Biomedical subjects

A Winokur

Publications and source records attributed to A Winokur.

113 records · Page 7Linked to original sources

PubMedDate not supplied

The oCRH stimulation test before and after clinical recovery from depression.

A substantial body of data suggests that excessive cortisol secretion in depression may result from a dysregulation at several sites within the hypothalamic-pituitary-adrenocortical (HPA) axis. These alterations in regulatory mechanisms are thought to be the result of a hypothalamic 'overdrive' of corticotropin-releasing hormone (CRH). Previous studies have demonstrated a diminished adrenocorticotropin (ACTH) secretory response, as well as a heightened adrenocortical responsiveness after ovine-CRH administration in depressed patients. In the present investigation, we examined pituitary and adrenocortical responsiveness after an ovine-CRH stimulation test before and during clinical recovery in seven depressed patients. Cumulative ACTH responses increased significantly during clinical recovery (P = 0.014). Paradoxically, maximum and peak cortisol responses increased after recovery, suggesting that heightened adrenocortical responsiveness to ACTH during depression may take longer to 'normalize' than abnormal pituitary responsiveness to ovine-CRH stimulation.

Adrenocorticotropic Hormone↗

PubMedDate not supplied

Immunohistochemical localization of TRH in rat CNS: comparison with RIA studies.

The localization of thyrotropin releasing hormone (TRH) in rat brain determined by use of avidin-biotin immunoperoxidase histochemistry was compared with the distribution and quantitation by radioimmunoassay (RIA). Male Sprague-Dawley rats received intracisternal injections of 100 micrograms of colchicine or saline and were sacrificed 24 hours later. Brains were either perfused with lysine-periodate fixative and processed for TRH immunohistochemistry or were dissected into 9 brain regions for TRH RIA. In colchicine pretreated rats. TRH immunoreactive perikarya were observed only in nuclei of the hypothalamus and brain stem. No cell body staining was observable in non-colchicine treated rats. With the exception of the olfactory bulb, brain regions exhibiting dense TRH staining contained high concentrations of TRH as measured by RIA. Colchicine pretreatment did not alter the concentration of TRH in most brain regions, however, there was a significant increase in brain stem TRH content 24 hours following colchicine administration. These findings indicate that immunohistochemical localization of TRH corresponds well with endogenous concentrations of TRH determined by RIA.

Animals↗

PubMedDate not supplied

Spinal cord immunoreactive TRH is altered after local traumatic injury.

The effect of impaction-induced spinal trauma on the concentration of immunoreactive TRH (TRH-ir) in the spinal cord was studied. Samples were obtained from tissues proximal to, distal to, and at the site of injury at 30 min, 1 hr, 4 hr, and 6 weeks after impaction. After an initial 38% depletion of TRH-ir at the injury site at 30 min, concentrations were progressively elevated over time at all sites. These elevations reached statistical significance in the proximal and distal segments by 4 hr posttrauma. By 6 weeks, a rostral-caudal gradient of TRH-ir concentration was observed, indicating that axoplasmic transport was restricted. The gradient was characterized by a significant TRH-ir elevation proximal to, and a 60% depletion distal to, the injury. The short-term TRH-ir elevation measured indicates that the ability of exogenously administered TRH to reduce the incidence of posttraumatic functional deficit stems from a restoration of endogenous TRH action. The role of the raphe-spinal tract in the development of traumatic paralysis is considered.

Animals↗

PubMedDate not supplied

Diurnal variation of growth hormone secretion following thyrotropin-releasing hormone infusion in normal men.

Growth hormone (GH) secretion following a standard intravenous dose of thyrotropin-releasing hormone (TRH) was studied in eight healthy young men in the morning (0800h), in the evening (2000h), and after an acute 12-hr shift of the rest-activity cycle. The maximal increment in serum GH concentration following TRH administration was significantly greater in the evening than in either the morning or evening after reversal of the rest-activity cycle (p less than 0.02). Seven of the eight subjects showed an increase in serum GH following TRH in the evening but not after rest--activity reversal (p less than 0.01). Only one subject showed a GH response during one of two morning trials. Serum GH concentration was also increased in two of six subjects following saline infusion in the evening. These findings indicate that the GH response to TRH may depend on the phase of GH secretory activity at the time of testing. The GH responses to TRH reported in various disease states may, therefore, reflect alterations in the GH secretory rhythm or disturbances in circadian rest--activity patterns.

Adult↗

PubMedDate not supplied

Association between subjective sleep quality and depression on immunocompetence in low-income women at risk for cervical cancer.

OBJECTIVE: The purpose of this study was to investigate whether subjective sleep quality is more strongly associated with immunocompetence than depression among women at risk for cervical cancer. METHODS: Participants were 91 women referred for colposcopy because of abnormal results on a Pap smear. On the day of the procedure. participants completed the Center for Epidemiological Studies Depression Scale, two indices of subjective sleep quality (ie, satisfaction with sleep obtained and degree of sleep restfulness), and a health behaviors assessment questionnaire. Levels of peripheral blood lymphocyte subpopulations (helper T, cytotoxic/suppressor T, NK, and B cells) were also assessed at this time. Approximately 10 days later, the presence of depressive disorder was assessed using the Structured Clinical Interview for DSM-III-R. RESULTS: Hierarchical regression analyses revealed that satisfaction with the amount of sleep obtained was significantly associated with the circulating number and percentage of helper T cells (T(H)/CD4+) and the percentage of cytotoxic/suppressor T cells (T(C)/CD8+), after controlling for confounder variables (ie, age, smoking status, and drug use). Depression was significantly associated only with the percentage of T(C) cells. Sleep satisfaction remained significantly associated with the number and percentage of T(H) cells and percentage of T(C) cells after controlling for the variance explained by depression. CONCLUSIONS: Results of this study suggest that subjective sleep quality shares a significant and independent portion of the variance with immunity that is not accounted for by depression. Although the long-term impact of these immune alterations on disease progression needs to be directly explored, it may be important to systematically screen for and manage sleep disturbance in women at high risk for cervical cancer.

Adolescent↗