No abstract

Cardiovascular disease is currently the leading cause of death among women in the United States. To investigate the effect of postmenopausal hormone therapy on atherogenesis, we studied 75 cholesterol-fed female rabbits for 19 wk. The rabbits were randomly assigned to five groups. Four groups underwent bilateral ovariectomy followed by treatment with either 17 #l-estradiol, 17 f-estradiol plus norethisterone acetate, 17 ,-estradiol plus levonorgestrel, or placebo. The fifth group had a sham operation and received placebo. The hormone groups had only one-third of the aortic accumulation of cholesterol found in the placebo groups, a difference that was highly statistically significant (P < 0.0001). No significant differences in aortic accumulation of cholesterol were found in the hormone groups. This indicates that estrogen attenuates atherogenesis in cholesterolfed ovariectomized rabbits and that two commonly prescribed progestogens do not counteract the effect. The beneficial effect of estradiol could only partly be explained by its lowering effects on serum total cholesterol or VLDL cholesterol, which implies that estradiol possesses additional beneficial effects, possibly a direct action on the arterial wall. (J. Clin. Invest.

This study aimed to determine the dimensions of the thoracic aorta and the predictors of aortic dimensions in girls and young women with Turner syndrome (TS). A cross-sectional study was performed at a secondary care center. The study compared 41 TS patients with 50 healthy age-matched control subjects. The mean age of the patients was 17 +/- 3.3 years. Magnetic resonance imaging was performed for all the patients. The thoracic aortic diameters of the patients were measured at nine positions. Adjustment for body surface area (BSA) was performed. The outcome for the patients was measured in terms of absolute and BSA-adjusted aortic dilation. In TS, both the absolute and the BSA-adjusted mean aortic diameters were smaller than or comparable with those of the control subjects. However, individual aortic dilation at one to four positions was found in four TS patients according to the uncorrected data and in five TS patients after BSA-adjustment. The aortic diameters correlated with height, weight, body mass index (BMI), and BSA at all positions (R = 0.34-0.60; all p < 0.04). The diameters of the aortic arch and the descending aorta correlated with a history of aortic coarctation (R = 0.35-0.52; p < 0.03). The presence of bicuspid aortic valves correlated at the descending part of the aorta (R = 0.38; p < 0.03). The mean thoracic aortic dimensions were not enlarged in girls or young TS patients. The BSA predicted aortic size at all positions. The prevalence of aortic dilation and aneurysm was lower in this population of girls and younger women with TS than in older TS populations.

Two groups of 18 rabbits were fed Isocalorlc, cholesterol-enriched diets for 8 weeks. The diet for one group was supplemented with 5% corn oil. The concentration of cholesterol in plasma was determined weekly and the amount of cholesterol In the diet was adjusted Individually so that each rabbit had a mean plasma cholesterol concentration of about 45 mM during the experimental period. The aortic cholesterol concentrations were 122 ± 29 and 193 ± 38 (mean ± SEM) /xmol/g protein for the cornoil group and the control group, respectively (p<0.05). In a similar experiment, each of 36 rabbits was given a mean plasma cholesterol level of about 20 mM over a period of 12 weeks. One-third of the rabbits received 10% to 15% corn oil, another third 10% to 15% olive oil, while the last third served as a control group. The aortic cholesterol concentrations were 98 ± 25, 57 ± 9, and 131 ± 32 ^mol/g protein, respectively. The value for the olive-oil group was significantly (p<0.01) lower than the value for the control group. The trlglycerlde concentrations and the distributions of cholesterol between HDL, LDL, and VLDL In plasma showed no significant differences between the plant-oil groups and their control groups. This suggests that plant oils have a direct effect on the aortic cholesterol metabolism. (Arteriosclerosis 8:281-287, May/June 1988)

Recently, a new oral liver-specific manganese-based MR agent (CMC-001) has been introduced. This contrast medium is delivered to the liver in high concentrations in the portal vein and very low doses in the hepatic artery, as only small amounts of manganese enter the general circulation. It is taken up by the hepatocytes and excreted in the bile. Our initial experience with the new MR contrast medium in a variety of patients is reported. A total of 20 patients (11 males and 9 females) were studied with MR imaging 2 h after oral ingestion of the contrast agent. Sixteen patients were referred for evaluation of focal liver lesion(s), whereas in the remaining four patients, evaluation of the biliary tract was requested. In the 17 patients without biliary obstruction, there was an increased signal intensity of the liver parenchyma, whereas in the three patients with biliary obstruction, the uptake was delayed. There was excellent visualization of the biliary system on the T1-weighted images in the 16 patients without biliary obstruction referred for evaluation of a focal liver lesion. In seven patients, the uptake was patchy. In patients with focal liver lesions or biliary tract diseases, it is possible to increase the signal intensity of the liver parenchyma after the oral intake of CMC-001. In patients without biliary tract obstruction, the biliary system is easily visualized. Oral manganese seems to be useful in hepatobiliary MRI. Further research is strongly warranted.