Tumor vascular signals in renal masses: detection with Doppler US

The vascularity of 49 renal masses (26 malignant and 23 benign lesions) was investigated with duplex Doppler ultrasound. Doppler signals obtained at the margins of renal masses were defined as "tumor signals" when the Doppler-shifted frequency of the lesion exceeded the frequency shift in the ipsilateral main renal artery. These exceeded 2.5 kHz with a 3-MHz insonating frequency. Among the 26 renal masses that subsequently proved to be malignant, tumor signals were obtained in 15 of 18 (83%) untreated renal cell carcinomas, in three of four Wilms tumors, and in two patients with metastases to the kidney, but not in the one patient with lymphoma. None of the 23 benign renal masses demonstrated tumor signals. Tumor vascularity in malignant lesions gives rise to abnormal, high-velocity, Doppler-shifted signals that can help in the differential diagnosis of renal masses.     

Structural Basis for Hyperpermeability of Tumor Vessels in Advanced Lung Adenocarcinoma Complicated by Pleural Effusion

BackgroundMalignant pleural effusion (MPE) has a profound impact on quality of life and survival in patients with lung cancer. Identification of the factors within the tumor and its environment that mediate MPE is still lacking.Patients and MethodsIntratumoral microvessel density (MVD), endothelial cell and pericyte (PC) capillary coverage, endothelial cell (EC)-PC relationship, lymphatic endothelium integrity, and the expression of receptor tyrosine kinases were all assessed immunohistochemically in pleural tumor biopsy specimens from 24 patients with lung adenocarcinoma (ADC) with and without pleural disease, with the aim to evaluate the involvement with MPE.ResultsIn the effusion-positive (⁺) specimens, MVD values were found to be significantly higher, and a number of vessels were noted to lack immunoreactivity for ECs (CD31). Likewise, PC α–smooth muscle actin (αSMA) expression was also less extensive in the MPE⁺ cases. The observation of only sporadic staining of PCs can also explain the findings regarding platelet-derived growth factor receptors (PDGFRs), the expression of which, although more prominent in MPE⁺ samples, were almost exclusively detected on tumor stromal cells and not on vascular PCs. Conversely, vascular endothelial growth factor receptors (VEGFRs) appeared on both kinds of cells. With respect to lymphatic vessels, lymphatic intraluminal tumor cells were occasionally found in MPE⁺ specimens.ConclusionOur study suggests that disturbed vessel wall integrity, as well as abnormalities of fluid clearance by the lymphatic system, together with overexpression of growth factors, may take part in the pleural fluid accumulation in lung ADCs. Results of the decreased PC capillary coverage and PDGFR expression in MPE are discussed.     

Statin research in critical illness: hampered by poor trial design?

Statin therapy may prevent an excessive inflammatory response after cardiopulmonary bypass for cardiac surgery. In a recent issue of Critical Care, Morgan and colleagues present data from a well-conducted systematic review and meta-analysis of randomised controlled trials using inflammatory markers as primary outcome measure. They find that pre-operative statin therapy, compared with placebo, may reduce various post-operative markers of systemic inflammation (IL-6, IL-8, C-reactive protein, tumour necrosis factor-alpha). Their ability to make definitive conclusions is limited, however, by the suboptimal methodological quality of the primary studies. Their review suggests that ICU researchers should focus on developing valid surrogate markers and use these to accurately describe the mechanisms and effectiveness of novel therapies before proceeding to large pragmatic trials using mortality as primary outcome.     

Detection of reactive oxygen species (ROS) and apoptosis in human fragmented embryos

In human in-vitro fertilization (IVF)-embryo transfer, the in-vitro culture environment differs from in-vivo conditions in that the oxygen concentration is higher, and in such conditions the mouse embryos show a higher concentration of reactive oxygen species (ROS) in simple culture media. ROS are believed to cause damage to cell membranes and DNA fragmentation in somatic cells. This study was conducted to ascertain the level of H2O2 concentration within embryos and the morphological features of cell damage induced by H2O2. A total of 62 human oocytes and embryos (31 fragmented, 15 non-fragmented embryos, 16 unfertilized oocytes) was obtained from the IVF-embryo transfer programme. The relative intensity of H2O2 concentrations within embryos was measured using 2',7'-dichlorodihydrofluorescein diacetate by Quanti cell 500 fluorescence imaging and DNA fragmentation was observed with transmission electron microscopy and an in-situ apoptosis detection kit. The H2O2 concentrations were significantly higher in fragmented embryos (72.21 +/- 9.62, mean +/- SEM) compared to non-fragmented embryos (31.30 +/- 3.50, P < 0.05) and unfertilized oocytes (30.75 +/- 2.67, P < 0.05). Apoptosis was observed only in fragmented embryos, and was absent in non-fragmented embryos. Electron microscopic findings confirmed apoptotic bodies and cytoplasmic condensation in the fragmented blastomeres. We conclude that there is a direct relationship between increased H2O2 concentration and apoptosis, and that further studies should be undertaken to confirm these findings.