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186 result(s) for "Everett, Allen"
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Blood Biomarkers for Evaluation of Perinatal Encephalopathy
Recent research in identification of brain injury after trauma shows many possible blood biomarkers that may help identify the fetus and neonate with encephalopathy. Traumatic brain injury shares many common features with perinatal hypoxic-ischemic encephalopathy. Trauma has a hypoxic component, and one of the 1st physiologic consequences of moderate-severe traumatic brain injury is apnea. Trauma and hypoxia-ischemia initiate an excitotoxic cascade and free radical injury followed by the inflammatory cascade, producing injury in neurons, glial cells and white matter. Increased excitatory amino acids, lipid peroxidation products, and alteration in microRNAs and inflammatory markers are common to both traumatic brain injury and perinatal encephalopathy. The blood-brain barrier is disrupted in both leading to egress of substances normally only found in the central nervous system. Brain exosomes may represent ideal biomarker containers, as RNA and protein transported within the vesicles are protected from enzymatic degradation. Evaluation of fetal or neonatal brain derived exosomes that cross the blood-brain barrier and circulate peripherally has been referred to as the \"liquid brain biopsy.\" A multiplex of serum biomarkers could improve upon the current imprecise methods of identifying fetal and neonatal brain injury such as fetal heart rate abnormalities, meconium, cord gases at delivery, and Apgar scores. Quantitative biomarker measurements of perinatal brain injury and recovery could lead to operative delivery only in the presence of significant fetal risk, triage to appropriate therapy after birth and measure the effectiveness of treatment.
Risk Factors and Clinical Outcomes in Preterm Infants with Pulmonary Hypertension
Pulmonary hypertension (PH) is a significant cause of morbidity in preterm infants, but no screening guidelines exist. We sought to identify risk factors and clinical outcomes associated with PH in preterm infants to develop a PH risk score. Retrospective analysis of two separate populations of preterm infants (NICU cohort n = 230; Clinic registry n = 580). 8.3% of the NICU cohort had PH after 4 weeks of age, while 14.8% of the clinic registry had PH after 2 months of age. Lower birth weights and longer initial hospitalizations were associated with PH in both populations (p<0.001 for all tests). Using adjusted logistic regression, patent ductus arteriosus (PDA) requiring ligation was associated with PH in both the NICU cohort (OR: 3.19; p = 0.024) and the clinic registry (OR: 2.67; p<0.001). Risk factors (birth weight ≤780 grams, home supplemental oxygen use, and PDA ligation) identified in the clinic registry (training dataset) were validated in the NICU cohort with 0-1 factors present were associated with ≤1.5% probability of having PH, any 2 factors with a 25% probability, and all 3 factors with a 40% probability. Lower birth weight, PDA ligation, and respiratory support were associated with PH in both populations. A PH risk score based on clinical indicators from the training dataset predicted PH in the validation set. This risk score could help focus resources to preterm infants at higher risk for PH. Further work is needed to determine whether earlier or more aggressive management of ductal lesions could alter PH outcomes.
Circulating Brain-Derived Neurotrophic Factor Has Diagnostic and Prognostic Value in Traumatic Brain Injury
Brain-derived neurotrophic factor (BDNF) is important for neuronal survival and regeneration. We investigated the diagnostic and prognostic values of serum BDNF in traumatic brain injury (TBI). We examined serum BDNF in two independent cohorts of TBI cases presenting to the emergency departments (EDs) of the Johns Hopkins Hospital (JHH; n = 76) and San Francisco General Hospital (SFGH, n = 80), and a control group of JHH ED patients without TBI (n = 150). Findings were subsequently validated in the prospective, multi-center Transforming Research and Clinical Knowledge in TBI (TRACK-TBI) Pilot study (n = 159). We investigated the association between BDNF, glial fibrillary acidic protein (GFAP), and ubiquitin C-terminal hydrolase-L1 (UCH-L1) and recovery from TBI at 6 months in the TRACK-TBI Pilot cohort. Incomplete recovery was defined as having either post-concussive syndrome or a Glasgow Outcome Scale Extended score <8 at 6 months. Median day-of-injury BDNF concentrations (ng/mL) were lower among TBI cases (JHH TBI, 17.5 and SFGH TBI, 13.8) than in JHH controls (60.3; p = 0.0001). Among TRACK-TBI Pilot subjects, median BDNF concentrations (ng/mL) were higher in mild (8.3) than in moderate (4.3) or severe TBI (4.0; p = 0.004. In the TRACK-TBI cohort, the 75 (71.4%) subjects with very low BDNF values (i.e.,
Weight Loss Differentially Impacts Sex Hormones in Women and Men With Type 2 Diabetes: Look AHEAD Sex Hormone Study
Despite sex differences in type 2 diabetes (T2D), few studies have examined the role of sex hormones. We sought to assess the impact of weight loss, the cornerstone of T2D management, on sex hormone levels. This was an ancillary study to the Look AHEAD (Action for Health In Diabetes) Study [n = 850 postmenopausal females, n = 890 males, with T2D and body mass index (BMI) ≥25 kg/m2]. We measured total testosterone (T), estradiol (E2), and SHBG and calculated bioavailable T (bioT). We examined the effect of the intensive lifestyle intervention (ILI) on hormone changes and whether changes were mediated by waist circumference and sex differences in treatment effect. The baseline mean age was 60 years with a higher proportion of Black females (21%) vs males (9%) and higher mean BMI in females vs males (36.3 vs 34.8 kg/m2). At year 1 in females, ILI decreased E2 by 15% and bioT by 13% and increased SHBG by 21%. At year 1 in males, ILI did not change E2 levels but increased T by 14% and increased SHBG by 18%. The effect was attenuated over 4 years; there were statistically significant sex differences in treatment effect and change in waist circumference due to ILI at year 1 was a significant mediator of sex hormone changes. Weight loss in T2D resulted in sex hormone changes, which varied by sex and were mediated by changes in waist circumference. Changes in sex hormones due to weight loss in T2D should be considered in the context of an individual's health risks, including cardiovascular conditions, bone health, menopausal symptoms, and cognitive function.
Targeted inhibition of thrombin attenuates murine neonatal necrotizing enterocolitis
Necrotizing enterocolitis (NEC) is an inflammatory bowel necrosis of premature infants and an orphan disease with no specific treatment. Most patients with confirmed NEC develop moderate-severe thrombocytopenia requiring one or more platelet transfusions. Here we used our neonatal murine model of NEC-related thrombocytopenia to investigate mechanisms of platelet depletion associated with this disease [K. Namachivayam, K. MohanKumar, L. Garg, B. A. Torres, A. Maheshwari, Pediatr. Res. 81, 817–824 (2017)]. In this model, enteral administration of immunogen trinitrobenzene sulfonate (TNBS) in 10-d-oldmouse pups produces an acute necrotizing ileocolitis resembling human NEC within 24 h, and these mice developed thrombocytopenia at 12 to 15 h. We hypothesized that platelet activation and depletion occur during intestinal injury following exposure to bacterial products translocated across the damaged mucosa. Surprisingly, platelet activation began in our model 3 h after TNBS administration, antedating mucosal injury or endotoxinemia. Platelet activation was triggered by thrombin, which, in turn, was activated by tissue factor released from intestinal macrophages. Compared to adults, neonatal platelets showed enhanced sensitivity to thrombin due to higher expression of several downstream signaling mediators and the deficiency of endogenous thrombin antagonists. The expression of tissue factor in intestinal macrophages was also unique to the neonate. Targeted inhibition of thrombin by a nanomedicine-based approach was protective without increasing interstitial hemorrhages in the inflamed bowel or other organs. In support of these data, we detected increased circulating tissue factor and thrombin-antithrombin complexes in patients with NEC. Our findings show that platelet activation is an important pathophysiological event and a potential therapeutic target in NEC.
Resistin predicts disease severity and survival in patients with pulmonary arterial hypertension
Background Abnormal remodeling of distal pulmonary arteries in patients with pulmonary arterial hypertension (PAH) leads to progressively increased pulmonary vascular resistance, followed by right ventricular hypertrophy and failure. Despite considerable advancements in PAH treatment prognosis remains poor. We aim to evaluate the potential for using the cytokine resistin as a genetic and biological marker for disease severity and survival in a large cohort of patients with PAH. Methods Biospecimens, clinical, and genetic data for 1121 adults with PAH, including 808 with idiopathic PAH (IPAH) and 313 with scleroderma-associated PAH (SSc-PAH), were obtained from a national repository. Serum resistin levels were measured by ELISA, and associations between resistin levels, clinical variables, and single nucleotide polymorphism genotypes were examined with multivariable regression models. Machine-learning (ML) algorithms were applied to develop and compare risk models for mortality prediction. Results Resistin levels were significantly higher in all PAH samples and PAH subtype (IPAH and SSc-PAH) samples than in controls ( P  < .0001) and had significant discriminative abilities (AUCs of 0.84, 0.82, and 0.91, respectively; P  < .001). High resistin levels (above 4.54 ng/mL) in PAH patients were associated with older age ( P  = .001), shorter 6-min walk distance ( P  = .001), and reduced cardiac performance (cardiac index, P  = .016). Interestingly, mutant carriers of either rs3219175 or rs3745367 had higher resistin levels (adjusted P  = .0001). High resistin levels in PAH patients were also associated with increased risk of death (hazard ratio: 2.6; 95% CI: 1.27–5.33; P  < .0087). Comparisons of ML–derived survival models confirmed satisfactory prognostic value of the random forest model (AUC = 0.70, 95% CI: 0.62–0.79) for PAH. Conclusions This work establishes the importance of resistin in the pathobiology of human PAH. In line with its function in rodent models, serum resistin represents a novel biomarker for PAH prognostication and may indicate a new therapeutic avenue. ML-derived survival models highlighted the importance of including resistin levels to improve performance. Future studies are needed to develop multi-marker assays that improve noninvasive risk stratification.
Exploratory factor analysis yields grouping of brain injury biomarkers significantly associated with outcomes in neonatal and pediatric ECMO
In this two-center prospective cohort study of children on ECMO, we assessed a panel of plasma brain injury biomarkers using exploratory factor analysis (EFA) to evaluate their interplay and association with outcomes. Biomarker concentrations were measured daily for the first 3 days of ECMO support in 95 participants. Unfavorable composite outcome was defined as in-hospital mortality or discharge Pediatric Cerebral Performance Category > 2 with decline ≥ 1 point from baseline. EFA grouped 11 biomarkers into three factors. Factor 1 comprised markers of cellular brain injury (NSE, BDNF, GFAP, S100β, MCP1, VILIP-1, neurogranin); Factor 2 comprised markers related to vascular processes (vWF, PDGFRβ, NPTX1); and Factor 3 comprised the BDNF/MMP-9 cellular pathway. Multivariable logistic models demonstrated that higher Factor 1 and 2 scores were associated with higher odds of unfavorable outcome (adjusted OR 2.88 [1.61, 5.66] and 1.89 [1.12, 3.43], respectively). Conversely, higher Factor 3 scores were associated with lower odds of unfavorable outcome (adjusted OR 0.54 [0.31, 0.88]), which is biologically plausible given the role of BDNF in neuroplasticity. Application of EFA on plasma brain injury biomarkers in children on ECMO yielded grouping of biomarkers into three factors that were significantly associated with unfavorable outcome, suggesting future potential as prognostic instruments.
Pediatric ECMO: unfavorable outcomes are associated with inflammation and endothelial activation
BackgroundInflammatory and endothelial activation responses during extracorporeal membrane oxygenation (ECMO) support in children are poorly understood. In this study, we aimed to determine if circulating inflammatory, endothelial activation, and fibrinolytic markers are associated with mortality and with neurologic outcomes in children on ECMO.MethodsWe conducted a secondary analysis of a two-center prospective observational study of 99 neonatal and pediatric ECMO patients. Inflammatory (interferon gamma [IFNγ], interleukin-6 [IL-6], IL-1β, tumor necrosis factor alpha [TNFα]), endothelial activation (E-selectin, P-selectin, intercellular adhesion molecule-3 [ICAM-3], thrombomodulin [TM]), and fibrinolytic markers (tissue plasminogen activator [tPA], plasminogen activator inhibitor-1 [PAI-1]) were measured in plasma on days 1, 2, 3, 5, 7, and every third day thereafter during the ECMO course.ResultsAll ECMO day 1 inflammatory biomarkers were significantly elevated in children with abnormal vs. normal neuroimaging. ECMO day 1 and peak levels of IL-6 and PAI-1 were significantly elevated in children who died compared to those who survived to hospital discharge. Tested biomarkers showed no significant association with long-term neurobehavioral outcomes measured using the Vineland Adaptive Behavioral Scales, Second Edition.ConclusionsHigh levels of circulating inflammatory, endothelial activation, and fibrinolytic markers are associated with mortality and abnormal neuroimaging in children on ECMO.ImpactThe inflammatory, endothelial activation, and fibrinolytic profile of children on ECMO differs by primary indication for extracorporeal support.Proinflammatory biomarkers on ECMO day 1 are associated with abnormal neurologic imaging in children on ECMO in univariable but not multivariable models.In multivariable models, a pronounced proinflammatory and prothrombotic biomarker profile on ECMO day 1 and longitudinally was significantly associated with mortality.Further studies are needed to identify inflammatory, endothelial, and fibrinolytic profiles associated with increased risk for neurologic injury and mortality through potential mediation of bleeding and thrombosis.
Insulin-like growth factor binding protein-2: a new circulating indicator of pulmonary arterial hypertension severity and survival
Background Pulmonary arterial hypertension (PAH) is a fatal disease that results from cardio-pulmonary dysfunction with the pathology largely unknown. Insulin-like growth factor binding protein 2 (IGFBP2) is an important member of the insulin-like growth factor family, with evidence suggesting elevation in PAH patients. We investigated the diagnostic and prognostic value of serum IGFBP2 in PAH to determine if it could discriminate PAH from healthy controls and if it was associated with disease severity and survival. Methods Serum IGFBP2 levels, as well as IGF1/2 levels, were measured in two independent PAH cohorts, the Johns Hopkins Pulmonary Hypertension program (JHPH, N  = 127), NHLBI PAHBiobank (PAHB, N  = 203), and a healthy control cohort ( N  = 128). The protein levels in lung tissues were determined by western blot. The IGFBP2 mRNA expression levels in pulmonary artery smooth muscle cells (PASMC) and endothelial cells (PAEC) were assessed by RNA-seq, secreted protein levels by ELISA. Association of biomarkers with clinical variables was evaluated using adjusted linear or logistic regression and Kaplan-Meier analysis. Results In both PAH cohorts, serum IGFBP2 levels were significantly elevated ( p  < 0.0001) compared to controls and discriminated PAH from controls with an AUC of 0.76 ( p  < 0.0001). A higher IGFBP2 level was associated with a shorter 6-min walk distance (6MWD) in both cohorts after adjustment for age and sex (coefficient − 50.235 and − 57.336 respectively). Cox multivariable analysis demonstrated that higher serum IGFBP2 was a significant independent predictor of mortality in PAHB cohort only (HR, 3.92; 95% CI, 1.37–11.21). IGF1 levels were significantly increased only in the PAHB cohort; however, neither IGF1 nor IGF2 had equivalent levels of associations with clinical variables compared with IGFBP2. Western blotting shown that IGFBP2 protein was significantly increased in the PAH vs control lung tissues. Finally, IGFBP2 mRNA expression and secreted protein levels were significantly higher in PASMC than in PAEC. Conclusions IGFBP2 protein expression was increased in the PAH lung, and secreted by PASMC. Elevated circulating IGFBP2 was associated with PAH severity and mortality and is a potentially valuable prognostic marker in PAH.