Resistance of calves to gastrointestinal parasites

International audienc

Computational approaches to shed light on molecular mechanisms in biological processes

Computational approaches based on Molecular Dynamics simulations, Quantum Mechanical methods and 3D Quantitative Structure-Activity Relationships were employed by computational chemistry groups at the University of Milano-Bicocca to study biological processes at the molecular level. The paper reports the methodologies adopted and the results obtained on Aryl hydrocarbon Receptor and homologous PAS proteins mechanisms, the properties of prion protein peptides, the reaction pathway of hydrogenase and peroxidase enzymes and the defibrillogenic activity of tetracyclines. © Springer-Verlag 2007

Supra-Molecular Assemblies of ORAI1 at Rest Precede Local Accumulation into Puncta after Activation

The Ca2+ selective channel ORAI1 and endoplasmic reticulum (ER)-resident STIM proteins form the core of the channel complex mediating store operated Ca2+ entry (SOCE). Using liquid phase electron microscopy (LPEM), the distribution of ORAI1 proteins was examined at rest and after SOCEactivation at nanoscale resolution. The analysis of over seven hundred thousand ORAI1 positions revealed a number of ORAI1 channels had formed STIM-independent distinct supra-molecular clusters. Upon SOCE activation and in the presence of STIM proteins, a fraction of ORAI1 assembled in micron-sized two-dimensional structures, such as the known puncta at the ER plasma membrane contact zones, but also in divergent structures such as strands, and ring-like shapes. Our results thus question the hypothesis that stochastically migrating single ORAI1 channels are trapped at regions containing activated STIM, and we propose instead that supra-molecular ORAI1 clusters fulfill an amplifying function for creating dense ORAI1 accumulations upon SOCE-activation

Anti-CD47 antibodies induce phagocytosis of live, malignant B cells by macrophages via the Fc domain, resulting in cell death by phagoptosis

When expressed on the surface of cells, CD47 inhibits phagocytosis of these cells by phagocytes. Most human cancers overexpress CD47, and antibodies to CD47 have shown a remarkable ability to clear a range of cancers in animal models. However, the mechanism by which these antibodies cause cancer cell death is unclear. We find that CD47 is expressed on the surface of three B-cell lines from human malignancies: 697 (pre-B-ALL lymphoblasts), Ramos and DG-75 (both mature B-cells, Burkitt's lymphoma), and anti-CD47 antibodies greatly increase the phagocytosis of all three cell line by macrophages. In the presence of macrophages, the antibodies cause clearance of the lymphoblasts within hours, but in the absence of macrophages, the antibodies have no effect on lymphoblast viability. Macrophages engulf viable lymphoblasts containing mitochondria with a normal membrane potential, but following engulfment the mitochondrial membrane potential is lost indicating a loss of viability. Inhibition of phagocytosis protects lymphoblasts from death indicating that phagocytosis is required for anti-CD47 mediated cell death. Blocking either the antibody Fc domain or Fc receptors inhibits antibody-induced phagocytosis. Antibodies against cell surface markers CD10 or CD19 also induced Fc-domain-dependent phagocytosis, but at a lower level commensurate with expression. Thus, phagoptosis may contribute to the efficacy of a number of therapeutic antibodies used in cancer therapy, as well as potentially endogenous antibodies. We conclude that anti-CD47 antibodies induce phagocytosis by binding CD47 on lymphoblast and Fc receptors on macrophages, resulting in cell death by phagocytosis, i.e. phagoptosis.This research was funded by the Leukaemia & Lymphoma Research (Bloodwise, 10027) UK

Infected Necrosis in Severe Pancreatitis - Combined Nonsurgical Multi-Drainage with Directed Transabdominal High-Volume Lavage in Critically Ill Patients

Background: Infection of pancreatic necrosis is a life-threatening complication during the course of acute pancreatitis. In critically ill patients, surgical or extended endoscopic interventions are associated with high morbidity and mortality. Minimally invasive procedures on the other hand are often insufficient in patients suffering from large necrotic areas containing solid or purulent material. We present a strategy combining percutaneous and transgastric drainage with continuous high-volume lavage for treatment of extended necroses and liquid collections in a series of patients with severe acute pancreatitis. Patients and Methods: Seven consecutive patients with severe acute pancreatitis and large confluent infected pancreatic necrosis were enrolled. In all cases, the first therapeutic procedure was placement of a CT-guided drainage catheter into the fluid collection surrounding peripancreatic necrosis. Thereafter, a second endosonographically guided drainage was inserted via the gastric or the duodenal wall. After communication between the separate drains had been proven, an external to internal directed high-volume lavage with a daily volume of 500 ml up to 2,000 ml was started. Results: In all patients, pancreatic necrosis/liquid collections could be resolved completely by the presented regime. No patient died in the course of our study. After initiation of the directed high-volume lavage, there was a significant clinical improvement in all patients. Double drainage was performed for a median of 101 days, high-volume lavage for a median of 41 days. Several endoscopic interventions for stent replacement were required (median 8). Complications such as bleeding or perforation could be managed endoscopically, and no subsequent surgical therapy was necessary. All patients could be dismissed from the hospital after a median duration of 78 days. Conclusion: This approach of combined percutaneous/endoscopic drainage with high-volume lavage shows promising results in critically ill patients with extended infected pancreatic necrosis and high risk of surgical intervention. Neither surgical nor endoscopic necrosectomy was necessary in any of our patients. Copyright (C) 2009 S. Karger AG, Basel and IA

Tolvaptan use during hyperhydration in paediatric intracranial lymphoma with SIADH

An 11-year-old boy developed severe syndrome of inappropriate antidiuretic hormone secretion (SIADH) after diagnosis of an intracranial B-cell lymphoma. His sodium levels dropped to 118-120 mmol/L despite 70% fluid restriction. For chemotherapy, he required hyperhydration, which posed a challenge because of severe hyponatraemia. Tolvaptan is an oral, highly selective arginine vasopressin V2-receptor antagonist, which has been licensed in adults for the management of SIADH and has been used in treating paediatric heart failure. Tolvaptan gradually increased sodium levels and allowed liberalisation of fluid intake and hyperhydration. Tolvaptan had profound effects on urinary output in our patient with increases up to 8 mL/kg/h and required close monitoring of fluid balance, frequent sodium measurements and adjustments to intake. After hyperhydration, tolvaptan was stopped, and the lymphoma went into remission with reversal of SIADH. We report one of the first uses of tolvaptan in a child with SIADH, and it was an effective and safe treatment to manage severe SIADH when fluid restriction was not possible or effective. However, meticulous monitoring of fluid balance and sodium levels and adjustments of fluid intake are required to prevent rapid sodium changes. LEARNING POINTS: Tolvaptan can be used in paediatric patients with SIADH to allow hyperhydration during chemotherapy.Tolvaptan has profound effects on urinary output and meticulous monitoring of fluid balance and sodium levels is therefore warranted.Tolvaptan was well tolerated without significant side effects.This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector

Preoperative radiological characterization of hepatic angiomyolipoma using magnetic resonance imaging and contrast-enhanced ultrasonography: a case report

<p>Abstract</p> <p>Introduction</p> <p>A hepatic angiomyolipoma is a rare benign tumor of the liver composed of a mixture of smooth muscle cells, blood vessels and a variable amount of adipose tissue. Differentiating them from malignant liver tumors can often be very difficult.</p> <p>Case presentation</p> <p>We report the case of a 43-year-old Caucasian man presenting with a large liver mass in the right lobe. The results of magnetic resonance imaging and contrast-enhanced ultrasonography were consistent with a well-demarcated adipose tissue- containing tumor, showing prolonged hyperperfusion in comparison with the surrounding liver tissue. Surgery was performed and the diagnosis of hepatic angiomyolipoma was made with histopathology.</p> <p>Conclusion</p> <p>Preoperative radiological characterization using magnetic resonance imaging and contrast-enhanced ultrasonography may improve diagnostic accuracy of hepatic angiomyolipoma. Identification of smooth muscle cells, blood vessels and adipose tissue with a positive immunohistochemical reaction for HMB-45 is the final evidence for an angiomyolipoma.</p

Optimization of sample preparation and instrumental parameters for the rapid analysis of drugs of abuse in hair samples by MALDI-MS/MS imaging

Matrix-assisted laser desorption/ionization-mass spectrometry imaging (MALDI-MSI) has been employed to rapidly screen longitudinally sectioned drug user hair samples for cocaine and its metabolites using continuous raster imaging. Optimization of the spatial resolution and raster speed were performed on intact cocaine contaminated hair samples. The optimized settings (100 × 150 μm at 0.24 mm/s) were subsequently used to examine longitudinally sectioned drug user hair samples. The MALDI-MS/MS images showed the distribution of the most abundant cocaine product ion at m/z 182. Using the optimized settings, multiple hair samples obtained from two users were analyzed in approximately 3 h: six times faster than the standard spot-to-spot acquisition method. Quantitation was achieved using longitudinally sectioned control hair samples sprayed with a cocaine dilution series. A multiple reaction monitoring (MRM) experiment was also performed using the 'dynamic pixel' imaging method to screen for cocaine and a range of its metabolites, in order to differentiate between contaminated hairs and drug users. Cocaine, benzoylecgonine, and cocaethylene were detectable, in agreement with analyses carried out using the standard LC-MS/MS method. Graphical Abstract ᅟ

Assessment of HIF-1α expression and release following endothelial injury in-vitro and in-vivo

Background: Endothelial injury is an early and enduring feature of cardiovascular disease. Inflammation and hypoxia may be responsible for this, and are often associated with the up-regulation of several transcriptional factors that include Hypoxia Inducible Factor-1 (HIF-1). Although it has been reported that HIF-1α is detectable in plasma, it is known to be unstable. Our aim was to optimize an assay for HIF-1α to be applied to in vitro and in vivo applications, and to use this assay to assess the release kinetics of HIF-1 following endothelial injury. Methods: An ELISA for the measurement of HIF in cell-culture medium and plasma was optimized, and the assay used to determine the best conditions for sample collection and storage. The results of the ELISA were validated using Western blotting and immunohistochemistry (IHC). In vitro, a standardized injury was produced in a monolayer of rat aortic endothelial cells (RAECs) and intracellular HIF-1α was measured at intervals over 24 hours. In vivo, a rat angioplasty model was used. The right carotid artery was injured using a 2F Fogarty balloon catheter. HIF-1α was measured in the plasma and in the arterial tissue (0, 1, 2, 3 and 5 days post injury). Results: The HIF-1α ELISA had a limit of detection of 2.7 pg/ mL and was linear up to 1000 pg/ mL. Between and within-assay coefficient of variation values were less than 15%. HIF-1α was unstable in cell lysates and plasma, and it was necessary to add a protease inhibitor immediately after collection, and to store samples at -800C prior to analysis. The dynamics of HIF-1α release were different for the in vitro and in vivo models. In vitro, HIF-1α reached maximum concentrations approximately 2h post injury, whereas peak values in plasma and tissues occurred approximately 2 days post injury, in the balloon injury model. Conclusion: HIF-1α can be measured in plasma, but this requires careful sample collection and storage. The carotid artery balloon injury model is associated with the transient release of HIF-1α into the circulation that probably reflects the hypoxia induced in the artery wall