Effects of preconditioning on myocardial interstitial levels of ATP and its catabolites during regional ischemia and reperfusion in the rat

The interstitial accumulation of adenine nucleotide breakdown products (ANBP) in the myocardium during ischemia has been shown to provide a useful index of the ischemic injury, whereas reperfusion ANBP washout rate has been regarded as an index of reperfusion damage. The purpose of this study was, using cardiac microdialysis, to examine in the rat model of regional ischemia/reperfusion the relationship between the duration of ischemia and these indices and to assess the profile of interstitial ATP concentrations and the beneficial effects of ischemic preconditioning (IP). The rats underwent 10, 20, 30 or 40 min of coronary artery occlusion and 50 min of reperfusion. Regional ischemia, with its duration, provoked a progressive increase in dialysate ANBP in the ischemic zone. The rate of purine washout during reperfusion exponentially declined with an increase in duration of the ischemic period. IP, induced by three 5-min episodes of ischemia, each separated by 5 min of reperfusion, significantly reduced the accumulation of ANBP during the 30-min period of sustained ischemia and resulted in a marked acceleration of reperfusion ANBP washout, indicating the improvement of postischemic microcirculation. These effects were suggested to be, at least in part, responsible for the infarct size limitation observed. Using the relationship between the duration of ischemia and ANBP washout rate, it could be demonstrated that IP produced similar facilitation of purine washout as shortening of the ischemic period in nonpreconditioned rats from 30 to approximately 7 min. Regional 20-min ischemia induced an early peak increase in interstitial fluid ATP which correlated with the maximal incidence of ventricular arrhythmias, whereas IP abolished both ATP release and arrhythmias during the sustained ischemia. These findings suggest that ATP may be an important mediator of ischemia-induced ventricular arrhythmias. Received: 20 April 1999, Returned for 1. revision: 11 May 1999, 1. Revision received: 23 June 1999, Returned for 2. revision:15 July 1999, 2. Revision received: 27 September 1999, Accepted: 29 September 1999     

Knowledge and attitude regarding human immunodeficiency virus/acquired immunodeficiency syndrome in dermatological outpatients

Background  Dermatologists are often the first-line specialists who recognize and diagnose human immunodeficiency virus (HIV) infection because of pathognomic skin signs. It is therefore important to investigate attitudes and knowledge regarding HIV/acquired immunodeficiency syndrome (AIDS) amongst dermatological patients in order to provide information for dermatologists and to draw their attention to the issues.
Objectives  Awareness of HIV/AIDS, its prevention, and hypothetical behaviour were surveyed in dermatological outpatients.
Patients/method  The anonymous cross-sectional survey was conducted with consecutive German-speaking outpatients aged 18–65 years, who registered at the dermatological outpatient's clinic (excluding venereology, genitourinary or HIV medicine) of the University of Munich (Germany).
Results  Three hundred forty-seven (77.5%) questionnaires were accepted for analysis. Most of the patients knew about HIV incurability (89.4%), HIV transmissibility during needle sharing (95.3%), or vaginal (87.4%) and anal intercourse (79.5%), as well as about HIV prevention by condom use (97.8%), and use of single needles (76.2%). However, knowledge gaps and misconceptions were detected regarding the risk of HIV transmission during oral sex, and the efficacy of sexual fidelity and avoidance of blood transfusions in HIV prevention. The lowest knowledge level (< 50% correct answers) was detected in patients aged 50–59 years, in unemployed, divorced/widowed, and in those without or with incomplete school education.
Conclusions  Patient education about HIV/AIDS in dermatological ambulant settings should be performed differentially with regard to socio-demographic factors, and focused on the topic of oral sexual HIV transmission and on some other specific misconceptions.

Conflicts of interest

None declared.