181 research outputs found

    Thermal Analysis of Human Tissues Exposed to Focused Beam THz Radiations

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    The thermal response of human tissues exposed to a focused beam terahertz electromagnetic radiation is evaluated through a combined analytical electromagnetic wave solution and a step-by-step finite element numerical model, which solves Pennes’ bioheat equation. The computational procedure is applied to a three-layer model of the human tissues for wave frequencies ranging from 0.025 THz to 1 THz and compared with a more detailed five-layer model. The effects of the Gaussian beam parameters of the electromagnetic radiation on the temperature elevation are finally evaluated

    Structural characterization of phytotoxic terpenoids from Cestrum parqui.

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    Isolation, chemical characterization and phytotoxicity of nine polyhydroxylated terpenes (five C13 nor-isoprenoids, two sesquiterpenes, a spirostane and a pseudosapogenin) from Cestrum parqui LHerr are reported. In this work we completed the phytochemical investigation of the terpenic fraction of the plant and described the structural elucidation of polar isoprenoids using NMR methods. All the configurations of the compounds have been assigned by NOESY experiments. Four new structures have been identified as (3S,5R,6R,7E,9R)-5,6,9-trihydroxy-3-isopropyloxy-7-megastigmene, 5a-spirostan-3b,12b,15a-triol, and 26-O-(30-isopentanoyl)-b-Dglucopyranosyl- 5a-furost-20(22)-ene-3b,26-diol, and as an unusual tricyclic sesquiterpene. The compounds have been assayed for their phytotoxicity on lettuce at the concentrations ranging between 104 and 107 M. The activities of some compounds were similar to that of the herbicide pendimethalin

    De arbitris.

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    Marca tip.L. gĂłt. --2 tam. --2 col. --69 lĂ­n. --Min. p. inic

    LRRK2 G2019S kinase activity triggers neurotoxic NSF aggregation

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    Parkinson’s disease (PD) is characterized by the progressive degeneration of dopaminergic neurons within the substantia nigra pars compacta and the presence of protein aggregates in surviving neurons. LRRK2 G2019S mutation is one of the major determinants of familial PD cases and leads to late-onset PD with pleomorphic pathology, including alpha-synuclein accumulation and deposition of protein inclusions. We demonstrated that LRRK2 phosphorylates N-ethylmaleimide sensitive factor (NSF). We observed aggregates containing NSF in basal ganglia specimens from G2019S carrier PD patients and in cellular and animal models expressing the LRRK2 G2019S variant. We found that LRRK2 G2019S kinase activity induces the accumulation of NSF in toxic aggregates. Noteworthy, the induction of autophagy cleared NSF aggregation and rescued motor and cognitive impairment observed in aged hG2019S BAC mice. We suggest that LRRK2 G2019S pathological phosphorylation hampers substrate catabolism, thus causing the formation of cytotoxic protein inclusions

    Neurophysiological investigations of hepatic encephalopathy: ISHEN practice guidelines

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    By studying neuronal activity through neuronal electrogenesis, neurophysiological investigations provide a functional assessment of the nervous system and, therefore, has been used for quantitative assessment and follow-up of hepatic encephalopathy (HE). The different clinical neurophysiological approaches can be classified depending on the function to explore and their sensitivity to HE. The reliable techniques are those that reflect cortical function, i.e., cognitive-evoked potentials (EPs) (P300 paradigm), electroencephalogram (EEG), visual EPs (latency > 100 ms) and somatosensory EPs (SEPs) (latency between 25 and 100 ms). Short-latency EPs (brainstem acoustic EPs, SEPs of a latency < 25 ms) are in principle insensitive to HE, but can disclose brainstem conduction deficits due to oedema. SEPs and motor EPs can disclose myelopathies. Because of its parallelism to the clinical examination, clinical neurophysiology can complement the neurological examination: (i) to provide evidence of HE in patients who have normal consciousness; (ii) to rule out, at least under some conditions, disturbances of consciousness due to other causes (e.g. drug-induced disturbances, non-convulsive status epilepticus) with the reservation that the mildest degrees of encephalopathy might be associated with an EEG pattern similar to that induced by drugs; and (iii) to demonstrate the worsening or, conversely improvement, of HE in the follow-up period

    Mitochondrial Alterations Induced by the p13II Protein of Human T-cell Leukemia Virus Type 1 CRITICAL ROLE OF ARGININE RESIDUES

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    Abstract Human T-cell leukemia virus type 1 encodes a number of "accessory" proteins of unclear function; one of these proteins, p13II, is targeted to mitochondria and disrupts mitochondrial morphology. The present study was undertaken to unravel the function of p13II through (i) determination of its submitochondrial localization and sequences required to alter mitochondrial morphology and (ii) an assessment of the biophysical and biological properties of synthetic peptides spanning residues 9–41 (p139–41), which include the amphipathic mitochondrial-targeting sequence of the protein. p139–41 folded into an α helix in micellar environments. Fractionation and immunogold labeling indicated that full-length p13II accumulates in the inner mitochondrial membrane. p139–41 induced energy-dependent swelling of isolated mitochondria by increasing inner membrane permeability to small cations (Na+, K+) and released Ca2+ from Ca2+-preloaded mitochondria. These effects as well as the ability of full-length p13II to alter mitochondrial morphology in cells required the presence of four arginines, forming the charged face of the targeting signal. The mitochondrial effects of p139–41 were insensitive to cyclosporin A, suggesting that full-length p13II might alter mitochondrial permeability through a permeability transition pore-independent mechanism, thus distinguishing it from the mitochondrial proteins Vpr and X of human immunodeficiency virus type 1 and hepatitis B virus, respectively

    The tectonic puzzle of the Messina area (Southern Italy): Insights from new seismic reflection data

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    The Messina Strait, that separates peninsular Italy from Sicily, is one of the most seismically active areas of the Mediterranean. The structure and seismotectonic setting of the region are poorly understood, although the area is highly populated and important infrastructures are planned there. New seismic reflection data have identified a number of faults, as well as a crustal scale NE-trending anticline few km north of the strait. These features are interpreted as due to active right-lateral transpression along the north-eastern Sicilian offshore, coexisting with extensional and right-lateral transtensional tectonics in the southern Messina Strait. This complex tectonic network appears to be controlled by independent and overlapping tectonic settings, due to the presence of a diffuse transfer zone between the SE-ward retreating Calabria subduction zone relative to slab advance in the western Sicilian side

    The Italian registry of pulmonary non-tuberculous mycobacteria - IRENE:The study protocol

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    Background: A substantial increase in pulmonary and extra-pulmonary diseases due to non-tuberculous mycobacteria (NTM) has been documented worldwide, especially among subjects suffering from chronic respiratory diseases and immunocompromised patients. Many questions remain regarding the epidemiology of pulmonary disease due to NTM (NTM-PD) mainly because reporting of NTM-PD to health authorities is not mandated in several countries, including Italy. This manuscript describes the protocol of the first Italian registry of adult patients with respiratory infections caused by NTM (IRENE). Methods: IRENE is an observational, multicenter, prospective, cohort study enrolling consecutive adult patients with either a NTM respiratory isolate or those with NTM-PD. A total of 41 centers, including mainly pulmonary and infectious disease departments, joined the registry so far. Adult patients with all of the following are included in the registry: 1) at least one positive culture for any NTM species from any respiratory sample; 2) at least one positive culture for NTM isolated in the year prior the enrolment and/or prescribed NTM treatment in the year prior the enrolment; 3) given consent to inclusion in the study. No exclusion criteria are applied to the study. Patients are managed according to standard operating procedures implemented in each IRENE clinical center. An online case report form has been developed to collect patients' demographics, comorbidities, microbiological, laboratory, functional, radiological, clinical, treatment and outcome data at baseline and on an annual basis. An IRENE biobank has also been developed within the network and linked to the clinical data of the registry. Conclusions: IRENE has been developed to inform the clinical and scientific community on the current management of adult patients with NTM respiratory infections in Italy and acts as a national network to increase the disease's awareness

    Comparison of different conditions for DNA extraction in sputum : A pilot study

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    Background: The analysis of microbiome in respiratory samples is a topic of great interest in chronic respiratory diseases. The method used to prepare sputum samples for microbiome analysis is very heterogeneous. The selection of the most suitable methodology for DNA extraction is fundamental to have the most representative data. The objective of this study was to compare different conditions for DNA extraction from sputum in adult patients with bronchiectasis. Methods: Five sputum samples from bronchiectasis patients were collected at the Policlinico Hospital in Milan, Italy. Eighteen conditions for DNA extraction were compared, including two enzyme-based (Roche and Zymo) and one beads-based (Mobio) technique. These techniques were tested with/without Dithiothreitol (DTT) and with/without lysostaphin (0.18 and 0.36 mg/mL) step. DNA was quantified, tested using Real-time PCR for 16S rDNA and S. aureus and, then, microbiome was evaluated. Results: Although 16S rDNA was similarly detected across all the different techniques, Roche kit gave the highest DNA yield. The lowest Ct values for Real-time PCR for S. aureus was identified when lysostaphin was added. Considering genera from microbiome, alpha diversity indices did not show any significant differences between techniques, while relative abundances were more similar in presence of DTT. Conclusions: None of the conditions emerged to be superior to the others even if enzyme-based kits seem to be needed in order to have a higher extraction yield

    Antamanide, a Derivative of Amanita phalloides, Is a Novel Inhibitor of the Mitochondrial Permeability Transition Pore

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    Antamanide is a cyclic decapeptide derived from the fungus Amanita phalloides. Here we show that antamanide inhibits the mitochondrial permeability transition pore, a central effector of cell death induction, by targeting the pore regulator cyclophilin D. Indeed, (i) permeability transition pore inhibition by antamanide is not additive with the cyclophilin D-binding drug cyclosporin A, (ii) the inhibitory action of antamanide on the pore requires phosphate, as previously shown for cyclosporin A; (iii) antamanide is ineffective in mitochondria or cells derived from cyclophilin D null animals, and (iv) abolishes CyP-D peptidyl-prolyl cis-trans isomerase activity. Permeability transition pore inhibition by antamanide needs two critical residues in the peptide ring, Phe6 and Phe9, and is additive with ubiquinone 0, which acts on the pore in a cyclophilin D-independent fashion. Antamanide also abrogates mitochondrial depolarization and the ensuing cell death caused by two well-characterized pore inducers, clotrimazole and a hexokinase II N-terminal peptide. Our findings have implications for the comprehension of cyclophilin D activity on the permeability transition pore and for the development of novel pore-targeting drugs exploitable as cell death inhibitors
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