Microradiographic and histological evaluation of the bone-screw and bone-plate interface of orthodontic miniplates in patients

SummaryObjectives: To describe the tissue reactions at the bone-titanium interface of orthodontic miniplates in humans. Materials and methods: Forty-two samples, consisting of tissue fragments attached or not to miniplates or their fixation screws, were collected from 24 orthodontic patients treated with miniplate anchorage, at the time of removal of their miniplates. The samples were embedded in methylmethacrylate and cut into undecalcified sections which were submitted to microradiographic analysis. The sections were also stained and examined under ordinary light. Results: Three types of reactions were observed both on the histological sections and on the microradiographs. 1. The majority of the stable miniplates were easy to remove (34/42). The tissue samples collected consisted mainly in mature lamellar bone with some medullary spaces containing blood vessels, 2. two screws were highly osseointegrated and required the surgeon to remove them by trephining (2/42). They were surrounded by bone tissue which extended to the miniplate. The histological features were similar to the previous group, though the bone-screw contact was higher, and 3. in six samples obtained after unstable miniplate removal during the treatment, we observed either some woven bone trabeculae or loose connective tissue, without any histological sign of inflammation. Limitations and Conclusion: For evident ethical reasons, our data were limited by the size of the tissue fragments and the limited number of patients and variety of clinical presentations. The healing reactions consisted mainly in mature lamellar bone tissue sparsely in contact with the screw or the miniplate, with signs of a moderate remodelling activit

Crystal Structure of Two Anti-Porphyrin Antibodies with Peroxidase Activity

We report the crystal structures at 2.05 and 2.45 Å resolution of two antibodies, 13G10 and 14H7, directed against an iron(III)-αααβ-carboxyphenylporphyrin, which display some peroxidase activity. Although these two antibodies differ by only one amino acid in their variable λ-light chain and display 86% sequence identity in their variable heavy chain, their complementary determining regions (CDR) CDRH1 and CDRH3 adopt very different conformations. The presence of Met or Leu residues at positions preceding residue H101 in CDRH3 in 13G10 and 14H7, respectively, yields to shallow combining sites pockets with different shapes that are mainly hydrophobic. The hapten and other carboxyphenyl-derivatized iron(III)-porphyrins have been modeled in the active sites of both antibodies using protein ligand docking with the program GOLD. The hapten is maintained in the antibody pockets of 13G10 and 14H7 by a strong network of hydrogen bonds with two or three carboxylates of the carboxyphenyl substituents of the porphyrin, respectively, as well as numerous stacking and van der Waals interactions with the very hydrophobic CDRH3. However, no amino acid residue was found to chelate the iron. Modeling also allows us to rationalize the recognition of alternative porphyrinic cofactors by the 13G10 and 14H7 antibodies and the effect of imidazole binding on the peroxidase activity of the 13G10/porphyrin complexes

La sécheresse de ces dernières semaines n’est pas anecdotique

La sécheresse de ces dernières semaines n’est pas anecdotique. Elle annonce une série de crises et nous oblige à un changement radical. Sinon, la justice climatique ne sera pas.13. Climate action10. Reduced inequalities12. Responsible consumption and productio

シェアビジネスにおけるSNSの信頼性に関する研究-シェアビジネスの先端事例ケーススタディとSNSの信頼性の影響に関する実証分析

Otaru University of Commerce（小樽商科大学）博士（商学）doctoralcours

Study of the Histamine Electrochemical Oxidation Catalyzed by Nickel Sulfate

Thin layer technique was applied to the indirect anodic oxidation of histamine, catalyzed by NiSO4. Coulometric determination of the electron number demonstrates that histamine complexes Ni(II) and resulting adducts can be electrochemically oxidized in a single‐electron reaction, to lead Ni(III)‐histamine. The system Ni(III)/Ni(II) acts as ‘redox mediator’ for histamine oxidation. The equilibrium constant of the Ni(II)‐histamine complex formation was 106 , value showing the strong affinity between species. High content of histamine (>0.1 M), detected in fresh fish (previously exposed to the sun) extracts, showing potentialities for future design of a sensor for direct measurement in fish

Functionalized artificial bidomain proteins based on an α-solenoid protein repeat scaffold : a new class of artificial diels-alderases

This is an open access article published under an ACS AuthorChoice License, which permits copying and redistribution of the article or any adaptations for non-commercial purposes.αRep is a family of entirely artificial repeat proteins. Within the previously described αRep library, some variants are homodimers displaying interdomain cavities. Taking advantage of these properties, one of these homodimers called αRep A3 was converted into entirely artificial single chain bidomain metalloenzymes. A nonmutated A3 domain was covalently linked with an A3' domain bearing a unique cysteine on a chosen mutated position (F119C or Y26C). This single mutation ensured the covalent coupling of a 1:1 copper(II)/phenanthroline or copper(II)/terpyridine complex as a catalytic center within the interdomain cavity which was maintained large enough to accommodate two substrates of the Diels-Alder (D-A) reaction. This allowed us to obtain four new artificial Diels-Alderases that were fully characterized by matrix-assisted laser desorption ionization time-of-flight mass spectrometry, UV-vis spectroscopy, and size exclusion chromatography analyses and were then further used for the catalysis of the D-A reaction. They were found to be able to catalyze the enantioselective D-A reaction of azachalcone with cyclopentadiene with up to 38% yield and 52% enantiomeric excess, which validates the proposed strategy. Moreover, the data were rationalized with a computational strategy suggesting the key factors of the selectivity. These results suggest that artificial metalloenzymes based on bidomain A3-A3 proteins modified with nitrogen donor ligands may be suitable for further catalyst optimization and may constitute valuable tools toward more efficient and selective artificial biocatalysts

Evaluation expérimentale de la phytodisponibilité du cuivre et du cobalt dans les sols des écosystèmes métallifères de l’Arc cuprifère katangais

International audienceIn metalliferous soils, the bioavailability of potentially toxic metals is known as the main driver of the nature and distribution of vegetation communities. Bioavailability is controlled by factors such as the nature of the parental material and the physical-chemical conditions, Bogaert J., Colinet G. & Mahy G., 2018. Anthropisation des paysages katangais. Gembloux, Belgique : Presses Universitaires de Liège-Agronomie-Gembloux. Anthropisation des paysages katangais 194 which drive the behaviour of metals in the soil solution. We aimed to assess the Cu and Co bioavailability in the soils of representative vegetation units from metalliferous ecosystems of the Tenke Fungurume complex in the Katangan Copperbelt. Anisopappus davyi was cultivated in pots on these soils as well as on both contaminated and non-contaminated reference soils. The bioavailability was assessed through plant behaviour (survival, size, content in Cu and Co) and was related to the soil characteristics. The latter included the chemical fractionation of Cu and Co evaluated by geochemical modelling and chemical extraction (HF+HNO 3 +HClO 4 for total content, CH 3 COONH 4 + EDTA at pH 4.65 for available fractions and CaCl 2 for soluble fractions). Results showed a strong effect of soils properties on the behaviour and characteristics of A. davyi, which appeared to be linked to the degree of soil contamination. The available and soluble fractions were both highly correlated to the total fraction. However, the available fraction seemed to be the most closely related to plant response. In soils, pH controls the availability and solubility of elements for similar levels of total content. According to geochemical modelling, Cu was mainly linked to organic fractions and Fe oxides while Co was linked to organic fractions and Mn oxides. Our study confirmed the complementary nature of the various approaches used for the evaluation of metal phytoavailability.Dans les sols métallifères, la biodisponibilité des éléments potentiellement toxiques est un fac-teur important de la nature et de la distribution des communautés végétales qui s'y développent. Cette disponibilité est contrôlée par plusieurs facteurs dont la nature des matériaux parentaux et les conditions physico-chimiques dans les sols qui conditionnent le comportement des métaux dans la solution du sol. Notre étude vise à évaluer la biodisponibilité du Cu et du Co dans les sols de quelques unités de végétation caractéristiques des écosystèmes métallifères du complexe Tenke Fungurume dans l'Arc cuprifère katangais. Une culture en pots d'Anisopappus davyi a été réalisée sur ces sols, ainsi que sur un témoin contaminé par l'industrie minière et un témoin non contaminé. La biodisponibilité a été évaluée par les réponses plantes (survie, taille et teneurs en Cu et Co) et mise en relation avec les caractéristiques du sol, dont le fractionnement chimique estimé par modélisation géochimique ou par extraction chimique (HF+HNO 3 +HClO 4 pour les teneurs totales, CH 3 COONH 4 + EDTA à pH 4,65 pour les fractions disponibles et CaCl 2 pour les fractions solubles). Les résultats indiquent un effet marqué des sols sur le comportement et les caractéristiques de A. davyi qui peut être expliqué par le degré de contamination des sols. Les fractions disponibles et solubles sont fortement corrélées à la fraction totale. Néanmoins, c'est la fraction disponible qui semble la mieux reliée à la réponse plante. Le pH contrôle la disponibilité et la solubilité des éléments pour des niveaux équivalents de teneurs totales. D'après la modèli-sation géochimique, le Cu est majoritairement lié aux fractions organiques et aux oxydes de Fe tandis que le Co est lié aux fractions organiques et aux oxydes de Mn. Les différentes approches se montrent complémentaires pour la caractérisation de la phytodisponibilité des métaux étudiés

Modified Miniplates for Temporary Skeletal Anchorage in Orthodontics: Placement and Removal Surgeries

Skeletal anchorage systems are increasingly used in orthodontics. This article describes the techniques of placement and removal of modified surgical miniplates used for temporary orthodontic anchorage and reports surgeons’ perceptions of their use

La reemergencia del Virus del ébola en África

Los miembros de la familia Filoviridae, que actualmente consiste en los virus del Ebola y Marburg, ocasionan severas y frecuentemente mortales fiebres hemorrágicas en humanos y primates no humanos. La identificación y aislamiento reciente de un nuevo virus del Ebola de un solo caso humano no fatal en Côte d’Ivoire y el brote más reciente de fiebre hemorrágica del Ebola en y alrededor de Kikwit, Zaire, ha elevado el interés sobre la amenaza en la salud pública de estos patógenos humanos. Los Filovirus se clasifican como agentes de nivel 4 de bioseguridad a causa de la extrema patogenicidad de ciertas cepas y la carencia de una vacuna protectora o de una efectiva droga antiviral. Además, los filovirus están entre los grupos de virus más misteriosos conocidos porque sus reservorios y la historia natural permanecen indefinidos y sus patogénesis es pobremente entendida.Facultad de Ciencias Veterinaria