Life Support Courses: Are They Effective?

Study objective: To determine the effectiveness of life support courses for health care providers on the basis of one of three outcomes: (1) patient mortality and morbidity, (2) retention of knowledge or skills, and (3) change in practice behavior. Methods: English-language articles from 1975 to 1992 were identified through MEDLINE and ERIC searches, bibliographies of articles, and current abstracts. Studies were considered relevant if they included a study population of life support providers, an intervention of any of the identified life support courses, and assessment of at least one of the three listed outcomes. Relevant studies were selected and validity scores were assigned to them by agreement of two independent reviewers, using a structured form to assess validity. Data on setting, methods, participants, intervention, and outcomes were then abstracted and verified. Results: Seventeen of 67 identified studies pertaining to life support courses met the inclusion criteria. (1) All three mortality and morbidity studies indicated a positive impact, with an overall odds ratio of .28 (95% confidence interval [CI], .22 to .37). (2) No net increase in scores was found in 5 of 8 studies of retention of knowledge and in 8 of 9 studies of skills retention. Two of three studies reporting refresher activities yielded positive effects on knowledge retention. Outcomes were not significantly different between groups taught with modular or didactic techniques. (3) Studies assessing behavioral outcome were methodologically weak. Conclusion: Among providers, retention of knowledge and skills acquired by participation in support courses is poor. However, refresher activities increase knowledge retention. Modular courses are as good as lectures for learning course material. There is evidence that use of the Advanced Trauma Life Support course has decreased mortality and morbidity. Further studies of patient outcome and provider behaviors are warranted. [Jabbour M, Osmond MH, Klassen TP: Life support courses: Are they effective? Ann Emerg Med December 1996;28:690-698.]     

Surface membrane vesicles from mononuclear cells stimulate erythroid stem cells to proliferate in culture

In order to examine the contribution of cell surface materials to erythroid burst-promoting activity (BPA), we separated media conditioned by a variety of human cell types into pellets and supernatants by centrifugation. When added to serum-restricted cultures of nonadherent human marrow cells, pellets contained about half of the total stimulatory activity. Freeze-fracture electron microscopy of the pellets revealed the presence of unilamellar membrane vesicles ranging from 0.10 to 0.40 microM in diameter. The amount of BPA in culture increased with added vesicle concentration in a saturable fashion. Preparation of leukocyte conditioned medium (LCM) from 125I-wheat germ agglutinin labeled cells and studies comparing the glycoprotein composition of vesicles with that of leukocyte plasma membranes suggest that LCM-derived vesicles are of plasma membrane origin. Moreover, partially purified leukocyte plasma membrane preparations also contained BPA. While disruption of vesicles by freezing/thawing and hypotonic lysis did not alter BPA, heat, trypsin, or pronase treatment removed greater than 65% of BPA, implying that vesicle surface rather than intravesicular molecules express BPA. Results of BPA assays performed in two-layer clots indicated that proximity to target cells is required for vesicle BPA expression. We conclude that membrane vesicles spontaneously shed from cell surfaces may be important regulators of erythroid burst proliferation in vitro.     

Dental caries and erosion status of 12-year-old Hong Kong children

Background

We examined the association of alcohol use disorders (AUD) with adherence to and health-related quality of life (HRQOL) outcomes of antiretroviral treatment (ART) for HIV/AIDS patients.

Methods

A cross-sectional multi-site survey was conducted in 468 drug users and 648 non-drug users (age: 35.4 ± 7.0 years; 63.8% male) in 3 epicentres of Vietnam. AUD, ART adherence, and HRQOL were measured using the Alcohol Use Disorders Identification Test - Consumption (AUDIT-C), the self-reported Visual Analogue Scale (VAS), and the World Health Organization Quality of Life instrument (WHOQOL-HIV BREF).

Results

35.0% of drug users were hazardous drinkers, compared to 25.9% of non-drug users. 22.3% of drug users engaged in binge drinking, and 25.9% reported suboptimal ART adherence. Adjusting for propensity scores of AUD, patients who had either at-risk or binge drinking behaviour were about twice as likely to be treatment non-adherent as those who did not have AUD. Hazardous drinkers reported small to medium decrements in the Performance, Physical, Social, Spirituality, and Environment quality of life domains. Binge drinkers had a slightly higher score in Social dimension.

Conclusion

AUD is prevalent and negatively affecting adherence to and HRQOL outcomes of ART services in injection-driven HIV epidemics. Screening and intervention are recommended for AUD, especially during the stable periods of ART. Other social and psychological interventions might also enhance patients’ responses to and outcomes of ART in Vietnam.     

Multimorbidity and Evidence Generation

Most people with a chronic disease actually have more than one, a condition known as multimorbidity. Despite this, the evidence base to prevent adverse disease outcomes has taken a disease-specific approach. Drawing on a conference, Improving Guidelines for Multimorbid Patients, the goal of this paper is to identify challenges to the generation of evidence to support the care of people with multimorbidity and to make recommendations for improvement. We identified three broad categories of challenges: 1) challenges to defining and measuring multimorbidity; 2) challenges related to the effects of multimorbidity on study design, implementation and analysis; and 3) challenges inherent in studying heterogeneity of treatment effects in patients with differing comorbid conditions. We propose a set of recommendations for consideration by investigators and others (reviewers, editors, funding agencies, policymaking organizations) involved in the creation of evidence for this common type of person that address each of these challenges. The recommendations reflect a general approach that emphasizes broader inclusion (recruitment and retention) of patients with multimorbidity, coupled with more rigorous efforts to measure comorbidity and comorbidity burden and the influence of multimorbidity on outcomes and the effects of therapy. More rigorous examination of heterogeneity of treatment effects requires careful attention to prioritizing the most important comorbid-related questions, and also requires studies that provide greater statistical power than conventional trials have provided. Relatively modest changes in the orientation of current research along these lines can be helpful in pointing to and partially addressing selected knowledge gaps. However, producing a robust evidence base to support patient-centered decision making in complex individuals with multimorbidity, exposed to many different combinations of potentially interacting factors that can modify the risks and benefits of therapies, is likely to require a clinical research enterprise fundamentally restructured to be more fully integrated with routine clinical practice.     

Is there a practical way of predicting therapeutic success in type 2 diabetes on the basis of psychological features? Development and validation of the Psychological Predictors of Therapeutic success in Diabetes (PPTD) questionnaire

Many psychiatric disorders and symptoms have been associated with impaired metabolic control in type 2 diabetes; several studies focused on non-pathological psychological features. Aims of this observational, longitudinal study are: the assessment of the impact of a wide range of psychological factors on metabolic control in type 2 diabetes; and the development and validation of a simple questionnaire to assess the impact of psychological factors on therapeutic success. To identify psychological factors interfering with attainment of glycemic targets, a prospective 1-year study was performed on a sample of 250 patients with type 2 diabetes. The impact of identified factors on therapeutic outcome was then subsequently verified on a further, independent sample of 200 patients. The first phase of the study allowed the development of a 19-items questionnaire, the Psychological Predictors of Therapeutic success in Diabetes (PPTD) questionnaire. Validation analyses showed that the questionnaire was able to predict therapeutic success. Patients with HbA1c ≤7 % (53 mmol/mol) at follow-up showed higher test scores than those with HbA1c >7 % [31.0 (26.2; 35.0) vs 28.0 (23.0; 32.0); p = 0.016]. The attainment and maintenance of therapeutic goals in patients with type 2 diabetes depend on a wide range of factors. The PPTD is an attempt at condensing the complexity of psychological factors affecting glycemic control in a simple and easy-to-use self-reported questionnaire, which can be used in wide-scale research.     

胚胎干细胞与胚胎生殖细胞的生物学特性及应用前景

目的:分析胚胎干细胞和胚胎生殖细胞的生物学特性、体外培养条件、周围微环境对其增殖分化的影响,了解胚胎干细胞和胚胎生殖细胞的关系和应用前景。方法:应用计算机检索万方数据库2000/2007有关生殖细胞、胚胎干细胞、胚胎生殖细胞的相关研究文章,检索词:生殖细胞,胚胎干细胞,胚胎生殖细胞,并限定文章语言种类为中文;同时应用计算机检索PUBMED2000/2006相关文章,检索词:Germ Cells,Primordial germ cells,Embryonic stem cells,Embryonic Germ Cells,限定文章语言种类为“English”。对资料进行初审,纳入标准为有关生殖细胞、胚胎干细胞、胚胎生殖细胞的生物学特性、体外培养及生长抑制因子的作用等相关文章,并查找全文。主要选择基础研究类文章,无论有无对照组均纳入。结果:共检索到相关文章59篇,排除比较陈旧的文章,最后纳入38篇进行总结分析。胚胎干细胞与胚胎生殖细胞分别从附置前早期胚胎内细胞团和早期胎儿生殖嵴原始生殖细胞分离克隆出来,均具有自我更新、无限增殖能力及多向分化潜能,在体外培养条件下可保持稳定的二倍体核型,诱导分化后可形成3种胚胎生殖层。饲养层细胞是人胚胎生殖细胞体外培养的必要条件,常用饲养层细胞有鼠STO细胞系、鼠胚胎成纤维细胞,体外生长所需主要细胞因子包括干细胞生长因子、碱性成纤维细胞生长因子和白血病抑制因子,然而只要在培养基中加入鼠成纤维细胞的上清液和碱性成纤维细胞生长因子,胚胎干细胞可在无饲养层的条件下进行体外培养。结论:胚胎干细胞和胚胎生殖细胞具有相似的增殖特性,一定条件下可以分化为包括生殖细胞在内的所有功能细胞,并可相互转变,在胚胎发育、基因治疗、药物筛选、新药开发、生殖医学及人类疾病的移植治疗中具有广泛的应用前景。     

Minimal forced use without constraint stimulates spontaneous use of the impaired upper extremity following motor cortex injury

The purpose of this study was to determine if recovery of neurologically impaired hand function following isolated motor cortex injury would occur without constraint of the non-impaired limb, and without daily forced use of the impaired limb. Nine monkeys (Macaca mulatta) received neurosurgical lesions of various extents to arm representations of motor cortex in the hemisphere contralateral to the preferred hand. After the lesion, no physical constraints were placed on the ipsilesional arm/hand and motor testing was carried out weekly with a maximum of 40 attempts in two fine motor tasks that required use of the contralesional hand for successful food acquisition. These motor tests were the only “forced use” of the contralesional hand. We also tested regularly for spontaneous use of the contralesional hand in a fine motor task in which either hand could be used for successful performance. This minimal intervention was sufficient to induce recovery of the contralesional hand to such a functional level that eight of the monkeys chose to use that hand on some trials when either hand could be used. Percentage use of the contralesional hand (in the task when either hand could be used) varied considerably among monkeys and was not related to lesion volume or recovery of motor skill. These data demonstrate a remarkable capacity for recovery of spontaneous use of the impaired hand following localized frontal lobe lesions. Clinically, these observations underscore the importance of therapeutic intervention to inhibit the induction of the learned nonuse phenomenon after neurological injury.