Nailfold capillary microscopy patterns in 22 patients with mixed connective tissue disease (MCTD) were compared with those of 21 patients with systemic lupus erythematosus (SLE) and 30 patients with systemic sclerosis (scleroderma [SD]). Microvascular data were classified blindly as follows: normal, nonspecific abnormalities, SD pattern, and SLE pattern, with special attention to the presence of dystrophic, branched "bushy" capillary formations. Of the 22 patients with MCTD, 63.6% had an SD pattern, 22.7% had an SLE pattern, 13.6% had nonspecific abnormalities, and 72.7% had bushy capillary formations. Compared with SLE microangiopathy, MCTD microangiopathy exhibited significantly greater capillary loss (P < 0.05), more frequent SD patterns (P < 0.001), and more frequent bushy capillaries (P < 0.001). Compared with SD patients, MCTD patients displayed less frequent SD patterns (P < 0.02) and more frequent bushy capillary formations (P < 0.01). The presence of bushy capillaries was suggestive of MCTD. For diagnostic purposes, bushy capillaries displayed 72% sensitivity, 80% specificity, and 87.2% negative predictive value. The quantitative and qualitative expressions of microangiopathy were different in MCTD and SLE, respectively. This supports the hypothesis that each disease is a distinct entity. Nevertheless, there were many resemblances

Hemodynamic parameters and systemic arterial compliance were measured in patients with arteriosclerosis obliterans of the lower limbs before and after acute administration of propranolol. Arterial compliance was evaluated from a simple viscoelastic model, enabling the calculation of diastoiic drainage and diastoiic blood flow as indices of the reservoir role of the large arteries in overall circulation, in comparing basal conditions with normal subjects of the same age, patients with arteriosclerosis obliterans exhibited a significant decrease in arterial compliance (p < 0.01) and heart rate (p < 0.02) with a significant increase in systolic pressure (p < 0.001). Diastoiic drainage was increased (p < 0.01) and was positively correlated with diastoiic time (r = 0.73, p < 0.001). Diastoiic blood flow remained within normal ranges (52 ± 2 vs 49 ± 3 ml/m 2 /sec). After acute propranolol intravenous administration, heart rate and stroke volume decreased (p < 0.001), while total peripheral resistance increased (p < 0.001). Systemic arterial compliance and diastoiic blood flow significantly decreased (p < 0.01). The study provided evidence that in patients with arteriosclerosis obliterans, the diastoiic blood flow was maintained in basal conditions despite the observed reduction in arterial compliance, and that intravenous propranolol administration decreased systemic arterial compliance and diastoiic blood flow. (Arteriosclerosis 2:266-271, May/June 1982)

Proliferation of arterial smooth muscle cells is regarded as an important event in atherogenesis, which according to in vitro culture studies is influenced by diabetes and insulin. To assess whether this holds true in vivo, we studied the cellular kinetics of thoracic aorta in normal and streptozocin-induced diabetic rats with and without insulin treatment. We measured the incorporation of [3H]thymidine into intima-media, as well as its DNA content, 2 and 14 days after endothelial denudation. We found that the mitotic response of an injured artery is not modified by diabetes but is depressed by insulin treatment in nondiabetic rats, probably due to hypoglycemia. Our data in insulin-treated diabetic rats support but do not definitely settle the view that insulin is mitogenic as long as the treatment does not cause sustained hypoglycemia.