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The objective of this autopsy-based study was to investigate the pathology of human blast lung injury using histology, Fat Red 7B staining, immunohistochemistry, and scanning electron microscopy on lung specimens from eight medicolegal autopsy cases of fatal close-range detonations of chemical explosives. The micromorphologic equivalents of human blast lung injury can be summarized as follows: diffuse alveolar overdistension, circumscribed interstitial hemorrhages showing a cufflike pattern around pulmonary vessels, venous air embolism, bone marrow embolism, and pulmonary fat embolism. Hemorrhages within the lung parenchyma that were present in this study in blast victims without coexisting blunt or penetrating chest trauma must be regarded as potentially life-threatening intrapulmonary bleeding sites in survivors. In addition, the potential clinical importance of the presence of massive pulmonary fat embolism, which has, to the best of our knowledge, not been described previously in human blast lung injury, must be emphasized because pulmonary fat embolism may be a leading cause of the rapid respiratory deterioration with progressive hypoxia and development of acute respiratory distress syndrome in blast victims who survive. Furthermore, this study provides evidence that air embolism presenting in blast victims is not a mere ventilation-induced artifact.

The purpose was to analyze magnetic resonance (MR) plaque imaging at 3.0 Tesla and 1.5 Tesla in correlation with histopathology. MR imaging (MRI) of the abdominal aorta and femoral artery was performed on seven corpses using T1-weighted, T2-weighted, and PD-weighted sequences at 3.0 and 1.5 Tesla. Cross-sectional images at the branching of the inferior mesenteric artery and the profunda femoris were rated with respect to image quality. Corresponding cross sections of the imaged vessels were obtained at autopsy. The atherosclerotic plaques in the histological slides and MR images were classified according to the American Heart Association (AHA) and analyzed for differences. MRI at 3.0 Tesla offered superior depiction of arterial wall composition in all contrast weightings, rated best for T2-weighted images. Comparing for field strength, the highest differences were observed in T1-weighted and T2-weighted techniques (both P< or =0.001), with still significant differences in PD-weighted sequence (P< or =0.005). The majority of plaques were histologically classified as calcified plaques. In up to 21% of the cases, MRI at both field strengths detected signal loss characteristic of calcification although calcified plaque was absent in histology. MRI at 3.0 Tesla offers superior plaque imaging quality compared with 1.5 Tesla, but further work is necessary to determine whether this translates in superior diagnostic accuracy.

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OBJECTIVE To investigate the effect of cyclooxygenase‐2 (COX‐2) on microvessel density (MVD) and on the clinical prognosis in patients with non‐muscle invasive urothelial carcinoma of the bladder, as COX‐2 expression is significantly greater in epithelial tumours and there is increasing evidence that COX‐2 might contribute to tumour neovascularization. PATIENTS AND METHODS We assessed tumour samples from 110 patients undergoing transurethral resection for primary pTa/pT1 bladder carcinoma (pTa, 84; pT1, 26; grade 1, 22; grade 2, 81; grade 3, seven). Paraffin sections were assessed immunohistochemically using antibodies against COX‐2, CD34 (endothelial cells) and CD105 (proliferating vessels). COX‐2 expression was quantified by the number of stained cells (negative, +, ++) and the MVD calculated as vessels per field. RESULTS Of the 110 tumours, 45 (41%) had no immunostaining for COX‐2, 40 had faint staining with at least isolated positive cells (+) and 25 stained ++. COX‐2 positive tumours had significantly greater vascularization for proliferating vessels. In COX‐2 negative tumours the MVD was 22.1, identified by CD34 immunostaining, and 3.4 for proliferating vessels (CD105), whereas COX‐2 positive tumours had a MVD of 18.3 (CD34), and of 5.8, respectively (CD105). Complete follow‐up data were available in 91 patients; after a mean follow‐up of 25 months, 18 (20%) had tumour recurrences. There was no significant difference in the recurrence rates or disease‐free survival between COX‐2‐positive (19%, 25.6 months) or ‐negative patients (21%, 25.2 months). CONCLUSION These results confirm the involvement of COX‐2 in angiogenesis in bladder cancer, as COX‐2 promoted blood vessel proliferation in the tumour zone, and indicate the usefulness of COX‐2‐inhibiting drugs in preventing and treating superficial bladder cancer.

Background: Several highly proliferative human cells transiently activate telomerase, a ribonucleoprotein with reverse transcriptase activity, to counterbalance replication-associated telomere erosion and to increase stress resistance. Quiescent human hepatocytes exhibit very low or undetectable levels of telomerase activity. However, hepatocytes display a remarkable proliferative capability following liver injury. To investigate whether liver regeneration by compensatory hyperplasia is associated with telomerase activation, we measured telomerase activity in pig livers after 70 to 80% partial hepatectomy using a fully quantitative real-time telomeric repeat amplification protocol. In contrast to commonly studied inbred laboratory mouse strains, telomere length and telomerase activity in porcine tissues are comparable to humans.

The case of an 80-year-old woman who presented with epigastric symptoms is reported. Upper gastrointestinal endoscopy displayed Candida esophagitis and a localized swelling of the fundic mucosa. Histologic examination of the gastric biopsy showed a distinctive accumulation of numerous uniform plasma cells filled with so-called Russell bodies. On low-power view, the lesion resembled a neoplastic process due to the marked expansion of the lamina propria with distension of fundic glands. However, immunohistochemistry confirmed a polyclonal pattern of the plasma cells. This unusual reactive lesion of the gastric mucosa has only rarely been described and has been termed Russell body gastritis.