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.     

Method for maximising measurements of muscular pulmonary arteries.

Using a digitiser for assessing the media and intima of muscular pulmonary arteries, we have previously shown that the most sensible measurements are those of medial and intimal area and that artery size should be defined in terms of the total length of internal elastic lamina. These measurements do not vary with the collapse or constriction of the artery. A cross sectional cut and a well defined internal elastic lamina are essential for measurement using our technique. This study explores methods for obtaining the above three measurements for cross sectionally cut arteries with an ill defined internal elastic lamina, with a view to increasing the number of arteries measured. The methods were tested on three subjects, using arteries for which the true values of the three variables were known. Acceptable estimates of medial and intimal area could be obtained by simply delineating the boundaries of the intima and media and ignoring the crinkles in the elastic laminae. It was also found that muscular pulmonary arteries may not be uniformly collapsed or constricted round the circumference of their walls and that the overall degree of collapse or constriction seemed to be affected by the size of the artery. An acceptable estimate of the total length of an internal elastic lamina was most readily obtained by multiplying the length of the boundary between intima and media by a crinkle factor based on an optical assessment of the amount of crinkling in that internal elastic lamina.     

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.      

Exposure to polybrominated diphenyl ethers (PBDEs): changes in thyroid, vitamin A, glutathione homeostasis, and oxidative stress in American kestrels (Falco sparverius).

Polybrominated diphenyl ethers (PBDEs), a class of additive flame retardants, are temporally increasing in wildlife tissues and capable of disrupting normal endocrine function. We determined whether in ovo and post-hatch exposure of captive American kestrels (Falco sparverius) to environmentally relevant PBDEs alter thyroid, retinol, and oxidative stress measures. Control eggs were injected with safflower oil and subsequent nestlings fed the same vehicle; dosed eggs received PBDE congeners (BDE-47, -99, -100, -153), which mainly comprise the Penta-BDE commercial mixture, dissolved in safflower oil at concentrations (1500 ng/g total [Sigma] PBDEs) approximating those in Great Lakes gull eggs. Nestlings hatching from dosed eggs were orally exposed for 29 days to variable SigmaPBDE concentrations that are similar to levels reported in tissues of Great Lakes trout (100 ng/g). Treatment kestrels had lower plasma thyroxine (T(4)), plasma retinol, and hepatic retinol and retinyl palmitate concentrations, but unaltered triiodothyronine (T(3)) concentrations and thyroid glandular structure. BDE-47, -100, and -99 were negatively associated with plasma T(4), plasma retinol (BDE-100, -99) and hepatic retinol (BDE-47). Despite an antioxidant-rich diet, PBDE exposure induced hepatic oxidative stress, particularly in females, with an increased hepatic GSSG:GSH ratio, a marginal increase in lipid peroxidation, and increased oxidized glutathione. Positive associations were found between concentrations of BDE-183 and thiols and, in males, between BDE-99 and reduced GSH, but a negative association occurred between BDE-99 and TBARS. Subsequently, concentrations of PBDE congeners in wild birds may alter thyroid hormone and vitamin A concentrations, glutathione metabolism and oxidative stress.     

A Hodgkin cell-specific antigen is expressed on a subset of auto- and alloactivated T (helper) lymphoblasts

A Hodgkin cell-specific antigen detected by the monoclonal antibody Ki- 1 was found on T helper lymphocytes after activation by autologous and allogeneic stimulator cells. About 50% of lymphoblasts generated by auto- and alloactivation reacted with the antibody. In contrast, only less than 6% of lymphoblasts stimulated with Con-A, phytohemagglutinin (PHA), or protein A, and none of lymphoblasts activated by oxidative mitogenesis, expressed this antigen. Among several permanent cell lines tested, the K562, MOLT-4, HL-60, and EBV transformed B lymphoblastoid cells reacted with the Ki-1 antibody. The results may indicate possible relationships between the autoreactive subset of T lymphocytes and the pathogenesis of Hodgkin's disease.