Differentially expressed Leishmania major gp63 genes encode cell surface leishmanolysin with distinct signals for glycosylphosphatidylinositol attachment.

The Leishmania cell surface metalloproteinase, leishmanolysin or GP63, is expressed in all stages of Leishmania major. Initial studies reported that in L. major the gp63 genes were arranged as five homologous, tandemly repeated genes (gp63 genes 1-5) and a sixth, less conserved gp63 gene located 8 kb downstream of gp63 gene 5. This study compared the sequences of L. major gp63 gene 1 and gp63 gene 6 and identified a seventh L. major gp63 gene located downstream from gp63 gene 6. The L. major gp63 genes exhibited stage-specific differences in their expression: gp63 genes 1-5 were expressed in promastigotes only, gp63 gene 6 was expressed in promastigotes and amastigotes, while gp63 gene 7 was expressed predominantly in stationary phase promastigotes and in amastigotes. Analysis of the predicted protein sequence of gp63 gene 6 (GP63-6) and gp63 gene 1 (GP63-1) showed that these two proteins were homologous in terms of overall predicted domain structure. L. major GP63-1 has been reported to contain a glycosylphosphatidylinositol (GPI) membrane anchor while sequence analysis predicted that GP63-6 contained a different hydrophobic C-terminus that may act as a transmembrane region. Transfection studies using L. major gp63 gene 1 and gp63 gene 6 expressed in L. donovani promastigotes showed that GP63-6 was expressed at the cell surface and that the distinct GP63-6 C-terminus was capable of mediating GPI anchor attachment.

Paradoxical vocal cord motion in the recovery room: a masquerader of pulmonary dysfunction.

PURPOSE: We report a case of paradoxical vocal cord motion as an unusual cause of postoperative stridor and wheezing. A means of diagnosis and management is discussed. CLINICAL FINDINGS: A 71-yr-old man developed paradoxical vocal cord motion following uncomplicated hip replacement. He was treated with standard therapy for postoperative stridor and wheezing. After extensive evaluation, a flexible fibreoptic laryngoscope was used and the vocal cords noted to move paradoxically. This was the cause of his postoperative stridor and wheezing. Paradoxical vocal cord motion should be suspected as a cause of postoperative stridor and wheezing when the airway is easily maintained by a bag and mask, there is previous history of psychological problems, and there exists an unexplained history of previous postoperative airway distress. The definitive diagnosis may be made using a fibreoptic laryngoscope. In this patient, intubation was deferred and a plan of conservative therapy pursued. CONCLUSION: Paradoxical vocal cord motion is an unusual cause of postoperative respiratory distress. A definitive diagnosis may be made by the use of a flexible fibreoptic laryngo-scope using topical anaesthesia.