[Irreversible loss of brain function : Requirements and Clinical diagnosis]. / Irreversibler Hirnfunktionsausfall : Voraussetzungen und Klinische Diagnostik.

Brain death (irreversible loss of brain function), according to German regulations, is investigated exclusively by qualified specialists in a strictly hierarchical three-step pattern and a four-eyes principle. In step 1 all necessary prerequisites are to be checked and the pathophysiology of brain damage has to be classified. Step 2 comprises the clinical investigation of reactivity to external stimuli and the upper, middle and lower brain stem reflexes including apnea testing. Step 3 exclusively checks for irreversibility of this condition. The latter is achieved by appropriate technical investigations or by repeated clinical examinations within context-specified intervals (range 12-72 h). However, exclusion of contributing primarily infratentorial pathologies is necessary to avoid limitations of the clinical findings. In this paper, both the initiation of brain death diagnostics and the approved clinical tests regarding to their execution, their alternatives and limits are presented and special situations like conditions with extracorporeal membrane oxygenation (ECMO) are also examined.

A novel model concept for modelling the leaching of natural toxins: results for the case of ptaquiloside.

Phytotoxins are a large class of highly diverse emerging environmental contaminants that have been detected at high concentrations in plants, water and soils. This study presents a novel modelling approach for assessing the fate of plant toxins in the soil-plant-atmosphere continuum, developed for the specific case of ptaquiloside (PTA), a carcinogenic phytotoxin produced by Pteridium aquilinum. The mechanistic model DAISY has been adapted for reproducing phytotoxin dynamics in plants, covering processes such as toxin generation in the canopy, wash off by precipitation and toxin recovery in the canopy after depletion events. Transport of the toxin in the soil was simulated by the advection-dispersion equation assuming weak sorption and degradation for two Danish soils. The model simulates realistic toxin contents in the plant during the growing season, where the actual PTA content is dynamic and a function of the biomass. An average of 48% of the PTA produced in the canopy is washed off by precipitation, with loads in the soil often in the order of mg m-2 and up to a maximum of 13 mg m-2 in a single rain event. Degradation in the soil removes 99.9% of the total PTA input to the soil, while only 0.1% leaches into the soil. The median annual flux-averaged predicted environmental concentrations during single events are often in the order of µg L-1, reaching up to 60 µg L-1 for the worst-case scenario. The simulated results for both degradation and wash off are of the same order of magnitude as the published data. Based on the results, we conclude that DAISY, with the newly implemented processes, is a useful tool for understanding, describing and predicting the fate of PTA in the soil. Further work comparing the model results with real data is needed for the calibration and validation of the model.

[New guidelines for the diagnosis of irreversible loss of brain function : Concept and limitations, organizational demands, and implementation]. / Neue Richtlinien zur Diagnostik des irreversiblen Hirnfunktionsausfalls : Konzept und Limitationen, organisatorische Vorgaben und Ausführung.

In 2015, the German Medical Association (Bundesärztekammer) issued new guidelines on the diagnosis of the "irreversible loss of brain function" (ILBF). ILBF replaced the colloquial term "brain death" in order to leave the notion that concepts of death might vary such as "cardiac death" or "apparent death" and stress the objective medical-scientific matter. The German Transplantation Law describes ILBF as "the final, irreversible loss of all function of the cerebrum, cerebellum, and brainstem." The new guidelines are to be followed closely. They demand higher qualifications of physicians involved in the diagnosis of ILBF and emphasize at the same time the interdisciplinary approach and the mandatory involvement of at least one specialist in the neurological field. Several technical methods were added as additional tools to support the ILBF diagnosis such as CT-angiography and duplex ultrasound of brain and neck vessels. The new guidelines thereby raise the impact of demonstrating complete cerebral circulatory arrest but leave other options to prove irreversibility. Many procedures, such as the apnea test, were specified in more detail. This article summarizes the new features of the new guideline with a practical overview on who must be involved in the diagnosis of ILBF, how often, how the diagnosis is achieved stepwise from stage I to III and how it is secured as well as what technical methods may be involved at what stage of the procedure.

Thrombectomy vs. Systemic Thrombolysis in Acute Embolic Stroke with High Clot Burden: A Retrospective Analysis.

PURPOSE: The efficacy of i. v. thrombolysis in acute stroke with high clot burden is limited. Successful recanalization is very unlikely if the thrombus length exceeds 7 mm. Thus this retrospective controlled study evaluated the efficacy and safety of neurothrombectomy in the treatment of acute embolic stroke in patients selected by a thrombus length of ≥ 8 mm using the stent retriever Trevo(®) device. MATERIALS AND METHODS: 40 patients with acute occlusion of the anterior intracranial arteries with a thrombus length of ≥ 8 mm were treated with neurothrombectomy. We compared the outcome with a historical cohort of 42 patients with a thrombus length of ≥ 8 mm that received i. v. thrombolysis only. Clinical outcome was assessed by modified Rankin scale in both groups at discharge and on day 90. RESULTS: Patients did not differ in age, mRS on admission, thrombus length or time from symptom onset to i. v. thrombolysis, but the thrombectomy group had higher NIHSS on admission. Successful recanalization was achieved in 33/40 patients (83 %) with neurothrombectomy. 15 patients received i. v. thrombolysis prior to neurothrombectomy. Median mRS at discharge was 3.5 (1.25 - 5) vs. 5 (4 - 6; p < 0.01) and on day 90 3 (1 - 4) vs. 5 (4 - 6; p < 0.01). Symptomatic hemorrhage occurred in 3 vs. 7 patients. 3 vs. 17 patients died within 90 days (thrombectomy vs. control each). There were only a few intervention-related complications. CONCLUSION: Thrombectomy in acute stroke with high clot burden using the Trevo(®) device has a low risk and improved clinical outcome compared to i. v. thrombolysis alone. Treatment selection by a clot length of ≥ 8 mm might be a powerful approach to improve the outcome of mechanical thrombectomy. KEY POINTS: • Clot length of ≥ 8 mm might be a valuable criterion for indicating neurothrombectomy. • Thrombolysis only in high clot burden is associated with poor clinical outcome. • Thrombectomy using the Trevo(®) stent retriever is safe and effective.

A three-step test of phosphate sorption efficiency of potential agricultural drainage filter materials.

Phosphorus (P) eutrophication of lakes and streams, coming from drained farmlands, is a serious problem in areas with intensive agriculture. Installation of P sorbing filters at drain outlets may be a solution. Efficient sorbents to be used for such filters must possess high P bonding affinity to retain ortho-phosphate (Pi) at low concentrations. In addition high P sorption capacity, fast bonding and low desorption is necessary. In this study five potential filter materials (Filtralite-P(®), limestone, calcinated diatomaceous earth, shell-sand and iron-oxide based CFH) in four particle size intervals were investigated under field relevant P concentrations (0-161 µM) and retentions times of 0-24 min. Of the five materials examined, the results from P sorption and desorption studies clearly demonstrate that the iron based CFH is superior as a filter material compared to calcium based materials when tested against criteria for sorption affinity, capacity and stability. The finest CFH and Filtralite-P(®) fractions (0.05-0.5 mm) were best with P retention of ≥90% of Pi from an initial concentration of 161 µM corresponding to 14.5 mmol/kg sorbed within 24 min. They were further capable to retain ≥90% of Pi from an initially 16 µM solution within 1½ min. However, only the finest CFH fraction was also able to retain ≥90% of Pi sorbed from the 16 µM solution against 4 times desorption sequences with 6 mM KNO3. Among the materials investigated, the finest CFH fraction is therefore the only suitable filter material, when very fast and strong bonding of high Pi concentrations is needed, e.g. in drains under P rich soils during extreme weather conditions.

Adsorption of the disinfectant benzalkonium chloride on montmorillonite. Synergistic effect in mixture of molecules with different chain lengths.

The biocide benzalkonium chloride (BAC) is a mix of cationic alkylbenzyldimethylammonium surfactants having different alkyl chain lengths. A comparative study of adsorption on the phyllosilicate clay montmorillonite of two of these surfactants, with alkyl chains having respectively 12 C atoms (BAC-12) and 14 C atoms (BAC-14), and a mixture of both surfactants is presented in this work. Adsorption isotherms were performed for individual surfactants and for a 1:1 mixture BAC-12+BAC-14. The adsorption was investigated in an ample concentration range that covers almost seven orders of magnitude in concentrations (from 1 nM to 10 mM), range that includes environmentally relevant concentrations. Quantification of BAC was performed by HPLC-UV and LC-MS and the results were completed with powder X-Ray diffraction. The adsorption of both surfactants leads to adsorption isotherms with two well differentiated steps. The first step corresponds almost exclusively to a cation exchange process, and the binding constant is very similar for both surfactants. The second step of the isotherms is observed at higher concentrations and adsorption is mainly driven by lateral interactions between surfactant molecules. The binding constant of this step is larger for BAC-14 than for BAC-12. Adsorption from a BAC-12+BAC-14 mixture shows a synergistic behaviour, possibly due to a better packing arrangement in the interlayer. Calculations show that in natural systems silicate clays are major sorbents of BAC at low concentrations whereas binding to humic acid is predominant at high concentrations.

Dissipation and leaching of acephate, chlorpyrifos, and their main metabolites in field soils of Malaysia.

Preventive treatment with insecticides at high dosing rates before planting of a new crop- soil drenching- is a common practice in some tropical intensive cropping systems, which may increase the risk of leaching, soil functioning, and pesticide uptake in the next crop. The degradation rates and migration of acephate and chlorpyrifos and their primary metabolites, methamidophos and 3,5,6-trichloropyridinol (TCP), have been studied in clayey red yellow podzolic (Typic Paleudults), alluvial (Typic Udorthents), and red yellow podzolic soils (Typic Kandiudults) of Malaysia under field conditions. The initial concentrations of acephate and chlorpyrifos in topsoils were found to strongly depend on solar radiation. Both pesticides and their metabolites were detected in subsoils at the deepest sampling depth monitored (50 cm) and with maximum concentrations up to 2.3 mg kg(-1) at soil depths of 10 to 20 cm. Extraordinary high dissipation rates for weakly sorbed acephate was in part attributed to preferential flow which was activated due to the high moisture content of the soils, high precipitation and the presence of conducting macropores running from below the A horizons to at least 1 m, as seen from a dye tracer experiment. Transport of chlorpyrifos and TCP which both sorb strongly to soil organic matter was attributed to macropore transport with soil particles. The half-lives for acephate in topsoils were 0.4 to 2.6 d while substantially longer half-lives of between 12.6 and 19.8 d were observed for chlorpyrifos. The transport through preferential flow of strongly sorbed pesticides is of concern in the tropics.

[The problem of performing medical procedures without informed consent in unconscious patients]. / Zwischen Patientenautonomie und ärztlicher Garantenstellung. Die Frage der Einwilligung von Patienten mit Bewusstseinsstörungen.

The principle of informed consent to invasive diagnostic or therapeutic procedures is not applicable in most patients suffering from consciousness disorders. As in other medical situations, German law assigns priority to the patient's autonomy and employs the concept of presumed will inferred from third-party (e.g. relatives) communications or deduced from a living will. While discussion concerning the validity of such advance directives is ongoing, their applicability needs to be checked carefully in every case. When the patient's attitude or wish however remains unclear or not discernible, in an emergency situation medical activities must be directed without loss of time towards damage reduction and life preservation under all circumstances ("guaranteed provision of medical attention"). In clinical practice, efforts to deduce the patient's will must relate to the urgency and invasiveness of the intended medical procedures. This paper describes the framework of current legal rules and important case decisions involved in the process of decision-making for patients unable to give informed consent. Any such decisions must be documented comprehensively in hospital records.

Ergot alkaloids in rye flour determined by solid-phase cation-exchange and high-pressure liquid chromatography with fluorescence detection.

Ergot alkaloids are mycotoxins that are undesirable contaminants of cereal products, particularly rye. A method was developed employing clean-up by cation-exchange solid-phase extraction, separation by high-performance liquid chromatography under alkaline conditions and fluorescence detection. It is capable of separating and quantifying both C8-isomers of ergocornine, alpha-ergocryptine, ergocristine, ergonovine, and ergotamine. The average recovery was 61% +/- 10% with limits of detection from 0.2 to 1.1 microg kg(-1). Twenty-four unknown rye flour samples from Danish mills contained on average 46 microg kg(-1) with a maximum content of 234 microg kg(-1). The most common ergot alkaloids were ergotamine and alpha-ergocryptine including their C8-isomers. A total of 54% of the ergot alkaloids were detected as C(8)-S isomers.

Migraine and delayed ischaemic neurological deficit after subarachnoid haemorrhage in women: a case-control study.

The aim of the present case-control study was to investigate the role of migraine as a potential risk factor for a delayed ischaemic neurological deficit (DIND) after subarachnoid haemorrhage (SAH). A telephone interview was performed in patients or their relatives to determine the prevalence of migraine. Thirty-six women aged <60 years had SAH with Hunt & Hess grade I-III and DIND (group A). This group was compared with an age-matched group of 36 female SAH patients, Hunt & Hess grade I-III without DIND (group B). The two populations were also characterized regarding hypertension, smoking, diabetes mellitus and alcohol use. A significant difference was only found for the prevalence of migraine with 47% in group A and 25% in group B (P < 0.05; odds ratio: 2.68, confidence interval: 0.99-7.29). Migraineurs revealed similar prevalences of risk factors independently of the presence of DINDs. This retrospective study suggests that women with migraine have a higher risk to develop a DIND than women without migraine.

Sorption and fractionation of dissolved organic matter and associated phosphorus in agricultural soil.

Mobility of dissolved organic matter (DOM) strongly affects the export of nitrogen (N) and phosphorus (P) from soils to surface waters. To study the sorption and mobility of dissolved organic C and P (DOC, DOP) in soil, the pH-dependent sorption of DOM to samples from Ap, EB, and Bt horizons from a Danish agricultural Humic Hapludult was investigated and a kinetic model applicable in field-scale models tested. Sorption experiments of 1 to 72 h duration were conducted at two pH levels (pH 5.0 and 7.0) and six initial DOC concentrations (0-4.7 mmol L(-1)). Most sorption/desorption occurred during the first few hours. Dissolved organic carbon and DOP sorption decreased strongly with increased pH and desorption dominated at pH 7, especially for DOC. Due to fractionation during DOM sorption/desorption at DOC concentrations up to 2 mmol L(-1), the solution fraction of DOM was enriched in P indicating preferred leaching of DOP. The kinetics of sorption was expressed as a function of how far the solution DOC or DOP concentrations deviate from "equilibrium." The model was able to simulate the kinetics of DOC and DOP sorption/desorption at all concentrations investigated and at both pH levels making it useful for incorporation in field-scale models for quantifying DOC and DOP dynamics.

Distribution of multiple pesticide residues in apple segments after home processing.

The effects of washing, storing, boiling, peeling, coring and juicing on pesticide residue were investigated for field-sprayed Discovery and Jonagold apples. Residues of chlorpyrifos, cypermethrin, deltamethrin, diazinon, endosulfan, endosulfan sulfate, fenitrothion, fenpropathrin, iprodione, kresoxim-methyl, lambda-cyhalothrin, quinalphos, tolylfluanid and vinclozolin in the processed apples were analysed by gas chromatography. Statistical analysis showed that reductions of 18-38% were required to obtain significant effects of processing practices, depending on pesticide and apple variety. Juicing and peeling the apples significantly reduced all pesticide residues. In the case of detectable pesticide residues, 1-24% were distributed in the juice and in the peeled apple. None of the pesticide residues was significantly reduced when the apples were subject to simple washing or coring. Storing significantly reduced five of the pesticide residues: diazinon, chlorpyrifos, fenitrothion, kresoxim-methyl and tolylfluanid, by 25-69%. Residues of the metabolite endosulfan sulfate were increased by 34% during storage. Boiling significantly reduced residues of fenitrothion and tolylfluanid by 32 and 81%, respectively. Only a few of the observed effects of processing could be explained by the physical or chemical characteristics of the pesticides. No differences in effect of processing due to apple variety were identified.

Sorption of lambda-cyhalothrin, cypermethrin, deltamethrin and fenvalerate to quartz, corundum, kaolinite and montmorillonite.

Sorption to mineral surfaces may be important for retention and degradation of hydrophobic pesticides in subsoils and aquifers poor in organic matter. In this work the title pyrethroids have been used to investigate selective interactions with the surfaces of four minerals. Sorption of the four pyrethroids was quantified in batch experiments with initial pyrethroid concentrations of 1-100 microg/l. Sorption to centrifuge tubes used in the batch experiments accounted for 25-60% of total sorption. Net sorption was obtained from total sorption after subtracting the amounts of pyrethroids sorbed to centrifuge tubes used. All isotherms could be fitted by the Freundlich equation with n ranging between 0.9 and 1.1. Bonding affinities per unit surface area decreased in the order: corundum > quartz > montmorillonite approximately equal kaolinite. A similar sequence as found for the total surface tension of the minerals. All minerals showed the same selectivity order with respect to sorption affinity of the four pyrethroids: lambda-cyhalothrin > deltamethrin > cypermethrin > fenvalerate, which shows that the most hydrophobic compound is sorbed most strongly. Stereochemical properties of the four pyrethroid formulations may also contribute to the selectivity pattern.

Outcome after endovascular therapy of ruptured intracranial aneurysms: morbidity and impact of rebleeding.

We evaluated midterm functional outcome after endovascular occlusion of aneurysms in patients with subarachnoid haemorrhage (SAH) and determined the incidence of late rebleeding as an additional prognostic parameter. We treated 79 consecutive patients with SAH from an intracranial aneurysm admitted from a neurological intensive care unit by the endovascular route between 1993 and 1997 and 52 survivors were followed up in 1999-2000. The mean interval between SAH and follow-up was 41 months (range 13-74 months). Outcome was determined by the Glasgow outcome (GOS) and Rankin (RS) scales and by questions concerning neuropsychological disorders. The patients were analysed according to Hunt and Hess (H & H) grades I-III or IV-V on admission. We observed two episodes of rebleeding (3%) with impact on outcome at 907 and 2010 days after SAH, respectively. A complete recovery (GOS 5) was achieved in 53% of H & H grade I-III and 17% of grade IV-V patients; with death rates 19% and 50%, and morbidity according to the RS (5-2) 18% and 29%, respectively. Midterm morbidity after endovascular therapy is thus low. Rebleeding with an impact on outcome can be observed up to 2010 days after SAH, suggesting that long-term angiographic follow-up is indispensable.

Starch-encapsulated chlorpyrifos: release rate, insecticidal activity and degradation in soil.

Incorporation of chlorpyrifos into starch matrices was achieved by thermal gelatinization. The level of amylose content in the starch matrices (10 and 52%) and the addition of auxiliary agents, i.e. solvent, emulsifiers or both, were varied and eight different formulations were prepared. According to differential scanning calorimetry (DSC) and X-ray diffraction measurements, chlorpyrifos was partly present in a crystalline form in all the starch formulations. The formulations had controlled release properties, and the release rate into water could be described by a linear model. In a bioassay, the formulations killed all larvae of the cabbage root fly at a dosing of 1.4 kg a.i. per ha. The degradation of chlorpyrifos in soil from the starch formulations could be described in a non-linear logistic model and the half-life was predicted to be 88 days. Differences in the amount of amylose in the starch as well as the addition of solvent and emulsifiers in the preparation procedure had no systematic influence on the release rate, the insecticidal effect and the degradation rate. No correlation between release rate into water and degradation in soil could be established. Two commercial chlorpyrifos formulations Lorsban 15 G (granular) and Cyfos 500 gl(-1) (emulsifiable concentrate), were included in the study for comparison.

Serovars of Salmonella isolated from Danish turkeys between 1995 and 2000 and their antimicrobial resistance.

The prevalence of Salmonella serovars and their antimicrobial resistance patterns were investigated among Danish turkeys between 1995 and 2000, by sampling the flocks approximately 14 days before they were slaughtered. Within the flocks, the prevalence of salmonella varied from 7.1 per cent to 25 per cent, and 24 different serovars were detected. The five most prevalent, which accounted for 58.5 per cent of the isolates were Salmonella Heidelberg (16.2 per cent of the isolates), Salmonella Agona (15.8 per cent), Salmonella Derby (12.4 per cent), Salmonella Muenster (7.3 per cent) and Salmonella Anatum (6.8 per cent). In addition, a few rough isolates and isolates belonging to the antigenically incomplete formulae 6,7:-:- and 4,12:b:- were found. The level of antimicrobial resistance was low; the highest resistance was recorded to ampicillin (13.7 per cent) and streptomycin (9.0 per cent) followed by tetracycline (8.5 per cent), sulphonamides (7.7 per cent) and spectinomycin (4.7 per cent). Resistance to quinolones was very low: four isolates were resistant to nalidixic acid, and only one was resistant to enrofloxacin. No resistance was recorded to colistin, apramycin, ceftiofur, florfenicol, or amoxycillin with clavulanic acid. Only 24 isolates were resistant to two or more compounds in various combinations of up to six compounds; one Salmonella Havana isolate was resistant to six compounds. Six isolates were serovar Typhimurium, but none of them belonged to phage type DT104.