Naïve and memory CD8 T cell pool homeostasis in advanced aging: impact of age and of antigen-specific responses to cytomegalovirus.

Alterations in the circulating CD8+ T cell pool, with a loss of naïve and accumulation of effector/effector memory cells, are pronounced in older adults. However, homeostatic forces that dictate such changes remain incompletely understood. This observational cross-sectional study explored the basis for variability of CD8+ T cell number and composition of its main subsets: naïve, central memory and effector memory T cells, in 131 cytomegalovirus (CMV) seropositive subjects aged over 60 years.

Glucoreceptors located in the brain mediate NPY release induced by hypoglycemia in normal men.

The NPY secretory pattern after an insulin tolerance test (ITT) (0.15 IU/kg body weight) was evaluated in 8 normal men. They were infused with normal saline (control test), glucose or fructose.

Naloxone decreases the inhibitory effect of alprazolam on the release of adrenocorticotropin/cortisol induced by physical exercise in man.

What Is Already Known About This Subject: • Alprazolam (ALP), a benzodiazepine activating GABAergic receptors, is involved in ACTH secretion.

What This Study Adds: • This study demonstrates a partial opioid influence in the inhibitory effect of ALP on the release of ACTH/cortisol during physical exercise.

Aims: To establish the possible involvement of alprazolam (ALP) and/or opiates in the mechanism underlying the ACTH/cortisol response to physical exercise.

Naloxone decreases the inhibitory effect of somatostatin on GH release induced by cigarette smoking in man.

To establish whether somatostatin (SRIH) exerts its inhibitory effect on the nicotine-induced release of GH by interacting with an opioid pathway, normal volunteers were treated with naloxone during (2 no-filter) cigarettes smoking and with SRIH. Nicotine significantly increased serum GH levels about 3.5 fold.

Increased arginine-vasopressin response to hypertonic stimulation and upright posture in idiopathic hyperprolactinemia.

To evaluate the possible influence of idiopathic hyperprolactinemia on the arginine-vasopressin (AVP) response to osmotic and pressure-volumetric stimuli, 14 idiopathic hyperprolactinemic women and 13 normoprolactinemic women were studied during a hypertonic saline infusion test (0.51M NaCl infusion for 2h) and an orthostatic test (standing upright and maintaining an orthostatic position for 20min). In both experimental conditions, the AVP response was significantly higher in women with idiopathic hyperprolactinemia than in normal normoprolactinemic women.

Oxytocin does not modify GH, ACTH, cortisol and prolactin responses to Ghrelin in normal men.

Background: In order to test the possible effect of Oxytocin (OT) on Ghrelin-stimulated GH, PRL, ACTH and cortisol, ten healthy normal men were studied.

Tests: Ghrelin (0.2 μg/kg body weight (BW)) as an iv bolus; Ghrelin plus OT (2 IU as bolus plus 0.

Intense antiextracellular adaptive immune response to human cytomegalovirus in very old subjects with impaired health and cognitive and functional status.

Human aging is characterized by expanded and altered adaptive immune responses to human CMV (HCMV). It is unclear whether this expansion has its origins in age-related homeostatic disturbances or viral reactivation, whether anti-CMV immune surveillance may still be effective, and what are the consequences of this expanded immune response for health and longevity. We conducted an observational cross-sectional study in groups of HCMV-seropositive subjects aged >or=65 y of variable health status to compare the intensity of Ab responses against HCMV with those against EBV and with CD4(+) and CD8(+) T cell proinflammatory effector responses directed to HCMV-derived pp65 and immediate-early protein 1 synthetic peptides.