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.     

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.      

Specific somatic sensory relays in the mammalian diencephalon

There are five major domains within the diencephalon that receive input from ascending somatic sensory pathways serving the limbs, trunk and viscera. These domains include the ventroposterolateral nucleus (VPL), the posterior group complex (PO), the zona incerta (ZI), the intralaminar complex and the thalamic reticular nucleus. Of these five domains, VPL is commonly considered a "specific" somatic "relay". The reasons for this view are that VPL receives dense, synaptically secure and precisely organized input from the equally precisely organized dorsal column nuclei (DCN), that most of VPL's neurons have small, unimodal cutaneous receptive fields which reflect their input from DCN, and that these neurons project this information in a precise way to the somatic sensory cortex. Several lines of evidence suggest that this rather simple view of VPL be modified. First, not only does VPL receive complex patterns of partially converging input from other ascending somatic pathways besides the DCN, but the pattern of its input from DCN appears to be more complex than once thought. Second, such input convergence and complex connective patterns also occur within PO and ZI (although the characteristics of the patterns differ between the three domains). Third, the response properties of neurons within VPL differ in its different parts and are not necessarily precise mirrors of the response properties of neurons within DCN. Fourth, although the responses of neurons in PO on the whole differ from those in VPL, there are some similarities. The same conclusion may prove true for neurons in the DCN-recipient portion of ZI.(ABSTRACT TRUNCATED AT 250 WORDS)