注射用硫酸链霉素细菌内毒素检查法的探讨

按照《中国兽药典》二○○五年版一部[1]中注射用硫酸链霉素细菌内毒素检查法对样品复核检验,试验表明该方法是可行的;并与《美国药典》进行了比较,结果说明《中国兽药典》注射用硫酸链霉素细菌内毒素检查法对细菌内毒素的限值表达比《美国药典》29版[2]更合理、更科学。     

UHT乳在货架期内理化性质的变化研究

本文研究了UHT全脂乳在37℃温度下,酸度、黏度、蛋白水解度和酒精稳定性的变化情况,并得出UHT乳在37℃温度下的货架期。     

滁菊挥发油提取工艺研究

目的:采用正交试验法筛选滁菊挥发油最优提取工艺。方法:以挥发油得率为考察指标,分别以药材粉碎度、加水量、浸泡时间、蒸馏时间为考察因素进行正交试验设计,确定滁菊挥发油的最佳提取工艺。结果:影响滁菊挥发油提取的最主要因素为粉碎度,其次为蒸馏时间、加水量、浸泡时间,滁菊中挥发油最佳提取工艺条件为:菊花粉碎度80-100目,14倍加水量,浸泡10 h,提取13 h。结论:此提取工艺合理可行,试验重复性较好,可用于滁菊挥发油的提取。     

家蚕新品种夏芳×秋白的试验与推广

经过小区试验,夏芳×秋白比(苏_3·秋_3)×(苏_4·苏_12)在结茧率、万头蚕产茧量、全茧量、茧层率等成绩方面略优于苏字号.夏芳×秋白与黄鹤×朝霞的试验成绩,经方差分析,其结茧率、克蚁产茧量、万头蚕收茧量在品种间差异极其显著,全茧量差异也达到了显著水平.中试成绩显示:无论是1994年秋还是1997年秋,夏芳×秋白的单产成绩大大优于(苏_3·秋_3)×(苏_1·苏_12),两年单产分别增产57.6%和46.1%.通过对中试控制点调查数据的方差分析,品种间和季节间的单产差异都达到了极显著水平,尤其是品种间的差异大大超过了极显著水平.干茧的缫丝成绩是:夏芳×秋白的光折比(苏_3·秋_3)×(苏_4·苏_12)少8.05公斤,出丝率高3.19%.     

Isotype-specific antibodies in horses and dogs with immune-mediated hemolytic anemia

Classes of antibody bound to erythrocytes were determined using direct immunofluorescence (DIF) flow cytometry in 3 horses and 12 dogs with immune-mediated hemolytic anemia (IMHA). Background levels of antibody binding were determined in samples from 12 horses and 12 dogs that were free of clinical disease. The range of nonspecific binding of a fluorescein isothiocyanate (FITC)-conjugated goat anti-equine immunoglobulin G (IgG) was 19.9–36.7%, but was eliminated by the use of the F(ab)₂ fragment of FITC-conjugated goat anti-equine IgG. Background binding by other class-specific antibodies to equine and canine erythrocytes was negligible. The DIF results were compared to the direct antiglobulin (Coombs) test in 5 horses and 20 dogs with anemia. The former assay was more sensitive in dogs with IMHA than was the Coombs' test (100% versus 58%). In contrast, the Coombs' test had better specificity than the DIF assay (100% versus 87.5%, respectively). Using clinical parameters or response to therapy as the comparison, the positive and negative predictive values for the DIF test were 92% and 100% compared to the values of the Coombs' test of 100% and 62%. The DIF assay detected low levels of cells bound with antibody (<30%) in 5 dogs that were Coombs' test-negative. For both species, performance of the DIF test was independent of the prozone effect. Five dogs with IMHA had IgG and IgM on erythrocytes, 5 had IgG, and 2 had IgM. Three horses had surface-bound IgG, including a horse with suspected penicillin-induced IMHA, a foal with neonatal isoerythrolysis, and a foal with clostridial septicemia. The DIF method was valuable in monitoring the response to therapy in the foal with neonatal isoerythrolysis.     

Failure of young goats to acquire resistance to Haemonchus contortus

Two experiments were carried out to investigate the acquisition by goats of resistance to Haemonchus contortus. In Experiment 1, five Saanen wethers reared worm-free and averaging 51/2 months of age at the start of the experiment, were dosed with 200 H. contortus infective larvae three times per week for 10 weeks (approximately 23 infective larvae/kg mean initial liveweight/week) and then given anthelmintic treatment. Each goat and an equal number of worm-free controls were then challenged with 10,000 infective larvae. Post mortem worm counts were carried out 30 days later. In Experiment 2, eight worm-free Saanen wethers, 14 months old at the start of the experiment, were dosed with 825 infective larvae per week for 14 weeks (approximately 23 infective larvae/kg mean initial liveweight/week) except for one week when only 300 larvae were given and one week when no larvae were given. After anthelmintic treatment, each received, together with seven worm-free control animals, a challenge dose of 15,000 infective larvae. Post-mortem worm counts were carried out 28 days later. There were no significant dii- ferences in post-mortem worm counts between previously infected and uninfected groups in either experiment. In both experiments, serum pepsinogen values rose significantly as a result of infection but there was no significant (p>0.5) correlation between worm counts and pepsinogen values on the day of slaughter.     

甘肃陇西黄芩灰霉病病原菌分离鉴定及田间药剂防治

为探明黄芩(Scutellaria baicalensis Georgi)茎基部和根部灰霉病的病原菌,本文于2019—2021年春季对甘肃陇西县采集的黄芩病样进行病原菌的分离培养,运用形态学和内转录间隔区(Internal transcribed spacer, ITS)、甘油醛-3-磷酸脱氢酶(Glyceraldehyde-3-phosphate dehydrogenase,G3PDH)、热激蛋白60(Heat shock protein 60,HSP60)和RNA聚合酶亚基II(The second largest subunit of the nuclear RNA polymerase enzyme II,RPB2)多基因方法鉴定,采用菌丝生长抑制法进行药剂室内毒力测定和田间药剂防治试验。结果表明：引起黄芩灰霉病的病原菌为灰葡萄孢(Botrytis cinerea),春季发病时表现为地上部分枯死不发芽,靠近地表的根表面呈暗绿色水渍状,随后地下根木质部变软呈黄褐色腐烂,病健交界明显;室内毒力测定表明,97%咯菌腈对灰葡萄孢菌的抑菌作用最强,EC₅₀为0.01...     

Thyroid Hormone-disrupting Effects and the Amphibian Metamorphosis Assay

There are continued concerns about endocrine-disrupting chemical effects, and appropriate vertebrate models for assessment of risk are a high priority. Frog tadpoles are very sensitive to environmental substances because of their habitat and the complex processes of metamorphosis regulated by the endocrine system, mainly thyroid hormones. During metamorphosis, marked alteration in hormonal factors occurs, as well as dramatic structural and functional changes in larval tissues. There are a variety of mechanisms determining thyroid hormone balance or disruption directly or indirectly. Direct-acting agents can cause changes in thyroxine synthesis and/or secretion in thyroid through effects on peroxidases, thyroidal iodide uptake, deiodinase, and proteolysis. At the same time, indirect action may result from biochemical processes such as sulfation, deiodination and glucuronidation. Because their potential to disrupt thyroid hormones has been identified as an important consideration for the regulation of chemicals, the OECD and the EPA have each established guidelines that make use of larval African clawed frogs (Xenopus laevis) and frog metamorphosis for screening and testing of potential endocrine disrupters. The guidelines are based on evaluation of alteration in the hypothalamic-pituitary-thyroid axis. One of the primary endpoints is thyroid gland histopathology. Others are mortality, developmental stage, hind limb length, snout-vent length and wet body weight. Regarding histopathological features, the guidelines include core criteria and additional qualitative parameters along with grading. Taking into account the difficulties in evaluating amphibian thyroid glands, which change continuously throughout metamorphosis, histopathological examination has been shown to be a very sensitive approach.