Studies on Aspergillus Fumigatus; Toxin Production Ry Different Strains and Serological Comparison of the Strains

Saline extracts of mycelial material from 14 different strains of Aspergillus fumigatus showed haemolytic and toxic activities. These activities were present in filtrates obtained from mycelial material incubated at 20°C for 6, 15 and 30 days and at 37°C for 6 days. The haemolysin and toxin titers decreased with an increase in incubation time and at higher incubation temperatures.The haemolytic and toxic activities could be inactivated by heating the filtrates at 70°C for 10 min.The results of serological tests demonstrated immunological uniformity for the haemolytic and toxic factors.     

Influence of creep feeding and weaning on brush border enzyme activities in the piglet small intestine

The activities of the enterocyte brush border enzymes lactase (beta-D galactoside galactohydrolase, EC 3.2.1.23) and sucrase (sucrose alpha-D glucohydrolase, EC 3.2.1.48) were measured at set percentage lengths along the small intestines of 112 piglets killed between 21 and 32 days of age. The influences on these activities of consumption of creep feed and of weaning were recorded. Weaning at three weeks old resulted in large, rapid reductions in lactase activity at most sites along the small intestine; sucrase activity declined temporarily and then recovered. Minimum values were recorded about four to five days after weaning. Similar changes were observed whether or not creep feed was consumed before weaning. Continued consumption of creep feed by unweaned pigs over the 21 to 32 day period also produced small but significant reductions in lactase activities. The large loss of digestive enzyme activities at brush borders in weaned animals coincided with a reduced ability to absorb xylose and to checks in growth rate in otherwise healthy piglets.     

不同n-6/n-3多不饱和脂肪酸比值对LPS诱导的断奶仔猪肠道形态的影响

为探讨n-6/n-3多不饱和脂肪酸(PUFA)比值为10或20对断奶仔猪生长性能及LPS诱导的肠道形态的影响,试验选用24头28 d断奶、平均体重(6.8±0.55)kg的荣昌小公猪,采用2×2因子试验设计,日粮类型(n-6/n-3PUFA比值为10和20)和免疫应激(注射LPS和生理盐水),试验期21 d。第21天,每日粮处理组一半的仔猪腹膜注射大肠杆菌脂多糖(LPS)或生理盐水,3 h后屠宰仔猪采集肠道样品。结果表明:在试验的0~7 d和0~21 d,采食n-6/n-3 PUFA比值为10日粮的仔猪饲料转化效率显著高于采食n-6/n-3 PUFA比值为20日粮的仔猪(P<0.05);注射LPS显著降低了断奶仔猪空肠绒毛高度与隐窝深度的比率(P=0.01),但两种n-6/n-3 PUFA比值的日粮对LPS诱导的仔猪肠道形态损害没有缓解作用。     

猪α-干扰素在毕赤酵母中的分泌表达和下游工艺的研究

通过小量发酵、摇瓶发酵、大量发酵,研究猪α-IFN在毕赤酵母中表达的下游工艺,微量细胞板法测猪α-IFN体外抗VSV、PRRSV、TGEV的活性.猪α-IFN抗VSV的活性达到4.04×10~6IU/L,在PK15上抗TGEV的活性为10~7～10~8IU/L,在Mare 145上抗PRRSV的活性为10~6～10~7lU/L.30℃诱导培养96 h、甲醇添加1%、pH值6.0、DO 20%、0.25%～0.4%甲醛灭活,获得高活性的、安全的IFN.仔猪免疫后临床症状正常,未出现病理学变化.猪α-IFN体外抗病毒活性高,发酵后的抗病毒活性未下降,免疫动物未产生临床症状和病理变化,可用于临床治疗病毒性疾病.     

粗狭肋鳃金龟的生物学特性及防治

粗狭肋鳃金龟（Holotrichia scrobiculata Brenske）是蓝莓主要害虫,以幼虫在地下啃食根系为害。为掌握该虫在麻江的发生特点,探讨有效的综合防控措施,采用定期定点调查及室内饲养相结合的方法,对该虫的生物学特性进行了系统研究。结果表明：粗狭肋鳃金龟在贵州省黔东南州麻江县1年发生1代,以蛹越冬;翌年3月下旬至6月下旬成虫羽化出土,5月上旬开始产卵,5月下旬幼虫孵化,12月上旬老熟幼虫开始作蛹室化蛹并在土中越冬。成虫于每晚6点至10点集中出土并转移至壳斗科植物上进行取食或生殖活动,出土高峰期为4月下旬至6月上旬,寿命22.50-24.40 d;晚上20:00-21:00为成虫交配高峰期,交配后4-7天开始产卵,卵期10-20 d,产卵高峰期为6月,单雌产卵量30-50粒,散产;7月为幼虫孵化盛期,幼虫共3龄,历期219-252 d。此外,提出了黑光灯诱杀、人工采虫、冬季深耕翻土等有效的防治方法。     

Single-dose treatment of neonatal calf pneumonia with the new macrolide antibiotic tilmicosin

Tilmicosin, a new macrolide antibiotic, 20-deoxo-20-(3,5-dimethylpiperidin-l-yl)desmycosin, formerly identified as EL-870, has been evaluated in three experiments as a single subcutaneous injection at dosages of 10, 20 or 30 mg/kg for the treatment of naturally occurring pneumonia in neonatal calves. Male Holstein calves, under five days of age, were shipped from Wisconsin and housed in pens. They were assigned sequentially to a treatment group when their temperature was greater than or equal to 39.7 degrees C for two consecutive days or greater than or equal to 39.7 degrees C and signs of respiratory disease were present. Clinical signs were evaluated daily for 14 days after the tilmicosin treatment. Calves that died and those that survived for the 14 day experimental period were examined post mortem. Treatment with tilmicosin was effective at all dosage levels, as determined by significant (P less than or equal to 0.05) reductions in body temperature within 24 hours, in the number of animals that died, in the incidence and severity of clinical signs, in the number of Pasteurella species found in lung tissue and in the severity of the pneumonic lesions. In two of the three experiments severe outbreaks of cryptosporidiosis resulted in significant mortalities within a few days after the arrival of the calves. Treatment with tilmicosin was effective against respiratory disease even in the presence of this severe concurrent disease.     

Effect of feeding selected short-chain fatty acids on the in vivo attachment of Salmonella typhimurium in chick ceca.

Two groups of 20 chicks each were fed 1% fatty acid continuously starting at 1 day of age, while a control group of 20 chicks received unsupplemented feed. At 2 days of age, chicks were inoculated orally with 1 ml of Salmonella typhimurium (1 x 10(6) colony-forming units/ml). Ceca were obtained from six chicks of each group at 7, 14, and 21 days of age. At 14 days of age, formic and propionic acids had statistically reduced Salmonella recovery by 2.56 logs and 3.09 logs, respectively, compared with controls. At 21 days of age, both test groups showed significant reductions of approximately 3.6 logs compared with controls. There were no statistical differences in body weights among the groups at 21 days of age.     

Assessment of an oxfendazole pulsed release bolus for control of parasitic gastroenteritis in calves in a rotational grazing system

A group of 71 Friesian bullocks, aged six to nine months, vaccinated against lungworm, were randomly allocated on a liveweight basis to two groups of 40 and 31 animals. At turn-out each calf in the group of 40 calves was dosed orally with a pulsed release bolus designed to deliver five doses of oxfendazole at regular intervals during a period of up to 130 days, the first dose being released about 21 days after administration. The group treated with the bolus grazed 2.4 ha and the control group grazed 3.6 ha of permanent pasture for six weeks before having additional access to similar areas of silage aftermath. The control group was treated 99 days after turn-out and when they were housed with fenbendazole (7.5 mg/kg). Faecal worm egg counts, plasma pepsinogen activities, pasture larval counts and liveweights were recorded fortnightly. Significant reductions in worm egg counts and plasma pepsinogen activities were recorded in the calves dosed with the pulsed release bolus together with significant improvements in the liveweight of younger calves compared with control animals. Pasture larval counts were lower in the fields grazed by animals treated with the bolus.     

Incidence of Transfusion Reactions and Retention of Procoagulant and Anticoagulant Factor Activities in Equine Plasma

Background: The extent of preservation of clotting factors and incidence of transfusion reactions to noncommercial equine plasma is not documented.
Hypothesis: Equine frozen plasma would retain its coagulation factor activity within the reference range and the incidence of transfusion reactions would be low.
Animals: Ten plasma donor horses. Fifty clinically ill hospitalized horses receiving plasma were reviewed to determine the incidence of reactions.
Methods: In vitro study and retrospective case review. Plasma was prepared by gravity sedimentation from whole blood refrigerated for 48 hours. The activities of factors VII through XII, antithrombin (AT), and Protein C were measured. Factor activities were compared for plasma samples obtained before blood collection (S0), after 48 hours of gravity sedimentation at 5 °C and after plasma separation (S1), and after 90 days of storage at −20 °C (S90). The medical records of 50 consecutive clinically ill horses receiving frozen plasma were reviewed to determine the incidence of transfusion reactions.
Results: The combined effect of plasma harvest, gravity sedimentation, decantation, and freezing caused significant reductions in factors IX, (43% P = .0013), X, (33% P = .0001), XI, (48% P = .0008), AT, (10% P = .02), and Protein C (26% P = .0001). Activities for all factors analyzed, except factor X, remained within the reference ranges. Transfusion reactions were recorded for 5/50 horses.
Conclusions and Clinical Relevance: Clotting factors, AT, and Protein C were well preserved. The incidence of reactions to frozen plasma was 10%.     

蛋白质组学技术解析急性免疫应激影响肉仔鸡肉品质的机理

旨在探讨免疫应激对肉仔鸡胸肌肉品质的影响机理。采用非标定量蛋白质组学技术研究免疫应激对AA肉仔鸡胸肌肉品质和蛋白质组学变化的影响。本试验选取120只1日龄健康AA肉仔公鸡，随机分为2个处理，分别为对照组和免疫应激处理组，每个处理6个重复，每个重复10只鸡。分别在36、38、40日龄时，于腹腔注射1 mL生理盐水（对照组）或5.0 mg·kg^-1体重的LPS溶液（免疫应激组）。42日龄时，每重复随机抽取2只鸡，采集胸肌肌肉组织测定滴水损失、蒸煮损失、肌苷酸含量和pH，及蛋白质组的定性、定量分析。结果显示：1）与对照组相比，免疫应激显著增加了肉鸡胸肌的滴水损失和蒸煮损失（P<0.05），显著降低了胸肌内肌苷酸（IMP）含量（P<0.05）；免疫应激对肉鸡胸肌宰后静置24和48 h的pH影响不显著（P>0.05）；免疫应激组肉鸡胸肌肌纤维的横截面周长和面积均极显著增加（P<0.01）。2）定性蛋白质组学分析结果显示，对照组特异表达蛋白质功能富集到了细胞呼吸、有氧呼吸、己糖代谢与生物合成过程、单糖生物合成过程、葡萄糖代谢过程和糖异生生物学过程；而免疫应激组特异表达蛋白质富集到了紧密连接代谢通路和大分子复合物分解、蛋白质分解与解聚、核酸合成和代谢、糖基化合物合成与代谢和含碱基小分子物质代谢生物学过程。3）定量蛋白质组学分析表明，免疫应激组和对照组有21个蛋白质发生差异化表达，其中15个蛋白质在免疫应激组上调表达，6个蛋白质在免疫应激组下调表达；免疫应激组上调表达的蛋白包括参与碳水化合物代谢和能量产生相关蛋白（AMPD1、GPD1L2、LDHA、UQCRC2）、肌肉收缩相关蛋白（MYH1C、MYH1A、CASQ2、TMEM38A）和参与免疫反应保护细胞免受损伤相关蛋白（HMGB1、PPP1R1A、LOC101747971、PRDX1、ABCF2）；免疫应激组下调表达的蛋白有HBBA、CS、ATP5A1WL、HSP90B1、ABCB6和SYNJ2。综上所述，LPS诱导的免疫应激通过改变肉鸡肌肉与能量代谢和肌肉收缩相关蛋白质的表达，从而增加了肌纤维的面积，并降低了肌细胞持水力，导致肉品质下降。     

Experimental infection of pregnant ewes with Listeria monocytogenes

Eight 18-month-old ewes were infected orally with Listeria monocytogenes between 77 and 91 days of pregnancy. Only one ewe aborted, 10 days after the first infecting dose, at 94 days of gestation; L monocytogenes was isolated from several sites in both its aborted fetuses. Two days after the first infecting dose all the ewes exhibited mild illness and pyrexia lasting for two to three days but the ewe which aborted was seriously ill until nine to 10 days after aborting. Agglutination tests carried out on 2-mercaptoethanol reduced sera revealed a strong immunological response in all the infected ewes but in the ewe which aborted this response was delayed. Four uninfected ewes which were kept as controls remained healthy throughout the experiment and showed no evidence of 2-mercaptoethanol resistant antibodies to L monocytogenes. Growth retardation lines, occurring at the time of and after experimental infection, were found in the bones of 14 of 17 newborn lambs in both the infected and control groups; in the aborted lambs these lines occurred before the infection.     

Influence of dietary conjugated linoleic acid isomers on early inflammatory responses in male broiler chickens

1. The influence of dietary conjugated linoleic acid isomer (CLA, 0 and 10 g/kg) on the metabolic and physiological responses to immune stimulation induced by a single injection of Salmonella enteritidis lipopolysaccharide (LPS) or repeated injections of LPS and Sephadex G-50 was determined in male broiler chicks. 2. In experiment 1, 10-d-old chicks were fed on experimental diets for 14 d and half of the birds fed on each diet were injected intraperitoneally with LPS (1.5 mg/kg body weight). In experiment 2,7-d-old chicks were fed on experimental diets for 18 d. Immune stimulation was started at 19 d old and continued for 5 d. Half of the birds fed on each diet were injected intraperitoneally with 0.25 mg/kg body weight of LPS at 19, 21 and 23 d of age, and with 250 mg/kg body weight of Sephadex at 20 and 22 d of age to stimulate the immune system. 3. In experiment 1, giving CLA prevented an increase in blood heterophil to lymphocyte ratio 7 h after a single injection of LPS, and increases in plasma ceruloplasmin and alpha 1 acid glycoprotein (AGP) 24 h after the injection, but not 7 h after the injection. CLA also prevented a decrease in food intake for 24 h after LPS injection. 4. In experiment 2, the CLA diet partially prevented reductions in body weight gain and weight gain to feed intake ratio caused by repeated injections of LPS and Sephadex. Feeding CLA prevented increases in plasma ceruloplasmin and AGP at 24 d of age caused by repeated injections of LPS and Sephadex, but not at 20 d of age. 5. These results suggest that feeding CLA alleviates some undesirable metabolic and physiological changes induced by immunological stimulation in male broiler chicks.     

Ghrelin and truncated ghrelin variant plasmid vectors administration into skeletal muscle augments long-term growth in rats

Ghrelin is an acylated peptide recently identified as an endogenous ligand for the growth hormone (GH) secretagogues (GHSs) receptor (GHS-R) and is involved in a novel system for regulating GH release. To study the biological activities of ghrelin using plasmid vector administration, we constructed myogenic expression vectors containing the full length cDNA of swine ghrelin-28 (pGEM-wt-sGhln) and truncated variant (pGEM-tmt-sGhln) consisting of the first seven residues of ghrelin (including Ser3 substituted with Trp3) with addition of a basic amino acid, Lys (K) at the C-terminus. After intramuscular injection of pGEM-wt-sGhln and pGEM-tmt-sGhln, RT-PCR analysis demonstrated that the ectopic expressions of ghrelin and its variant were observed 30 days post-injection. The level of GH increased in rat serum, and was significantly higher than that of the control group 20 days post-injection with pGEM-tmt-sGhln (P < 0.05). Administration of 150 microg of pGEM-wt-sGhln and pGEM-tmt-sGhln enhanced growth in rats over 30 days and great stimulatory responses were observed at day 10 and 20 post-injection respectively, whose body weight gains were on average 15% (P < 0.05) and 21% P < 0.033 significantly heavier than controls. These results suggested that skeletal muscle might have the potential to perform post-translational acylation for ghrelin, and short ghrelin variant might have the biological effects as wild type ghrelin.     

吡喹酮注射剂早期治疗小鼠血吸虫病效果的初步研究

为探索吡喹酮新制剂早期治疗血吸虫病效果,对人工感染日本血吸虫20d的小鼠皮下给药进行减虫率、肝脏减卵率统计,并在不同时间点对口服组和皮下注射吡喹酮新制剂组的未感染小鼠在给药后采集血浆,高效液相色谱法建立药时曲线。结果显示新制剂600mg/kg剂量治疗的3次试验的减虫率分别为72.88%、82.69%和56.7%,肝脏减卵率分别为81.7%、94.8%和70.7%,对感染20d期别的血吸虫有较好效果。而高效液相色谱法检测血药浓度显示,新制剂经皮下给药方式可使有效杀虫浓度(约0.3μg/mL)持续10d以上,具有缓释作用。吡喹酮新注射制剂能杀灭20d童虫,减少血吸虫病的危害,对血吸虫病的防治有较大的意义。     

Depression of lymphocyte responses to phytohaemagglutinin in lambs experimentally infected with bovine respiratory syncytial virus.

Eight lambs were experimentally infected with bovine respiratory syncytial virus (BRSV) and the responses of their peripheral blood lymphocytes to the mitogen phytohaemagglutinin and BRSV antigen compared with that of control lambs injected with tissue culture fluid. The lymphocyte transformation responses to phytohaemagglutinin were significantly reduced five and 10 days after experimental infection with BRSV (P less than 0.05). It appears that these reductions were associated with CD4+ lymphocytes because CD4-enriched lymphocytes obtained five days after infection had more significantly reduced responses to phytohaemagglutinin than those obtained from the same group before infection and from the control group five days after inoculation (P less than 0.01). There were no significant lymphocyte transformation responses to BRSV antigen in both groups of lambs up to 21 days after inoculation (P greater than 0.05).     

The effect of Duddingtonia flagrans on trichostrongyle infections of Saanen goats on pasture

Four groups of nine Saanen goat does with a naturally acquired mixed trichostrongylid infection were grazed on four paddocks. Two groups received a daily dose of Duddingtonia flagrans at the rate of 5 x 10(7) chlamydospores per animal per day for the 26-day grazing period. After a 19-day pasture resting period, 20 worm free 12-week-old tracer kids were introduced to the paddocks for 14 days prior to removal for worm burden analysis. Four groups of five does and four kids were drenched then turned out onto the paddocks and faecal egg count (FEC) monitored. The FEC between groups was comparable throughout the initial grazing period. There were significant reductions in number of Teladorsagia circumcincta (54.8%, P=0.004) and Haemonchus contortus (85.0%, P=0.02) worms recovered from tracer animals. FEC of animals subsequently grazing pasture were significantly reduced (P=0.036) with reductions of 44% observed 4 weeks post-turnout. No significant difference was observed after 6 weeks grazing. This trial has demonstrated the potential of D. flagrans to reduce larval numbers on pasture grazed by goats under New Zealand conditions.     

干旱胁迫及复水对黄连花幼苗生长和生理特性的影响

以盆栽黄连花(Lysimachia davurica)幼苗为材料,研究了20d的干旱胁迫和复水对植株部分形态特征及叶片抗旱相关生理指标的影响。结果表明,随着胁迫时间的增加,其生长发育逐渐受到抑制。当胁迫时间低于10d以及土壤含水量不低于14.52%时,其地上部生长受到一定的抑制,叶片失水,单叶面积减小,叶绿素含量、MDA含量、可溶性糖、脯氨酸以及抗氧化酶(POD、CAT)活性升高,此时复水,除了茎尖,植株可以迅速恢复生长。当胁迫时间持续增加到15d,叶片严重失水,地上部干枯,此时复水,66.66%的植株可以重新长出幼苗。但当胁迫时间达到20d时,植株因缺水干旱死亡。因此,黄连花在管理养护时,在持续干旱时间超过10d,土壤含水量低于14.52%时,应及时复水救苗。     

N-乙酰半胱氨酸对脂多糖刺激仔猪小肠黏膜免疫应激的影响

研究N-乙酰半胱氨酸(NAC)对脂多糖(LPS)刺激仔猪免疫应激的影响。选取18头健康仔猪,随机分成3个处理(对照组、LPS组和NAC组),每个处理6个重复。对照组和LPS组饲喂基础日粮,NAC组饲喂基础日粮+500 mg/kgNAC。试验期为20 d。LPS组和NAC组于试验第10、13、20天腹膜注射100μg/kg BW的LPS,对照组注射相应剂量的灭菌生理盐水。第10、20天注射LPS后3 h采血,第21天屠宰,取小肠黏膜。结果表明:NAC缓解了LPS刺激导致的血浆和小肠黏膜中TNF-α、IL-6、PGE2含量的升高(P<0.05),缓解了小肠黏膜HSP70相对表达量的升高(P<0.05)。由此可见,日粮中添加500 mg/kg NAC可有效抑制LPS刺激导致的血浆及小肠黏膜中炎性因子的升高,缓解免疫应激。     

Anthelmintic activities of B1a fraction of avermectin against gastrointestinal nematodes in calves

Anthelmintic activities of the B1a fraction of avermectin were evaluated in a controlled experiment. Twenty 12-week-old calves artificially infected with gastrointestinal nematodes were allotted to four groups. Calves in group 1 were used as nonmedicated controls; other calves in groups 2, 3, and 4 were given (orally) B1a avermectin at dosage levels of 50, 100, and 200 microgram/kg of body weight, respectively. These treatments were given 35 days after calves were inoculated with infective nematode larvae. In groups 2, 3, and 4, overall reductions (based on geometric means) were 98.6%, 98.7%, and 98.4%, respectively. These reductions were highly significantly different (P less than 0.01) from the control calves. Nematodes in the calves were Haemonchus contortus. Ostertagia ostertagi, Trichostrongylus axei, T colubriformis, Cooperia oncophora, C punctata, and Oesophagostomum radiatum.     

游泳应激对小鼠肾脏、肺脏和脑组织脂质过氧化状态的影响

为探讨游泳应激对小鼠肾脏、肺脏和脑组织脂质过氧化水平的影响,本试验选取50只小鼠进行游泳试验,于游泳前、游泳10、20、30、50 min后分别随机选取10只小鼠眼眶采血致死,采集肾脏、肺脏和脑组织,测定样品中MDA含量、SOD和GSH-Px活性。结果表明,10或20 min游泳应激后,小鼠肾脏、肺脏和脑组织MDA含量均显著增加(P<0.05),之后均有不同程度的降低;游泳过程中小鼠肾脏SOD活性持续升高,30和50 min后均显著升高(P<0.05),游泳20 min后肺脏SOD活性显著降低(P<0.05),30 min后有所回升,50 min后又轻微下降,游泳过程中脑组织SOD活性均无显著性变化;游泳20和30 min后,肾脏GSH-Px活性显著增加(P<0.05),50 min后显著下降(P<0.05),游泳前40 min过程中肺脏GSH-Px持续下降,30 min组显著降低(P<0.05),游泳10和20 min后,脑组织GSH-Px活性显著降低(P<0.05),之后发生波动性变化。结果提示,游泳应激显著影响小鼠肾脏、肺脏和脑组织脂质过氧化水平,推测游泳应激可能引起小鼠全身脂质过氧化反应。