Role of succinyl substituents in the mannose-capping of lipoarabinomannan and control of inflammation in Mycobacterium tuberculosis infection.

The covalent modification of bacterial (lipo)polysaccharides with discrete substituents may impact their biosynthesis, export and/or biological activity. Whether mycobacteria use a similar strategy to control the biogenesis of its cell envelope polysaccharides and modulate their interaction with the host during infection is unknown despite the report of a number of tailoring substituents modifying the structure of these glycans. Here, we show that discrete succinyl substituents strategically positioned on Mycobacterium tuberculosis (Mtb) lipoarabinomannan govern the mannose-capping of this lipoglycan and, thus, much of the biological activity of the entire molecule. We further show that the absence of succinyl substituents on the two main cell envelope glycans of Mtb, arabinogalactan and lipoarabinomannan, leads to a significant increase of pro-inflammatory cytokines and chemokines in infected murine and human macrophages. Collectively, our results validate polysaccharide succinylation as a critical mechanism by which Mtb controls inflammation.

Children with cancer at the end of life in a middle-income country: integrated pediatric palliative care improves outcomes.

BACKGROUND: In 2020, the Global Cancer Observatory reported 280,000 cases of childhood cancer worldwide, with a higher burden of disease and mortality rates in low- and middle-income countries. In 2022, the National Institute of Health reported 1708 new cases of childhood cancer in Colombia and an overall survival rate of approximately 55%. The aim of this study is to compare outcomes in children with cancer in the hospital setting during the last 72 h of life who received concurrent Pediatric Palliative Care (PPC) versus oncology care alone. METHODS: An observational descriptive study was conducted between January 2013 and June 2022 in a center for pediatric patients with oncological diagnoses. In 2017, the PPC team was created. Patients between 28 days and 17 years of age who were hospitalized at least 72 h before death were included. A retrospective review of the medical records of patients in the last 72 h of life was performed. Two cohorts were established: oncology-alone group received exclusive management by oncology, and oncology and PPC received concurrent oncology and PPC management since the diagnosis. RESULTS: We evaluated 257 medical records of deceased pediatric patients with cancer diagnoses. For the first cohort (2013-2017), 136 patients were included; for the second cohort (2018 and 2022), 121 patients were evaluated. The most frequent diagnosis was leukemia [47.1% (n = 121)]. No significant difference was found in either group between dyspnea, pain, and seizures. Dyspnea was the most frequent symptom in both groups. Agitation and anxiety were reported more frequently in children from the oncology-alone group (22.1% and 13.2%, respectively). The oncology and PPC group received more psychology and social work consultation (94.2% and 70.2% vs. 84.6 and 54.4% in the oncology alone group) and had a higher percentage of advance care planning (79.3% vs. 62.5% in the oncology alone group). CONCLUSIONS: This retrospective study highlights that PPC at the end of life (EoL) offers a holistic approach to the physical and psychosocial symptoms experienced by children with cancer; these patients received more comfort through symptom management and less aggressive treatment at the EoL. The availability of a PPC team may contribute to improvements in the quality of end-of-life care. TRIAL REGISTRATION: retrospectively registered.

Treatment-related mortality in children with cancer in low-income and middle-income countries: a systematic review and meta-analysis.

BACKGROUND: Approximately 90% of children with cancer live in low-income and middle-income countries (LMICs), where 5-year survival is lower than 20%. Treatment-related mortality in high-income countries is approximately 3-5%; however, in LMICs, treatment-related mortality has been reported in up to 45% of children with cancer. This study aimed to systematically explore the burden of treatment-related mortality in children with cancer in LMICs and to explore the association between country income level and treatment-related mortality. METHODS: For this systematic review and meta-analysis we identified articles published between Jan 1, 2010, and June 22, 2021, describing treatment-related mortality in paediatric patients (aged 0-21 years) with cancer in LMICs. We searched PubMed, Trip, Web of Science, Embase, and the WHO Global Metric Index databases. The search was limited to full-text articles and excluded case reports (<10 patients) and haematopoietic stem-cell transplantation recipients. Two reviewers independently screened studies for eligibility, extracted data from included publications, and evaluated data quality. Random and mixed-effects models were used to estimate treatment-related mortality burden and trends. The Cochran-Q statistic was used to assess heterogeneity between studies. This study is registered on PROSPERO (CRD42021264849). FINDINGS: Of 13 269 identified abstracts, 501 studies representing 68 351 paediatric patients with cancer were included. The treatment-related mortality estimate was 6·82% (95% CI 5·99-7·64), accounting for 30·9% of overall mortality (4437 of 14 358 deaths). Treatment-related mortality was inversely related to country income. Treatment-related mortality was 14·19% (95% CI 9·65-18·73) in low-income countries, 9·21% (7·93-10·49) in lower-middle-income countries, and 4·47% (3·42-5·53) in upper-middle-income countries (Cochran-Q 42·39, p<0·0001). In upper-middle-income countries, the incidence of treatment-related mortality decreased over time (slope -0·002, p=0·0028); however, outcomes remained unchanged in low-income (p=0·21) and lower-middle-income countries (p=0·16). INTERPRETATION: Approximately one in 15 children receiving cancer treatment in LMICs die from treatment-related complications. Although treatment-related mortality has decreased in upper-middle-income countries over time, it remains unchanged in LMICs. There is an urgent need for targeted supportive care interventions to reduce global disparities in childhood cancer survival. FUNDING: American Lebanese Syrian Associated Charities and National Cancer Institute.

Going Virtual: Adapting an Institutional Annual Bereavement Event During the COVID-19 Pandemic.

Our institution's annual bereaved family event was modified to a virtual format during the COVID-19 pandemic. While necessary to comply with physical distancing directives, the transition also provided greater accessibility for families. Virtual events were feasible and appreciated by attendees. Future hybrid bereavement events should be considered to allow families more flexibility and accessibility.

Racial and ethnic disparities in influenza vaccination coverage among pregnant women in the United States: The contribution of vaccine-related attitudes.

OBJECTIVE: Racial and ethnic disparities in influenza vaccination coverage among pregnant women in the United States have been documented. This study assessed the contribution of vaccine-related attitudes to coverage disparities. METHODS: Surveys were conducted following the 2019-2020 and 2020-2021 influenza seasons in a US research network. Using electronic health record data to identify pregnant women, random samples were selected for surveying; non-Hispanic Black women and influenza-unvaccinated women were oversampled. Regression-based decomposition analyses were used to assess the contribution of vaccine-related attitudes to racial and ethnic differences in influenza vaccination. Data were combined across survey years, and analyses were weighted and accounted for survey design. RESULTS: Survey response rate was 41.2% (721 of 1748) for 2019-2020 and 39.3% (706 of 1798) for 2020-2021. Self-reported influenza vaccination was higher among non-Hispanic White respondents (79.4% coverage, 95% CI 73.1%-85.7%) than Hispanic (66.2% coverage, 95% CI 52.5%-79.9%) and non-Hispanic Black (55.8% coverage, 95% CI 50.2%-61.4%) respondents. For all racial and ethnic groups, a high proportion (generally >80%) reported being seen for care, recommended for influenza vaccination, and offered vaccination. In decomposition analyses, vaccine-related attitudes (e.g., worry about vaccination causing influenza; concern about vaccine safety and effectiveness) explained a statistically significant portion of the observed racial and ethnic disparities in vaccination. Maternal age, education, and health status were not significant contributors after controlling for vaccine-related attitudes. CONCLUSIONS: In a setting with relatively high influenza vaccination coverage among pregnant women, racial and ethnic disparities in coverage were identified. Vaccine-related attitudes were associated with the disparities observed.

Health literacy on quality of life for children with cancer: modules on pediatric palliative care.

Objective: To describe the development of educational materials for parents and other caregivers of children with cancer, which utilized a culturally sensitive approach to reduce acceptance barriers to palliative care (PC). Methods: The Pan American Health Organization (PAHO), St. Jude Children's Research Hospital, and partners in Latin America and the Caribbean collaborated in a three-phase project, beginning with a needs assessment survey of caregivers of children with cancer in Peru. Based on this finding, an interdisciplinary team of pediatric PC experts developed educational content that was designed and validated by an international committee of PC and communication experts. Results: The collaboration resulted in the development of an eight-module series that introduces caregivers to key concepts of pediatric PC, including management of pain, quality of life, and end of life care. The series was designed to reduce caregiver stigma associated with PC through culturally sensitive education that addresses the low levels of health literacy among caregivers in Latin America and the Caribbean. In the 15 months since the launch, these modules have been distributed throughout Latin America and were downloaded 2 825 times. Conclusions: Educational materials and anticipatory guidance of PC were considered to be a priority for parents and other caregivers of children with cancer throughout Latin America. The materials developed through this project have been widely utilized and are available through the PAHO website and the Together by St. Jude™ online resource.

Collaboration for success: the Global Initiative for Childhood Cancer in Latin America.

The Global Initiative for Childhood Cancer (GICC) aims to increase the cure rate for children with cancer globally by improving healthcare access and quality. The Pan American Health Organization (PAHO), St. Jude Children's Research Hospital (St. Jude), and collaborators have joined efforts to improve outcomes of children with cancer in Latin America and the Caribbean (LAC) using the CureAll framework. In this article, we describe the process of developing regional resources aimed at accelerating the GICC implementation in LAC. In March 2021, PAHO formed regional working groups to develop core projects aligned with CureAll pillars and enablers. Seven working groups emerged from regional dialogues: early detection, nursing, psychosocial, nutrition, supportive care, treatment abandonment, and palliative care. PAHO arranged regular online meetings under the mentorship and support of St. Jude regional/transversal programs and international mentors. Between April and December 2021, 202 multidisciplinary experts attended 43 online meetings to promote the dialogue between stakeholders to improve childhood cancer outcomes. Fourteen technical outputs were produced: four regional snapshots, four technical documents, two virtual courses, one set of epidemiological country profiles, one educational content series for parents/caregivers, and two communication campaigns. The ongoing dialogue and commitment of PAHO, St. Jude, LAC working committees, and international collaborators are essential foundations to successfully accelerate GICC implementation. This is achievable through the development of materials of regional and global relevance. Further research and evaluation are needed to determine the impact of these strategies and resources on childhood cancer outcomes in LAC and other regions.

La Iniciativa Mundial contra el Cáncer Infantil tiene como objetivo aumentar a nivel mundial la tasa de curación del cáncer infantil mediante la mejora del acceso a la atención de salud y de su calidad. La Organización Panamericana de la Salud (OPS), el St. Jude Children's Research Hospital y los colaboradores han aunado esfuerzos para mejorar los resultados en la población infantil con cáncer en América Latina y el Caribe valiéndose del marco CureAll. En este artículo describimos el proceso de elaboración de recursos regionales destinados a acelerar la aplicación de la Iniciativa Mundial en América Latina y el Caribe.En marzo del 2021, la OPS formó grupos de trabajo regionales para elaborar proyectos básicos que estuvieran en consonancia con los pilares y los elementos facilitadores del CureAll. De los diálogos regionales surgieron siete grupos de trabajo: detección temprana, enfermería, aspectos psicosociales, nutrición, tratamientos de apoyo, abandono del tratamiento y cuidados paliativos. La OPS organizó con regularidad reuniones virtuales en las que se contó con la tutoría y el apoyo de programas regionales o transversales del St. Jude Children's Research Hospital y de mentores internacionales.Entre abril y diciembre del 2021 hubo 43 reuniones virtuales a las que asistieron 202 expertos multidisciplinarios, con el objetivo de promover el diálogo entre las partes interesadas para mejorar los resultados en materia de cáncer infantil. Se elaboraron catorce productos técnicos: cuatro panoramas regionales, cuatro documentos técnicos, dos cursos virtuales, un conjunto de perfiles epidemiológicos de países, una serie con contenidos educativos para padres y cuidadores y dos campañas de comunicación.El diálogo y el compromiso constantes de la OPS, el St. Jude Children's Research Hospital, los comités de trabajo de América Latina y el Caribe y los colaboradores internacionales son las bases fundamentales para conseguir que se acelere la aplicación de la Iniciativa Mundial. Esto se puede lograr mediante la elaboración de materiales que resulten pertinentes a nivel regional y mundial. Son necesarias más investigaciones y evaluaciones para determinar el impacto que tienen estas estrategias y recursos en los resultados que se obtienen en el cáncer infantil en América Latina y el Caribe y en otras subregiones.

A Iniciativa Global para o Câncer Infantil tem como objetivo aumentar a taxa de cura de crianças com câncer no mundo todo, melhorando o acesso a cuidados e a qualidade da assistência médica. A Organização Pan-Americana da Saúde (OPAS), o St. Jude Children's Research Hospital (St. Jude) e colaboradores uniram esforços para melhorar o desfecho de crianças com câncer na América Latina e no Caribe (ALC) no âmbito do marco CureAll. Neste artigo, descrevemos o processo de desenvolvimento de recursos regionais com o objetivo de acelerar a implementação da Iniciativa na ALC.Em março de 2021, a OPAS formou grupos de trabalho regionais para desenvolver projetos centrais alinhados com os pilares e facilitadores do CureAll. A partir das reuniões de diálogo regionais, foram criados sete grupos de trabalho: detecção precoce, enfermagem, atenção psicossocial, nutrição, cuidados de suporte, abandono do tratamento e cuidados paliativos. A OPAS organizou reuniões virtuais regulares sob a orientação e o apoio dos programas regionais e transversais do St. Jude e de mentores internacionais.Entre abril e dezembro de 2021, 202 especialistas multidisciplinares participaram de 43 reuniões virtuais para promover o diálogo entre as partes interessadas a fim de melhorar os desfechos do câncer infantil. Foram produzidos 14 materiais técnicos: quatro panoramas regionais, quatro documentos técnicos, dois cursos virtuais, um conjunto de perfis epidemiológicos nacionais, uma série de conteúdo educacional para pais e cuidadores e duas campanhas de comunicação.O diálogo e o compromisso contínuos da OPAS, do St. Jude, dos comitês de trabalho da ALC e dos colaboradores internacionais são bases essenciais para acelerar com sucesso a implementação da Iniciativa Global para o Câncer Infantil. Isso é possível por meio do desenvolvimento de materiais de relevância regional e mundial. São necessárias mais pesquisas e avaliações para determinar o impacto dessas estratégias e recursos nos resultados do câncer infantil na ALC e em outras regiões.

Receipt of COVID-19 Vaccine During Pregnancy and Preterm or Small-for-Gestational-Age at Birth - Eight Integrated Health Care Organizations, United States, December 15, 2020-July 22, 2021.

COVID-19 vaccines are recommended during pregnancy to prevent severe maternal morbidity and adverse birth outcomes; however, vaccination coverage among pregnant women has been low (1). Concerns among pregnant women regarding vaccine safety are a persistent barrier to vaccine acceptance during pregnancy. Previous studies of maternal COVID-19 vaccination and birth outcomes have been limited by small sample size (2) or lack of an unvaccinated comparison group (3). In this retrospective cohort study of live births from eight Vaccine Safety Datalink (VSD) health care organizations, risks for preterm birth (<37 weeks' gestation) and small-for-gestational-age (SGA) at birth (birthweight <10th percentile for gestational age) after COVID-19 vaccination (receipt of ≥1 COVID-19 vaccine doses) during pregnancy were evaluated. Risks for preterm and SGA at birth among vaccinated and unvaccinated pregnant women were compared, accounting for time-dependent vaccine exposures and propensity to be vaccinated. Single-gestation pregnancies with estimated start or last menstrual period during May 17-October 24, 2020, were eligible for inclusion. Among 46,079 pregnant women with live births and gestational age available, 10,064 (21.8%) received ≥1 COVID-19 vaccine doses during pregnancy and during December 15, 2020-July 22, 2021; nearly all (9,892; 98.3%) were vaccinated during the second or third trimester. COVID-19 vaccination during pregnancy was not associated with preterm birth (adjusted hazard ratio [aHR] = 0.91; 95% CI = 0.82-1.01). Among 40,627 live births with birthweight available, COVID-19 vaccination in pregnancy was not associated with SGA at birth (aHR = 0.95; 95% CI = 0.87-1.03). Results consistently showed no increased risk when stratified by mRNA COVID-19 vaccine dose, or by second or third trimester vaccination, compared with risk among unvaccinated pregnant women. Because of the small number of first-trimester exposures, aHRs for first-trimester vaccination could not be calculated. These data add to the evidence supporting the safety of COVID-19 vaccination during pregnancy. To reduce the risk for severe COVID-19-associated illness, CDC recommends COVID-19 vaccination for women who are pregnant, recently pregnant (including those who are lactating), who are trying to become pregnant now, or who might become pregnant in the future (4).

Adverse Outcomes in Pregnant Women Hospitalized With Respiratory Syncytial Virus Infection: A Case Series.

We identified 10 women hospitalized with respiratory syncytial virus infection during pregnancy. Diagnoses included pneumonia/atelectasis (5), respiratory failure (2), and sepsis (2). Six had obstetrical complications during hospitalization, including 1 induced preterm birth. One required intensive care unit admission and mechanical ventilation. Four infants had complications at birth.

Disruption of the SucT acyltransferase in Mycobacterium smegmatis abrogates succinylation of cell envelope polysaccharides.

Similar to other prokaryotes, mycobacteria decorate their major cell envelope glycans with minor covalent substituents whose biological significance remains largely unknown. We report on the discovery of a mycobacterial enzyme, named here SucT, that adds succinyl groups to the arabinan domains of both arabinogalactan (AG) and lipoarabinomannan (LAM). Disruption of the SucT-encoding gene in Mycobacterium smegmatis abolished AG and LAM succinylation and altered the hydrophobicity and rigidity of the cell envelope of the bacilli without significantly altering AG and LAM biosynthesis. The changes in the cell surface properties of the mutant were consistent with earlier reports of transposon mutants of the closely related species Mycobacterium marinum and Mycobacterium avium harboring insertions in the orthologous gene whose ability to microaggregate and form biofilms were altered. Our findings point to an important role of SucT-mediated AG and LAM succinylation in modulating the cell surface properties of mycobacteria.

Barriers to the early integration of palliative care in pediatric oncology in 11 Eurasian countries.

BACKGROUND: The early integration of palliative care significantly improves quality of life for children with cancer. However, cultural, structural, and socioeconomic barriers can delay the integration of palliative care into cancer care, particularly in low-income and middle-income countries. To date, little is known regarding the timing of and barriers to palliative care integration in Eurasia. METHODS: The Assessing Doctors' Attitudes on Palliative Treatment (ADAPT) survey evaluates physician perceptions regarding palliative care integration into pediatric oncology in Eurasia. This evidence-based survey was adapted to the regional context; iteratively reviewed by US and regional panelists; and piloted in English, Russian, and Mongolian. After distribution to physicians caring for children with cancer, statistical analysis was complemented by qualitative analysis of open-ended responses. RESULTS: A total of 424 physician responses were received from 11 countries in the Eurasian region. Study findings demonstrated wide variability in access to palliative care experts across countries (18%-96%), with the majority of providers (64%) reporting that the initial palliative care consultation typically occurs when curative options are no longer available. Providers desired an earlier initial palliative care consultation than what currently occurs in their setting (P < .001). Primary barriers to timely consultation included limited access to palliative care services and specialists, lack of physician education, and perceived family resistance. CONCLUSIONS: The current study is the first to identify physician perceptions of the delayed timing of palliative care integration into childhood cancer care and associated barriers in Eurasia. These findings will inform the development of targeted interventions to mitigate local structural and cultural barriers to access and facilitate earlier palliative care integration in the region.

A multicountry assessment in Eurasia: Alignment of physician perspectives on palliative care integration in pediatric oncology with World Health Organization guidelines.

BACKGROUND: The World Health Organization (WHO) advocates for early integration of palliative care for all children with life-threatening illness. Provider awareness and misperceptions, however, can impede this imperative. In the Eurasian region, little is known about physician knowledge and perspectives on palliative care. METHODS: The Assessing Doctors' Attitudes on Palliative Treatment survey was developed as an evidence-based and culturally relevant assessment of physician perceptions on palliative care integration into childhood cancer care in Eurasia. Iteratively tested by American and Eurasian palliative care experts, the survey was culturally adapted, translated, and piloted in English, Russian, and Mongolian. The survey was distributed to physicians caring for children with cancer. Fifteen statements were scored in accordance with WHO guidelines to evaluate provider knowledge. The statistical analysis was complemented by a qualitative analysis of open-ended responses. RESULTS: This study received 424 responses from 11 countries in Eurasia. The mean alignment between provider perspectives and WHO recommendations was 70% (range, 7%-100%). Significant independent predictors of higher alignment included country, prior palliative care education, and greater experience with patient death. Respondents primarily described palliative care as end-of-life care and symptom management. Two-thirds of respondents (67%) reported not feeling confident about delivering at least 1 component of palliative care. CONCLUSIONS: This is the first study assessing physician perspectives and knowledge of palliative care in Eurasia and reveals wide variability in alignment with WHO guidelines and limited confidence in providing palliative care. Study findings will inform targeted educational interventions, which must be tailored to the local political, economic, and cultural context.

Lack of Specificity of Phenotypic Screens for Inhibitors of the Mycobacterium tuberculosis FAS-II System.

Phenotypic screening of inhibitors of the essential Mycobacterium tuberculosis FAS-II dehydratase HadAB led to the identification of GSK3011724A, a compound previously reported to inhibit the condensation step of FAS-II. Whole-cell-based and cell-free assays confirmed the lack of activity of GSK3011724A against the dehydratase despite evidence of cross-resistance between GSK3011724A and HadAB inhibitors. The nature of the resistance mechanisms is suggestive of alterations in the FAS-II interactome reducing access of GSK3011724A to KasA.

The use of natural language processing to identify vaccine-related anaphylaxis at five health care systems in the Vaccine Safety Datalink.

PURPOSE: The objective was to develop a natural language processing (NLP) algorithm to identify vaccine-related anaphylaxis from plain-text clinical notes, and to implement the algorithm at five health care systems in the Vaccine Safety Datalink. METHODS: The NLP algorithm was developed using an internal NLP tool and training dataset of 311 potential anaphylaxis cases from Kaiser Permanente Southern California (KPSC). We applied the algorithm to the notes of another 731 potential cases (423 from KPSC; 308 from other sites) with relevant codes (ICD-9-CM diagnosis codes for anaphylaxis, vaccine adverse reactions, and allergic reactions; Healthcare Common Procedure Coding System codes for epinephrine administration). NLP results were compared against a reference standard of chart reviewed and adjudicated cases. The algorithm was then separately applied to the notes of 6 427 359 KPSC vaccination visits (9 402 194 vaccine doses) without relevant codes. RESULTS: At KPSC, NLP identified 12 of 16 true vaccine-related cases and achieved a sensitivity of 75.0%, specificity of 98.5%, positive predictive value (PPV) of 66.7%, and negative predictive value of 99.0% when applied to notes of patients with relevant diagnosis codes. NLP did not identify the five true cases at other sites. When NLP was applied to the notes of KPSC patients without relevant codes, it captured eight additional true cases confirmed by chart review and adjudication. CONCLUSIONS: The current study demonstrated the potential to apply rule-based NLP algorithms to clinical notes to identify anaphylaxis cases. Increasing the size of training data, including clinical notes from all participating study sites in the training data, and preprocessing the clinical notes to handle special characters could improve the performance of the NLP algorithms. We recommend adding an NLP process followed by manual chart review in future vaccine safety studies to improve sensitivity and efficiency.

Suspected Pediatric Influenza Risk-Stratification Algorithm: A Clinical Decision Tool.

BACKGROUND AND OBJECTIVES: Influenza causes significant annual burden among children. Current guidelines recommend empiric treatment for a broadly defined group of children at high risk for influenza complications, resulting in overtreatment or costly viral testing. This study creates an algorithm for clinicians to risk stratify children with influenza-like illness (ILI) according to likelihood of influenza infection. METHODS: A retrospective analysis was performed on 818 children seen in the emergency department from November 2012 to April 2013 for ILI. We reviewed medical records for symptoms, influenza risk factors, and viral assay results. Classification and regression tree analyses were performed separately for children older and younger than 2 years. RESULTS: In children younger than 2 years, populations likely to test positive were those with an influenza-positive contact, unimmunized children, and those presenting in high-incidence influenza periods. In this subgroup, immunized patients in low-incidence seasons and those with absence of cough are low risk for influenza infection. For children 2 years and older, high-risk populations were unimmunized children, those presenting in high-incidence influenza periods and those with myalgia or absence of diarrhea. CONCLUSIONS: These risk-stratification analyses were summarized into Suspected Pediatric Influenza Risk-Stratification Algorithm (SPIRA). For those in whom influenza infection is likely, clinicians may consider empiric treatment. Conversely, patients whom SPIRA identifies as unlikely to be infected with influenza are candidates for viral testing and targeted treatment. In assessing children with ILI, SPIRA aids clinicians in determining who to test versus treat empirically, saving children from costly viral testing or unnecessary antiviral exposure.

Impact of the epoxide hydrolase EphD on the metabolism of mycolic acids in mycobacteria.

Mycolic acids are the hallmark of the cell envelope in mycobacteria, which include the important human pathogens Mycobacterium tuberculosis and Mycobacterium leprae Mycolic acids are very long C60-C90 α-alkyl ß-hydroxy fatty acids having a variety of functional groups on their hydrocarbon chain that define several mycolate types. Mycobacteria also produce an unusually large number of putative epoxide hydrolases, but the physiological functions of these enzymes are still unclear. Here, we report that the mycobacterial epoxide hydrolase EphD is involved in mycolic acid metabolism. We found that orthologs of EphD from M. tuberculosis and M. smegmatis are functional epoxide hydrolases, cleaving a lipophilic substrate, 9,10-cis-epoxystearic acid, in vitro and forming a vicinal diol. The results of EphD overproduction in M. smegmatis and M. bovis BCG Δhma strains producing epoxymycolic acids indicated that EphD is involved in the metabolism of these forms of mycolates in both fast- and slow-growing mycobacteria. Moreover, using MALDI-TOF-MS and 1H NMR spectroscopy of mycolic acids and lipids isolated from EphD-overproducing M. smegmatis, we identified new oxygenated mycolic acid species that accumulated during epoxymycolate depletion. Disruption of the ephD gene in M. tuberculosis specifically impaired the synthesis of ketomycolates and caused accumulation of their precursor, hydroxymycolate, indicating either direct or indirect involvement of EphD in ketomycolate biosynthesis. Our results clearly indicate that EphD plays a role in metabolism of oxygenated mycolic acids in mycobacteria.

Structural determinants in a glucose-containing lipopolysaccharide from Mycobacterium tuberculosis critical for inducing a subset of protective T cells.

Mycobacteria synthesize intracellular, 6-O-methylglucose-containing lipopolysaccharides (mGLPs) proposed to modulate bacterial fatty acid metabolism. Recently, it has been shown that Mycobacterium tuberculosis mGLP specifically induces a specific subset of protective γ9δ2 T cells. Mild base treatment, which removes all the base-labile groups, reduces the specific activity of mGLP required for induction of these T cells, suggesting that acylation of the saccharide moieties is required for γ9δ2 T-cell activation. On the basis of this premise, we used analytical LC/MS and NMR methods to identify and locate the acyl functions on the mGLP saccharides. We found that mGLP is heterogeneous with respect to acyl functions and contains acetyl, isobutyryl, succinyl, and octanoyl groups and that all acylations in mGLP, except for succinyl and octanoyl residues, reside on the glucosyl residues immediately following the terminal 3-O-methylglucose. Our analyses also indicated that the octanoyl residue resides at position 2 of an internal glucose toward the reducing end. LC/MS analysis of the residual product obtained by digesting the mGLP with pancreatic α-amylase revealed that the product is an oligosaccharide terminated by α-(1→4)-linked 6-O-methyl-d-glucosyl residues. This oligosaccharide retained none of the acyl groups, except for the octanoyl group, and was unable to induce protective γ9δ2 T cells. This observation confirmed that mGLP induces γ9δ2 T cells and indicated that the acylated glucosyl residues at the nonreducing terminus of mGLP are required for this activity.

Development and evaluation of a computable phenotype to identify pediatric patients with leukemia and lymphoma treated with chemotherapy using electronic health record data.

BACKGROUND: Widespread implementation of electronic health records (EHR) has created new opportunities for pediatric oncology observational research. Little attention has been given to using EHR data to identify patients with pediatric hematologic malignancies. METHODS: This study used EHR-derived data in a pediatric clinical data research network, PEDSnet, to develop and evaluate a computable phenotype algorithm to identify pediatric patients with leukemia and lymphoma who received treatment with chemotherapy. To guide early development, multiple computable phenotype-defined cohorts were compared to one institution's tumor registry. The most promising algorithm was chosen for formal evaluation and consisted of at least two leukemia/lymphoma diagnoses (Systematized Nomenclature of Medicine codes) within a 90-day period, two chemotherapy exposures, and three hematology-oncology provider encounters. During evaluation, the computable phenotype was executed against EHR data from 2011 to 2016 at three large institutions. Classification accuracy was assessed by masked medical record review with phenotype-identified patients compared to a control group with at least three hematology-oncology encounters. RESULTS: The computable phenotype had sensitivity of 100% (confidence interval [CI] 99%, 100%), specificity of 99% (CI 99%, 100%), positive predictive value (PPV) and negative predictive value (NPV) of 100%, and C-statistic of 1 at the development institution. The computable phenotype performance was similar at the two test institutions with sensitivity of 100% (CI 99%, 100%), specificity of 99% (CI 99%, 100%), PPV of 96%, NPV of 100%, and C-statistic of 0.99. CONCLUSION: The EHR-based computable phenotype is an accurate cohort identification tool for pediatric patients with leukemia and lymphoma who have been treated with chemotherapy and is ready for use in clinical studies.

Clinical and Radiographic Response of Extramedullary Leukemia in Patients Treated With Gemtuzumab Ozogamicin.

Extramedullary leukemia (EML) is common in pediatric acute leukemia and can present at diagnosis or relapse. CD33 is detected on the surface of myeloid blasts in many patients with acute myelogenous leukemia and is the target of the antibody drug conjugate gemtuzumab ozogamicin (GO). Here we present 2 patients with CD33 EML treated with GO. They achieved significant response, with reduction of EML on both clinical and radiographic exams, specifically fluorine fluorodeoxyglucose positron emission tomography/computed tomography, demonstrating potential for targeted therapy with GO as a means of treating EML in patients with CD33 leukemia and the utility of fluorine fluorodeoxyglucose positron emission tomography/computed tomography monitoring in EML.