In situ saphenous vein bypass grafts: angiographic evaluation and interventional repair of complications

In situ saphenous vein grafts are being used with increasing frequency for bypass procedures involving the femoral and popliteal arteries. Complications of these procedures include anastomotic stenoses and persistent arteriovenous fistulae that may result in failure of the graft. Balloon angioplasty and embolotherapy with detachable balloons were employed successfully in three or four recent cases of patients with complications from in situ grafts. Tailored angiography is essential for evaluating in situ grafts, and interventional techniques are extremely useful for managing complications.     

Myocardial ischaemia and ventricular arrhythmias precipitated by physiological concentrations of adrenaline in patients with coronary heart disease.

The clinical and haemodynamic effects of adrenaline infusion (30 ng kg-1 min-1) producing plasma adrenaline concentrations in the range seen during acute myocardial infarction and of placebo were investigated in a crossover design in 14 patients with stable coronary heart disease. Adrenaline infusion resulted in electrocardiographic evidence of myocardial ischaemia (greater than or equal to 1 mm (0.1 mV) horizontal or downsloping ST segment depression) in 10 patients and angina in four, although the mean (SEM) increase in heart rate was modest (14 (2) beats/min) and mean coronary vascular resistance fell from 1.56 (0.21) to 1.16 (0.14) mm Hg min ml-1 (p less than 0.005). New or increasingly frequent or complex ventricular arrhythmias occurred in five patients. Placebo infusion had no effect on the variables measured. Supine bicycle exercise during infusion of the saline placebo was associated with a similar degree of ST segment depression (0.9 (0.2) mm) as adrenaline infusion at rest (0.9 (0.1) mm) but exercise performed during adrenaline infusion (10 patients) resulted in more pronounced ST segment depression (1.9 (0.3) mm) (p less than 0.005) than either intervention alone. Angina occurred in three of 11 patients during control exercise and in six of 10 during the combination of adrenaline infusion and exercise. Such potentially adverse consequences of low dose adrenaline infusion in patients with stable coronary heart disease are consistent with the suggestion that adrenal activation is detrimental during acute myocardial infarction, being both arrhythmogenic and proischaemic.     

Human papillomavirus type 16 alters human epithelial cell differentiation in vitro.

Human papillomavirus (HPV) types 16, 18, 31, and 33 have been implicated as etiologic agents of cervical and penile cancer. Using a cell culture system for keratinocytes which allows stratification and production of differentiation-specific keratins, we have examined the effects of one of these viruses, HPV-16, on the differentiation capabilities of human epithelial cells. A plasmid containing the HPV-16 genome and a neomycin-selectable marker was transfected into primary human epidermal cells and SCC-13 cells, an immortalized squamous cell carcinoma cell line. Cloned neomycin-resistant cell lines were isolated and examined by cell culture on raised collagen rafts. Cell lines containing HPV-16 DNA retained the ability to stratify and express differentiation-specific keratins in the raft system but otherwise failed to differentiate normally. The histological abnormalities induced by HPV-16 closely resembled those seen in genital intraepithelial neoplasia in vivo. Hence, our results support the role of HPV-16 as an etiologic agent in the development of genital neoplasias and suggest a specific system for the study of HPV-16-induced epithelial cancers.