Safety and efficacy of in ovo administration of infectious bursal disease viral vaccines

In ovo vaccination against Marek's disease virus and infectious bursal disease virus (IBDV) in commercial broilers in the United States is common. Little information exists as to the safety and efficacy of intermediate IBDV vaccines given in ovo. Experiments were initiated to determine the safety and efficacy of three commercially available live intermediate IBDV vaccines by in ovo route. Commonly used vaccines were given at 18 days of embryonation to specific-pathogen-free (SPF) broiler embryos (first and second study) or to commercial broiler embryos (third study) that had maternal antibody against IBDV. When any of the antigenic standard vaccines was given at full dose to SPF embryos, embryonic and 3-wk posthatch mortality increased. Vaccines also caused significant microscopic lesions in the bursa of Fabricius at 1 and 3 wk posthatch. In contrast, there was no adverse effect on embryonic or posthatch mortality when vaccines were given at half dose to SPF or commercial broiler embryos. However, significant microscopic lesions were evident at 1 and 3 wk posthatch in the bursae of SPF embryos given the vaccines at half dose. When vaccines were given at half dose to commercial broiler embryos, lesions were evident at 1 but not 3 wk of age. In the third study, in ovo vaccinated chickens were challenged with either a virulent standard (APHIS) or antigenic variant (variant E) IBDV virus at 3 wk of age. All vaccines produced at least 87% protection against the standard and 60% protection against the variant challenge IBDV, as measured by bursal weight to body weight ratios. This study was the first to examine the safety and efficacy of the three commonly used intermediate IBDV vaccines given in ovo in protection against standard and antigenic variant IBDV challenge viruses.     

Safety and efficacy of an experimental reovirus vaccine for in ovo administration

A commercial reovirus vaccine alone or experimental reovirus vaccine plus antibody complex were inoculated into 18-day-old specific pathogen free (SPF) broiler embryos at 0.1 of the recommended chick dose. The following groups were used: group 1A was not vaccinated or challenged; group 1B was not vaccinated, but was challenged with virulent reovirus; group 2 received the vaccine complexed with 1/4 dilution of antiserum; group 3 received the vaccine with 1/8 dilution of antiserum; group 4 received the vaccine with 1/16 dilution of antiserum, and group 5 received vaccine alone. At 1, 3, 6, 9, and 12 days of age, serum was collected and antibody against avian reovirus was analyzed by enzyme-linked immunosorbent assay (ELISA). At the same times, spleens were collected and vaccine virus detected by inoculating chicken embryo fibroblasts (CEFs) and examining for cytopathic effect. At 15 days of age, chickens in groups 2-5 were challenged with reovirus. At 22 days of age, birds were euthanatized and weighed. Efficacy of the vaccines was based on safety, percent protection, and antibody response. In ovo vaccination with the commercial or experimental vaccines did not adversely affect hatchability of SPF chickens. The vaccine complexed with antibody resulted in significantly less posthatch mortality (3.7%) when compared to mortality of chickens that received vaccine alone (17%). Both vaccine virus recovery and antibody response were delayed at least 3 days in birds receiving the experimental vaccines. In evo administration of reovirus antibody complex vaccines provided at least 70% protection. The experimental reovirus-antibody complex vaccines were safe and efficacious when given in ovo to SPF broiler embryos.     

Melatonin Supplementation During In Vitro Maturation and Development Supports the Development of Porcine Embryos

Melatonin has been reported to improve the in vitro development of embryos in some species. This study was conducted to investigate the effect of melatonin supplementation during in vitro maturation (IVM) and development culture on the development and quality of porcine embryos. In the first experiment, when the in vitro fertilized embryos were cultured with different concentrations of melatonin (0, 10, 25 and 50 ng/ml) for 8 days, the blastocyst formation rate of embryos cultured with 25 ng/ml melatonin (10.7%) was significantly increased (p < 0.05) compared to the control embryos cultured without melatonin (4.2%). The proportion of DNA‐fragmented nuclei in blastocysts derived from embryos cultured with 50 ng/ml melatonin was significantly lower (p < 0.05) than that of embryos cultured without melatonin (2.1% vs 7.2%). In the second experiment, when oocytes were cultured in the maturation medium supplemented with different concentrations of melatonin (0, 10, 25 and 50 ng/ml), fertilized and then cultured with 25 ng/ml melatonin for 8 days, there were no significant differences in the rates of cleavage and blastocyst formation among the groups. However, the proportions (2.7–5.4%) of DNA‐fragmented nuclei in blastocysts derived from oocytes matured with melatonin were significantly decreased (p < 0.05) compared to those (8.9%) from oocytes matured without melatonin, irrespective of the concentration of melatonin. Our results suggest that supplementation of the culture media with melatonin (25 ng/ml) during IVM and development has beneficial effects on the developmental competence and quality of porcine embryos.     

Low-Temperature Nonoxidative Activation of Methane over H-Galloaluminosilicate (MFI) Zeolite

Conversion of methane to higher hydrocarbons by its low-temperature activation without forming undesirable carbon oxides is of great scientific and practical importance. Methane can be highly activated, yielding high rates of conversion to higher hydrocarbons and aromatics (10 to 45 percent) at low temperatures (400° to 600°C), by its reaction over H-galloaluminosilicate ZSM-5 type (MFI) zeolite in the presence of alkenes or higher alkanes. The methane activation results from its hydrogen-transfer reaction with alkenes.     

The use of oral recombinant feline interferon omega in two cats with type II diabetes mellitus and concurrent feline chronic gingivostomatitis syndrome

Feline Chronic Gingivostomatitis Syndrome (FCGS) is a common disease in clinical practice. Among the therapeutic options available, long-acting corticosteroids are frequently used due to their anti-inflammatory and immunosuppressive properties. Although they may improve the clinical symptoms, they can lead to a progressive form of the disease that becomes refractory to treatment. Furthermore, their direct relationship with type II diabetes mellitus (DM) is well known. Consequently, these drugs are controversial and not recommended for routine management of FCGS. Recombinant feline interferon-omega (rFeIFN-ω) is an immunomodulatory compound. Recently, its daily oral administration has been shown to be successful in treating refractory cases of FCGS. This case study describes two clinical cases of type II DM complicated by FCGS. Both animals were calicivirus positive and they had been previously treated with long-acting corticosteroids, which may have been the major cause of DM. The two cats were treated with glargine insulin (Lantus, starting dose 1 IU/cat twice daily (BID)), achieving remission 10 and 18 weeks later respectively. Considering the difficulty with control of FCGS in these animals, an oral daily dose of rFeIFN-ω was started as an alternative to long-acting corticosteroids. In both cats oral clinical signs gradually improved and 60 days after the start of therapy the owners reported a significant relief of pain during mastication. According to the authors’ knowledge, this is the first case report that describes the successful use of rFeIFN-ω in the management of FCGS in type II diabetic cats, in which long-acting corticosteroids are contraindicated.     

水杨酸诱导下人参培养物差异表达基因片段的克隆

本研究以人参愈伤悬浮细胞为材料,在其生长的第28天添加1×10^-3mg／L水杨酸,测定水杨酸添加后,过氧化物酶、多酚氧化酶和苯丙氨酸解氨酶等3种酶在72h内的变化及皂苷含量,结果表明：水杨酸添加后对过氧化物酶和苯丙氨酸解氨酶的活力影响最大,分别在24h和48h达到最大峰值,在18h开始影响多酚氧化酶的活力,培养物生长的第28天添加水杨酸可以明显提高人参愈伤组织中皂苷的合成。确定添加水杨酸后24h提取总RNA,进行cDNA-RDA分析,筛选差异片段。确定差异基因并在GenBank中注册,注册号为FE900130。为探讨水杨酸作为诱导子对人参次生代谢的影响奠定基础。     

Coarse-spray immunization of one-day-old broilers against enteric reovirus infections.

Coarse-spray (CS) administration of a commercial S1133 reovirus vaccine was evaluated in 1-day-old specific-pathogen-free broilers for prevention of clinical infection induced by intratracheal challenge with two enteric reovirus isolates. In Expt. 1, chickens were challenged at 4 days of age with either the 2408 or CO8 isolate. In Expt. 2, chickens were challenged at 7 days of age with either isolate. In Expt. 3, chickens were challenged at 3, 5, or 7 days of age with the 2408 isolate. In Expt. 1, vaccinated birds showed significant protection against challenge with either isolate at 4 days of age as measured by morbidity, mortality, gross lesions, and body weight. In Expt. 2, vaccinated birds showed greater protection against challenge at 7 days of age. In Expt. 3, resistance in vaccinated birds increased with time between vaccination and challenge. Vaccinated birds challenged at 3 days of age showed no significant protection, whereas vaccinated birds challenged at 5 or 7 days of age had increased resistance. This vaccine did not induce a drop in weight gain, morbidity, mortality, or microscopic lesions in the tendons.     

片麻岩石质山地火炬树幼林集水保墒措施优化

通过对比火炬树幼林地树木生长及光合生理指标,配合土壤水分测定,对河北平山片麻岩石质山区不同微地形集水保墒措施进行了优化。结果表明:①不同集水保墒措施下,翼式鱼鳞坑+保水剂(YY+B)、翼式鱼鳞坑+石子(YY+S)都能有效提高土壤的保水能力,其中YY+S持续时间较长,雨后第6天,YY+S比CK(不做处理)的土壤含水量高出43.19%。到雨后第14天,YY+S的土壤含水率仍大于CK。②YY+S和翼式鱼鳞坑+植物覆盖(YY+Z)对树木生长的影响最大。YY+S处理的火炬树树高年生长量为12.09 cm,极显著高于对照3.03倍。YY+S、YY+Z处理的地径年生长量分别为0.43、0.40 cm,是CK地径生长量的2.15、2.00倍。③YY+Z、YY+B及YY+S处理树木的净光合速率显著高于翼式鱼鳞坑(YY)和CK处理,增幅52.91%～59.23%。④各种处理方法火炬树幼树的光响应曲线趋势基本一致,各处理的光补偿点为500 mol.m-2.s-1,光饱和点为1 600 mol.m-2.s-1。随着光强的增加,光合有效辐射(PAR)(600～2 000μmol.m-2.s-1)时,YY+B及YY+Z处理幼树的净光合速率显著高于对照。从降雨后土壤含水量的变化趋势、年终树木生长量、光合速率、光响应曲线综合看来,翼式鱼鳞坑+石子覆盖的集水保墒效果最优。     

Detection and differentiation of avian reoviruses using SYBR-Green I-based two-step real-time reverse transcription PCR with melting curve analysis

A two-step SYBR-Green I-based real-time PCR with melting curve analysis was developed to detect and differentiate the avian reovirus (ARV) sigmaC gene in field and vaccine ARVs. Three primer sets were used to amplify the sigmaC gene from its 5', center, and 3' regions and analyze the melting point temperatures of nine ARVs. By combining the melting curves of the three ARV sigmaC gene regions, melting curve analysis could accurately distinguish the ARVs of different subtypes, and the results were consistent with phylogenetic analysis. The ARV sigmaC gene polymorphisms from different strains were also used to explain the differences in melting point temperatures. Compared with traditional subtyping methods, the current melting curve analysis provided an accurate test for separating ARVs, thereby making it a useful method for the improved selection of ARV vaccines.     

Influence of a reovirus-antibody complex vaccine on efficacy of Marek's disease vaccine administered in ovo

Two experiments determined the influence of an experimental reovirus-antibody complex vaccine on Mareks disease virus (MDV) vaccine when used in ovo. Designs were the same except that specific-pathogen-free (SPF) broiler eggs were used in Experiment 1 and commercial broiler eggs with maternal antibodies against reovirus were used in Experiment 2. At 18 days of incubation, embryos were separated into four groups and inoculated with either diluent, MDV vaccine, reovirus-antibody complex vaccine, or a combination of reovirus-antibody complex and MDV vaccine. At 5 days of age, half the chickens in each group were challenged with MDV. At 7 wk old, all were euthanatized, weighed, and examined. At 7 days of age, remaining chickens in each group were challenged with reovirus. At 21 days old, chickens were euthanatized and weighed. No vaccine adversely affected hatchability or posthatch mortality in SPF or commercial chickens. There were no significant differences in protection against reovirus challenge when vaccines were used separately or in combination, and lesion scores were nearly identical in all vaccinated groups in both experiments. However, percentage of protection against reovirus was lower in Experiment 2, indicating an adverse effect of maternal immunity on efficacy of the reovirus vaccine. There were no significant differences in protection against MDV when the vaccines were used separately or combined. Severity of MDV lesions was nearly identical in all vaccinated groups in both experiments. However, the combination of vaccines gave numerically lower protection against MDV than MDV vaccine alone. Use of a larger number of birds, as in field conditions, may result in statistically lower protection for the vaccine combination. Large field trials are needed to determine the potential of the reovirus-antibody complex vaccine.