We employed fluorocarbon-23 (trifluoromethane) as a nuclear magnetic resonance gaseous indicator of cerebral blood flow in seven cats. Pulsed inhalation of this indicator and switching between two coils allowed the acquisition of both an arterial input and a cerebral response function, making possible multicompartmental curve fits to cerebral uptake and clearance data. The brain:blood partition...

OBJECTIVE The authors examined the effect of panic provocation on the subsequent development of panic attacks and panic disorder in nonclinical subjects with no history of spontaneous panic. METHOD Sixty-two subjects who had completed a study examining fearful responses to a single vital capacity inhalation of 35% CO2 were reevaluated 1 year following the challenge test. RESULTS Challenge-i...

Background: Hazardous chemical agents in the welding operation are a mixture of metal fumes and toxic gases, the inhalation of which causes adverse health effects among welders. The emission of gases in the workplace is a logical cause for concern regarding the potential development of respiratory disease. The aim of the present study was to determine the concentration values of gases discharge...

Individuals with cor pulmonale secondary to chronic pulmonary emphysema tend to have pulmonary ventilation which is less than normal both at rest and during exercise, despite the presence of factors ordinarily making for increased ventilation such as anoxemia and acidosis (1), and despite the fact that these ventilatory levels may be appreciably less than the observed maximum breathing capacity...

In order to estimate to what extent the stimulatory action of CO2 on ventilation is mediated by the formation of H+, we studied effects on the temporal profile of ventilatory response to CO2 of carbonic anhydrase (CA) inhibition with acetazolamide in the halothane anesthetized spontaneously breathing rat. Since hydration reaction of CO2 yielding H+ is delayed by CA inhibition, the time courses ...

Circulatory, chemical, and ventilatory response factors in Cheyne-Stokes respiration (CSR) were studied by experimental procedures and by mathematical analysis. Hemodynamic, ventilatory, and blood gas patterns in 16 patients with heart disease and CSR (group A) and 16 patients with congestive heart failure (CHF) without CSR (group B) were compared. CO2 and oxygen were administered to group A. T...

Circulatory, chemical, and ventilatory response factors in Cheyne-Stokes respiration (CSR) were studied by experimental procedures and by mathematical analysis. Hemodynamic, ventilatory, and blood gas patterns in 16 patients with heart disease and CSR (group A) and 16 patients with congestive heart failure (CHF) without CSR (group B) were compared. CO2 and oxygen were administered to group A. T...