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1.
Gynecol Oncol ; 164(3): 498-504, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35063276

RESUMO

OBJECTIVE: The phase IIIb OPINION trial (NCT03402841) investigated olaparib maintenance monotherapy in patients without a deleterious or suspected deleterious germline BRCA1/BRCA2 mutation (gBRCAm) who had platinum-sensitive relapsed ovarian cancer (PSROC) and had received ≥2 previous lines of platinum-based chemotherapy. METHODS: In this single-arm, open-label, international study, patients who had responded to platinum-based chemotherapy received maintenance olaparib tablets (300 mg twice daily) until disease progression or unacceptable toxicity. The primary endpoint was investigator-assessed progression-free survival (PFS) (modified RECIST version 1.1). A key secondary endpoint was PFS by homologous recombination deficiency (HRD) and somatic BRCAm (sBRCAm) status. The primary analysis of PFS was planned for 18 months after the last patient received their first dose. RESULTS: Two hundred and seventy-nine patients were enrolled and received olaparib. At data cutoff (October 2, 2020), 210 PFS events had occurred (75.3% maturity) and median PFS was 9.2 months (95% confidence interval [CI], 7.6-10.9) in the overall population. At 12 and 18 months, 38.5% and 24.3% of patients were progression-free, respectively. In the predefined biomarker subgroups, median PFS was 16.4, 11.1, 9.7, and 7.3 months in sBRCAm, HRD-positive including sBRCAm, HRD-positive excluding sBRCAm, and HRD-negative patients, respectively. The most common treatment-emergent adverse events (TEAEs) were nausea (48.4%) and fatigue/asthenia (44.1%). TEAEs led to dose interruption, dose reduction, and treatment discontinuation in 47.0%, 22.6%, and 7.5% of patients, respectively. CONCLUSION: Maintenance olaparib demonstrated clinical benefit in patients without a gBRCAm, and across all subgroups, compared with historical placebo controls. There were no new safety signals.


Assuntos
Recidiva Local de Neoplasia , Neoplasias Ovarianas , Ftalazinas , Piperazinas , Proteína BRCA1/genética , Proteína BRCA2/genética , Carcinoma Epitelial do Ovário/tratamento farmacológico , Carcinoma Epitelial do Ovário/genética , Feminino , Células Germinativas , Mutação em Linhagem Germinativa , Humanos , Quimioterapia de Manutenção , Mutação , Recidiva Local de Neoplasia/tratamento farmacológico , Recidiva Local de Neoplasia/genética , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/genética , Ftalazinas/efeitos adversos , Piperazinas/efeitos adversos , Platina/uso terapêutico
2.
Pol J Vet Sci ; 23(1): 43-50, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32233287

RESUMO

To date, only a few studies on the azithromycin (AZM) pharmacokinetics in ornamental birds have been published. In the current study AZM concentrations in domestic pigeon (Columba livia domestica) plasma samples were analyzed using a validated ultra-high performance liquid chromatography tandem mass spectrometry method. The aim of the current study was to carry out an analysis of the pharmacokinetics and pharmacodynamics after administration of a single oral dose of a sustained-release AZM formulation and to conduct a simulation of treatment based on selected minimal inhibitory values. The study was performed with 12 healthy adult pigeons, both sexes. The pigeons tolerated AZM very well and no adverse effects were observed in any animal during the study. Based on the observed characteristics of the pharmacokinetics/ /pharmacodynamics profiles of AZM in pigeons, it should be noted that 35 mg/kg per os as a single starting dose and 25 mg/kg every 24 h are recommended for treatment of both suscep- tible and less susceptible pathogens.


Assuntos
Antibacterianos/farmacocinética , Azitromicina/farmacocinética , Columbidae/sangue , Animais , Antibacterianos/administração & dosagem , Antibacterianos/sangue , Azitromicina/administração & dosagem , Azitromicina/sangue , Preparações de Ação Retardada
3.
Poult Sci ; 98(11): 5971-5980, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31309225

RESUMO

Intensive chicken production leads to overuse of antibiotics on poultry farms. For food safety control, there is great need for means to use non-conventional matrices allowing analysis of antibiotics during poultry breeding. The main goal of this study was to demonstrate feathers as suitable material for non-invasive detection of doxycycline treatment in poultry. Transfer to and depletion of doxycycline in chicken feathers were investigated after therapeutic, spray, and subtherapeutic treatment. For the quantitative determination of doxycycline in feathers, a validated ultra-high-performance liquid chromatography - tandem mass spectrometry method was used. High concentrations of doxycycline in feathers were detectable for 22 D post treatment in each experimental group, and they were much higher than those in muscle and liver. A washing experiment with the same solvent as for extraction showed different ratios between extractable and non-extractable residues in feathers of chickens treated therapeutically, by spraying and subtherapeutically, which demonstrates the ability of feather analysis to distinguish different forms of treatment. After a segmentation procedure, high amounts of doxycycline were found to be deposited in the upper part of feathers in each treatment group. The obtained results showed that chicken feathers are a suitable material for the detection and non-invasive surveillance of doxycycline.


Assuntos
Antibacterianos/análise , Galinhas , Doxiciclina/análise , Resíduos de Drogas/análise , Plumas/química , Inocuidade dos Alimentos/métodos , Animais , Cromatografia Líquida de Alta Pressão/veterinária , Espectrometria de Massas em Tandem/veterinária , Fatores de Tempo , Distribuição Tecidual
5.
Transplant Proc ; 50(7): 2150-2153, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30177128

RESUMO

Pregnancy following renal or liver transplant is safe for the mother, fetus, and allograft if standard practice guidelines are strictly followed. Cesarean delivery is often required for the safety of the mother and child. The aim of this paper was the evaluation of delivery method in patients after liver (G1) and kidney transplantation (G2) in comparison with the population of healthy pregnant women (G0). MATERIALS: Retrospective analysis included 51 (G1) and 59 (G2) women who delivered between 2000 and 2016. Control group (G0) consisted of 170 nontransplanted patients, who delivered between 2014 and 2016. The results were compared using nonparametric and parametric tests (Fisher exact test, t test). The SAS 9.2 was used for the analysis. RESULTS: The rate of cesarean delivery was high in all pregnancies following kidney (G1 = 80.4%) or liver transplantation (G2 = 67.8%) compared with control group (G0 = 44.1%; P < .05). The most common indication for cesarean delivery in G1 was gestational hypertension/preeclampsia (n = 18; 43.9%), threatening intrauterine asphyxia (n = 12; 29.3%), and failure to progress (n = 2; 4.9%). The most common indications for cesarean delivery in G2 were threatening intrauterine asphyxia (n = 14; 35%), failure to progress (n = 9; 22.5%), and gestational hypertension/preeclampsia (n = 2; 5%). CONCLUSION: Cesarean delivery in patients after kidney or liver transplantation is performed mainly for obstetric reasons. The reported incidence of cesarean delivery in pregnancy following transplant is high, reflecting the high degree of clinical caution exercised in these patients.


Assuntos
Cesárea/estatística & dados numéricos , Parto Obstétrico/métodos , Transplante de Rim , Transplante de Fígado , Adolescente , Adulto , Feminino , Humanos , Gravidez , Complicações na Gravidez/epidemiologia , Resultado da Gravidez , Estudos Retrospectivos , Fatores de Risco , Adulto Jovem
6.
Transplant Proc ; 50(6): 1889-1891, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30056922

RESUMO

BACKGROUND: Chronic immunosuppression constitutes a risk factor of human papillomavirus (HPV) related cervical cancer development. Maintenance immunosuppression with mammalian target of rapamycin (mTOR) inhibitors is associated with decreased incidence of de novo malignancies in kidney graft recipients. Recently published data suggest that mTOR inhibitors interfere with viral replication. The aim of the study was to assess if there is a difference in prevalence of HPV cervical infection in women on immunosuppressive regimens with or without mTOR inhibitors. MATERIAL AND METHODS: Cervical swabs taken from 64 immunosuppressed women on renal replacement therapy were analyzed for the presence of high-risk (HR) HPV DNA by means of an Amplicor HPV test and assessed taking into account the recorded data on mTOR inhibitor use. RESULTS: The testing revealed the presence of HR HPV DNA in none of the women that were treated with mTOR inhibitors and in 21.4% of patients that were administered immunosuppressive regimens without mTOR inhibitors (P = .08). Interestingly, 32% of women from the mTOR(-) group in contrast to 12.5% in the mTOR(+) group declared having had more than 2 lifetime sexual partners. CONCLUSIONS: Our results suggest that mTOR inhibitors might constitute a promising therapy modification in women at risk of HPV cervical malignancy development, but the effectiveness of such strategy requires further studies.


Assuntos
Colo do Útero/virologia , Imunossupressores/uso terapêutico , Infecções por Papillomavirus/epidemiologia , Terapia de Substituição Renal , Sirolimo/uso terapêutico , Adulto , DNA Viral , Feminino , Humanos , Terapia de Imunossupressão/métodos , Incidência , Pessoa de Meia-Idade , Papillomaviridae/efeitos dos fármacos , Prevalência , Fatores de Risco , Serina-Treonina Quinases TOR/antagonistas & inibidores , Neoplasias do Colo do Útero/virologia
7.
J Vet Pharmacol Ther ; 41(1): 166-169, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28675463

RESUMO

The objective of this study was to investigate the influence of enrofloxacin (ENR) traces on doxycycline (DC) pharmacokinetic depletion phase parameters in plasma and lungs of healthy and Mycoplasma gallisepticum (MG)-infected chicken broilers. The multiple-dose oral administration of DC to chickens which were permanently exposed on ENR traces significantly increased concentration of DC in plasma and lung. It also prolonged the DC elimination time in both healthy and infected animals after final dose. The obtained result indicated that simultaneous administration of DC and ENR in chicken broilers therapy should be avoided.


Assuntos
Antibacterianos/farmacologia , Doxiciclina/farmacocinética , Fluoroquinolonas/administração & dosagem , Infecções por Mycoplasma/veterinária , Mycoplasma gallisepticum/efeitos dos fármacos , Doenças das Aves Domésticas/tratamento farmacológico , Animais , Antibacterianos/uso terapêutico , Doxiciclina/uso terapêutico , Interações Medicamentosas , Enrofloxacina , Infecções por Mycoplasma/tratamento farmacológico , Doenças das Aves Domésticas/microbiologia
9.
J Vet Pharmacol Ther ; 40(6): e39-e44, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28456999

RESUMO

The penetration of oxytetracycline (OTC) into the oral fluid and plasma of pigs and correlation between oral fluid and plasma were evaluated after a single intramuscular (i.m.) dose of 20 mg/kg body weight of long-acting formulation. The OTC was detectable both in oral fluid and plasma from 1 hr up to 21 day after drug administration. The maximum concentrations (Cmax ) of drug with values of 4021 ± 836 ng/ml in oral fluid and 4447 ± 735 ng/ml in plasma were reached (Tmax ) at 2 and 1 hr after drug administration respectively. The area under concentration-time curve (AUC), mean residence time (MRT) and the elimination half-life (t1/2ß ) were, respectively, 75613 ng × hr/ml, 62.8 hr and 117 hr in oral fluid and 115314 ng × hr/ml, 31.4 hr and 59.2 hr in plasma. The OTC concentrations were remained higher in plasma for 48 hr. After this time, OTC reached greater level in oral fluid. The strong correlation (r = .92) between oral fluid and plasma OTC concentrations was observed. Concentrations of OTC were within the therapeutic levels for most sensitive micro-organism in pigs (above MIC values) for 48 hr after drug administration, both in the plasma and in oral fluid.


Assuntos
Antibacterianos/farmacocinética , Oxitetraciclina/farmacocinética , Saliva/química , Animais , Antibacterianos/administração & dosagem , Antibacterianos/análise , Antibacterianos/sangue , Preparações de Ação Retardada , Meia-Vida , Injeções Intramusculares/veterinária , Oxitetraciclina/administração & dosagem , Oxitetraciclina/análise , Oxitetraciclina/sangue , Suínos/metabolismo
10.
Transplant Proc ; 46(10): 3268-72, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25498036

RESUMO

INTRODUCTION: Organ transplantation has improved the quality and length of life for many people suffering from end-stage diseases, among them women of reproductive age. Therefore, it has made pregnancy possible for those previously unable to conceive. Nevertheless, conception itself should be desired and properly timed in these specific patients to ensure the best possible perinatal outcome. OBJECTIVE: The objective of the study was to assess whether female graft recipients apply proper family planning methods and use effective contraception. METHODS: In a single-center, observational study, information was collected using a self-administered questionnaire distributed among 100 female graft recipients (post-transplant group [TG]) and 67 healthy female volunteers (control group [CG]). The survey covered data regarding present menstrual patterns, sexual activity, gynecological counseling, and contraceptive methods used. RESULTS: Female graft recipients were more sexually active after than before transplantation (87% vs 64%, P = .0001) and equally active as controls. Sexually active post-transplantation patients used contraception less frequently than sexually active controls (51.72% vs 82.76%, P < .0001). Condoms were the most frequently used method in TG, and oral contraception in CG. Oral contraception was used more rarely by counseled graft recipients than by counseled controls (3.9% vs 60.7%, P < .0001). After counseling, intrauterine device usage increased and oral contraception usage decreased in TG. Among women with chronic diseases, intrauterine device was used more often in TG (4% vs 0%), whereas oral contraception was used more often in CG (8.3% vs 50%, P < .0001). CONCLUSIONS: Despite the fact that post-transplantation women of reproductive age have many indications for highly effective contraception, only few of them actually use it. Contraceptive counseling has to be included as part of routine post-transplantation care by all health professionals involved in the management of female graft recipients of reproductive age.


Assuntos
Anticoncepção/métodos , Aconselhamento/métodos , Transplante de Órgãos , Adolescente , Adulto , Feminino , Humanos , Gravidez , Comportamento Sexual , Adulto Jovem
13.
Transplant Proc ; 43(8): 3043-7, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21996220

RESUMO

INTRODUCTION: Liver transplantations give female recipients an ability to carry pregnancies successfully. However, solid organ transplantations exacerbate the pregnancy including maternal and neonatal outcomes. The aim of our study was to evaluate and identify the obstetric outcomes in women with a prior liver transplantation. METHODS: We analyzed all pregnant woman who had undergone a prior liver transplantation and afterward delivered from 2001 to 2011. Complete data were assessed in 39 deliveries and 40 live births. Three women were pregnant twice after liver transplantation. RESULTS: The mean gestational age at birth measured 37.2±2.2 weeks. The most common obstetric complications were premature labor (12/39,30.8%), hypertension (10/39, 25.6%), and symptomatic urinary tract infections (7/39, 18%). Other complications were pregestational diabetes (n=1), cholestasis (n=3), and of severe anemia treated with blood transfusions (n=2). The mean time from organ transplantation to delivery was 67.6±47.2 months. Acute graft rejections occurred among pregnant women 7.7% (3/39) of studied. Only 8 (20.5%) deliveries were finished vaginally. Infants small for gestational age were diagnosed in 20% (8/40). One case displayed a congenital urinary tract malformation. None of the neonates died neonatally. CONCLUSIONS: Pregnancies are possible after liver transplantation and likely end with successful maternal and newborn outcomes. Some cases experience an increased risk of obstetric complications. Therefore, posttransplant pregnancies must be regularly monitored with a multidisciplinary approach.


Assuntos
Transplante de Fígado/efeitos adversos , Complicações na Gravidez/etiologia , Adulto , Peso ao Nascer , Cesárea , Feminino , Rejeição de Enxerto/etiologia , Humanos , Hipertensão/etiologia , Recém-Nascido , Recém-Nascido Pequeno para a Idade Gestacional , Trabalho de Parto Prematuro/etiologia , Gravidez , Complicações Cardiovasculares na Gravidez/etiologia , Complicações Infecciosas na Gravidez/etiologia , Resultado da Gravidez , Fatores de Risco , Infecções Urinárias/etiologia , Adulto Jovem
14.
Transplant Proc ; 43(8): 3048-51, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21996221

RESUMO

BACKGROUND: Neonates born to mothers, who underwent organ transplantation require close medical monitoring. It is unknown how chronically diseased mother's organs or immunosuppressive drugs affect fetal growth and development; some immunosuppressants are teratogenic and contraindicated during pregnancy. The aim of this study was to determine the prevalence of prematurity and intrauterine growth restriction in neonates born to women who have undergone renal or liver transplantation. METHODS: Our retrospective analysis identified 53 (25 renal and 28 liver) cases of neonates delivered by female graft recipients between January 2005 and December 2009. Hypotrophy was defined as a birth weight<10th percentile for gestational age. We excluded newborns diagnosed with severe hypotrophy (<5th percentile). RESULTS: Neonates born prematurely were predominate in the renal (16/25, 64%), but less than half of the liver cohort (13/28, 46%). Hypotrophy less than the 10th percentile was noted significantly more often among renal than liver recipients; 36% versus 14% (P<.05). Severe hypotrophy was also observed significantly more often among renal than liver transplant neonates: 28% versus 3.6% (P<.001). CONCLUSIONS: Compared with liver insufficiency, chronic kidney diseases have stronger effects on the fetus, leading to adverse neonatal complications. A greater prevalence of preterm births, as well as hypotrophic newborns, especially less than the 5th percentile, was observed among neonates delivered by mothers after kidney transplantation.


Assuntos
Retardo do Crescimento Fetal/etiologia , Transplante de Rim/efeitos adversos , Transplante de Fígado/efeitos adversos , Complicações na Gravidez/etiologia , Nascimento Prematuro/etiologia , Peso ao Nascer , Feminino , Humanos , Hipertensão/etiologia , Imunossupressores/efeitos adversos , Recém-Nascido , Recém-Nascido Pequeno para a Idade Gestacional , Gravidez , Complicações Cardiovasculares na Gravidez/etiologia , Estudos Retrospectivos , Fatores de Risco
15.
J Inorg Biochem ; 104(7): 774-89, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20421133

RESUMO

The synthesis, structural characterization and biological activity of eight ortho-quinone(N-aryl)-oximine rhenium(I) complexes are described. The reaction of the halogenido complexes (CO)(5)ReX (X = Cl (4), Br (5)) with 2-nitroso-N-arylanilines {(C(6)H(3)ClNO)NH(C(6)H(4)R)} (R = p-Cl, p-Me, o-Cl, H) (3a-d) in tetrahydrofurane (THF) yields the complexes fac-(CO)(3)XRe{(C(6)H(3)ClNO)NH(C(6)H(4)R)} (6a-d, 7a-d) with the tautomerized ligand acting as a N,N'-chelate. The substitution of two carbonyl ligands leads to the formation of a nearly planar 5-membered metallacycle. During coordination the amino-proton is shifted to the oxygen of the nitroso group which can be observed in solution for 6 and 7 by (1)H NMR spectroscopy and in solid state by crystal structure analysis. After purification, all compounds have been fully characterized by their (1)H and (13)C NMR, IR, UV/visible (UV/Vis) and mass spectra. The X-ray structure analyses revealed a distorted octahedral coordination of the CO, X and N,N'-chelating ligands for all Re(I) complexes. Biological activity of four oximine rhenium(I) complexes was assessed in vitro in two highly aggressive cancer cell lines: human metastatic melanoma A375 and human chronic myelogenous leukemia K562. Chlorido complexes (6a and 6c) were more efficient than bromido compounds (7d and 7b) in inducing apoptotic cell death of both types of cancer cells. Melanoma cells were more susceptible to tested rhenium(I) complexes than leukemia cells. None of the ligands (3a-d) showed any significant anticancer activity.


Assuntos
Compostos de Anilina/química , Antineoplásicos/química , Leucemia/tratamento farmacológico , Melanoma/tratamento farmacológico , Rênio/química , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Humanos , Isomerismo , Leucemia/patologia , Ligantes , Melanoma/patologia
16.
Br J Pharmacol ; 157(8): 1451-62, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19627286

RESUMO

BACKGROUND AND PURPOSE: Several anticancer drugs with diverse chemical structures can induce differentiation of cancer cells. This study was undertaken to explore the potential contribution of caspase-3 to pharmacologically-induced differentiation of K562 cells. EXPERIMENTAL APPROACH: We assessed differentiation by measuring the expression of glycophorin A and haemoglobin synthesis in K562 cells treated with low concentrations of doxorubicin, hydroxyurea, cytosine arabinoside, cisplatin and haemin. Caspase-3 activation, mitochondrial membrane potential dissipation and viability were assessed by FACS. GATA-1-binding activity was evaluated by EMSA. KEY RESULTS: Treatment of K562 cells with low concentrations of the tested drugs activated caspase-3 but did not trigger detectable apoptosis. Instead, elevated levels of haemoglobin-positive and glycophorin A/caspase-3-double-positive cells were observed, suggesting involvement of caspase-3 in drug-induced differentiation. Inhibition of caspase-3 activity significantly reduced the ability of K562 cells to execute the differentiation programme. Mitochondrial membrane potential dissipation was observed, indicating involvement of the mitochondrial pathway. Binding activity of GATA-1, transcription factor responsible for differentiation and cell survival, was not diminished by increased caspase-3 activity during drug-stimulated differentiation. CONCLUSIONS AND IMPLICATIONS: Our results could explain how anticancer drugs, with diverse structures and modes of action, can stimulate erythroid differentiation in leukaemic cells with appropriate genetic backgrounds. Our findings imply that some similarities exist between pharmacologically-induced differentiation of erythroleukaemic cells and normal erythropoiesis, both involving caspase-3 activation at high levels of anti-apoptotic protein Bcl-X(L) and chaperone protein Hsp70 (heat shock protein 70). Therefore, the functions of caspase-3, unrelated to cell death, can be extended to pharmacologically-induced differentiation of some cancer cells.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Caspase 3/fisiologia , Diferenciação Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Cisplatino/farmacologia , Citarabina/farmacologia , Doxorrubicina/farmacologia , Fator de Transcrição GATA1/metabolismo , Proteínas de Choque Térmico HSP70/metabolismo , Humanos , Hidroxiureia/farmacologia , Células K562 , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Relação Estrutura-Atividade , Proteína bcl-X/metabolismo
17.
Apoptosis ; 11(6): 1049-59, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16544100

RESUMO

The ubiquitin Carboxyl-terminal Hydrolase-L1 gene (UCHL1) is a key enzyme in the protein degradation pathway; however, its precise role in protecting cells under stress conditions is unclear. In the present study we investigated the activity of this gene in human NT2/D1 embryonal carcinoma cells subjected to oxygen-glucose deprivation (OGD) and reoxygenation. OGD/reoxygenation cause global metabolic changes due to energy withdrawal and the subsequent generation of reactive oxygen species which initiates either a stress-adaptation-survival response or cell death, depending on the severity of the insult. A bi-phasic change in UCHL1 expression was observed by Q-PCR, Western blotting and flow cytometry. Down regulation of UCHL1 was detected immediately after OGD treatment and its expression was subsequently restored and increased 6 h after OGD treatment as well as during reoxygenation. Furthermore, flow cytometry analysis detected a lower level of UCHL1 only in apoptotic cells that had severe loss of mitochondrial membrane potential. Accordingly, down-regulation of endogenous UCHL1 by antisense cDNA in mouse N2a neuroblastoma cells increased the cell's sensitivity to OGD treatment. This down-regulation of endogenous UCHL1 led to the accumulation of p27, suggesting that UCHL1 is an essential gene to maintain cell homeostasis under normal growth and oxidative stress conditions.


Assuntos
Regulação Enzimológica da Expressão Gênica/fisiologia , Estresse Oxidativo/fisiologia , Ubiquitina Tiolesterase/genética , Linhagem Celular Tumoral , Sobrevivência Celular/fisiologia , Humanos , Ubiquitina Tiolesterase/biossíntese
18.
Cell Death Differ ; 12(11): 1368-77, 2005 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-15920534

RESUMO

DNA fragmentation in apoptosis, especially in lymphocytic cells, is initiated at scaffold/matrix attachment regions (S/MARs) and is preceded by the degradation of nuclear proteins. The present study was performed to establish whether the same mechanism occurred in human NT2 cells subjected to oxygen and glucose deprivation (OGD). We analyzed the integrity of c-myc S/MAR containing a base-unpairing region (BUR)-like element, which we established to be a binding site of the transcription factor Sox2. An accumulation of DNA breaks in close proximity to this element and a degradation of Sox2 were observed early in the OGD-induced apoptotic response. Identification of Sox2 as a novel c-myc BUR-binding protein was achieved through yeast one-hybrid screening and the Sox2/DNA interaction was confirmed by electrophoretic mobility shift assay and immunoprecipitation with Sox2 antibody. Our data support the notion that early proteolysis of unique BUR-binding proteins might represent a universal mechanism that renders these DNA sites vulnerable to endonucleolysis.


Assuntos
Apoptose/fisiologia , DNA de Neoplasias/metabolismo , Proteínas de Ligação a DNA/metabolismo , Genes myc/fisiologia , Proteínas HMGB/metabolismo , Regiões de Interação com a Matriz/fisiologia , Neurônios/citologia , Fatores de Transcrição/metabolismo , Apoptose/genética , Sequência de Bases , Carcinoma Embrionário/genética , Carcinoma Embrionário/metabolismo , Linhagem Celular Tumoral , Dano ao DNA , DNA de Neoplasias/genética , Proteínas de Ligação a DNA/genética , Genes myc/genética , Proteínas HMGB/genética , Humanos , Células Jurkat , Regiões de Interação com a Matriz/genética , Neurônios/metabolismo , Reação em Cadeia da Polimerase , Fatores de Transcrição SOXB1 , Fatores de Transcrição/genética
19.
Neurobiol Dis ; 18(3): 618-27, 2005 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15755687

RESUMO

Neuronal cells depend on mitochondrial oxidative phosphorylation for most of their energy needs and therefore are at a particular risk for oxidative stress. Mitochondria play an important role in energy production and oxidative stress-induced apoptosis. In the present study, we have demonstrated that external oxidative stress induces mitochondrial dysfunction leading to increased ROS generation and ultimately apoptotic cell death in neuronal cells. Furthermore, we have investigated the role of Coenzyme Q10 as a neuroprotective agent. Coenzyme Q10 is a component of the mitochondrial respiratory chain and a potent anti-oxidant. Our results indicate that total cellular ROS generation was inhibited by Coenzyme Q10. Further, pre-treatment with Coenzyme Q10 maintained mitochondrial membrane potential during oxidative stress and reduced the amount of mitochondrial ROS generation. Our study suggests that water-soluble Coenzyme Q10 acts by stabilizing the mitochondrial membrane when neuronal cells are subjected to oxidative stress. Therefore, Coenzyme Q10 has the potential to be used as a therapeutic intervention for neurodegenerative diseases.


Assuntos
Mitocôndrias/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Ubiquinona/análogos & derivados , Ubiquinona/farmacologia , Morte Celular/efeitos dos fármacos , Morte Celular/fisiologia , Linhagem Celular Tumoral , Coenzimas , Humanos , Mitocôndrias/fisiologia , Neurônios/fisiologia , Estresse Oxidativo/fisiologia
20.
Toxicol Appl Pharmacol ; 201(1): 21-31, 2004 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-15519605

RESUMO

Neuronal cell death induced by oxidative stress is correlated with numerous neurodegenerative diseases, including Alzheimer's disease (AD), Parkinson's disease (PD), and stroke. The causes of sporadic forms of age-related neurodegenerative diseases are still unknown. Recently, a correlation between paraquat exposure and neurodegenerative diseases has been observed. Paraquat, a nonselective herbicide, was once widely used in North America and is still routinely used in Taiwan. We have used differentiated Human Neuroblastoma (SHSY-5Y) cells as an in vitro model to study the mechanism of cell death induced by paraquat. We observed that paraquat-induced oxidative stress in differentiated SHSY-5Y cells as indicated by an increase in the production of cellular reactive oxygen species (ROS). Furthermore, apoptosis was evident as indicated by cellular and nuclear morphology and DNA fragmentation. Interestingly, pretreatment of SHSY-5Y cells with water-soluble Coenzyme Q10 (CoQ10) before paraquat exposure inhibited ROS generation. Pretreatment with CoQ10 also significantly reduced the number of apoptotic cells and DNA fragmentation. We also analyzed the effect of paraquat and CoQ10 on isolated mitochondria. Our results indicated that treatment with paraquat induced the generation of ROS from isolated mitochondria and depolarization of the inner mitochondrial membrane. Pretreatment with CoQ10 was able to inhibit ROS generation from isolated mitochondria as well as the collapse of mitochondrial membrane potential. Our results indicate that water-soluble CoQ10 can prevent oxidative stress and neuronal damage induced by paraquat and therefore, can be used for the prevention and therapy of neurodegenerative diseases caused by environmental toxins.


Assuntos
Apoptose/efeitos dos fármacos , Herbicidas/toxicidade , Síndromes Neurotóxicas/etiologia , Estresse Oxidativo , Paraquat/toxicidade , Ubiquinona/análogos & derivados , Ubiquinona/uso terapêutico , Células Cultivadas , Coenzimas , Ensaio Cometa , Herbicidas/antagonistas & inibidores , Humanos , Peroxidação de Lipídeos/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Neuroblastoma , Neurônios/efeitos dos fármacos , Paraquat/antagonistas & inibidores
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