RESUMO
This study describes the effects of extracts and fractions of Persea willdenovii leaves against goat gastrointestinal nematodes and their cytotoxicity on Vero cells. The in vitro ovicidal and larvicidal activities of the crude ethanolic, hexane, ethyl acetate (EAE), butanolic and residual hydroethanolic extracts were assessed through the inhibition of egg hatching and larval motility assays. The most active extract (EAE) was then fractionated by chromatography in an open column containing silica gel, to furnish six fractions (Fr1-Fr6), which were also tested. The cytotoxicity of active extracts and fractions was determined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and trypan blue exclusion assay. The EAE and two fractions (Fr1 and Fr2) showed inhibitory activity in the egg hatching of gastrointestinal nematodes of goats in a concentration-dependent manner. The effective concentrations for 50% inhibition (EC50) of egg hatching were 2.3, 0.12 and 2.94 mg/ml for EAE, Fr1 and Fr2, respectively. All extracts and fractions were not effective in inhibiting 50% of motility of infective larvae. EAE and Fr2 had IC50 values (50% inhibitory concentration) of 4.95 and 2.66 mg/ml, respectively. Fr1 showed a slight cytotoxic effect (cellular inviability <30%) only after 48 h of treatment (MTT test). Gas chromatography-mass spectrometry (GC-MS) analysis showed the presence of six fatty acid ethyl esters, a fatty acid methyl ester and a long-chain ketone in the most active fraction. These constituents identified in P. willdenovii can be related to the high ovicidal activity and relatively non-toxic effect of the extracts.
Assuntos
Anti-Helmínticos/farmacologia , Anti-Helmínticos/toxicidade , Nematoides/efeitos dos fármacos , Persea/química , Extratos Vegetais/farmacologia , Extratos Vegetais/toxicidade , Animais , Anti-Helmínticos/química , Anti-Helmínticos/isolamento & purificação , Bioensaio , Sobrevivência Celular/efeitos dos fármacos , Chlorocebus aethiops , Cromatografia Gasosa-Espectrometria de Massas , Cabras , Concentração Inibidora 50 , Larva/efeitos dos fármacos , Larva/fisiologia , Locomoção/efeitos dos fármacos , Nematoides/fisiologia , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Folhas de Planta/química , Células VeroRESUMO
BACKGROUND: Prostate-specific antigen (PSA) screening for prostate cancer results in a large number of unnecessary prostate biopsies. There is a need for specific molecular markers that can be used in combination with PSA to improve the specificity of PSA screening. We examined GADD45a methylation in blood DNA as a molecular marker for prostate cancer diagnosis. METHODS: The study included 82 men, with PSA levels >4 ng ml(-1) and/or abnormal digital rectal exam, who underwent prostate biopsy. We compared GADD45a methylation in DNA from serum and buffy coat in 44 patients (22 prostate cancer and 22 benign). GADD45a methylation in serum DNA was examined in 82 patients (34 cancer and 48 benign). RESULTS: There was no significant difference in buffy coat GADD45a methylation between cancer and benign patients. Serum GADD45a methylation was significantly higher in cancer than in benign patients. Classification and regression tree predictive model for prostate cancer including risk groups defined by PSA, free circulating DNA (fcDNA) level and GADD45a methylation yielded specificity of 87.5%, sensitivity of 94.1% and receiver operator characteristic curve area of 0.937. CONCLUSIONS: Serum GADD45a methylation in combination with PSA and fcDNA level was useful in distinguishing benign from prostate cancer patients.
Assuntos
Biomarcadores Tumorais , Proteínas de Ciclo Celular/sangue , Metilação de DNA , Proteínas Nucleares/sangue , Hiperplasia Prostática/diagnóstico , Neoplasias da Próstata/diagnóstico , Biomarcadores Tumorais/sangue , Biomarcadores Tumorais/genética , Proteínas de Ciclo Celular/genética , DNA/sangue , Diagnóstico Diferencial , Humanos , Masculino , Proteínas Nucleares/genética , Valor Preditivo dos Testes , Antígeno Prostático Específico/sangue , Hiperplasia Prostática/sangue , Hiperplasia Prostática/genética , Neoplasias da Próstata/sangue , Neoplasias da Próstata/genética , Sensibilidade e EspecificidadeRESUMO
The antioxidant activity of Tetragonisca angustula honey (TAH) and its ethanolic extract (TAEE) were investigated. The total levels of phenolic (TPC) and flavonoids (TFC) were also evaluated. The results for TPC were 19.91 ± 0.38 and 29.37 ± 1.82 mg GAE g-1 and for TFC 0.20 ± 0.02 and 0.14 ± 0.01 mg QE g-1 of TAH and TAEE, respectively. Antioxidant activities were 73.29 ± 0.49% and 93.36 ± 0.27% in the DPPHâ assay and 71.73 ± 4.07% and 97.86 ± 0.35% in ABTSâ+ for TAH and TAEE, respectively. The total reducing activity was determined by the method of reducing power (PR) and iron ion (Fe III) and the results varied in PR from 151.7 ± 25.7 and 230.7 ± 25.2 mg GAE L-1, for TAH and TAEE respectively and for (Fe III) in EC50 0.284 in TAEE and 0.687 in TAH. Chemical analysis by HPLC-DAD of the ethanolic extract (TAEE) revealed the presence of ferulic acid as majority phenolic component in the extract. The 1H NMR analysis confirmed this structure and showed the also presence of glucose, citric acid, succinic acid, proline and hydrocarbon derivatives. In addition, the botanical origin was also investigated and showed a multifloral characteristic, having found 19 pollen types with a botanical predominance of the Anacardiaceae family, with Tapirira pollen occurring as predominant (42.6%) and Schinus as secondary (25.7%). The results showed that T. angustula honey is an interesting source of antioxidant phenolic compounds due to its floral origin and can act as a protector of human health when consumed.
Assuntos
Antioxidantes , Mel , Animais , Brasil , Ácidos Cumáricos , Mel/análise , Humanos , Fenóis/análiseRESUMO
We assessed differences in locoregional outcome based on receptor status combinations in a cohort of stage II-III breast cancer patients treated with modern trimodality therapy. Medical records of 582 consecutively treated patients receiving post-mastectomy radiation (PMRT) between 1/1999 and 12/2009 were reviewed. Rate of local regional recurrence (LRR) was estimated by the method of cumulative incidence allowing for competing risks. The effect of prognostic factors was examined by Gray's test and by Fine and Gray's modeling approach. Median follow-up was 44.7 months. Five-year progression-free survival (PFS) was 73.9% and overall survival (OS) was 84%. The cumulative 5-year incidence of LRR as first site of failure was 6.2% (95% CI 4.2-8.7). Five-year cumulative incidence of LRR was 8.6 versus 4.4% for estrogen receptor (ER) negative versus ER positive (P = 0.017), 8.5 versus 3.4% for progesterone receptor (PR) negative versus PR positive (P = 0.011), and 1.7 versus 7.5% for HER2 positive (86% received trastuzamab) versus HER2 negative (P = 0.032). Five-year cumulative incidence of LRR was 11.8% for the triple negative subtype and 3.9% for other receptor combinations (P < 0.001). Among patients whose disease is ER positive, 5-year LRR rate was 7.8 versus 3.4% for PR negative versus PR positive (P = 0.130). The prognostic value of the triple negative and HER2 negative subtypes was maintained on multivariate analysis. In the era of HER-2 targeted therapy, tumors that are HER-2 over expressing and are treated with trastuzumab have a very low rate of LRR. ER negative, PR negative, and triple negative status are associated with increased risk of LRR.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias da Mama/patologia , Neoplasias da Mama/terapia , Mastectomia , Recidiva Local de Neoplasia , Radioterapia , Risco , Adulto , Idoso , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/mortalidade , Terapia Combinada , Feminino , Humanos , Pessoa de Meia-Idade , Prognóstico , Receptor ErbB-2/metabolismo , Receptores de Estrogênio/metabolismo , Receptores de Progesterona/metabolismo , Resultado do TratamentoRESUMO
Abstract The antioxidant activity of Tetragonisca angustula honey (TAH) and its ethanolic extract (TAEE) were investigated. The total levels of phenolic (TPC) and flavonoids (TFC) were also evaluated. The results for TPC were 19.91 ± 0.38 and 29.37 ± 1.82 mg GAE g-1 and for TFC 0.20 ± 0.02 and 0.14 ± 0.01 mg QE g-1 of TAH and TAEE, respectively. Antioxidant activities were 73.29 ± 0.49% and 93.36 ± 0.27% in the DPPH assay and 71.73 ± 4.07% and 97.86 ± 0.35% in ABTS+ for TAH and TAEE, respectively. The total reducing activity was determined by the method of reducing power (PR) and iron ion (Fe III) and the results varied in PR from 151.7 ± 25.7 and 230.7 ± 25.2 mg GAE L-1, for TAH and TAEE respectively and for (Fe III) in EC50 0.284 in TAEE and 0.687 in TAH. Chemical analysis by HPLC-DAD of the ethanolic extract (TAEE) revealed the presence of ferulic acid as majority phenolic component in the extract. The 1H NMR analysis confirmed this structure and showed the also presence of glucose, citric acid, succinic acid, proline and hydrocarbon derivatives. In addition, the botanical origin was also investigated and showed a multifloral characteristic, having found 19 pollen types with a botanical predominance of the Anacardiaceae family, with Tapirira pollen occurring as predominant (42.6%) and Schinus as secondary (25.7%). The results showed that T. angustula honey is an interesting source of antioxidant phenolic compounds due to its floral origin and can act as a protector of human health when consumed.
Resumo A atividade antioxidante do mel de Tetragonisca angustula (TAH) e seu extrato etanólico (TAEE) foram investigados. Os níveis totais de fenólicos (TPC) e flavonóides (TFC) também foram avaliados. Os resultados para TPC foram 19,91 ± 0,38 e 29,37 ± 1,82 mg GAE g-1 e para TFC 0,20 ± 0,02 e 0,14 ± 0,01 mg QE g-1 de TAH e TAEE, respectivamente. As atividades antioxidantes foram 73,29 ± 0,49% e 93,36 ± 0,27% no ensaio DPPH e 71,73 ± 4,07% e 97,86 ± 0,35% no ABTS+ para TAH e TAEE, respectivamente. A atividade redutora total foi determinada pelo método de poder redutor (PR) e íon ferrico (Fe III) e os resultados variaram em PR de 151,7 ± 25,7 e 230,7 ± 25,2 mg GAE L-1, para TAH e TAEE respectivamente e para (Fe III) em EC50 0,284 em TAEE e 0,687 em TAH. A análise química por HPLC-DAD do extrato etanólico (TAEE) revelou a presença de ácido ferúlico como componente majoritário no extrato. A análise de RMN 1H confirmou esta estrutura e mostrou a presença de glicose, ácido cítrico, ácido succínico, prolina e derivados de hidrocarbonetos no TAEE. Além disso, a origem botânica também foi investigada e apresentou característica multifloral, tendo encontrado 19 tipos polínicos com predomínio botânico da família Anacardiaceae, sendo o pólen Tapirira predominante (42,6%) e o Schinus secundário (25,7%). Os resultados mostraram que o mel de T. angustula é uma interessante fonte de compostos fenólicos antioxidantes devido à sua origem floral e pode atuar como protetor da saúde humana quando consumido.
RESUMO
Abstract The antioxidant activity of Tetragonisca angustula honey (TAH) and its ethanolic extract (TAEE) were investigated. The total levels of phenolic (TPC) and flavonoids (TFC) were also evaluated. The results for TPC were 19.91 ± 0.38 and 29.37 ± 1.82 mg GAE g-1 and for TFC 0.20 ± 0.02 and 0.14 ± 0.01 mg QE g-1 of TAH and TAEE, respectively. Antioxidant activities were 73.29 ± 0.49% and 93.36 ± 0.27% in the DPPH● assay and 71.73 ± 4.07% and 97.86 ± 0.35% in ABTS●+ for TAH and TAEE, respectively. The total reducing activity was determined by the method of reducing power (PR) and iron ion (Fe III) and the results varied in PR from 151.7 ± 25.7 and 230.7 ± 25.2 mg GAE L-1, for TAH and TAEE respectively and for (Fe III) in EC50 0.284 in TAEE and 0.687 in TAH. Chemical analysis by HPLC-DAD of the ethanolic extract (TAEE) revealed the presence of ferulic acid as majority phenolic component in the extract. The 1H NMR analysis confirmed this structure and showed the also presence of glucose, citric acid, succinic acid, proline and hydrocarbon derivatives. In addition, the botanical origin was also investigated and showed a multifloral characteristic, having found 19 pollen types with a botanical predominance of the Anacardiaceae family, with Tapirira pollen occurring as predominant (42.6%) and Schinus as secondary (25.7%). The results showed that T. angustula honey is an interesting source of antioxidant phenolic compounds due to its floral origin and can act as a protector of human health when consumed.
Resumo A atividade antioxidante do mel de Tetragonisca angustula (TAH) e seu extrato etanólico (TAEE) foram investigados. Os níveis totais de fenólicos (TPC) e flavonóides (TFC) também foram avaliados. Os resultados para TPC foram 19,91 ± 0,38 e 29,37 ± 1,82 mg GAE g-1 e para TFC 0,20 ± 0,02 e 0,14 ± 0,01 mg QE g-1 de TAH e TAEE, respectivamente. As atividades antioxidantes foram 73,29 ± 0,49% e 93,36 ± 0,27% no ensaio DPPH● e 71,73 ± 4,07% e 97,86 ± 0,35% no ABTS●+ para TAH e TAEE, respectivamente. A atividade redutora total foi determinada pelo método de poder redutor (PR) e íon ferrico (Fe III) e os resultados variaram em PR de 151,7 ± 25,7 e 230,7 ± 25,2 mg GAE L-1, para TAH e TAEE respectivamente e para (Fe III) em EC50 0,284 em TAEE e 0,687 em TAH. A análise química por HPLC-DAD do extrato etanólico (TAEE) revelou a presença de ácido ferúlico como componente majoritário no extrato. A análise de RMN 1H confirmou esta estrutura e mostrou a presença de glicose, ácido cítrico, ácido succínico, prolina e derivados de hidrocarbonetos no TAEE. Além disso, a origem botânica também foi investigada e apresentou característica multifloral, tendo encontrado 19 tipos polínicos com predomínio botânico da família Anacardiaceae, sendo o pólen Tapirira predominante (42,6%) e o Schinus secundário (25,7%). Os resultados mostraram que o mel de T. angustula é uma interessante fonte de compostos fenólicos antioxidantes devido à sua origem floral e pode atuar como protetor da saúde humana quando consumido.
Assuntos
Humanos , Animais , Mel/análise , Antioxidantes , Fenóis/análise , Brasil , Ácidos CumáricosRESUMO
Little is known about the etiology of pancreatic cancer, which is an important cause of cancer mortality in developed countries. We hypothesize that exposure to cadmium is a cause of pancreatic cancer. Cadmium is a nonessential metal that is known to accumulate in the human pancreas. The major risk factors for pancreatic cancer (increasing age, cigarette smoking, residence in Louisiana, and occupations involving exposure to metalworking and pesticides) are all associated with increased exposure to cadmium. Our meta-analysis of cohorts with high exposure to cadmium is also consistent with an increased risk of pancreatic cancer (standardized mortality ratio = 166; 95% confidence interval, 98-280; P = 0.059). Cadmium can cause the transdifferentiation of pancreatic cells, increases in the synthesis of pancreatic DNA, and increases in oncogene activation. Thus, cadmium is a plausible pancreatic carcinogen. The cadmium hypothesis provides a coherent explanation for much of the descriptive epidemiology of pancreatic cancer and suggests new avenues for analytical research.
Assuntos
Cádmio/efeitos adversos , Oncogenes/genética , Neoplasias Pancreáticas/etiologia , Fatores Etários , DNA/metabolismo , Humanos , Louisiana/epidemiologia , Ocupações , Neoplasias Pancreáticas/epidemiologia , Neoplasias Pancreáticas/patologia , Medição de Risco , Fumar/efeitos adversosRESUMO
OBJECTIVE: To propose a method to assess patterns of intra-familiar distribution of undernutrition and apply it to different socioeconomic strata of the Brazilian population. DESIGN: A large nationally representative cross-sectional anthropometric survey undertaken in 1989 is the primary source of information. Undernutrition was defined as body mass index (adults) and weight-for-age (children) below the 5th percentile of a healthy and non-malnourished reference population. Log-linear models were used to assess patterns of intra-familiar distribution of nutritional status in four income strata. SUBJECTS: Two thousand, one hundred and seventy-four families composed by at least one child 6-36 month-old and his/her father and mother. SETTING: All regions in Brazil. RESULTS: Undernutrition was significantly associated among household members only for the 25% poorest families (P < 0.0001). In this group, the presence of undernutrition in the mother or the father increased 1.6-1.9 times the risk of undernutrition in the child and the presence of undernutrition in the father made it 2.7 times more frequent in the mother. The relatively small prevalence ratios suggest that even in extremely poor families only a small proportion of undernutrition could be attributed to common household determinants. CONCLUSION: Our results are consistent with the hypothesis that in transitional societies undernutrition would appear as a global family problem only for those at the earlier stages of the nutrition transition. Policies and strategies to overcome undernutrition should take this fact into account.
Assuntos
Deficiências Nutricionais/epidemiologia , Família , Pobreza , Adolescente , Adulto , Antropometria , Brasil/epidemiologia , Pré-Escolar , Estudos Transversais , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Inquéritos Nutricionais , Estado Nutricional , PrevalênciaRESUMO
OBJECTIVE: The purpose of this study was to determine whether there are aged-based variations in the association between clinically detected and radiographically detected caries and whether the prevalence of clinically undetected radiographic caries varies across adult age groups. STUDY DESIGN: The data for the analysis were from a clinical study that evaluated the efficacy of guidelines for prescribing dental radiographs. A total of 460 subjects had clinical examinations and interpretation made on full-mouth radiographs. Analysis was conducted to determine the tooth-specific and subject-specific prevalences of clinically undetected caries and to establish whether the association between clinical signs and radiographic signs varied by subject age. RESULTS: In total, approximately 5.8% of clinically sound teeth showed radiographic evidence of dentinal caries, and the prevalence increased with patient age. The prevalence of clinical signs of medium and large caries was 7.8% in 12,358 teeth in which caries was both clinically and radiographically present. However, for more than 80% of the teeth with clinically undetected caries, the lesions were evident on the interproximal radiographs. The associations between clinical and radiographic signs of dentinal caries were homogeneous across age groups. CONCLUSION: The findings demonstrate that adolescents and adults continue to have medium and large caries, although the location of the caries differs by age group, with higher proportions of gingival caries in older patients.
Assuntos
Cárie Dentária/diagnóstico , Cárie Dentária/epidemiologia , Adolescente , Adulto , Fatores Etários , Cárie Dentária/diagnóstico por imagem , Humanos , Pessoa de Meia-Idade , Razão de Chances , Prevalência , Radiografia InterproximalRESUMO
The principles and planning of a sample of consultations undertaken in the public health services belonging to or financed by INAMPS (Brazilian federal social welfare service), are gave. It was describe the epidemiological profile of the population assisted over a twelve-month period. The sampling technique of clustering in two stages, with probabilities proportional to size (PPS), was used. The health services are the Primary Sampling Unit (PSU) and the estimated number of consultations for each one, over the period, is the measure of its size (Mj). The Brazilian states were taken as strata named domains. The sample size of consultations of Health Services was defined by means of simulations studies. The overall sampling fraction was defined by f = n/N = a.Mj/epsilon Mj.b/Mj; where b = 250. The calculations, which include intervals for the systematic sampling of consultations (Ic) in the second stage of selection, defined by Ic = Mj/(epsilon Mj) : n/N; are also given.
Assuntos
Sistemas de Informação em Atendimento Ambulatorial , Necessidades e Demandas de Serviços de Saúde , Pesquisa sobre Serviços de Saúde , Sistemas de Informação , Brasil , Estudos de AmostragemRESUMO
The octopus Octopus cf. vulgaris is a potential species to diversify aquaculture. Due to absence of balanced commercial diet, growth of the O. cf. vulgaris is based on natural diet with local and low-cost inputs. In Brazil, studies on experimental octopus ongrowing are recent and there is little available data. We evaluated the performance, survival and food consumption of O. vulgaris fed on mussel Perna perna for 20 days. Six octopuses with initial weight of 415±12.73g (mean±standard deviation) were divided into two groups (n=3 octopuses/group) according to the diet: MC Group (frozen mussels) and MV Group (live mussels). The Weight Gain of octopuses was 273.33±94.52g and 340.00±26.46g; the Absolute Growth Rate was 13.67±4.73 and 17.00±1.32g.dia-1 and the Specific Growth Rate of 2.95±0.58 and 2.64±0.37%.day-1 to MC and MV groups, respectively. There was no significant difference in performance between groups and the survival rate was 100%. Octopuses well accepted both diets and despite the amount of frozen mussels (129±31) was higher than in live mussels (100±19), there was no significant difference regarding the consumption between groups. Our results demonstrate that the mussel Perna perna can be used frozen or live as monodiet in O. cf. vulgaris ongrowing.(AU)
Assuntos
Animais , Dieta/veterinária , Perna (Organismo) , Octopodiformes/crescimento & desenvolvimento , Aquicultura/métodosRESUMO
The inexistence of nutritionally adequate diets in paralarval rearing is the main bottleneck for commercial production of the common octopus Octopus cf. vulgaris. We report the feeding behavior of O. vulgaris Type II paralarvae fed on Artemia sp (0.1 individual. mL-1) nauplii enriched with microalgae Isocrysis galbana and Pavlova lutheri microalgae from 0 to 7 Day After Hatching (DAH).; metanauplii enriched with microalgae and DHA SELCO® lipid emulsion from the 8 DAH. The paralarvae showed active swimming and predation by the 14 DAH, feeding in the most superficial portion of the water column. From the 15 DAH, the paralarvae remained near the bottom and there a decrease in the consumption of artemia was observed. The mortality observed from the 18 DAH and mass mortality of paralarvae on 20 DAH can be attributed mainly to the nutritional composition of the diet. Studies analyzing the biochemical composition and ontogeny of the digestive system during the early life stages should shed some light on the running for an appropriate feeding protocol to the paralarval rearing.(AU)
Assuntos
Animais , Comportamento Alimentar , Octopodiformes/metabolismo , ArtemiaRESUMO
INTRODUCTION: We assessed racial differences in progression-free survival (PFS) and overall survival (OS) in relation to subtype in uniformly treated stage II-III breast cancer patients. METHODS: We reviewed records of 582 patients receiving post-mastectomy radiation (PMRT) between 1/1999 and 12/2009 and evaluated the effect of demographic, tumor, and treatment characteristics on PFS and OS. RESULTS: Median follow up was 44.7 months. 24% of patients were black and 76% white. All had mastectomy and PMRT; 98% had chemotherapy; Estrogen receptor (ER)+ patients received endocrine therapy. Black patients were more likely to have ER- (56% vs. 38%, p=0.0001), progesterone receptor (PR)- (69% vs. 54%, p = 0.002), and triple negative (TN) (46% vs. 24%, p < 0.0001) tumors. Overall, black patients had worse PFS (60.6% vs. 78.3%, p = 0.001) and OS (72.8% vs. 87.7%, p < 0.0001). There was no racial difference in PFS (p = 0.229 and 0.273 respectively) or OS (p = 0.113 and 0.097 respectively) among ER- or TN. Among ER+, black patients had worse PFS (55% vs. 81%, p < 0.001) and OS (73% vs. 91%, p < 0.0001). The difference in PFS was seen in the ER+/PR+/HER2- subgroup (p = 0.002) but not ER+/PR-/HER2- (p = 0.129), and in the post-menopausal ER+/HER2- subgroup (p = 0.004) but not pre/peri-menopausal ER+/HER2- (p = 0.150). CONCLUSIONS: Black women had worse survival outcomes in this cohort. This disparity was driven by (1) a higher proportion of ER- and TN tumors in black women and (2) worse outcome of similarly treated black women with ER+ breast cancer. The underlying causes of racial disparity within hormone receptor categories must be further examined.
Assuntos
Negro ou Afro-Americano/estatística & dados numéricos , Neoplasias da Mama/etnologia , Neoplasias da Mama/terapia , Neoplasias Hormônio-Dependentes/etiologia , Neoplasias Hormônio-Dependentes/terapia , População Branca/estatística & dados numéricos , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias da Mama/metabolismo , Quimioterapia Adjuvante , Estudos de Coortes , Terapia Combinada , Feminino , Seguimentos , Humanos , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Neoplasias Hormônio-Dependentes/metabolismo , Prognóstico , Radioterapia Adjuvante , Receptor ErbB-2/metabolismo , Receptores de Estrogênio/metabolismo , Receptores de Progesterona/metabolismo , Estados Unidos/epidemiologia , Adulto JovemRESUMO
This paper presents the results of a Monte Carlo study comparing the performance, in terms of size and power, of six exact and six asymptotic tests for the homogeneity of odds ratios in several 2 x 2 contingency tables. With a small sample size or sparse data structure, the exact tests performed better than the asymptotic tests because they maintained the nominal size and, in some situations, had slightly higher power. Among the exact tests, we recommend the Zelen, Pearson chi-square and scores tests. Among the asymptotic tests, the Breslow-Day and Pearson chi-square tests were slightly better in some situations than the unconditional and conditional score tests. However, both exact and asymptotic tests had low power for small strata sizes, even with moderate to large heterogeneity of odds ratios. Corroborating previous findings, the asymptotic unconditional likelihood ratio test was too liberal in terms of size.