Prevalence and Impact of Treatment-Resistant Depression in Latin America: a Prospective, Observational Study.

Approximately one-third of patients with major depressive disorder (MDD) have treatment-resistant depression (TRD). The TRAL study will evaluate the prevalence and impact of TRD among patients with MDD in four Latin American countries. In this multicenter, prospective, observational study, patients with MDD were recruited from 33 reference sites in Mexico, Colombia, Brazil, and Argentina.

Alterations in GAP-43-immunoreactive innervation in the aging rat pituitary.

The levels and distribution of the growth-associated protein, GAP-43, were examined in the pituitary glands of young and aging Sprague-Dawley rats, using immunohistochemical techniques on tissue sections and Western blot analyses. GAP-43-immunoreactive innervation was observed in sections in the intermediate and neural lobes of animals aged 8-15 months, while in the oldest rats studied (17 months), stained fibers were observed mainly in the neural, but not the intermediate lobe. Western blots revealed reduced levels of GAP-43 in samples from 15 month old animals, as compared to 12 month old rats, in the neurointermediate lobes.

Regulation of pituitary beta-endorphin secretion in aging rats: in vitro responsiveness to dopamine.

The intermediate lobe of the mammalian pituitary is highly responsive to dopamine inhibition of beta-endorphin secretion. In this study, the ability of aged (12 months) intermediate lobes to respond to dopamine was compared to that of young (6 weeks) tissue, using a short-term in vitro incubation of isolated rat neurointermediate lobes, with measurement of peptide release by radioimmunoassay. Tissue from the aged rats released greater amounts of beta-endorphin peptide than amounts measured from young tissue at all time periods studied.

GAP-43-Immunoreactive Nerve Fibers in the Rat Pituitary: Modulation after 6-Hydroxydopamine-Induced Degeneration and Regeneration.

This study demonstrates the presence of the growth-associated protein, GAP-43, in nerve fibers innervating the adult rat neurointermediate pituitary. Previous studies demonstrated that innervation to the proopiomelanocortin cells of the intermediate pituitary could undergo degeneration after chemical denervation with 6-hydroxydopamine (6-OHDA), followed by recovery/regeneration of terminals 3 to 4 weeks after drug treatment. Here, we investigated the modulation of GAP-43 levels following chemical denervation of the pituitary.

Effects of the enkephalin analog (D-Met2,Pro5)-enkephalinamide on alpha-melanocyte-stimulating hormone secretion.

We used the met-enkephalin analog (D-Met2,Pro5)-enkephalinamide (DMPEA) to investigate enkephalinergic control of alpha-melanocyte-stimulating hormone (alpha-MSH) secretion. Systemic (s.c.