A structural classification of the variant surface glycoproteins of the African trypanosome.

Long-term immune evasion by the African trypanosome is achieved through repetitive cycles of surface protein replacement with antigenically distinct versions of the dense Variant Surface Glycoprotein (VSG) coat. Thousands of VSG genes and pseudo-genes exist in the parasite genome that, together with genetic recombination mechanisms, allow for essentially unlimited immune escape from the adaptive immune system of the host. The diversity space of the "VSGnome" at the protein level was thought to be limited to a few related folds whose structures were determined more than 30 years ago.

Structural similarities between the metacyclic and bloodstream form variant surface glycoproteins of the African trypanosome.

During infection of mammalian hosts, African trypanosomes thwart immunity using antigenic variation of the dense Variant Surface Glycoprotein (VSG) coat, accessing a large repertoire of several thousand genes and pseudogenes, and switching to antigenically distinct copies. The parasite is transferred to mammalian hosts by the tsetse fly. In the salivary glands of the fly, the pathogen adopts the metacyclic form and expresses a limited repertoire of VSG genes specific to that developmental stage.

Ferrocene compounds. XXXIX. 1-Ferrocenylisochromane.

In the title compound, [Fe(C(5)H(5))(C(14)H(13)O)], the plane of the heterocyclic ring is almost perpendicular to the plane of the substituted cyclopentadienyl ring, and the heterocyclic ring adopts a half-chair conformation. The conformation of the nearly parallel cyclopentadienyl (Cp) rings [the dihedral angle between their planes is 2.7 (1) degrees ] is almost halfway between eclipsed and staggered, and the rings are mutually twisted by about 19.

[Implantation of artificial lenses in primary and secondary management of severe eye injuries in warfare].

The authors report their experience concerning intraocular implantation of artificial lenses during primary management of the eye war injuries as well as during secondary management, after shorter or longer period of consolidation, on 16 eyes of the same number of patients. Primary intraocular implantation was performed on 5 eyes simultaneously with primary management of the injured eye, while secondary implantation was performed on 11 eyes later, after more or less time of consolidation of the primary wound treatment. In regard to anatomical and functional consequences of severe trauma of the eye and the surgery itself, the functional state of the eyes operated on was satisfactory.

Laparoscopic cholecystectomy in Zimbabwe: initial report.

The laparoscopic approach has become the preferred technique of doing cholecystectomy in many parts of the world. In our initial experience with 19 patients we had no mortalities and no major complications. The average hospital stay was 2.