转基因小鼠技术及其在肿瘤研究中的应用

本文综述了近年来出现的一些转基因新方法，诸如精子载体法、核移植法及逆转录病毒法等，并介绍了转基因小鼠技术在肿瘤研究中的一些应用。     

流感病毒检测方法研究进展

近些年,流感在全球范围的频繁暴发,使科研工作者关注的焦点转移到对流感病毒进行方便、快速、准确的鉴定上.论文介绍了国内外流感病毒的检测方法,重点介绍了免疫学检测方法,尤其是酶联免疫法和胶体金免疫标记法.通过对各方法优缺点的比较,提出了免疫学检测方法在方便、快速检测流感病毒方法中的特有优势,尤其是胶体金免疫标记法和酶联免疫...     

In vitro evaluation of five canine tibial plateau leveling methods

OBJECTIVE: To compare application time, accuracy of tibial plateau slope (TPS) correction, presence and magnitude of rotational and angular deformities, and mechanical properties of 5 canine tibial plateau leveling methods. SAMPLE POPULATION: 27 canine tibial replicas created by rapid prototyping methods. PROCEDURE: The application time, accuracy of TPS correction, presence and magnitude of rotational and angular deformation, and construct axial stiffness of 3 internal fixation methods (tibial plateau leveling osteotomy, tibial wedge osteotomy, and chevron wedge osteotomy [CWO]) and 2 external skeletal fixation (ESF) methods (hinged hybrid circular external fixation and wedge osteotomy linear fixation [WOLF]) were assessed. RESULTS: Mean bone model axial stiffness did not differ among methods. Mean application time was more rapid for WOLF than for other methods. Mean TPSs did not differ from our 5 degrees target and were lower for ESF methods, compared with internal fixation methods. Mean postoperative rotational malalignment did not differ from our target or among groups. Mean postoperative medio-lateral angulation did not differ from our target, except for CWO. Internal fixation methods lead to axially stiffer constructs than ESF methods. Reuse of ESF frames did not lead to a decrease in axial stiffness. CONCLUSIONS AND CLINICAL RELEVANCE: The 5 tibial plateau leveling methods had acceptable geometric and mechanical properties. External skeletal fixation methods were more accurate as a result of precise data available for determining the exact magnitude of correction required to achieve a 5 degrees TPS.     

三聚氰胺检测方法的研究进展

全面分析和比较了目前三聚氰胺的检测方法,主要包括色谱检测法（高效液相色谱法、液相色谱—质谱/质谱法、气相色谱—质谱联用法和超高效液相色谱—质谱联用法）、离子色谱法、光谱检测法（拉曼光谱法、红外光谱法、近红外线吸收检测法和核磁共振法）、容量分析法（苦味酸法、升华法、电位滴定法、毛细管电泳检测法和试剂盒检测法）及其他检测方法（比色法、纳米粒子颜色法、化学发光法和浊度法）。     

家畜消化道菌群的分子生物学研究方法

消化道菌群多样性对于维持家畜机体健康起着至关重要的作用,因此,对家畜消化道中定植菌群的种类和功能进行分析就显得尤为关键。由于所有动物的消化道是厌氧环境,所以在体外的好氧环境中,有些菌种不易培养,而这些菌种信息的缺失,会导致消化道优势菌群的分析结果出现偏差。借助一些广泛应用的分子生物学研究方法,可以避免这种情况的发生。这些方法主要是测序法和定性定量分析法。测序法包括指纹图谱法和高通量测序法,定性定量分析法包括荧光原位杂交法和实时荧光定量PCR法。这些方法均基于分子生物学水平,可避免菌体培养步骤,直接分析消化道菌群的组成和功能。综述了上述方法的原理以及各自的优点和缺点,并对它们在动物消化道菌群多样性分析中的应用进行了讨论,以期为研究动物消化道微生物时不同分子生物学方法的选择和联合使用提供参考。     

Culture methods differ on the isolation of Salmonella enterica serotypes from naturally contaminated swine fecal samples.

Four culture methods (A, B, C, and D) were comparatively evaluated for their ability to isolate Salmonella enterica from pooled swine fecal samples (n = 100). None of the methods was able to isolate Salmonella from all positive samples. The relative sensitivity of the culture methods evaluated was 82%, 94%, 95%, and 78% for methods A, B, C, and D, respectively. The comparison of sensitivities showed that methods B and C performed significantly better (P < 0.05) than methods A and D. Although relative sensitivities of methods B and C were equal, from the 89 positive samples concomitantly detected by both, 35 (39.3%) had different serotypes (no match) isolated by each method. On the basis of the results of this study, it was concluded that culture methods differ on the isolation of S. enterica serotypes from naturally contaminated swine fecal samples. Depending on the objective(s) of investigations on the ecology and epidemiology of S. enterica in swine populations, a method or a combination of methods should be considered for more reliable results.     

Research Progress on Microbiological Detection Methods for Residual Antibacterials in Animal Food

Antibacterials are used for the treatment or prevention of animal diseases by direct administration or feed additives. The inappropriate use of antibacterials in aquaculture inevitably lead to excessive residue of antibacterials in animal food. Microbiological methods are the earliest methods for the detection of antibacterials residues. Compared with other detection methods, microbiological methods are widely used for detecting residual antibacterials in livestock and poultry, milk and others animal food because it is easy to operate, low cost and high throughput. The purpose of this paper is to review the development history of microbiological methods and its application status for the detection of residual antibacterials in milk, feeding livestock and poultry, eggs, aquatic products and honey, which provides a theoretical and practical basis for the subsequent development of new microbiological methods. This review also makes a prospect of the development of microbiological methods.     

Methods and Errors in Measurements of Synovial Fluid Volume in Stifles with Low Volume and High Viscosity Synovial Fluid. An Experimental Study in Goats

Synovial fluid (SF) volume was calculated using various methods in the stifles of goats, in which the cranial cruciate ligament had been transected on one side. Measurements were performed prior to surgery and again 4,8, and 18 weeks following surgery, by measuring the dilution of an injected radioactive tracer diluted by the SF. Later, 7 months following surgery, SF volume measurements using simple arthrocentesis were performed on stifles in 9 of the goats, and the SF that could not be aspirated, was calculated using 2 indirect methods simultaneously on identical fluids in 3 of these goats. SF was also collected directly during staged arthrotomy of the stifles in 4 goats.There were conflicting results between methods, but the resulting calculated SF volumes seemed to be larger in the operated stifles compared to the controls for all the methods at about the same degree. The 2 indirect methods used to calculate the fluid remaining in the joints following arthrocentesis gave disparate volume calculations. The experiments revealed sources of error in all methods. Direct methods failed to acquire the total fluid volume, and indirect methods were subject to improper mixing and escape of the injected fluid or synovial fluid or both. It was concluded that none of the methods could be used to measure the “true” volume of SF, if such a concept exists and can be defined. None of the methods were considered reliable to compare volumes in different type of joints containing this type of fluid. It was, however, concluded that all the methods gave indication of increased SF volume present on a relative basis when paired joints were compared.     

Challenges in measuring moisture content of feeds

Accurate determination of the moisture (water) content in individual feed ingredients and mixed feeds is critical throughout the feed industry. Most analytical methods used to determine apparent water content of feedstuffs are empirical, estimating water by evaporation and loss of weight on drying (oven drying methods). These methods differ greatly in effectiveness, resulting in bias. Bias associated with measuring the water content of feedstuffs is a concern not only because of the lack of confidence in the moisture value itself, but also because moisture determinations affect accurate quantification and expression of other nutrient values. Methods for determining moisture in feeds have frequently been borrowed from the cereal, forage, or other applications without validating the extension of the method. Methods such as Karl Fischer titration measure water by direct comparison to a calibration standard for water and can be used as reference methods for the evaluation of empirical methods. The objective of this paper is to review methods for determining moisture, review comparisons among moisture methods for various feedstuffs, make recommendations for a reference method, and make general recommendations toward improving the results of moisture testing. The need to evaluate and improve moisture methods and standardize practices in laboratories is evident from this study. It also is evident that the methods appropriate for a specific feed ingredient or feed should not be extended to all feeds without proper validation to the new matrices. Part of the validation for empirical methods should be comparison to Karl Fischer or other the direct methods. It also is recommended that the results obtained using oven methods not be termed "moisture;" rather, they should be termed "loss on drying," and the drying conditions should become part of the term.     

Comparison of five culture methods for Salmonella isolation from swine fecal samples of known infection status

The current study was conducted to evaluate 5 bacteriologic culture methods (methods 1, 2, 3, 4, and 5) for recovery of Salmonella enterica from swine feces, both for sensitivity of detection (ability to recover Salmonella from a positive sample) and for specificity (not to inadvertently identify an organism as a Salmonella species in a negative sample). Fifty-six negative samples and 46 positive samples were processed using each of the 5 methods, which differed primarily in the combinations of enrichment media used. All negative samples were negative for Salmonella when cultured by all 5 methods (100% specificity). Two of the methods (methods 1 and 4) resulted in the recovery of significantly less (P < 0.05) Salmonella when compared with the remaining 3 methods (methods 2, 3, and 5). No one method was successful in recovering Salmonella from all positive samples, although recovery with method 2 was statistically similar to the total number of positive samples analyzed (42 vs. 46 Salmonella-positive samples, P > 0.05). This study shows that culture methods differ significantly in their performance regarding the isolation of Salmonella from swine fecal samples.     

测定猪饲料氨基酸利用率的体外法研究进展

本文综述了几种体外 (invitro)测定饲料氨基酸利用率的方法 :化学法、微生物法、两步酶水解法、透析管法、回直肠吻合猪十二指肠活动尼龙袋法 (MNBT)、近红外反射光谱瞬间分析技术 (NIRS)。并对它们的技术特点 ,适用性和缺点进行了简要的归纳。     

动物源性食品中抗菌药残留的微生物学检测技术研究进展

抗菌药通过直接用药或用作饲料添加剂投入养殖业中,用于治疗或预防动物疾病。养殖业不当使用抗菌药,不可避免地造成抗菌药在动物源性食品中残留过量。微生物学法是最早用于抗菌药残留检测的方法,较其他检测方法而言,微生物学法操作简单、成本低、高通量,广泛应用于牛奶、畜禽组织等动物源性食品中抗菌药残留快速筛选检测,为后期的化学分析确证法节约大量成本。文章主要综述了微生物学法的发展历程及微生物学法在牛奶、可食性畜禽组织、鸡蛋、水产品、蜂蜜等动物源性食品中抗菌药残留检测的应用情况,为后续研制新微生物学法提供理论依据和实践基础,并对未来的微生物学法的发展做出展望。     

Alternative prediction methods of protein and energy evaluation of pig feeds

Precise knowledge of the actual nutritional value of individual feedstuffs and complete diets for pigs is important for efficient livestock production. Methods of assessment of protein and energy values in pig feeds have been briefly described. In vivo determination of protein and energy values of feeds in pigs are time-consuming,expensive and very often require the use of surgically-modified animals. There is a need for more simple, rapid,inexpensive and reproducible methods for routine feed evaluation. Protein and energy values of pig feeds can be estimated using the following alternative methods: 1) prediction equations based on chemical composition; 2)animal models as rats, cockerels and growing pigs for adult animals; 3) rapid methods, such as the mobile nylon bag technique and in vitro methods. Alternative methods developed for predicting the total tract and ileal digestibility of nutrients including amino acids in feedstuffs and diets for pigs have been reviewed. This article focuses on two in vitro methods that can be used for the routine evaluation of amino acid ileal digestibility and energy value of pig feeds and on factors affecting digestibility determined in vivo in pigs and by alternative methods. Validation of alternative methods has been carried out by comparing the results obtained using these methods with those acquired in vivo in pigs. In conclusion, energy and protein values of pig feeds may be estimated with satisfactory precision in rats and by the two-or three-step in vitro methods providing equations for the calculation of standardized ileal digestibility of amino acids and metabolizable energy content. The use of alternative methods of feed evaluation is an important way for reduction of stressful animal experiments.     

Comparison of selected diagnostic methods for identification of Cryptosporidium parvum and Cryptosporidium andersoni in routine examination of faeces

This study involved the comparison of suitability of different methods for routine diagnostics of Cryptosporidium spp. Two staining methods, one concentration-sedimentation method, seven concentration-floatation methods and one combined floatation-sedimentation method were compared. The methods were tested with two concentrations (1 x 10(5) and 1 x 10(6)/g) of C. parvum and C. andersoni. The methods were evaluated using light microscope, magnification 400x for concentration methods and 1000x for stained samples respectively. Specificity of both staining methods was 95-100%. Ziehl-Neelsen with P < 0.01 is more suitable for identification of C. andersoni and modified Milácek-Vítovec with P < 0.01 for identification of C. parvum. Concerning specificity and sensitivity, the floatation-concentration method by Sheather was found to provide the best results of all selected methods. The merthiolate iodine formaldehyde concentration (MIFC) method was the least specific one. The least suitable method concerning sensitivity and costs was the floatation method with caesium chloride (CsCl) with a specificity of 29%.     

非甾体类抗炎药前处理及检测方法研究进展

非甾体类抗炎药是目前兽医临床中使用最为广泛的一类药物，但此类药物在动物源性食品中的残留对人类的健康造成严重威胁。通过综述国内外非甾体类抗炎药在动物源性食品中的前处理方法和检测方法的研究现状，总结不同前处理方法的优缺点以及多种检测方法的灵敏度和准确性，对非甾体类药物的残留检测发展趋势进行展望，旨在为今后的检测方法开发提供参考。     

单胃动物饲料消化能评定方法剖析

从单胃动物消化能评定方法的研究进展入手,详细综述了评定饲料消化能的各种非生物学方法,并对这些方法的实际应用效果和应用价值进行了评价。同时,对各种方法所存在的问题进行了剖析,从生物学和营养学的角度探讨了非生物学法评定饲料消化能值的可行性。     

牛隐孢子虫卵囊分离和纯化方法的比较试验

运用3种粪便漂浮法、3种染色法和2种分离提纯法对10头犊牛的粪便进行卵囊检查、分离纯化，对这些方法进行比较。试验结果显示：饱和硫酸锌漂浮法结合姬姆萨氏染色法检查隐孢子虫卵囊，检出率最高、效果最佳；蔗糖密度梯度离心法分离纯化隐孢子虫卵囊。收集的卵囊最多，效果最好。     

几种DNA多态性的研究方法

DNA多态性研究是对遗传学、免疫学、流行病学以及基因突变相关疾病等方面研究非常有效并且得到广泛应用的方法。作者介绍了PCR RFLP、PCR SSCP、HMA及DGGE 4种DNA多态性分析的方法，并对这些方法的原理及其在应用过程中常见问题，解决问题的方法和优缺点作一综述。     

微生物原生质体融合技术研究进展

原生质体融合技术在遗传学、动植物远缘杂交育种、生物学、免疫学、兽医学以及医药、食品、农业等方面都有广泛的应用价值,文章就原生质体制备、再生及其融合过程中的影响因素做了综述,另外还对原生质体融合方法和融合子的筛选方法进行了比较,为选择适宜有效的诱导融合方法和筛选方法提供依据。