Duty hours as viewed through a professionalism lens

Understanding medical professionalism and its evaluation is essential to ensuring that physicians graduate with the requisite knowledge and skills in this domain. It is important to consider the context in which behaviours occur, along with tensions between competing values and the individual’s approach to resolving such conflicts. However, too much emphasis on behaviours can be misleading, as they may not reflect underlying attitudes or professionalism in general. The same behaviour can be viewed and evaluated quite differently, depending on the situation. These concepts are explored and illustrated in this paper in the context of duty hour regulations. The regulation of duty hours creates many conflicts that must be resolved, and yet their resolution is often hidden, especially when compliance with or violation of regulations carries significant consequences. This article challenges attending physicians and the medical education community to reflect on what we value in our trainees and the attributions we make regarding their behaviours. To fully support our trainees’ development as professionals, we must create opportunities to teach them the valuable skills they will need to achieve balance in their lives.[P]rofessionalism has no meaningful existence independent of the interactions that give it form and meaning. There is great folly in thinking otherwise.Hafferty and Levinson (2008)[1]Understanding and evaluating professionalism is essential to excellence in medical education and is mandated by organizations that oversee medical training [2]. Historically, attention has been focused largely on the professionalism of individual students or residents, at least for the purposes of evaluation. Yet there is now a growing appreciation that professionalism can be defined, understood, and evaluated from multiple perspectives [3]. Importantly, context has been recognized as critical to shaping trainees’ behaviours, and hence as important to our understanding of them [4]. A restriction in duty hours for trainees is clearly an important environmental and contextual factor to consider in evaluating professional behaviour. In this paper I will review some key issues with respect to understanding and evaluating professionalism, and then discuss these in the context of duty hour reform. Readers should note that this is not intended to be a comprehensive review of the literature of either professionalism or duty hour reform, but rather a critical narrative review that uses selected articles.     

On estimation of linkage test power

Two methods of estimating linkage test power are proposed. The first method is based on the maximum likelihood (ML) estimate of the recombination fraction and is intended for use with a likelihood ratio test (LRT) in the form of a χ² or lod score. The power is estimated through a noncentral χ² distribution with a specially chosen noncentrality parameter. The second method uses the LRT constructed for a simple alternative hypothesis regarding the recombination fraction value. The approximate distribution of this test and a method of estimating its power is proposed. Using simulated pedigree data, the power estimates for these two methods were shown to be satisfactory. Comparisons among these two methods and the computer simulation approach of Boehnke [1986] are performed. © 1996 Wiley-Liss, Inc.     

定量组织速度成像技术评价阿霉素诱导兔心肌病模型：与常规经胸超声心动图比较

目的:采用定量组织速度成像技术评价阿霉素诱导兔心肌病模型,并与常规经胸超声心动图比较其评估优势。方法:实验于2005-06/2006-08在大连医科大学完成。①实验分组及处理:取纯种新西兰白兔22只,雌雄不限,随机分成阿霉素组12只,给予阿霉素每次2mg/kg,以1g/L耳缘静脉注射,每周1次,注射8周;对照组10只每周注射2mL/kg生理盐水,共8周。②实验评估:每周应用HPSonos5500型彩色多普勒超声诊断仪(美国Agilent公司生产)对两组兔心脏进行左室收缩末期和舒张末期内径明、室间隔厚度、E峰、射血分数、左室短轴缩短率等常规超声参数测量,使用GEVivid7型彩色多普勒超声诊断仪(美国GE公司生产)进行收缩期和舒张期峰值速度、收缩期加速度定量组织速度成像参数测定。结果:22只兔进入统计。①对照组1～12周各参数与阿霉素组基础状态下比较无明显差异(P>0.05)。②第4周阿霉素组二尖瓣环运动的平均收缩期和舒张期峰值速度、收缩期加速度较基础状态明显减低(P均<0.05)。③第7周阿霉素组二尖瓣环运动的收缩期和舒张期峰值速度、收缩期加速度较基础状态明显减低(P<0.01),E峰较基础状态明显减低(P<0.05)。④第8周阿霉素组二尖瓣环运动的收缩期和舒张期峰值速度、收缩期加速度较基础状态明显减低(P<0.01),E峰较基础状态明显减低(P<0.01),左室收缩末期和舒张末期内径明显增大(P<0.05)。⑤第12周阿霉素组二尖瓣环运动的收缩期和舒张期峰值速度、收缩期加速度较基础状态明显减低(P<0.01),左室收缩末期和舒张末期内径明显增大(P<0.01),室间隔厚度、左室后壁厚度明显变薄(P<0.05),射血分数、左室短轴缩短率和E峰明显减低(P<0.01)。结论:定量组织速度成像参数可有效评价阿霉素诱导心肌病模型兔心肌的病理变化,较常规超声参数更敏感。     

Spontaneous thrombosis in mice carrying the factor V Leiden mutation

A polymorphism in coagulation factor V, factor V Leiden (FVL), is the major known genetic risk factor for thrombosis in humans. Approximately 10% of mutation carriers experience clinically significant thrombosis in their lifetime. In a small subset of patients, thrombosis is associated with coinheritance of other prothrombotic gene mutations. However, the potential contribution of additional genetic risk factors in the majority of patients remains unknown. To gain insight into the molecular basis for the variable expressivity of FVL, mice were generated carrying the homologous mutation (R504Q [single-letter amino acid codes]) inserted into the endogenous murine Fv gene. Adult heterozygous (FvQ/+) and homozygous (FvQ/Q) mice are viable and fertile and exhibit normal survival. Compared with wild-type mice, adult FvQ/Q mice demonstrate a marked increase in spontaneous tissue fibrin deposition. No differences in fetal development or survival are observed among FvQ/Q, FvQ/+ or control littermates on the C57BL/6J genetic background. In contrast, on a mixed 129Sv-C57BL/6J genetic background, FvQ/Q mice develop disseminated intravascular thrombosis in the perinatal period, resulting in significant mortality shortly after birth. These results may explain the high degree of conservation of the R504/R506 activated protein C cleavage site within FV among mammalian species and suggest an important contribution of other genetic factors to the thrombosis associated with FVL in humans. (Blood. 2000;96:4222-4226)     

Plasminogen activator inhibitor-1 and vitronectin promote vascular thrombosis in mice

Occlusive thrombosis depends on the net balance between platelets, coagulation, and fibrinolytic factors. Epidemiologic information suggests that plasminogen activator inhibitor-1 (PAI-1), a central regulator of the fibrinolytic system, plays an important role in determining the overall risk for clinically significant vascular thrombosis. Vitronectin (VN), an abundant plasma and matrix glycoprotein, binds PAI-1 and stabilizes its active conformation. This study assessed the role of PAI-1 and VN expression in the formation of occlusive vascular thrombosis following arterial or venous injury. The common carotid arteries of 17 wild-type (WT) mice and 8 mice deficient in PAI-1 were injured photochemically while blood flow was continuously monitored. WT mice developed occlusive thrombi at 52.0 +/- 3.8 minutes (mean +/- SEM) following injury; mice deficient in PAI-1 developed occlusive thrombosis at 127 +/- 15 minutes (P <.0001). Mice deficient in VN (n = 12) developed vascular occlusion 77 +/- 11 minutes after injury, intermediate between the values observed for WT mice (P <.03) and mice deficient in PAI-1 (P <.01). PAI-1 and VN also affected the time to occlusion after injury to the jugular vein. Three WT mice developed occlusive venous thrombosis an average of 39.7 +/- 1 minutes following the onset of injury, whereas the jugular veins of 4 mice deficient in PAI-1 and 4 deficient in VN occluded 56.7 +/- 5 and 58.7 +/- 2 minutes, respectively, following injury (P <.04 and P <.01 compared to WT mice). These results suggest that endogenous fibrinolysis and its regulation by PAI-1 and VN have important roles in the development of occlusive vascular thrombosis after vascular injury. (Blood. 2000;95:577-580)     

Intramural ectopic pregnancy implanting in adenomyosis

The clinical course of this 33-year-old gravida presenting at 16 weeks' gestation with hemoperitoneum was typical for suspected uterine rupture. Pathologic examination of the hysterectomy specimen supports the diagnosis of intramural pregnancy, representing the 15th case reported to date in the literature. Furthermore, there was histologic evidence of adenomyosis both within the sinus tract leading to the implantation site and throughout the myometrium. Documentation of implantation and development of ectopic pregnancy in adenomyotic myometrium should alert the clinician to the possibility of this rare pregnancy complication.     

Variation of movement characteristics with washing and capacitation of spermatozoa. I. Univariate statistical analysis and detection of sperm hyperactivation

Movement alterations as spermatozoa are washed and capacitated in preparation for the zona-free sperm penetration assay were investigated using a videomicrographic computer-assisted system for tracking and analysis of sperm trajectories. Thirty-three semen samples from infertile men and 17 fertile controls were studied. Despite significant differences on the sperm penetration assay, univariate comparisons of movement characteristics between infertile and control samples failed to detect differences. For all samples combined, significant alterations in movement characteristics were detected after washing. After an 18-hour sperm capacitation, mean velocity, head yawing amplitude, and head yawing frequency still were significantly increased over seminal plasma values. Videomicrographic motion analysis thus allows detection of changes that are consistent with hyperactivated motility, as has been described for capacitating spermatozoa.