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PubMed1991

Effects of chronic exposure to sublethal concentrations of lead acetate on heme synthesis and immune function in red-tailed hawks.

Red-tailed hawks were exposed to sublethal levels of lead acetate for periods of 3 or 11 weeks. Alterations in the heme biosynthetic pathway were demonstrated after the first week of exposure to 0.82 mg lead per kilogram body weight per day. Activity of erythrocyte porphobilinogen synthase (aminolevulinic acid dehydratase) was depressed significantly and did not return to normal levels until 5 weeks after the termination of lead treatments. A rapid and relatively brief increase in erythrocyte free protoporphyrin and a slower but more prolonged increase in its zinc complex were also demonstrated with exposure to this dose of lead for 3 weeks. Less substantial decreases in hematocrit and hemoglobin levels occurred but only in the longer experiment with exposure to higher lead levels. Short term, low level lead exposure did not effect immune function significantly in the hawks, as measured by antibody titers to foreign red blood cells or by the mitogenic stimulation of T-lymphocytes. Increased lead exposure produced a significant decrease in the mitogenic response but had no effect on antibody titers.

Animals↗
PubMed1999

Skin surgery under local anesthesia leads to stress-induced alterations of psychological, physical, and immune functions.

BACKGROUND: Although excision of nevi under local anesthesia is a frequent and harmless operation, it apparently causes increased stress in many patients. However, thus far no studies have focused on the question of whether there are measurable effects on psychological, physiological, and immunological parameters. OBJECTIVE: To assess the perioperative stress reactions of patients undergoing skin surgery under local anesthesia for nevocellular nevi. METHODS: Fifty consecutive patients with pigmented nevi were examined at five points of measurement: 1 week and 30 minutes before the operation, during the operation, 30 minutes and 1 week after the operation. Somatic parameters included blood pressure, pulse, respiratory rate, and the level of pain. Lymphocyte subpopulations, white blood cell count, and cortisol in saliva were determined. Anxiety and general psychological distress were evaluated with validated questionnaires. RESULTS: There was a significant increase in anxiety at the time of surgery. In parallel, the physiological parameters as well as the CD56+ lymphocytes changed significantly. Preoperation anxiety and intraoperation pain were significantly higher in women (P <.001), but did not depend on age. CONCLUSION: There appears to be an interaction between physiological and emotional components in the operative stress reaction under local anesthesia. In patients with skin cancer, the perioperative stress may lead to transient impairment of immune function.

Adolescent↗
PubMed1993

[The relationship between concentrations of B(a)P in blood, urine and immune function of coking workers].

The surroundings of a coking plant were contaminated with benzo(a)pyrene [B(a)P] in various degrees. B(a)P in urine and blood of the coking workers was detected, and levels of B(a)P in urine and blood showed correlated. Also, the relationship between the contents of B(a)P in urine and the surroundings of the plant was found. The levels of immunoglobulin (IgG, IgA, IgM) and complement C3 in serum of the coking workers decreased. The levels of IgG and C3 in the workers were significantly different from those in controls. And, the serum contents of B(a)P in the workers also correlated with their immune function.

Adult↗
PubMed1987

Mammary cancer chemoprevention by inorganic and organic selenium: single agent treatment or in combination with vitamin E and their effects on in vitro immune functions.

The chemopreventive efficacies of selenate, selenite, selenium dioxide, selenomethionine and selenocystine were examined during the promotion phase of carcinogenesis in the 7,12-dimethylbenz[a]anthracene-induced mammary tumor model in rats. Each agent was added to the diet at a final concentration of 3 p.p.m. selenium. In general there was no significant difference in the potency of these five selenium compounds in inhibiting the development of mammary tumors. The interaction of vitamin E (500 p.p.m.) with either selenite or selenomethionine was further characterized in a second carcinogenesis study. Results of this experiment suggested that vitamin E enhanced the protective effect of selenite but not that of selenomethionine. In an attempt to explore the synergistic mechanism of selenium and vitamin E, the effects of these two agents on mitogen-induced blastogenesis and natural killer cytotoxic activity were also investigated. No consistent changes in these in vitro immune functions were detected resulting from supranutritional feeding of either selenite or vitamin E or both. The metabolism of inorganic versus organic selenium was discussed in relation to their role in the control of neoplastic growth as well as to their selective modulation by vitamin E.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed2005

Tetrahydrocannabinol suppresses immune function and enhances HIV replication in the huPBL-SCID mouse.

Epidemiologic studies identify marijuana as a potential cofactor in the development and progression of HIV infection. To evaluate this interaction we employed a hybrid model in which human peripheral blood leukocytes (PBL) were implanted into severe combined immunodeficient mice (huPBL-SCID) and infected with an HIV reporter construct in the presence or absence of tetrahydrocannabinol (THC) exposure. Administration of THC alone, in the absence of HIV, decreased CD4 counts and the CD4:CD8 ratio. Co-administration of THC and HIV did not reduce CD4 counts further, but significantly increased the percentage of HIV-infected PBL when compared to saline-treated animals (17+/-4.6% vs. 7+/-1.4%). Quantitative PCR confirmed a 50-fold increase in systemic viral load in THC-treated animals. The CCR5 and CXCR4 chemokine receptors function as coreceptors essential for HIV infection. Administration of THC for 5 days increased the percentage of PBL expressing CCR5 and, to a lesser extent, CXCR4. This effect was lost after 10 days of THC administration, but the number of HIV-infected cells had significantly increased by that time suggesting a role for early upregulation of these coreceptors in the pathogenic effect of THC. Finally, the impact of treatment on the number of human interferon-gamma (IFN-gamma) producing cells was determined by ELISPOT. Both THC and HIV infection independently decreased the number of IFN-gamma producing cells and co-administration produced additive effects. These results suggest that exposure to THC in vivo can suppress immune function, increase HIV coreceptor expression, and act as a cofactor to significantly enhance HIV replication.

Animals↗
PubMed1993

Selected scientific aspects of marathon racing. An update on fluid replacement, immune function, psychological factors and the gender difference.

Four topics are addressed: fluid/fuel replacement during the marathon, marathoning and susceptibility to infection, psychological aspects of elite marathoners and the gender gap in marathon performance. Although these topics are diverse, they all relate to practical questions raised by coaches and athletes. Evidence from laboratory and field studies indicates that it is advisable for marathoners to consume 800 to 1000 L/h of sports drink providing 45 to 60 g/h of carbohydrate. It is strongly suggested to practice fluid consumption during training sessions as it is probable that tolerance to drinking during running is a trainable adaptation. Epidemiological and clinical research support the concept that marathon training and racing increase the runner's risk of upper respiratory tract infections because of negative changes in immune function. Susceptibility to infection may be reduced by proper nutrition, adequate sleep, appropriate recovery between vigorous workouts and minimal exposure to sick people during periods of heavy training and major races. Although psychological research in this area is still limited, evidence suggests that elite marathoners rely primarily on associative strategies during competition while judiciously dissociating in order to cope with pain. It is recommended that coaches and athletes interested in employing psychological interventions seek assistance from professionals well trained in the fields of both psychology and exercise science. Will women soon outrun men? Over the past 2 decades societal views and training practices of women distance runners have changed greatly, yet certain performance-related biological differences between men and women are unlikely to change.

Disease Susceptibility↗
PubMed1997

Glucocorticoids and the immune function in the human immunodeficiency virus infection: a study in hypercortisolemic and cortisol-resistant patients.

Immunological studies in human immunodeficiency virus (HIV)-positive patients suggest that the disease progression is accompanied by a defective production of type 1 cytokines (interleukin-2 (IL-2) and IL-12], an increased production of type 2 cytokines (IL-4, IL-6, and IL-10), and an increased production of IgE. HIV infection is also associated with activation of the hypothalamo-pituitary-adrenal axis function and increased plasma and urinary cortisol concentrations. As cortisol is involved in the physiological regulation of cytokines, a study was conducted to examine cytokine patterns in two groups of hypercortisolemic patients, one with normal sensitivity to glucocorticoids and the other with glucocorticoid resistance. Ten HIV-infected patients with normal receptor affinity to glucocorticoids (AIDS-C), 10 HIV-infected patients with low receptor affinity to glucocorticoids (AIDS-GR), and 20 healthy subjects were studied. Receptor characteristics of peripheral blood mononuclear cells were evaluated by [3H]dexamethasone binding. Serum cortisol and urinary free cortisol were measured by RIA. Serum ACTH and IgE were measured by immunoradiometric assay, and IL-2, IL-4, and IL-10 cytokines and interferon-gamma were measured by enzyme-linked immunosorbent assay. AIDS-C patients showed low IL-2 and high IL-4, IL-10, and IgE concentratios; conversely, AIDS-GR patients showed high IL-2 and low IL-4 and IgE concentrations. Thus, in HIV infection, elevated cortisol levels suppress cell-mediated immunity and stimulate humoral immunity, whereas this response is not detected in cortisol-resistant patients. These findings indicate that cortisol and its receptors are critically involved in the regulation of immune function in HIV infection.

Adrenocorticotropic Hormone↗
PubMed1998

Exercise training restores decreased cellular immune functions in obese Zucker rats.

This study investigated whether exercise training had a beneficial effect on the decreased mitogen response and improved a decreased expression of glucose transporter 1 (GLUT-1) in splenocytes from obese Zucker rats. Experimental groups were lean and sedentary and exercise-trained obese Zucker rats. Exercise training, running on a motor-driven treadmill for 5 days/wk for 40 wk, did not induce a significant decrease in body weight in obese Zucker rats. The plasma insulin concentration, showing a significant increase compared with lean Zucker rats, was unaffected by exercise training. However, the plasma triglyceride concentration in obese Zucker rats was significantly depressed by exercise training, whereas it was still higher than that in lean Zucker rats. In addition, natural killer cell activity and concanavalin A-induced mitogenesis of splenic lymphocytes of obese Zucker rats were significantly restored. In these splenic lymphocytes, glucose uptake was significantly lower compared with that in lean Zucker rats, which was also improved by exercise training. Although the expression of GLUT-1, the major glucose transporter in immune cells, was depressed in splenic lymphocytes of obese Zucker rats, exercise training induced a significant improvement. These results suggest that exercise training has a beneficial effect on the decreased cellular immune functions in obese Zucker rats, which is associated, in part, with the improvement in GLUT-1 expression.

Animals↗
PubMed1993

Depressed immune function in patients with cirrhosis before emergence of hepatocellular carcinoma.

Hepatocellular carcinomas 1 cm in diameter with high or low echogenicity can be detected on ultrasonography and confirmed on fine-needle biopsy, but it is still very difficult to detect small hepatocellular carcinomas with isoechogenicity. In this study, we assessed lymphokine-activated killer cell activity and interferon-gamma production prospectively every 1 to 3 mo for 23 +/- 4 mo (mean +/- 1 S.D.) in 227 patients with cirrhosis. Transient depression of lymphokine-activated killer activity was detected in 43 patients (defective lymphokine-activated killer group), and hepatocellular carcinoma was detected in 24 cases before the end of the 18-mo follow-up. Twenty-one (87.5%) of the 24 hepatocellular carcinoma patients were included in the defective lymphokine-activated killer group. Defective lymphokine-activated killer activity was detected more than 6 mo before detection of a space occupying lesion in the liver or elevation of alpha-fetoprotein level above 400 ng/ml. Serum alpha-fetoprotein level was elevated above 400 ng/ml in only five cases in which hepatocellular carcinoma was detected as a space-occupying lesion. Our results indicate that sequential assessment of lymphokine-activated killer activity may be a predictor of hepatocellular carcinoma and that the depression of immune function in cirrhotic patients is a serious risk factor for hepatocellular carcinoma emergence.

Adult↗
PubMed1996

Immune function early in acute pancreatitis.

Circulating lymphocyte numbers and activation together with granulocyte function were measured in 20 patients in the early stages of an attack of acute pancreatitis and in 20 healthy controls. Circulating lymphocytes, T lymphocytes, and CD4 and CD8 T lymphocyte subsets were decreased in both mild pancreatitis (67-80 per cent of controls) and severe pancreatitis (22-40 per cent of controls). CD4:CD8 ratios were unchanged and median (interquartile range) interleukin 2 receptor expression was increased from less than 1 per cent in controls to 14(6) per cent in severe pancreatitis, suggesting lymphocyte activation. Median granulocyte chemiluminescence was increased to 293 per cent of controls in severe pancreatitis and random motility was reduced to 77 per cent of controls, indicating increased metabolic activity. Complement-mediated antibody-independent opsonization and chemotaxis toward endotoxin were normal. Immune function is not reduced early in acute pancreatitis. Granulocyte hyperactivity may be important in the development of multiple organ failure.

Acute Disease↗
PubMed2003

The hypothalamic-pituitary-gonadal axis: immune function and autoimmunity.

GnRH and sex steroids play an important role in immune system modulation and development. GnRH and the GnRH receptor are produced locally by immune cells, suggesting an autocrine role for GnRH. Experimental studies show a stimulatory action of exogenous GnRH on the immune response. The immune actions of GnRH in vivo are, however, less well established. Oestrogen and androgen receptors are expressed in primary lymphoid organs and peripheral immune cells. Experimental data have established that oestrogens enhance the humoral immune response and may have an activating role in autoimmune disorders. Testosterone enhances suppressor T cell activity. Although there are some clinical studies consistent with these findings, the impact of sex steroids in autoimmune disease pathogenesis and the risk or benefits of their usage in normal and autoimmune-disordered patients remain to be elucidated. There are neither experimental nor clinical data evaluating functional GnRH-sex steroid interactions within the human immune system, and there is a paucity of data relating to GnRH analogues, hormone replacement therapy and oral contraceptive and androgen action in autoimmune diseases. However, a growing body of experimental evidence suggests that an extra-pituitary GnRH immune mechanism plays a role in the programming of the immune system. The implications of these findings in understanding immune function are discussed.

Androgens↗
PubMed2002

Effects of electro-acupuncture on immune function after chemotherapy in 28 cases.

PURPOSE: To observe the effects of electroacupuncture therapy on T cells and activity of NK cell in the patient of Chemotherapy. METHOD: Electro-acupuncture therapy was simultaneously applied during chemotherapy, T cells and activity of NK cell of patients were determined before electroacupuncture treatment (before chemotherapy) and after 4-course electro-acupuncture treatments. RESULTS: Before chemotherapy, CD3 was low within the normal range, CD4 was much lower than the normal range, and CD8, CD4/CD8 and activity of NK cell were within the normal range. After one month of chemotherapy combined with electro-acupuncture, no decline of all the indices was found (P > 0.05). CONCLUSION: Electro-acupuncture can really increase the immune function of patients of chemotherapy.

Adolescent↗
PubMed1995

[The effect of dynorphin A on intracellular cAMP and cGMP contents in spleen cells of burn rats and its relation to immune function].

The lymphocyte response to Con A and IL-2 synthesis was clearly suppressed in rats after thermal injury. In burn rats, the cAMP content in lymphocytes was significantly increased, but cGMP level was not changed. The serum of burn rat could inhibit Con A-induced lymphocyte proliferation and IL-2 production. The burn rat serum could also increase intracellular cAMP concentration. Dynorphin A enhanced lymphocyte proliferation and IL-2 synthesis, increased cAMP level in lymphocytes. Naloxone could inhibit the action of dynorphin A. Moreover, ynorphin A could partly reversed suppression effect of burn serum on lymphocyte proliferation and suppressed the increase of intracellular cAMP content induced by burn and rat serum. Our results suggested that dynorphin A augmented immune function of burn rats, and the action of dynorphin A was mediated by cAMP pathway.

Adjuvants, Immunologic↗
PubMed2001

Immune function of microglia.

During the past decade, mechanisms involved in the immune surveillance of the central nervous system (CNS) have moved to the forefront of neuropathological research mainly because of the recognition that most neurological disorders involve activation and, possibly, dysregulation of microglia, the intrinsic macrophages of the CNS. Increasing evidence indicates that, in addition to their well-established phagocytic function, microglia may also participate in the regulation of non specific inflammation as well as adaptive immune responses. This article focuses on the signals regulating microglia innate immune functions, the role of microglia in antigen presentation, and their possible involvement in the development of CNS immunopathology.

Animals↗
PubMed2003

Immune function and hematology of male cotton rats (Sigmodon hispidus) in response to food supplementation and methionine.

We examined effects of supplementation of food quantity and quality (=enhanced methionine) on hematologic and immunologic parameters of wild, but enclosed, adult male cotton rats (Sigmodon hispidus) in north-central Oklahoma. Sheet metal enclosures were stocked with a high density of wild-caught cotton rats (160 animals/ha) and randomly assigned a treatment of no supplementation, mixed-ration supplementation or methionine-enhanced supplementation. Aside from small increases in counts of red blood cells and hematocrit levels, most indices of erythrocytic characteristics were not affected by supplementation with the mixed-ration or enhanced methionine. In contrast, platelet counts were highest in mixed-ration and methionine treatments and counts of total white blood cells were highest with methionine supplementation, albeit relative proportions of different leukocytes did not differ among treatments. Immunologically, neither delayed-type hypersensitivity response nor hemolytic-complement activity differed among treatments. Supplementation of food quantity and quality did not broadly affect hematologic parameters and immune function of male cotton rats, but enhanced platelet and leukocyte counts may confer advantages to overall health. Clarification of the role of such effects on population limitation or regulation requires additional research.

Animals↗
PubMed2006

Iron chelators: correlation between effects on Plasmodium spp. and immune functions.

Iron chelating agents, which permeate through erythrocytic and parasite membranes, are effective against Plasmodium falciparum in vitro. However, the protective effect in humans is transient. We examined the antiplasmodial capacity of several iron chelators in vitro and in vivo. The chelators 3/3hb/2m and 3/2hb/b (together, MoB) were more effective against P. falciparum in vitro than desferrioxamine (DFO) and Salicylaldehyde isonicotinoyl hydrazone (SIH) (together, DoS). Despite similar pharmacokinetics of all iron chelators, mice infected with Plasmodium vinckei and treated with MoB succumbed to malaria, whereas DoS-treated mice survived. However, even in the surviving mice, peak parasitemias were above 30%. These results indicate that the direct effects of the drugs on the parasites were not responsible alone for the complete recovery of the mice. We suggest that the recovery is related to differential effects of the drugs on various immune functions. We concentrated on the effect of the iron chelators on B cell and T cell proliferation and on allogeneic stimulation (MLR), interleukin-10 (IL-10), gamma-interferon (gamma-IFN), tumor necrosis factor-alpha (TNF-alpha), and radical production. All the iron chelators examined inhibited the in vitro proliferation of B cells and T cells, and MLR. This may explain why iron chelators are only slightly efficient in treating human malaria. However, the inhibitory effects of MoB on B cell and T cell proliferation and on MLR were more pronounced than those of DoS. In addition, the release of free radicals by effector cells was inhibited to a greater extent by MoB than by DoS. These results may explain why MoB, which was more efficient in vitro, was not effective in vivo. The DoS effects on the in vitro secretion of cytokines correlate with their in vivo effect; there was a decrease of IL-10 and a parallel increase in gamma-IFN and TNF-alpha production by human mononuclear cells. MoB, which could not rescue the animals from malaria, did not affect IL-10 and TNF-alpha, but reduced gamma-IFN levels. Identical results were obtained when using monocytes instead of mononuclear cells (except for gamma-IFN, which is not produced by monocytes). Our results indicate that an iron chelator, or any antiparasitic drug that kills the parasites in vitro, should also be selected for further evaluation on the basis of its reaction with immune components; it should not interfere with crucial protective immunological processes, but it may still alleviate parasitemia by positive immune modulation.

Aldehydes↗
PubMed1987

Effects of human growth hormone on immune functions: in vitro studies on cells of normal and growth hormone-deficient children.

We have studied the in vitro effects of human growth hormone on cell surface markers and mitogenic responses of peripheral blood lymphocytes (PBL) of normal and growth hormone-deficient children before, during and after treatment with growth hormone. Growth hormone resulted in a decrease in B cell expression but it did not affect expression of T cell subsets. Growth hormone depressed the proliferation of PBL of normal and untreated growth hormone-deficient children. The proliferative responses to phytohemagglutinin (PHA) versus PHA with growth hormone were not statistically different, though the responses of most normal and on treatment children were diminished by the addition of growth hormone. PBL derived from growth hormone-deficient children during treatment with human growth hormone exhibited significantly greater spontaneous proliferation then the PBL of normal children. Growth hormone further significantly enhanced their proliferation. PHA and PHA with growth hormone resulted in significantly greater proliferation of these patients' PBL when compared to those of normal children. We demonstrated that human growth hormone had substantial in vitro effects on immune functions. These effects, some of which depend on the treatment status of the children, may need to be considered in the clinical use of human growth hormone.

Child↗
PubMed2001

Genetically engineered macrophages expressing IFN-gamma restore alveolar immune function in scid mice.

Reversal of immunodeficiency in the lung by gene therapy is limited in part by the difficulty of transfecting lung cells in vivo. Many options exist for successfully transfecting cells in vitro, but they are not easily adapted to the in vivo condition. To overcome this limitation, we transduced macrophages in vitro with the murine IFN-gamma (mIFN-gamma) gene and intratracheally delivered the macrophages to express mIFN-gamma in vivo. A recombinant retroviral vector pSF91 system was modified to encode mIFN-gamma and enhanced green fluorescent protein (EGFP). A murine macrophage cell line J774A.1 transduced with the retroviral supernatant increased secretion from undetectable levels to 131.6 +/- 4.2 microg/ml mIFN-gamma at 24 h in vitro. The mIFN-gamma-producing macrophages were intratracheally instilled into mechanically ventilated scid mice. mIFN-gamma levels in the bronchoalveolar lavage increased from undetectable levels at baseline to 158.8 +/- 5.1 pg/ml at 48 h (P < 0.001). Analysis of the lavaged cells for EGFP expression revealed that EGFP expression was directly proportional to the number of transduced macrophages instilled into the lung. Immune function was partially restored in the alveolar spaces of scid mice with evidence of enhanced MHC class II antigen expression and increased phagocytosis (P < 0.05). Tumor necrosis factor alpha was increased from undetectable at baseline to 103.5 +/- 11.4 pg/ml. In contrast, i.p. administration of the engineered macrophages did not enhance IFN-gamma levels in the lung. Our study suggests airway delivery of genetically engineered macrophages expressing mIFN-gamma gene can partially restore significant immune activity in the lungs of immunodeficient mice.

Animals↗