Literature review of the subject of a research project

It can be very complicated to obtain relevant information through searching the medical literature if you do not know how it is organized and indexed or if you do not know how to use the specialized databases. For a successful review of the literature, you need to know what you are looking for and the key words for an effective search of the specialized databases and libraries and especially of the internet. It is essential to critically evaluate the information selected. Finally, using a reference manager can facilitate the gathering, organization, systematization, and integration of the bibliographic references in the documents generated in the study. This article aims to provide guidelines for efficient searching for information and for accurate, critical use of the literature. It makes recommendations about strategies for managing references to help to ensure the success of a research project.     

Donor room personnel attitudes toward autologous donors

Patients with serious illnesses who donate their blood for autologous use create anxiety for many phlebotomists. Donor room staff were surveyed at three donor centers, using confidential questionnaires, to identify their concerns and to evaluate factors associated with reduced anxiety toward autologous donors. Among respondents (n = 93), 58 percent had patient care experience within the last 5 years, which correlated with diminished concern about phlebotomizing cardiac patients (r = .21; p = 0.04). Fifty-seven percent of respondents had drawn blood from greater than 50 autologous donors. Surprisingly, the experience of drawing blood from relatively large numbers of autologous donors did not correlate with increased confidence in phlebotomizing pediatric, cardiac, and elderly patients (r = -.04; p = 0.75). Those respondents who felt that they had adequate medical support agreed with more liberal donor criteria and were more confident about phlebotomizing pediatric, cardiac, and elderly patients (r = -.32; p = 0.001). Those respondents who believed most strongly in the benefits of autologous transfusion had the least anxiety toward donors who were medically more complex (r = .39; p = 0.0001). It is concluded that, contrary to what might be expected, phlebotomizing large numbers of autologous donors does not reduce the anxiety of staff members when they encounter donors with complex medical problems. Factors that do reduce anxiety include dependable physician and other medical support services, previous experience in direct patient care, and knowledge of the benefits of autologous transfusion.     

Donation reactions among autologous donors

Studies of risk factors associated with reactions among autologous blood donors have been limited. Therefore, 2091 autologous and 4737 homologous donations were examined. Donors at greatest risk for reaction were autologous donors who had reactions at first donation; among 45 who made repeat donations for the same surgery, 17 (38%) had repeat reactions. The group least likely to experience reactions were the autologous donors greater than or equal to 66 years old; they experienced a 1.9 greater than or equal to percent (6/310) incidence of reactions. More reactions were seen in both autologous and homologous donors in the categories of first-time donor, female gender, decreasing age, and lower weight. Multiple logistic regression analysis showed that all of these variables were independent predictors of donor reaction, with first-time donation (odds ratio, 2.4) and female gender (odds ratio, 1.9) being the strongest predictors of reaction. Donor room personnel should be alerted that autologous donors who react at first donation are very likely to react at subsequent donations. Contrary to common concern, elderly autologous donors are least likely to have reactions.     

大剂量免疫球蛋白预防肾移植术后肺部感染:随机对照

目的:肾移植术后半年内发生的并发症主要为感染,尤以肺部感染为重。静脉注射大剂量免疫球蛋白预防肾移植术后早期肺部感染的效果值得临床应用中予以总结提高。方法:①实验对象及分组:选择2002-01/2006-12于海南省人民医院肾内科就诊的肾移植术后半年内患者40例,对实验及治疗方案均知情同意,且得到医院伦理道德委员会批准。按随机数字表法分为2组,免疫球蛋白组、对照组各20例。②实验分组:免疫球蛋白组在应用免疫抑制剂基础上用0.4g/(kg·d)免疫球蛋白治疗;对照组应用免疫抑制剂。③实验评估:观察两组患者普通肺炎、重症肺炎发生率及血清IgG和T淋巴细胞亚群水平变化。结果:40例患者全部进入结果分析。①免疫球蛋白组患者的普通肺炎感染率及重症肺炎感染率均低于对照组(P<0.01)。②免疫球蛋白组患者血IgG、T淋巴细胞亚群CD3 ,CD4 ,CD8 水平均高于对照组(P<0.05),用免疫球蛋白治疗未见副作用。结论:随机对照结果显示,肾移植术后早期应用大剂量免疫球蛋白能明显减少肺部感染发生,减少并发症,提高肾移植患者生存率。     

Adverse reactions in patients transfused with cryopreserved marrow

Marrow is cryopreserved for use in autologous bone marrow transplants, but little is known of the incidence of reactions in patients transfused with these cryopreserved marrows. Reactions in patients transfused during a 4-year period with 134 autologous marrows cryopreserved in dimethyl sulfoxide (DMSO) were compared with those in patients transfused with marrow that had been collected from HLA-compatible donors and that had not been cryopreserved. Patients transfused with cryopreserved marrow had significantly more nausea (44.8 vs. 14.1%; p less than 0.0005), vomiting (23.9 vs. 8.5%; p less than 0.01), chills (31.3 vs. 1.4%; p less than 0.0005), and fever (17.9 vs. 0%; p less than 0.005) than patients transfused with fresh allogeneic marrow. The incidence of emesis correlated with the dose of DMSO received, but that of nausea did not. All cryopreserved marrows were cultured for bacteria at the time of transfusion and 17 (12.7%) were found to be positive. Only 1 of the 17 patients transfused with culture-positive marrow developed sepsis during the transplant course with the same organism that was present in the transfused marrow. Although the reactions in donors transfused with cryopreserved marrow were readily treated, this study suggests that the incidence of some reactions might be decreased by reducing the dose of DMSO transfused. Bacterial contamination of transfused marrow was a worrisome complication, and efforts should be made to improve marrow collection and processing techniques to minimize that risk.     

Quality indicators and specifications for strategic and support processes in laboratory medicine

BACKGROUND: This work is the second part of a study regarding indicators and quality specifications for the non-analytical processes in laboratory medicine. Five primary care and five hospital laboratories agreed on the indicators for two strategic processes (quality planning and project development) and various support processes (client relationships, instrument and infrastructure maintenance, safety and risk prevention, purchases and storage, personnel training). METHODS: In the majority of cases, the median values recorded over 1 year is considered to be the state-of-the-art in our setting and proposed as the quality specification for the indicators stated. Values have been stratified according to primary care and hospital laboratory for referred tests and group of personnel for training. In some cases, the specifications have been set equal to zero events, such as serious incidents in the infrastructure maintenance process and number of work accidents in the safety and risk prevention process. RESULTS AND CONCLUSIONS: In light of this study, an effort is needed to optimize decisions regarding corrective actions and to move from a subjective individual criterion to systematic and comparative management. This preliminary study provides a comprehensive vision of a subject that could motivate further research and advances in the quality of laboratory services.     

In vitro and in vivo persistence of reticulocytes from donor red cells

BACKGROUND: Reticulocytes are important in the phenotyping of transfused patients. Reticulocytes can persist in blood units for the shelf life of the unit. STUDY DESIGN AND METHODS: Temperature dependence of reticulocyte persistence was examined in vitro at 4, 24, and 37 degrees C by using thiazole orange staining and flow cytometric analysis. Two-color flow cytometric analysis was used to evaluate the persistence of donor reticulocytes in transfused patients. RESULTS: Flow cytometric analysis using thiazole orange demonstrated that persistence of reticulocytes in units of stored CPDA-1 blood was temperature-dependent. Reticulocytes disappeared over 13 and 6 days at 24 degrees C and 37 degrees C, respectively, but at 4 degrees C the reticulocyte count changed little over 35 days. Two-color flow cytometric analysis of reticulocyte antigens was used to follow donor reticulocytes in 14 transfusion events in nine different patients. Donor reticulocytes persisted through 24 hours in 75 percent of the patients and were detectable at 48 hours in three patients. CONCLUSION: This study demonstrates that reticulocytes persist during refrigerated storage; they are detectable in the circulation of most recipients for the first 24 hours after transfusion and in the circulation of a few recipients after 48 hours. These findings may have relevance for separation techniques based on reticulocyte density in samples drawn shortly after transfusion and for evaluation of reticulocyte counts in patients with hematologic abnormalities.     

Down综合征16三体小鼠胃的神经发育观察

目的　研究Dow n 综合征动物模型16 三体和正常同窝鼠支配胃的神经发育。方法　采用16三体鼠培育,同窝鼠胚胎龄(em bryonic days, ED)13～18 天细胞遗传学分析,蛋白基因产物9.5(proteingene product 9.5, PGP9.5)免疫组化等方法对16 三体小鼠胃的神经发育进行了研究。结果　正常同窝鼠,胎龄13 天(ED13)来源于外胚层神经嵴的神经母细胞迁移并进驻胃壁;ED14 神经元发出突起,形成原始神经网络;ED15 形成简单排列的肌间神经丛,开始出现早期的神经节;ED16 有分布规则的肌间神经丛;ED17 神经母细胞进驻粘膜下层,形成粘膜下神经丛;ED18 完整的胃神经丛形成,即粘膜下浅、深神经丛和肌间神经丛。与正常同窝鼠比较,16 三体鼠胃神经系发育迟缓,ED14 胃壁始有散在分布神经元。此后,胃神经系的发育与分化均较正常延迟,至ED18 仅有肌间神经丛。根据胃神经系的发育程度和PGP9.5 免疫反应强度作半定量分析及秩和检验,16 三体鼠胃神经的发育明显落后于它们正常的同窝鼠,两者比较有显著性差异(P< 0.05)。结论　16 三体小鼠是公认的Dow n 综合征动物模型,它除了有多系统和多器官的畸型外,还发现有小鼠胃神经丛发育迟缓,粘膜下神经丛缺失。     

Differentiation of viable and nonviable myocardium by the use of three-dimensional tagged MRI in 2-day-old reperfused canine infarcts

BACKGROUND: To limit ischemic myocardial injury, it is important to differentiate viable from infarcted myocardium. Three dimensional (3D) tagged MRI has the ability to quantify myocardial 3D deformation and strain (noninvasively and precisely), and can achieve a true comparison of contraction not only from region to region, but also at different levels of function. In this study, we investigated whether regional strain mapping obtained by 3D-tagged MRI can differentiate between viable but stunned myocardium and nonviable myocardium. METHODS AND RESULTS: We examined 7 dogs 2 days after a 90-minute closed-chest left anterior descending coronary artery occlusion followed by 48 hours of reperfusion. 3D-tagged MR images spanning the entire left ventricle were acquired both at rest and during dobutamine infusion (5 microg. kg-1. min-1 IV). Regional blood flow was measured with radioactive microspheres and used to define risk regions. Infarcted regions were defined as 2,3,5 triphenyltetrazolium chloride negative regions. Strains in infarcted regions were greatly impaired compared with remote regions (P<0.001) and remained unchanged during dobutamine stress. Risk regions showed a dysfunction at rest, with improved function during dobutamine infusion. Receiver operating characteristics analysis showed that radial strain was more accurate for identifying viable regions. CONCLUSIONS: When coupled with a stress test, 3D strain mapping by the use of tagged MRI is a sensitive and noninvasive method for characterizing ischemic injury. Regional strain can be used to differentiate between viable but stunned and nonviable myocardium within the postischemic injured myocardium.