Recent observations have demonstrated the presence of activated T lymphocytes and macrophages in human atherosclerotic lesions. Cells found within these lesions produce cytokines that alter vascular homeostasis in a manner that promotes atherogenesis. To elucidate the role of these immunocompetent cells in human atherosclerosis, the localization of various cytokines with an analysis of immunophenotypic features of the cellular infiltrates was studied in normal aortas from children; and in later phases of the disease (including fatty streaks and fibrous or atheromatous plaques). Semi-quantitative analysis of cytokine-expressing cells was also investigated with serial sectioning. In 4 of 9 young subjects, the grossly normal aorta contained relatively cell-rich areas which were located preferentially around the ostia of intercostal arteries and were composed of isolated or layered T lymphocytes and macrophages. In these prelesional areas, interleukin-1 (IL-1), IL-2 receptor (IL-2R) and tumour necrosis factor (TNF) were detected in the cytoplasm of the infiltrating cells, whereas no detectable reactivity was noted for IL-2, IL-6, interferon-gamma (IFN-gamma) or lymphotoxin (LT). In fatty streaks and full-grown atheromas including "cap" and "shoulder" regions, various numbers of T lymphocytes, macrophages and macrophage foam cells were present. In these lesion areas, especially where the cellular infiltrates were numerous, macrophage foam cells and smooth muscle cells expressed not only IL-1 and TNF but also IL-6. The ratio of IL-2R positive cells showed a tendency to decrease with advance of the disease process. Electron-microscopic examination of lesion areas demonstrated ultrastructural aspects of the cognate cell-to-cell interaction, as shown by the direct apposition of lymphocytes to macrophages or macrophage foam cells. These results suggest that a specific in situ, cell mediated hypersensitivity plays a pivotal role in the nascent as well as the progression stages of human atherosclerosis.

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The syndrome of intermittent claudication can be induced not only by vascular insufficiency of the lower limbs but also by diseases of the spinal cord and cauda equina. The authors describe a sixty-year-old man with intermittent claudication due to spinal canal stenosis who was successfully treated with beraprost sodium, a stable prostaglandin I2 analogue. This drug has a long biological half-life and is orally effective in vasodilation, which is suggested to be beneficial in treating this syndrome. Beraprost sodium may become one of the major drugs for conservative therapy of intermittent claudication induced by spinal canal stenosis.

SUMMARYWe studied urinary N‐acetyl‐ß‐D‐glucosaminidase (NAG) in the early stage of diabetic nephropathy in 27 non‐insulin‐dependent diabetes mellitus (NIDDM) patients with a microalbumin level below 20 mg on 24‐hour urine sample. Microalbumin and NAG excretion were measured in 24‐hour urine samples collected on three separate occasions within seven days of admission. Creatinine clearance was determined simultaneously. There was a significant negative correlation between the creatinine clearance and 24‐hour urinary NAG (r=‐0.38, p<0.05). Elevation of urinary NAG may indicate decreased renal function during early stage NIDDM nephropathy.

The aim of this study was to examine the suppressive effect of simvastatin on intramural coronary arterial lesions in cholesterol-fed rabbits. In one experiment, six groups of rabbits were fed laboratory chow alone or with added 0.1%, 0.2%, 0.3%, 0.5% or 1.0% cholesterol for 16 weeks. In another experiment, four groups of rabbits were fed a 0.5% cholesterol diet and treated with simvastatin at 1, 3, or 5 mg/kg/day or placebo. In each rabbit, the levels of serum total cholesterol (TC) were determined at 1-week intervals to calculate the integrated values. The lesion induction ratio was defined as the ratio of intramural coronary arteries 50-150 microm in diameter with arterial lipoidosis to the total number of arteries of the same diameter. In the two experiments, there were positive correlations between the lesion induction ratio and integrated TC (r=0.785, P<0.0001 and r=0.763, P<0.0001, respectively). The slopes of the regression lines for integrated TC obtained in the two experiments were similar, but the lesion induction ratio in the simvastatin-treated group was always lower, by about 14%, in comparison with that in the non-simvastatin-treated group. These findings suggest that simvastatin induces lesion reduction not only by reducing the levels of circulating cholesterol but also by directly suppressing the development of lipoidosis.