257 research outputs found
Exploration of network alternatives for middleware-centric embedded system design
No full textThe paper addresses the design-space exploration of network alternatives for complex distributed systems of embedded devices, e.g., for smart power grid or telecommunication services. While past research mainly provided efficient programming abstractions and HW/SW simulation tools, this work introduces the network perspective in the verification of different design solutions (e.g., different task decomposition and assignment to network nodes). To do that, network simulation capability has been added to the so-called Abstract Middleware Environment and its effectiveness has been shown experimentally through the design of a wireless sensor network application taken from a real-world case study
I MICRORNA NELLE DISTROFIE MIOTONICHE
No full textMyotonic dystrophy (DM), the most common form of muscular dystrophy in adults, is a dominantly inherited disorder with a peculiar and rare pattern of multisystemic clinical features affecting skeletal muscle, the heart, the eye, and the endocrine system.
Classical DM (first described by Steinert and called Steinert’s disease or DM1) has been identified as an autosomal dominant disorder associated with the presence of an abnormal expansion of a CTG trinucleotide repeat in the 3’ untranslated region of the dystrophia myotonica-protein kinase (DMPK) gene on chromosome 19q13.3. Recently, the expansion of a CCTG tetranucleotide repeat located in the intron of the zinc finger 9 (ZNF9) gene on chromosome 19q13.3 was identified as the mutation responsible for DM2. Both mutations lead to the production of mRNA transcripts containing expanded tri- or tetranucleotide repeats (CUG/CCUG) that are retained in muscle nuclei as ribonuclear inclusions and interact with RNA-binding proteins. These interaction are supposed to disrupt the regulation of alternative splicing of several transcripts. Clinical and molecular parallels strongly support that DM1 and DM2 physiopathology is in part the pathogenic consequence of an RNA gain of toxic function.
MicroRNAs (miRNAs) are short non-coding RNAs (~22 nucleotides) regulating gene expression post-trascriptionally either via the degradation of target mRNAs or the inhibition of protein translation. MicroRNAs have been shown to be involved in a range of biological processes, including myogenesis and muscle regeneration. miRNAs are expressed in cardiac and skeletal muscle, and dysregulated miRNA expression has been correlated with muscle-related diseases, including cardiac hypertrophy, cardiac arrhythmias and muscular dystrophy. Given the emerging roles of microRNAs, we have performed miRNAs expression profiling in DM1 and DM2 patients on muscle biopsies and primary cell culture line. Using fast real time PCR, we report here the differences in miRNAs expression profiles between DM1 (n=15), DM2 (n=9) and control subjects (n=14) of 24 specific miRNAs. miRNAs expression profiles in muscle biopsies of DM1 showed up-regulation of miR-1 and miR-335 and down-regulation of miR-29b, miR-29c, miR-33, establishing a provisional DM1 miRNA signature. A similar trend in miRNA modulation was observed in DM2 patients. However, none of the differences reached statistical significance. In order to assess whether DM1 signature miRNA deregulations and DM2 were cell autonomous events, primary cultures of skeletal muscle satellite cells obtained from either DM1 patients (n=5), DM2 patients (n=5) or controls (n=5) were examined. Myoblasts were cultured in growth factor rich medium and then switched to differentiation medium for five days. DM1 and DM2 myoblasts did not display overt morphological alterations of differentiation. When DM1 miRNA signature was examined, we found that miR-29b was strongly down-modulated in differentiated DM1 myotubes. Conversely, miR-335 was enhanced in DM1 myoblasts in growth medium whereas, upon switching to differentiation medium, it increased to a similar level both in DM1 and control myoblasts. When DM2 myoblasts and myotubes was examined, we not found significance statistical differences in miRNAs expression compared with control myoblasts and myotubes.
Furthermore, The cellular localization of DM1 signature miRNAs was assayed by in situ hybridization on cryostat muscle sections derived from DM1 (n=5) and control (n=5) biopsies using digoxigenin labelled LNA probes. We found that miR-29b, -29c, -33 and -335 were either barely detectable or did not show any overt abnormal localization in DM1 compared to control biopsies. Conversely, miR-1 was readily detectable and its intracellular distribution was disrupted. Specifically, in control samples, miR-1 displayed a peculiar enrichment in the perinuclear area. In DM1 sections, centrally nucleated myofibers, a hallmark of DM1, also exhibited a centralization of miR-1 localization. Very small fibers with nuclear clumps, a typical histopathological DM1 alteration, displayed intense miR-1 staining. Certain myofibers displayed an extremely intense and polarized miR-1 accumulation. Atrophic fibers in DM1 muscle are predominantly type I fibers (slow fibers). Aberrant miR-1 distribution was present both in type I and type II myofibers, as assessed by the myosin heavy chain slow isoform counterstaining.
We also tested the cellular localization of two more muscle specific microRNAs, miR-133b and -206, albeit no overt deregulation of their expression was found in whole skeletal muscle RNAs. In control biopsies we found that miR-133b displayed a perinuclear distribution similar to that of miR-1; in keeping with previous findings, miR-206 was barely detectable. In DM1 patients, both miR-133b and -206 exhibited centralization in centrally nucleated myofibers and accumulated in association to small myofibers nuclear clumps. Finally, miRNAs have been shown not only to inhibit protein translation, but also to induce mRNA degradation, at least for certain targets. Thus, in order to assess whether miRNA deregulation was functionally relevant, we examined the impact of the identified miRNAs deregulation on the expression of their potential target genes in DM1 patients. Specifically, we focused on miR-29, that displayed the strongest deregulation, and miR-1, that plays a crucial role in muscle differentiation. Search of the potential targets was performed using Pictar and Targetscan prediction algorithms, given their reported specificity. Indeed, to maximize the accuracy, only targets identified by both softwares were considered. A sub-pool of the identified targets were analyzed, selected among these with a potential link to DM1 physio-pathology. Specifically, selected genes were previously demonstrated to be expressed in skeletal muscle and to be involved in events such as muscle development, atrophy, arrhythmia and splicing. Potential targets were assayed by qPCR and shows that both miR-29 and miR-1 targets were significantly up-regulated in DM1 patients. In conclusion, we identified a small subset of miRNA whose expression and/or localization were deregulated in DM. These findings may improve our understanding of the molecular mechanisms linking (CTG)n/(CCTG)n expansion to disease and may serve as potential prognostic/diagnostic markers
Common micro-RNA signature in skeletal muscle damage and regeneration induced by Duchenne muscular dystrophy and acute ischemia
No full textThe aim of this work was to identify
micro-RNAs (miRNAs) involved in the pathological
pathways activated in skeletal muscle damage and regeneration
by both dystrophin absence and acute ischemia.
Eleven miRNAs were deregulated both in MDX
mice and in Duchenne muscular dystrophy patients
(DMD signature). Therapeutic interventions ameliorating
the mdx-phenotype rescued DMD-signature alterations.
The significance of DMD-signature changes was
characterized using a damage/regeneration mouse
model of hind-limb ischemia and newborn mice. According
to their expression, DMD-signature miRNAs
were divided into 3 classes. 1) Regeneration miRNAs,
miR-31, miR-34c, miR-206, miR-335, miR-449, and miR-
494, which were induced in MDX mice and in DMD
patients, but also in newborn mice and in newly formed
myofibers during postischemic regeneration. Notably,
miR-206, miR-34c, and miR-335 were up-regulated following
myoblast differentiation in vitro. 2) Degenerative-
miRNAs, miR-1, miR-29c, and miR-135a, that were
down-modulated in MDX mice, in DMD patients, in the
degenerative phase of the ischemia response, and in
newborn mice. Their down-modulation was linked to
myofiber loss and fibrosis. 3) Inflammatory miRNAs,
miR-222 and miR-223, which were expressed in damaged
muscle areas, and their expression correlated with
the presence of infiltrating inflammatory cells. These
findings show an important role of miRNAs in physiopathological
pathways regulating muscle response to
damage and regeneration.—Greco, S., De Simone, M.,
Colussi, C., Zaccagnini, G., Fasanaro, P., Pescatori, M.,
Cardani, R., Perbellini, R., Isaia, E., Sale, P., Meola, G.,
Capogrossi, M. C., Gaetano, C., Martelli, F. Common
micro-RNA signature in skeletal muscle damage and
regeneration induced by Duchenne muscular dystrophy
and acute ischemia
[Chemodectomas of the glomus caroticum]
No full textThe authors review the nature, biological evolution, diagnosis and treatment of carotid body tumors both on the basis of data reported in the literature and in the light of their own experience with a population of 11 carotid body chemodectomas. All patients (except one) were subjected to total resection of the neoplasm. In one case, surgery was confined to a partial resection. Operative mortality was nil, and complications consisted in one case of Claude-Bernard-Horner syndrome, one lesion of the XII cranial nerve and one lesion of the X cranial nerve. Follow-up of the patients (min. 6 months, max. 10 years) has shown no recurrences or metastases
Biological monitoring of occupational exposure to N,N-dimethylacetamide with identification of a new metabolite.
No full textAcute trichloroethylene poisoning by ingestion: clinical and pharmacokinetic aspects
No full textFive hours after ingestion of an unknown amount of trichloroethylene (TCE) a 32-year-old woman was admitted to hospital in deep coma. The neurological condition remained unchanged for 3 days, after which there was an improvement of the central nervous system function. The concentrations of TCE in the blood, which were measured during 7 days after the solvent ingestion, gave us the opportunity to study some toxicokinetic parameters of TCE. Using a physiologically based pharmacokinetic model, the toxicokinetic parameters and blood concentrations of TCE are discussed in relation to the neurological conditions. Moreover the same model has suggested that the alveolar hyperventilation during the first 12 h following the TCE poisoning is the only treatment which may shorten the duration of the poisoning
Liquid-liquid extraction procedure for trace determination of cyclophosphamide in human urine by high-performance liquid chromatography tandem mass spectrometry
No full textA sensitive, specific and accurate high performance liquid chromatography/ionspray-tandem mass spectrometry procedure (HPLC/MS/MS) has been developed to quantify cyclophosphamide in human urine from hospital personnel involved in drug preparation and administration of antineoplastic alkylating agents. This methodology, which includes liquid-liquid extraction with ethylacetate, requires no derivatization procedures, preventing cyclophosphamide (CP) from possible thermal and chemical decomposition reactions. We detected the excretion of this unmetabolized alkylating drug in 50% of all the study participants. The amount of CP ranged from 0.1 ng microL-1 to 1.9 ng microL-1 urine. This methodology was validated by the use of ifosfamide as internal standard. The assay was linear over the range 0 to 3.2 ng microL-1 urine, with a lower limit of quantification of 0.2 microL-1. The limit of detection was assessed at 0.05 ng microL-1 urine. This method is characterized by a coefficient of variation < 10%. Standard calibration curves, obtained on three different days, had correlation coefficients always greater than 0.998. The intra and interday precision were within 11%, and accuracy was in the range 99-103%. The mean extracted recovery assessed at three different concentrations (0.5, 0.8, 3.2 ng microL-1) was always more than 85%. The extraction efficiency of cyclophosphamide from urine samples was also studied at six different pH values (pH 4, 5, 6, 7, 8, 10). The maximum extraction efficiency was obtained when the pH of urine solutions was adjusted to 7.
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