An additional imaging sign preceding spontaneous fragmentation and embolization of an implanted subclavian vein catheter

Analysis of chest roentgenograms performed before spontaneous fragmentation and distal embolization of an implanted subclavian vein catheter revealed discontinuity of the catheter's radiopaque marker in addition to kinking of the area proximal to the breakage point. To the authors' knowledge the case presented in this article is the first report of this imaging sign before catheter fragmentation. Lateral catheter placement and early recognition of subtle imaging signs may assist in decreasing the incidence of this significant complication.

Degradation artefacts during sample preparation for sodium dodecyl sulphate polyacrylamide gel electrophoresis

Preparation of samples for sodium dodecyl sulphate polyacrylamide gel electrophoresis routinely involves heating the protein in solution containing detergent and reducing agent for at least two minutes. Here we show that this treatment causes fragmentation of the protein glycogen phosphorylase, whether purified or as a component of a skeletal muscle preparation. The fragments are detected as minor bands on western blots and represent the products of discrete breakage point in the peptide sequence. Protease inhibitors cannot suppress the fragmentation. Such small amounts of immunoreactive fragments may be incorrectly identified on western blots as contaminants that were originally present in the antigen preparation. They may also be a source of ambiguity in studies that search for degradation intermediates during proteolysis.

Genetic analysis of an unequal chromosomal translocation in Aspergillus nidulans

SUMMARYTranslocation T(III–VIII) in Aspergillus nidulans has been analysed by the detection of meiotic linkage between markers previously located separately on linkage groups III and VIII. The breakage points have been mapped by the detection of linkage between the crinkled type and genetic markers in the region of the break. A segment from linkage group III, approximately 43 units long and including the markers moC96, sC12, sA1 and cnxH3, has been translocated into linkage group VIII. The breakage point is between su6proA and moC96 and the attachment point is close to cha in linkage group VIII. It seems probable that the segment has been inserted into linkage group VIII.