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1.
Infect Dis Ther ; 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38771550

RESUMO

INTRODUCTION: Ropeginterferon alfa-2b is a novel mono-pegylated proline-interferon. This clinical study aimed to evaluate its antiviral efficacy of ropeginterferon alfa-2b against SARS-CoV-2 infection. METHODS: This is a multicenter, randomized, open-label study. Adult patients with confirmed SARS-CoV-2 infection with initial cycle threshold (Ct) value < 30 and symptom onset within 4 days were enrolled. Eligible patients were randomized in a 2:1 ratio to receive a single 250-µg dose of ropeginterferon alfa-2b subcutaneously plus standard of care (SOC) or to receive SOC alone. The primary endpoint was the proportion of patients with a negative RT-PCR result for SARS-CoV-2 or discharged from the hospital before Day 8. Change in clinical status based on the World Health Organization (WHO) clinical progression scale and pulmonary infiltrations through chest radiograph were also evaluated. RESULTS: A total of 132 patients were enrolled and treated with study medication. Higher percentages of patients who achieved Ct ≥ 30 or were discharged from the hospital were observed on Day 8 and every other time point of assessment, i.e., Days 5, 11, 15, and 22, in the ropeginterferon alfa-2b group compared to the SOC alone group. However, the difference was statistically significant on Day 11 but not on Day 8. The primary endpoint was not met. The ropeginterferon alfa-2b group showed a higher improvement rate in lung infiltration on Day 5 (27.6% vs. 0.0%, p = 0.0087) and a higher improvement rate in WHO clinical progression scores on Day 8 (69.4% vs. 35.3%, p = 0.03) than those in the SOC group. No ropeginterferon alfa-2b-related serious adverse event was observed. CONCLUSION: Our data show that ropeginterferon alfa-2b with SOC shortened the duration of SARS-CoV-2 shedding compared with SOC alone. In addition, ropeginterferon alfa-2b as an additional therapy could be beneficial by improving lung infiltration.

2.
Carcinogenesis ; 39(8): 1045-1055, 2018 07 30.
Artigo em Inglês | MEDLINE | ID: mdl-29846560

RESUMO

Estrogen plays an important role in breast cancer development. While the mechanism of the estrogen effects is not fully elucidated, one possible route is by increasing the stem cell-like properties in the tumors. Tocopherols are known to reduce breast cancer development and progression. The aim of the present study is to investigate the effects of tocopherols on the regulation of breast cancer stemness mediated by estrogen. To determine the effects of tocopherols on estrogen-influenced breast cancer stem cells, the MCF-7 tumorsphere culture system, which enriches for mammary progenitor cells and putative breast cancer stem cells, was utilized. Treatment with estrogen resulted in an increase in the CD44+/CD24- subpopulation and aldehyde dehydrogenase activity in tumorspheres as well as the number and size of tumorspheres. Tocopherols inhibited the estrogen-induced expansion of the breast cancer stem population. Tocopherols decreased the levels of stem cell markers, including octamer-binding transcription factor 4 (OCT4), CD44 and SOX-2, as well as estrogen-related markers, such as trefoil factor (TFF)/pS2, cathepsin D, progesterone receptor and SERPINA1, in estrogen-stimulated tumorspheres. Overexpression of OCT4 increased CD44 and sex-determining region Y-box-2 levels and significantly increased cell invasion and expression of the invasion markers, matrix metalloproteinases, tissue inhibitors of metalloproteinase and urokinase plasminogen activator, and tocopherols inhibited these OCT4-mediated effects. These results suggest a potential inhibitory mechanism of tocopherols in estrogen-induced stemness and cell invasion in breast cancer.


Assuntos
Neoplasias da Mama/tratamento farmacológico , Estrogênios/metabolismo , Células-Tronco Neoplásicas/efeitos dos fármacos , Fator 3 de Transcrição de Octâmero/metabolismo , Tocoferóis/farmacologia , Neoplasias da Mama/patologia , Movimento Celular/efeitos dos fármacos , Feminino , Humanos , Células MCF-7 , Invasividade Neoplásica/patologia , Invasividade Neoplásica/prevenção & controle , Células-Tronco Neoplásicas/metabolismo , Receptores de Estrogênio/metabolismo , Tocoferóis/uso terapêutico
3.
Stat Med ; 37(5): 687-709, 2018 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-29205435

RESUMO

Prospective randomized clinical trials addressing biomarkers are time consuming and costly, but are necessary for regulatory agencies to approve new therapies with predictive biomarkers. For this reason, recently, there have been many discussions and proposals of various trial designs and comparisons of their efficiency in the literature. We compare statistical efficiencies between the marker-stratified design and the marker-based precision medicine design regarding testing/estimating 4 hypotheses/parameters of clinical interest, namely, treatment effects in each marker-positive and marker-negative cohorts, marker-by-treatment interaction, and the marker's clinical utility. As may be expected, the stratified design is more efficient than the precision medicine design. However, it is perhaps surprising to find out how low the relative efficiency can be for the precision medicine design. We quantify the relative efficiency as a function of design factors including the marker-positive prevalence rate, marker assay and classification sensitivity and specificity, and the treatment randomization ratio. It is interesting to examine the trends of the relative efficiency with these design parameters in testing different hypotheses. We advocate to use the stratified design over the precision medicine design in clinical trials with predictive biomarkers.


Assuntos
Biomarcadores , Ensaios Clínicos como Assunto/métodos , Medicina de Precisão/métodos , Projetos de Pesquisa , Simulação por Computador , Humanos , Sensibilidade e Especificidade
4.
Cancer Prev Res (Phila) ; 10(12): 694-703, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28972008

RESUMO

Despite experimental evidence elucidating the antitumor activities of tocopherols, clinical trials with α-tocopherol (α-T) have failed to demonstrate its beneficial effects in cancer prevention. This study compared the chemopreventive efficacy of individual tocopherols (α-, δ-, and γ-T) and a γ-T-rich tocopherol mixture (γ-TmT) in the August-Copenhagen Irish (ACI) rat model of estrogen-mediated mammary cancer. Female ACI rats receiving 17ß-estradiol (E2) implants were administered with 0.2% α-T, δ-T, γ-T, or γ-TmT for 30 weeks. Although α-T had no significant effects on mammary tumor growth in ACI rats, δ-T, γ-T, and γ-TmT reduced mammary tumor volume by 51% (P < 0.05), 60% (P < 0.01), and 59% (P < 0.01), respectively. Immunohistochemical analysis revealed that δ-T, γ-T, and γ-TmT reduced levels of the cell proliferation marker, proliferating cell nuclear antigen, in the rat mammary tumors. To gain further insight into the biological functions of different forms of tocopherols, RNA-seq analysis of the tumors was performed. Treatment with γ-T induced robust gene expression changes in the mammary tumors of ACI rats. Ingenuity Pathway Analysis identified "Cancer" as a top disease pathway and "Tumor growth" and "Metastasis" as the top signaling pathways modulated by γ-T. Although the results need further functional validation, this study presents an unbiased attempt to understand the differences between biological activities of individual forms of tocopherols at the whole transcriptome level. In conclusion, δ-T and γ-T have superior cancer preventive properties compared to α-T in the prevention of estrogen-mediated mammary carcinogenesis. Cancer Prev Res; 10(12); 694-703. ©2017 AACR.


Assuntos
Estrogênios/metabolismo , Regulação Neoplásica da Expressão Gênica , Neoplasias Mamárias Experimentais/tratamento farmacológico , Tocoferóis/farmacologia , Animais , Anticarcinógenos/farmacologia , Antineoplásicos/farmacologia , Antioxidantes/metabolismo , Apoptose , Carcinogênese , Adesão Celular , Proliferação de Células , Transformação Celular Neoplásica/efeitos dos fármacos , Progressão da Doença , Matriz Extracelular/metabolismo , Feminino , Neoplasias Mamárias Animais/tratamento farmacológico , Neoplasias Mamárias Animais/metabolismo , Neoplasias Mamárias Experimentais/metabolismo , Metástase Neoplásica , Neovascularização Patológica , Ratos , Ratos Endogâmicos ACI , Transdução de Sinais , alfa-Tocoferol/farmacologia , gama-Tocoferol/farmacologia
5.
J Pediatr ; 184: 45-50.e1, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-28108102

RESUMO

OBJECTIVE: To assess the effects of a soybean lipid emulsion infusions on levels of unbound (free) bilirubin (Bf) and unbound free fatty acids (FFAu) as well as changes in Bf and total serum bilirubin (TSB) during phototherapy in infants born preterm. STUDY DESIGN: Ninety-seven infants born preterm (birth weight: 500-2000 g; gestational age: 23-34 weeks) were enrolled to investigate the effect of 0, 1, 2, and 3 g/kg/d of intralipid infusion on Bf and FFAu. Pre- and postphototherapy TSB, FFAu, and Bf also were analyzed in 91 infants to assess the effects of phototherapy. FFAu levels were measured with the fluorescent probe ADIFAB2 and Bf by the fluorescent Bf sensor BL22P1B11-Rh during intralipid infusion and at start and end of phototherapy. TSB and plasma albumin were measured by the diazo and bromcresol green techniques, respectively. Bilirubin-albumin dissociation constants were calculated based on Bf and plasma albumin. RESULTS: Bf and FFAu increased with increasing intralipid dosage across all gestational ages. TSB and Bf were correlated significantly when infants received 0 or 1 g/kg/d of intralipid but not at greater doses of intralipid (2 and 3 g/kg/d). Although phototherapy effectively reduced both TSB and Bf in the total phototherapy group (by 32% and 12%, respectively), it reduced TSB, but not Bf, in infants less than 28 weeks of gestation. CONCLUSIONS: Increasing intralipid doses result in increasing FFAu levels, which are associated with increased Bf independent of TSB. In infants born extremely preterm (<28 weeks of gestation), phototherapy effectively reduces TSB but not Bf.


Assuntos
Bilirrubina/sangue , Ácidos Graxos não Esterificados/sangue , Fosfolipídeos/farmacologia , Fototerapia , Óleo de Soja/farmacologia , Emulsões/administração & dosagem , Emulsões/farmacologia , Feminino , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Infusões Intravenosas , Masculino , Fosfolipídeos/administração & dosagem , Óleo de Soja/administração & dosagem
6.
Stat Med ; 35(17): 2880-6, 2016 07 30.
Artigo em Inglês | MEDLINE | ID: mdl-27374355

RESUMO

This communication comments on the three papers by the FDA CDER research team on the regulatory perspective of the missing data problem. The focus is on two topics: causal estimand and sensitivity analysis. Copyright © 2016 John Wiley & Sons, Ltd.


Assuntos
Interpretação Estatística de Dados , Projetos de Pesquisa , Humanos , Pesquisa , Estatística como Assunto , Estados Unidos , United States Food and Drug Administration
7.
Contemp Clin Trials ; 47: 40-8, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26674739

RESUMO

Sample size plays a crucial role in clinical trials. Flexible sample-size designs, as part of the more general category of adaptive designs that utilize interim data, have been a popular topic in recent years. In this paper, we give a comparative review of four related methods for such a design. The likelihood method uses the likelihood ratio test with an adjusted critical value. The weighted method adjusts the test statistic with given weights rather than the critical value. The dual test method requires both the likelihood ratio statistic and the weighted statistic to be greater than the unadjusted critical value. The promising zone approach uses the likelihood ratio statistic with the unadjusted value and other constraints. All four methods preserve the type-I error rate. In this paper we explore their properties and compare their relationships and merits. We show that the sample size rules for the dual test are in conflict with the rules of the promising zone approach. We delineate what is necessary to specify in the study protocol to ensure the validity of the statistical procedure and what can be kept implicit in the protocol so that more flexibility can be attained for confirmatory phase III trials in meeting regulatory requirements. We also prove that under mild conditions, the likelihood ratio test still preserves the type-I error rate when the actual sample size is larger than the re-calculated one.


Assuntos
Ensaios Clínicos como Assunto , Tamanho da Amostra , Estatística como Assunto , Humanos , Funções Verossimilhança , Projetos de Pesquisa
8.
Cancer Prev Res (Phila) ; 8(9): 807-16, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26130252

RESUMO

This study evaluated the anticancer activity and mechanism of action of a γ-tocopherol-rich tocopherol mixture, γ-TmT, in two different animal models of estrogen-induced breast cancer. The chemopreventive effect of γ-TmT at early (6 weeks), intermediate (18 weeks), and late (31 weeks) stages of mammary tumorigenesis was determined using the August-Copenhagen Irish rat model. Female rats receiving 17ß-estradiol (E2) implants were administered with different doses (0%, 0.05%, 0.1%, 0.3%, and 0.5%) of γ-TmT diet. Treatment with 0.3% and 0.5% γ-TmT decreased tumor volume and multiplicity. At 31 weeks, serum concentrations of E2 were significantly decreased by γ-TmT. γ-TmT preferentially induced expression of the E2-metabolizing enzyme CYP1A1, over CYP1B1 in the rat mammary tissues. Nrf2-dependent antioxidant response was stimulated by γ-TmT, as evident from enhanced expression of its downstream targets, NQO1, GCLM, and HMOX1. Serum concentrations of the oxidative stress marker, 8-isoprostane, were also decreased in the γ-TmT-treated groups. Treatment with γ-TmT increased expression of PPARγ and its downstream genes, PTEN and p27, whereas the cell proliferation marker, PCNA, was significantly reduced in γ-TmT-treated mammary tumors. In an orthotopic model in which human MCF-7 breast cancer cells were injected into the mammary fat pad of immunodeficient mice, γ-TmT inhibited E2-dependent tumor growth at all the doses tested. In conclusion, γ-TmT reduced mammary tumor development, in part through decreased E2 availability and reduced oxidative stress in mammary tissues; γ-TmT could thus be an effective agent for the prevention and treatment of E2-induced breast cancer.


Assuntos
Antioxidantes/metabolismo , Inibidor de Quinase Dependente de Ciclina p27/metabolismo , Estrogênios/metabolismo , PPAR gama/metabolismo , PTEN Fosfo-Hidrolase/metabolismo , Antígeno Nuclear de Célula em Proliferação/metabolismo , gama-Tocoferol/uso terapêutico , Animais , Linhagem Celular Tumoral , Dinoprosta/análogos & derivados , Dinoprosta/química , Estradiol/administração & dosagem , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Técnicas Imunoenzimáticas , Imuno-Histoquímica , Células MCF-7 , Glândulas Mamárias Animais/metabolismo , Neoplasias Mamárias Animais/prevenção & controle , Neoplasias Mamárias Experimentais/prevenção & controle , Camundongos , Camundongos Nus , Transplante de Neoplasias , Estresse Oxidativo , RNA Mensageiro/metabolismo , Ratos , Fatores de Tempo
9.
Int J Oncol ; 44(6): 2139-45, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24647860

RESUMO

Because K-Ras mutation and cyclooxygenase-2 (COX-2) overexpression are hallmarks of majority of pancreatic cancer patients, an approach to inhibit the progression and growth of pancreatic cancer using the simultaneous administration of agents that inhibit the function of both targets, should be considered. In the present study, we assessed the effects of atorvastatin (Lipitor), celecoxib (Celebrex) and tipifarnib (Zarnestra) on the growth of human pancreatic cancer. In the in vitro studies, we found that treatment of human pancreatic tumor cells with a combination of atorvastatin, celecoxib and tipifarnib had a stronger inhibitory effect on growth and a stronger stimulatory effect on apoptosis than each drug alone or for any combination of two drugs. We also found that treatment of Panc-1 cells with a combination of all three drugs strongly decreased the levels of phosphorylated Erk1/2 and Akt. In an animal model of xenograft tumors in severe combined immunodeficient (SCID) mice, we found that daily i.p. injections of a combination of atorvastatin, celecoxib and tipifarnib had a stronger inhibitory effect on the growth of the tumors in mice than each drug alone or for any combination of two drugs. The results of our study indicate that a combination of atorvastatin, celecoxib and tipifarnib may be an effective strategy for the treatment of pancreatic cancer.


Assuntos
Antineoplásicos/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Ácidos Heptanoicos/administração & dosagem , Neoplasias Pancreáticas/tratamento farmacológico , Pirazóis/administração & dosagem , Pirróis/administração & dosagem , Quinolonas/administração & dosagem , Sulfonamidas/administração & dosagem , Animais , Antineoplásicos/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Apoptose/efeitos dos fármacos , Atorvastatina , Celecoxib , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Feminino , Ácidos Heptanoicos/uso terapêutico , Humanos , Injeções Intraperitoneais , Camundongos , Camundongos SCID , Neoplasias Experimentais , Neoplasias Pancreáticas/patologia , Pirazóis/uso terapêutico , Pirróis/uso terapêutico , Quinolonas/uso terapêutico , Sulfonamidas/uso terapêutico , Ensaios Antitumorais Modelo de Xenoenxerto
10.
Biostatistics ; 15(3): 540-54, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24511081

RESUMO

When there is evidence of long-term survivors, cure models are often used to model the survival curve. A cure model is a mixture model consisting of a cured fraction and an uncured fraction. Traditional cure models assume that the cured or uncured status in the censored set cannot be distinguished. But in many practices, some diagnostic procedures may provide partial information about the cured or uncured status relative to certain sensitivity and specificity. The traditional cure model does not take advantage of this additional information. Motivated by a clinical study on bone injury in pediatric patients, we propose a novel extension of a traditional Cox proportional hazards (PH) cure model that incorporates the additional information about the cured status. This extension can be applied when the latency part of the cure model is modeled by the Cox PH model. Extensive simulations demonstrated that the proposed extension provides more efficient and less biased estimations, and the higher efficiency and smaller bias is associated with higher sensitivity and specificity of diagnostic procedures. When the proposed extended Cox PH cure model was applied to the motivating example, there was a substantial improvement in the estimation.


Assuntos
Modelos de Riscos Proporcionais , Sensibilidade e Especificidade , Criança , Humanos , Fraturas da Tíbia/epidemiologia , Fraturas da Tíbia/terapia
11.
Stat Med ; 33(13): 2191-205, 2014 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-24515845

RESUMO

We can apply both fixed and random effects models to multi-regional clinical trial (MRCT) design and data analysis. Thoroughly, understanding the features of these models in an MRCT setting will help assessing their applicability to an MRCT. In this paper, we discuss the interpretations of trial results from these models. We also evaluate the impact of the number of regions and the sample size configuration across the regions on the required total sample size for the overall treatment effect assessment. For quantifying treatment effects of individual regions, the empirical shrinkage estimator and the James-Stein type shrinkage estimator associate with smaller variability compared with the regular sample estimator. We conduct computation and simulation to compare the performance of these estimators when they are applied to assess consistency of treatment effects across regions. We use a multinational trial example to illustrate the application of these methods.


Assuntos
Ensaios Clínicos como Assunto/métodos , Modelos Estatísticos , Avaliação de Resultados em Cuidados de Saúde , Projetos de Pesquisa , Interpretação Estatística de Dados , Avaliação de Resultados em Cuidados de Saúde/estatística & dados numéricos , Tamanho da Amostra
12.
Nutr Cancer ; 65(7): 1002-13, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24070239

RESUMO

Ultraviolet B (UVB)-pretreated SKH-1 mice were treated with water, caffeine (0.1 mg/ml), voluntary running wheel exercise (RW) or caffeine together with RW for 14 wk. Treatment of the mice with caffeine, RW, or caffeine plus RW decreased skin tumors per mouse by 27%, 35%, and 62%, respectively, and the tumor volume per mouse was decreased by 61%, 70%, and 85%, respectively. In mechanistic studies, mice were treated with water, caffeine, RW, or caffeine plus RW for 2 wk prior to a single irradiation with UVB. Caffeine plus RW increased RW activity by 22% when compared with RW alone. Caffeine ingestion was not significantly different between groups. Treatment of mice with caffeine plus RW for 2 wk decreased the weight of the parametrial fat pads and stimulated the formation of UVB-induced apoptosis to a greater extent than treatment with caffeine or RW alone. An antibody array revealed that caffeine plus RW administered to mice fed a high-fat diet and irradiated with UVB decreased the epidermal levels of lipopolysaccharide-induced CXC chemokine, soluble TNF alpha receptor-1, and macrophage inflammatory protein-1γ. Overall, caffeine during RW exerts a stronger effect than either treatment alone for decreasing tissue fat, increasing UVB-induced apoptosis, lowering the levels of cytokines associated with inflammation and for inhibiting UVB-induced carcinogenesis.


Assuntos
Cafeína/administração & dosagem , Carcinogênese/efeitos dos fármacos , Inflamação/tratamento farmacológico , Condicionamento Físico Animal , Neoplasias Cutâneas/tratamento farmacológico , Neoplasias Cutâneas/prevenção & controle , Raios Ultravioleta/efeitos adversos , Tecido Adiposo/efeitos dos fármacos , Tecido Adiposo/metabolismo , Administração Oral , Animais , Apoptose/efeitos dos fármacos , Apoptose/efeitos da radiação , Quimiocinas CC/metabolismo , Citocinas/metabolismo , Dieta Hiperlipídica , Feminino , Lipopolissacarídeos/efeitos adversos , Camundongos , Camundongos Knockout , Neoplasias Cutâneas/etiologia , Fator de Necrose Tumoral alfa/metabolismo
13.
Cancer Prev Res (Phila) ; 6(9): 959-70, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23856074

RESUMO

HER2 (or ErbB2), a member of ErbB receptor tyrosine kinases, is overexpressed in approximately 20% of human breast cancer, and the ErbB2 signaling pathway is a critical therapeutic target for ErbB2-overexpressing breast cancer. We investigated the inhibitory effects of the Gemini vitamin D analog BXL0124, the synthetic triterpenoid CDDO-Im and the combination on the tumorigenesis of ErbB2-overexpressing breast cancer. MMTV-ErbB2/neu transgenic mice were treated with BXL0124, CDDO-Im, or the combination from three months of age until the end of the experiment. Formation and growth of MMTV-ErbB2/neu mammary tumors were monitored every week, and all three treatments delayed the development of mammary tumors without significant toxicity. Decreased activation of ErbB2 as well as other ErbB receptors, ErbB1 and ErbB3, in MMTV-ErbB2/neu mammary tumors was shown by all treatments. Protein levels of downstream targets of the ErbB2 signaling pathway, including activated-Erk1/2, activated-Akt, c-Myc, CycD1, and Bcl2, were repressed by all three treatments, with the combination treatment exhibiting the strongest effects. To investigate therapeutic efficacy, the combination of BXL0124 and CDDO-Im was given to MMTV-ErbB2/neu mice after mammary tumors were established between 23 and 30 weeks of age. Short-term treatment with the combination did not show effects on tumor growth nor the ErbB2 signaling pathway. The present study shows BXL0124, CDDO-Im, and the combination as potential agents for prevention, but not treatment, against the tumorigenesis of ErbB2-overexpressing breast cancer.


Assuntos
Calcitriol/análogos & derivados , Transformação Celular Neoplásica/efeitos dos fármacos , Imidazóis/administração & dosagem , Neoplasias Mamárias Animais/prevenção & controle , Ácido Oleanólico/análogos & derivados , Receptor ErbB-2/fisiologia , Transdução de Sinais/efeitos dos fármacos , Administração Oral , Animais , Protocolos de Quimioterapia Combinada Antineoplásica , Western Blotting , Calcitriol/administração & dosagem , Calcitriol/farmacologia , Transformação Celular Neoplásica/patologia , Feminino , Humanos , Imidazóis/farmacologia , Neoplasias Mamárias Animais/metabolismo , Neoplasias Mamárias Animais/patologia , Vírus do Tumor Mamário do Camundongo/genética , Camundongos , Camundongos Transgênicos , Microscopia de Fluorescência , Ácido Oleanólico/administração & dosagem , Ácido Oleanólico/farmacologia , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa
14.
Carcinogenesis ; 34(9): 2184-91, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23671133

RESUMO

Each enantiomer of the diastereomeric pair of bay-region dibenz[a,h]anthracene 3,4-diol-1,2-epoxides in which the benzylic 4-hydroxyl group and epoxide oxygen are either cis (isomer 1) or trans (isomer 2) were evaluated for mutagenic activity. In strains TA 98 and TA 100 of Salmonella typhimurium, the diol epoxide with (1S,2R,3S,4R) absolute configuration [(-)-diol epoxide-1] had the highest mutagenic activity. In Chinese hamster V-79 cells, the diol epoxide with (1R,2S,3S,4R) absolute configuration [(+)-diol epoxide-2] had the highest mutagenic activity. The (1R,2S,3R,4S) diol epoxide [(+)-diol epoxide-1] also had appreciable activity, whereas the other two bay-region diol epoxide enantiomers had very low activity. In tumor studies, the (1R,2S,3S,4R) enantiomer was the only diol epoxide isomer tested that had strong activity as a tumor initiator on mouse skin and in causing lung and liver tumors when injected into newborn mice. This stereoisomer was about one-third as active as the parent hydrocarbon, dibenz[a,h]anthracene as a tumor initiator on mouse skin; it was several-fold more active than dibenz[a,h]anthracene as a lung and liver carcinogen when injected into newborn mice. (-)-(3R,4R)-3ß,4α-dihydroxy-3,4-dihydro-dibenz[a,h]anthracene [(-)-3,4-dihydrodiol] was slightly more active than dibenz[a,h]anthracene as a tumor initiator on mouse skin, whereas (+)-(3S,4S)-3α,4ß-dihydroxy-3,4-dihydro-dibenz[a,h]anthracene [(+)-3,4-dihydrodiol] had only very weak activity. The present investigation and previous studies with the corresponding four possible enantiopure bay-region diol epoxide enantiomers/diastereomers of benzo[a]pyrene, benz[a]anthracene, chrysene, benzo[c]phenanthrene, dibenz[c,h]acridine, dibenz[a,h]acridine and dibenz[a,h]anthracene indicate that the bay-region diol epoxide enantiomer with [R,S,S,R] absolute stereochemistry has high tumorigenic activity on mouse skin and in newborn mice.


Assuntos
Carcinogênese/patologia , Crisenos/farmacologia , Compostos de Epóxi/farmacologia , Neoplasias Cutâneas/induzido quimicamente , Animais , Carcinogênese/induzido quimicamente , Carcinogênese/química , Crisenos/química , Crisenos/toxicidade , Cricetinae , Compostos de Epóxi/toxicidade , Humanos , Camundongos , Mutagênese/efeitos dos fármacos , Mutagênicos/farmacologia , Mutagênicos/toxicidade , Salmonella typhimurium/efeitos dos fármacos , Salmonella typhimurium/genética , Neoplasias Cutâneas/patologia , Estereoisomerismo , Relação Estrutura-Atividade
15.
Stat Med ; 32(10): 1691-706, 2013 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-22855311

RESUMO

Multi-regional clinical trials have been widely used for efficient global new drug developments. Both a fixed-effect model and a random-effect model can be used for trial design and data analysis of a multi-regional clinical trial. In this paper, we first compare these two models in terms of the required sample size, type I error rate control, and the interpretability of trial results. We then apply the empirical shrinkage estimation approach based on the random-effect model to two criteria of consistency assessment of treatment effects across regions. As demonstrated in our computations, compared with the sample estimator, the shrinkage estimator of the treatment effect of an individual region borrowing information from the other regions is much closer to the estimator of the overall treatment effect, has smaller variability, and therefore provides much higher probability for demonstrating consistency. We use a multinational trial example with time to event endpoint to illustrate the application of the method.


Assuntos
Ensaios Clínicos como Assunto/estatística & dados numéricos , Teorema de Bayes , Bioestatística , Interpretação Estatística de Dados , Preparações de Ação Retardada , Descoberta de Drogas , Insuficiência Cardíaca/tratamento farmacológico , Humanos , Metoprolol/administração & dosagem , Modelos Estatísticos , Estudos Multicêntricos como Assunto/estatística & dados numéricos , Probabilidade , Ensaios Clínicos Controlados Aleatórios como Assunto/estatística & dados numéricos , Tamanho da Amostra , Fatores de Tempo
16.
Nutr Cancer ; 64(7): 1029-37, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23061906

RESUMO

The effect of oral caffeine or voluntary running wheel exercise (RW) alone or in combination on the progression of human androgen-dependent LNCaP prostate tumors to androgen independence in male severe combined immunodeficiency mice was determined. The mice were injected subcutaneously with LNCaP cells, and when the tumors reached a moderate size, the mice were surgically castrated and treated with caffeine (0.40 mg/ml drinking water) or RW alone or in combination for 42 days. We found that caffeine administration or RW inhibited the progression and growth of androgen-dependent LNCaP tumors to androgen independence, and a combination of the 2 regimens was more effective than the individual regimens alone. The ratios of the percent mitotic cells/caspase-3 positive cells in tumors from the caffeine-treated, RW-treated, or combination-treated mice were decreased by 34%, 38%, and 52%, respectively. Caffeine treatment increased the percentage of mitotic tumor cells undergoing apoptosis (lethal mitosis) whereas RW inhibited the increase in interleukin-6 that occurred during the progression of LNCaP tumors from androgen dependence to androgen independence. Our results indicate that oral administration of caffeine in combination with voluntary exercise may be an effective strategy for the prevention of prostate cancer progression from androgen dependence to androgen independence.


Assuntos
Androgênios/metabolismo , Cafeína/administração & dosagem , Progressão da Doença , Atividade Motora , Neoplasias da Próstata/patologia , Administração Oral , Animais , Apoptose/efeitos dos fármacos , Caspase 3/genética , Caspase 3/metabolismo , Linhagem Celular Tumoral , Modelos Animais de Doenças , Teste de Esforço , Interleucina-6/metabolismo , Masculino , Camundongos , Camundongos SCID , Antígeno Prostático Específico/sangue
17.
Cancer Prev Res (Phila) ; 5(11): 1310-20, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22964476

RESUMO

Tocopherol, a member of the vitamin E family, consists of four forms designated as α, ß, γ, and δ. Several large cancer prevention studies with α-tocopherol have reported no beneficial results, but recent laboratory studies have suggested that δ- and γ-tocopherol may be more effective. In two different animal models of breast cancer, the chemopreventive activities of individual tocopherols were assessed using diets containing 0.3% of tocopherol (α-, δ-, or γ-) or 0.3% of a γ-tocopherol rich mixture (γ-TmT). Although administration of tocopherols did not prevent human epidermal growth factor receptor 2 (HER2/neu)-driven tumorigenesis, δ- and γ-tocopherols inhibited hormone-dependent mammary tumorigenesis in N-methyl-N-nitrosourea (NMU)-treated female Sprague-Dawley rats. NMU-treated rats showed an average tumor burden of 10.6 ± 0.8 g in the control group at 11 weeks, whereas dietary administration of δ- and γ-tocopherols significantly decreased tumor burden to 7.2 ± 0.8 g (P < 0.01) and 7.1 ± 0.7 g (P < 0.01), respectively. Tumor multiplicity was also reduced in δ- and γ-tocopherol treatment groups by 42% (P < 0.001) and 32% (P < 0.01), respectively. In contrast, α-tocopherol did not decrease tumor burden or multiplicity. In mammary tumors, the protein levels of proapoptotic markers (BAX, cleaved caspase-9, cleaved caspase-3, cleaved PARP) were increased, whereas antiapoptotic markers (Bcl-2, XIAP) were inhibited by δ-tocopherol, γ-tocopherol, and γ-TmT. Furthermore, markers of cell proliferation (PCNA, PKCα), survival (PPAR-γ, PTEN, phospho-Akt), and cell cycle (p53, p21) were affected by δ- and γ-tocopherols. Both δ- and γ-tocopherols, but not α-tocopherol, seem to be promising agents for the prevention of hormone-dependent breast cancer.


Assuntos
Carcinoma/dietoterapia , Transformação Celular Neoplásica/efeitos dos fármacos , Neoplasias Mamárias Experimentais/dietoterapia , Receptores de Estrogênio/genética , Tocoferóis/administração & dosagem , gama-Tocoferol/administração & dosagem , Animais , Neoplasias da Mama/dietoterapia , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Carcinoma/genética , Carcinoma/patologia , Suplementos Nutricionais , Modelos Animais de Doenças , Regulação para Baixo/efeitos dos fármacos , Feminino , Neoplasias Mamárias Experimentais/genética , Neoplasias Mamárias Experimentais/patologia , Camundongos , Camundongos Transgênicos , Ratos , Ratos Sprague-Dawley , Receptor ErbB-2/genética , Receptor ErbB-2/metabolismo , Receptores de Estrogênio/metabolismo , Tocoferóis/farmacologia , gama-Tocoferol/farmacologia
18.
J Biopharm Stat ; 22(4): 700-18, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22651110

RESUMO

Parameter estimation following an adaptive design or group sequential design has been extremely challenging due to potential random high from its face value estimate. In this paper, we introduce a new framework to model clinical trial data flow based on a marked point process (MPP). The MPP model allows us to use methods of stochastic calculus for analyses of any adaptive clinical trial. As an example, we apply this method to a two stage treatment selection design and derive a procedure to estimate the treatment effect. Numerical examples will be used to evaluate the performance of the proposed procedure.


Assuntos
Ensaios Clínicos como Assunto/estatística & dados numéricos , Modelos Estatísticos , Resultado do Tratamento , Algoritmos , Ensaios Clínicos como Assunto/métodos , Simulação por Computador , Interpretação Estatística de Dados , Humanos , Tamanho da Amostra
19.
Proc Natl Acad Sci U S A ; 109(23): 9065-70, 2012 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-22615388

RESUMO

Removal of the parametrial fat pads (partial lipectomy) from female SKH-1 mice fed a high-fat diet inhibited UVB-induced carcinogenesis, but this was not observed in mice fed a low-fat chow diet. Partial lipectomy in high-fat-fed mice decreased the number of keratoacanthomas and squamous cell carcinomas per mouse by 76 and 79%, respectively, compared with sham-operated control mice irradiated with UVB for 33 wk. Immunohistochemical analysis indicated that partial lipectomy increased caspase 3 (active form) positive cells by 48% in precancerous epidermis away from tumors, by 68% in keratoacanthomas, and by 224% in squamous cell carcinomas compared with sham-operated control mice. In addition, partial lipectomy decreased cell proliferation away from tumors and in tumors. RT-PCR analysis for adipokines revealed that mRNAs for TIMP1, MCP1, and SerpinE1 (proinflammatory/antiapoptotic cytokines) in the parametrial fat pads of sham-operated control mice were 54- to 83-fold higher than levels in compensatory fat that returned after surgery in partially lipectomized mice at the end of the tumor study. Feeding mice high-fat diets for 2 wk increased levels of TIMP1 and other adipokines in serum and epidermis, and these increases were inhibited by removal of the parametrial fat pads. Our results are a unique demonstration that surgical removal of a specific tissue fat results in inhibition of carcinogenesis in obese mice. This inhibition was associated with an increase in apoptosis and a decrease in proliferation in tumors and in precancerous areas away from tumors.


Assuntos
Tecido Adiposo/cirurgia , Apoptose/fisiologia , Carcinoma de Células Escamosas/prevenção & controle , Ceratoacantoma/prevenção & controle , Lipectomia/métodos , Neoplasias Induzidas por Radiação/prevenção & controle , Raios Ultravioleta , Absorciometria de Fóton , Animais , Bromodesoxiuridina , Carcinoma de Células Escamosas/cirurgia , Caspase 3 , Dieta Hiperlipídica , Feminino , Imuno-Histoquímica , Ceratoacantoma/cirurgia , Camundongos , Neoplasias Induzidas por Radiação/cirurgia , Reação em Cadeia da Polimerase Via Transcriptase Reversa
20.
Stat Med ; 31(19): 2055-67, 2012 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-22415966

RESUMO

It is well-known that both frequentist and Bayesian clinical trial designs have their own advantages and disadvantages. To have better properties inherited from these two types of designs, we developed a Bayesian-frequentist two-stage single-arm phase II clinical trial design. This design allows both early acceptance and rejection of the null hypothesis ( H(0) ). The measures (for example probability of trial early termination, expected sample size, etc.) of the design properties under both frequentist and Bayesian settings are derived. Moreover, under the Bayesian setting, the upper and lower boundaries are determined with predictive probability of trial success outcome. Given a beta prior and a sample size for stage I, based on the marginal distribution of the responses at stage I, we derived Bayesian Type I and Type II error rates. By controlling both frequentist and Bayesian error rates, the Bayesian-frequentist two-stage design has special features compared with other two-stage designs.


Assuntos
Teorema de Bayes , Ensaios Clínicos Fase II como Assunto/estatística & dados numéricos , Projetos de Pesquisa , Tamanho da Amostra , Viés , Distribuição Binomial , Ensaios Clínicos Fase II como Assunto/normas , Interpretação Estatística de Dados , Relação Dose-Resposta a Droga , Determinação de Ponto Final , Humanos , Modelos Estatísticos
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