RESUMO
Newcomer Latinx immigrant youths in the United States are currently in a syndemic of increased risk of behavioral health concerns, disparities in access to related services, and are disproportionately impacted by the COVID-19 pandemic. This study used qualitative inquiry to examine the impact that the transition to telehealth had on a school-based group prevention program for immigrant youth, Fuerte, within the context of this syndemic. Data included semi-structured interviews with group leaders, and focus groups with youth program participants. Themes indicated both positive and negative impacts of the transition to telehealth on program component implementation, youth participant engagement, and youth participant social connectedness. Despite the telehealth model, youth participants reported that they felt socially connected to each other through the program. This study's results provide implications for the potential value and drawbacks of a telehealth prevention model for newcomer immigrant youth, as well as deepening understanding of how virtual behavioral health programs may operate in socially isolating contexts around the world.
Assuntos
COVID-19 , Emigrantes e Imigrantes , Hispânico ou Latino , Telemedicina , Adolescente , Humanos , COVID-19/prevenção & controle , Pandemias , Sindemia , Estados Unidos , Serviços de Saúde EscolarRESUMO
The current study uplifts the efforts of community-based college access and success programs (CAS) to support the college preparation, matriculation, and persistence of underserved students during COVID-19. Fifty-eight CAS across the United States completed an online survey that gathered information about organizational demographics, COVID-19 challenges, responses to challenges, and communication with constituents and funding needs during COVID-19. Results suggested CAS faced multiple challenges due to COVID-19 that affected the organization, staff, and constituents. Results also revealed organizations of varying sizes, locations, and demographics responded to challenges by revising existing programming for students, creating new programming for students and caretakers, and updating staff policies to meet ongoing and emergent needs despite limited resources. CAS are essential service providers for students who are under- and mis-served in formal education systems. Recommendations are provided for how such organizations can be invested in and better prepared for future disruptions.
Assuntos
COVID-19 , Humanos , Organizações , Estudantes , Estados Unidos , UniversidadesRESUMO
An engineered reversal of the ß-oxidation cycle (r-BOX) and the fatty acid biosynthesis (FAB) pathway are promising biological platforms for advanced fuel and chemical production in part due to their iterative nature supporting the synthesis of various chain length products. While diverging in their carbon-carbon elongation reaction mechanism, iterative operation of each pathway relies on common chemical conversions (reduction, dehydration, and reduction) differing only in the attached moiety (acyl carrier protein (ACP) in FAB vs Coenzyme A in r-BOX). Given this similarity, we sought to determine whether FAB enzymes can be used in the context of r-BOX as a means of expanding available r-BOX components with a ubiquitous set of well characterized enzymes. Using enzymes from the type II FAB pathway (FabG, FabZ, and FabI) in conjunction with a thiolase catalyzing a non-decarboxylative condensation, we demonstrate that FAB enzymes support a functional r-BOX. Pathway operation with FAB enzymes was improved through computationally directed protein design to develop FabZ variants with amino acid substitutions designed to disrupt hydrogen bonding at the FabZ-ACP interface and introduce steric and electrostatic repulsion between the FabZ and ACP. FabZ with R126W and R121E substitutions resulted in improved carboxylic acid and alcohol production from one- and multiple-turn r-BOX compared to the wild-type enzyme. Furthermore, the ability for FAB enzymes to operate on functionalized intermediates was exploited to produce branched chain carboxylic acids through an r-BOX with functionalized priming. These results not only provide an expanded set of enzymes within the modular r-BOX pathway, but can also potentially expand the scope of products targeted through this pathway by operating with CoA intermediates containing various functional groups.
Assuntos
Oxirredutases do Álcool , Escherichia coli K12 , Ácidos Graxos , Complexos Multienzimáticos , Oxirredutases do Álcool/genética , Oxirredutases do Álcool/metabolismo , Escherichia coli K12/enzimologia , Escherichia coli K12/genética , Ácidos Graxos/biossíntese , Ácidos Graxos/genética , Complexos Multienzimáticos/genética , Complexos Multienzimáticos/metabolismoRESUMO
An extensive mass spectrometry analysis of the human milk peptidome has revealed almost 700 endogenous peptides from 30 different proteins. Two in-house computational tools were created and used to visualize and interpret the data through both alignment of the peptide quasi-molecular ion intensities and estimation of the differential enzyme participation. These results reveal that the endogenous proteolytic activity in the mammary gland is remarkably specific and well conserved. Certain proteins-not necessarily the most abundant ones-are digested by the proteases present in milk, yielding endogenous peptides from selected regions. Our results strongly suggest that factors such as the presence of specific proteases, the position and concentration of cleavage sites, and, more important, the intrinsic disorder of segments of the protein drive this proteolytic specificity in the mammary gland. As a consequence of this selective hydrolysis, proteins that typically need to be cleaved at specific positions in order to exert their activity are properly digested, and bioactive peptides encoded in certain protein sequences are released. Proteins that must remain intact in order to maintain their activity in the mammary gland or in the neonatal gastrointestinal tract are unaffected by the hydrolytic environment present in milk. These results provide insight into the intrinsic structural mechanisms that facilitate the selectivity of the endogenous milk protease activity and might be useful to those studying the peptidomes of other biofluids.
Assuntos
Endopeptidases/química , Proteínas do Leite/química , Leite Humano/química , Peptídeos/análise , Proteoma/química , Sequência de Aminoácidos , Endopeptidases/metabolismo , Feminino , Humanos , Proteínas do Leite/metabolismo , Dados de Sequência Molecular , Mapeamento de Peptídeos , Peptídeos/química , Peptídeos/metabolismo , Proteólise , Proteoma/metabolismo , Especificidade por SubstratoRESUMO
An empirically observed correlation between ion mobility cross sections in helium and nitrogen buffer gases was examined as a function of temperature, molecular size, and shape. Experimental cross sections were determined for tetraglycine, bradykinin, angiotensin 2, melittin, and ubiquitin at 300 K and in the range from 80 to 550 K on home-built instruments and calculated by the projection superposition approximation (PSA) method. The PSA was also used to predict cross sections for larger systems such as human pancreatic alpha-amylase, concanavalin, Pichia pastoris lysyl oxidase, and Klebsiella pneumoniae acetolactate synthase. The data show that the ratio of cross sections in helium and nitrogen depends significantly on the temperature of the buffer gas as well as the size and shape of the analyte ion. Therefore, the analysis of the data indicates that a simple formula that seeks to quantitatively relate the momentum transfer cross sections observed in two distinct buffer gases lacks a sound physical basis.
RESUMO
A variety of proteases release hundreds of endogenous peptide fragments from intact bovine milk proteins. Mass spectrometry-based peptidomics allows for high throughput sequence assignment of a large number of these peptides. Mastitis is known to result in increased protease activity in the mammary gland. Therefore, we hypothesized that subclinically mastitic milks would contain higher concentrations of released peptides. In this work, milks were sampled from three cows and, for each, one healthy and one subclinically mastitic teat were sampled for milk. Peptides were analyzed by nano-liquid chromatography quadrupole time of flight tandem mass spectrometry and identified with database searching. In total, 682 peptides were identified. The total number of released peptides increased 146% from healthy to subclinically mastitic milks (p < 0.05), and the total abundance of released peptides also increased significantly (p < 0.05). Bioinformatic analysis of enzyme cleavage revealed increases in activity of cathepsin D and elastase (p < 0.05) with subclinical mastitis.
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Accurate prediction and modeling of an enzyme's active site are critical for engineering efforts as well as providing insight into an enzyme's naturally occurring function. Previous efforts demonstrated that the integration of constraints enforcing strict geometric orientations between catalytic residues significantly improved the modeling accuracy for the active sites of monomeric enzymes. In this study, a similar approach was explored to evaluate the effect on the active sites of homomeric enzymes. A benchmark of 17 homomeric enzymes with known structures and a bound ligand relevant to the established chemistry were identified from the protein data bank. The enzymes identified span multiple classes as well as symmetries. Unlike what was observed for the monomeric enzymes, upon the application of catalytic geometric constraints, there was no significant improvement observed in modeling accuracy for either the active site of the protein structure or the accuracy of the subsequently docked ligand. Upon further analysis, it is apparent that the symmetric interface being modeled is inaccurate and prevented the active sites from being modeled at atomic-level accuracy. This is consistent with the challenge others have identified in being able to predict de novo protein symmetry. To further improve the accuracy of active site modeling for homomeric proteins, new methodologies to accurately model the symmetric interfaces of these complexes are needed.
RESUMO
OBJECTIVES: to assess the anti-inflammatory effect of the flavonoid fraction of Lepechinia meyenii (Walp.) Epling on leukocytes of patients with rheumatoid arthritis (RA). MATERIALS AND METHODS: Plants of the species Lepechinia meyenii (Walp.) Epling were collected and then different flavonoid fractions were extracted by column and thin layer chromatography. The superoxide anion production was evaluated by means of the reduction of nitroblue tetrazolium assay technique in neutrophils obtained from the blood of patients with RA, divided into three groups: negative control, which consisted of neutrophils (5x105 cells); positive control, made up of PMA (phorbol myristate acetate)-activated neutrophils (150 ng/mL), and the treatments, comprised of neutrophils activated and treated with different concentrations of the flavonoid fraction LM8 (60, 120, and 180 ug/mL). The expression of pro- inflammatory genes was studied by RTqPCR in mononuclear leukocytes obtained from patients with RA, divided into three groups: negative control, which consisted of mononuclear leukocytes (5x105 cells); positive control, made up of phytohaemagglutinin (PHA) (150 ug/ml)-activated mononuclear leukocytes, and the treatment, comprised of mononuclear leukocytes activated and treated with the flavonoid fraction LM8 (120 ug/mL). RESULTS: Several flavonoid fractions were purified, with fraction LM8 showing the best immunomodulating effect. Said fraction diminished the superoxide anion production dependent on concentration. On the other hand, it diminished the expression of TNFα, IL8, and IL17 in mononuclear leukocytes. CONCLUSIONS: These results are encouraging in terms of the immunomodulating effect of this Peruvian medicinal plant and justify the continuation of their study for a potential clinical application.
OBJETIVOS: Evaluar el efecto antiinflamatorio de la fracción flavonoide de Lepechinia meyenii (Walp.) Epling sobre leucocitos de pacientes con artritis reumatoide (AR). MATERIALES Y MÉTODOS: Se recolectaron plantas de la especie Lepechinia meyenii (Walp.) Epling extrayendo diferentes fracciones flavonoides por cromatografía de columna y de capa fina. Se evaluó la producción de anión superóxido mediante la técnica de ensayo reducción nitroblue tetrazolium, en neutrófilos obtenidos de sangre de pacientes con AR, separados en tres grupos: control negativo, que consistió de neutrófilos (5x105 células), control positivo, formado por neutrófilos activados con PMA (phorbol myristate acetate) (150 ng/mL) y los tratamientos, formados por neutrófilos activados y tratados con diferentes concentraciones de la fracción flavonoide LM8 (60, 120 y 180 ug/mL). La expresión de genes proinflamatorios se estudió por RTqPCR, en leucocitos mononucleares obtenidos de pacientes con AR separados en tres grupos: control negativo, que consistió de leucocitos mononucleares (5x105 células), control positivo formado por leucocitos mononucleares activados con fitohemaglutinina (PHA) (150 ug/mL) y el tratamiento formado por leucocitos mononucleares activados y tratados con la fracción flavonoide LM8 (120 ug/mL). RESULTADOS: Se purificaron varias fracciones flavonoides, resultando la fracción LM8 con el mejor efecto inmunomodulador. Dicha fracción disminuyó la producción de anión superóxido en una manera dependiente de la concentración. Por otro lado, disminuyó la expresión de TNFα, IL8 e IL17 en leucocitos mononucleares. CONCLUSIONES: Estos resultados son alentadores respecto al efecto inmunomodulador de esta planta medicinal peruana y justifican continuar su estudio para una posible aplicación clínica.
Assuntos
Anti-Inflamatórios/farmacologia , Artrite Reumatoide/imunologia , Flavonoides/farmacologia , Leucócitos/efeitos dos fármacos , Extratos Vegetais/farmacologia , Salvia , HumanosRESUMO
RESUMEN Objetivos . Evaluar el efecto antiinflamatorio de la fracción flavonoide de Lepechinia meyenii (Walp.) Epling sobre leucocitos de pacientes con artritis reumatoide (AR). Materiales y métodos. Se recolectaron plantas de la especie Lepechinia meyenii (Walp.) Epling extrayendo diferentes fracciones flavonoides por cromatografía de columna y de capa fina. Se evaluó la producción de anión superóxido mediante la técnica de ensayo reducción nitroblue tetrazolium, en neutrófilos obtenidos de sangre de pacientes con AR, separados en tres grupos: control negativo, que consistió de neutrófilos (5x105 células), control positivo, formado por neutrófilos activados con PMA (phorbol myristate acetate) (150 ng/mL) y los tratamientos, formados por neutrófilos activados y tratados con diferentes concentraciones de la fracción flavonoide LM8 (60, 120 y 180 ug/mL). La expresión de genes proinflamatorios se estudió por RTqPCR, en leucocitos mononucleares obtenidos de pacientes con AR separados en tres grupos: control negativo, que consistió de leucocitos mononucleares (5x105 células), control positivo formado por leucocitos mononucleares activados con fitohemaglutinina (PHA) (150 ug/mL) y el tratamiento formado por leucocitos mononucleares activados y tratados con la fracción flavonoide LM8 (120 ug/mL). Resultados . Se purificaron varias fracciones flavonoides, resultando la fracción LM8 con el mejor efecto inmunomodulador. Dicha fracción disminuyó la producción de anión superóxido en una manera dependiente de la concentración. Por otro lado, disminuyó la expresión de TNFα, IL8 e IL17 en leucocitos mononucleares. Conclusiones. Estos resultados son alentadores respecto al efecto inmunomodulador de esta planta medicinal peruana y justifican continuar su estudio para una posible aplicación clínica.
ABSTRACT Objectives. to assess the anti-inflammatory effect of the flavonoid fraction of Lepechinia meyenii (Walp.) Epling on leukocytes of patients with rheumatoid arthritis (RA). Materials and Methods. Plants of the species Lepechinia meyenii (Walp.) Epling were collected and then different flavonoid fractions were extracted by column and thin layer chromatography. The superoxide anion production was evaluated by means of the reduction of nitroblue tetrazolium assay technique in neutrophils obtained from the blood of patients with RA, divided into three groups: negative control, which consisted of neutrophils (5x105 cells); positive control, made up of PMA (phorbol myristate acetate)-activated neutrophils (150 ng/mL), and the treatments, comprised of neutrophils activated and treated with different concentrations of the flavonoid fraction LM8 (60, 120, and 180 ug/mL). The expression of pro- inflammatory genes was studied by RTqPCR in mononuclear leukocytes obtained from patients with RA, divided into three groups: negative control, which consisted of mononuclear leukocytes (5x105 cells); positive control, made up of phytohaemagglutinin (PHA) (150 ug/ml)-activated mononuclear leukocytes, and the treatment, comprised of mononuclear leukocytes activated and treated with the flavonoid fraction LM8 (120 ug/mL). Results. Several flavonoid fractions were purified, with fraction LM8 showing the best immunomodulating effect. Said fraction diminished the superoxide anion production dependent on concentration. On the other hand, it diminished the expression of TNFα, IL8, and IL17 in mononuclear leukocytes. Conclusions. These results are encouraging in terms of the immunomodulating effect of this Peruvian medicinal plant and justify the continuation of their study for a potential clinical application.