37 research outputs found

    A novel anti-B7-H3 chimeric antigen receptor from a single-chain antibody library for immunotherapy of solid cancers

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    B7-H3 (CD276) has emerged as a target for cancer immunotherapy by virtue of consistent expression in many malignancies, relative absence from healthy tissues, and an emerging role as a driver of tumor immune inhibition. Recent studies have reported B7-H3 to be a suitable target for chimeric antigen receptor-modified T cell (CAR-T) therapy using CARs constructed from established anti-B7-H3 antibodies converted into single-chain Fv format (scFv). We constructed and screened binders in an scFv library to generate a new anti-B7-H3 CAR-T with favorable properties. This allowed access to numerous specificities ready formatted for CAR evaluation. Selected anti-human B7-H3 scFvs were readily cloned into CAR-T and evaluated for anti-tumor reactivity in cytotoxicity, cytokine, and proliferation assays. Two binders with divergent complementarity determining regions were found to show optimal antigen-specific cytotoxicity and cytokine secretion. One binder in second-generation CD28-CD3ζ CAR format induced sustained in vitro proliferation on repeat antigen challenge. The lead candidate CAR-T also demonstrated in vivo activity in a resistant neuroblastoma model. An empirical approach to B7-H3 CAR-T discovery through screening of novel scFv sequences in CAR-T format has led to the identification of a new construct with sustained proliferative capacity warranting further evaluation

    Evaluation of Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry for Molecular Typing of Acinetobacter baumannii in Comparison with Orthogonal Methods

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    Colonization and subsequent health care-associated infection (HCAI) with Acinetobacter baumannii are a concern for vulnerable patient groups within the hospital setting. Outbreaks involving multidrug-resistant strains are associated with increased patient morbidity and mortality and poorer overall outcomes. Reliable molecular typing methods can help to trace transmission routes and manage outbreaks. In addition to methods deployed by reference laboratories, matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) may assist by making initial in-house judgments on strain relatedness. However, limited studies on method reproducibility exist for this application. We applied MALDI-TOF MS typing to A. baumannii isolates associated with a nosocomial outbreak and evaluated different methods for data analysis. In addition, we compared MALDI-TOF MS with whole-genome sequencing (WGS) and Fourier transform infrared spectroscopy (FTIR) as orthogonal methods to further explore their resolution for bacterial strain typing. A related subgroup of isolates consistently clustered separately from the main outbreak group by all investigated methods. This finding, combined with epidemiological data from the outbreak, indicates that these methods identified a separate transmission event unrelated to the main outbreak. However, the MALDI-TOF MS upstream approach introduced measurement variability impacting method reproducibility and limiting its reliability as a standalone typing method. Availability of in-house typing methods with well-characterized sources of measurement uncertainty could assist with rapid and dependable confirmation (or denial) of suspected transmission events. This work highlights some of the steps to be improved before such tools can be fully integrated into routine diagnostic service workflows for strain typing. IMPORTANCE Managing the transmission of antimicrobial resistance necessitates reliable methods for tracking outbreaks. We compared the performance of MALDI-TOF MS with orthogonal approaches for strain typing, including WGS and FTIR, for Acinetobacter baumannii isolates correlated with a health care-associated infection (HCAI) event. Combined with epidemiological data, all methods investigated identified a group of isolates that were temporally and spatially linked to the outbreak, yet potentially attributed to a separate transmission event. This may have implications for guiding infection control strategies during an outbreak. However, the technical reproducibility of MALDI-TOF MS needs to be improved for it to be employed as a standalone typing method, as different stages of the experimental workflow introduced bias influencing interpretation of biomarker peak data. Availability of in-house methods for strain typing of bacteria could improve infection control practices following increased reports of outbreaks of antimicrobial-resistant organisms during the COVID-19 pandemic, related to sessional usage of personal protective equipment (PPE)

    Ancient mitochondrial DNA provides high-resolution time scale of the peopling of the Americas

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    The exact timing, route, and process of the initial peopling of the Americas remains uncertain despite much research. Archaeological evidence indicates the presence of humans as far as southern Chile by 14.6 thousand years ago (ka), shortly after the Pleistocene ice sheets blocking access from eastern Beringia began to retreat. Genetic estimates of the timing and route of entry have been constrained by the lack of suitable calibration points and low genetic diversity of Native Americans. We sequenced 92 whole mitochondrial genomes from pre-Columbian South American skeletons dating from 8.6 to 0.5 ka, allowing a detailed, temporally calibrated reconstruction of the peopling of the Americas in a Bayesian coalescent analysis. The data suggest that a small population entered the Americas via a coastal route around 16.0 ka, following previous isolation in eastern Beringia for ~2.4 to 9 thousand years after separation from eastern Siberian populations. Following a rapid movement throughout the Americas, limited gene flow in South America resulted in a marked phylogeographic structure of populations, which persisted through time. All of the ancient mitochondrial lineages detected in this study were absent from modern data sets, suggesting a high extinction rate. To investigate this further, we applied a novel principal components multiple logistic regression test to Bayesian serial coalescent simulations. The analysis supported a scenario in which European colonization caused a substantial loss of pre-Columbian lineages

    Terapia miofuncional para mejorar eficiencia en la succión en recién nacidos pretérmino

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    Resumen: Objetivo: Comparar las características de los neonatos pretérmino que recibieron terapia miofuncional con los que no la recibieron, y analizar el tiempo que cada grupo toma en llegar desde la primera succión a la mayor eficiencia en la succión (ES) de su estancia. Métodos: Estudio de cohorte retrospectivo que incluyó 442 neonatos de entre 28 y 36.6 semanas de gestación (SG) al nacimiento ingresados a la Unidad de Cuidados Intensivos Neonatales (UCIN) del Hospital Español de México entre marzo de 2014 y octubre de 2016. Los pacientes se dividieron en dos grupos: 1) los que recibieron terapia miofuncional por parte de un especialista, y 2) los que no la recibieron. Se registraron antecedentes; se midió el tiempo en días desde la primera succión hasta la mayor ES según SG y peso. Resultados: Un total de 123 neonatos recibieron terapia miofuncional. Se observaron diferencias entre grupos, siendo el grupo intervenido el de menor SG y peso al nacimiento, con más comorbilidades y días de estancia intrahospitalaria. El grupo que no recibió terapia logró alcanzar la mayor ES significativamente en menos días que el grupo que la recibió, ajustando por SG y peso a la primera succión (diferencia de medias de 2.18 a 6.15 días; p = 0.06 a p < 0.001). Conclusión: El bajo peso, la edad gestacional al nacimiento, un mayor número de comorbilidades y días de estancia intrahospitalaria son factores que podrían retrasar la obtención de una adecuada ES. La terapia miofuncional debería comenzarse antes de iniciarse la succión nutritiva. Abstract: Objective: Compare the characteristics of the preterm newborns who received myofunctional therapy with those who didn’t received it, and to analyze the time each group takes to reach effective sucking since the first sucking to the best one during their intrahospital stay. Methods: Retrospective cohort study which included 442 preterm newborns between 28 to 36.6 weeks of gestational age admitted to the Neonatal Intensive Care Unit of Hospital Español de México between March 2014 to October 2016. The patients were divided in two groups: 1) the ones that received myofunctional therapy carried out by two people specialized in early intervention of the premature, and 2) the ones that did not. We registered perinatal history and measure the time it was taken to achieve an efficient sucking since the first sucking according to gestational age and weight. Results: 123 were exposed to myofunctional therapy. We observed a significant difference between both groups, being the exposed group the patients with lower gestational age and weight at birth and the ones presenting more comorbidities and days in hospital. The group that did not received myofunctional therapy achieved an earlier effective sucking than the one that received myofunctional therapy adjusted by gestational age and weight presented in the first sucking (mean 2.18 to 6.15 days; p = 0.06 to p < 0.001). Conclusion: Small for gestational age, lower gestational weight at birth, more comorbidities and longer length of stay are factors that may delay the acquisition of efficiency in sucking. The myofunctional therapy should be started before starting nutritive sucking. Palabras clave: Succión, Recién nacido pretérmino, Terapia miofuncional, Keywords: Sucking, Preterm newborn, Myofunctional therap

    Concentração de proteínas na urina de indivíduos normais Urine protein concentration in normal population

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    A fim de determinar os valores normais de concentração proteica na urina, em amostra de população sadia, foi usada uma reação de biureto, em 62 amostras de urina coletadas ao acaso. A concentração proteica média em todo o grupo foi de 6,0mg% (&plusmn; 3,2) com a amplitude de 2,0 - 14,5mg%. Tais resultados concordam com aqueles previamente relatados na literatura.<br>In order to determinate the normal values for urine protein concentration in one sample of healthy population it was used a biuret reaction in 62 urine samples collected at random. The mean protein concentration in the whole group was 6.0mg% (SD &plusmn;3.2) with a range of 2.0 - 14.5mg%. Those results agreed with the previously reported, in the literature

    Presión arterial en recién nacidos sanos de término y pretérmino tardío en la Ciudad de México

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    Objetivo: Describir medidas de presión arterial sistólica (PAS), diastólica (PAD) y media (PAM) en recién nacidos sanos de término y pretérmino tardío para establecer parámetros de normalidad. Método: Estudio transversal realizado en el cunero fisiológico del Hospital Español, Ciudad de México. Se incluyeron 551 pacientes recién nacidos sanos. Las tomas de PA fueron realizadas dentro de las primeras 48 horas de vida con método oscilométrico. Posterior a la evaluación de normalidad, se realizó un análisis descriptivo de la población y cálculo de percentiles (25, 50 y 75) específicos para cada semana de gestación. Todos los análisis fueron realizados en STATA v14.2. Resultados: Los recién nacidos del sexo masculino tuvieron un valor medio de PAS de 64.6 mmHg en la semana 35 de gestación, este valor aumentó a 69.8 mmHg en la semana 40. El valor de la PAD fue de 42.6 mmHg en la semana 35 de gestación, disminuyendo a 40.8 mmHg para la semana 40. Los valores medios de PAS en los recién nacidos del sexo femenino, fueron de 65.5 mmHg en la semana 35, teniendo un incremento a 73.5 mmHg en la semana 40. El valor de la PAD en la semana 35 de gestación fue 38 mmHg, incrementando a 41.3 mmHg en la semana 40. Conclusiones: Los valores de PA en recién nacidos sanos se modifican con la edad gestacional y el sexo. Estos resultados pueden servir como referencia para otros médicos ubicados en países o ciudades con alturas similares a la Ciudad de México

    Airway inflammation and dysbiosis in antibody deficiency despite the presence of IgG

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    Background: Patients with antibody deficiency suffer chronic respiratory symptoms, recurrent exacerbations, and progressive airways disease despite systemic replacement of IgG. Little is known about the respiratory tract biology of these patients. Objective: We sought to measure immunoglobulin levels, inflammatory cytokines, and mediators of tissue damage in serum and sputum from patients with antibody deficiency and healthy controls; to analyze the respiratory microbiome in the same cohorts. Methods: We obtained paired sputum and serum samples from 31 immunocompetent subjects and 67 antibody-deficient patients, the latter divided on computed tomography scan appearance into “abnormal airways” (bronchiectasis or airway thickening) or “normal airways.” We measured inflammatory cytokines, immunoglobulin levels, neutrophil elastase, matrix-metalloproteinase-9, urea, albumin, and total protein levels using standard assays. We used V3-V4 region 16S sequencing for microbiome analysis. Results: Immunodeficient patients had markedly reduced IgA in sputum but higher concentrations of IgG compared with healthy controls. Inflammatory cytokines and tissue damage markers were higher in immunodeficient patients, who also exhibited dysbiosis with overrepresentation of pathogenic taxa and significantly reduced alpha diversity compared with immunocompetent individuals. These differences were seen regardless of airway morphology. Sputum matrix-metalloproteinase-9 and elastase correlated inversely with alpha diversity in the antibody-deficient group, as did sputum IgG, which correlated positively with several inflammatory markers, even after correction for albumin levels. Conclusions: Patients with antibody deficiency, even with normal lung imaging, exhibit inflammation and dysbiosis in their airways despite higher levels of IgG compared with healthy controls

    Evaluation of Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry for Molecular Typing of Acinetobacter baumannii in Comparison with Orthogonal Methods

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    Colonization and subsequent health care-associated infection (HCAI) with Acinetobacter baumannii are a concern for vulnerable patient groups within the hospital setting. Outbreaks involving multidrug-resistant strains are associated with increased patient morbidity and mortality and poorer overall outcomes. Reliable molecular typing methods can help to trace transmission routes and manage outbreaks. In addition to methods deployed by reference laboratories, matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) may assist by making initial in-house judgments on strain relatedness. However, limited studies on method reproducibility exist for this application. We applied MALDI-TOF MS typing to A. baumannii isolates associated with a nosocomial outbreak and evaluated different methods for data analysis. In addition, we compared MALDI-TOF MS with whole-genome sequencing (WGS) and Fourier transform infrared spectroscopy (FTIR) as orthogonal methods to further explore their resolution for bacterial strain typing. A related subgroup of isolates consistently clustered separately from the main outbreak group by all investigated methods. This finding, combined with epidemiological data from the outbreak, indicates that these methods identified a separate transmission event unrelated to the main outbreak. However, the MALDI-TOF MS upstream approach introduced measurement variability impacting method reproducibility and limiting its reliability as a standalone typing method. Availability of in-house typing methods with well-characterized sources of measurement uncertainty could assist with rapid and dependable confirmation (or denial) of suspected transmission events. This work highlights some of the steps to be improved before such tools can be fully integrated into routine diagnostic service workflows for strain typing. IMPORTANCE Managing the transmission of antimicrobial resistance necessitates reliable methods for tracking outbreaks. We compared the performance of MALDI-TOF MS with orthogonal approaches for strain typing, including WGS and FTIR, for Acinetobacter baumannii isolates correlated with a health care-associated infection (HCAI) event. Combined with epidemiological data, all methods investigated identified a group of isolates that were temporally and spatially linked to the outbreak, yet potentially attributed to a separate transmission event. This may have implications for guiding infection control strategies during an outbreak. However, the technical reproducibility of MALDI-TOF MS needs to be improved for it to be employed as a standalone typing method, as different stages of the experimental workflow introduced bias influencing interpretation of biomarker peak data. Availability of in-house methods for strain typing of bacteria could improve infection control practices following increased reports of outbreaks of antimicrobial-resistant organisms during the COVID-19 pandemic, related to sessional usage of personal protective equipment (PPE)
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