Trichinella spiralis infection induces β-actin co-localized with thymosin β4

A serological survey for Neospora caninum and Besnoitia besnoiti was carried out in beef and dairy cattle in South Australia. Serum samples of dairy cattle (n=133) from 9 properties and tank milk samples from a further 122 dairy herds were tested. An additional 810 sera from beef cattle from 51 properties were also tested. Testing at the individual animal level by IDEXX NEOSPORA X2 Ab test ELISA revealed a low prevalence of N. caninum antibodies of only 2.7% (95% CI; 1.6-3.7%) sera positive, as did the milk testing that showed 2.5% (95% CI; 1.4-3.6%) of tank milks being positive. At the herd level, 29.4% (95% CI; 16.9-41.9%) of beef, and 44.4% (95% CI; 12.0-76.9%) of dairy cattle herds showed serum antibodies. The highest within-herd prevalence in beef was 20% and 25%in dairy, which explains the low herd prevalence in dairy detected by bulk milk testing. Testing for B. besnoiti antibodies by PrioCHECK(?) Besnoitia Ab 2.0 ELISA initially identified 18.4% (95% CI: 15.8-21.0%) of 869 individual cattle sera as positive by ELISA at the manufacturer's suggested cut-off threshold (15 PP). Additional tests by immunoblot and IFAT, however, could not confirm any of the ELISA results. The use of a higher (40 PP) threshold in the ELISA is suggested to improve specificity. There is thus no evidence of B. besnoiti infection in South Australian cattle.     

Detection of β2-agonists in milk replacer

₂-Agonist drugs may be illegally used as growth promoters for feedlot calves, when mixed into milk replacer immediately before feeding. To check for the presence of clenbuterol, salbutamol and terbutaline in such food, an analytical system was established using a screening method based on two commercial qualitative competitive ELISA tests, with antibodies raised against the arylamino group and thet-butyl group. The extraction procedure was based on precipitation of the milk samples with acetonitrile followed by filtration. The absence of any significant interference by other substances in the filtrate allowed detection of ₂-agonist drugs in spiked samples at the lowest concentration having a repartitioning effect (50 ppb for clenbuterol, mabuterol and terbutaline, 500 ppb for salbutamol). In view of a false positive response with tetracycline in milk samples and a cross-reaction between clenbuterol and mabuterol, an HPLC-MS technique was developed which, after extraction and purification of the samples with SPE C18 Polar Plus, was able to confirm the presence of these drugs. The good recovery after extraction (ranging from 84% to 90.2%) and the low detection limit with this method (250 ng/ml for clenbuterol, mabuterol and terbutaline, and 2.5 µg/ml for salbutamol) allowed easy confirmation and simultaneous detection of the four ₂-agonists at the lowest concentrations at which they are used in adulterated milk for calves.Abbreviations B optical density of the sample - B maximal optical density in total absence of competition - %B/B ₀ percentage of inhibition - ELISA enzyme-linked immunosorbent assay - EIA enzyme immunoassay - HPLC-MS high-performance liquid chromatography-mass spectrometry - m/z mass to charge ratio - ppb parts per billion - ppm parts per million - SPE solid-phase extraction     

Characterization of β-catenin expression in canine osteosarcoma

Osteosarcoma (OSA) is the most frequently occurring malignant primary bone tumour in dogs and children and arises from cells of the osteoblast lineage. Inappropriate Wnt signalling activity has been implicated in human OSA. Altered expression of β-catenin, an integral member of the Wnt signalling pathway, has been associated with numerous human cancers, including OSA. In this study, 30 of the 37 primary canine OSA tissues and 2 of the 3 metastatic OSAs were positive for β-catenin expression as determined by immunohistochemistry, whereas 2 normal bones stained negative for β-catenin. No mutations were identified in exon 3 of β-catenin in the three OSA cases in which DNA sequencing was performed. Finally, there was no relationship between β-catenin expression and overall survival time or disease-free interval. Our results indicate β-catenin is frequently expressed within the cytoplasm of neoplastic cells in canine OSA but contains no detectable mutations in exon 3, similar to human OSA.     

Evaluation of Rat Neutrophil β-adrenergic Receptors by Microphysiometry

Veterinary Research Communications -     

Protein heterogeneity of bovine β-casein in Danish dairy breeds and association of rare β-casein F with milk coagulation properties

A proteomic approach was applied to characterize genetic variation and relative protein content of β-casein (β-CN) in milk from two minor native dairy breeds in Denmark; Red Danish 1970 and Jutland cows in comparison to the major dairy breeds; Danish Holstein and Danish Jersey. Genetic β-CN variants were related to the relative concentration of β-CN. Furthermore, a very high frequency of variant F in the native breeds was found. This was remarkable as this variant is only found in a very low frequency in the major Danish breeds. Novel associations were found between β-CN variant F and milk coagulation properties in the native breeds, which is an important finding for understanding the genetic background for non- and poor coagulating milk and potential exploitation of β-CN variants in selective breeding programs. Furthermore, in Red Danish 1970 a very high prevalence of non-coagulating milk was found (18%).     

Haemophilus influenzae and the β-adrenergic system: A review

Haemophilus influenzae is a bacterium that often can be isolated from the deeper respiratory airways of patients with chronic asthmatic bronchitis. In the present study the effects ofH. influenzae vaccination on guinea pig pulmonary -adrenoceptor number and function (in vitro and in vivo) have been evaluated. Functioning of -adrenoceptors is determined by measuring the -mimetic effect of isoprenaline on the inhibition of anaphylactic mediator release and isolated tracheal strip relaxation. The number of -adrenoceptor binding sites was measured by means of a³H-dihydroalprenolol binding assay.Also the mechanism of action underlying the changes in -adrenoceptor functioning was evaluated. Furthermore, it was established that the effect on the -adrenoceptor system was not specific forH. influenzae and that other respiratory pathogens were also biologically active in this respect.     

Trichinella spiralis infection induces angiogenic factor thymosin β4 expression

Trichinella spiralis (T. spiralis) has been reported to up-regulate the expression of the angiogenic molecule vascular endothelial cell growth factor (VEGF) during nurse cell formation. In order to analyze the induction of angiogenesis by T. spiralis, the expression patterns of angiogenesis-related proteins were investigated by immunohistochemical analysis. VEGF expression was induced in the infected muscles at an early stage of infection (10 days after infection) and diminished after 3 weeks. Thymosin β4, a major factor which induces VEGF, showed increased expression in muscle fibers 10 days after infection, and the expression remained high in the nurse cells for 6 weeks, when the formation of the nurse cell complex was completed. The hypoxia inducible factor (HIF)-1α showed a diffuse expression pattern around the infected muscle fibers and was strongly expressed in inflammatory cells but was not related to the hypoxic condition caused by nurse cell formation. Localization of the hypoxic regions by the hypoxia marker, pimonidazole showed T. spiralis infection does not induce a hypoxic condition in nurse cells. These results suggest that the expression of VEGF and thymosin β4 induce angiogenesis and the expression of thymosin β4 remained elevated to potentially regulate nurse cell formation and maintenance.     

山羊FSH β基因多态性与产羔数的相关性研究

本试验对250只波尔山羊、成都麻羊的FSHβ基因多态性与产羔数的相关性进行了分析。结果发现:在两个品种试验羊的FSHβ基因5′调控区712bp处存在A→G突变,形成A、B 2种等位基因及AA、AB、BB 3种基因型,且A等位基因为优势等位基因。在平均窝产羔数方面,两种山羊初产和经产的平均窝产羔数均为基因型AA基因型AB基因型BB,经产个体的AA型与AB型、BB型差异显著(P0.05),初产个体各基因型间差异不显著(P0.05)。由此推测,FSHβ基因可能是控制山羊繁殖性能的一个主效基因,为下一步育种工作提供了有力的理论依据。     

Point-of-care β-hydroxybutyrate measurement for the diagnosis of feline diabetic ketoacidaemia

Objectives : To evaluate accuracy and precision of a hand‐held ketone meter measuring β‐hydroxybutyrate and to determine its diagnostic performance to rule out ketoacidaemia in diabetic cats. Methods : The ketone meter was validated by calculating within‐day precision at different β‐hydroxybutyrate concentrations and by comparison with a laboratory method. To determine its diagnostic performance to diagnose ketoacidaemia, 217 sets of data (venous blood gas analysis and β‐hydroxybutyrate measurements) were retrospectively analysed. Sensitivities and specificities were calculated with the help of receiver‐operating characteristic curves. Results : The ketone meter reliably detected β‐hydroxybutyrate at concentrations >0·1 mmol/L and reproducibility was acceptable. Measurements highly correlated with laboratory results (r=0·97; P<0·001), but a significant negative bias was found at high concentrations. A β‐hydroxybutyrate concentration of >2·55 mmol/L had a sensitivity of 94% and a specificity of 68% for diagnosing ketoacidaemia. Many cats with high β‐hydroxybutyrate concentrations and normal blood pH had an elevated chloride gap suggestive of superimposed hypochloraemic metabolic alkalosis. Clinical Significance : The commercially available point‐of‐care ketone meter Precision Xtra is a valid tool to measure β‐hydroxybutyrate in diabetic cats. Concentration <2·55 mmol/L enable ketoacidaemia to be excluded and should lead to redirection of differential diagnoses.     

黑曲霉MA-56 β-甘露聚糖酶的生产条件研究

本文通过Plackect-Burman设计及单因素试验,研究了影响黑曲霉菌株MA-56生产β-甘露聚糖酶的主要因子,并优化了影响β-甘露聚糖酶固体生产的因素.结果表明,硫酸亚铁、牛肉膏、磷酸二氢钾和玉米浆粉4个因素对β-甘露聚糖酶生产影响显著,可信度大于90%.但均为产酶负影响因子;尿素、氯化钙和硫酸镁为产酶的正影响因子,但影响不显著.单因子试验表明,黑曲霉菌株MA-56产β-甘露聚糖酶的最适培养基条件为:麸皮8 g,豆粕2 g,魔芋粉0.1 g(以10 g干基为标准).当固形物与加水比10:9,接种孢子悬浮液2.5mL(以一支菌种斜面加30 mL无菌水为标准),300 mL三角瓶中装量7 g培养基,发酵56 h时,产酶量达到2.01×105U/g.     

Effect of β-carotene Supplementation on Italian Trotter Mare Peripartum

When the mare’s estrous cycle resumes in winter, the β-carotene content of hay is depleted. Sixty Italian trotter mares were randomly assigned to a Control or a Treated Group. Treated Group received 1g/d synthetic β-carotene for 15 days from parturition. Blood samples collected at parturition and on days 5, 10 and 15 after partum were analysed for β-carotene, vitamins A, progesterone, 17 β-estradiol, the energy parameters (glucose, cholesterol, NEFA), the protein profile (total protein, albumin, urea) and LDH. Some changes in these measures were attributable to treatment, which significantly affected β-carotene and 17 β-estradiol concentrations. A significant effect was also found on the resumption of estrous activity (χ² test=P<0.052).     

Effect of β-glucosidase on the meat quality and digestibility in broilers

This study investigated the effects of supplementary β-glucosidase on the carcass composition, meat quality, weight of digestive organ and apparent digestibility in male broilers. Two hundred and forty male, 1-day avine broiler chicks were randomly allocated into four treatment groups and fed with corn-soya bean meal supplemented with 0 (control), 0.6, 1.2 and 1.8 U/g of β-glucosidase respectively. The results showed that there were no significant differences (p > 0.05) among groups in carcass composition (percentages of eviscerated yield, half-eviscerated yield, muscle yield of breast and leg). However, adding 0.6 U/g β-glucosidase to the diet not only altered the meat quality by decreasing the drip loss ratio (p < 0.05) and relative lightness (L*) value (p < 0.01), increasing relative redness (a*) value (p < 0.01), but also significantly decreased the pancreas to body weight ratio (p < 0.05), however, with little effect on liver, proventriculus and gizzard to body weight ratio (p > 0.05). The length and width of duodenum villus were not affected by the addition of β-glucosidase, but the coefficients of total tract apparent digestibility of protein and fat increased by 9.02% (p < 0.05) and 7.40% (p < 0.01) respectively; the parameters of ash were not affected by β-glucosidase addition (p < 0.05). This study provided valuable information for evaluation of the effect of supplementary β-glucosidase on the meat quality and digestibility of broilers.     

Role of soybean β-conglycinin subunits as potential dietary allergens in piglets

β-Conglycinin, a major seed-storage protein in soybeans, is one of the primary antigenic proteins responsible for soybean-meal hypersensitivity in weaned piglets. The protein is a heterotrimer composed of subunits α, α′ and β. It is currently unknown which of the β-conglycinin subunits are allergenic for piglets. The aim of this study was to identify potential allergenic subunits of β-conglycinin for soybean sensitive piglets and to characterise these subunits by immunoglobulin (Ig) G and E immunoblotting, ELISA, ‘skin prick’ and whole blood histamine-release testing. The IgG and IgE binding capabilities of the purified α, α′ and β subunits of β-conglycinin were determined by immunoblot analysis and ELISA with sera from β-conglycinin sensitised piglets. Skin prick testing and whole blood histamine release testing were also performed to detect the activated effector cell response to specific allergens. Specific IgG and E antibodies were identified that recognised all three subunits of β-conglycinin in the sera of β-conglycinin sensitised piglets. All three subunits of β-conglycinin elicited positive skin test and specific histamine release responses from the whole blood of β-conglycinin sensitised piglets. These results suggest that all three β-conglycinin subunits are potential allergens for piglets.     

Prevalence of extended-spectrum β-lactamase-producing Escherichia coli and Klebsiella pneumoniae in food-producing animals

To evaluate the diversity of extended-spectrum β-lactamases (ESBL) genes among food-producing animals, 48 isolates of ESBL-producing Escherichia coli isolates were obtained from rectal samples of broilers, layers, beef cattle and pigs, at the slaughterhouse level. ESBL-carrying E. coli were isolated from 60.0% of individual broiler rectal samples, 5.9% of layers, 12.5% of beef cattle and 3% of pigs. One ESBL-producing Klebsiella pneumoniae was isolated from a broiler. The ESBL-positive E. coli isolates from broilers harbored various ESBL genes: bla (SHV-12), bla(CTX-M-2), bla(CTX-M-14), bla(CTX-M-15) and bla(CTX-M-44). The plasmid DNAs were analyzed by restriction patterns. Homogeneous band patterns were yielded in those of K. pneumoniae and E. coli isolates harboring the bla(CTX-M-2) gene from different farms. No genetic relation between the 2 CTX-M-14 ESBL-producing strains was found by pulsed-field gel electrophoresis, although 2 plasmids in these strains, obtained from different broiler farms, were similar to each other. This study provides evidence that the proliferation of CTX-M-producing E. coli is due to the growth of indigenous CTX-M-producing strains and the possible emergence of strains that acquired CTX-M genes by horizontal transfer in different broiler farms. CTX-M-producing coliforms in broilers should be controlled due to the critical importance of cephalosporins and the zoonotic potential of ESBL-producing bacteria.     

α- and β-adrenergic influences on metabolism in heart and skeletal muscle

Using fenylephrine, isoprenaline, noradrenaline, adrenaline and receptor blockers, adrenergic regulation of metabolism in working heart as well as in skeletal resting muscle of rats was investigated. Changes were determined in: phosphocreatine level and³²P incorporation into phosphocreatine; phosphorolytic and hydrolytic activities of glycogenolysis; glycogen synthetase activity and¹⁴C-glucose incorporation into glycogen; and the level of cAMP. It was found that, contrary to the β-receptor, stimulation of the α-adrenergic receptor inhibits catabolism of macroenergetic phosphates and diminishes glycogen decomposition on the phosphorolytic pathway while increasing the hydrolysis of glycogen and glycogen synthetase activity as well as glucose incorporation into glycogen. On the basis of these data a hypothesis may be put forward that the influence of the α-adrenergic receptor results in the diminishing of energy utilization and in the activation of glycogen anabolism in heart and skeletal muscle. An adrenergic intrasystemic receptor antagonism in the regulation of energy consumption by heart and skeletal muscle is indicated. The α-receptor seems to be an adrenergic intrasystemic moderator of the metabolism rate which is accelerated by β-receptor influence. This suggests that besides sympathetico-parasympathetic intersystemic antagonism regulating the heart work and thereby cardiac energy consumption, there is a separate adrenergic mechanism directly controlling the balance between catabolism and anabolism in heart muscle. This mechanism, based on α- and β-adrenergic receptor antagonism, also controls the metabolic balance in skeletal muscles.     

天府肉羊FSH β基因SNPs及其与产羔数的关联分析

本试验选取334只天府肉羊、波尔山羊和成都麻羊为试验材料,对山羊FSH β基因进行了PCR扩增,采用PCR-SSCP和SNP技术分析了该基因在山羊中的多态性。结果表明,试验羊FSH β基因5′调控区存在第712位A→G突变,形成了AA、AB和BB 3种基因型。适合性检验和最小二乘分析结果显示,山羊FSH β基因不同基因型的平均窝产羔数存在显著差异;天府肉羊和成都麻羊的FSH β多态位点处于Hardy-Weinberg平衡状态（P＞0.05）,波尔山羊极显著偏离了Hardy-Weinberg平衡（P＜0.01）。由此推测,FSH β基因可能对于山羊繁殖性能具有较大影响或与控制繁殖性能的主基因连锁,可以尝试将其作为一个重要的分子标记用于山羊的育种实践。