Cytokine production in major depressed patients before and after clomipramine treatment.

Cytokine production by peripheral blood mononuclear cells (PBMC) was assessed in 10 major depressed patients (5 men and 5 women) before and after 4 weeks of clomipramine treatment and in age- and gender-matched healthy controls. A significant reduction in interleukin-1B (IL-1B), interleukin-2 (IL-2) and interleukin-3-like activity (IL-3-LA) was observed in untreated depressed patients when compared to controls. IL-1B and IL-3-LA synthesis was significantly increased after drug treatment. The suppression of cytokine production by PBMC in depressed patients may be attributed to the depression per se, or it may be related to depression-associated hyperactivity of the hypothalamic-pituitary-adrenal axis. The mode of interaction between depression and cellular immune function and the mediators responsible for the reduced cytokine production need to be studied further.

Cytokine production in obsessive-compulsive disorder.

Cytokine production was previously demonstrated to be reduced in untreated major affective patients. In addition, recovery from depression following clomipramine (CMI) treatment was accompanied by the restoration of interleukin-1 beta (IL-1 beta) and interleukin-3-like activity (IL-3-LA) to normal range. In the present study we assessed the in vitro production of IL-1 beta IL-2, and IL-3-LA by peripheral blood mononuclear cells (PBMC) in 11 nondepressed patients with obsessive compulsive disorder (OCD) before and after 8 weeks of CMI treatment. Results were compared with those of 11 healthy subjects. CMI treatment induced a significant improvement in OCD symptoms. No alteration was observed in cytokine production in OCD patients before treatment as compared to control subjects. Moreover, 8 weeks of drug treatment had no effect on cytokine production. In conclusion, OCD per se, as well as CMI treatment, have no effect on interleukin production as measured in this study.

Immunomodulatory effect of peripheral benzodiazepine receptor ligands on human mononuclear cells.

Immunomodulatory effect of ligands active at the peripheral benzodiazepine receptor (PBR) was examined in human peripheral blood mononuclear cells (PBMC). Ro5-4864, PK11195 and diazepam suppressed phytohemagglutinin (PHA) and concanavalin A (ConA) induced proliferation of PBMC. All three ligands inhibited interleukin-3-like activity (IL-3-LA) secretion, while the production of interleukin-2 (IL-2) was inhibited by Ro5-4864 and diazepam only. The selective central benzodiazepine ligand clonazepam did not affect the cellular immune functions examined. Our results indicate an in-vitro immuno-suppressive activity of peripheral and mixed, but not central type benzodiazepine ligands.

The effect of partial splenectomy on platelet production in mice.

The effect of total and partial splenectomy on the number and production of circulating platelets was studied in mice. Five days after total and partial splenectomy the number of the peripheral blood platelets increased by 87% and 60%, respectively and the incorporation of 75selenium methionine (75Se-Met) into platelets was enhanced indicating that the thrombocytosis was due to increased platelet production. The results obtained by the two operative procedures were compared. Since previous work from our laboratory has shown that a factor produced by splenic lymphocytes affects the platelet number in mice, it is suggested that the differences in the number of circulating platelets observed in animals after total and partial splenectomy may reflect a difference in the number of spleen lymphocytes removed.

SEM observations on the mechanism of platelet release from megakaryocytes.

Normal human bone marrow megakaryocytes were examined with the scanning electron microscope (SEM) to clarify the mechanism of platelet release. Several types of megakaryocytes were dtected according to their surface appearance, i.e. with wrinkles, ridges, villous formations, round blebs and cells with platelets still attached to the cell membrane. These observations are consistent with the concept that bleb formation is at least one of the mechanisms for platelet liberation.

Cytokine production in anorexia nervosa.

The capacity of peripheral blood mononuclear cells (PBMCs) of anorexia nervosa (AN) patients to produce interleukin-1 (IL-1), interleukin-2 (IL-2), and interleukin-3-like activity (IL-3-LA) was studied. A significantly lower (-49%, p < 0.005) capacity to synthesize IL-2 and an almost significantly impaired ability (-35%, p = 0.058) to release IL-3-LA by PBMCs of AN patients was found, as compared with cells of the control group. IL-1 production, either spontaneous or after stimulation with lipopolysaccharide (LPS), did not differ significantly between AN patients and healthy subjects. The lessened capacity to produce IL-2 was accompanied by an enhanced stimulatory activity of the patient sera on the production of this cytokine by PBMCs of healthy subjects. It is therefore suggested that the serum of AN patients contains a stimulatory factor or factors for cytokine production that compensates for the lower production of cytokines by AN PBMCs. Such a compensatory mechanism may explain why AN patients do not have an higher susceptibility to infections.

Effect of human colostrum on interleukin-2 production and natural killer cell activity.

The effect of human colostrum on the production of interleukin-2 (IL-2) and on natural killer (NK) cell activity by peripheral blood mononuclear cells (PBMC) was investigated in 50 healthy women. At concentrations as low as 0.5%, human colostrum stimulated IL-2 production; at a higher concentration (10%), IL-2 secretion was inhibited. A time and dose dependent inhibitory effect of colostrum on NK cytotoxicity was also observed. This inhibition could be reversed by the addition of human recombinant IL-2 (hrIL-2). The stimulation of IL-2 production induced by human colostrum might compensate for its inhibitory effect on NK cell activity. These findings suggest an additional mechanism by which breast feeding may affect the neonatal immune system.

Quantitative determination of human plasma erythropoietin using embryonic mouse liver erythroblasts.

An in vitro bioassay for the quantitative detection of erythropoietin (Ep) in human plasma is described. The method is based on the increased 3H-uridine incorporation into 12-day embryonic mouse liver erythroblasts due to Ep. It was found that 11 out of 12 anaemic patients showed high plasma Ep level, while 7 out of 8 patients suffering from polycythaemia revealed low Ep values. In 4 out of 8 patients with chronic renal failure the Ep level was within the normal range, whereas in the remaining 4 it was higher than normal. The relative simplicity of the method and the reproducibility of the results make it useful even in the routine laboratory.

Pattern of liver erythropoiesis in embryos of polycythemic mice.

Polycythemia induced by hypoxia in pregnant mice caused a marked reduction in the total number of erythroid precursors in the 10th, 11th, and 12th day embryonic livers, as compared with controls. In addition, the maturation of the erythroid precursors in the 11th day embryonic livers of polycythemic mice was markedly inhibited in comparison with that of controls, whereas on the following days of gestation the erythropoiesis in embryonic livers of both polycythemic and control mice exhibited a similar pattern. It is suggested that the reduced erythropoiesis in the 11th day embryonic liver of polycythemic mothers provides a stimulation for embryonic erythropoietin production. Subsequently, it triggers the maturation of progenitor erythroid cells in the livers and induces an increased erythropoietic activity in the plasma of 12th and 13th day pregnant polycythemic mice as was observed in our previous study.

Increased erythropoiesis in embryonic spleen of polycythemic mice. An indicator for erythropoietin production by the embryo.

The hemopoietic events in the embryonic mouse spleen were investigated in fetuses of polycythemic mothers. 12th and 13th day embryonic spleens showed a marked increase in the number of erythroid precursors at an advanced maturation stage, as compared to controls. In addition, an increased erythropoietic activity, measured by 59Fe incorporation into red blood cells of posthypoxic polycythemic mice, was found in the plasma of 12th and 13th day pregnant polycythemic mice, compared with controls, i.e. plasma of nonpregnant nonpolycythemic mice, of nonpregnant polycythemic mice, and of 12th and 13th day pregnant nonpolycythemic mice. Since polycythemic mice are presumed to have low erythropoietin level, the stimulation of erythropoiesis in the embryonic spleens of polycythemic mothers suggests that fetal erythropoiesis is independent of the maternal one. Moreover, the present results indicate that fetuses of polycythemic mothers not only produce their own erythropoietin, but are also able to increase markedly the maternal erythropoietin as a consequence of hypoxemic conditions.

The effect of nifedipine on protein synthesis and surface morphology of peripheral blood cells.

Peripheral blood polymorphonuclear cells, lymphocytes, and platelets, incubated with nifedipine, showed a marked dose-dependent inhibition of the cell capacity to synthesize proteins. The possible role of the drug as a Ca2+ blocker for the explanation of this finding is discussed. In addition, the drug induced surface alterations in all three cell types, the most prominent being observed on the platelets which showed elongation of their pseudopodia. This phenomenon, accompanied by an increase in the negative membranal electric charge, may explain the previously reported inhibition of platelet aggregation caused by nifedipine.

Effect of lipid emulsion on IL-2 production by mononuclear cells of newborn infants and adults.

The in vitro effect of a lipid emulsion (intralipid) on interleukin-2 (IL-2) production by cord blood mononuclear cells (CBMC) of preterm and term newborn infants was examined and compared to that of peripheral blood mononuclear cells (PBMC) of adults. Intralipid, added at concentrations accepted in clinical practice, caused a dose-dependent inhibition of IL-2 activity tested by bioassay. IL-2 levels, tested by radioimmunoassay (RIA), were found to be reduced only in supernatants derived from CBMC of term infants and not in those derived from MC of preterm infants or adults. The capacity of the IL-2 dependent cell line CTLL-2 to respond to IL-2 was abolished in the presence of intralipid, suggesting an interference with the binding of IL-2 to its receptor on these cells. It is conceivable that administration of intralipid to preterm infants may interfere with the binding of IL-2 to the specific receptors on their activated lymphocytes, with a possible subsequent suppression of their immune response.

Ultrastructural observations on mast cell degranulation and its prevention.

The surface alterations of rat peritoneal mast cells during degranulation induced by calcium chloride (CaCl2) and its prevention by salbutamol sulfate (Sal. Sulf.), chlorpheniramine maleate (CM), and disodium cromoglycate (DSCG) were followed with a scanning electron microscope. CaCl2 caused a protuberation of the cytoplasmic granules already after 30 s, an advanced degranulation after 60-75 s, and a complete destruction of the cells after 180 s of incubation. The degranulation process was prevented by Sal. Sulf., CM, and DSCG. A comparison of the surface changes induced by these agents with the ultrastructural findings observed with a transmission electron microscope showed that neither Sal. Sulf. nor CM prevented the alterations of the internal structure of the cells, suggesting that these substances act mainly on the cytoplasmic membrane. The best prevention for both the surface and the internal structure of the cells was obtained by DSCG, indicating that this substance is a stabilizer of both membrane and internal organelles of the mast cells.

Transfer of iron-dextran across the placenta.

In pregnant mice. 55Fe-labeled iron-dextran (Imferon) is transferred across the placenta. It was detected in the bone marrow, liver, spleen and peripheral blood of the pregnant animal, as well as in the embryonic liver erythroid precursors and peripheral blood. Uptake by liver and peripheral blood cells of pregnant anemic mice and by liver erythroid precursors of anemic embryos was significantly higher than in normal control animals. Electron-microscopic examination revealed that the iron deposits in the embryonic liver erythroid precursors had the same structure as the injected Imferon.

Ultrastructural and functional studies on human platelets incubated with diclofenac sodium (Voltaren).

The in vitro effect of diclofenac sodium (Voltaren) on the ultrastructure of healthy donors' platelets was examined and compared with those induced by aspirin (ASA). In distinction to ASA, which causes loss of platelet pseudopodia, Voltaren induced an increase and marked elongation of these pseudopodia. The implication of this finding in the explanation of the decreased platelet aggregation caused by the drug is discussed. Voltaren increased the phagocytotic activity of the individual platelet, although the overall ability of the cells to phagocytize latex particles was not markedly increased. Platelets incubated with Voltaren showed a decrease in their total protein synthesizing capacity. Voltaren did not exert any effect on the internal ultrastructure, platelet factor 3, and calcium content of the incubated platelets.

Synthesizing activity and ultrastructural findings of human blood cells after incubation with cis-platinum "in vitro".

The synthesizing activity and ultrastructural appearance of human polymorphonuclears, lymphocytes and platelets obtained from healthy donors were examined after incubation with cis-platinum (cis-Pt). The drug caused a statistically significant inhibition of DNA, RNA and protein synthesis of the lymphocytes, but their ultrastructure appeared unchanged. On the other hand, incubation of polymorphonuclears with cis-Pt did not affect their protein synthesis but caused a decrease in the number of cytoplasmic granules, mitochondrial alterations, and appearance of membrane ruffles. The drug induced neither inhibition of platelet protein synthesis, nor ultrastructural alterations. The selective effect of this drug on the synthesizing activities of human lymphocytes may be of potential value in the treatment of lymphoproliferative and immunological disorders in man.

The effect of tetracycline administration on iron absorption in mice.

The effect of perorally administered tetracycline, chloramphenicol and streptomycin, antibiotics known as inhibitors of protein synthesis, on the iron absorption in mice was examined. Tetracycline caused a marked decrease in iron absorption observed shortly after its administration. On the other hand, both chloramphenicol and streptomycin caused a marked increase in iron absorption. There was no difference between results when bivalent or trivalent iron was given. The possible mechanisms for the explanation of the effect of these antibiotics on iron transfer through the small intestine mucosa are discussed.

Effects of anesthesia based on large versus small doses of fentanyl on natural killer cell cytotoxicity in the perioperative period.

Surgical stress and general anesthesia suppress immune functions, including natural killer cell cytotoxicity (NKCC). This suppression could be attributable, at least in part, to opiates. We have previously shown that large-dose fentanyl administration suppressed NKCC in rats. The present study sought to compare the effects of two anesthetic protocols, based on large- (LDFA) versus small (SDFA)-dose fentanyl anesthesia on NKCC in the perioperative period. Forty patients were included in this study; half were assigned to each protocol of anesthesia. In each anesthetic group, half the patients were undergoing surgery for malignant diseases, and half for benign conditions. Blood samples were collected during the perioperative period. NKCC was assessed using the chromium release assay. Initially, both types of anesthesia similarly suppressed NKCC, with a peak effect 24 h after surgery. The two types of anesthesia, however, differed in the rate of recovery of NKCC suppression. By the second postoperative day, NKCC returned to control values in the SDFA patients, whereas NKCC was still significantly suppressed after LDFA. These results indicate that LDFA causes prolonged suppression of NK cell function. Whether this suppression might have a long-term impact on the overall outcome, especially in cancer patients, remains to be determined.

IL-2 receptor gene expression and IL-2 production by human preterm newborns' cells.

IL-2 receptor (IL-2R) gene expression in human umbilical cord blood mononuclear cells (CBMC) of preterm and term newborns was examined following stimulation for 18 h with phytohaemagglutinin (PHA) and compared with that of adult peripheral blood mononuclear cells (PBMC; mothers and control group). mRNA for IL-2R could not be detected in CBMC of preterm infants, whereas the mRNA levels for IL-2R found in full term neonates were similar to those observed in PBMC of adults. IL-2 activity in conditioned medium (CM) of mononuclear cells stimulated with either optimal or suboptimal PHA concentrations for 24 h and 48 h was also determined. At 24 h of stimulation, IL-2 activity found in CM obtained from CBMC of preterm and term newborns was significantly higher than that found in CM of adults' PBMC. A further enhancement of IL-2 activity (six to eight times) was observed in CM of preterm and term cells stimulated for 48 h, whereas no significant difference was found in IL-2 activity in CM from adult cells tested at the two incubation periods. The present findings may provide an additional explanation for the impaired function of the immune system, and the high susceptibility to infections observed in preterm newborns.

IL-1 beta and IL-3-like activity in preterm infants.

The capacity of peripheral blood mononuclear cells (PBMC) of preterm neonates to release IL-1 beta and IL-3-like activity (IL-3-LA) has been investigated. In the present study it was found that this capacity is significantly lower than that of their mothers and of control adults. In addition, the results showed that preterm serum has a lower stimulatory effect on IL-1 beta production and an inhibitory effect on IL-3-LA secretion by PBMC of adult controls, in comparison with maternal and adult sera. These findings suggest an additional feedback mechanism for control of haematopoiesis in premature neonates. It is possible that the lower production of IL-1 beta and IL-3-LA may be involved in the increased susceptibility to infections of preterm newborns.