Glucose addiction of TSC null cells is caused by failed mTORC1-dependent balancing of metabolic demand with supply.

The mTORC1-signaling pathway integrates environmental conditions into distinct signals for cell growth by balancing anabolic and catabolic processes. Accordingly, energetic stress inhibits mTORC1 signaling predominantly through AMPK-dependent activation of TSC1/2. Thus, TSC1/2-/- cells are hypersensitive to glucose deprivation, and this has been linked to increased p53 translation and activation of apoptosis. Herein, we show that mTORC1 inhibition during glucose deprivation prevented not only the execution of death, but also induction of energetic stress. mTORC1 inhibition during glucose deprivation decreased AMPK activation and allowed ATP to remain high, which was both necessary and sufficient for protection. This effect was not due to increased catabolic activities such as autophagy, but rather exclusively due to decreased anabolic processes, reducing energy consumption. Specifically, TSC1/2-/- cells become highly dependent on glutamate dehydrogenase-dependent glutamine metabolism via the TCA cycle for survival. Therefore, mTORC1 inhibition during energetic stress is primarily to balance metabolic demand with supply.

A longitudinal study of empathy in pre-clinical and clinical medical students and clinical supervisors.

BACKGROUND: Although appropriate empathy in health professionals is essential, a loss of empathy can occur during medical education. The structure of clinical learning may be one factor that is implicated in a loss of empathy. This study examines student and doctor empathy, and possible associations between empathy and the structure of clinical learning. METHODS: There were three groups of participants: medical students (n = 281), who completed a longitudinal survey consisting of the Jefferson Scale of Empathy and an open question about empathy at the beginning and end of the 2013 academic year; private doctors (medical practitioners) in South Australia (n = 78) who completed a survey consisting of the Jefferson Scale of Empathy and an open question about empathy at the end of the students' academic year; and doctors (medical practitioners) from public teaching hospitals (n = 72) in southern Adelaide, South Australia who completed a survey consisting of the Jefferson Scale of Empathy at the end of the students' academic year . RESULTS: Year one students' empathy scores at the end of the year (102.8 ± 17.7) were significantly lower than at the start of the year (112.3 ± 9.6) p < .05). There were no other significant differences in students' empathy scores by year groups or across the two time points. Empathy scores were almost identical for private and hospital clinicians and higher than average scores for students. Free-text comments highlighted the importance students and doctors place on empathy. Students described issues that adversely affected their empathy, including specific incidents, systemic issues, and course structure, but also described some positive role models. Doctors' comments focused on the importance of empathy but qualified its meaning in the therapeutic setting. CONCLUSION: Medical students and practitioners alike ascribe importance to empathy in clinical practice, yet its developmental course remains poorly understood with possible decrement across the course of medical education. A more sophisticated understanding of empathy in medical students is needed, with attention to issues that might adversely impact on this crucial aspect of their development. TRIAL REGISTRATION: This was not undertaken as the research did not involve a health care intervention on human participants.

Urban general practice and medical education: Academic outcomes from a unique urban, longitudinal integrated community-based program.

BACKGROUND: In 2009, Flinders University established an urban, community-based, longitudinal integrated program providing medical students extended placements that offered continuities of patient care, clinical supervision and peer group. OBJECTIVE: The aim of this research was to analyse academic outcomes of the new placement program. METHODS: The results of all students undertaking Year 3 exams from 2011 to 2014 were collected and analysed. The Years 1 and 2 exam results for students in the new program were also analysed. RESULTS: Students in the new placement program achieved significantly higher grades than those who undertook the traditional rotations program, with aver-age scores of 69.05, compared with 66.45 (P = 0.03). Analysis of average class ranking for students who undertook the new program showed a statistically significant improvement from 59th in class to 48th in class (P = 0.03). DISCUSSION: This evaluation shows that an urban, community-based, longitudinal integrated clerkship centred in general practice provides at least academically equivalent outcomes to traditional rotations-based programs.

Population pharmacokinetics of ciprofloxacin in neonates and young infants less than three months of age.

Ciprofloxacin is used in neonates with suspected or documented Gram-negative serious infections. Currently, its use is off-label partly because of lack of pharmacokinetic studies. Within the FP7 EU project TINN (Treat Infection in NeoNates), our aim was to evaluate the population pharmacokinetics of ciprofloxacin in neonates and young infants <3 months of age and define the appropriate dose in order to optimize ciprofloxacin treatment in this vulnerable population. Blood samples were collected from neonates treated with ciprofloxacin and concentrations were quantified by high-pressure liquid chromatography-mass spectrometry. Population pharmacokinetic analysis was performed using NONMEM software. The data from 60 newborn infants (postmenstrual age [PMA] range, 24.9 to 47.9 weeks) were available for population pharmacokinetic analysis. A two-compartment model with first-order elimination showed the best fit with the data. A covariate analysis identified that gestational age, postnatal age, current weight, serum creatinine concentration, and use of inotropes had a significant impact on ciprofloxacin pharmacokinetics. Monte Carlo simulation demonstrated that 90% of hypothetical newborns with a PMA of <34 weeks treated with 7.5 mg/kg twice daily and 84% of newborns with a PMA ≥34 weeks and young infants receiving 12.5 mg/kg twice daily would reach the AUC/MIC target of 125, using the standard EUCAST MIC susceptibility breakpoint of 0.5 mg/liter. The associated risks of overdose for the proposed dosing regimen were <8%. The population pharmacokinetics of ciprofloxacin was evaluated in neonates and young infants <3 months old, and a dosing regimen was established based on simulation.

Compensation of the AKT signaling by ERK signaling in transgenic mice hearts overexpressing TRIM72.

The AKT and ERK signaling pathways are known to be involved in cell hypertrophy, proliferation, survival and differentiation. Although there is evidence for crosstalk between these two signaling pathways in cellulo, there is less evidence for cross talk in vivo. Here, we show that crosstalk between AKT and ERK signaling in the hearts of TRIM72-overexpressing transgenic mice (TRIM72-Tg) with alpha-MHC promoter regulates and maintains their heart size. TRIM72, a heart- and skeletal muscle-specific protein, downregulates AKT-mTOR signaling via IRS-1 degradation and reduces the size of rat cardiomyocytes and the size of postnatal TRIM72-Tg hearts. TRIM72 expression was upregulated by hypertrophic inducers in cardiomyocytes, while IRS-1 was downregulated by IGF-1. TRIM72 specifically regulated IGF-1-dependent AKT-mTOR signaling, resulting in a reduction of the size of cardiomyocytes. Postnatal TRIM72-Tg hearts were smaller than control-treated hearts with inhibition of AKT-mTOR signaling. However, adult TRIM72-Tg hearts were larger than of control despite the suppression of AKT-mTOR signaling. Activation of ERK, PKC-α, and JNK were observed to be elevated in adult TRIM72-Tg, and these signals were mediated by ET-1 via the ET receptors A and B. Altogether, these results suggest that AKT signaling regulates cardiac hypertrophy in physiological conditions, and ERK signaling compensates for the absence of AKT signaling during TRIM72 overexpression, leading to pathological hypertrophy.

Challenges in transformation of the "traditional block rotation" medical student clinical education into a longitudinal integrated clerkship model.

BACKGROUND: Longitudinal integrated clerkships (LIC) in the first major clinical year in medical student training have been demonstrated to be at least equivalent to and in some areas superior to the "traditional block rotation" (TBR). Flinders University School of Medicine is starting a pilot changing the traditional teaching at the major Academic Medical Centre from TBR to LIC (50% of students in other locations in the medical school already have a partial or full LIC programme). METHODS: This paper summarises the expected challenges presented at the "Rendez-Vous" Conference in October 2012: (a) creating urgency, (b) training to be a clinician rather than imparting knowledge, (c) resistance to change. RESULTS: We discuss the unexpected challenges that have evolved since then: (a) difficulty finalising the precise schedule, (b) underestimating time requirements, (c) managing the change process inclusively. DISCUSSION: Transformation of a "block rotation" to "LIC" medical student education in a tertiary academic teaching hospital has many challenges, many of which can be anticipated, but some are unexpected.

How social accountability can be incorporated into an urban community-based medical education program: an Australian initiative.

BACKGROUND: Medical schools play a role in ensuring that their outcomes ultimately have positive effects on the health status of communities. We describe an initiative that translates this broad intent into meaningful activities that foster positive attitudes to social accountability among medical students in the context of an already full curriculum. METHODS: Faculty members from an urban community-based medical education program undertook broad consultation with its community groups. Medical students then undertook activities designed to assist in the well-being of socio-economically disadvantaged adolescents through near-peer counselling and health education. RESULTS: Early evaluation from medical students, secondary students, community organisations and faculty indicates that the activities undertaken to-date have been of value to stakeholders. DISCUSSION: This initiative is intended to develop one model for incorporating social accountability into the medical curriculum with sustainable activities that benefit the community and medical students. Further research and evaluation of the impact of this initiative on both the community group involved and on medical students is essential.

Down-regulation of CMTM8 induces epithelial-to-mesenchymal transition-like changes via c-MET/extracellular signal-regulated kinase (ERK) signaling.

The acquisition of an invasive phenotype is a critical turning point for malignant tumor cells. CMTM8, a potential tumor suppressor, is frequently down-regulated in solid tumors, and its overexpression induces tumor cell apoptosis. Here, we identify a new role for CMTM8 in regulating tumor cell migration. Reducing CMTM8 expression in HepG2 hepatocellular carcinoma cells results in the acquisition of epithelial-to-mesenchymal transition (EMT) features, including a morphological change from organized epithelial sheets to scattered fibroblast-like shapes, reduction of the epithelial marker E-cadherin, and an increased invasive and migratory ability. These phenotypic changes are mediated in large part by the ERK-MAPK pathway, as the MEK inhibitor U0126 and shRNA-mediated knockdown of ERK2 significantly reversed these phenotypes. Hepatocyte growth factor binding to the c-MET receptor is known to induce EMT in HepG2 cells. We found that CMTM8 knockdown in HepG2 cells induced c-MET signaling and ERK activation. Inhibition of c-MET signaling with the small molecule inhibitor SU11274 or c-MET RNAi blocked the EMT-like changes following CMTM8 knockdown. CMTM8 overexpression in HepG2 cells inhibited hepatocyte growth factor-induced EMT-like morphological changes and cell motility. Down-regulation of CMTM8 also promoted an EMT-like change in MCF-10A cells, indicating a broader role for CMTM8 in regulating cellular transformation.

DNA methylation of developmental genes in pediatric medulloblastomas identified by denaturation analysis of methylation differences.

DNA methylation might have a significant role in preventing normal differentiation in pediatric cancers. We used a genomewide method for detecting regions of CpG methylation on the basis of the increased melting temperature of methylated DNA, termed denaturation analysis of methylation differences (DAMD). Using the DAMD assay, we find common regions of cancer-specific methylation changes in primary medulloblastomas in critical developmental regulatory pathways, including Sonic hedgehog (Shh), Wingless (Wnt), retinoic acid receptor (RAR), and bone morphogenetic protein (BMP). One of the commonly methylated loci is the PTCH1-1C promoter, a negative regulator of the Shh pathway that is methylated in both primary patient samples and human medulloblastoma cell lines. Treatment with the DNA methyltransferase inhibitor 5-aza-2'-deoxycytidine (5-aza-dC) increases the expression of PTCH1 and other methylated loci. Whereas genetic mutations in PTCH1 have previously been shown to lead to medulloblastoma, our study indicates that epigenetic silencing of PTCH1, and other critical developmental loci, by DNA methylation is a fundamental process of pediatric medulloblastoma formation. This finding warrants strong consideration for DNA demethylating agents in future clinical trials for children with this disease.

A review of longitudinal community and hospital placements in medical education: BEME Guide No. 26.

BACKGROUND: Traditionally, clinical learning for medical students consists of short-term and opportunistic encounters with primarily acute-care patients, supervised by an array of clinician preceptors. In response to educational concerns, some medical schools have developed longitudinal placements rather than short-term rotations. Many of these longitudinal placements are also integrated across the core clinical disciplines, are commonly termed longitudinal integrated clerkships (LICs) and often situated in rural locations. This review aimed to explore, analyse and synthesise evidence relating to the effectiveness of longitudinal placements, for medical students in particular to determine which aspects are most critical to successful outcomes. METHOD: Extensive search of the literature resulted in 1679 papers and abstracts being considered, with 53 papers ultimately being included for review. The review group coded these 53 papers according to standard BEME review guidelines. Specific information extracted included: data relating to effectiveness, the location of the study, number of students involved, format, length and description of placement, the learning outcomes, research design, the impact level for evaluation and the main evaluation methods and findings. We applied a realist approach to consider what works well for whom and under what circumstances. FINDINGS: The early LICs were all community-based immersion programs, situated in general practice and predominantly in rural settings. More recent LIC innovations were situated in tertiary-level specialist ambulatory care in urban settings. Not all placements were integrated across medical disciplines but were longitudinal in relation to location, patient base and/or supervision. Twenty-four papers focussed on one of four programs from different viewpoints. Most evaluations were student opinion (survey, interview, focus group) and/or student assessment results. Placements varied from one half day per week for six months through to full time immersion for more than 12 months. The predominant mechanism relating to factors influencing effectiveness was continuity of one or more of: patient care, supervision and mentorship, peer group and location. The success of LICs and participation satisfaction depended on the preparation of both students and clinical supervisors, and the level of support each received from their academic institutions. CONCLUSION: Longitudinal placements, including longitudinal integrated placements, are gaining in popularity as an alternative to traditional block rotations. Although relatively few established LICs currently exist, medical schools may look for ways to incorporate some of the principles of LICs more generally in their clinical education programmes. Further research is required to ascertain the optimum length of time for placements depending on the defined learning outcomes and timing within the programme, which students are most likely to benefit and the effects of context such as location and type of integration.

Relaxation as an Educational Strategy for Stress Management and Resiliency.

BACKGROUND: Prelicensure nursing students experience higher levels of stress, anxiety, and depression than the remainder of the student body. PURPOSE: The purpose of this study was to identify whether implementation of Stress Management and Resiliency Training (SMART) and a relaxation room decreased perceived stress levels in prelicensure nursing students. METHODS: This quasi-experimental pre- and posttest interventional study used a within-subjects design. Nursing students were asked to use a relaxation room for 15 minutes following a discussion on stress management and resiliency strategies. The students evaluated their stress level at baseline and at the conclusion of using the relaxation room. RESULTS: The self-reported stress levels decreased for nearly 90% of the participants following the use of the interventions. CONCLUSIONS: Stress management and resiliency interventions during academic hours decreased the reported stress levels of nursing students. The strategies are beneficial options to reduce stress and improve resiliency skills among prelicensure nursing students.

No such thing as a free lunch: The direct marginal costs of breastfeeding.

Understanding costs associated with breastfeeding is critical to developing maximally effective policy to support breastfeeding by addressing financial barriers. Breastfeeding is not without cost; direct costs include those of equipment, modified nutritional intake, and time (opportunity cost). Breastfeeding need not require more equipment than formula feeding, though maternal equipment use varies by maternal preference. Meeting increased nutritional demands requires increased spending on food and potentially dietary supplementation, the marginal cost of which depends on a mother's baseline diet. The opportunity cost of the three to four hours per day breastfeeding demands may be prohibitively high, particularly to low-income workers. These costs are relatively highest for low-income individuals, a group disproportionately comprising racial and ethnic minorities, and who demonstrate lower rates of breastfeeding than their white and higher-income peers. Acknowledging and addressing these costs and their regressive nature represents a critical component of effective breastfeeding policy and promotion.

Urban community based medical education - general practice at the core of a new approach to teaching medical students.

BACKGROUND: The benefits of community based medical education for both students and teachers are becoming increasingly clear. Rural programs offering year-long general practice based clinical training for medical students are well established and highly successful. Urban general practice teaching is currently more likely to be based on short term placements. OBJECTIVE: To describe a new model for urban community based medical education - the Onkaparinga Clinical Education Program - and to discuss its impact on general practitioners, community based specialists and other stakeholders. DISCUSSION: New approaches have been used to successfully translate rural community based medical education models to the urban setting. There is significant potential for urban community based medical education to be extended if adequate support and funding is available. Programs that allow students to access the rich patient care environment of community practice in urban areas can be rewarding for all involved.

Long-Term Outcomes of Cardiovascular Operations in Children With Connective Tissue Disorders.

Connective tissue disorders can be associated with significant cardiovascular morbidity needing cardiac surgery during childhood. In this retrospective study, we used the Pediatric Cardiac Care Consortium, a multicenter United States-based registry of pediatric cardiac interventions, to describe the long-term outcomes of patients who underwent their first surgery for connective tissue-related cardiovascular conditions aged <21 years. Between 1982 and 2003, a total of 103 patients were enrolled who underwent cardiac surgery for a connective tissue-related cardiovascular disorder, including 3 severe infantile cases operated on within the first year of life. Most patients underwent aortic site surgery (n = 85) as a composite graft (n = 50), valve-sparing (n = 33), or other aortic surgery (n = 2). The remaining patients underwent atrioventricular valve surgery (mitral 17, tricuspid 1). Of the 99 patients surviving to discharge, 80 (including the 3 infantile) had adequate identifiers for tracking long-term outcomes through 2019 through linkage with the National Death Index and the Organ Procurement. Over a median period of 19.5 years (interquartile range 16.0 to 23.1), 29 deaths and 1 transplant occurred in the noninfantile group, whereas all 3 infantile patients died before the age of 4 years. The postdischarge survival for the noninfantile group was 92.2%, 68.2%, and 56.7% at 10, 20, and 25 years, respectively. Cardiovascular-related pathology contributed to all deaths in the infantile and 89% (n = 27) of deaths for the noninfantile cases after hospital discharge. The significant late attrition from cardiovascular causes emphasizes the need for close monitoring and ongoing management in this population.

Caring for critically ill adults in paediatric intensive care units in England during the COVID-19 pandemic: planning, implementation and lessons for the future.

OBJECTIVE: To describe the experience of paediatric intensive care units (PICUs) in England that repurposed their units, equipment and staff to care for critically ill adults during the first wave of the COVID-19 pandemic. DESIGN: Descriptive study. SETTING: Seven PICUs in England. MAIN OUTCOME MEASURES: (1) Modelling using historical Paediatric Intensive Care Audit Network data; (2) space, staff, equipment, clinical care, communication and governance considerations during repurposing of PICUs; (3) characteristics, interventions and outcomes of adults cared for in repurposed PICUs. RESULTS: Seven English PICUs, accounting for 137 beds, repurposed their space, staff and equipment to admit critically ill adults. Neighbouring PICUs increased their bed capacity to maintain overall bed numbers for children, which was informed by historical data modelling (median 280-307 PICU beds were required in England from March to June). A total of 145 adult patients (median age 50-62 years) were cared for in repurposed PICUs (1553 bed-days). The vast majority of patients had COVID-19 (109/145, 75%); the majority required invasive ventilation (91/109, 85%). Nearly, a third of patients (42/145, 29%) underwent a tracheostomy. Renal replacement therapy was provided in 20/145 (14%) patients. Twenty adults died in PICU (14%). CONCLUSION: In a rapid and unprecedented effort during the first wave of the COVID-19 pandemic, seven PICUs in England were repurposed to care for adult patients. The success of this effort was underpinned by extensive local preparation, close collaboration with adult intensivists and careful national planning to safeguard paediatric critical care capacity.

A novel role for Gtb1p in glucose trimming of N-linked glycans.

Glucosidase II (GluII) is a glycan-trimming enzyme active on nascent glycoproteins in the endoplasmic reticulum (ER). It trims the middle and innermost glucose residues (Glc2 and Glc1) from N-linked glycans. The monoglucosylated glycan produced by the first GluII trimming reaction is recognized by calnexin/calreticulin and serves as the signal for entry into this folding pathway. GluII is a heterodimer of alpha and beta subunits corresponding to yeast Gls2p and Gtb1p, respectively. While Gls2p contains the glucosyl hydrolase active site, the Gtb1p subunit has previously been shown to be essential for the Glc1 trimming event. Here we demonstrate that Gtb1p also determines the rate of Glc2 trimming. In order to further dissect these activities we mutagenized a number of conserved residues across the protein. Our data demonstrate that both the MRH and G2B domains of Gtb1p contribute to the Glc2 trimming event but that the MRH domain is essential for Glc1 trimming.