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1.
Multidiscip Respir Med ; 15(1): 508, 2020 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-32269774

RESUMO

INTRODUCTION: In several countries of the world, smartphone applications have been designed to contribute to the treatment of asthma. However, none of these applications has been developed in Saudi Arabia. Therefore, the objective of this article is to design a smartphone application for the treatment of asthma based on the opinions of healthcare providers from the Kingdom of Saudi Arabia. METHODS: In order to know the opinion of the healthcare providers from Saudi Arabia about the design of an asthma App, we used a purposive sampling method and conducted a cross sectional survey employing a questionnaire which was distributed through the QuestionPro.com website to all healthcare providers working in this country. The questionnaire was sent to 376 healthcare providers and the response rate was 25%. RESULTS: The data indicated that the majority of the respondents opined that the following features were important or very important in the design of a smartphone application for asthma treatment in Saudi Arabia: information about patient diagnosis (98%), primary physician access information(83%), patient satisfaction with the therapeutic process (91%), push notifications about reminder for drugs (95%), push notification for treatment of inhaler and other drugs (92%), push notifications about reminders of clinic visits and therapy sections (81%), push notifications to ask for help sending SMS to primary physician about patients' attacks (89%), pathophysiology of asthma (82%), asthma triggers (98%), drug guidelines (94%), drug side effects (93%), number of asthma attacks (98%), medication statistics (88%), visual inputs such as peak flow (91%), data to link patients to healthcare providers and to healthcare centers (82%), and Global Initiative for Asthma (GINA) references (72%). CONCLUSIONS: According to the opinion of the majority of healthcare providers (92%), the proposed smartphone application designed based on medical guidelines will contribute to improve the treatment of patients with asthma in the Kingdom of Saudi Arabia, and will help to reduce the number of asthma cases that need hospitalization, and the number of asthma cases in the emergency departments of the hospitals of the Kingdom.

2.
Transplantation ; 103(8): 1630-1638, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-30896677

RESUMO

BACKGROUND: Hepatocyte transplantation (Hctx) is a potentially attractive method for the treatment of acute liver failure and liver-based metabolic disorders. Unfortunately, the procedure is hampered by the instant blood-mediated inflammatory reaction (IBMIR), a thromboinflammatory response elicited by the vascular innate immune system, causing activation of the coagulation and complement systems and clearance of transplanted cells. Observations have also revealed platelets adhered to the surface of the hepatocytes (Hc). To establish Hctx as a clinical treatment, all factors that trigger IBMIR need to be identified and controlled. This work explores the expression of von Willebrand factor (VWF) on isolated Hc resulting in tethering of platelets. METHODS: VWF on Hc was studied by flow cytometry, confocal microscopy, immunoblot, and real-time polymerase chain reaction. Interaction between Hc and platelets was studied in a Chandler loop model. Adhesion of platelets to the hepatocyte surface was demonstrated by flow cytometry and confocal microscopy. RESULTS: Isolated Hc constitutively express VWF on their cell surface and mRNA for VWF was found in the cells. Hc and platelets, independently of coagulation formed complexes, were shown by antibody blocking studies to be dependent on hepatocyte-associated VWF and platelet-bound glycoprotein Ibα. CONCLUSIONS: VWF on isolated Hc causes, in contact with blood, adhesion of platelets, which thereby forms an ideal surface for coagulation. This phenomenon needs to be considered in hepatocyte-based reconstitution therapy and possibly even in other settings of cell transplantation.


Assuntos
Plaquetas/metabolismo , Regulação da Expressão Gênica , Hepatócitos/metabolismo , Transplante de Fígado , Adesividade Plaquetária/fisiologia , RNA/genética , Fator de von Willebrand/genética , Western Blotting , Criopreservação , Feminino , Citometria de Fluxo , Hepatócitos/patologia , Hepatócitos/transplante , Humanos , Masculino , Microscopia Confocal , Ligação Proteica , Fator de von Willebrand/biossíntese
3.
Int J Med Microbiol ; 308(7): 969-976, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30064820

RESUMO

Escherichia coli-induced hemolytic uremic syndrome (eHUS) is a life-threatening complication of infection with Shiga toxin (Stx), in particular Stx2a-producing Escherichia coli. Enhanced coagulation activation with formation of microthrombi seems to be a key event in development of eHUS. Platelet activation has been postulated as a possible, but controversially debated mechanism. The present study investigated the effect of Stx2a on plasmatic coagulation and platelets. Binding studies were initially performed with ELISA and co-immunoprecipitation and supported by quartz crystal microbalance with dissipation monitoring (QCM-D). Antithrombin (AT) activity was measured using the automated BCS XP® system. ROTEM® was used for functional coagulation testing. Platelet binding and activation was studied with FACS and light-transmission aggregometry. We found binding of Stx2a to AT, an important inhibitor of blood coagulation, but only a mild albeit significant reduction of AT activity against FXa in the presence of Stx2a. QCM-D analysis also showed binding of Stx2a to heparin and an impaired binding of AT to Stx2a-bound heparin. ROTEM® using Stx2a-treated platelet-poor plasma revealed a significant, but only moderate shortening of clotting time. Neither binding nor activation of platelets by Stx2a could be demonstrated. In summary, data of this study suggest that Stx2a binds to AT, but does not induce major effects on plasmatic coagulation. In addition, no interaction with platelets occurred. The well-known non-beneficial administration of heparin in eHUS patients could be explained by the interaction of Stx2a with heparin.


Assuntos
Antitrombinas/metabolismo , Coagulação Sanguínea/fisiologia , Heparina/metabolismo , Agregação Plaquetária/imunologia , Toxina Shiga II/metabolismo , Plaquetas/imunologia , Síndrome Hemolítico-Urêmica/microbiologia , Humanos , Ligação Proteica/fisiologia , Escherichia coli Shiga Toxigênica/patogenicidade
4.
Nanomedicine ; 14(3): 735-744, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29277639

RESUMO

Iron-oxide nanoparticles (NPs) generated by environmental events are likely to represent health problems. α-Fe2O3 NPs were synthesized, characterized and tested in a model for toxicity utilizing human whole blood without added anticoagulant. MALDI-TOF of the corona was performed and activation markers for plasma cascade systems (complement, contact and coagulation systems), platelet consumption and release of growth factors, MPO, and chemokine/cytokines from blood cells were analyzed. The coronas formed on the pristine α-Fe2O3 NPs contained contact system proteins and they induced massive activation of the contact (kinin/kallikrein) system, as well as thrombin generation, platelet activation, and release of two pro-angiogeneic growth factors: platelet-derived growth factor and vascular endothelial growth factor, whereas complement activation was unaffected. The α-Fe2O3 NPs exhibited a noticeable toxicity, with kinin/kallikrein activation, which may be associated with hypotension and long-term angiogenesis in vivo, with implications for cancer, arteriosclerosis and pulmonary disease.


Assuntos
Coagulação Sanguínea , Compostos Férricos/química , Imunidade Inata/efeitos dos fármacos , Sistema Calicreína-Cinina , Nanopartículas Metálicas/administração & dosagem , Humanos , Nanopartículas Metálicas/química , Fator de Crescimento Derivado de Plaquetas/metabolismo , Coroa de Proteína/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo
5.
Immunol Rev ; 274(1): 245-269, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27782319

RESUMO

Innate immunity is fundamental to our defense against microorganisms. Physiologically, the intravascular innate immune system acts as a purging system that identifies and removes foreign substances leading to thromboinflammatory responses, tissue remodeling, and repair. It is also a key contributor to the adverse effects observed in many diseases and therapies involving biomaterials and therapeutic cells/organs. The intravascular innate immune system consists of the cascade systems of the blood (the complement, contact, coagulation, and fibrinolytic systems), the blood cells (polymorphonuclear cells, monocytes, platelets), and the endothelial cell lining of the vessels. Activation of the intravascular innate immune system in vivo leads to thromboinflammation that can be activated by several of the system's pathways and that initiates repair after tissue damage and leads to adverse reactions in several disorders and treatment modalities. In this review, we summarize the current knowledge in the field and discuss the obstacles that exist in order to study the cross-talk between the components of the intravascular innate immune system. These include the use of purified in vitro systems, animal models and various types of anticoagulants. In order to avoid some of these obstacles we have developed specialized human whole blood models that allow investigation of the cross-talk between the various cascade systems and the blood cells. We in particular stress that platelets are involved in these interactions and that the lectin pathway of the complement system is an emerging part of innate immunity that interacts with the contact/coagulation system. Understanding the resulting thromboinflammation will allow development of new therapeutic modalities.


Assuntos
Plaquetas/imunologia , Proteínas do Sistema Complemento/metabolismo , Células Endoteliais/fisiologia , Inflamação/imunologia , Trombose/imunologia , Animais , Coagulação Sanguínea , Homeostase , Humanos , Imunidade Inata , Calicreínas/metabolismo , Cininas/metabolismo
6.
Chem Commun (Camb) ; 52(5): 966-9, 2016 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-26587574

RESUMO

We have developed the first chondroitin sulfate polymer coated gold nanoparticles that can simultaneously overcome mulidrug resistance in cancer cells and suppress thromboinflammation triggered by the chemotherapeutic drug.

7.
Thromb Haemost ; 114(6): 1207-17, 2015 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-26293614

RESUMO

Complement component C3 has a potential role in thrombotic pathologies. It is transformed, without proteolytic cleavage, into C3(H2O) upon binding to the surface of activated platelets. We hypothesise that C3(H2O) bound to activated platelets and to platelet-derived microparticles (PMPs) contributes to platelet-PMN complex (PPC) formation and to the binding of PMPs to PMNs. PAR-1 activation of platelets in human whole blood from normal individuals induced the formation of CD16+/CD42a+ PPC. The complement inhibitor compstatin and a C5a receptor antagonist inhibited PPC formation by 50 %, while monoclonal antibodies to C3(H2O) or anti-CD11b inhibited PPC formation by 75-100 %. Using plasma protein-depleted blood and blood from a C3-deficient patient, we corroborated the dependence on C3, obtaining similar results after reconstitution with purified C3. By analogy with platelets, PMPs isolated from human serum were found to expose C3(H2O) and bind to PMNs. This interaction was also blocked by the anti-C3(H2O) and anti-CD11b monoclonal antibodies, indicating that C3(H2O) and CD11b are involved in tethering PMPs to PMNs. We confirmed the direct interaction between C3(H2O) and CD11b by quartz crystal microbalance analysis using purified native C3 and recombinant CD11b/CD18 and by flow cytometry using PMP and recombinant CD11b. Transfectants expressing CD11b/CD18 were also shown to specifically adhere to surface-bound C3(H2O). We have identified contact-activated C3(H2O) as a novel ligand for CD11b/CD18 that mediates PPC formation and the binding of PMPs to PMNs. Given the various roles of C3 in thrombotic reactions, this finding is likely to have important pathophysiological implications.


Assuntos
Plaquetas/metabolismo , Antígeno CD11b/metabolismo , Antígenos CD18/metabolismo , Micropartículas Derivadas de Células/metabolismo , Ativação do Complemento , Complemento C3/metabolismo , Neutrófilos/metabolismo , Animais , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/farmacologia , Antígeno CD11b/imunologia , Antígenos CD18/imunologia , Células CHO , Cricetinae , Cricetulus , Humanos , Fragmentos de Peptídeos/farmacologia , Peptídeos Cíclicos/farmacologia , Ligação Proteica , Mapeamento de Interação de Proteínas , Receptor da Anafilatoxina C5a/antagonistas & inibidores , Receptor PAR-1/agonistas , Receptor PAR-1/metabolismo , Proteínas Recombinantes/metabolismo , Transfecção
8.
Stem Cells Dev ; 24(19): 2269-79, 2015 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-26192403

RESUMO

While therapeutic mesenchymal stromal/stem cells (MSCs) have usually been obtained from bone marrow, perinatal tissues have emerged as promising new sources of cells for stromal cell therapy. In this study, we present a first safety follow-up on our clinical experience with placenta-derived decidual stromal cells (DSCs), used as supportive immunomodulatory and regenerative therapy for patients with severe complications after allogeneic hematopoietic stem cell transplantation (HSCT). We found that DSCs are smaller, almost half the volume of MSCs, which may favor microvascular passage. DSCs also show different hemocompatibility, with increased triggering of the clotting cascade after exposure to human blood and plasma in vitro. After infusion of DSCs in HSCT patients, we observed a weak activation of the fibrinolytic system, but the other blood activation markers remained stable, excluding major adverse events. Expression profiling identified differential levels of key factors implicated in regulation of hemostasis, such as a lack of prostacyclin synthase and increased tissue factor expression in DSCs, suggesting that these cells have intrinsic blood-activating properties. The stronger triggering of the clotting cascade by DSCs could be antagonized by optimizing the cell graft reconstitution before infusion, for example, by use of low-dose heparin anticoagulant in the cell infusion buffer. We conclude that DSCs are smaller and have stronger hemostatic properties than MSCs, thus triggering stronger activation of the clotting system, which can be antagonized by optimizing the cell graft preparation before infusion. Our results highlight the importance of hemocompatibility safety testing for every novel cell therapy product before clinical use, when applied using systemic delivery.


Assuntos
Células da Medula Óssea/citologia , Transplante de Células-Tronco Mesenquimais/métodos , Células-Tronco Mesenquimais/citologia , Adolescente , Adulto , Anticoagulantes/administração & dosagem , Anticoagulantes/farmacologia , Coagulação Sanguínea/efeitos dos fármacos , Coagulação Sanguínea/fisiologia , Células da Medula Óssea/metabolismo , Células da Medula Óssea/fisiologia , Criança , Pré-Escolar , Sistema Enzimático do Citocromo P-450/genética , Decídua/citologia , Decídua/metabolismo , Feminino , Expressão Gênica , Doença Enxerto-Hospedeiro/terapia , Heparina/administração & dosagem , Heparina/farmacologia , Humanos , Lactente , Recém-Nascido , Oxirredutases Intramoleculares/genética , Masculino , Células-Tronco Mesenquimais/metabolismo , Células-Tronco Mesenquimais/fisiologia , Pessoa de Meia-Idade , Placenta/citologia , Placenta/metabolismo , Gravidez , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Tromboplastina/genética , Resultado do Tratamento
9.
Mol Immunol ; 67(1): 108-18, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25886718

RESUMO

In recent years, the view of platelets has changed from mere elements of hemostasis to immunological multitaskers. They are connected in manifold ways to other cellular and humoral components of the immune network, one of which is the complement system, a potent player in soluble innate immunity. Our article reviews the crucial and complex interplay between platelets and complement, focusing on mutual regulation of these two interaction partners by their respective molecular mechanisms. Furthermore, the putative relevance of these processes to infectious diseases, inflammatory conditions, and autoimmune disorders, as well as the treatment of patients with biomaterials is highlighted.


Assuntos
Doenças Autoimunes/imunologia , Infecções Bacterianas/imunologia , Plaquetas/imunologia , Proteínas do Sistema Complemento/imunologia , Micoses/imunologia , Viroses/imunologia , Doenças Autoimunes/genética , Doenças Autoimunes/patologia , Infecções Bacterianas/genética , Infecções Bacterianas/microbiologia , Infecções Bacterianas/patologia , Plaquetas/patologia , Ativação do Complemento , Proteínas Inativadoras do Complemento C3b/genética , Proteínas Inativadoras do Complemento C3b/imunologia , Proteínas do Sistema Complemento/genética , Regulação da Expressão Gênica , Humanos , Imunidade Inata , Micoses/genética , Micoses/microbiologia , Micoses/patologia , Receptores de Complemento/genética , Receptores de Complemento/imunologia , Transdução de Sinais , Viroses/genética , Viroses/patologia , Viroses/virologia
10.
Mol Immunol ; 67(1): 101-7, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25746915

RESUMO

Abundant reports have shown that there is a strong relationship between C3 and C3a-desArg levels, adipose tissue, and risk factors for cardiovascular disease, metabolic syndrome and diabetes. The data indicate that complement components, particularly C3, are involved in lipid metabolism. The C3 fragment, C3a-desArg, functions as a hormone that has insulin-like effects and facilitates triglyceride metabolism. Adipose tissue produces and regulates the levels of complement components, which promotes generation of inflammatory initiators such as the anaphylatoxins C3a and C5a. The anaphylatoxins trigger a cyto/chemokine response in proportion to the amount of adipose tissue present, and induce inflammation and mediate metabolic effects such as insulin resistance. These observations support the concept that complement is an important participant in lipid metabolism and in obesity, contributing to the metabolic syndrome and to the low-grade inflammation associated with obesity.


Assuntos
Tecido Adiposo/imunologia , Doenças Cardiovasculares/imunologia , Complemento C3a/imunologia , Diabetes Mellitus/imunologia , Metabolismo dos Lipídeos/imunologia , Síndrome Metabólica/imunologia , Obesidade/imunologia , Tecido Adiposo/metabolismo , Tecido Adiposo/patologia , Apolipoproteínas/genética , Apolipoproteínas/imunologia , Apolipoproteínas/metabolismo , Doenças Cardiovasculares/genética , Doenças Cardiovasculares/metabolismo , Doenças Cardiovasculares/patologia , Complemento C3a/genética , Complemento C3a/metabolismo , Complemento C5a/genética , Complemento C5a/imunologia , Complemento C5a/metabolismo , Diabetes Mellitus/genética , Diabetes Mellitus/metabolismo , Diabetes Mellitus/patologia , Regulação da Expressão Gênica , Humanos , Resistência à Insulina/imunologia , Síndrome Metabólica/genética , Síndrome Metabólica/metabolismo , Síndrome Metabólica/patologia , Obesidade/genética , Obesidade/metabolismo , Obesidade/patologia , Receptores de Complemento/genética , Receptores de Complemento/imunologia , Receptores de Complemento/metabolismo , Fatores de Risco , Triglicerídeos/genética , Triglicerídeos/imunologia , Triglicerídeos/metabolismo
11.
Biomaterials ; 36: 55-65, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25292422

RESUMO

Inappropriate complement activation is often responsible for incompatibility reactions that occur when biomaterials are used. Complement activation is therefore a criterion included in legislation regarding biomaterials testing. However, no consensus is yet available regarding appropriate complement-activation-related test parameters. We examined protein adsorption in plasma and complement activation/cytokine release in whole blood incubated with well-characterized polymers. Strong correlations were found between the ratio of C4 to its inhibitor C4BP and generation of 10 (mainly pro-inflammatory) cytokines, including IL-17, IFN-γ, and IL-6. The levels of complement activation products correlated weakly (C3a) or not at all (C5a, sC5b-9), confirming their poor predictive values. We have demonstrated a direct correlation between downstream biological effects and the proteins initially adhering to an artificial surface after contact with blood. Consequently, we propose the C4/C4BP ratio as a robust, predictor of biocompatibility with superior specificity and sensitivity over the current gold standard.


Assuntos
Materiais Biocompatíveis/efeitos adversos , Ativação do Complemento/efeitos dos fármacos , Inflamação/sangue , Inflamação/induzido quimicamente , Polímeros/efeitos adversos , Proteína de Ligação ao Complemento C4b/imunologia , Complexo de Ataque à Membrana do Sistema Complemento/imunologia , Proteínas do Sistema Complemento/imunologia , Humanos , Inflamação/imunologia , Interferon gama/imunologia , Interleucina-17/sangue , Interleucina-17/imunologia , Interleucina-6/sangue , Interleucina-6/imunologia
12.
Stem Cells ; 32(9): 2430-42, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24805247

RESUMO

We have recently reported that therapeutic mesenchymal stromal cells (MSCs) have low engraftment and trigger the instant blood mediated inflammatory reaction (IBMIR) after systemic delivery to patients, resulting in compromised cell function. In order to optimize the product, we compared the immunomodulatory, blood regulatory, and therapeutic properties of freeze-thawed and freshly harvested cells. We found that freeze-thawed MSCs, as opposed to cells harvested from continuous cultures, have impaired immunomodulatory and blood regulatory properties. Freeze-thawed MSCs demonstrated reduced responsiveness to proinflammatory stimuli, an impaired production of anti-inflammatory mediators, increased triggering of the IBMIR, and a strong activation of the complement cascade compared to fresh cells. This resulted in twice the efficiency in lysis of thawed MSCs after 1 hour of serum exposure. We found a 50% and 80% reduction in viable cells with freshly detached as opposed to thawed in vitro cells, indicating a small benefit for fresh cells. In evaluation of clinical response, we report a trend that fresh cells, and cells of low passage, demonstrate improved clinical outcome. Patients treated with freshly harvested cells in low passage had a 100% response rate, twice the response rate of 50% observed in a comparable group of patients treated with freeze-thawed cells at higher passage. We conclude that cryobanked MSCs have reduced immunomodulatory and blood regulatory properties directly after thawing, resulting in faster complement-mediated elimination after blood exposure. These changes seem to be paired by differences in therapeutic efficacy in treatment of immune ailments after hematopoietic stem cell transplantation.


Assuntos
Criopreservação/métodos , Imunoterapia/métodos , Transplante de Células-Tronco Mesenquimais/métodos , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/imunologia , Adolescente , Adulto , Idoso , Diferenciação Celular/fisiologia , Proliferação de Células/fisiologia , Células Cultivadas , Criança , Pré-Escolar , Feminino , Humanos , Imunomodulação , Imunofenotipagem/métodos , Lactente , Masculino , Células-Tronco Mesenquimais/metabolismo , Pessoa de Meia-Idade , Adulto Jovem
13.
Eur J Clin Invest ; 44(6): 587-96, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24754458

RESUMO

BACKGROUND: In several reports, C3 and C4 have been linked to diabetes and cardiovascular disease (CVD). Here, we investigate this link and the degree of C3 activation in elderly individuals. METHODS: In this study, C3 and C4 and the activation fragment C3a-desArg were analysed in 1016 subjects aged 70, in which blood pressure, lipid variables and fasting blood glucose were assessed. RESULTS: C3 levels were related to all the investigated classical cardiovascular risk factors and the metabolic syndrome (BMI, waist circumference, fat distribution, blood pressure, blood glucose levels, TG) except total cholesterol and LDL cholesterol in a highly significant fashion (Spearman up to 0,5; P < 0·0001). C4 and C3a-desArg were associated in the same fashion but less significantly, while the ratios C4/C3 or C3a-desArg/C3 were not, indicating that the association was not directly related to complement activation. The levels C3 and to a lesser degree C4 and C3a-desArg were associated particularly with CRP, but also with E-selectin and ICAM-1. In addition, C3 and C4 levels were shown to decline significantly in 15 female subjects enrolled in a weight-reduction programme over 4 months. CONCLUSION: A strong relation between C3, C4 and C3a-desArg levels, adipose tissue and risk factors of CVD was established. The data support that the adipose tissue produces complement components and generates initiators of inflammation, such as C3a and C5a, able to trigger a cyto/chemokine response, in proportion to the amount of adipose tissue. This corroborates the concept that complement contributes to the low-grade inflammation associated with obesity.


Assuntos
Gordura Abdominal/metabolismo , Doenças Cardiovasculares/etiologia , Complemento C3/metabolismo , Complemento C4/metabolismo , Idoso , Biomarcadores/metabolismo , Glicemia/metabolismo , Doenças Cardiovasculares/metabolismo , Citocinas/metabolismo , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Síndrome Metabólica/metabolismo , Obesidade/complicações , Obesidade/metabolismo , Fatores de Risco , Relação Cintura-Quadril , Redução de Peso/fisiologia
14.
PLoS One ; 9(1): e85040, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24454787

RESUMO

Investigation into predictors for treatment outcome is essential to improve the clinical efficacy of therapeutic multipotent mesenchymal stromal cells (MSCs). We therefore studied the possible harmful impact of immunogenic ABO blood groups antigens - genetically governed antigenic determinants - at all given steps of MSC-therapy, from cell isolation and preparation for clinical use, to final recipient outcome. We found that clinical MSCs do not inherently express or upregulate ABO blood group antigens after inflammatory challenge or in vitro differentiation. Although antigen adsorption from standard culture supplements was minimal, MSCs adsorbed small quantities of ABO antigen from fresh human AB plasma (ABP), dependent on antigen concentration and adsorption time. Compared to cells washed in non-immunogenic human serum albumin (HSA), MSCs washed with ABP elicited stronger blood responses after exposure to blood from healthy O donors in vitro, containing high titers of ABO antibodies. Clinical evaluation of hematopoietic stem cell transplant (HSCT) recipients found only very low titers of anti-A/B agglutination in these strongly immunocompromised patients at the time of MSC treatment. Patient analysis revealed a trend for lower clinical response in blood group O recipients treated with ABP-exposed MSC products, but not with HSA-exposed products. We conclude, that clinical grade MSCs are ABO-neutral, but the ABP used for washing and infusion of MSCs can contaminate the cells with immunogenic ABO substance and should therefore be substituted by non-immunogenic HSA, particularly when cells are given to immunocompentent individuals.


Assuntos
Sistema ABO de Grupos Sanguíneos/imunologia , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais/citologia , Sistema ABO de Grupos Sanguíneos/sangue , Sistema ABO de Grupos Sanguíneos/genética , Adolescente , Adsorção , Adulto , Idoso , Anticorpos/imunologia , Células Cultivadas , Criança , Metilação de DNA/genética , Genótipo , Humanos , Pessoa de Meia-Idade , Regiões Promotoras Genéticas/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Resultado do Tratamento , Regulação para Cima
15.
Biomaterials ; 35(11): 3688-96, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24462362

RESUMO

Liposomes are becoming increasingly important as drug delivery systems, to target a drug to specific cells and tissues and thereby protecting the recipient from toxic effects of the contained drug. Liposome preparations have been described to activate complement. In this study, we have investigated complement activation triggered by neutral dimyristoyl-phosphocholine (DMPC) liposomes in human plasma and whole-blood systems. Incubation in plasma led to the generation of complement activation products (C3a and sC5b-9). Unexpectedly, investigations of surface-bound C3 revealed contact activated, conformationally changed C3 molecules on the liposomes. These changes were characterized by Western blotting with C3 monoclonal antibodies, and by incubating liposomes with purified native C3 and factors I and H. Quartz crystal microbalance analysis confirmed binding of C3 to planar DMPC surfaces. In addition, we demonstrated that DMPC liposomes bound to or were phagocytized by granulocytes in a complement-dependent manner, as evidenced by the use of complement inhibitors. In summary, we have shown that C3 is activated both by convertase-dependent cleavage, preferentially in the fluid phase, by mechanisms which are not well elucidated, and also by contact activation into C3(H2O) on the DMPC surface. In particular, this contact activation has implications for the therapeutic regulation of complement activation during liposome treatment.


Assuntos
Ativação do Complemento/efeitos dos fármacos , Complemento C3/metabolismo , Lipossomos/metabolismo , Fosfolipídeos/farmacologia , Adsorção , Sistemas Computacionais , Dimiristoilfosfatidilcolina/farmacologia , Eletroforese em Gel de Poliacrilamida , Citometria de Fluxo , Humanos , Modelos Biológicos , Fagocitose/efeitos dos fármacos , Ligação Proteica/efeitos dos fármacos , Proteólise/efeitos dos fármacos , Técnicas de Microbalança de Cristal de Quartzo
16.
Adv Exp Med Biol ; 735: 257-70, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23402033

RESUMO

Medicine today uses a wide range of biomaterials, most of which make contact with blood permanently or transiently upon implantation. Contact between blood and nonbiological materials or cells or tissue of nonhematologic origin initiates activation of the cascade systems (complement, contact activation/coagulation) of the blood, which induces platelet and leukocyte activation. Although substantial progress regarding biocompatibility has been made, many materials and medical treatment procedures are still associated with severe side effects. Therefore, there is a great need for adequate models and guidelines for evaluating the blood compatibility of biomaterials. Due to the substantial amount of cross talk between the different cascade systems and cell populations in the blood, it is advisable to use an intact system for evaluation. Here, we describe three such in vitro models for the evaluation of the biocompatibility of materials and therapeutic cells and tissues. The use of different anticoagulants and specific inhibitors in order to be able to dissect interactions between the different cascade systems and cells of the blood is discussed. In addition, we describe two clinically relevant medical treatment modalities, the integration of titanium implants and transplantation of islets of Langerhans to patients with type 1 diabetes, whose mechanisms of action we have addressed using these in vitro models.


Assuntos
Incompatibilidade de Grupos Sanguíneos , Proteínas do Sistema Complemento/fisiologia , Teste de Histocompatibilidade/métodos , Histocompatibilidade , Teste de Materiais/métodos , Animais , Anticoagulantes/farmacologia , Coleta de Amostras Sanguíneas , Guias como Assunto , Teste de Histocompatibilidade/instrumentação , Humanos , Inflamação/imunologia , Teste de Materiais/instrumentação
17.
Stem Cells ; 30(7): 1565-74, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22522999

RESUMO

Multipotent mesenchymal stromal cells (MSCs) are tested in numerous clinical trials. Questions have been raised concerning fate and function of these therapeutic cells after systemic infusion. We therefore asked whether culture-expanded human MSCs elicit an innate immune attack, termed instant blood-mediated inflammatory reaction (IBMIR), which has previously been shown to compromise the survival and function of systemically infused islet cells and hepatocytes. We found that MSCs expressed hemostatic regulators similar to those produced by endothelial cells but displayed higher amounts of prothrombotic tissue/stromal factors on their surface, which triggered the IBMIR after blood exposure, as characterized by formation of blood activation markers. This process was dependent on the cell dose, the choice of MSC donor, and particularly the cell-passage number. Short-term expanded MSCs triggered only weak blood responses in vitro, whereas extended culture and coculture with activated lymphocytes increased their prothrombotic properties. After systemic infusion to patients, we found increased formation of blood activation markers, but no formation of hyperfibrinolysis marker D-dimer or acute-phase reactants with the currently applied dose of 1.0-3.0 × 10(6) cells per kilogram. Culture-expanded MSCs trigger the IBMIR in vitro and in vivo. Induction of IBMIR is dose-dependent and increases after prolonged ex vivo expansion. Currently applied doses of low-passage clinical-grade MSCs elicit only minor systemic effects, but higher cell doses and particularly higher passage cells should be handled with care. This deleterious reaction can compromise the survival, engraftment, and function of these therapeutic cells.


Assuntos
Células-Tronco Mesenquimais/citologia , Terapia Baseada em Transplante de Células e Tecidos , Células Endoteliais/citologia , Humanos , Células-Tronco Mesenquimais/imunologia , Trombose/sangue
18.
Adv Exp Med Biol ; 946: 185-205, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-21948369

RESUMO

Platelet activation during thrombotic events is closely associated with complement and contact system activation, which in turn leads to inflammation. Here we review the interactions between activated platelets and the complement and contact activation systems in clotting blood. Chondroitin sulfate A (CS-A), released from alpha granules during platelet activation, is a potent mediator of crosstalk between platelets and the complement system. CS-A activates complement in the fluid phase, generating anaphylatoxins that mediate leukocyte activation. No complement activation seems to occur on the activated platelet surface, but C3 in the form of C3(H(2)O) is bound to the surfaces of activated platelets . This finding is consistent with the strong expression of membrane-bound complement regulators present at the platelet surface. CS-A exposed on the activated platelets is to a certain amount responsible for recruiting soluble regulators to the surface. Platelet-bound C3(H(2)O) acts as a ligand for leukocyte CR1 (CD35), potentially enabling platelet-leukocyte interactions. In addition, platelet activation leads to the activation of contact system enzymes, which are specifically inhibited by antithrombin, rather than by C1INH, as is the case when contact activation is induced by material surfaces. Thus, in addition to their traditional role as initiators of secondary hemostasis, platelets also act as mediators and regulators of inflammation in thrombotic events.


Assuntos
Plaquetas/imunologia , Proteínas do Sistema Complemento/imunologia , Inflamação/imunologia , Ativação Plaquetária/imunologia , Trombose/imunologia , Humanos
19.
Arab J Gastroenterol ; 12(3): 139-42, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22055592

RESUMO

BACKGROUND AND STUDY AIMS: Global hypomethylation is one of the most consistent epigenetic changes in cancer. Development of hepatocellular carcinoma (HCC) must be understood as a multistep process with accumulation of genetic and epigenetic alterations. In the last decades, in addition to genetic alterations, epigenetic changes have been recognized as an important and alternative mechanism in tumourigenesis. We investigated the clinical implications of global hypomethylation in the sera of patients with hepatocellular carcinoma (HCC). PATIENTS AND METHODS: PCR was used to assess the methylation status of long interspersed nuclear element type 1 (LINE-1) repetitive sequences in genomic DNA derived from sera of 50 patients with HCC, 20 patients with cirrhosis, 20 patients with chronic hepatitis C and 10 healthy subjects. RESULTS: Serum genome hypomethylation was significantly increased in patients with HCC (p<0.001). The levels of serum LINE-1 hypomethylation at initial presentation correlated significantly with tumour size, tumour number and alpha-foetoprotein level. Moreover high serum LINE-1 hypomethylation correlates significantly with poor survival. CONCLUSION: Serum LINE-1 hypomethylation may serve as a prognostic marker for patients with HCC.


Assuntos
Carcinoma Hepatocelular/sangue , Metilação de DNA , DNA de Neoplasias/genética , Neoplasias Hepáticas/sangue , Elementos Nucleotídeos Longos e Dispersos/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/sangue , Biomarcadores Tumorais/genética , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/mortalidade , Egito/epidemiologia , Eletroforese em Gel de Poliacrilamida , Feminino , Seguimentos , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/mortalidade , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Prognóstico , Estudos Retrospectivos , Taxa de Sobrevida/tendências , Adulto Jovem
20.
J Egypt Soc Parasitol ; 41(3): 737-44, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22435165

RESUMO

Conservative surgery with adjuvant chemotherapy has made the preservation of fertility even in patient with advanced disease. The increase in cure rate has shifted to research for the long term menstrual reproductive and gynecologic outcome in these patients. The current study is retrospective for 25 cases of ovarian malignant germ cell tumor from January 2006 to January 2011, at El Hussian and Sayed Galal University Hospitals. The uterus and contralateral ovary were retained to preserve ovarian function with or without chemotherapy, followed up for two years. The mean age of most patients ranged from 15-28 years (average 21.5 years). According to International Federation of Gynecology and Obstetrics, the histological subtypes were ten dysgerminoma (40%). Five immature teratoma (20%), three endodermal sinus tumor (12%), four mixed germ cell tumor (16%) three embryonic cell tumours (12%). Stage I: tumors 15 cases (60%), Stage II: tumors one case (4%), Stage III tumors 6 cases (24%), Stage IV tumors 3 cases (12%). Adjuvant chemotherapy was administered to 15 cases 60% and followed up for two years. There were two recurrences, one died at 7th day postoperative of massive pulmonary embolism with past history of D.V.T, five healthy live births in the chemotherapy group without birth defects, and one infertility case 4%.


Assuntos
Neoplasias Embrionárias de Células Germinativas/cirurgia , Neoplasias Ovarianas/cirurgia , Ovariectomia/métodos , Adolescente , Adulto , Antineoplásicos/uso terapêutico , Feminino , Fertilidade , Humanos , Recidiva Local de Neoplasia , Estadiamento de Neoplasias , Neoplasias Embrionárias de Células Germinativas/tratamento farmacológico , Neoplasias Ovarianas/tratamento farmacológico , Ovário/fisiologia , Estudos Retrospectivos , Adulto Jovem
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