Resilience of the immune system in healthy young students to 30-hour sleep deprivation with psychological stress.

OBJECTIVE: Young adults often encounter sleep deprivation and stressful events. Both have been separately reported to modulate immunity, and occasionally they occur simultaneously. We assessed the combined effects of these conditions on immune competence in healthy students. METHODS: Twenty-three participants (mean age 24 years; SD 1.86; 14 females) were exposed to 30 h of sleep deprivation during which they conducted physiological, social and cognitive tasks. The control group consisted of 18 participants (mean age 23.67 years; SD 1.46; 11 females). All participants underwent cognitive and psychological evaluations at 10:00 AM, followed by blood and saliva collection, 3 days before sleep deprivation induction and on the morning following it. Immune/endocrine measures included blood counts of lymphocytes, granulocytes, monocytes and natural killer (NK) cells; levels of several cell surface markers; NK cytotoxicity; plasma levels of interleukin (IL)-6, IL-10, dehydroepiandrosterone and neuropeptide Y, and plasma and salivary cortisol levels. RESULTS: Although the experimental protocol significantly elevated state anxiety and psychological dissociation levels, no effects were evident in any of the immunological/endocrine indices. In contrast, expected sex differences in immune measures were found, including significantly higher NK cytotoxicity and monocyte counts in males, validating the integrity of the measurements. CONCLUSIONS: The findings suggest resilience of the immune system to a combined sleep deprivation and stressful exposure in young adults, while previous studies reported immune perturbations following either of these conditions separately. These apparent contradictions might reflect differences in the study design or in the methodology used for immunological assessments, including the time of sample collection, the combination of sleep deprivation with stress and our in vivo assessment of cytokine levels.

Effect of beta blocker combined with COX-2 inhibitor on colonic anastomosis in rats.

PURPOSE: Pharmacologic modulation of the perioperative physiologic stress response, using the beta-blocker propranolol, combined with the COX-2 inhibitor etodolac, has been shown to reduce metastatic spread and increase survival rates following surgery for primary tumor excision in rodents. Prior to implantation of this pharmacological approach in clinical trials in patients with colon cancer, the safety of this technique has to be evaluated. This study assessed the effects of these drugs on the healing of colonic anastomosis in rats. METHODS: Forty-eight F344 rats were divided into two groups, which were given seven daily subcutaneous injections of either vehicle, or propranolol (up to 1.2 mg/kg/day) combined with etodolac (12.5 mg/kg/day), starting the day before surgery. Each animal underwent laparotomy, colotomy of the descending colon, and anastomosis. Anastomotic leak rate and bursting pressure were compared at 1 week after the operation. The harvested anastomosis was histologically assessed for wound healing parameters. RESULTS: Forty-three rats survived the operation and were eligible for analysis at 1 week. No significant difference in survival, anastomotic leakage, or bursting pressure was found between animals that received propranolol and etodolac versus those receiving vehicle (drugs 179 mmHg ± 45.4; vehicle 187 mmHg, SD ± 35.0, p = 0.54). Histologic assessment of fibrosis, necrosis, cell infiltration, and tissue reaction zone did not differ between the two groups. CONCLUSIONS: Perioperative administration of propranolol and etodolac seems safe in colon operations in rats and does not affect anastomotic failure or colon healing.