Evaluation of the effect of probiotic cultures added to commercial yogurt over a known population of Listeria monocytogenes and Escherichia coli O157:H7

The effect of probiotic cultures over Listeria monocytogenes and Escherichia coli O157:H7 during yogurt storage was evaluated. Two different yogurt brands, one with additional probiotic cultures (Lactobacillus casei and L. acidophilus) were inoculated with known populations (106 UFC/g) of either L. monocytogenes or E. coli O157:H7 in three different times and stored for 32 days at 5 degrees C. Every four days the count of lactic bacteria, the added pathogens and pH was evaluated, according to the methodology described in the Bacteriological Analytical Manual. The pH and lactic bacteria population were constant during the testing period. Yogurt with additional probiotic cultures reduced the population of L. monocytogenes in 8 days, the population of E. coli O157:H7 in 16; yogurt with no additional probiotics took 20 days to reduce L. monocytogenes to non-detectable levels and even after 28 days of storage, E. coli O157:H7 was cultured. In this work, the beneficial effects of additional probiotic cultures in yogurt is confirmed again.     

The BTA test in the diagnosis of bladder tumors. Usefulness in the hospital setting

INTRODUCTION AND OBJECTIVES: The minimum value of dP/dT is a parameter of diastolic function that can be estimated noninvasively by analyzing the profile of velocity of the mitral regurgitant jet, recorded by continuous-wave Doppler. This estimation requires a complex analysis of the curves that impedes its practical use. Our objective was to validate a simplified method to estimate noninvasively the value of dP/dTmin when mitral regurgitation exists. We calculated the pendient of the profile of velocity of the curve of mitral regurgitation during its deceleration, between 3 and 1.5 m/s, an interval that defines a difference in pressure using the formula delta p = (4v2(1) - 4v2(2)). We divided this interval by the time needed by the jet to decelerate from 3 to 1.5 m/s, obtaining the rate of pressure decay, in mmHg/s. METHODS: We provoked mitral regurgitation in five pigs and registered dP/dT and the curve velocity of mitral regurgitation simultaneously, by micromanometer-tipped catheter and continuous-wave Doppler, respectively. The rate of pressure decay was calculated on the mitral regurgitation curve. RESULTS: We obtained 29 simultaneous registers. The coefficient for the correlationship between dP/dT and the rate of pressure decay was with an r value of 0.62 (p < 0.0001). The rate of pressure decay underestimated systematically the value of dP/dT. Intra and interobserver variability of TDP was 9 and 11%, respectively. CONCLUSIONS: This study validates a simplified method to estimate dP/dT noninvasively, with acceptable correlation with invasive measurements and adequate reproducibility.