Decrease In Fibronectin Concentration Research Articles

The Effects of Perioperatively Administered Colloids and Crystalloids on Primary Platelet-Mediated Hemostasis and Clot Formation

The Effects of Perioperatively Administered Colloids and Crystalloids on Primary Platelet-Mediated Hemostasis and Clot Formation

Hydroxethyl starch: effects on hemostasis

HES are high-polymeric glucose compounds obtained via hydrolysis and subsequent hydroxyethylation from the highly-branched amylopectin contained in maize. Initially, the HES were only characterized by their in vitro molecular weight (Mw), without consideration of the in vivo hydrolysis by alpha-amylase. The degree of substitution and the molar substitution ratio quantify the hydroxyethylation. The glucose units can be substituted at carbon 2, 3 and 6 leading to various substitution patterns. This pattern is described with the C2/C6 hydroxyethylation ratio. The higher the degree of substitution and the C2/C6 ratio, the less the starch is metabolized. The in vitro Mw, the degree of substitution and the C2/C6 ratio are the main determinants of the in vivo Mw which is clinically relevant. Haemorrhagic complications that occur after infusing larger volumes of HES can be avoided with a starch of low in vivo Mw. This is not only due to a lesser effect on the coagulation system which prevents an acquired type I von Willebrand syndrome, but also to a smaller decrease in platelet volume, since platelet volume and platelet function are positively correlated. In addition, HES with low in vivo Mw has significantly better rheological effects than HES with a high in vivo Mw, as high Mw macromolecules affect plasma viscosity negatively. Furthermore high Mw HES macromolecules lead to a distinctive decrease in fibronectin concentration that reflects saturation of the reticuloendothelial system. Another advantage of low in vivo Mw HES is its rather short half-life. Patients with an increased bleeding risk, microcirculatory disturbance or affected RES should receive HES with low in vivo Mw. In the future, HES should be mainly characterized by the in vivo and not the in vitro Mw.

Plasma fibronectin and angiotensin-converting enzyme: markers of primary pulmonary injury in burn patients

Plasma fibronectin (FBN) and angiotensin I-converting enzyme (ACE) were prospectively measured in 50 burn patients from the day of admission to day 28 after the trauma with the aim of finding biochemical markers of pulmonary injury by smoke inhalation. Patients were divided into three groups on the basis of fiberoptic bronchoscopy results (group I: healthy lungs; group II: burned lungs; group III: infected lungs). A decrease in FBN concentrations was observed in the three groups but was larger in group II than in the other groups, especially at day 2 ( P < 0.05). A similar profile was observed for plasma ACE activity. Factors other than lung injury may influence plasma FBN and ACE levels, in particular the burned body surface area, an acute event such as septicemia, or outcome. However, repeated measurements of both markers could help in the assessment of lung injury in the follow-up of burn patients.

Cerebrospinal fluid concentration of fibronectin in patients with HIV-1 infection and central nervous system disorders.

To evaluate the fibronectin concentrations in the cerebrospinal fluid of HIV-1 infected patients with central nervous system disorders. Fibronectin was determined by an immunoturbidimetric assay in 41 HIV-1 infected patients with AIDS dementia complex, progressive multifocal leucoencephalopathy, and opportunistic infections. A significant decrease in fibronectin concentrations in the cerebrospinal fluid of patients with AIDS and dementia complex and progressive multifocal leucoencephalopathy was observed, as well as in those with opportunistic infections of the central nervous system (p < 0.0001). In particular, a significant decrease in fibronectin concentration in cerebrospinal fluid was observed in patients with cerebral toxoplasmosis and cryptococcal meningitis (p < 0.0001). Because fibronectin can bind to several viruses, fungi, and protozoa, it is conceivable to suppose that the consumption of fibronectin in the cerebrospinal fluid of patients with neurological disorders may be related to the binding of fibronectin to HIV itself, or to viral proteins, or to organisms responsible for opportunistic infections.

Plasma fibronectin concentration in animal models of sepsis and endotoxemia

Plasma fibronectin is a nonspecific opsonin which mediates phagocytosis of particulate matter by macrophages. Fibronectin depletion results in depression of reticuloendothelial system phagocytic function. This may potentiate microvascular embolization and sludging in critical illness. It has been hypothesized that sepsis is a major cause of fibronectin depletion. To explore this hypothesis, plasma fibronectin concentrations were measured in rats with intraabdominal abscesses and in rabbits subjected to the generalized Shwartzman reaction (spaced doses of endotoxin). In both groups of animals there was a significant increase ( P < 0.05) rather than decrease in fibronectin concentrations at times when sepsis and disseminated intravascular coagulation were manifest. This study does not support the hypothesized relationship between sepsis and fibronectin depletion. Until the kinetics of fibronectin production and utilization are further delineated, caution must be exercised in the interpretation of immunoreactive plasma fibronectin levels.