RESUMO
OBJECTIVE: Ustekinumab (UST) is an anti-IL12/23 antibody for the treatment of Crohn's Disease (CD). The aim of this study was to compare the efficacy and safety of UST in a large population-based cohort of CD patients who failed previous treatment with other biologics. PATIENTS AND METHODS: 194 CD patients (108 males and 86 females, mean age 48 years (range 38-58 years) were retrospectively reviewed. 147 patients were already treated with anti-TNFα (75.8%), and 47 (24.2%) patients were already treated with anti-TNFα and vedolizumab. Concomitant treatment with steroids was present in 177 (91.2%) patients. RESULTS: At week 12, clinical remission was achieved in 146 (75.2%) patients. After a mean follow-up of 6 months, clinical remission was maintained in 135 (69.6%) patients; at that time, mucosal healing was assessed in 62 (31.9%) patients, and it was achieved in 33 (53.2) patients. Three (1.5%) patients were submitted to surgery. Steroid-free remission was achieved in 115 (59.3%) patients. Both serum C-Reactive Protein and Fecal Calprotectin (FC) levels were significantly reduced with respect to baseline levels during follow-up. A logistic regression, UST therapy as third-line therapy (after both anti-TNFα and vedolizumab), FC >200 µg/g, and HBI ≥8 were significantly associated with lack of remission. Adverse events occurred in 5 (2.6%) patients, and four of them required suspension of treatment. CONCLUSIONS: UST seemed to be really effective and safe in CD patients unresponsive to other biologic treatments, especially when used as second-line treatment.
Assuntos
Doença de Crohn/tratamento farmacológico , Ustekinumab/uso terapêutico , Adulto , Estudos de Coortes , Feminino , Humanos , Itália , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Ustekinumab/administração & dosagem , Ustekinumab/efeitos adversosRESUMO
La pandemia de COVID-19 producida por SARS-CoV-2 actualmente en curso anticipa una gran demanda por ventiladores mecánicos (VM), ya que un porcentaje relevante de los contagiados cae rápidamente en insuficiencia respiratoria y requiere de cuidados intensivos. Anticipándose a ese exceso de demanda y considerando que es muy probable que el número actual de ventiladores mecánicos en las unidades de cuidados intensivos (UCI) sean insuficientes, se ha solicitado a la SACH un informe técnico en relación al uso de las máquinas de anestesia como VM.
Assuntos
Pneumonia Viral/terapia , Pneumonia Viral/epidemiologia , Ventiladores Mecânicos/provisão & distribuição , Infecções por Coronavirus/terapia , Infecções por Coronavirus/epidemiologia , Pandemias , Betacoronavirus , Anestesia/métodos , Chile/epidemiologiaRESUMO
En diciembre de 2019, una serie de casos de neumonía de causa desconocida surgieron en Wuhan, Hubei, China, con presentaciones clínicas muy parecidas a la neumonía viral. El análisis de secuenciación profunda de muestras del tracto respiratorio inferior indicó un nuevo coronavirus, que se denominó nuevo coronavirus 2019 (2019-nCoV o SARS-CoV2) [15]. La propagación del virus ha sido extremadamente rápida, tanto así que el 11 de marzo de 2020 y luego de más de 118.000 infectados en 114 países con 4.300 fallecidos a esa fecha, la organización mundial de la salud declaró a la enfermedad COVID-19, causada por 2019-nCoV, como una pandemia.
Assuntos
Pneumonia Viral/prevenção & controle , Desinfecção das Mãos , Infecções por Coronavirus/diagnóstico , Assistência Perioperatória/enfermagem , Período Perioperatório/enfermagem , Extubação/instrumentação , BetacoronavirusRESUMO
Posthepatectomy liver failure (PHLF) still represents a severe complication after major liver resection associated with a high mortality. In addition to an insufficient residual liver volume various factors play an important role in the pathophysiology of PHLF. These include the quality of the parenchyma, liver function, perfusion, i.e. maintenance of adequate inflow and outflow, as well as the condition of the patient and comorbidities. While the liver volume is relatively easy to evaluate using modern imaging techniques, the evaluation of liver function and liver quality require a differentiated approach. Both factors can be influenced by the constitutional status of the patient, medical history and previous treatment and must be given sufficient consideration in the risk evaluation. An adequate perfusion, e.g. portal and arterial circulation and adequate outflow by at least one hepatic vein as well an adequate biliary drainage should be always guaranteed in order to allow regeneration of the residual liver tissue. Only the understanding of all these aspects will support the surgeon in a correct and safe evaluation of the resectability. Additionally, the liver surgeon should be aware of all available perioperative and postoperative options to treat and to prevent PHLF. In this review article the most important questions regarding the risk factors related to PHLF are presented and the potential therapeutic and prophylactic management is described. The main goal is to ensure functional operability of the patient if oncological resectability is possible. In other words: in the case of correct oncological indication, the liver surgeon should be able to resect what is resectable or, alternatively, make resectable what primarily was not resectable.
Assuntos
Falência Hepática , Neoplasias Hepáticas , Hepatectomia , Humanos , Fígado , Testes de Função Hepática , Neoplasias Hepáticas/cirurgia , Cuidados Pré-OperatóriosRESUMO
Cyst abundance and identity are essential for understanding and predicting blooms, and for assessing the dispersal of toxic target dinoflagellate species by natural or human mediated ways, as with ballast waters. The aim of this study was to apply rapid, specific and sensitive qPCR assays to enumerate toxic dinoflagellate cysts in sediment samples collected from Adriatic harbours. The molecular standard curves of various target species allowed obtaining the rDNA copy number per cyst. The analytical sensitivity for specific standard curves was determined to be 2 or 10 rDNA copies per reaction. The abundance varied in the range of 1-747â¯dinoflagellate cystsâ¯g-1â¯dry weight. The assays showed greater sensitivity as compared to counts by light microscopy. This qPCR method revealed a powerful tool for the quantification of cysts from toxic dinoflagellate resting stages in sediment samples from Adriatic ports.
Assuntos
Monitoramento Biológico/métodos , Dinoflagellida/genética , Proliferação Nociva de Algas , Reação em Cadeia da Polimerase em Tempo Real/métodos , Variações do Número de Cópias de DNA , DNA Ribossômico/genética , Dinoflagellida/fisiologia , Sedimentos Geológicos/microbiologia , Mar Mediterrâneo , Plasmídeos , Reprodutibilidade dos Testes , Estações do Ano , Sensibilidade e Especificidade , NaviosRESUMO
INTRODUCTION: Many studies aimed at validating the application of Dual Energy Computed Tomography (DECT) in clinical practice where conventional CT is not exhaustive. An example is given by bone marrow oedema detection, in which DECT based on water/calcium (W/Ca) decomposition was applied. In this paper a new DECT approach, based on water/cortical bone (W/CB) decomposition, was investigated. MATERIALS AND METHODS: Eight patients suffering from marrow oedema were scanned with MRI and DECT. Two-materials density decomposition was performed in ROIs corresponding to normal bone marrow and oedema. These regions were drawn on DECT images using MRI informations. Both W/Ca and W/CB were considered as material basis. Scatter plots of W/Ca and W/CB concentrations were made for each ROI in order to evaluate if oedema could be distinguished from normal bone marrow. Thresholds were defined on the scatter plots in order to produce DECT images where oedema regions were highlighted through color maps. The agreement between these images and MR was scored by two expert radiologists. RESULTS: For all the patients, the best scores were obtained using W/CB density decomposition. CONCLUSIONS: In all cases, DECT color map images based on W/CB decomposition showed better agreement with MR in bone marrow oedema identification with respect to W/Ca decomposition. This result encourages further studies in order to evaluate if DECT based on W/CB decomposition could be an alternative technique to MR, which would be important when short scanning duration is relevant, as in the case of aged or traumatic patients.
Assuntos
Medula Óssea/diagnóstico por imagem , Osso Cortical/diagnóstico por imagem , Osso Cortical/metabolismo , Edema/diagnóstico por imagem , Edema/metabolismo , Tomografia Computadorizada por Raios X , Água/metabolismo , Adulto , Idoso , Medula Óssea/metabolismo , Estudos de Viabilidade , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Pessoa de Meia-IdadeRESUMO
INTRODUCTION: Synovial sarcomas are rare malignant tumors of soft tissues, arising mainly from periarticular structures. Gastrointestinal localizations are unusual presentation of these rare sarcomas. METHODS: We present the case of a 56- years old man with monophasic synovial sarcoma, arising primarily from the ileum, and causing intussusception. A review of the literature was conducted to gather information about this rare sarcoma. RESULTS: We found that the criteria normally used to determine the prognosis in patients with monophasic synovial sarcoma of soft tissue are poorly applicable for gastrointestinal localizations. CONCLUSIONS: A better characterization of these tumors could identify them as a distinct entity, compared with monophasic synovial sarcomas of soft tissues.
Assuntos
Neoplasias do Íleo/complicações , Neoplasias do Íleo/cirurgia , Intussuscepção/etiologia , Intussuscepção/cirurgia , Sarcoma Sinovial/complicações , Sarcoma Sinovial/cirurgia , Biomarcadores Tumorais/genética , Humanos , Neoplasias do Íleo/genética , Neoplasias do Íleo/patologia , Masculino , Pessoa de Meia-Idade , Prognóstico , Proteínas Proto-Oncogênicas/genética , Proteínas Repressoras/genética , Sarcoma Sinovial/genética , Sarcoma Sinovial/patologia , Resultado do TratamentoRESUMO
Epithelial-to-mesenchymal transition (EMT) promotes cell motility, which is important for the metastasis of malignant cells, and blocks CD95-mediated apoptotic signaling triggered by immune cells and chemotherapeutic regimens. CD95L, the cognate ligand of CD95, can be cleaved by metalloproteases and released as a soluble molecule (cl-CD95L). Unlike transmembrane CD95L, cl-CD95L does not induce apoptosis but triggers cell motility. Electron paramagnetic resonance was used to show that EMT and cl-CD95L treatment both led to augmentation of plasma membrane fluidity that was instrumental in inducing cell migration. Compaction of the plasma membrane is modulated, among other factors, by the ratio of certain lipids such as sphingolipids in the membrane. An integrative analysis of gene expression in NCI tumor cell lines revealed that expression of ceramide synthase-6 (CerS6) decreased during EMT. Furthermore, pharmacological and genetic approaches established that modulation of CerS6 expression/activity in cancer cells altered the level of C16-ceramide, which in turn influenced plasma membrane fluidity and cell motility. Therefore, this study identifies CerS6 as a novel EMT-regulated gene that has a pivotal role in the regulation of cell migration.
Assuntos
Membrana Celular/fisiologia , Movimento Celular/genética , Transição Epitelial-Mesenquimal/genética , Fluidez de Membrana/genética , Proteínas de Membrana/genética , Neoplasias/patologia , Esfingosina N-Aciltransferase/genética , Células Cultivadas , Regulação para Baixo , Regulação Neoplásica da Expressão Gênica , Células HL-60 , Humanos , Células Jurkat , Células K562RESUMO
Relata-se a ocorrência de um surto de brucelose em um rebanho de aproximadamente 1000 animais, livre da doença há 18 anos, certificado pelo Ministério da Agricultura, Pecuária e Abastecimento desde 2006. Dois animais reagiram aos testes sorológicos de diagnóstico por ocasião dos procedimentos de recertificação em 2008. Após o sacrifício deles, Brucella abortus, biovariedade 1, amostra não vacinal, foi isolada e identificada por meio de provas bioquímicas e de biologia molecular (PCR AMOS). A origem do agente no rebanho é de difícil determinação. No entanto, a adoção de procedimentos preconizados pelo Programa Nacional de Controle e Erradicação da Brucelose permitiu evitar a disseminação da enfermidade. Ocorrências como essas, em que rebanhos livres foram infectados após anos sem a ocorrência de brucelose, nunca haviam sido relatadas no Brasil.
A Brucellosis outbreak is reported in a bovine herd free from the disease for over 18 years, officially free since 2006. One heifer and one cow tested positive in serological tests for the 2008 annual recertification in a herd of almost 1000 animals. Isolation and identification by biochemical tests and molecular biology (AMOS PCR) confirmed the infection by a Brucella abortus biovar 1 field strain. It wasn't possible to find the source of the infection. However, adoption of standard procedures prescribed by the Brazilian National Brucellosis and Tuberculosis Control and Eradication Program hindered the spread of the disease. This is the first report of a Brucella infection in an officially Brucellosis-free bovine herd in Brazil.
Assuntos
Animais , Bovinos , Brucella abortus , Brucelose Bovina/diagnóstico , Brucelose Bovina/transmissão , Doenças dos Bovinos/diagnóstico , Doenças dos Bovinos/transmissão , Surtos de Doenças/veterináriaRESUMO
BACKGROUND: The performance of eight currently available paediatric propofol pharmacokinetic models in target-controlled infusions (TCIs) was assessed, in healthy children from 3 to 26 months of age. METHODS: Forty-one, ASA I-II children, aged 3-26 months were studied. After the induction of general anaesthesia with sevoflurane and remifentanil, a propofol bolus dose of 2.5 mg kg(-1) followed by an infusion of 8 mg kg(-1) h(-1) was given. Arterial blood samples were collected at 1, 2, 3, 5, 10, 20, 40, and 60 min post-bolus, at the end of surgery, and at 1, 3, 5, 30, 60, and 120 min after stopping the infusion. Model performance was visually inspected with measured/predicted plots. Median performance error (MDPE) and the median absolute performance error (MDAPE) were calculated to measure bias and accuracy of each model. RESULTS: Performance of the eight models tested differed markedly during the different stages of propofol administration. Most models underestimated propofol concentration 1 min after the bolus dose, suggesting an overestimation of the initial volume of distribution. Six of the eight models tested were within the accepted limits of performance (MDPE<20% and MDAPE<30%). The model derived by Short and colleagues performed best. CONCLUSIONS: Our results suggest that six of the eight models tested perform well in young children. Since most models overestimate the initial volume of distribution, the use for TCI might result in the administration of larger bolus doses than necessary.
Assuntos
Anestésicos Intravenosos/farmacocinética , Propofol/farmacocinética , Algoritmos , Anestésicos Intravenosos/sangue , Calibragem , Pré-Escolar , Cromatografia Líquida de Alta Pressão , Fenda Labial/cirurgia , Fissura Palatina/cirurgia , Interpretação Estatística de Dados , Feminino , Humanos , Lactente , Masculino , Modelos Estatísticos , Monitorização Intraoperatória , Propofol/sangue , Estudos Prospectivos , Valores de Referência , Reprodutibilidade dos TestesRESUMO
BACKGROUND: To evaluate the influence of radiotherapy on the selenium serum levels of breast cancer patients. PATIENTS AND METHODS: This prospective study includes 209 breast cancer patients treated by external beam radiotherapy from December 2007 until August 2008. Plasma selenium concentrations were determined before and at the end of the radiotherapeutic treatment. Age, clinical stage, prior chemotherapy, body mass index (BMI) and personal habits (smoking and alcoholism) were recorded for each patient. RESULTS: The mean age was 61 years; the mean BMI was 28.7. One hundred and seventy-four patients (83.3%) were nonsmokers. One hundred and eighty-nine patients (90.4%) showed no drinking habits and 110 (52.6%) have no prior chemotherapy. Sixty patients (28.7%) were in clinical stage I, 141 (67.5%) in clinical stage II and 8 (3.8%) in clinical stage III. At the beginning of radiotherapy, the mean selenium value for all patients was 86.4 µg/l and after radiation this value dropped to 47.8 µg/l. Multivariate analysis showed statistically significant difference in the plasma selenium concentration before and after radiotherapy for age (P > 0.001), BMI (P > 0.001), smoking (P > 0.001), alcoholism (P > 0.001), chemotherapy (P > 0.001) and clinical stage (P > 0.001). CONCLUSIONS: Significant reduction in plasma levels of selenium is recorded in patients undergoing radiotherapy, suggesting attention to the nutritional status of this micronutrient and other antioxidant agents.
Assuntos
Neoplasias da Mama/radioterapia , Selênio/sangue , Antioxidantes/metabolismo , Feminino , Humanos , Pessoa de Meia-Idade , Análise Multivariada , Estado Nutricional , Estudos Prospectivos , Radioterapia/efeitos adversosRESUMO
BACKGROUND: The objective of this study was to develop a pharmacokinetic (PK) model to characterize the influence of obesity on propofol PK parameters. METHODS: Nineteen obese ASA II patients undergoing bariatric surgery were studied. Patients received propofol 2 mg kg(-1) bolus dose followed by a 5-20-40-120 min, 10-8-6-5 mg kg(-1) h(-1) infusion. Arterial blood samples were withdrawn at 1, 3, 5 min after induction, every 10-20 min during propofol infusion, and every 10-30 min for 2 h after stopping the propofol infusion. Arterial samples were processed by high-performance liquid chromatography. Time-concentration data profiles from this study were pooled with data from two other propofol PK studies available at http://www.opentci.org. Population PK modelling was performed using non-linear mixed effects model. RESULTS: The study involved 19 obese adults who contributed 163 observations. The pooled analysis involved 51 patients (weight 93 sd 24 kg, range 44-160 kg; age 46 sd 16 yr, range 25-81 yr; BMI 33 sd 9 kg m(-2), range 16-52 kg m(-2)). A three-compartment model was used to investigate propofol PK. An allometric size model using total body weight (TBW) was superior to all other models investigated (linear TBW, free fat mass, lean body weight, normal fat mass) for all clearance parameters. Variability in V2 and Q2 was reduced by a function showing a decrease in both parameters with age. CONCLUSIONS: We have derived a population PK model using obese and non-obese data to characterize propofol PK over a wide range of body weights. An allometric model using TBW as the size descriptor of volumes and clearances was superior to other size descriptors to characterize propofol PK in obese patients.
Assuntos
Anestésicos Intravenosos/sangue , Modelos Biológicos , Obesidade/sangue , Propofol/sangue , Adulto , Idoso , Idoso de 80 Anos ou mais , Anestésicos Intravenosos/administração & dosagem , Antropometria , Cirurgia Bariátrica , Índice de Massa Corporal , Peso Corporal , Esquema de Medicação , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Obesidade/cirurgia , Propofol/administração & dosagemAssuntos
Apendicite/diagnóstico , Doença de Crohn/diagnóstico , Dor Abdominal/etiologia , Adulto , Apendicite/tratamento farmacológico , Apendicite/etiologia , Apendicite/patologia , Budesonida/uso terapêutico , Colonoscopia , Doença de Crohn/complicações , Doença de Crohn/tratamento farmacológico , Doença de Crohn/patologia , Diagnóstico Diferencial , Feminino , Glucocorticoides/uso terapêutico , HumanosRESUMO
BACKGROUND AND OBJECTIVES: Our aim was to assess the efficacy and safety of infliximab (IFX) in clinical practice in three Primary Care, Hospital Centers. MATERIAL AND METHODS: From September 2004 to December 2008 62 patients (28 males, 34 females, mean age 30.25 years, range 15-55 years), affected by ulcerative colitis (UC) (23 pts) or by Crohn's disease (CD) (39 patients) were treated. Clinical efficacy, safety, mucosal healing and quality of life were assessed both in UC and CD. RESULTS: A total of 746 infusions were performed. IFX was administered for a mean of 26 months (range 8-44 months). 33/39 (84.61%) pts with CD were in remission under treatment with IFX for a mean time of 19 months (range 12-44 months). Mean Crohn Disease Activity Index (CDAI) score decreased from 295 (range 258-346) to 136 (range 98-136) (p < 0.005). Inflammatory Bowel Disease Quality of Life (IBDQL) improved from 48 (at entry) to 198 (at the end of the study) (p < 0.005). 20/23 (86.95%) patients with UC were in remission under treatment with IFX for a mean of 18 months (range 8-34 months). Mean Disease Activity Index (DAI) decreased from 11 (range 9-12) to < 3 (range 2-3) (p < 0.05). Mean Mayo Subscore for Endoscopy decreased from 3 to < 1 (range 0-1). IBDQL improved from 56 (at entry) to 194 (at the end of the study) (p < 0.005). Only 5 patients (8.06%) experienced side-effects. CONCLUSIONS: Long-term outpatients treatment with IFX seems to be safe and effective in managing patients affected by IBD in clinical practice.
Assuntos
Anti-Inflamatórios/uso terapêutico , Anticorpos Monoclonais/uso terapêutico , Fármacos Gastrointestinais/uso terapêutico , Doenças Inflamatórias Intestinais/tratamento farmacológico , Adolescente , Adulto , Assistência Ambulatorial , Anti-Inflamatórios/efeitos adversos , Anticorpos Monoclonais/efeitos adversos , Colite Ulcerativa/tratamento farmacológico , Colite Ulcerativa/patologia , Doença de Crohn/tratamento farmacológico , Doença de Crohn/patologia , Feminino , Fármacos Gastrointestinais/efeitos adversos , Humanos , Infliximab , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento , Adulto JovemRESUMO
Nowadays, calprotectin, a cytoplasmatic protein, released by activated neutrophilic polymorphonuclear cells (PMN) and/or monocytes-macrophages (MØ), is considered a good indicator of inflammation in several diseases. Accordingly, fecal calprotectin represents a good predictor of clinical relapse in ulcerative colitis (UC) patients, whereas conflicting results have been reported in Crohn's disease (CD) patients. In our study, in 76 IBD patients (29 CD and 47 UC) fecal calprotectin has been evaluated by a commercial ELISA kit. Results demonstrate that levels of this protein in the stool are significantly more elevated in active CD and UC patients than in normal volunteers. In quiescent CD and UC a trend to higher levels of calprotectin than in the normal counterpart is, however, evident. These data suggest that a low-grade inflammation of the intestinal wall is always present in CD and UC patients, which may predict a clinical relapse risk. In the same group of patients calprotectin levels also were analyzed according to sex and age. A trend to higher values of calprotectin was present in male patients with active or quiescent CD than in their female counterparts. Only in UC patients in remission a trend to calprotectin increase was more marked in the male group than in the female counterpart. When CD and UC patients were divided up according to age, calprotectin positivity peaked between 30-39 years in active CD patients, while in quiescent CD maximum positivity was between 40 and 49 years. However, in both active and quiescent UC patients, calprotectin positivity increased with age. The more precocious detectability of fecal calprotectin in CD patients, as a marker of intestinal mucosa inflammation, may be related to the different histopathology of the two diseases (CD versus UC). However, reduced PMN and/or MØ trafficking from peripheral blood to intestinal mucosa with age by effects of chronic treatment should not be ignored in CD patients.
Assuntos
Fezes/química , Doenças Inflamatórias Intestinais/metabolismo , Complexo Antígeno L1 Leucocitário/metabolismo , Adolescente , Adulto , Idoso , Envelhecimento/metabolismo , Biomarcadores , Colite Ulcerativa/metabolismo , Doença de Crohn/metabolismo , Feminino , Humanos , Complexo Antígeno L1 Leucocitário/análise , Masculino , Pessoa de Meia-Idade , Caracteres SexuaisRESUMO
The drug capecitabine (CAP) is a thymidine Pi-deoxyribosyltransferase (TP) activated oral fluorpyrimidine that generates 5-fluorouracil (5-FU), preferentially, within tumors. Here, in 38 patients with pancreatic cancer we analyzed immunohistochemical TP expression in pancreatic cancer tissue (PCT) and adjacent nonmalignant pancreatic tissue (ANMPT). In addition, a correlation with the main clinical pathological features was made. Furthermore, TP-positive macrophages (MO) isolated from neoplastic tissue were determined. The mean of TP-positive epithelial cells and endothelial cells in terms of microvessel density was significantly higher in PCT than in ANMPT. Because pancreatic cancer is sensitive to 5-FU, TP-activated oral CAP in tumoral and endothelial cells and tumor infiltrating MO could increase the concentration of 5-FU at tumor site, thus resulting in an enhanced antitumor activity.
Assuntos
Movimento Celular/imunologia , Desoxicitidina/análogos & derivados , Desoxicitidina/uso terapêutico , Macrófagos/enzimologia , Macrófagos/patologia , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/patologia , Timidina Fosforilase/biossíntese , Idoso , Capecitabina , Desoxicitidina/farmacologia , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/enzimologia , Células Endoteliais/patologia , Feminino , Fluoruracila/análogos & derivados , Humanos , Imuno-Histoquímica , Macrófagos/efeitos dos fármacos , Masculino , Pessoa de Meia-Idade , Pâncreas/efeitos dos fármacos , Pâncreas/enzimologia , Neoplasias Pancreáticas/enzimologia , Timidina Fosforilase/análiseRESUMO
O artigo não apresenta resumo.
RESUMO
Hepatitis C virus (HCV)-specific CD8(+) cytotoxic T lymphocytes (CTL) are believed to play an important role in the pathogenesis of liver cell injury and viral clearance in HCV infection. Because HCV does not efficiently infect human cells in vitro and primary infected hepatocytes cannot be used as stimulator/target cells for CTL analysis, development of efficient systems to activate and expand CTL in vitro, reproducing antigen presentation to CTL occurring during natural infection, is mandatory to study CTL activity and to define the hierarchy of immunodominance of CTL epitopes. To achieve this goal, 5 different defective adenoviruses carrying structural and nonstructural HCV genes (core, core-E1-E2, E2, NS3-NS4A, NS3-NS5A) were used to induce the endogenous synthesis of HCV proteins in human adherent mononuclear cells in vitro and to allow their entry into the HLA class I cytosolic pathway of antigen processing. The cytolytic activity of peripheral blood lympho-mononuclear cells (PBMC) from HLA-A2(+) HCV-infected patients stimulated with recombinant adenovirus-infected cells was tested against target cells either pulsed with a panel of synthetic peptides containing the HLA-A2 binding motif or infected with recombinant vaccinia viruses carrying HCV genes. Our study defines a reproducible system to stimulate and expand HCV-specific CTL in vitro that mimics the conditions of antigen encounter in vivo. By this approach, we have identified several HLA-A2-restricted epitopes that should correspond to immunodominant HCV sequences recognized by CTL during natural infection. Therefore, these amino acid sequences represent ideal candidates for the design of therapeutic vaccines for chronic HCV infection.