WBAs provide trainees with a justified reason to approach trainers for feedback. WBAs, however, are not being reified as the formative assessments originally intended. A culture change may be required to change the focus of WBA research and reconceptualise this set of tools and methods as a workplace learning .

Muscle protein wasting occurs in human immunodeficiency virus (HIV)-infected individuals and is often the initial indication of acquired immunodeficiency syndrome (AIDS). Little is known about the alterations in muscle protein metabolism that occur with HIV infection. Nine subjects with AIDS wasting (CD4 < 200/mm3), chronic stable opportunistic infections (OI), and ≥10% weight loss, fourteen HIV-infected men and one woman (CD4 > 200/mm3) without wasting or OI (asymptomatic), and six HIV-seronegative lean men (control) received a constant intravenous infusion of [1-13C]leucine (Leu) and [2-15N]glutamine (Gln). Plasma Leu and Gln rate of appearance (Ra), whole body Leu turnover, disposal and oxidation rates, and [13C]Leu incorporation rate into mixed muscle protein were assessed. Total body muscle mass/fat-free mass was greater in controls (53%) than in AIDS wasting (43%; P = 0.04). Fasting whole body proteolysis and synthesis rates were increased above control in the HIV+ asymptomatic group and in the AIDS-wasting group ( P = 0.009). Whole body Leu oxidation rate was greater in the HIV+ asymptomatic group than in the control and AIDS-wasting groups ( P < 0.05). Fasting mixed muscle protein synthesis rate was increased in the asymptomatic subjects (0.048%/h; P = 0.01) but was similar in AIDS-wasting and control subjects (0.035 vs. 0.037%/h). Plasma Gln Ra was increased in AIDS-wasting subjects but was similar in control and HIV+ asymptomatic subjects ( P < 0.001). These findings suggest that AIDS wasting results from 1) a preferential reduction in muscle protein, 2) a failure to sustain an elevated rate of mixed muscle protein synthesis while whole body protein synthesis is increased, and 3) a significant increase in Gln release into the circulation, probably from muscle. Several interesting explanations for the increased Gln Ra in AIDS wasting exist.

Context: Figured Worlds is a socio-cultural theory drawing on Vygotskian and Bakhtinian traditions, which has been applied in research into the development of identities of both learners and teachers in the wider education literature. It is now being adopted in medical education.Objective: The objective of this paper is to show what Figured Worlds can offer in medical education. Having explained some of its central tenets, we apply it to an important tension in our field. Application:The assumption that there is a uniform 'good doctor' identity, which must be inculcated into medical students, underlies much of what medical educators do, and what our regulators enforce. While diversity is encouraged when students are selected for medical school, pressure to professionalise students creates a drive towards a standardised professional identity by graduation. Using excerpts from reflective pieces written by two junior medical students, we review the basic concepts of Figured Worlds and demonstrate how it can shed light on the implications of this tension. Taking a Bakhtinian approach to discourse, we show how Adam and Sarah develop their professional identities as they negotiate the multiple overlapping and competing ways of being a doctor which they encounter in the world of medical practice. Each demonstrates agency by 'authoring' a unique identity in the cultural world of medicine, as they appropriate and re-voice the words of others.Discussion: Finally, we consider some important areas in medical education where Figured Worlds might prove to be a useful lens: the negotiation of discourses of gender, sexuality and social class, career choice as identification within specialty-specific cultural worlds, and the influence of hidden and informal curricula on doctor identity.

The product of the obese gene (ob) is the protein leptin, which is synthesized in and secreted from adipocytes. Fasting serum leptin concentrations are closely related to body fat content and are higher in obese than in normal-weight individuals. Leptin may contribute to body weight regulation. Overproduction of leptin in certain pathologic conditions such as acquired immunodeficiency syndrome (AIDS) might in principle contribute to the low body fat content associated with body wasting. We measured fasting serum leptin levels by radioimmunoassay in individuals infected with the human immunodeficiency virus (HIV) and in a group of healthy lean men to determine whether HIV infection increases leptin levels. Thirteen HIV-infected men aged 26 to 50 years with a body mass index (BMI) of 15 to 26 kg/m2 and 4 to 24 kg body fat (7% to 29% body fat) had serum leptin levels (3.4 +/- 1.6 ng/mL) that were not elevated compared with the levels in 17 healthy men (4.0 +/- 1.4 ng/mL) matched for age (23 to 47 years), BMI (18 to 26 kg/m2), and body fat (5 to 21 kg; 9% to 28%). In both groups of men, serum leptin concentrations were correlated with percent body fat and body fat content (P < .001), and these relationships were not different between the two groups. In both groups, leptin concentrations were not correlated with lean body mass (P > or = .24). Energy intake in the HIV-infected men, assessed from 3-day intake records, was within the normal range. These findings extend the hypothesis that circulating leptin concentrations directly reflect adipose tissue mass, even in HIV-infected men with low body fat content. These findings do not support the hypothesis that HIV infection is associated with high circulating leptin concentrations, and suggest that low leptin levels do not stimulate food intake in HIV-infected individuals.