Phagocytosis of chemically modified carbon materials.

An oxidizing treatment of carbon fibres in boiling nitric acid leads to significant changes in the chemical state of their surface. As a result of the chemical treatment on a hydrophobic carbon surface, hydrophilic domains are formed and phenolic, carbonyl and carboxyl groups appear. In this work the intensity of phagocytosis of carbon fibres obtained by carbonization of polyacrylonitrile was studied both for HNO3 etched and non-etched fibres. Part of the powdered material studied was placed in plasma before it was contacted with cells. To study the material, which was first placed in plasma and then contacted with cells, X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy were used. It was found that the powders made from the etched fibres are phagocytized more intensively. It was also found that the absorption of plasma proteins enhances the phagocytosis only for the fibres oxidized in HNO3 and has no influence in the case of powders obtained from non-etched fibres.

Different isoenzyme patterns of nonspecific esterases and the level of IL6 production as markers of macrophage functions.

We examined the isoenzyme patterns of alpha and beta naphtyl acetate esterase and the IL6 production of two macrophage cell lines, which were cloned from a single fusion of macrophage tumor cells and spleen adherent cells. These clones were phenotypically indistinguishable but differ functionally as line 59 presents antigen to Th 1 lymphocytes while line 63 induces suppressor T lymphocytes. Cell extracts of these lines exhibit different isoenzyme patterns of alpha and beta naphtyl acetate esterase at both pH 7.5 and 5.8 but do not differ significantly in the level of produced IL6. Treatment with nitrogranulogen (NG), a derivative of cyclophosphamide, changes the isoenzyme pattern in line 59 and decreases severalfold IL6 production, while in similarly treated line 63 cells isoenzyme pattern remains unaffected but the production of IL6 is significantly increases. We assume that the observed differences between these two cell lines are due to distinct intracellular translation of the membrane signal delivered by NG. The different behaviour of these two parameters can thus be used as a useful tool to further delineate different macrophage subpopulations. We regard it likely that nonspecific esterases may play a role in intracellular processing or trafficking of antigen.

Differential effects of chlorination of bacteria on their capacity to generate NO, TNF-alpha and IL-6 in macrophages.

Activated rodent macrophages produce high amounts of nitric oxide (NO). NO as a tumoricidal and defence molecule against intracellular parasites is commonly accepted. However, its role as an obligatory killing factor for extracellular bacteria is controversial. In the present study we stimulated murine peritoneal macrophages by heat-killed bacteria (Staphylococcus aureus, S. epidermidis and Escherichia coli). In some groups bacteria were pretreated with HOCl, to replace the chlorinating system in activated neutrophils that operates as a bactericidal system in vivo. High levels of NO, tumour necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) were detected after stimulation by all non-chlorinated bacteria strains tested. However, after chlorination Gram-positive bacteria lost their ability to induce NO and TNF-alpha, whereas phagocytosis and IL-6 production were not affected by chlorination.

In vitro enhanced destruction of erythrocytes as a result of their chlorination.

Subarachnoidal haemorrhage is followed by accumulation of granulocytes and macrophages in cerebrospinal fluid (CSF). As a result erythrocytes are destroyed and removed from CSF. Activated granulocytes chlorinate many species including erythrocytes. It has been shown that chlorinated erythrocytes are more sensitive to phagocytosis by macrophages than the native ones.

Ribonuclease from cytosolic fraction of human erythrocytes.

Ribonuclease (RNase) activity is detectable in only one third of specimens of human erythrocyte haemolysates. On the other hand, treatment of erythrocytic cytosoles with sulphosalicylic acid reveals an inhibitor-bound RNase activity which is present in all erythrocyte specimens studied. The level of the erythrocyte inhibitor-bound RNase activity is comparable to that in human lymphocytes. Isolated RNase from the cytosolic fraction of human erythrocytes is poly-C avid RNase with maximum activity at pH 6.5. The enzyme is resistant to treatment with strong acids and heating up to 95 degrees C. Molecular filtration of the erythrocyte RNase shows that it is composed of two fractions differing in molecular mass, 19 000 and 15 000. No difference in enzymic properties between these fractions was found. The general properties of erythrocyte cytosolic RNase are much like those of acid RNases of human granulocytes and lymphocytes. As the erythrocytes do not metabolize RNA no function for the inhibitor-bound RNase can be suggested. Assuming that the observed erythrocyte RNase is the residual enzyme, persisting in the cell since it was functioning in the nucleated erythrocyte precursors, one may surmise that levels of free and inhibitor-bound erythrocyte RNase activity may be related to the normality or abnormality of erythrocyte maturation.

Econometric analysis of phase duration for blood morphology and basophil count alterations in chronic granulocytic leukaemia.

The retrospective analysis of 40 cases with chronic granulocytic leukemia revealed an average survival time of 39 months. Modal proportions between the chronic, accelerated and acute blastic crisis amounted to 25:6:8 months. The characteristic points and curves for peripheral white cell, blast cell, basophil cell and thrombocyte counts as well as haemoglobin levels were determined separately in 20 patients with long and in 20 with short survival time. Comparisons indicate among others that Busulphan sensitivity is an essential factor for a longer survival time of CGL patients.