Astrocytes: Role in pathogenesis and effect of commonly misused drugs in the HIV infected brain.

The roles of astrocytes as reservoirs and producers of a subset of viral proteins in the HIV infected brain have been studied extensively as a key to understanding HIV-associated neurocognitive disorders (HAND). However, their comprehensive role in the context of intersecting substance use and neurocircuitry of the reward pathway and HAND has yet to be fully explained. Use of methamphetamines, cocaine, or opioids in the context of HIV infection have been shown to lead to a faster progression of HAND. Glutamatergic, dopaminergic, and GABAergic systems are implicated in the development of HAND-induced cognitive impairments. A thorough review of scientific literature exploring the variety of mechanisms in which these drugs exert their effects on the HIV brain and astrocytes has revealed marked areas of convergence in overexcitation leading to increased drug-seeking behavior, inflammation, apoptosis, and irreversible neurotoxicity. The present review investigates astrocytes, the neural pathways, and mechanisms of drug disruption that ultimately play a larger holistic role in terms of HIV progression and drug use. There are opportunities for future research, therapeutic intervention, and preventive strategies to diminish HAND in the subset population of patients with HIV and substance use disorder.

Avoidant restrictive food intake disorder and pediatric feeding disorder: the pediatric gastroenterology perspective.

PURPOSE OF REVIEW: Avoidant/restrictive food intake disorder (ARFID) and pediatric feeding disorder (PFD) are the newest evolutions of frameworks for dysfunctional feeding and share overlapping features but maintain notable differences. This review will compare the two frameworks, highlighting some of the latest advances in diagnosis and management. RECENT FINDINGS: Dysfunctional feeding, particularly withing the PFD definition, benefits from multidisciplinary care with equal attention to medical, nutritional, skill-based, and behavioral domains. Management requires medical attention, often with functional gastrointestinal disease and anxiety. Pharmacologic appetite stimulation may play a role. A single empirically proved behavioral approach has not been described and multiple options exist regarding type, location, and intensity of feeding therapy. SUMMARY: ARFID and PFD not only share areas of overlap, but also differ, likely based on the origins of each framework. Ultimately, both frameworks describe dysfunctional feeding and require input from medical providers. The more effective approaches tend to be multidisciplinary, addressing medical, nutritional, skill-based, and/or behavioral aspects of the disorder (the PFD model). Future evolution of both ARFID and PFD frameworks is likely to generate refinement in their defining criteria, hopefully generating a structured link between the two.

Blockade of beta adrenergic receptors protects the blood brain barrier and reduces systemic pathology caused by HIV-1 Nef protein.

Combination antiretroviral therapy (cART) targets viral replication, but early viral protein production by astrocytes may still occur and contribute to the progression of HIV-1 associated neurocognitive disorders and secondary complications seen in patients receiving cART. In prior work with our model, astrocytic HIV-1 Nef expression exhibits neurotoxic effects leading to neurological damage, learning impairment, and immune upregulation that induces inflammation in the lungs and small intestine (SI). In this follow-up study, we focus on the sympathetic nervous system (SNS) as the important branch for peripheral inflammation resulting from astrocytic Nef expression. Male and female Sprague Dawley rats were infused with transfected astrocytes to produce Nef. The rats were divided in four groups: Nef, Nef + propranolol, propranolol and naïve. The beta-adrenergic blocker, propranolol, was administered for 3 consecutive days, starting one day prior to surgery. Two days after the surgery, the rats were sacrificed, and then blood, brain, small intestine (SI), and lung tissues were collected. Levels of IL-1ß were higher in both male and female rats, and treatment with propranolol restored IL-1ß to basal levels. We observed that Nef expression decreased staining of the tight junction protein claudin-5 in brain tissue while animals co-treated with propranolol restored claudin-5 expression. Lungs and SI of rats in the Nef group showed histological signs of damage including larger Peyer's Patches, increased tissue thickness, and infiltration of immune cells; these findings were abrogated by propranolol co-treatment. Results suggest that interruption of the beta adrenergic signaling reduces the peripheral organ inflammation caused after Nef expression in astrocytes of the brain.

Electrocardiogram Before Tricyclic Antidepressant Use: Minimal Impact in Pediatric Functional Gastrointestinal Disorders.

OBJECTIVES: The aim of this study was to determine the effect of electrocardiogram (ECG) findings on the initiation of tricyclic antidepressants (TCAs) for functional gastrointestinal disorders (FGIDs) and to evaluate cardiac outcomes related to low dose TCA use. METHODS: We performed a retrospective chart review of all pediatric outpatients at a tertiary pediatric hospital with an ECG ordered by a pediatric gastroenterologist when considering initiation of a TCA between January 2011 and February 2018. We collected demographics, previous cardiovascular testing results, TCA dosing, and pertinent outcomes, including cardiology referrals, emergency department, and hospital admissions, and death during the study period. All ECGs were reviewed for corrected QT (QTc) interval, heart rate, and other abnormalities. RESULTS: Of 233 patients with screening ECGs, most (84.1%) were prescribed a TCA. Functional abdominal pain or dyspepsia account for 82.0% of diagnoses. Initial TCA dosing of amitriptyline varied widely, 10-50 mg/day, and the dose was not associated with QTc intervals. TCAs were not started in only 1.7% (4/233) due to ECG results. A significant ECG abnormality prompting cardiology referral was found in eight (3.4%) with a prolonged QTc interval in one (0.4%). In 10.7% (25/233) of patients, screening ECG was obtained despite available ECG in the chart. No deaths and no emergency department or hospital visits for arrhythmia or drug overdose occurred. CONCLUSION: Screening ECGs infrequently influence TCA initiation and may lead to increased resource utilization. The overall frequency of cardiology referral due to ECG results is low. Serious adverse cardiac events are unlikely with low dose TCA administration.

Building a Diverse Workforce and Thinkforce to Reduce Health Disparities.

The Research Centers in Minority Institutions (RCMI) Program was congressionally mandated in 1985 to build research capacity at institutions that currently and historically recruit, train, and award doctorate degrees in the health professions and health-related sciences, primarily to individuals from underrepresented and minority populations. RCMI grantees share similar infrastructure needs and institutional goals. Of particular importance is the professional development of multidisciplinary teams of academic and community scholars (the "workforce") and the harnessing of the heterogeneity of thought (the "thinkforce") to reduce health disparities. The purpose of this report is to summarize the presentations and discussion at the RCMI Investigator Development Core (IDC) Workshop, held in conjunction with the RCMI Program National Conference in Bethesda, Maryland, in December 2019. The RCMI IDC Directors provided information about their professional development activities and Pilot Projects Programs and discussed barriers identified by new and early-stage investigators that limit effective career development, as well as potential solutions to overcome such obstacles. This report also proposes potential alignments of professional development activities, targeted goals and common metrics to track productivity and success.

Alternating Hemiplegia of Childhood: gastrointestinal manifestations and correlation with neurological impairments.

BACKGROUND: Alternating Hemiplegia of Childhood (AHC) is caused by mutations of the ATP1A3 gene which is expressed in brain areas that include structures controling autonomic, gastrointestinal, gut motility and GABAergic functions. We aimed to investigate, in a cohort of 44 consecutive AHC patients, two hypotheses: 1) AHC patients frequently manifest gastrointestinal, particularly motility, problems. 2) These problems are often severe and their severity correlates with neurological impairments. RESULTS: 41/44 (93%) exhibited gastrointestinal symptoms requiring medical attention. For these 41 patients, symptoms included constipation (66%), swallowing problems (63%), vomiting (63%), anorexia (46%), diarrhea (44%), nausea (37%), and abdominal pain (22%). Symptoms indicative of dysmotility occurred in 33 (80%). The most common diagnoses were oropharyngeal dysphagia (63%) and gastroesophageal reflux (63%). 16 (39%) required gastrostomy and two fundoplication. Severity of gastrointestinal symptoms correlated with non-paroxysmal neurological disability index, Gross Motor Function Classification System scores, and with the presence/absence of non-gastrointestinal autonomic dysfunction (p = 0.031, 0.043, Spearman correlations and 0.0166 Cramer's V, respectively) but not with the paroxysmal disability index (p = 0.408). CONCLUSIONS: Most AHC patients have gastrointestinal problems. These are usually severe, most commonly are indicative of dysmotility, often require surgical therapies, and their severity correlates with that of non-paroxysmal CNS manifestations. Our findings should help in management-anticipatory guidance of AHC patients. Furthermore, they are consistent with current understandings of the pathophysiology of AHC and of gastrointestinal dysmotility, both of which involve autonomic and GABAergic dysfunction.

TGFßRI antagonist inhibits HIV-1 Nef-induced CC chemokine family ligand 2 (CCL2) in the brain and prevents spatial learning impairment.

BACKGROUND: HIV-1-associated neurocognitive disorders (HAND) progression is related to continued inflammation despite undetectable viral loads and may be caused by early viral proteins expressed by latently infected cells. Astrocytes represent an HIV reservoir in the brain where the early viral neurotoxin negative factor (Nef) is produced. We previously demonstrated that astrocytic expression of Nef in the hippocampus of rats causes inflammation, macrophage infiltration, and memory impairment. Since these processes are affected by TGFß signaling pathways, and TGFß-1 is found at higher levels in the central nervous system of HIV-1+ individuals and is released by astrocytes, we hypothesized a role for TGFß-1 in our model of Nef neurotoxicity. METHODS: To test this hypothesis, we compared cytokine gene expression by cultured astrocytes expressing Nef or green fluorescent protein. To determine the role of Nef and a TGFßRI inhibitor on memory and learning, we infused astrocytes expressing Nef into the hippocampus of rats and then treated them daily with an oral dose of SD208 (10 mg/kg) or placebo for 7 days. During this time, locomotor activity was recorded in an open field and spatial learning tested in the novel location recognition paradigm. Postmortem tissue analyses of inflammatory and signaling molecules were conducted using immunohistochemistry and immunofluorescence. RESULTS: TGFß-1 was induced in cultures expressing Nef at 24 h followed by CCL2 induction which was prevented by blocking TGFßRI with SD208 (competitive inhibitor). Interestingly, Nef seems to change the TGFßRI localization as suggested by the distribution of the immunoreactivity. Nef caused a deficit in spatial learning that was recovered upon co-administration of SD208. Brain tissue from Nef-treated rats given SD208 showed reduced CCL2, phospho-SMAD2, cluster of differentiation 163 (CD163), and GFAP immunoreactivity compared to the placebo group. CONCLUSIONS: Consistent with our previous findings, rats treated with Nef showed deficits in spatial learning and memory in the novel location recognition task. In contrast, rats treated with Nef + SD208 showed better spatial learning suggesting that Nef disrupts memory formation in a TGFß-1-dependent manner. The TGFßRI inhibitor further reduced the induction of inflammation by Nef which was concomitant with decreased TGFß signaling. Our findings suggest that TGFß-1 signaling is an intriguing target to reduce neuroHIV.

Infusion of HIV-1 Nef-expressing astrocytes into the rat hippocampus induces enteropathy and interstitial pneumonitis and increases blood-brain-barrier permeability.

Even though HIV-1 replication can be suppressed by combination antiretroviral therapy (cART) inflammatory processes still occur, contributing to comorbidities. Comorbidities are attributed to variety of factors, including HIV-1 mediated inflammation. Several HIV-1 proteins mediate central nervous system (CNS) inflammation, including Nef. Nef is an early HIV-1 protein, toxic to neurons and glia and is sufficient to cause learning impairment similar to some deficits observed in HIV-1 associated neurocognitive disorders. To determine whether hippocampal Nef expression by astrocytes contributes to comorbidities, specifically peripheral inflammation, we infused Sprague Dawley rats with GFP- (control) or Nef-transfected astrocytes into the right hippocampus. Brain, lung, and ileum were collected postmortem for the measurement of inflammatory markers. Increased blood-brain-barrier permeability and serum IL-1ß levels were detected in the Nef-treated rats. The lungs of Nef-treated rats demonstrated leukocyte infiltration, macrophage upregulation, and enhanced vascular permeability. Ileal tissue showed reactive follicular lymphoid hyperplasia, increased permeability and macrophage infiltration. The intracerebroventricular application of IL-1 receptor antagonist reduced infiltration of immune cells into ileum and lung, indicating the important role of IL-1ß in mediating the spread of inflammation from the brain to other tissues. This suggests that localized expression of a single viral protein, HIV-1 Nef, can contribute to a broader inflammatory response by upregulation of IL-1ß. Further, these results suggest that Nef contributes to the chronic inflammation seen in HIV patients, even in those whose viremia is controlled by cART.

The Research Centers in Minority Institutions (RCMI) Translational Research Network: Building and Sustaining Capacity for Multi-Site Basic Biomedical, Clinical and Behavioral Research.

The Research Centers in Minority Institutions (RCMI) program was established by the US Congress to support the development of biomedical research infrastructure at minority-serving institutions granting doctoral degrees in the health professions or in a health-related science. RCMI institutions also conduct research on diseases that disproportionately affect racial and ethnic minorities (ie, African Americans/Blacks, American Indians and Alaska Natives, Hispanics, Native Hawaiians and Other Pacific Islanders), those of low socioeconomic status, and rural persons. Quantitative metrics, including the numbers of doctoral science degrees granted to underrepresented students, NIH peer-reviewed research funding, peer-reviewed publications, and numbers of racial and ethnic minorities participating in sponsored research, demonstrate that RCMI grantee institutions have made substantial progress toward the intent of the Congressional legislation, as well as the NIH/NIMHD-linked goals of addressing workforce diversity and health disparities. Despite this progress, nationally, many challenges remain, including persistent disparities in research and career development awards to minority investigators. The continuing underrepresentation of minority investigators in NIH-sponsored research across multiple disease areas is of concern, in the face of unrelenting national health inequities. With the collaborative network support by the RCMI Translational Research Network (RTRN), the RCMI community is uniquely positioned to address these challenges through its community engagement and strategic partnerships with non-RCMI institutions. Funding agencies can play an important role by incentivizing such collaborations, and incorporating metrics for research funding that address underrepresented populations, workforce diversity and health equity.

Pediatric Feeding Disorder: Consensus Definition and Conceptual Framework.

Pediatric feeding disorders (PFDs) lack a universally accepted definition. Feeding disorders require comprehensive assessment and treatment of 4 closely related, complementary domains (medical, psychosocial, and feeding skill-based systems and associated nutritional complications). Previous diagnostic paradigms have, however, typically defined feeding disorders using the lens of a single professional discipline and fail to characterize associated functional limitations that are critical to plan appropriate interventions and improve quality of life. Using the framework of the World Health Organization International Classification of Functioning, Disability, and Health, a unifying diagnostic term is proposed: "Pediatric Feeding Disorder" (PFD), defined as impaired oral intake that is not age-appropriate, and is associated with medical, nutritional, feeding skill, and/or psychosocial dysfunction. By incorporating associated functional limitations, the proposed diagnostic criteria for PFD should enable practitioners and researchers to better characterize the needs of heterogeneous patient populations, facilitate inclusion of all relevant disciplines in treatment planning, and promote the use of common, precise, terminology necessary to advance clinical practice, research, and health-care policy.

Safety of Appetite Manipulation in Children with Feeding Disorders Admitted to an Inpatient Feeding Program.

OBJECTIVE: Appetite manipulation can be effective in weaning children off gastrostomy tube feeding dependence but can cause dehydration, hypoglycaemia, and ketone body production, which is anorexigenic. As the safety of this approach has not been described, our aim was to describe adverse events observed when weaning children from G-tube dependence using our appetite manipulation protocol. METHODS: This was a retrospective study of prospectively collected data of patients who completed our inpatient tube-weaning protocol. Daily safety parameters included twice-daily urine specific gravities and urine ketones and fasting capillary blood glucose. Graded clinical interventions to manage adverse events were collected. RESULTS: A total of 143 children with a mean age of 4.8 ±â€Š2.4 years were seen in the inpatient feeding program of which 74 (51.7%) were male. The children were hospitalized 10.1 ±â€Š2.5 days with the vast majority being discharged between days 11 and 14. Overall, 78.2% of patients experienced at least 1 adverse event: urine specific gravity >1.020 was seen in 60.5%, ketonuria in 48.9%, and hypoglycemia (≤60 mg/dL) in 13.4%. Only 2 children had blood glucose levels <40 mg/dL and these were corrected with oral supplementation. Graded clinical interventions to manage adverse events included oral rehydration in 89.9% of children and supplemental tube feeding in 25.2%. CONCLUSIONS: Adverse effects are common when appetite manipulation is used to wean children off G-tube dependence. Anticipating, monitoring, and having a clear intervention plan in a closely monitored setting are necessary to safely use this method.

Longitudinal Analysis of Cerebrospinal Fluid and Plasma HIV-1 Envelope Sequences Isolated From a Single Donor with HIV Asymptomatic Neurocognitive Impairment.

OBJECTIVE: Combined antiretroviral treatment (cART) has changed the clinical presentation of HIV-associated neurocognitive disorders (HAND) to that of the milder forms of the disease. Asymptomatic neurocognitive impairment (ANI) is now more prevalent and is associated with increased morbidity and mortality risk in HIV-1-infected people. HIV-1 envelope (env) genetic heterogeneity has been detected within the central nervous system (CNS) of individuals with ANI. Changes within env determine co-receptor use, cellular tropism, and neuropathogenesis. We hypothesize that compartmental changes are associated with HIV-1 env C2V4 during ANI and sought to analyze paired HIV-1 env sequences from plasma and cerebrospinal fluid (CSF) of a female subject undergoing long-term cART. METHODS: Paired plasma and CSF samples were collected at 12-month intervals and HIV-1 env C2V4 was cloned and sequenced. RESULTS: Phylogenetic analysis of paired samples consistently showed genetic variants unique to the CSF. Phenotypic prediction showed CCR5 (R5) variants for all CSF-derived sequences and showed minor X4 variants (or dual-tropic) in the plasma at later time points. Viral compartmentalization was evident throughout the study, suggesting that the occurrence of distinctive env strains may contribute to the neuropathogenesis of HAND. CONCLUSIONS: Our study provides new insights about the genetic characteristics within the C2V4 of HIV-1 env that persist after long-term cART and during the course of persistent ANI.

Beyond the GRE: using a composite score to predict the success of Puerto Rican students in a biomedical PhD program.

The use and validity of the Graduate Record Examination General Test (GRE) to predict the success of graduate school applicants is heavily debated, especially for its possible impact on the selection of underrepresented minorities into science, technology, engineering, and math fields. To better identify candidates who would succeed in our program with less reliance on the GRE and grade point average (GPA), we developed and tested a composite score (CS) that incorporates additional measurable predictors of success to evaluate incoming applicants. Uniform numerical values were assigned to GPA, GRE, research experience, advanced course work or degrees, presentations, and publications. We compared the CS of our students with their achievement of program goals and graduate school outcomes. The average CS was significantly higher in those students completing the graduate program versus dropouts (p < 0.002) and correlated with success in competing for fellowships and a shorter time to thesis defense. In contrast, these outcomes were not predicted by GPA, science GPA, or GRE. Recent implementation of an impromptu writing assessment during the interview suggests the CS can be improved further. We conclude that the CS provides a broader quantitative measure that better predicts success of students in our program and allows improved evaluation and selection of the most promising candidates.

Otolaryngologic surgeries are frequent in children with eosinophilic esophagitis.

OBJECTIVE: The aim was to study the prevalence of otolaryngologic surgeries in pediatric patients with eosinophilic esophagitis (EoE). METHODS: Retrospective cohort study at a tertiary care center. The type of otolaryngologic surgeries performed in patients with diagnosis of EoE was recorded during a 5-year period. RESULTS: Seventy-five percent of patients were male, with average age of EoE diagnosis at 7.5 years with an 83% incidence of atopy. Cohort analysis revealed that 33% (119/362) had a total of 275 otolaryngologic surgeries. Surgeries performed on 119 patients are as follows: 20% bilateral myringotomy with tubes, 14% tonsillectomy, 18.5% adenoidectomy, 1.4% sinus irrigation, 3.3% bronchoscopy, and 1.4% laryngotracheoplasty (LTP); 63% of patients underwent multiple procedures. Thirty percent of patients undergoing bilateral myringotomy with tube placement (BMT) needed additional tubes. Four of 5 LTP patients had successful operations. Twelve percent of patients had EoE diagnosis prior to an otolaryngologic surgery. CONCLUSION: Thirty-three percent of children with EoE required otolaryngologic surgical intervention and nearly one-third who underwent BMT required additional ear tubes. A large fraction of children with EoE will undergo an otolaryngologic surgery, only a minority with a preoperative EoE diagnosis. Until the nature of this relationship is clarified, the high coincidence with otolaryngologic surgeries dictates that otolaryngologists should be familiar with diagnosis of EoE in patients.

HIV gp120 sequence variability associated with HAND in Hispanic Women.

OBJECTIVE: HIV-1 variants with different tropisms are associated with various neuropathologies. This study intends to determine if this correlation is determined by unique viral env sequences. We hypothesize that HIV-1 envelope gene sequence changes are associated with cognition status. METHODS: Viral RNA was extracted from peripheral blood mononuclear cells (PBMCs) co-cultures derived from HIV-1 infected Hispanic women that had been characterized for HIV associated neurocognitive disorders (HAND). RESULTS: Analyses of the C2V4 region of HIV gp120 demonstrated that increased sequence diversity correlates with cognition status as sequences derived from subjects with normal cognition exhibited less diversity than sequences derived from subjects with cognitive impairment. In addition, differences in V3 and V4 loop charges were also noted as well as differences in the N-glycosylation of the V4 region. CONCLUSIONS: Our data suggest that the genetic signature within the C2V4 region may contribute to the pathogenesis of HAND. HIV env sequence characteristics for the isolates grouped in milder forms of HAND can provide insightful information of prognostic value to assess neurocognitive status in HIV+ subjects, particularly during the era of highly prevalent milder forms of HAND.