[Processed EEG for personalized dosing of anesthetics during general anesthesia]. / Das prozessierte EEG zur personalisierten Dosierung von Anästhetika während Allgemeinanästhesie.

Electroencephalogram (EEG)-guided anesthesia is indispensable in modern operating rooms and has become established as the standard form of monitoring. Many anesthesiologists rely on processed EEG indices in the hope of averting anesthesia-related complications, such as intraoperative awareness, postoperative delirium and other cognitive complications in their patients. This educational review aims to provide information on the five most prevalent monitors used to guide depth of sedation during general anesthesia. This article elucidates the principles underpinning the application of these monitors where known, which are generally based on power in various EEG frequency bands and on the burst suppression pattern. Convinced that EEG-guided anesthesia has the potential of benefitting many surgical patients, it is felt that many basic principles and shortcomings of processed EEG indices need to be better understood in the clinical practice. After discussing the different monitors and clinically relevant data from the literature, the article gives a short practical guidance on how to critically interpret processed EEG information and troubleshooting of confounded indices in the context of clinical situations.

[The quantitative EEG in electroencephalogram-based brain monitoring during general anesthesia]. / Das quantifizierte EEG im elektroenzephalogrammbasierten Monitoring während Allgemeinanästhesie.

The electroencephalogram (EEG) is increasingly being used in the clinical routine of anesthesia in German-speaking countries. In over 90% of patients the frontal EEG changes somewhat predictably in response to administration of the normally used anesthetic agents (propofol and volatile gasses). An adequate depth of anesthesia and appropriate concentrations of anesthetics in the brain generate mostly frontal oscillations between 8 and 12 Hz as well as slow delta waves between 0.5 and 4 Hz. The frontal EEG channel is well-suited for avoidance of insufficient depth of anesthesia and excessive administration of anesthetics. This article explains the clinical interpretation of the most important EEG patterns and the biophysical background. Also discussed are important limitations and pitfalls for the clinical routine, which the anesthetist should know in order to utilize the EEG as an admittedly incomplete but clinically extremely important parameter for the level of consciousness.

Pansteatitis in polluted Olifants River impoundments: nutritional perspectives on fish in a eutrophic lake, Lake Loskop, South Africa.

This study compares the aetiology of pansteatitis in Lake Loskop, relative to two other impoundments along the Olifants River. Macroscopic and microscopic pathology, age determination and analysis of stomach content, fatty acids and stable isotopes explain the high prevalence of pansteatitis in Oreochromis mossambicus (Peters) and several other species in Lake Loskop. All the dietary indicator comparisons between pansteatitis-affected and healthy fish fail to support a systemic cause. Pansteatitis in Lake Loskop was linked to size and weight of O. mossambicus, but not to ontogenic age. Fish in Lake Loskop showed abnormally high omega-3 to omega-6 fatty acid ratios normally only found in marine fish with no significant difference in degree of assimilation of these fatty acids between pansteatitis-affected and healthy fish. This explains the vulnerability to, but not the occurrence of, pansteatitis. As a cause for the pansteatitis, these results point towards sporadic vitamin E-depleting trigger events, known sporadic fish die-off occurrences that provide surviving fish with a rich source of rancid fats on which to scavenge. The mechanism ties pansteatitis to eutrophication and trophic cascade effects, the intrinsic drivers of the disease and suggests an adaptive management strategy that might be applied by relevant conservation authorities.

On the structure and dynamics of water associated with single-supported zwitterionic and anionic membranes.

We have used high-resolution quasielastic neutron scattering (QENS) to investigate the dynamics of water molecules (time scale of motion ∼10-11-10-9 s) in proximity to single-supported bilayers of the zwitterioniclipid DMPC (1,2-dimyristoyl-sn-glycero-3-phosphorylcholine) and the anionic lipid DMPG (1,2-dimyristoyl-sn-glycero-3-phosphoglycerol) in the temperature range 160-295 K. For both membranes, the temperature dependence of the intensity of neutronsscattered elastically and incoherently from these samples indicates a series of freezing/melting transitions of the membrane-associated water, which have not been observed in previous studies of multilayer membranes. We interpret these successive phase transitions as evidence of different types of water that are common to the two membranes and which are defined by their local environment: bulk-like water located furthest from the membrane and two types of confined water in closer proximity to the lipids. Specifically, we propose a water type termed "confined 2" located within and just above the lipid head groups of the membrane and confined 1 water that lies between the bulk-like and confined 2 water. Confined 1 water is only present at temperatures below the freezing point of bulk-like water. We then go on to determine the temperature dependence of the translational diffusion coefficient of the water associated with single-supported DMPG membranes containing two different amounts of water as we have previously done for DMPC. To our knowledge, there have been no previous studies comparing the dynamics of water in proximity to zwitterionic and anionic membranes. Our analysis of the water dynamics of the DMPG and DMPC membranes supports the classification of water types that we have inferred from their freezing/melting behavior. However, just as we observe large differences in the freezing/melting behavior between these model membranes for the same water type, our measurements demonstrate variation between these membranes in the dynamics of their associated water over a wide temperature range. In particular, there are differences in the diffusive motion of water closest to the lipid head groups. Previously, QENS spectra of the DMPC membranes have revealed the motion of water bound to the lipid head groups. For the DMPG membrane, we have found some evidence of such bound water molecules; but the signal is too weak for a quantitative analysis. However, we observe confined 2 water in the DMPG membrane to undergo slow translational diffusion in the head group region, which was unobserved for DMPC. The weak temperature dependence of its translational diffusion coefficient allows extrapolation to physiological temperatures for comparison with molecular dynamics simulations.

Evaluating the solid electrolyte interphase formed on silicon electrodes: a comparison of ex situ X-ray photoelectron spectroscopy and in situ neutron reflectometry.

This work details the in situ characterization of the interface between a silicon electrode and an electrolyte using a linear fluorinated solvent molecule, 0.1 M lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) in deuterated dimethyl perfluoroglutarate (d6-PF5M2) (1.87 × 10(-2) mS cm(-1)). The solid electrolyte interphase (SEI) composition and thickness determined via in situ neutron reflectometry (NR) and ex situ X-ray photoelectron spectroscopy (XPS) were compared. The data show that SEI expansion and contraction (breathing) during electrochemical cycling were observed via both techniques; however, ex situ XPS suggests that the SEI thickness increases during Si lithiation and decreases during delithiation, while in situ NR suggests the opposite. The most likely cause of this discrepancy is the selective removal of SEI components (top 20 nm of the SEI) during the electrode rinse process, which is required to remove the electrolyte residue prior to ex situ analysis, demonstrating the necessity of performing SEI characterization in situ.

Association between intraoperative electroencephalographic suppression and postoperative mortality.

BACKGROUND: Low bispectral index values frequently reflect EEG suppression and have been associated with postoperative mortality. This study investigated whether intraoperative EEG suppression was an independent predictor of 90 day postoperative mortality and explored risk factors for EEG suppression. METHODS: This observational study included 2662 adults enrolled in the B-Unaware or BAG-RECALL trials. A cohort was defined with >5 cumulative minutes of EEG suppression, and 1:2 propensity-matched to a non-suppressed cohort (≤5 min suppression). We evaluated the association between EEG suppression and mortality using multivariable logistic regression, and examined risk factors for EEG suppression using zero-inflated mixed effects analysis. RESULTS: Ninety day postoperative mortality was 3.9% overall, 6.3% in the suppressed cohort, and 3.0% in the non-suppressed cohort {odds ratio (OR) [95% confidence interval (CI)]=2.19 (1.48-3.26)}. After matching and multivariable adjustment, EEG suppression was not associated with mortality [OR (95% CI)=0.83 (0.55-1.25)]; however, the interaction between EEG suppression and mean arterial pressure (MAP) <55 mm Hg was [OR (95% CI)=2.96 (1.34-6.52)]. Risk factors for EEG suppression were older age, number of comorbidities, chronic obstructive pulmonary disease, and higher intraoperative doses of benzodiazepines, opioids, or volatile anaesthetics. EEG suppression was less likely in patients with cancer, preoperative alcohol, opioid or benzodiazepine consumption, and intraoperative nitrous oxide exposure. CONCLUSIONS: Although EEG suppression was associated with increasing anaesthetic administration and comorbidities, the hypothesis that intraoperative EEG suppression is a predictor of postoperative mortality was only supported if it was coincident with low MAP. CLINICAL TRIAL REGISTRATION: NCT00281489 and NCT00682825.

Characteristics in response rates for surveys administered to surgery residents.

BACKGROUND: Surveys are important research tools that permit the accumulation of information from large samples that would otherwise be impractical to collect. Resident surveys have been used frequently to monitor the quality of postgraduate training. Low response rates threaten the utility of this research tool. The purpose of this study was to determine the standard response rate of surveys administered to surgery residents and identify characteristics associated with achieving greater response rates. METHODS: A search of peer-reviewed literature published between September 2003 and June 2011 was performed with the use of PubMed with Medical Subject Headings: "internship and residency," "surgery," "data collection," and "questionnaires." For inclusion, articles must have described a survey given to active surgery residents within the United States. Surveys were evaluated based on the following criteria: population size, response rate, incentive use, follow-up use, survey format (online vs paper), and institution versus national. RESULTS: Of 433 initial results, 47 met inclusion criteria with a mean response rate of 65.3%. Surveys administered in paper format had a greater response rate compared with those given electronically (mean 78.6% vs 36.4%, respectively, P < .001). Greatest mean response rates were seen for institutional surveys compared with those given nationally (83.1% vs 42% respectively, P < .001). CONCLUSION: Our review demonstrated that paper surveys administered at the institutional level and during assemblies integrated into residents' schedules demonstrated enhanced response rates. The validity and generalizability of data collected through such surveys will improve as the aspects which dictate response rate are better understood and implemented.

Identification of a uniquely southern African clade of coastal pipefishes Syngnathus spp.

The taxonomic status of two southern African coastal pipefish species, Syngnathus temminckii and Syngnathus watermeyeri, was investigated using a combination of morphological and genetic data. Morphological data showed that S. temminckii is distinct from the broadly distributed European pipefish Syngnathus acus, and a molecular phylogeny reconstructed using mitochondrial DNA recovered S. temminckii and S. watermeyeri as sister taxa. The southern African species share an evolutionary origin with north-eastern Atlantic Ocean and Mediterranean Sea species, including S. acus. These data support the existence of a distinct southern African clade of Syngnathus pipefishes that has diverged in situ to form the two species present in the region today.

Confinement-driven phase separation of quantum liquid mixtures.

We report small-angle neutron scattering studies of liquid helium mixtures confined in Mobil Crystalline Material-41 (MCM-41), a porous silica glass with narrow cylindrical nanopores (d=3.4 nm). MCM-41 is an ideal model adsorbent for fundamental studies of gas sorption in porous media because its monodisperse pores are arranged in a 2D triangular lattice. The small-angle scattering consists of a series of diffraction peaks whose intensities are determined by how the imbibed liquid fills the pores. Pure (4)He adsorbed in the pores show classic, layer-by-layer film growth as a function of pore filling, leaving the long range symmetry of the system intact. In contrast, the adsorption of (3)He-(4)He mixtures produces a structure incommensurate with the pore lattice. Neither capillary condensation nor preferential adsorption of one helium isotope to the pore walls can provide the symmetry-breaking mechanism. The scattering is consistent with the formation of randomly distributed liquid-liquid microdomains ∼2.3 nm in size, providing evidence that confinement in a nanometer scale capillary can drive local phase separation in quantum liquid mixtures.

Integrated boost IMRT with FET-PET-adapted local dose escalation in glioblastomas. Results of a prospective phase II study.

PURPOSE: Dose escalations above 60 Gy based on MRI have not led to prognostic benefits in glioblastoma patients yet. With positron emission tomography (PET) using [(18)F]fluorethyl-L-tyrosine (FET), tumor coverage can be optimized with the option of regional dose escalation in the area of viable tumor tissue. METHODS AND MATERIALS: In a prospective phase II study (January 2008 to December 2009), 22 patients (median age 55 years) received radiochemotherapy after surgery. The radiotherapy was performed as an MRI and FET-PET-based integrated-boost intensity-modulated radiotherapy (IMRT). The prescribed dose was 72 and 60 Gy (single dose 2.4 and 2.0 Gy, respectively) for the FET-PET- and MR-based PTV-FET((72 Gy)) and PTV-MR((60 Gy)). FET-PET and MRI were performed routinely for follow-up. Quality of life and cognitive aspects were recorded by the EORTC-QLQ-C30/QLQ Brain20 and Mini-Mental Status Examination (MMSE), while the therapy-related toxicity was recorded using the CTC3.0 and RTOG scores. RESULTS: Median overall survival (OS) and disease-free survival (DFS) were 14.8 and 7.8 months, respectively. All local relapses were detected at least partly within the 95% dose volume of PTV-MR((60 Gy)). No relevant radiotherapy-related side effects were observed (excepted alopecia). In 2 patients, a pseudoprogression was observed in the MRI. Tumor progression could be excluded by FET-PET and was confirmed in further MRI and FET-PET imaging. No significant changes were observed in MMSE scores and in the EORTC QLQ-C30/QLQ-Brain20 questionnaires. CONCLUSION: Our dose escalation concept with a total dose of 72 Gy, based on FET-PET, did not lead to a survival benefit. Acute and late toxicity were not increased, compared with historical controls and published dose-escalation studies.

[The importance of a developmental approach in psychiatric assessment and treatment of adults with intellectual disability]. / Die Bedeutung des emotionalen Entwicklungsniveaus bei der psychiatrischen Behandlung von Menschen mit geistiger Behinderung.

INTRODUCTION: Mental disorders are 3-4 times more frequent in individuals with intellectual disabilities than in those without. From a developmental perspective the reason for this high prevalence could be, besides biological aberrations, a personality development with a difference between cognitive and emotional developmental levels. This discrepancy renders the person being highly vulnerable for the onset of problem behaviour and psychiatric disorders. For a proper insight into processes which have led to the disorder, it is necessary to evaluate the level of emotional development. This can be determined by the "schema of emotional development (SEO)" developed by A. Dosen. METHODS: By means of a case description the authors demonstrate the application of SEO in the assessment and utilization of the concept of the level of emotional development in clinical practice. RESULTS: The knowledge of the level of emotional development contributes to the explaining and understanding of the disorder, and also facilitates the establishment of an integrated diagnosis and the creation of appropriate integrated treatment strategies. Hence, temper tantrums, sleep patterns and mood improved in the case described. CONCLUSION: Besides biopsychosocial aspects, the developmental aspect, and in particular the level of emotional development should be taken into consideration in the diagnostic work-up and treatment of individuals with intellectual disabilities and mental health problems. The data generated by the SEO may help in understanding the disorder and developing a treatment approach for these individuals.

[Maurice Raynaud (1834-1881) and the syndrome named after him]. / Maurice Raynaud (1834-1881) und das nach ihm benannte Syndrom.

Approximately 150 years ago Maurice Raynaud described in his doctoral thesis a set of symptoms characterized by intermittent pallor and cyanosis of the extremities which in severe cases could lead to the development of gangrene. Because the symptoms could be triggered by spasms in small blood vessels the exclusion of an organic vascular disease is a prerequisite of the diagnosis. Raynaud had not yet recognized that this often observed syndrome could sometimes be advance or initial symptoms of a severe general disease. This is the reason why nowadays these are referred to as primary and secondary Raynaud syndromes. Simultaneously to his doctoral thesis Raynaud had submitted his PhD thesis with two noteworthy publications on the history of medicine. His postdoctoral thesis encompassed a comprehensive study of the"efferent process". Raynaud worked in various Paris clinics, occupied himself with many problems and was considered to be a good academic teacher. For political reasons he was neither promoted to professor nor did he receive a chair in the history of medicine.

[Bloodletting and rheumatism.: a retrospective view]. / Aderlass und "Rheuma" : Ein Rückblick.

Bloodletting was widely used in antiquity in the setting of a humoral-pathological concept as a general treatment for all ailments, as well as during the middle ages primarily as a remedy for the treatment of inflammatory and infectious diseases. The general population was convinced of the efficacy of this treatment for centuries, even requesting it on occasion on a prophylactic basis. Although questioned early in history, the number of sceptical voices increased in the 17th and 18th centuries. In 1835, P. Louis introduced statistics to medicine in Paris, thereby proving the inefficacy of bloodletting in inflammatory diseases. Today, bloodletting is used in scientific medicine in only a few rare disease.As long as rheumatic diseases remained undifferentiated, all cases were treated with bloodletting. After acute articular rheumatism 1591 was recognised as an independent disease entity, bloodletting remained the treatment of choice for most doctors right up to the end of the 19th century. Bloodletting was also the standard treatment for gout from antiquity up to the beginning of the 19th century. Following its differentiation in 1800, chronic articular rheumatism was no longer treated with venae sectio. Today, there is no indication for bloodletting therapy in rheumatology.

The role of prior model calibration on predictions with ensemble Kalman filter.

This paper, based on a real world case study (Limmat aquifer, Switzerland), compares inverse groundwater flow models calibrated with specified numbers of monitoring head locations. These models are updated in real time with the ensemble Kalman filter (EnKF) and the prediction improvement is assessed in relation to the amount of monitoring locations used for calibration and updating. The prediction errors of the models calibrated in transient state are smaller if the amount of monitoring locations used for the calibration is larger. For highly dynamic groundwater flow systems a transient calibration is recommended as a model calibrated in steady state can lead to worse results than a noncalibrated model with a well-chosen uniform conductivity. The model predictions can be improved further with the assimilation of new measurement data from on-line sensors with the EnKF. Within all the studied models the reduction of 1-day hydraulic head prediction error (in terms of mean absolute error [MAE]) with EnKF lies between 31% (assimilation of head data from 5 locations) and 72% (assimilation of head data from 85 locations). The largest prediction improvements are expected for models that were calibrated with only a limited amount of historical information. It is worthwhile to update the model even with few monitoring locations as it seems that the error reduction with EnKF decreases exponentially with the amount of monitoring locations used. These results prove the feasibility of data assimilation with EnKF also for a real world case and show that improved predictions of groundwater levels can be obtained.

[A history of joint puncture and injection]. / Gelenkpunktion und -injektion - Die Geschichte.

Up until the middle of the 20th century joint puncture was considered a dangerous surgical intervention performed primarily to drain pus. The differential diagnostic significance of synovial analysis only became clear in the second half of the 20th century. Thus it became possible to reliably distinguish between inflammatory and non-inflammatory diseases, and establish whether arthritides are bacterial or crystal-induced. Attempts to inject disinfecting or anti-inflammatory solutions into the joint go back to the end of the 19th century. In the mid 20th century, cortisone became the panacea of intraarticular therapy. After surgeons at the end of the 19th century succeeded in surgically removing the inflamed synovium, internal medicine specialists attempted to destroy the synovial membrane by injecting it with various chemicals around the mid 20th century; however, hardly any of these substances survived. Only with "internal radiation" by injecting radionuclides was a breakthrough seen in the middle of the 20th century. Since then radiosynoviorthesis and synovialectomy have become standard methods in the treatment of chronic inflammatory joint disease.

[Autism in adults with intellectual disabilities]. / Autismus bei erwachsenen Menschen mit geistiger Behinderung.

According to the World Health Organization (WHO) the estimated prevalence of intellectual disabilities (ID) is about 1-3% and 1 out of 4 individuals with ID suffer from an additional autistic spectrum disorder (ASD) (arithmetic mean 24.6%, 19 studies, n=9,675) whereby the prevalence increases with the severity of ID (IQ 50-70: 9.9%, IQ<50: 31.7%). Therefore, it is of particular importance for physicians treating individuals with ID who have psychiatric disorders or behavioral problems to take ASD into account as a differential diagnosis so that appropriate treatment can be initiated.Irrespective of the IQ the diagnosis is based on an impairment of social interaction and communication and restricted repetitive interests presenting before the age of 3 (infantile or Kanner autism). ASD can be diagnosed as a separate disorder in adults with ID, however, the social and communicative abilities in respect of the cognitive and developmental level have to be considered.Due to reduced verbal capacity, high prevalence of physical and mental disorders, difficulties in taking the past medical history and presentation of atypical symptoms, the diagnostic assessment for autism in adults with ID is challenging.This article describes the typical symptoms, diagnostic approach, frequent comorbidities, differential diagnoses treatment options and their limitations for adults with ID suspected of having ASD.

Determination of intrarenal resistance index (RI) in patients with multiple myeloma.

BACKGROUND: Renal impairment is a common complication of multiple myeloma occurring in up to 50 % of patients at some stage in their disease. Due to occurrence of cast nephropathies we hypothesized circulatory dysregulation (vasoconstriction) in the kidneys with measurable elevation of the resistance index among these patients which would have a diagnostic impact. SUBJECTS AND METHODS: 36 patients with treated multiple myeloma (21 females, 15 males, mean age 61.6 +/- 8.5 years) were prospectively examined by conventional abdominal ultrasound with focussed investigation of the kidneys. First, length of the organs, parenchymal width and characterization of parenchymal echogenicity were determined. Then, intrarenal RI values were measured in segmental and arcuate arteries, respectively, in both kidneys. Additionally, serum creatinine, BUN and GFR of each patient were evaluated. RI values were compared to values of 78 healthy control subjects. RESULTS: Mean renal RI was 0.68 +/- 0.07 which was slightly higher than in controls with 0.62 +/- 0.05, but without statistical significance. Due to the laboratory analyses patients were subdivided in those with normal ( group 1, n = 21) and those with impaired (group 2, n = 15) renal function. In both groups kidney size and parenchymal width were normal. Significant more group 2 patients (60%) revealed hyperechogenic parenchyma than group 1 patients (24%) (p<0.01). Mean renal RI indices were 0.67 +/- 0.06 (right) and 0.69 +/- 0.06 (left) in group 1 patients and 0.71 +/- 0.08 (right) and 0.71 +/- 0.07 (left) in group 2 patients and showed no significant difference (p = 0.06 and 0.15). CONCLUSION: Renal RI values are not significantly elevated in patients with multiple myeloma even in those with renal impairment so that no hints to a relevant vasoconstriction could be evaluated. RI seems not to be a relevant parameter for the diagnosis of cast nephropathy of multiple myeloma patients. Routinely performed ultrasound examination should be more focussed on the qualification of parenchymal echogenicity.