Arterial blood pressure during early sepsis and outcome

Objective: To evaluate the association between arterial blood pressure (ABP) during the first 24h and mortality in sepsis. Design: Retrospective cohort study. Setting: Multidisciplinary intensive care unit (ICU). Patients and participants: A total of 274 septic patients. Interventions: None. Measurements and results: Hemodynamic, and laboratory parameters were extracted from a PDMS database. The hourly time integral of ABP drops below clinically relevant systolic arterial pressure (SAP), mean arterial pressure (MAP), and mean perfusion pressure (MPP=MAP−central venous pressure) levels was calculated for the first 24h after ICU admission and compared with 28-day-mortality. Binary and linear regression models (adjusted for SAPS II as a measure of disease severity), and a receiver operating characteristic (ROC) analysis were applied. The areas under the ROC curve were largest for the hourly time integrals of ABP drops below MAP60mmHg (0.779 vs. 0.764 for ABP drops below MAP55mmHg; P≤0.01) and MPP 45mmHg. No association between the hourly time integrals of ABP drops below certain SAP levels and mortality was detected. One or more episodes of MAP<60mmHg increased the risk of death by 2.96 (CI 95%, 1.06-10.36, P=0.04). The area under the ROC curve to predict the need for renal replacement therapy was highest for the hourly time integral of ABP drops below MAP75mmHg. Conclusions: A MAP level≥60mmHg may be as safe as higher MAP levels during the first 24h of ICU therapy in septic patients. A higher MAP may be required to maintain kidney functio

Monotonic Alpha-divergence Minimisation

In this paper, we introduce a novel iterative algorithm which carries out $\alpha$-divergence minimisation by ensuring a systematic decrease in the $\alpha$-divergence at each step. In its most general form, our framework allows us to simultaneously optimise the weights and components parameters of a given mixture model. Notably, our approach permits to build on various methods previously proposed for $\alpha$-divergence minimisation such as gradient or power descent schemes. Furthermore, we shed a new light on an integrated Expectation Maximization algorithm. We provide empirical evidence that our methodology yields improved results, all the while illustrating the numerical benefits of having introduced some flexibility through the parameter $\alpha$ of the $\alpha$-divergence

L\u27Observatoire Geopolitique des Drogues; Svjetski atlas droga

Prijevod s francuskog: Silva Mežnarić

Aryl Hydrocarbon Hydroxylase, Epoxide Hydrolase, and Benzo[a]pyrene Metabolism in Human Epidermis: Comparative Studies in Normal Subjects and Patients with Psoriasis

Prior studies have shown that human skin possesses a cytochrome P-450-dependent microsomal enzyme that is capable of metabolizing drugs and polycyclic aromatic hydrocarbon (PAH) carcinogens. This study characterized benzo[a]pyrene (BP) metabolism in human epidermis of normal and psoriatic individuals. The basal level of the cytochrome P-450-dependent microsomal enzyme aryl hydrocarbon hydroxylase (AHH) and epoxide hydrolase (EH) were measured in freshly keratomed epidermis from 12 normal individuals and from uninvolved skin sites of 12 patients with psoriasis. The induction response of AHH following the in vitro addition of the PAH benz[A]anthracene (BA) was also assessed. The basal activity (mean ± SE) of AHH in normal epidermis was 62.1 ± 5.6 units (fmol 3-hydroxybenzo[a]pyrene, 3-OH-BP/min/mg protein) whereas the activity in uninvolved skin of psoriatic individuals was 62.9 ± 5.1 units (NS), Epoxide hydrolase activity was 25.1 ± 1.1 (pmol BP 4,5-diol/min/mg protein) units in normal epidermis and 24.8 ± 2.1 units in epidermis from patients with psoriasis (NS). Following addition of BA (100μM), in vitro, AHH activity in normal epidermis increased by a mean value of 165% whereas activity in nonlesional epidermis of psoriatic individuals increased 320%. Kinetic studies in normal epidermis revealed that the AHH reaction was linear up to 60 min and to 50 μg protein, had a pH optimum of 7.4, and the Km for BP was 0.62 MM. High-performance liquid chromatography (HPLC) confirmed that the pattern of metabolism of BP was quite similar in epidermal microsomes prepared from normal and psoriatic individuals, insofar as the formation of diols, phenols, and quinones was concerned. These studies indicate that human epidermis is capable of metabolizing BP and that there is no significant difference between normal individuals and patients with psoriasis insofar as basal AHH activity or total BP metabolism is concerned. Furthermore, the epidermal enzyme system in patients with psoriasis has a greater responsiveness to environmental PAH than does that of normal individuals

The ff-divergence expectation iteration scheme

This paper introduces the $f$-EI$(\phi)$ algorithm, a novel iterative algorithm which operates on measures and performs $f$-divergence minimisation in a Bayesian framework. We prove that for a rich family of values of $(f,\phi)$ this algorithm leads at each step to a systematic decrease in the $f$-divergence and show that we achieve an optimum. In the particular case where we consider a weighted sum of Dirac measures and the $\alpha$-divergence, we obtain that the calculations involved in the $f$-EI$(\phi)$ algorithm simplify to gradient-based computations. Empirical results support the claim that the $f$-EI$(\phi)$ algorithm serves as a powerful tool to assist Variational methods

Pulse pressure variation and volume responsiveness during acutely increased pulmonary artery pressure: an experimental study

We found that pulse pressure variation (PPV) did not predict volume responsiveness in patients with increased pulmonary artery pressure. This study tests the hypothesis that PPV does not predict fluid responsiveness during an endotoxin-induced acute increase in pulmonary artery pressure and right ventricular loading