Methylenebisphosphonic acid alters the pattern of pericellular glycosaminoglycans and binding properties of CD44 in human endothelial cells

The effect of methylenebisphosphonic acid (MBPA) on glycosaminoglycan metabolism, adhesive and proliferative properties of human endothelial cells has been investigated. It was demonstrated that MBPA (100 microM) inhibited the synthesis of all studied groups of glycosaminoglycans, but promoted the accumulation of heparan sulphate in endothelial pericellular matrix. Simultaneously, the redistribution of hyaluronic acid from pericellular matrix to the conditioned medium was observed. The decreased adhesion of endothelial cells to immobilized hyaluronic acid was not mediated by the alterations of CD44 expression. It was also demonstrated that MBPA affected the proliferative properties of endothelial cells. The alterations of glycosaminoglycan metabolism are considered to be involved in antiangiogenic effects of MBPA.     

HIV-1 integrase-hydrolyzing antibodies from sera of HIV-infected patients

Autoantibodies with enzymic activities (abzymes) are a distinctive feature of autoimmune diseases. It was interesting whether Abs from patients with viral diseases can hydrolyze viral proteins. Electrophoretically and immunologically homogeneous IgGs were isolated from sera of AIDS patients by chromatography on several affinity sorbents. We present evidence showing that 89.5% IgGs purified from the sera of HIV-infected patients using several affinity resins including Sepharose with immobilized integrase specifically hydrolyze only HIV integrase (IN) but not many other tested proteins. Several rigid criteria have been applied to show that the IN-hydrolyzing activity is an intrinsic property of AIDS IgGs but not from healthy donors. Similar to autoimmune proteolytic abzymes, IN-hydrolyzing IgGs from some patients were inhibited by specific inhibitors of serine and metal-dependent proteases but a significant inhibition of the activity by specific inhibitors of acidic- and thiol-like proteases was observed for the first time. Although HIV infection leads to formation of Abs to many viral and human antigens, no possible biological role for most of them is known. Since anti-IN IgG can efficiently hydrolyze IN, a positive role of abzymes in counteracting the infection cannot be excluded. In addition, detection of IN-hydrolyzing activity can be useful for diagnostic purposes and for estimation of the immune status in AIDS patients.     

Leptin and metabolic syndrome

Obesity is characterized by increased concentration of leptin and disturbance of the feedback between hyperleptinaemia and enhanced appetite. The hyperleptinaemia is often combined with hyperglycaemia and arterial hypertension and seems to be a predictor of acute cardiovascular events. Leptin inhibitors might be used in the future for therapy in case of the metabolic syndrome.     

The direct stimulating action of thyroliberin on the biosynthesis of total protein in cultured liver cells of rat fetuses]

In experiments using fetal rat liver cultured cells TRH was shown to stimulate total protein synthesis but not RNA synthesis during long incubation. Somatostatin affected neither protein synthesis nor RNA synthesis in cultured liver cells. Possible physiological role of peripheral TRH during perinatal period in the rat is discussed.     

Preliminary lymphocyte activation by a mitogen as a condition for demonstrating the ability of the Fab-fragment of normal IgG to inhibit lymphocyte transformation

Peculiarities attending inhibition of the PHA-induced blast-cell transformation of human lymphocytes by F(ab')2 fragment of rabbit IgG were studied. It was shown that the fragment did not affect the intensity of blast-cell transformation if the lymphocytes were preliminarily incubated with the fragment for 24 h at 37 degrees or 4 degrees C and then transferred to the fresh medium containing PHA. However, if the fragment was added to the cells 24 or 48 h following PHA it produced a significant inhibition of the blast-cell transformation. These data may indicate that F(ab')2 fragment interferes with the lymphocyte transformation only when the cells are already activated with PHA.     

Influence of gold nanoparticles on activation of human blood neutrophils

Activation of neutrophils in the presence of gold nanoparticles is accompanied by formation of free-radical peroxidation products, recorded as a flash of chemiluminescence. The basis for the activation mechanism has its origins most likely in the influence of the gold particles on the membrane surface potential of neutrophils. Assessment of changes in the fluorescence intensity of the negatively charged ANS probe on the surface of model membranes upon adding different concentrations of gold nanoparticles indicates a change in the membrane surface charge density, which can cause cell activation.     

Solid-state and membrane-surface liquid cultures of micromycetes: Specific features of their development and enzyme production (a Review)

Specific features in the development of micromycetes, typical mechanisms of their enzyme production, and conditions providing for an increase in enzyme secretion by the microscopic fungi in solid-state (on natural substrates and inert carriers) and membrane-surface liquid cultures are considered. The prospects and advantages of these fermentation methods for the production of extracellular enzymes are discussed and compared with submerged cultures.     

Interactions of mononuclear cells of peripheral blood with islet cells in vitro

Peripheral blood mononuclear cells from Type I diabetic patients health donors or Wistar rats were cultured with rat islet cells for 18 h. Then TNF content of the medium and basal and stimulated insulin release were determined. Mononuclear cells from both healthy donors and diabetic patients could inhibit the insulin release with no correlation to TNF content. Addition of lipopolysaccharide resulted in a 5-7 times increase of TNF content of the medium followed by a more pronounced inhibition of insulin release. Rat mononuclear cells inhibited the beta-cell function almost completely and initially produced large amounts of TNF. The data indicate that inhibition of insulin release by blood mononuclear cells in vitro does not reflect anti beta-cell specific cellular immunity, involves cytokines and, probably depends upon the initial properties of the cells.