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At least 631 records · Page 35Linked to original sources
PubMed1999

Carotenoids, sexual signals and immune function in barn swallows from Chernobyl.

Carotenoids have been hypothesized to facilitate immune function and act as free-radical scavengers, thereby minimizing the frequency of mutations. Populations of animals exposed to higher levels of free radicals are thus expected to demonstrate reduced sexual coloration if use of carotenoids for free-radical scavenging is traded against use for sexual signals. The intensity of carotenoid-based sexual coloration was compared among three populations of barn swallows Hirundo rustica differing in exposure to radioactive contamination. Lymphocyte and immunoglobulin concentrations were depressed, whereas the heterophil:lymphocyte ratio, an index of stress, was enhanced in Chernobyl swallows compared to controls. Spleen size was reduced in Chernobyl compared to that of two control populations. Sexual coloration varied significantly among populations, with the size of a secondary sexual character (the length of the outermost tail feathers) being positively related to coloration in the two control populations, but not in the Chernobyl population. Thus the positive covariation between coloration and sexual signalling disappeared in the population subject to intense radioactive contamination. These findings suggest that the reliable signalling function of secondary sexual characters breaks down under extreme environmental conditions, no longer providing reliable information about the health status of males.

Animals↗
PubMed2001

[A study on the effects of CD3AK cells on the improvement of cellular immune function in burned patients].

OBJECTIVE: To explore new ways of correcting postburn immune suppression in severely burned patients. METHODS: CD3AK cells were cultured in serum-free medium and were employed to treat patients with major burns. Similar patients treated by routine treatment were set to be control group. The changes of cellular immunological indices were dynamically observed in the patients of two groups at different time points. RESULTS: Compared to those in control group, the ratio of CD4+ cell of T cell subgroup increased in patients treated by CD3AK, in concomitant with the decrease of the ratio of CD8+ cells and the increase of the ratio of CD4/CD8. Serum soluble IL-2R level decreased. T lymphocyte transforming activity increased and NK cell activity increased. CONCLUSION: CD3AK cells cultured in serum-free medium could improve and restore the decreased cellular immune function in burn patients.

Adult↗
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↗
PubMed1999

Evolutionary process and the ecology of human immune function.

Evolutionary principles inform central design features of human immune defenses and provide key insights into this complicated host defense system. This article explores the selection pressures and adaptive responses that have elaborated the immune system over the course of evolution and discusses their implications for understanding contemporary immune development and function. Special attention is given to the challenges posed by diverse, rapidly evolving pathogens and the mammalian response to these challenges. The process of lymphocyte diversity generation and subsequent clonal selection is quintessentially Darwinian: pathogens provide selection pressure that drives differential replication of host immune cell lines, resulting in changes in genetic frequencies within an individual's population of lymphocytes. The immune system also incorporates nongenetic transgenerational processes in the transfer of antibodies from mother to offspring through the placenta and breast milk. The consequences of these observations for human development, health, and the ecology of immune function are considered throughout the life cycle. Specifically, evolutionary processes provide insight into autoimmunity, thymic function, lymphocyte development, infectious disease risk, and lactation. While much work in evolutionary medicine focuses on the discordance between evolved biology and rapidly changing cultural environments, with respect to the immune system, evolutionary processes may be most revealing when applied within individuals. Am. J. Hum. Biol. 11:705-717, 1999. Copyright 1999 Wiley-Liss, Inc.

Journal Article↗
PubMed2006

Rank in a food competition test and humoral immune functions in male Brandt's voles (Lasiopodomys brandtii).

Social status can influence an animal's immune and reproductive functions, eventually leading to alterations in immunocompetence and reproductive success. Here, we report that rank assessed in a food competition test, considered as an index of social status, has significant influences on humoral immune functions in male Brandt's voles (Lasiopodomys brandtii) living in a group. Our data reveal a negative correlation of the spleen mass and serum antibody levels with social status, as well as a positive correlation of serum cortisol levels with social status. Males winning in food competition had a smaller spleen, a lower level of serum antibodies, and a higher level of serum cortisol than did their conspecific counterparts. These data indicate interactions between social status and humoral immune functions and might illustrate a trade-off between infection risks and reproductive success in male Brandt's voles.

Animals↗
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↗
PubMed2001

Nutritional modulation of immune function.

The inflammatory response to injury and infection, although an essential part of immune function, carries the risk of severe tissue depletion and immunosuppression. These outcomes increase morbidity and delay recovery. Evidence is accumulating that single-nucleotide polymorphisms in the genes controlling pro-inflammatory cytokine production adversely influence the response. Immunonutrition provides a means of modulating the inflammatory response to injury and infection, and thereby improves clinical outcome. n-3 Polyunsaturated fatty acids (n-3 PUFA), glutamine, arginine, S amino acids and nucleotides are important components of immunonutrient mixes. While animal model studies suggest that all these components may exert a beneficial effect in patients, the number of large randomized placebo-controlled trials utilizing immunonutrition is fairly limited and the observed effects are relatively small. Meta-analyses suggest that while immunonutrition may not reduce mortality rates, a reduction in hospital length of stay, decreased requirements for ventilation and lower infection rates are achieved by this mode of nutrition. The present paper discusses some underlying reasons for the difficulty in demonstrating the clinical efficacy of immunonutrition. Paramount among these reasons is the antioxidant status and genetic background of the patient. A number of studies suggest that there is an inverse relationship between inflammation and T-cell function. Immuno-enhancive effects have been shown in a number of studies in which n-3 PUFA, glutamine and N-acetyl cysteine have been employed. All these nutrients may exert their effects by suppressing inflammation; n-3 PUFA by direct suppression of the process and glutamine and N-acetyl cysteine by acting indirectly on antioxidant status. Glutamine and nucleotides exert a direct effect on lymphocyte proliferation. Preliminary data suggests that not all genotypes are equally sensitive to the effects of immunonutrition. When further studies have been conducted to discern the precise interaction between each individual's genotype of relevance to the response to injury and infection, and immunonutrients, the level of precision in the application of immunonutrition will undoubtedly improve.

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↗