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Orthodontic Forced Eruption of Permanent Anterior Teeth with Subgingival Fractures: A Systematic Review.
No full text(1) Background: To assess orthodontic forced eruption (OFE) as a pre-restorative procedure for non-restorable permanent teeth with subgingival dental hard tissue defects after dental trauma. (2) Methods: A systematic electronic search of three databases, namely, MEDLINE, Cochrane Library, and EMBASE, revealed a total of 2757 eligible publications. Randomized controlled clinical trials (RCT), retro- and prospective clinical studies, or case series (with a minimum of three patients) were reviewed. (3) Results: Thirteen full-text papers were included: one RCT, one prospective clinical trial, two retrospective cohort studies, and nine case series. Within case series, statistical significance between age and cause of fracture (p < 0.03) was determined. The mean extrusion rate of OFE was 1.5 mm a week within a four to six weeks treatment period followed by retention. Three OFE protocols for maxillary single teeth are available: 1. OFE without migration of gingiva and alveolar bone, 2. OFE with gingival migration and slight alveolar bone migration, and 3. OFE with migration of both gingiva and alveolar bone. (4) Conclusions: The current state of the evidence suggests that OFE is a feasible pre-treatment option for non-restorable permanent teeth. OFE can promote the migration of tooth surrounding hard and soft tissues in the esthetic zone. Root resorption does not seem to be a relevant side effect of OFE
Identification of a 1-deoxy-D-xylulose-5-phosphate synthase (DXS) mutant with improved crystallographic properties.
No full textIn this report, we describe a truncated Deinococcus radiodurans 1-deoxy-D-xylulose-5-phosphate synthase (DXS) protein that retains enzymatic activity, while slowing protein degradation and showing improved crystallization properties. With modern drug-design approaches relying heavily on the elucidation of atomic interactions of potential new drugs with their targets, the need for co-crystal structures with the compounds of interest is high. DXS itself is a promising drug target, as it catalyzes the first reaction in the 2-C-methyl-D-erythritol 4-phosphate (MEP)-pathway for the biosynthesis of the universal precursors of terpenes, which are essential secondary metabolites. In contrast to many bacteria and pathogens, which employ the MEP pathway, mammals use the distinct mevalonate-pathway for the biosynthesis of these precursors, which makes all enzymes of the MEP-pathway potential new targets for the development of anti-infectives. However, crystallization of DXS has proven to be challenging: while the first X-ray structures from Escherichia coli and D. radiodurans were solved in 2004, since then only two additions have been made in 2019 that were obtained under anoxic conditions. The presented site of truncation can potentially also be transferred to other homologues, opening up the possibility for the determination of crystal structures from pathogenic species, which until now could not be crystallized. This manuscript also provides a further example that truncation of a variable region of a protein can lead to improved structural data
A genome-wide transcriptomic analysis of embryos fathered by obese males in a murine model of diet-induced obesity.
No full textPaternal obesity is known to have a negative impact on the male's reproductive health as well as the health of his offspring. Although epigenetic mechanisms have been implicated in the non-genetic transmission of acquired traits, the effect of paternal obesity on gene expression in the preimplantation embryo has not been fully studied. To this end, we investigated whether paternal obesity is associated with gene expression changes in eight-cell stage embryos fathered by males on a high-fat diet. We used single embryo RNA-seq to compare the gene expression profile of embryos generated by males on a high fat (HFD) versus control (CD) diet. This analysis revealed significant upregulation of the Samd4b and Gata6 gene in embryos in response to a paternal HFD. Furthermore, we could show a significant increase in expression of both Gata6 and Samd4b during differentiation of stromal vascular cells into mature adipocytes. These findings suggest that paternal obesity may induce changes in the male germ cells which are associated with the gene expression changes in the resulting preimplantation embryos
Expanding the Scope of Detectable Microbial Natural Products by Complementary Analytical Methods and Cultivation Systems.
No full textOuter membrane vesicles (OMVs) are universally produced by prokaryotes and play important roles in symbiotic and pathogenic interactions. They often contain DNA, but a mechanism for its incorporation is lacking. Here, we show that Dinoroseobacter shibae, a dinoflagellate symbiont, constitutively secretes OMVs containing DNA. Time-lapse microscopy captured instances of multiple OMV production at the septum during cell division. DNA from the vesicle lumen was up to 22-fold enriched for the region around the terminus of replication (ter). The peak of coverage was located at dif, a conserved 28-bp palindromic sequence required for binding of the site-specific tyrosine recombinases XerC/XerD. These enzymes are activated at the last stage of cell division immediately prior to septum formation when they are bound by the divisome protein FtsK. We suggest that overreplicated regions around the terminus have been repaired by the FtsK-dif-XerC/XerD molecular machinery. The vesicle proteome was clearly dominated by outer membrane and periplasmic proteins. Some of the most abundant vesicle membrane proteins were predicted to be required for direct interaction with peptidoglycan during cell division (LysM, Tol-Pal, Spol, lytic murein transglycosylase). OMVs were 15-fold enriched for the saturated fatty acid 16:00. We hypothesize that constitutive OMV secretion in D. shibae is coupled to cell division. The footprint of the FtsK-dif-XerC/XerD molecular machinery suggests a novel potentially highly conserved route for incorporation of DNA into OMVs. Clearing the division site from small DNA fragments might be an important function of vesicles produced during exponential growth under optimal conditions.IMPORTANCE Gram-negative bacteria continually form vesicles from their outer membrane (outer membrane vesicles [OMVs]) during normal growth. OMVs frequently contain DNA, and it is unclear how DNA can be shuffled from the cytoplasm to the OMVs. We studied OMV cargo in Dinoroseobacter shibae, a symbiont of dinoflagellates, using microscopy and a multi-omics approach. We found that vesicles formed during undisturbed exponential growth contain DNA which is enriched for genes around the replication terminus, specifically, the binding site for an enzyme complex that is activated at the last stage of cell division. We suggest that the enriched genes are the result of overreplication which is repaired by their excision and excretion via membrane vesicles to clear the divisome from waste DNA
Autophagy-A Story of Bacteria Interfering with the Host Cell Degradation Machinery.
No full textAutophagy is a highly conserved and fundamental cellular process to maintain cellular homeostasis through recycling of defective organelles or proteins. In a response to intracellular pathogens, autophagy further acts as an innate immune response mechanism to eliminate pathogens. This review will discuss recent findings on autophagy as a reaction to intracellular pathogens, such as Salmonella typhimurium, Listeria monocytogenes, Mycobacterium tuberculosis, Staphylococcus aureus, and pathogenic Escherichia coli. Interestingly, while some of these bacteria have developed methods to use autophagy for their own benefit within the cell, others have developed fascinating mechanisms to evade recognition, to subvert the autophagic pathway, or to escape from autophagy
Eradication of chronic HCV infection: improvement of dysbiosis only in patients without liver cirrhosis.
No full textIt is well accepted that liver diseases and their outcomes are associated with intestinal microbiota but causality is difficult to establish. The intestinal microbiota is altered in patients with hepatitis C. As chronic HCV infection can now be cured in almost all patients, it is an ideal model to study the influence of liver disease on the microbiota. We aimed to analyze prospectively the changes in the gut microbiome in patients who received direct acting antivirals (DAA) and achieved sustained virological response (SVR). Amplicon sequencing of the V1-V2 region in the 16S rRNA gene was performed in stool samples of patients with chronic hepatitis C. Patients in the treatment group received direct acting antivirals (n=65) whereas in the control group no DAA were given (n=33). Only patients achieving SVR were included. The alpha diversity increased numerical but not significantly from baseline to SVR24/48 (2.784±0.248 vs. 2.846±0.224; p= 0.057). When stratifying for the presence of liver cirrhosis, a significant increase in diversity was only seen in patients without cirrhosis. Differences in the microbial community structure induced by the achievement of SVR were only observed in patients without liver cirrhosis. In patients with liver cirrhosis and in the control group, no significant differences were observed. In conclusion, the achievement of SVR24/48 in patients with chronic HCV was associated with changes in the intestinal microbiota. However, these changes were only seen in patients without liver cirrhosis. A major role of liver remodeling on the intestinal microbiota is indicated by the dynamics of the intestinal microbial community structure depending on the stage of fibrosis in patients resolving chronic hepatitis C
Induced Arp2/3 Complex Depletion Increases FMNL2/3 Formin Expression and Filopodia Formation.
No full textThe Arp2/3 complex generates branched actin filament networks operating in cell edge protrusion and vesicle trafficking. Here we employ a conditional knockout mouse model permitting tissue- or cell-type specific deletion of the murine Actr3 gene (encoding Arp3). A functional Actr3 gene appeared essential for fibroblast viability and growth. Thus, we developed cell lines for exploring the consequences of acute, tamoxifen-induced Actr3 deletion causing near-complete loss of functional Arp2/3 complex expression as well as abolished lamellipodia formation and membrane ruffling, as expected. Interestingly, Arp3-depleted cells displayed enhanced rather than reduced cell spreading, employing numerous filopodia, and showed little defects in the rates of random cell migration. However, both exploration of new space by individual cells and collective migration were clearly compromised by the incapability to efficiently maintain directionality of migration, while the principal ability to chemotax was only moderately affected. Examination of actin remodeling at the cell periphery revealed reduced actin turnover rates in Arp2/3-deficient cells, clearly deviating from previous sequestration approaches. Most surprisingly, induced removal of Arp2/3 complexes reproducibly increased FMNL formin expression, which correlated with the explosive induction of filopodia formation. Our results thus highlight both direct and indirect effects of acute Arp2/3 complex removal on actin cytoskeleton regulation
The Impact of the COVID-19 Pandemic on Self-Reported Health.
No full textBackground: The pandemic caused by the coronavirus SARS-CoV-2 and the countermeasures taken to protect the public are having a substantial effect on the health of the population. In Germany, nationwide protective measures to halt the spread of the virus were implemented in mid-March for 6 weeks.
Methods: In May, the impact of the pandemic was assessed in the German National Cohort (NAKO). A total of 113 928 men and women aged 20 to 74 years at the time of the baseline examination conducted 1 to 5 years earlier (53%) answered, within a 30-day period, a follow-up questionnaire on SARS-CoV-2 test status, COVID-19- associated symptoms, and self-perceived health status.
Results: The self-reported SARS-CoV-2 test frequency among the probands was 4.6%, and 344 participants (0.3%) reported a positive test result. Depressive and anxiety-related symptoms increased relative to baseline only in participants under 60 years of age, particularly in young women. The rate of moderate to severe depressive symptoms increased from 6.4% to 8.8%. Perceived stress increased in all age groups and both sexes, especially in the young. The scores for mental state and self-rated health worsened in participants tested for SARS-CoV-2 compared with those who were not tested. In 32% of the participants, however, self-rated health improved.
Conclusion: The COVID-19 pandemic and the protective measures during the first wave had effects on mental health and on self-rated general health
A New PqsR Inverse Agonist Potentiates Tobramycin Efficacy to Eradicate Pseudomonas aeruginosa Biofilms
No full textPseudomonas aeruginosa (PA) infections can be notoriously difficult to treat and are often accompanied by the development of antimicrobial resistance (AMR). Quorum sensing inhibitors (QSI) acting on PqsR (MvfR) – a crucial transcriptional regulator serving major functions in PA virulence – can enhance antibiotic efficacy and eventually prevent the AMR. An integrated drug discovery campaign including design, medicinal chemistry‐driven hit‐to‐lead optimization and in‐depth biological profiling of a new QSI generation is reported. The QSI possess excellent activity in inhibiting pyocyanin production and PqsR reporter‐gene with IC50 values as low as 200 and 11 × 10−9 m, respectively. Drug metabolism and pharmacokinetics (DMPK) as well as safety pharmacology studies especially highlight the promising translational properties of the lead QSI for pulmonary applications. Moreover, target engagement of the lead QSI is shown in a PA mucoid lung infection mouse model. Beyond that, a significant synergistic effect of a QSI‐tobramycin (Tob) combination against PA biofilms using a tailor‐made squalene‐derived nanoparticle (NP) formulation, which enhance the minimum biofilm eradicating concentration (MBEC) of Tob more than 32‐fold is demonstrated. The novel lead QSI and the accompanying NP formulation highlight the potential of adjunctive pathoblocker‐mediated therapy against PA infections opening up avenues for preclinical development.H2020 Marie Skłodowska-Curie Action
Three New Derivatives of Zopfinol from Pseudorhypophila Mangenotii gen. et comb. nov
No full textTriangularia mangenotti was analyzed for the production of secondary metabolites, resulting in the isolation of known zopfinol (1) and its new derivatives zopfinol B-C (2-4), the 10-membered lactones 7-O-acetylmultiplolide A (5) and 8-O-acetylmultiplolide A (6), together with sordarin (7), sordarin B (8), and hypoxysordarin (9). The absolute configuration of 1 was elucidated by the synthesis of MPTA-esters. Compound 1 showed antimicrobial activity against the Gram-positive bacteria Bacillus subtilis and Staphylococcus aureus and the fungus Mucor hiemalis. While 4 was weakly antibacterial, 3 showed stronger antibiotic activity against the Gram-positive bacteria and weak antifungal activity against M. hiemalis and Rhodotorula glutinis. We furthermore observed the cytotoxicity of 1, 3 and 4 against the mammalian cell lines KB3.1 and L929. Moreover, the new genus Pseudorhypophila is introduced herein to accommodate Triangularia mangenotii together with several species of Zopfiella-Z. marina, Z. pilifera, and Z. submersa. These taxa formed a well-supported monophyletic clade in the recently introduced family Navicularisporaceae, located far from the type species of the respective original genera, in a phylogram based on the combined dataset sequences of the internal transcribed spacer region (ITS), the nuclear rDNA large subunit (LSU), and fragments of the ribosomal polymerase II subunit 2 (rpb2) and β-tubulin (tub2) genes. Zopfiella submersa is synonymized with P. marina due to the phylogenetic and morphological similarity. The isolation of zopfinols 1-4 and sordarins 7-9 confirms the potential of this fungal order as producers of bioactive compounds and suggests these compounds as potential chemotaxonomic markers