Generation of a monoclonal antibody (Epenl) which binds selectively to murine ependymal cells

In order to define surface antigens unique to ependymal cells, spleen cells from C57/B16 mice immunized with a suspension of 70-80% purified isolated ependymal cells from syngeneic animals were fused with NS-1 myeloma cells. Five hybridomas were found which secrete monoclonal antibodies that recognize ependymal cells both by indirect immunofluorescence and radioimmunoassay. One of them, Epenl, appears to be a relatively specific surface marker of murine and rat ependymal cells, whereas the 4 others also recognize neurons, astrocytes, and/or oligodendrocytes. Absorption of Epenl with murine cerebral cortex did not affect its binding, whereas absorption with ependymal cells abolished it. Labeling of in vivo sections with Epenl demonstrates prominent binding to ependymal cells lining ventricular cavities. Epenl does not bind to neurons or astrocytes in culture, and binds only minimally to isolated oligodendrocytes. It does, however, recognize an antigenic determinant present in lung tissue.     

A three‐dimensional axis for the study of femoral neck orientation

A common problem in the quantification of the orientation of the femoral neck is the difficulty to determine its true axis; however, this axis is typically estimated visually only. Moreover, the orientation of the femoral neck is commonly analysed using angles that are dependent on anatomical planes of reference and only quantify the orientation in two dimensions. The purpose of this study is to establish a method to determine the three‐dimensional orientation of the femoral neck using a three‐dimensional model. An accurate determination of the femoral neck axis requires a reconsideration of the complex architecture of the proximal femur. The morphology of the femoral neck results from both the medial and arcuate trabecular systems, and the asymmetry of the cortical bone. Given these considerations, two alternative models, in addition to the cylindrical one frequently assumed, were tested. The surface geometry of the femoral neck was subsequently used to fit one cylinder, two cylinders and successive cross‐sectional ellipses. The model based on successive ellipses provided a significantly smaller average deviation than the two other models (P < 0.001) and reduced the observer‐induced measurement error. Comparisons with traditional measurements and analyses on a sample of 91 femora were also performed to assess the validity of the model based on successive ellipses. This study provides a semi‐automatic and accurate method for the determination of the functional three‐dimensional femoral neck orientation avoiding the use of a reference plane. This innovative method has important implications for future studies that aim to document and understand the change in the orientation of the femoral neck associated with the acquisition of a bipedal gait in humans. Moreover, the precise determination of the three‐dimensional orientation has implications in current research involved in developing clinical applications in diagnosis, hip surgery and rehabilitation.     

Coronary angiography after the age of 70 years

100 patients over the age of 70 years underwent coronary angiography. The indications for this examination at this age were different from those in younger patients. After the age of 70 years, 58 per cent of coronary angiographies are performed as part of the haemodynamic survey of valvular disease. The risk of the examination appears to be higher, as two deaths occurred in this small series, while the mortality is estimated to be 2 per thousand in younger patients. Coronary angiography is very useful at this age in patients with valvular disease to determine the need for an associated coronary graft and also to determine contraindications for operation because of the severity of the lesions. A surgical indication was confirmed in 50 patients, but surgery was only performed in 36 of them. The follow-up of these patients demonstrates that patients operated for valvular disease had a longer survival that those considered to be inoperable or who refused operation. On the other hand, there was no difference in survival between grafted and non-operated patients over the age of 70 years.