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1.
Nat Chem Biol ; 20(7): 812-822, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38167917

RESUMO

Sirtuins are nicotinamide adenine dinucleotide (NAD+)-dependent protein lysine deacylases regulating metabolism and stress responses; however, characterization of the removed acyl groups and their downstream metabolic fates remains incomplete. Here we employed untargeted comparative metabolomics to reinvestigate mitochondrial sirtuin biochemistry. First, we identified N-glutarylspermidines as metabolites downstream of the mitochondrial sirtuin SIR-2.3 in Caenorhabditis elegans and demonstrated that SIR-2.3 functions as a lysine deglutarylase and that N-glutarylspermidines can be derived from O-glutaryl-ADP-ribose. Subsequent targeted analysis of C. elegans, mouse and human metabolomes revealed a chemically diverse range of N-acylspermidines, and formation of N-succinylspermidines and/or N-glutarylspermidines was observed downstream of mammalian mitochondrial sirtuin SIRT5 in two cell lines, consistent with annotated functions of SIRT5. Finally, N-glutarylspermidines were found to adversely affect C. elegans lifespan and mammalian cell proliferation. Our results indicate that N-acylspermidines are conserved metabolites downstream of mitochondrial sirtuins that facilitate annotation of sirtuin enzymatic activities in vivo and may contribute to sirtuin-dependent phenotypes.


Assuntos
Caenorhabditis elegans , Mitocôndrias , Sirtuínas , Sirtuínas/metabolismo , Caenorhabditis elegans/metabolismo , Animais , Mitocôndrias/metabolismo , Humanos , Camundongos , Proliferação de Células , Metabolômica
2.
Proc Natl Acad Sci U S A ; 119(45): e2200477119, 2022 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-36322753

RESUMO

IGF2BP2 binds to a number of RNA transcripts and has been suggested to function as a tumor promoter, although little is known regarding the mechanisms that regulate its roles in RNA metabolism. Here we demonstrate that IGF2BP2 binds to the 3' untranslated region of the transcript encoding ATP6V1A, a catalytic subunit of the vacuolar ATPase (v-ATPase), and serves as a substrate for the NAD+-dependent deacetylase SIRT1, which regulates how IGF2BP2 affects the stability of the ATP6V1A transcript. When sufficient levels of SIRT1 are expressed, it catalyzes the deacetylation of IGF2BP2, which can bind to the ATP6V1A transcript but does not mediate its degradation. However, when SIRT1 expression is low, the acetylated form of IGF2BP2 accumulates, and upon binding to the ATP6V1A transcript recruits the XRN2 nuclease, which catalyzes transcript degradation. Thus, the stability of the ATP6V1A transcript is significantly compromised in breast cancer cells when SIRT1 expression is low or knocked-down. This leads to a reduction in the expression of functional v-ATPase complexes in cancer cells and to an impairment in their lysosomal activity, resulting in the production of a cellular secretome consisting of increased numbers of exosomes enriched in ubiquitinated protein cargo and soluble hydrolases, including cathepsins, that together combine to promote tumor cell survival and invasiveness. These findings describe a previously unrecognized role for IGF2BP2 in mediating the degradation of a messenger RNA transcript essential for lysosomal function and highlight how its sirtuin-regulated acetylation state can have significant biological and disease consequences.


Assuntos
Neoplasias , ATPases Vacuolares Próton-Translocadoras , Humanos , ATPases Vacuolares Próton-Translocadoras/genética , ATPases Vacuolares Próton-Translocadoras/metabolismo , Sirtuína 1/metabolismo , RNA/metabolismo , Processos Neoplásicos , Lisossomos/genética , Lisossomos/metabolismo , Neoplasias/metabolismo , Linhagem Celular Tumoral , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo
3.
Anal Chem ; 94(41): 14185-14194, 2022 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-36190014

RESUMO

The excited-state lifetime is an intrinsic property of fluorescent molecules that can be leveraged for multiplexed imaging. An advantage of fluorescence lifetime-based multiplexing is that signals from multiple probes can be gathered simultaneously, whereas traditional spectral fluorescence imaging typically requires multiple images at different excitation and emission wavelengths. Additionally, lifetime and spectra could both be utilized to expand the multiplexing capacity of fluorescence. However, resolving exogenous molecular probes based exclusively on the fluorescence lifetime has been limited by technical challenges in analyzing lifetime data. The phasor approach to lifetime analysis offers a simple, graphical solution that has increasingly been used to assess endogenous cellular autofluorescence to quantify metabolic factors. In this study, we employed the phasor analysis of FLIM to quantitatively resolve three exogenous, antibody-targeted fluorescent probes with similar spectral properties based on lifetime information alone. First, we demonstrated that three biomarkers that were spatially restricted to the cell membrane, cytosol, or nucleus could be accurately distinguished using FLIM and phasor analysis. Next, we successfully resolved and quantified three probes that were all targeted to cell surface biomarkers. Finally, we demonstrated that lifetime-based quantitation accuracy can be improved through intensity matching of various probe-biomarker combinations, which will expand the utility of this technique. Importantly, we reconstructed images for each individual probe, as well as an overlay of all three probes, from a single FLIM image. Our results demonstrate that FLIM and phasor analysis can be leveraged as a powerful tool for simultaneous detection of multiple biomarkers with high sensitivity and accuracy.


Assuntos
Corantes Fluorescentes , Imagem Óptica , Microscopia de Fluorescência/métodos , Imagem Molecular , Sondas Moleculares
4.
Proc Natl Acad Sci U S A ; 119(11): e2117013119, 2022 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-35259022

RESUMO

SignificanceThe study provided a long-sought molecular mechanism that could explain the link between fatty acid metabolism and cancer metastasis. Further understanding may lead to new strategies to inhibit cancer metastasis. The chemical proteomic approach developed here will be useful for discovering other regulatory mechanisms of protein function by small molecule metabolites.


Assuntos
Acil Coenzima A/metabolismo , Nucleosídeo NM23 Difosfato Quinases/antagonistas & inibidores , Neoplasias/metabolismo , Neoplasias/patologia , Neoplasias da Mama , Endocitose , Feminino , Humanos , Metástase Neoplásica , Neoplasias/etiologia , Ligação Proteica , Proteoma , Proteômica/métodos
5.
ACS Chem Biol ; 16(7): 1266-1275, 2021 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-34139124

RESUMO

Because of their involvement in various biological pathways, the sirtuin enzyme family members SIRT1, SIRT2, and SIRT3 play both tumor-promoting and tumor-suppressing roles, based on the context and experimental conditions. Thus, an interesting question is whether inhibiting one of them or inhibiting all of them would be better for treating cancers. Pharmacologically, this is difficult to address, due in part to potential off-target effects of different compounds. Compounds with almost identical properties but differing in SIRT1-3 selectivity will be useful for addressing this question. Here, we have developed a pan SIRT1-3 inhibitor (NH4-6) and a SIRT2-selective inhibitor (NH4-13) with very similar chemical structures, with the only difference being the substitution of an ester bond to an amide bond. Such a minimal difference allows us to accurately compare the anticancer effect of pan SIRT1-3 inhibition and SIRT2-selective inhibition in cellular and mouse models. NH4-6 showed stronger cytotoxicity than NH4-13 in cancer cell lines. In mice, both inhibitors showed similar anticancer efficacy. However, NH4-6 is toxic to mice, which hinders the use of higher dosages. These results highlight the advantage of SIRT2-selective inhibitors as potential anticancer therapeutics.


Assuntos
Antineoplásicos/uso terapêutico , Inibidores de Histona Desacetilases/uso terapêutico , Sirtuína 1/antagonistas & inibidores , Sirtuína 2/antagonistas & inibidores , Sirtuína 3/antagonistas & inibidores , Animais , Antineoplásicos/farmacocinética , Carbamatos/farmacocinética , Carbamatos/uso terapêutico , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Inibidores de Histona Desacetilases/farmacocinética , Humanos , Lisina/análogos & derivados , Lisina/farmacocinética , Lisina/uso terapêutico , Masculino , Camundongos , Ensaios Antitumorais Modelo de Xenoenxerto
6.
Cancers (Basel) ; 13(9)2021 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-33922599

RESUMO

Testicular germ cell tumors (TGCTs) are exceptionally sensitive to genotoxic chemotherapy, resulting in a high cure rate for the young men presenting with these malignancies. However, this treatment is associated with significant toxicity, and a subset of malignant TGCTs demonstrate chemoresistance. Mixed nonseminomas often contain pluripotent embryonal carcinoma (EC) cells, the cancer stem cells (CSCs) of these tumors. We hypothesized that differentiation therapy, a treatment strategy which aims to induce differentiation of tumor-propagating CSCs to slow tumor growth, could effectively treat mixed nonseminomas without significant toxicity. The FDA-approved antipsychotic thioridazine and the agricultural antibiotic salinomycin are two drugs previously found to selectively target CSCs, and here we report that these agents differentiate EC cells in vitro and greatly reduce their tumorigenic potential in vivo. Using a novel transformed induced pluripotent stem cell allograft model and a human xenograft model, we show that thioridazine extends the survival of tumor-bearing mice and can reduce the number of pluripotent EC cells within tumors. These results suggest that thioridazine could be repurposed as an alternative TGCT treatment that avoids the toxicity of conventional chemotherapeutics.

7.
Oncogene ; 40(9): 1644-1658, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33479498

RESUMO

SIRT5 is a member of the sirtuin family of NAD+-dependent protein lysine deacylases implicated in a variety of physiological processes. SIRT5 removes negatively charged malonyl, succinyl, and glutaryl groups from lysine residues and thereby regulates multiple enzymes involved in cellular metabolism and other biological processes. SIRT5 is overexpressed in human breast cancers and other malignancies, but little is known about the therapeutic potential of SIRT5 inhibition for treating cancer. Here we report that genetic SIRT5 disruption in breast cancer cell lines and mouse models caused increased succinylation of IDH2 and other metabolic enzymes, increased oxidative stress, and impaired transformation and tumorigenesis. We, therefore, developed potent, selective, and cell-permeable small-molecule SIRT5 inhibitors. SIRT5 inhibition suppressed the transformed properties of cultured breast cancer cells and significantly reduced mammary tumor growth in vivo, in both genetically engineered and xenotransplant mouse models. Considering that Sirt5 knockout mice are generally normal, with only mild phenotypes observed, these data establish SIRT5 as a promising target for treating breast cancer. The new SIRT5 inhibitors provide useful probes for future investigations of SIRT5 and an avenue for targeting SIRT5 as a therapeutic strategy.


Assuntos
Neoplasias da Mama/tratamento farmacológico , Isocitrato Desidrogenase/genética , Sirtuínas/genética , Animais , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Inibidores Enzimáticos/farmacologia , Feminino , Xenoenxertos , Humanos , Isocitrato Desidrogenase/antagonistas & inibidores , Camundongos , Camundongos Knockout , Estresse Oxidativo/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Sirtuínas/antagonistas & inibidores
8.
Toxicon ; 188: 95-107, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33065200

RESUMO

Crotamine and crotamine-like peptides are non-enzymatic polypeptides, belonging to the family of myotoxins, which are found in high concentration in the venom of the Crotalus genus. Helleramine was isolated and purified from the venom of the Southern Pacific rattlesnake, Crotalus oreganus helleri. This peptide had a similar, but unique, identity to crotamine and crotamine-like proteins isolated from other rattlesnakes species. The variability of crotamine-like protein amino acid sequences may allow different toxic effects on biological targets or optimize the action against the same target of different prey. Helleramine was capable of increasing intracellular Ca2+ in Chinese Hamster Ovary (CHO) cell line. It inhibited cell migration as well as cell viability (IC50 = 11.44 µM) of C2C12, immortalized skeletal myoblasts, in a concentration dependent manner, and promoted early apoptosis and cell death under our experimental conditions. Skeletal muscle harvested from mice 24 h after helleramine injection showed contracted myofibrils and profound vacuolization that enlarged the subsarcolemmal space, along with loss of plasmatic and basal membrane integrity. The effects of helleramine provide further insights and evidence of myotoxic activities of crotamine-like peptides and their possible role in crotalid envenomings.


Assuntos
Venenos de Crotalídeos/farmacologia , Crotalus , Placa Motora/efeitos dos fármacos , Músculo Estriado/efeitos dos fármacos , Sequência de Aminoácidos , Animais , Células CHO , Linhagem Celular , Cricetulus , Camundongos , Placa Motora/ultraestrutura , Músculo Estriado/ultraestrutura , Peptídeos
9.
Methods Mol Biol ; 1983: 151-171, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31087297

RESUMO

New therapeutics directed against established and novel molecular targets are urgently needed to intervene against cancer. Recently, it was reported that several members of the sirtuin family (SIRT1-7), the mammalian orthologs of the silent information regulator 2 (Sir2) protein in Saccharomyces cerevisiae, play important roles in carcinogenesis. Although SIRT2 has been attributed both tumor-promoting and tumor-suppressing activities in different contexts, selective SIRT2 inhibition with a small molecule mechanism-based inhibitor known as Thiomyristoyl lysine (TM) repressed the growth of breast cancer cell lines. In light of the anticancer effect of SIRT2 inhibition in cell culture, it was critical to assess the efficacy of TM as a potential anticancer therapy in vivo. This was accomplished by testing the SIRT2 inhibitor in genetically engineered and xenotransplantation mouse models of breast cancer, using the procedures detailed in this chapter.


Assuntos
Antineoplásicos/farmacologia , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos , Inibidores de Histona Desacetilases/farmacologia , Neoplasias/metabolismo , Sirtuína 2/antagonistas & inibidores , Animais , Antineoplásicos/química , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Cromatografia Líquida , Monitoramento de Medicamentos , Feminino , Inibidores de Histona Desacetilases/química , Masculino , Espectrometria de Massas , Camundongos , Camundongos Transgênicos , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Ensaios Antitumorais Modelo de Xenoenxerto
10.
Ultrastruct Pathol ; 42(2): 116-123, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29466088

RESUMO

Crotamine is a cationic, non-enzymatic, protein integrating a minor family of myotoxins, composed of 42 amino acid residues, described in Viperidae and Crotalidae snake's families that has been used in neuroscience research, drug progressing and molecular diversity reports. Crotamine-like protein (CLP) from C.o.helleri venom was isolated in fraction 5 from 7 peaks obtained by sulfopropyl waters protein pak cationic exchange column. In tricine-SDS-PAGE under non-reduced conditions this CLP showed a single band of ~8 kDa molecular weight. CLP induced toxicity of K-562 cells with a CC50 of 11.09 µM. In mice adrenal gland after 24 h of CLP injection, cortical cells exhibited swollen mitochondria with scarce tubular cristae, some elements of smooth and rough endoplasmic reticula, widened nuclear envelope, slightly osmiophilic lipid droplets, and autophagic vacuoles. In some areas cortical cells plasma membrane and endothelial walls disappeared, which indicated a necrosis process. In other areas, endothelial cell cytoplasm did not present the normal caveolae and pinocytotic vesicles. To our knowledge, this is the first report on mice adrenal gland damages, caused by the injection of CLP from rattlesnakes. Our results propose that adrenal cortex lesions may be significant in the envenoming etiopathogenesis by CLP.


Assuntos
Glândulas Suprarrenais/efeitos dos fármacos , Glândulas Suprarrenais/ultraestrutura , Venenos de Crotalídeos/toxicidade , Glândulas Suprarrenais/patologia , Animais , Linhagem Celular Tumoral , Crotalus , Humanos , Camundongos
11.
Acta colomb. psicol ; 19(1): 68-78, Jan.-June 2016. tab
Artigo em Inglês | LILACS | ID: lil-783505

RESUMO

El objetivo principal del presente estudio es analizar y caracterizar la influencia de las variables educativas y sociodemográficas sobre el grado de desarrollo de las creencias epistemológicas (CE) en estudiantes universitarios y de último año de bachillerato. Para conseguir este objetivo se administró un instrumento llamado EQEBI, que mide las CE a una muestra de 1.387 alumnos en Bogotá (Colombia). La metodología utilizada fue cuantitativa y no experimental. Para comparar las CE de acuerdo con los grupos conformados según las variables analizadas, se utilizaron las pruebas estadísticas no paramétricas de Mann-Whitney y Kruskal-Wallis. Los resultados indican diferencias significativas en las CE por sexo, nivel socioeconómico y nivel educativo de los estudiantes y de sus padres. Sin embargo, no se encontraron diferencias según el entorno de procedencia (rural o urbano), ni por la repetición de curso. Este estudio tiene implicaciones para el diseño de programas educativos específicos, según las características de los alumnos, que favorezcan el desarrollo de las CE.


The main goal of the present study is to analyze and characterize the influence of educational and socio-demographic variables on the Epistemological Beliefs (EB) of senior year and university students. With this aim, an instrument that measures EB, called EQEBI, was applied to a sample of 1387 students in Bogota-Colombia. The methodology used was quantitative, non experimental, and the nonparametric statistics tests of Mann-Whitney and Kruskal-Wallis were used to compare the EB according to the groups formed by the variables analyzed. Results indicate significant differences in EB by sex, socioeconomic status and educational level of students and his parents, but no differences according to the environmental background (rural or urban) and grade repetition. This study has implications for the design of specific educational programs, according to the characteristics of students, to encourage the development of EB.


O objetivo principal do presente estudo é analisar e caracterizar a influência de variáveis educativas e sociodemográficas sobre o grau de desenvolvimento das crenças epistemológicas (CE) em estudantes universitários e do último ano do ensino médio. Para atingir esse objetivo, administrou-se um instrumento chamado EQEBI, que mede as CE a uma amostra de 1.387 alunos em Bogotá (Colômbia). A metodologia utilizada foi quantitativa e não experimental. Para comparar as CE de acordo com os grupos formados segundo as variáveis analisadas, utilizaram-se as provas estatísticas não paramétricas de Mann-Whitney e Kruskal-Wallis. Os resultados indicam diferenças significativas nas CE por sexo, nível socioeconômico e nível educativo dos estudantes e de seus pais. Contudo, não se encontraram diferenças segundo o ambiente de procedência (rural ou urbano) nem pela repetição de curso. Este estudo tem implicações para o desenho de programas educativos específicos, conforme as características dos alunos, que favoreçam o desenvolvimento das CE.


Assuntos
Humanos , Masculino , Feminino , Adolescente , Testes Psicológicos , Adolescente
12.
Rev Med Inst Mex Seguro Soc ; 51(4): 372-7, 2013.
Artigo em Espanhol | MEDLINE | ID: mdl-24021064

RESUMO

BACKGROUND: traumatic brain injury is a main cause of hospital admission and death in children. Our objective was to identify prognostic factors of pediatric traumatic brain injury. METHODS: this was a dynamic cohort study of traumatic brain injury with 6 months follow-up. The exposition was: mild or moderate/severe traumatic brain injury, searching for prognosis (morbidity-mortality and decreased Glasgow scale). Relative risk and logistic regression was estimated for prognostic factors. RESULTS: we evaluated 440 patients with mild traumatic brain injury and 98 with moderate/severe traumatic brain injury. Morbidity for mild traumatic brain injury was 1 %; for moderate/severe traumatic brain injury, 5 %. There were no deaths. Prognostic factors for moderate/severe traumatic brain injury were associated injuries (RR = 133), fractures (RR = 60), street accidents (RR = 17), night time accidents (RR = 2.3) and weekend accidents (RR = 2). Decreased Glasgow scale was found in 9 %, having as prognostic factors: visible injuries (RR = 3), grown-up supervision (RR = 2.5) and time of progress (RR = 1.6). CONCLUSIONS: there should be a prognosis established based on kinetic energy of the injury and not only with Glasgow Scale.


Introducción: en los niños con traumatismo, las lesiones craneoencefálicas son las principales causas de hospitalización y muerte. El objetivo de esta investigación fue identificar los factores pronóstico del traumatismo craneoencefálico en los niños. Métodos: cohorte dinámica con seis meses de seguimiento. El trauma craneoencefálico se estratificó como leve o moderado-severo, se identificó morbilidad y se realizó evaluación con la escala de coma de Glasgow. Se estimó riesgo relativo (RR) y regresión logística para factores pronóstico. Resultados: se identificaron 440 pacientes con trauma craneoencefálico leve y 98 con moderado-severo; se observó morbilidad en 1 y 5 %, respectivamente. No hubo defunciones. Los factores pronóstico para el trauma moderado-severo fueron los siguientes: lesiones relacionadas (RR = 133), fracturas (RR = 60), accidentes en la calle (RR = 17), horario nocturno (RR = 2.3) y fin de semana (RR = 2). Se presentó deterioro en la puntuación de Glasgow en 9 %, con los siguientes factores pronóstico: lesiones visibles (RR = 3), supervisión por adulto (RR = 2.5) y tiempo de evolución (RR = 1.6). Conclusiones: en los niños con trauma craneoencefálico debe establecerse el pronóstico según la energía cinética de la lesión y con la escala Glasgow.


Assuntos
Lesões Encefálicas , Lesões Encefálicas/diagnóstico , Lesões Encefálicas/epidemiologia , Criança , Pré-Escolar , Estudos de Coortes , Feminino , Seguimentos , Humanos , Escala de Gravidade do Ferimento , Masculino , Prognóstico
13.
MEDICC Rev ; 15(3): 11-5, 2013 07.
Artigo em Inglês | MEDLINE | ID: mdl-23934421

RESUMO

INTRODUCTION: Knowledge of prognostic factors in end-stage renal disease patients has improved dialysis management and methods for reducing morbidity and mortality, underlining the importance of identification, prevention and control of these factors. OBJECTIVE: Identify factors affecting prognosis (survival or death) in hemodialysis patients at the Medical-Surgical Research Center in Havana over a ten-year period. METHODS: Descriptive, prospective study of 81 end-stage renal disease patients who received hemodialysis at the Medical-Surgical Research Center from 1995 to 2004. Prognostic factors were identified at initiation of and during dialysis treatment, using chi square, t test, McNemar test, Kaplan Meier analysis, log-rank test and Cox regression model, with significance threshold set at p <0.05. RESULTS: Hypertension and diabetes were the leading causes of end-stage renal disease. Six patients were referred late. Mean survival was 4.4 years; with survival of 86.6%, 54.7% and 26.6% at one, three and five years respectively. Factors predictive of decreased survival that were most frequent at initiation of hemodialysis were hypertension and chronic anemia (both present in 95.9% of cases); malnutrition, hypoalbuminemia, cardiovascular disease and chronic liver disease increased during treatment while hypertension decreased. In multivariate analysis, prognostic factors that significantly predicted decreased survival were hypertension, inadequate vascular access and diabetes. Patients aged ≥ 60 years and those with malnutrition, hypoalbuminemia, anemia, cardiovascular disease or liver disease had lower survival figures at the end of the study period. Leading causes of death were infections (45.2%) and cardiovascular disease (41.9%); the latter was present in 93.5% of deaths, independent of underlying cause of death. CONCLUSIONS: Survival of hemodialysis patients diminished at five years. Some negative predictive factors are present at initiation of hemodialysis, such as diabetes, hypertension and chronic anemia; others increased later, including malnutrition, hypoalbuminemia, cardiovascular disease and liver disease.


Assuntos
Falência Renal Crônica/diagnóstico , Diálise Renal/mortalidade , Adulto , Anemia/complicações , Cuba/epidemiologia , Feminino , Humanos , Hipertensão/complicações , Falência Renal Crônica/etiologia , Falência Renal Crônica/mortalidade , Masculino , Prognóstico , Estudos Prospectivos , Análise de Sobrevida
14.
Cancer Causes Control ; 21(10): 1693-700, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20617376

RESUMO

INTRODUCTION: We present a large feasibility evaluation of high-risk HPV (HR-HPV) DNA testing and cervical cytology as a primary screening strategy for cervical cancer precursor lesions in Mexican women, as part of a routine cancer control program (CCP). METHODS: A community-based study was carried out in 50,159 women aged 20-70 years who visited the CCP in 12 federal entities located in Northern, Central, and Southern Mexico, including a total of 48 primary health care units of the Instituto Mexicano del Seguro Social (IMSS). Cervical specimens for cytology and HR-HPV tests were collected at baseline. Women with cytological abnormalities (ASCUS or greater) were referred to colposcopy for further evaluation and treatment if necessary. A subset of HR-HPV-positive women without cervical lesions, in Morelos state, were tested again for HR-HPV DNA within a year, and repeat-positive women were referred to colposcopy. RESULTS: HR-HPV prevalence among all women was 8.6% (95% CI: 8.3-8.9). Prevalence by age group was 12.2% (95% CI: 11.0-13.3) before 30 years of age and decreased to 7.4% (95% CI: 6.7-8.0) between 46 and 50 years of age. A second minor prevalence peak (8.1%; 95% CI: 7.2-9.0) was observed in women more than 55 years of age. Overall prevalence of cytological abnormalities was relatively low (2.2%; 95% CI: 2.0-2.3) with the highest frequency of abnormal cytology (ASCUS or greater) in the 41-45 year age group (2.5%: 95% CI 2.1-2.7). No correlation between cervical abnormalities and HR-HPV prevalence, by region, was observed. A total of 370 (0.7%) women had an abnormal cytology as well as a positive HR-HPV result; 736 (1.5%) had an abnormal cytology and a negative HR-HPV test; 3,941 (7.9%) women had a positive HR-HPV test and a normal cytology; and 45,112 (89.9%) women were negative in both tests. The first two groups were immediately referred to colposcopy, 72.7% of the women from the cytology-positive and HR-HPV-positive group and 58.0% from the cytology-positive and HR-HPV-negative group successfully completing evaluation. Among the 269 cytology-positive and HR-HPV-positive women, 53 (19.7%) CIN2/3+ cases were detected, whereas among the 427 cytology-positive and HR-HPV-negative participants, only 13 (3.0%) CIN2/3+ cases were documented. In Morelos state, a sample of 287 women with a negative cytology smear and a positive HR-HPV test at baseline were re-screened after ~12 months, by means of cytology and HR-HPV testing. Among these women, 106 (36.9%) were again HR-HPV positive and were referred to colposcopy. Of whom, 76 (71.7%) were successfully evaluated; among these women, 9 CIN2/3+ (11.8%) were documented. Sensitivity of cervical cytology for detecting histologically confirmed CIN2/3+ cases was only 40.0% (95% CI 38.5-41.4) compared to 93.3% (95% CI 92.5-94.0) for HPV DNA testing considering the additional cases detected among women with persistent HPV infection. The specificity of cytology was 97.0 vs. 89.2% for the HPV DNA test. DISCUSSION: Population-based programs using HR-HPV testing can improve cervical cancer prevention and control in Mexican and other populations where cytological screening is inadequate for detecting precursors of cervical cancer.


Assuntos
DNA Viral/isolamento & purificação , Detecção Precoce de Câncer/métodos , Infecções por Papillomavirus/diagnóstico , Neoplasias do Colo do Útero/diagnóstico , Neoplasias do Colo do Útero/virologia , Esfregaço Vaginal , Adulto , Idoso , Colposcopia , Citodiagnóstico , Feminino , Humanos , Programas de Rastreamento/métodos , México , Pessoa de Meia-Idade , Papillomaviridae/genética , Projetos Piloto , Valor Preditivo dos Testes , Sensibilidade e Especificidade , Previdência Social , Adulto Jovem , Displasia do Colo do Útero/diagnóstico , Displasia do Colo do Útero/virologia
15.
Planta Med ; 76(7): 705-7, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-19960415

RESUMO

A pharmacological screening of the ethanol extract and fractions of two Peruvian medicinal plants, Plagiochila disticha and Ambrosia peruviana, led to the isolation and characterization of three ENT-2,3-secoaromadendrane-type sesquiterpenoids, named plagiochiline A ( 1), I ( 2), and R ( 3), as well as of two pseudoguaianolids, damsin ( 4) and confertin ( 5), which exhibited significant cytotoxic activity against a panel of human tumor cell lines. Compounds 1, 4, and 5 were also investigated for their in vitro antileishmanial, trypanocidal, and antituberculosis activity against Leishmania amazonensis axenic amastigotes and Trypanosoma cruzi trypomastigotes, as well as against MDR and sensitive strains of Mycobacterium tuberculosis, respectively.


Assuntos
Anti-Infecciosos/isolamento & purificação , Antineoplásicos Fitogênicos/isolamento & purificação , Asteraceae/química , Azulenos/isolamento & purificação , Compostos de Epóxi/isolamento & purificação , Piranos/isolamento & purificação , Sesquiterpenos/isolamento & purificação , Linhagem Celular Tumoral , Avaliação Pré-Clínica de Medicamentos , Humanos , Peru , Plantas Medicinais/química
16.
Immunopharmacol Immunotoxicol ; 30(4): 883-96, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18800269

RESUMO

Earlier studies have revealed the ability of sera from several mammals to neutralize the toxic effects of snake venom. The Venezuelan opossum (Didelphis marsupialis) is one that has been found to inhibit hemorrhagic and proteolytic activities of venoms from many species of snakes. In this article it is shown that the opossum sera and its 0.15DM fraction were able to completely neutralize both hemorrhagic and hydrolysis (proteolysis) of casein effects induced by venom of the Lansberg's hognose pit viper (Porthidium lansbergii hutmanni). We have used DEAE-cellulose ion exchange chromatography to collect protein fractions from D. marsupialis sera which were able to defend mice from the lethal effects of P.l. hutmanni venom. The fractions separated were homogeneous by conventional electrophoresis using SDS-PAGE. The protein bands obtained contained molecular weights of approximately 6 to 220 kDa. These results revealed the presence of proteases inhibitors in the opossum sera fractions and the inhibition of venom activity by opossum sera suggesting a reciprocal adaptation at the molecular level.


Assuntos
Cromatografia DEAE-Celulose/métodos , Venenos de Crotalídeos/antagonistas & inibidores , Venenos de Crotalídeos/toxicidade , Hemorragia/prevenção & controle , Gambás/sangue , Peptídeo Hidrolases/metabolismo , Soro , Animais , Fracionamento Químico , Didelphis/sangue , Hemorragia/induzido quimicamente , Masculino , Camundongos , Soro/química , Mordeduras de Serpentes/tratamento farmacológico , Mordeduras de Serpentes/metabolismo
17.
Int Braz J Urol ; 33(4): 493-500; discussion 501, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17767753

RESUMO

OBJECTIVE: To determine the efficacy of Bixa Orellana (BO) in patients with benign prostatic hyperplasia (BPH) presenting moderate lower urinary tract symptoms (LUTS). MATERIALS AND METHODS: It is a prospective double-blind randomized placebo-controlled study. One thousand four hundred and seventy eight patients presenting moderate LUTS associated to BPH were interviewed, from whom we selected 136 to fulfill the criteria of inclusion and exclusion. Assignation was performed at random in blocks of four to receive B0 at a dose of 250 mg 3 times a day or placebo (Pbo) for 12 months, 68 patients were assigned to each group. From the patients in the study we obtained data of demographic, epidemiologic, symptom score, uroflowmetry and post void residual urine variables. RESULTS: Basically both groups were compared clinically, demographically and biochemically. Throughout the study variations of symptom score, mean delta symptom score during each visit and the final average delta were similar for both groups (BO - 0.79 +/- 1.87 and Pbo - 1.07 +/- 1.49) (p = 0.33). Similarly variations of Qmax mean, Qmax average delta and final average delta were similar (BO 0.44 +/- 1.07 and Pbo 0.47 +/- 1.32) (p = 0.88). Variations of post void residual urine mean, post void residual urine average delta in each visit and the final average delta were similar for both groups (BO 4.24 +/- 11.69 and Pbo 9.01 +/- 18.66) (p = 0.07). No differences were found in the answers of clinically significant improvement assessed with relative risk and risk differences, even though the proportion of adverse effects was similar for both groups. CONCLUSION: Patients with BPH that present moderate LUTS did not show any benefit receiving BO when compared to placebo.


Assuntos
Bixaceae/química , Fitoterapia , Extratos Vegetais/uso terapêutico , Hiperplasia Prostática/complicações , Prostatismo/tratamento farmacológico , Obstrução do Colo da Bexiga Urinária/tratamento farmacológico , Idoso , Método Duplo-Cego , Humanos , Masculino , Pessoa de Meia-Idade , Peru , Placebos , Extratos Vegetais/efeitos adversos , Folhas de Planta/química , Estudos Prospectivos , Prostatismo/etiologia , Resultado do Tratamento , Obstrução do Colo da Bexiga Urinária/etiologia
18.
Int. braz. j. urol ; 33(4): 493-501, July-Aug. 2007. ilus, tab
Artigo em Inglês | LILACS | ID: lil-465785

RESUMO

OBJECTIVE: To determine the efficacy of Bixa Orellana (BO) in patients with benign prostatic hyperplasia (BPH) presenting moderate lower urinary tract symptoms (LUTS). MATERIALS AND METHODS: It is a prospective double-blind randomized placebo-controlled study. One thousand four hundred and seventy eight patients presenting moderate LUTS associated to BPH were interviewed, from whom we selected 136 to fulfill the criteria of inclusion and exclusion. Assignation was performed at random in blocks of four to receive B0 at a dose of 250 mg 3 times a day or placebo (Pbo) for 12 months, 68 patients were assigned to each group. From the patients in the study we obtained data of demographic, epidemiologic, symptom score, uroflowmetry and post void residual urine variables. RESULTS: Basically both groups were compared clinically, demographically and biochemically. Throughout the study variations of symptom score, mean delta symptom score during each visit and the final average delta were similar for both groups (BO - 0.79 ± 1.87 and Pbo - 1.07 ± 1.49) (p = 0.33). Similarly variations of Qmax mean, Qmax average delta and final average delta were similar (BO 0.44 ± 1.07 and Pbo 0.47 ± 1.32) (p = 0.88). Variations of post void residual urine mean, post void residual urine average delta in each visit and the final average delta were similar for both groups (BO 4.24 ± 11.69 and Pbo 9.01 ± 18.66) (p = 0.07). No differences were found in the answers of clinically significant improvement assessed with relative risk and risk differences, even though the proportion of adverse effects was similar for both groups. CONCLUSION: Patients with BPH that present moderate LUTS did not show any benefit receiving BO when compared to placebo.


Assuntos
Idoso , Humanos , Masculino , Pessoa de Meia-Idade , Bixaceae/química , Fitoterapia , Extratos Vegetais/uso terapêutico , Hiperplasia Prostática/complicações , Prostatismo/tratamento farmacológico , Obstrução do Colo da Bexiga Urinária/tratamento farmacológico , Método Duplo-Cego , Peru , Placebos , Estudos Prospectivos , Extratos Vegetais/efeitos adversos , Folhas de Planta/química , Prostatismo/etiologia , Resultado do Tratamento , Obstrução do Colo da Bexiga Urinária/etiologia
19.
Exp Toxicol Pathol ; 59(2): 129-37, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17616380

RESUMO

This study explored the toxic effects of crotoxin isolated from Crotalus durissus cumanensis venom on the ultrastructure of mice cardiac autonomic nervous system. Mice were intravenously injected with saline (control group) and crotoxin diluted in saline venom (study group) at a dose of 0.107 mg/kg mouse body weight. Samples from the inter-ventricular septum were prepared for electron microscopy after 6 h (G1), 12 h (G2), 24 h (G3) and 48 h (G4). The G1 group showed some cardiomyocyte with pleomorphic mitochondria. Capillary swollen walls, nerve cholinergic endings with depleted acetylcholine vesicles in their interior and other depletions were observed. A space completely lacking in contractile elements was noticed. The G2 group demonstrated a myelinic figure, a subsarcolemic region with few myofibrils and nervous cholinergic terminal with scarce vacuoles in their interior. The G3 group demonstrated a structure with a depleted axonic terminal, mitochondrias varying in size and enhanced electron density. In addition, muscular fibers with myofibrillar structure disorganization, a depleted nervous structure surrounded by a Schwann cell along with an abundance of natriuretic peptides, were seen. An amyelinic terminal with depleted Schwann cell and with scarce vesicles was also observed. Finally, axonic lysis with autophagic vacuoles in their interior and condensed mitochondria was observed in the G4 group. This work describes the first report of ultrastructural damage caused by crotoxin on mice cardiac autonomic nervous system.


Assuntos
Sistema Nervoso Autônomo/efeitos dos fármacos , Sistema Nervoso Autônomo/ultraestrutura , Crotalus , Crotoxina/toxicidade , Coração/inervação , Acetilcolina/metabolismo , Animais , Capilares/efeitos dos fármacos , Capilares/ultraestrutura , Vasos Coronários/efeitos dos fármacos , Vasos Coronários/ultraestrutura , Crotoxina/química , Masculino , Camundongos , Microscopia Eletrônica de Transmissão , Mitocôndrias Cardíacas/efeitos dos fármacos , Mitocôndrias Cardíacas/ultraestrutura , Neurônios Motores/efeitos dos fármacos , Neurônios Motores/metabolismo , Neurônios Motores/ultraestrutura , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/ultraestrutura , Terminações Nervosas/efeitos dos fármacos , Terminações Nervosas/ultraestrutura , Retículo Sarcoplasmático/efeitos dos fármacos , Retículo Sarcoplasmático/ultraestrutura , Células de Schwann/efeitos dos fármacos , Células de Schwann/ultraestrutura
20.
J Ethnopharmacol ; 88(2-3): 199-204, 2003 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-12963143

RESUMO

The antimicrobial activity of 36 ethanol extracts from 24 plants, all of them currently used in the Peruvian traditional medicine for the treatment of several infectious and inflammatory disorders, was tested by means of the agar-well diffusion assay against four bacteria (Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa) and four fungi (Candida albicans, Trichophyton mentagrophytes, Microsporum gypseum and Sporothrix schenckii). Twenty-five (69%) extracts showed some degree of antimicrobial activity against at least one microorganism. The plants with the greatest antimicrobial activity were Cestrum auriculatum L. Heritier (Solanaceae), Iryanthera lancifolia Ducke Suesseng (Myristicaceae), Lepechinia meyenii (Walp.) Epling (Lamiaceae) and Ophryosporus peruvianus (Gmelin) King & H. Rob. (Asteraceae).


Assuntos
Anti-Infecciosos/farmacologia , Medicina Tradicional , Plantas Medicinais , Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Anti-Infecciosos/isolamento & purificação , Antifúngicos/isolamento & purificação , Antifúngicos/farmacologia , Testes de Sensibilidade Microbiana , Peru , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/farmacologia , Plantas Medicinais/química , Plantas Medicinais/classificação
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