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Recent documents in eScholarship@UMMS
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Excipients in Oral Antihistamines Can Perpetuate Allergic Contact Dermatitis

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

Propylene glycol is a well-documented causative agent of allergic contact dermatitis (ACD). It is also reported to cause systemic dermatitis after ingestion of foods or medicines containing it and after intravenous injection of a medicine with propylene glycol in its base. We describe two adolescents with sensitivity to propylene glycol confirmed by patch testing whose dermatitis improved dramatically after cessation of oral antihistamines containing propylene glycol. We report these cases to alert providers to the potential for worsening of ACD due to systemic exposure to propylene glycol in patients with a cutaneous sensitivity to the allergen.

Delivery of Adeno-Associated Virus Gene Therapy by Intravascular Limb Infusion Methods

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

Recombinant adeno-associated virus (rAAV) can be delivered to the skeletal muscle of the limb (pelvic or thoracic) by means of regional intravascular delivery. This review summarizes the evolution of this technique to deliver rAAV either via the arterial blood supply or via the peripheral venous circulation. The focus of this review is on applications in large animal models, including preclinical studies. Based on this overview of past research, we aim to inform the design of preclinical and clinical studies.

Perspectives in Implementing a Pragmatic Pediatric Primary Care-Based Intervention Trial

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

The 2013 U.S. Preventive Services Task Force (USPSTF) concluded that behavioral interventions are effective in reducing initiation of smoking in youth, recommending primary care clinicians provide education or brief counseling to prevent initiation, and that there are promising trends toward behavioral interventions improving cessation in this population. Our primary care-based intervention RCT conducted between 2000 and 2004, Air It Out, informed these USPSTF recommendations. Our trial was designed to determine whether a pediatric primary care practice-based smoking prevention and cessation intervention would be effective in increasing abstinence rates among adolescents under usual clinic conditions, to inform clinical practice. Therefore, the trial was designed to be largely a pragmatic trial. In this paper, we describe where each of the Air It Out study components falls along the pragmatic-explanatory continuum regarding participant eligibility criteria, intervention and comparison condition design, follow-up and outcomes, compliance and adherence assessments, and analysis. Such an assessment assists researchers by providing a framework to guide decisions regarding study design and implementation. We then share a few principles and lessons learned in developing and implementing the primary care-based intervention trial, focusing on study setting selection, engaging providers who will be delivering the intervention and the target population who will be receiving it in designing the trial and interventions to be tested, and the need to carefully plan recruitment and retention procedures. The hope is to increase the number of well-designed studies that can be included in the evidence reviews to guide future USPSTF recommendation statements.

Cell-Associated HIV-1 DNA and RNA Decay Dynamics During Early Combination Antiretroviral Therapy in HIV-1-Infected Infants

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

BACKGROUND: The decay of human immunodeficiency virus type 1 (HIV-1)-infected cells during early combination antiretroviral therapy (cART) in infected infants is not defined.

METHODS: HIV-1 DNA, including 2-long terminal repeat (2-LTR) circles, and multiply spliced (ms-) and unspliced (us-) HIV-1 RNA concentrations were measured at 0, 24, 48, and 96 weeks of cART in infants from the IMPAACT P1030 trial receiving lopinavir-ritonavir-based cART. The ratio of HIV-1 DNA concentrations to replication-competent genomes was also estimated. Linear mixed effects models with random intercept and linear splines were used to estimate patient-specific decay kinetics of HIV-1 DNA.

RESULTS: The median HIV-1 DNA concentration before cART at a median age of 2 months was 3.2 log10 copies per million PBMC. With cART, the average estimated patient-specific change in HIV-1 DNA concentrations was -0.040 log10/week (95% confidence interval [CI], -.05, -.03) between 0 and 24 weeks and -0.017 log10/week between 24 and 48 weeks (95% CI, -.024, -.01). 2-LTR circles decreased with cART but remained detectable through 96 weeks. Pre-cART HIV-1 DNA concentration was correlated with time to undetectable plasma viral load and post-cART HIV-1 DNA at 96 weeks; although HIV-1 DNA concentrations exceeded replication-competent HIV-1 genomes by 148-fold. Almost all infants had ms- and usRNA detected pre-cART, with 75% having usRNA through 96 weeks of cART.

CONCLUSIONS: By 2 months of age, a large pool of HIV-1-infected cells is established in perinatal infection, which influences time to undetectable viral load and reservoir size. This has implications for informing novel approaches aimed at early restriction of HIV-1 reservoirs to enable virologic remission and cure.

Hereditary mucoepithelial dysplasia and severe respiratory distress

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

Hereditary mucoepithelial dysplasia (HMD) is a rare autosomal dominant disorder characterized by mucoepithelial disruption of the skin, hair and mucous membranes. It results from defective gap junction formation and leads to non-scarring alopecia, mucosal erythema, perineal erythematous intertrigo, involvement of the conjunctival mucosa, and pulmonary disease. We present a case of severe respiratory distress in an initially healthy full term infant born to a mother with HMD. This infant later developed signs and symptoms of HMD. A high index of suspicion for pulmonary infection with atypical organism is essential in infants with a family history of HMD who present with respiratory distress.

Early antiretroviral therapy in children perinatally infected with HIV: a unique opportunity to implement immunotherapeutic approaches to prolong viral remission

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

From the use of antiretroviral therapy to prevent mother-to-child transmission to the possibility of HIV cure hinted at by the Mississippi baby experience, paediatric HIV infection has been pivotal to our understanding of HIV pathogenesis and management. Daily medication and indefinite antiretroviral therapy is recommended for children infected with HIV. Maintenance of life-long adherence is difficult and the incidence of triple-class virological failure after initiation of antiretroviral therapy increases with time. This challenge shows the urgent need to define novel strategies to provide long-term viral suppression that will allow safe interruption of antiretroviral therapy without viral rebound and any associated complications. HIV-infected babies treated within a few days of birth have a unique combination of a very small pool of integrated viruses, a very high proportion of relatively HIV resistant naive T cells, and an unparalleled capacity to regenerate an immune repertoire. These features make this group the optimum model population to investigate the potential efficacy of immune-based therapies. If successful, these investigations could change the way we manage HIV infection.

Translating Developmental Science to Address Childhood Adversity

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

Demystifying child development is a defining element of pediatric care, and pediatricians have long appreciated the profound influences that families and communities have on both child development and life course trajectories. Dramatic advances in the basic sciences of development are beginning to reveal the biologic mechanisms underlying well-established associations between a spectrum of childhood adversities and less than optimal outcomes in health, education and economic productivity. Pediatricians are well positioned to translate this new knowledge into both practice and policy, but doing so will require unprecedented levels of collaboration with educators, social service providers, and policy makers. Pediatricians might recognize the negative impact of family-level adversities on child development, but developing an effective response will likely require the engagement of community partners. By developing collaborative, innovative ways to promote the safe, stable, and nurturing relationships that are biologic prerequisites for health, academic success, and economic productivity, family-centered pediatric medical homes will remain relevant in an era that increasingly values wellness and population health.

Sleep in Autism Spectrum Disorder and Attention Deficit Hyperactivity Disorder

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

Sleep problems are common in autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD). Sleep problems in these disorders may not only worsen daytime behaviors and core symptoms of ASD and ADHD but also contribute to parental stress levels. Therefore, the presence of sleep problems in ASD and ADHD requires prompt attention and management. This article is presented in 2 sections, one each for ASD and ADHD. First, a detailed literature review about the burden and prevalence of different types of sleep disorders is presented, followed by the pathophysiology and etiology of the sleep problems and evaluation and management of sleep disorders in ASD and ADHD.

Progress with Recombinant Adeno-Associated Virus Vectors for Gene Therapy of Alpha-1 Antitrypsin Deficiency

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

The pathway to a clinical gene therapy product often involves many changes of course and strategy before obtaining successful results. Here we outline the methodologies, both clinical and preclinical, that went into developing a gene therapy approach to the treatment of alpha-1 antitrypsin deficiency lung disease using muscle-targeted recombinant adeno-associated virus. From initial gene construct development in mouse models through multiple rounds of safety and biodistribution studies in rodents, rabbits, and nonhuman primates to ultimate human trials, this review seeks to provide insight into what clinical translation entails and could thereby inform the process for future investigators.

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.