The continuous assessment of cerebrovascular reactivity: a validation of the method in healthy volunteers.

UNLABELLED: Using transcranial Doppler ultrasonography, we investigated the moving correlation between slow waves in arterial blood pressure (ABP) and blood flow velocity (FV) at different levels of cerebrovascular vasodilation provoked by changing PETCO2. Fourteen healthy volunteers were examined. The FV in middle cerebral arteries, PETCO2, and ABP were recorded during normocapnia, hypercapnia, and hypocapnia. The moving correlation coefficients between ABP and mean FV (FVm) or systolic FV (FVs) during spontaneous fluctuations in ABP were calculated for 3-min epochs and averaged for each investigation, thus yielding the mean index (Mx) and systolic index (Sx). As a reference method, Aaslid's cuff tests were performed to obtain the rate of regulation (RoR). RoR, Mx, and Sx significantly depended on PETCO2 (analysis of variance, P < 0.00001). At high PETCO2, cerebrovascular reactivity was disturbed as reflected in RoR values of < 0.17/s for all volunteers and increased values of Mx (> 0.4 in 86% of volunteers) and Sx (> 0.2 in 79% of volunteers). Overall, there was a reasonably good correlation of both Mx and Sx with RoR (R2 = 0.65 and 0.58, respectively). IMPLICATIONS: Indices derived from the correlation between spontaneous fluctuations of blood flow velocity wave form and arterial blood pressure may be used for the noninvasive continuous monitoring of cerebrovascular reactivity.

AIDS and women: an international perspective.

This article focuses on HIV infection, HIV problems that are female specific (in the biological, psychological, and sociological spheres), a national and international perspective on HIV infection, and the challenges facing women as "women at risk for HIV infection," including childbearing and childrearing. The article discusses HIV infection in females worldwide, high risk categories (including behaviors, groups, and physiological indicators), physiological parameters of HIV infection in females, and health care challenges throughout the world. The framework for AIDS assessment, risk reduction, and intervention in women is the same as for other major health problems. However, we must first know the female specific HIV risks and "HIV disease course" and incorporate that knowledge in our assessment and intervention strategies.

PIP: This article begins by casting AIDS as a diagnostic category that rests at the tip of the HIV iceberg and by briefly noting the primary modes of HIV transmission. The next two sections review AIDS incidence in the US as of October 1988 and international AIDS incidence and concludes that the HIV infection rates among women are increasing nationally and internationally. The paper continues with a look at 1) high-risk behavior, 2) high-risk groups, 3) high-risk physiological indicators, and 4) other factors that increase risk of infection. The discussion of AIDS in women is introduced by reporting that at least 100,000 women in the US carried the AIDS virus as of 1988. Consideration is then given to the three specific health conditions that should trigger assessment of a woman's HIV risk: respiratory infections, gynecological infections, and pregnancy. Additional challenges facing women include 1) the legal and other implications for prostitutes who are HIV positive, 2) caring for the infected children of dying women, 3) socioeconomic burdens faced by women, 4) access to health care, 5) impediments to child bearing caused by HIV, 6) HIV-induced changes in families, 7) testing and counseling, 8) receiving adequate treatment, 9) consideration of women as vectors instead of victims, and 10) the disproportionate number of minority women affected.

Time: a speeding train or wind-driven sand? The estimation of fixed temporal intervals as related to images of time.

Relationship between Knapp's metaphor scale of attitudes toward time and subjective estimation of fixed time intervals, measured by a modification of Lovett Doust's method, was described. Results were discussed within the framework of studies relating the measurements of cognitive styles and altered consciousness states to the dilated or accelerated perceptions of time.