细菌受体分析在禽类血清四环素族残留物检测中的应用

目的:以商售 Charm 细菌四环素族受体与四环素族的特异性结合反应为基础,应用其对活体禽类动物血清中四环素族抗生素残留总量进行快速筛选,重点对方法的灵敏度、选择性、基质影响和准确性等进行综合评价。方法:血清经缓冲液稀释,其中的四环素族抗生素残留与~3H 标记的金霉素竞争结合特异性细菌受体。竞争反应温育时间5 min,温度35℃。3300r·min~(-1),5 min 离心分离倾去未结合的游离化合物,复合物沉淀用水溶解,加入闪烁液混匀后放置1 min,进行[~3H]通道的60s 液体闪烁计数。结果:在大于95%的置信水平,血清中四环素、土霉素和金霉素的检测低限分别为80,55,15μg·L~(-1);样本测试表明筛选水平为200μg·L~(-1)时,假阴性率为0,阳性检出结果中假阳性率不超过15%。结论:与色谱法相比,其快速、灵敏、选择性高,可对活体禽类动物血清中四环素族残留物进行高通量筛选。     

Prevention and identification of Salmonella Enteritidis infection via novel diagnostic stained antigens and polyclonal antibodies

Analysis of Salmonella Enteritidis with specific antisera and stained antigen helps to reduce the identification time of the infection and offers clinical and epidemiological advantages both for poultry health and food industry for the control of salmonellosis. In this study, S. Enteritidis O and H specific antisera were obtained from rabbits immunised subcutaneously using formalin-treated whole bacterial cells as antigens. S. Enteritidis specific stained O and H antigens were prepared and tested for their diagnostic usefulness. In order to eliminate cross reactivity, Salmonella Adeyo was used as an antigen for the production of H specific polyclonal antibody and stained H antigen. Enzyme-linked immunosorbent assay results of antisera were obtained, ranging from 273,300±0.041–312,200±0.028 A492 nm. Stained O and H antigen preparations were achieved with a stronger binding degree to the hyperimmune rabbit sera and without being shown cross-reactivity between O and H antigens.     

Bacillus spp. as direct-fed microbial antibiotic alternatives to enhance growth,immunity, and gut health in poultry

The increasing occurrence of antibiotic-resistant bacteria combined with regulatory pressure and consumer demands for foods produced without antibiotics has caused the agricultural industry to restrict its practice of using antibiotic growth promoters (AGP) in food animals. The poultry industry is not immune to this trend, and has been actively seeking natural alternatives to AGP that will improve the health and growth performance of commercial poultry flocks. Bacillus probiotics have been gaining in popularity in recent years as an AGP alternative because of their health-promoting benefits and ability to survive the harsh manufacturing conditions of chicken feed production. This review provides an overview of several modes of action of some Bacillus direct-fed microbials as probiotics. Among the benefits of these direct-fed microbials are their production of naturally synthesized antimicrobial peptides, gut flora modulation to promote beneficial microbiota along the gastrointestinal tract, and various immunological and gut morphological alterations. The modes of action for increased performance are not well defined, and growth promotion is not equal across all Bacillus species or within strains. Appropriate screening and characterization of Bacillus isolates prior to commercialization are necessary to maximize poultry growth to meet the ultimate goal of eliminating AGP usage in animal husbandry.     

Efficacy of live attenuated influenza vaccine against influenza illness in children as a function of illness severity

A recent study of inactivated influenza vaccine (IIV) in children aged 3–8 years demonstrated higher efficacy against moderate/severe influenza. A meta-analysis of all previous published randomized clinical trials of live attenuated influenza vaccine (LAIV) that collected information on illness severity in children aged 24–71 months was conducted. Moderate/severe influenza was defined as fever >39 °C, acute otitis media, or lower respiratory tract illness; other cases were classified as milder influenza. LAIV efficacy versus placebo was 95.4% [95% confidence interval: 88.5, 98.1] (year 1) and 88.5% [77.4, 94.9] (year 2) against moderate/severe influenza and 91.4% [77.9, 96.7] (year 1) and 84.2% [56.7, 94.3] (year 2) against milder influenza. The relative efficacy of LAIV versus IIV was 52.2% [31.6, 66.6] for moderate/severe influenza and 45.0% [28.6, 57.5] for milder influenza. Efficacy against all influenza illnesses, regardless of severity, is critical to prevent influenza illness and transmission in the community.     

Impact of live attenuated influenza vaccination programme for healthy children in Northern Ireland: A comparison of seven influenza seasons, 2010/11–2016/17

Seasonal influenza vaccination for healthy children was introduced in Northern Ireland in the 2013/14 flu season, with an initial pilot year involving two specific cohorts, followed by rollout to all children aged 4–11 years in subsequent seasons. This study aimed to examine the impact of that programme on the burden of flu in primary care over the study period 2010/11–2016/17.Two routine indicators were used to measure impact – GP in-hour consultations and out-of-hour calls for influenza and influenza-like-illness (ILI). Analysis was conducted overall and stratified by age; rates in children under 14 years of age to measure direct impact and rates in individuals 14 years and over to measure indirect impact. Seven influenza seasons were included, three pre-programme seasons (2010/11–2012/13: phase 0), one pilot season (2013/14: phase 1), and three post-programme seasons (2014/15–2016/17: phase 2).High uptake of vaccination was observed from the programme introduction, with consistent uptake of over 50% in pre-school age groups and over 75% in primary school age groups. Statistically significant reductions were found in GP in-hours consultations and in out-of-hour calls in phase 2 compared to phase 0, both overall (GP in-hours RR 0.61, 95% CI 0.38–0.98, p = .040; out-of-hours RR 0.51, 95% CI 0.27–0.97, p = .041) and in the under 14 years group (GP in-hours RR 0.38, 95% CI 0.19–0.75, p = .006; out-of-hours RR 0.39, 95% CI 0.19–0.83, p = .014).Our results suggest that there have been reductions in the burden of flu in primary care settings overall and in children aged under 14 years in the seasons since the introduction of healthy children influenza vaccination. Further seasons should be added to subsequent analyses to strengthen this evidence.     

Ⅱ型排卵障碍女性使用克罗米芬或来曲唑诱导排卵的AID临床结局及妊娠结局比较

目的比较Ⅱ型排卵障碍女性使用克罗米芬(CC)方案或来曲唑(LE)方案诱导排卵后供精人工授精(AID)周期的临床结局和妊娠结局。方法回顾性分析2012年1月至2019年8月578名Ⅱ型排卵障碍妇女在我中心完成的1253个AID周期的超声监测数据及临床资料。比较单用CC或LE或联合促性腺激素(Gn)诱导排卵的AID周期的参数和临床结局。采用单因素和多因素Logistic回归分析,探讨诱导排卵方案与宫内妊娠和活产的关系。比较CC及LE方案的妊娠结局和新生儿出生状况。结果总体上4种方案的宫内妊娠率和活产率无显著差异(P>0.05);校正混杂因素后,与单用CC相比,CC联合Gn及LE联合Gn均显著促进宫内妊娠(分别为OR=1.641,P=0.024;OR=1.543,P=0.019)和活产(分别为OR=1.589,P=0.047;OR=1.508,P=0.034),而单用LE与单用CC相比均无显著差异(P>0.05);各种妊娠结局的发生率及新生儿出生状况在CC及LE方案之间均无显著差异(P>0.05)。结论在宫内妊娠和活产方面,无论单用还是与Gn联用,LE与CC疗效相当,且联用Gn优于单用;LE和CC方案的妊娠结局及新生儿出生状况基本可比。     

Efficacy of the NS1-truncated live attenuated influenza virus vaccine for swine against infection with viruses of major North American and European H3N2 lineages

Control of swine influenza A virus (swIAV) in North America and Europe is complicated because multiple antigenically distinct swIAV strains co-circulate in the field, and no vaccine is available that can provide broad cross-protection against all these swIAVs. In 2017, the first live attenuated influenza vaccine (LAIV) for swine was licensed in the US. The non-structural protein 1 (NS1)-truncated cluster I H3N2 strain A/swine/Texas/4199-2/98 NS1del126 (TX98 LAIV) in this vaccine provides partial cross-protection against heterologous North American cluster II and IV H3N2 swIAV strains. Its efficacy against European or more recent North American H3N2 lineages remains to be investigated. In this study, we evaluated the level of cross-protection against heterologous IAVs representative of the major H3N2 swIAV lineages in Europe and North America. TX98 LAIV prevented both nasal shedding and replication in the lungs of a North American cluster IV H3N2 swIAV for 2/4 pigs, prevented considerable nasal shedding of a North American novel human-like H3N2 swIAV for 2/4 pigs, and reduced replication of a European H3N2 swIAV in the lower respiratory tract to minimal titers for 1/3 pigs. Although TX98 LAIV elicited neutralizing antibodies against the homologous virus in serum and to a lesser extent in nose and lungs, no significant cross-reactive antibody titers against the heterologous swIAVs were detected. Partial cross-protection therefore likely relies on cellular and mucosal immune responses against conserved parts of the swIAV proteins. Since TX98 LAIV can offer partial protection against a broad range of H3N2 swIAVs, it might be a suitable priming vaccine for use in a heterologous prime-boost vaccination strategy.     

Restricted replication of the live attenuated influenza A virus vaccine during infection of primary differentiated human nasal epithelial cells

Live Attenuated Influenza Vaccine (LAIV) strains are associated with cold adapted, temperature sensitive and attenuated phenotypes that have been studied in non-human or immortalized cell cultures as well as in animal models. Using a primary, differentiated human nasal epithelial cell (hNEC) culture system we compared the replication kinetics, levels of cell-associated viral proteins and virus particle release during infection with LAIV or the corresponding wild type (WT) influenza viruses. At both 33 °C and 37 °C, seasonal influenza virus and an antigenically matched LAIV replicated to similar titers in MDCK cells but seasonal influenza virus replicated to higher titers than LAIV in hNEC cultures, suggesting a greater restriction of LAIV replication in hNEC cultures. Despite the disparity in infectious virus production, the supernatants from H1N1 and LAIV infected hNEC cultures had equivalent amounts of viral proteins and hemagglutination titers, suggesting the formation of non-infectious virus particles by LAIV in hNEC cultures.     

Progesterone use in assisted reproductive technology

Progesterone is the main hormone in the luteal phase. It plays a key role in preparing the uterus for a possible pregnancy, and in maintaining it after it has occurred. In assisted reproduction treatments, there is usually a luteal phase deficiency, so it is necessary to supplement this critical phase to obtain the best results, not only of implantation but also of ongoing pregnancy. Among all the available options, exogenously administered progestogens are the most used, as they have proven their efficacy and safety. This review will address the most relevant aspects of luteal phase support with progesterone in the different scenarios an embryo transfer can be performed, such as the stimulated cycle, the artificial cycle, or the natural cycle. Although there is no evidence of the perfect protocol for all patients, recent studies point to the need of individualizing luteal phase support according to the needs of each patient.