Diagnostic performance of transvesical ultrasound in clinically suspected ectopic pregnancy in a public and tertiary hospital setup.

BACKGROUND: Ectopic pregnancy consists 1.2 to 1.4% of all reported pregnancies and an increasing accordance has been documented in many parts of the world OBJECTIVE: To evaluate the performance of transvesical ultrasound (TVS) in the diagnosis of ectopic pregnancy in the public hospital setup. METHODS: Review of medical records of 117 patients who were admitted to St Paul's Hospital with the diagnosis of ectopic pregnancy between the years 2005 and 2008 was made. Data on demographic & clinical information, and laboratory investigations done and transvesical ultrasound records were collected. Outcomes after Laparatomy were used as confirmations or gold standard for final diagnosis. RESULTS: Of the 117 admitted patients for ectopic pregnancy, 99 (84.6%) had transvesical ultrasound done & in 65 (65.9%) of those 99 patients, it suggested diagnosis of ectopic pregnancy. Sixty-four (55%) had pervaginal bleeding and lower abdominal pain as presenting complaint. Documentation of uterine, adnexal & cul-de-sac findings fall the three diagnostic variables) was noted in 71/99 (71.7%) two of the three and only one of the three diagnostic variables were seen 20.2% and 8.1% of the sonographic studies respectively. Of patients whose ultrasound report suggested ectopic pregnancy, in 46 (70.8%) a complex adnexal mass and in 33 (50.8%) moderate to large amount of cul-de-sac fluid, and in 9 (19.8%) patients fluid in the uterine cavity were detected The overall sensitivity and specificity of transvesical ultrasound study in the diagnosis of ectopic pregnancy were 83.3% and 33.3% respectively, with positive & negative predictive values of 73.5% and 47.4% respectively and accuracy of 68%. CONCLUSION: About 83.3% of admitted patients were diagnosed sonographically to have ectopic gestation prior to surgery. Quality of the ultrasound report with respect to completeness in number of sonographic diagnostic variables has a statistically significant (P < 0.05) role in enhancing the accuracy of transvesical ultrasonography in the diagnosis and exclusion of ectopic pregnancy.

The prion protein binds thiamine.

Although highly conserved throughout evolution, the exact biological function of the prion protein is still unclear. In an effort to identify the potential biological functions of the prion protein we conducted a small-molecule screening assay using the Syrian hamster prion protein [shPrP(90-232)]. The screen was performed using a library of 149 water-soluble metabolites that are known to pass through the blood-brain barrier. Using a combination of 1D NMR, fluorescence quenching and surface plasmon resonance we identified thiamine (vitamin B1) as a specific prion ligand with a binding constant of ~60 µM. Subsequent studies showed that this interaction is evolutionarily conserved, with similar binding constants being seen for mouse, hamster and human prions. Various protein construct lengths, both with and without the unstructured N-terminal region in the presence and absence of copper, were examined. This indicates that the N-terminus has no influence on the protein's ability to interact with thiamine. In addition to thiamine, the more biologically abundant forms of vitamin B1 (thiamine monophosphate and thiamine diphosphate) were also found to bind the prion protein with similar affinity. Heteronuclear NMR experiments were used to determine thiamine's interaction site, which is located between helix 1 and the preceding loop. These data, in conjunction with computer-aided docking and molecular dynamics, were used to model the thiamine-binding pharmacophore and a comparison with other thiamine binding proteins was performed to reveal the common features of interaction.