Search

Importance: Management of maternal cardiac arrest (MCA) requires understanding the unique physiology of pregnancy and modifications to life support. Health care professionals have historically demonstrated inadequate knowledge and skills necessary to treat MCA., Objective: To evaluate the effect of Obstetric Life Support (OBLS) education on health care professionals' cognitive performance, skills, and self-efficacy in managing MCA., Design, Setting, and Participants: In this single-masked randomized clinical trial, 46 health care professionals, including emergency medical service and hospital staff representing diverse specialties, were randomized to intervention or control groups at a single academic medical center in Farmington, Connecticut between May 1, 2022, and July 23, 2023., Intervention: The intervention group received OBLS education, which included a blended learning curriculum with simulation-based training on common maternal medical emergencies that lead to MCA. Participants were assessed for knowledge, confidence, and skills (eg, megacode scores as team leaders during MCA simulations). Intervention participants were compared with control group participants who received no OBLS education., Main Outcomes and Measures: The primary outcome was cognitive scores. Secondary outcomes included megacode scores rated by experienced OBLS instructors masked to assignment groups, combined assessment pass rates, and cognitive and confidence scores at baseline and 6 and 12 months after education. Data were analyzed from January 2024 to May 2024., Results: Forty-six participants (mean [SD] age, 41.1 [16.2] years; 24 [52%] women) were randomized. Despite most participants holding certification in basic and advanced cardiac life support, significant between-group differences were identified in knowledge, skills, and confidence. Mean (SD) cognitive scores were 79.5% (9.4%) in the intervention group vs 63.4% (12.3%) in the control group (P < .001). Mean (SD) megacode skills were higher in the intervention vs control group (91.0% [5.0%] vs 61.0% [12.0%], P < .001), as were confidence scores (72.7 [13.3] vs 56.2 [17.9] points, P = .002). Combined assessment pass rates were 90% in the intervention group compared with 10% in the control group (P < .001)., Conclusions and Relevance: In this randomized clinical trial, OBLS education significantly improved health care professionals' knowledge, skills, and confidence in managing MCA. These findings underscore the urgent need for implementation of a standardized MCA curriculum nationwide, especially as the US continues to face unacceptably high maternal mortality rates., Trial Registration: ClinicalTrials.gov Identifier: NCT05355519.

Purpose: The objective of this study was to determine the recommended Phase 2 dose (RP2D) of pevonedistat, a first in class inhibitor of NEDD8 activating enzyme, in combination with irinotecan (IRN) and temozolomide (TMZ) in children with cancer., Methods: This Phase 1 study used a rolling 6 design to evaluate escalating doses of pevonedistat in combination with standard doses of IRN and TMZ in pediatric patients with recurrent/refractory solid or CNS tumors. During cycle 1, pevonedistat was administered intravenously on days 1, 8, 10, and 12, with IRN (IV, 50 mg/m 2 ) and TMZ (orally, 100 mg/m 2 ), on days 8-12 of a 28-day cycle. In subsequent cycles, pevonedistat was administered on days 1, 3, and 5, with IRN/TMZ on days 1-5 of a 21-day cycle., Results: Thirty patients enrolled; all were eligible and evaluable for toxicity. Six patients each enrolled on pevonedistat dose levels (DL) 1 (15 mg/m 2 ), 2 (20 mg/m 2 ), 3 (25 mg/m 2 ) and 4 (35 mg/m 2 ) as well as an expanded pharmacokinetic (PK) cohort at DL4. The maximum tolerated dose (MTD) was not exceeded. 2/12 (17 %) patients treated at the RP2D (35 mg/m 2 ) experienced a cycle 1 dose limiting toxicity (DLT). IRN is unlikely to affect the pharmacokinetics of pevonedistat. Two patients had a partial response and 6 patients had prolonged stable disease (> 6 cycles)., Conclusions: Pevonedistat in combination with IRN/TMZ is well tolerated in children with solid or CNS tumors. The RP2D of pevonedistat is 35 mg/m 2 on days 1, 3, 5 in combination with IRN/TMZ., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Objectives: We sought to determine if the early months of the coronavirus disease 2019 (COVID-19) pandemic influenced pediatric diabetic ketoacidosis (DKA) hospitalization characteristics., Methods: This is a cross-sectional study of youth with laboratory-confirmed DKA admitted to a large tertiary children's hospital in the USA. Data were collected from admissions in March through July 2019 and March through July 2020, respectively. We evaluated the clinical characteristics of hospitalization, including demographic data and DKA severity. We used univariable ordinal logistic regression followed by multiple ordinal logistic regression to adjust for potential confounders., Results: We included 137 children with diabetes admitted for DKA in the relevant period in 2019 and 173 patients admitted for DKA in the same period in 2020. Hemoglobin A1C (HbA 1c ) upon admission was higher in 2020 (median=12.2 %) than in 2019 (11.5 %, p=0.018). Children who were admitted with DKA in 2020 were less likely to be autoantibody positive than those in 2019 (83 vs. 91 %, p=0.028). In the univariable model, being admitted in 2020 was significantly associated with more severe DKA (p=0.038), as was HbA 1c (p=0.001). After adjusting for HbA 1c upon admission, admission year was no longer significantly associated with more severe DKA., Conclusions: In this study of pediatric diabetes of any type and duration of diabetes, youth admitted for DKA at the start of the COVID-19 pandemic, compared with those admitted during the year before, were more likely to have autoantibody-negative diabetes and had significantly higher HbA 1c . Additionally, higher HbA 1c seemed to mediate more severe DKA during the pandemic., (© 2024 Walter de Gruyter GmbH, Berlin/Boston.)

The catalytic function of DNA polymerase β (pol β) fulfills the gap-filling requirement of the base excision DNA repair pathway by incorporating a single nucleotide into a gapped DNA substrate resulting from the removal of damaged DNA bases. Most importantly, pol β can select the correct nucleotide from a pool of similarly structured nucleotides to incorporate into DNA in order to prevent the accumulation of mutations in the genome. Pol β is likely to employ various mechanisms for substrate selection. Here, we use dCTP analogues that have been modified at the β,γ-bridging group of the triphosphate moiety to monitor the effect of leaving group basicity of the incoming nucleotide on precatalytic conformational changes, which are important for catalysis and selectivity. It has been previously shown that there is a linear free energy relationship between leaving group p K a and the chemical transition state. Our results indicate that there is a similar relationship with the rate of a precatalytic conformational change, specifically, the closing of the fingers subdomain of pol β. In addition, by utilizing analogue β,γ-CHX stereoisomers, we identified that the orientation of the β,γ-bridging group relative to R183 is important for the rate of fingers closing, which directly influences chemistry.

Background: The transition of the Accreditation Council for Graduate Medical Education (ACGME) to milestone assessment creates opportunities for collaboration and shared assessments across graduate medical programs. Breaking bad news is an essential communication skill that is a common milestone across almost every medical specialty. The purpose of this study was to develop and pilot an integrated milestone assessment (IMA) tool for breaking bad news using ACGME milestone criteria and to compare the IMA tool with the existing SPIKES protocol., Methods: The IMA tool was created using sub-anchors in professionalism and interpersonal communication skills that are applicable to every specialty and to the ability to break bad news. Two cases of breaking bad news, designed to be "easy" and "intermediate" in difficulty, were used to assess basic skills in breaking bad news in first-year medical residents from six residency specialties. Eight standardized patients were trained to portray the cases in sessions held in November 2013 and May 2014. Standardized patients completed an assessment checklist to evaluate each resident's performance in breaking bad news based on their use of the SPIKES protocol and IMA tool. Residents answered post-encounter questions about their training and comfort in breaking bad news. The association between SPIKES and IMA scores was investigated by simple linear regression models and Spearman rank correlations., Results: There were 136 eligible medical residents: 108 (79.4%) participated in the first session and 97 (71.3%) participated in the second session, with 96 (70.6%) residents participating in both sessions. Overall, we were able to identify residents that performed at both extremes of the assessment criteria using the integrated milestone assessment (IMA) and the SPIKES protocol. Interestingly, residents rated themselves below "comfortable" on average., Conclusion: We developed an integrated milestone assessment (IMA) that was better than the SPIKES protocol at assessing the skill of breaking bad news. This collaborative assessment tool can be used as supplement tool in the era of milestone transformation. We aim assess our tool in other specialties and institutions, as well as assess other shared milestones across specialties., (© 2024. The Author(s).)

Background: Metabolic conditions may worsen asthma. There is a need to define a composite biomarker of metabolic dysfunction that has relevance to asthma outcomes., Objective: To determine the association of the triglyceride-glucose index (TyG), a biomarker of metabolic syndrome and insulin resistance, with risk of severe asthma exacerbation., Methods: A 5-year retrospective cohort of patients with asthma receiving health care from the US Veterans Health Administration from January 1, 2015, to December 31, 2019, was constructed. Fasting TyG values were extracted. Patients were followed for a severe asthma exacerbation, defined as an asthma-related corticosteroid prescription fill or an emergency encounter or hospitalization for asthma. Adjusted models estimated the relative hazard of exacerbation associated with elevated TyG, accounting for known exacerbation risk factors., Results: A total of 108,219 patients fulfilled study criteria. Over 286,343 person-years of follow-up, 21,467 exacerbations were identified, corresponding to a crude rate of 7.5 exacerbations/100 person-years. In exploratory analysis, we found a threshold effect at a TyG of 8.3, which was defined as elevated. In a fully adjusted model, patients with an elevated TyG had a 6% (95% CI, 3%-10%) higher hazard for severe asthma exacerbation, independent of eosinophil count, smoking, obesity, and asthma treatment intensity., Conclusions: Elevated TyG is a risk factor for severe asthma exacerbation independent of conventional predictors. Elevated TyG may identify patients who warrant more intensive asthma treatment and who are candidates for future clinical trials of metabolic intervention for purposes of improving asthma morbidity., (Copyright © 2023 American Academy of Allergy, Asthma & Immunology. All rights reserved.)

Background: Cyclin D has been shown to play an essential role in acute lymphoblastic leukemia (ALL) initiation and progression, providing rationale for targeting the CDK4/6-cyclin D complex that regulates cell cycle progression., Procedure: The Children's Oncology Group AINV18P1 phase 1 trial evaluated the CDK4/6 inhibitor, palbociclib, in combination with standard four-drug re-induction chemotherapy in children and young adults with relapsed/refractory B- and T-cell lymphoblastic leukemia (ALL) and lymphoma. Palbociclib (50 mg/m 2 /dose) was administered orally once daily for 21 consecutive days, first as a single agent (Days 1-3) and subsequently combined with re-induction chemotherapy. This two-part study was designed to determine the maximum tolerated dose (MTD) or recommended phase 2 dose (RP2D), followed by an expansion pharmacokinetic cohort., Results: Twelve heavily pretreated patients enrolled, all of whom were evaluable for toxicity. One dose-limiting hematologic toxicity (DLT) occurred at the starting dose of 50 mg/m 2 /dose orally for 21 days. No additional DLTs were observed in the dose determination or pharmacokinetic expansion cohorts, and overall rates of grade 3/4 nonhematologic toxicities were comparable to those observed with the chemotherapy platform alone. Five complete responses were observed, two among four patients with T-ALL and three among seven patients with B-ALL. Pharmacokinetic studies showed similar profiles with both liquid and capsule formulations of palbociclib., Conclusions: Palbociclib in combination with re-induction chemotherapy was well tolerated with a RP2D of 50 mg/m 2 /day for 21 days. Complete responses were observed among heavily pretreated patients., (© 2023 Wiley Periodicals LLC.)

Objective: To assess the knowledge, skills, and self-efficacy of health care participants completing a simulation-based blended learning training curriculum on managing maternal medical emergencies and maternal cardiac arrest (Obstetric Life Support)., Methods: A formative assessment of the Obstetric Life Support curriculum was performed with a prehospital cohort comprising emergency medical services professionals and a hospital-based cohort comprising health care professionals who work primarily in hospital or urgent care settings and respond to maternal medical emergencies. The training consisted of self-guided precourse work and an instructor-led simulation course using a customized low-fidelity simulator. Baseline and postcourse assessments included multiple-choice cognitive test, self-efficacy questionnaire, and graded Megacode assessment of the team leader. Megacode scores and pass rates were analyzed descriptively. Pre- and post-self-confidence assessments were compared with an exact binomial test, and cognitive scores were compared with generalized linear mixed models., Results: The training was offered to 88 participants between December 2019 and November 2021. Eighty-five participants consented to participation; 77 participants completed the training over eight sessions. At baseline, fewer than half of participants were able to achieve a passing score on the cognitive assessment as determined by the expert panel. After the course, mean cognitive assessment scores improved by 13 points, from 69.4% at baseline to 82.4% after the course (95% CI 10.9-15.1, P <.001). Megacode scores averaged 90.7±6.4%. The Megacode pass rate was 96.1%. There were significant improvements in participant self-efficacy, and the majority of participants (92.6%) agreed or strongly agreed that the course met its educational objectives., Conclusion: After completing a simulation-based blended learning program focused on managing maternal cardiac arrest using a customized low-fidelity simulator, most participants achieved a defensible passing Megacode score and significantly improved their knowledge, skills, and self-efficacy., (Copyright © 2023 Written work prepared by employees of the Federal Government as part of their official duties is, under the U.S. Copyright Act, a “work of the United States Government” for which copyright protection under Title 17 of the United States Code is not available. As such, copyright does not extend to the contributions of employees of the Federal Government.)

Background Type 1 diabetes (T1D) is a common, chronic pediatric health condition with complicated management demands. African American and Latino children with T1D have troubling disparities in glycemic outcomes and acute complications. While there are empirically supported behavioral interventions to support disease management in youth with T1D, there are few that specifically aim to reduce health disparities in this population. While collaborative parent involvement with the child with T1D management tasks is important to promote optimal glycemic outcomes during childhood, our formative research identified multiple individual, family, and broader system factors that impede or facilitate collaborative parental involvement among African American and Latino parents of children with T1D. Methods This paper describes the development, design, and study protocol for the Type 1 Diabetes Empowerment And Management (TEAM) pilot trial. The TEAM intervention is a novel, group-based behavioral intervention designed to enhance collaborative involvement in T1D management for African American and Latino parents of children aged 5-10. This randomized pilot trial's primary aim is to evaluate the TEAM intervention's feasibility and acceptability. The secondary aim is to examine preliminary intervention outcomes (i.e., children's HbA1c, treatment adherence, collaborative parent involvement in T1D management, parent/child quality of life, and parent's diabetes-related distress, depressive symptoms, and self-efficacy) compared to usual T1D care. Discussion The trial will provide preliminary information about whether optimizing appropriate parent involvement during the school-age years may increase T1D treatment adherence and stabilize or improve glycemic control in African American and Latino school-aged children., (Copyright © 2022. Published by Elsevier Inc.)

Background: The maximum tolerated dose of peanut protein following peanut oral immunotherapy (POIT) is unknown because most research studies have not examined very high thresholds., Objective: To define the maximum dose tolerated by patients on POIT and severity of allergic reactions after a 1-month period of treatment discontinuation., Methods: In a phase 2 3-year POIT open-label study, we enrolled participants age 5 to 13 years with a 1-year build-up period followed by a 2-year daily maintenance dose of 3900 mg with assessment of the maximum tolerated dose using double-blind placebo-controlled food challenges (DBPCFCs) of 26,225 mg cumulative dose of peanut protein. The DBPCFC was performed at baseline, after 12-month build-up, at 2 year of maintenance, and after a 1-month period of treatment discontinuation. Biomarkers were assessed every 6 weeks for the first 6 months of therapy. A general linear mixed model was used for analysis., Results: The mean maximum cumulative tolerated dose after 12 months increased by 12,063 mg (P < .001) (n = 12), slightly decreased during maintenance (n = 11), and significantly decreased by 7593 mg after avoidance for 1 month (P = .03) (n = 6). Biomarker analysis revealed decreases in cytokine expression within the first 6 weeks of initiation of POIT and decreased peanut-IgG 4 and increased cytokine expression after 1 month of discontinuation. The DBPCFC reaction severity, examined through a symptom score with 1 point for each defined symptom, decreased after 12 months, but did not significantly change after 1 month of POIT discontinuation., Conclusions: The evaluation of POIT and sustained unresponsiveness by maximum tolerated dose by DBPCFCs in this small phase 2 trial showed that desensitization is diminished, with 100% loss of tolerated dose after 1 month of avoidance following 3 years of treatment., (Copyright © 2021. Published by Elsevier Inc.)

The occurrence of resistances in Gram negative bacteria is steadily increasing to reach extremely worrying levels and one of the main causes of resistance is the massive spread of very efficient β-lactamases which render most β-lactam antibiotics useless. Herein, we report the development of a series of imino-analogues of β-lactams (namely azetidinimines) as efficient non-covalent inhibitors of β-lactamases. Despite the structural and mechanistic differences between serine-β-lactamases KPC-2 and OXA-48 and metallo-β-lactamase NDM-1, all three enzymes can be inhibited at a submicromolar level by compound 7dfm, which can also repotentiate imipenem against a resistant strain of Escherichia coli expressing NDM-1. We show that 7dfm can efficiently inhibit not only the three main clinically-relevant carbapenemases of Ambler classes A (KPC-2), B (NDM-1) and D (OXA-48) with Ki's below 0.3 μM, but also the cephalosporinase CMY-2 (class C, 86% inhibition at 10 μM). Our results pave the way for the development of a new structurally original family of non-covalent broad-spectrum inhibitors of β-lactamases., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier Masson SAS. All rights reserved.)

Background: Oxidative stress (OxS) and mitochondrial dysfunction are implicated as causative factors for aging. Older adults (OAs) have an increased prevalence of elevated OxS, impaired mitochondrial fuel-oxidation (MFO), elevated inflammation, endothelial dysfunction, insulin resistance, cognitive decline, muscle weakness, and sarcopenia, but contributing mechanisms are unknown, and interventions are limited/lacking. We previously reported that inducing deficiency of the antioxidant tripeptide glutathione (GSH) in young mice results in mitochondrial dysfunction, and that supplementing GlyNAC (combination of glycine and N-acetylcysteine [NAC]) in aged mice improves naturally-occurring GSH deficiency, mitochondrial impairment, OxS, and insulin resistance. This pilot trial in OA was conducted to test the effect of GlyNAC supplementation and withdrawal on intracellular GSH concentrations, OxS, MFO, inflammation, endothelial function, genotoxicity, muscle and glucose metabolism, body composition, strength, and cognition., Methods: A 36-week open-label clinical trial was conducted in eight OAs and eight young adults (YAs). After all the participants underwent an initial (pre-supplementation) study, the YAs were released from the study. OAs were studied again after GlyNAC supplementation for 24 weeks, and GlyNAC withdrawal for 12 weeks. Measurements included red-blood cell (RBC) GSH, MFO; plasma biomarkers of OxS, inflammation, endothelial function, glucose, and insulin; gait-speed, grip-strength, 6-min walk test; cognitive tests; genomic-damage; glucose-production and muscle-protein breakdown rates; and body-composition., Results: GlyNAC supplementation for 24 weeks in OA corrected RBC-GSH deficiency, OxS, and mitochondrial dysfunction; and improved inflammation, endothelial dysfunction, insulin-resistance, genomic-damage, cognition, strength, gait-speed, and exercise capacity; and lowered body-fat and waist-circumference. However, benefits declined after stopping GlyNAC supplementation for 12 weeks., Conclusions: GlyNAC supplementation for 24-weeks in OA was well tolerated and lowered OxS, corrected intracellular GSH deficiency and mitochondrial dysfunction, decreased inflammation, insulin-resistance and endothelial dysfunction, and genomic-damage, and improved strength, gait-speed, cognition, and body composition. Supplementing GlyNAC in aging humans could be a simple and viable method to promote health and warrants additional investigation., (© 2021 The Authors. Clinical and Translational Medicine published by John Wiley & Sons Australia, Ltd on behalf of Shanghai Institute of Clinical Bioinformatics.)

Nucleoside 5'-triphosphate (dNTP) analogues in which the β,γ-oxygen is mimicked by a CXY group (β,γ-CXY-dNTPs) have provided information about DNA polymerase catalysis and fidelity. Definition of CXY stereochemistry is important to elucidate precise binding modes. We previously reported the ( R )- and ( S )-β,γ-CHX-dGTP diastereomers (X = F, Cl), prepared via P,C-dimorpholinamide CHCl ( 6a , 6b ) and CHF ( 7a , 7b ) bisphosphonates (BPs) equipped with an ( R )-mandelic acid as a chiral auxiliary, with final deprotection using H 2 /Pd. This method also affords the β,γ-CHCl-dTTP ( 11a , 11b ), β,γ-CHF ( 12a , 12b ), and β,γ-CHCl ( 13a , 13b ) dATP diastereomers as documented here, but the reductive deprotection step is not compatible with dCTP or the bromo substituent in β,γ-CHBr-dNTP analogues. To complete assembly of the toolkit, we describe an alternative synthetic strategy featuring ethylbenzylamine or phenylglycine-derived chiral BP synthons incorporating a photolabile protecting group. After acid-catalyzed removal of the ( R )-(+)-α-ethylbenzylamine auxiliary, coupling with activated dCMP and photochemical deprotection, the individual diastereomers of β,γ-CHBr- ( 33a , 33b ), β,γ-CHCl- ( 34a , 3 4b ), β,γ-CHF-dCTP ( 35a , 35b ) were obtained. The β,γ-CH(CH 3 )-dATPs ( 44a , 44b ) were obtained using a methyl ( R )-(-)-phenylglycinate auxiliary. 31 P and 19 F NMR Δδ values are correlated with CXY stereochemistry and p K a2-4 values for 13 CXY-bisphosphonic acids and imidodiphosphonic acid are tabulated.

Background: Diet therapies may be recommended for pediatric functional gastrointestinal disorders (FGIDs). However, little is known about the frequency with which diet therapy is recommended in FGIDs. Our aims were to determine and contrast the frequency and types of diet recommendations provided to children with FGIDs by pediatric gastroenterologists (PGIs) versus primary care pediatricians (PCPs)., Methods: A retrospective chart review was performed using data from a large, metropolitan children's academic healthcare system to identify subjects meeting Rome IV criteria for functional abdominal pain, functional dyspepsia, irritable-bowel syndrome (IBS), and/or abdominal migraine over a period of 23 months., Results: Of 1929 patient charts reviewed, 268 were included for further analyses. Of these, 186 patients (69%) were seen by a PGI and 82 (31%) by a PCP. The most common diagnosis was IBS (49% for PGIs and 71% for PCPs). Diet recommendations were provided to 115 (43%) patients (PGI group: 86 [75%] vs PCP group: 29 [25%]; P < .1). The most frequent recommendations were high fiber (PGI: 15%; PCP: 14%) and low fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs) diet (PGI: 12%; PCP: 4%). Of those provided with diet recommendations, only 20% (n = 23) received an educational consult by a dietitian. Provision of diet recommendations was not affected by years in practice., Conclusion: Despite increasing awareness of the role of diet in the treatment of childhood FGIDs, a minority of patients receive diet recommendations in tertiary care or primary care settings. When diet recommendations were given, there was great variability in the guidance provided., (© 2020 American Society for Parenteral and Enteral Nutrition.)

As liver biopsy in children poses inherent risks, noninvasive measures of liver fibrosis are needed. This was a cross-sectional, liver biopsy validation pilot study of 16 participants evaluating the ability of shear wave elastography, aspartate transaminase to platelet ratio index (APRI), fibrosis index based on the 4 factors, and novel serum biomarkers to stage liver fibrosis in children with chronic hepatitis B or C. There was very high intrasegmental shear wave speed variation in our participants and little correlation with fibrosis. APRI and monocyte chemoattractant protein (MCP-1) were higher in fibrosis stage F2-3 versus F0-1 ( P = .02, P = .06, respectively). Soluble Fas (sFas) was lower in F2-3 versus F0-1 ( P = .046). A logistic regression analysis calculated by (APRI × MCP-1)/sFas demonstrated an area under the receiver operating characteristic curve of 0.92 ( P < .001), suggesting that this combination can differentiate fibrosis stage F0-1 from F2-3 in children with chronic viral hepatitis., Competing Interests: Declaration of Conflicting Interests: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (© The Author(s) 2020.)

Individual diastereomers of CXY bisphosphonate analogues of dNTPs or NTPs are useful chemical stereoprobes to investigate interactions within the chiral active site environment of enzymes such as polymerases and kinases. We previously reported synthetic access to β,γ-CHX-dGTPs (X = F or Cl) via a bisphosphonate synthon with an (R)-methyl mandelate auxiliary and have extended this approach to dTTP and dATP analogues. As removal of the chiral auxiliary by (Pd/C) hydrogenolysis is incompatible with the cytosine heterocycle and also with X = Br, we have now designed bisphosphonate synthons using (R)-(+)-α-ethylbenzylamine or methyl (R)-(-)-phenylglycine auxiliaries and equipped with an o-nitrobenzyl ester protecting group allowing photochemical deprotection. These new synthons have made possible the first syntheses of individual dCTP and monobromo-substituted dNTP β,γ-CHX diastereomers.

We examine the DNA polymerase β (pol β) transition state (TS) from a leaving group pre-steady-state kinetics perspective by measuring the rate of incorporation of dNTPs and corresponding novel β,γ-CXY-dNTP analogues, including individual β,γ-CHF and -CHCl diastereomers with defined stereochemistry at the bridging carbon, during the formation of right (R) and wrong (W) base pairs. Brønsted plots of log k pol versus p K a4 of the leaving group bisphosphonic acids are used to interrogate the effects of the base identity, the dNTP analogue leaving group basicity, and the precise configuration of the C-X atom in R and S stereoisomers on the rate-determining step ( k pol ). The dNTP analogues provide a range of leaving group basicity and steric properties by virtue of monohalogen, dihalogen, or methyl substitution at the carbon atom bridging the β,γ-bisphosphonate that mimics the natural pyrophosphate leaving group in dNTPs. Brønsted plot relationships with negative slopes are revealed by the data, as was found for the dGTP and dTTP analogues, consistent with a bond-breaking component to the TS energy. However, greater multiplicity was shown in the linear free energy relationship, revealing an unexpected dependence on the nucleotide base for both A and C. Strong base-dependent perturbations that modulate TS relative to ground-state energies are likely to arise from electrostatic effects on catalysis in the pol active site. Deviations from a uniform linear Brønsted plot relationship are discussed in terms of insights gained from structural features of the prechemistry DNA polymerase active site.

Background: Ontuxizumab is a humanized IgG monoclonal antibody that targets the cell-surface glycoprotein endosialin (tumor endothelial marker-1[TEM-1]/CD248) found on activated mesenchymal cells and certain tumors. Ontuxizumab binding to endosialin may interfere with platelet-derived growth factor signaling, prevent tumor stroma organization, and prevent new vessel formation., Methods: Ontuxizumab was administered intravenously on days 1, 8, 15, and 22 of a 28-day cycle at three dose levels (4, 8, and 12 mg/kg). Further dose escalation to 16 mg/kg was planned if the maximum tolerated dose (MTD) was not reached and the ontuxizumab systemic clearance was ≥30% higher in children compared to adults. Following determination of the MTD/recommended phase 2 dose, an additional cohort of six patients (<12 years) was enrolled for further pharmacokinetics (PK) evaluation., Results: Twenty-seven eligible patients (17 male, median age 15 years, range 3-21 years) were enrolled. Twenty-two patients (neuroblastoma [5], Ewing sarcoma [4], rhabdomyosarcoma [4], and other tumors [9]) were fully evaluable for toxicity. Five patients did not complete cycle 1 due to tumor progression. Two of 10 patients experienced dose-limiting toxicity of bacteremia (n = 1) and hyponatremia (n = 1) at 12 mg/kg. Grade ≤2 fever or infusion-related reactions occurred in 10 patients. Clearance was dose dependent and within 30% of adult value at 12 mg/kg., Conclusion: Ontuxizumab administered weekly at 12 mg/kg appears to be well tolerated in children with relapsed or refractory solid tumors. The PK of ontuxizumab does not appear to be significantly different in children compared to adults., (© 2018 Wiley Periodicals, Inc.)

Ynamides were used as precursors for the in situ generation of highly reactive ketenimines that could be trapped with imines in a [2+2] cycloaddition. This imino-Staudinger synthesis led to a variety of imino-analogs of β-lactams, namely azetidinimines (20 examples), that could be further functionalized through a broad range of transformations., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

An estimated 6000 patients who are undocumented immigrants have end-stage renal disease (ESRD) and routinely present to public safety-net hospitals for life-saving emergent dialysis treatments. Because these patients lack a dialysis unit, they often do not have access to medication management consistently coordinated by a nephrologist, and this can result in more frequent emergency department (ED) utilization and cost of care. We hypothesized that patients who were taking loop diuretics had fewer ED visits for emergency dialysis. Loop diuretics can potentially take advantage of residual renal function and mitigate excess fluid gain that can induce heart failure and high potassium, the two most common indications for emergency dialysis. In our univariable analysis, patients on furosemide had 3.1 fewer ED visits on average compared with patients who are not on furosemide. After adjusting for vintage and serum potassium measures, the average number of ED visits was about 1.1 visits less in furosemide-treated patients compared with patients not receiving furosemide (95% confidence interval, -4.4 to 2.1). These results suggest that loop diuretics may have an important role in undocumented patients with ESRD with residual renal function. Further study to develop practical approaches to the care of undocumented patients with ESRD is greatly needed., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Maternal and fetal outcomes of pregnant women with advanced chronic kidney disease (CKD stage 4 and 5) are not well chronicled. Since 1980, we could locate only five published case series'studying this population. This study examines nine pregnant women with severe CKD (defined as estimated GFR < 30 mL/min) and compares their materno-fetal outcomes with a cohort of women with an eGFR 45 - 100 mL/min and pre-pregnancy proteinuria (mild CKD). This is a retrospective, single-center study nd statistical analyses include Fisher' exact test, nonparametric Wilcoxon rank sum, and exact logistic regression. Compared to women with mild CKD, women with severe CKD have higher rates of pre-term delivery (89% vs. 41%, p = 0.02) and a higher average eGFR reduction during pregnancy (26.1% vs. 0%, p = 0.04). Both groups had similar rate of caesarean section, pre-eclampsia, and adverse fetal outcomes including perinatal death, oligohydramnios, and intrauterine growth retardation. Compared to published outcomes of pregnant women receiving hemodialysis, our cohort of women with severe CKD and not on dialysis had a higher incidence of pre-eclampsia and premature birth. In conclusion, the incidence of preterm delivery, small for gestational age, and decline of maternal renal function increased with a reduction in eGFR. Women with severe CKD (eGFR < 30 mL/min) may experience a reduced rate of pre-eclampsia and longer gestation with earlier initiation of dialysis.

Guidelines for HIV primary care include visits every 3 months (up to 6 months in those with stable HIV). During pregnancy, women with HIV commonly attend once weekly to once monthly visits; however, after delivery, many are lost to follow-up. Our goal was to assess the frequency of loss to primary care follow-up postpartum and to identify predictors of loss to care. A retrospective chart review of HIV-infected women in a Houston prenatal program was done. Optimal care was defined as one visit to HIV primary care providers (PCPs) every 6 months within the first year after delivery, and loss to follow-up as no visits within the first postpartum year. Multivariate logistic regression analysis was used to identify factors associated with loss to follow-up. Charts (n=213) were analyzed for follow-up with PCPs. The loss to follow-up rate was 39% in the first postpartum year. Associated factors were younger age, black race, late entry to prenatal care, and no plans for contraception. Predictors of loss to primary care after pregnancy can be used to identify specific subpopulations of pregnant women at highest risk for falling out of care.

N-acylhomoserine lactone (AHL)-mediated quorum-sensing (QS) regulates virulence functions in plant and animal pathogens such as Agrobacterium tumefaciens and Pseudomonas aeruginosa. A chemolibrary of more than 3500 compounds was screened using two bacterial AHL-biosensors to identify QS-inhibitors (QSIs). The purity and structure of 15 QSIs selected through this screening were verified using HPLC MS/MS tools and their activity tested on the A. tumefaciens and P. aeruginosa bacterial models. The IC50 value of the identified QSIs ranged from 2.5 to 90 µg/ml, values that are in the same range as those reported for the previously identified QSI 4-nitropyridine-N-oxide (IC50 24 µg/ml). Under the tested culture conditions, most of the identified QSIs did not exhibit bacteriostatic or bactericidal activities. One third of the tested QSIs, including the plant compound hordenine and the human sexual hormone estrone, decreased the frequency of the QS-regulated horizontal transfer of the tumor-inducing (Ti) plasmid in A. tumefaciens. Hordenine, estrone as well as its structural relatives estriol and estradiol, also decreased AHL accumulation and the expression of six QS-regulated genes (lasI, lasR, lasB, rhlI, rhlR, and rhlA) in cultures of the opportunist pathogen P. aeruginosa. Moreover, the ectopic expression of the AHL-receptors RhlR and LasR of P. aeruginosa in E. coli showed that their gene-regulatory activity was affected by the QSIs. Finally, modeling of the structural interactions between the human hormones and AHL-receptors LasR of P. aeruginosa and TraR of A. tumefaciens confirmed the competitive binding capability of the human sexual hormones. This work indicates potential interferences between bacterial and eukaryotic hormonal communications.

Production of reactive oxygen species (ROS) has been implicated in the pathology of many conditions, including cardiovascular, inflammatory and degenerative diseases, aging, muscular dystrophy, and muscle fatigue. NADPH oxidases (Nox) have recently gained attention as an important source of ROS involved in redox signaling. However, our knowledge of the source of ROS has been limited by the relatively impoverished array of tools available to study them and the limitations of all imaging probes to provide meaningful spatial resolution. By linking redox-sensitive GFP (roGFP) to the Nox organizer protein, p47(phox), we have developed a redox sensitive protein to specifically assess Nox activity (p47-roGFP). Stimulation of murine macrophages with endotoxin resulted in rapid, reversible oxidation of p47-roGFP. In murine skeletal muscle, both passive stretch and repetitive electrical stimulation resulted in oxidation of p47-roGFP. The oxidation of p47-roGFP in both macrophages and skeletal muscle was blocked by a Nox specific peptide inhibitor. Furthermore, expression of p47-roGFP in p47(phox) deficient cells restored Nox activity. As Nox has been linked to pathological redox signaling, our newly developed Nox biosensor will allow for the direct assessment of Nox activity and the development of therapeutic Nox inhibitors.

The copper(I) catalyzed reaction of an enamide with an iminoiodane, in the presence of an alcohol, triggers the direct alkoxyamination of the double bond. This transformation represents a straightforward access to α-amino aminals in a completely regio- and diastereoselective manner. Use of a chiral Box ligand allows this reaction to be carried out in an enantioselective fashion., (© 2011 American Chemical Society)

Colloidal gold nanoparticles are investigated as a potential scaffold for the assisted immobilisation of probe oligonucleotides on silicon surfaces. A preliminary study is devoted to the examination of the immobilisation of DNA-modified gold nanoparticles as a function of time, concentration, salt and pH. The DNA-modified nanoparticles self-assembled onto solid surfaces in a three-dimensional self-assembled architecture. The functionalised surfaces are evaluated in diagnostic assays, where their potential to improve the efficiency of the hybridisation reaction is tested. The system utilising DNA-modified nanoparticles produced an enhancement in the hybridisation efficiency and the sensitivity limit by a factor 10 to 100 as compared to a conventional DNA immobilisation system on a planar surface.

The objective of the Registry was to characterize the population of infants receiving prophylaxis for respiratory syncytial virus (RSV) disease by describing the patterns and scope of usage of palivizumab in a cross section of US infants. RSV hospitalization outcomes were also described. The Palivizumab (Synagis, MedImmune, Inc., 25 West Watkins Mill Road, Gaithersburg, MD 20878) Outcomes Registry was a prospective multicenter survey conducted at 63 sites. Demographics, injection history, and RSV hospitalization outcomes were collected on 2,116 infants receiving palivizumab. Infants were enrolled in the Registry between September 1, 2000-March 1, 2001, at the time of their first injection. Infants born at less than 32 weeks of gestation accounted for 47% of infants enrolled, and those between 32-35 weeks accounted for 45%; approximately 8% were greater than 35 weeks of gestation. Lower RSV hospitalization rates were observed in infants who had greater adherence to regularly scheduled injections. Nearly one-half of all hospitalizations occurred within the first and second injection intervals, suggesting the importance of early RSV protection. The confirmed RSV hospitalization rate of all infants in the Registry was 2.9%; the rate was 5.8% in infants with chronic lung disease of infancy, and 2.1% in premature infants without chronic lung disease. In conclusion, these data support the continued effectiveness of palivizumab prophylaxis for severe RSV lower respiratory tract disease in a large cohort of high-risk infants from geographically diverse pediatric offices and clinics. The Palivizumab Outcomes Registry provides an opportunity to assess palivizumab utilization and clinical effectiveness in the US., (Copyright 2003 Wiley-Liss, Inc.)

The synthesis of a polyphenylene dendrimer carrying three perylenemonoimide dyes as well as one biotin group is presented. Due to the hydrophobic polyphenylene scaffold, this dendrimer is insoluble in water thus preventing investigations in aqueous media. However, the use of an appropriate detergent results in the formation of well-defined supramolecular dendrimer-detergent complexes being soluble in aqueous media. The dendrimer-detergent complexes have a constant hydrodynamic radius of 7.1 nm measured by light scattering and fluorescence correlation spectroscopy and exhibit a high stability in the presence of blood serum proteins. The specific binding of the dendrimer-detergent complexes carrying a single biotin group to the protein streptavidin is demonstrated using a magnetic bead assay.

(Polymer-oligonucleotide) conjugates were obtained via direct ON synthesis from the poly(ethylene-alt-maleic anhydride: PEMA) grafted onto glass bead surfaces. The effect of the ON number per polymer chain on binding was evaluated through Tm experiments. Results were correlated with ELOSA (Enzyme Linked Oligosorbent Assay) tests run with conjugates in the capture step.

Oligonucleotide-polymer conjugates have been described to improve the sensitivity of an enzyme-linked oligosorbent assay diagnostic test. To understand the influence of their structure and conformation in solution on the efficiency of the test during the capture step, two different ways of synthesizing these conjugates were compared. The first consisted of coupling 5' amino modified oligonucleotides to poly(maleic anhydride-alt-methylvinyl ether) and poly(maleic anhydride-alt-ethylene). The second resulted from direct synthesis of oligonucleotides from poly(maleic anhydride-alt-ethylene) previously grafted onto a controlled pore glass support. The different conjugates were analyzed by size-exclusion chromatography and viscometry. The former method for conjugate synthesis produced aggregates, which was not the case for the latter. These conjugates were then used in the capture phase of a hybridization assay using a HBV DNA target, on a bioMérieux VIDAS instrument. Different parameters were studied, such as the purity of the conjugate solution and the number of oligonucleotides per polymer chain. The amount of conjugate coated on the solid-phase receptacle surface at the time of the capture phase was evaluated by radioactive labeling. Finally, it was demonstrated that conjugates produced an amplification factor of 50 versus the capture oligonucleotide probe used as the reference. The detection limit reached 10(8) copies/mL.