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At least 253 records · Page 14Linked to original sources
PubMed1996

Innate immune function as a bioindicator of pollution stress in fish.

Immunotoxicological studies, based on processing of samples in the field and laboratory, were conducted on fish collected from a stream receiving point-source contaminants near its headwaters. Previous studies in this stream have revealed that cytochrome P4501A activity, liver somatic indices, macrophage aggregates, and parasitic liver lesions are significantly elevated in sunfish with the degree of impact decreasing with distance from the contaminant source. Fish collected from each sampling site were equally divided, One group was sacrificed in the field and the spleen and anterior kidney tissues were removed and placed in buffer on ice. The other group was kept in MS-222 for 2 hr and transported to the laboratory for processing. The spleen and anterior kidney from each fish were then prepared as a single cell suspension and shipped overnight to Mississippi State University. Cells were then evaluated for PMA-stimulated phagocyte oxidative burst and non-specific cytotoxic cell (NCC) activity against K562 tumor targets. Oxidative burst responses were dramatically suppressed in both groups at sampling sites near the headwaters but returned to reference levels further downstream. There were no differences between processing strategies at each station. NCC activities did not follow gradient-response patterns observed with phagocyte oxidative burst data and there were inconsistent differences between processing strategies at each site. These data indicate that simple immune function assays, such as phagocyte oxidative burst responses, can be used as a ancillary bioindicator in fish health monitoring and that immune function in these fish can be reliably assessed even if samples are not immediately processed.

Analysis of Variance↗
PubMed1996

Pharmacological profile of SB 203580, a selective inhibitor of cytokine suppressive binding protein/p38 kinase, in animal models of arthritis, bone resorption, endotoxin shock and immune function.

SB 203580 [4-(4-fluorophenyl)-2-(4-methylsulfinylphenyl)-5-(4- pyridyl)imidazole], a selective cytokine suppressive binding protein/p38 kinase inhibitor, was evaluated in several models of cytokine inhibition and inflammatory disease. It was demonstrated clearly to be a potent inhibitor of inflammatory cytokine production in vivo in both mice and rats with IC50 values of 15 to 25 mg/kg. SB 203580 possessed therapeutic activity in collagen-induced arthritis in DBA/LACJ mice with a dose of 50 mg/kg resulting in significant inhibition of paw inflammation and serum amyloid protein levels. Antiarthritic activity was also observed in adjuvant-induced arthritis in the Lewis rat when SB 203580 was administered p.o. at 30 and 60 mg/kg. Evidence for disease-modifying activity in this model was indicated by an improvement in bone mineral density and by histological evaluation. Additional evidence for beneficial effects on bone resorption was provided in the fetal rat long bone assay in which SB 203580 inhibited 45Ca release with an IC50 of 0.6 microM. In keeping with the inhibitory effects on lipopolysaccharide-induced tumor necrosis factor-alpha in mice, SB 203580 was found to reduce mortality in a murine model of endotoxin-induced shock. In immune function studies in mice treated with SB 203580 (60 mg/kg/day for 2 weeks), there was some suppression of an antibody response to ovalbumin, whereas cellular immune functions measured ex vivo were unaffected. This novel profile of activity strongly suggests that cytokine inhibitors could provide significant benefit in the therapy of chronic inflammatory disease.

Animals↗
PubMed1984

Studies of immune function and host resistance in B6C3F1 mice exposed to formaldehyde.

A series of immune function and host resistance parameters were examined in female B6C3F1 mice following a 21-day (6 hr/day) inhalation exposure to 15 ppm of formaldehyde (HCHO). Immune parameters examined included delayed hypersensitivity to keyhole limpet hemocyanin, antibody plaque-forming cell response to sheep erythrocytes (T-lymphocyte-dependent antigen) and TNP-Ficoll (T-lymphocyte-independent antigen), lymphoid organ weights and histopathology, routine hematology, bone marrow cellularity and CFU progenitor cell enumeration, lymphocyte subpopulation quantitation by cell surface markers, mitogen-induced lymphocyte blastogenesis, macrophage function parameters, and host resistance to challenge with the bacterium Listeria monocytogenes and transplantable tumor cells. Lymphoid organ weight, bone marrow cellularity, and hematology parameters were unchanged in HCHO exposed mice. Similarly, the percentage of T and B lymphocytes and their proliferative responses to mitogens were not significantly altered. Antibody (IgM) plaque-forming cell response following antigen challenge was unchanged. Macrophage function was normal although some evidence of enhanced H2O2 production associated with elevated bactericidal activity was observed in resident macrophages. Resistance to challenge with the bacteria Listeria monocytogenes was significantly enhanced, while resistance to tumor challenge remained unchanged. No evidence of immunosuppression following short-term exposure to HCHO was observed.

Animals↗
PubMed1995

Effects of vitamin E on immune function of dairy cows.

The effect of vitamin E supplementation on the immune function of dairy cows was studied. Twelve cows were assigned to 1 of the 2 experimental groups: control (no vitamin E supplementation), and vitamin E-supplemented. Supplementation of vitamin E started 4 weeks before and continued up to 8 weeks after parturition and included oral supplementation of vitamin E at the rate of 3,000 IU/cow/d. In addition, the same group of cows received 1 injection of vitamin E (5,000 IU), 1 week prior to the expected date of parturition. Data indicated that blood neutrophils isolated from control cows produced twofold less (P < 0.05) superoxide anion after parturition, compared with the corresponding value before parturition. Furthermore, blood macrophages isolated from control cows produced 15 and 35% (P < 0.05) less interleukin 1 (IL-1) and major histocompatibility (MHC) class-II antigens, respectively, after parturition, compared with the corresponding values before parturition. These data, collectively, indicate that functions of blood macrophages and neutrophils are depressed during the early postpartum period in control cows. In contrast, there were no differences in superoxide anion production by blood neutrophils, or in IL-1 production, and MHC class-II antigen expression by blood macrophages before and after parturition in cows supplemented with vitamin E. There were no differences in lymphocyte proliferation, or IL-1 production and MHC class-II antigen expression by mammary macrophages when control and vitamin E-supplemented cows were compared. We conclude that vitamin E prevented suppression of blood neutrophil and macrophage function during the early postpatum period.

Analysis of Variance↗
PubMed1996

Changes in local immune functions in Mooren's ulcer.

PURPOSE: To the investigate changes in local immune functions of the cornea and the adjacent conjunctiva, and their roles in the mechanism of the disease. METHOD: The cornea and adjacent bulbar conjunctiva taken from 14 patients with Mooren's ulcer were stained immunohistochemically for CD3, CD4, CD8, HLA-DR, CD1 and CD25. RESULT: An aberrant expression of HLA-DR antigen by a large number of kerato-conjunctival epithelial cells and keratocytes in the corneal stroma was found. The CD4+/CD8+ ratio is significantly higher than normal control. CONCLUSION: The aberrant expression of MHC-II antigen in the resident cells at the peripheral cornea and the adjacent conjunctiva, along with a raised local TH/Ts ratio leading to an excessive autoimmune reactivity is possibly the direct cause of Mooren's ulcer.

Adult↗
PubMed1991

Immunization with soluble murine CD4 induces an anti-self antibody response without causing impairment of immune function.

The T cell surface molecule CD4 (L3T4 in mouse) is important in the T lymphocyte response to Ag presented in association with MHC class II molecules. To examine the role of CD4 in immune function, we expressed a soluble form of murine CD4 by deleting the transmembrane and cytoplasmic regions of the L3T4 gene and transfecting the altered gene into Chinese hamster ovary cells. The recombinant soluble mouse CD4 (smCD4) retained the native conformation of the external portion, as indicated by the binding of L3T4 mAb. In vitro, smCD4 did not inhibit class II-dependent, Ag-specific, T cell proliferation or MLR, even at concentrations 300-fold greater, on a molar basis, than that of anti-CD4 mAb. Immunization of mice with smCD4 induced a strong anti-CD4 response. These antibodies showed some binding to native cell surface CD4, indicating that immunization with smCD4 generated an anti-self response. Analysis of lymphoid cells from spleen, lymph node, and thymus of smCD4-treated mice revealed no alteration in subset phenotypes. Also, Th cell function, as measured by response to soluble Ag, was not compromised. Thus, smCD4 did not inhibit T cell activity in vitro, and the autoimmune response arising from immunization with smCD4 had no apparent consequences for normal immune function.

Animals↗
PubMed1985

The effects of lead ion on immune function of rabbit alveolar macrophages: quantitation of immune phagocytosis and rosette formation by 51Cr in vitro.

Experiments by a 51Cr-labeling technique were performed to investigate the effects of lead (Pb2+) on immune phagocytosis and Fc-rosette formation of rabbit pulmonary alveolar macrophages (PAMs). Evidence is presented that Pb2+ at concentrations of 10(-3) and 10(-4)M could inhibit these functions of PAMs. The degree of inhibition corresponded to the concentration of this heavy metal ion in vitro.

Animals↗
PubMed1989

[Enhancement of the therapeutic effect and red cell immune function by radix Trichosanthis in mice bearing Ehrlich ascites carcinoma].

Various red cell immune functions were determined in 60 mice bearing Ehrlich ascites carcinoma treated and untreated with Radix Trichosanthis(RT), and compared with these of 30 normal mice. In mice bearing Ehrlich ascites carcinoma treated with RT, the rosette formation of red cell C3b receptor, the rosette formation of red cell immune complex, the rosette formation rate of red cell round cancer, the rate of PMN phagocytosis were enhanced, and the activity of superoxide dismutase (SOD) was satisfactory higher than those in mice bearing Ehrlich ascites carcinoma untreated with RT, and almost same as those in normal mice, while the rosette inhibition rate of red cell C3b receptor in serum was satisfactory lower than that in mice bearing Ehrlich ascites carcinoma untreated with RT, and almost same as that in normal mice.

Animals↗
PubMed1992

Humoral and cellular immune functions are not compromised by the anticarcinogenic Bowman-Birk inhibitor.

Previous studies have demonstrated that the soybean-derived Bowman-Birk protease inhibitor (BBI) is effective as a cancer chemopreventive agent in several animal model systems. Proteases represent a key component of several aspects of immune function; therefore the immune system is a primary target for potential toxicity. The present investigation examines the effect of dietary and intraperitoneally administered BBI on antibody response to keyhole limpet hemocyanin and delayed-type hypersensitivity response to dinitrochlorobenzene. Primary antibody response was not altered by BBI treatment; however, an elevated secondary response was observed in animals receiving dietary BBI at two weeks of age. This effect was not observed at later time points. No change in delayed-type hypersensitivity response was observed in any of the treatment groups.

Animals↗
PubMed1989

Nutritional status, grip strength, and immune function in institutionalized elderly.

The effects of vitamin supplementation on grip strength and immune function was studied in a group of institutionalized elderly with a relatively higher prevalence of low and below acceptable biochemical parameters of vitamin C, pyridoxine, folic acid, riboflavin, iron and zinc nutriture. The vitamin supplementation has resulted in a statistically significant increase in the level of biochemical parameters related to added vitamins, and the number of subjects with inadequate vitamin values was reduced to zero. The improved vitamin status had a positive and statistically significant effect on the delayed cutaneous hypersensitivity one of the parameters of cellular immunity. The calculation of multiple correlation after inclusion of all biochemical parameters into the stepwise regression analysis has shown that the coefficient of multiple regression between examined biochemical parameters of nutrition status and delayed cutaneous hypersensitivity was R = .599 (p less than 0.001) which indicates that about 36% of the variability in the cellular immunity would be affected by the vitamin and mineral nutrition status.

Aged↗
PubMed1996

Photoperiod and population density interact to affect reproductive and immune function in male prairie voles.

Seasonal breeding of rodents is often associated with changes in adrenal function; altered adrenal function could account, in part, for seasonal changes in immune function and, ultimately, influence seasonal fluctuations in survival. Animals commonly monitor the annual change in photoperiod to ascertain the time of year and to make appropriate seasonal adjustments in physiology and behavior. Several extrinsic factors affect reproductive responsiveness to photoperiod. The interaction between population density and reproductive and adrenal responsiveness to photoperiod was assessed in the present experiment. Adult male prairie voles (Microtus ochrogaster) were maintained individually for 10 wk in long [light:dark (LD) 16:8] or short (LD 8:16) photoperiods in rooms with either high (10.96 animals/m3) or low (0.18 animals/m3) population densities. Regardless of population density, short-day voles regressed the size of their reproductive organs; reproductive organ masses were higher in long-day voles housed in high-density compared with low-density rooms. Paired adrenal masses were reduced in short-day voles, but were unaffected by population density; serum corticosterone concentrations were significantly elevated in short-day compared with long-day animals. In both photoperiods, basal blood corticosterone levels were higher in voles from low-density compared with high-density rooms. Splenic masses were unaffected by day length, but were elevated among high-density animals. Similarly, serum immunoglobulin (IgG) levels were elevated among high-density animals. These results suggest that population density per se, in the absence of behavioral interactions, can affect reproductive size, and possibly function, in long-day conditions, and that prairie voles, which are highly social, exhibit higher corticosterone and lower IgG levels in low compared with high densities. These results may be important in understanding arvicoline population fluctuations, as well as improving animal husbandry practices in the lab.

Animals↗
PubMed1991

Stimulatory effects of FK156 in a panel of tests designed to detect changes in immune function.

There is a need to evaluate the utility of experimental models in immune function assessment if these are to be accepted in preclinical safety studies. We have evaluated a panel of tests measuring cellularity and functions of the lymphoid system in the Fischer rat in order to determine whether they would detect immunostimulation, rather than suppression. Injection of the peptide immunostimulant FK156 (D-lactyl-L-alanyl-y-D-glutamyl-(L)-meso-diaminopimelyl- (L)-glycine) increased the numbers of macrophages recovered from the peritoneal cavity, and stimulated their activity, as measured by chemiluminescence, adherence, and secretion of interleukin 1. In vitro, T lymphocytes had an increased background incorporation of tritiated thymidine, increased response to sub-optimal concentrations of concanavalin A, and an increase in secretion of interleukin 2 at optimal concentrations of concanavalin A. There was no change in the proliferative responses of B lymphocytes in vitro. Antibody responses to tetanus toxoid in vivo were increased. These changes were not reflected in consistent, statistically significant alterations in the numbers of lymphocytes bearing either lineage markers or the interleukin 2 receptor as a marker of activation.

Adjuvants, Immunologic↗
PubMed1994

Stressor-induced alterations of immune function: mechanisms and issues.

This paper reviews the role of catecholamines and the hypothalamic-pituitary-adrenal system in the mediation of stress-induced immune changes in both human and animal subjects. There is evidence to support the importance of these factors in mediating stressor effects on certain immune parameters, but further research is needed to define the specific circumstances in which they are relevant. Therefore, discussion of such issues as sex, genotype, stress history, environment, and stressor characteristics is provided to suggest possible ways to increase our understanding of stressor effects on immune function. Since the imposition of a stressor disrupts physiological homeostasis, understanding the capacity of the immune system to function under such conditions is of prime importance in predicting disease onset and outcome.

Animals↗
PubMed1990

Nutrition and immune function.

Despite provision of adequate calories and nitrogen, patients receiving current nutrition support formulations often have suppression of immune function. Certain nutrients may act pharmacologically on the immune system. The choice of nutrients appropriate for a given disease state must take into consideration the nutritional status of the subject, presence of infection, injury or hypermetabolism, and the specific immune defect. Nutritional therapy specific for certain disease states is complex and in its infancy but may hold promise for improved patient outcome. Randomized prospective trials to evaluate efficacy are mandatory. Continued research into individual nutrients to elucidate mechanisms of immunomodulation must follow. In the meantime, broad application of products shown to be effective for a specific indication is inappropriate.

Enteral Nutrition↗
PubMed1998

A phospholipase A2-related snake venom (from Crotalus durissus terrificus) stimulates neuroendocrine and immune functions: determination of different sites of action.

Immune neuroendocrine interactions are vital for the individual's survival in certain physiopathological conditions, such as sepsis and tissular injury. It is known that several animal venoms, such as those from different snakes, are potent neurotoxic compounds and that their main component is a specific phospholipase A type 2 (PLA2). It has been described recently that the venom from Crotalus durissus terrificus [snake venom (SV), in the present study] possesses some cytotoxic effect in different in vitro and in vivo animal models. In the present study, we investigated whether SV and its main component, PLA2 (obtained from the same source), are able to stimulate both immune and neuroendocrine functions in mice, thus characterizing this type of neurotoxic shock. For this purpose, several in vivo and in vitro designs were used to further determine the sites of action of SV-PLA2 on the hypothalamo-pituitary-adrenal (HPA) axis function and on the release of the pathognomonic cytokine, tumor necrosis factor alpha (TNF alpha), of different types of inflammatory stress. Our results indicate that SV (25 microg/animal) and PLA2 (5 microg/animal), from the same origin, stimulate the HPA and immune axes when administered (i.p.) to adult mice; both preparations were able to enhance plasma glucose, ACTH, corticosterone (B), and TNF alpha plasma levels in a time-related fashion. SV was found to activate CRH- and arginine vasopressin-ergic functions in vivo and, in vitro, SV and PLA2 induced a concentration-related (0.05-10 microg/ml) effect on the release of both neuropeptides. SV also was effective in changing anterior pituitary ACTH and adrenal B contents, also in a time-dependent fashion. Direct effects of SV and PLA2 on anterior pituitary ACTH secretion also were found to function in a concentration-related fashion (0.001-1 microg/ml), and the direct corticotropin-releasing activity of PLA2 was additive to those of CRH and arginine vasopressin; the corticotropin-releasing activity of both SV and PLA2 were partially reversed by the specific PLA2 inhibitor, manoalide. On the other hand, neither preparation was able to directly modify spontaneous and ACTH-stimulated adrenal B output. The stimulatory effect of SV and PLA2 on in vivo TNF alpha release was confirmed by in vitro experiments on peripheral mononuclear cells; in fact, both PLA2 (0.001-1 microg/ml) and SV (0.1-10 microg/ml), as well as concavalin A (1-100 microg/ml), were able to stimulate TNF alpha output in the incubation medium. Our results clearly indicate that PLA2-dependent mechanisms are responsible for several symptoms of inflammatory stress induced during neurotoxemia. In fact, we found that this particular PLA2-related SV is able to stimulate both HPA axis and immune functions during the acute phase response of the inflammatory processes.

Adrenal Glands↗
PubMed1981

Long-term effect of postoperative irradiation on the immune functions in patients with mammary carcinoma.

The effect of postoperative irradiation on the immune functions of 13 patients with breast carcinoma is reported, using as parameters the peripheral blood lymphocyte count, percentages of E and EAC rosette forming cells, and lymphocyte proliferative responses to PHA, Con A and PPD. After irradiation the number of peripheral blood lymphocytes was reduced during 8 months. The percentages of E and EAC rosette forming cells were not altered during the observation time of 7 to 36 months. In the proliferative responses of lymphocytes to PHA, Con A and PPD, the postoperative irradiation caused a decrease which, regarding PHA and Con A, lasted up to 8 months and then recovered. The decrease in the proliferative responses to PPD was stronger and lasted during the whole observation time. In the mitogenic responses of patients with recurrent or disseminating disease no difference could be demonstrated as compared with the patients living recurrence-free.

Adult↗
PubMed1996

Does fluoridation harm immune function?

There have been suggestions, mainly in the lay press, that fluoridation might affect immunity. Careful examination of various studies on fluoride and immune function do not support this suggestion. Whilst fluoride at high concentrations can have inhibitory effects on lymphocyte and polymorphonuclear leucocyte function, these concentrations are many times higher than levels which would be expected from fluoridation. Fluoride can act as an immunological adjuvant. There is no evidence of any deleterious effect on specific immunity following fluoridation nor any confirmed reports of allergic reactions.

Adjuvants, Immunologic↗