In this study, the presence of calcification in an aneurysm was the sole marker of adverse outcome. Larger aneurysms tended to be more likely to be calcified. Size by itself did not have an adverse affect on outcome. Clipping or clip reconstruction of calcified aneurysms is a significant source of morbidity in the treatment of unruptured aneurysms (Odds ratio 7.8).

The influence of systemic or intracerebroventricular (icv) administration of angiotensin II on the intakes of NaCl solution, water, and food was investigated in BALB/c mice. Systemic administration of angiotensin II had little, if any, influence on these ingestive behaviors. On the other hand, icv infusion of angiotensin II at 70 ng/day increased (P less than 0.05) intakes of NaCl solution and water by the third day of infusion. The amount of NaCl ingested daily during the infusion was two to three times body sodium content. The mean daily water intake increased to 40-60% of body weight. The vast increase in NaCl intake was not secondary to a natriuresis caused by the icv infusion of angiotensin II. The results suggest that angiotensin II has a direct effect on neural systems involved in sodium appetite in this species.

Background: An association between obstructive sleep apnea (OSA) and Alzheimer's disease has been suggested but little is known about amyloid-␤ and tau deposition in this syndrome. Objective: To determine amyloid and tau burden and cognitive function in OSA in comparison with those without a diagnosis of OSA. Methods: The status of OSA was determined by asking participants about history of polysomnographic diagnosis of OSA and the use of Continuous Positive Airway Pressure (CPAP). A comprehensive neuropsychological battery measured cognitive function. Positron emission tomography (PET) was used to measure standardized uptake value ratio (SUVR) of 18 F-florbetaben and 18 F-AV1451, to quantify amyloid and tau burden. Results: 119 male Vietnam veterans completed assessment. Impairment in visual attention and processing speed and increased body mass index (BMI) were seen in subjects with OSA compared with those without a diagnosis OSA. The cortical uptake of 18 F-florbetaben was higher in the OSA group than in the control group (SUVR: 1.35 ± 0.21 versus 1.27 ± 0.16, p = 0.04). There were more apolipoprotein E 4 allele (APOE 4) carriers in the OSA group than in the control group. In multilinear regression analysis, the significance of OSA in predicting 18 F-florbetaben uptake remained independent of age and vascular risk factors but not when BMI or APOE 4 was adjusted. The reported use of CPAP (n = 14) had no effect on cognitive or amyloid PET findings. There was no significant difference in 18 F-AV1451 uptake between the two groups. Conclusions: Obstructive sleep apnea is associated with Alzheimer's disease pathology, but this relationship is moderated by APOE 4 and BMI.

A main vector of the effects of stress is secretion of corticotrophin releasing factor (CRF), adrenocorticotrophin (ACTH), and adrenal steroids. Systemic administration of ACTH (2.8 microgram/day sc) for 7 days in BALB/c mice caused a very large increase of voluntary intake of 0.3 M NaCl equivalent to turnover of total body sodium content each day. Intracerebroventricular infusion of ACTH (20 ng/day) had no effect. Intracerebroventricular infusion of ovine CRF (10 ng/h for 7 days) caused an increase of sodium intake. The large sodium appetite-stimulating effect of systemic ACTH was not influenced by concurrent systemic infusion of captopril (2 mg/day). Induction of stress by immobilization of mice on a running wheel caused an increase in Na appetite associated with a 50% decrease of thymus weight, indicative of corticosteroid effects. The present data suggest that stress and the hormone cascade initiated by stress evoke a large sodium appetite in mice, which may be an important survival mechanism in environmental conditions causing stress.