Alcohol enhances oxysterol-induced apoptosis in human endothelial cells by a calcium-dependent mechanism

Controversy exists about the net effect of alcohol on atherogenesis. A protective effect is assumed, especially from the tannins and phenolic compounds in red wine, owing to their inhibition of low density lipoprotein (LDL) oxidation. However, increased atherogenesis occurs in subjects with moderate to heavy drinking habits. The purpose of this study was to investigate the influence of alcohol in combination with oxysterols on the endothelium. Cultured human arterial endothelial cells (HAECs) served as an in vitro model to test the cellular effects of various oxysterols. Oxysterols (7beta-hydroxycholesterol, 7-ketocholesterol, and cholesterol-5,6-epoxides), which are assumed to be the most toxic constituents of oxidized LDL, induced apoptosis in HAECs through calcium mobilization followed by activation of caspase-3. Ethanol, methanol, isopropanol, tert-butanol, and red wine all potentiated oxysterol-induced cell death up to 5-fold, paralleled by further induction of caspase-3. The alcohol effect occurred in a dose-dependent manner and reached a plateau at 0.05% concentration. Alcohol itself did not affect endothelial cell viability, nor did other solvents such as dimethyl sulfoxide mimic the alcohol effect. So far as the physiologically occurring oxysterols are concerned, this effect was apparent only for oxysterols oxidized at the steran ring. The possibility of alcohol facilitating the uptake of oxysterols into the cell was not supported by the data from an uptake study with radiolabeled compounds. Finally, alcohol in combination with oxysterols did cause a dramatic increase in cytosolic calcium influx. Blockage of calcium influx by the calcium channel blocker aurintricarboxylic acid or the calcium chelator ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid abrogated the alcohol-mediated enhancement of oxysterol toxicity. We describe for the first time a mechanistic concept explaining possible adverse effects of alcohol in conjunction with physiologically occurring oxysterols on atherogenesis.     

Evaluation of mitral regurgitation by cine magnetic resonance imaging

We used cine magnetic resonance imaging (MRI) to assess mitral regurgitation (MR) in 40 patients with coronary and/or valvular disease and 10 normal subjects and compared results to pulsed (n = 30) or color flow Doppler mapping (n = 20). Mitral regurgitation produced a dynamic signal void in the left atrium in systole in 15 of 16 patients with MR by pulsed Doppler and in an additional 15 of 16 patients whose MR was demonstrated by color flow Doppler. There were no false positives (sensitivity 94%, specificity 100% for both). The ratio of single-plane, maximal jet area to left atrial area was used to grade MR severity with mild defined as less than 20%, moderate between 20 and 40% and severe greater than 40%. Cine MRI classification was identical to pulsed Doppler echocardiography in 26 of 30 patients and to color flow Doppler in 16 of 20 patients with no differences of greater than 1 grade. Cine MRI consistently depicted smaller flow disturbances than pulsed Doppler (slope = 0.65) or color flow Doppler (slope = 0.60). Nonetheless, the cine MRI area ratio correlated well with pulsed Doppler (r = 0.78) and with color flow Doppler (r = 0.74). Thus, planar analysis of cine MRI in patients with MR of varying severity gave results that were similar to Doppler echocardiography. At present, for routine clinical assessment of MR, the benefits of cine MRI may be limited to patients in whom transthoracic Doppler echocardiography is not adequate.     

Non-compliance in surveillance for patients with previous resection of large (≥1 cm) colorectal adenomas

AIM: To assess the extent and reasons of noncompliance in surveillance for patients undergoing polypectomy of large (≥ 1 cm) colorectal adenomas.METHODS: Between 1995 and 2002, colorectal adenomas ≥ 1 cm were diagnosed in 210 patients and subsequently documented at the Erlangen Registry of Colorectal Polyps. One hundred and fifty-eight patients (75.2%) could be contacted by telephone and agreed to be interviewed. Additionally, records were obtained from the treating physicians.RESULTS: Fifty-four out of 158 patients (34.2%)neglected any surveillance. Reasons for non-compliance included lack of knowledge concerning surveillance intervals (45.8%), no symptoms (29.2%), fear of examination (18.8%) or old age/severe illness (6.3%).In a multivariate analysis, the factors including female gender (P = 0.036) and age ≥ 62 years (P = 0.016)proved to be significantly associated with non-compliance in surveillance.CONCLUSION: Efforts to increase compliance in surveillance are of utmost importance, This applies particularly to women's compliance. Effective strategies for avoiding metachronous colorectal adenoma and cancer should focus on both the improvement in awareness and knowledge of patients and information about physicians for surveillance.     

The Secretion of Endothelin-1 by Microvascular Endothelial Cells from Human Benign Prostatic Hyperplasia is Inhibited by Vascular Endothelial Growth Factor

Prostate growth seems to be influenced by paracrine factors like endothelin-1 (ET-1), originating from the microvascular endothelium. Recently, we reported on the first isolation and primary culture of microvascular endothelial cells (HPEC) derived from tissue of human benign prostatic hyperplasia (BPH). Therefore, direct investigation of growth factor secretion by HPEC is now possible.

BPH tissue was cut into small cubes and gently squeezed after incubation with dispase. HPEC were cultured from the resulting cell suspension after a stepwise selection by use of superparamagnetic beads coated with antibodies against endothelial specific antigens. HPEC were characterized by flow cytometry. After the incubation of HPEC either with vascular endothelial growth factor (VEGF), tumor necrosis factor α (TNF-α), or adenosine triphosphate (ATP), the secretion of ET-1 was measured by ELISA.

HPEC showed a typical endothelial morphology. They were positive for von Willebrand factor and CD31. The ET-1 secretion of HPEC was inhibited by VEGF, but was unaffected by TNF-α or ATP. Furthermore, histochemistry revealed that in vivo microvascular endothelial cells were negative for ET-1. Because of the suppression by the widespread VEGF, it is unlikely that ET-1 from the microvascular endothelium acts as a growth factor in human BPH.     

Radiological landmarks for the safe extra-capsular placement of supra-acetabular half pins for external fixation

Purpose

Low anterior external fixators are constructed by placing half pins in the dense bone tunnel of the supra-acetabular region in an anterior to posterior direction. Although the placement of these pins is extra-articular, they may still breach the hip capsule on the anterior inferior iliac spine and thus be intra-capsular. We aim to provide radiological markers for the most superior fibres of the capsule to allow safe extra-capsular pin placement within the supra-acetabular bone tunnel.

Methods

Thirteen cadaveric pelves were used for this study. The supra-acetabular bone tunnel was visualised with an image intensifier. The proximal most fibres of the hip joint capsule were marked with a K-wire so that their relation to the bone tunnel could be clearly seen on the images. Once all images were acquired they were calibrated and analysed to estimate the dimensions of the supra-acetabular bone tunnel and the reflection of the hip capsule.

Results

The median height of the bone tunnel was 23.6 mm (18.9–33.2) and maximum width was 11.4 mm (7.6–16.3). The inferior margin of the bone tunnel was 6.7 mm (1.1–14.5) superior to the acetabular dome, and the most proximal fibres of the capsule were 9.3 mm (4.7–6.1) superior to the acetabular dome. The inferior portion of the tunnel was 3.7 mm (0.3–8.9) within the joint.

Conclusion

Half pins for the construction of a pelvic external fixator should be placed in the upper half of the supra-acetabular bone corridor to minimise the risk of intra-capsular placement.     

Regulation of vertebrate forelimb development and wing reduction in the flightless emu

The vertebrate limb is a dynamic structure which has evolved into many diverse forms to facilitate complex behavioral adaptations. The principle molecular and cellular processes that underlie development of the vertebrate limb are well characterized. However, how these processes are altered to drive differential limb development between vertebrates is less well understood. Several vertebrate models are being utilized to determine the developmental basis of differential limb morphogenesis, though these typically focus on later patterning of the established limb bud and may not represent the complete developmental trajectory. Particularly, heterochronic limb development can occur prior to limb outgrowth and patterning but receives little attention. This review summarizes the genetic regulation of vertebrate forelimb diversity, with particular focus on wing reduction in the flightless emu as a model for examining limb heterochrony. These studies highlight that wing reduction is complex, with heterochronic cellular and genetic events influencing the major stages of limb development. Together, these studies provide a broader picture of how different limb morphologies may be established during development.     

A 62‐Year‐Old Female With an Intranasal Mass Extending into the Lamina Cribrosa

Malignant tumors with neuroendocrine differentiation of the nasal cavity include neuroendocrine carcinoma, small cell undifferentiated carcinoma, olfactory neuroblastoma (esthesioneuroblastoma), and sinonasal undifferentiated carcinoma (SNUC). The rarity of these tumors and overlapping clinical, histological and immunohistochemical findings make the correct diagnosis difficult. However accurate diagnosis is critical for therapy and the outcome differs significantly between these entities. Here we describe the case of a 62‐year‐old woman with an intranasal tumor extending into the adjacent anatomical compartments and with infiltration of the meninges. The suspected preoperative diagnosis was olfactory neuroblastoma. Histological and immunohistochemical analysis showed a lobulated tumor with neuroendocrine differentiation and we ultimately diagnosed the process as a SNUC. In this report, we discuss the differential diagnosis at hand and present histological findings found in the specimen indicating that the process originated from local glands present in the nasal mucosa.