Angiogenic and prothrombotic markers in extensive slow-flow vascular malformations: implications for antiangiogenic/antithrombotic strategies.

BACKGROUND: Venous and combined malformations are slow-flow haemodynamically inactive lesions that are present at birth and worsen slowly with advancing age, showing no tendency towards involution. The pathogenesis of vascular anomalies has not been fully elucidated, but their formation and progression are closely related to angiogenesis. Localized intravascular coagulation associated with venous or combined malformations is characterized by low fibrinogen, high D-dimers, and normal platelet count. OBJECTIVES: To assess the relationship of angiogenic factors with prothrombotic and endothelial damage/dysfunction markers in patients with extensive slow-flow vascular malformations. METHODS: A 2-year study (2005-2007) included 31 consecutive patients with extensive slow-flow vascular malformations from one centre. RESULTS: Serum levels of the endothelial receptor tyrosine kinase TIE-2, matrix metalloproteinase (MMP)-9 and angiopoietin (Ang)-2 and plasma levels of D-dimer, plasminogen activator inhibitor type 1 (PAI-1), tissue-type plasminogen activator and von Willebrand factor (vWf) were significantly increased in patients compared with healthy controls, whereas serum levels of vascular endothelial growth factor (VEGF)-C, VEGF-D, MMP-2, Ang-1, platelet-derived growth factor (PDGF)-AB and PDGF-BB were significantly decreased in patients compared with controls. A strong positive correlation was present between Ang-1 and PDGF-AB levels (r = 0.63, P < 0.001), between PDGF-AB and PDGF-BB levels (r = 0.67, P < 0.001), and between fibrinogen and PAI-1 levels (r = 0.41, P = 0.031). A strong negative correlation was present between Ang-1 and vWf levels (r = -0.48, P = 0.006), between D-dimer and fibrinogen levels (r = -0.71, P < 0.001), and between PDGF-AB and vWf levels (r = -0.42, P = 0.017). CONCLUSIONS: These findings suggest that angiogenic, coagulation and endothelial damage/dysfunction markers are possibly linked in pathogenesis of extensive slow-flow vascular malformations, and might have therapeutic implications.

Simultaneous evaluation of phagocytosis and Fc gamma R-mediated oxidative burst in human monocytes by a simple flow cytometry method.

In this study we describe a fast, simple, and objective flow cytometry method to quantify simultaneously phagocytosis and Fc gamma R-mediated oxidative burst in human monocytes. Peripheral blood monocytes isolated by elutriation were sequentially incubated with 2',7'-dichlorofluorescein-diacetate (DCFH-DA) and sheep erythrocytes opsonized with rabbit IgG (SRBC-IgG), and then analysed by flow cytometry. Two parameters were studied simultaneously in the same cell population: forward scatter modifications (grade of phagocytosis) and fluorescence intensity of DCFH oxidation (index of oxidative burst). We found a statistically significant correlation (r = 0.96274) between the forward scatter increase and the amount of phagocytosis as determined by light microscopy. We also found a significant correlation between the oxidative burst and phagocytosis studied both microscopically (r = 0.7714) and by flow cytometry (r = 0.78056). As the presence of DCFH did not impair monocyte phagocytosis, we conclude that this simple method could be a useful tool in functional studies of monocytes.

The measurement of transforming growth factor type beta (TGF beta) levels produced by peripheral blood mononuclear cells requires the efficient elimination of contaminating platelets.

In recent years there has been an increasing interest in measuring the levels of TGF beta produced by peripheral blood mononuclear cells (PBMC), since its abnormal regulation seems to be involved in several pathological states. Platelet-contamination, a common feature in PBMC populations isolated by the standard Ficoll-Paque method, would theoretically disturb the measurement of the levels of TGF beta produced by mononuclear cells, since platelets represent an important source of this cytokine. In this study, supernatants of PBMC cultures from healthy subjects, either platelet-contaminated or uncontaminated, were assayed for TGF beta activity in three different bioassays. We report that the presence of platelets led in most cases to an important overestimation of the TGF beta levels produced by MNC in the Swiss-3T3 bioassay and in a PBMC proliferation assay. In contrast, in the Mv1Lu bioassay these levels were significantly underestimated, an effect which we attribute to the presence of other platelet-derived growth factors. These results suggest that the elimination of platelets from PBMC cultures is essential if TGF beta production by mononuclear cells is to be studied.

Membranous glomerulonephritis secondary to hydatid disease.

To study the association of hydatid disease of the liver with a nephrotic syndrome we processed renal biopsy tissue for light microscopy, immunofluorescence and electron microscopy studies. These procedures disclosed the typical features of a membranous nephropathy whereas indirect immunofluorescence revealed glomerular deposits of hydatid antigen. Rabbits, previously immunized with bovine hydatid fluid, provided the specific antiserum. Clearly, the pathogenicity of this parasitosis derives, in part, from its immunologic repercussions. In this regard, our results support an etiopathogenic role for hydatid antigen in an immune-mediated glomerulonephritis.

Defective mononuclear phagocyte function in systemic lupus erythematosus: relationship of FcRII (CD32) with intermediate cytoskeletal filaments.

To investigate the mechanisms of impaired Fc receptor-mediated mononuclear phagocyte system (MPS) clearance in systemic lupus erythematosus (SLE), we have examined FcRII (CD32) and vimentin function in 25 patients with SLE and 36 healthy adults. In SLE, FcR-mediated phagocytosis of IgG-sensitized bovine erythrocytes was decreased (5.9 +/- 2.47 vs. 8.3 +/- 3.59 erythrocytes phagocytosed/monocyte/h; p < 0.05), and CD32 and vimentin expression was within the normal range; however, the percentage of simultaneously CD32+ and vimentin+ cells was increased (30 +/- 12 vs. 20 +/- 13; p < 0.05). Circulating immune complexes (CIC) were positive in 11 SLE patients, and levels were positively correlated with proteinuria (r = 0.53; p < 0.05) and disease activity (r = 0.40; p < 0.05). The mobility of membrane molecules, measured as the percentage of patients that showed patching and/or capping of CD32, was increased compared with controls, but not significantly (p < 0.1). At the same time, redistribution of vimentin filaments was observed. In conclusion, our data seem to support the possibility of a functional and/or structural alteration in the relationship between Fc receptors and intermediate cytoskeletal filaments as a causative factor in the deficient internalization of ligands bound to Fc receptors in monocytes of SLE patients.

Subacute cutaneous lupus erythematosus--clinical, histopathological and immunophenotypical study of five cases.

Subacute cutaneous lupus erythematosus (SCLE) is a recently described distinct subset of lupus erythematosus (LE) having characteristic clinical, serological and genetic features. The clinicopathological and serological findings of 5 patients are reported. From a clinical point of view, we describe two types of cutaneous lesions: psoriasiform and annular pattern. ANA were present in 80% of the cases, anti-Ro was present in 60%, and anti-La in 20%; anti-RNP was positive in 1 patient. Circulating immune complexes were detected in 2 patients, and low levels of complement factors (C3, C4) in another 2 patients. The B- cell alloantigens HLA-A2, HLA-Bw4 or HLA-DR3 were present in 60% of the cases. The cutaneous histopathology revealed important changes in the epidermis. Our findings are similar to those described by most other authors. Also, we would like to emphasize the low disease activity and benign course of our patients.

[Active immunotherapy in the treatment of haematological neoplasias]. / Inmunoterapia activa en el tratamiento de neoplasias hematológicas.

The continuous search for therapeutic approaches that improve the conventional treatments of neoplasms, together with an improved understanding of the immune system, has led in recent years to the development of Immunotherapy. Basically, a distinction can be made between two forms of immunotherapy: passive immunotherapy, which consists in the transfer of antibodies or cells previously generated in vitro that are directed against the tumour, and active immunotherapy, which attempts to activate in vivo the immune system and induce it to elaborate a specific response against the tumor antibodies. Hematological neoplasms, specifically some B lymphomas, express in their membrane an immunoglobulin that is considered a specific antigen of the tumour, which is why these diseases have become the ideal target for immunotherapy treatments. There are many alternatives, ranging from protein vaccines, which have already shown clinical benefits, to those of the second generation, which make use of the new techniques of molecular biology to increase the efficacy of the vaccines and obtain their production in a quicker and less costly way, but with which there are not yet definitive clinical results.

[Renal enzymology: experimental patterns and clinical symptoms]. / Enzimologia renal: patrones experimentales y semiologia clinica

This is a study of the changes, both in serum and urine, of a wide enzymatic pattern whose origin is well known to be the renal parenchyma (LDH, LAP, AP and lysozyme), in the course of two experimental prototype lesions induced in rats. Simultaneously a similar enzymatic study was carried out in a group of patients with nephropathies. The experimental lesions were a toxic tubular dysfunction using a mercury salt and an immune glomerulonephritis of two types: by foreign proteins (human albumin) and by rabbit nephrotoxic serum. In all these cases, there has been a convincing evidence, both direct (histological and inmunofluorescent) and indirect (marked proteinuria), of the induced lesions which were similar to the experimental models reported in the literature. The isolated enzymatic changes we observed in serum made us conceed less value to this pattern in comparison to the urinary one which proved to be more important in our study. It was possible to define the following urinary enzymatic patterns for each of the experimental groups: a) The acute toxic tubular dysfunction has a marked rise in the activity of LDH and LAP, and less so in the activity of AP and lysozyme. The retarded tubular lesion has a moderate rise in LAP. b) The glomerular lesion has a moderate and exclusive rise in the activity of LDH and LAP. Likewise the clear similarity between each experimental group and its clinical equivalent was demonstrated as refers to the urinary enzymatic pattern.

[Toll type receptors: molecular bases of the relationship between innate and adaptation responses of the immune system]. / Receptores tipo Toll: bases moleculares de la relación entre respuestas innatas y adaptativas del sistema inmunitario.

Microbes have on their surface molecular patterns that are common among a broad range of pathogens. These patterns are recognized by a wide variety of cellular receptors, the most important of which are a family of transmembrane proteins termed "Toll-like receptors" (TLR). TLRs are pattern-recognition receptors that have key roles in detecting pathogens and initiating inflammatory responses. The receptor of Gram negative bacterial LPS, TLR4, is the best characterized member of the TLR family. So far, ten mammalian toll-like receptors (TLR1-TLR10) have been identified. Recent studies revealed that the TLR signaling pathway is a critical mediator of sepsis. An understanding of TLRs and their signaling pathway will reveal a therapeutic target in sepsis and other immune mediated diseases.

[Protein A: an immunomodulator in cancer patients]. / Proteína A: inmunomodulador en pacientes con cáncer.

Protein A defined as one of the components of the wall of Staphylococcus Aureus Cowans 1 has shown its effects as modifier of the immune response: it induce changes in cellular receptors, polyclonal activation of T and B lymphocytes, liberation of lymphokines, increase in the production of gamma-interferon (probably as the result of activation of NK cells). In the present work we have studied NK activity and its modifications by Protein A and gamma-interferon in blood of 50 patients with solid tumours. The method used was the Cr 51 liberation assay. The effectors cells were non-adherent lymphocytes treated with different doses and times of incubation of Protein A and gamma-interferon. As target cells we utilized the cellular line K-562 for NK activity and autologous tumoral cells isolated from surgical specimen for tumour-specific cytotoxicity. The results obtained allow us to state the following conclusions: 1. NK activity against K-562 cells is not always a specific parameter of such activity. 2. Tumour-specific cytotoxicity can vary according to the histological type of tumour. 3. Protein A is a potent inducer of tumour-specific cytotoxicity in a higher degree than gamma-interferon.

[Cytokines-endothelium interaction: its role in the thrombotic process]. / Interacción citoquinas-endotelio: su papel en el proceso trombótico.

The in vivo relationship between the immune and the coagulation systems is a well documented fact. In a number of pathological conditions, thrombosis is not understood isolately, but in the context of inflammation and immunity. The mediators in these complex multidirectional interactions are the cytokines, a group of soluble peptides which act on surface cellular receptors, with immunoregulatory properties. These molecules influence negatively the physiological antithrombogenic situation by two different mechanisms. They are involved in processes which disrupt the endothelial integrity, and at the same time, they are capable of activating the endothelium in a prothrombotic manner, by stimulating procoagulant activities and by inhibiting different anticoagulants.

[Oxidizing agents and free radicals in biomedicine]. / Oxidantes y radicales libres en biomedicina.

The reactions which involve oxidants and free radicals species have played an essential role at the beginning of aerobic life, and they are an intrinsic part in the regulation of the cellular processes. However, as a result of the derived toxic effects of these oxidative processes, antioxidants molecules appeared in the very early stages of the evolution and they are able to control the production of these reactants and their dangerous effects. Oxidants and antioxidants have a clear function in the cellular physiology. When this delicate balance change many biochemical and cellular reactions are altered, and that may cause different pathologic diseases. In addition, free radicals of oxygen are thought to play a growing role in the biological process of ageing (1). It is not unusual to find papers about these reactants in every topic of the biomedicine. The main oxidants and free radicals in the organisms are oxygen-related agents, which are globally called reactive oxygen intermediates (ROI). These unavoidable, useful and dangerous biological oxidants are well characterized, although the recent implications they received in some pathologies deserve, in our opinion, a general review.

[Past, present and future of anti-idiotype vaccination]. / Pasado, presente y futuro de la vacunación anti-idiotipo.

Cancer vaccines are conceived as therapeutic tools, in contrast to the prophylactic vaccines used to fight against infectious diseases. Among the most potent therapeutic vaccines, anti-idiotype vaccination is directed against the tumor idiotype, the only well-characterized tumor antigen displayed in neoplastic B-cells. Anti-idiotype vaccines have demonstrated clinical benefit against follicular lymphoma and are currently being evaluated in two different phase III clinical trials. Additional emerging strategies, which include the use of dendritic cells and the production of vaccines via molecular means will surely allow us to draw important conclusions concerning the treatment of cancer patients.