Performance of a cryo-cooled crystal monochromator illuminated by hard X-rays with MHz repetition rate at the European X-ray Free-Electron Laser.

Due to the high intensity and MHz repetition rate of photon pulses generated by the European X-ray Free-Electron Laser, the heat load on silicon crystal monochromators can become large and prevent ideal transmission in Bragg diffraction geometry due to crystal deformation. Here, we present experimental data illustrating how heat load affects the performance of a cryogenically cooled monochromator under such conditions. The measurements are in good agreement with a depth-uniform model of X-ray dynamical diffraction taking beam absorption and heat deformation of the crystals into account.

Pump-probe X-ray holographic imaging of laser-induced cavitation bubbles with femtosecond FEL pulses.

Cavitation bubbles can be seeded from a plasma following optical breakdown, by focusing an intense laser in water. The fast dynamics are associated with extreme states of gas and liquid, especially in the nascent state. This offers a unique setting to probe water and water vapor far-from equilibrium. However, current optical techniques cannot quantify these early states due to contrast and resolution limitations. X-ray holography with single X-ray free-electron laser pulses has now enabled a quasi-instantaneous high resolution structural probe with contrast proportional to the electron density of the object. In this work, we demonstrate cone-beam holographic flash imaging of laser-induced cavitation bubbles in water with nanofocused X-ray free-electron laser pulses. We quantify the spatial and temporal pressure distribution of the shockwave surrounding the expanding cavitation bubble at time delays shortly after seeding and compare the results to numerical simulations.

Materials Imaging and Dynamics (MID) instrument at the European X-ray Free-Electron Laser Facility.

The Materials Imaging and Dynamics (MID) instrument at the European X-ray Free-Electron Laser (EuXFEL) facility is described. EuXFEL is the first hard X-ray free-electron laser operating in the MHz repetition range which provides novel science opportunities. The aim of MID is to enable studies of nano-structured materials, liquids, and soft- and hard-condensed matter using the bright X-ray beams generated by EuXFEL. Particular emphasis is on studies of structure and dynamics in materials by coherent scattering and imaging using hard X-rays. Commission of MID started at the end of 2018 and first experiments were performed in 2019.

Selective Nonoperative Management of Abdominal Stab Wounds with Isolated Omental Evisceration is Safe: A South African Experience.

BACKGROUND AND AIMS: Selective nonoperative management of abdominal stab wound is well established, but its application in the setting of isolated omental evisceration remains controversial. The aim of the study is to establish the role of selective nonoperative management in the setting of isolated omental evisceration. MATERIALS AND METHODS: A retrospective study was conducted over an 8-year period from January 2010 to December 2017 at a major trauma center in South Africa to determine the outcome of selective nonoperative management. RESULTS: A total of 405 consecutive cases were reviewed (91% male, mean age: 27 years), of which 224 (55%) cases required immediate laparotomy. The remaining 181 cases were observed clinically, of which 20 (11%) cases eventually required a delayed laparotomy. The mean time from injury to decision for laparotomy was <3 h in 92% (224/244), 3-6 h in 6% (14/244), 6-12 h 2% (4/244), and 12-18 h in 1% (2/244). There was no significant difference between the immediate laparotomy and the delayed laparotomy group in terms of length of stay, morbidity, or mortality. Ninety-eight percent (238/244) of laparotomies were positive and 96% of the positive laparotomies (229/238) were considered therapeutic. CONCLUSION: Selective nonoperative management for abdominal stab wound in the setting of isolated omental evisceration is safe and does not result in increased morbidity or mortality. Clinical assessment remains valid and accurate in determining the need for laparotomy but must be performed by experienced surgeons in a controlled environment.

Correlation between the level of the external wound and the internal injury in penetrating neck injury does not favour an initial zonal management approach.

BACKGROUND: Many current protocols for managing penetrating neck injuries (PNIs) still suggest zonal approaches. This study was undertaken to determine the correlation between the zone of the external wound and the level of the internal injury, and to verify whether a 'no-zone' approach to PNI is valid. METHODS: Patients admitted with a PNI to a tertiary trauma care centre between January 2011 and May 2018 were identified from a trauma database. Those with confirmed injury to the vascular system or an aerodigestive tract injury (ADTI) were included in the study. The medical records of each patient were reviewed with regard to the zone of the external wound and the level of internal injury, and the findings were compared. RESULTS: In the period under review, 1075 patients were treated for a PNI. Of these, 298 (27·7 per cent) had a confirmed vascular injury or ADTI and were included in the cohort. In 176 patients (59·1 per cent) the site of the internal injury was in the same zone as the external wound. In a further 70 patients (23·5 per cent) there was no correlation between the site of the internal injury and the external wound, and in the remaining 52 patients (17·4 per cent) the correlation could not be determined. In this cohort, all clinically assessable patients with significant injuries had either physical signs suggestive of injury or deep surgical emphysema on radiological examination. CONCLUSION: An approach to PNI based on zones is questionable, and this study supports a no-zone approach based on imaging guided by clinical examination.

ANTECEDENTES: Muchos protocolos actuales para el manejo de lesiones penetrantes en el cuello (penetrating neck injury, PNI) aún proponen un enfoque zonal. Este estudio se llevó a cabo para determinar la correlación entre la zona de la herida externa y el nivel de la lesión interna y para comprobar si sería válido un enfoque "sin zonas" para la PNI. MÉTODOS: Los pacientes con PNI ingresados en un centro terciario de traumatología entre enero de 2011 y mayo de 2018 fueron identificados a partir de la base de datos del centro. Se incluyeron pacientes con lesión confirmada vascular o lesión del tracto aero-digestivo (aero-digestive tract injury, ADTI). Se revisaron las historias clínicas de cada paciente con respecto a la zona de la herida externa y el nivel de lesión interna, comparándose dichos hallazgos. RESULTADOS: En el período de estudio, 1.075 pacientes fueron tratados por una PNI. De estos, 298 (27,7%) tenían una lesión vascular o una ADTI confirmadas y se incluyeron en la cohorte. En 176 pacientes (59,1%), la lesión interna estaba localizada en la misma zona de la herida externa. En otros 70 pacientes (23,5%), no hubo correlación entre la localización de la lesión interna y la herida externa y en los 52 pacientes restantes (17,4%) no se pudo determinar dicha correlación. En esta cohorte, todos los pacientes clínicamente evaluables con lesiones significativas presentaban signos físicos sugestivos de lesión o enfisema profundo con indicación quirúrgica en el examen radiológico. CONCLUSIÓN: El enfoque de la PNI basado en zonas es cuestionable y este estudio apoya un enfoque de "sin zonas" basado en pruebas de imágen basadas en los hallazgos clíncos.

Measurement of dust-borne MRSA in pig farms using different approaches.

AIMS: To obtain knowledge about (i) how to sample airborne methicillin-resistant Staphylococcus aureus (MRSA) and dust in the pig farm environment including effects of sampler on (a) measured exposure, (b) MRSA survival and (c) spatial and temporal variation in exposure, and (ii) the association between exposure to MRSA, dust and optical density OD. METHODS AND RESULTS: Airborne dust was sampled on five pig farms using five active and one passive samplers. Staphylococcus aureus and MRSA (as a subset of S. aureus) were quantified using selective agar media and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The Andersen sampler, electrostatic dust collectors (EDC), and Gesamtstaubprobenahme (GSP) and Institute of Occupational Medicine samplers with polycarbonate or Teflon filters were applicable for sampling airborne MRSA. The half-life of MRSA was not reduced by active sampling. A significant correlation was found between dust and S. aureus exposure within, but not between, farm section and farms. A significant spatial and temporal variation in dust and MRSA exposure was found within a stable. The dust sampling rate and the concentration of MRSA in the sampled dust decreased after 5 days of sampling. CONCLUSION: Sampling using the GSP can be performed for 1 h without affecting the following half-life of MRSA. Sampling for MRSA using the EDC should not exceed 3 days due to overloading and the die-off of MRSA. The measurement of OD may be used as a proxy measure for dust exposure. To obtain knowledge about potential exposure, samples should be taken repeatedly and in different areas within a stable section. SIGNIFICANCE AND IMPACT OF THE STUDY: Sampling method, sampling time and number of samples taken, but not force of airflow on the filter, influence the measured potential exposure to MRSA and dust.

Absorbable subcuticular staples versus suture for caesarean section closure: a randomised clinical trial.

OBJECTIVE: To compare outcomes of efficiency, safety, patient, and surgeon satisfaction between absorbable subcuticular staples and subcuticular suture for caesarean section skin closure. DESIGN: A prospective, randomised, non-blinded, parallel-group trial. SETTING: Mayo Clinic Family Birth Center in Rochester, MN, USA. POPULATION: At least 18 years old and 24 weeks' gestation, undergoing caesarean section. Exclusion criteria were body mass index >50, chorioamnionitis, intrauterine fetal death, and multifetal gestation. METHODS: Patients were stratified by prior caesarean section, body mass index, and surgeon level and randomised to absorbable subcuticular staples or subcuticular suture. Electronic medical records and surveys were used. MAIN OUTCOME MEASURES: Primary outcomes were total operating time, from incision start to close. Secondary outcomes included subcuticular skin closure time, patient and surgeon satisfaction, percutaneous injuries, pain (analgesic use), cosmesis, and wound complications. RESULTS: Of 220 randomised patients, 206 were included in the final analysis (103 per group). Baseline characteristics were similar. The primary outcome of total operative time was not significantly different between groups [54.0 (44.9-63.6) versus 58.0 (50.4-68.2) minutes, P = 0.053]. The subcuticular staple group had shorter subcuticular skin closure time [median 2.6 (1.8-4.0) versus 8.5 (6.2-10.5) minutes, P < 0.001]. There were no differences in analgesic use, wound complications, cosmesis or patient satisfaction. One needlestick injury occurred with suture. Surgeons were more likely to recommend (97% versus 85%, P = 0.004) and use (98% versus 82%, P < 0.001) absorbable subcuticular staples. CONCLUSION: For caesarean section skin closure, absorbable subcuticular staples did not result in significantly different total operative times compared with sutures. Analgesic use, wound complications, and cosmesis were comparable. Patient and surgeon satisfaction were high with both methods. TWEETABLE ABSTRACT: Absorbable subcuticular staples associated with a similar total operative time compared with suture.

Development of a hard X-ray split-and-delay line and performance simulations for two-color pump-probe experiments at the European XFEL.

A hard X-ray Split-and-Delay Line (SDL) under construction for the Materials Imaging and Dynamics station at the European X-Ray Free-Electron Laser (XFEL) is presented. This device aims at providing pairs of X-ray pulses with a variable time delay ranging from -10 ps to 800 ps in a photon energy range from 5 to 10 keV for photon correlation and X-ray pump-probe experiments. A custom designed mechanical motion system including active feedback control ensures that the high demands for stability and accuracy can be met and the design goals achieved. Using special radiation configurations of the European XFEL's SASE-2 undulator (SASE: Self-Amplified Spontaneous Emission), two-color hard x-ray pump-probe schemes with varying photon energy separations have been proposed. Simulations indicate that more than 109 photons on the sample per pulse-pair and up to about 10% photon energy separation can be achieved in the hard X-ray region using the SDL.

Design, synthesis, and time-gated cell imaging of carbon-bridged triangulenium dyes with long fluorescence lifetime and red emission.

Time-resolved fluorescence offers many advantages over normal steady-state detection and becomes increasingly important in bioimaging. However, only very few fluorophores with emission in the visible range and fluorescence lifetimes above 5 ns are available. In this work, we prepare a series of new aza/oxa-triangulenium dyes where one of the usual oxa or aza bridges is replaced by an isopropyl bridge. This leads to a significant redshift of fluorescence with only moderate reductions of quantum yields and a unique long fluorescence lifetime. The fluorescence of the isopropyl bridged diazatriangulenium derivative CDATA+ is red-shifted by 50 nm (1400 cm-1) as compared to the oxygen-bridged DAOTA+ chromophore and has intense emission in the red region (600-700 nm) with a quantum yield of 61%, and a fluorescence lifetime of 15.8 ns in apolar solution. When the CDATA+ dye is used as cell stain, high photostability and efficient time-gated cell imaging is demonstrated.

Kinesiophobia is associated with pain intensity but not pain sensitivity before and after exercise: an explorative analysis.

OBJECTIVE: To compare clinical pain intensity, exercise performance, pain sensitivity and the effect of aerobic and isometric exercise on local and remote pressure pain thresholds (PPTs) in patients with chronic musculoskeletal pain with high and low levels of kinesiophobia. DESIGN: An experimental pre-post within-subject study. SETTING: An exercise laboratory in a multidisciplinary pain clinic. PARTICIPANTS: Fifty-four patients with chronic musculoskeletal pain. INTERVENTIONS: Acute aerobic and isometric leg exercises. MAIN OUTCOME MEASURES: Clinical pain intensity (numerical rating scale, range 0 to 10), Tampa Scale of Kinesiophobia, aerobic and isometric exercise performances (intensity and maximal voluntary contraction), and PPTs at local and remote body areas before and after exercise conditions. RESULTS: Patients with a high degree of kinesiophobia demonstrated increased pain intensity compared with patients with a low degree of kinesiophobia [high degree of kinesiophobia: 7.3 (1.6) on NRS; low degree of kinesiophobia: 6.3 (1.6) on NRS; mean difference 1.0 (95% confidence interval 0.08 to 1.9) on NRS]. Aerobic and isometric exercises increased PPTs, but no significant group differences were found in PPTs before and after exercise. CONCLUSIONS: Clinical pain intensity was significantly higher in patients with a high degree of kinesiophobia compared with patients with a low degree of kinesiophobia. Despite a difference in isometric exercise performance, the hypoalgesic responses after cycling and isometric knee exercise were comparable between patients with high and low degrees of kinesiophobia. If replicated in larger studies, these findings indicate that although kinesiophobic beliefs influence pain intensity, they do not significantly influence PPTs and exercise-induced hypoalgesia in patients with chronic musculoskeletal pain.

A multiphysics approach for modeling early atherosclerosis.

This work is devoted to the development of a mathematical model of the early stages of atherosclerosis incorporating processes of all time scales of the disease and to show their interactions. The cardiovascular mechanics is modeled by a fluid-structure interaction approach coupling a non-Newtonian fluid to a hyperelastic solid undergoing anisotropic growth and a change of its constitutive equation. Additionally, the transport of low-density lipoproteins and its penetration through the endothelium is considered by a coupled set of advection-diffusion-reaction equations. Thereby, the permeability of the endothelium is wall-shear stress modulated resulting in a locally varying accumulation of foam cells triggering a novel growth and remodeling formulation. The model is calibrated and applied to an murine-specific case study, and a qualitative validation of the computational results is performed. The model is utilized to further investigate the influence of the pulsatile blood flow and the compliance of the artery wall to the atherosclerotic process. The computational results imply that the pulsatile blood flow is crucial, whereas the compliance of the aorta has only a minor influence on atherosclerosis. Further, it is shown that the novel model is capable to produce a narrowing of the vessel lumen inducing an adaption of the endothelial permeability pattern.

Computed Tomography Angiography is the Definitive Vascular Imaging Modality for Penetrating Neck Injury: A South African Experience.

BACKGROUND AND AIMS: Computed tomography angiography has become central to the diagnostic algorithm for penetrating neck injury, but despite its widespread use the literature to support this adoption is limited. We reviewed our experience with computed tomography angiography for the identification of vascular trauma in hemodynamically stable patients with penetrating neck injury at a major trauma center in South Africa. MATERIALS AND METHODS: A prospectively kept trauma registry capturing data in real time was retrospectively reviewed. All patients with penetrating neck injury investigated with computed tomography angiography as the initial vascular investigation during a 47-month period were included. RESULTS: A total of 380 patients were included. Indications for computed tomography angiography were as follows: hard signs (13), soft signs (201), no signs but proximity/zone I or III wounds (141), and undefined signs of vascular injury (25). Of the 380 scans, 7 (1.8%) were indeterminate, 299 (78.7%) negative, and 74 (19.5%) positive for a vascular injury (54 arterial and 20 isolated venous injury). Eight were false positive and 4 false negative. The sensitivity, specificity, positive, and negative predictive values for detecting arterial injury were 93.9%, 97.5%, 85.2%, and 99.1%, respectively. Overall, the yield for demonstrating "true arterial injury" was 12.1% (46/380); hard signs: 76.9% (10/13), soft signs: 16.4% (33/201), and no signs: 2.1% (3/141) which all were secondary to gunshot wounds). Only 8.4% (32/380) required intervention for arterial injury and none for isolated venous injury (hard signs: 62.0%, soft signs: 11.4%, and no signs: 0.7%). No serious complications resulted from computed tomography angiography. CONCLUSION: Computed tomography angiography is a safe and effective imaging modality for the investigation of vascular trauma post penetrating neck injury. Asymptomatic patients with stab wounds do not need to be imaged regardless of proximity concerns. Symptomatic stable patients including a subgroup with hard signs should be imaged rather than explored. Computed tomography angiography provides an interventional road map and can identify injuries amenable to endovascular or conservative management.

Evaluation of air samplers and filter materials for collection and recovery of airborne norovirus.

AIMS: The aim of this study was to identify the most efficient sampling method for quantitative PCR-based detection of airborne human norovirus (NoV). METHODS AND RESULTS: A comparative experiment was conducted in an aerosol chamber using aerosolized murine norovirus (MNV) as a surrogate for NoV. Sampling was performed using a nylon (NY) filter in conjunction with four kinds of personal samplers: Gesamtstaubprobenahme sampler (GSP), Triplex-cyclone sampler (TC), 3-piece closed-faced Millipore cassette (3P) and a 2-stage NIOSH cyclone sampler (NIO). In addition, sampling was performed using the GSP sampler with four different filter types: NY, polycarbonate (PC), polytetrafluoroethylene (PTFE) and gelatine (GEL). The sampling efficiency of MNV was significantly influenced by both sampler and filter type. The GSP sampler was found to give significantly (P < 0·05) higher recovery of aerosolized MNV than 3P and NIO. A higher recovery was also found for GSP compared with TC, albeit not significantly. Finally, recovery of aerosolized MNV was significantly (P < 0·05) higher using NY than PC, PTFE and GEL filters. CONCLUSIONS: The GSP sampler combined with a nylon filter was found to be the best method for personal filter-based sampling of airborne NoV. SIGNIFICANCE AND IMPACT OF THE STUDY: The identification of a suitable NoV air sampler is an important step towards studying the association between exposure to airborne NoV and infection.

Whole-genome sequencing for identification of the source in hospital-acquired Legionnaires' disease.

Acquisition of Legionnaires' disease is a serious complication of hospitalization. Rapid determination of whether or not the infection is caused by strains of Legionella pneumophila in the hospital environment is crucial to avoid further cases. This study investigated the use of whole-genome sequencing to identify the source of infection in hospital-acquired Legionnaires' disease. Phylogenetic analyses showed close relatedness between one patient isolate and a strain found in hospital water, confirming suspicion of nosocomial infection. It was found that whole-genome sequencing can be a useful tool in the investigation of hospital-acquired Legionnaires' disease.

MET amplification and epithelial-to-mesenchymal transition exist as parallel resistance mechanisms in erlotinib-resistant, EGFR-mutated, NSCLC HCC827 cells.

Although many epidermal growth factor receptor (EGFR)-mutated lung cancer patients initially benefit from the EGFR-inhibitor erlotinib, all acquire resistance. So far, several mechanisms implicated in resistance have been identified, but the existence of multiple resistance mechanisms in parallel have only been sparsely investigated. In this study, we investigated parallel resistance mechanisms acquired by HCC827, an EGFR-mutated adenocarcinoma cell line dependent on EGFR activity and sensitive to erlotinib. The cell line was treated with erlotinib by stepwise escalation of the drug-concentration and erlotinib-resistant (HCC827ER) cells created. HCC827ER cells depicted a mixed epithelial and mesenchymal phenotype. To clarify potential parallel resistance mechanisms, 14 resistant subclones were established by limited dilution. Interestingly, all HCC827ER subclones harbored either a MET-amplification (6/14) or underwent EMT (8/14), mechanisms both found in previous studies, but not in co-occurrence. Both subclone-types were resistant to erlotinib, but only MET-subclones responded to the MET-inhibitors crizotinib and capmatinib. EMT-subclones on the other hand had markedly increased FGFR1 expression and responded to the FGFR-inhibitor AZD4547, whereas MET-subclones did not. Monitoring gene expression through the development of HCC827ER revealed upregulation of FGFR1 expression as an early response to erlotinib. In addition, FGFR1 expression increased upon short-term erlotinib treatment (48 h) identifying a physiological role immediately after erlotinib exposure. The high FGFR1 expression seen in EMT-subclones was stable even after five passages without erlotinib. Here we show, that parallel resistance mechanisms appear during erlotinib-resistance development in EGFR-mutated NSCLC cells and highlight a role for FGFR1 expression changes as an early response to erlotinib as well as a bypass-signaling mechanism.

Assessment of airborne bacteria and noroviruses in air emission from a new highly-advanced hospital wastewater treatment plant.

Exposure to bioaerosols can pose a health risk to workers at wastewater treatment plants (WWTPs) and to habitants of their surroundings. The main objective of this study was to examine the presence of harmful microorganisms in the air emission from a new type of hospital WWTP employing advanced wastewater treatment technologies. Air particle measurements and sampling of inhalable bacteria, endotoxin and noroviruses (NoVs) were performed indoor at the WWTP and outside at the WWTP ventilation air exhaust, downwind of the air exhaust, and upwind of the WWTP. No significant differences were seen in particle and endotoxin concentrations between locations. Bacterial concentrations were comparable or significantly lower in the exhaust air than inside the WWTP and in the upwind reference. Bacterial isolates were identified using matrix-assisted laser desorption-ionization time-of-flight mass spectrometry. In total, 35 different bacterial genera and 64 bacterial species were identified in the air samples. Significantly higher genus and species richness was found with an Andersen Cascade Impactor compared with filter-based sampling. No pathogenic bacteria were found in the exhaust air. Streptomyces was the only bacterium found in the air both inside the WWTP and at the air emission, but not in the upwind reference. NoV genomes were detected in the air inside the WWTP and at the air exhaust, albeit in low concentrations. As only traces of NoV genomes could be detected in the exhaust air they are unlikely to pose a health risk to surroundings. Hence, we assess the risk of airborne exposure to pathogenic bacteria and NoVs from the WWTP air emission to surroundings to be negligible. However, as a slightly higher NoV concentration was detected inside the WWTP, we cannot exclude the possibility that exposure to airborne NoVs can pose a health risk to susceptible to workers inside the WWTP, although the risk may be low.

Exercise increases pressure pain tolerance but not pressure and heat pain thresholds in healthy young men.

BACKGROUND: Exercise causes an acute decrease in the pain sensitivity known as exercise-induced hypoalgesia (EIH), but the specificity to certain pain modalities remains unknown. This study aimed to compare the effect of isometric exercise on the heat and pressure pain sensitivity. METHODS: On three different days, 20 healthy young men performed two submaximal isometric knee extensions (30% maximal voluntary contraction in 3 min) and a control condition (quiet rest). Before and immediately after exercise and rest, the sensitivity to heat pain and pressure pain was assessed in randomized and counterbalanced order. Cuff pressure pain threshold (cPPT) and pain tolerance (cPTT) were assessed on the ipsilateral lower leg by computer-controlled cuff algometry. Heat pain threshold (HPT) was recorded on the ipsilateral foot by a computer-controlled thermal stimulator. RESULTS: Cuff pressure pain tolerance was significantly increased after exercise compared with baseline and rest (p < 0.05). Compared with rest, cPPT and HPT were not significantly increased by exercise. No significant correlation between exercise-induced changes in HPT and cPPT was found. Test-retest reliability before and after the rest condition was better for cPPT and CPTT (intraclass correlation > 0.77) compared with HPT (intraclass correlation = 0.54). CONCLUSIONS: The results indicate that hypoalgesia after submaximal isometric exercise is primarily affecting tolerance of pressure pain compared with the pain threshold. These data contribute to the understanding of how isometric exercise influences pain perception, which is necessary to optimize the clinical utility of exercise in management of chronic pain. SIGNIFICANCE: The effect of isometric exercise on pain tolerance may be relevant for patients in chronic musculoskeletal pain as a pain-coping strategy. WHAT DOES THIS STUDY ADD?: The results indicate that hypoalgesia after submaximal isometric exercise is primarily affecting tolerance of pressure pain compared with the heat and pressure pain threshold. These data contribute to the understanding of how isometric exercise influences pain perception, which is necessary to optimize the clinical utility of exercise in management of chronic pain.

A crystal structure prediction enigma solved: the gallic acid monohydrate system - surprises at 10 K.

The seemingly unpredictable structure of gallic acid monohydrate form IV has been investigated using accurate X-ray diffraction measurements at temperatures of 10 and 123 K. The measurements demonstrate that the structure is commensurately modulated at 10 K and disordered at higher temperatures. Aided by charge-density modeling and periodic DFT calculations we show that the disorder gives a substantial stabilization of the structure.

High molecular weight PEGylation of human pancreatic polypeptide at position 22 improves stability and reduces food intake in mice.

BACKGROUND AND PURPOSE: Human pancreatic polypeptide (hPP) is known to suppress appetite and food intake, thereby representing a potential therapeutic approach against obesity and associated metabolic disorders. The aim of this study was to improve hPP stability by covalent PEGylation with diverse molecular weight polyethylene glycols (PEGs) at two positions using promising lead structures while maintaining target activity. EXPERIMENTAL APPROACH: Modified peptides were synthesized by combined solid-phase and solution-phase peptide synthesis. Their potency was investigated in constitutively expressing human epithelial cells and isolated human colonic mucosa as well as receptor-transfected artificial cell lines. Human blood plasma and porcine liver homogenates were used to examine the in vitro stability of the analogues. The most promising variants were injected s.c. in C57BL/6JRj mice to monitor fasting-induced food intake and bioavailability. KEY RESULTS: In human epithelia and colonic mucosal preparations, activity of the modified hPP peptides depended on the core sequence and latency of the peptides was related to PEG size. Peptides modified with a 22 kDa PEG (PEG22) remained intact in blood plasma and on incubation with liver homogenates for more than 96 h. Finally, hPP2-36 , [K22 (PEG22)]hPP2-36 and [K22 (PEG22),Q34 ]hPP significantly reduced cumulative food intake in mice over 16 h after s.c. administration. CONCLUSIONS AND IMPLICATIONS: Modification with PEG22 at position 22 stabilizes hPP significantly while extending its biological activities and could be used in drug development prospectively.

Oral 2-oleyl glyceryl ether improves glucose tolerance in mice through the GPR119 receptor.

The intestinal G protein-coupled receptor GPR119 is a novel metabolic target involving glucagon-like peptide-1 (GLP-1)-derived insulin-regulated glucose homeostasis. Endogenous and diet-derived lipids, including N-acylethanolamines and 2-monoacylglycerols (2-MAG) activate GPR119. The purpose of this work is to evaluate whether 2-oleoyl glycerol (2-OG) improves glucose tolerance through GPR119, using wild type (WT) and GPR 119 knock out (KO) mice. We here show that GPR119 is essential for 2-OG-mediated release of GLP-1 and CCK from GLUTag cells, since a GPR119 specific antagonist completely abolished the hormone release. Similarly, in isolated primary colonic crypt cultures from WT mice, GPR119 was required for 2-OG-stimulated GLP-1 release while there was no response in crypts from KO mice. In vivo, gavage with 2-oleyl glyceryl ether ((2-OG ether), a stable 2-OG analog with a potency of 5.3 µM for GPR119 with respect to cAMP formation as compared to 2.3 µM for 2-OG), significantly (P < 0.05) improved glucose clearance in WT littermates, but not in GPR119 KO mice. Finally, deletion of GPR119 in mice resulted in lower glucagon levels, whereas the levels of insulin and GIP were unchanged. In the present study we show that 2-OG stimulates GLP-1 secretion through GPR119 activation in vitro, and that fat-derived 2-MAGs are potent candidates for mediating fat-induced GLP-1 release through GPR119 in vivo. © 2016 BioFactors, 42(6):665-673, 2016.