Modulation of HIV protease flexibility by the T80N mutation.

The flexibility of HIV protease (HIVp) plays a critical role in enabling enzymatic activity and is required for substrate access to the active site. While the importance of flexibility in the flaps that cover the active site is well known, flexibility in other parts of the enzyme is also critical for function. One key region is a loop containing Thr 80, which forms the walls of the active site. Although not situated within the active site, amino acid Thr80 is absolutely conserved. The mutation T80N preserves the structure of the enzyme but catalytic activity is completely lost. To investigate the potential influence of the T80N mutation on HIVp flexibility, wide-angle X-ray scattering (WAXS) data was measured for a series of HIVp variants. Starting with a calculated WAXS pattern from a rigid atomic model, the modulations in the intensity distribution caused by structural fluctuations in the protein were predicted by simple analytic methods and compared with the experimental data. An analysis of T80N WAXS data shows that this variant is significantly more rigid than the WT across all length scales. The effects of this single point mutation extend throughout the protein, to alter the mobility of amino acids in the enzymatic core. These results support the contentions that significant protein flexibility extends throughout HIVp and is critical to catalytic function.

Short term outcomes of neonatal opioid withdrawal syndrome: a comparison of two approaches.

OBJECTIVE: To evaluate outcomes in opioid exposed neonates (OENs) assessed by the Eat, Sleep, Console (ESC) tool compared to the Finnegan Neonatal Abstinence Scoring System (FNASS). METHODS: Retrospective analysis of a statewide database of OENs from 2017 to 2020 with birthing hospitals classified based on the assessment tool used. Four main outcomes were examined using multivariable and Poisson logistic regression models. RESULTS: Of 2375 OENs, 42.1% received pharmacotherapy (PT) with a consistent decrease in PT, length of treatment (LOT), and length of stay (LOS) over the study period. There was no change in use of mother's own milk (MoM). While outcomes were significantly associated with several specific variables, there were no differences in outcomes between assessment methods. CONCLUSION: While there was a significant decrease over time in PT, LOT, and LOS, improvements were independent of the assessment tool used and likely related to the increased use of non-pharmacologic care.

Evaluating the Impact of a Pediatric Inpatient Social Care Program in a Community Hospital.

OBJECTIVES: To evaluate the impact of implementing a stakeholder-informed social risk screening and social service referral system in a community hospital setting. METHODS: We implemented a stakeholder-informed social care program at a community hospital in April 2022. The evaluation included patients aged 0 to 17 years admitted to the pediatric unit between April 2021 and March 2022 (1 year preimplementation) and between April 2022 and March 2023 (1 year postimplementation). For a random subset of 232 preimplementation and 218 postimplementation patients, we performed manual data extraction, documenting program process measures and preliminary effectiveness outcomes. We used χ square and Wilcoxon rank tests to compare outcomes between the preimplementation and postimplementation groups. Multivariable logistic regression was used to assess the preliminary effectiveness of the social care program in identifying social risks. RESULTS: Screening rates were higher in the postimplementation group for nearly all social domains. Compared with preimplementation, the postimplementation group had higher rates of social risks identified (17.4% vs 7.8% [P < .01]: adjusted odds ratio 2.9 [95% confidence interval 1.5-5.5]) on multivariate testing. Social work consults were completed more frequently and earlier for the postimplementation group (13.8.% vs 5.6% [P < .01]) and median (19 hours vs 25 hours [P = .03]), respectively. Rates of communication of social risks in discharge summaries were higher in the postimplementation group (46.8% vs 8.2% [P < .001]). CONCLUSIONS: The implementation of a stakeholder-informed social care program within a community hospital setting led to the increased identification of social risks and social work consultations and improved timeliness of social work consultations and written communication of social risks in discharge summaries for primary care providers.

Neonatal Opioid Withdrawal Syndrome: A Comparison of As-Needed Pharmacotherapy.

BACKGROUND AND OBJECTIVE: Methadone and morphine are commonly administered medications for neonatal opioid withdrawal syndrome (NOWS). Infants are increasingly treated with as-needed or "pro re nata" (PRN) medication. The optimal pharmacologic agent for PRN treatment of NOWS has not been examined. This study's objective is to compare NOWS hospital outcomes between infants treated with PRN methadone versus morphine. METHODS: We performed a retrospective cohort study of infants pharmacologically treated for NOWS across 4 Massachusetts hospitals between January 2018 and February 2021. Infants born ≥36 weeks gestation with prenatal opioid exposure treated with PRN methadone or morphine were included. Mixed effects logistic and linear regression models were employed to evaluate differences in transition rates to scheduled dosing, length of stay, and number of PRN doses administered depending on PRN treatment agent. RESULTS: There were 86 infants in the methadone group and 52 in the morphine group. There were no significant differences in NOWS hospital outcomes between groups in adjusted models: transition to scheduled dosing (methadone 31.6% vs morphine 28.6%, adjusted odds ratio 1.21, 95% confidence interval [CI] 0.87-1.19), mean length of stay (methadone 15.5 vs morphine 14.3 days, adjusted risk ratio 1.06, 95% CI 0.80-1.41), and the mean number of PRN doses (methadone 2.3 vs morphine 3.4, adjusted risk ratio 0.65, 95% CI 0.41-1.02). There was an association with nonpharmacologic care practices and improved NOWS hospital outcomes. CONCLUSIONS: There were no significant differences in NOWS hospitalization outcomes based on pharmacologic agent type; nonpharmacologic care practices were most strongly associated with improved NOWS hospitalization outcomes.

A quality improvement initiative to implement the eat, sleep, console neonatal opioid withdrawal syndrome care tool in Massachusetts' PNQIN collaborative.

OBJECTIVE: To support hospitals in the Massachusetts PNQIN collaborative with adoption of the ESC Neonatal Opioid Withdrawal Syndrome (NOWS) Care Tool© and assess NOWS hospitalization outcomes. STUDY DESIGN: Statewide QI study where 11 hospitals adopted the ESC NOWS Care Tool©. Outcomes of pharmacotherapy and length of hospital stay (LOS) and were compared in Pre- and Post-ESC implementation cohorts. Statistical Process Control (SPC) charts were used to examine changes over time. RESULTS: The Post-ESC group had lower rates of pharmacotherapy (OR 0.35, 95% CI 0.26, 0.46) with shorter LOS (RR 0.79, 95% CI 0.76, 0.82). The 30-day NOWS readmission rate was 1.2% in the Pre- and 0.4% in the Post-ESC cohort. SPC charts indicate a shift in pharmacotherapy from 54.8 to 35.0% and LOS from 14.2 to 10.9 days Post-ESC. CONCLUSIONS: The ESC NOWS Care Tool was successfully implemented across a state collaborative with improvement in NOWS outcomes without short-term adverse effects.

Hydrophobic sliding: a possible mechanism for drug resistance in human immunodeficiency virus type 1 protease.

Hydrophobic residues outside the active site of HIV-1 protease frequently mutate in patients undergoing protease inhibitor therapy; however, the mechanism by which these mutations confer drug resistance is not understood. From analysis of molecular dynamics simulations, 19 core hydrophobic residues appear to facilitate the conformational changes that occur in HIV-1 protease. The hydrophobic core residues slide by each other, exchanging one hydrophobic van der Waal contact for another, with little energy penalty, while maintaining many structurally important hydrogen bonds. Such hydrophobic sliding may represent a general mechanism by which proteins undergo conformational changes. Mutation of these residues in HIV-1 protease would alter the packing of the hydrophobic core, affecting the conformational flexibility of the protease. Therefore these residues impact the dynamic balance between processing substrates and binding inhibitors, and thus contribute to drug resistance.

Retrospective Application of BRUE Criteria to Patients Presenting With ALTE.

OBJECTIVES: To apply recently published brief resolved unexplained events (BRUE) guidelines to patients who presented with apparent life-threatening event (ALTE) to determine: (1) characteristics of these patients; (2) which patients meet BRUE criteria, including risk stratification; and (3) patient outcomes. METHODS: A retrospective chart review of patients presenting to the emergency department or directly to the inpatient unit of a community hospital was performed over the 3 years preceding publication of BRUE guidelines. International Classification of Diseases, Ninth Revision and International Classification of Diseases, 10th Revision billing data for infants <1 year of age were used to screen for patients. After 2-physician review, patients presenting with ALTE diagnostic criteria were identified. Characteristics of the patients and event were analyzed. RESULTS: A total of 321 charts were screened, of which 87 patients were determined to have been diagnosed with ALTE. Twenty patients (23%) met criteria for diagnosis of BRUE. Only 1 patient met criteria for lower-risk BRUE. Of patients with ALTE, 79% of patients presented to the emergency department, of which 65% were admitted, 25% were discharged from the hospital, and 9% were transferred to a tertiary care hospital. Of the 63 inpatients, most were discharged from the hospital after brief observation, and 5% required transfer to a higher level of care. CONCLUSIONS: The majority of patients with ALTE presenting to this institution did not meet the BRUE definition primarily because of ongoing symptoms and/or a specific diagnosis explaining the event. With this finding, we highlight the importance of characterizing the events on the basis of history and physical examination when diagnosing and caring for these patients.

Cooperative effects of drug-resistance mutations in the flap region of HIV-1 protease.

Understanding the interdependence of multiple mutations in conferring drug resistance is crucial to the development of novel and robust inhibitors. As HIV-1 protease continues to adapt and evade inhibitors while still maintaining the ability to specifically recognize and efficiently cleave its substrates, the problem of drug resistance has become more complicated. Under the selective pressure of therapy, correlated mutations accumulate throughout the enzyme to compromise inhibitor binding, but characterizing their energetic interdependency is not straightforward. A particular drug resistant variant (L10I/G48V/I54V/V82A) displays extreme entropy-enthalpy compensation relative to wild-type enzyme but a similar variant (L10I/G48V/I54A/V82A) does not. Individual mutations of sites in the flaps (residues 48 and 54) of the enzyme reveal that the thermodynamic effects are not additive. Rather, the thermodynamic profile of the variants is interdependent on the cooperative effects exerted by a particular combination of mutations simultaneously present.

Molecular Basis for Drug Resistance in HIV-1 Protease.

HIV-1 protease is one of the major antiviral targets in the treatment of patients infected with HIV-1. The nine FDA approved HIV-1 protease inhibitors were developed with extensive use of structure-based drug design, thus the atomic details of how the inhibitors bind are well characterized. From this structural understanding the molecular basis for drug resistance in HIV-1 protease can be elucidated. Selected mutations in response to therapy and diversity between clades in HIV-1 protease have altered the shape of the active site, potentially altered the dynamics and even altered the sequence of the cleavage sites in the Gag polyprotein. All of these interdependent changes act in synergy to confer drug resistance while simultaneously maintaining the fitness of the virus. New strategies, such as incorporation of the substrate envelope constraint to design robust inhibitors that incorporate details of HIV-1 protease's function and decrease the probability of drug resistance, are necessary to continue to effectively target this key protein in HIV-1 life cycle.