827 research outputs found

    Turbinate Surgery in Chronic Rhinosinusitis: Techniques and Ultrastructural Outcomes

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    Chronic nasal obstruction due to hypertrophic rhinitis is commonly associated with perennial allergic and nonallergic rhinitis. It is not a simple enlargement of mucosal and submucosal tissues, but it is characterized by deep histological modifications. This pathology, a very frequent condition encountered in rhinological practice, has a significant impact on quality of life. Patients usually complain about sneezing, rhinorrhea, frontal headache, postnasal drip, snoring, blocked nasal ducts, and sleep disorders. When medical therapy fails, surgical reduction of inferior turbinates is mandatory. A large variety of surgical techniques in literature exist, but there is a lack of consensus about which is the proper technique to perform. In this chapter, we describe the most important techniques of inferior turbinate reduction with advantages and disadvantages of each one

    pH dependence of structural and functional properties of oxidized cytochrome c" from Methylophilus methylotrophus.

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    Cytochrome c" from Methylophilus methylotrophus is an unusual monoheme protein that undergoes a major redox-linked change in the heme arrangement: one of the two axial histidines bound to the iron in the oxidized form is detached upon reduction and a proton is taken up. The kinetics of reduction by sodium dithionite and the spectroscopic properties of the oxidized cytochrome c" have been investigated over the pH range between 1.4 and 10.0. The rate of reduction displays proton-linked transitions of pKa congruent with 5.5 and 2.4, and a spectroscopic transition with a pKa congruent with 2.4 is also observed. The protein displays a complete reversibility after exposure to low pH, and both electronic absorption and resonance Raman spectroscopic properties suggest that the transition at lower pH brings about a drastic change in the heme coordination geometry. Circular dichroism spectra indicate that over the same proton-linked transition, the protein undergoes a marked decrease (approximately 60%) of the alpha-helical content toward a random coil arrangement, which is recovered upon increasing the ionic strength. The structural change at low pH is linked to a concerted two-proton transition, suggesting the detachment and protonation of axial histidine(s). Such kinetic and spectroscopic features along with the remarkable capacity of this protein to recover its native structure after exposure to extremely low pH values makes it a promising model for studying folding processes and stability in heme proteins

    Interleukin-31: a new cytokine involved in inflammation of the skin.

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    Cytokines affect immune functions involved inmotility, chemotaxis, phagocytosis, cytotoxicityand antigen presentation (1). Interleukins (IL) arepleiotropic cytokines with diverse receptorsignaling pathways whose expression is controlledat multiple levels (2). Interleukin receptors (ILR)have intrinsic roles in regulating and amplifyingthe inflammatory response (3-12).Skin is the largest organ of the body with thespecific immune defense and its inflammatoryconditions include atopic dermatitis, allergies,psoriasis etc. (13-19). Infiltrated lymphocytesproliferate in an activated state in the skin lesion inan autocrine and/or paracrine manner and produceTH2-type cytokines that might evoke immunologicabnormalities (20-23)...

    Ultrastructural features of the nasal mucosa after massive removal of all soft tissues in the inferior turbinate hypertrophy

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    The nasal respiratory mucosa plays a key role in conditioning the inhaled air and in regulating the immune response against foreign particles. Many authors recom- mend mucosal sparing techniques for the surgical management of the inferior turbinate hypertrophy, such as laser surgery, radiofrequency electrocautery, cryosurgery, etc. In spite of their conservative purposes, ultrastructural studies demonstrate that these methods produce irreversible changes in the nasal mucosa. The aim of this study was to analyze ultrastructural features of the healing process after Microde- brider Assisted Turbinoplasty, alternative procedure that provides a radical interven- tion with removal of both mucosal and submucosal soft tissues of the inferior turbi- nate. Nasal mucosa biopsies from 7 patients (mean age 42+10) affected with inferior turbinate hypertrophy were taken before operation and 4 months after surgery and compared with 2 unaffected controls of the same age. Preoperative samples, routinely processed for Transmission Electron Microscopy (1), displayed a number of ultrastructural changes compared to normal controls such as disrupture of tight junctions, disappearance of pseudostratification, loss of cilia, fibrosis, and abundant inflamma- tory infiltrates. By contrast, in postoperative samples the nasal mucosa showed a normal appearance, with restoration of the pseudostratified ciliated pattern, intercellular connections and normal cellular morphology; collagen showed a normal organization in bundle and fibrosis and submucosal oedema were considerably reduced. In the light of these observations and previous Scanning Electron Microscopy findings (2), we can conclude that Microdebrider Assisted Turbinoplasty is a surgical procedure able to radically remove the inflamed tissue typical of hypertophic rynopathy and, consequently, to allow the resident stem cells to re-epithelize the nasal mucosa and restore its normal function

    Smell and Taste in Severe CoViD-19: Self-Reported vs. Testing

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    One of the most striking reported symptoms in CoViD-19 is loss of smell and taste. The frequency of these impairments and their specificity as a potential central nervous system function biomarker are of great interest as a diagnostic clue for CoViD-19 infection as opposed to other similar symptomatologic diseases and because of their implication in viral pathogenesis. Here severe CoViD-19 was investigated by comparing self-report vs. testing of smell and taste, thus the objective severity of olfactory impairment and their possible correlation with other symptoms. Because a significant discrepancy between smell and taste testing vs. self-report results (p < 0.001) emerges in our result, we performed a statistical analysis highlighting disagreement among normosmia (p < 0.05), hyposmia, severe hyposmia, and anosmia (p < 0.001) and, in hypogeusia and severe hypogeusia, while no differences are observed in normogeusia and ageusia. Therefore, we analyzed the olfactory threshold by an objective test revealing the distribution of hyposmic (34%), severe hyposmic (48%), and anosmic (13%) patients in severe CoViD-19. In severe CoViD-19 patients, taste is lost in 4.3% of normosmic individuals, 31.9% of hyposmic individuals, 46.8% of severe hyposmic individuals, and 17% of anosmic individuals. Moreover, 95% of 100 CoViD-19 patients objectively tested were affected by smell dysfunction, while 47% were affected by taste dysfunction. Furthermore, analysis by objective testing also highlighted that the severity of smell dysfunction in CoViD-19 subjects did not correlate with age and sex. In conclusion, we report by objective testing that the majority of CoViD-19 patients report severe anosmia, that most of the subjects have olfactory impairment rather than taste impairment, and, finally, that the olfactory impairment correlate with symptom onset and hospitalization (p < 0.05). Patients who exhibit severe olfactory impairment had been hospitalized for about a week from symptom onset; double time has taken place in subjects with normosmia. Our results may be limited by the relatively small number of study participants, but these suggest by objective testing that hyposmia, severe hyposmia, and anosmia may relate directly to infection severity and neurological damage. The smell test assessment could be a potential screening symptom that might contribute to the decision to test suspected cases or guide quarantine instructions, further therapeutic approach, and evaluation of neurological damage

    Effect of tonsillectomy in a child with obesity and obstructive sleep apnea: A case report and review of the literature

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    Obstructive sleep apnea (OSA) is an increasingly recognized disorder in children. Adenotonsillectomy is the primary surgical treatment for OSA in children with adenotonsillar hypertrophy (ATH). We present the case of an obese 4-year-old boy hospitalized for severe desaturation during sleep and severe ATH. Nasal steroid therapy proved ineffective with persistent symptoms. Polygraphy documented severe OSA with an apnea–hypopnea index (AHI) equal to 11. Tonsillectomy resulted in prompt symptom improvement and a substantial reduction of the AHI (2.2). In this case, tonsillectomy alone resulted effective in treating OSA, despite obesity. We concluded that the presence of obesity should not postpone/exclude surgical treatment of preschool children for whom ATH is the most important cause of OSA

    Impact of neuropeptide substance P an inflammatory compound on arachidonic acid compound generation

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    There is much evidence that neuropeptide substance P is involved in neurogenic inflammation and is an important neurotransmitter and neurmodulator compound. In addition, substance P plays an important role in inflammation and immunity. Macrophages can be activated by substance P which provokes the release of inflammatory compounds such as interleukins, chemokines and growth factors. Substance P is involved in the mechanism of pain through the trigeminal nerve which runs through the head, temporal and sinus cavity. Substance P also activates mast cells to release inflammatory mediators such as arachindonic acid compound, cytokines/chemokines and histamine. The release of these chemical mediators is crucial for inflammatory response. Among these mediators there are prostoglandins and leukotrines. Here we review the impact of substance P on inflammatory compounds

    Les droits disciplinaires des fonctions publiques : « unification », « harmonisation » ou « distanciation ». A propos de la loi du 26 avril 2016 relative à la déontologie et aux droits et obligations des fonctionnaires

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    The production of tt‟ , W+bb‟ and W+cc‟ is studied in the forward region of proton–proton collisions collected at a centre-of-mass energy of 8 TeV by the LHCb experiment, corresponding to an integrated luminosity of 1.98±0.02 fb−1 . The W bosons are reconstructed in the decays W→ℓΜ , where ℓ denotes muon or electron, while the b and c quarks are reconstructed as jets. All measured cross-sections are in agreement with next-to-leading-order Standard Model predictions.The production of tt‟t\overline{t}, W+bb‟W+b\overline{b} and W+cc‟W+c\overline{c} is studied in the forward region of proton-proton collisions collected at a centre-of-mass energy of 8 TeV by the LHCb experiment, corresponding to an integrated luminosity of 1.98 ±\pm 0.02 \mbox{fb}^{-1}. The WW bosons are reconstructed in the decays W→ℓΜW\rightarrow\ell\nu, where ℓ\ell denotes muon or electron, while the bb and cc quarks are reconstructed as jets. All measured cross-sections are in agreement with next-to-leading-order Standard Model predictions

    Multidifferential study of identified charged hadron distributions in ZZ-tagged jets in proton-proton collisions at s=\sqrt{s}=13 TeV

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    Jet fragmentation functions are measured for the first time in proton-proton collisions for charged pions, kaons, and protons within jets recoiling against a ZZ boson. The charged-hadron distributions are studied longitudinally and transversely to the jet direction for jets with transverse momentum 20 <pT<100< p_{\textrm{T}} < 100 GeV and in the pseudorapidity range 2.5<η<42.5 < \eta < 4. The data sample was collected with the LHCb experiment at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 1.64 fb−1^{-1}. Triple differential distributions as a function of the hadron longitudinal momentum fraction, hadron transverse momentum, and jet transverse momentum are also measured for the first time. This helps constrain transverse-momentum-dependent fragmentation functions. Differences in the shapes and magnitudes of the measured distributions for the different hadron species provide insights into the hadronization process for jets predominantly initiated by light quarks.Comment: All figures and tables, along with machine-readable versions and any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-013.html (LHCb public pages
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