Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 19 de 19
Filtrar
1.
Front Public Health ; 11: 1228304, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37663832

RESUMO

Background: Globally, it has been reported that different social determinants of health affect health outcomes in lung cancer (LC). Research on the therapeutic trajectories of patients (TTP) is a novel field for identifying barriers and facilitators in health. The objective of this study was to reveal perceived differences in TTP with LC in Chile according to selected social determinants of health (SDH) and the experiences of patients, health professionals, and civil society leaders. Methods: This is a qualitative paradigm, one case-study design. Online semi-structured interviews were conducted with patients with LC, health professionals, and civil society leaders. The strategies for the recruitment process included social networks, civil society organizations, health professionals, and the snowball technique. A thematic analysis was carried out. Results: Selected SDH impact LC's TTP in Chile, particularly concerning health system access, health services, information, and patient navigation experiences. The analysis of the experiences of the participants allowed us to identify barriers related to the selected SDH in three stages of the TTP: initiation, examinations, and diagnosis and treatment. Individuals with limited education, those residing outside the capital, women, and those in the public health system encountered more barriers throughout their TTP. Discussion: Study findings suggest that being a woman with low education, from the public health system, and not from the capital might represent one of the most powerful intersections for experiencing barriers to effective healthcare in LC in Chile. It is necessary to monitor the TTP from an SDH perspective to guarantee the rights of access, opportunity, quality, and financial protection.


Assuntos
Neoplasias Pulmonares , Humanos , Adulto , Feminino , Chile , Neoplasias Pulmonares/terapia , Pesquisa Qualitativa , Escolaridade , Atenção à Saúde
2.
Value Health Reg Issues ; 33: 42-48, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36228530

RESUMO

OBJECTIVES: This study aimed to characterize 5 approaches that have been developed in research on patients and health coverage, which reveal information from the perspective of patients: (1) access to healthcare, (2) therapeutic trajectories, (3) social participation in decision making on health coverage, (4) tacit knowledge, and (5) communities of practice. METHODS: This is a narrative literature review, based on searches performed in PubMed/MEDLINE and Web of Science, between August and December 2021. A total of 45 scientific articles were selected for analysis, which were complemented by a gray literature search that provided 6 additional manuscripts. RESULTS: Improving access to health services requires an understanding of the meaning of the concept of access from the users themselves. The patient trajectory approach contributes by emphasizing that the focus of analysis must adopt the patient's perspective, given that it provides valuable information for the decision making on health coverage. In addition, the role that social participation has in the process to grant trust and legitimacy is described. Tacit knowledge makes explicit the importance of revealing it as a source of information that adds value to the decision-making process. Finally, communities of practice are described as spaces where new ways of experiencing the disease originate, as well as ways of relating to the health system and its actors. CONCLUSIONS: The article raises the relevance that various social actors know these approaches, as well as strategies to integrate them into the assessment processes in terms of health coverage.

3.
Clin Rheumatol ; 35(8): 2079-2086, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27236512

RESUMO

This study aimed to apply the recently proposed Oslo hand osteoarthritis magnetic resonance imaging (MRI) scoring system to evaluate MRI findings in a cohort of patients affected by long-standing erosive hand osteoarthritis (EHOA). Eleven female EHOA patients (median 59 [interquartile range 62-52] years, disease duration 9.5 [interquartile range 13-3.75] years) underwent MRI (1.5 T) of the dominant hand, and synovitis, bone marrow lesions (BMLs), joint space narrowing, osteophytes, cysts, malalignment, and erosions were scored using the Oslo scoring system. Intra- and inter-reader reliability were assessed. The patients also underwent X-ray examination, and bone features were evaluated using the same scoring system. Pain and tenderness were assessed during a physical examination. Spearman's non-parametric test was used to analyze the correlations between variables. MRI intra- and inter-reader reliability were found between good and moderate for many features. No statistical differences were found between the radiographs and MRI with regard to detection of JSN, malalignment, and bone erosions. Synovitis was detected in 39.8 % of the 80 joints examined (in a mild form in 80 %), erosions were found in 51.1 %, and BMLs were identified in 20.5 and 23.9 % at the distal and the proximal side, respectively. BMLs at both the proximal and distal ends were correlated with tender joints (BML distal p = 0.0013, BML proximal p = 0.012). The presence of synovitis was correlated with tenderness (p = 0.004) and erosions at both the distal and proximal joints (p = 0.004). The presence of erosions correlated with tender joints (p < 0.01) and the mean visual analog scale (VAS) score (distal p = 0.03, proximal p = 0.01). Synovitis and BMLs were correlated with clinical symptoms in our patients affected with long-standing EHOA.


Assuntos
Medula Óssea/patologia , Articulação da Mão/patologia , Imageamento por Ressonância Magnética/normas , Osteoartrite/diagnóstico por imagem , Índice de Gravidade de Doença , Sinovite/epidemiologia , Artralgia/etiologia , Feminino , Humanos , Itália , Pessoa de Meia-Idade , Osteoartrite/complicações , Medição da Dor , Reprodutibilidade dos Testes
4.
Eur J Intern Med ; 24(1): 11-5, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23102569

RESUMO

This review focuses on biomarkers in erosive hand osteoarthritis (EHOA), a subset of hand osteoarthritis (HOA), that primarily affects interphalangeal joints and is characterized by abrupt onset, severe pain and functional impairment, as well as signs of inflammation, in particular stiffness, swelling, erythema, paraesthesiae, and worse outcome. Inflammatory features and radiographic erosions are the main diagnostic hallmarks of this particular disease subset. As in other fields of OA, EHOA biomarkers can be classified as dry and soluble. Soluble biomarkers which are found in serum, synovial fluid and urine can be specific indicators of joint inflammation and degradation. With regard to inflammatory markers, C-reactive protein and myeloperoxidase have been found to be increased in EHOA, with respect to non-erosive HOA. All these markers have, moreover, been found to be correlated with disease activity. Another interesting marker linked to inflammation is hyaluronic acid, considered to be a marker of synovitis, which is frequently found in EHOA. The most useful cartilage markers in both erosive and non-erosive HOA, seems to be collagen (Coll) 2-1, Coll 2-1NO(2) and Col2-3/4C(short). Immunogenetic markers were also determined and an association between EHOA and a single nucleotide polymorphism on the gene encoding interleukin-1ß was found in HLA and there was an increased frequency of HLA-B44 and HLA-DRB1*07 in EHOA.


Assuntos
Articulação da Mão , Osteoartrite/sangue , Biomarcadores/sangue , Proteína C-Reativa/análise , Colágeno Tipo II/sangue , Humanos
5.
Joint Bone Spine ; 79(5): 507-9, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22840479

RESUMO

To describe an unexpected association between a patient affected with erosive hand osteoarthritis (EHOA) and systemic sclerosis (SSc). We report a case of SSc presenting typical radiological findings of EHOA in a 60-year-old woman referred to our outpatient Rheumatology Unit. Physical examination revealed puffy hands with sclerodactyly and concomitant adduction of the thumb and subluxation of the first carpometacarpal (CMC) and metacarpophalangeal (MCP) joints bilaterally and nodose deformities of the distal interphalangeal (DIP). Hand X-rays showed joint space narrowing, osteophytosis and bone sclerosis of the proximal interphalangeal (PIP) joints. The DIP joints showed central bone erosion, collapse of the subchondral bone plate and typical "gull-wing" type deformity. EHOA is a particularly aggressive subset of osteoarthritis (OA). In light of its still unclear pathogenesis, peculiarities in the disease characteristics may be useful to better define the EHOA patient profile. One of these is an unexpected association with some autoimmune diseases. EHOA and SSc in the same patient is not uncommon, and it could speculate that there may be a genetic and autoimmune involvement.


Assuntos
Articulação da Mão , Osteoartrite/epidemiologia , Escleroderma Sistêmico/epidemiologia , Autoimunidade/fisiologia , Comorbidade , Feminino , Articulação da Mão/diagnóstico por imagem , Humanos , Articulação Metacarpofalângica/diagnóstico por imagem , Pessoa de Meia-Idade , Osteoartrite/diagnóstico por imagem , Osteoartrite/imunologia , Radiografia , Escleroderma Sistêmico/imunologia , Polegar/diagnóstico por imagem
6.
J Rheumatol ; 39(9): 1844-9, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22798267

RESUMO

OBJECTIVE: Anterior chest wall (ACW) involvement is difficult to evaluate in patients with spondyloarthritis (SpA). Bone scan is sensitive to ACW involvement, while magnetic resonance imaging (MRI) detects early alterations in SpA. We compared the sensitivity and specificity of bone scans and MRI in assessing ACW in early SpA. METHODS: Out of 110 patients with early SpA attending the Outpatient Rheumatology Unit Clinic of Padua University from January 2008 to December 2010, the 40 complaining of pain and/or tenderness [60% with psoriatic arthritis (PsA), 12.5% with ankylosing spondylitis, and 27.5% with undifferentiated SpA] underwent bone scans and MRI. RESULTS: At clinical examination, sternocostoclavicular joints were involved in 87.5% on the right, 77.5% on the left, and 35% on the sternum. Bone scan was positive in 100% and MRI in 62.5% of these patients. Early MRI signs (bone edema, synovial hyperemia) were observed in 27.5%, swelling in 5%, capsular structure thickness in 37.5%, erosions in 15%, bone irregularities in 15%, osteoproductive processes in 12.5%, and osteophytes in 5%. A higher prevalence of Cw6, Cw7, B35, and B38 was found in 15%, 48%, 28%, and 12%, respectively, of the patients with PsA who had bone scans. CONCLUSION: Noted mainly in women, ACW involvement was frequent in early SpA. Both bone scans and MRI are useful in investigating ACW inflammation. Bone scans were found to have high sensitivity in revealing subclinical involvement, but a low specificity. MRI provides useful information for therapeutic decision making because it reveals the type and extent of the process. The significant associations of HLA-Cw6 and Cw7 with PsA could suggest that genetic factors influence ACW involvement.


Assuntos
Osso e Ossos/diagnóstico por imagem , Imageamento por Ressonância Magnética , Espondilartrite/patologia , Parede Torácica/patologia , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Radiografia , Sensibilidade e Especificidade , Espondilartrite/diagnóstico por imagem , Parede Torácica/diagnóstico por imagem
7.
J Tissue Eng Regen Med ; 6(4): 299-313, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21706777

RESUMO

The selection of appropriate biomaterials that promote cellular adhesion and growth is particularly important for the in vitro reconstruction of neuronal network. This study focused on the development of new polymeric membranes in flat and tubular (hollow-fibre) configurations as novel biomaterials for neuronal outgrowth. Two membrane systems constituted by modified polyetheretherketone (PEEK-WC) and polyacrylonitrile (PAN) membranes were developed and used for the culture of hamster hippocampal neurons. We demonstrated that all investigated membranes supported the adhesion and growth of hippocampal neurons enhancing neuronal differentiation and neurite alignment. The differences in cell behaviours between cells cultured on flat and hollow-fibre (HF) membranes were highlighted by the quantitative analysis of neuronal marker fluorescence intensity, morphometric analysis, RT-PCR analysis and also by metabolic activity measurements. In particular, the PAN HF membranes showed ideal growth culture conditions, guaranteeing adequate levels of metabolic features. Primary hippocampal cells cultured on PAN HF membranes were able to recreate in vitro a 3D neural tissue-like structure that, mimicking the hippocampal tissue, could be used as a tool for the study of natural and pathological neurobiological events.


Assuntos
Hipocampo/citologia , Membranas Artificiais , Rede Nervosa/fisiologia , Neurônios/fisiologia , Engenharia Tecidual/métodos , Resinas Acrílicas/farmacologia , Animais , Benzofenonas , Forma Celular/efeitos dos fármacos , Cricetinae , Regulação da Expressão Gênica , Cetonas/farmacologia , Microscopia Confocal , Microscopia Eletrônica de Varredura , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Rede Nervosa/efeitos dos fármacos , Neurônios/citologia , Neurônios/efeitos dos fármacos , Neurônios/ultraestrutura , Polietilenoglicóis/farmacologia , Polilisina/farmacologia , Polímeros , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores de AMPA/genética , Receptores de AMPA/metabolismo , Tubulina (Proteína)/metabolismo
8.
Biomaterials ; 32(34): 8848-59, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21871658

RESUMO

The realization of organotypic liver model that exhibits stable phenotype is a major challenge in the field of liver tissue engineering. In this study we developed liver organotypic co-culture systems by using synthetic and biodegradable membranes with primary human hepatocytes and human umbilical vein endothelial cells (HUVEC). Synthetic membranes prepared by a polymeric blend constituted of modified polyetheretherketone (PEEK-WC) and polyurethane (PU) and biodegradable chitosan membranes were developed by phase inversion technique and used in homotypic and organotypic culture systems. The morphological and functional characteristics of cells in the organotypic co-culture membrane systems were evaluated in comparison with homotypic cultures and traditional systems. Hepatocytes in the organotypic co-culture systems exhibit compact polyhedral cells with round nuclei and well demarcated cell-cell borders like in vivo, as a result of heterotypic interaction with HUVECs. In addition HUVECs formed tube-like structures directly through the interactions with the membranes and hepatocytes and indirectly through the secretion of ECM proteins which secretion improved in the organotypic co-culture membrane systems. The heterotypic cell-cell contacts have beneficial effect on the hepatocyte albumin production, urea synthesis and drug biotransformation. The developed organotypic co-culture membrane systems elicit liver specific functions in vitro and could be applied for the realization of engineered liver tissues to be used in tissue engineering, drug metabolism studies and bioartificial liver devices.


Assuntos
Técnicas de Cocultura/instrumentação , Hepatócitos/citologia , Células Endoteliais da Veia Umbilical Humana/citologia , Fígado Artificial , Membranas Artificiais , Benzofenonas , Células Cultivadas , Quitosana/química , Hepatócitos/metabolismo , Humanos , Cetonas/química , Polietilenoglicóis/química , Polímeros , Poliuretanos/química
10.
Autoimmun Rev ; 10(6): 305-10, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21224015

RESUMO

Glucocorticoids (GCs) are potent anti-inflammatory and immunosuppressive agents which exert multiple effects on immune cell functions. Although their use dates back 60 years, their functions and mode of action have not been completely elucidated yet. GCs act through different genomic and non genomic mechanisms which are mediated by the binding to cytosolic glucocorticoid receptor as well as to cell membrane receptors, or by interacting directly with enzymes and other cell proteins. T cell subtypes have a different sensitivity and response to GCs; in fact, GCs have an immunosuppressive effect on pro-inflammatory T cells, while they stimulate regulatory T cell activity. The effect of GCs on B cells is less clear. Interestingly, treatment with GCs may determine apoptosis of autoreactive B cells by reducing the B cell activator factor (BAFF). Tolerogenic dendritic cells which express low levels of Major Histocompatibility Complex class II, co-stimulatory molecules and cytokines, such as IL-1ß, IL-6, and IL-12, can be induced by GCs. GCs at low levels stimulate and at high levels inhibit macrophage activity; moreover, they reduce the number of basophils, stimulate the transcription of inhibitors of leukocyte proteinases and the apoptosis of neutrophils and eosinophils. Finally, GCs inhibit the synthesis and function of some cytokines, particularly T helper type 1 cytokines, and to a lesser extent the secretion of chemokines and co-stimulatory molecules from immune and endothelial cells.


Assuntos
Glucocorticoides/farmacologia , Sistema Imunitário/efeitos dos fármacos , Imunossupressores/farmacologia , Humanos , Receptores de Glucocorticoides/genética , Receptores de Glucocorticoides/metabolismo
11.
Acta Biomater ; 7(1): 171-9, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20691288

RESUMO

The insufficient availability of donor organs for orthotopic liver transplantation worldwide has urgently increased the requirement for new therapies for acute and chronic liver disease. The creation of an unlimited source of donor cells for hepatocyte transplantation therapy and pharmaceutical applications may be the isolation and expansion of liver progenitor cells or stem cells. Here we report the expansion and functional differentiation of rat embryonic liver cells on biodegradable and synthetic polymeric membranes in comparison with traditional substrates, such as collagen and polystyrene culture dishes. Membranes prepared from chitosan and modified polyetheretherketone were used for the culture of liver progenitor cells derived from rat embryonic liver. Cells proliferated, with a significant increase in their number within 8-11 days. The cells displayed functional differentiation showing urea synthesis, albumin production and diazepam biotransformation on all substrates investigated. In particular, on a chitosan membrane liver-specific functions were expressed at significantly higher levels for prolonged times compared with other synthetic membranes, utilizing traditional substrates (collagen and PSCD) as references. These results demonstrate that chitosan membranes offer cells favourable conditions to promote the expansion and functional differentiation of embryonic liver cells that could be effectively used in liver tissue engineering and in pharmaceutical applications.


Assuntos
Materiais Biocompatíveis/farmacologia , Diferenciação Celular/efeitos dos fármacos , Hepatócitos/citologia , Hepatócitos/efeitos dos fármacos , Fígado/citologia , Fígado/embriologia , Membranas Artificiais , Animais , Proliferação de Células/efeitos dos fármacos , Quitosana/farmacologia , Diazepam/metabolismo , Hepatócitos/metabolismo , Hepatócitos/ultraestrutura , Microscopia Confocal , Especificidade de Órgãos/efeitos dos fármacos , Ratos , Fatores de Tempo , Água/química
12.
Swiss Med Wkly ; 140(13-14): 187-201, 2010 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-20175004

RESUMO

During pregnancy the maternal immune system is modified in order to achieve immune tolerance toward paternal antigen expressed on foetal cells. These modifications, which occur both at the foeto-maternal interface and in the systemic circulation, are driven by oestrogens and progesterone whose blood concentrations increase during pregnancy. The cytokine profile is also modified. Th2 cytokines are enhanced while the Th1 response is inhibited. This could explain why Th1-mediated autoimmune diseases tend to improve and Th2-mediated diseases, such as systemic lupus erythematosus (SLE), tend to worsen during pregnancy. However, whether or not SLE relapses more frequently during pregnancy is still a matter of debate. Steroid hormone and cytokine profiles differ in SLE patients compared with healthy subjects during pregnancy leading to a dysregulation of the balance between cell-mediated and humoral immune response, which, in turn, could explain the variability of the SLE course during gestation. This review focuses on hormonal-related cytokine changes observed during pregnancy in healthy subjects and SLE patients.


Assuntos
Hormônios Esteroides Gonadais/imunologia , Lúpus Eritematoso Sistêmico/imunologia , Complicações na Gravidez/imunologia , Gravidez/imunologia , Citocinas/imunologia , Estrogênios/imunologia , Feminino , Humanos , Progesterona/imunologia , Prolactina/imunologia
13.
Auto Immun Highlights ; 1(2): 63-72, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26000109

RESUMO

Impairment of the clearance of apoptotic material seems to contribute to autoantigen exposure, which can initiate or maintain an autoimmune response in predisposed individuals. Complement component C1q, Creactive protein (CRP), serum amyloid P (SAP), mannose-binding lectin (MBL), apolipoprotein A-1 (Apo A-1) and long pentraxin 3 (PTX3) are molecules involved in the removal of apoptotic bodies and pathogens, and in other antiinflammatory pathways. For this reason they have been called "protective" molecules. C1q has a key role in the activation of the complement cascade and acts as a bridging molecule between apoptotic bodies and macrophages favouring phagocytosis. In addition to other functions, CRP, SAP and MBL bind to the surface of numerous pathogens as well as cellular debris and activate the complement cascade, thus stimulating their clearance by immune cells. The role of PTX3 is more controversial. In fact, PTX also promotes the clearance of microorganisms, but the activation of the complement cascade through C1q and removal of apoptotic material can be either stimulated or inhibited by this molecule. Antibodies against protective molecules have been recently reported in systemic lupus erythematosus and other autoimmune rheumatic diseases. Some of them seem to be pathogenetic and others protective. Thus, protective molecules and their cognate antibodies may constitute a regulatory network involved in autoimmunity. Dysregulation of this system might contribute to the development of autoimmune diseases in predisposed individuals.

14.
BMJ Case Rep ; 20092009.
Artigo em Inglês | MEDLINE | ID: mdl-21686550

RESUMO

Erythema nodosum (EN) is an inflammatory disease of the skin and subcutaneous tissue that may be found in association with many systemic diseases such as infectious diseases, sarcoidosis, Behçet disease, inflammatory bowel diseases and tumours, in particular lymphoma. EN may be also induced by some drugs, including mainly estroprogestinics, salicylic acid, minocycline and sulfamidic acid. Due to the numerous possible causes, sometimes it may be very difficult to achieve a correct diagnostic interpretation, especially when an isolated EN represents the revealing feature, as in the following case. We describe the case of a patient, of young age and good clinical condition, who developed EN during the course of abdominal tuberculosis. The diagnosis was obtained by histologic examination of the abdominal formation since positron emission tomography and total body axial tomography were not useful in discriminating EN from malignancies.

15.
Autoimmun Rev ; 8(1): 76-82, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18718877

RESUMO

Associations between rheumatoid arthritis (RA) susceptibility and polymorphism in multiple immunoregulatory genes suggest a role of altered T cell function in the disease. The growing relevance of the oxidative stress in RA synovitis, which results in a number of T cell signalling abnormalities, is reinforced by the demonstration of a direct NO inducing activity through the shared epitope of the HLA class II molecules HLA-DRbeta1, with secondary lymphocytes oxidative damage. Direct T cell/macrophage contact-dependent activation, one of the driving mechanisms of synovitis, is mediated by co-stimulatory molecules as well as cell membrane cytokines and may also result in an impaired suppressive function of T regulatory cells (Treg) in RA joints. The fusion of CTLA4 extracellular binding domain to the Fcgamma1 allows to obtain a soluble CTLA4 receptor, the dimeric recombinant human fusion protein abatacept (CTLA4-Ig). The improved knowledge of the CTLA4-B7 co-stimulation regulatory mechanisms by signals delivered into DCs and Tregs provides multiple potential targets for the abatacept treatment. CTLA4-Ig shows the capacity, either ex vivo or in vivo, to interrupt at multiple steps the ongoing inflammatory and destructive process, and to concur in restoring the immunoregulatory balance in RA.


Assuntos
Antígenos CD/metabolismo , Artrite Reumatoide/imunologia , Imunoconjugados/uso terapêutico , Subpopulações de Linfócitos T/metabolismo , Linfócitos T Reguladores/metabolismo , Abatacepte , Animais , Antígenos CD/genética , Antígenos CD/imunologia , Artrite Reumatoide/terapia , Antígeno B7-1/metabolismo , Antígeno CTLA-4 , Predisposição Genética para Doença , Antígenos HLA-DR , Humanos , Tolerância Imunológica/efeitos dos fármacos , Ativação Linfocitária/efeitos dos fármacos , Mimetismo Molecular , Estresse Oxidativo , Polimorfismo Genético , Receptores de IgG/genética , Proteínas Recombinantes de Fusão , Transdução de Sinais , Subpopulações de Linfócitos T/patologia , Linfócitos T Reguladores/patologia
16.
J Biotechnol ; 132(1): 65-74, 2007 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-17905461

RESUMO

In this study we developed a PEEK-WC hollow fiber (HF) membrane bioreactor for the maintenance of human peripheral lymphocytes as model system for the in vitro investigation of disease pathogenesis, chemical effects and individual drug sensitivity. Peripheral lymphocytes isolated from donor's human buffy coat were cultured in the shell compartment of the PEEK-WC-HF bioreactor and stimulated with PHA 5microg/mL for the first 48h of culture to enhance cytokine production and cell proliferation. Thereafter, cells were cultured in the presence of Hypericum perforatum (St. John's wort) in order to induce cytochrome P450s enzymes, CYP2E, involved in the biotransformation of endogenous molecules and exogenous compounds. The metabolic activity of cells with respect to glucose consumption and oxygen uptake was maintained for all the culture time without the addition of mitogen. Two cytokines IL-2 and IL-10, which are specific pattern of lymphocytes T helper 1 and T helper 2, respectively, were produced in the bioreactor up to 14 days of culture. Lymphocytes were also able to biotransform acetaminophen through the formation of the main metabolite paracetamidofenil-beta-glucuronide, which is the product of glucuronidation reaction, as a result of the Hypericum perforatum administration that induced the catalytic activity of the CYP2E1. These results demonstrated the usefulness of the bioreactor as the support system that reproduces physiological parameters such as a constant perfusion of medium, nutrients and oxygen maintaining the in vitro integrity of lymphocyte viability and functions.


Assuntos
Materiais Biocompatíveis , Reatores Biológicos , Cetonas , Linfócitos/citologia , Membranas Artificiais , Polietilenoglicóis , Acetaminofen/farmacocinética , Benzofenonas , Biotecnologia , Biotransformação , Técnicas de Cultura de Células , Glucose/metabolismo , Humanos , Interleucina-10/biossíntese , Interleucina-2/biossíntese , Linfócitos/imunologia , Linfócitos/metabolismo , Microscopia Eletrônica de Varredura , Polímeros
17.
Macromol Biosci ; 7(5): 671-80, 2007 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-17457942

RESUMO

The viability and liver specific functions of human hepatocytes in a multibore fiber bioreactor are reported. Human hepatocytes were cultured in the intraluminal compartment of the bioreactor. Human hepatocytes on the membranes maintained their round shape and showed focal adhesions as sites of interaction with the membrane surface. Cells in the bioreactor expressed liver specific functions, including synthetic and detoxification activity up to 14 d of culture. The results demonstrate that human hepatocytes cultured in the multibore fiber bioreactor are able to sustain the same in vivo liver functions in vitro.


Assuntos
Reatores Biológicos , Hepatócitos/citologia , Hepatócitos/fisiologia , Fígado Artificial , Técnicas de Cultura de Células , Células Cultivadas , Humanos
18.
Biomaterials ; 26(33): 6625-34, 2005 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-15927248

RESUMO

In this study, we tested the ability of microporous membranes synthesised from a polymeric blend of modified polyetheretherketone (PEEK-WC) and polyurethane (PU) to support long-term maintenance and differentiation of human liver cells. The effect of isoliquiritigenin (ISL), which is a component of liquorice extract, exhibiting growth stimulatory and antiproliferative dose-dependent effect was investigated by comparing cultures treated with ISL with those untreated. To this purpose, flat-sheet membranes were prepared by a blend of PEEK-WC and PU polymers by phase inverse technique. The morphological and physico-chemical properties were characterised, respectively, by scanning electron microscopy and water contact angle measurements. Human hepatocytes cultured on PEEK-WC-PU membranes were constant up to 1 month albumin production and urea synthesis as well as the synthesis of total proteins. The liver-specific functions were expressed at high levels when cells were cultured on membranes with respect to collagen. Also the biotransformation functions were maintained for all culture periods: the ISL elimination rate increased during the culture time and high values were measured up to 22 days. Thereafter, a decrease was observed. ISL stimulated the proliferation of hepatocytes cultured on both substrata but did not affect their liver-specific functions. Hepatocytes cultured on PEEK-WC-PU membranes responded very well to ISL and expressed high levels of P450 cytochrome. These results demonstrated that long-term maintenance of human liver differentiation can be achieved on PEEK-WC-PU membranes. The incubation with ISL at the investigated concentration could stimulate the proliferation of human hepatocytes in biohybrid systems.


Assuntos
Chalcona/análogos & derivados , Hepatócitos/metabolismo , Cetonas/química , Polietilenoglicóis/química , Poliuretanos/química , Benzofenonas , Materiais Biocompatíveis/química , Técnicas de Cultura de Células , Membrana Celular/metabolismo , Proliferação de Células , Sobrevivência Celular , Células Cultivadas , Chalcona/química , Chalconas , Cromatografia Líquida de Alta Pressão , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/química , Hepatócitos/citologia , Humanos , Fígado/metabolismo , Microscopia Eletrônica de Varredura , Polímeros/química , Fatores de Tempo , Ureia/farmacologia
19.
Biomaterials ; 26(21): 4432-41, 2005 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15701372

RESUMO

In this paper we report on the metabolic response of human hepatocytes grown on polyethersulfone membranes surface modified with a plasma-deposited acrylic acid coating and RGD peptide covalently immobilized through a "spacer arm" molecule. The modified surfaces were characterized by means of X-ray photoelectron spectroscopy and water contact angle measurements. The performance of modified and unmodified membranes was evaluated by assessing the expression of liver specific and biotransformation functions of human hepatocytes. Diclofenac, a non-steroidal anti-inflammatory drug, was used to investigate the biotransformation functions. Surface-modified membranes elicit specific cellular responses and induce hepatocytes to enhance the synthesis rate of albumin and urea, particularly in the presence of diclofenac. Also the biotransformation functions were expressed at high levels.


Assuntos
Hepatócitos/citologia , Hepatócitos/metabolismo , Fígado Artificial , Fígado/citologia , Fígado/metabolismo , Oligopeptídeos/farmacologia , Engenharia Tecidual/métodos , Adsorção , Albuminas/biossíntese , Biotransformação , Técnicas de Cultura de Células/métodos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Materiais Revestidos Biocompatíveis/química , Materiais Revestidos Biocompatíveis/farmacologia , Hepatócitos/efeitos dos fármacos , Temperatura Alta , Humanos , Fígado/efeitos dos fármacos , Teste de Materiais , Membranas Artificiais , Oligopeptídeos/química , Ligação Proteica , Propriedades de Superfície , Ureia/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA