1,648 research outputs found

    Letter to the editor: autoimmune pathogenic mechanisms in amyotrophic lateral sclerosis

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    The innate immune system may affect the function and survival of motor neurons in ALS by at least three mechanisms. First, there is evidence to suggest that aggregates of mutant SOD1—which is derived from microglial and astroglial cells—activate neighbouring microglia by binding to TLR2, TLR4, and CD14, and subsequently promote neuronal cell death [9]. Second, the release of pro- inflammatory cytokines may drive motor neuron damage. Third, although poorly understood, a mechanism has been suggested on the basis of the functional analysis of microglial cells that express mutant SOD1 [10]. These cells showed impaired overall motility and a reduced capacity to clear neuronal cell debris. Impairment of microglial cell phagocytosis may therefore contribute to the accumulation of further immunostimulatory proteins, including mutant SOD1, chromogranin A, and dsRNA, thereby resulting in disease progression

    Letter to the editor: autoimmune pathogenic mechanisms in Huntington’s disease

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    Letter to the Editor: Autoimmune pathogenic mechanisms in Huntington's disease

    Tracheocutaneous fistula in patients undergoing supracricoid partial laryngectomy: the role of chronic aspiration

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    The aim of the present retrospective controlled study was to analyse and compare risk factors for tracheocutaneous fistula in patients who received tracheostomy after supracricoid partial laryngectomy with those who received tracheostomy for other causes. We enrolled 39 patients with tracheocutaneous fistulas who were divided into two groups. The first received temporary tracheostomy for supracricoid partial laryngectomies (n = 21), while the control group consisted of patients who received temporary tracheostomy for other causes (n = 18). Risk factors believed to play a role in the pathogenesis of tracheocutaneous fistula were examined including advanced age, cardiopathy, local infections, radiotherapy, elevated body mass index, malnutrition, decannulation time and aspiration grade. The Leipzig and Pearson scale score was significantly higher in the supracricoid partial laryngectomy group (p = 0.006 and 0.031 for univariate and multivariate analyses, respectively). The penetration/aspiration scale score was significantly higher in the supracricoid partial laryngectomy group as determined by univariate analysis (p = 0.014). The decannulation time was significantly lower in the supracricoid partial laryngectomy group (p = 0.004 and 0.0004 for univariate and multivariate analyses, respectively). The number of surgical closures for tracheocutaneous fistula was significantly higher in the supracricoid partial laryngectomy group by univariate analysis (p = 0.027). These results suggest that chronic aspiration and related cough may be important pathogenic factors for tracheocutaneous fistula and could be responsible for the significantly higher rates of closure failure in patients after supracricoid partial laryngectomy

    Spin-dependent direct gap emission in tensile-strained Ge films on Si substrates

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    The circular polarization of direct gap emission of Ge is studied in optically-excited tensile-strained Ge-on-Si heterostructures as a function of doping and temperature. Owing to the spin-dependent optical selection rules, the radiative recombinations involving strain-split light (cG-LH) and heavy hole (cG-HH) bands are unambiguously resolved. The fundamental cG-LH transition is found to have a low temperature circular polarization degree of about 85% despite an off-resonance excitation of more than 300 meV. By photoluminescence (PL) measurements and tight binding calculations we show that this exceptionally high value is due to the peculiar energy dependence of the optically-induced electron spin population. Finally, our observation of the direct gap doublet clarifies that the light hole contribution, previously considered to be negligible, can dominate the room temperature PL even at low tensile strain values of about 0.2%

    Biological activity of metabolites extracted from Citrus spp. on Ceratitis capitata (Wiedemann) (Diptera: Tephritidae)

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    The Mediterranean fruit fly (medfly), Ceratitis capitata (Wiedemann) (Diptera: Tephritidae), is one of the most injurious pest at global level. During the last years, several electrophysiological and behavioural studies have been carried out in order to investigate plant volatile compound-insect interactions with the aim to use this knowledge in sustainable control techniques. It has been observed that lemons are not attacked by medfly, probably because of the peel oil, that is toxic to other fruit flies. In the present paper electrophysiological recordings were conducted to evaluate the insect sensitivity to peel extract and peel oil of two Sicilian cultivars (Interdonato and Lunario) of Citrus x limon (L.) Burm.f. on C. capitata females. Behavioural bioassays were also performed to show their possible biological activity (repellent, antioviposition, insecticidal). C. limon peel extracts in different solvents (petroleum ether, dichloromethane and methanol) were investigated at various concentrations using a single cell recording technique (stimulation of tarsal taste chemosensilla). Different tarsal taste cell responses to the two cultivars were recorded. The higher sensitivity was evoked by C. limon Interdonato, particularly to the methanol extract, which elicited significant increases in the spike frequency at increasing concentrations. The peel oil of the same cultivars as well as that ones of other two C. limon varieties (Monachello and Femminello) have been tested by EAG techniques. The EAG data showed a high sensitivity (about -8.0/8.5mV) of the medfly antennae to the oils of Citrus spp. and a clear dose-response relationship. Responses of adult females (virgin and mated) to Citrus spp. peel extract were quantified in a double-choice test using yellow spheres (diameter 7.0cm) housed in field cages. Preliminary tests conducted on three extracts of C. limon Interdonato and Lunario have provided interesting results. It was recorded a general decrease of the oviposition on treated spheres compared to control and in the case of the cultivar Lunario, a mortality of insects

    First data on the repellent activity of essential oils of Citrus limon towards medfly (Ceratitis capitata)

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    The biological activity of peel essential oils of two Sicilian cultivars of C. limon, ‘Interdonato’ and ‘Lunario’, was investigated by electrophysiological recordings (EAG) and field trials on Ceratitis capitata (Wiedemann) (Diptera Tephritidae). The EAG data showed a remarkable dose-response relationship and a low activation threshold dose (10-3M) for both essential oil extracts. In field tests, essential oils showed a good repellent and antiovipositional activi- ty on ‘Navelina’ oranges, and in particular the essential oils of ‘Lunario’ pro- vided the same results of kaolin. Potential applications of essential oils from C. limon cultivars against C. capitata in organic farming are discussed

    Electrophysiological and Behavioral Responses of Oriental Fruit Moth to the Monoterpenoid Citral Alone and in Combination With Sex Pheromone

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    The monoterpenoid citral synergized the electroantennogram (EAG) response of male Grapholita molesta (Busck) antennae to its main pheromone compound Z8 Ð12:OAc. The response to a 10-g pheromone stimulus increased by 32, 45, 54, 71 and 94% with the addition of 0.1, 1, 10, 100 and 1,000 g of citral, respectively. There was no detectable response to 0.1, 1, or 10 g of citral; the response to 100 and 1,000 g of citral was 31 and 79% of the response to 10 g of Z8 Ð12:OAc. In a ßight tunnel, citral affected the mate-seeking behavior of males. There was a 66% reduction in the number of males orientating by ßight to a virgin calling female when citral was emitted at 1,000 ng/min 1 cm downwind from a female. Pheromone and citral induced sensory adaptation in male antennae, but citral did not synergize the effect of pheromone. The exposure of antennae to 1 ng Z8Ð12:OAc/m3 air, 1 ng citral/m3 air, 1 ng Z8 Ð12:OAc 1 ng citral/m3 air, or to 1 ng Z8 Ð12:OAc 100 ng citral/m3 air for 15 min resulted in a similar reduction in EAG response of 47Ð63%. The exposure of males to these same treatments for 15 min had no effect on their ability to orientate to a virgin calling female in a ßight tunnel. The potential for using citral to control G. molesta by mating disruption is discusse

    Evaluation of inductively coupled plasma tandem mass spectrometry for determination of as in agricultural inputs with high REE contents.

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    In the present work, an inductively coupled plasma-tandem mass spectrometer (ICP-MS/MS) operating in single quadrupole and mass shift modes were evaluated for As determination in mineral fertilizers and agricultural gypsum with high contents of rare earth elements. For MS/MS mode, oxygen was the gas introduced into the octopole reaction system (ORS3 ). Samples were prepared by microwave-assisted digestion with diluted nitric acid solution. The accuracy was checked by analysis of a fertilizer certified reference material (NIST SRM 695) and by addition and recovery experiments. When operating in single quadrupole mode, recoveries ranged from 59 to 151%; while values obtained by MS/MS mode varied from 81 to 105% when 0.30 mL min-1 O2 was introduced into the ORS3 . Limits of detection for As+ in single quadrupole and AsO+ in MS/MS mass shift mode were 6 and 9 ng L-1, respectively

    Evidence and role of autoantibodies in chronic rhinosinusitis with nasal polyps.

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    In this study, we review our current knowledge of the autoimmune etiopathogenesis of chronic rhinosinusitis with nasal polyps including bacterial infections, viral infections and immunomediated mechanisms and to discuss pathogenesis with relevance for pharmacotherapy. Relevant publications on the etiopathogenesis and treatment of chronic rhinosinusitis with nasal polyps (CRSwNP) from 1977 to 2013 were analyzed. The characteristic signs and symptoms include appearance of relapsing nasal polyps, with typical symptoms such as nasal obstruction, nasal discharge and, usually, loss of the sense of smell. The etiology and pathogenesis remain unknown. Proposed theories of causation include bacterial or viral infections and immunomediated mechanisms. The autoimmune aetiology of of unknown origin or failure to respond to classic pharmacological treatments with nasal and oral steroids is now suspected. At present, the nature of the antigen trigger, the exact role played by B/T cells and anti-dsDNA autoantibodies in the pathogenesis of nasal polyposis remains unclear. Corticosteroids and surgery are the first line of treatment in CRSwNP. In the case of corticosteroid treatment failure, other drugs can be used such as rituximab, belimumab or omalizumab which have demonstrated clinical efficacy in the treatment of nasal polyposis with comorbid asthma. Immunosuppressive drugs such as methotrexate, and cyclophosphamide have also been used with varying degrees of success
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