Liver transplantation: a life-saving procedure following amatoxin mushroom poisoning

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A proteomic approach to investigating gene cluster expression and secondary metabolite functionality in Aspergillus fumigatus.

A combined proteomics and metabolomics approach was utilised to advance the identification and characterisation of secondary metabolites in Aspergillus fumigatus. Here, implementation of a shotgun proteomic strategy led to the identification of non-redundant mycelial proteins (n = 414) from A. fumigatus including proteins typically under-represented in 2-D proteome maps: proteins with multiple transmembrane regions, hydrophobic proteins and proteins with extremes of molecular mass and pI. Indirect identification of secondary metabolite cluster expression was also achieved, with proteins (n = 18) from LaeA-regulated clusters detected, including GliT encoded within the gliotoxin biosynthetic cluster. Biochemical analysis then revealed that gliotoxin significantly attenuates H2O2-induced oxidative stress in A. fumigatus (p>0.0001), confirming observations from proteomics data. A complementary 2-D/LC-MS/MS approach further elucidated significantly increased abundance (p<0.05) of proliferating cell nuclear antigen (PCNA), NADH-quinone oxidoreductase and the gliotoxin oxidoreductase GliT, along with significantly attenuated abundance (p<0.05) of a heat shock protein, an oxidative stress protein and an autolysis-associated chitinase, when gliotoxin and H2O2 were present, compared to H2O2 alone. Moreover, gliotoxin exposure significantly reduced the abundance of selected proteins (p<0.05) involved in de novo purine biosynthesis. Significantly elevated abundance (p<0.05) of a key enzyme, xanthine-guanine phosphoribosyl transferase Xpt1, utilised in purine salvage, was observed in the presence of H2O2 and gliotoxin. This work provides new insights into the A. fumigatus proteome and experimental strategies, plus mechanistic data pertaining to gliotoxin functionality in the organism

Severe influenza A H7N9 pneumonia with rapid virological response to intravenous zanamivir

postprin

COPD Exacerbations, Air Pollutant Fluctuations, and Individual-Level Factors in the Pandemic Era

Sahar Mikaeeli,1– 3 Dany Doiron,1 Jean Bourbeau,1,4,5 Pei Zhi Li,1 Shawn D Aaron,6 Kenneth R Chapman,7 Paul Hernandez,8 François Maltais,9 Darcy D Marciniuk,10 Denis E O’Donnell,11 Don D Sin,12 Brandie L Walker,13 Wan C Tan,12 Simon Rousseau,3 Bryan A Ross1,4,5 On behalf of the CanCOLD Collaborative Research Group and the Canadian Respiratory Research Network1Respiratory Epidemiology and Clinical Research Unit, Centre for Outcomes Research and Evaluation, Research Institute of the McGill University Health Centre (RI-MUHC), Montreal, Quebec, Canada; 2Division of Experimental Medicine, Department of Medicine, McGill University Health Centre, Montreal, Quebec, Canada; 3Meakins-Christie Laboratories, Research Institute at McGill University Health Centre, Montreal, Canada; 4Division of Respiratory Medicine, Department of Medicine, McGill University Health Centre, Montreal, Quebec, Canada; 5Montreal Chest Institute, McGill University Health Centre, Montreal, QC, Canada; 6The Ottawa Hospital Research Institute, University of Ottawa, Ottawa, Ontario, Canada; 7Toronto General Hospital Research Institute, University of Toronto, Toronto, Ontario, Canada; 8Department of Medicine, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada; 9Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec, Québec, Canada; 10Respiratory Research Centre and Division of Respirology, Critical Care and Sleep Medicine; University of Saskatchewan, Saskatoon, Saskatchewan, Canada; 11Department of Medicine, Queen’s University, Kingston, Ontario, Canada; 12Centre for Heart Lung Innovation, St. Paul’s Hospital, University of British Columbia, Vancouver, British Columbia, Canada; 13Department of Medicine, University of Calgary, Calgary, Alberta, CanadaCorrespondence: Bryan A Ross, Respiratory Epidemiology and Clinical Research Unit (RECRU), Research Institute of the McGill University Health Centre (RI-MUHC), 5252 De Maisonneuve, Room 3D.57, Montreal, QC, H4A 3S5, Canada, Tel +1-514-843-1465, Email [email protected]: Pandemic-era associations between air pollutant exposures and exacerbations of chronic obstructive pulmonary disease (COPD) are under-explored. Given the considerable observed pandemic-era pollutant fluctuations, these associations were investigated along with possible individual-level risk factors.Patients and Methods: Participants with spirometry-confirmed COPD from Canadian Cohort Obstructive Lung Disease (CanCOLD) were included, with data collected before (“pre-pandemic”) and during (“pandemic”) the COVID-19 pandemic. Nitrogen dioxide (NO2), fine particulate matter (PM2.5), ground-level ozone (O3), total oxidant (Ox) and weather data were obtained from national databases. Associations between each air pollutant and “symptom-based” exacerbations (increased dyspnea or sputum volume/purulence ≥ 48hrs) and “event-based” exacerbations (“symptom-based” plus requiring antibiotics, corticosteroids, or unscheduled healthcare use) were estimated in separate models. Generalized estimating equations (GEE) models were reported as rate ratios (RRs) per interquartile range (IQR) increment in pollutant concentration with 95% confidence intervals (95% CIs).Results: NO2, PM2.5, and Ox (NO2+O3) concentrations (but not O3) fell significantly during the pandemic. In the 673 participants with COPD included, both symptom-based and event-based exacerbation rates were likewise significantly higher during the pre-pandemic period. During the pre-pandemic period, Ox was positively associated with symptom-based exacerbations (RR: 1.21 [1.08,1.36]). During the pandemic period, Ox was positively associated with symptom-based (1.46 [1.13,1.89]) and event-based (1.43 [1.00,2.05]) exacerbations. Fewer self-reported pandemic protective behaviors, and higher viral infectious symptoms, were also associated with exacerbations. In stepwise multivariable risk-factor analyses, female gender (1.23 [1.04,1.45] and 1.41 [1.13,1.76]) and co-morbid asthma (1.65 [1.34,2.03] and 1.54 [1.19,2.00]) were associated with symptom-based and event-based exacerbations, respectively, blood eosinophils (1.42 [1.10,1.84]) were associated with event-based exacerbations, and each IQR increment in Ox was associated with symptom-based exacerbations (1.31 [1.06,1.61]).Conclusion: Ox exposure was consistently associated with symptom-based COPD exacerbations, and female gender, co-morbid asthma, and blood eosinophilia were found to be relevant risk factors.Plain language summary: Previous research has identified air pollution as a relevant non-infectious trigger for episodic ‘lung attacks’, referred to as exacerbations, in patients living with chronic obstructive pulmonary disease (COPD). Very few studies, however, have studied this relationship during the COVID-19 pandemic. During that time, there were large fluctuations in key forms of air pollution (air pollutants). The few studies available used population-level approaches and relied on hospital administrative coding of visits to classify the disease and to identify exacerbation events. This approach may lead to potentially missing clinically important non-severe events and may limit individual-level risk factor assessment around this period.This study was conducted in participants with COPD as confirmed by the gold-standard test, spirometry, who were living in 9 Canadian cities across 6 provinces. The results showed that while the air pollutants nitrogen dioxide (NO2), fine particulate matter (PM2.5), and total oxidant (Ox) concentrations were all notably higher before the pandemic (pre-pandemic), only ambient Ox concentration was consistently associated with exacerbations. This relationship was seen across both pre-pandemic and pandemic periods. Female gender, co-morbid asthma, and eosinophilia were identified as notable risk factors for exacerbations and were effect modifiers for the association between Ox exposure and exacerbations. This study adds to a very limited existing literature on the relationship between air pollutant fluctuations and exacerbations of COPD around the pandemic era and highlights important risk factors to guide targeted public health and exposure response interventions.Keywords: Chronic obstructive pulmonary disease, acute exacerbations of chronic obstructive pulmonary disease, ambient air pollution, COVID-19 pandemic, total oxidant concentratio

Recombinant Expression, Purification, and Functional Characterisation of Connective Tissue Growth Factor and Nephroblastoma-Overexpressed Protein

The CCN family of proteins, especially its prominent member, the Connective tissue growth factor (CTGF/CCN2) has been identified as a possible biomarker for the diagnosis of fibrotic diseases. As a downstream mediator of TGF-β1 signalling, it is involved in tissue scarring, stimulates interstitial deposition of extracellular matrix proteins, and promotes proliferation of several cell types. Another member of this family, the Nephroblastoma-Overexpressed protein (NOV/CCN3), has growth-inhibiting properties. First reports further suggest that these two CCN family members act opposite to each other in regulating extracellular matrix protein expression and reciprocally influence their own expression when over-expressed. We have established stable HEK and Flp-In-293 clones as productive sources for recombinant human CCN2/CTGF. In addition, we generated an adenoviral vector for recombinant expression of rat NOV and established protocols to purify large quantities of these CCN proteins. The identity of purified human CCN2/CTGF and rat CCN3/NOV was proven by In-gel digest followed by ESI-TOF/MS mass spectrometry. The biological activity of purified proteins was demonstrated using a Smad3-sensitive reporter gene and BrdU proliferation assay in permanent cell line EA•hy 926 cells. We further demonstrate for the first time that both recombinant CCN proteins are N-glycosylated

Mitochondrial Morphogenesis, Dendrite Development, and Synapse Formation in Cerebellum Require both Bcl-w and the Glutamate Receptor δ2

Bcl-w belongs to the prosurvival group of the Bcl-2 family, while the glutamate receptor δ2 (Grid2) is an excitatory receptor that is specifically expressed in Purkinje cells, and required for Purkinje cell synapse formation. A recently published result as well as our own findings have shown that Bcl-w can physically interact with an autophagy protein, Beclin1, which in turn has been shown previously to form a protein complex with the intracellular domain of Grid2 and an adaptor protein, nPIST. This suggests that Bcl-w and Grid2 might interact genetically to regulate mitochondria, autophagy, and neuronal function. In this study, we investigated this genetic interaction of Bcl-w and Grid2 through analysis of single and double mutant mice of these two proteins using a combination of histological and behavior tests. It was found that Bcl-w does not control the cell number in mouse brain, but promotes what is likely to be the mitochondrial fission in Purkinje cell dendrites, and is required for synapse formation and motor learning in cerebellum, and that Grid2 has similar phenotypes. Mice carrying the double mutations of these two genes had synergistic effects including extremely long mitochondria in Purkinje cell dendrites, and strongly aberrant Purkinje cell dendrites, spines, and synapses, and severely ataxic behavior. Bcl-w and Grid2 mutations were not found to influence the basal autophagy that is required for Purkinje cell survival, thus resulting in these phenotypes. Our results demonstrate that Bcl-w and Grid2 are two critical proteins acting in distinct pathways to regulate mitochondrial morphogenesis and control Purkinje cell dendrite development and synapse formation. We propose that the mitochondrial fission occurring during neuronal growth might be critically important for dendrite development and synapse formation, and that it can be regulated coordinately by multiple pathways including Bcl-2 and glutamate receptor family members