Browsing by Author "Lopes, C"
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- Assessment of strategies to increase chondrocyte viability in cryopreserved human osteochondral allografts: evaluation of the glycosylated hydroquinone, arbutin.Publication . Rosa, SC; Gonçalves, J; Judas, F; Lopes, C; Mendes, AFOBJECTIVE: Allogeneic cartilage is used to repair damaged areas of articular cartilage, requiring the presence of living chondrocytes. So far, no preservation method can effectively meet that purpose. Identification of more effective cryoprotective agents (CPAs) can contribute to this goal. The aim of this study was to determine whether the glycosylated hydroquinone, arbutin, alone or in combination with low concentrations of other CPAs, has cryoprotective properties towards human articular cartilage. MATERIAL AND METHODS: Human tibial plateaus were procured from multi-organ donors, with the approval of the Ethics Committee of the University Hospital of Coimbra. The tibial plateaus were treated with or without arbutin (50 or 100mM), alone or in combination with various concentrations of dimethyl sulfoxide (DMSO) and glycerol, for 0.5-1.5h/37 degrees C, then frozen at -20 degrees C and 24h later transferred to a biofreezer at -80 degrees C. Two to 3 months later, thawing was achieved by immersion in cell culture medium at 37 degrees C/1h. Chondrocyte viability was assessed before and after freeze-thawing using a colorimetric assay based on the cell's metabolic activity and fluorescent dyes to evaluate cell membrane integrity. RESULTS: Before freezing, chondrocyte metabolic activity was identical in all the conditions tested. After freeze-thawing, the highest activity, corresponding to 34.2+/-2.1% of that in the Fresh Control, was achieved in tibial plateaus incubated in 50mM arbutin for 1h whereas in those left untreated it was 11.1+/-4.7. Addition of DMSO and glycerol to arbutin did not increase chondrocyte viability any further. Fluorescence microscopy confirmed these results and showed that living chondrocytes were mainly restricted to the superficial cartilage layers. CONCLUSION: Arbutin seems to be an effective cryoprotective agent for osteochondral allografts with potential benefits over DMSO and glycerol.
- Avaliação e tratamento do doente com acne – Parte I: Epidemiologia, etiopatogenia, clínica, classificação, impacto psicossocial, mitos e realidades, diagnóstico diferencial e estudos complementaresPublication . Figueiredo, A; Massa, A; Picoto, A; Soares, AP; Basto, AS; Lopes, C; Resende, C; Rebelo, C; Brandão, FM; Marques-Pinto, G; Oliveira, HS; Selores, M; Gonçalo, Margarida; Bello, RTO Portuguese Acne Advisory Board (PAAB), grupo de dermatologistas portugueses que, à semelhança de grupos congéneres internacionais, tem dedicado particular atenção à definição de linhas de orientação para o tratamento da acne, pretende que o presente documento constitua uma ferramenta útil na abordagem dos doentes com esta patologia. Elaborou-se um dossier, para educação médica contínua, subdividido em 2 partes: Parte I – etiopatogenia e clínica; Parte II – abordagem terapêutica. Nesta Parte I, revêem-se os principais aspectos da clínica e da fisiopatogenia da acne à luz dos conhecimentos actuais. Discute-se a importância do impacto psicológico e social desta entidade e analisam-se os principais mitos e realidades com ela relacionados. Descrevem-se, sucintamente, as patologias mais relevantes no diagnóstico diferencial das lesões de acne. Enumeram-se as indicações para estudo hormonal, bem como os exames a efectuar nos doentes com esta patologia. The Portuguese Acne Advisory Board (PAAB), a group of Portuguese dermatologists with a special interest in acne, develop, as other international groups in this field, consensus recommendations for the treatment of acne. Overall, the goal is to provide a practice guideline to all physicians dealing with this entity. The continuing medical education dossier was divided in two parts: Part I – etiopathogeny and clinical features; Part II – therapy. This Part I reviews acne pathophysiology, clinical aspects, psychological and social impact and several myths surrounding this disease. Some other entities relevant for the differential diagnosis are described. The need of hormonal evaluation is also discussed
- Avaliação e tratamento do doente com acne - Parte I: Epidemiologia, etiopatogenia, clínica, classificação, impacto psicossocial, mitos e realidades, diagnóstico diferencial e estudos complementaresPublication . Figueiredo, A; Massa, A; Picoto, A; Soares, AP; Basto, AS; Lopes, C; Resende, C; Rebelo, C; Brandão, FM; Marques-Pinto, G; Oliveira, HS; Selores, M; Gonçalo, Margarida; Bello, RTO Portuguese Acne Advisory Board (PAAB), grupo de dermatologistas portugueses que, à semelhança de grupos congéneres internacionais, tem dedicado particular atenção à definição de linhas de orientação para o tratamento da acne, pretende que o presente documento constitua uma ferramenta útil na abordagem dos doentes com esta patologia. Elaborou-se um dossier, para educação médica contínua, subdividido em 2 partes: Parte I – etiopatogenia e clínica; Parte II – abordagem terapêutica. Nesta Parte I, revêem-se os principais aspectos da clínica e da fisiopatogenia da acne à luz dos conhecimentos actuais. Discute-se a importância do impacto psicológico e social desta entidade e analisam-se os principais mitos e realidades com ela relacionados. Descrevem-se, sucintamente, as patologias mais relevantes no diagnóstico diferencial das lesões de acne. Enumeram-se as indicações para estudo hormonal, bem como os exames a efectuar nos doentes com esta patologia.
- Avaliação e tratamento do doente com acne - Parte II: tratamento tópico, sistémico e cirúrgico, tratamento da acne na grávida, algoritmo terapêuticoPublication . Figueiredo, A; Massa, A; Picoto, A; Soares, AP; Basto, AS; Lopes, C; Resende, C; Rebelo, C; Brandão, FM; Marques-Pinto, G; Oliveira, HS; Selores, M; Gonçalo, Margarida; Bello, RTO Portuguese Acne Advisory Board (PAAB), grupo de dermatologistas portugueses que, à semelhança de grupos congéneres internacionais, tem dedicado particular atenção à definição de linhas de orientação para o tratamento da acne, pretende que o presente documento constitua uma ferramenta útil na abordagem dos doentes com esta patologia. Elaborou-se um dossier, para educação médica contínua, subdividido em 2 partes: Parte I – etiopatogenia e clínica; Parte II – abordagem terapêutica. Nesta Parte II discute-se a abordagem terapêutica – tópica e sistémica – em cada forma clínica de acne, dando particular ênfase aos retinóides e aos antimicrobianos, e salientam-se as estratégias a adoptar para limitar a crescente resistência bacteriana aos antibióticos. Referem-se as indicações específicas para terapêutica hormonal e analisam-se as particularidades do tratamento da acne na grávida e lactante. Descrevem-se algumas técnicas para correcção das cicatrizes da acne. Por último, publica-se um algoritmo que pretende ilustrar a classificação da acne e definir, para cada tipo clínico, a abordagem terapêutica consensualmente recomendada.
- Avaliação e tratamento do doente com acne - Parte II: tratamento tópico, sistémico e cirúrgico, tratamento da acne na grávida, algoritmo terapêuticoPublication . Figueiredo, A; Massa, A; Picoto, A; Soares, AP; Basto, AS; Lopes, C; Resende, C; Rebelo, C; Brandão, FM; Marques-Pinto, G; Oliveira, HS; Selores, M; Gonçalo, M; Bello, RTO Portuguese Acne Advisory Board (PAAB), grupo de dermatologistas portugueses que, à semelhança de grupos congéneres internacionais, tem dedicado particular atenção à definição de linhas de orientação para o tratamento da acne, pretende que o presente documento constitua uma ferramenta útil na abordagem dos doentes com esta patologia. Elaborou-se um dossier, para educação médica contínua, subdividido em 2 partes: Parte I – etiopatogenia e clínica; Parte II – abordagem terapêutica. Nesta Parte II discute-se a abordagem terapêutica – tópica e sistémica – em cada forma clínica de acne, dando particular ênfase aos retinóides e aos antimicrobianos, e salientam-se as estratégias a adoptar para limitar a crescente resistência bacteriana aos antibióticos. Referem-se as indicações específicas para terapêutica hormonal e analisam-se as particularidades do tratamento da acne na grávida e lactante. Descrevem-se algumas técnicas para correcção das cicatrizes da acne. Por último, publica-se um algoritmo que pretende ilustrar a classificação da acne e definir, para cada tipo clínico, a abordagem terapêutica consensualmente recomendada. The Portuguese Acne Advisory Board (PAAB), a group of Portuguese dermatologists with a special interest in acne, develop, as other international groups in this field, consensus recommendations for the treatment of acne. Overall, the goal is to provide a practice guideline to all physicians dealing with this entity. The continuing medical education dossier was divided in two parts: Part I – etiopathogeny and clinical features; Part II – therapy. This Part II reviews the therapeutic approach of acne patients, including topical and oral medications, according to the clinical acne type. Retinoids and antimicrobial agents are discussed and strategies for limiting antibiotic resistance are provided. Appropriate patient selection for hormonal therapy and treatment of acne during pregnancy are also discussed. A variety of surgical techniques useful in the management of acne scars are referred. Finally, the recommendations outlined in the treatment algorithm reflect a consensus approach that takes into account the severity and the specific clinical subtypes of acne.
- Chondrocyte Viability in Fresh and Frozen Large Human Osteochondral Allografts: Effect of Cryoprotective AgentsPublication . Judas, F; Rosa, S; Teixeira, L; Lopes, C; Mendes, AFChondrocyte survival is a major goal for the effective storage and clinical performance of human osteochondral allografts. The majority of animal and human cryopreservation studies conducted so far have been performed in small osteochondral cylinders. Using human tibial plateaus as a model for large osteochondral pieces, this work sought to evaluate the cryoprotective efficiency of glycerol and dimethylsulfoxide (DMSO), and to identify cryopreservation conditions suitable for use in tissue banks. Human tibial plateaus harvested from 7 cadaveric tissue donors were incubated in the presence or absence of cryoprotective agents (CPA): 10% or 15% glycerol and 10% DMSO in a Ham F-12 nutrient mixture. Chondrocyte viability was assessed immediately after thawing, using the MTT reduction assay and a fluorescence microscopic method. The tibial plateaus frozen in the absence of CPA showed a significant decrease in chondrocyte viability. The use of CPA significantly increased chondrocyte viability compared with cartilage frozen without CPA (nearly 50% versus 80% living chondrocytes with 10% glycerol versus 10% DMSO, respectively) relative to that in fresh cartilage. In this regard, 10% DMSO was slightly more effective than either 10% or 15% glycerol, eliciting the recovery of approximately 15% relative to the living chondrocyte content in fresh cartilage. In all conditions, fluorescence microscopic studies showed that surviving chondrocytes were restricted to the superficial cartilage layer. Human tibial plateaus seemed to be a good experimental model to establish cryopreservation methods applicable to large human osteochondral pieces in tissue banks.
- External validation of a classification for methylene blue magnification chromoendoscopy in premalignant gastric lesionsPublication . Areia, A; Amaro, P; Dinis-Ribeiro, M; Cipriano, MA; Marinho, C; Costa-Pereira, A; Lopes, C; Moreira-Dias, L; Romãozinho, JM; Gouveia, H; Freitas, D; Leitão, MBACKGROUND: Conventional endoscopy has low sensitivity, specificity, and interobserver agreement for the diagnosis of gastric atrophy, intestinal metaplasia, and dysplasia. Magnification chromoendoscopy (ME) may optimize the evaluation of premalignant gastric lesions. OBJECTIVE AND DESIGN: As part of a multicenter trial, we aimed at validating a previously proposed classification for gastric methylene blue ME at a different center. SETTING, PATIENTS, AND INTERVENTIONS: A sample of patients (n = 42) with previously diagnosed chronic atrophic gastritis with or without intestinal metaplasia underwent ME (Pentax EG-3430Z) with 1% methylene blue by 2 endoscopists. MAIN OUTCOME MEASUREMENTS: A simplified version of a previously published ME classification (group I, group II [further divided into subgroups IIE and IIF], and group III) was used for macroscopic lesions (n = 203) with Sydney-Houston and Vienna classifications being used for histologic analysis (n = 479 biopsy specimens). RESULTS AND LIMITATIONS: Excellent reproducibility (wK = 0.92 [95% CI, 0.88-0.96]) was observed for classification in groups and substantial reproducibility (wK = 0.78 [95% CI, 0.72-0.84]) was found for classification in subgroups. Global validity was 82% (range 78%-86%), showing no false negatives (sensitivity of 100% [1/1 biopsy]) and a very low rate of false positives (specificity 99% [297/299 biopsies]) for dysplasia detection. CONCLUSIONS: This classification for methylene blue ME was highly reproducible and valid for the diagnosis of premalignant gastric lesions when used in a center different from that involved in its conception. Despite requiring an unconventional endoscope and a longer procedure, these results could reinforce ME as a valuable technique in the surveillance of patients at risk for gastric cancer.
- Human Papillomavirus Type Distribution in Cervical Intraepithelial Neoplasia Grade 2/3 and Cervical Cancer in Portugal: A CLEOPATRE II StudyPublication . Pista, A; Oliveira, CF; Lopes, C; Cunha, MJ; CLEOPATRE Portugal Study GroupOBJECTIVE: Cervical cancer is the third most frequent cancer in women, worldwide and etiologically associated with infection by human papillomavirus (HPV). Following the results of the first epidemiologic population-based CLEOPATRE study in Portugal, it was important to understand the HPV type-specific distribution in women with cervical intraepithelial neoplasia (CIN) grades 2 and 3 and invasive cervical cancer (ICC). METHODS: This was an observational, multicenter, cross-sectional study with retrospective data collection. Between January 2008 and May 2009, paraffin-embedded samples of histologically confirmed cases of CIN2, CIN3, and ICC were collected from the 5 regional health administrations in mainland Portugal. Eligible samples were sent to 2 central laboratories for histological reassessment and HPV genotyping. Prevalence estimates were calculated together with 95% confidence intervals. RESULTS: A total of 582 samples, 177 cases of CIN2, 341 of CIN3, and 64 of ICC, were included. The mean age of participants was 41.8 years (range, 20-88 years). The overall HPV prevalence was 97.9% with a higher prevalence of high-risk genotypes, particularly HPV 16. Multiple infections were observed in 11.2% of the cases. Human papillomavirus prevalence was 95.5% in CIN2, 99.4% in CIN3, and 96.9% in ICC. The 8 more frequent genotypes in order of decreasing frequency were HPV 16, 31, 58, 33, 51, 52, 18, and 35 in CIN2 and HPV 16, 31, 33, 58, 52, 35, 18, and 51 in CIN3. In ICC cases, the 12 detected HPV genotypes were HPV 16, 18, 31, 33, 45, 51, 52, 53, 56, 58, 59, and 73. However, HPV 53 and 73 were always associated to other high-risk genotypes. Human papillomavirus types 31, 51, 52, 56, and 59 were detected in 1 case each. CONCLUSIONS: Human papillomavirus prevalence and patterns of type-specific HPV positivity were comparable with other studies. Current HPV vaccines should protect against HPV genotypes responsible for 77.4% of ICC in Portugal.
- Impaired glucose transporter-1 degradation and increased glucose transport and oxidative stress in response to high glucose in chondrocytes from osteoarthritic versus normal human cartilagePublication . Rosa, SC; Gonçalves, J; Judas, F; Mobasheri, A; Lopes, C; Mendes, AFINTRODUCTION: Disorders that affect glucose metabolism, namely diabetes mellitus (DM), may favor the development and/or progression of osteoarthritis (OA). Thus far, little is known regarding the ability of chondrocytes to adjust to variations in the extracellular glucose concentration, resulting from hypoglycemia and hyperglycemia episodes, and so, to avoid deleterious effects resulting from deprivation or intracellular accumulation of glucose. The aim of this study was to compare the ability of normal and OA chondrocytes to regulate their glucose transport capacity in conditions of insufficient or excessive extracellular glucose and to identify the mechanisms involved and eventual deleterious consequences, namely the production of reactive oxygen species (ROS). METHODS: Chondrocytes, isolated from normal and OA human cartilage, were maintained in high-density monolayer cultures, in media without or with 10 or 30 mM glucose. Glucose transport was measured as the uptake of 2-deoxy-D-glucose (2-DG). Glucose transporter-1 (GLUT-1) mRNA and protein content were evaluated by real-time RT-PCR and western blot, respectively. ROS production was measured with 2',7'-dichlorodihydrofluorescein diacetate. RESULTS: Basal and IL-1beta-induced 2-DG uptake, including the affinity (1.066 +/- 0.284 and 1.49 +/- 0.59 mM) and maximal velocity (0.27 +/- 0.08 and 0.33 +/- 0.08 nmol/microg protein/hour), and GLUT-1 content were identical in normal and OA chondrocytes. Glucose deprivation increased 2-DG uptake and GLUT-1 protein both in normal and OA chondrocytes. Exposure to high glucose (30 mM) for 18 or 48 hours decreased those parameters in normal but not in OA chondrocytes. GLUT-1 mRNA levels were unaffected by high glucose, either in normal or OA chondrocytes. The high glucose-induced reduction in GLUT-1 protein in normal chondrocytes was reversed by treatment with a lysosome inhibitor. High glucose induced ROS production, which lasted significantly longer in OA than in normal chondrocytes. CONCLUSIONS: Normal human chondrocytes adjust to variations in the extracellular glucose concentration by modulating GLUT-1 synthesis and degradation which involves the lysosome pathway. Although capable of adjusting to glucose deprivation, OA chondrocytes exposed to high glucose were unable downregulate GLUT-1, accumulating more glucose and producing more ROS. Impaired GLUT-1 downregulation may constitute an important pathogenic mechanism by which conditions characterized by hyperglycemia, like DM, can promote degenerative changes in chondrocytes that can facilitate the progression of OA
- Infection à VIH et tuberculose, à propos de 32 casPublication . Lopes, C; Alves, H; Rabadão, E; Oliveira, J; Pombo, V; Saraiva da Cunha, JG; Côrte-Real, R; Meliço-Silvestre, A