268 research outputs found

    Inhibitory Studies of Tamarindus indica Seed Extract and Fractions on Hematological Activities of Bitis arietans Venom

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    Envenomation is a serious public health and occupational hazard in tropical and subtropical countries. Antivenom serum treatment has been related to extreme hypersensitivity, high cost, and inaccessibility. Consequently, therapeutic plants have been investigated to give an alternative treatment. The aim of this study was to evaluate the ability of the methanolic extract and fractions of Tamarindus indica seeds to neutralize the hemolytic, anticoagulant and hemorrhagic activities of Bitis arietans venom. The powdered form of Tamarindus indica seed was extracted using methanol. The methanol extract was further fractionated using butanol solvent. The aqueous fraction of the methanolic extract inhibited hemolysis caused by crude venom by 95.5%, while methanolic extract significantly reduced the anticoagulant time of crude venom to 10.2%. The in vivo hemorrhagic activity of the crude venom of Bitis arietans was neutralized by both the crude methanolic extract and the subsequent two fractions of Tamarindus indica seed. However, the crude methanolic extract was found to be the most active by reducing the hemorrhage diameter caused by crude venom to 39%. The findings of this present research work demonstrated a very good antivenom properties of the seeds of Tamarindus indica, which suggests that it could be a potential source of effective, and safe compounds with inhibitory activities against Bitis arietans envenomation

    Stress-based performance evaluation of osseointegrated dental implants by finite-element simulation

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    In this paper biomechanical interaction between osseointegrated dental implants and bone is numerically investigated through 3D linearly elastic finite-element analyses, when static functional loads occur. Influence of some mechanical and geometrical parameters on bone stress distribution is highlighted and risk indicators relevant to critical overloading of bone are introduced. Insertions both in mandibular and maxillary molar segments are analyzed, taking into account different crestal bone loss configurations. Stress-based performances of five commercially-available dental implants are evaluated, demonstrating as the optimal choice of an endosseous implant is strongly affected by a number of shape parameters as well as by anatomy and mechanical properties of the site of placement. Moreover, effectiveness of some double-implant devices is addressed. The first one is relevant to a partially edentulous arch restoration, whereas other applications regard single-tooth restorations based on non-conventional endosteal mini-implants. Starting from computer tomography images and real devices, numerical models have been generated through a parametric algorithm based on a fully 3D approach. Furthermore, effectiveness and accuracy of finite-element simulations have been validated by means of a detailed convergence analysis

    Fixture-abutment connection surface and micro-gap measurements by 3D micro-tomographic technique analysis

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    X-ray micro-tomography (micro-CT) is a miniaturized form of conventional computed axial tomography (CAT) able to investigate small radio-opaque objects at a-few-microns high resolution, in a non-destructive, non-invasive, and tri-dimensional way. Compared to traditional optical and electron microscopy techniques, which provide two-dimensional images, this innovative investigation technology enables a sample tri-dimensional analysis without cutting, coating or exposing the object to any particular chemical treatment. X-ray micro-tomography matches ideal 3D microscopy features: the possibility of investigating an object in natural conditions and without any preparation or alteration; non-invasive, non-destructive, and sufficiently magnified 3D reconstruction; reliable measurement of numeric data of the internal structure (morphology, structure and ultra-structure). Hence, this technique has multi-fold applications in a wide range of fields, not only in medical and odontostomatologic areas, but also in biomedical engineering, materials science, biology, electronics, geology, archaeology, oil industry, and semi-conductors industry. This study shows possible applications of micro-CT in dental implantology to analyze 3D micro-features of dental implant to abutment interface. Indeed, implant-abutment misfit is known to increase mechanical stress on connection structures and surrounding bone tissue. This condition may cause not only screw preload loss or screw fracture, but also biological issues in peri-implant tissues

    Prevalence of Enterococci and Vancomycin Resistance in the Throat of Non-Hospitalized Individuals Randomly Selected in Central Italy

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    Enterococci are commonly found in the environment and humans as a part of the normal microbiota. Among these, Enterococcus faecalis and Enterococcus faecium can convert into opportunistic pathogens, making them a major cause of nosocomial infections. The rapid diffusion of vancomycin-resistant strains and their impact on nosocomial settings is of considerable concern. Approximately one-third of the E. faecium infections in Italy are caused by vancomycin-resistant strains. This study explored the hypothesis that the oral cavity could represent a silent reservoir of virulent enterococci. A sample of 862 oral flora specimens collected from healthy human volunteers in Central Italy was investigated by real-time PCR to detect E. faecalis and E. faecium, as well as the genetic elements that most frequently determine vancomycin resistance. The prevalence of E. faecalis was 19%, a value that was not associated with alcohol consumption, tobacco smoking, or age of the subjects. Less frequently detected, with an overall prevalence of 0.7%, E. faecium was more common among people older than 49 years of age. The genes conferring vancomycin resistance were detected in only one sample. The results indicate that the oral cavity can be considered a reservoir of clinically relevant enterococci; however, our data suggest that healthy individuals rarely carry vancomycin-resistant strains

    The alpha-synuclein RT-QuIC products generated by the olfactory mucosa of patients with parkinson’s disease and multiple system atrophy induce inflammatory responses in SH-SY5Y cells

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    Parkinson’s disease (PD) and multiple system atrophy (MSA) are caused by two distinct strains of disease-associated α-synuclein (αSynD). Recently, we have shown that olfactory mucosa (OM) samples of patients with PD and MSA can seed the aggregation of recombinant α-synuclein by means of Real-Time Quaking-Induced Conversion (αSyn_RT-QuIC). Remarkably, the biochemical and morphological properties of the final α-synuclein aggregates significantly differed between PD and MSA seeded samples. Here, these aggregates were given to neuron-like differentiated SH-SY5Y cells and distinct inflammatory responses were observed. To deepen whether the morphological features of α-synuclein aggregates were responsible for this variable SH-SY5Y inflammatory response, we generated three biochemically and morphologically distinct α-synuclein aggregates starting from recombinant α-synuclein that were used to seed αSyn_RT-QuIC reaction; the final reaction products were used to stimulate SH-SY5Y cells. Our study showed that, in contrast to OM samples of PD and MSA patients, the artificial aggregates did not transfer their distinctive features to the αSyn_RT-QuIC products and the latter induced analogous inflammatory responses in cells. Thus, the natural composition of the αSynD strains but also other specific factors in OM tissue can substantially modulate the biochemical, morphological and inflammatory features of the αSyn_RT-QuIC products

    Airway stenting in a child with spondyloepiphyseal dysplasia congenita: 13-Year survival.

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    We describe the case of a boy with spondyloepiphyseal dysplasia congenita. At birth, he experienced severe respiratory distress necessitating tracheotomy. Endoscopy done because mechanical ventilation failed to resolve desaturations disclosed severe tracheo-bronchomalacia. A Polyflex silicone stent was placed in the trachea (replaced by Y-Dumon stent) and 2 Palmaz metallic stents in the mainstem bronchi (overlapped with 2 Jomed stents 5 years later). Airway stenting guaranteed a suitable respiratory status and allowed a child who was expected to die at birth, to reach 13.5 years old in good conditions

    Management of pregnant women infected with Ebola virus in a treatment centre in Guinea, June 2014

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    We report two cases of confirmed Ebola virus disease in pregnant women, who presented at the Médecins Sans Frontières Ebola treatment centre in Guéckédou. Despite the very high risk of death, both pregnant women survived. In both cases the critical decision was made to induce vaginal delivery. We raise a number of considerations regarding the management of Ebola virus-infected pregnant women, including the place of amniocentesis and induced delivery, and whether certain invasive medical acts are justified

    Next-Generation Sequencing in Clinical Practice. Is It a Cost-Saving Alternative to a Single-Gene Testing Approach?

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    Objectives: This study aimed to compare the costs of a next-generation sequencing-based (NGS-based) panel testing strategy to those of a single-gene testing-based (SGT-based) strategy, considering different scenarios of clinical practice evolution. Methods: Three Italian hospitals were analysed, and four different testing pathways (paths 1, 2, 3, and 4) were identified: two for advanced non-small-cell lung cancer (aNSCLC) patients and two for unresectable metastatic colon-rectal cancer (mCRC) patients. For each path, we explored four scenarios considering the current clinical practice and its expected evolution. The 16 testing cases (4 scenarios × 4 paths) were then compared in terms of differential costs between the NGS-based and SGT-based approaches considering personnel, consumables, equipment, and overhead costs. Break-even and sensitivity analyses were performed. Data gathering, aimed at identifying the hospital setup, was performed through a semi-structured questionnaire administered to the professionals involved in testing activities. Results: The NGS-based strategy was found to be a cost-saving alternative to the SGT-based strategy in 15 of the 16 testing cases. The break-even threshold, the minimum number of patients required to make the NGS-based approach less costly than the SGT-based approach, varied across the testing cases depending on molecular alterations tested, techniques adopted, and specific costs. The analysis found the NGS-based approach to be less costly than the SGT-based approach in nine of the 16 testing cases at any volume of tests performed; in six cases, the NGS-based approach was found to be less costly above a threshold (and in one case, it was found to be always more expensive). Savings obtained using an NGS-based approach ranged from €30 to €1249 per patient; in the unique testing case where NGS was more costly, the additional cost per patient was €25. Conclusions: An NGS-based approach may be less costly than an SGT-based approach; also, generated savings increase with the number of patients and different molecular alterations tested
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