Evidence of deregulated cholesterol efflux in abdominal aortic aneurysm.

Previous studies indicated that lipids may be associated with abdominal aortic aneurysm (AAA); however the molecular mechanism involved is unclear. Our study aimed to investigate the expression pattern of cholesterol efflux related proteins in AAA. Liver X receptors (LXRα and LXRß), ATP-binding-cassette transporter A1 (ABCA1), Apolipoprotein AI (ApoAI), smooth muscle α-actin (α-SM) and vimentin expression levels were evaluated in human AAA, atherosclerotic (ATH) and normal abdominal aortic tissues. We found significant differences in LXRα, LXRß and ABCA1 mRNA expression levels between AAA, ATH and normal whole aortic tissues and also within the AAA, ATH and normal "intima-media" layers. Specifically, LXRα, LXRß and ABCA1 mRNA levels were decreased in AAA compared to ATH-whole tissues, as well as in AAA "intima-media" compared to ATH and normal "intima-media" layers. Moreover, immunohistochemical evaluation revealed that LXRα and ABCA1 immunoreactivities (IR) were reduced in the AAA media compared to the normal and ATH media layers and that they were also reduced in the intima layer of AAA and ATH tissues, whereas ApoAI-IR was increased in the AAA and ATH aortic walls compared to normal pointing to possible deregulation of the cholesterol efflux mechanism in AAA. Furthermore, double staining for vimentin and α-SM showed vimentin expression in the intima and inner media layer of AAA with sparse vimentin positive SMCs designating possible SMCs phenotype switch from contractile to synthetic form. In addition, histochemical analysis showed excessive lipid accumulation in the AAA wall, while co-staining using Oil Red O with α-SM or CD68 revealed lipid accumulation in SMCs and macrophages, respectively. Our study provides novel evidence for impaired cholesterol efflux in AAA associated with lipid accumulation in SMCs and macrophages, as well as switch of SMCs phenotype from contractile to synthetic form.

Left dominant arrhythmogenic cardiomyopathy: a morbid association of ventricular arrhythmias and unexplained infero-lateral T-wave inversion.

Left-dominant arrhythmogenic cardiomyopathy is a subtype of arrhythmogenic right ventricular cardiomyopathy characterized by early predominant left ventricular involvement. Α 34-year-old man presented with palpitations and a history of frequent ventricular extrasystoles of both LBBB and RBBB configuration. Cardiac workup revealed repolarization abnormalities at infero-lateral leads in the absence of diagnostic structural/functional alterations or obstructive coronary artery disease. Six months later he died suddenly. Histopathology was diagnostic for arrhythmogenic right ventricular cardiomyopathy affecting predominantly the left ventricle at subepicardial/midwall myocardial layers. Thus, ventricular arrhythmias accompanied by unexplained infero-lateral T-wave inversion should warn of a possible morbid association underlying left-dominant arrhythmogenic cardiomyopathy.

Adenocarcinomas of the prostatic duct in necropsy material.

The general consensus about prostatic duct adenocarcinomas is that they have a rather aggressive biological behavior. In addition, studies or reports of latent adenocarcinoma of the prostatic duct in necropsy material are scarce in the literature. We report here three cases of adenocarcinoma of the prostatic duct that were found incidentally among 39 cases of latent acinar prostate adenocarcinomas in necropsy material. We examined the morphologic and histological features of these prostatic duct adenocarcinomas, in order to better understand their biological behavior. We identified two cases of mixed ductal-acinar adenocarcinoma and one case of pure ductal adenocarcinoma. The pure form had a favorable histological differentiation, while the mixed forms had intermediate histological differentiation patterns. Invasiveness was related to both volume and histological differentiation. The finding of prostatic ductal adenocarcinomas among autopsy material, as well as some of their histological features, suggest that these tumors might have a similar biological potential as prostatic acinar cancer.

Associations among benign prostate hypertrophy, atypical adenomatous hyperplasia and latent carcinoma of the prostate.

AIM: To investigate the frequency of atypical adenomatous hyperplasia (AAH) and its associations with benign prostate hypertrophy (BPH) and latent histological carcinoma of the prostate (LPC) in autopsy material. METHODS: Two hundred and twelve prostate specimens obtained from autopsy material were subjected to whole mount analysis in an attempt to investigate the associations among BPH, AAH and LPC. RESULTS: Most histological carcinomas and AAH lesions were found in enlarged prostates with intense hypertrophy. No statistically significant relation was found between BPH and the main characteristics of LPC, such as tumor volume, histological differentiation and biological behavior. Our data regarding multi-focal tumors showed a tendency for multi-focal carcinomas to develop in larger prostates, and a tendency of AAH lesions to develop in larger prostates. No statistically significant relation was found between AAH and LPC. CONCLUSION: There seems not any causative aetiopathogenetical or topographical relation between AAH lesions and prostate adenocarcinoma. AAH lesion seems to be a well-defined mimicker of prostatic adenocarcinoma, and the reported association of AAH with prostatic carcinoma could probably be an epiphenomenon.