猪圆环病毒2型核酸疫苗的小鼠免疫保护试验

为了研究猪圆环病毒2型(PCV2)核酸疫苗在小鼠攻毒试验中的免疫保护效果,以PCV-2 GXWZ-1株为模板,扩增出ORF2基因及其截短基因8个片段(A(ORF2)、B(51-100aa)、C(101-150aa)、D(181-235aa)、E(151-200aa)、F(51-150aa)、G(101-235aa)、H(51-235aa)),将其插入到pcDNA3.0载体中,构建出真核表达质粒,并将其转染至PK-15细胞,用间接免疫荧光试验检测其瞬时表达情况。将试验小鼠随机分成9组,其中免疫组7组,阴阳性对照各1组,将纯化的真核表达质粒对小鼠进行组合免疫;二免后,用经处理过的PCV-2 GXWZ-2株阳性病料悬液腹腔注射免疫组和非免疫对照组小鼠,阴性对照组用生理盐水腹腔注射;其后进行体重记录、病理切片制作及PCR检测。结果表明:共有6个真核表达质粒成功在PK-15细胞中表达。在攻毒后的3周内,阳性对照组小鼠PCR诊断均为阳性;免疫组中,部分组小鼠在攻毒后第1周或在第2周为阳性,到第3周时各免疫组小鼠全部为阴性;阴性对照组始终为阴性。免疫组在病理保护学方面明显优于非免疫对照组,非免疫对照组的体重增长速率略低于免疫组和阴性对照组。由此可见猪圆环病毒2型核酸疫苗在小鼠攻毒试验中有明显的保护作用。     

猪传染性胸膜肺炎放线杆菌和猪圆环病毒2型二重实时荧光定量PCR检测方法的建立

以胸膜肺炎放线杆菌(App)apx ⅣA基因和猪圆环病毒2型(PCV-2)ORF2基因为靶基因,分别设计特异性引物和探针,建立App和PCV-2的二重荧光PCR方法。App引物扩增的目的片段大小为132bp,PCV-2为169bp。建立的方法可在同一反应体系中同时对App和PCV-2进行定量检测鉴别,其敏感性分别为1×101拷贝和1×100拷贝,对其他猪病病原核酸的检测为阴性。利用该方法对10份人工感染临床样品进行检测试验,其结果符合率达100%,说明该方法可用于对临床样品中App和PCV-2的检测。     

Closed system anaesthesia in dogs using liquid sevoflurane injection; evaluation of the square-root-of-time model and the influence of CO2 absorbent

Objective To determine whether predictable alveolar concentrations of sevoflurane are reliably produced in dogs when liquid sevoflurane is injected into closed circuit breathing systems, as calculated by Lowe's square‐root‐of‐time anaesthetic uptake model, and to confirm the validity of the model using soda lime and calcium hydroxide lime. Study design Prospective clinical study. Animals Eleven healthy dogs with a mean body mass of 34 ± 9 kg scheduled for pelvic limb orthopaedic surgery. Materials and methods Following pre‐anaesthetic medication, anaesthesia was induced with propofol and maintained with sevoflurane in a closed circle system. Epidural anaesthesia was performed with morphine and bupivacaine. Liquid sevoflurane was injected into the circuit by syringe, using dosages and time intervals derived from Lowe's square‐root‐of‐time anaesthetic uptake model. The target alveolar concentration chosen was 1.1 × MAC (2.6% end‐tidal sevoflurane). Either soda lime (group S; n = 6) or calcium hydroxide lime (Amsorb; group A; n = 5) were used for CO₂ absorption. Sevoflurane concentration and the respiratory gas composition were measured with an infrared gas analyser. Results End‐tidal sevoflurane concentrations were close to the predicted value of 2.6% at 9 minutes (2.53 ± 0.1% group S; 2.60 ± 0.26% group A) and 16 minutes (2.55 ± 0.30 group S; 2.52 ± 0.28% group A) but declined thereafter to reach 50% (group S) and 64% (group A) of the predicted value at 121 minutes. There was a constant trend towards higher end‐tidal sevoflurane concentrations in group A but the difference was not statistically significant. Conclusions The square‐root‐of‐time model leads to significantly lower alveolar concentrations than expected, suggesting that the rate of sevoflurane uptake in dogs declines less rapidly than predicted. The use of Amsorb tends to reduce the deviation from predicted concentrations. Clinical relevance The model used in this study provided only an approximate guide to the volume of liquid sevoflurane required. Consequently, the definitive dose schedule must be based on measured anaesthetic concentrations and clinical monitoring.     

First report of porcine circovirus type 2 infections in Cuba

To obtain information about the porcine circovirus type 2 (PCV2) infection status of pigs in Cuba and the probable association of PCV2 with other porcine viruses, tissue samples collected from ill pigs were evaluated using polymerase chain reaction (PCR). The PCR analysis showed that 67.7% of the samples (23/34) from seven swine herds of six different geographic regions were detected to be positive for PCV2. Ten of the 23 PCV2 positive samples (43.5%) shown a concurrent infection with porcine parvovirus (PPV) and 17 of 23 PCV2 positive samples (73.9%) exhibited a concomitant infection with classical swine fever virus (CSFV). This study is the first report of PCV2 infecting pigs with different clinical conditions in Cuban swine herds and provides evidence of PCV2 co-infection with PPV and CSFV in the field.     

南阳牛IGF2基因第2外显子多态性及其与生长发育相关性研究

以126头纯种南阳黄牛为研究材料，利用PCR-RFLPs技术对胰岛素样生长因子2（IGF2）第2外显子的多态性及其与生长发育的相关性进行了分析。结果表明：南阳牛在该位点的遗传多态性丰富。检测到2种等位基因A和B，频率分别为0．6865和0．3135，A等位基因在群体中是优势等位基因；BB型个体的6、12、18、24月龄体斜长和胸围，12、18和24月龄的坐骨端宽，初生、6月龄和24月龄体重等体征性状显著地优于AA型；6月龄体斜长、12月龄的胸围、18月龄和24月龄坐骨端宽也显著优于杂合型。初步推断JGF2基因是非常有价值的辅助选择标记，可为南阳牛肉用型方向选择提供理论依据。     

Transthoracic echocardiographic measurement of patent ductus arteriosus in dogs

BACKGROUND: Patent ductus arteriosus (PDA) size and morphology influence the selection of the kind and the size of the embolization device used to effect shunt closure. HYPOTHESIS: That echocardiographic measurement of PDA in dogs is accurate. ANIMALS: Forty-five client-owned dogs with PDA. METHODS: Prospective observational study. Echocardiographic and angiographic data were compared. RESULTS: Measurement of the ductus in color Doppler echocardiography (CD-E) and 2-dimensional echocardiography (2D-E) was achieved from left parasternal views in 43 of 45 unsedated dogs (96%). In these 43 dogs, the angiographic minimal PDA diameter was 3.72 +/- 1.59 mm, and the diameter of the PDA ampulla was 8.46 +/- 3.01 mm. The CD-E minimal PDA diameter ranged from 2.3 to 9.5 mm (median, 4.0 mm). There was a significant mean difference to the angiographic measurements (1.15 +/- 0.95 mm; P < .0001). An agreement in a 1-mm range was found in 21 of 43 dogs (48%). The 2D-E minimal PDA diameter was 3.73 +/- 1.78 mm, and the mean difference to the angiographic measurements was not significant (0.00 +/- 0.72 mm; P = .98). An agreement in a 1-mm range was found in 31 of 43 dogs (72%). The 2D-E measurement of the PDA ampulla revealed a significant mean difference to the angiographic data (1.95 +/- 2.43 mm, P < .0001). An agreement in a 2-mm range was found in 21 of 43 dogs (49%). CONCLUSIONS AND CLINICAL IMPORTANCE: The 2D-E from the left cranial parasternal view is an excellent noninvasive method to estimate the PDA minimal diameter before doing catheter intervention.     

Identification of polymorphisms and association analysis with meat quality traits in the porcine KIAA1717 and HUMMLC2B genes

Skeletal muscle genes are potential candidates for production and meat quality. Screening a subtracted cDNA library constructed with mRNA obtained from longissimus dorsi muscles of F1 hybrids Landrace × Yorkshire and their female parents Yorkshire, we isolated two partial sequences coding for the H3-K4-specific methyltransferase (KIAA1717) and skeletal muscle myosin regulatory light chain (HUMMLC2B) genes. Database search revealed KIAA1717 and HUMMLC2B encoded proteins with SET domain and EF-hand calcium binding motif, respectively. In the present work we identified their partial polymorphisms and two SNPs, one (C1354T) at the 3&#x2032; untranslated region (UTR) of KIAA1717 and one (A345G) at the SINE (PRE-1) element of HUMMLC2B, both created/disrupted a restriction site for endonuclease Msp I. The selected pigs were genotyped at the KIAA1717 C1354T and HUMMLC2B A345G sites by means of a PCR-RFLP protocol. Significant associations were observed for the KIAA1717 C1354T polymorphic site with meat marbling (longissimus doris (p < 0.05), biceps femoris (p < 0.01)) and intramuscular fat (p < 0.01). HUMMLC2B A345G were significantly associated with meat pH (longissimus doris (p < 0.05), biceps femoris (p < 0.01)), drip loss (p < 0.01), water holding capacity (p < 0.01) and meat color value (longissimus doris (p < 0.01), biceps femoris (p < 0.05)). Further studies are needed to confirm these preliminary results.     

鸡传染性法氏囊病毒VP2蛋白B细胞抗原表位预测

以鸡传染性法氏囊病毒VP2蛋白的基因组序列为基础,采用Garnier-Robson方法、Chou-Fasman方法和Karplus-Schultz方法预测VP2蛋白质的二级结构;用Kyte-Doolittle方案预测蛋白质的亲水性;用Emini方案预测蛋白质的表面可能性;用Jameson-Wolf方案预测氨基酸的抗原性指数。综合分析,预测VP2蛋白的抗原表位。通过以上几种方法预测IBDV病毒VP2蛋白的B细胞表位位于VP2蛋白N端3-10、30-45、77-84、150-157、197-206、211-222、278-288、298-303、315-325、376-381、386-394、403-411、415-425区段。