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Biomedical subjects

I Miler

Publications and source records attributed to I Miler.

At least 37 records · Page 2Linked to original sources
PubMed1988

The potential immunosuppressive effect of bilirubin.

The effect of bilirubin on the cells of the immune system was studied using various in vitro and in vivo systems. Bilirubin was found to inhibit the in vitro chemotactic (migratory) activity of human granulocytes; on the other hand, a temporary stimulation of phagocytic activity of both granulocytes and monocytes was found in mice injected with a single i.p. injection of bilirubin. Continuous i.v. infusion of bilirubin produced a significant decrease of antibody (plaque) forming cells in the spleens of mice immunized with sheep red blood cells. In newborns suffering from hyperbilirubinaemia, enhanced proportion of "activated" lymphocytes occurred. Finally, bilirubin possessed a significant in vitro cytotoxic effect in human adult and newborn blood lymphocytes and granulocytes. A brief survey of so far known immunological effects of bilirubin is discussed.

Antibody Formation↗
PubMed1988

Phagocytosis of microspheric hydrophile particles (MSHP) by peripheral blood glass-adherent phagocytes of newborns.

The phagocytic activity of glass-adherent peripheral blood leukocytes of 58 healthy term newborns and 19 adult donors was examined using a micromethod employing a new type of synthetic hydrophilic particles based on 2-hydroxyethylmethacrylate. It was found that both the proportion of actively phagocytosing cells and the number of engulfed particles within the cells was significantly lower in neonates as compared with adults.

Cell Adhesion↗
PubMed1988

Effects of bilirubin on murine peritoneal and spleen cells.

The effect of bilirubin on murine peritoneal and spleen cells was investigated. Bilirubin was found to have a strong and rapid effect on the expression of various kinds of Fc receptors on peritoneal macrophages. Significant changes were observed 30 min after the infection of bilirubin. The return to normal values was not observed earlier than after 24 h. The effect of bilirubin on Fc receptor expression of splenic macrophages was less pronounced. Expression of Ia antigen on macrophages was not influenced by bilirubin. The changes in percentage of sIg+ and Thy 1.2+ lymphocytes reflect a change in the ratio of T to B cells in the peritoneal cavity, as bilirubin caused 40% increase in numbers of B cells and a similar decrease in numbers of T cells. The percentage of splenic B lymphocytes was not influenced by bilirubin injection; but the ratio of T helper to suppressor cells was altered.

Animals↗
PubMed1987

Phagocytosis of cadmium microcrystals by glass-adherent peripheral blood leucocytes of newborns with various perinatal risks.

Using cadmium microcrystals saturated with human serum albumin as particles for the phagocytic assay, the phagocytic activity of peripheral blood glass-adherent leucocytes of 32 preterm infants, 15 small-for-date newborns, 14 term newborns with perinatal asphyxia and 27 term newborns of diabetic mothers was compared with healthy term newborns and normal adults. A statistically significant increase in both the percent of phagocytosing cells and in the mean number of engulfed particles per cell was found in all groups of "stressed" infants as compared with cells of adults. No difference in the proportion of actively phagocytosing cells was found between term healthy and stressed neonates; as regards the mean number of ingested particles per cell, a slight increase (however, statistically not significant) was found in all groups of infants with perinatal risks compared with normal infants suggesting a temporary stimulation of these cells.

Asphyxia Neonatorum↗
PubMed1986

Interaction of bilirubin with human lymphocytes and granulocytes--the effect on bilirubin metabolism.

An in vitro degradation of bilirubin by isolated human granulocytes and lymphocytes is described. Changes in the bilirubin concentration during interaction with these cells were determined spectrophotometrically. The dependence of the reaction velocity on the original bilirubin concentration followed an adsorption isotherm, typical of enzyme processes with a Km of 79 microM at a cell concentration of 500/microL. The primary event is the adsorption of bilirubin to the cell surface and, in addition, its detoxication. Cyanide and sonic treatment of cells inhibit the reaction, salicylic acid enhances the cell activity. The bilirubin-detoxicating effect is discussed with respect to the therapy of hyperbilirubinaemia in neonates.

Bilirubin↗
PubMed1985

The in vitro cytotoxic effect of bilirubin on human lymphocytes and granulocytes.

Using an in vitro cytotoxicity assay (51Cr-release), it was shown that bilirubin exerts a cytotoxic effect on both adult and newborn human lymphocytes after a 1-d incubation of cells with bilirubin. The effect of bilirubin on human granulocytes was less pronounced; the association of the cytotoxic effect with a functional immunological perturbation of these cells is discussed.

Adult↗
PubMed1985

The effect of bilirubin on the Fc receptor expression and phagocytic activity of mouse peritoneal macrophages.

The effect of bilirubin on the phagocytic activity of mouse peritoneal macrophages and on the expression of Fc receptors and receptors for SRBC was studied. Intraperitoneally administered bilirubin influenced the expression of Fc receptors for IgM, IgG2B, IgA and IgE, whereas the expression of other receptors as well as the phagocytic activity of peritoneal macrophages remained unchanged. The possible mechanism of the effect of bilirubin on Fc receptors is discussed.

Animals↗
PubMed1985

The effect of bilirubin on the phagocytic activity of mouse peripheral granulocytes and monocytes in vivo.

Using an in vitro phagocytic assay with synthetic 2-hydroxyethylmethacrylate copolymer particles, the phagocytic activity of leukocytes of bilirubin-treated mice (85 and 170 mumol/L in 0.5 mL intraperitoneally) was studied. Bilirubin treatment significantly stimulated the phagocytosis of both peripheral blood granulocytes and monocytes; the increase of phagocytosis persisted for 6 h after bilirubin injection. The potential immunostimulating and/or immunotoxic effect of bilirubin is discussed.

Animals↗
PubMed1984

Effect of bilirubin on an in vitro correlate of cell-mediated immunity--the migration inhibition test.

The effect of bilirubin on one of the basic cell-mediated immunity reactions, i.e. the migration inhibition test was assessed. For this purpose the model of tuberculin hypersensitivity in rabbits was employed and the effect of bilirubin was studied on the migration inhibition test and its two main phases; the process of MIF production and the effect of already preformed MIF on the effector system. It was found that the neutralizing effect of bilirubin on the migration inhibition (caused by specific antigen) was due to the effect of bilirubin on the process of MIF production.

Animals↗
PubMed1982

Comparative phagocytosis of cadmium microcrystals by peripheral blood glass-adherent cells of newborn and healthy adults.

Microcrystals of cadmium, saturated with human serum albumin, were employed as a microassay for phagocytosis by glass-adherent blood cells. Using this assay, it was found that leukocytes of newborns possess significantly higher phagocytic activity and that a higher proportion of active phagocytic cells is present in newborns than in adults. In contrast, adult sera contain higher level of opsonins for cadmium microcrystals than cord sera. Heat inactivation and zymosan absorption of both adult and cord sera decreased significantly the opsonic power of sera, thus suggesting the participation of complement in opsonization of these particles.

Adult↗