Publications

Streptococcus sanguinisis a leading cause of infective endocarditis, a life-threatening infection of the cardiovascular system. An important interaction in the pathogenesis of infective endocarditis is attachment of the organisms to host platelets.S. sanguinisexpresses a serine-rich repeat adhesin, SrpA, similar in sequence to platelet-binding adhesins associated with increased virulence in this disease. In this study, we determined the first crystal structure of the putative binding region of SrpA (SrpABR) both unliganded and in complex with a synthetic disaccharide ligand at 1.8 and 2.0 Å resolution, respectively. We identified a conserved Thr-Arg motif that orients the sialic acid moiety and is required for binding to platelet monolayers. Furthermore, we propose that sequence insertions in closely related family members contribute to the modulation of structural and functional properties, including the quaternary structure, the tertiary structure, and the ligand-binding site.

BACKGROUND AND AIMS

Endoscopic treatment of anorectal bleeding can be challenging. We report use of the endoscopic over-the-scope clip (OTSC) to treat massive bleeding from the transitional zone of the anorectum. The aim of this retrospective study was to assess the clinical outcome and efficacy of the OTSC and to describe the technique of its use in acute severe bleeding occurring at the transitional zone of the anorectum.

METHODS

We treated 5 consecutive patients (age range, 36-79 years, 5 men) with severe bleeding from the transitional zone of the anorectum caused by hemorrhoid therapy, digital trauma, and a Dieulafoy lesion. We analyzed the efficacy, safety, and outcome of endoscopic treatment using the OTSC.

RESULTS

Primary hemostasis was successfully achieved in all the patients using a single OTSC. The OTSC deployment technique was adapted from the endoscopic band ligation of hemorrhoids. There was no immediate or late rebleeding. We observed that there were no adverse events from OTSC placement in the anorectum.

CONCLUSIONS

This case series provides evidence that OTSCs may be effective in controlling bleeding from the transitional zone of the anorectum. Although use of OTSCs for bleeding elsewhere in the GI tract has been described, this case series is the first to show its application in the transitional zone of the anorectum.