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We present a dynamic model of global copper stocks and flows which allows a detailed analysis of recycling efficiencies, copper stocks in use, and dissipated and landfilled copper. The model is based on historical mining and refined copper production data (1910-2010) enhanced by a unique data set of recent global semifinished goods production and copper end-use sectors provided by the copper industry. To enable the consistency of the simulated copper life cycle in terms of a closed mass balance, particularly the matching of recycled metal flows to reported historical annual production data, a method was developed to estimate the yearly global collection rates of end-of-life (postconsumer) scrap. Based on this method, we provide estimates of 8 different recycling indicators over time. The main indicator for the efficiency of global copper recycling from end-of-life (EoL) scrap--the EoL recycling rate--was estimated to be 45% on average, ± 5% (one standard deviation) due to uncertainty and variability over time in the period 2000-2010. As uncertainties of specific input data--mainly concerning assumptions on end-use lifetimes and their distribution--are high, a sensitivity analysis with regard to the effect of uncertainties in the input data on the calculated recycling indicators was performed. The sensitivity analysis included a stochastic (Monte Carlo) uncertainty evaluation with 10(5) simulation runs.
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Cobre , Modelos Teóricos , Método de Monte Carlo , ReciclagemRESUMO
BACKGROUND: Phenoxodiol, a synthetic analog of Genistein, is being assessed in several clinical studies against a range of cancer types and was shown to have a good efficacy and safety profile. In this study we tested the effects of Phenoxodiol against prostate cancer cell lines. METHODS: Cell-cycle analysis, plasmatic membrane damage, clonogenic assay, comet assay, and Western blot methodologies were employed to assess the effects of Phenoxodiol on prostate cancer cell lines. An in vivo model confirmed the potential therapeutic efficacy of Phenoxodiol when administered orally to tumor bearing mice. RESULTS: Phenoxodiol treatment promoted a marked inhibition of proliferation and loss of colony formation in LNCaP cells in a dose- and time-dependent manner. Similar effects were also observed in the metastatic prostate cell lines PC3 and DU145. Activation of poly(ADP ribose) polymerase 1 (PARP-1) clearly indicates the induction of DNA damage by Phenoxodiol. Oral administration of Phenoxodiol induced a considerable growth inhibition of malignant tumors generated by inoculation of LNCaP cells into Balb/c nu/nu athymic mice. CONCLUSIONS: These data demonstrated that Phenoxodiol promotes apoptosis, as determined by PARP-1 degradation, via mitochondrial depolarization and G1/S cell-cycle arrest thereby confirming that it is active against androgen-dependent and independent prostate cancer cells. Although a precise target for Phenoxodiol has not been identified, these data contribute to our understanding of the mechanism by which this drug promotes cell death in prostate cancer cells, and warrants the continued clinical development of Phenoxodiol as a therapeutic for the treatment of metastatic prostate cancer.
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Isoflavonas/farmacologia , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/patologia , Animais , Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Processos de Crescimento Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Ensaio Cometa , Dano ao DNA , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Neoplasias Hormônio-Dependentes/tratamento farmacológico , Neoplasias Hormônio-Dependentes/genética , Neoplasias Hormônio-Dependentes/metabolismo , Neoplasias Hormônio-Dependentes/patologia , Poli(ADP-Ribose) Polimerase-1 , Inibidores de Poli(ADP-Ribose) Polimerases , Poli(ADP-Ribose) Polimerases/metabolismo , Neoplasias da Próstata/genética , Neoplasias da Próstata/metabolismo , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
BACKGROUND: Human immunodeficiency virus (HIV)-associated tuberculosis is difficult to treat, given the propensity for drug interactions between the rifamycins and the antiretroviral drugs. We examined the pharmacokinetics of rifabutin before and after the addition of lopinavir-ritonavir. METHODS: We analyzed 10 patients with HIV infection and active tuberculosis in a state tuberculosis hospital. Plasma was collected for measurement of rifabutin, the microbiologically active 25-desacetyl-rifabutin, and lopinavir by validated high-performance liquid chromatography assays. Samples were collected 2-4 weeks after starting rifabutin at 300 mg thrice weekly without lopinavir-ritonavir, 2 weeks after the addition of lopinavir-ritonavir at 400 and 100 mg, respectively, twice daily to rifabutin at 150 mg thrice weekly, and (if rifabutin plasma concentrations were below the normal range) 2 weeks after an increase in rifabutin to 300 mg thrice weekly with lopinavir-ritonavir. Noncompartmental and population pharmacokinetic analyses (2-compartment open model) were performed. RESULTS: Rifabutin at 300 mg without lopinavir-ritonavir produced a low maximum plasma concentration (C(max)) in 5 of 10 patients. After the addition of lopinavir-ritonavir to rifabutin at 150 mg, 9 of 10 had low C(max) values. Eight patients had dose increases to 300 mg of rifabutin with lopinavir-ritonavir. Most free rifabutin (unbound to plasma protein) C(max) values were below the tuberculosis minimal inhibitory concentration. For most patients, values for the area under the plasma concentration-time curve were as low or lower than those associated with treatment failure or relapse and with acquired rifamycin resistance in Tuberculosis Trials Consortium/US Public Health Service Study 23. One of the 10 patients experienced relapse with acquired rifamycin resistance. CONCLUSION: The recommended rifabutin doses for use with lopinavir-ritonavir may be inadequate in many patients. Monitoring of plasma concentrations is recommended.
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Antibióticos Antituberculose/farmacocinética , Antivirais/farmacocinética , Infecções por HIV/complicações , Infecções por HIV/tratamento farmacológico , Pirimidinonas/farmacocinética , Rifabutina/farmacocinética , Ritonavir/farmacocinética , Tuberculose/complicações , Tuberculose/tratamento farmacológico , Adulto , Antibióticos Antituberculose/sangue , Antibióticos Antituberculose/uso terapêutico , Antivirais/sangue , Antivirais/uso terapêutico , Interações Medicamentosas , Feminino , Humanos , Lopinavir , Masculino , Pessoa de Meia-Idade , Pirimidinonas/sangue , Pirimidinonas/uso terapêutico , Rifabutina/sangue , Rifabutina/uso terapêutico , Ritonavir/sangue , Ritonavir/uso terapêuticoRESUMO
RESUMEN Presentamos la experiencia del Policlínico de la Peruvian American Medical Society (PAMS) en Chincha, en la ejecución de misiones médico-educativas en la región Chincha. El Policlínico PAMS presta atención médica general y especializada a la población de la zona, seis días a la semana. Además, recibe misiones médicas que vienen generalmente de los EE. UU. Desde 2011, se han recibido 43 misiones médicas. La composición y la naturaleza de las misiones han cambiado con el tiempo. Los primeros años se atraía a especialistas con el énfasis de traer equipos e insumos para mejorar la infraestructura del Policlínico. Ahora estamos limitados por la renuencia de voluntarios de venir al Perú en parte debido a que el gobierno americano considera que viajes al Perú son de alto riesgo. Esta limitación nos ha brindado la oportunidad de hacer misiones médicas juntamente con dos excelentes universidades peruanas. La experiencia ha sido positiva.
ABSTRACT We present the experience of the Polyclinic of the Peruvian American Medical Society (PAMS) in Chincha, in the execution of medical educational missions in the Chincha region. The PAMS Polyclinic provides general and specialized medical care to the population of the area, six days a week. In addition, the Polyclinic receives medical missions generally coming from the EE.UU. Since 2011, we have received 43 medical missions. The composition and nature of the missions have changed over time. The first years attracted specialists with the emphasis on bringing equipment and supplies to improve the infrastructure of the Polyclinic. We are now limited by the reluctance of volunteers to come to Peru in part because the U.S. government considers travel to Peru to be high-risk. This limitation has given us the opportunity to do medical missions together with two excellent Peruvian universities. This experience has been positive.
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Protein kinase D localizes in the Golgi and regulates protein transport from the Golgi to the plasma membrane. In the present study, we found that PKD3, a novel member of the PKD family, and its fluorescent protein fusions localized in the Golgi and in the vesicular structures that are in part marked by endosome markers. Fluorescent recovery after photobleaching (FRAP) showed that the PKD3-associated vesicular structures were constantly forming and dissolving, reflecting active subcellular structures. FRAP on plasma membrane-located PKD3 indicated a slower recovery of PKD3 fluorescent signal compared to those of PKC isoforms, implying a different targeting mechanism at the plasma membrane. VAMP2, the vesicle-localized v-SNARE, was later identified as a novel binding partner of PKD3 through yeast two-hybrid screening. PKD3 directly interacted with VAMP2 in vitro and in vivo, and colocalized in part with VAMP2 vesicles in cells. PKD3 did not phosphorylate VAMP-GFP and the purified GST-VAMP2 protein in in vitro phosphorylation assays. Rather, PKD3 was found to promote the recruitment of VAMP2 vesicles to the plasma membrane in response to PMA, while the kinase dead PKD3 abolished this effect. Thus, the kinase activity of PKD3 was required for PMA-induced plasma membrane trafficking of VAMP2. In summary, our findings suggest that PKD3 localizes to vesicular structures that are part of the endocytic compartment. The vesicular distribution may be attributed in part to the direct interaction between PKD3 and vesicle-associated membrane protein VAMP2, through which PKD3 may regulate VAMP2 vesicle trafficking by facilitating its recruitment to the target membrane.
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Vesículas Citoplasmáticas/enzimologia , Proteína Quinase C/metabolismo , Proteína 2 Associada à Membrana da Vesícula/metabolismo , Animais , Células CHO , Membrana Celular/enzimologia , Cricetinae , Cricetulus , Citosol/enzimologia , Endossomos/enzimologia , Complexo de Golgi/enzimologia , Humanos , Fosforilação , Ligação Proteica , Transporte Proteico , Proteínas Recombinantes de Fusão/metabolismoRESUMO
We report the irradiation of TiO(2) suspensions containing Br(-) and dissolved organic carbon (DOC). In the absence of DOC, we found no evidence for the formation of BrO(3)(-) upon irradiation of 1gL(-1) P25 suspensions with UV light for initial Br(-) concentrations up to 10mgL(-1). In the presence of DOC (Lake Hohloh, Germany and salicylic acid), we found no evidence for the formation of either BrO(3)(-) or trihalomethanes (THMs). However, small amounts of adsorbable organic halogen (AOX) were formed at high bromide concentrations (3mgL(-1)). When irradiating P25 suspensions containing bromide and 2,4-dihydroxybenzoic acid (DHBA, high bromoform formation potential), we observed the formation of significant amounts of bromoform (up to 10microgL(-1)). Bromoform appeared only after the DHBA had been degraded.
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Bromo/química , Carbono/química , Titânio/química , Cromatografia Líquida , SolubilidadeRESUMO
BACKGROUND: Dental caries is a multifactorial disease that affects the general population. After reviewing the scientific literature, no studies were found on the index of decayed, missing and filled teeth (DMFT) in the Peruvian police population. The objective was to evaluate the DMFT index and severity level of the disease in police personnel of the Ancash region, Peru. MATERIAL AND METHODS: Cross-sectional prevalence study. The medical records of the police personnel in activity were reviewed and each subject was examined from May 2012 to May 2013. The study was authorized by the Director of the PNP-Huaraz Ancash Polyclinic as part of the activities of the civil SERUMS personnel in the area of odontology. The sample was census with 925 subjects. The data was systematized following the methodology recommended by the World Health Organization (WHO). The statistics were analyzed by Chi square test with significance p<0.05, Pearson test and ANOVA. RESULTS: The prevalence of caries in the police population was 73.4%. The DMFT index was 10.63 ± 4.96 (p<0.01). The severity of the disease in relation to age was 0.77 ± 0.41 with a high risk in this population. The DMFT index in females 128/925 and males 797/925 was 10.43 and 10.67 respectively. There is an inversely proportional relationship in the number of teeth filled with dental amalgam in policemen older than 35 years versus the number of teeth sealed with material other than dental amalgam in policemen under 35 years. Only 0.8% 7/925 had dental prostheses and 58.6% (542/925) of the subjects needed oral rehabilitation. CONCLUSIONS: The severity of dental caries is high, strategies are required to improve intervention in this sector, developing effective programs in oral health in the short, medium and long term. Key words:Dental caries severity, oral health, dental caries prevalence, peruvian police.
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La pandemia del COVID-19 tuvo un impacto significativo en el cuidado y la educación médicos en el Perú. En respuesta, la Sociedad Médica Peruano Americana (PAMS), una organización médica benéfica con sede en los EE.UU., adoptó sus misiones médicas y educativas en Perú usando estrategias virtuales. Desarrollamos colaboración con varias facultades de medicina y la Asociación Peruana de Facultades de Medicina (ASPEFAM) y ofrecimos un panel de veinte y cuatro miembros para brindar conferencias y seminarios multidisciplinarios en español. Hicimos 19 seminarios, incluyendo temas relacionados y no relacionados al COVID-19, que en los últimos dos años atrajo a 14 489 participantes de 23 países. Ellas fueron la base de 20 publicaciones en revistas médicas peruanas. Nuestro concurso de investigaciones clínicas y nuestro proyecto piloto de mentoría de investigación fueron recibidos positivamente. La pandemia del COVID-19 tuvo un efecto positivo en la misión educativa de PAMS en Perú.
The COVID-19 pandemic had a significant impact on medical care and medical education in Peru. In response, the Peruvian American Medical Society (PAMS), a charitable medical organization based in the USA, pursued its medical and educational missions in Peru by adopting virtual learning technology. We developed closer collaborative relationships with several medical schools and the Peruvian Association of Medical Schools (ASPEFAM) while offering a faculty panel of twenty-four members to provide lectures and multidisciplinary webinars in Spanish. We conducted 19 webinars including COVID -19 and non-COVID-19 related topics that over the last two years attracted 14,489 participants from 23 countries. They were the foundation for twenty publications in Peruvian medical journals. Our clinical investigations competition was positively received as was our pilot project on research mentorship. The COVID -19 pandemic had a positive effect on the educational mission of PAMS in Peru.
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Environmental pollutants inducing oxidative stress stimulate chronic inflammatory responses in the lung leading to pulmonary tissue dysfunction. In response to oxidative stress, alveolar macrophages produce both reactive oxygen species and reactive nitrogen species, which induce the expression of a wide variety of immune-response genes. We found that a prolonged exposure of alveolar macrophages to a nonlethal dose (8 microg/ml) of JP-8, the kerosene-based hydrocarbon jet fuel, induced the persistent expression of IL-1, iNOS, and COX-2, as well as cell adhesion molecules (ICAM-1 and VCAM-1). Because poly(ADP-ribose) polymerase (PARP-1), a coactivator of NF-kappaB, regulates inflammatory responses and associated disorders in the airways, we determined whether JP-8 induces the poly(ADP-ribosyl)ation automodification of PARP-1 in alveolar macrophages. We observed that PARP-1 is activated in a time-dependent manner, which was temporally coincident with the prolonged activation of NF-kappaB and with the augmented expression of the proinflammatory factors described above. The 4 microg/ml dilution of JP-8 also increased the activity of PARP-1 as well as the expression of iNOS and COX-2, indicating that lower doses of JP-8 also affect the regulation of proinflammatory factors in pulmonary macrophages. Together, these results demonstrate that an extensive induction of PARP-1 might coordinate the persistent expression of proinflammatory mediators in alveolar macrophages activated by aromatic hydrocarbons that can result in lung injury from occupational exposure.
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Citocinas/genética , Poluentes Ambientais , Hidrocarbonetos/toxicidade , Macrófagos Alveolares/fisiologia , Poli(ADP-Ribose) Polimerases/metabolismo , Animais , Linhagem Celular , Meios de Cultura , Combustíveis Fósseis/toxicidade , Glutationa/metabolismo , Modelos Animais , Exposição Ocupacional , Ácido Peroxinitroso/metabolismo , Poli(ADP-Ribose) Polimerases/genética , Ratos , Espécies Reativas de Oxigênio/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
The photoinitiated degradation of bisphenol A (BPA, 520 micromol/L) was investigated using a solar simulator in the absence/presence of NO(3)(-), Fe(III), and HCO(3)(-). The concentrations of NO(3)(-), Fe(III), and HCO(3)(-) were 0-160, 0-10, and 0-820 micromol/L, respectively, and were chosen to simulate a natural aquatic environment. The experimental region was explored using a Box-Behnken design for three factors, extended to experimentally include all eight possible combinations of presence/absence of the factors studied. The results show that, after 7h of irradiation, photolysis occurs only to a minimal degree (2%) in the absence of NO(3)(-) and HCO(3)(-). Increasing the concentration of NO(3)(-) and HCO(3)(-) gives rise to up to 24% degradation after 7h of irradiation. The concentration of Fe(III) was found to play no active role under the conditions studied. A simple linear model is given that very well describes the results obtained.
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Bicarbonatos/química , Compostos Férricos/química , Nitratos/química , Fenóis/química , Compostos Benzidrílicos , Cromatografia Líquida de Alta Pressão , Raios UltravioletaRESUMO
Acute mastoiditis, an infectious inflammatory process in the temporal bone, is an uncommon complication of otitis media. Here we describe a fatal case of mastoiditis complicated by thrombosis of the sigmoid sinus and intracerebral abscess caused by an unusual pathogen (Nocardia asteroides) in a person with HIV infection. Sulfonamides have remained the first-line agents for the management of Nocardia infections, but mortality remains high in patients with intracerebral infection.
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Infecções Oportunistas Relacionadas com a AIDS/microbiologia , Abscesso Encefálico/microbiologia , Infecções por HIV/complicações , Mastoidite/complicações , Infecções Oportunistas Relacionadas com a AIDS/tratamento farmacológico , Infecções Oportunistas Relacionadas com a AIDS/patologia , Adulto , Cavidades Cranianas/patologia , Evolução Fatal , Infecções por HIV/tratamento farmacológico , Infecções por HIV/microbiologia , Infecções por HIV/patologia , Cabeça/diagnóstico por imagem , Humanos , Masculino , Mastoidite/microbiologia , Mastoidite/patologia , Nocardia asteroides/isolamento & purificação , Radiografia , Trombose dos Seios IntracranianosRESUMO
The transcription factor E2F-1 is implicated in the activation of S-phase genes as well as induction of apoptosis, and is regulated by interactions with Rb and by cell cycle-dependent alterations in E2F-1 abundance. We earlier demonstrated a pivotal role for poly(ADP-ribose) polymerase-1 (PARP-1) in the regulation of E2F-1 expression and promoter activity during S-phase re-entry when quiescent cells re-enter the cell cycle. We now investigate the putative mechanism(s) by which PARP-1 may upregulate E2F-1 promoter activity during S-phase re-entry. DNase-1 footprint assays with purified PARP-1 showed that PARP-1 did not directly bind the E2F-1 promoter in a sequence-specific manner. In contrast to p53, a positive acceptor in poly(ADP-ribosyl)ation reactions, E2F-1 was not poly(ADP-ribosyl)ated by wild-type PARP-1 in vitro, indicating that PARP-1 does not exert a dual effect on E2F-1 transcriptional activation. Protein-binding reactions and coimmunoprecipitation experiments with purified PARP-1 and E2F-1, however, revealed that PARP-1 binds to E2F-1 in vitro. More significantly, physical association of PARP-1 and E2F-1 in vivo also occurred in wild-type fibroblasts 5 h after re-entry into S phase, coincident with the increase in E2F-1 promoter activity and expression of E2F-1-responsive S-phase genes cyclin A and c-Myc. Mapping of the interaction domains revealed that full-length PARP-1 as well as PARP-1 mutants lacking either the catalytic active site or the DNA-binding domain equally bind E2F-1, whereas a PARP-1 mutant lacking the automodification domain does not, suggesting that the protein interaction site is located in this central domain. Finally, gel shift analysis with end-blocked E2F-1 promoter sequence probes verified that the binding of PARP-1 to E2F-1 enhances binding to the E2F-1 promoter, indicating that PARP-1 acts as a positive cofactor of E2F-1-mediated transcription.
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Proteínas de Ciclo Celular , Proteínas de Ligação a DNA , Poli(ADP-Ribose) Polimerases/metabolismo , Fase S/fisiologia , Fatores de Transcrição/metabolismo , Transcrição Gênica , Animais , Sítios de Ligação , Ciclina A/metabolismo , Fatores de Transcrição E2F , Fator de Transcrição E2F1 , Genes myc/fisiologia , Humanos , Testes de PrecipitinaRESUMO
INTRODUCTION: Hispanic adolescents domiciling in Florida rank second in the U.S. with respect to HIV/AIDS incidence and prevalence. Extending studies showing that risky sexual behavior is associated with limited access to information, this project surveyed knowledge about HIV etiology, prevention and treatment. METHODS: The sample consisted of 400 Hispanic youth between 11-18 years of age living in Miami, Florida. The sample is enrolled in an ongoing project Role of Brain Derived Neurotrophic Factor in Decision Making (ROBIM). The HIV Knowledge Questionnaire (HIV-KQ-18), an 18 item self-administered questionnaire was used to measure HIV knowledge, particularly transmission and prevention. RESULTS: Less than 10% of the sample had comprehensive knowledge about HIV/AIDS. Approximately 25% incorrectly answered all of the questions. Questions pertaining to transmission were incorrectly answered by more than half of the sample. The most frequent topics reflecting absence of knowledge are related to high-risk sexual behaviors (sex during the menses) and infection prevention methods (e.g. condoms). A majority of youth believed incorrectly that HIV could be cured (61%), an effective vaccine is available (61%), and antibiotics protect against HIV infection (76%). School (28%) and parents (26%) were the most frequent sources of knowledge about HIV/AIDS. However, youth receiving information from parents had significantly higher knowledge scores than peers receiving education in school (7.4 ± 4.15 vs. 6.1 ± 4.5 scores, p = 0.037). Yet, 68% of the sample had never discussed condom use with their parents. CONCLUSIONS: These findings indicate Hispanic youths, although at very high risk, are poorly informed about prevention of HIV/AIDS. Moreover, the most frequent source of information, namely schools, inculcates less knowledge than parents. Lastly, youths who discuss sex with parents do not typically dialog about condoms, the most readily available protection from HIV/AIDS. These findings identify gaps that need to be addressed for lowering the high rate of HIV infection in Hispanic youths.
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1. The mechanism of toxicity of sulphur mustard was investigated by examining the biochemical effects of the analog 2-chloroethylethyl sulphide (CEES) in both human Jurkat cells as well as normal human lymphocytes. 2. Exposure of both types of cells to CEES resulted in a marked decrease in the intracellular concentration of the reduced form of glutathione (GSH), and CEES-induced cell death was potentiated by l-buthionine sulphoximine, an inhibitor of GSH synthesis. 3. CEES increased the endogenous production of reactive oxygen species (ROS) in Jurkat cells, and CEES-induced cell death was potentiated by hydrogen peroxide. 4. CEES induced various hallmarks of apoptosis, including collapse of the mitochondrial membrane potential, proteolytic processing and activation of procaspase-3, and cleavage of poly (ADP-ribose) polymerase. 5. The effects of CEES on the accumulation of ROS, the intracellular concentration of GSH, the mitochondrial membrane potential, and caspase-3 activity were all inhibited by pretreatment of cells with the GSH precursor N-acetyl cysteine or with GSH-ethyl ester. Furthermore, CEES-induced cell death was also prevented by these antioxidants. 6. CEES toxicity appears to be mediated, at least in part, by the generation of ROS and consequent depletion of GSH. Given that sulphur mustard is still a potential biohazard, the protective effects of antioxidants against CEES toxicity demonstrated in Jurkat cells and normal human lymphocytes may provide the basis for the development of a therapeutic strategy to counteract exposure to this chemical weapon.
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Antioxidantes/farmacologia , Apoptose/efeitos dos fármacos , Linfócitos/efeitos dos fármacos , Gás de Mostarda/análogos & derivados , Gás de Mostarda/toxicidade , Apoptose/fisiologia , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Humanos , Células Jurkat , Linfócitos/metabolismo , Espécies Reativas de Oxigênio/metabolismoRESUMO
We determined whether alterations in the expression of p53, p16(INK4) and p21(WAF1/CIP1) influence the invasiveness of a subset of gastric adenocarcinomas co-expressing TGFalpha and EGFR. Immunopositivity for TGFalpha-EGFR (26%) was observed in both early and advanced adenocarcinomas, and 88% of these showed immunoreactivity for p53. SSCP analysis revealed that in 81% of these tumors the p53 gene was mutated in exons 5-8. The intensity of p53 immunoreactivity was significantly higher (P < 0.013) in deeply invasive tumors. p16(INK4) and p21(WAF1/CIP1) immunoreactivity was detected in 93 and 76% of the samples co-expressing TGFalpha-EGFR but the levels were not correlated with those of p53 and other clinico-pathological parameters. We conclude that gastric adenocarcinomas potentially dependent upon the TGFalpha-EGFR autocrine loop for growing exhibit increased aggressiveness in the presence of aberrant p53.
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Adenocarcinoma/genética , Adenocarcinoma/patologia , Receptores ErbB/biossíntese , Genes p53 , Invasividade Neoplásica , Neoplasias Gástricas/genética , Neoplasias Gástricas/patologia , Fator de Crescimento Transformador alfa/biossíntese , Inibidor p16 de Quinase Dependente de Ciclina/biossíntese , Inibidor p16 de Quinase Dependente de Ciclina/farmacologia , Inibidor de Quinase Dependente de Ciclina p21 , Ciclinas/biossíntese , Ciclinas/farmacologia , Análise Mutacional de DNA , Inibidores Enzimáticos/farmacologia , Humanos , Imuno-Histoquímica , Transdução de SinaisRESUMO
The jet fuel JP-8 is widely used and a large number of military and civilian personnel is, therefore, exposed to it. Treatment of several cell lines, including human Jurkat cells, with JP-8 induces cell death that exhibits various biochemical and morphological characteristics of apoptosis. The molecular mechanism of JP-8 cytotoxicity, however, has remained unclear. The effects of exposure of Jurkat cells to JP-8 (1/10,000 dilution) for 4 h on gene expression have now been examined by cDNA macroarray analysis. We had previously shown in these cells that under the above conditions, JP-8 causes significant apoptosis, based upon the observation that caspase-3 activation occurs at approximately 4 h and consequently most of the other classical apoptotic biochemical and morphological alterations progress until apoptotic cell death at 24 h. Of the 439 apoptosis- or stress response-related genes examined, the expression of 16 genes was up-regulated and that of ten genes was down-regulated by a factor of > or =2. The changes in the expression of 11 of these 26 genes were confirmed by reverse transcription and polymerase chain reaction analysis. These results provide insight into the mechanism of JP-8 toxicity and the associated induction of apoptosis.
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Regulação da Expressão Gênica/efeitos dos fármacos , Hidrocarbonetos/toxicidade , Apoptose/efeitos dos fármacos , Caspase 3 , Caspases/metabolismo , Humanos , Células Jurkat/efeitos dos fármacos , Células Jurkat/fisiologia , Análise de Sequência com Séries de Oligonucleotídeos , RNA/química , RNA/genética , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
PURPOSE: High levels of BCL-2 family members in colorectal carcinoma cause resistance to treatment. Inhibition of NANOG or its paralog NANOGP8 reduces the proliferation, stemness, and tumorigenicity of colorectal carcinoma cells. Our hypothesis was that inhibition of NANOG/NANOGP8 enhances the cytotoxic effect of BH3 mimetics targeting BCL-2 family members in colorectal carcinoma cells through reducing expression of MCL-1, a prosurvival BCL-2 protein. EXPERIMENTAL DESIGN: Lentiviral vector (LV) shRNA to NANOG (shNG-1) or NANOGP8 (shNp8-1) transduced colorectal carcinoma cells that were also exposed to the BH3 mimetics ABT-737 or ABT-199 in vivo in colorectal carcinoma xenografts and in vitro where proliferation, protein and gene expression, and apoptosis were measured. RESULTS: Clone A and CX-1 were sensitive to ABT-737 and ABT-199 at IC50s of 2 to 9 µmol/L but LS174T was resistant with IC50s of 18 to 30 µmol/L. Resistance was associated with high MCL-1 expression in LS174T. LVshNG-1 or LVshNp8-1 decreased MCL-1 expression, increased apoptosis, and decreased replating efficiency in colorectal carcinoma cells treated with either ABT-737 or ABT-199 compared with the effects of either BH3 mimetic alone. Inhibition or overexpression of MCL-1 alone replicated the effects of LVshNG-1 or LVshNp8-1 in increasing or decreasing the apoptosis caused with the BH3 mimetic. The combination therapy inhibited the growth of LS174T xenografts in vivo compared with untreated controls or treatment with only LV shRNA or ABT-737. CONCLUSIONS: Inhibition of NANOGP8 or NANOG enhances the cytotoxicity of BH3 mimetics that target BCL-2 family members. Gene therapy targeting the NANOGs may increase the efficacy of BH3 mimetics in colorectal carcinoma.
Assuntos
Proteína Agonista de Morte Celular de Domínio Interatuante com BH3/genética , Neoplasias Colorretais/genética , Regulação para Baixo/genética , Proteínas de Homeodomínio/antagonistas & inibidores , Proteína de Sequência 1 de Leucemia de Células Mieloides/genética , Animais , Apoptose/efeitos dos fármacos , Apoptose/genética , Compostos de Bifenilo/farmacologia , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Linhagem Celular , Linhagem Celular Tumoral , Neoplasias Colorretais/tratamento farmacológico , Regulação para Baixo/efeitos dos fármacos , Células HEK293 , Células HT29 , Humanos , Masculino , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Proteína Homeobox Nanog , Nitrofenóis/farmacologia , Piperazinas/farmacologia , RNA Interferente Pequeno/genética , Sulfonamidas/farmacologia , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Herein we report the photocatalytic degradation of natural organic matter from a bog lake (Lake Hohloh, Black Forest, Germany) in the presence of 0, 5, and 10 µmol L(-1) of added Cu(2+), Mn(2+), Zn(2+) and Fe(3+). The reactions were followed by size exclusion chromatography with organic carbon detection (SEC-DOC) and by measurements of low molecular weight organic acids. Addition of Cu(2+) had the largest effect of all four studied metals, leading to a retardation in the molecular size changes in NOM: degradation of the larger molecular weight fraction was inhibited leading to reduced production of smaller molecular weight metabolites. Similarly, addition of Cu(2+) reduced the production of formic and oxalic acids, and reduced the bioavailability of the partially degraded NOM.
Assuntos
Ácidos/química , Metais/química , Compostos Orgânicos/química , Fotoquímica , Cromatografia em Gel , Cromatografia por Troca Iônica , Cobre/química , Íons/química , Manganês/química , Peso Molecular , Esgotos/microbiologia , Zinco/químicaRESUMO
The degradation of natural organic matter (NOM) in homogeneous and heterogeneous advanced oxidation processes (AOP) was simulated using a simple underlying physical model. By treating the NOM molecules as linear chains and allowing them to be cleaved at any point selected at random, it is possible to reproduce well the results for homogeneous AOP experiments. To simulate a heterogeneous process, a bias was introduced (in the form of different weights for different chain lengths) according to literature data on the adsorption of NOM onto TiO(2) nanoparticle agglomerates. After introduction of the (adsorption) bias, the simulation closely followed the degradation sequence observed in heterogeneous photocatalysis with TiO(2) suspensions. Thus, the experimental results for homogeneous AOP may well be explained by a random breakdown of the NOM molecules; that is, we find no evidence for a selective degradation of the large molecular size material. However, a selectivity is present in the heterogeneous system due to the differential adsorption of NOM onto the reactive surface.
Assuntos
Modelos Químicos , Eliminação de Resíduos/métodos , Carbono/análise , Peróxido de Hidrogênio , Cinética , Oxirredução , Fotólise , Titânio , Raios UltravioletaRESUMO
We report the formation of bromoform in TiO(2) suspensions (P25) under simulated solar UV irradiation at different concentrations of photocatalyst (0.5-1.5 g L(-1)) as well as initial concentrations of bromide ions (1-3mg L(-1)) and 2,4-dihydroxybenzoic acid (2-10mg L(-1)). The extent of bromoform formation (3-17microg L(-1)) was most strongly affected by the amount of photocatalyst present and by the initial bromide concentration, increasing either of which leads to increased bromoform formation. Important interaction effects were observed when simultaneously increasing the concentrations of TiO(2) and bromide as well as of bromide and DHBA. The time it takes for bromoform to appear in measurable concentrations in the irradiated TiO(2) suspensions was between 10 and 90 min and most strongly depended on the initial concentration of dissolved organic carbon present in the suspensions, along with the amount of photocatalyst, also in interaction with the initial bromide concentration.