Effect of the expression of CD62P and thrombin generation on patients using central venous catheters for hemodialysis.

The formation of thrombi in medical devices that come into contact with blood is a common cause of increased morbidity and mortality. Prolonged use of central venous catheters (CVCs) may cause high infection rates or compromise CVC patency due to thrombus development. In this study, we sought insights into possible changes in the hemostatic system during prolonged use of inserted CVCs for hemodialysis by assessing platelets by CD62P and CD41a expression and the potential for thrombin generation (TG). This study included patients with chronic renal failure who were undergoing hemodialysis three times a week using a CVC, and healthy subjects as controls. The participants were distributed into three groups: Group 1: clinically and laboratorially healthy individuals matched by sex and age to the patients (controls); Group II: patients who had completed 1 month of CVC insertion; and Group III: the same patients after they had completed 4 months of CVC insertion. Platelet activation analysis and TG evaluation were performed using blood samples obtained through two different accesses, that is, through a peripheral vein and directly from the CVC lumen. The data showed platelet activation and an increase in the generation of thrombin, particularly after 4 months of CVC use. The results also indicated that insertion of the catheter into the blood stream stimulated the intrinsic rather than the extrinsic pathway. Taken together, the data showed a direct relationship between the use of CVCs in hemodialysis patients and a state of hypercoagulability, most likely associated with endothelial damage and the contact of the medical device with blood components such as platelets and coagulation factors.

Exogenous normal lymph alleviates lipopolysaccharide-induced acute lung injury through lessening the adhesion molecules.

PURPOSE: To evaluate the role of exogenous normal lymph (ENL) on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in rats. METHODS: ALI was induced by the jugular vein injection of LPS (iv, 15 mg/kg) in rats of the LPS and LPS+ENL groups within 15 min, then, ENL without cell components (5 ml/kg) was infused at the speed of 0.5 ml per minute in the LPS+ENL group, the same amount of saline was administered in the LPS group. The rats in the sham group received the same surgical procedure and saline. The histomorphology and the levels of P-selectin, intercellular adhesion molecule-1 (ICAM-1), myeloperoxidase (MPO) in pulmonary tissue were assessed. RESULTS: LPS induced pulmonary injury as well as increased the wet/dry weight ratio (W/D) and the levels of P-selectin, ICAM-1, and MPO in pulmonary tissues. These deleterious effects of LPS were significantly ameliorated by ENL treatment. CONCLUSION: Exogenous normal lymph could markedly alleviate the acute lung injury induced by lipopolysaccharide, and its effects might be related to lessening the adhesion molecules.

Exogenous normal lymph alleviates lipopolysaccharide-induced acute lung injury through lessening the adhesion molecules

PURPOSE: To evaluate the role of exogenous normal lymph (ENL) on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in rats. METHODS: ALI was induced by the jugular vein injection of LPS (iv, 15 mg/kg) in rats of the LPS and LPS+ENL groups within 15 min, then, ENL without cell components (5 ml/kg) was infused at the speed of 0.5 ml per minute in the LPS+ENL group, the same amount of saline was administered in the LPS group. The rats in the sham group received the same surgical procedure and saline. The histomorphology and the levels of P-selectin, intercellular adhesion molecule-1 (ICAM-1), myeloperoxidase (MPO) in pulmonary tissue were assessed. RESULTS: LPS induced pulmonary injury as well as increased the wet/dry weight ratio (W/D) and the levels of P-selectin, ICAM-1, and MPO in pulmonary tissues. These deleterious effects of LPS were significantly ameliorated by ENL treatment. CONCLUSION: Exogenous normal lymph could markedly alleviate the acute lung injury induced by lipopolysaccharide, and its effects might be related to lessening the adhesion molecules. .

The effects of proresolution of ellagic acid in an experimental model of allergic airway inflammation.

Asthma is a disease of airway inflammation characterized by airway hyperresponsiveness, eosinophilic inflammation, and hypersecretion of mucus. Ellagic acid, a compound derived from medicinal plants and fruits, has shown anti-inflammatory activity in several experimental disease models. We used the classical experimental model, in BALB/c mice, of sensibilization with ovalbumin to determine the effect of ellagic acid (10 mg/kg; oral route) in the resolution of allergic airways response. Dexamethasone (1 mg/kg; subcutaneous route) was used as a positive control. The control group consisted of nonimmunized mice that received challenge with ovalbumin. Ellagic acid and dexamethasone or vehicle (water) were administered before or after intranasal allergen challenge. Ellagic acid accelerated the resolution of airways inflammation by decreasing total leukocytes and eosinophils numbers in the bronchoalveolar lavage fluid (BALF), the mucus production and lung inflammation in part by reducing IL-5 concentration, eosinophil peroxidase (EPO) activity, and P-selectin expression, but not activator protein 1 (AP-1) and nuclear factor kappa B (NF-κB) pathways. In addition, ellagic acid enhanced alveolar macrophage phagocytosis of IgG-OVA-coated beads ex vivo, a new proresolving mechanism for the clearance of allergen from the airways. Together, these findings identify ellagic acid as a potential therapeutic agent for accelerating the resolution of allergic airways inflammation.

Effect of ischemia preconditioning on renal ischemia/reperfusion injury in rats

To study the effect of ischemia preconditioning (IP) on renal ischemia/reperfusion (I/R)-associated functional injury and expression of renal adhesion molecules in rats.

The ischemia preconditioning plan adopted in this experiment involved renal warm ischemia for 6 min. and blood flow for 4 min., repeated four times. The Wistar rat kidneys used for warm ischemia preconditioning were subjected to 60 min of renal warm ischemia followed by reperfusion. The rat kidneys with ischemia/reperfusion were compared with the ischemia preconditioning group to observe rat renal function and changes in the expression of renal adhesion molecules ICAM-1, P--Selectin, and E-Selectin.

The expression of rat renal adhesion molecules (ICAM-1, P-Selectin, and E-Selectin) with ischemia preconditioning was significantly lower than that of the ischemia/reperfusion group. Serum creatinine was significantly lower than that in the ischemia/reperfusion group after 48 hours.

Ischemia preconditioning has a protective effect on renal function. Reduced expression of renal adhesion molecules is likely a mechanism involved in the observed protection. .

Effect of ischemia preconditioning on renal ischemia/reperfusion injury in rats.

OBJECTIVE: To study the effect of ischemia preconditioning (IP) on renal ischemia/reperfusion (I/R)-associated functional injury and expression of renal adhesion molecules in rats. MATERIALS AND METHODS: The ischemia preconditioning plan adopted in this experiment involved renal warm ischemia for 6 min. and blood flow for 4 min., repeated four times. The Wistar rat kidneys used for warm ischemia preconditioning were subjected to 60 min of renal warm ischemia followed by reperfusion. The rat kidneys with ischemia/reperfusion were compared with the ischemia preconditioning group to observe rat renal function and changes in the expression of renal adhesion molecules ICAM-1, P-Selectin, and E-Selectin. RESULTS: The expression of rat renal adhesion molecules (ICAM-1, P-Selectin, and E-Selectin) with ischemia preconditioning was significantly lower than that of the ischemia/reperfusion group. Serum creatinine was significantly lower than that in the ischemia/reperfusion group after 48 hours. CONCLUSIONS: Ischemia preconditioning has a protective effect on renal function. Reduced expression of renal adhesion molecules is likely a mechanism involved in the observed protection.

La atorvastatina no modifica el incremento agudo de los niveles de p-selectina y fibrinógeno inducido con esfuerzo físico máximo / Atovastatin does not modify the acutely increased levels of P-selectin and fibrinogen induced by maximal physical exercise

Introducción: Las estatinas han demostrado disminuir los eventos cardiovasculares en sujetos con y sin enfermedad aterosclerótica establecida. Se ha demostrado, que sus efectos benéficos no sólo dependen de la reducción del colesterol, sino que también podrían ser secundarios a otros efectos de las estatinas, como su efectos de reducción de inflamación y/ o trombogénesis entre otros. Sin embargo, no existen trabajos que demuestren que las estatinas sean capaces de frenarla activación de la cascada de inflamación y/o trombogénesis. Objetivos: Determinar el efecto de la administración oral de atorvastatina por 7 días sobre los niveles plasmáticos de proteína C- reactiva ultrasensible (PCR us), fibrinógeno y P-selectina, pre y post prueba de esfuerzo máximo inmediato y a las 24 horas de su ejecución. Métodos: Ensayo clínico en 50 hombres sanos (18 a 50 años), randomizado atorvastatina 80 mg/día - placebo por 7 días, doble ciego. Muestras tomadas en sangre para PCRus, fibrinógeno y P-selectina, perfil lipídico, creatin kinasa y transaminasas hepáticas, pre y post test de esfuerzo, y a las 24 horas. Los resultados para datos continuos se expresan como medias +/- desviación estándar, test de student para muestras independientes, ANOVA para muestras repetidas. Programa estadístico SPSS 14.0. Resultados: Un grupo de 44 sujetos completaron el estudio: atorvastatina 80 mg (n=24) o placebo (n=20). En el grupo atorvastatina, después de una semana de tratamiento, los niveles de LDLc disminuyeron en 38 por ciento (LDL basal: 97 +/- 27 mg/dL vs LDL post: 62 +/- 31 mg/dL, p < 0.001). Sin embargo, no se observaron cambios en ese mismo período en los niveles de PCRus, fibrinógeno y P-selectina con respecto a placebo. Los niveles de fibrinógeno se elevaron 8 por ciento entre la etapa pre y post ejercicio inmediato (341 +/- 56 mg/dL vs 368 +/- 65 mg/dL, p<0.001), retornando a los niveles basales a las 24 horas; no hubo diferencias entre atorvastatina - placebo...

Background: Chronic statin therapy is known to decrease ínflammation and platelet aggregation. However, little data exist regarding acute effect of statins upon these variables. Exercise can be used to induce ínflammation and platelet aggregation. Aim: to determine the acute effect of atorvastatin upon plasma levels of ultra sensitive C reactive protein (US-PCR), fibrinogen and P selectin before, immediately after and 24 hr following a maximal exercise test in healthy subjects. Methods: This was a double blind, randomized prospective study Fifty healthy male subjects (aged 18to 50years) received atorvastatin 80 mg or placebo daily for 7 days. US-PCR, fibrinogen, P-selectin, blood lipids, total creatin-kinase (CK) and transaminases were determined pre and immediately after maximal treadmill exercise. Repeat determinations were performed 24 following the test. Results were analyzed using the SPSS statistical package, and are expressed as mean +/- SD. Student's t and repeated measures ANOVA were used as appropriate. Results: 44 subjects completed the study (atorvastatin =24; placebo= 20). LDL cholesterol decreased from 97 +/- 27 to 62 +/- 31 mg/dl in the atorvastatin group (p<0.001). US-PCR, After 1 week, Fibrinogen and P-selectin were not significantly modified from baseline, and no differences were observed between groups (atorvastatin vs. control). However, fibrinogen increased 8 percent from baseline to immediately post exercise (341 +/- 6 vs. 368 +/- 65mg/dl (95 percent CI. 21/.3 - 33.6). 24hr after exercise, fibrinogen levels returned to baseline. Similar changes were observed for P-selectin (25 +/- 5, 28 +/- 1.7 ng/dl, baseline and post exercise respectively p<0.01), again returning to baseline 24hr after exercise. No significant changes were observed for US-PCR after exercise in neither group. CK increased 43 percent in the atorvastatin group and 12 percent in controls (NS). Conclusion: Atorvastatin...

Efecto de los leucocitos sobre la lesión por almacenamiento en plaquetas de aferesis / Effect of leukocytes on the storage lesion in apheresis platelet

En el Banco de Sangre , las plaquetas sufren una serie de cambios físicos, metabólicos y fisiológicos que se denominan "lesión por almacenamiento" (LA), que depende de varios factores: métodos de preparación del concentrado, tipo de bolsa utilizada, concentración de plaquetas, número de leucocitos presentes en la unidad y acumulación de citoquinas. Todos ellos podrían producir activación plaquetaria y así afectar la calidad del producto, lo cual se reflejaría en una menor sobrevida de las plaquetas transfundidas. Basándose en lo anterior, se plantea que la remoción precoz de leucocitos aminoraría la LA en los concentrados plaquetarios (CPs) obtenidos por aféresis. Se estudiaron veinte CPs obtenidos mediante dos métodos de aféresis que difieren en el número de leucocitos residuales que permanecen en el producto final; un CP leucoreducido (Cobe Spectra) y otro estándar (Baxter CS 3000 plus). Las determinaciones se realizaron el día cero (prealmacenamiento) y al quinto día de almacenamiento. La evaluación de la LA incluyó marcadores de menbrana plaquetaria: p-selectina (CD62-P), glicoproteína Ib (CD42b), fosfatidilserina (Ax V.), factor tisular (CD142), formación de micropartículas (MPs), los cuales se analizaron por citometría de flujo, y citoquinas liberadas por los leucocitos y/o plaquetas activadas (IL-1. IL-6,FNT y RANTES), las cuales se analizaron por ELISA. El principal marcador de activación de las plaquetas (p-selectina) se encontró significativamente aumentado en los CP leucorreducidos (P: 0.001) y en los obtenidos en forma estándar (p: 0.02). La expresión de GPIb disminuyó significativamente solo en las plaquetas no leucorreducidas (p: 0.01). En relación a la actividad procoagulante de las plaquetas, se observó un aumento significativo en la expresión de fosfatidilserina sobre la cara externa de la membrana (p: 0.019) y de MPs plasmáticas (p: 0.025) solo en las plaquetas leucorreducidas y un muy leve aumento de la expresión de factor tisular...

Under Blood Bank storage conditions, platelet undergo a series of physical, metabolic and physiological changes that are denominated "platelet storage lesion" (PSL). This condition depends on several factors: the platelets number and the methodology used for the preparations of platelet concentrates (PC), type of storage bag, the number of leukocytes present in the cell unit, cytokines release, among others. All these factors may produce platelet activation and thus affect the quality of the product, which would be reflected in a shorter survival of the transfused platelets. Based on the previous knowledge, we hypothesized that early removal of leukocytes from the apheresis concentrate will diminish platelets "activation/lesion" during storage. We studied twenty PC obtained by two methods of apheresis that differed in the number of residual leukoreduced PC (Cobe Spectra) and a standard PC (3000 Baxter CS extra). The determinations were made at day zero (pre-storage) and at the fifth day of storage. The evaluation included markers present in platelets membrane, such as, p-selectin (CD62-P), glycoprotein Ib (CD42b), phosphatydilserine expression (PS). Tissue Factor (CD142) and microparticles (MPs) generation, that were analyzed by flow cytometry. Cytokines released by leucocytes or activated platelet (IL-1). IL-6, TNF and RANTES), were analysed by the ELISA technique. The most important marker of platelets activation, CD62-P, was significantly more increased in leukoreduced CP (P: 0.001) than in the standard method (p: 0.02). The expression of GPIb diminished significantly only in non-leukoreduced platelets (p: 0.01). With regard to the procoagulant activity of platelets, a significant increase in the PS expression was observed on the external face of the platelet membranes (p: 0.019) and on MPs (p: 0.025) only in leukoreduced preparations, changes that were accompanied by a very slight increase of tissue factor expression (p: 0.055). The determinations...

Ativação plaquetária em diferentes formas de apresentação da doença arterial coronária: importância da P-selectina e outros marcadores nas anginas estável e instável / Platelet activation in different clinical forms of the coronary artery disease: roll of -Selectin and others platelet markers in the stable and unstable angina

Objetivo: Os marcadores da ativação plaquetária estão geralmente elevados na doença arterial coronária. Desse modo, procuramos identificar a presença e as potenciais associações de diferentes marcadores da ativação plaquetária. Métodos: nós estudamos pacientes com angina instável (n=28), pacientes com angina estável (n=36) e pacientes sem doença arterial coronária / Purpose: markers of platelet activation are elevated in coronary artery disease. We sought to identify the presence and the potential associations of different markers of platelet activation. Methods: we studied patients with unstable angina (n=28), patients with stable angina (n=36) and patients without coronary artery disease (n+30); sex and age measured...

RNA and DNA aptamers as potential tools to prevent cell adhesion in disease.

Recent research has shown that receptor-ligand interactions between surfaces of communicating cells are necessary prerequisites for cell proliferation, cell differentiation and immune defense. Cell-adhesion events have also been proposed for pathological conditions such as cancer growth, metastasis, and host-cell invasion by parasites such as Trypanosoma cruzi. RNA and DNA aptamers (aptus = Latin, fit) that have been selected from combinatorial nucleic acid libraries are capable of binding to cell-adhesion receptors leading to a halt in cellular processes induced by outside signals as a consequence of blockage of receptor-ligand interactions. We outline here a novel approach using RNA aptamers that bind to T. cruzi receptors and interrupt host-cell invasion in analogy to existing procedures of blocking selectin adhesion and function in vitro and in vivo.

RNA and DNA aptamers as potential tools to prevent cell adhesion in disease

Recent research has shown that receptor-ligand interactions between surfaces of communicating cells are necessary prerequisites for cell proliferation, cell differentiation and immune defense. Cell-adhesion events have also been proposed for pathological conditions such as cancer growth, metastasis, and host-cell invasion by parasites such as Trypanosoma cruzi. RNA and DNA aptamers (aptus = Latin, fit) that have been selected from combinatorial nucleic acid libraries are capable of binding to cell-adhesion receptors leading to a halt in cellular processes induced by outside signals as a consequence of blockage of receptor-ligand interactions. We outline here a novel approach using RNA aptamers that bind to T. cruzi receptors and interrupt host-cell invasion in analogy to existing procedures of blocking selectin adhesion and function in vitro and in vivo

The expression of adhesion molecules in cigarette smoke-induced airways obstruction.

Cigarette smoking produces peripheral airway inflammation in all smokers, and chronic airways obstruction in approximately 20% of heavy smokers. The present study was designed to test the hypothesis that airways obstruction is related to changes in the expression of adhesion molecules involved in the recruitment of cells to sites of inflammation in the lung. Freshly resected lungs from heavy smokers with airways obstruction (n = 10) and from heavy smokers with normal lung function (n = 10) were collected in the operating room, inflated with optimal cutting temperature (OCT) medium and frozen over liquid nitrogen. Six micrometres thick cryostat sections cut from random samples of this tissue were stained, using immunohistochemistry, with monoclonal antibodies to the adhesion molecules on leucocytes: L-selectin, very late activation antigen-4 (VLA-4), CD11a/CD18, CD11b/CD18, CD11c/CD18; and on endothelial and epithelial surfaces: E-selectin, P-selectin, vascular cell adhesion molecule (VCAM-1), intercellular adhesion molecule (ICAM)-1 and ICAM-2 using the alkaline phosphatase anti-alkaline phosphatase (APAAP) technique. The slides were coded and the expression of each molecule scored by three observers using a semiquantitative grading system. Two inducible adhesion molecules, E-selectin on endothelium and CD11b on leucocytes, were also evaluated using quantitative morphometric analysis. The results showed a distribution of adhesion molecules that was consistent with the inflammatory response in the airways and parenchyma of all subjects but failed to show any differences between those with or without airways obstruction. We conclude that development of airways obstruction in heavy smokers cannot be explained by differences in the expression of adhesion molecules known to be involved in the control of cell traffic in the lung.