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Query: UMLS:C0011570 (depression)
 172,036 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Millions of people have been exposed to silicones which are present in consumer goods such as cosmetics and toiletries, processed foods and household products. In addition, silicones have been used extensively in medical practice as a lubricant in tubing and syringes, and as implantable devices. A silicone widely used in medical practice is polydimethylsiloxane. This study was undertaken to determine the immunotoxicologic potential of long term exposure to the principal constituents of breast implants: silicone fluid, silicone gel and silicone elastomer. An alternative covering for devices containing silicone gels, polyurethane, was also included in the study. Silicone fluid and gel were injected subcutaneously into female B6C3F1 mice (1 ml/mouse) and 6 mm disks of silicone elastomer or polyurethane were implanted subcutaneously. There were no treatment-related deaths or overt signs of toxicity during the 180 day exposure. None of the tested materials had notable effects on body or organ weights, erythrocytes or leukocytes in the blood, blood chemistries such as alanine aminotransferase, urea nitrogen, glucose, albumin or total protein, or serum CH 50 or C3 levels. The cellularity of the bone marrow and responses to CSF-GM and CSF-M were normal. The tested silicones and polyurethane marginally reduced the level of Ig+ cells in the spleen but did not consistently alter the distribution of T cell surface markers. The antibody response to sheep erythrocytes was not markedly altered, nor were proliferative responses to concanavalin A, phytohemagglutinin, lipopolysaccharide or allogeneic cells. Reticuloendothelial function was normal, as was phagocytosis of chicken erythrocytes and Covaspheres by adherent peritoneal cells. Natural killer cell activity was depressed in all silicone treatment groups and in mice implanted with polyurethane. No silicone or polyurethane treatment group displayed altered susceptibility to a challenge with Listeria monocytogenes, Streptococcus pneumoniae or the B16F10 tumor. The only consistent effect of 180 day exposure to silicone materials or polyurethane was a modest depression of natural killer cell activity.
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PMID:Immunotoxicity of 180 day exposure to polydimethylsiloxane (silicone) fluid, gel and elastomer and polyurethane disks in female B6C3F1 mice. 798 84

One of the most consistently reported immunological abnormalities in major depression is blunted ex vivo natural killer cell activity (NKCA). This study was designed to investigate the number and percentage of circulating natural killer cells (NKC) in a group of patients with unipolar depression. In addition, the number and percentage of other phagocytic/cytotoxic cells were determined. The following cell subsets were investigated: number of leukocytes, monocytes, neutrophils, lymphocytes, NKC (CD16+ or CD56+), and non-MHC-restricted cytotoxic T lymphocytes (CTL) in 17 healthy controls and 79 depressed subjects. There were no differences either in absolute number or percentage of NKC, or CTL between healthy controls, minor, simple major, and melancholic depressed subjects. Depression per se was characterized by a leukocytosis due to monocytosis and neutrophilia. Our results do not support the thesis that depression-related blunted NKCA is caused by a decreased number or percentage of NKC in peripheral blood.
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PMID:Absolute number and percentage of circulating natural killer, non-MHC-restricted T cytotoxic, and phagocytic cells in unipolar depression. 804 41

The effects of skeletal unloading using antiorthostatic tail suspension on the mouse immune system are tissue specific. This phenomenon was demonstrated by analyzing cells from the lymph nodes, spleen, and bone marrow. Phytohemagglutinin-induced T-cell proliferation was depressed in lymph nodes after 11 days of antiorthostatic suspension. In contrast, splenic T-cell proliferation in response to phytohemagglutinin was enhanced. Splenic natural killer cell cytotoxicity was unchanged after suspension, which demonstrated the organ- and cell-specific effects of skeletal unloading. Whereas antiorthostatic suspension induced minimal changes in bone, there was a significant depression in the number of macrophage precursors in the bone marrow. Overall, skeletally unloaded animals had slightly higher blood corticosterone levels than did control animals; however, it did not appear to be responsible for the observed changes. In conclusion, skeletal unloading produces organ- and cell-specific changes in the murine immune system rather than a generalized immunosuppression.
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PMID:Skeletal unloading causes organ-specific changes in immune cell responses. 812 97

In the new field of psychoneuroimmunology essential ground has already been broken. Precisely in man, however, only hypotheses are possible in important areas: one that is commonly voiced is that stress weakens the immune system and would favour the onset of disease. A situation report is presented which summarizes, classifies and compares all 67 published studies relating psychic influences to immunologic factors in healthy human beings. A notable proportion turned out to be doubtful from the formal standpoint, e.g. no controls (40 publications) or with fewer than 30 probands (19). In 13 of these studies neuroendocrinologic parameters were taken into account and in 14 biological (health/disease) parameters. 42 studies were based on "externally defined" stress situations (partner loss, examinations, care of severely ill family members, space shuttle mission, etc.), 16 on specific personality traits and 9 on experimental stress situations or relaxation efforts. Since the studies varied widely in design, psychic starting position, psychic assessment (91 different methods) and immunity (68 varying parameters) and also in regard to the biological result (various "endpoints" of health/disease), only a few general conclusions can be drawn. Subjective or objective stress can be associated with diminished lymphocyte functions such as reduced mitogen stimulation and natural killer cell activity, elevated antibody titers against some latent and/or ubiquitous viruses, and reduced immunoglobulin A in saliva. This is confirmed to varying degrees, usually on a shortterm basis and not in all studies. Others contain evidence that the immunologic changes mentioned may be associated with particular personality traits (anxiety, depression, loneliness, good coping, power motive syndrome, social support, etc.). What the immunologic changes had in common was that they moved within a relatively narrow range and overstepped the norm little or only marginally. Whether the immunologic "anomalies" observed reflect a weakened immune system or an adequate "homeostatic" immune modulation by psychic signals, or point to adequate immune defence in an altered "antigen situation" arising from a changed lifestyle in stress situations, cannot be said. There is little evidence of a relationship to disease onset. While the present review shows certain relationships between psychic and immunologic factors, their biological relevance remains unclear. The often voiced hypothesis that stress weakens the immune system and a larger number of diseases therefore ensue cannot be confirmed or denied by the available data. The results permit other, contradictory hypotheses.
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PMID:[Psyche and immunity. A selected literature study of psychoneuroimmunology in healthy persons]. 827 8

Despite undergoing a curative resection, many patients with colorectal cancer will develop and die of metastatic disease. It has been shown clinically and experimentally that surgery causes a transient period of immunosuppression, and it is postulated that this may encourage both the implantation of surgically disseminated tumor cells and the growth of existing micrometastases. The present study used natural killer cell cytotoxicity (NKCC) and tumor burden to evaluate perioperative modulation of immunocompetence in a murine model. We measured NKCC and tumor burden responses to a standardized surgical stress (SSS) alone, and to either morphine sulfate (MS) (15 mg/kg subcutaneously x 4 doses), ketorolac (a prostaglandin synthetase--prostaglandin E2--inhibitor) (2.5 mg/kg subcutaneously x 4 doses), or interleukin 2 (2,000 units intraperitoneally x 3 doses) administration with the SSS. In this model, we found that both low-dose interleukin-2 (IL-2) and ketorolac reversed the NKCC suppression associated with surgery, whereas morphine resulted in further depression of NKCC. In addition, IL-2 significantly decreased tumor incidence, whereas continuous MS exposure markedly increased tumor burden after surgery. These data suggest that IL-2 and ketorolac may be effective agents for the restoration of perioperative immune competence, whereas the use of continuous morphine might have significant deleterious effects.
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PMID:Perioperative immunomodulation in cancer surgery. 831 Nov 30

A meta-analysis indicated that clinical depression was associated with several large alterations in cellular immunity. Analyzing only methodologically sound studies, reliable immune alterations included lowered proliferative response of lymphocytes to mitogens (effect size rs = .24-.45), lowered natural killer cell activity (r = .28), and alterations in numbers of several white blood cell populations (rs = .11-.77). Immune alterations were greater in both older and hospitalized samples. There was also evidence of a linear relation between intensity of depressive affect and indicators of cellular immunity. Estimates of sample sizes needed to detect reliable effects for each immune outcome are provided. How neuroendocrine mechanisms or health practices might link depression to immunity is discussed, and design features needed to better understand these pathways are specified.
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PMID:Depression and immunity: a meta-analytic review. 831 10

We studied natural killer cell (NK) activity in 20 severely handicapped children and investigated the relationship between NK activity and malnutrition. We divided our patients into two groups with regard to frequency of infections: high frequency group (group 1) and low frequency group (group 2). NK activity in group 1 was low in comparison with group 2. Calorie intake and Rohrer's index were lower in group 1. Serum albumin (Alb) and iron (Fe) in group 1 were also lower than those in group 2, and serum zinc (Zn) and hemoglobin (Hb) were slightly lower in group 1. NK activity was positively correlated with calorie intake, Alb, Zn and Hb. Six patients with low NK activity were given supplementary diet; two patients were given protein-enriched diet; three patients were given protein-enriched diet and zinc sulfate; one patient was given increased diet. NK activity rose in 4 patients. These results indicated that the depression of NK activity was associated with frequent infections and correlated with nutritional conditions of the severely handicapped children.
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PMID:[Natural killer cell activity in severely handicapped children: correlation with malnutrition and frequent infections]. 841 95

This study examined relationships between psychologic characteristics and enumerative immune responses to an acute laboratory stressor. Lymphocyte subsets were measured in 104 subjects at rest and following a 6-minute laboratory naturalistic speaking stressor. Multiple linear regression was utilized to assess relationships between immune reactivity (change scores) and anger expression, hostility, anxiety, depression, and stress. The task resulted in significant increases over baseline in WBC (p < 0.001), T-suppressor/cytotoxic CD8 cells (p = 0.010) natural killer CD56 cells (p < 0.0001), and CD57 (p < 0.0001) cells, and significant decreases in T-cells (p = 0.012), T-helper cells (p = 0.003), B-cells (p < 0.001), and the T-helper/suppressor ratio (p < 0.001). In general, the regression suggested that moderate associations exist between certain psychologic attributes and acute subset redistribution. For example, the increase in natural killer cell subsets was significantly negatively associated with anger expression, hostility, and depression. Suppressor/cytotoxic (CD8) cell reactivity was associated with baseline as well as with the task-induced changes in anxiety. B-cell (CD19) responses were related to the subject's age, expression of anger, and depression scores. As with the cardiovascular reactivity literature, these findings suggest that a relationship exists between certain psychologic characteristics such as anger and anxiety and immune reactivity to acute stress.
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PMID:Psychologic characteristics associated with acute stressor-induced leukocyte subset redistribution. 873 22

Decreased immunity in depressive as compared with control subjects has been well documented, although some depressed patients have severe alterations whereas others have milder ones or not at all. Since for equal severities of depression, there may be individual differences in the degree of perceived control over one's condition, we investigated the interaction of perceived control with immunological variations. Immune function (T and B lymphocytes, lymphocyte proliferation and natural killer cell activity (NKCA)) were evaluated in 34 adult major depressives and in 18 healthy controls. Lymphocyte proliferation did not differ between the two groups, but NKCA was significantly lower in the depressed patient group. Among the depressed subjects, those who experienced less subjective control also showed significantly lower NKCA. An internal locus of control appears to act as a buffer against the decrease in cellular immunity observed in major depression. Further studies should focus on methods of coping and on degree of perceived control rather than on diagnostic and nosographic variables alone.
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PMID:From health locus of control to immune control: internal locus of control has a buffering effect on natural killer cell activity decrease in major depression. 884 55

Interferon-gamma (IFN-gamma) has the most potent immunomodulatory activity of all the interferons. This phase II-B study was performed to define time- and dose-dependent immunomodulatory effects mediated by IFN-gamma in a subset of patients with melanoma treated in the dose-seeking therapeutic trial conducted by the Eastern Cooperative Oncology Group E4687 (13). The effects of IFN-gamma (Genentech, San Francisco, CA) were evaluated for phenotype and function of peripheral blood lymphocytes obtained twice prestudy, and on days 2, 9, and 29 of IFN-gamma therapy for 50 patients. Early significant increases in CD4/CD8 ratio (p = 0.001) were noted, largely due to a rise in CD4+ and fall in CD8+ T-cell populations sustained through day 29 at only the lowest dosage. Increased natural killer cell (NK) activity (p = 0.001 on day 9; p = 0.01 on day 29) was accompanied by durable increases in circulating activated NK cells (CD56+DR+% p = 0.001, day 9; p = 0.001, day 29). After initial depression of CD56+ and CD16+ cells on day 2, the total percent of CD56+ and CD16+ cells increased significantly by day 29. Increases in NK cell activity were maximal at doses > or =0.1 mg. Monocyte CD14+ expression of DQ+ rose early (p = 0.011 and 0.001 on days 2 and 9), accompanied by elevation in CD14+DR+ cells that was less significant. Immunomodulatory effects of IFN-gamma reported in this trial have major implications for interpretation of past and current clinical trials, and the design of future trials. This is the first trial in which IFN-gamma has been shown to have significant effects on the T-cell compartment of the immune system.
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PMID:Immunomodulatory function of interferon-gamma in patients with metastatic melanoma: results of a phase II-B trial in subjects with metastatic melanoma, ECOG study E 4987. Eastern Cooperative Oncology Group. 908 87


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