142 research outputs found

    Patterns of Pathomorphological Changes in Acute Necrotizing Pancreatitis

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    Acinar necrosis is the basic microscopic sign of acute necrotizing pancreatitis (ANP). Microcirculation disorder is one of the major factors in the pathogenesis and morphogenesis of ANP besides free radicals and damage of enzymatic origin. This study is dedicated to the description of microscopic changes in the pancreatic stroma in ANP, which leads to destruction of the exocrine pancreas with a putative mechanism of endocrine function preservation. This study has been carried out on histological samples of pancreas from 224 patients with ANP. Histological staining was performed with hematoxylin-eosin (H&E), Masson, Gomori methods, and PAS. Microscopy was performed with magnifications of 40×, 100×, and 400×. Vascular endothelial desquamation, stasis, and sludge are typical changes in microcirculation observed in early stages of ANP. Initially, parietal circular intravascular microthrombosis accompanied by endothelial desquamation as early as stromal swelling occurs with no detectable necrosis. Residual stroma appears between areas of necrosis and intact pancreatic tissue. Mucoid swelling is first seen in the perivascular spaces extending to the parenchyma and changing into fibrinoid imbibition causing further necrosis. Reticulin argyrophilic backbone surrounding the pancreatic acini and small ducts decompose. Pancreatic structures, which may be preserved in necrotic tissue, include nerves, major ducts, and Langerhans islets

    Immune-metabolic genesis of pathological processes

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    This article deals with metabolic-immune processes at rest and under stress conditions, which, in turn, results in the development of immune-dependent and immune-associated disorders. The authors also analyzed metabolic effects of immunomodulators. Based on the analysis of the literature and own clinical and experimental data, the authors identified the ability of metabolic factors to regulate immunological processe

    (2,2′-Bipyridine-κ2 N,N′)bis­(N-ethyl-N-methyl­dithio­carbamato-κ2 S,S′)zinc(II)

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    The complete mol­ecule of the title compound, [Zn(C4H8NS2)2(C10H8N2)], is generated by crystallographic twofold symmetry, with the Zn atom lying on the rotation axis; the axis also bis­ects the central C—C bond of the 2,2′-bipyridine mol­ecule. The metal atom is chelated by two S,S′-bidentate dithio­carbamate anions and the N,N′-bidentate heterocycle, resulting in a distorted cis-ZnN2S4 octa­hedral geometry. The methyl and ethyl groups of the anion are statistically disordered

    Surgical treatment of glossopharyngeal nerve schwannomas: Results of two-center study (14 patients included) and literature review

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    Objective: This study is aimed to analyze the outcomes of surgical treatment of glossopharyngeal schwannomas based on pre- and postoperative neurological status assessment. Materials and methods: This paper is a retrospective analysis of examination and surgical treatment of 14 patients who were operated on in two large clinics from 2018 to 2021 inclusive. When analyzing the collected data, gender, age, disease symptoms, tumor size and location, surgical approach, tumor to cranial nerves (CN) ratio, jugular foramen (JF) condition, and tumor removal volume were taken into account. All tumors were divided into groups depending on tumor location relative to the JF. Particular attention was paid to assessing cranial nerves functions. Facial nerve function was assessed as per House-Brackmann Scale (HBS), hearing function as per Gardner-Robertson Scale (GRS). Results: 3 (21.4%) patients had total tumor removal: 2 patients had type A tumors and one had type B tumor. Subtotal resection took place in 7 (50%) cases. In 4 cases, a tumor was partially removed: 3 patients had type D tumors and one had type B tumor. 3 (21.4%) patients had preoperative FN deficit (HBS Grade II) and mild dysfunction. 5 (35.7%) patients had postoperative facial nerve deficit: HBS ІІ, 2; ІІІ, 1; V, 2. Preoperative sensorineural type hearing impairment on the affected side was diagnosed in 13 (92.6%) patients. Before surgery, 6 patients had non-serviceable hearing, which remained at the same level after surgery. None of the patients with grade I or II hearing before surgery had any hearing impairment postoperatively. In 2 (14.3%) cases, hearing improved from grade V to grade III after surgery. 6 (42.9%) patients developed new neurological deficit in the caudal group CN. Postoperative deficit of the caudal group CN occurred in type D tumors in 3 patients, type A tumors 2 patients, and type B tumors one patient. Conclusions: Applying a retrosigmoid approach only makes it possible to achieve total tumor removal in case of type A tumors. To remove other tumor types, it is necessary to select approaches that enable access to the jugular foramen and infratemporal fossa. Intraoperative neurophysiological monitoring is an extremely important tool in glossopharyngeal schwannoma surgery. The most common postoperative complication is a developed or increased deficit of the caudal CN group, which can lead to persistent impairments in the patients’ quality of life. Preservation of the CN VII and VIII function in most cases is a feasible task and shall be ensured as a standard for this pathology

    Determination of the muon charge sign with the dipolar spectrometers of the OPERA experiment

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    The OPERA long-baseline neutrino-oscillation experiment has observed the direct appearance of ντ\nu_\tau in the CNGS νμ\nu_\mu beam. Two large muon magnetic spectrometers are used to identify muons produced in the τ\tau leptonic decay and in νμCC\nu_\mu^{CC} interactions by measuring their charge and momentum. Besides the kinematic analysis of the τ\tau decays, background resulting from the decay of charmed particles produced in νμCC\nu_\mu^{CC} interactions is reduced by efficiently identifying the muon track. A new method for the charge sign determination has been applied, via a weighted angular matching of the straight track-segments reconstructed in the different parts of the dipole magnets. Results obtained for Monte Carlo and real data are presented. Comparison with a method where no matching is used shows a significant reduction of up to 40\% of the fraction of wrongly determined charges.Comment: 10 pages. Improvements in the tex

    Immune reactions as induction factors and correction of the pathology

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    On clinical models of infectious, somatic, malignant, and other diseases, the ability of immune responses to induce pathological processes due to competition, “pathogenicity”, hypersensitivity, and insufficiency has been shown. We are talking about the competitiveness of antibacterial and antiviral immunity, when the deployment of cellular and humoral immune responses weaken both defense mechanisms, competition of allergy and immune deficiency, which aggravates and modifies it, and antiviral immunity often induces a number of pathological conditions of the body. This is due to the inability of antiviral antibodies to completely inactivate the antireceptor structures of virions, interact with them without changing their function, and even stimulate a viral infection, induce autoimmune reactions. The protective system of interferons, which often cause side reactions, is also faulty. In  the  body, immunopathological reactions develop, manifested by immediate and delayed hypersensitivity, which have alternative properties – protective and damaging and autoimmune reactions, mainly with a negative effect. The mechanisms of the processes are discussed in detail in the review. The “inferiority” of immune reactions, respectively, cellular, humoral, phagocytic links, incomplete consistency of anticancer immunity, virus-induced immunodeficiencies are comprehensively covered. Such “alternativeness” of the considered immune reactions, at the same time, turns out to be a necessary condition for eliminating the emerging disorders of the organism’s reactivity. These include specificity and non-specificity, stimulation and suppression, variability and integration of immune responses. At the same time, immunoregulatory reactions are individual and interrelated, develop regionally and systemically and provide degradation of exogenous and endogenous objects and immune activation. All these aspects are discussed in detail in the review

    Limits on muon-neutrino to tau-neutrino oscillations induced by a sterile neutrino state obtained by OPERA at the CNGS beam

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    The OPERA experiment, exposed to the CERN to Gran Sasso νμ\nu_\mu beam, collected data from 2008 to 2012. Four oscillated ντ\nu_\tau Charged Current interaction candidates have been detected in appearance mode, which are consistent with νμντ\nu_\mu \to \nu_\tau oscillations at the atmospheric Δm2\Delta m^2 within the "standard" three-neutrino framework. In this paper, the OPERA ντ\nu_\tau appearance results are used to derive limits on the mixing parameters of a massive sterile neutrino.Comment: 11 pages, 4 figures; reference to Planck result updated in the Introduction. Submitted to JHE

    Observation of nu_tau appearance in the CNGS beam with the OPERA experiment

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    The OPERA experiment is searching for nu_mu -> nu_tau oscillations in appearance mode i.e. via the direct detection of tau leptons in nu_tau charged current interactions. The evidence of nu_mu -> nu_tau appearance has been previously reported with three nu_tau candidate events using a sub-sample of data from the 2008-2012 runs. We report here a fourth nu_tau candidate event, with the tau decaying into a hadron, found after adding the 2012 run events without any muon in the final state to the data sample. Given the number of analysed events and the low background, nu_mu -> nu_tau oscillations are established with a significance of 4.2sigma.Comment: Submitted to Progress of Theoretical and Experimental Physics (PTEP

    Procedure for short-lived particle detection in the OPERA experiment and its application to charm decays

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    The OPERA experiment, designed to perform the first observation of νμντ\nu_\mu \rightarrow \nu_\tau oscillations in appearance mode through the detection of the τ\tau leptons produced in ντ\nu_\tau charged current interactions, has collected data from 2008 to 2012. In the present paper, the procedure developed to detect τ\tau particle decays, occurring over distances of the order of 1 mm from the neutrino interaction point, is described in detail. The results of its application to the search for charmed hadrons are then presented as a validation of the methods for ντ\nu_\tau appearance detection
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