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Acute Gastric Volvulus in a 16-Year-Old Male Adolescent: A Case Report

Mon, 11/14/2016 - 10:01pm

OBJECTIVE: We described a case of acute mesenteroaxial gastric volvulus in a male adolescent who presented to the pediatric emergency department (ED).

CASE: A previously healthy male adolescent presented to the pediatric ED with gradual onset of epigastric pain, emesis, and a soft and nondistended abdomen. After evaluation, management, and resolution of the pain, the patient was discharged home with a primary care follow-up plan. Approximately 5 hours after discharge, the patient returned to the pediatric ED with worsening abdominal pain, the inability to tolerate oral intake, and a firm and distended abdomen. Subsequent evaluation identified an acute mesenteroaxial gastric volvulus. Pediatric surgeons performed an exploratory laparotomy, reduction of the gastric volvulus, and gastropexy, and the patient was discharged after a brief hospitalization.

CONCLUSIONS: Acute gastric volvulus can present with symptoms similar to benign abdominal etiologies. Timely diagnosis and intervention are key to improved outcomes for patients.

Activated Kupffer cells inhibit insulin sensitivity in obese mice

Mon, 11/14/2016 - 10:01pm

Obesity promotes insulin resistance associated with liver inflammation, elevated glucose production, and type 2 diabetes. Although insulin resistance is attenuated in genetic mouse models that suppress systemic inflammation, it is not clear whether local resident macrophages in liver, denoted Kupffer cells (KCs), directly contribute to this syndrome. We addressed this question by selectively silencing the expression of the master regulator of inflammation, NF-kappaB, in KCs in obese mice. We used glucan-encapsulated small interfering RNA particles (GeRPs) that selectively silence gene expression in macrophages in vivo. Following intravenous injections, GeRPs containing siRNA against p65 of the NF-kappaB complex caused loss of NF-kappaB p65 expression in KCs without disrupting NF-kappaB in hepatocytes or macrophages in other tissues. Silencing of NF-kappaB expression in KCs in obese mice decreased cytokine secretion and improved insulin sensitivity and glucose tolerance without affecting hepatic lipid accumulation. Importantly, GeRPs had no detectable toxic effect. Thus, KCs are key contributors to hepatic insulin resistance in obesity and a potential therapeutic target for metabolic disease.

Development and evaluation of a web-based assent for adolescents considering an HIV vaccine trial

Mon, 11/14/2016 - 10:00pm

HIV vaccine trials with minors will likely require parental permission and informed assent from adolescents. For this to be a valid process, the information needs to be presented in a manner that promotes adolescent comprehension. Previous studies suggest that adolescent comprehension of assent is often insufficient. We developed an interactive web-based assent that included interspersed quiz questions for a hypothetical HIV vaccine trial. Efficacy of the web-based assent was compared to a standard paper assent with and without interspersed questions. One hundred twenty teen participants, ages 15-17 years, from five community organizations were randomized to self-administered web-based assent (n=60) or investigator-administered paper assent with (n=29) or without (n=31) interspersed quiz questions. After reviewing the assent, participants completed a 27-item comprehension test. Comprehension scores were compared between groups. The mean number of correctly answered questions were 21.2 for the full paper group and 21.1 for the web-based group (t118=-0.08, p=0.94). Scores were 20.2 for the paper without interspersed questions sub-group and 22.1 for the paper with interspersed questions sub-group (t58=1.96, p=0.055). Participants in the web-based group performed as well on the comprehension test as those in the paper group, and those in the paper with questions sub-group performed better than those in the paper without questions sub-group, suggesting that interspersed quiz questions may improve understanding of a traditional paper assent. The minimal investigator time and standardized administration of the web-based assent as well as ability to tailor the assent discussion to topics identified by incorrect comprehension test responses are advantages worthy of further investigation.

Regulation of CYBB Gene Expression in Human Phagocytes by a Distant Upstream NF-kappaB Binding Site

Mon, 11/14/2016 - 10:00pm

The human CYBB gene encodes the gp91-phox component of the phagocyte oxidase enzyme complex, which is responsible for generating superoxide and other downstream reactive oxygen species essential to microbial killing. In the present study, we have identified by sequence analysis a putative NF-kappaB binding site in a DNase I hypersensitive site, termed HS-II, located in the distant 5' flanking region of the CYBB gene. Electrophoretic mobility assays showed binding of the sequence element by recombinant NF-kappaB protein p50 and by proteins in nuclear extract from the HL-60 myeloid leukemia cell line corresponding to p50 and to p50/p65 heterodimers. Chromatin immunoprecipitation demonstrated NF-kappaB binding to the site in intact HL-60 cells. Chromosome conformation capture (3C) assays demonstrated physical interaction between the NF-kappaB binding site and the CYBB promoter region. Inhibition of NF-kappaB activity by salicylate reduced CYBB expression in peripheral blood neutrophils and differentiated U937 monocytic leukemia cells. U937 cells transfected with a mutant inhibitor of kappaB "super-repressor" showed markedly diminished CYBB expression. Luciferase reporter analysis of the NF-kappaB site linked to the CYBB 5' flanking promoter region revealed enhanced expression, augmented by treatment with interferon-gamma. These studies indicate a role for this distant, 15 kb upstream, binding site in NF-kappaB regulation of the CYBB gene, an essential component of phagocyte-mediated host defense.

Training future physicians in the era of genomic medicine: trends in undergraduate medical genetics education

Mon, 11/14/2016 - 10:00pm

PURPOSE: Advances in genomic technologies are transforming medical practice, necessitating the expertise of genomically-literate physicians. This study examined 2013-2014 trends in genetics curricula in US and Canadian medical schools to ascertain whether and how curricula are keeping pace with this rapid evolution.

METHODS: Medical genetics course directors received a 60-item electronic questionnaire covering curriculum design, assessment, remediation of failing grades, and inclusion of specific topics.

RESULTS: The response rate was 74%. Most schools teach the majority of genetics during the first 2 years, with an increase in the number of integrated curricula. Only 26% reported formal genetics teaching during years 3 and 4, and most respondents felt the amount of time spent on genetics was insufficient preparation for clinical practice. Most participants are using the Association of Professors of Human and Medical Genetics Core Curriculum(1) as a guide. Topics recently added include personalized medicine (21%) and direct-to-consumer testing (18%), whereas eugenics (17%), linkage analysis (16%), and evolutionary genetics (15%) have been recently eliminated. Remediation strategies were heterogeneous across institutions.

CONCLUSION: These findings provide an important update on how genetics and genomics is taught at US and Canadian medical schools. Continuous improvement of educational initiatives will aid in producing genomically-literate physicians.

Lamin Mutations Accelerate Aging via Defective Export of Mitochondrial mRNAs through Nuclear Envelope Budding

Sun, 11/13/2016 - 8:58pm

Defective RNA metabolism and transport are implicated in aging and degeneration [1, 2], but the underlying mechanisms remain poorly understood. A prevalent feature of aging is mitochondrial deterioration [3]. Here, we link a novel mechanism for RNA export through nuclear envelope (NE) budding [4, 5] that requires A-type lamin, an inner nuclear membrane-associated protein, to accelerated aging observed in Drosophila LaminC (LamC) mutations. These LamC mutations were modeled after A-lamin (LMNA) mutations causing progeroid syndromes (PSs) in humans. We identified mitochondrial assembly regulatory factor (Marf), a mitochondrial fusion factor (mitofusin), as well as other transcripts required for mitochondrial integrity and function, in a screen for RNAs that exit the nucleus through NE budding. PS-modeled LamC mutations induced premature aging in adult flight muscles, including decreased levels of specific mitochondrial protein transcripts (RNA) and progressive mitochondrial degradation. PS-modeled LamC mutations also induced the accelerated appearance of other phenotypes associated with aging, including a progressive accumulation of polyubiquitin aggregates [6, 7] and myofibril disorganization [8, 9]. Consistent with these observations, the mutants had progressive jumping and flight defects. Downregulating marf alone induced the above aging defects. Nevertheless, restoring marf was insufficient for rescuing the aging phenotypes in PS-modeled LamC mutations, as other mitochondrial RNAs are affected by inhibition of NE budding. Analysis of NE budding in dominant and recessive PS-modeled LamC mutations suggests a mechanism by which abnormal lamina organization prevents the egress of these RNAs via NE budding. These studies connect defects in RNA export through NE budding to progressive loss of mitochondrial integrity and premature aging.

Emerging Technologies in the Analysis of C. elegans Nicotinic Acetylcholine Receptors

Sun, 11/13/2016 - 8:58pm

Genetic studies in the model organism Caenorhabditis elegans have made valuable contributions to continuing advances in our understanding of cholinergic synapse biology and cholinergic transmission. C. elegans possesses a large and diverse family of nicotinic acetylcholine receptor (nAChR) subunits that share significant sequence similarity with vertebrate nAChR subunits. As is the case for vertebrates, C. elegans nAChR subtypes mediate excitatory synaptic responses to ACh release at the neuromuscular junction and are also widely expressed in the nervous system. Detailed knowledge of C. elegans neural connectivity patterns (wiring diagram), coupled with the ease of genetic manipulations in this system, enables high-resolution investigations into functional roles for specific receptor subtypes in the context of anatomically defined circuits. In this chapter, we review methods for the analysis of C. elegans nAChRs with an emphasis on strategies for identifying and characterizing genes involved in their biological regulation in the nervous system. These methods can be easily adapted to the study of other organisms as well as other receptor classes.

Memory-Relevant Mushroom Body Output Synapses Are Cholinergic

Sun, 11/13/2016 - 8:58pm

Memories are stored in the fan-out fan-in neural architectures of the mammalian cerebellum and hippocampus and the insect mushroom bodies. However, whereas key plasticity occurs at glutamatergic synapses in mammals, the neurochemistry of the memory-storing mushroom body Kenyon cell output synapses is unknown. Here we demonstrate a role for acetylcholine (ACh) in Drosophila. Kenyon cells express the ACh-processing proteins ChAT and VAChT, and reducing their expression impairs learned olfactory-driven behavior. Local ACh application, or direct Kenyon cell activation, evokes activity in mushroom body output neurons (MBONs). MBON activation depends on VAChT expression in Kenyon cells and is blocked by ACh receptor antagonism. Furthermore, reducing nicotinic ACh receptor subunit expression in MBONs compromises odor-evoked activation and redirects odor-driven behavior. Lastly, peptidergic corelease enhances ACh-evoked responses in MBONs, suggesting an interaction between the fast- and slow-acting transmitters. Therefore, olfactory memories in Drosophila are likely stored as plasticity of cholinergic synapses.

Nicotine Enhances the Hypnotic and Hypothermic Effects of Alcohol in the Mouse

Sun, 11/13/2016 - 8:58pm

BACKGROUND: Ethanol (EtOH) and nicotine abuse are 2 leading causes of preventable mortality in the world, but little is known about the pharmacological mechanisms mediating co-abuse. Few studies have examined the interaction of the acute effects of EtOH and nicotine. Here, we examine the effects of nicotine administration on the duration of EtOH-induced loss of righting reflex (LORR) and characterize the nature of their pharmacological interactions in C57BL/6J mice.

METHODS: We assessed the effects of EtOH and nicotine and the nature of their interaction in the LORR test using isobolographic analysis after acute injection in C57BL/6J male mice. Next, we examined the importance of receptor efficacy using nicotinic partial agonists varenicline and sazetidine. We evaluated the involvement of major nicotinic acetylcholine receptor (nAChR) subtypes using nicotinic antagonist mecamylamine and nicotinic α4- and α7-knockout mice. The selectivity of nicotine's actions on EtOH-induced LORR was examined by testing nicotine's effects on the hypnotic properties of ketamine and pentobarbital. We also assessed the development of tolerance after repeated nicotine exposure. Last, we assessed whether the effects of nicotine on EtOH-induced LORR extend to hypothermia and EtOH intake in the drinking in the dark (DID) paradigm.

RESULTS: We found that acute nicotine injection enhances EtOH's hypnotic effects in a synergistic manner and that receptor efficacy plays an important role in this interaction. Furthermore, tolerance developed to the enhancement of EtOH's hypnotic effects by nicotine after repeated exposure of the drug. α4* and α7 nAChRs seem to play an important role in nicotine-EtOH interaction in the LORR test. In addition, the magnitude of EtOH-induced LORR enhancement by nicotine was more pronounced in C57BL/6J than DBA/2J mice. Furthermore, acute nicotine enhanced ketamine and pentobarbital hypnotic effects in the mouse. Finally, nicotine enhanced EtOH-induced hypothermia but decreased EtOH intake in the DID test.

CONCLUSIONS: Our results demonstrate that nicotine synergistically enhances EtOH-induced LORR in the mouse.

A Qualitative Study of Difficult Nurse-Patient Encounters in Home Health Care

Wed, 11/09/2016 - 11:10am

The purpose of this study was to explore nurse-patient encounters from the perspective of the home health care registered nurse. A qualitative descriptive design was used to collect data from a purposive sample of 20 nurses from Connecticut, Massachusetts, and Rhode Island currently or previously employed as a home health care nurse. Four themes and 1 interconnecting theme emerged from the data: objective language; navigating the unknown; mitigating risk; looking for reciprocality in the encounter; and the interconnecting theme of acknowledging not all nurse-patient encounters go well. Three types of encounters-constructive, nonconstructive, and destructive-were defined.

Exploratory Study of Nurse-Patient Encounters in Home Healthcare: A Dissertation

Wed, 11/09/2016 - 11:07am

The purpose of this study was to explore nurse-patient encounters from the perspective of the Home Healthcare Registered Nurse. A qualitative descriptive design was used to collect data from a purposive sample of 20 home healthcare registered nurses from Connecticut, Massachusetts, and Rhode Island currently or previously employed as a home healthcare nurse. Four themes and one interconnecting theme emerged from the data: Objective Language; Navigating the Unknown; Mitigating Risk; Looking for Reciprocality in the Encounter; and the interconnecting theme of Acknowledging Not All Nurse-Patient Encounters Go Well. One goal of the study was to propose an empirically informed definition of what constituted a difficult encounter. An important early finding was that the terms difficult patient and difficult encounter were not generally used by study participants. HHC RNs voiced a preference for objective and nonjudgmental language to communicate outcomes of nurse-patient encounters. Three types of HHC RN-patient interactions emerged from the data, with constructive encounters the norm and non-constructive or destructive encounters less frequent. A constructive encounter is when two or more human beings, the nurse on the one side, and the patient, caregiver, or both on the other, interact to achieve a mutually agreed upon outcome. A nonconstructive encounter is when one or more human beings obstruct efforts to achieve at least one positive outcome. A destructive encounter is when one or more human beings direct anger at or physically aggress toward another human being. Strategies to promote reciprocality are routinely employed during HHC RN-patient encounters, but HHC RNs who miss cues that a strategy is ineffective or failed may be at risk in the home. Study data lend support to key concepts, assumptions, and propositions of Travelbee’s (1971) Human-to-Human Relationship Model. Study results provide a foundation for further research to increase the understanding, recognition, and development of empirically derived responses to non-constructive or destructive encounters such that HHC RNs are safe and best able to meet patients’ healthcare needs.

Is secondhand smoke exposure associated with increased exacerbation severity among children hospitalized for asthma?

Tue, 11/08/2016 - 10:04am

OBJECTIVE: To determine the association between secondhand smoke (SHS) exposure and length of stay (LOS) and other exacerbation severity indicators in children hospitalized for asthma.

METHODS: We conducted a retrospective chart review at 2 children's hospitals. Patients aged 2 to 18 hospitalized for asthma in 2012 were included. Outcome variables included LOS, PICU, magnesium, and intravenous (IV) steroids. Bivariate analysis determined differences between SHS-exposed and non-SHS-exposed groups. Geometric means were used for LOS to account for skewed distribution. Logistic and zero-truncated negative binomial regression models were used to determine the independent association between SHS exposure and hospitalization severity indicators.

RESULTS: A total of 623 patients were included; 41% reported SHS exposure. Mean LOS was 47.5 hours. In the SHS-exposed group, LOS was 50.0 (95% confidence interval [CI] 46.7-54.0) and in the nonexposed group it was 45.8 (95% CI 43.4-48.4) (P = .02). In regression analysis, institution modified the effect of SHS exposure on LOS. At Children's Hospital Colorado, SHS exposure was associated with a 20% increase in LOS (incidence rate ratio 1.2, 95% CI 1.1-1.3). At the Medical University of South Carolina, there was no significant association. SHS-exposed patients were more likely to receive IV steroids (odds ratio 1.6, 95% CI 1.1-2.3).

CONCLUSIONS: Among children hospitalized for asthma, we identified a significant association at 1 institution between SHS exposure and LOS and found that IV steroid use was significantly associated with LOS at both institutions. Eliminating SHS exposure among children with asthma is important.

Supported Education (SEd): State of the Practice

Tue, 11/08/2016 - 8:39am

Investigators at the Transitions Research and Training Center at the University of Massachusetts Medical School partnered with RTI International to conduct the "Feasibility Study for Demonstration of Supported Education to Promote Educational Attainment and Employment among Individuals with Serious Mental Illness". The study was funded by the Assistant Secretary for Planning and Evaluation (ASPE).

Monitoring cell-cell contacts in vivo in transgenic animals

Mon, 11/07/2016 - 10:12pm

We used a synthetic genetic system based on ligand-induced intramembrane proteolysis to monitor cell-cell contacts in animals. Upon ligand-receptor interaction in sites of cell-cell contact, the transmembrane domain of an engineered receptor is cleaved by intramembrane proteolysis and releases a protein fragment that regulates transcription in the interacting partners. We demonstrate that the system can be used to regulate gene expression between interacting cells, both in vitro and in vivo, in transgenic Drosophila We show that the system allows for detection of interactions between neurons and glia in the Drosophila nervous system. In addition, we observed that when the ligand is expressed in subsets of neurons with a restricted localization in the brain it leads to activation of transcription in a selected set of glial cells that interact with those neurons. This system will be useful to monitor cell-cell interactions in animals, and can be used to genetically manipulate cells that interact with one another.