首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
转基因动物研究进展   总被引:9,自引:1,他引:8  
在综合了转基因动物近年来的研究进展基础上 ,简述了目前使用的各种转基因方法 ,对各种转基因方法整合表达过程中存在的问题以及提高表达效果等方面进行了初步探讨  相似文献   

2.
Veterinary ophthalmology in laboratory animal studies   总被引:1,自引:1,他引:0  
In this overview the current status of the role of veterinary ophthalmology in laboratory animal studies is discussed. Attention is devoted to current regulatory requirements and study construction, examination techniques commonly used in studies, and a consideration of species characteristics that may be important to investigators. Methods for recording data are discussed with examples of recording systems.  相似文献   

3.
Vaccine efficacy may be estimated by comparing affected proportions or incidence rates between groups of vaccinates and non-vaccinates. This paper discusses vaccine efficacy assessment and reviews interval estimation methods for summary measures from clinical trials and cohort studies of a protective exposure. The measures considered are the attributable fraction as the complement of the risk ratio or incidence density ratio, and the difference in risks or incidence densities. A simple formula is developed for the score method of estimating the incidence density ratio. The application of these methods is illustrated using recent reports of veterinary vaccine studies.  相似文献   

4.
5.
6.
In veterinary medicine, prospective clinical trials are increasingly utilized to address questions regarding effectiveness of therapies and patient prognosis. A large number of these trials involve time-to-event (TTE) endpoints, which require special methods of analysis to handle data in which not all subjects are observed to have the event of interest. Analyses and interpretation of the results can be further complicated when an endpoint of interest is not observed in some patients because they incur a competing risk, such as death from an unrelated cause. Competing risks have been the source of confusion in many epidemiologic analyses leading to the potential for misinterpretation. In this article, we review key considerations for the TTE analysis in the setting of competing risks. We briefly review standard TTE tools, namely Kaplan–Meier survival curves and Cox regression. In the setting of outcomes with competing risks, we provide guidance on the appropriate analysis techniques, such as cumulative incidence curves, to estimate the risk of an event of interest. We also describe a common pitfall of treating competing risks as censoring in Kaplan–Meier survival curve analysis, which can overestimate the event rate of interest. We describe two common regression methods that examine associated risk factors in the presence of competing risks and highlight the different research questions these methods address. This article provides an introductory overview and illustrates concepts with examples from veterinary trials and with example data sets.  相似文献   

7.
8.
Correct classification of the true status of herds is an important component of epidemiologic studies and animal disease-control programs. We review theoretical aspects of herd-level testing through consideration of test performance (herd-level sensitivity, specificity and predictive values), the factors affecting these estimates, and available software for calculations. We present new aspects and considerations concerning the effect of precision and bias in estimation of individual-test performance on herd-test performance and suggest methods (pooled testing, targeted sampling of subpopulations with higher prevalence, and use of combinations of tests) to improve herd-level sensitivity when the expected within-herd prevalence is low.  相似文献   

9.
Epidemiological field studies of animal populations.   总被引:1,自引:1,他引:0       下载免费PDF全文
Numerous survey designs have been developed for epidemiological field studies of human populations, most of which are also applicable to field studies of animal poulations. Each design has its own advantages and disadvantages. The final design selected for a particular study depends upon such factors as the overall purpose of the study, the geographic dimensions of the study area, the diseases incidence or prevalence and species to be studied as well as the planned use for the data. Population dynamics including the distribution and density of the species to be studied are factors that should also be considered in the initial design of a study. A surveillance system, using mailed questionnaire data and a subsequent survey using direct interviews of validate the data in a statewide study of swine birth defects are used to illustrate some of the techniques that can be applied to domestic animal populations in a fairly large geographic area. The type of data collected, its use and its limitations are also considered.  相似文献   

10.
11.
家畜"猝死症"研究进展   总被引:2,自引:1,他引:2  
本文对我国家畜“猝死症”的流行、病因、临床症状、病理变化、诊断及防制的研究进行了概述。  相似文献   

12.
13.
重流行区动物血吸虫病疫情控制技术研究   总被引:3,自引:0,他引:3  
本文对动物血吸虫病重流行区疫情控制技术进行了研究,通过在重流行区设点调查,查晴了重疫区动物血吸虫的流行规律及其疫情居高不下的原因,是放牧动物重复感染所致,导致重复感染的主要因素是钉螺大量存在,病原污染环境,经实施农业工程灭螺,新安全放牧技术,先进的查治技术和方法的应用,有效地控制了动物血吸虫病疫情。血吸虫基因工程苗研制也获得突破性进展。  相似文献   

14.
Transgenic animal models have been used in small numbers in gene function studies in vivo for a period of time, but more recently, the use of a single transgenic animal model has been approved as a second species, 6-month alternative (to the routine 2-year, 2-animal model) used in short-term carcinogenicity studies for generating regulatory application data of new drugs. This article addresses many of the issues associated with the creation and use of one of these transgenic models, the rasH2 mouse, for regulatory science. The discussion includes strategies for mass producing mice with the same stable phenotype, including constructing the transgene, choosing a founder mouse, and controlling both the transgene and background genes; strategies for developing the model for regulatory science, including measurements of carcinogen susceptibility, stability of a large-scale production system, and monitoring for uniform carcinogenicity responses; and finally, efficient use of the transgenic animal model on study. Approximately 20% of mouse carcinogenicity studies for new drug applications in the United States currently use transgenic models, typically the rasH2 mouse. The rasH2 mouse could contribute to animal welfare by reducing the numbers of animals used as well as reducing the cost of carcinogenicity studies. A better understanding of the advantages and disadvantages of the transgenic rasH2 mouse will result in greater and more efficient use of this animal model in the future.  相似文献   

15.
The extensive pig production in Spain is traditionally characterised by: the use of the Iberian pig, an autochthonous breed perfectly integrated into the environment in which they have developed; a long duration of the productive cycle for about 23–24 months; a high level of animal welfare level, specially in the fattening process with freedom of movement and feeding base on natural sources: acorns and grass, and an equilibrated “dehesa” agro-forestry system where this activity has been developed. Nowadays, the introduction of more intensificated methods due to the increasing demand led to important changes, such as: the shortening of the productive cycle (10–12 months); freeing from the territorial base; changes during the fattening period, fattening with mixed feed and less animal freedom. All these facts may implicate a loss of the animal welfare condition. These circumstances lead us to question it from an ethical point of view.  相似文献   

16.
Systematic reviews and meta-analyses of animal studies are important for improving estimates of the effects of treatment and for guiding future clinical studies on humans. The purpose of this systematic review was to assess the methodological quality of systematic reviews and meta-analyses of animal studies in dentistry through using a validated checklist. A literature search was conducted independently and in duplicate in the PubMed and LILACS databases. References in selected systematic reviews were assessed to identify other studies not captured by the electronic searches. The methodological quality of studies was assessed independently and in duplicate by using the AMSTAR checklist; the quality was scored as low, moderate, or high. The reviewers were calibrated before the assessment and agreement between them was assessed using Cohen's Kappa statistic. Of 444 studies retrieved, 54 systematic reviews were selected after full-text assessment. Agreement between the reviewers was regarded as excellent. Only two studies were scored as high quality; 17 and 35 studies were scored as medium and low quality, respectively. There is room for improvement of the methodological quality of systematic reviews of animal studies in dentistry. Checklists, such as AMSTAR, can guide researchers in planning and executing systematic reviews and meta-analyses. For determining the need for additional investigations in animals and in order to provide good data for potential application in human, such reviews should be based on animal experiments performed according to sound methodological principles.  相似文献   

17.
18.
19.
Veterinary surgeons in Italy were surveyed about their current practice with regard to the use of propofol and intravenous opioids during anaesthesia and for treatment of acute pain in small animals. Questionnaires were e-mailed to all 171 members of the Italian Society of Veterinary Regional Anaesthesia and Pain Medicine. Information was requested on the type of practice the veterinarians worked in, the administration techniques used and the perceived benefit of pumps with target-controlled infusion (TCI) capability implementing small animal pharmacokinetic models. A total of 168 responses were received (response rate 98.2 per cent). Of the respondents, 121 (72.0 per cent) worked in a first-opinion private practice, 25 (14.9 per cent) worked in a 24/7 private practice, 11 (6.5 per cent) worked in a referral private practice, eight (4.8 per cent) worked in a university hospital, two (1.2 per cent) were not currently practising with small animals and one (0.6 per cent) had retired. Of the 130 (78.8 per cent) practising respondents who reported using a syringe pump, eight (4.8 per cent) used a TCI system, 31 (18.8 per cent) used manual TCI, 40 (24.2 per cent) used a bolus-elimination-transfer scheme and 51 (31 per cent) used a constant-rate infusion. As a result, 79 of 165 (47.9 per cent) practising respondents used a pharmacokinetic model-driven method of drug delivery. The majority of respondents (81.2 per cent) believed that the use of pumps with TCI capability would improve practice and patient care.  相似文献   

20.
The popularity of amphibians in research, zoological exhibits, and as pets is on the rise. With this increased popularity comes a need for veterinarians to develop methods for managing these animals for various diagnostic and surgical procedures. For many of these procedures, the provision of anesthesia is a must. Fortunately, there are a number of different anesthetics available to the veterinary clinician for anesthetizing amphibians, including tricaine methanesulfonate, clove oil, propofol, isoflurane, and ketamine. In addition to the variety of anesthetics at our disposal, there is also a wider range of methods for delivering the anesthetics than are generally available for higher vertebrates, including immersion, topical, and intracoelomic routes of delivery. The purpose of this article is to review the different methods that can be used to successfully manage an amphibian patient through an anesthetic event.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号