A microcomputer-based device to simulate biomechanical environments for cultured cells.

We describe software and hardware for a microcomputer-based cyclic strain device which applies programmed cycles of elongation and relaxation to cultured cells. This system has the potential to simulate many of the complex mechanically active environments found in living systems. As a sample application, we use it to simulate the cyclic stresses to which vascular smooth muscle cells in the arterial system are exposed.

Plasma MHPG levels in lactate and isoproterenol anxiety states.

It has been claimed that an increase in brain noradrenergic activity plays a role in panic disorder and that enhanced noradrenergic activity may be reflected by plasma levels of MHPG. We investigated plasma MHPG levels in panic disorder patients at baseline and during lactate- and isoproterenol-induced anxiety states. These infusions and 5% dextrose infusions were given to 10 panic disorder patients and 9 healthy control subjects.

Cholinergic REM induction response: separation of anxiety and depression.

Five groups of subjects underwent EEG sleep recordings, arecoline rapid eye movement (REM) induction response testing, and Schedule for Affective Disorders and Schizophrenia (SADS) interview. Group I: 20 patients with primary major depressive disorder (MDD) (endogenous) without any coexisting anxiety disorder; Group II: 19 primary MDD (endogenous) patients with secondary panic, GAD, or phobic disorders; Group III: 18 patients with primary anxiety disorder without coexisting MDD; Group IV: 14 patients with primary anxiety plus secondary MDD; Group V: 26 normal controls. Modified Research Diagnostic Criteria (RDC) were used for diagnosis, based on the SADS interview.

Ambulatory monitoring of panic disorder.

Twelve patients with panic disorder and 11 control subjects received 24-hour ambulatory monitoring of heart rate, finger temperature, ambient temperature, and self-rated anxiety. No differences were found between groups in tonic levels of any measure or in their patterns of variation throughout the day. However, substantial heart rate increases and finger temperature changes did occur in panic attacks but not during control periods having equally high anxiety ratings.