Erythrocyte membrane cholesterol and lipid core growth in a rabbit model of atherosclerosis: Modulatory effects of rosuvastatin

Background

Lipid core expansion is partly responsible for the conversion of a stable atherosclerotic lesion to a rupture-prone plaque. Intraplaque hemorrhage contributes to the accumulation of cholesterol within unstable plaques. In the present study, we investigated, using a rabbit model of atherosclerosis, the extent to which diet-induced increases in cholesterol content of erythrocyte membranes (CEM) contribute to lipid core expansion and the modulatory effect of rosuvastatin use.

Methods and results

Rabbits fed with atherogenic diet (0.75% cholesterol) for 5 months exhibited advanced atherosclerotic lesions (mean plaque area, 0.39 ± 0.03 mm²), and lipid core size was associated with the concentration–time integral (CTI) of CEM levels (r = 0.567, P = 0.004) independent of other established predictors of lipid core size. Further experiments were performed by feeding rabbits atherogenic diet (1% cholesterol) for 3 months, followed by either normal diet or normal diet plus rosuvastatin for the next 3 months. Although no differences were observed in total plaque area between both groups, administration of rosuvastatin was associated with significantly smaller lipid cores, fewer macrophages within the lipid core, less microvessels as well as with lower CTI of CEM levels compared to normal diet alone. Moreover, intraplaque erythrocyte membranes covered a smaller lipid core area in rabbits under rosuvastatin plus normal diet as opposed to rabbits under diet alone.

Conclusions

Increased CEM levels, induced by high-cholesterol diet, are associated with lipid core growth. Ingestion of a potent HMG-CoA reductase inhibitor (rosuvastatin) may decrease CEM levels, and this effect may contribute to regression of the lipid core.     

Aktuelle Diagnostik und Therapie der akuten Lungenembolie

Diagnosing pulmonary embolism (PE) remains a challenge due to the often confusing clinical presentation of the disease. Plasma D-dimer testing with ELISA is increasingly becoming part of the initial diagnostic work up. Due to the high specificity of the assay, a negative test can reliably exclude PE. Importantly, massive PE can be promptly diagnosed or excluded by echocardiography which is a particularly valuable noninvasive method for detection of right ventricular dysfunction at the bedside. High-risk patients can thus be identified and treated immediately without further time-consuming examinations. Confirmation of PE in patients with inconclusive or normal echocardiograms is often based on lung scans, but diagnostic uncertainty is common with this procedure. The popularity of pulmonary angiography is decreasing due to its invasiveness, whereas spiral CT appears to be a promising alternative. Search for (residual) deep vein thrombosis is useful for guiding therapy in stable patients with small pulmonary emboli, since their risk is determined by the potential for PE recurrence. Recent evidence confirmed that right ventricular dysfunction predicts an unfavorable prognosis and might therefore justify thrombolytic treatment of massive PE regardless of systemic hemodynamics. On the other hand, simplified anticoagulation regimens with low-molecular weight heparins have yielded very promising results in stable patients. These diagnostic and therapeutic principles based on cardiovascular risk stratification will hopefully result in a more effective approach to patients with venous thromboembolism in the future.     

Arthroscopic debridement of the osteoarthritic knee under local anaesthesia

This prospective study compared the efficacy of arthroscopic debridement in osteoarthritic knees under local, general or peridural anaesthesia. Between 1997 and 2001, 201 arthroscopic debridements were performed in 197 patients (173 partial meniscectomies, 192 articular trimmings, 119 microfractures, 201 lavage procedures) in 197 patients. Patients were treated under local (Group "L", n = 67), general (Group "G", n = 65) or peridural anesthesia ( Group "P", n = 65). No tourniquet was used. The follow-up ranged from 24 to 72 months (mean: 32 months). No major complication was noted. Results were assessed according to the scale of Baumgaertner et al independently from the type of anaesthesia used (p = 0.71). Results were excellent in 85 cases (L: 30, G: 27, E: 28), good in 75 (L: 25, G: 24, E: 26), fair in 27 (L: 9, G: 8, E: 10), poor in 14 (L: 7, G: 4, E: 3). Arthroscopic debridement of the osteoarthritic knee under local anaesthesia appears as an efficient, simple, safe, painless and cost-effective method of treatment.     

Comparison of digital systems and conventional dental film for the detection of approximal enamel caries

Objectives

The aims of this study were (1) to compare the accuracy of the detection of approximal enamel caries lesions using three intraoral storage phosphor plate digital systems and one conventional film-based radiographic system; and (2) to determine whether there is a correlation between the histological and radiographic measurements of enamel caries.

Methods

160 approximal surfaces were radiographed under standardized conditions using three storage phosphor stimulable systems (DenOptix and Digora FMX with white and blue plates), and one film system (Insight film). 17 observers scored the images for the presence and depth of caries using a 4-point scale. The presence of caries was validated histologically (gold standard). Two-way analysis of variance was used to test the differences in sensitivity, specificity and overall accuracy (TP + TN). The data from the radiographic and histological measurements were statistically analysed by Spearman’s rank correlation coefficient.

Results

Two-way analysis of variance and the post hoc t-test demonstrated that Digora (white plate) had higher specificity and overall accuracy values than DenOptix (P = 0.021); there was no statistically significant difference among the other imaging modalities (P > 0.05). There was no significant correlation between the histological depth measurements and the radiographic measurements from Digora (blue plate) (P = 0.43), Digora (white plate) (P = 0.15), DenOptix (P = 0.17) and Insight film (P = 0.06).

Conclusions

The results suggest that (1) the performance of the three storage phosphor image plate systems was similar to that of the Insight film for detection of approximal enamel caries, and (2) the increase in histological depth of enamel caries was not significantly correlated with radiographic measurements.     

Transabdominal versus endovaginal pelvic sonography: prospective study

Transabdominal and endovaginal pelvic sonograms were obtained in 108 nonpregnant patients referred for pelvic sonography. The studies were independently obtained by two radiologists and interpreted on the basis of identical clinical information. The sonograms were then compared for anatomic detail and abnormalities. A determination was made about which examination, if either, was superior. Follow-up was performed through a review of the medical records and follow-up studies. Overall, the endovaginal study was judged superior in 65 cases (60.2%), equal in 39 (36.1%), and inferior in four (3.7%). The authors conclude that the endovaginal examination can effectively replace the transabdominal examination as the initial approach for routine pelvic sonography.