In vitro antimicrobial sensitivity of Mycoplasmas isolated from the bovine genital tract.

The in vitro antimicrobial sensitivity of 14 mycoplasma and 13 ureaplasma strains isolated from the genital tracts of bulls was examined. It was found that at relatively low concentrations, tetracycline, declomycin and tylosin were lethal to both types of organisms. Lincospectin, berenil, streptomycin and erythromycin were lethal to mycoplasmas but were only inhibitory to the ureaplasma strains at the same concentrations. Polymyxin B and novobiocin were ineffective at the levels tested.     

Effects of diet concentrate level and sodium bicarbonate on site and extent of forage fiber digestion in the gastrointestinal tract of wethers

Four adult wethers (45 kg) with permanent ruminal and abomasal cannulae were used in a repeated measures Latin-square arrangement of treatments to quantitate the effects of diet concentrate level and sodium bicarbonate (NaHCO3) on site and extent of forage fiber digestion in the gastrointestinal tract. Experimental diets consisted of Kentucky-31 tall fescue hay, soybean meal and a semi-purified concentrate mixture in ratios of 95:5:0, 76:4:20, 57:3:40 and 38:2:60; NaHCO3 represented 0 or 7.5% of the concentrate mixture. Ruminal digestion (% of intake) of neutral detergent fiber (NDF) and hemicellulose decreased linearly (P less than .05), whereas acid detergent fiber (ADF) digestion responded in a cubic (P less than .05) fashion to increasing concentrate level; NaHCO3 improved ruminal digestion of NDF (P less than .10) and ADF (P less than .05), but not hemicellulose. Post-ruminal digestion (% of rumen non-degraded) of NDF and ADF tended to increase, whereas hemicellulose digestion responded in a cubic (P less than .05) fashion to increasing concentrate level; NaHCO3 decreased (P less than .05) post-ruminal digestion of all fiber fractions. Total tract digestion of NDF and ADF showed a cubic (P less than .05) response, whereas hemicellulose digestion responded in a quadratic (P less than .05) fashion to increasing concentrate level; NaHCO3 had no effect on total tract digestion of any fiber fraction. Correlations of ruminal hemicellulose digestion with mean pH (r = .33; P = .07) and minimum pH (r = .30; P = .09) were attained in a 24-h feeding cycle.(ABSTRACT TRUNCATED AT 250 WORDS)     

Virulence Genes in Heterodera glycines: Allele Frequencies and Ror Gene Groups Among Field Isolates and Inbred Lines

ABSTRACT Genetic variation in field populations of Heterodera glycines is a key issue for both resistance gene deployment and basic understanding of virulence-gene flow in populations. In this study, we examined phenotypically defined genes for virulence under selection from host resistance. We separated the most common H. glycines genotypes in the United States into two virulence groups, based on their reproductive abilities on the resistant soybean plant introduction (PI) 88788. These groups correspond to previously identified virulence genes in the nematode, as follows: the dominant gene in H. glycines to PI88788, and the recessive genes to PI90763 and Pickett/Peking. Virulence allele frequencies and virulence genotype frequencies of selected field isolates were investigated by testing the host range of single-female-derived lines, which were developed through single-female inoculation on the standard susceptible soybean 'Lee 68'. By comparing virulence genotype frequencies between the original field isolates and their single-female-derived lines, we were able to determine allele frequencies in the field populations. The results suggest that tremendous variation in H. glycines virulence genes exists among field populations. Potential mechanisms of selection which could cause virulence genotype frequency increases are discussed as related to population genetics equilibrium theory.     

A comparison of the survival times of dogs treated with mitotane or trilostane for pituitary-dependent hyperadrenocorticism

The survival times of 148 dogs treated for pituitary-dependent hyperadrenocorticism were studied using clinical records from 3 UK veterinary centers between 1998 and 2003. Of these animals, 123 (83.1%) were treated with trilostane, while 25 (16.9%) were treated with mitotane. Treatment groups were compared using t-tests and analysis of variance (or their nonparametric equivalents) and chi-square tests. Survival data were analyzed using Kaplan-Meier survival plots and Cox proportional hazard methods. There was no significant difference between the population attributes from each center or between treatment groups. The median survival time for animals treated with trilostane was 662 days (range 8-1,971) and for mitotane it was 708 days (range 33-1,399). There were no significant differences between the survival times for animals treated with trilostane and those treated with mitotane. In the multivariable model (including drug, center, breed group, weight, diagnostic group, and age at diagnosis), only age at diagnosis and weight were significantly negatively associated with survival. Importantly, there was no significant effect of drug choice on survival.     

云南切梢小蠹细胞色素P450基因的克隆与分析

利用RACE技术,从云南切梢小蠹Tomicus yunnanensis中克隆获得了一个细胞色素P450基因cDNA序列。该基因简写为TyunP450,其序列长1 524 bp,开放性阅读框为1 269 bp,编码422个氨基酸,预测蛋白分子量为48.50 ku,pI为8.94。通过MotifScan分析发现,TyunP450氨基酸序列中潜在1个酰胺化位点(XGR265-268)、4个N-糖基化位点(NLSV33-36、NDSV87-90、NGST97-100和NASK372-375)、4个酪蛋白激酶Ⅱ磷酸位点(SVTE176-179、TQRD187-190、SDED217-220和TIDE420-423)、5个N-豆蔻酰化位点(GNVFGF2-7、GNVYND40-45、GGQNAA163-168、GGILSD213-218和GTNIAI340-345)、8个蛋白质激酶C磷酸化位点(SLK77-79、STK99-101、TQR187-189、SLK210-212、SLR288-289、SHK417-419、SLK431-433和TLR443-445)、1个P450细胞色素血红素铁配体的半胱氨酸位点(FSSGPRDCLG384-393),204~316氨基酸区域具有典型的细胞色素P450结合位点结构,317~441氨基酸区域具有典型的细胞色素P450结合位点结构,9~28氨基酸区域具有DUF321蛋白的未知函数结构域,1~441氨基酸区域具有典型的细胞色素P450结合位点结构。TyunP450与埃及伊蚊Aedes aegypt、家蚕Bombyx mori、丽蝇蛹集金小蜂Nasonia vitripennis、赤拟谷盗Tribolium castaneum和豌豆蚜Acyrthosiphon pisum的P450氨基酸序列相似性分别为19%、20%、21%、23%和15%。