Characterization and Formation of Iodinated Disinfection Byproducts from Organic and Inorganic Precursors

Many drinking water sources are impacted by medical waste that contain iodinated contrast media (ICM) or their biodegradation products. When dissolved iodine enters a drinking water treatment plant, it can be a precursor to iodinated disinfection byproducts (I-DBPs) in the finished water, such as iodinated trihalomethanes (I-THMs) and iodoacids (IAs), that have higher relative toxicity compared to regulated DBPs. The goal of this research was to advance our understanding of I-DBP formation in drinking water and evaluate strategies to reduce consumer exposure. The first objective was to develop a method for resolving and quantifying four IAs from nine other haloacetic acids in a drinking water matrix, since current methods lack sensitivity and quality assurance for measuring their occurrence. With a multi-step extraction process that utilizes liquid-liquid and solid-phase extractions, four IAs were reproducibly concentrated from ng/L to the µg/L levels required for detection. The second objective was to evaluate medical waste-impacted surface waters in the US state of North Carolina that are used as downstream drinking water sources. The surface waters receiving such wastewater residues showed measurable levels of organic iodine and downstream drinking water treatment plants had I-DBPs in the finished water. Non-target chemical analysis confirmed that ICMs and their transformation products were responsible for at least a portion of the total organic iodine load in the drinking water source. In the third objective, organic iodine was also tracked through each unit process in the drinking water treatment plant to evaluate I-DBP formation. Utilizing adsorption isotherms, an optimized use of powdered activated carbon was proposed to meet the plant’s current usage objective for taste and odor control while decreasing I-DBP formation in the finished water. When free chlorine was applied at any location in the treatment plant and total dissolved iodine was present, I-THMs formed. Once in the distribution system, I-THMs degraded in the presence of residual disinfectant leading to spatial variability in the water delivered to the consumers. This research demonstrates that I-DBP precursors can originate from anthropogenic sources thus increasing the need for drinking water source protection together with enhanced treatment processes to ensure a high-quality drinking water for consumers.Doctor of Philosoph

Berberine Inhibits HIV Protease Inhibitor-Induced Inflammatory Response by Modulating ER Stress Signaling Pathways in Murine Macrophages

Background HIV protease inhibitor (PI)-induced inflammatory response plays an important role in HIV PI-associated dyslipidemia and cardiovascular complications. This study examined the effect of berberine, a traditional herb medicine, on HIV PI-induced inflammatory response and further investigated the underlying cellular/molecular mechanisms in macrophages. Methodology and Principal Findings Cultured mouse J774A.1 macrophages and primary mouse macrophages were used in this study. The expression of TNF-α and IL-6 were detected by real-time RT-PCR and ELISA. Activations of ER stress and ERK signaling pathways were determined by Western blot analysis. Immunofluorescent staining was used to determine the intracellular localization of RNA binding protein HuR. RNA-pull down assay was used to determine the association of HuR with endogenous TNF-α and IL-6. Berberine significantly inhibited HIV PI-induced TNF-α and IL-6 expression by modulating ER stress signaling pathways and subsequent ERK activation, in turn preventing the accumulation of the RNA binding protein HuR in cytosol and inhibiting the binding of HuR to the 3′-UTRs of TNF-α and IL-6 in macrophages. Conclusions and Significance Inhibition of ER stress represents a key mechanism by which berberine prevents HIV PI-induced inflammatory response. Our findings provide a new insight into the molecular mechanisms of berberine and show the potential application of berberine as a complimentary therapeutic agent for HIV infection

Inhibition of P-Glycoprotein by HIV Protease Inhibitors Increases Intracellular Accumulation of Berberine in Murine and Human Macrophages

Background HIV protease inhibitor (PI)-induced inflammatory response in macrophages is a major risk factor for cardiovascular diseases. We have previously reported that berberine (BBR), a traditional herbal medicine, prevents HIV PI-induced inflammatory response through inhibiting endoplasmic reticulum (ER) stress in macrophages. We also found that HIV PIs significantly increased the intracellular concentrations of BBR in macrophages. However, the underlying mechanisms of HIV PI-induced BBR accumulation are unknown. This study examined the role of P-glycoprotein (P-gp) in HIV PI-mediated accumulation of BBR in macrophages. Methodology and Principal Findings Cultured mouse RAW264.7 macrophages, human THP-1-derived macrophages, Wild type MDCK (MDCK/WT) and human P-gp transfected (MDCK/P-gp) cells were used in this study. The intracellular concentration of BBR was determined by HPLC. The activity of P-gp was assessed by measuring digoxin and rhodamine 123 (Rh123) efflux. The interaction between P-gp and BBR or HIV PIs was predicated by Glide docking using Schrodinger program. The results indicate that P-gp contributed to the efflux of BBR in macrophages. HIV PIs significantly increased BBR concentrations in macrophages; however, BBR did not alter cellular HIV PI concentrations. Although HIV PIs did not affect P-gp expression, P-gp transport activities were significantly inhibited in HIV PI-treated macrophages. Furthermore, the molecular docking study suggests that both HIV PIs and BBR fit the binding pocket of P-gp, and HIV PIs may compete with BBR to bind P-gp. Conclusion and Significance HIV PIs increase the concentration of BBR by modulating the transport activity of P-gp in macrophages. Understanding the cellular mechanisms of potential drug-drug interactions is critical prior to applying successful combinational therapy in the clinic

Pathogenic NR2F1 variants cause a developmental ocular phenotype recapitulated in a mutant mouse model.

Pathogenic NR2F1 variants cause a rare autosomal dominant neurodevelopmental disorder referred to as the Bosch-Boonstra-Schaaf Optic Atrophy Syndrome. Although visual loss is a prominent feature seen in affected individuals, the molecular and cellular mechanisms contributing to visual impairment are still poorly characterized. We conducted a deep phenotyping study on a cohort of 22 individuals carrying pathogenic NR2F1 variants to document the neurodevelopmental and ophthalmological manifestations, in particular the structural and functional changes within the retina and the optic nerve, which have not been detailed previously. The visual impairment became apparent in early childhood with small and/or tilted hypoplastic optic nerves observed in 10 cases. High-resolution optical coherence tomography imaging confirmed significant loss of retinal ganglion cells with thinning of the ganglion cell layer, consistent with electrophysiological evidence of retinal ganglion cells dysfunction. Interestingly, for those individuals with available longitudinal ophthalmological data, there was no significant deterioration in visual function during the period of follow-up. Diffusion tensor imaging tractography studies showed defective connections and disorganization of the extracortical visual pathways. To further investigate how pathogenic NR2F1 variants impact on retinal and optic nerve development, we took advantage of an Nr2f1 mutant mouse disease model. Abnormal retinogenesis in early stages of development was observed in Nr2f1 mutant mice with decreased retinal ganglion cell density and disruption of retinal ganglion cell axonal guidance from the neural retina into the optic stalk, accounting for the development of optic nerve hypoplasia. The mutant mice showed significantly reduced visual acuity based on electrophysiological parameters with marked conduction delay and decreased amplitude of the recordings in the superficial layers of the visual cortex. The clinical observations in our study cohort, supported by the mouse data, suggest an early neurodevelopmental origin for the retinal and optic nerve head defects caused by NR2F1 pathogenic variants, resulting in congenital vision loss that seems to be non-progressive. We propose NR2F1 as a major gene that orchestrates early retinal and optic nerve head development, playing a key role in the maturation of the visual system

Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

TACKing Together Efficient Authentication, Revocation, and Privacy in VANETs (CMU-CyLab-08-011)

Vehicular Ad Hoc Networks (VANETs) require some mechanism to help authenticate messages, identify valid vehicles, and re- move malevolent vehicles. A Public Key Infrastructure (PKI) can provide this functionality using certificates and fixed public keys. However, fixed keys allow an eavesdropper to associate a key with a vehicle and a location, violating drivers’ privacy. In this work we examine a VANET key management scheme based on Temporary Anonymous Certified Keys (TACKs). Our scheme efficiently prevents eavesdroppers from linking a vehicle’s different keys and provides timely revocation of misbehaving participants while maintaining the same or less overhead for vehicle-to- vehicle communication as the current IEEE 1609.2 standard for VANET security