Inhibition of Host Cell Lysosome Spreading by Trypanosoma cruzi Metacyclic Stage-Specific Surface Molecule gp90 Downregulates Parasite Invasion.

Successful infection by Trypanosoma cruzi, the agent of Chagas' disease, is critically dependent on host cell invasion by metacyclic trypomastigote (MT) forms. Two main metacyclic stage-specific surface molecules, gp82 and gp90, play determinant roles in target cell invasion in vitro and in oral T. cruzi infection in mice. The structure and properties of gp82, which is highly conserved among T. cruzi strains, are well known. Information on gp90 is still rather sparse. Here, we attempted to fill that gap. gp90, purified from poorly invasive G strain MT and expressing gp90 at high levels, inhibited HeLa cell lysosome spreading and the gp82-mediated internalization of a highly invasive CL strain MT expressing low levels of a diverse gp90 molecule. A recombinant protein containing the conserved C-terminal domain of gp90 exhibited the same properties as the native G strain gp90: it counteracted the host cell lysosome spreading induced by recombinant gp82 and exhibited an inhibitory effect on HeLa cell invasion by CL strain MT. Assays to identify the gp90 sequence associated with the property of downregulating MT invasion, using synthetic peptides spanning the gp90 C-terminal domain, revealed the sequence GVLYTADKEW. These data, plus the findings that lysosome spreading was induced upon HeLa cell interaction with CL strain MT, but not with G strain MT, and that in mixed infection CL strain MT internalization was inhibited by G strain MT, suggest that the inhibition of target cell lysosome spreading is the mechanism by which the gp90 molecule exerts its downregulatory role.

Aortic Root Replacement for Bicuspid Aortic Valve and Annuloaortic Ectasia in a Patient with Ankylosing Spondylitis / 日本心臓血管外科学会雑誌

A 48-year-old man was admitted with shortness of breath. He had been given a diagnosis of ankylosing spondylitis by an orthopedic surgeon 20 years previously. A grade III/VI to-and-fro murmur was audible at the left sternal border. Echocardiography revealed moderate to severe aortic regurgitation with annular dilatation. He had also suffered complained rigidity of the neck muscles and back pain for 20 years. He underwent aortic root replacement and his postoperative course was uneventful. Aortic valve regurgitation with ankylosing spondylitis in Japan has been seldom reported, compared with European or American. We discuss surgical problems and the management of these lesions are discussed.

A Case of Swelling of Lower Extremity due to Iliac Vein Occlusion with IgG4-Related Idiopathic Retroperitoneal Fibrosis / 日本心臓血管外科学会雑誌

A 62-year-old man presented with a chief complaint of swelling of the left lower extremity. Idiopathic retroperitoneal fibrosis had been diagnosed 6 years previously. Enhanced computed tomography demonstrated occlusion of the left common iliac vein, but without deep vein thrombosis, and a thick dense fibrous layer around the abdominal aorta and in front of the sacrum. After we administered steroid and anticoagulant therapy, remission of the swelling of the left lower extremity was obtained. Presently steroids are being gradually tapered, and he has remained free of recurrence of the swelling of his left lower extremity.

A Case of Cystic Adventitial Disease of the Popliteal Artery and Study of 116 Cases Reported in Japan / 日本心臓血管外科学会雑誌

We report a rare case of cystic adventitial disease of the popliteal artery causing intermittent claudication. About 2 months previously, a 21-year-old man had sudden intermittent claudication in the left leg. The left-sided ankle brachial pressure index (ABI) at rest was 0.66. Computed tomography revealed that the arterial occlusion was segmentally caused by cystic lesions. A cystic adventitial lesion of the popliteal artery, measuring 9 cm in diameter, was surgically removed and reconstruction was performed with a saphenous vein graft. Postoperatively the left ABI improved to 1.01, and his symptoms disappeared. The histopathological diagnosis was cystic adventitial disease and the cysts were in the adventitia. The postoperative course was uneventful and he has been without recurrence for 14 months.