In a recent Nature Genetics letter, entitled “Recurrent AAV2-related insertional mutagenesis in human hepatocellular carcinomas,” Nault and colleaguesdocument that of 193 patients with hepatocellular carcinoma (HCC), 11 contained an integrated genome sequence of the wild-type adeno-associated virus 2 (AAV2), and suggest that AAV2 is associated with oncogenic insertional mutagenesis in human HCC.
Because AAV2 has long been known to be a nonpathogenic human parvovirus and, in fact, has been shown to possess antitumor activity, it is critical that the scientific and clinical implications of these studies be rigorously assessed to justify their conclusions. We have carefully analyzed the data presented by Nault and colleaguesand reached a conclusion that is at variance with that of the authors.
Human C9ORF72 Hexanucleotide Expansion Reproduces RNA Foci and Dipeptide Repeat Proteins but Not Neurodegeneration in BAC Transgenic Mice
A non-coding hexanucleotide repeat expansion in the C9ORF72 gene is the most common mutation associated with familial amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). To investigate the pathological role of C9ORF72 in these diseases, we generated a line of mice carrying a bacterial artificial chromosome containing exons 1 to 6 of the human C9ORF72 gene with approximately 500 repeats of the GGGGCC motif. The mice showed no overt behavioral phenotype but recapitulated distinctive histopathological features of C9ORF72 ALS/FTD, including sense and antisense intranuclear RNA foci and poly(glycine-proline) dipeptide repeat proteins. Finally, using an artificial microRNA that targets human C9ORF72 in cultures of primary cortical neurons from the C9BAC mice, we have attenuated expression of the C9BAC transgene and the poly(GP) dipeptides. The C9ORF72 BAC transgenic mice will be a valuable tool in the study of ALS/FTD pathobiology and therapy.
Upper gastrointestinal (UGI) bleeding is generally defined as bleeding proximal to the ligament of Treitz, which leads to hematemesis. There are several causes of UGI bleeding necessitating a detailed history to rule out comorbid conditions, medications, and possible exposures. In addition, the severity, timing, duration, and volume of the bleeding are important details to note for management purposes. Despite the source of the bleeding, acid suppression with a proton-pump inhibitor has been shown to be effective in minimizing rebleeding. Endoscopy remains the interventional modality of choice for both nonvariceal and variceal bleeds because it can be diagnostic and therapeutic.
New highly active antiplatelet agents with dual specificity for platelet P2Y1 and P2Y12 adenosine diphosphate receptors
Currently approved platelet adenosine diphosphate (ADP) receptor antagonists target only the platelet P2Y12 receptor. Moreover, especially in patients with acute coronary syndromes, there is a strong need for rapidly acting and reversible antiplatelet agents in order to minimize the risk of thrombotic events and bleeding complications. In this study, a series of new P(1),P(4)-di(adenosine-5') tetraphosphate (Ap4A) derivatives with modifications in the base and in the tetraphosphate chain were synthesized and evaluated with respect to their effects on platelet aggregation and function of the platelet P2Y1, P2Y12, and P2X1 receptors. The resulting structure-activity relationships were used to design Ap4A analogs which inhibit human platelet aggregation by simultaneously antagonizing both P2Y1 and P2Y12 platelet receptors. Unlike Ap4A, the analogs do not activate platelet P2X1 receptors. Furthermore, the new compounds exhibit fast onset and offset of action and are significantly more stable than Ap4A to degradation in plasma, thus presenting a new promising class of antiplatelet agents.
The congenital sideroblastic anemias (CSAs) are relatively uncommon diseases characterized by defects in mitochondrial heme synthesis, iron-sulfur (Fe-S) cluster biogenesis, or protein synthesis. Here we demonstrate that mutations in HSPA9, a mitochondrial HSP70 homolog located in the chromosome 5q deletion syndrome 5q33 critical deletion interval and involved in mitochondrial Fe-S biogenesis, result in CSA inherited as an autosomal recessive trait. In a fraction of patients with just 1 severe loss-of-function allele, expression of the clinical phenotype is associated with a common coding single nucleotide polymorphism in trans that correlates with reduced messenger RNA expression and results in a pseudodominant pattern of inheritance.
Early High-Frequency Oscillatory Ventilation in Pediatric Acute Respiratory Failure. A Propensity Score Analysis
RATIONALE: The use of high-frequency oscillatory ventilation (HFOV) for acute respiratory failure in children is prevalent despite the lack of efficacy data.
OBJECTIVES: To compare the outcomes of patients with acute respiratory failure managed with HFOV within 24-48 hours of endotracheal intubation with those receiving conventional mechanical ventilation (CMV) and/or late HFOV.
METHODS: This is a secondary analysis of data from the RESTORE (Randomized Evaluation of Sedation Titration for Respiratory Failure) study, a prospective cluster randomized clinical trial conducted between 2009 and 2013 in 31 U.S. pediatric intensive care units. Propensity score analysis, including degree of hypoxia in the model, compared the duration of mechanical ventilation and mortality of patients treated with early HFOV matched with those treated with CMV/late HFOV.
MEASUREMENTS AND MAIN RESULTS: Among 2,449 subjects enrolled in RESTORE, 353 patients (14%) were ever supported on HFOV, of which 210 (59%) had HFOV initiated within 24-48 hours of intubation. The propensity score model predicting the probability of receiving early HFOV included 1,064 patients (181 early HFOV vs. 883 CMV/late HFOV) with significant hypoxia (oxygenation index > /= 8). The degree of hypoxia was the most significant contributor to the propensity score model. After adjusting for risk category, early HFOV use was associated with a longer duration of mechanical ventilation (hazard ratio, 0.75; 95% confidence interval, 0.64-0.89; P = 0.001) but not with mortality (odds ratio, 1.28; 95% confidence interval, 0.92-1.79; P = 0.15) compared with CMV/late HFOV.
CONCLUSIONS: In adjusted models including important oxygenation variables, early HFOV was associated with a longer duration of mechanical ventilation. These analyses make supporting the current approach to HFOV less convincing.
Recent consortium guidelines support research-based screening for those at high risk of pancreatic cancer (pancreatic ductal adenocarcinoma (PDAC)). Genetic testing plays an important role in the establishment of high-risk PDAC research clinics by delineating those individuals who would benefit from screening protocols. We retrospectively examined patients referred for PDAC-related genetic testing from January 2009 to June 2014. Patients were referred for a personal and/or family history of PDAC or a questioned diagnosis of hereditary pancreatitis (HP). Of the 75 referred patients, 36 underwent testing, of which 11 (31%) were mutation-positive. In total, 36% of patients with chronic pancreatitis carried a mutation, 11% of patients with a family history of PDAC carried a mutation, and 20% of patients with a personal history of PDAC carried a mutation. The most common barrier to testing was lack of insurance coverage. Genetic testing yields a suitable number of mutation-positive individuals who may benefit from increased screening. Subjects with possible HP yielded the highest positive rate. Individuals with idiopathic pancreatitis, onset of pancreatitis before the age of 30 years, and those with a family history of PDAC should be considered for testing. Sub-optimal insurance coverage remains a major deterrent to obtaining testing.
Medical education has evolved through the years with the emergence of an emphasis on interprofessionalism to improve multidisciplinary healthcare communication and to enhance collaborative practice, especially among physicians and nurses. Whereas successful stories of physician-nurse collaboration have been linked to positive patient outcomes (Irwin et al., 2012; Manojlovich and deCicco, 2007), poor relationships have been associated with unhealthy work environments and fragmented communication that may jeopardize the quality of patient care (Larson, 1999).
In 2007 the Association of Medical School Pediatric Department Chairs (AMSPDC) became concerned about the high turnover rate of pediatric department chairs (PDC). In a study of 123 departments, there was a mean annual turnover rate of 17%,1 and the rate was particularly high among new and female PDC. A later study showed that there were very high rates of dissatisfaction and high “burnout” scores among PDC.2 To address this concern, AMSPDC developed a New Chair's Committee charged with developing a formal mentoring program specifically for new PDC.
Efficient and Targeted Transduction of Nonhuman Primate Liver With Systemically Delivered Optimized AAV3B Vectors
Recombinant adeno-associated virus serotype 3B (rAAV3B) can transduce cultured human liver cancer cells and primary human hepatocytes efficiently. Serine (S)- and threonine (T)-directed capsid modifications further augment its transduction efficiency. Systemically delivered capsid-optimized rAAV3B vectors can specifically target cancer cells in a human liver cancer xenograft model, suggesting their potential use for human liver-directed gene therapy. Here, we compared transduction efficiencies of AAV3B and AAV8 vectors in cultured primary human hepatocytes and cancer cells as well as in human and mouse hepatocytes in a human liver xenograft NSG-PiZ mouse model. We also examined the safety and transduction efficacy of wild-type (WT) and capsid-optimized rAAV3B in the livers of nonhuman primates (NHPs). Intravenously delivered S663V+T492V (ST)-modified self-complementary (sc) AAV3B-EGFP vectors led to liver-targeted robust enhanced green fluorescence protein (EGFP) expression in NHPs without apparent hepatotoxicity. Intravenous injections of both WT and ST-modified rAAV3B.ST-rhCG vectors also generated stable super-physiological levels of rhesus chorionic gonadotropin (rhCG) in NHPs. The vector genome predominantly targeted the liver. Clinical chemistry and histopathology examinations showed no apparent vector-related toxicity. Our studies should be important and informative for clinical development of optimized AAV3B vectors for human liver-directed gene therapy.
Children enter foster care with a myriad of exposures and experiences, which can threaten their physical and mental health and development. Expanding evidence and evolving guidelines have helped to shape the care of these children over the past two decades. These guidelines address initial health screening, comprehensive medical evaluations, and follow-up care. Information exchange, attention to exposures, and consideration of how the adversities, which lead to foster placement, can impact health is crucial. These children should be examined with a trauma lens, so that the child, caregiver, and community supports can be assisted to view their physical and behavioral health from the perspective of what we now understand about the impact of toxic stress. Health care providers can impact the health of foster children by screening for the negative health consequences of trauma, advocating for trauma-informed services, and providing trauma-informed anticipatory guidance to foster parents. By taking an organized and comprehensive approach, the health care provider can best attend to the needs of this vulnerable population.
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.
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.
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
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 (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
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.
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 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
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.