RESUMO
We tested the hypothesis that underrepresented students in active-learning classrooms experience narrower achievement gaps than underrepresented students in traditional lecturing classrooms, averaged across all science, technology, engineering, and mathematics (STEM) fields and courses. We conducted a comprehensive search for both published and unpublished studies that compared the performance of underrepresented students to their overrepresented classmates in active-learning and traditional-lecturing treatments. This search resulted in data on student examination scores from 15 studies (9,238 total students) and data on student failure rates from 26 studies (44,606 total students). Bayesian regression analyses showed that on average, active learning reduced achievement gaps in examination scores by 33% and narrowed gaps in passing rates by 45%. The reported proportion of time that students spend on in-class activities was important, as only classes that implemented high-intensity active learning narrowed achievement gaps. Sensitivity analyses showed that the conclusions are robust to sampling bias and other issues. To explain the extensive variation in efficacy observed among studies, we propose the heads-and-hearts hypothesis, which holds that meaningful reductions in achievement gaps only occur when course designs combine deliberate practice with inclusive teaching. Our results support calls to replace traditional lecturing with evidence-based, active-learning course designs across the STEM disciplines and suggest that innovations in instructional strategies can increase equity in higher education.
Assuntos
Logro , Grupos Minoritários/educação , Aprendizagem Baseada em Problemas , Avaliação Educacional , Engenharia/educação , Humanos , Matemática/educação , Ciência/educação , Estudantes , Tecnologia/educação , Estados Unidos , UniversidadesRESUMO
BACKGROUND: Attrition during the period from HIV testing to antiretroviral therapy (ART) initiation is high worldwide. We assessed whether same-day HIV testing and ART initiation improves retention and virologic suppression. METHODS AND FINDINGS: We conducted an unblinded, randomized trial of standard ART initiation versus same-day HIV testing and ART initiation among eligible adults ≥18 years old with World Health Organization Stage 1 or 2 disease and CD4 count ≤500 cells/mm3. The study was conducted among outpatients at the Haitian Group for the Study of Kaposi's Sarcoma and Opportunistic infections (GHESKIO) Clinic in Port-au-Prince, Haiti. Participants were randomly assigned (1:1) to standard ART initiation or same-day HIV testing and ART initiation. The standard group initiated ART 3 weeks after HIV testing, and the same-day group initiated ART on the day of testing. The primary study endpoint was retention in care 12 months after HIV testing with HIV-1 RNA <50 copies/ml. We assessed the impact of treatment arm with a modified intention-to-treat analysis, using multivariable logistic regression controlling for potential confounders. Between August 2013 and October 2015, 762 participants were enrolled; 59 participants transferred to other clinics during the study period, and were excluded as per protocol, leaving 356 in the standard and 347 in the same-day ART groups. In the standard ART group, 156 (44%) participants were retained in care with 12-month HIV-1 RNA <50 copies, and 184 (52%) had <1,000 copies/ml; 20 participants (6%) died. In the same-day ART group, 184 (53%) participants were retained with HIV-1 RNA <50 copies/ml, and 212 (61%) had <1,000 copies/ml; 10 (3%) participants died. The unadjusted risk ratio (RR) of being retained at 12 months with HIV-1 RNA <50 copies/ml was 1.21 (95% CI: 1.04, 1.38; p = 0.015) for the same-day ART group compared to the standard ART group, and the unadjusted RR for being retained with HIV-1 RNA <1,000 copies was 1.18 (95% CI: 1.04, 1.31; p = 0.012). The main limitation of this study is that it was conducted at a single urban clinic, and the generalizability to other settings is uncertain. CONCLUSIONS: Same-day HIV testing and ART initiation is feasible and beneficial in this setting, as it improves retention in care with virologic suppression among patients with early clinical HIV disease. TRIAL REGISTRATION: This study is registered with ClinicalTrials.gov number NCT01900080.
Assuntos
Fármacos Anti-HIV/uso terapêutico , Controle de Doenças Transmissíveis/métodos , Infecções por HIV/diagnóstico , Infecções por HIV/tratamento farmacológico , Adulto , Feminino , Haiti , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de TempoRESUMO
Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease worldwide. We have previously shown that hepatic reticuloendothelial system (RES) iron deposition is associated with an advanced degree of nonalcoholic steatohepatitis (NASH) in humans. In this study, we aimed to determine differentially expressed genes related to iron overload, inflammation and oxidative stress pathways, with the goal of identifying factors associated with NASH progression. Seventy five patients with NAFLD were evaluated for their biochemical parameters and their liver tissue analyzed for NASH histological characteristics. Gene expression analysis of pathways related to iron homeostasis, inflammation and oxidative stress was performed using real-time PCR. Gene expression was compared between subjects based on disease status and presence of hepatic iron staining. We observed increased gene expression of hepcidin (HAMP) (2.3 fold, p = 0.027), transmembrane serine proteinase 6 (TMPRSS6) (8.4 fold, p = 0.003), signal transducer and activator of transcription 3 (STAT3) (5.5 fold, p = 0.004), proinflammatory cytokines; IL-1? (2.7 fold, p = 0.046) and TNF-? (3.8 fold, p = 0.001) in patients with NASH. TMPRSS6, a negative regulator of HAMP, is overexpressed in patients with NASH and HIF1? (hypoxia inducible factor-1) is downregulated. NAFLD patients with hepatic iron deposition exhibited higher hepcidin expression (3.1 fold, p = 0.04) but lower expression of cytokines. In conclusion, we observed elevated hepatic HAMP expression in patients with NASH and in NAFLD patients who had hepatic iron deposition, while proinflammatory cytokines displayed elevated expression only in patients with NASH, suggesting a regulatory role for hepcidin in NAFL to NASH transition and in mitigating inflammatory responses.
Assuntos
Inflamação/genética , Sobrecarga de Ferro/genética , Ferro/análise , Fígado/química , Hepatopatia Gordurosa não Alcoólica/genética , Estresse Oxidativo/genética , Adulto , Feminino , Regulação da Expressão Gênica , Hepcidinas/genética , Humanos , Inflamação/sangue , Inflamação/diagnóstico , Mediadores da Inflamação/sangue , Interleucina-1beta/sangue , Interleucina-1beta/genética , Sobrecarga de Ferro/sangue , Sobrecarga de Ferro/diagnóstico , Fígado/patologia , Masculino , Proteínas de Membrana/genética , Pessoa de Meia-Idade , Hepatopatia Gordurosa não Alcoólica/sangue , Hepatopatia Gordurosa não Alcoólica/diagnóstico , Reação em Cadeia da Polimerase em Tempo Real , Fator de Transcrição STAT3/genética , Serina Endopeptidases/genética , Fator de Necrose Tumoral alfa/sangue , Fator de Necrose Tumoral alfa/genéticaRESUMO
Introductory biology for majors is one of the most consequential courses in STEM, with annual enrollments of several hundred thousand students in the United States alone. To support increased student success and meet current and projected needs for qualified STEM professionals, it will be crucial to redesign majors biology by using explicit learning objectives (LOs) that can be aligned with assessments and active learning exercises. When a course is designed in this way, students have opportunities for the practice and support they need to learn, and instructors can collect the evidence they need to evaluate whether students have mastered key concepts and skills. Following an iterative process of review, revision, and evaluation, which included input from over 800 biology instructors around the country, we produced a nationally endorsed set of lesson-level LOs for a year-long introductory biology for major's course. These LOs are granular enough to support individual class sessions and provide instructors with a framework for course design that is directly connected to the broad themes in Vision and Change and the general statements in the BioCore and BioSkills Guides. Instructors can implement backward course design by aligning these community endorsed LOs with daily and weekly learning activities and with formative and summative assessments.
Assuntos
Biologia , Currículo , Biologia/educação , Humanos , Aprendizagem , Estudantes , Estados Unidos , Aprendizagem Baseada em ProblemasRESUMO
Giardiasis is a neglected parasitic diarrheal disease that is particularly associated with poverty. Current treatment options are limited in the face of growing resistance, but the reduced kinome of Giardia lamblia increases the likelihood of identifying nonredundant essential kinases as potential drug targets. Repurposing known and newly identified kinase inhibitors in drug development programs for novel giardiasis therapeutics could therefore be a cost-effective and time saving approach. Innovative improvements to physiologically-based pharmacokinetic modeling coupled with emerging imaging technologies and a CRISPR-interference method could accelerate progress toward the goal of more effective giardiasis therapeutics based on kinase inhibition.
Assuntos
Antiprotozoários , Giardia lamblia , Giardíase , Preparações Farmacêuticas , Giardíase/tratamento farmacológico , HumanosRESUMO
Giardia has 198 Nek kinases whereas humans have only 11. Giardia has a complex microtubule cytoskeleton that includes eight flagella and several unique microtubule arrays that are utilized for parasite attachment and facilitation of rapid mitosis and cytokinesis. The need to regulate these structures may explain the parallel expansion of the number of Nek family kinases. Here we use live and fixed cell imaging to uncover the role of Nek8445 in regulating Giardia cell division. We demonstrate that Nek8445 localization is cell cycle regulated and this kinase has a role in regulating overall microtubule organization. Nek8445 depletion results in short flagella, aberrant ventral disk organization, loss of the funis, defective axoneme exit, and altered cell shape. The axoneme exit defect is specific to the caudal axonemes, which exit from the posterior of the cell, and this defect correlates with rounding of the cell posterior and loss of the funis. Our findings implicate a role for the funis in establishing Giardia's cell shape and guiding axoneme docking. On a broader scale our results support the emerging view that Nek family kinases have a general role in regulating microtubule organization.
Assuntos
Citocinese , Giardia lamblia/citologia , Giardia lamblia/enzimologia , Microtúbulos/metabolismo , Proteínas Quinases/metabolismo , Proteínas de Protozoários/metabolismo , Axonema/metabolismo , Axonema/ultraestrutura , Flagelos/metabolismoRESUMO
BACKGROUND: Recommendations for universal antiretroviral therapy have greatly increased the number of HIV-infected patients who qualify for treatment, particularly with early clinical disease. Less intensive models of care are needed for clinically stable patients. SETTING: A rapid pathway (RP) model of expedited outpatient care for clinically stable patients was implemented at the Haitian Group for the Study of Kaposi's Sarcoma and Opportunistic Infections (GHESKIO) Center, Port-au-Prince, Haiti. Expedited visits included nurse-led assessments and point-of-service antiretroviral therapy dispensing. METHODS: We conducted a retrospective analysis including patients who initiated RP care between June 1, 2014, and September 30, 2015, comparing outcomes of patients with timely visit attendance (never >3 days late) with patients with ≥1 nontimely visit within 6 months before RP enrollment. We calculated retention in care and adherence at 12 months, and assessed predictors of both outcomes. RESULTS: Of the 2361 patients who initiated RP care during the study period, 1429 (61%) had timely visit attendance and 932 (39%) had ≥1 nontimely visit before RP enrollment. Among RP-enrolled patients, 94% were retained at 12 months and 75% had ≥90% adherence, with higher proportions in those with timely pre-RP visits (95% vs. 92%; 87% vs. 55%). In multivariable analysis, pre-RP visit timeliness was associated with both retention (adjusted odds ratio: 1.67; 95% confidence interval: 1.08 to 2.59) and adherence (adjusted odds ratio: 4.53; 95% confidence interval: 3.58 to 5.72). CONCLUSIONS: RP care was associated with high levels of retention and adherence for clinically stable patients. Timeliness of pre-RP visits was predictive of outcomes after RP initiation.
Assuntos
Fármacos Anti-HIV/administração & dosagem , Infecções por HIV/tratamento farmacológico , Modelos Teóricos , Adulto , Fármacos Anti-HIV/uso terapêutico , Feminino , Haiti , Humanos , Masculino , Adesão à Medicação , Pessoa de Meia-Idade , Estudos RetrospectivosRESUMO
There is need for a more efficient cell-based assay amenable to high-throughput drug screening against Giardia lamblia. Here, we report the development of a screening method utilizing G. lamblia engineered to express red-shifted firefly luciferase. Parasite growth and replication were quantified using D-luciferin as a substrate in a bioluminescent read-out plateform. This assay was validated for reproducibility and reliability against the Medicines for Malaria Venture (MMV) Pathogen Box compounds. For G. lamblia, forty-three compounds showed ≥ 75% inhibition of parasite growth in the initial screen (16 µM), with fifteen showing ≥ 95% inhibition. The Pathogen Box was also screened against Nanoluciferase expressing (Nluc) C. parvum, yielding 85 compounds with ≥ 75% parasite growth inhibition at 10 µM, with six showing ≥ 95% inhibition. A representative set of seven compounds with activity against both parasites were further analyzed to determine the effective concentration that causes 50% growth inhibition (EC50) and cytotoxicity against mammalian HepG2 cells. Four of the seven compounds were previously known to be effective in treating either Giardia or Cryptosporidium. The remaining three shared no obvious chemical similarity with any previously characterized anti-parasite diarrheal drugs and offer new medicinal chemistry opportunities for therapeutic development. These results suggest that the bioluminescent assays are suitable for large-scale screening of chemical libraries against both C. parvum and G. lamblia.
Assuntos
Antiprotozoários/farmacologia , Cryptosporidium parvum/efeitos dos fármacos , Giardia lamblia/efeitos dos fármacos , Antiprotozoários/efeitos adversos , Antiprotozoários/química , Bioensaio , Sobrevivência Celular/efeitos dos fármacos , Descoberta de Drogas , Regulação da Expressão Gênica/efeitos dos fármacos , Células Hep G2 , Humanos , Relação Estrutura-AtividadeRESUMO
In September 2015, the World Health Organization updated their guidelines to recommend antiretroviral therapy (ART) for all people living with HIV. Countries are now in the process of implementing strategies to provide universal HIV treatment. We analyzed the rate of retention and time to ART eligibility (according to 2013 WHO guidelines) among 3,345 adult patients receiving positive HIV test results between February 1, 2003 and March 31, 2013 at the GHESKIO Clinic in Haiti, with WHO stage 1 or 2 disease and initial CD4 cell count >500 cells/mm3. Among the 3,345 patients, 2,423 (72%) were female, the median age was 33 years, 3,089 (92%) lived in Port-au-Prince, and 1,944 (58%) had attended no school or primary school only. The median initial CD4 cell count was 668 cells/mm3 (IQR: 572-834); over the subsequent 2 years, 1,485 patients (44%) were lost to follow-up and 7 (<1%) died pre-ART, 1,041 (31%) were retained in pre-ART care, and 819 (24%) initiated ART. In multivariate analysis, secondary education (aOR 1.27; 95% CI: 1.10-1.47), female gender (aOR: 1.28; 95% CI: 1.09-1.50), co-habitation (aOR: 1.31; 95% CI: 1.09-1.57), and residence in Port-au-Prince (aOR: 1.43; 95% CI: 1.09-1.88) were associated with retention in care. The median time from baseline CD4 count to ART eligibility was 1.7 years. Prior to the implementation of universal treatment, pre-ART attrition was high among patients who did not qualify for ART at presentation. Though implementing WHO recommendations for universal ART will require service expansion, it will likely result in improved retention for those at risk of being lost to follow-up.
Assuntos
Fármacos Anti-HIV/uso terapêutico , Infecções por HIV/tratamento farmacológico , Perda de Seguimento , Adulto , Contagem de Linfócito CD4 , Escolaridade , Feminino , Haiti , Humanos , Estimativa de Kaplan-Meier , Masculino , Análise Multivariada , Modelos de Riscos Proporcionais , Características de Residência/estatística & dados numéricos , Fatores de Risco , Fatores Sexuais , Fatores de Tempo , Organização Mundial da SaúdeRESUMO
Giardiasis is widely acknowledged to be a neglected disease in need of new therapeutics to address toxicity and resistance issues associated with the limited available treatment options. We examined seven protein kinases in the Giardia lamblia genome that are predicted to share an unusual structural feature in their active site. This feature, an expanded active site pocket resulting from an atypically small gatekeeper residue, confers sensitivity to "bumped" kinase inhibitors (BKIs), a class of compounds that has previously shown good pharmacological properties and minimal toxicity. An initial phenotypic screen for biological activity using a subset of an in-house BKI library found that 5 of the 36 compounds tested reduced trophozoite growth by at least 50% at a concentration of 5 µM. The cellular localization and the relative expression levels of the seven protein kinases of interest were determined after endogenously tagging the kinases. Essentiality of these kinases for parasite growth and infectivity were evaluated genetically using morpholino knockdown of protein expression to establish those that could be attractive targets for drug design. Two of the kinases were critical for trophozoite growth and attachment. Therefore, recombinant enzymes were expressed, purified and screened against a BKI library of >400 compounds in thermal stability assays in order to identify high affinity compounds. Compounds with substantial thermal stabilization effects on recombinant protein were shown to have good inhibition of cell growth in wild-type G. lamblia and metronidazole-resistant strains of G. lamblia. Our data suggest that BKIs are a promising starting point for the development of new anti-giardiasis therapeutics that do not overlap in mechanism with current drugs.
Assuntos
Antiprotozoários/farmacologia , Giardia lamblia/enzimologia , Giardíase/parasitologia , Inibidores de Proteínas Quinases/farmacologia , Proteínas Quinases/metabolismo , Proteínas de Protozoários/metabolismo , Motivos de Aminoácidos , Antiprotozoários/química , Domínio Catalítico , Descoberta de Drogas , Giardia lamblia/química , Giardia lamblia/efeitos dos fármacos , Giardia lamblia/genética , Humanos , Cinética , Inibidores de Proteínas Quinases/química , Proteínas Quinases/química , Proteínas Quinases/genética , Proteínas de Protozoários/antagonistas & inibidores , Proteínas de Protozoários/genéticaRESUMO
Abstract: Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease worldwide. We have previously shown that hepatic reticuloendothelial system (RES) iron deposition is associated with an advanced degree of nonalcoholic steatohepatitis (NASH) in humans. In this study, we aimed to determine differentially expressed genes related to iron overload, inflammation and oxidative stress pathways, with the goal of identifying factors associated with NASH progression. Seventy five patients with NAFLD were evaluated for their biochemical parameters and their liver tissue analyzed for NASH histological characteristics. Gene expression analysis of pathways related to iron homeostasis, inflammation and oxidative stress was performed using real-time PCR. Gene expression was compared between subjects based on disease status and presence of hepatic iron staining. We observed increased gene expression of hepcidin (HAMP) (2.3 fold, p = 0.027), transmembrane serine proteinase 6 (TMPRSS6) (8.4 fold, p = 0.003), signal transducer and activator of transcription 3 (STAT3) (5.5 fold, p = 0.004), proinflammatory cytokines; IL-1β (2.7 fold, p = 0.046) and TNF-α (3.8 fold, p = 0.001) in patients with NASH. TMPRSS6, a negative regulator of HAMP, is overexpressed in patients with NASH and HIF1α (hypoxia inducible factor-1) is downregulated. NAFLD patients with hepatic iron deposition exhibited higher hepcidin expression (3.1 fold, p = 0.04) but lower expression of cytokines. In conclusion, we observed elevated hepatic HAMP expression in patients with NASH and in NAFLD patients who had hepatic iron deposition, while proinflammatory cytokines displayed elevated expression only in patients with NASH, suggesting a regulatory role for hepcidin in NAFL to NASH transition and in mitigating inflammatory responses.