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Biomedical subjects

H Bessler

Publications and source records attributed to H Bessler.

At least 55 records · Page 3Linked to original sources

Peripheral-type benzodiazepine receptor ligands modulate human natural killer cell activity.

Following our earlier work, we evaluated the in vitro effect of ligands active at the peripheral-type benzodiazepine receptors on human natural killer cell activity. Peripheral blood mononuclear cells were incubated with benzodiazepine receptor ligands. After 4 h we observed a nonspecific inhibition of natural killer cell activity induced by both peripheral (Ro5-4864 and PK 11195) and central (clonazepam) benzodiazepine receptor ligands; after 24 h, the suppressive activity was specific to peripheral and mixed (diazepam) ligands, and the central-type ligand had no effect. This significant, specific suppression of NK cell activity was completely reversed by the addition of human recombinant interleukin-2 or human leukocyte interferon. Our research provides additional information on the immunomodulatory effects of peripheral-type benzodiazepine ligands. Further studies are needed to clarify the underlying mechanism of natural killer cell inhibition and to determine the clinical implications of these findings.

Humans↗

Elevated serum ferritin level in acute myocardial infarction.

Serum ferritin level was determined in 20 patients with acute myocardial infarction (AMI) during the first 10 days post infarction. Starting on the second day, a gradual increase in serum ferritin level was detected, reaching a maximum of four times the initial level on the sixth day after the infarction. In addition, a significant increase in ferritin content was found in the peripheral blood monocytes on the fifth day after the event. The control group comprised six patients suffering from chest pains not due to AMI. In all of them the serum ferritin level was found to be within normal limits. Peripheral blood monocytes derived from healthy individuals incubated with hydrocortisone, showed a significant enhancement of their ferritin content, a finding suggesting that these cells activated by steroids during stress could be a source of the increased serum ferritin level following AMI. It is concluded that measurement of serum ferritin may be used as a complementary tool for confirming the diagnosis of AMI.

Aged↗

Ultrastructure of human colostral cells.

The ultrastructural architecture of colostral cells of mothers of pre- and full-term infants is described. The polymorphonuclears were engaged in vivid phagocytosis of fat droplets. Similar findings were observed on the macrophages. The lymphocytes appeared normal in size and ultrastructure. A small number of eosinophils and basophils were also detected. The number of colostral cells was higher in the colostrum of mothers of preterm newborns. The number of the cells in the colostrum in mothers of both groups decreased with advancement of lactation.

Animals↗

Significant inhibition of spontaneous IgA secretion by selective peripheral-type benzodiazepine receptor ligands.

The in vitro effect of benzodiazepine (BZ) receptor ligands on the secretion of immunoglobulin isotypes IgM, IgG, and IgA by human peripheral blood mononuclear cells (PBMCs) was examined. It was found that the specific peripheral-type BZ receptor (PBR) ligands (Ro5-4864 and PK 11195) inhibit the spontaneous secretion of IgA by human PBMCs in a dose-dependent manner, in the micromolar range. The decreased secretion of IgG and IgM induced by these ligands did not reach significant levels. The mixed BZ ligands (diazepam and flunitrazepam) had no consistent or significant effect on the production of the three immunoglobulin isotypes tested in the current study. The central-type ligand (clonazepam) did not affect IgM, IgG, or IgA secretion. The significant inhibitory effect of PBR ligands was confined to the spontaneous secretion of IgA by human PBMCs, and no such effect was detected in cells stimulated by pokeweed mitogen to produce immunoglobulins. It seems that PBR ligands are capable of suppressing spontaneous IgA secretion, but fail to affect the augmented production induced by mitogen.

Anti-Anxiety Agents↗

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.

Adult↗

Ultrastructural observations on bone marrow cells of 26 patients with myelodysplastic syndromes.

Bone marrow aspirates from 26 patients with myelodysplastic syndrome (MDS) were examined using transmission electron microscopy. The red blood cell precursors in 9 patients showed varying degrees of dyserythropoiesis including the presence of 2 or more nuclei, nuclei with bizarre shape and iron deposits in the mitochondria. The myeloid series showed a tendency to hypogranulation (5 patients) and in 2 patients there were signs of platelet phagocytosis. The monocytes had a normal ultrastructure except for one patient with chronic myelomonocytic leukemia (CMML) with transformation to acute myelo-monocytic leukemia (AMML). In this case, the monocytes were immature, with markedly convoluted nuclei and scanty heterochromatin. The lymphocytes also had a normal appearance, except for one patient in whom the lymphocytes were immature, with lobulated nuclei and suggested transformation of MDS to acute lymphoblastic leukemia. The plasma cells in 3 patients were slightly increased in number and in one of them Russell bodies were seen both in the cytoplasm and the nucleus. The megakaryocytic series showed a shift to the left and in one patient there were signs of emperipolesis. The alterations in the hematopoietic cells in patients with MDS described in the present study indicate that the electron microscope may supplement light microscopic findings and help in the establishment of a correct diagnosis. This may be also evident in those cases of MDS in which the very early stages of leukemic transformation cannot be easily detected by light microscopy.

Adolescent↗

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.

Adult↗

Vincristine-induced alterations in Schwann cells of mouse peripheral nerve.

The sciatic nerve of C57Bl mice was examined with a transmission electron microscope to study the ultrastructural alterations in Schwann cells following treatment with escalating doses of vincristine. Results indicated that the drug exerts a dose-related effect. Total doses up to 8 micrograms/mouse did not cause any visible damage to Schwann cells. Higher doses induced not only damage to individual cells, but also affected a greater percentage of them. The myelin sheath was the most affected organelle. Schwann cells of myelinated fibers showed greater damage than those of unmyelinated fibers.

Animals↗

Effect of oral chemotherapy on the mitochondrial size of mouse intestinal cells.

Since orally given cytotoxic agents may cause intestinal disfunction, the effect of oral administration of three cytotoxics, i.e., methotrexate (MTX), cyclophosphamide (CPA), and ftoral, a derivative of 5-fluorouracil (5-FU), on the gastric, liver, and small-intestine cells of C57B1 mice was studied by transmission electron microscopy. Although no ultrastructural alterations could be detected in the cells of the first two organs, the epithelial cells of the small intestine showed a marked increase in size of their mitochondria. In the control animals the mitochondrial size was in the range of 0.04-1.8 micron (mean +/- SE 0.54 +/- 0.01 micron). In the treated animals the size of the mitochondria ranged between 0.15 and 4.33 micron (mean +/- SE 0.73 micron) for those treated with MTX, 0.24-2.88 micron (mean +/- SE 0.80 +/- 0.02 micron) for those given CPA, and 0.28-5.3 micron (mean +/- SE 1.18 +/- 0.48 micron) for those treated with 5-FU. These findings were significantly different from those obtained in controls (P < 0.0001). In addition, in animals treated with MTX the mitochondria of the jejunal cells were surrounded by channels of rough endoplasmic reticulum. The cytoplasm contained long, winding channels of smooth endoplasmic reticulum, vacuoles, and myelin figures. Fluid retention in the small intestine due to administration of cytotoxic drugs is suggested as a possible mechanism for distention of the mitochondria.

Administration, Oral↗

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.

Adult↗

Effect of dexamethasone on IL-2 and IL-3 production by mononuclear cells in neonates and adults.

The effect of dexamethasone on interleukin 2 (IL-2) and interleukin 3 (IL-3) production by mononuclear cells in preterm and term infants and adults was evaluated. The capacity of mononuclear cells to produce these cytokines, in preterm infants with bronchopulmonary dysplasia (BPD) and treated with dexamethasone, was compared with that before treatment. Twenty six preterm and 36 term neonates and 24 healthy adults were included in the study. Mononuclear cells isolated from neonatal cord blood (CBMC) and adult peripheral blood (PBMC) were stimulated with phytohaemagglutinin (PHA) in the absence or presence of dexamethasone at concentrations between 10(-8)M and 10(-5)M. IL-2 and IL-3 activities in the supernatant fluids were tested using bioassays. The in vivo effect of the drug on the production of these cytokines by PBMC in 10 preterms was determined before and 24 hours after dexamethasone administration (0.5 mg/kg/day). The production of both cytokines was inhibited in a dose dependent manner. A difference in the sensitivity of mononuclear cells to the inhibitory effect of the drug was found between neonatal cord blood cells and adult PBMC, the former being more sensitive. PBMC from preterm infants treated with dexamethasone for BPD produced significantly less IL-2 and IL-3 as early as 24 hours after the initiation of the treatment (43% and 31%; P < 0.05, respectively). It is concluded that mononuclear cells from preterm and term neonates are more sensitive to the inhibitory effect of dexamethasone on IL-2 and IL-3 production.

Adult↗

Human colostrum stimulates cytokine production.

The effect of human colostrum on the production of IL-1, IL-3 and IL-6 by peripheral blood mononuclear cells (PBMCs) has been investigated. The aqueous phase of human colostrum significantly stimulated the production of these three cytokines. These findings show the importance of breast feeding not only as a well-balanced nutrient supply but also as a source for growth-promoting factors. It is suggested that the enhanced secretion of IL-1, IL-3 and IL-6 induced by human colostrum may compensate for the lower capacity of neonatal PBMCs to produce these cytokines. It is also possible that, by stimulating the secretion of these cytokines, breast feeding may provide an additional mechanism for the regulation of the neonatal immune system and hematopoiesis.

Colostrum↗

Effect of high doses of 2-CdA on Schwann cells of mouse peripheral nerve.

The present study was undertaken to examine the effect of 2-CdA (Leustatin) on the Schwann cells of myelinated and unmyelinated fibers of peripheral mouse nerve. Two groups of mice were injected intravenously for seven days with 2-CdA: one group received daily doses of 1 mg/kg and the other 0.5 mg/kg. Both doses exceeded those accepted in clinical practice. Mice injected with saline served as controls. The sciatic nerve was then dissected and examined with a transmission electron microscope. The Schwann cells of both the myelinated and unmyelinated nerve fibers of the animals receiving the higher doses of 2-CdA showed nuclear and nucleolus damage, loss of heterochromatin, vacuolization and disorganization of the myelin sheaths. The mesaxons and the axons were also damaged. The Schwann cells of the animals treated with the lower doses appeared undamaged. The results indicate that in contrast to other anticancer drugs known to produce peripheral neuropathy, 2-CdA may cause damage to the Schwann cells only at doses exceeding the therapeutic ones.

Animals↗

The effect of acyclovir on the proliferative capacity of mononuclear cells from patients with chronic lymphocytic leukemia.

The cellular response of peripheral blood mononuclear cells (PBMC) from patients with B-cell chronic lymphocytic leukemia to increasing doses of acyclovir was examined by their capacity to incorporate 3H-TdR, and their response to phytohemagglutinin, concanavalin A and pokeweed mitogen. PBMC from healthy donors served as controls. Acyclovir caused a dose-dependent inhibition of 3H-TdR incorporation and mitogenic response in both leukemic and control cells, the effect on the latter being more pronounced. Although the results suggest that leukemic cells are less vulnerable than the controls, the toxic effect of acyclovir on the cellular immune response should be considered in the treatment of leukemic and other immunosuppressed patients.

Acyclovir↗

Cytokine production in drug-free and neuroleptic-treated schizophrenic patients.

A line of evidence indicates changes of the immune system in schizophrenic patients. We investigated the production of cytokines by peripheral blood mononuclear cells (PBMCs) in drug-free and neuroleptic-treated schizophrenic patients compared to healthy, normal controls. A significant reduction in interleukin (IL)-2 production was detected in untreated schizophrenic patients (-59.6%; p < .05) as well as in IL-3-like activity (IL-3-LA) production (-27.4%; p < .05) in treated patients compared to controls. No alteration was observed in IL-1 beta production. It seems that schizophrenia is associated with diminished IL-2 production, while neuroleptic treatment interferes with the capacity of immunocompetent cells to synthesize and/or release Il-3-LA. The alteration in cytokine production did not correlate with either the severity of the disorder or the serum prolactin levels.

Adult↗

Interferon alpha-2b modulates beta-galactoside alpha-2,6-sialyltransferase gene expression in rat testes.

Sperm surface glycoproteins are modified during passage through the epididymis, a process believed to be important in the production of functionally mature spermatozoa. The effect of various cytokines on reproductive events has recently been investigated, with conflicting results. In the present investigation, the effect of interferon-alpha-2b (IFN alpha 2b) on sialyltransferase (ST) activity and beta-galactoside alpha-2,6-sialyltransferase (Gal 2,6-ST) mRNA expression was studied in rat testicular tissue. The results revealed the presence of Gal 2,6-ST mRNA in rat testicular tissue, similar in molecular size to that found previously in rat spleen, lung, ovary, kidney, heart, and brain. In addition, we observed that IFN alpha 2b reduced Gal 2,6-ST mRNA and ST activity in rat testes by a comparable magnitude. These findings provide insight into an additional mechanism by which cytokines may affect the reproductive system.

Animals↗