St Bartholomew's Hospital

About: St Bartholomew's Hospital is a healthcare organization based out in London, United Kingdom. It is known for research contribution in the topics: Population & Cancer. The organization has 11054 authors who have published 13229 publications receiving 501102 citations. The organization is also known as: St. Bartholomew's Hospital & The Royal Hospital of St Bartholomew.

Automatic Measurement of the Myocardial Interstitium: Synthetic Extracellular Volume Quantification Without Hematocrit Sampling.

Abstract: Objectives The authors sought to generate a synthetic extracellular volume fraction (ECV) from the relationship between hematocrit and longitudinal relaxation rate of blood. Background ECV quantification by cardiac magnetic resonance (CMR) measures diagnostically and prognostically relevant changes in the extracellular space. Current methodologies require blood hematocrit (Hct) measurement—a complication to easy clinical application. We hypothesized that the relationship between Hct and longitudinal relaxation rate of blood (R1 = 1/T1blood) could be calibrated and used to generate a synthetic ECV without Hct that was valid, user-friendly, and prognostic. Methods Proof-of-concept: 427 subjects with a wide range of health and disease were divided into derivation (n = 214) and validation (n = 213) cohorts. Histology cohort: 18 patients with severe aortic stenosis with histology obtained during valve replacement. Outcome cohort: For comparison with external outcome data, we applied synthetic ECV to 1,172 consecutive patients (median follow-up 1.7 years; 74 deaths). All underwent CMR scanning at 1.5-T with ECV calculation from pre- and post-contrast T1 (blood and myocardium) and venous Hct. Results Proof-of-concept: In the derivation cohort, native R1blood and Hct showed a linear relationship (R2 = 0.51; p Conclusions Synthetic ECV provides validated noninvasive quantification of the myocardial extracellular space without blood sampling and is associated with cardiovascular outcomes.

Accuracy and limitations of the ultrasonic Doppler blood velocimeter and zero crossing detector.

Abstract: The zero crossing detector processes blood velocity signals from a Doppler ultrasonic velocimeter to give an output that can be recorded on paper. Although this output gives an indication of the instantaneous velocity averaged across the vessel the system does have limitations when used for quantitative work. This paper explains the working of the zero crossing detector and illustrates how errors can arise due to changes in amplitude and frequency content of the signal. Suggestions are made for reducing the errors, and other more accurate methods of analysis are discussed.

Delayed puberty associated with inflammatory bowel disease.

Abstract: Delayed puberty frequently complicates the clinical course of young patients with inflammatory bowel disease, more often in Crohn's disease than ulcerative colitis. Undernutrition has been thought to be the main reason for delayed puberty in these patients. However, puberty may be delayed despite a normal nutritional status. Observations in patients with inflammatory bowel disease and in rats with experimental colitis suggest that inflammatory mediators may have a direct adverse influence, independent of undernutrition, on the onset and progression of puberty. Serum androgens are consistently reported to be reduced in patients with delayed puberty and inflammatory bowel disease. This reduction is not necessarily secondary to a reduction in gonadotrophins as serum concentrations of gonadotrophins have been reported to be normal or even increased in some studies. Management of delayed puberty involves calorie supplements to correct undernutrition and treatment of inflammation. Observations in boys with delayed puberty and controlled studies in experimental models of intestinal inflammation suggest that testosterone therapy can accelerate puberty.