Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 13 de 13
Filtrar
1.
Cancer ; 129(19): 2975-2985, 2023 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-37254580

RESUMO

BACKGROUND: Acute myeloid leukemia (AML) has been considered an oncologic emergency that requires initiation of chemotherapy immediately after diagnosis. With the introduction of novel targeted therapies, there is a potential benefit associated with delaying definitive treatment for identification of actionable therapeutic targets. Unfortunately, cytogenetic/molecular testing can take >7 days to return, and there is not a consensus regarding the prognostic impact of time from diagnosis to treatment (TDT) in AML. METHODS: A literature review and meta-analysis of studies done to date that evaluate TDT was conducted. Studies that reported baseline characteristics, TDT, and outcomes for patients with AML were selected. Outcomes included overall survival (OS), complete remission (CR), and mortality. Studies that measured CR rates within each TDT range and data to calculate odds ratios were included in the meta-analysis. The remaining outcomes were synthesized descriptively for literature review. RESULTS: Thirteen studies were identified, which comprised a total of 14,946 patients. Median TDT values were between 1 and 8 days. Several studies found a significant association between prolonged TDT and older age and lower proliferation burden. Four of 11 studies did not detect a significant relationship between TDT and OS. No studies found a significant association between TDT and early death. Six of eight studies did not find a significant association between TDT and CR rate. The meta-analysis found a significant association between prolonged TDT and decreased achievement of CR (p < .05). CONCLUSIONS: Results were highly variable but suggest it may be feasible to pursue cytogenetic/molecular testing in patients who are clinically stable, particularly in those aged 60 years and older.


Assuntos
Leucemia Mieloide Aguda , Humanos , Pessoa de Meia-Idade , Idoso , Prognóstico , Leucemia Mieloide Aguda/diagnóstico , Leucemia Mieloide Aguda/tratamento farmacológico , Indução de Remissão
2.
Med Teach ; 41(6): 656-661, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30689478

RESUMO

Background: The Social Empathy Index (SEI) measures self-reported empathy for individuals and for vulnerable groups. In a previous study, we published first-year medical students' SEI scores before and after completing a course on the social determinants of health. We re-administered the SEI to the original student cohort entering their 4th year. Methods: Survey data were analyzed for individual and social empathy components using repeated measures ANOVA. Associations of demographic data and the latest scores were analyzed using either two sample t-test or ANOVA. Results: Of 130 4th-year eligible medical students, 76 (58%) completed all three surveys. The mean "Affective Mentalizing" score increased by 0.15 points from the first to fourth year of medical school, p < 0.05. A concomitant decline was observed in "Emotional Regulation" decreasing 0.68 points, p < 0.001. "Contextual Understanding of Systemic Barriers" (CU) increased in mean score by 0.26 points, p = 0.006. Discussion: Our findings support promoting interventions to combat a decline of emotional regulation in their clinical years. The consistent increase in CU at each follow-up testing point may indicate a need to focus on students' sense of self-efficacy in addressing the social determinants of health. Social empathy scores might predict which students are likely to choose primary care specialties.


Assuntos
Educação de Graduação em Medicina , Empatia , Estudantes de Medicina/psicologia , Adulto , Feminino , Humanos , Masculino , Grupos Raciais , Fatores Sexuais , Determinantes Sociais da Saúde , Fatores de Tempo , Adulto Jovem
3.
J Biol Chem ; 287(17): 14192-200, 2012 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-22378781

RESUMO

Phosphorylation of signal transducer and activator of transcription 3 (STAT3) on a single tyrosine residue in response to growth factors, cytokines, interferons, and oncogenes activates its dimerization, translocation to the nucleus, binding to the interferon γ (gamma)-activated sequence (GAS) DNA-binding site and activation of transcription of target genes. STAT3 is constitutively phosphorylated in various cancers and drives gene expression from GAS-containing promoters to promote tumorigenesis. Recently, roles for unphosphorylated STAT3 (U-STAT3) have been described in response to cytokine stimulation, in cancers, and in maintenance of heterochromatin stability. However, the mechanisms underlying U-STAT3 binding to DNA has not been fully investigated. Here, we explore STAT3-DNA interactions by atomic force microscopy (AFM) imaging. We observed that U-STAT3 molecules bind to the GAS DNA-binding site as dimers and monomers. In addition, we observed that U-STAT3 binds to AT-rich DNA sequence sites and recognizes specific DNA structures, such as 4-way junctions and DNA nodes, within negatively supercoiled plasmid DNA. These structures are important for chromatin organization and our data suggest a role for U-STAT3 as a chromatin/genome organizer. Unexpectedly, we found that a C-terminal truncated 67.5-kDa STAT3 isoform recognizes single-stranded spacers within cruciform structures that also have a role in chromatin organization and gene expression. This isoform appears to be abundant in the nuclei of cancer cells and, therefore, may have a role in regulation of gene expression. Taken together, our data highlight novel mechanisms by which U-STAT3 binds to DNA and supports U-STAT3 function as a transcriptional activator and a chromatin/genomic organizer.


Assuntos
Cromatina/química , DNA/química , Fator de Transcrição STAT3/metabolismo , Sítios de Ligação , Linhagem Celular Tumoral , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Cinética , Masculino , Microscopia de Força Atômica/métodos , Fosforilação , Plasmídeos/metabolismo , Ligação Proteica , Isoformas de Proteínas , Estrutura Terciária de Proteína , Frações Subcelulares
4.
AIDS Behav ; 16(3): 491-8, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22327371

RESUMO

Intimate partner violence (IPV) has been significantly associated with HIV among heterosexual individuals. Yet a similar relationship has not been so clearly described among men who have sex with men (MSM). The aim of this study was to investigate the association of IPV with HIV seroprevalence among MSM. Participants consisted of 7,844 MSM clients who visited the Whitman Walker Clinic in Washington DC from 2000 through 2007, the majority of whom were Caucasian with a median age of 30. The univariate analysis showed that self-reported IPV was significantly associated with HIV (OR: 1.67, CI: 1.14-2.45) among the sampled MSM clients. However, when adjusting for sexually transmitted infection (STI) status and self-reported risk behaviors including recreational drug use, condom use, number of male sex partners, and having sex with a positive HIV partner, the association of IPV with HIV was not statistically significant. Results indicated that the strong independent association of recreational drug use with HIV seroprevalence decreased the association of IPV with HIV significantly (with recreational drug use, OR: 1.36, CI: 0.93-2.00 vs. without recreational drug use, OR: 1.51, CI: 1.03-2.22).


Assuntos
Infecções por HIV/epidemiologia , Soroprevalência de HIV , Drogas Ilícitas/efeitos adversos , Parceiros Sexuais , Maus-Tratos Conjugais/estatística & dados numéricos , Transtornos Relacionados ao Uso de Substâncias/epidemiologia , Adolescente , Idoso , Homossexualidade Masculina , Humanos , Masculino , Pessoa de Meia-Idade , Assunção de Riscos , Estudos Soroepidemiológicos , Comportamento Sexual , Adulto Jovem
5.
Stat Methods Med Res ; 31(7): 1207-1223, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35404188

RESUMO

Basket trials pool histologic indications sharing molecular pathophysiology, improving development efficiency. Currently, basket trials have been confirmatory only for exceptional therapies. Our previous randomized basket design may be generally suitable in the resource-intensive confirmatory phase, maintains high power even with modest effect sizes, and provides nearly k-fold increased efficiency for k indications, but controls false positives for the pooled result only. Since family wise error rate by indications may sometimes be required, we now simulate a variant of this basket design controlling family wise error rate at 0.025k, the total family wise error rate of k separate randomized trials. We simulated this modified design under numerous scenarios varying design parameters. Only designs controlling family wise error rate and minimizing estimation bias were allowable. Optimal performance results when k=3,4. We report efficiency (expected # true positives/expected sample size) relative to k parallel studies, at 90% power ("uncorrected") or at the power achieved in the basket trial ("corrected," because conventional designs could also increase efficiency by sacrificing power). Efficiency and power (percentage active indications identified) improve with a higher percentage of initial indications active. Up to 92% uncorrected and 38% corrected efficiency improvement is possible. Even under family wise error rate control, randomized confirmatory basket trials substantially improve development efficiency. Initial indication selection is critical.


Assuntos
Modelos Estatísticos , Projetos de Pesquisa , Viés , Tamanho da Amostra
6.
Comput Stat Data Anal ; 55(11): 3059-3072, 2011 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-21850152

RESUMO

A new comprehensive procedure for statistical analysis of two-dimensional polyacrylamide gel electrophoresis (2D PAGE) images is proposed, including protein region quantification, normalization and statistical analysis. Protein regions are defined by the master watershed map that is obtained from the mean gel. By working with these protein regions, the approach bypasses the current bottleneck in the analysis of 2D PAGE images: it does not require spot matching. Background correction is implemented in each protein region by local segmentation. Two-dimensional locally weighted smoothing (LOESS) is proposed to remove any systematic bias after quantification of protein regions. Proteins are separated into mutually independent sets based on detected correlations, and a multivariate analysis is used on each set to detect the group effect. A strategy for multiple hypothesis testing based on this multivariate approach combined with the usual Benjamini-Hochberg FDR procedure is formulated and applied to the differential analysis of 2D PAGE images. Each step in the analytical protocol is shown by using an actual dataset. The effectiveness of the proposed methodology is shown using simulated gels in comparison with the commercial software packages PDQuest and Dymension. We also introduce a new procedure for simulating gel images.

7.
Fam Med ; 53(3): 215-219, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33723821

RESUMO

BACKGROUND AND OBJECTIVES: Academic promotion is critical in academic medicine. Traditionally, peer-reviewed journal articles have been at the core of advancement deliberations. With the increasing prominence digital content and social media, an increasing number of academics have begun linking their scholarly value with their online activities. It is unclear whether and how US academic medical institutions have updated their promotion criteria to reflect the changing environment and digital practices of faculty members. METHODS: We reviewed publicly available advancement and promotion policies and faculty handbooks of 148 allopathic medical schools in the United States (April 2018 through September 2018), to see if social media was explicitly included in their scholarship criteria. RESULTS: Of the 148 allopathic institutions only 12 (8.1%) stated that digital and social media products would be factored into the scholarship and/or other domains of the promotion application. There were no associations between acceptability of social media in the tenure process and schools' characteristics. CONCLUSIONS: Digital media use has the potential to distribute scholarship widely. Including digital scholarship in promotion would help destigmatize the use of digital platforms and promote science dissemination to the public. Medical institutions should embrace new models of digital scholarship and lead the way in defining and ensuring quality.


Assuntos
Faculdades de Medicina , Mídias Sociais , Docentes de Medicina , Bolsas de Estudo , Humanos , Internet , Estados Unidos
8.
Stat Methods Med Res ; 30(2): 396-410, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-32955400

RESUMO

Previous work has shown that individual randomized "proof-of-concept" (PoC) studies may be designed to maximize cost-effectiveness, subject to an overall PoC budget constraint. Maximizing cost-effectiveness has also been considered for arrays of simultaneously executed PoC studies. Defining Type III error as the opportunity cost of not performing a PoC study, we evaluate the common pharmaceutical practice of allocating PoC study funds in two stages. Stage 1, or the first wave of PoC studies, screens drugs to identify those to be permitted additional PoC studies in Stage 2. We investigate if this strategy significantly improves efficiency, despite slowing development. We quantify the benefit, cost, benefit-cost ratio, and Type III error given the number of Stage 1 PoC studies. Relative to a single stage PoC strategy, significant cost-effective gains are seen when at least one of the drugs has a low probability of success (10%) and especially when there are either few drugs (2) with a large number of indications allowed per drug (10) or a large portfolio of drugs (4). In these cases, the recommended number of Stage 1 PoC studies ranges from 2 to 4, tracking approximately with an inflection point in the minimization curve of Type III error.


Assuntos
Preparações Farmacêuticas , Análise Custo-Benefício , Estudo de Prova de Conceito
9.
J Immigr Minor Health ; 22(4): 675-681, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32189161

RESUMO

Female Genital Mutilation or Cutting (FGM/C) is a human rights violation used to claim asylum in the US. We sought to understand the nature of these asylum requests. Analysis of 121 FGM/C-focused medical affidavits, and 132 legal case reports. Of 119 eligible affidavits analyzed, 84% were reportedly cut: 4.6% Type I, 84.6% Type II, 16.5% Type III. Average age: 9. Reported acute effects: bleeding (76.3%), infection (27.6%), shock (6.7%), broken bones (2.7%), and hospitalization (2.7%). Reported chronic issues: intercourse difficulty (81.7%), pregnancy complications (54.2%), chronic pain (42.4%), scarring (37.3%), urinary difficulty (31.8%). Psychological consequences included PTSD (72.4%), depression (65.9%), anxiety (51.1%), and lack of trust (10.1%). Co-occurring abuses included domestic violence (62.4%), forced marriage (46%), rape (33.3%), torture (33.3%), child marriage (31.3%), assault due to LGBTQ + status (2.9%). Women claiming asylum based on FGM/C report high rates of chronic health issues. Their histories suggest FGM/C co-occurs with other forms of gender-based violence.


Assuntos
Circuncisão Feminina/estatística & dados numéricos , Direitos Humanos , Refugiados/estatística & dados numéricos , Adolescente , Adulto , Circuncisão Feminina/efeitos adversos , Circuncisão Feminina/etnologia , Feminino , Nível de Saúde , Humanos , Pessoa de Meia-Idade , Delitos Sexuais/etnologia , Delitos Sexuais/estatística & dados numéricos , Fatores Socioeconômicos , Estados Unidos , Adulto Jovem
10.
J Clin Sleep Med ; 14(3): 409-417, 2018 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-29458695

RESUMO

STUDY OBJECTIVES: Obstructive sleep apnea (OSA) and chronic insomnia are two common sleep disorders and both are considered independent risk factors for heart disease. The aim of this study was to investigate the prevalence of comorbid insomnia with OSA and to compare its clinical characteristics with those of OSA without insomnia. METHODS: Patients who visited two tertiary university hospital sleep centers were screened. Those with a diagnosis of OSA using polysomnography were divided into two groups based on their scores on the Korean version of the Insomnia Severity Index (ISI-K): OSA with insomnia (OSA+I) (ISI-K score ≥ 15) and OSA without insomnia (OSA-I) (ISI-K score < 15). Subjective symptoms were evaluated using sleep questionnaires including ISI-K. Demographic and clinical characteristics of OSA+I and OSA-I were compared. RESULTS: Out of 476 patients with OSA, 139 (29.2%) had significant insomnia. Patients in the OSA+I group had a higher percentage of females (35.3% versus 19.6%, P < .001) and have higher rates of heart disease (19.4% versus 8.6%, P < .001). OSA+I group showed lower quality of life, lower quality of sleep, higher sleep propensity, and higher depression as measured by the Korean versions of the Short-Form 36-Item Health Survey, Pittsburgh Sleep Quality Index, Epworth Sleepiness Scale, and Beck Depression Inventory, respectively. There were no significant differences in adherence to continuous positive airway pressure between the groups. CONCLUSIONS: There is a high prevalence of comorbid insomnia with OSA (29.2%), consistent with previous findings in Western studies. Comorbid insomnia with OSA may constitute a cumulative risk factor for cardiovascular disease. These findings warrant further investigation into the mechanisms involved in its pathogenesis and devising more efficient treatments.


Assuntos
Apneia Obstrutiva do Sono/complicações , Distúrbios do Início e da Manutenção do Sono/complicações , Comorbidade , Depressão/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Polissonografia , Qualidade de Vida , Estudos Retrospectivos , Fatores de Risco , Apneia Obstrutiva do Sono/epidemiologia , Distúrbios do Início e da Manutenção do Sono/epidemiologia , Inquéritos e Questionários
11.
J Natl Cancer Inst ; 106(10)2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25258390

RESUMO

BACKGROUND: Tamoxifen is metabolically activated via a CYP2D6 enzyme system to the more potent hydroxylated derivatives 4-hydroxytamoxifen and endoxifen. This study addresses the pharmacological importance of endoxifen by simulating clinical scenarios in vitro. METHODS: Clinical levels of tamoxifen metabolites in postmenopausal breast cancer patients previously genotyped for CYP2D6 were used in vitro along with clinical estrogen levels (estrone and estradiol) in postmenopausal patients determined in previous studies. The biological effects on cell growth were evaluated in a panel of estrogen receptor-positive breast cancer cell lines via cell proliferation assays and real-time polymerase chain reaction (PCR). Data were analyzed with one- and two-way analysis of variance and Student's t test. All statistical tests were two-sided. RESULTS: Postmenopausal levels of estrogen-induced proliferation of all test breast cancer cell lines (mean fold induction ± SD vs vehicle control: MCF-7 = 11 ± 1.74, P < .001; T47D = 7.52 ± 0.72, P < .001; BT474 = 1.75 ± 0.23, P < .001; ZR-75-1 = 5.5 ± 1.95, P = .001. Tamoxifen and primary metabolites completely inhibited cell growth regardless of the CYP2D6 genotype in all cell lines (mean fold induction ± SD vs vehicle control: MCF-7 = 1.57 ± 0.38, P = .54; T47D = 1.17 ± 0.23, P = .79; BT474 = 0.96 ± 0.2, P = .98; ZR-75-1 = 0.86 ± 0.67, P = .99). Interestingly, tamoxifen and its primary metabolites were not able to fully inhibit the estrogen-stimulated expression of estrogen-responsive genes in MCF-7 cells (P < .05 for all genes), but the addition of endoxifen was able to produce additional antiestrogenic effect on these genes. CONCLUSIONS: The results indicate that tamoxifen and other metabolites, excluding endoxifen, completely inhibit estrogen-stimulated growth in all cell lines, but additional antiestrogenic action from endoxifen is necessary for complete blockade of estrogen-stimulated genes. Endoxifen is of supportive importance for the therapeutic effect of tamoxifen in a postmenopausal setting.


Assuntos
Antineoplásicos Hormonais/farmacologia , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Moduladores de Receptor Estrogênico/farmacologia , Pós-Menopausa , Tamoxifeno/análogos & derivados , Tamoxifeno/metabolismo , Tamoxifeno/farmacologia , Idoso , Antineoplásicos Hormonais/metabolismo , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Citocromo P-450 CYP2D6/metabolismo , Estradiol/metabolismo , Moduladores de Receptor Estrogênico/metabolismo , Estrona/metabolismo , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Células MCF-7 , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase em Tempo Real , Projetos de Pesquisa , Tamoxifeno/química
12.
Br J Pharmacol ; 171(24): 5624-35, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25073551

RESUMO

BACKGROUND AND PURPOSE: Tamoxifen is a prodrug that is metabolically activated by 4-hydroxylation to the potent primary metabolite 4-hydroxytamoxifen (4OHT) or via another primary metabolite N-desmethyltamoxifen (NDMTAM) to a biologically active secondary metabolite endoxifen through a cytochrome P450 2D6 variant system (CYP2D6). To elucidate the mechanism of action of tamoxifen and the importance of endoxifen for its effect, we determined the anti-oestrogenic efficacy of tamoxifen and its metabolites, including endoxifen, at concentrations corresponding to serum levels measured in breast cancer patients with various CYP2D6 genotypes (simulating tamoxifen treatment). EXPERIMENTAL APPROACH: The biological effects of tamoxifen and its metabolites on cell growth and oestrogen-responsive gene modulation were evaluated in a panel of oestrogen receptor-positive breast cancer cell lines. Actual clinical levels of tamoxifen metabolites in breast cancer patients were used in vitro along with actual levels of oestrogens observed in premenopausal patients taking tamoxifen. KEY RESULTS: Tamoxifen and its primary metabolites (4OHT and NDMTAM) only partially inhibited the stimulant effects of oestrogen on cells. The addition of endoxifen at concentrations corresponding to different CYP2D6 genotypes was found to enhance the anti-oestrogenic effect of tamoxifen and its metabolites with an efficacy that correlated with the concentration of endoxifen; at concentrations corresponding to the extensive metabolizer genotype it further inhibited the actions of oestrogen. In contrast, lower concentrations of endoxifen (intermediate and poor metabolizers) had little or no anti-oestrogenic effects. CONCLUSIONS AND IMPLICATIONS: Endoxifen may be a clinically relevant metabolite in premenopausal patients as it provides additional anti-oestrogenic actions during tamoxifen treatment.


Assuntos
Adenocarcinoma/tratamento farmacológico , Antineoplásicos Hormonais/farmacologia , Neoplasias da Mama/tratamento farmacológico , Proliferação de Células/efeitos dos fármacos , Citocromo P-450 CYP2D6/genética , Pré-Menopausa , Tamoxifeno/análogos & derivados , Tamoxifeno/farmacologia , Adenocarcinoma/genética , Antineoplásicos Hormonais/metabolismo , Antineoplásicos Hormonais/uso terapêutico , Neoplasias da Mama/genética , Linhagem Celular Tumoral , Feminino , Variação Genética , Genótipo , Humanos , Técnicas In Vitro , Células MCF-7 , Tamoxifeno/metabolismo , Tamoxifeno/uso terapêutico
13.
Electrophoresis ; 29(19): 4017-26, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18958894

RESUMO

We present a novel application of independent component analysis (ICA), an exploratory data analysis technique, to two-dimensional electrophoresis (2-DE) gels, which have been used to analyze differentially expressed proteins across groups. Unlike currently used pixel-wise statistical tests, ICA is a data-driven approach that utilizes the information contained in the entire gel data. We also apply ICA on wavelet-transformed 2-DE gels to address the high dimensionality and noise problems typically found in 2-DE gels. Also, we use an analysis-of-variance (ANOVA) approach as a benchmark for comparison. Using simulated data, we show that ICA detects the group differences accurately in both the spatial and wavelet domains. We also apply these techniques to real 2-DE gels. ICA proves to be much faster than ANOVA, and unlike ANOVA it does not depend on the selection of a threshold. Application of principal component analysis reduces the dimensionality and tends to improve the performance by reducing the noise.


Assuntos
Simulação por Computador , Eletroforese em Gel Bidimensional , Análise de Componente Principal , Algoritmos , Análise de Variância , Interpretação Estatística de Dados , Distribuição Normal
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa