Magnesium sulfate for aneurysmal subarachnoid hemorrhage: the end of the road or more trials?

Delayed cerebral ischemia (DCI) is a feared complication and an important cause of poor outcome after aneurysmal subarachnoid hemorrhage (SAH). In the current study, Wong and colleagues performed a systematic review and meta-analysis of randomized controlled trials that investigated the efficacy of magnesium sulfate in patients with aneurysmal SAH. Outcome measures were DCI, cerebral infarction, and functional outcome 3 and 6 months after SAH. Magnesium sulfate decreased the rate of cerebral infarction, but not of DCI or poor functional outcome. Regarding outcome, a beneficial effect of magnesium sulfate on outcome can not be ruled out because of sample size limitations. Even if this meta-analysis had shown an effect on outcome, the question remains which treatment protocol should be applied in daily practice, since the administration of magnesium sulfate differed between most included studies. The present meta-analysis also underlines the importance of defining clinically relevant endpoints in SAH trials. Clinical deterioration due to DCI is more subject to inter-observer bias compared to cerebral infarction, which represents the ultimate outcome of the ischemic event. The Magnesium in Aneurysmal Subarachnoid Hemorrhage-II (MASH-II: ISRCTN68742385) phase III clinical trial nears completion. It aims to include 1,200 patients, and its results are urgently awaited

The effect of directives within the area of direct taxation on the interpretation and application of tax treaties

The effect of directives within the area of direct taxation on tax treaties has become more and more relevant in light of the increasing overlap between situations covered by directives and tax treaties, the changing nature of obligations arising from directives, and the interpretation by the EU Court of Justice of terms in directives that are similar to terms used in tax treaties. This book contains an analysis of the effect of directives on the interpretation and application of tax treaties from the perspectives of public international law and the laws of the EU. Regarding the effect of directives on the interpretation of tax treaties, this book addresses the question whether directives qualify must be taken into account when resorting to article 3(2) OECD Model and article 31 Vienna Convention 1969 and, if so, to what extent they could affect the interpretation of a tax treaty (while taking into account the duty of conforming interpretation). Additionally, this book looks into to what extent directives could affect the application of tax treaties under the conflict rules of public international law (lex posterior, lex specialis) as well as by means of the primacy of directives under the laws of the EUGrenzen van fiscale soevereinitei

Salt minerals and waters from soils in Konya [Turkey] and Kenya

This study deals with the relation between the mineralogical composition of salt assemblages and the composition of groundwaters from which these salts precipitated. A comparison was made between salts and waters sampled in the Konya Basin in Turkey and waters sampled in three different regions in Kenya.The chemical composition of waters from rivers entering the Konya Basin is different from the composition of those from rivers in Kenya. The initial composition of these rivers determines the type of minerals that will precipitate during evaporation of these river waters. The ratio of calcium to carbonate at the moment the solution becomes saturated with respect to calcite, usually the first mineral to precipitate, determines whether the final solution will become carbonate-rich or carbonate-poor. The ratio of magnesium to silica and the ratio of calcium to sulphate at the moment the solution becomes saturated with respect to sepiolite and gypsum respectively, determine the magnesium and sulphate content of the final solution. In this way six different types of concentrated brines originate and six different types of salt assemblages precipitate from these brines during evaporation.The concentrated waters and the salt assemblages in the Konya Basin belong mainly to the Na-Mg-SO 4 -Cl-type. The evolution of the groundwater composition and the type of minerals which precipitated from these groundwaters can be explained by assuming successive precipitation of calcite, sepiolite and gypsum.The concentrated waters and the salt assemblages from Kenya belong mainly to the Na-CO 3 -SO 4 -Cl-type. The behaviour of the dissolved species and the type of salt minerals can be explained by assuming calcite and sepiolite precipitation only.The crystallographic properties of some salt minerals were determined by means of X-ray diffraction analysis and the morphological properties by Scanning Electron Microscopy. The presence of halite causes a salt crust to become dense and sealing. The porosity of a salt crust increases when bloedite or trona is present.Prediction of the sequence of salt minerals which will precipitate from a concentrated solution requires an accurate knowledge of the thermodynamic properties of concentrated electrolyte solutions. Unfortunately, these properties are still unknown for carbonate-rich solutions. Only recently a theory was developed for carbonate-poor solutions.The watersamples were evaporated in the laboratory in evaporating dishes under ambient conditions. The mineralogical composition of the precipitates was compared with the assemblages that occur in the field.The carbonate-containing salt assemblages both from the field and from the laboratory experiments were investigated by means of log PCO 2 - log aH 2 O diagrams. It appeared that neither the field nor the laboratory salt assemblages were in equilibrium with the CO 2 - pressures of the solutions from which they precipitated. These CO 2 -pressures were calculated from the analytical data.The carbonate-free salt assemblages from the Konya Basin were investigated by means of Jänecke-diagrams. For a few selected samples the theoretical mineral sequences were calculated under the assumption of equilibrium precipitation with the help of the computerprogram of Harvie & Weare (1980). It appeared that prediction of mineral assemblages in salt efflorescences is difficult even with a sound thermodynamic theory. Salt assemblages in natural salt efflorescences could best be predicted assuming precipitation under equilibrium conditions, whereas mineral assemblages in evaporating dishes in the laboratory could best be predicted assuming both metastable mineral formation and fractional crystallization. This conclusion is supported by the presence of the two new minerals, konyaite and eugsterite, which have been discovered in this study. Both are metastable minerals under ambient conditions.The oxygen and hydrogen isotopic composition of some waters from the Konya Basin in Turkey and of the watersamples from the Amboseli Basin in Kenya were determined. The isotope fractionation caused by evaporation is different in groundwater and surface water. Processes of evaporation and water-rock interaction could be distinguished

Secondary infarction in single or in multiple vascular territories: two different entities following subarachnoid hemorrhage?

The pathogenesis of secondary infarctions (SI) after aneurysmal subarachnoid hemorrhage (SAH) is poorly understood. To assess whether SI in single (SSI) or multiple (MSI) vascular territories represent different disease entities, we compared clinical profiles of patients with these patterns of SI. CT/MRI-examinations of 448 patients were reviewed for new infarctions within 28 days after SAH, and categorized into SSI or MSI. Only patients with adequate follow-up imaging excluding any new infarctions were included for analysis (269 patients). Procedure-related infarctions were excluded. Odds ratios (ORs) with corresponding 95% confidence intervals (CI) were calculated for patients with SSI or MSI versus patients without SI to analyze differences in demographic characteristics, vascular risk factors, disease-related characteristics and treatment modalities. Thirty-six patients had SSI, 53 MSI and 180 no SI. ORs in MSI-patients were >1.5 times higher compared with ORs in SSI-patients for multiple vascular risk factors [MSI:5.4 (2.3–13) versus SSI:1.2 (0.5–2.8)], poor clinical condition on admission [MSI:4.6 (2.4–8.9) versus SSI:2.4 (1.1–5.2)], initial loss of consciousness [MSI:2.6 (1.3–5.3) versus SSI:1.1 (0.5–2.3)] and large amounts of intraventricular blood [MSI:2.9 (1.4–5.8) versus SSI:1.5 (0.7–3.2)]. In multivariate analysis ORs remained higher in MSI for presence of multiple vascular risk factors [MSI:1.9 (1.2–2.9) versus SSI:1.1 (0.8–1.7)] and initial loss of consciousness [MSI:3.0 (1.0–8.9) versus SSI:1.6 (0.6–4.0)]. Our findings suggest that SSI and MSI after SAH are not distinct disease entities. MSI was related to the same characteristics as SSI but to a larger extent, specifically to the presence of multiple vascular risk factors, initial loss of consciousness, larger amounts of intraventricular blood, and poor clinical status on admission

Pitfalls in interpreting red blood cell parameters in elite high-altitude and sea-level athletes:A unique case series

Standard routine hematological measurements are commonly used to investigate differences in blood parameters between high-altitude athletes (HAA) and sea-level athletes (SLA), and to monitor the effect of high-altitude training. In this way, red blood cell (RBC) parameters are usually expressed as relative parameters (concentration) rather than absolute parameters (total amount). In this unique case series of elite HAA and SLA, we describe how different ways of parameter expression can affect the interpretation of blood tests. In a group of 42 elite athletes, relative and absolute RBC parameters were compared between HAA and SLA. Absolute parameters were calculated by multiplying relative values with formula-based estimated blood volume (BV-e). Additionally, in two individual athletes, one HAA and one SLA, absolute parameters were also calculated with blood volume (BV) obtained by measurement with a dilution method (BV-m). In men, HAA had a significantly higher hemoglobin (Hb) concentration (+7.8%; p = 0.001) and total Hb mass per kg body weight (BW) (+12.0%; p = 0.002). When not corrected for BW, HAA had a lower, non-significant, total Hb mass (-7.8%; p = 0.055). In women, no significant differences between HLA and SLA were observed. The two individual athletes showed that, based on BV-m, in the HAA, total Hb mass and total Hb mass per kg BW were respectively 14.1 and 31.0% higher than in the SLA, whereas based on BV-e, in the HAA, total Hb mass was 20.8% lower and total Hb mass per kg BW was only 2.4% higher. Similar inconsistencies were observed for total RBC count. Thus, different ways of parameter expression, and different methods of BV assessment for the calculation of absolute parameter values, influence the interpretation of blood tests in athletes, which may lead to misinterpretation and incorrect conclusions