Genetic Engineering Approaches to Pig Production*

Modern biotechnology promises a number of new applications in animal breeding and production. Although conventional pig breeding has achieved a high level of efficiency and productivity numerous problems have been encountered with animal health and the loss of meat quality. Selection based on phenotypic performance data of individual animals does not take into account the importance of specific genes and their relevance within a complex regulatory system. In most cases it is therefore difficult to trace back the genetic origins of clinically important disorders. The application of genetic engineering techniques in pig production will facilitate diagnosis, improvement of productivity, and animal health by allowing direct genetic manipulation. Attention must be focussed on the physical and genetic analysis of the procine genome. The isolation and characterisation of genes, DNA-markers, polymorphic DNA-fragments, and their chromosomal assignment will be important prerequisites and tools for the elucidation of genetic disorders. Especially the detection of heterozygous carriers of recessive disorders and their elimination from the breeding stock will increase selection accuracy and decrease the generation intervals. But also the rapid and simple detection of infectious diseases, which is sometimes difficult if not impossible at present, will improve animal health and welfare. Although the production of transgenic animals either by DNA-microinjection into zygotes or the use of embryonal stem cells manipulated in vitro is less straightforward than DNA-based diagnosis it will play an important role in the direct manipulation of the porcine genome and genes. Breeding programmes including the use of transgenic livestock have already been developed. There is no doubt that genetic engineering has reached a degree of practical feasibility, allowing it to play an important role in pig breeding in particular and animal production in general.     

健骨注射液硬膜外腔注射治疗腰腿痛52例的疗效观察

用中草药健骨注射液行硬膜外腔注射治疗急慢性腰腿痛52例,结果症状消失与功能恢复者占40.7％,总有效率为92.3％,其疗效不亚于用普鲁卡因加强的松龙注射液,且未见有何副作用,使用无禁忌症。     

Preparation of gfp-bcl-XL-contained recombinant adenovirus vector by the homologous recombination in bacteria

AIM: To prepare gfp-bcl-X_L-contained recombinant adenovirus(rAd-gfp-bcl-X_L).METHODS: Bcl-X_L gene was amplified from pEGFP-C₃-bcl-X_L, subcloned into shuttle plasmid and formed transfer plasmid of pAdTrack-CMV-bcl-X_L. Then pAdTrack-CMV-bcl-X_L was linealinzed with PmeI and co-transformed into BJ5183 bacteria with adenovirus genomic plasmid of pAdEasy-1. The identified recombinant adenovirus plasmid was digested with PacI and transfected into 293 cells to package recombinant adenovirus particles. The target gene was detected by PCR.RESULTS: There were about 35% positive recombinant bacterial clones after the co-transformation of pAdTrack-CMV-bcl-X_L and pAdEasy-1 into BJ5183. Recombinant adenovirus particle were produced and further amplified after the transfection of pAdEasy-1-gfp-bcl-X_L into 293 cells. PCR test indicated that the recombinant Ad contained bcl-X_L gene. The titer of the purified rAd-gfp-bcl-X_L was 6.5×10¹² PFU/L. CONCLUSIONS: The homologous recombination in bacteria is a convenient and high efficient method to prepare rAd-gfp-bcl-X_L. This affords a good gene transfer vector for the gene therapy in human’s diseases.     

Results from the treatment of advanced stage squamous cell carcinoma of the nasal planum in cats, using a combination of intralesional carboplatin and superficial radiotherapy: a pilot study

Six cats with an advanced stage squamous cell carcinoma (SCC) of the nasal planum were treated with a combination of superficial radiotherapy and intralesional carboplatin therapy. This multimodality protocol was well tolerated by the majority of cats and resulted in complete responses in all cats (100%). Median follow‐up for all cats is 268 days, and the median time‐to‐recurrence, time‐to‐progression and overall survival have not yet been reached. Our study, although limited in number of animals and with a relatively short median follow‐up compared to other studies for this disease, suggests that a combination of radiotherapy and intralesional carboplatin is a useful treatment option for an advanced stage SCC of the nasal planum in cats and warrants further application of the multimodality approach presented here.     

Effect of dasatinib in a xenograft mouse model of canine histiocytic sarcoma and in vitro expression status of its potential target EPHA2

Canine histiocytic sarcoma (HS) is an aggressive and highly metastatic tumor. Previously, the kinase inhibitor dasatinib was shown to have potent growth inhibitory activity against HS cells in vitro, possibly via targeting the EPHA2 receptor. Here, the in vivo effect of dasatinib in HS cells was investigated using a xenograft mouse model. Moreover, the expression status of EPHA2 was examined in six HS cell lines, ranging from insensitive to highly sensitive to dasatinib. In the HS xenograft mouse model, dasatinib significantly suppressed tumor growth, as illustrated by a decrease in mitotic and Ki67 indices and an increase in apoptotic index in tumor tissues. On Western blot analysis, EPHA2 was only weakly detected in all HS cell lines, regardless of sensitivity to dasatinib. Dasatinib likely results in the inhibition of xenograft tumor growth via a mechanism other than targeting EPHA2. The findings of this study suggest that dasatinib is a targeted therapy drug worthy of further exploration for the treatment of canine HS.     

A comparison of the effect of short-acting and long-acting cloxacillin-based dry-cow therapy on somatic cell counts after calving in cows also given internal teat sealants

AIM: To compare, in cows treated with an internal teat sealant, the effect of short-acting and long-acting cloxacillin-based dry-cow therapy on somatic cell counts (SCC) after calving.

METHODS: Cows from a spring-calving, pasture-based dairy farm in the Manawatu-Whanganui region of New Zealand were randomly allocated to receive either a short-acting cloxacillin and ampicillin dry-cow therapy and internal teat sealant (n=291) or a long-acting cloxacillin and ampicillin dry-cow therapy and internal teat sealant (n=288) at the end of lactation. Cows were managed on-farm with routine husbandry procedures through the dry period and following calving. A multivariable logistic regression model was used to determine the association between length of action of dry-cow therapy and the proportion of cows with a SCC >150,000?cells/mL at the first herd test after calving.

RESULTS: Age of cow, mean SCC for the preceding season and interval from calving to the first post-calving herd test were all associated with the proportion of cows with an individual SCC >150,000?cells/mL at the first herd test (p<0.001) Treatment with the short-acting dry-cow therapy was not associated with decreased odds of cows having a SCC >150,000?cells/mL at the first herd test compared with treatment with long-acting dry-cow therapy (OR=0.724; 95% CI=0.40–1.30).

CONCLUSIONS AND CLINICAL RELEVANCE: In this herd, which routinely used internal teat sealants, the use of short-acting cloxacillin-based dry-cow therapy did not result in an increased proportion of cows with elevated SSC post-calving. This was a single farm, single year study but indicates that in this herd, changing from a long-acting to a short-acting antimicrobial may have no impact on the prevalence of subclinical mastitis.     

伊维菌素浇泼剂治疗猪疥螨病的效果观察

应用0.5%伊维菌素浇泼剂,按0.1~0.12mL/kg剂量治疗112头疥螨病患猪。结果表明,给药后14d治愈率达100%。     

牙鲆盾纤毛虫病的药物防治试验

试验结果表明:CH3OH(>400.0×10-6)和CuSO4(淡水条件下)对牙鲆盾纤毛虫病有较好的杀除效果;结合使用中草药"盾纤虫清"能彻底治愈此病。淡水浸泡、H2O2、KMnO4等方法可杀死牙鲆体内盾纤毛虫。     

益生菌对类风湿关节炎的改善作用研究进展

类风湿关节炎是一种威胁全球人类健康的自身免疫性疾病,肠道菌群的平衡与类风湿关节炎密切相关。由于益生菌在改善肠道菌群紊乱、恢复正常肠道菌群中发挥重要作用,因此给益生菌治疗类风湿关节炎提供了可能。本文综述类风湿关节炎病因、机制及患者肠道菌群的变化,总结近年来益生菌在治疗类风湿关节炎中的研究现状,为进一步临床试验和今后的应用提供依据。     

Salivary cortisol and behavior in therapy dogs during animal-assisted interventions: A pilot study

Animal-assisted interventions (AAIs) have been associated with positive effects on human psychological and physiological health. Although the perception of quality standards in AAIs is high, only few investigations have focused on potential welfare implications for therapy dogs linked to their performance in AAIs. The standardized program “multiprofessional animal-assisted intervention (MTI)” has been carried out in adult mental health care, significantly improving patients' prosocial behaviors. In the present study, we monitored salivary cortisol and behavioral measures in therapy dogs that participated in MTI group therapy sessions in an in-patient substance abuse treatment facility. Work-related activity (lay, sit, stand, walk, and run), behavior (lip licking, yawning, paw lifting, body shake, tail wagging, and panting), response to human action (taking food treats and obeying commands), and salivary cortisol levels were analyzed over the course of 5 subsequent MTI working sessions in experienced therapy dogs (N = 5), aged 5.4 ± 2.8 years (mean ± standard deviation). Salivary cortisol levels decreased from presession to postsession in sessions 1, 2, and 3. However, only in session 4 and 5, postsession cortisol levels were significantly lower than presession levels (P = 0.043). There was no difference between salivary cortisol levels sampled on a nonworking day at home and work-related levels sampled at the therapy site. None of the behavioral parameters varied significantly over the course of the 5 MTI sessions. Both lip licking (P = 0.038) and body shake (P = 0.021) were positively correlated with the decline in cortisol during session 5. The study results suggest that trained dogs are not being stressed by repeated participation in in-patient substance abuse therapy sessions. Further investigation into the effects of animal-assisted therapy on dogs' physiological markers and behavior is warranted.