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Journal Article 2004; 25(3): 207-210 PubMed PMID: 15349087 Citation  Keywords:  Adult, Concanavalin A:pharmacology, Depression:immunology, Depressive Disorder:immunology, Female, Humans, Lymphocyte Activation:drug effects, Male, Middle Aged, Mitogens:pharmacology, Phytohemagglutinins:pharmacology, Reference Values, T-Lymphocytes:drug.   

BACKGROUND: The biological basis of treatment resistance in depression still remains unclear. Some studies suggest that there exists a relationship between a disturbance in the immune system and depression.

AIMS: To investigate the immune status of patients with treatment resistant depression, we compared the in-vitro lymphocytic responses to three different mitogens in 10 drug-free patients with treatment resistant depression and 10 normal controls matched for age and sex.

RESULTS: We observed a marked increase in the lymphocyte mitogenic activity to mitogens of T lymphocytes.

DISCUSSION: This activation of lymphocyte function may be indicative of a pathological stimulation in cell-mediated immunity in patients with treatment resistant depression....

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Journal Article 2003; 24(3-4): 263-268 PubMed PMID: 14523368 Citation  Keywords:  Aging, Biogenic Amines:metabolism, CD4-Positive T-Lymphocytes:metabolism, CD8-Positive T-Lymphocytes:metabolism, Cell Division, Child, Preschool, Humans, Image Interpretation, Computer-Assisted, Immunohistochemistry, Infant, Peptide Hormones:biosynthesis,.   

OBJECTIVES: The immunocytochemical study of the localization of hormones in thymic cells has been performed to clarify possible correlations of their expression with proliferative activity of thymocytes.

METHODS: We used commercial antibodies to serotonin, melatonin, somatostatin, glucagon, gastrin, beta-endorphin and histamine, and ABP or BSP kits for visualization of reaction. Computer image analysis was used to find correlations between hormone production and proliferative activity of thymocytes.

RESULTS: Different subpopulations of thymocytes are able to produce hormones: precursors of T-lymphocytes (CD4-CD8-) contain serotonin and melatonin, immature cortical cells (CD4+CD8+) produce only serotonin, mature medullar cells (CD4+CD8-) show immunoreactivity to serotonin, melatonin, beta-endorphin and histamine. The expression of serotonin, somatostatin and gastrin is localized in thymic epithelial cells, formatting Gassal's bodies. Proliferative activity of thymocytes depends from the expression of serotonin and somatostatin in thymic cells.

CONCLUSION: The data received testify the expression of different hormones in human thymic cells and showing by this fact high endocrine activity of thymus. The presence of correlations between hormonal expression and cell proliferative activity could be considered as the bright illustration of important role of neuroimmunoendocrine mechanisms in the regulation of local thymic homeostasis....

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Journal Article 2003; 24(3-4): 215-223 PubMed PMID: 14523360 Citation  Keywords:  Aging:metabolism, Animals, Autoradiography, Cell Division:drug effects, DNA:biosynthesis, Male, Melatonin:pharmacology, Microscopy, Electron, Rats, Rats, Sprague-Dawley, Spleen:cytology, T-Lymphocytes:drug effects, Thymus Gland:drug effects,.   

OBJECTIVES: In this study we investigated the effect of melatonin treatment on the proliferative activity, the rate of DNA synthesis and the histopathological changes of splenic and thymic lymphocytes in old rats.

METHODS: Two subgroups of old rats (25-months-old) were used in this study. One subgroup was given melatonin in the drinking water (250-300 mg/day/rat) for 3 months while the second subgroup was given water containing diluent. A third group consisted of young rats (3-months-old) which served as an additional control.

RESULTS: A (3)H-thymidine autoradiographic investigation showed a reduction in both the proliferative activity and the rate of DNA synthesis in splenic and thymic lymphocytes in old rats. In addition, light and electron microscopy showed severe histopathological changes in these cells from diluent-treated old rats. Melatonin administration increased the proliferative activity and the rate of DNA synthesis in the lymphocytes of both the spleen and thymus of the old animals. Also, histopathological changes were partially reversed by melatonin treatment with the tissues appearing similar to those in the young rats.

CONCLUSION: The stimulation of the lymphocyte activity by melatonin is a beneficial response, especially in old rats, since aging results in an inhibition in lymphocytic functions....

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