Low doses of dexamethasone affect immune parameters in the absence of immunological stimulation.

Recent findings suggest an important role of subtle changes in the plasma levels of inflammatory cytokines within the brain-immune interplay. It is unclear how such changes are regulated in the absence of acute inflammatory or infectious stimuli. Endocrine systems are a good candidate, because innate immunity and the hypothalamo-pituitary-adrenal (HPA)-system are closely related: glucocorticoids have immunosuppressive properties and modulate cytokine release from stimulated mononuclear blood cells in vitro and the immune response in vivo, but it still remains unclear, whether they also modulate circulating cytokine levels in the absence of immunological stimuli. We measured the influence of 1.5 or 3.0 mg dexamethasone (DEX) per os at 09:00 or 21:00 hours on body temperature, cortisol plasma levels, differential white blood cell counts, and cytokine plasma levels in 40 healthy male volunteers using a double-blind, placebo-controlled study design. In addition to significant morning-evening differences in tympanic temperature and several immune parameters, we found that DEX-intake significantly increased tympanic temperature, decreased cortisol plasma levels, altered differential white blood cell counts and induced changes in unstimulated plasma cytokine levels. Whereas the levels of TNF-alpha and sTNF-R p75 were reduced, the levels of sTNF-R p55 increased after a transient decrease.

Estriol ameliorates autoimmune demyelinating disease: implications for multiple sclerosis.

OBJECTIVE: To evaluate the use of estriol in the treatment of experimental autoimmune encephalomyelitis (EAE) and other cell mediated autoimmune diseases. BACKGROUND: Experimental autoimmune encephalomyelitis is a T helper 1 (Th1)-mediated autoimmune demyelinating disease that is a useful model for the study of immune responses in MS. Interestingly, both EAE and MS have been shown to be ameliorated during late pregnancy. METHODS: Estriol, progesterone, and placebo pellets were implanted in mice during the effector phase of adoptive EAE. Disease scores were compared between treatment groups, and autoantigen-specific humoral and cellular responses were examined. RESULTS: Estriol treatment reduced the severity of EAE significantly compared with placebo treatment whereas progesterone treatment had no effect. Estriol doses that induced serum estriol levels that approximated estriol levels during late pregnancy were capable of ameliorating disease. Estriol-treated EAE mice had significantly higher levels of serum antibodies of the immunoglobulin (Ig) G1 isotype specific for the autoantigen myelin basic protein (MBP). Further, MBP-specific T-lymphocyte responses from estriol-treated EAE mice were characterized by significantly increased production of the Th2 cytokine interleukin 10 (IL-10). T lymphocytes were shown to be the primary source of IL-10 within antigen-stimulated splenocyte populations. CONCLUSIONS: Estriol as a hormone involved in immune changes during pregnancy may provide a basis for the novel therapeutic use of estriol for MS and other putative Th1-mediated autoimmune diseases that improve during late pregnancy.

Normal plasma levels of orexin A (hypocretin-1) in narcoleptic patients.

Deficient orexin signaling has been shown to cause narcolepsy-like conditions in animals. In human narcolepsy, CSF levels of orexin A (hypocretin-1) were reported to be low in most cases. The authors measured CSF and plasma orexin A levels in patients with narcolepsy and in controls. Confirming earlier studies, they found CSF orexin A levels to be extremely low in patients with narcolepsy. However, plasma orexin A levels did not differ from those observed in controls. These results suggest that orexin deficiency in patients with narcolepsy is a phenomena restricted to the CNS.

Genetic analysis of field germination in soybean (Glycine max. (L) merill.).

Genetic analysis for germination percentage was carried out in the F3 and F4 generations of a diallel cross involving six promising genotypes of soybean. Results indicated a high amount of genetic variability and a moderately high heritability together with genetic advance, suggesting a possible improvement for this character through hybridization and selection. Correlations at different levels revealed a strong negative association of germination with only one seed character: seed weight. This observation was further confirmed from path coefficient analysis. These findings strongly suggest that to base selection on seed weight which may not influence the seed quality of soybean.