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.
Positive reinforcement training techniques were used to gain the cooperation of a socially housed, 3-year-old, insulin-dependent diabetic chimpanzee (Pan troglodytes) in obtaining blood and urine samples for monitoring of glucose levels. A urine collection device, adaptable to many types of caging, allowed collection of urine from the diabetic subject as well as other trained, socially housed animals in their home cages. Four years after initial training, the diabetic subject continued to urinate into the container any time of the day or night, usually within 2 min of presentation of the cue, without removal from the home cage or separation from her companions. Blood samples were readily obtained from the subject by heel puncture or venipuncture. © 1996 Wiley-Liss, Inc.  相似文献   

2.
A growing number of protein interactions are found to be mediated by a large globular region in one protein binding to a comparatively short, peptide stretch in another. Regions that bind a common protein often show a similar sequence pattern or linear motif that mediates the binding. The past year has seen reports of new techniques that can uncover these motifs directly from interaction data. These studies have suggested that the fraction of interactions mediated by these regions is greater than previously anticipated. Concurrently, other work has demonstrated that it is possible to target these interactions using small molecules. Together these developments hold great promise for future efforts to target chemically precise details of complex systems.  相似文献   

3.
This study compared 25-hydroxyvitamin D [25(OH)D] measurements in capillary and venous blood samples collected, respectively by fingerprick and venipuncture. Capillary blood for measuring 25(OH)D has potential advantages by reducing blood volume required (2mL versus 0.3mL for venipuncture and capillary sampling, respectively), facilitating blood collection for those populations in whom venipuncture is difficult (e.g. infants and children), improving patient convenience and reducing costs associated with phlebotomy. The results demonstrated a highly significant relationship between 25(OH)D levels in serum derived from venous and capillary blood samples (r(2)=0.901). Despite statistically higher 25(OH)D levels in fingerprick samples (108+/-9nmol/L) compared with venipuncture samples (90+/-7nmol/L), the correlation between venous and capillary samples provides support for this approach as a practical alternative to venipuncture for vitamin D determination. However, clinical application may require the incorporation of a correction factor for the assessment of insufficiency, and research studies should avoid using the two methods interchangeably. Studying vitamin D's role in health and disease requires collection techniques and measurement methods that are reliable, reproducible, easily accessible, inexpensive and minimally burdensome to the patient. The option to collect patient samples by fingerprick may facilitate the collection process.  相似文献   

4.
Advances in pain therapeutics   总被引:5,自引:0,他引:5  
Recent work in defining molecular targets for neuropathic pain has been plentiful and varied. Three novel targets have received much attention recently: N-methyl-D-aspartate receptor subtypes such as the glycine and NR2B sites, and the tetrodotoxin-resistant voltage-gated sodium channel (Na(v) 1.8; SNS/PN3). Preclinical data have been encouraging as a number of selective NR2B and glycine site antagonists have shown efficacy in animal models. Selective Na(v) 1.8 channel blockers have yet to emerge; however, strong genetic evidence and data from non-selective Na channel blockers indicate that this target too may hold much promise.  相似文献   

5.
Microscale techniques have been applied to biological assays for nearly two decades, but haven't been widely integrated as common tools in biological laboratories. The significant differences between several physical phenomena at the microscale versus the macroscale have been exploited to provide a variety of new types of assays (such as gradient production or spatial cell patterning). However, the use of these devices by biologists seems to be limited by issues regarding biological validation, ease of use, and the limited available readouts for assays done using microtechnology. Critical validation work has been done recently that highlights the current challenges for microfluidic methods and suggest ways in which future devices might be improved to better integrate with biological assays. With more validation and improved designs, microscale techniques hold immense promise as a platform to study aspects of cell biology that are not possible using current macroscale techniques.  相似文献   

6.
7.
Stem and progenitor cells are present in cord blood at a high frequency making these cells a major target population for experimental and clinical studies. Over the past decade there has been considerable developments in cord blood research and transplantation but despite the rapid progress many problems remain. The initial hope that cord blood would be an alternative source of haemopoietic cells for transplantation has been tempered by the fact that there are insufficient cells in most cord blood collections to engraft an adult of average weight. In attempts to increase the cell number, a plethora of techniques for ex-vivo expansion have been developed.These techniques have also proved useful for gene therapy. As cord blood cells possess unique properties this allows them to be utilised as suitable vehicles for gene therapy and long-term engraftment of transduced cells has been achieved. Current work examining the nature of the stem cells present in this haematological source indicates that cord blood contains not only haemopoietic stem cells but also primitive non-haemopoietic cells with high proliferative and developmental potential. As attention focuses on stem cell biology and the controversies surrounding the potential use of embryonic stem cells in treatment of disease, the properties of stem cells from other sources including cord blood are being re-appraised. The purpose of this article is to review some of the current areas of work and highlight biological problems associated with the use of cord blood cells. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

8.
Eight capuchins were trained in a capture and venipuncture procedure. Samples taken immediately following capture indicated that subjects experienced rising cortisol levels over the first 5 weeks of training followed by a return to baseline (equivalent to day 1 levels) in the sixth and seventh weeks. After 7 weeks, samples taken 60 min after initial capture revealed that behaviorally habituated animals exhibited significantly lower cortisol levels in response to venipuncture as opposed to naive and experienced but nonbehaviorally habituated subjects. © 1996 Wiley-Liss, Inc.  相似文献   

9.
Over the last decade, there has been a rapid growth in the application of quantitative genetic techniques to evolutionary studies of natural populations. Whereas this work yields enormous insight into evolutionary processes in the wild, the use of modelling techniques and strategies adopted from animal breeders means that estimates of trait heritabilities (h(2)) are highly vulnerable to misinterpretation. Specifically, when estimated using animal models, h(2) will not generally be comparable across studies and must be interpreted as being conditioned on any fixed effects included in the model. Failure to realize the model dependency of published h(2) estimates will give a very misleading, and in most cases upwardly biased, impression of the potential for trait evolution.  相似文献   

10.
Nanoparticles as targeting ligands   总被引:1,自引:0,他引:1  
A recently published technique enables the attachment of small molecules to nanoparticles for improved targeting of nanomaterials. This new methodology has been compared with some of the other nanoparticle-based techniques for target discovery and found to be more versatile and specific. This approach has potential for high-throughput drug discovery, improved drug delivery and linking of diagnostics to therapeutics for the development of personalized medicines.  相似文献   

11.
NMR spectroscopy has played a developing role in the study of polysaccharide structures for over 30 years. Many new bacterial polysaccharide repeat unit structures have recently been published as a result of the application of modern NMR techniques. NMR can also be used to elucidate the structures of both regular and heterogeneous polysaccharides from fungal and plant sources, as well as complex glycosaminoglycans of animal origin. In addition to covalent structure, conformation and dynamics of polysaccharides are susceptible to NMR analysis, both in solution and in the solid state. Improvements in NMR technology with potential applications to polysaccharide studies hold promise for the future.  相似文献   

12.
Separation of and cholesterol synthesis by human lymphocytes and monocytes.   总被引:3,自引:0,他引:3  
We have devised techniques for the isolation of human monocytes which do not require the adherence of the cells to a surface. In 15 consecutive experiments using density-gradient and counterflow centrifugations, a population of mononuclear cells that was 75 +/- 11% monocytes was obtained within 2 hours of venipuncture. These cells had never been pelleted and represented approximately three-fourths of the monocytes that had been present in the whole blood. In another 22 consecutive experiments using sedimentation in gelatin followed by counterflow and density-gradient centrifugations, a population of lymphocytes that was 99.5 +/- 0.5% pure and a population of monocytes that was 94 +/- 3% pure were obtained within 3 hours of venipuncture. When these freshly isolated cells were incubated in the lipoprotein-deficient fraction of serum (d > 1.21 g/ml) or in solvent-extracted serum, the monocytes incorporated 10-20 times more [2-(14)C]acetate into sterols than did the lymphocytes. Monocytes were seen to constitute between 6 and 46% of the mononuclear cells isolated from normal individuals by the usual density-gradient centrifugation of whole blood on Ficoll-Hypaque. We conclude that future studies of cholesterol metabolism utilizing human mononuclear cells must take into account this large variation in the percentage of monocytes and their disproportionately greater activity during short-term incubations in media that induce sterol synthesis.-Fogelman, A. M., J. Seager, M. Hokom, and P. A. Edwards. Separation of and cholesterol synthesis by human lymphocytes and monocytes.  相似文献   

13.
The Senoi Semai of Malaysia have frequently been cited as examples in the debates over the wellsprings of human violence. Numerous writers have employed selected Semai ethnographic material to support assertions that, their apparent peacefulness notwithstanding, Semai are in reality bloodthirsty killers. This assertion has in turn been used as evidence in support of a variety of approaches whose common thread is a view of aggressiveness and violence as somehow innate in human beings. The authors of this article, whose publications form the basis of most anthropological knowledge of Semai life and culture, draw on their own published and unpublished work as well as on documentation from other sources to refute these interpretations. We hold that Semai life is, as first-hand observers have described it, notably free of interpersonal violence, and we argue that misrepresentations rooted in particular theoretical or philosophical a priori assumptions are scientifically untenable and culturally slanderous.  相似文献   

14.
Scientific investigations depend on the reliability of the observations that can be made. This reliability is determined in part by the understanding of the techniques and technology used to make the observations. The limitations and the strengths of the methodology and the equipment used must be evaluated thoroughly. The extent to which this is and has been the case for the use of the metal based stains in neuroscience is the subject of this paper. I evaluate the metallic stains used for neuroscience from several perspectives. I review briefly the state of neurohistology prior to its “golden years,” 1870–1910. Then I trace the development of the silver based stains used for neurohistology. I wanted to discuss the reasoning used by the originators of the silver based techniques in developing their specific procedures, but discovered that while procedures may be published, the methods and ideas used to arrive at the final procedures are not usually described in published work.  相似文献   

15.
Scientific investigations depend on the reliability of the observations that can be made. This reliability is determined in part by the understanding of the techniques and technology used to make the observations. The limitations and the strengths of the methodology and the equipment used must be evaluated thoroughly. The extent to which this is and has been the case for the use of the metal based stains in neuroscience is the subject of this paper. I evaluate the metallic stains used for neuroscience from several perspectives. I review briefly the state of neurohistology prior to its “golden years,” 1870-1910. Then I trace the development of the silver based stains used for neurohistology. I wanted to discuss the reasoning used by the originators of the silver based techniques in developing their specific procedures, but discovered that while procedures may be published, the methods and ideas used to arrive at the final procedures are not usually described in published work.  相似文献   

16.
Scientific investigations depend on the reliability of the observations that can be made. This reliability is determined in part by the understanding of the techniques and technology used to make the observations. The limitations and the strengths of the methodology and the equipment used must be evaluated thoroughly. The extent to which this is and has been the case for the use of the metal based stains in neuroscience is the subject of this paper. I evaluate the metallic stains used for neuroscience from several perspectives. I review briefly the state of neurohistology prior to its "golden years," 1870-1910. Then I trace the development of the silver based stains used for neurohistology. I wanted to discuss the reasoning used by the originators of the silver based techniques in developing their specific procedures, but discovered that while procedures may be published, the methods and ideas used to arrive at the final procedures are not usually described in published work.  相似文献   

17.
The purpose of this study was to determine the effect of training on the rating of perceived exertion (RPE) at the ventilatory threshold. College students were assigned to either training (n = 17) or control (n = 10) groups. Trainers completed 18 interval training sessions (five X 5 min cycling at 90-100% VO2max) and 8 continuous training sessions (40 min running or cycling) in 6 weeks. Pre- and post-training, cardiorespiratory, metabolic, and perceptual variables were measured at the ventilatory threshold during graded exercise tests on a cycle ergometer. Ventilatory threshold was that point above which VE X VO2-1 increased abruptly relative to work rate. Post-training means of trained and control subjects were compared using analysis of covariance, with pre-training values as covariates. Following training, the adjusted means for the trained subjects were significantly greater (p less than 0.05) than for controls for VO2max (6%), and for work rate (20%), VO2 (23%), and %VO2max (13%) at the ventilatory threshold. However, adjusted means for RPE at the ventilatory threshold were not significantly different (2%). Both before and after training, exercise at the ventilatory threshold was perceived as 'somewhat hard' to 'hard' (RPE = 13-15) by both groups. The relationship between RPE and %VO2max was altered by training, with trained subjects having a lower RPE at a given %VO2max. It is concluded that RPE at the ventilatory threshold is not affected by training, despite that after training the ventilatory threshold occurs at a higher work rate and is associated with higher absolute and relative metabolic and cardiorespiratory demands.  相似文献   

18.
The first author trained 12 laboratory-housed common marmosets (Callithrix jacchus) in pairs to assess the practicality of positive reinforcement training as a technique in the management of these nonhuman animals. Behaviors taught were (a) target training to allow in homecage weighing and (b) providing urine samples. Between 2 to 13, 10-minute training sessions established desired behaviors. Training aggressive animals only after they had been fed eliminated aggression during training. Trained animals proved extremely reliable, and data collection using trained animals was considerably faster than collection using current laboratory techniques. The results suggest that positive reinforcement training is a practical option in the management of laboratory-housed marmosets.  相似文献   

19.
Brucellosis is a widespread zoonosis. Currently the diagnosis of this zoonosis is based on microbiological and serological laboratory tests. Polymerase chain reaction (PCR) has been used to detect DNA from Brucella. Different target genes, primer pairs, PCR techniques, and extraction procedures have previously been published for Brucella detection. But only a few of these primers have been used in human samples, and only one study has been carried out to compare sensitivity between them. In the present study, 3 sets of primers and 3 different PCR protocols amplifying 3 different regions of the Brucella genome were compared for detection of Brucella DNA in a peripheral-blood PCR assay to conclude which is most suitable for the clinical diagnostic laboratory. These 3 pairs of primers amplify 3 different fragments included in (i) a gene encoding a 31 kDa Brucella abortus antigen (B4/B5), (ii) a sequence 16S rRNA of B. abortus (F4/R2), and (iii) a gene encoding an outer membrane protein (omp-2) (JPF/JPR). Some modifications on the reported techniques were applied during the present work to improve the outcome. The results showed that the B4/B5 primer pair had the highest sensitivity for detection of positive samples (98%), the JPF/JPR primer pair detected 88.4% of positive samples, whereas F4/R2 primer pair was the least sensitive, being able to detect only 53.1% of positive samples. The specificity of the 3 techniques was 100%. The B4/B5 primer pair was also able to detect the smallest number of bacteria (700 cfu/mL), whereas JPF/JPR was able to detect 7 x 105 cfu/mL and F4/R2 was able to detect 7 x 107 cfu/mL. It is thus concluded that using the B4/B5 primer PCR with the suggested modifications is a robust assay, which meets the sensitivity requirements to be used for testing of human blood samples for brucellosis in the diagnostic laboratory.  相似文献   

20.
A novel synthesis has been elaborated for the pharmacologically remarkable 2-arylapomorphines described and characterized in the last few years. This new procedure contains two alternative synthetic routes and has allowed the preparation of several hitherto unknown compounds as well. The pharmacological profile of the previously published and the novel 2-alkyl- and arylapomorphines has been determined with the application of in vitro and in vivo techniques. For 2-phenyl- (2) and 2-(4-hydroxyphenyl)apomorphines (3) the superior dopamine agonist profile has been confirmed and for the novel compounds some remarkable results have been observed.  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