Cluster Grid based Response-time analysis module for the PIPE Tool.

Generalized Stochastic Petri Nets (GSPNs) are a widely used high-level formalism used for modelling discrete-event systems. The Platform Independent Petri net Editor (PIPE) is an open source software project that allows creation, analysis and simulation of Petri Nets. This tool paper presents a PIPE module for response-time analysis of a Petri net’s underlying Continuous Time Markov Chain (CTMC). Jobs are submitted via a web interface, from within PIPE or from a browser. The parallel computations are run using Grid Engine on a cluster hosted at Imperial College London. 1

Intermolecular interaction and solid state characterization of abietic acid/chitosan solid dispersions possessing antimicrobial and antioxidant properties

The aim of this work was to prepare and characterize solid dispersions of abietic acid (AB) and chitosan (CS) to investigate how formulation of the mixture may help in the battle against microbial colonization in different areas, such as the biomedical field or the food industry. Solid dispersions were characterized by differential scanning calorimetry, infrared spectroscopy, Raman spectroscopy, polarized optical microscopy, zeta potential and size analysis. The data showed that the dispersion/solvent evaporation method formed solid dispersions in which abietic acid was molecularly dispersed in the carrier. A synergistic effect between the two components in terms of antioxidant and antimicrobial properties was found, especially in the formulations obtained with 1/1 AB/CS molar ratio. Interestingly, the aggregation state (amorphous/crystalline) of AB seemed to affect the antimicrobial activity of the formulation, suggesting increased bioactivity when the drug was in the amorphous state. These findings, together with the demonstrated biocompatibility of the formulations, seem to open promising perspectives for a successful application of the developed AB/CS formulations in the biomedical field or in the food industry

Cytosolic chaperones influence the fate of a toxin dislocated from the endoplasmic reticulum

The plant cytotoxin ricin enters target mammalian cells by receptor-mediated endocytosis and undergoes retrograde transport to the endoplasmic reticulum (ER). Here, its catalytic A chain (RTA) is reductively separated from the cell-binding B chain, and free RTA enters the cytosol where it inactivates ribosomes. Cytosolic entry requires unfolding of RTA and dislocation across the ER membrane such that it arrives in the cytosol in a vulnerable, nonnative conformation. Clearly, for such a dislocated toxin to become active, it must avoid degradation and fold to a catalytic conformation. Here, we show that, in vitro, Hsc70 prevents aggregation of heat-treated RTA, and that RTA catalytic activity is recovered after chaperone treatment. A combination of pharmacological inhibition and cochaperone expression reveals that, in vivo, cytosolic RTA is scrutinized sequentially by the Hsc70 and Hsp90 cytosolic chaperone machineries, and that its eventual fate is determined by the balance of activities of cochaperones that regulate Hsc70 and Hsp90 functions. Cytotoxic activity follows Hsc70-mediated escape of RTA from an otherwise destructive pathway facilitated by Hsp90. We demonstrate a role for cytosolic chaperones, proteins typically associated with folding nascent proteins, assembling multimolecular protein complexes and degrading cytosolic and stalled, cotranslocational clients, in a toxin triage, in which both toxin folding and degradation are initiated from chaperone-bound states

Cytosolic chaperones influence the fate of a toxin dislocated from the endoplasmic reticulum

The plant cytotoxin ricin enters target mammalian cells by receptor-mediated endocytosis and undergoes retrograde transport to the endoplasmic reticulum (ER). Here, its catalytic A chain (RTA) is reductively separated from the cell-binding B chain, and free RTA enters the cytosol where it inactivates ribosomes. Cytosolic entry requires unfolding of RTA and dislocation across the ER membrane such that it arrives in the cytosol in a vulnerable, nonnative conformation. Clearly, for such a dislocated toxin to become active, it must avoid degradation and fold to a catalytic conformation. Here, we show that, in vitro, Hsc70 prevents aggregation of heat-treated RTA, and that RTA catalytic activity is recovered after chaperone treatment. A combination of pharmacological inhibition and cochaperone expression reveals that, in vivo, cytosolic RTA is scrutinized sequentially by the Hsc70 and Hsp90 cytosolic chaperone machineries, and that its eventual fate is determined by the balance of activities of cochaperones that regulate Hsc70 and Hsp90 functions. Cytotoxic activity follows Hsc70-mediated escape of RTA from an otherwise destructive pathway facilitated by Hsp90. We demonstrate a role for cytosolic chaperones, proteins typically associated with folding nascent proteins, assembling multimolecular protein complexes and degrading cytosolic and stalled, cotranslocational clients, in a toxin triage, in which both toxin folding and degradation are initiated from chaperone-bound states

Lung function in South African children with cystic fibrosis

Objective: To determine the pattern of lung function in stable cystic fibrosis (CF) patients and to investigate the relationship of abnormal lung function to demographic variables, CF genotype and pulmonary colonisation with Pseudomonas aeruginosa (PA)Design: A descriptive study done at the CF clinic at Red Cross War Memorial Children's Hospital in Cape Town.Methods: Data were recorded and pulmonary function testing (PFT) was performed in 42 CF patients.Results: 29 patients (69%) had mild disease,. while 11 (26%) and 2 (5%) had moderate and severe disease respectively. Twenty-four patients (57'%) demonstrated lower airway obstruction (LAO). Patients with moderate or severe disease were significantly older than those with mild disease (13.3 (3.7) years (mean (SD)) compared with 11.1 (3.0) years (t =2.1; P =OM)). PA colonisation status differed significantly with the pattern of lung function (X2 =6.6; P = 0.04) and severity of lung disease (X2=12.6; P =0.002.). Nine (35%) of the 26 patients tested before and after broncbodilator therapy showed a positive response.Conclusion: The majority of patients had mildly impaired or normal lung function, with LAO predominating. A minority of patients were bronchodilator-responsive. PA colonisation may be associated with the development of abnormal lung function and more severe pulmonary disease.

Resuscitation in major burns: The problem of fluid creep

We have noticed an alarming tendency for burn patients to be over-resuscitated, and we believe that protocols should be reviewed in light of our own and international experience. We recently managed an 8-year-old boy with 52% fullthickness burns, who developed abdominal and limb compartment syndromes during the period of resuscitation. The fluid volumes infused above those calculated were 1.6 and 4.7 litres on days 1 and 2 respectively to maintain haemodynamic stability and urine output above 2 ml/kg/h. Within 48 hours of the injury, he developed poor peripheral perfusion and a distended abdomen; the intravesical pressure was 32 mmHg and the abdominal perfusion pressure 23 mmHg. Abdominal decompression and three limb fasciotomies were performed, but small-bowel and lower limb muscle necrosis had developed. The patient deteriorated rapidly despite inotropic support and died

Multicomponent analysis of the tumour microenvironment reveals low CD8 T cell number, low stromal caveolin-1 and high tenascin-C and their combination as significant prognostic markers in non-small cell lung cancer

The complex interplay of the tumour microenvironment (TME) and its role in disease progression and response to therapy is poorly understood. The majority of studies to date focus on individual components or molecules within the TME and so lack the power correlative analysis. Here we have performed a multi-parameter analysis of the TME in 62 resectable non-small cell lung cancer (NSCLC) specimens detailing number and location of immune infiltrate, assessing markers of cancer-associated fibroblasts, caveolin-1 and tenascin-C, and correlating with clinicopathological details, as well as markers of disease progression such as epithelial-to-mesenchymal transition (EMT). The influence of individual parameters on overall survival was determined in univariate and multivariate analysis and the combination of risk factors and interplay between components analysed. Low numbers of CD8 T cells, low stromal levels of caveolin-1 or high levels of tenascin-C were significant prognostic markers of decreased overall survival in both univariate and multivariate analysis. Patients with two or more risk factors had dramatically reduced overall survival and those with all three a median survival of just 7.5 months. In addition, low levels of tumour E-cadherin correlated with reduced immune infiltrate into the tumour nests, possibly linking EMT to the avoidance of CD8 T cell control. The multicomponent approach has allowed identification of the dominant influences on overall survival, and exploration of the interplay between different components of the TME in NSCLC

Doing research with children and young people who do not use speech for communication

Despite emphasis in policy on participation of disabled children, we still know relatively little about how to obtain the views of disabled children with significant communication impairment and their views are often overlooked in planning and service provision. This article describes how the views of children who do not use speech were accessed in research aiming to identify disabled children and young people's priorities regarding outcomes of social care and support services. The main challenge was to develop a method that was reliable, non-threatening, enjoyable and relevant to individual children, as well as enabling children to think beyond their everyday life and express what they aspire to