Biomedical subjects

H Bessler

Publications and source records attributed to H Bessler.

At least 37 records · Page 2Linked to original sources

PubMed2000

Interleukin-3 and stress.

The importance of cytokines as mediators in numerous physiologic and pathologic processes became apparent in the early seventies. In a relatively short period of time the number of characterized and functionally defined interleukins increased rapidly. Concomitantly, the understanding of their role in various important reactions in different systems of the organism in general, and in the interaction between the immune, central nervous and neuroendocrine systems in particular increased. IL-3 is one of the cytokines of great significance for hematopoiesis. In addition, it was shown that interleukin-3 (IL-3) participates in the response of the organism to various types of stress. Surprisingly enough, the reports on its production and activation during or following stress are rather scarce. Therefore, the purpose of this review is to try and compile the information on IL-3 and its role in different types of stress, and also to contribute our own modest experience on the subject.

Animals↗

PubMed2000

Effect of diazepam on the immune response of rats exposed to acute and chronic swim stress.

To examine the effect of the anti-stress agent diazepam on the immune response, rats were exposed either to acute swim stress, i.e., swimming once only for 30 minutes (non-trained swimmers), or to chronic stress with gradual progressive training for 6 weeks (trained swimmers). Both groups of animals were divided into subgroups treated before swimming with and without diazepam, 1 mg/kg, administered i.m. The phagocytic capacity and superoxide anion generation of the peritoneal macrophages was examined. In addition, the proliferative response of the splenic cells (splenocytes) to concanavalin A (Con A) and phytohemagglutinin (PHA), as well as the serum corticosterone levels were investigated. Diazepam abolished increased superoxide anion production in both non-trained and trained swimmers. In non-trained swimmers, the number of latex particles internalized by each cell was decreased and further reduced by the drug. In trained rats treated with diazepam, the percentage of phagocytosing cells remained reduced compared to controls, whereas the drug prevented a decrease in the engulfing capacity of individual cells. Diazepam lowered the suppressed proliferative response of the splenocytes to PHA found in non-trained swimmers. It is concluded that diazepam modifies the immune response of rats exposed to acute and chronic swim stress.

Animals↗

PubMed2000

Effect of cefotaxime on cytokine production in newborns and adults in vitro.

The in vitro effect of cefotaxime on the production of interleukin (IL)-1beta, IL-2, IL-6 and tumor necrosis factor alpha (TNFalpha) was studied in term neonates and was compared with that of adults. The addition of cefotaxime caused a significant enhancement of IL-2 production by cells of both adults and neonates, and increased the secretion of TNFalpha by peripheral blood mononuclear cells (PBMC) of adults, whereas the synthesis of this cytokine by cord blood mononuclear cells (CBMC) of the newborns was not affected. In contrast with the described stimulatory effects of cefotaxime, this drug induced dose-dependent inhibition of the spontaneous and lipopolysaccharide (LPS)-induced IL-1beta production by cells of the two groups, but had no effect on the in vitro production of IL-6. These data suggest that cefotaxime, apart from its known antimicrobial activity, may modify the host immune response of both newborns and adults, via the alteration of cytokine production.

Adult↗

PubMed2000

Hypothermia affects the phagocytic activity of rat peritoneal macrophages.

To examine the effect of hypothermia on the phagocytic capacity of rat peritoneal macrophages for latex particles, male Wistar rats were exposed to 4 degrees C for 8 and 72 h. While the shorter exposure to cold did not affect body temperature and macrophage function, animals exposed to 4 degrees C for 72 h showed a mean decrease of their body temperature by 1.5 degrees C. The superoxide anion production was significantly increased whereas the number of phagocytic cells decreased. In addition, the mean number of latex particles engulfed by each individual cell was lower than that of controls. Peripheral blood mononuclear cells (PBMC) of these animals showed lower mitogen response to phytohaemagglutinin (PHA), while that for concanavalin A (Con-A) remained unchanged. Peritoneal macrophages exposed in vitro to 24 degrees C for 60 min showed a decreased phagocytic capacity in comparison with macrophages kept at 37 degrees C, an observation suggesting the development of an indigenous cell defect for phagocytosis at lower temperatures. On the other hand, the effect of additional humoral factor(s) on macrophage activity, such as an increase in serum level of catecholamines and corticosterone, cannot be excluded. The results of the study may contribute to understanding the predisposition to infections during exposure to cold.

Animals↗

PubMed2000

Effect of indomethacin on IL-1beta, IL-6 and TNFalpha production by mononuclear cells of preterm newborns and adults.

The in vitro effect of indomethacin (IM) on the production of interleukin (IL)-1beta, IL-6 and tumor necrosis factor (TNF)alpha by cord blood mononuclear cells (CBMC) from preterm newborns was compared to that of peripheral blood MC of adults (PBMC). MC isolated from peripheral blood of adults (PBMC) and cord blood of preterm newborns (CBMC) were incubated without or with lipopolysaccharide (LPS) in the absence or presence of various concentrations of IM. The levels of IL-1beta, IL-6 and TNFalpha in the supernatants were tested by ELISA. MC isolated from preterm newborns were less sensitive to the in vitro effect of IM on IL-1beta and TNFalpha secretion than adult cells. While the spontaneous secretion of IL-1beta and TNFalpha and the production of TNFalpha induced by LPS were significantly increased following incubation of adult PBMC with IM, only the spontaneous synthesis of TNFalpha by CBMC of preterm newborns was affected by this drug. The in vitro production of IL-6 by MC in the two groups was not affected by the addition of IM. It is suggested that IM may affect the preterm's immune response. However, the role of the drug in the frequency and severity of infections in the neonatal intensive care unit needs further investigation.

Adult↗

PubMed1999

Decreased phagocytic capacity of rat peritoneal macrophages following photon abdominal irradiation.

Photon irradiation of the abdomen may be accompanied by complications due to a decrease in the immune defense of the recipient. Since peritoneal macrophages are an important component of the immune system, we examined the phagocytic activity and oxygen superoxide anion generation by peritoneal macrophages from rats 2 and 4 weeks after abdominal irradiation with 6 MV photons applying a single dose of 2 Gy. Two and 4 weeks after irradiation, peritoneal macrophages were harvested and their capacity to engulf latex particles and to produce oxygen superoxide anions was determined. Non-irradiated rats, treated identically otherwise, served as controls. Two weeks after irradiation the phagocytic capacity and oxygen superoxide anion generation decreased by 61 and 70%, respectively, compared with controls. This tendency persisted after 4 weeks post irradiation, the decrease in both functions being 50 and 74%, respectively. It is suggested that the altered function of peritoneal macrophages following irradiation may further compromise the immune defense in patients receiving abdominal radiotherapy.

Abdomen↗

PubMed1999

The effect of interferon on mouse myocardial capillaries: an ultrastructural study.

BACKGROUND: Cardiotoxicity, including ischemia and myocardial infarction, is one of the complications observed after treatment with interferon (IFN). Therefore, the question has been raised whether IFN may cause damage to the small myocardial blood vessels. METHODS: In this study, 400 U of IFN-alpha-2b per g of body weight were injected intraperitoneally into 2 groups of C57 B1 mice, 5 days a week for 3 and 5 months, respectively. Thin sections of the myocardium were examined with a transmission electron microscope and the ultrastructure of the capillaries was compared with that of control animals. RESULTS: The results showed a statistically significant increase in the thickness of the endothelial processes of the myocardial capillary walls in the mice treated with IFN, with a subsequent decrease in the size of the capillary lumen. The entire capillary area was not affected. CONCLUSIONS: These findings may serve as an additional explanation for the cardiac complications observed in patients treated with IFN.

Animals↗

PubMed1999

Phototherapy for neonatal hyperbilirubinemia affects cytokine production by peripheral blood mononuclear cells.

The capacity of peripheral blood mononuclear cells (PBMC) to produce interleukin (IL) IL-1beta, IL-2, IL-3, IL-6, IL-10 and tumor necrosis factor-alpha (TNFalpha) was examined in term newborns with hyperbilirubinemia after 24 hours' exposure to phototherapy (wave length 425-475 nm). The results were compared with those from untreated neonates. Fifty newborns spontaneously delivered at term were included in the study. Blood samples were collected from 20 newborns before and 24 h after phototherapy. The control group consisted of 30 neonates examined on two consecutive days. PBMC isolated from blood samples were incubated in vitro for cytokine production. The concentration of cytokines in the supernatants was tested using ELISA kits (for IL-1beta, IL-6, IL-10 and TNFalpha), or by bioassays (for IL-2 and IL-3). Phototherapy caused a 70% increase in IL-2 secretion (123 +/- 27 vs 208 +/- 30 units/ml, P < 0.01) and 56% in IL-10 production (1.07 +/- 0.19 vs 1.67 +/- 0.33 ng/ml, P < 0. 03), whereas the spontaneous secretion of IL-1beta was reduced by 43% (13.7 +/- 2.3 vs 7.3 +/- 1.7 ng/ml, P < 0.02). In the control group the secretion of these cytokines was similar on the two consecutive days and did not differ significantly from secretion in the other group before phototherapy. On the other hand, lipopolysaccharide induced TNFalpha production was higher on the second day in the two groups of newborns irrespective of phototherapy (388 +/- 58 vs 683 +/- 88 pg/ml, P < 0.001, in the control group and 384 +/- 75 vs 588 +/- 91, P < 0.05, before and after phototherapy). The synthesis of IL-3 and IL-6 did not change significantly between the two days of the study. The results demonstrate that in addition to the well-known positive effect of phototherapy on the neonate serum bilirubin level, this treatment affects the function of the immune system in newborns via alterations in cytokine production.

Cytokines↗

PubMed1999

Effect of a garlic derivative (alliin) on peripheral blood cell immune responses.

The in vitro effect of the garlic derivative alliin, on the mitogen induced peripheral blood mononuclear cell (PBMC) proliferation and cytokine production was examined. In addition, its effect on the engulfing capacity of phagocyting cells was evaluated. The results showed an increase in pokeweed mitogen (PWM) induced cell proliferation, IL-1beta and TNF-alpha production, as well as in the engulfing capacity of both percentage of phagocyting cells and number of latex particles phagocytized by each individual cell. The Con-A induced cell proliferation and IL-6 production decreased following incubation with alliin, whereas PHA-induced cell proliferation, IL-2 and superoxide anion generation remained unchanged. It is concluded that alliin in vitro exerts an immunomodulatory effect on certain functions of the peripheral blood cells.

Blood Cells↗

PubMed1999

IL-1 beta, IL-2, IL-6 and TNF-alpha production by peripheral blood mononuclear cells from patients with Parkinson's disease.

The capacity of peripheral blood mononuclear cells (PBMC) from patients with treated Parkinson's disease (PD) to produce interleukin (IL) IL-1 beta IL-2, IL-6, tumor necrosis factor (TNF)-alpha and the proliferative response to mitogens, was compared with that from cells from healthy subjects. The production of IL-2 and the mitogen response were significantly lower in PD patients, whereas the secretion of IL-1 beta, IL-6 and TNF-alpha were significantly enhanced. To evaluate the role of levodopa in creating immunological alterations, PBMC of patients and controls were incubated with concentrations of the drug extrapolated from those used in clinical practice. Levodopa caused an inhibition of mitogen-induced proliferation, stimulation of IL-6 and TNF-alpha production, whereas the secretion of IL-1 beta and IL-2 was not affected. The results of the study provide a further support for the interrelationship between the central nervous and immune system. In addition, the data indicate that the immunological alterations found in PD may be partially attributed to levodopa administration.

Cell Division↗

PubMed1999

Decreased phagocytic function in patients with Parkinson's disease.

To determine the phagocytic function of the peripheral blood polymorphonuclears from patients with treated and untreated Parkinson's disease (PD), these cells were incubated with latex particles and the number of phagocytes, as well as the number of particles engulfed by each individual cell, were counted. Cells of untreated PD patients were significantly less phagocytotic than those of matched subjects without neurological or immune disorders (24% vs. 45%, P < 0.001). In addition, phagocytes from PD patients engulfed less particles per cell than those of the controls (8.4 +/- 0.7 vs. 16.5 +/- 1.3, P < 0.001). There was no significant difference in both functions in untreated and treated PD. The results indicate that in addition to the known immune alterations in patients with PD, the ability of their peripheral blood phagocytic cells to engulf latex particles is impaired.

Female↗

PubMed1999

The effect of drug cost on hypertension treatment decision.

The cost of medical care is constantly increasing. Therefore, ways of saving expenses should be considered. The aim of the present study is to evaluate the possibility than an awareness of the cost of drugs for treatment of hypertension may affect physicians' prescription decisions. A questionnaire containing the clinical data of a young and an elderly imaginary patient with moderate hypertension was given to 30 family physicians and 30 hospital physicians together with a list of appropriate drugs (phase I). This was repeated as phase II except that for this stage the cost of the drugs was brought to the participants' attention. Knowing the cost of the drugs caused a decrease in prescription of the more expensive drugs for the younger patients; of 60% (family physicians) and 87% (hospital physicians). For their elderly patients family physicians preferred the less expensive drugs at both phases. 25% of the hospital doctors changed their preference towards less expensive drugs at phase II. For the younger patient, no correlation was found between the number of years of physicians' practice and the cost of the drugs chosen. For the elderly patient, physicians from both groups preferred less expensive drugs at phase II without any relation to their years of practice. The results of this study indicate that a knowledge of the price of the drugs may affect physicians' prescription decisions, a fact that may result in considerable saving by health providing organizations.

Adult↗

PubMed1999

Effects of dexamethasone on IL-1beta, IL-6, and TNF-alpha production by mononuclear cells of newborns and adults.

The effects of dexamethasone on the production of interleukin (IL) 1beta, IL-6, and tumor necrosis factor alpha were studied in preterm newborns, term infants, and adults. Twenty preterm and 22 term newborns and 30 healthy adults were included in the study. Mononuclear cells (MC) isolated from cord blood of newborns and peripheral blood of adults were incubated without or with lipopolysaccharide in the absence or presence of dexamethasone at concentrations between 10(-8) and 10(-5) M. The cytokine concentration in the supernatants was tested using enzyme-linked immunosorbent assay kits. Although a dose-dependent inhibition of the cytokine production was observed at pharmacological doses of dexamethasone in individuals of the three groups, differences in the intensity of the effect were observed between the groups. Spontaneous secretion of IL-1beta or IL-6 by MC of preterm neonates was less inhibited by dexamethasone as compared with cells from adults. In contrast, the inhibitory effect of the drug on lipopolysaccharide-induced IL-6 and tumor necrosis factor alpha production was more pronounced on neonatal cells. As for term newborns, MC were more sensitive to the inhibitory effect of the drug on LPS-induced IL-6 production than cells of adults. The results suggest that dexamethasone treatment of preterm newborns may affect cytokine production with a consequent modulation of the host's immune response.

Adult↗

PubMed1999

Effect of training on the phagocytic capacity of peritoneal macrophages from rats exposed to swim stress.

Since strenuous effort may affect the immune system, a study was designed to examine the impact of the progressive training of rats exposed to swim stress. Rats (trained swimmers) were forced to swim daily in a water bath for progressively longer periods. At the end of the study, which continued for a total of 6 weeks, the superoxide anion generation and phagocytic capacity of peritoneal macrophages, the mitogen response of splenic cells (splenocytes) and the serum corticosterone level were examined. The results, compared to those of animals taken in and out of their cages (nonswimmers), showed an increase in superoxide anion generation, as well as a decrease in both the percentage of phagocytosing cells and the number of particles internalized by each individual cell. In trained swimmers, the mitogen response to phytohemagglutinin and concanavalin A (Con A), as well as the corticosterone level, did not change significantly from those of nonswimmers. A third group of animals were forced to swim once only for 30 min, until the appearance of signs of marked fatigue (acute swimmers). Their peritoneal macrophages showed an increased superoxide anion generation and a significantly decreased response to Con A compared to those of the nonswimmers. The serum corticosterone level in acute swimmers was found to be increased compared to that of an additional group of animals kept at complete rest. The findings indicate that the progressive training of rats exposed to swim stress does not prevent alterations in certain immune responses, a fact that should be considered by intensive exercisers.

Animals↗

PubMed1998

Effect of sodium thiopentone anesthesia on the phagocytic activity of rat peritoneal macrophages.

To elucidate the effect of sodium thiopentone anesthesia on the function of phagocytic cells, albino rats were anesthetized with 60 mg/kg. of sodium thiopentone. After 90 min., peritoneal macrophages were harvested and their capacity for superoxide anion generation was detected. Following anesthesia for 90 min. latex particles were injected intraperitoneally, and after additional 30 min. the macrophages were derived, embedded in agar and the number of cells engaged in phagocytosis, as well as the number of latex particles engulfed by each individual cell were counted in semi-thick sections. Macrophages of anesthetized animals showed a statistically significant decrease of both superoxide anion generation and mean number of phagocytic cells, and engulfed fewer particles than those of the controls. Similar results were obtained following incubation of the cells with sodium thiopentone in vitro. The serum corticosterone level in anesthetized rats was significantly higher than that of the control animals. The results indicate that impaired phagocytosis following anesthesia induced by sodium thiopentone, in addition to alterations of the immune system caused by surgical trauma, may be one of the reasons for increased susceptibility to infections of surgical patients during the postoperative period.

Anesthesia↗

PubMed1998

Effects of mild perioperative hypothermia on cellular immune responses.

BACKGROUND: Unintentional perioperative hypothermia is a common complication of anesthesia and surgery associated with adverse effects on several systems, including impaired wound healing and more frequent wound infections. Mild hypothermia affects various immune functions. In the current study, the authors sought to determine whether immune alterations in the perioperative period might be induced, at least in part, by impaired thermoregulation during this period. METHODS: Sixty patients undergoing abdominal surgery were randomly assigned to two thermal care groups: routine care or forced-air warming. The patients' anesthetic care was standardized. Venous blood samples were collected 90 min before induction of anesthesia and immediately, 24 h, and 48 h after surgery. White cells were separated and frozen. Peripheral blood mononuclear cells were used to test cytokine production (interleukins [IL] -1beta, -2, and -6; tumor necrosis factor-alpha [TNF-alpha]), mitogens-induced proliferation, and natural killer NK cell cytotoxicity. Plasma cortisol levels were also determined. RESULTS: Patients in the normothermia group maintained normal body core temperature, whereas temperature decreased by approximately 1 degree C in the hypothermia group. Mitogenic responses were suppressed in cells from patients in the hypothermia but not in the normothermia group 24 and 48 h after surgery. Proinflammatory cytokine (IL-1beta, IL-6, TNF-alpha) production increased in both groups, although the production of IL-1beta was significantly higher in the normothermia group 24 h after surgery. Production of IL-2 was suppressed in the hypothermia but not in the normothermia group at 24 h. CONCLUSIONS: Mild perioperative hypothermia suppressed mitogen-induced activation of lymphocytes and reduced the production of certain cytokines, IL-1beta and IL-2, and in this way may contribute to the immune alterations observed in the perioperative period.

Antibody-Dependent Cell Cytotoxicity↗

PubMed1998

Labor affects cytokine production in newborns.

PROBLEM: To investigate whether the mode of delivery or the drugs given to the mother during labor may affect the newborns' immune system. METHOD OF STUDY: Three groups of term newborns were included: A, spontaneously delivered with i.v. analgesia (n = 37); B, spontaneously delivered with epidural analgesia (n = 26); and C, delivered by cesarean section under general anesthesia (n = 29). Natural killer (NK) cell cytotoxicity, mitogenic response, and the capacity of peripheral blood mononuclear cells (PBMCs) to produce interleukin (IL)-1 beta, IL-2, IL-3, IL-6, and tumor necrosis factor (TNF)-alpha were examined. RESULTS: NK cell cytotoxicity increased significantly in all three groups of newborns on the second day of life. Decreased IL-2 production was observed in newborns delivered by cesarean section. Spontaneous IL-1 beta secretion was higher in newborns to mothers treated with epidural analgesia. Spontaneous IL-6 secretion was elevated in infants to mothers undergoing general anesthesia and surgery or epidural analgesia. TNF-alpha production was increased in newborns delivered by cesarean section. CONCLUSION: The immune response of the newborn is affected by the mode of delivery and/or drugs given to the mother during labor.

Analgesia, Epidural↗

PubMed1998

Effect of three days starvation on the phagocytic activity of rat peritoneal macrophages.

To examine the effect of starvation on the phagocytic activity of rat peritoneal macrophages, 8 animals were kept for 3 days on water supply only. The cells showed an increased capacity for superoxide anion production and a marked decrease in their ability to engulf latex particles. The corticosterone level of the fasting animals was markedly increased, an observation suggesting that the alteration of macrophage function could be hormonally mediated. The findings in the present study indicate that the decreased phagocytic capacity of peritoneal macrophages following starvation may be one of the factors responsible for the increased susceptibility to infections in malnourished individuals.

Animals↗