Noninvasive quantitation of blood flow turbulence in patients with aortic valve disease using online digital computer analysis of Doppler velocity data.

Previous experimental studies have demonstrated that aortic valve disease is associated with significant downstream turbulence (T). In this study, we developed a noninvasive method on the basis of Doppler velocity recording for quantitating aortic blood flow T in patients with aortic valve disease. The instantaneous blood velocity at a point in the aorta is equal to the sum of a mean periodic velocity component with a random or turbulent velocity component. According to the ensemble average method, time mean absolute T intensity is the root-mean-square value of turbulent velocity averaged over time and T is better quantitated by the relative T intensity (TIr), which is the ratio of absolute T intensity to the ensemble average velocity averaged over time. We computed TIr in 18 patients with mild to severe aortic stenosis and in 13 healthy volunteers from instantaneous modal velocities of 70 cycle length-matched heart beats recorded in the proximal part of the descending aorta by pulsed Doppler using an ultrasound system with an output port for online digital data transfer into a microcomputer. TIr was greater in patients with aortic valve disease (18.4 +/- 5.1%, range 11.2%-28.9%) than in control patients (7.9 +/- 1.9%, range 4.8%-9.8%; P =.0001). In patients with aortic valve disease, TIr was better linearly related to the ratio of postvalvular aorta to valvular orifice cross-sectional areas (r = 0.89, P =.0001) than to other parameters of valve restriction: transvalvular pressure gradient (r = 0.78, P =.0001); valve area (r = -0.56, P =.01); and valve resistance (r = 0.72, P =.0002). Thus, T that can be computed noninvasively from direct digital transfer of Doppler velocity data appears to be linearly related to indices of aortic valve restriction. Our data support the concept of the postvalvular aorta to valvular orifice cross-sectional areas ratio as a new important hemodynamic parameter in patients with aortic valve disease.     

Doctor,What Does my Knee Arthroplasty Weigh?

The aim of this study was to compare the weight of the total knee arthroplasty (TKA) implants and the weight of the natural knee. A prospective study was conducted with two different brands of cemented primary TKA. During the procedure, we collected the removed bone, soft tissues and the post-implantation cement and weighed them all separately at the end. In both groups, the implants plus cement were significantly heavier than the removed bone and soft tissues. The average weight gained was 266.7 ± 35.1 g for group 1 and 279.1 ± 48.7 g for group 2. This significant local weight gained after TKA is a new parameter that should be taken into account for further studies and when creating new implants.     

Urinary cystatin C as a specific marker of tubular dysfunction.

BACKGROUND: Cystatin C (CST3), a strong inhibitor of cysteine proteinases, is freely filtered by the kidney glomerulus and is reabsorbed by the tubules, where it is almost totally catabolized, with the remainder then eliminated in urine. In tubular diseases, it seems sensible to postulate that CST3 degradation would be reduced and consequently an increase in its urinary elimination would be observed. METHODS: We report here the development of an automatic quantitative assay to measure CST3 concentrations in urine using a Behring N-Latex Cystatin C kit on a BNII laser nephelometer. We tested its clinical relevance on several kidney disease patients. RESULTS: This assay is sensitive (limit of detection 0.008 mg/L) and precise (within- and between-day CVs < 4%). Reference values for freshly collected urine samples range from 0.03 to 0.18 mg/L. Mean urine CST3 concentrations obtained from 52 patients with kidney tubular disease (4.31 +/- 3.85 mg/L) were significantly higher than those for 60 controls (0.096 +/- 0.044 mg/L; p < 0.0001) and 47 glomerular disease patients (0.106 +/- 0.133 mg/L; p < 0.0001). CONCLUSION: Increased urinary CST3 concentrations allow the accurate detection of tubular dysfunction among pure and mixed nephropathies. Because of its ability to be processed on automated clinical chemistry analyzers, this assay could easily be used as an adjunct to the standard panel used to screen kidney pathologies, even in emergency situations.     

Early Closure of Defunctioning Loop Ileostomy: Is It Beneficial for the Patient? A Meta-analysis

World Journal of Surgery - To perform a meta-analysis to answer the question, whether early closure (EC) of defunctioning loop ileostomy may be beneficial for patient as compared with late closure...