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1.
Microb Cell Fact ; 21(1): 50, 2022 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-35366869

RESUMO

BACKGROUND: Reactive oxygen species (ROS) trigger different morphogenic processes in filamentous fungi and have been shown to play a role in the regulation of the biosynthesis of some secondary metabolites. Some bZIP transcription factors, such as Yap1, AtfA and AtfB, mediate resistance to oxidative stress and have a role in secondary metabolism regulation. In this work we aimed to get insight into the molecular basis of this regulation in the industrially important fungus Penicillium chrysogenum through the characterization of the role played by two effectors that mediate the oxidative stress response in development and secondary metabolism. RESULTS: In P. chrysogenum, penicillin biosynthesis and conidiation are stimulated by the addition of H2O2 to the culture medium, and this effect is mediated by the bZIP transcription factors PcYap1 and PcRsmA. Silencing of expression of both proteins by RNAi resulted in similar phenotypes, characterized by increased levels of ROS in the cell, reduced conidiation, higher sensitivity of conidia to H2O2 and a decrease in penicillin production. Both PcYap1 and PcRsmA are able to sense H2O2-generated ROS in vitro and change its conformation in response to this stimulus. PcYap1 and PcRsmA positively regulate the expression of brlA, the first gene of the conidiation central regulatory pathway. PcYap1 binds in vitro to a previously identified regulatory sequence in the promoter of the penicillin gene pcbAB: TTAGTAA, and to a TTACTAA sequence in the promoter of the brlA gene, whereas PcRsmA binds to the sequences TGAGACA and TTACGTAA (CRE motif) in the promoters of the pcbAB and penDE genes, respectively. CONCLUSIONS: bZIP transcription factors PcYap1 and PcRsmA respond to the presence of H2O2-generated ROS and regulate oxidative stress response in the cell. Both proteins mediate ROS regulation of penicillin biosynthesis and conidiation by binding to specific regulatory elements in the promoters of key genes. PcYap1 is identified as the previously proposed transcription factor PTA1 (Penicillin Transcriptional Activator 1), which binds to the regulatory sequence TTAGTAA in the pcbAB gene promoter. This is the first report of a Yap1 protein directly regulating transcription of a secondary metabolism gene. A model describing the regulatory network mediated by PcYap1 and PcRsmA is proposed.


Assuntos
Penicillium chrysogenum , Fatores de Transcrição de Zíper de Leucina Básica/genética , Regulação Fúngica da Expressão Gênica , Peróxido de Hidrogênio/metabolismo , Estresse Oxidativo , Penicillium chrysogenum/genética , Penicillium chrysogenum/metabolismo , Metabolismo Secundário/genética
2.
J Biol Inorg Chem ; 24(2): 271-285, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30701359

RESUMO

The aim of this work was to study the antitumor effects and the mechanisms of toxic action of a series of 6-methoxyquinoline (6MQ) complexes in vitro. The Cu(II) and Zn(II) complexes (Cu6MQ and Zn6MQ) are formulated as M(6MQ)2Cl2; the Co(II) and Ag(I) compounds (Co6MQ and Ag6MQ) are ionic with formulae [Ag(6MQ)2]+NO3- and H(6MQ)+[Co(6MQ)Cl3]- (where H(6MQ)+ is the protonated ligand). We found that the copper complex, outperformed the Co(II), Zn(II) and Ag(I) complexes with a lower IC50 (57.9 µM) in A549 cells exposed for 24 h. Cu6MQ decreased cell proliferation and induced oxidative stress detected with H2DCFDA at 40 µM, which reduces GSH/GSSG ratio. This redox imbalance induced oxidative DNA damage revealed by the Micronucleus test and the Comet assay, which turned into a cell cycle arrest at G2/M phase and induced apoptosis. In multicellular spheroids, the IC50 values tripled the monolayer model (187.3 µM for 24 h). At this concentration, the proportion of live/dead cells diminished, and the spheroids could not proliferate or invade. Although Zn6MQ also decreased GSH/GSSG ratio from 200 µM and the cytotoxicity is related to oxidative stress, the induction of the hydrogen peroxide levels only doubled the control value. Zn6MQ induced S phase arrest, which relates with the increased micronucleus frequency and with the induction of necrosis. Finally, our results reveal a synergistic activity with a 1:1 ratio of both complexes in the monolayer and multicellular spheroids.


Assuntos
Antineoplásicos/farmacologia , Complexos de Coordenação/farmacologia , Quinolinas/farmacologia , Esferoides Celulares/efeitos dos fármacos , Células A549 , Antineoplásicos/síntese química , Antineoplásicos/química , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Complexos de Coordenação/síntese química , Complexos de Coordenação/química , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Estrutura Molecular , Estresse Oxidativo/efeitos dos fármacos , Quinolinas/química , Esferoides Celulares/patologia , Relação Estrutura-Atividade
3.
Neurologia ; 32(8): 487-493, 2017 Oct.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-27091681

RESUMO

INTRODUCTION: ADHD symptoms begin to appear at preschool age. ADHD may have a significant negative impact on academic performance. In Spain, there are no standardized tools for detecting ADHD at preschool age, nor is there data about the incidence of this disorder. OBJECTIVE: To evaluate developmental factors and learning difficulties associated with probable ADHD and to assess the impact of ADHD in school performance. METHODS: We conducted a population-based study with a stratified multistage proportional cluster sample design. RESULTS: We found significant differences between probable ADHD and parents' perception of difficulties in expressive language, comprehension, and fine motor skills, as well as in emotions, concentration, behaviour, and relationships. Around 34% of preschool children with probable ADHD showed global learning difficulties, mainly in patients with the inattentive type. According to the multivariate analysis, learning difficulties were significantly associated with both delayed psychomotor development during the first 3 years of life (OR: 5.57) as assessed by parents, and probable ADHD (OR: 2.34) CONCLUSIONS: There is a connection between probable ADHD in preschool children and parents' perception of difficulties in several dimensions of development and learning. Early detection of ADHD at preschool ages is necessary to start prompt and effective clinical and educational interventions.


Assuntos
Transtorno do Deficit de Atenção com Hiperatividade/epidemiologia , Deficiências da Aprendizagem , Desempenho Psicomotor/fisiologia , Transtorno do Deficit de Atenção com Hiperatividade/diagnóstico , Desenvolvimento Infantil , Pré-Escolar , Feminino , Humanos , Masculino , Pais/psicologia , Espanha , Inquéritos e Questionários
4.
Arch Soc Esp Oftalmol (Engl Ed) ; 96(2): 63-68, 2021 Feb.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-33268284

RESUMO

INTRODUCTION: Burnout syndrome refers to the physical and psychological fatigue suffered by workers as a result of their professional activity. It has three main characteristics: emotional exhaustion, depersonalization and lack of personal fulfillment. PURPOSE: To determine the prevalence of burnout syndrome among Andalusian ophthalmologists, both consultants and residents, analyzing its relationship with several sociodemographic variables. MATERIAL AND METHODS: Descriptive cross-sectional study. All the sociodemographic variables were included in a Google® form together with the standardized questionnaire Maslach Burnout Inventory-Human Services Survey (MBI-HSS). This form was sent to the Andalusian ophthalmological community by different electronic means (Andalusian Society of Ophthalmology, instant messaging mobile apps, etc.). RESULTS: One hundred fourty two ophthalmologists answered the form, with a similar distribution by sex and a mean age of 43.77 years, with 67.1% of them meeting criteria of burnout syndrome. Its prevalence was higher among young ophthalmologists, with fewer years of clinical practice, divorced/separated, those with fewer children, belonging to centers in the province of Huelva, workers in rural/regional areas, those with exclusive public activity, consultants with temporary contracts and four-year residents. Regarding subspecialties, its prevalence was higher among those who focused on cornea-ocular surface-refractive surgery. CONCLUSIONS: This study quantify for the first time in Andalusia the prevalence of burnout syndrome among ophthalmologists. The fact that two thirds of the analyzed sample meet criteria proves the need to implement improvements in the clinical and professional conditions of our group.

5.
J Cutan Pathol ; 37(5): 542-8, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-19638168

RESUMO

BACKGROUND: WT1, first recognized as a tumor suppressor gene involved in the development of Wilms' tumor, may have apparently contradictory findings and functions. As WT1 has been identified as a molecular target for cancer immunotherapy, immunodetection of WT1 in tumor cells has become an essential step in cancer studies. METHODS: We compare the expression of this protein among different types of melanocytic nevi and among stages in primary melanoma progression. Tissue microarrays containing normal tissues and 271 primary melanocytic lesion samples (163 primary melanomas and 108 nevi) were studied by immunohistochemistry using monoclonal antibody against WT1. RESULTS AND DISCUSSION: The present study shows these: 1. WT1 protein is predominantly expressed in the cytoplasm of the neoplastic cells. 2. A higher rate of WT1 staining in melanocytic nevi against melanomas has been observed. 3. WT1 expression is increased in advanced stages of melanoma progression: a significant (p < 0.05) increase of expression of WT1 was detected in vertical cases 46.5% vs. radial cases 16.0%, in high levels of Clark (IV, V) 57.4% vs. low levels (I, II, III) 33.0% and when comparing depth of invasion within thickness subgroups. 4. Finally, this study establishes an association of WT1 protein expression with shorter overall survival in melanoma.


Assuntos
Derme/metabolismo , Melanoma/metabolismo , Nevo/metabolismo , Neoplasias Cutâneas/metabolismo , Proteínas WT1/metabolismo , Biomarcadores Tumorais/metabolismo , Derme/patologia , Progressão da Doença , Humanos , Imuno-Histoquímica , Melanoma/mortalidade , Melanoma/patologia , Invasividade Neoplásica/patologia , Nevo/patologia , Neoplasias Cutâneas/mortalidade , Neoplasias Cutâneas/patologia , Análise Serial de Tecidos
6.
J Proteomics ; 221: 103757, 2020 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-32247173

RESUMO

Atherosclerosis remains the leading cause of ischemic syndromes such as myocardial infarction or brain stroke, mainly promoted by plaque rupture and subsequent arterial blockade. Identification of vulnerable or high-risk plaques constitutes a major challenge, being necessary to identify patients at risk of occlusive events in order to provide them with appropriate therapies. Clinical imaging tools have allowed the identification of certain structural indicators of prone-rupture plaques, including a necrotic lipidic core, intimal and adventitial inflammation, extracellular matrix dysregulation, and smooth muscle cell depletion and micro-calcification. Additionally, alternative approaches focused on identifying molecular biomarkers of atherosclerosis have also been applied. Among them, proteomics has provided numerous protein markers currently investigated in clinical practice. In this regard, it is quite uncertain that a single molecule can describe plaque rupture, due to the complexity of the process itself. Therefore, it should be more accurate to consider a set of markers to define plaques at risk. Herein, we propose a selection of 76 proteins, from classical inflammatory to recently related markers, all of them identified in at least two proteomic studies analyzing unstable atherosclerotic plaques. Such panel could be used as a prognostic signature of plaque instability.


Assuntos
Aterosclerose , Placa Aterosclerótica , Biomarcadores , Humanos , Inflamação , Proteômica
7.
Am J Dermatopathol ; 31(1): 84-7, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19155733

RESUMO

Dermatofibroma or cutaneous fibrous histiocytoma is a common benign skin lesion with multiple, distinct histologic variants, including cellular, aneurismal, epithelioid, atypical, lipidized "ankle-type," palisading, and cholesterotic. Although dermatofibromas are considered benign neoplasms, certain variants including cellular and aneurismal ones have shown to have a notable tendency to locally recur after excision. Indeed, although extremely rarely, metastases have been associated with the cellular and aneurysmal/atypical variants. Signet-ring cells are formed by cytoplasmic accumulations of various substances that push the nucleus toward the cellular border. The finding of signet-ring cells in a skin neoplasm always raises the suspicion of metastatic adenocarcinoma, although a number of reports have shown their occurrence in primitive cutaneous neoplasms as well. Signet-ring cell formation, however, has never been described in dermatofibroma. We present, for the first time, a new, distinctive variant of dermatofibroma, so-called signet-ring cell dermatofibroma, in a 16-year-old man with a slowly growing skin tumor on the lateral side of his right leg. Histologic examination demonstrated a striking signet-ring cell appearance of most of the cells in an otherwise fibrohistiocytic looking proliferation. Histochemical and immunohistochemical stainings confirmed the diagnosis of dermatofibroma. The phenomenon described in this case enlarges the histologic spectrum of cutaneous fibrous histiocytoma and may cause substantial differential diagnostic problems.


Assuntos
Histiocitoma Fibroso Benigno/patologia , Neoplasias Cutâneas/patologia , Adolescente , Núcleo Celular/patologia , Histiocitoma Fibroso Benigno/metabolismo , Humanos , Masculino , Neoplasias Cutâneas/metabolismo
8.
Arch Soc Esp Oftalmol (Engl Ed) ; 94(4): 200-203, 2019 Apr.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-30449636

RESUMO

A case is presented of a 5 year-old patient with bilateral hereditary retinoblastoma treated with radiotherapy in the right eye and enucleation of the left eye. After three years without evidence of progression, the patient presented with a right orbital mass that compromised the frontal bone. After surgical excision, the histology analysis was consistent with a diagnosis of giant cell tumour. Primary orbital bone neoplasms, such as giant cell tumours, are extremely rare. Both radiological and histopathology studies are essential to establish the differential diagnosis of orbital mass lesions.


Assuntos
Neoplasias Ósseas/diagnóstico por imagem , Osso Frontal , Tumor de Células Gigantes do Osso/diagnóstico por imagem , Neoplasias Primárias Múltiplas/diagnóstico por imagem , Neoplasias da Retina/diagnóstico por imagem , Retinoblastoma/diagnóstico por imagem , Pré-Escolar , Feminino , Humanos , Neoplasias da Retina/patologia , Retinoblastoma/patologia
9.
Environ Toxicol Pharmacol ; 72: 103219, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31494513

RESUMO

Epidemiological studies have reported that exposure to toxic metals like cadmium (Cd) may promote the development of musculoskeletal diseases, such as osteoporosis, rheumatoid arthritis (RA), and osteoarthritis (OA), among others. The objective of this review is to summarize the molecular mechanisms of inflammation and oxidative stress activated by Cd at the bone level, particularly in osteoporosis, RA, and OA. Cadmium can increase bone resorption, affect the activity of osteoclasts and calcium (Ca) absorption, and impair kidney function, which favors the development of osteoporosis. In the case of RA, Cd interferes with the activity of antioxidant proteins, like superoxide dismutase (SOD) and catalase (CAT). It also promotes an inflammatory state, inducing the process of citrullination, which affects the proteins of immune response. On the other hand, accumulation of Cd in the tissues and blood of smokers has been related to the development of some musculoskeletal diseases. Therefore, knowing the negative impact of Cd toxicity at the articular level can help understand the damage mechanisms it produces, leading to the development of such diseases.


Assuntos
Cádmio/toxicidade , Poluentes Ambientais/toxicidade , Doenças Musculoesqueléticas/induzido quimicamente , Animais , Cádmio/normas , Exposição Ambiental/normas , Poluentes Ambientais/normas , Humanos
12.
Rev Neurol ; 66(S01): S115-S120, 2018 Mar 01.
Artigo em Espanhol | MEDLINE | ID: mdl-29516463

RESUMO

INTRODUCTION: There are few studies about preschool attention deficit hyperactivity disorder (ADHD) prevalence. AIM: To study the prevalence of ADHD in preschoolers using an specific scale (ADHD-RS-IV-P-Es) developed for this age range. SUBJECTS AND METHODS: We evaluated the prevalence of possible ADHD in a representative sample of preschoolers in Navarra and La Rioja, Spain. RESULTS: We find a range of prevalence between 2.5-4.1% depending on the criteria that was used (more or less strict). CONCLUSIONS: There are specific tools that can be use in preschool ADHD study. The prevalence of preschool ADHD in Spain is similar than in other countries. The frequency of symptoms in this age range is similar to the found in school age children.


TITLE: Trastorno por deficit de atencion/hiperactividad en niños en edad preescolar. Prevalencia epidemiologica en Navarra y La Rioja, España.Introduccion. La prevalencia del trastorno por deficit de atencion/hiperactividad (TDAH) esta en constante estudio, y hay pocas publicaciones sobre la prevalencia en niños preescolares. Objetivo. Estudiar la prevalencia de sintomas de TDAH en niños preescolares usando una escala especifica (ADHD Rating Scale-IV, version preescolar, validada para España) desarrollada para esta franja de edad. Sujetos y metodos. Se evalua la prevalencia de posible TDAH en una muestra representativa de preescolares en Navarra y La Rioja usando diferentes puntos de corte. Resultados. Se encuentra un rango de prevalencia de sintomas de TDAH del 2,5-4,1% segun el criterio usado (mas o menos estricto). Conclusiones. Existen herramientas especificas que pueden usarse para evaluar el TDAH en preescolares. La prevalencia de posible TDAH en preescolares en España es similar a la encontrada en otros paises. La frecuencia de sintomas en esta franja de edad no es mas alta que en otras edades, por lo que no es cierto que los sintomas de TDAH sean muy prevalentes en la poblacion general de niños preescolares.


Assuntos
Transtorno do Deficit de Atenção com Hiperatividade/epidemiologia , Transtorno do Deficit de Atenção com Hiperatividade/diagnóstico , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Prevalência , Estudos de Amostragem , Espanha/epidemiologia , Avaliação de Sintomas
13.
Transplant Proc ; 38(8): 2431-3, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17097958

RESUMO

The beneficial action of statins on the lipid profile, cardiovascular disease, and death is well known. Besides their lipid-lowering role, these drugs have pleiotropic action that derive from their prevention of the synthesis of isoprenoids, mediators in cell signaling. Thus, due to their antioxidant capacity, statins can decrease the production of reactive oxygen species by inhibiting NAD(P)H oxidase activity. Previous studies by our group have described increased oxidative stress status in renal transplantation that might benefit from HMG CoA reductase inhibitor therapy. The aim of this study was to assess the influence of statins on stress parameters and their relevance to renal function in kidney transplantation. In 58 transplanted patients a first blood sample was obtained, without statins followed by 21 patients treated with statins (group 1) and 37 patients without drug (group 0) for a 6-month study period. We collected clinical data as well biochemical results on lipid profile, creatinine and oxidative stress. Lipid profile reduction was significant among group 1 compared with group 0. An increased glutathione peroxidase (GPx) among observed in all patients was greater in the statin-treated group (P = .006). No differences in creatinine or Cockroft-Gault values were observed between before versus after drug administration. In conclusion, statin treatment in renal transplantation improves the lipid profile and may increase GPx-measured antioxidant capacity but appears to have no short-term effect on renal function.


Assuntos
Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Hiperlipidemias/tratamento farmacológico , Testes de Função Renal , Transplante de Rim/fisiologia , Estresse Oxidativo/efeitos dos fármacos , Humanos , Hipercolesterolemia/sangue , Lipídeos/sangue , Lipoproteínas/sangue , Complicações Pós-Operatórias/tratamento farmacológico
15.
Biochim Biophys Acta ; 983(1): 82-90, 1989 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-2503036

RESUMO

The role of Ca2+ in stimulation of H+ gastric secretion by cAMP-dependent and -independent secretagogues was studied in isolated rabbit glands using Ca2+ ionophore, A23187, and an intracellular Ca2+ chelator (BAPTA, 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid) incorporated as its acetoxymethyl ester (BAPTA-AM). Acetylcholine (ACh), tetragastrin (TG), histamine and forskolin induced a transitory increase of intracellular Ca2+ concentration, [Ca2+]i, measured in gastric glands loaded with Ca2+-sensitive dye fura-2, and provoked an acid secretory response evaluated with aminopyrine accumulation ratio (AP ratio). The Ca2+-ionophore A23187 also induced an increase in [Ca2+]i and in AP ratio. cAMP-dependent secretagogues were more potent stimulants of acid secretion than cAMP-independent secretagogues. cAMP analogue, 8-bromo-adenosine 3',5'-cyclic monophosphate (8-BR-cAMP) induced an increase in AP ratio without modifying [Ca2+]i. BAPTA-AM (5-25 microM) induced a transient decrease of resting [Ca2+]i which returned to basal level due to extracellular Ca2+ entry. Increases in [Ca2+]i produced by ACh and TG were abolished by BAPTA and those produced by Ca2+ ionophore A23187 were partially buffered. BAPTA inhibited in a dose-dependent manner H+ secretion induced by cholinergic and gastrinergic stimulants in the presence of cimetidine. A23187 increased the AP ratio to values similar to those obtained with ACh or TG and was not inhibited by BAPTA. BAPTA partially inhibited (40%) the increase in AP ratio induced by forskolin and histamine inspite of the complete inhibition of the Ca2+ response. BAPTA did not inhibit the response to 8-BR-cAMP. BAPTA inhibition of forskolin stimulation was reversed by A23187 and the response was potentiated. These results indicate that ACh and TG response are completely dependent on an increase of [Ca2+]i. The response to cAMP-dependent agonists histamine and forskolin depend both on Ca2+ and cAMP. For forskolin stimulation the response may be the result of a potentiation between Ca2+ and cAMP.


Assuntos
Calcimicina/farmacologia , Cálcio/fisiologia , Quelantes/farmacologia , Ácido Egtázico/farmacologia , Ácido Gástrico/metabolismo , Mucosa Gástrica/metabolismo , 8-Bromo Monofosfato de Adenosina Cíclica/farmacologia , Acetilcolina/farmacologia , Aminopirina/metabolismo , Benzofuranos , Cálcio/metabolismo , Colforsina/farmacologia , Fura-2 , Mucosa Gástrica/efeitos dos fármacos , Histamina/farmacologia , Cinética
16.
Biochim Biophys Acta ; 1094(3): 269-80, 1991 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-1911878

RESUMO

Ajoene, (E,Z)-4,5,9-trithiadodeca-1,6,11-triene 9-oxide, is a potent antiplatelet compound isolated from alcoholic extracts of garlic. In vitro, ajoene reversibly inhibits platelet aggregation as well as the release reaction induced by all known agonists. In this paper we show that ajoene has a unique locus of action, that is not shared by any other known antiplatelet compound. For example, ajoene inhibits agonist-induced exposure of fibrinogen receptors, as well as intracellular responses such as activation of protein kinase C and the increase in cytoplasmic free calcium induced by receptor-dependent agonists (collagen, ADP, PAF, low-dose thrombin). On the other hand, with agonists that can by-pass (at least partially) the receptor-transductor-effector sequence, such as high-dose thrombin, PMA, NaF, only the exposure of fibrinogen receptors is blocked by ajoene. Binding of fibrinogen to chymotrypsin-treated platelets is only slightly inhibited by ajoene. The results reported here also show that: (a) ajoene does not act as a calcium chelator, does not impair the initial agonist-receptor interaction and does not influence the basal levels of intracellular inhibitors of platelet activation such as cyclic GMP; (b) the locus of action of ajoene is a yet unknown molecular step that links, in the case of physiological agonists, specific agonist-receptor complexes to the sequence of the signal transduction system on the plasma membrane of platelets. In the case of non-physiological, receptor-independent agonists (PMA, NaF), we can only speculate on the hypothesis that they somehow mimic the effect of the agonist-receptor complexes on the signal transduction system; and (c) the exposure of fibrinogen receptors is not a direct consequence of other intracellular processes. These observations clearly show, for the first time, that the exposure of fibrinogen receptors is a membrane event proximally and obligatorily coupled to the occupancy of other membrane receptors by their agonists without any intervention by the cytoplasmic biochemical processes. Additional results support the involvement of G-proteins in these early events of platelet activation. Furthermore, a role of the beta tau subunits of G-proteins in the exposure of fibrinogen receptors is proposed.


Assuntos
Plaquetas/efeitos dos fármacos , Dissulfetos/farmacologia , Extratos Vegetais/farmacologia , Inibidores da Agregação Plaquetária/farmacologia , Glicoproteínas da Membrana de Plaquetas/efeitos dos fármacos , Glicoproteínas da Membrana de Plaquetas/metabolismo , Anticorpos Monoclonais , Plaquetas/metabolismo , Cálcio/metabolismo , Quimotripsina , Colágeno/metabolismo , Citoplasma/metabolismo , Ativação Enzimática/efeitos dos fármacos , Epinefrina/metabolismo , Fibrinogênio/metabolismo , Proteínas de Ligação ao GTP/metabolismo , Humanos , Fosforilação , Fator de Ativação de Plaquetas/metabolismo , Proteína Quinase C/efeitos dos fármacos , Proteína Quinase C/metabolismo , Fluoreto de Sódio/metabolismo , Sulfóxidos , Trombina/metabolismo
17.
Cell Death Differ ; 6(3): 271-80, 1999 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10200578

RESUMO

Induction of CD95 (Fas/APO-1) and CD95 ligand during chemotherapeutic treatment may contribute to the death by apoptosis of some tumor cells. In this study, we have analyzed the role of the CD95 system in genotoxic drug-induced death of human breast tumor cells. Incubation of the breast tumor cell lines MCF-7 and EVSA-T with doxorubicin or methotrexate caused apoptosis after 48 h of treatment. These drugs induced a marked increase in the level of CD95 mRNA and protein in wild-type p53-expressing MCF-7 cells. On the contrary, the breast cancer cell line EVSA-T that expresses high levels of an inactive form of p53, did not up-regulate CD95 upon drug treatment. Elevation of CD95 expression by DNA-damaging drugs was notably blocked in MCF-7 cells expressing the human papillomavirus type 16 E6 protein (E6 cells) which prevented p53 accumulation upon DNA damage. However, E6 cells were still killed by the drugs. Furthermore, the genotoxic drugs did not induce the expression of CD95 ligand in MCF-7 cells at doses that caused apoptosis in these breast tumor cells. Moreover, drug-induced apoptosis of breast tumor cells was not prevented in the presence of either a CD95 antagonistic antibody or a CD95 ligand blocking antibody. We also observed a strong synergism between lower doses of DNA-damaging drugs and CD95 agonistic antibody in the induction of apoptosis in MCF-7 cells. In summary, our data indicate that drug-induced apoptosis of breast tumor cells occurs by a CD95/CD95L-independent mechanism although by elevating the tumor suppressor proteins p53 and CD95, genotoxic drugs may sensitize breast tumor cells to CD95-mediated apoptosis.


Assuntos
Apoptose/efeitos dos fármacos , Neoplasias da Mama/tratamento farmacológico , Mutagênicos/farmacologia , Proteína Supressora de Tumor p53/metabolismo , Receptor fas/genética , Receptor fas/metabolismo , Apoptose/genética , Apoptose/fisiologia , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Dano ao DNA , Proteína Ligante Fas , Feminino , Humanos , Glicoproteínas de Membrana/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA Neoplásico/genética , RNA Neoplásico/metabolismo , Temperatura , Células Tumorais Cultivadas , Regulação para Cima/efeitos dos fármacos
18.
Diabetes ; 48(11): 2215-20, 1999 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-10535457

RESUMO

It is assumed that increased oxidative stress contributes to the development of complications in diabetes. In this study, several markers of protein structural modifications directly induced by free radicals were investigated in the liver and kidney cytosolic fractions of rats with streptozotocin-induced diabetes. Sulfydryl residue and side-chain amino group analyses, as well as immunoblotting and chromatographic measurements of protein-bound carbonyl, suggest that protein oxidative modification is not increased by diabetes, with the exception of sulfydryl groups in renal cytosol. The levels of the glycation-derived carbonyl N epsilon-fructosyl-lysine are significantly increased by diabetes. Furthermore, unchanged proteolytic activity against in vivo-oxidized proteins, significant decreases both in activity against H2O2-modified proteins and in proteasome activity, measured by the degradation of a specific fluorogenic substrate, suggest that the unchanged oxidative protein modification in the diabetic state cannot be attributed to an increased cytosolic proteolytic activity in these tissues. These results provide evidence against a generalized increase in protein oxidative damage and demonstrate a diabetes-induced alteration in cytosolic proteolytic pathways, suggesting that proteasome activity may be impaired in these organs.


Assuntos
Diabetes Mellitus Experimental/metabolismo , Rim/metabolismo , Fígado/metabolismo , Proteínas/metabolismo , Animais , Citosol/metabolismo , Glicosilação , Hidrazonas , Lisina/análogos & derivados , Lisina/análise , Especificidade de Órgãos , Oxirredução , Estresse Oxidativo , Proteínas/química , Ratos , Ratos Sprague-Dawley
19.
Transplant Proc ; 37(3): 1428-30, 2005 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15866626

RESUMO

Reactive oxygen species (ROS) trigger a biomolecular alteration that causes functional and structural changes. In renal transplantation, there is an increase in oxidative phenomena related to endothelial dysfunction, inflammation, and atherosclerosis, the main cause of cardiovascular complications and chronic allograft failure. The present study was designed to assess the oxidative state of transplant patients with stable renal function, in order to establish differences in oxidative, biochemical, and clinical parameters between patients treated with tacrolimus versus cyclosporine. We studied 67 stable kidney transplant patients treated with calcineurin inhibitors who were not receiving cholesterol-lowering therapy, and 14 healthy subjects. Data were collected on biochemical parameters: lipid profile (apoA, apoB, total cholesterol and fractions, and triglycerides); urea; and creatinine; oxidative parameters: malondialdehyde (MDA) as a lipid peroxidation marker, glutathione peroxidase (GPx), catalase, superoxide dismutase (SOD), glutathione reductase (GR), and antibodies against oxidized LDL; and clinical variables. Transplanted patients showed a higher oxidative status (MDA increase and GPx decrease) than healthy subjects. The oxidative status did not differ between the cyclosporine and tacrolimus cohorts. Some factors during the posttransplant period, such as delayed graft function, cytomegalovirus infection, and microalbuminuria, which may damage renal function, produce a decreased antioxidant capacity (lower GPx).


Assuntos
Transplante de Rim/fisiologia , Espécies Reativas de Oxigênio/metabolismo , Colesterol/sangue , Creatinina/sangue , Seguimentos , Glutationa Peroxidase/sangue , Glutationa Redutase/sangue , Humanos , Lipídeos/sangue , Lipoproteínas/sangue , Malondialdeído/sangue , Seleção de Pacientes , Valores de Referência , Superóxido Dismutase/sangue , Fatores de Tempo , Ácido Úrico/sangue
20.
Transplant Proc ; 37(9): 3796-8, 2005 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16386542

RESUMO

Reactive oxygen species (ROS) may participate in atheroma plaque formation, which may be noninvasively diagnosed by Doppler ultrasound of carotid artery. We sought to determine the relationship between the presence of carotid artery lesions and oxidative parameters to identify factors that may influence these lesions in renal transplant patients. Fifty renal transplanted patients with stable renal function and without diabetes mellitus were studied for more than 1 year posttransplantation. Echo Doppler examination of the carotid artery was performed to assess the intimal media thickness (IMT), atheroma plaques, calcification, and stenosis. Data were collected on oxidative parameters: malondialdehyde (MDA), glutathione peroxidase (GPx), catalase, superoxide dismutase (SOD), glutathione reductase (GR), and lipid profile. The serum GPx level among patients without atheroma plaques, calcification, or stenosis was higher than in those with ultrasound signs. The LDL cholesterol fraction was lower in patients with no ultrasound signs of atherosclerotic lesions; total cholesterol values showed the same behavior. In conclusion, transplanted patients with atheromatous plaques, calcification, and carotid stenosis have a greater degree of hypercholesterolemia and lower antioxidant activity (lower GPx). Recipient age was the principal risk factor for the presence of increased IMT, atheroma plaque, calcification, and/or stenosis of carotid artery in renal transplant patients.


Assuntos
Doenças das Artérias Carótidas/epidemiologia , Transplante de Rim/fisiologia , Estresse Oxidativo , Complicações Pós-Operatórias/fisiopatologia , Adulto , Biomarcadores/sangue , Doenças das Artérias Carótidas/sangue , Doenças das Artérias Carótidas/fisiopatologia , Catalase/sangue , Colesterol/sangue , LDL-Colesterol/sangue , Feminino , Seguimentos , Glutationa Peroxidase/sangue , Humanos , Transplante de Rim/efeitos adversos , Masculino , Malondialdeído/sangue , Pessoa de Meia-Idade , Superóxido Dismutase/sangue , Fatores de Tempo
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