Alchemical absolute protein-ligand binding free energies for drug design.

The recent advances in relative protein-ligand binding free energy calculations have shown the value of alchemical methods in drug discovery. Accurately assessing absolute binding free energies, although highly desired, remains a challenging endeavour, mostly limited to small model cases. Here, we demonstrate accurate first principles based absolute binding free energy estimates for 128 pharmaceutically relevant targets. We use a novel rigorous method to generate protein-ligand ensembles for the ligand in its decoupled state. Not only do the calculations deliver accurate protein-ligand binding affinity estimates, but they also provide detailed physical insight into the structural determinants of binding. We identify subtle rotamer rearrangements between apo and holo states of a protein that are crucial for binding. When compared to relative binding free energy calculations, obtaining absolute binding free energies is considerably more challenging in large part due to the need to explicitly account for the protein in its apo state. In this work we present several approaches to obtain apo state ensembles for accurate absolute ΔG calculations, thus outlining protocols for prospective application of the methods for drug discovery.

[Central neurological complication of an interscalene plexus catheter]. / Zentralneurologische Komplikation einer interskalenären Plexuskatheteranlage.

A 78-year-old patient received an interscalene plexus catheter for perioperative pain therapy during implantation of an inverse shoulder prothesis. After stimulation-assisted puncture under sonographic control, 25 ml of local anesthetic (LA) were first administered and then the catheter was placed using the through the needle technique. Immediately after the administration of another 5 ml of local anesthetic via the inserted catheter, the patient showed symptoms of total spinal anesthesia, so that she had to be intubated and ventilated. The following computed tomographic diagnostics of the neck revealed an intrathecal misalignment of the plexus catheter, the tip of which was lying dorsal to the vertebral artery at the level of the 5/6 cervical vertebrae. The catheter could then be removed without any problems and there were no neurological sequelae. The use of ultrasound with clear identification of the nerve roots C5-C7 and the surrounding structures provides additional security when installing an intrascalene catheter. The spread of the LA should be traceable at all times using ultrasound and should otherwise be immediately terminated. Furthermore, a strict adherence to the needle position while inserting the catheter without manipulation of the needle depth is necessary. The first injection of the catheter has to be performed under controlled conditions, preferably connected to surveillance monitors with neurological monitoring of the awake patient and control of vital signs with direct access to the emergency equipment.

Acidification and hypoxia interactively affect metabolism in embryos, but not larvae, of the coastal forage fish Menidia menidia.

Ocean acidification is occurring in conjunction with warming and deoxygenation as a result of anthropogenic greenhouse gas emissions. Multistressor experiments are critically needed to better understand the sensitivity of marine organisms to these concurrent changes. Growth and survival responses to acidification have been documented for many marine species, but studies that explore underlying physiological mechanisms of carbon dioxide (CO2) sensitivity are less common. We investigated oxygen consumption rates as proxies for metabolic responses in embryos and newly hatched larvae of an estuarine forage fish (Atlantic silverside, Menidia menidia) to factorial combinations of CO2×temperature or CO2×oxygen. Metabolic rates of embryos and larvae significantly increased with temperature, but partial pressure of CO2 (PCO2 ) alone did not affect metabolic rates in any experiment. However, there was a significant interaction between PCO2  and partial pressure of oxygen (PO2 ) in embryos, because metabolic rates were unaffected by PO2  level at ambient PCO2 , but decreased with declining PO2  under elevated PCO2 For larvae, however, PCO2  and PO2  had no significant effect on metabolic rates. Our findings suggest high individual variability in metabolic responses to high PCO2 , perhaps owing to parental effects and time of spawning. We conclude that early life metabolism is largely resilient to elevated PCO2  in this species, but that acidification likely influences energetic responses and thus vulnerability to hypoxia.

Ultrasound guided supra-inguinal Fascia Iliaca Compartment Blocks in hip fracture patients: An alternative technique.

INTRODUCTION: In the Emergency Department, regional anesthesia is increasingly used in elderly patients with hip fractures. An example is a Fascia Iliaca Compartment Block (FICB). Traditionally, this block is administered below the inguinal ligament. There is no Emergency Department data regarding effectivity of an alternative, more cranial approach above the inguinal ligament. The objective was to determine analgesic effects of an ultrasound-guided supra-inguinal FICB in hip fracture patients in the Emergency Department. METHODS: This case series included all Emergency Department hip fracture patients who were treated with a supra-inguinal FICB during a period of 10 months. All data were recorded prospectively. Primary study outcome was decrease in Numerical Rating Scale (NRS) pain scores 60 min after the FICB. Secondary outcomes included the proportion of patients achieving 1.5 NRS points decrease at 60 min; NRS differences at 30 and 120 min compared to baseline; need for additional analgesia and occurrence of adverse events. RESULTS: A total of 22 patients were included in the study. At 60 min median NRS pain scores decreased from 6.0 to 3.0 (p < 0.001). Of all patients, a total of 59% achieved a decrease in 1.5 NRS points after 60 min. Median pain scores at 30 and 120 min were 4.0 (Interquartile Range (IQR) 2.0-5.0) and 2.5 (IQR 0.8-3.0). Seven patients (31.8%) required additional opioid analgesia after the FICB. No adverse events were recorded. CONCLUSION: An ultrasound-guided supra-inguinal FICB decreases NRS pain scores in hip fracture patients both clinically relevant and statistically significantly after 60 min. CLINICAL TRIAL REGISTRATION: The study was registered in the ISRCTN database (ISRCTN74920258).

Abuse-related effects of synthetic cathinones:importance of DAT/SERT relationships / 中国药理学与毒理学杂志

OBJECTIVE Wide spread abuse of synthetic cathinones found in bath salts preparations has resulted in regulation of some cathinones internationally. Chemists skirt these laws by altering the chemical structures of first-generation cathinones (ie, MDPV, methylone, and mephedrone), resulting in second-generation cathinones (eg, α-PVP, α-PPP, MDPPP, and MDPBP). Although MDPV is a more effective reinforcer than cocaine, little is known about the reinforcing effectiveness of second-generation cathinones. To test the hypothesis that synthetic cathinones with higher selectivity for DAT relative to SERT are more effective reinforcers. METHODS Monoamine transporter inhibition was determined using synaptosomes prepared from rat brains. The relative reinforcing effectiveness of intravenously self-administered MDPV, MDPBP, MDPPP, α-PVP, α-PPP, and cocaine were directly compared through evaluations of ① dose- response curves under a progressive ratio (PR) schedule of reinforcement and ② demand curves obtained for each drug in male Sprague-Dawley rats. RESULTS Rank order selectivity for DAT/SERT was α-PVP>MDPV>α-PPP≈MDPBP>MDPPP>cocaine. Comparisons of the maximum number of infusions obtained under a PR schedule of reinforcement (α-PVP>MDPV>α-PPP>MDPBP≈MDPPP>cocaine) and the essential value obtained for each drug in demand analyses (α-PVP>MDPV>α-PPP≈MDPBP≈MDPPP>cocaine) suggest relative reinforcing effectiveness is related to DAT/SERT selectivity. CONCLUSION These data provide evidence that DAT/SERT selectivity accounts for select synthetic cathinones functioning as more effective reinforcers than cocaine and may predict the abuse-related effects of novel synthetic cathinones in humans.

Interleukin-1α is the major alarmin of lung epithelial cells released during photodynamic therapy to induce inflammatory mediators in fibroblasts.

BACKGROUND: Photodynamic therapy (PDT) causes tissue damage that initiates a local inflammatory response. Post-PDT reactions are considered to assist in mobilising the immune system thereby affecting tumour recurrence. The initiating process of the PDT-dependent tissue reaction remains to be determined. METHODS: Primary cultures of human lung cells were established. The photoreaction mediated by pyropheophorbide-a, at specific subcellular sites and levels resulting in the release of alarmins by epithelial cells (Eps), was defined by immunoblot analyses and expression profiling. The activity of Ep-derived factors to stimulate expression of proinflammatory mediators, including IL-6, and to enhance neutrophil binding by fibroblasts (Fbs) was determined by functional bioassays. RESULTS: Epithelial cells release IL-1ß as the primary Fb-stimulatory activity under basal conditions. Intracellular IL-1α, externalised following photoreaction, accounts for most of the PDT-mediated Fb activation. Expression of IL-1 is subject to increase or loss during oncogenic transformation resulting in altered alarmin functions mobilisable by PDT. Photoreaction by a cell surface-bound photosensitiser (PS) is 10-fold more effective than PSs localised to mitochondria or lysosomes. High-dose intracellular, but not cell surface, photoreaction inactivates IL-1 and reduces Fb stimulation. CONCLUSION: These in vitro data suggest that the subcellular site and intensity of photoreaction influence the magnitude of the stromal cell response to the local damage and, in part, support the relationship of PDT dose and level of post-PDT inflammatory response observed in vivo.

Interventional lung assist enables lung protective mechanical ventilation in acute respiratory distress syndrome.

BACKGROUND: The feasibility and safety of a pumpless arteriovenous extracorporeal lung assist system (pECLA) has been demonstrated in previous studies of patients with severe respiratory insufficiency. The aim of this report was to examine whether pECLA is feasible in a center that is new to the technology and to determine the positive and adverse effects associated with its use. METHODS: This was a retrospective case series of 13 consecutive patients with established acute respiratory distress syndrome (ICU patients with ARDS or ALI) at a university hospital. Management consisted of transcutaneous placement of a femoral arteriovenous pECLA to allow lung-protective ventilation. Nonparametric statistics were applied; all data are values and standard deviations (SD). RESULTS: Mean simplified acute physiology score (SAPS) II was 49.5 (26); ICU mortality was 54% (7/13). Mean length of ICU stay was 34.5 (65.3) days for survivors (S) and 36 (32.8) days for non-survivors (NS). Total time on arteriovenous pECLA was 12.0 (22.2) days (S) and 7.0(7.8) days (NS), total time on mechanical ventilation was 31.0 (28.2) (S) and 32.0 (15.2) days (NS). Hypercapnia was significantly (P<0.05) reduced from 80.0 (23.0) (pre-pECLA) to 48.0 (13.0) mmHg (day 7), as were minute ventilation and inspiratory pressure. pECLA was accompanied by a significant (P<0.05) increase in the PaO2/fraction of inspired oxygen (P/F) ratio from 100.0 (28.9) (pre-pECLA) to 191.1 (114.3) mmHg after 7 days of treatment. Major complications were two inadvertent decannulations in the first two patients treated; there was one minor bleeding event in a patient seen subsequently. CONCLUSION: pECLA is an effective and manageable technique to support gas exchange in ARDS patients. This retrospective case series demonstrates the feasibility of pECLA in a center that did not have prior experience with this technique. pECLA may decrease further lung injury by minimizing the amount of time for which the lung is exposed to high stress and/or strain.

[Disease with generalized pain. Guillain-Barré syndrome]. / Erkrankung mit generalisierten Schmerzen. Guillet-Barré Syndrom.

A 43-year-old women is suffering from immobilizing generalized muscular pain. Initial diagnostic course doesn't lead to diagnosis. Some days later after appearing of a facial palsy a Guillain-Barré syndrome is diagnosed after lumbar puncture showing a increased protein and normal white-cell count. Because the patient is seriously affected with immobilization a treatment with intravenous immunoglobulin is established, leading to a quick improvement. Pain as a leading symptom of Guillain- Barré syndrome and has a potential for leading to misdiagnosis effecting delay in therapy in possible harmful disease.

[Tracheostomy in the intensive care unit]. / Die Tracheotomie auf der Intensivstation.

Indication, timing and technique of tracheostomy have undergone considerable changes during the past years. Percutaneous tracheostomy has become a standard procedure in modern intensive care. It can be performed by the intensive medicine specialists themselves with low complication rates. Advantages are less stomal infections, better cosmetic results and cost savings in comparison to the surgical technique. Exact knowledge of the anatomic details, careful attention to contraindications and bronchoscopic supervision throughout the procedure are essential for optimal results. Exchange of the tracheostomy tube requires adequate preparation and training. If contraindications exist or permanent mechanical ventilation can be anticipated, surgical tracheostomy is indicated. The optimal timing of tracheostomy remains controversial.

[Utility of invasive diagnostics in acute lung injury]. / Stellenwert der invasiven Diagnostik beim akuten Lungenversagen.

Acute lung injury/acute respiratory distress syndrome (ARDS) may be induced by a variety of disease entities. Apart from supportive treatment including lung protective ventilation, identification of the underlying process is of crucial importance for optimal therapeutic results. Usually the cause of ARDS can be identified by history, laboratory and radiologicial tests. In some cases a diagnosis cannot be made in spite of an extensive, less invasive diagnostic work-up. In these situations the risks of empirical treatment have to be balanced against the procedural risk of invasive diagnostics, namely open lung biopsy. Today, reports on more than 500 lung biopsies performed in selected ARDS patients are available showing a relevant diagnostic yield at an acceptable procedure-associated risk. Intensive care physicians should be aware of this diagnostic instrument, which can represent the decisive diagnostic step in patients with ARDS of unknown origin.

[Spread of hyperbaric local anesthetics in a spinal canal model. The influence of Trendelenburg position and spinal configuration]. / Ausbreitung hyperbarer Lokalanästhetika im Spinalkanalmodell. Einfluss von Lagewechsel und Wirbelsäulenkonfiguration.

BACKGROUND: The influence of Trendelenburg positions and variations in spinal canal configuration on the spread of hyperbaric spinal anesthetics was examined in two models of the subarachnoid space. METHODS: Both models included simulations of the spinal cord, filum terminale and cerebrospinal fluid. Model I had a straight shape, thus omitting replications of lumbar lordosis and thoracic kyphosis. It allowed the evaluation of fluid dynamics and the spread of 0.5% hyperbaric bupivacaine and 4% hyperbaric mepivacaine in 0° (supine position), 5° and 10° head-down tilt positions. Model II included reconstructions of average adult spinal curvatures for closer analysis of the intrathecal spread of 0.5% hyperbaric bupivacaine in 0°, 5°, 10° and 15° head-down tilt positions. Concentration gradients within the artificial cerebrospinal fluid were calculated using a digital image processing technique. Data from both model investigations were compared to elaborate the effect of varying lumbar lordosis angles. RESULTS: Model I: Only the 5° head-down tilt caused a significant difference in maximum spread of both local anesthetics. Model II: A 15° head-down tilt resulted in the local anesthetic solution spilling over lumbar lordosis and effusing into the thoracic areas. With increasing degree of head-down tilt, the local anesthetic solution was also detectable in ventral parts of the spinal canal cross-section. CONCLUSIONS: Diffusion processes represent the decisive factor for distribution patterns of hyperbaric anesthetics in the supine position. Only the 5° head-down tilt demonstrated an influence of specific gravity. When tilted 10° head-down gravitation prevailed over differences in density. A 15° head-down tilt is a precondition for the mobilization of sacrally pooled local anesthetic. Data comparison of both model investigations showed that the extent of spread depends more on initial bidirectional distribution of the local anesthetic than on increasing flow rate due to the slope of lumbar lordosis.

[My great-grandfather Christian Batschelet (1813 - 1897) veterinarian in Walperswil (BE).]. / Mein Urgrossvater Christian Batschelet (1813 - 1897), Tierarzt in Walperswil (BE).

In the introduction I will start from a biographical novel on Friedrich Baumann, who was born in 1835 as an illegitimate child and later stood in high respect as building contractor, founder's president of the Swiss master builder's federation and politician, and we will look after his father who emigrated to America. In the following sections I will present the Batschelet family as well as the family of the veterinarian Christian Batschelet and the department for animal pharmaceutics of the academy in Bern. The time of the young veterinarian in Walperswil as well as his emigration and his life in the USA will also be examined and I will also introduce Christian Batschelet's son, Friedrich Baumann and his son, my father Erwin Friedrich Baumann.

[Heart rate measurement for determination of training intensity in outpatient pulmonary sport groups]. / Herzfrequenzmessung zur Bestimmung der Trainingsintensität in Lungensportgruppen.

BACKGROUND: Exercise training is an integral component of the management of patients with asthma and COPD. A training intensity of 60-80% of maximum oxygen uptake (VO(2)max) has been recommended. Instead of ergospirometry measurement of heart rate can be used for training guidance. It is unknown whether the given target can be reached in outpatient training groups with substantial heterogeneity concerning diagnosis, disease severity, and age. METHODS AND PATIENTS: 61 adult patients (m = 15, w = 46; 63 +/- 9 years) with asthma (n = 50) or COPD (n = 11) exercised in groups of ambulant lung sports. An individualized target heart rate was calculated corresponding to an intensity of 60% to 80% of calculated VO(2)max which was equivalent to a heart rate from 97 to 137 beats per minute in the population studied. Heart rate, as a measure of the intensity of charge, was measured continuously with pulse frequency meters. RESULTS: All but one asthma patient exercised in the targeted heart rate range. Patients reached 81 +/- 9% of the training goal of calculated 80% VO(2)max (asthma patients: 79 +/- 9% vs. COPD patients: 88 +/- 9%, p < 0.005) No significant differences regarding training intensities were observed in relation to severity of illness or age. CONCLUSIONS: In outpatient lung sport groups of considerable heterogeneity regarding diagnosis, severity of illness and age, participants reach their individualized heart rate target range. COPD patients were training at a significantly higher relative training intensity. Heart rate is an easy to use parameter for training guidance.

[Granulomatous bronchiolitis due to aspiration of lycopodium spores by fire-breathing]. / Granulomatöse Bronchiolitis nach Aspiration von Lycopodium-Sporen bei einem Feuerspucker.

BACKGROUND: Lung disease due to aspiration is often unsuspected and represents a diagnostic challenge. CASE REPORT: We report on a 23-year-old male patient with cough, fever and infiltrates on the chest radiograph. The lung biopsy showed granulomatous changes consistent with tuberculosis. The surgical lung biopsy revealed aspiration bronchiolitis with necrosis, granulomatous changes and particulate foreign material. RESULTS: The aspirated matter could be identified only after repeated interrogation specifically directed to the matter. The patient had aspirated Lycopodium spores in the course of occasional fire-breathing. CONCLUSIONS: This is the first report on pulmonary disease due to aspiration of Lycopodium spores in the course of fire-breathing. It shows that the anamnesis is as crucial as histology for the definitive diagnosis of aspiration disease.

Interleukin-6 trans signalling enhances photodynamic therapy by modulating cell cycling.

Photodynamic therapy (PDT) of solid tumours causes tissue damage that elicits local and systemic inflammation with major involvement of interleukin-6 (IL-6). We have previously reported that PDT-treated cells lose responsiveness to IL-6 cytokines. Therefore, it is unclear whether PDT surviving tumour cells are subject to regulation by IL-6 and whether this regulation could contribute to tumour control by PDT. We demonstrate in epithelial tumour cells that while the action of IL-6 cytokines through their membrane receptors is attenuated, regulation by IL-6 via trans-signalling is established. Soluble interleukin-6 receptor-alpha (IL-6Ralpha) (sIL-6Ralpha) and IL-6 were released by leucocytes in the presence of conditioned medium from PDT-treated tumour cells. Cells that had lost their membrane receptor IL-6Ralpha due to PDT responded to treatment with the IL-6R-IL-6 complex (Hyper-IL-6) with activation of signal transducers and activator of transcription (STAT3) and ERK. Photodynamic therapy-treated cells, which were maintained during post-PDT recovery in presence of IL-6 or Hyper-IL-6, showed an enhanced suppression of proliferation. Cytokine-dependent inhibition of proliferation correlated with a decrease in cyclin E, CDK2 and Cdc25A, and enhancement of p27kip1 and hypophosphorylated Rb. The IL-6 trans-signalling-mediated attenuation of cell proliferation was also effective in vivo detectable by an improved Colon26 tumour cure by PDT combined with Hyper-IL-6 treatment. Prevention of IL-6 trans-signalling using soluble gp130 reduced curability. The data suggest that the post-PDT tumour milieu contains the necessary components to establish effective IL-6 trans-signalling, thus providing a means for more effective tumour control.

[Intended and actual paths of epidural needles. Investigations with a test tissue model]. / Gedachter und tatsächlicher Weg von Epiduralnadeln. Modelluntersuchungen an Testgewebe.

Peridural anaesthesia needles (PDA) do not only differ in calibre or gauge but also vary in the design of the needle tip, which shows a special configuration to place a catheter in the epidural space. A laboratory model was performed to determine the influence of different types of virgin epidural needles concerning their path through tissue. In an additional test run we analysed the influence of a previous use on the path through tissue. We investigated 16 G and 18 G Tuohy needles for epidural anaesthesia and two different 18 G Tuohy needles for combined spinal-epidural anaesthesia. The experiments were performed in a standardised way using a precision drill press in order to make the test independent of the investigator. The test tissue was selected because of its close similarity to human tissue of the lumbar region. Every needle tested revealed a distinct deviation even after a 6 cm passage through the test tissue and regularly deviated away from the concave side of the needle tip. The comparison of the CSE needles tested revealed a significant deviation from the axis due to differences in cross-section and configuration of the needle tip. As expected, the average deviation of PDA needles depended on the diameter. No differences in the degree of deviation for virgin needles compared to previously used needles could be found. Thus, more than one application of the same needle in one patient is considered to be safe as long as the needle is not deformed in any way.

Effect of exercise, body composition, and nutritional intake on bone parameters in male elite rock climbers.

A low body mass index is considered essential for high performance in rock climbing; however its effect on bone may be negative. In this study we compared the BMD of competitive male rock climbers (n = 20) and age- and BMI-matched non-training controls (n = 11). Subjects with any medication or illness affecting bone metabolism or a family history of osteoporosis were not included in the analysis. Total body BMD was measured by dual-energy X-ray absorptiometry. Quantitative computed tomographic scans were made from the femoral neck and the lumbar spine. Dietary intake was assessed by a 5-day protocol. BMD of the TB-scan was significantly higher in the climbers group for all sub-regions except the skull (p = 0.191) and the lower extremities (p = 0.079). Trabecular and cortical BMD of the LS were significantly higher (p = 0.036 and p = 0.004) in the climbers. The same was true for total (p = 0.005) and cortical (p = 0.002) BMD of the FN. Trabecular BMD (p = 0.054), CSA (p < 0.343) and cortical thickness (p = 0.065) of the FN was non-significantly higher for the climbers. Our study indicates that the effect of climbing on bone parameters PER SE is not detrimental in elite male athletes. Contrarily climbers demonstrated significantly higher BMD values at all loaded regions without "steal effects" at skeletal sites with low mechanical impact. Although we determined a moderately negative effect of low BMI on BMD we could not decide whether a low BMI value should be used as an exclusion criterion in high level climbing competitions as practized by the Austrian Sportclimbing Organization.

[Clinical presentation, diagnosis and treatment of Mycoplasma pneumoniae pneumonia]. / Klinik, Diagnostik und Therapie der Mykoplasmen-Pneumonie.

Mycoplasma pneumoniae is a common respiratory pathogen in community acquired pneumonia. In severe cases extrapulmonary manifestations of the disease may be prominent. Proof of infection is found, though usually delayed, through serologic methods. A calculated therapy of community acquired pneumonia, especially in younger patients with interstitial infiltrates, should therefore include effective treatment for Mycoplasma pneumoniae. Macrolide antibiotics are the most commonly used antibiotics in the treatment of mycoplasma infection, alternatives include ketolides, quinolones and tetracyclines.