36 research outputs found
Online black-box failure prediction for mission critical distributed systems
No full textThis paper introduces a novel approach to failure prediction for mission critical distributed systems that has the distinctive features to be black-box, non-intrusive and online. The approach combines Complex Event Processing (CEP) and Hidden Markov Models (HMM) so as to analyze symptoms of failures that might occur in the form of anomalous conditions of performance metrics identified for such purpose. The paper describes an architecture named CASPER, based on CEP and HMM, that relies on sniffed information from the communication network of a mission critical system, only, for predicting anomalies that can lead to software failures. An instance of CASPER has been implemented, trained and tuned to monitor a real Air Traffic Control (ATC) system. An extensive experimental evaluation of CASPER is presented. The obtained results show (i) a very low percentage of false positives over both normal and under stress conditions, and (ii) a sufficiently high failure prediction time that allows the system to apply appropriate recovery procedures. © 2012 Springer-Verlag
Tenogenic differentiation protocol in xenogenic-free media enhances tendon-related marker expression in ASCs
No full textAdipose-derived stem cells (ASCs) are multipotent and immune-privileged mesenchymal cells, making them ideal candidates for therapeutic purposes to manage tendon disorders. Providing safe and regulated cell therapy products to patients requires adherence to good manufacturing practices. To this aim we investigated the in vitro tenogenic differentiation potential of ASCs using a chemically defined serum-free medium (SF) or a xenogenic-free human pooled platelet lysate medium (hPL) suitable for cell therapy and both supplemented with CTGF, TGFβ-3, BMP-12 and ascorbic acid (AA) soluble factors. Human ASCs were isolated from 4 healthy donors and they were inducted to differentiate until 14 days in both hPL and SF tenogenic media (hPL-TENO and SF-TENO). Cell viability and immunophenotype profile were analysed to evaluate mesenchymal stem cell (MSC) characteristics in both xenogenic-free media. Moreover, the expression of stemness and tendon-related markers upon cell differentiation by RT-PCR, protein staining and cytofluorimetric analysis were also performed. Our results showed the two xenogenic-free media well support cell viability of ASCs and maintain their MSC nature as demonstrated by their typical immunophenototype profile and by the expression of NANOG, OCT4 and Ki67 genes. Moreover, both hPL-TENO and SF-TENO expressed significant high levels of the tendon-related genes SCX, COL1A1, COL3A1, COMP, MMP3 and MMP13 already at early time points in comparison to the respective controls. Significant up-regulations in scleraxis, collagen and tenomodulin proteins were also demonstrated at in both differentiated SF and hPL ASCs. In conclusion, we demonstrated firstly the feasibility of both serum and xenogenic-free media tested to culture ASCs moving forward the GMP-compliant approaches for clinical scale expansion of human MSCs needed for therapeutical application of stem cells. Moreover, a combination of CTGF, BMP-12, TGFβ3 and AA factors strongly and rapidly induce human ASCs to differentiate into tenocyte-like cells
Pulmonary alveolar microlithiasis
No full textPulmonary Alveolar Microlithiasis (PAM) is a rare disease characterized by calcium salt deposits within the alveoli. In the literature, about 700 cases have been published up to April 2012. The disease develops slowly and is characterized by a progressive lung involvement, starting from the lower lobes with extension to the middle and upper lung zones. The chest radiograph gives a picture sandstorm-like which is often the first sign in the absence of clinical symptoms. The characteristic high resolution computed tomography (HRCT) is pathognomonic of the disease and the diagnosis is made, especially if the microliths are found in the BAL. Rarely, a biopsy is necessary for diagnosis.
Recently in these subjects was highlighted a mutation of SLC34A2 gene, which regulates the cotransport of sodium and phosphate within alveolar type II cells. It is thought that the gene mutation compromises the normal production of the protein which is involved in the clearance of the phosphorus ion from the alveolar spaces and this alteration causes the progressive accumulation of microliths. In this chapter, the incidence of the disease in the literature, the current pathogenetic hypotheses, the clinical features, the diagnostic criteria, and finally, the current therapeutic attempts are reviewed.
characterized by the progressive accumulation of calcifi c
elements, the microliths or calcospherites, into the alveolar
spaces
Homeodomain-interacting protein kinase2 in human idiopathic pulmonary fibrosis
No full textHomeodomain-interacting protein kinase 2 (Hipk2) is an emerging player in cell response to genotoxic agents that contributes to the cell's decision between cell cycle arrest or apoptosis. HIPK2 acts as co-regulator of an increasing number of transcription factors and modulates many different basic cellular processes such as apoptosis, proliferation, DNA damage response, differentiation. Idiopathic pulmonary fibrosis (IPF) is characterized by an anatomical disarrangement of the lung due to fibroblast proliferation, extracellular matrix deposition and lung function impairment. Although the role of inflammation is still debated, attention has been focused on lung cell functions as fibroblast phenotype and activity. Aim of the present study was to analyze the loss of heterozygosity (LOH) at HIPK2 locus 7q32.34 in human lung fibroblasts and the HIPK2 expression in 15 IPF samples and in four primary fibroblast cell cultures isolated from IPF biopsies using semi-quantitative RT-PCR, Western blots and immunohistochemistry. We demonstrated a frequency of LOH in IPF fibroblasts of 46% for the internal D7S6440 microsatellite and 26.6% for the external D7S2468 microsatellite. Furthermore, we demonstrated low HIPK2 protein expression in those fibroblasts from IPF patients that present the HIPK2 LOH. The restoration of HIPK2 expression in IPF derived cells induced a significant reduction of chemoresistance after treatment with cisplatin. The results obtained allow us to hypothesize that HIPK2 dysfunction may play a role in fibroblasts behavior and in IPF pathogenesis. HIPK2 may be considered as a novel potential target for anti-fibrosis therapy. J. Cell. Physiol. 228: 235241, 2013. (c) 2012 Wiley Periodicals, Inc
Amino Acids: Basolateral efflux and extracellular homeostasis control in vivo
No full textIn all living organisms, amino acids (AA) are essential building blocks, metabolites and signaling molecules. To reach their site of action AA need to pass through polar epithelial cells. Because AA cannot freely diffuse through the cell membrane, specific AA carriers ensure their transport across the apical and the basolateral membrane. Despite numerous flux studies and huge progress in the identification and characterization of those carrier proteins, AA transport across the basolateral membrane remains not fully understood. The best characterized basolateral transporters in the small intestine and kidney proximal tubule are the obligatory exchanger (antiporter) Lat2-4F2hc (Slc7a8) and y+Lat1-4F2hc (Slc7a7). Both require the presence of a "one-way transport" (uniporter) to achieve a net AA efflux. TAT1 (Slc16a10) and LAT4 (Slc43a2) fulfill this requirement with different substrate selectivities: TAT1 facilitates the diffusion of aromatic AA, whereas Lat4 transports branched chain AA, aromatic AA, Met and Pro. The functional cooperation between TAT1 and Lat2-4F2hc has previously been shown using the X. laevis oocyte expression system (Ramadan, Camargo et al. 2007). Furthermore, Lat4 could substitute for TAT1 function. Indeed, TAT1 shows the same localization as LAT2-4F2hc in epithelial cells and is further present in muscle sarcolemma and perivenous hepatocytes. The localization of Lat4 is still unknown, whereas the expression of the two uniporters overlaps only partially.
The question addressed in this dissertation is: what is the function of TAT1 and Lat4 in vivo? Using global knock out mouse models we have examined the effect of the absence of the two uniporters on the AA homeostasis and epithelial transport.
By inducing specific aminoaciduria in TAT1 defective mice (tat1-/-) under high protein diet, we could confirm the functional collaboration between TAT1 and LAT2-4F2hc in vivo. Furthermore, tat1-/- showed elevated aromatic AA in plasma, skeletal muscles and kidney, but not in liver. Thus, the absence of TAT1 prevents the AA balancing between plasma and liver and the consequent regulation of AA homeostasis. By means of everted gut sacs and microSPECT/CT imaging, we could show that the impairement of AA epithelial transport was caused by an intracellular accumulation of the AA substrates. The mild phenotype of tat1-/- strongly suggests a compensatory role of Lat4, which is also functionally redundant in the oocyte. In fact, Lat4 defective mice (lat4-/-) prematurely died within the first five days of life. After birth, the normal size, skin color and behavior of lat4-/- pups excluded possible prenatal impairments. Normal suckling behavior further excludes possible severe neurological disability. The reduced growth recorded between 24 and 48 hours indicated a disorder in food intake or in the reabsorption. Further investigations should aim to decipher the cause of death.
In conclusion, this study analyzes the function of two basolateral uniporters for the first time in vivo. We show that the basolateral transport machinery is still functional in the absence of TAT1, whereas it is impaired in the absence of Lat4. Furthermore, we have shown a new important role of TAT1 in the regulation of the aromatic AA concentrations by the coupling of liver cells and blood plasma. Further research should aim to better characterize the in vivo interplay between AA transporters by the study of combinatorial knock out mice. Finally, the results of the different protein rich diets and their influence on the urinary pattern open new questions about the regulation of AA transporters in vivo
Modified expression of peripheral blood lymphocyte muscarinic cholinergic receptors in asthmatic children
No full textLymphocytes possess an independent cholinergic system. We assessed the expression of muscarinic cholinergic receptors in lymphocytes from 49 asthmatic children and 10 age matched controls using Western blot. We demonstrated that CD4+ and CD8+ T cells expressed M2 and M4 muscarinic receptors which density were significantly increased in asthmatic children in comparison with controls. M2 and M4 receptor increase was strictly related with IgE and fraction of exhaled nitric oxide (FeNO) measurements and with impairment in objective measurements of airway obstruction. Increased lymphocyte muscarinic cholinergic receptor expression may concur with lung cholinergic dysfunction and with inflammatory molecular framework in asthma
Efficacy and cost effectiveness of rapid on site examination (ROSE) in management of patients with mediastinal lymphadenopathies
No full textBACKGROUND: The diagnostic and staging approach for the mediastinal lymphadenopathies, with or whithout pulmonary lesions endoscopically visible, is based on transbronchial needle aspiration (TBNA) during fiberoptic bronchoscopy and on mediastinoscopy. One important factor impacting on TBNA sensitivity is the rapid on site cytological examination (ROSE). AIM: The aim of this study was to evaluate the economic impact of TBNA and TBNA + ROSE, in the diagnosis of these lesions. PATIENTS AND METHODS: 120 patients, affected by mediastinal lymphadenopathies suspected for lung cancer, underwent TBNA during fiberoptic bronchoscopy: 60 patients without ROSE (group A) and other 60 with ROSE (group B). Whenever needle aspirations failed to provide diagnosis, the patient underwent mediastinoscopy. The economic impact of the diagnostic process was performed. RESULTS: In group A, 39 patients (65%) obtained a diagnosis with TBNA while 21 patients (35%) required mediastinoscopy. In group B, 48 patients (80%) obtained a diagnosis with TBNA + ROSE, while 12 patients (20%) required mediastinoscopy. With regards to the costs of the procedures performed in the diagnostic process, the use of TBNA with ROSE as first diagnostic approach has saved a considerable amount of euros (19,413) compared to the use of TBNA without ROSE and the combined procedure increased (p < 0.02; chi square test) the sensitivity of TBNA by 15%. CONCLUSIONS: ROSE significantly impacts on the diagnostic yield, as well as on the overall management costs of patients with mediastinal lymphadenopathy, suspected for lung cancer
Decreased expression of autophagic beclin 1 protein in idiopathic pulmonary fibrosis fibroblasts
No full textAutophagy is the main cellular pathway for degradation of long-lived proteins and organelles and regulates cell fate in response to stress. Beclin 1 is a key regulator of this process. In some settings autophagy and apoptosis seem to be interconnected. Recent reports indicate that fibroblasts in idiopathic pulmonary fibrosis (IPF) acquire resistance to apoptosis. Here, we examined the expression of beclin 1, and of the anti apoptotic protein Bcl-2 in human IPF fibroblasts using immunohistochemistry and molecular biology in bioptic sections, in primary cultures of fibroblasts taken from patients with IPF and in fibroblast cell lines. Expression of beclin 1 in fibroblasts from IPF was down-regulated in comparison with fibroblasts from normal lungs while the anti-apoptotic protein Bcl-2 expression was over-expressed. Treatment of fibroblast cell cultures with cisplatin induced a significant increase in beclin 1 and caspase 3 protein levels but a reduction in Bcl-2 expression. These observations were confirmed by the analysis of acid compartments and transmission electron microscopy. Our results demonstrate a modified expression of the apoptotic beclin 1 Bcl-2 proteins in human IPF fibroblasts suggesting the existence of an autophagy/apoptosis system dysfunction.© 2012 Wiley Periodicals, Inc
GMP cryopreservation of adipose-derived mesenchymal stem cells as a service for future medical needs
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