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1.
BMC Cancer ; 24(1): 878, 2024 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-39039514

RESUMO

PURPOSE: Oxaliplatin-containing adjuvant chemotherapy yields a significant survival benefit in stage III colon cancer and is the standard of care. Simultaneously, it causes dose-dependent peripheral neuropathy that may increase the risk of fall-related injury (FRI) such as fracture and laceration. Because these events carry significant morbidity and the global burden of colon cancer is on the rise, we examined the association between treatment with a full versus shortened course of adjuvant chemotherapy and post-treatment FRI and fracture. METHODS: In this overlap propensity score weighted, retrospective cohort study, we included patients aged ≥ 18 years with resected stage III colon cancer diagnosed 2007-2019 and treated with oxaliplatin-containing adjuvant chemotherapy (oxaliplatin plus a fluoropyrimidine; capecitabine [CAPOX] or 5-fluorouracil and leucovorin [FOLFOX]). Propensity score methods facilitate the separation of design from analysis and comparison of baseline characteristics across the weighted groups. Treatment groups were defined as 50% (4 cycles CAPOX/6 cycles FOLFOX) and > 85% (7-8 cycles CAPOX/11-12 cycles FOLFOX) of a maximal course of adjuvant chemotherapy to approximate the treatment durations received in the IDEA collaboration. The main outcomes were time to any FRI and time to fracture. We determined the subdistribution hazard ratios (sHR) estimating the association between FRI/fracture and treatment group, accounting for the competing risk of death. RESULTS: We included 3,461 patients; 473 (13.7%) received 50% and 2,988 (86.3%) received > 85% of a maximal course of adjuvant therapy. For post-treatment FRI, median follow-up was 4.6 years and total follow-up was 17,968 person-years. There were 508 FRI, 301 fractures, and 692 deaths. Treatment with > 85% of a maximal course of therapy conferred a sHR of 0.84 (95% CI 0.62-1.13) for post-treatment FRI and a sHR of 0.72 (95% CI 0.49-1.06) for post-treatment fracture. CONCLUSION: For patients with stage III colon cancer undergoing treatment with oxaliplatin-containing adjuvant chemotherapy, any potential neuropathy associated with longer durations of treatment was not found to result in greater rates of FRI and fracture. Within the limits of this retrospective study, our findings suggest concern about FRI, while mechanistically plausible, ought not to determine treatment duration.


Assuntos
Acidentes por Quedas , Protocolos de Quimioterapia Combinada Antineoplásica , Neoplasias do Colo , Fluoruracila , Leucovorina , Estadiamento de Neoplasias , Oxaliplatina , Humanos , Estudos Retrospectivos , Feminino , Masculino , Quimioterapia Adjuvante/métodos , Quimioterapia Adjuvante/efeitos adversos , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/patologia , Neoplasias do Colo/mortalidade , Pessoa de Meia-Idade , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Oxaliplatina/administração & dosagem , Oxaliplatina/efeitos adversos , Oxaliplatina/uso terapêutico , Idoso , Acidentes por Quedas/estatística & dados numéricos , Leucovorina/uso terapêutico , Leucovorina/efeitos adversos , Leucovorina/administração & dosagem , Fluoruracila/administração & dosagem , Fluoruracila/efeitos adversos , Fluoruracila/uso terapêutico , Fraturas Ósseas/etiologia , Fraturas Ósseas/epidemiologia , Capecitabina/administração & dosagem , Pontuação de Propensão , Adulto , Compostos Organoplatínicos
2.
Malar J ; 21(1): 60, 2022 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-35193585

RESUMO

BACKGROUND: Cerebral malaria is still a major cause of death in children in sub-Saharan Africa. Among survivors, debilitating neurological sequelae can leave children with permanent cognitive impairments and societal stigma, resulting in taxing repercussions for their families. This study investigated the effect of delay in presentation to medical care on outcome in children with cerebral malaria in Malawi. METHODS: This retrospective study included participants enrolled in a longstanding study of cerebral malaria between 2001 and 2021 and considered coma duration prior to arrival at hospital (with or without anti-malarial treatment), HIV status, blood lactate levels at admission and age as factors that could affect clinical outcome. Outcomes were categorized as full recovery, sequelae at the time of discharge, or death. A multinomial regression was fit and run controlling for coma duration, HIV status, lactate levels and age, to determine the association between each explanatory variable and outcome. RESULTS: A total of 1663 children with cerebral malaria, aged 6 months to 14 years were included. Longer coma duration (in hours) was associated with greater odds of developing sequelae (OR = 1.023, 95% CI 1.007-1.039, p = 0.006) but not death (OR = 1.00, 95% CI 0.986-1.015, p = 0.961). Younger age (in months) was also correlated with higher rates of sequelae, (OR = 0.990, 95% CI 0.983-0.997, p = 0.004) but not with increased mortality (OR = 0.998, 95% CI 0.993-1.003, p = 0.335). Blood lactate levels on admission were correlated with mortality (OR = 1.125, 95% CI 1.090-1.161, p < 0.001) but not associated with increased rates of sequelae (OR = 1.016, 95% CI 0.973-1.060, p = 0.475). Positive HIV status and treatment with an anti-malarial (artemisinin or non-artemisinin-based) prior to arrival at the hospital were not significantly associated with either adverse outcome. CONCLUSIONS: In Malawian children with cerebral malaria, higher rates of sequelae were significantly associated with extended coma duration prior to admission and younger age. Mortality rates were correlated with increased lactate levels on admission. The differential effects of variables on clinical outcomes suggest that there may be different pathogenic pathways leading to sequelae and death. Actions taken by parents and health care professionals are critical in defining when patients arrive at hospital and determining their ultimate outcome.


Assuntos
Antimaláricos , Malária Cerebral , Antimaláricos/uso terapêutico , Criança , Hospitais , Humanos , Lactente , Malária Cerebral/tratamento farmacológico , Malaui/epidemiologia , Estudos Retrospectivos
3.
Int J Mol Sci ; 23(3)2022 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-35163100

RESUMO

CD26 has been reported as a marker for colorectal cancer stem cells endowed with tumor-initiating properties and capable of colorectal cancer (CRC) metastasis. In this study, we investigated the functional effect of CD26 on CRC angiogenesis and metastasis, and the potential underlying mechanism. The functional effects of CD26 overexpression or repression were determined by a wound healing experiment, and cell migration and invasion assays in vitro and in mouse models. Differentially expressed genes regulated by CD26 were identified by genome-wide mRNA expression array and validated by quantitative PCR. CD26 functionally regulated CRC cell migration and invasion in vitro and angiogenesis and metastasis in vivo. Genome-wide mRNA expression array and qPCR showed that MMP1 was up-regulated in CD26+ subpopulation, and a subsequent experiment demonstrated the regulatory effect of CD26 on MMP1 in CRC cell lines with CD26 repression or overexpression. Furthermore, overexpression of CAV1 abrogated the CD26-regulated MMP1 induction in CRC cell lines. This study demonstrated the functional roles of CD26 in inducing CRC migration, invasion, angiogenesis and metastasis and identified the potential involvement of MMP1 and CAV1 in such process. CD26 is an attractive therapeutic target for combating tumor progression to improve the prognosis of CRC patients.


Assuntos
Caveolina 1/metabolismo , Neoplasias Colorretais/irrigação sanguínea , Neoplasias Colorretais/patologia , Dipeptidil Peptidase 4/metabolismo , Regulação Neoplásica da Expressão Gênica , Metaloproteinase 1 da Matriz/metabolismo , Neovascularização Patológica/patologia , Animais , Apoptose , Caveolina 1/genética , Movimento Celular , Proliferação de Células , Neoplasias Colorretais/genética , Neoplasias Colorretais/metabolismo , Dipeptidil Peptidase 4/genética , Humanos , Metaloproteinase 1 da Matriz/genética , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Metástase Neoplásica , Neovascularização Patológica/genética , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto
4.
CMAJ ; 193(21): E753-E760, 2021 05 25.
Artigo em Inglês | MEDLINE | ID: mdl-34035055

RESUMO

BACKGROUND: Reduced use of the emergency department during the COVID-19 pandemic may result in increased disease acuity when patients do seek health care services. We sought to evaluate emergency department visits for common abdominal and gynecologic conditions before and at the beginning of the pandemic to determine whether changes in emergency department attendance had serious consequences for patients. METHODS: We conducted a population-based analysis using administrative data to evaluate the weekly rate of emergency department visits pre-COVID-19 (Jan. 1-Mar. 10, 2020) and during the beginning of the COVID-19 pandemic (Mar. 11-June 30, 2020), compared with a historical control period (Jan. 1-July 1, 2019). All residents of Ontario, Canada, presenting to the emergency department with appendicitis, cholecystitis, ectopic pregnancy or miscarriage were included. We evaluated weekly incidence rate ratios (IRRs) of emergency department visits, management strategies and clinical outcomes. RESULTS: Across all study periods, 39 691 emergency department visits met inclusion criteria (40.2 % appendicitis, 32.1% miscarriage, 21.3% cholecystitis, 6.4% ectopic pregnancy). Baseline characteristics of patients presenting to the emergency department did not vary across study periods. After an initial reduction in emergency department visits, presentations for cholecystitis and ectopic pregnancy quickly returned to expected levels. However, presentations for appendicitis and miscarriage showed sustained reductions (IRR 0.61-0.80), with 1087 and 984 fewer visits, respectively, after the start of the pandemic, relative to 2019. Management strategies, complications and mortality rates were similar across study periods for all conditions. INTERPRETATION: Although our study showed evidence of emergency department avoidance in Ontario during the first wave of the COVID-19 pandemic, no adverse consequences were evident. Emergency care and outcomes for patients were similar before and during the pandemic.


Assuntos
Apendicite , COVID-19 , Colecistite , Serviço Hospitalar de Emergência/tendências , Utilização de Instalações e Serviços/tendências , Doenças dos Genitais Femininos , Aceitação pelo Paciente de Cuidados de Saúde/estatística & dados numéricos , Aborto Espontâneo/diagnóstico , Aborto Espontâneo/epidemiologia , Aborto Espontâneo/terapia , Adulto , Idoso , Apendicite/diagnóstico , Apendicite/epidemiologia , Apendicite/terapia , COVID-19/epidemiologia , COVID-19/psicologia , Colecistite/diagnóstico , Colecistite/epidemiologia , Colecistite/terapia , Estudos Transversais , Feminino , Doenças dos Genitais Femininos/diagnóstico , Doenças dos Genitais Femininos/epidemiologia , Doenças dos Genitais Femininos/terapia , Humanos , Masculino , Pessoa de Meia-Idade , Ontário/epidemiologia , Pandemias , Gravidez , Gravidez Ectópica/diagnóstico , Gravidez Ectópica/epidemiologia , Gravidez Ectópica/terapia , Índice de Gravidade de Doença
5.
Colorectal Dis ; 23(8): 2127-2136, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33973319

RESUMO

AIM: Clinical trials suggest that hyaluronate carboxymethylcellulose (HA/CMC) prevents adhesion-related complications after intra-abdominal surgery, but at a high upfront cost. This study evaluated the cost-effectiveness of HA/CMC for patients undergoing curative-intent open colorectal cancer surgery. METHODS: Using a Markov Monte Carlo microsimulation model, we conducted a cost-utility analysis comparing the cost-effectiveness of HA/CMC at curative-intent open colorectal cancer surgery versus standard management. We considered a scenario where HA/CMC was used at the index operation only, as well as where it was used at the index operation and any subsequent operations. The perspective was that of the third-party payer. Costs and utilities were discounted 1.5% annually, with a 1-month cycle length and 5-year time horizon. Model input data were obtained from a literature review. Outcomes included cost, quality-adjusted life-years (QALYs), small bowel obstructions (SBOs) and operations for SBO. RESULTS: Using HA/CMC at the index operation results in an incremental cost increase of CA$316 and provides 0.001 additional QALYs, for an incremental cost-effectiveness ratio of CA$310,000 per QALY compared to standard management. In our simulated cohort of 10,000 patients, HA/CMC prevented 460 SBOs and 293 surgeries for SBO. Probabilistic sensitivity analysis found that HA/CMC was cost-effective in 18.5% of iterations, at a cost-effectiveness threshold of CA$50,000 per QALY. Results of the scenario analysis where HA/CMC was used at the index operation and any subsequent operations were similar. CONCLUSIONS: Hyaluronate carboxymethylcellulose prevents adhesive bowel obstruction after open colorectal cancer surgery but is unlikely to be cost-effective given minimal long-term impact on healthcare costs and QALYs.


Assuntos
Adesivos , Carboximetilcelulose Sódica , Carboximetilcelulose Sódica/uso terapêutico , Análise Custo-Benefício , Humanos , Anos de Vida Ajustados por Qualidade de Vida , Aderências Teciduais
6.
Healthc Q ; 24(3): 76-81, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34792453

RESUMO

Canada's healthcare sector produces the third highest healthcare-related emissions per capita globally. However, Canada has no national strategy toward environmentally sustainable healthcare. Transforming Canada's health systems to be environmentally sustainable requires leadership from many stakeholders and collaboration between trainees and health leaders. This article provides an overview of student and trainee leadership among health-related fields in response to the climate crisis and highlights the formation of a trainee-led organization focused on building capacity among emerging leaders in healthcare. We share key lessons learned by this group that are essential for all leaders seeking to leverage interdisciplinary action toward sustainable health systems in Canada.


Assuntos
Programas Governamentais , Liderança , Canadá , Atenção à Saúde , Setor de Assistência à Saúde , Humanos
7.
J Org Chem ; 84(21): 13565-13571, 2019 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-31512872

RESUMO

The mechanism and origins of syn and anti selectivity of cross-benzoin reactions between furfural and α-amino aldehydes, catalyzed by a triazolium-based NHC, were investigated using density functional theory calculations. N-Boc-α-amino aldehydes were found to react with anti selectivity, while N-Bn-N-Boc-α-amino aldehydes react with syn selectivity. We find that the anti product is more thermodynamically favored than the syn product for reactions with N-Boc-α-amino aldehydes, and that the formation of the syn product for reactions involving N-Bn-N-Boc-α-amino aldehydes is kinetically favored. The switch in selectivity is a result of an intramolecular hydrogen bond in the N-Boc-α-amino aldehyde, whereas switching to N-Bn-N-Boc-α-amine removes the hydrogen bond. The steric and electronic interactions in the transition state are rationalized by a Felkin-Anh model.

8.
Int J Mol Sci ; 18(6)2017 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-28545226

RESUMO

Colorectal cancer results from genetic aberrations which accumulate over a long period of time, with malignant and metastatic properties acquired at a relatively late stage. A subpopulation of CD26+ colorectal cancer stem cells are known to be implicated in metastasis. We quantified CD26+ cancer cells in 11 primary tumor samples by flow cytometry, and showed that tumors having confirmed or suspected metastases harbored a relatively high CD26+ level in these samples. We hypothesized that this subpopulation of cancer stem cells arises in the late stage of carcinogenesis from the bulk of tumor daughter cells which are CD26-. The manipulation of PIK3CA and TP53, two genes commonly deregulated in the late stage, had an effect on the maintenance of the CD26+ cell population. When CD26- tumor daughter cells were sorted and cultured, the emergence of tumor spheres containing CD26+ cells occurred. These findings shed light to the origin of colorectal cancer stem cells with metastatic properties, which has an implication on conventional treatments by surgery or adjuvant chemotherapy for tumor debulking.


Assuntos
Biomarcadores Tumorais/metabolismo , Carcinogênese/metabolismo , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Dipeptidil Peptidase 4/metabolismo , Células-Tronco Neoplásicas/metabolismo , Idoso , Idoso de 80 Anos ou mais , Carcinogênese/patologia , Feminino , Humanos , Masculino
9.
Nat Methods ; 10(4): 354-60, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23474465

RESUMO

An inability to reliably predict quantitative behaviors for novel combinations of genetic elements limits the rational engineering of biological systems. We developed an expression cassette architecture for genetic elements controlling transcription and translation initiation in Escherichia coli: transcription elements encode a common mRNA start, and translation elements use an overlapping genetic motif found in many natural systems. We engineered libraries of constitutive and repressor-regulated promoters along with translation initiation elements following these definitions. We measured activity distributions for each library and selected elements that collectively resulted in expression across a 1,000-fold observed dynamic range. We studied all combinations of curated elements, demonstrating that arbitrary genes are reliably expressed to within twofold relative target expression windows with ∼93% reliability. We expect the genetic element definitions validated here can be collectively expanded to create collections of public-domain standard biological parts that support reliable forward engineering of gene expression at genome scales.


Assuntos
Escherichia coli/metabolismo , Regulação Bacteriana da Expressão Gênica , Fatores de Iniciação em Procariotos/metabolismo , Transcrição Gênica , Escherichia coli/genética , Regulação Bacteriana da Expressão Gênica/fisiologia , Biblioteca Gênica , Engenharia Genética , Genoma Bacteriano , Fatores de Iniciação em Procariotos/genética , Regiões Promotoras Genéticas/genética , RNA Bacteriano/genética , RNA Bacteriano/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
10.
Nat Methods ; 10(4): 347-53, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23474467

RESUMO

The practice of engineering biology now depends on the ad hoc reuse of genetic elements whose precise activities vary across changing contexts. Methods are lacking for researchers to affordably coordinate the quantification and analysis of part performance across varied environments, as needed to identify, evaluate and improve problematic part types. We developed an easy-to-use analysis of variance (ANOVA) framework for quantifying the performance of genetic elements. For proof of concept, we assembled and analyzed combinations of prokaryotic transcription and translation initiation elements in Escherichia coli. We determined how estimation of part activity relates to the number of unique element combinations tested, and we show how to estimate expected ensemble-wide part activity from just one or two measurements. We propose a new statistic, biomolecular part 'quality', for tracking quantitative variation in part performance across changing contexts.


Assuntos
Bioengenharia/métodos , Escherichia coli/metabolismo , Fatores de Iniciação de Peptídeos/metabolismo , Animais , Proteínas de Bactérias , Escherichia coli/genética , Regulação Bacteriana da Expressão Gênica/fisiologia , Biblioteca Gênica , Iniciação Traducional da Cadeia Peptídica , Fatores de Iniciação em Procariotos/metabolismo , Transcrição Gênica
11.
Hepatobiliary Pancreat Dis Int ; 15(5): 493-498, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27733318

RESUMO

BACKGROUND: Chemoembolization with doxorubucin-eluting beads (DEB) has been used to treat hepatocellular carcinoma (HCC) since 2007. This study compared the efficacy and survival between transarterial chemoembolization (TACE) with DEB and conventional approach (cTACE) in HCC treatment. METHODS: This retrospective case-control study compared the overall survival and tumor response of HCC patients to cTACE (n=190) and DEB (n=143) by the reassessment of computed tomography and serum alpha-fetoprotein (AFP). Multivariate analysis was used to determine the factors affecting tumor response. RESULTS: The median post-treatment to pre-treatment AFP level was 0.8 for a DEB session (n=258) and 1.0 for a cTACE session (n=452), showing a significantly greater decrease in AFP after DEB (P<0.05). More patients in the DEB group achieved objective response (complete and partial) compared with those in the cTACE group (P<0.05). Objective tumor response after DEB vs cTACE was 34.8% vs 15.4% in 0-3 months (P=0.001), 37.1% vs 20.0% in 3-6 months (P<0.05), and 50.0% vs 30.0% in 6-12 months (P=0.093). DEB predicted a 3.604 times odds of achieving at least one objective tumor response in a patient when compared to cTACE (P<0.0001). The median survival from first transcatheter therapy of patients having undergone at least once DEB was 12.53 months, while those having received cTACE only was 10.53 months (P=0.086). A tendency of improved survival appeared to maintain until >80 months after the first TACE session in the DEB group. CONCLUSION: DEB is a safe alternative to cTACE in HCC patients with better therapeutic efficacy.


Assuntos
Antibióticos Antineoplásicos/administração & dosagem , Carcinoma Hepatocelular/terapia , Quimioembolização Terapêutica , Doxorrubicina/administração & dosagem , Neoplasias Hepáticas/terapia , Idoso , Antibióticos Antineoplásicos/efeitos adversos , Carcinoma Hepatocelular/sangue , Carcinoma Hepatocelular/mortalidade , Carcinoma Hepatocelular/patologia , Quimioembolização Terapêutica/efeitos adversos , Distribuição de Qui-Quadrado , Doxorrubicina/efeitos adversos , Feminino , Hong Kong , Humanos , Estimativa de Kaplan-Meier , Neoplasias Hepáticas/sangue , Neoplasias Hepáticas/mortalidade , Neoplasias Hepáticas/patologia , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Razão de Chances , Estudos Retrospectivos , Fatores de Tempo , Tomografia Computadorizada por Raios X , Resultado do Tratamento , Carga Tumoral , alfa-Fetoproteínas/metabolismo
12.
Mol Cancer ; 14: 80, 2015 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-25884645

RESUMO

BACKGROUND: In colorectal carcinoma (CRC), activation of the Raf/MEK/ERK signaling pathway is commonly observed. In addition, the commonly used 5FU-based chemotherapy in patients with metastatic CRC was found to enrich a subpopulation of CD26(+) cancer stem cells (CSCs). As activation of the Raf/MEK/ERK signaling pathway was also found in the CD26(+) CSCs and therefore, we hypothesized that an ATP-competitive pan-Raf inhibitor, Raf265, is effective in eliminating the cancer cells and the CD26(+) CSCs in CRC patients. METHODS: HT29 and HCT116 cells were treated with various concentrations of Raf265 to study the anti-proliferative and apoptotic effects of Raf265. Anti-tumor effect was also demonstrated using a xenograft model. Cells were also treated with Raf265 in combination with 5FU to demonstrate the anti-migratory and invasive effects by targeting on the CD26(+) CSCs and the anti-metastatic effect of the combined treatment was shown in an orthotopic CRC model. RESULTS: Raf265 was found to be highly effective in inhibiting cell proliferation and tumor growth through the inhibition of the RAF/MEK/ERK signaling pathway. In addition, anti-migratory and invasive effect was found with Raf265 treatment in combination with 5FU by targeting on the CD26(+) cells. Finally, the anti-tumor and anti-metastatic effect of Raf265 in combination with 5FU was also demonstrated. CONCLUSIONS: This preclinical study demonstrates the anti-tumor and anti-metastatic activity of Raf265 in CRC, providing the basis for exploiting its potential use and combination therapy with 5FU in the clinical treatment of CRC.


Assuntos
Antineoplásicos/farmacologia , Neoplasias Colorretais/metabolismo , Imidazóis/farmacologia , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/metabolismo , Piridinas/farmacologia , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Autorrenovação Celular , Neoplasias Colorretais/patologia , Avaliação Pré-Clínica de Medicamentos , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Fluoruracila/farmacologia , Células HCT116 , Células HT29 , Humanos , Camundongos , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Proteínas Proto-Oncogênicas B-raf/metabolismo , Transdução de Sinais/efeitos dos fármacos
13.
Nucleic Acids Res ; 41(9): 5139-48, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23511967

RESUMO

The reliable forward engineering of genetic systems remains limited by the ad hoc reuse of many types of basic genetic elements. Although a few intrinsic prokaryotic transcription terminators are used routinely, termination efficiencies have not been studied systematically. Here, we developed and validated a genetic architecture that enables reliable measurement of termination efficiencies. We then assembled a collection of 61 natural and synthetic terminators that collectively encode termination efficiencies across an ∼800-fold dynamic range within Escherichia coli. We simulated co-transcriptional RNA folding dynamics to identify competing secondary structures that might interfere with terminator folding kinetics or impact termination activity. We found that structures extending beyond the core terminator stem are likely to increase terminator activity. By excluding terminators encoding such context-confounding elements, we were able to develop a linear sequence-function model that can be used to estimate termination efficiencies (r = 0.9, n = 31) better than models trained on all terminators (r = 0.67, n = 54). The resulting systematically measured collection of terminators should improve the engineering of synthetic genetic systems and also advance quantitative modeling of transcription termination.


Assuntos
Modelos Genéticos , Regiões Terminadoras Genéticas , Terminação da Transcrição Genética , Escherichia coli/genética , Dobramento de RNA
14.
Hepatology ; 58(2): 667-79, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23504997

RESUMO

UNLABELLED: Early reports suggested that actopaxin, a member of the focal adhesion proteins, regulates cell migration. Here we investigated whether actopaxin is involved in hepatocellular carcinoma (HCC) progression and metastasis. We examined actopaxin expression in human HCC samples using immunohistochemistry and western blotting. The functional and molecular effect of actopaxin was studied in vitro by overexpression in a nonmetastatic HCC cell line, as well as repression in a metastatic cell line. The in vivo effect of actopaxin repression was studied in nonobese diabetic and severe combined immunodeficient mice. We found that actopaxin was frequently overexpressed in human HCC patients and its overexpression positively correlated with tumor size, stage, and metastasis. Actopaxin expression also correlated with the metastatic potential of HCC cell lines. Actopaxin overexpression induced the invasion and migration ability of nonmetastatic HCC cells, whereas down-regulation of actopaxin reverted the invasive phenotypes and metastatic potential of metastatic HCC cells through regulating the protein expression of certain focal adhesion proteins including ILK, PINCH, paxillin, and cdc42, as well as regulating the epithelial-mesenchymal transition pathway. Furthermore, there was a close association between actopaxin and CD29. HCC cells with stronger CD29 expression showed a higher actopaxin level, whereas actopaxin repression attenuated CD29 activity. Finally, actopaxin down-regulation enhanced the chemosensitivity of HCC cells towards oxaliplatin treatment by way of a collective result of suppression of survivin protein, ß-catenin, and mammalian target of rapamycin pathways and up-regulation of p53. CONCLUSION: This study provides concrete evidence of a significant role of actopaxin in HCC progression and metastasis, by way of regulation of cell invasiveness and motility, an epithelial-mesenchymal transition process, and chemosensitivity to cytotoxic drugs.


Assuntos
Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/fisiopatologia , Movimento Celular/fisiologia , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/fisiopatologia , Proteínas dos Microfilamentos/antagonistas & inibidores , Metástase Neoplásica/fisiopatologia , Animais , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Carcinoma Hepatocelular/mortalidade , Linhagem Celular Tumoral , Células Cultivadas , Modelos Animais de Doenças , Progressão da Doença , Transição Epitelial-Mesenquimal/fisiologia , Feminino , Xenoenxertos , Humanos , Técnicas In Vitro , Integrina beta1/fisiologia , Neoplasias Hepáticas/mortalidade , Masculino , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Proteínas dos Microfilamentos/efeitos dos fármacos , Proteínas dos Microfilamentos/fisiologia , Pessoa de Meia-Idade , Invasividade Neoplásica/patologia , Invasividade Neoplásica/fisiopatologia , Metástase Neoplásica/patologia , Compostos Organoplatínicos/farmacologia , Oxaliplatina , RNA Interferente Pequeno/farmacologia , Taxa de Sobrevida
15.
PLoS One ; 19(8): e0309417, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39197032

RESUMO

Quality improvement approaches are increasingly being used to address the problem of healthcare's climate and ecological impact. While sustainability is increasingly recognized as a domain of quality, consensus is lacking on the most appropriate measures and metrics for those looking to reduce ecological impacts through quality improvement initiatives. We propose a scoping review to summarize approaches for selecting and quantifying ecological impacts in the published quality improvement literature. We will search multiple electronic databases (MEDLINE, EMBASE, CINAHL, and Scopus) from 2000 onwards, to identify published quality improvement initiatives in the human healthcare setting intended to address ecological impact with at least one quantitative measure of ecological impact, such as kilograms of carbon dioxide equivalent greenhouse gas. Two independent reviewers working in parallel will screen studies for inclusion and abstract study data, including publication, study, and ecological impact characteristics. Charted data will be synthesized narratively as well as with descriptive tables, figures, and summary statistics. In doing so, we will map areas of relative focus as well as gaps in the measurement of ecological impact across quality improvement initiatives. This map can in turn be used to raise awareness of ecological impacts requiring broader consideration, encouraging holistic and clinically relevant approaches to measuring ecological impact in future quality improvement work.


Assuntos
Conservação dos Recursos Naturais , Atenção à Saúde , Melhoria de Qualidade , Humanos , Conservação dos Recursos Naturais/métodos , Atenção à Saúde/normas , Projetos de Pesquisa
17.
Clin Colorectal Cancer ; 22(4): 431-441.e9, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37648568

RESUMO

INTRODUCTION: The International Duration Evaluation of Adjuvant Therapy (IDEA) collaboration in 2017 established 3 months of adjuvant therapy as an alternative to 6 months of therapy for stage III colon cancer. We determined the association between the IDEA publication, changes in clinical practice, and prescriber variation. PATIENTS AND METHODS: Using linked databases, we identified Ontarians aged ≥18 years at diagnosis of stage III colon cancer between 2007 and 2019 who received oxaliplatin-containing adjuvant therapy. The outcome was duration of therapy, categorized as ≤25%, >25% to ≤50%, >50% to ≤75%, and >75% of a 6-month course of therapy to approximate treatment durations in the IDEA collaboration. We examined trends in duration over time using an interrupted time series regression model. We analyzed treatment duration after accounting for patient and prescriber characteristics, using multivariable mixed effects logistic regression models to quantify between-prescriber variation. RESULTS: We included 4695 patients with stage III colon cancer who received oxaliplatin-containing adjuvant chemotherapy, of whom 77.5% initiated treatment pre-IDEA and 22.5% initiated treatment post-IDEA. Post-IDEA, there was a 16.4% (95% CI, 12.5%-20.3%) absolute increase in the proportion of patients treated with ≤50% of a maximal course of therapy. This trend was greatest among patients with low-risk tumors. Prescriber variation increased pre-IDEA to 15.6% post-IDEA (variance partition coefficient 5.4% pre-IDEA and 15.6% post-IDEA). CONCLUSION: The publication of IDEA was associated with increases in short duration adjuvant therapy and prescriber-level practice variation for stage III colon cancer. Clinicians should be better supported to make consistent recommendations about adjuvant duration under conditions of uncertainty and trade-offs.


Assuntos
Neoplasias do Colo , Fluoruracila , Humanos , Adolescente , Adulto , Oxaliplatina , Estudos Retrospectivos , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Neoplasias do Colo/patologia , Quimioterapia Adjuvante/efeitos adversos , Estadiamento de Neoplasias
18.
Curr Oncol ; 30(7): 6508-6532, 2023 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-37504338

RESUMO

PURPOSE: Few studies have examined the relationship between duration of oxaliplatin-containing adjuvant chemotherapy for stage III colon cancer and mortality in routine practice. We examined the association between treatment with 50% versus >85% of a maximal course of adjuvant therapy (eight cycles of CAPOX, twelve cycles of FOLFOX) and mortality in stage III colon cancer. METHODS: Using linked databases, we identified Ontarians aged ≥18 years at diagnosis of stage III colon cancer between 2007 and 2019. In the primary comparison, we compared patients who received 50% or >85% of a maximal course of adjuvant therapy; in a secondary comparison, we evaluated a dose effect across patients who received FOLFOX in one-cycle increments from six to ten cycles against >85% (more than ten cycles) of a maximal course of FOLFOX. The main outcomes were overall and cancer-specific mortality. Follow-up began 270 days after adjuvant treatment initiation and terminated at the first of the outcome of interest, loss of eligibility for Ontario's Health Insurance Program, or study end. Overlap propensity score weights accounted for baseline between-group differences. We determined the hazard ratio, estimating the association between mortality and treatment. Non-inferiority was concluded in the primary comparison for either outcome if the upper limit of the two-sided 95% CI was ≤1.11, which is the margin used in the International Duration Evaluation of Adjuvant Chemotherapy Collaboration. RESULTS: We included 3546 patients in the analysis of overall mortality; 486 (13.7%) received 50% and 3060 (86.3%) received >85% of a maximal course of therapy. Median follow-up was 5.4 years, and total follow-up was 20,510 person-years. There were 833 deaths. Treatment with 50% of a maximal course of adjuvant therapy was associated with a hazard ratio of 1.13 (95% CI 0.88 to 1.47) for overall mortality and a subdistribution hazard ratio of 1.31 (95% CI 0.91 to 1.87) for cancer-specific mortality versus >85% of a maximal course of therapy. In the secondary comparison, there was a trend toward higher overall mortality in patients treated with shorter durations of therapy, though confidence intervals overlapped considerably. CONCLUSION: We could not conclude that treatment with 50% of a maximal course is non-inferior to >85% of a maximal course of adjuvant therapy for mortality in stage III colon cancer. Clinicians and patients engaging in decision-making around treatment duration in this context should carefully consider the trade-off between treatment effectiveness and adverse effects of treatment.


Assuntos
Neoplasias do Colo , Fluoruracila , Humanos , Adolescente , Adulto , Oxaliplatina/uso terapêutico , Fluoruracila/uso terapêutico , Capecitabina , Estudos Retrospectivos , Intervalo Livre de Doença , Protocolos de Quimioterapia Combinada Antineoplásica , Leucovorina/uso terapêutico , Estadiamento de Neoplasias , Compostos Organoplatínicos/uso terapêutico , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/patologia , Quimioterapia Adjuvante
19.
BMJ Open Gastroenterol ; 10(1)2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37277204

RESUMO

BACKGROUND AND AIMS: Non-pharmacological interventions to improve patient-reported outcomes of colonoscopy may be effective at mitigating negative experiences and perceptions of the procedure, but research to characterise the extent and features of studies of these interventions is limited. METHODS: We conducted a scoping review searching multiple databases for peer-reviewed publications of randomised controlled trials conducted in adults investigating a non-pharmacological intervention to improve patient-reported outcomes of colonoscopy. Study characteristics were tabulated and summarised narratively and graphically. RESULTS: We screened 5939 citations and 962 full texts, and included 245 publications from 39 countries published between 1992 and 2022. Of these, 80.8% were full publications and 19.2% were abstracts. Of the 41.9% of studies reporting funding sources, 11.4% were unfunded. The most common interventions were carbon dioxide and/or water insufflation methods (33.9%), complementary and alternative medicines (eg, acupuncture) (20.0%), and colonoscope technology (eg, magnetic scope guide) (21.6%). Pain was as an outcome across 82.0% of studies. Studies most often used a patient-reported outcome examining patient experience during the procedure (60.0%), but 42.9% of studies included an outcome without specifying the time that the patient experienced the outcome. Most intraprocedural patient-reported outcomes were measured retrospectively rather than contemporaneously, although studies varied in terms of when outcomes were assessed. CONCLUSION: Research on non-pharmacological interventions to improve patient-reported outcomes of colonoscopy is unevenly distributed across types of intervention and features high variation in study design and reporting, in particular around outcomes. Future research efforts into non-pharmacological interventions to improve patient-reported outcomes of colonoscopy should be directed at underinvestigated interventions and developing consensus-based guidelines for study design, with particular attention to how and when outcomes are experienced and measured. PROSPERO REGISTRATION NUMBER: 42020173906.


Assuntos
Colonoscopia , Adulto , Humanos , Estudos Retrospectivos , Ensaios Clínicos Controlados Aleatórios como Assunto
20.
Mol Carcinog ; 51(5): 422-32, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-21678496

RESUMO

The role of X chromosome-linked inhibitor of apoptosis protein (XIAP)-associated factor 1 (XAF1) in mediating apoptosis has been reported but the underlying mechanism remains unclear. The present study was designed to examine the putative interaction between XAF1 and p53 and the functional importance of this interaction in regulation of apoptosis in human gastric and colon cancer cells. We first identified XAF1 as a novel target gene of p53 by the chromatin immunoprecipitation (CHIP) assay and demonstrated that wild-type p53, but not mutant p53, down-regulated XAF1 at both mRNA and protein levels, which acted mostly under the condition of high expression of XAF1 and was associated with the physical interaction between p53 and the XAF1 promoter. We also found that the over-expression of XAF1 led to activation of wild-type p53 via post-translational modification in cells with or without DNA damage, which resulting in p53 nuclear accumulation and its increased transcriptional activity and enhancing p53-dependent apoptosis. These findings suggest that a potential novel feedback loop exists between XAF1 and wild-type p53.


Assuntos
Apoptose/genética , Neoplasias do Colo/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas de Neoplasias/metabolismo , Neoplasias Gástricas/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Proteínas Adaptadoras de Transdução de Sinal , Proteínas Reguladoras de Apoptose , Linhagem Celular Tumoral , Neoplasias do Colo/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Proteínas de Neoplasias/genética , Regiões Promotoras Genéticas , Processamento de Proteína Pós-Traducional/genética , Neoplasias Gástricas/genética , Proteína Supressora de Tumor p53/genética
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