105 research outputs found

    Synthesis of 5-Hydroxyectoine from Ectoine: Crystal Structure of the Non-Heme Iron(II) and 2-Oxoglutarate-Dependent Dioxygenase EctD

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    As a response to high osmolality, many microorganisms synthesize various types of compatible solutes. These organic osmolytes aid in offsetting the detrimental effects of low water activity on cell physiology. One of these compatible solutes is ectoine. A sub-group of the ectoine producer's enzymatically convert this tetrahydropyrimidine into a hydroxylated derivative, 5-hydroxyectoine. This compound also functions as an effective osmostress protectant and compatible solute but it possesses properties that differ in several aspects from those of ectoine. The enzyme responsible for ectoine hydroxylation (EctD) is a member of the non-heme iron(II)-containing and 2-oxoglutarate-dependent dioxygenases (EC 1.14.11). These enzymes couple the decarboxylation of 2-oxoglutarate with the formation of a high-energy ferryl-oxo intermediate to catalyze the oxidation of the bound organic substrate. We report here the crystal structure of the ectoine hydroxylase EctD from the moderate halophile Virgibacillus salexigens in complex with Fe3+ at a resolution of 1.85 Å. Like other non-heme iron(II) and 2-oxoglutarate dependent dioxygenases, the core of the EctD structure consists of a double-stranded β-helix forming the main portion of the active-site of the enzyme. The positioning of the iron ligand in the active-site of EctD is mediated by an evolutionarily conserved 2-His-1-carboxylate iron-binding motif. The side chains of the three residues forming this iron-binding site protrude into a deep cavity in the EctD structure that also harbours the 2-oxoglutarate co-substrate-binding site. Database searches revealed a widespread occurrence of EctD-type proteins in members of the Bacteria but only in a single representative of the Archaea, the marine crenarchaeon Nitrosopumilus maritimus. The EctD crystal structure reported here can serve as a template to guide further biochemical and structural studies of this biotechnologically interesting enzyme family

    Detection of secondary structures in 17-mer Ru(II)-labeled single-stranded oligonucleotides from luminescence lifetime studies.

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    The emission properties of a non intercalating complex, [Ru(TAP)2(dip)]2+ (TAP = 1,4,5,8-tetraazaphenanthrene; dip = 4,7-diphenyl-1,10-phenanthroline), tethered to 17-mer single-stranded oligodeoxyribonucleotides (ODNs) either in the middle or at the 5'-end of the sequence, are determined. The results highlight the fact that the luminescence of this metallic compound is sufficiently sensitive to its microenvironment to probe self-structuration of these short single-stranded ODNs. It is shown that the weighted averaged emission lifetimes (tau(M)) along with the quenching rate constants of luminescence by oxygen reflect particularly well different structures adopted by the different ODNs sequences. The determination of these parameters thus offers an elegant way to examine possible structurations of synthetic single-stranded ODNs that play important roles in biological applications.Journal ArticleResearch Support, Non-U.S. Gov'tinfo:eu-repo/semantics/publishe

    Long-Term Results After Head Orthosis Therapy for Early Childhood Position-Related Cranial Deformities: Stability of Treatment Outcome and Parental Satisfaction

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    The purpose of this study was to determine whether different types of position-related cranial deformities show changes after completion of head orthosis therapy. We investigated how children's age at the begin of molding helmet therapy affects the duration and long-term stability of treatment. In addition, parental satisfaction with helmet therapy has been investigated. Between 2012 and 2019, 47 patients have been analyzed after undergoing helmet therapy. At the beginning of treatment different disease pattern were classified. Posterior deformational Plagiocephalus defined by a cranial vault index (CVA) > 1 cm and a cranial index (CI) 90%. Posterior deformational combined Plagio- and Brachycephalus defined by CVA > 1 cm and CI> 90%. At the beginning of therapy, the end of therapy and within 5-year-follow-up CI and CVA was measured by three-dimensional photogrammetry for 2 age groups (4- 6 and 7-12 months). Additionally, parents completed a standardized questionnaire to evaluate the personal assessment of treatment outcome. During treatment CI and CVA of all children decreased significantly (P< 0.001). Furthermore, CI significantly decreased after ending helmet therapy (P< 0.001). Cranial vault index decreased not significantly in the same period (P = 0.361). For the 4 to 6 months old group treatment time was significantly shorter than for the older group. Before starting helmet therapy nearly half of the parents graded the scull as moderate and onethird as severe deformed. After ending treatment, the majority of parents report satisfaction and compliance. However, one- third of parents noted a slight scull deformation and personal load during therapy. After completion of therapy an improvement of head shape can be expected for the majority of children. This is particularly evident for improvement of the CI and a shorter treatment time until the age of 6months at the beginning of therapy. Parents reported satisfaction and child compliance. Almost all parents were convinced that treatment was useful and would repeat it again

    Quantitative Evaluation of Focal Series in HRTEM

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    Santalene synthase

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    The invention is directed to a santalene synthase, to a nucleic acid encoding said santalene synthase, to an expression vector comprising said nucleic acid, to a host cell comprising said expression vector, to a method of preparing santalene, to a method of preparing santalol and to a method of preparing a santalene synthase. The invention is further directed to an antibody specific for the santalane synthase

    A retrospective analysis of social media posts pertaining to COVID-19 vaccination side effects

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    Objectives: With an uprising influence of social media platforms like Twitter and Instagram a multitude of worldwide accessible information is available. Since the beginning of COVID-19 pandemic the exchange of medical information about several topics related to this infectious disease and its vaccination has increased rapidly. The purpose of this investigation was to assess the content associated with COVID-19 vaccination and its side effects and evaluate its educational quality. Methods: We conducted this retrospective study to investigate 600 Twitter and Instagram posts by #covidvaccinesideeffects due to number of 'likes', comments, type of post, language, its purpose and source. In addition, posts were evaluated due to educational quality by three examiners of different edu-cational levels. Results: The majority of posts showed 0 to 50 likes and 0 to 5 comments in English language. A com-parison between Twitter and Instagram by the influence of application showed significant differences in number of posts and likes or comments (p < 0.05). The major post type were texts for Twitter (251; 83.7%) and videos for Instagram (104; 34.7%). While a majority of posts by #covidvaccinesideeffects report about the occurrence of side effects, the majority of them were mild and general COVID-19 vacci-nation feedback during the first 4 months was positive. But, only 3 to 7% were rated by excellent edu-cational and validatable content. Interrater reliability between all three examiners presented a high concordance with 89% (p = 0.001). Conclusions: This study presents an analysis of quantity and quality of social media content according to COVID-19 vaccinations and its side effects. It supports the deduction that most of the content on Twitter and Instagram is shared by patients and unclear sources and thus is limited informative. Nevertheless, influence of social media on medical information especially during COVID-19 pandemic is increasing and practitioners have to face its effect on their patients. (c) 2021 Elsevier Ltd. All rights reserved

    Comparison of two established 2D staging techniques to their appliance in 3D cone beam computer-tomography for dental age estimation

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    For medicolegal purposes, orthodontic or orthognathic treatment various stomatological staging technique for age estimation with appliance of conventional radiographic images have been published. It remains uninvestigated if cone beam computer-tomography delivers comparable staging results to the conventional radiographic stages of third molar analysis. We conducted a retrospective cross-sectional study of 312 patients aged 13-21 years. Dental age estimation staging technique, introduced by Nolla and Demirjian, were applied on the left lower third molar imaged by conventional panoramic radiographs and cone beam computer-tomography. It was investigated if 2D and 3D imaging presented different staging results for dental age estimation. In 21% the Demirjian's staging differed by a single stage between 2 and 3D images. The greatest congruence (87%) between 2 and 3D images was revealed for stage 7 (G). In contrary, stage 5 (E) presented the lowest level of congruence with 47.4%. The categorization of Nolla revealed divergences in staging for than two categorical variables in Nolla's stages 3, 4, 5 and 6. In general, the analysis of the data displayed the divergence for Nolla's stages 4-8. The staging results for 2D and 3D imaging in accordance to the rules of Nolla and Demirjian showed significant differences. Individuals of 18 years may present immature third molars, thus merely an immature third molar cannot reject legal majority. Nolla's and Demirjian's 2D and 3D imaging present significantly different staging results

    #facialtraumasurgery: Educational Content of Instagram as a Social Media Source for Facial Trauma Surgery

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    With an uprising influence of social media platforms like Instagram during the last decade, medical and healthcare related posts have accumulated majorly. In particular the head and face characterizes and signifies each individual's human character, which may be the reason why numerous posts are shared on social media platforms. The purpose of this investigation was to assess the content associated with facial trauma surgery and evaluate its educational quality. The authors performed a retrospective investigation on 550 Instagram posts by #facialtraumasurgery due to number of likes, comments, type of post, language, its purpose, and source. Furthermore, posts were evaluated due to their educational quality by 3 examiners of different educational levels. The majority of posts showed 0 to 50 likes and 0 to 5 comments in English language. The major post type were single photographs (289; 52.5%), multiple photographs (188; 34.2%), videos (73; 13.3%) and predominantly case reports (233; 42.4%). The source was 322 (58.5%) posts by surgeons, followed by 185 (33.6%) clinic posts. Only 10% to 18% of the posts were rated excellent. Interrater reliability between all 3 examiners presented a high concordance with 89% (P = 0.000). Our study presents an analysis of quantity and quality of social media content according to facial trauma surgery. It supports the deduction that most of the content on Instagram is shared by patients and unclear sources and thus is limited informative. Nevertheless, influence of social media on medical information is increasing and practitioners have to face its effect on their patients

    Surgical side infections of the tracheostomy- A retrospective cohort study of patients with head and neck cancer in intensive care

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    This study was conducted to reveal the relevant risk factors for surgical site infections (SSI) of the tracheostomy in ICU tracheostomy patients with oncologic history. Retrospectively, medical and ICU records of patients who received open tracheostomy in a uniform manner were investigated. Of 187 consecutive patients in total, patients with a peri/post-operative antibiotic prophylaxis (POABP) experienced significantly more Organ-Space SSI, whereas patients with a POABP developed less Superficial Incisional SSI and Deep Incisional SSI. Neck Dissection (p = 0.025), especially the more levels are included, and POABP (p = 0.005) have a significant impact on the occurrence of an SSI of the tracheostomy. Deep incisional SSI significantly prolonged a patient's dependency on a ventilator (p = 0.045, M = 3.92, SD = 4.718). The difference between Superficial Incisional, Deep Incisional and Organ-Space SSI should be taken in consideration regarding risk evaluation and treatment. Furthermore, a gram-negative facultative anaerobic biofilm should be taken into consideration in treatment options and thus an escalation regarding antibiotic treatment as a POABP. For fulminant SSI of the tracheostomy the use of piperacillin/tazobactam or 3rd generation cephalosporines or carbapenems is recommendable.(c) 2022 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved
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