“Background: We studied the interactions between uterine and placental hemodynamics during https://www.selleckchem.com/products/jq-ez-05-jqez5.html maternal hypotension in chronically instrumented fetal sheep. In addition, we investigated maternal hemodynamic characteristics, fetoplacental hemodynamics and fetal acid-base status when a retrograde diastolic uterine artery blood flow pattern
is present during maternal hypotension.\n\nMethods: Invasive maternal and fetal hemodynamic parameters, uterine (Q(UtA)) and placental (Q(UA)) volume blood flows and acid-base values were examined in 24 chronically instrumented sheep at baseline and during epidural-induced maternal hypotension at 117-132 (term 145) days of gestation. Uterine artery blood flow velocity waveforms were obtained by Doppler ultrasonography.\n\nResults: Maternal hypotension decreased Q(UtA) without affecting Q(UA). During hypotension, eight out of 24 sheep demonstrated a retrograde diastolic blood flow velocity waveform pattern in the uterine artery. Maternal systolic, diastolic and mean arterial blood pressures were significantly lower in the retrograde group
than in the antegrade group. No statistically significant differences in Q(UtA), Q(UA) and fetal blood gas values were detected between the two groups during hypotension.\n\nConclusions: An acute decrease in uterine artery volume blood flow during maternal hypotension is not compensated by increased placental volume blood
flow. A retrograde diastolic blood flow pattern in the uterine artery is related buy Quisinostat to lower maternal arterial pressures, especially during diastole. A uterine artery retrograde diastolic blood flow pattern does not have any additional detrimental short-term effects on fetal acid-base status.”
“The administration of anabolic steroids www.selleckchem.com/products/ag-881.html is one of the most important issues in doping control and is detectable through a change in the carbon isotopic composition of testosterone and/or its metabolites. Gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS), however, remains a very laborious and expensive technique and substantial amounts of urine are needed to meet the sensitivity requirements of the IRMS. This can be problematic because only a limited amount of urine is available for anti-doping analysis on a broad spectrum of substances. In this work we introduce a new type of injection that increases the sensitivity of GC-C-IRMS by a factor of 13 and reduces the limit of detection, simply by using solvent vent injections instead of splitless injection. This drastically reduces the amount of urine required. On top of that, by only changing the injection technique, the detection parameters of the IRMS are not affected and there is no loss in linearity. Copyright (c) 2012 John Wiley & Sons, Ltd.