Coronary thrombolysis in a community hospital: experience with an intravenous streptokinase protocol.

To determine whether intravenous streptokinase can be delivered safely and effectively in a community hospital without acute angiography, we treated 120 patients with intravenous infusion of 1.5 million units of streptokinase shortly after arrival in the emergency room. Average time from onset of pain to treatment was 2.7 hours. Therapy was well tolerated without significant complication. Reperfusion was clinically suspected in 78% of patients. Coronary angiography was done at referral hospitals in 94% of the surviving patients two to ten days after treatment. The infarcted vessel was patent in 74% of these patients. Of these, coronary angioplasty was performed in 36%, and 32% had bypass grafting. We conclude that intravenous streptokinase can be safely and effectively used in community hospitals without acute angiography in carefully selected patients with acute myocardial infarction.

Response to exercise in patients taking psychotropic drugs. Arrhythmias and the QT interval (QT wave peak).

Psychotropic drugs may prolong the QT interval, potentially predisposing to ventricular arrhythmias and/or sudden death. Exercise prescribed as therapy for depression may also prolong the QT interval and augment arrhythmia risk. To determine QT-interval (QT wave peak, or QTPK) response to exercise in patients receiving psychotropic drugs, treadmill exercise testing was performed on 20 mentally competent psychiatric inpatients clinically free of heart disease. Twenty-four-hour ambulatory ECGs were performed within one day of exercise testing to detect arrhythmias during routine daily activities. Exercise test results for psychiatric patients were compared with those of normal subjects receiving no medication. Separate regression lines relating heart rate of QTPK interval, calculated for each group, showed no significant difference. No serious arrhythmias occurred during routine daily activities or exercise. Patients without heart disease taking psychotropic drugs have appropriate QTPK-interval shortening with exercise.

Metabolic characteristics of cells infected with a herpesvirus of turkeys.

Chicken embryo fibroblasts infected with the nononcogenic herpesvirus of turkeys (HVT) displayed an increased rate of glucose uptake, a pronounced alteration of the pH of the medium, and an increased production of lactic acid when compared to mock-infected cultures. Objective estimates of cytopathology (quantifiable neutral red uptake and cell protein determination) showed that cell deterioration was a slow process in HVT-infected cells when compared to infection by herpes simplex virus. Experiments with irradiated host cells demonstrated that HVT required functional cell DNA for replication. The inactivation of the necessary host cell function displayed multihit kinetics. In agreement with data on other herpesviruses, HVT damaged by UV light could be photoreactivated in chick cells. The results indicate that HVT shares biologic properties in common with other herpes and transforming viruses.

Growth characteristics of a herpesvirus of turkeys.

The herpesvirus of turkeys remains associated with cells attached to the culture vessel throughout its growth cycle. The level of infectious centers is essentially constant between 24 and 48 hr when the culture medium is unchanged. Thereafter, the number of infectious centers decreases. The cessation of virus synthesis is not due to insufficient numbers of uninfected cells or interferon production. Herpesvirus of turkeys does not replicate at 22 C and is similar to other herpesviruses in its sensitivity to interferon. The results define conditions to be considered in the preparation of infected cell suspensions commonly used as a vaccine against Marek's disease virus.