The predictive validity of selection for entry into postgraduate training in general practice: evidence from three longitudinal studies

Background

The selection methodology for UK general practice is designed to accommodate several thousand applicants per year and targets six core attributes identified in a multi-method job-analysis study

Aim

To evaluate the predictive validity of selection methods for entry into postgraduate training, comprising a clinical problem-solving test, a situational judgement test, and a selection centre.

Design and setting

A three-part longitudinal predictive validity study of selection into training for UK general practice.

Method

In sample 1, participants were junior doctors applying for training in general practice (n = 6824). In sample 2, participants were GP registrars 1 year into training (n = 196). In sample 3, participants were GP registrars sitting the licensing examination after 3 years, at the end of training (n = 2292). The outcome measures include: assessor ratings of performance in a selection centre comprising job simulation exercises (sample 1); supervisor ratings of trainee job performance 1 year into training (sample 2); and licensing examination results, including an applied knowledge examination and a 12-station clinical skills objective structured clinical examination (OSCE; sample 3).

Results

Performance ratings at selection predicted subsequent supervisor ratings of job performance 1 year later. Selection results also significantly predicted performance on both the clinical skills OSCE and applied knowledge examination for licensing at the end of training.

Conclusion

In combination, these longitudinal findings provide good evidence of the predictive validity of the selection methods, and are the first reported for entry into postgraduate training. Results show that the best predictor of work performance and training outcomes is a combination of a clinical problem-solving test, a situational judgement test, and a selection centre. Implications for selection methods for all postgraduate specialties are considered.     

Neutralisation of SARS-CoV-2 by anatomical embalming solutions

Teaching and learning anatomy by using human cadaveric specimens has been a foundation of medical and biomedical teaching for hundreds of years. Therefore, the majority of institutions that teach topographical anatomy rely on body donation programmes to provide specimens for both undergraduate and postgraduate teaching of gross anatomy. The COVID-19 pandemic has posed an unprecedented challenge to anatomy teaching because of the suspension of donor acceptance at most institutions. This was largely due to concerns about the potential transmissibility of the SARS-CoV-2 virus and the absence of data about the ability of embalming solutions to neutralise the virus. Twenty embalming solutions commonly used in institutions in the United Kingdom and Ireland were tested for their ability to neutralise SARS-CoV-2, using an established cytotoxicity assay. All embalming solutions tested neutralised SARS-CoV-2, with the majority of solutions being effective at high-working dilutions. These results suggest that successful embalming with the tested solutions can neutralise the SARS-CoV-2 virus, thereby facilitating the safe resumption of body donation programmes and cadaveric anatomy teaching.     

淫羊藿总黄酮调控Wnt/β-catenin信号通路对去卵巢大鼠抗骨质疏松作用研究

目的 通过淫羊藿总黄酮(TFE)对去卵巢大鼠骨组织Wnt/β-catenin信号通路及腰椎骨和股骨生物力学性能影响研究,探讨TFE对去卵巢大鼠抗骨质疏松的可能机制.方法 选用40只90天龄的SPF级SD雌性大白鼠,随机分为4组:对照组、去卵巢组(OVX)组、去卵巢+己烯雌酚(DES)组、去卵巢+淫羊藿总黄酮(TFE)组.实验持续12周后处死全部大鼠,取腰椎骨、股骨分别测量生物力学参数及骨密度.免疫蛋白印迹法检测各组大鼠胫骨骨皮质区p-GSK3-β(thr9)、RANKL、OPG、β-catenin蛋白表达水平.结果 与对照组比较,OVX组大鼠股骨、腰椎骨的生物力学性能及骨密度下降(P＜0.05);DES组、TFE组股骨和腰椎骨的生物力学性能和骨密度较去卵巢OVX组明显改善(P＜0.05);两治疗组的组间差异无统计学意义(P＞0.05).免疫蛋白印迹法提示去卵巢大鼠分别加用TFE、DES治疗后,胫骨蛋白β-catenin、OPG表达上调,p-GSK3-β(thr9)、RANKL表达下调.结论 淫羊藿总黄酮能够改善去卵巢大鼠的骨生物力学性能,上调Wnt/β-catenin信号通路,从而改善骨质疏松.     

Approximate image synthesis in optical coherence tomography

Full-wave models of OCT image formation, which are based on Maxwell’s equations, are highly realistic. However, such models incur a high computational cost, particularly when modelling sample volumes consistent with those encountered in practice. Here, we present an approximate means of synthesizing volumetric image formation to reduce this computational burden. Instead of performing a full-wave scattered light calculation for each A-scan, we perform a full-wave scattered light calculation for a normally incident plane wave only. We use the angular spectrum field representation to implement beam focussing and scanning, making use of an assumption similar to the tilt optical memory effect, to approximately synthesize volumetric data sets. Our approach leads to an order of magnitude reduction in the computation time required to simulate typical B-scans. We evaluate this method by comparing rigorously and approximately evaluated point spread functions and images of highly scattering structured samples for a typical OCT system. Our approach also reveals new insights into image formation in OCT.     

Previously identified patellar tendinopathy risk factors differ between elite and sub‐elite volleyball players

Patellar tendinopathy is the most common knee injury incurred in volleyball, with its prevalence in elite athletes more than three times that of their sub‐elite counterparts. The purpose of this study was to determine whether patellar tendinopathy risk factors differed between elite and sub‐elite male volleyball players. Nine elite and nine sub‐elite male volleyball players performed a lateral stop–jump block movement. Maximum vertical jump, training history, muscle extensibility and strength, three‐dimensional landing kinematics (250 Hz), along with lower limb neuromuscular activation patterns (1500 Hz), and patellar tendon loading were collected during each trial. Multivariate analyses of variance (P < 0.05) assessed for between‐group differences in risk factors or patellar tendon loading. Significant interaction effects were further evaluated using post‐hoc univariate analysis of variance tests. Landing kinematics, neuromuscular activation patterns, patellar tendon loading, and most of the previously identified risk factors did not differ between the elite and sub‐elite players. However, elite players participated in a higher training volume and had less quadriceps extensibility than sub‐elite players. Therefore, high training volume is likely the primary contributor to the injury discrepancy between elite and sub‐elite volleyball players. Interventions designed to reduce landing frequency and improve quadriceps extensibility are recommended to reduce patellar tendinopathy prevalence in volleyball players.     

慢性移植肾失功后的移植肾切除手术分析

目的:分析总结因慢性移植肾失功而行移植肾切除手术患者的临床治疗经过,进一步探讨这类手术的安全性和适应证。方法:以慢性移植肾失功患者76例为研究对象,年龄23~72(36.6±13.5)岁,以上患者发生慢性移植肾失功的时间为术后11~91(35.8±24.6)个月,转入血液透析的时间为3~33(10.4±6.2)个月。76例患者均实施了移植肾切除手术,移植肾切除术后随访时间为6个月~5年。结果:平均手术时间50(35~180)min;术中平均出血量450(200~2 600)ml,平均输血量300(400~2 400)ml,其中67例进行了自体血液回收后输血。术后平均引流量250(20~1 100)ml,平均住院时间11(5~23)d。术后主要并发症:切口血肿8例,切口感染10例,消化道出血7例,心衰7例,肺部感染5例,肾上腺危象2例,下肢跛行2例。死亡4例。多数患者的体重指数、血红蛋白及血清白蛋白含量较术前有所提高。结论:慢性移植肾失功后的移植肾切除手术为高风险手术,应积极做好术前准备,同时加强围手术期护理,以降低手术并发症的发生率;积极适时地切除已经完全失功了的移植肾,有助于改善患者身体素质,避免免疫抑制的不良反应,同时有利于减轻患者本人及社会的经济负担。     

Purification of hemopoietic progenitor cells from human marrow using a fucose-binding lectin and cell sorting

Human peripheral blood granulocytes, but not lymphocytes, erythrocytes, or monocytes, bound the fucose-binding lectin from Lotus tetragonolobus (FBP), and this binding was competitively inhibited by the sugar alpha- L-fucose. The fluorescence-activated cell sorter was used to study the appearance of this receptor on human marrow cells during granulocyte differentiation and to prepare fractions enriched for granulocyte- macrophage progenitor cells (granulocyte-macrophage colony-forming cells--GM-CFC). Cell binding of fluoresceinated FBP increased for bone marrow cells in the sequence--lymphocytes, blast cells, promyelocytes and myelocytes, monocytes, and polymorphonuclear cells. Selection of cells with appropriate low-angle or high-angle light scatter characteristics achieved a 10-fold or 2-3-fold enrichment of progenitor cells, respectively. By selecting cells with intermediate fluorescence intensity, a further 2-3-fold enrichment for GM-CFC was obtained. Cell sorting using the optimal selection of these three parameters produced up to 36-fold enrichment of the progenitor cells from human bone marrow. The most enriched fraction was composed of 23% progenitor cells (colony- and cluster-forming cells) with a yield of 36%. In populations most highly enriched by GM-CFC, immature cells (blast cells, promyelocytes, and myelocytes) made up 95% of the cells present.     

Restraint stress and ethanol consumption in two mouse strains

Background: This study examined the interaction between restraint stress and ethanol drinking in mice that consume low and high amounts of ethanol. Methods: Two strains of mice (129SVEV and C57BL/6J) underwent 1 hour of restraint stress twice per day for 4 days in the presence of a CRF‐1 receptor antagonist, a glucocorticoid receptor antagonist or vehicle. Ethanol preference and consumption were assessed using a two bottle choice design. In another study, mice were implanted with pellets containing corticosterone; ethanol preference and consumption were assessed using a two bottle choice design. Results: Restraint stress significantly increased ethanol preference and consumption in 129SVEV mice but not in C57BL/6J mice. Then 129SVEV mice underwent the identical stress procedure; however, mice received either the CRF‐1 receptor antagonist, R121919 (15 or 20 mg/kg, ip) or vehicle 30 minutes prior to stress. R121919 did not block the stress‐induced change in ethanol preference despite causing a significant blunting in the HPA axis. Negative results were also obtained using the CRF‐1 receptor antagonist, Antalarmin (20 mg/kg, ip). In another study, 129SVEV mice were administered either the glucocorticoid receptor antagonist Mifepristone (25, 50 or 100 μg/kg, ip) or vehicle under the same procedure. Mifepristone did not alter ethanol preference. Moreover, the three receptor antagonist did not alter nonstress ethanol consumption either. In the last study, both mouse strains underwent active or sham adrenalectomy, then pellets containing corticosterone or placebo were implanted and preference for ethanol versus water was tested. Corticosterone administration decreased ethanol consumption in a strain‐dependent manner. Conclusion: These data show the restraint model for stress can modestly increase ethanol consumption in 129SVEV mice but not in C57BL/6J mice. Pharmacologic manipulation of CRF and corticosterone did not blunt baseline or stress‐induced change in ethanol preference nor did administration of corticosterone mimic the effects of restraint stress on ethanol consumption. These findings suggest the mechanism responsible for increasing ethanol consumption in this model is independent of the HPA axis and extra‐hypothalamic CRF.