored for 1-3 days prior to culture, P. insidiosum isolation rates were highest for the following techniques: kunkers stored at room temperature and plated on selective media (100%), kunkers stored at 4 C and then plated on either nonselective (91.7%) or selective (95.8%) media, kunkers stored on cold packs and then plated on either nonselective (93.8%) or selective (100%) media, kunkers stored in ampicillin solution and plated on selective media (100%), and kunkers stored in ampicillin/gentocin solution and plated on selective media (87.5%). For samples stored for 4-5 days, P. insidiosum isolation rates were highest for kunkers stored at 4 C and then plated on either nonselective (81.3%) or selective (87.5%) media, kunkers stored in ampicillin solution and then plated on selective media (87.5%), and kunkers stored in ampicillin/gentocin solution and plated on selective media (87.5%). Results of this study suggest that optimal isolation rates of P. insidiosum from infected equine tissues are achieved by culturing fresh kunkers on selective media. For samples that cannot be processed immediately, acceptable handling techniques include storage at room temperature for up to 3 days, refrigeration for up to 5 days, shipping on cold packs, and storage in antibiotic solution, each combined with subsequent inoculation on selective media.     

Physiological but not morphological adjustments along latitudinal gradients in a human commensal species,the Eurasian tree sparrow

Human commensal species take advantage of anthropogenic conditions that are less likely to be challenged by the selective pressures of natural environments. Their morphological and physiological phenotypes can therefore dissociate from habitat characteristics. Understanding how these species adjust their morphological and physiological traits across latitudinal gradients is fundamental to uncovering the eco-physiological strategies underlying coping mechanisms. Here, we studied morphological traits in breeding Eurasian tree sparrows (ETSs; Passer montanus) among low-latitude (Yunnan and Hunan) and middle-latitude (Hebei) localities in China. We then compared body mass; lengths of bill, tarsometatarsus, wing, total body, and tail feather; and baseline and capture stress-induced levels of plasma corticosterone (CORT) and the metabolites including glucose (Glu), total triglyceride (TG), free fatty acid (FFA), total protein, and uric acid (UA). None of the measured morphological parameters varied with latitude except in the Hunan population, which demonstrated longer bills than those in other populations. Stress-induced CORT levels significantly exceeded baseline levels and decreased with increasing latitude, but total integrated CORT levels did not vary with latitude. Capture stress-induced significantly increased Glu levels and decreased TG levels, independent of site. However, the Hunan population had significantly higher baseline CORT, baseline and stress-induced FFA levels, but lower UA levels, which differed from other populations. Our results suggest that rather than morphological adjustments, physiological adjustments are mainly involved in coping mechanisms for middle-latitude adaptation in ETSs. It is worth investigating whether other avian species also exhibit such dissociation from external morphological designs while depending on physiological adjustments.     

组成型雄烷受体与公猪膻味物质代谢关系的研究进展

饲养不去势公猪较去势公猪而言具有很多优势,但导致公猪膻味物质雄烯酮和粪臭素一直是限制其饲养的主要瓶颈。作者综述了组成型雄烷受体对膻味物质雄烯酮和粪臭素代谢关系的研究,为寻求一种较合适的方法减少公猪膻味提供参。