Teduglutide improves liver chemistries in short bowel syndrome-associated intestinal failure: Post hoc analysis.

BACKGROUND: Chronic hepatic complications are common in patients with short bowel syndrome-associated intestinal failure (SBS-IF). Teduglutide, a glucagon-like peptide-2 analogue, demonstrated efficacy in reducing parenteral nutrition and/or intravenous fluid dependence among patients with SBS-IF in phase 3 clinical studies. METHODS: This was a post hoc analysis of pooled data from two separate randomized, double-blind, placebo-controlled, multinational phase 3 clinical studies. Adult patients with SBS-IF with parenteral nutrition and/or intravenous fluid dependence without liver disease at baseline were randomized to treatment with the glucagon-like peptide-2 analogue teduglutide (0.05 or 0.10 mg/kg/day) or placebo subcutaneously once daily for 24 weeks. Mixed-effects models assessed the baseline predictors of change in liver chemistries. RESULTS: Between baseline and week 24, teduglutide treatment (n = 109) was associated with least squares mean reductions in aspartate aminotransferase (-7.51 IU/L; P = 0.014), alanine aminotransferase (-12.15 IU/L; P = 0.002), and bilirubin (-5.03 µmol/L [-0.057 mg/dl]; P < 0.001) compared with that of the placebo (n = 59). These values were independent of reductions in parenteral nutrition and/or intravenous fluid dependence. CONCLUSION: Teduglutide treatment was associated with reductions in liver chemistries by week 24, which is beneficial for patients with SBS-IF beyond improvements in parenteral nutrition and/or intravenous fluid dependence. Future studies should examine how long-term teduglutide might mitigate the risk of liver disease in patients with SBS-IF.

Evaluation in a porcine wound model and long-term clinical assessment of an autologous heterogeneous skin construct used to close full-thickness wounds.

Acute and chronic wounds involving deeper layers of the skin are often not adequately healed by dressings alone and require therapies such as skin grafting, skin substitutes, or growth factors. Here we report the development of an autologous heterogeneous skin construct (AHSC) that aids wound closure. AHSC is manufactured from a piece of healthy full-thickness skin. The manufacturing process creates multicellular segments, which contain endogenous skin cell populations present within hair follicles. These segments are physically optimized for engraftment within the wound bed. The ability of AHSC to facilitate closure of full thickness wounds of the skin was evaluated in a swine model and clinically in 4 patients with wounds of different etiologies. Transcriptional analysis demonstrated high concordance of gene expression between AHSC and native tissues for extracellular matrix and stem cell gene expression panels. Swine wounds demonstrated complete wound epithelialization and mature stable skin by 4 months, with hair follicle development in AHSC-treated wounds evident by 15 weeks. Biomechanical, histomorphological, and compositional analysis of the resultant swine and human skin wound biopsies demonstrated the presence of epidermal and dermal architecture with follicular and glandular structures that are similar to native skin. These data suggest that treatment with AHSC can facilitate wound closure.

Radiation-driven rotational motion of nanoparticles.

Focused synchrotron beams can influence a studied sample via heating, or radiation pressure effects due to intensity gradients. The high angular sensitivity of rotational X-ray tracking of crystalline particles via their Bragg reflections can detect extremely small forces such as those caused by field gradients. By tracking the rotational motion of single-crystal nanoparticles embedded in a viscous or viscoelastic medium, the effects of heating in a uniform gradient beam and radiation pressure in a Gaussian profile beam were observed. Changes in viscosity due to X-ray heating were measured for 42 µm crystals in glycerol, and angular velocities of 10-6 rad s-1 due to torques of 10-24 N m were measured for 340 nm crystals in a colloidal gel matrix. These results show the ability to quantify small forces using rotation motion of tracer particles.

Temporal cytokine and lymphoid responses to an inhaled TLR7 antedrug agonist in the cynomolgus monkey demonstrates potential safety and tolerability of this approach.

AZD8848 is a TLR7 agonist antedrug developed for administration by inhalation dosing for the treatment of allergic diseases, such as asthma. Allergic asthma is associated with increased levels of Th2 cytokines which are suppressed for extended periods by TLR7 agonists in a number of preclinical models of allergic airway inflammation. However, TLRs form a central part of innate immunity and their activation often results in proinflammatory responses. Whilst AZD8848's antedrug mechanism is designed to restrict its pharmacological action beyond the lung, the effect of chronic, supramaximal dosing to the target tissue has yet to be defined. To support clinical development of this potentially disease modifying approach the nonclinical safety and pharmacodynamics of AZD8848 were evaluated in cynomolgus monkeys in studies examining single or multiple weekly inhaled doses. Here we show that following a single dose nearly all responses returned to baseline within a week. During multiple dosing serum biomarkers were quantified over the dosing period and indicated a limited systemic response. The dose at which maximal interferon responses were seen was dependent on dose. Thorough histopathological examination revealed a dose related increase of size and cells of lymphoid tissues in the lung and nose. Local lymphoid responses were recovered after the treatment free period. These studies are the first to evaluate safety of an inhaled TLR7 agonist and demonstrate AZD8848 is safe with a no observed adverse effect level at 26µg/kg allowing progression to man with weekly inhalation dosing.

A 3D Human Airway Model Enables Prediction of Respiratory Toxicity of Inhaled Drugs In Vitro.

Respiratory tract toxicity represents a significant cause of attrition of inhaled drug candidates targeting respiratory diseases. One of the key issues to allow early detection of respiratory toxicities is the lack of reliable and predictive in vitro systems. Here, the relevance and value of a physiologically relevant 3D human airway in vitro model (MucilAir) were explored by repeated administration of a set of compounds with (n = 8) or without (n = 7) respiratory toxicity following inhalation in vivo. Predictability for respiratory toxicity was evaluated by readout of cytotoxicity, barrier integrity, viability, morphology, ciliary beating frequency, mucociliary clearance and cytokine release. Interestingly, the data show that in vivo toxicity can be predicted in vitro by studying cell barrier integrity by transepithelial electrical resistance (TEER), and cell viability determined by the Resazurin method. Both read-outs had 88% sensitivity and 100% specificity, respectively, while the former was more accurate with receiver operating characteristic (ROC) AUC of 0.98 (p = .0018) compared with ROC AUC of 0.90 (p = .0092). The loss of cell barrier integrity could mainly, but not fully, be attributed to a loss of cell coverage in 6 out of 7 compounds with reduced TEER. Notably, these effects occurred only at 400 µM, at concentration levels significantly above primary target cell potency, suggesting that greater attention to high local lung concentrations should be taken into account in safety assessment of inhaled drugs. Thus, prediction of respiratory toxicity in 3D human airway in vitro models may result in improved animal welfare and reduced attrition in inhaled drug discovery projects.

Nuclear incorporation of iron during the eukaryotic cell cycle.

Scanning X-ray fluorescence microscopy has been used to probe the distribution of S, P and Fe within cell nuclei. Nuclei, which may have originated at different phases of the cell cycle, are found to show very different levels of Fe present with a strongly inhomogeneous distribution. P and S signals, presumably from DNA and associated nucleosomes, are high and relatively uniform across all the nuclei; these agree with X-ray phase contrast projection microscopy images of the same samples. Possible reasons for the Fe incorporation are discussed.

The use of DAPI fluorescence lifetime imaging for investigating chromatin condensation in human chromosomes.

Chromatin undergoes dramatic condensation and decondensation as cells transition between the different phases of the cell cycle. The organization of chromatin in chromosomes is still one of the key challenges in structural biology. Fluorescence lifetime imaging (FLIM), a technique which utilizes a fluorophore's fluorescence lifetime to probe changes in its environment, was used to investigate variations in chromatin compaction in fixed human chromosomes. Fixed human metaphase and interphase chromosomes were labeled with the DNA minor groove binder, DAPI, followed by measurement and imaging of the fluorescence lifetime using multiphoton excitation. DAPI lifetime variations in metaphase chromosome spreads allowed mapping of the differentially compacted regions of chromatin along the length of the chromosomes. The heteromorphic regions of chromosomes 1, 9, 15, 16, and Y, which consist of highly condensed constitutive heterochromatin, showed statistically significant shorter DAPI lifetime values than the rest of the chromosomes. Differences in the DAPI lifetimes for the heteromorphic regions suggest differences in the structures of these regions. DAPI lifetime variations across interphase nuclei showed variation in chromatin compaction in interphase and the formation of chromosome territories. The successful probing of differences in chromatin compaction suggests that FLIM has enormous potential for application in structural and diagnostic studies.

Imperfection and radiation damage in protein crystals studied with coherent radiation.

Fringes and speckles occur within diffraction spots when a crystal is illuminated with coherent radiation during X-ray diffraction. The additional information in these features provides insight into the imperfections in the crystal at the sub-micrometre scale. In addition, these features can provide more accurate intensity measurements (e.g. by model-based profile fitting), detwinning (by distinguishing the various components), phasing (by exploiting sampling of the molecular transform) and refinement (by distinguishing regions with different unit-cell parameters). In order to exploit these potential benefits, the features due to coherent diffraction have to be recorded and any change due to radiation damage properly modelled. Initial results from recording coherent diffraction at cryotemperatures from polyhedrin crystals of approximately 2 µm in size are described. These measurements allowed information about the type of crystal imperfections to be obtained at the sub-micrometre level, together with the changes due to radiation damage.

Artemin-GFRα3 interactions partially contribute to acute inflammatory hypersensitivity.

The expression of artemin (ARTN), a glial cell line-derived neurotrophic factor (GDNF) family ligand, increases in pre-clinical models of nociception and recent evidence suggests this growth factor may play a causative role in inflammatory pain mechanisms. The aim of this study was to demonstrate functional inhibition of ARTN with monoclonal antibodies and to determine whether ARTN neutralisation could reverse inflammatory pain in mice. We show that monoclonal antibodies with high affinity to ARTN, completely inhibit ARTN-induced Ret and ERK activation in a human neuroblastoma cell line, and block capsaicin-induced CGRP secretion from primary rat DRG cultures. In addition, administration of anti-ARTN antibodies to mice provides a transient, partial reversal (41%) of FCA-induced mechanical hypersensitivity. Anti-ARTN antibodies had no effect on hypersensitivity in response to partial nerve ligation in mice. These data suggest that ARTN-GFRα3 interactions partially mediate early stage nociceptive signalling following an inflammatory insult.

Familial distal foregut atresia in a family with likely autosomal dominant inheritance pattern.

Familial occurrence of distal foregut atresia (DFA) (Type 1) is rare. Diagnosis is based upon the clinical symptomatology and confirmed by radiological studies, surgery and histology. A number of reports have described families in which several family members have been involved and suggested an autosomal recessive mode of inheritance. Little is known about the underlying genetic causes or indeed the likely pathogenic mechanism. We report a family in which there are five affected cases including three siblings where the DFA appears to be inherited in an autosomal dominant inheritance pattern with reduced penetrance.

PHACE syndrome: MRI of intracerebral vascular anomalies and clinical findings in a series of 12 patients.

BACKGROUND: PHACE (posterior fossa defects, haemangioma, arterial anomalies, coarctation of the aorta and cardiac defects, eye abnormalities) syndrome describes a constellation of abnormalities that can occur in association with segmental craniofacial infantile haemangioma. OBJECTIVE: To report the spectrum of clinical and imaging abnormalities seen in a cohort of children. MATERIALS AND METHODS: A retrospective review of the clinical and imaging records of all patients diagnosed with PHACE syndrome between 1998 and 2009 was performed. Information sought included patient demographics, craniofacial segments involved, imaging findings and other extracutaneous abnormalities. RESULTS: Twelve patients were diagnosed with PHACE syndrome over 11 years. All patients had a segmental craniofacial haemangioma. Involved facial segments, in order of frequency, were frontotemporal (12), maxillary (8), mandibular (5) and frontonasal (1). The most common extracutaneous abnormalities were neurovascular anomalies (10), with many patients having multiple anomalies. The spectrum of arterial anomalies ranged from hypoplasia (9) to ectasia (3), anomalous origin/course (2) and persistent fetal anastomosis (2). Other anomalies found included cardiac anomalies (3), coarctation of the aorta (2), posterior fossa malformations (1) and sternal region anomalies (1). CONCLUSION: Intracranial anomalies are the most common extracutaneous feature of PHACE syndrome. The contribution of the radiologist in the recognition of such anomalies is important for the diagnosis of PHACE syndrome.

Is psychological distress in people living with cancer related to the fact of diagnosis, current treatment or level of disability? Findings from a large Australian study.

OBJECTIVE: To investigate whether the observed elevated levels of psychological distress in cancer survivors relate specifically to aspects of cancer diagnosis, to treatment or to disability. DESIGN, PARTICIPANTS AND SETTING: Self-reported questionnaire data on demographic, health and lifestyle factors and mental health from 89574 Australian men and women aged 45 years or older, sampled from the Medicare database for the 45 and Up Study from 1 February 2006 to 30 April 2008. Logistic regression was used to examine the risk of high levels of psychological distress in relation to cancer diagnosis and disability, adjusting for age, sex, income and education. MAIN OUTCOME MEASURE: High psychological distress (Kessler Psychological Distress Scale score > or = 22). RESULTS: Overall, 7.5% of participants had high levels of psychological distress. Among cancer survivors, the median time since diagnosis was 7.3 years. Compared with people without cancer, the odds ratios (95% CIs) for psychological distress were: 1.17 (1.09-1.26) in people reporting having had any cancer apart from non-melanoma skin cancer; 1.34 (1.08-1.67) in those with cancer diagnosed in the previous year; 1.53 (1.33-1.76) for those reporting treatment for cancer in the previous month and 1.11 (1.03-1.19) for those with cancer but without recent treatment. Using individuals with neither cancer nor disability as the reference group, the adjusted odds ratio (95% CI) for psychological distress was 6.51 (5.95-7.12) in those reporting significant disability but no cancer, 1.14(1.04-1.24) in those without disability but with cancer and 5.81(4.88-6.91) in those with both cancer and disability. CONCLUSION: The risk of psychological distress in individuals with cancer relates much more strongly to their level of disability than it does to the cancer diagnosis itself.

Radiation driven collapse of protein crystals.

During coherent X-ray diffraction measurements on crystals of ferritin at room temperature using monochromatic undulator radiation from the Advanced Photon Source, a sudden lattice contraction was observed following a characteristic latent period and ultimately leading to the collapse of the crystal. The progression of this collapse is analysed using a two-state Hendricks-Teller model. It reveals that 55% of the layers collapse by 1.6% before the crystal completely stops diffracting.

Stability of neuropathic pain symptoms in partial sciatic nerve ligation in rats is affected by suture material.

Many factors affect the development of neuropathic pain behavior in animal models. In this letter, we describe the differences in the development of neuropathic pain behavior observed when the partial sciatic nerve ligation (PNL) is performed with either a synthetic silk or chromic catgut ligation. To characterize nociceptive changes over time after surgery, neutral plate, hot plate, Von Frey, pinprick, acetone spray and cold plate testing was performed. The results indicated that a chromic catgut ligature caused cold allodynia, chemical hyperreactivity, mechanical hyperalgesia and hypersensitivity that remained present for the entire 56 days post-surgical observation period. With the synthetic silk ligature, comparable functional deficits were present in the initial phase after surgery, but several of these deficits diminished over time 21-28 days post-surgery. In conclusion, performing the PNL using chromic catgut suture thread gives rise to more robust sensory deficits than when synthetic silk is used. Therefore, the material that is used for the ligature in the partial sciatic ligation model has an effect on the outcome of the observed sensory abnormalities.

Quinone bioreductive prodrugs as delivery agents.

Quinone bioreductive prodrugs were developed to target the hypoxic or the reductase- rich population of solid tumours. The mechanism of their selective activation is based on their ability to convert the quinone sub-structure to their activated semiquinone or hydroquinone species affording the active species. Recent studies on their biochemical activation process have resulted in their development as delivery agents that can effectively release a potent (but not necessarily a cytotoxic) agent under hypoxic/reductive conditions. This technology platform is currently being used to design/identify, and synthesise novel quinone bioreductive delivery agents to target cancer and other diseases where hypoxia and/or reductive enzymes play a major pathophysiological role.

International radiation safety standards.

The system of international safety standards of the International Atomic Energy Agency (IAEA) is described with explanations as to the purpose of each level of the hierarchy. There is a system of committees that advise the IAEA and approve the safety standards and one of these committees is the Radiation Safety Standards Committee (RASSC). The Committee meets twice a year (the last meeting was 24-27 March 2003) and this note outlines the current situation with respect to published safety standards documents at the fundamentals, requirements and guides levels and the status of documents under development. Guidance on how to find more information and to keep up to date on the development of documents is provided. The forward plans of the IAEA in this area are discussed briefly.