In vitro Evaluation der lateralen Guttapercha-Kondensationstechnik mit Fingerspreadern verschiedener Spitzengeometrie.

Ziel: Ziel der Studie war es, den Einfluss von Spreaderform und Aufbereitungstaper bei der lateralen Kondensation auf die Dichtigkeit der Wurzelfüllungen zu untersuchen. Für diese Studie wurde ein handelsüblicher Spreader so modifiziert, dass seine Arbeitsspitze durch Abflachung Pluggerfunktionalität erhält. Material&Methode: Insgesamt n=75 frisch extrahierte menschliche Zähne mit geraden Wurzeln wurden so vorbereitet, dass 75 gerade Zahnwurzeln. Diese Zahnwurzeln wurden randomisiert so auf 5 Gruppen aufgeteilt, mit rotierenden Ni/Ti Instrumenten vom Typ Profile 02/50 und 04/50 aufbereitet und unter Verwendung der lateraler Kondensation mit den konventionellen Spreadern „pointed“ sowie modifizierten Spreadern "flat tip“ gefüllt. Eine negative Kontrollgruppe wurde unter Anwendung der Zentralstifttechnik ohne Sealer abgefüllt. Die Wurzeln wurden bis auf 1 mm oberhalb des Apex mit Nagellack überzogen und anschließend verblindet. Nach Lagerung in 2%-Methylenblau für 4 Tage wurden die Proben in Kaltpolymerisat eingebettet und es wurden sechs serielle Querschnitte im Abstand von 0,8 mm ab dem Apex angefertigt. Die Querschnitte wurden digitalisiert. Bewertet wurden die Penetrationstiefe in mm ab dem Apex und der Penetrationsgrad. Ergebnisse: Alle Proben zeigten eine ausgeprägte Penetration. Lediglich der Parameter Penetrationsgrad konnte für eine Differenzierung zwischen den Prüfgruppen verwendet werden. Es zeigte sich ein signifikanter Unterschied zwischen der Kontrollgruppe und allen Prüfgruppen. Innerhalb der Prüfgruppen, welche als normalverteilt und varianzhomogen befunden wurden, wurde eine zweifaktorielle Varianzanalyse für die Faktoren "Spreader" und "Taper" durchgeführt. Es ergab sich für den Faktor "Spreader" ein signifikanter Unterschied (p=0,030) ebenso wie für den Faktor "Taper" (p=0,006). Wurzelfüllungen welche mit dem modifizierten Spreader angefertigt wurden zeigen demnach eine statistisch signifikant schlechtere Dichtigkeit (gemessen mittels Penetrationsgrad) als solche die mit konventionellem Spreader kondensiert wurden. Eine Aufbereitung auf einen Taper von 0,04 führt zu einer statistisch signifikant besseren Dichtigkeit (gemessen mittels Penetrationsgrad) als eine Aufbereitung auf einen ISO-normkonformen Taper von 0,02. Schlussfolgerung: Es konnte gezeigt werden, dass mit dem gewählten Spreaderdesign kein zusätzlicher Nutzen verbunden ist, ja sogar die Dichtigkeit der resultierenden Wurzelfüllungen abnahm. Es ist also nicht angezeigt, Spreader in der beschriebenen Form klinisch zu verwenden. Weiterhin konnte gezeigt werden, dass die Verwendung eines größeren Aufbereitungstapers auch bei lateraler Kondensation zu dichteren Füllungen führt. Klinisch sollte daher ein entsprechend großer Aufbereitungskonus angestrebt werden

Plasma levels of apelin are reduced in patients with liver fibrosis and cirrhosis but are not correlated with circulating levels of bone morphogenetic protein 9 and 10

Background: The peptide apelin is expressed in human healthy livers and is implicated in the development of hepatic fibrosis and cirrhosis. Mutations in the bone morphogenetic protein receptor type II (BMPR-II) result in reduced plasma levels of apelin in patients with heritable pulmonary arterial hypertension. Ligands for BMPR-II include bone morphogenetic protein 9 (BMP9), highly expressed in liver, and BMP10, expressed in heart and to a lesser extent liver. However, it is not known whether reductions in BMP9 and/or BMP10, with associated reduction in BMPR-II signalling, correlate with altered levels of apelin in patients with liver fibrosis and cirrhosis. Methods: Plasma from patients with liver fibrosis (n = 14), cirrhosis (n = 56), and healthy controls (n = 25) was solid-phase extracted using a method optimised for recovery of apelin, which was measured by ELISA. Results: Plasma apelin was significantly reduced in liver fibrosis (8.3 ± 1.2 pg/ml) and cirrhosis (6.5 ± 0.6 pg/ml) patients compared with controls (15.4 ± 2.0 pg/ml). There was no obvious relationship between apelin and BMP 9 or BMP10 previously measured in these patients. Within the cirrhotic group, there was no significant correlation between apelin levels and disease severity scores, age, sex, or treatment with β-blockers. Conclusions: Apelin was significantly reduced in plasma of patients with both early (fibrosis) and late-stage (cirrhosis) liver disease. Fibrosis is more easily reversible and may represent a potential target for new therapeutic interventions. However, it remains unclear whether apelin signalling is detrimental in liver disease or is beneficial and therefore, whether an apelin antagonist or agonist have clinical use

Rossby wave dynamics of the North Pacific extra-tropical response to El Niño: importance of the basic state in coupled GCMs

The extra-tropical response to El Nino in a "low" horizontal resolution coupled climate model, typical of the Intergovernmental Panel on Climate Change fourth assessment report simulations, is shown to have serious systematic errors. A high resolution configuration of the same model has a much improved response that is similar to observations. The errors in the low resolution model are traced to an incorrect representation of the atmospheric teleconnection mechanism that controls the extra-tropical sea surface temperatures (SSTs) during El Nino. This is due to an unrealistic atmospheric mean state, which changes the propagation characteristics of Rossby waves. These erroneous upper tropospheric circulation anomalies then induce erroneous surface circulation features over the North Pacific. The associated surface wind speed and direction errors create erroneous surface flux and upwelling anomalies which finally lead to the incorrect extra-tropical SST response to El Nino in the low resolution model. This highlights the sensitivity of the climate response to a single link in a chain of complex climatic processes. The correct representation of these processes in the high resolution model indicates the importance of horizontal resolution in resolving such processes

Nonlinearity of Mechanochemical Motions in Motor Proteins

The assumption of linear response of protein molecules to thermal noise or structural perturbations, such as ligand binding or detachment, is broadly used in the studies of protein dynamics. Conformational motions in proteins are traditionally analyzed in terms of normal modes and experimental data on thermal fluctuations in such macromolecules is also usually interpreted in terms of the excitation of normal modes. We have chosen two important protein motors - myosin V and kinesin KIF1A - and performed numerical investigations of their conformational relaxation properties within the coarse-grained elastic network approximation. We have found that the linearity assumption is deficient for ligand-induced conformational motions and can even be violated for characteristic thermal fluctuations. The deficiency is particularly pronounced in KIF1A where the normal mode description fails completely in describing functional mechanochemical motions. These results indicate that important assumptions of the theory of protein dynamics may need to be reconsidered. Neither a single normal mode, nor a superposition of such modes yield an approximation of strongly nonlinear dynamics.Comment: 10 pages, 6 figure

Prediction of photoperiodic regulators from quantitative gene circuit models

Photoperiod sensors allow physiological adaptation to the changing seasons. The external coincidence hypothesis postulates that a light-responsive regulator is modulated by a circadian rhythm. Sufficient data are available to test this quantitatively in plants, though not yet in animals. In Arabidopsis, the clock-regulated genes CONSTANS (CO) and FLAVIN, KELCH, F-BOX (FKF1) and their lightsensitive proteins are thought to form an external coincidence sensor. We use 40 timeseries of molecular data to model the integration of light and timing information by CO, its target gene FLOWERING LOCUS T (FT), and the circadian clock. Among other predictions, the models show that FKF1 activates FT. We demonstrate experimentally that this effect is independent of the known activation of CO by FKF1, thus we locate a major, novel controller of photoperiodism. External coincidence is part of a complex photoperiod sensor: modelling makes this complexity explicit and may thus contribute to crop improvement

Population genomics of domestic and wild yeasts

The natural genetics of an organism is determined by the distribution of sequences of its genome. Here we present one- to four-fold, with some deeper, coverage of the genome sequences of over seventy isolates of the domesticated baker's yeast, _Saccharomyces cerevisiae_, and its closest relative, the wild _S. paradoxus_, which has never been associated with human activity. These were collected from numerous geographic locations and sources (including wild, clinical, baking, wine, laboratory and food spoilage). These sequences provide an unprecedented view of the population structure, natural (and artificial) selection and genome evolution in these species. Variation in gene content, SNPs, indels, copy numbers and transposable elements provide insights into the evolution of different lineages. Phenotypic variation broadly correlates with global genome-wide phylogenetic relationships however there is no correlation with source. _S. paradoxus_ populations are well delineated along geographic boundaries while the variation among worldwide _S. cerevisiae_ isolates show less differentiation and is comparable to a single _S. paradoxus_ population. Rather than one or two domestication events leading to the extant baker's yeasts, the population structure of _S. cerevisiae_ shows a few well defined geographically isolated lineages and many different mosaics of these lineages, supporting the notion that human influence provided the opportunity for outbreeding and production of new combinations of pre-existing variation

Evidence for a Grooming Claw in a North American Adapiform Primate: Implications for Anthropoid Origins

Among fossil primates, the Eocene adapiforms have been suggested as the closest relatives of living anthropoids (monkeys, apes, and humans). Central to this argument is the form of the second pedal digit. Extant strepsirrhines and tarsiers possess a grooming claw on this digit, while most anthropoids have a nail. While controversial, the possible presence of a nail in certain European adapiforms has been considered evidence for anthropoid affinities. Skeletons preserved well enough to test this idea have been lacking for North American adapiforms. Here, we document and quantitatively analyze, for the first time, a dentally associated skeleton of Notharctus tenebrosus from the early Eocene of Wyoming that preserves the complete bones of digit II in semi-articulation. Utilizing twelve shape variables, we compare the distal phalanges of Notharctus tenebrosus to those of extant primates that bear nails (n = 21), tegulae (n = 4), and grooming claws (n = 10), and those of non-primates that bear claws (n = 7). Quantitative analyses demonstrate that Notharctus tenebrosus possessed a grooming claw with a surprisingly well-developed apical tuft on its second pedal digit. The presence of a wide apical tuft on the pedal digit II of Notharctus tenebrosus may reflect intermediate morphology between a typical grooming claw and a nail, which is consistent with the recent hypothesis that loss of a grooming claw occurred in a clade containing adapiforms (e.g. Darwinius masillae) and anthropoids. However, a cladistic analysis including newly documented morphologies and thorough representation of characters acknowledged to have states constituting strepsirrhine, haplorhine, and anthropoid synapomorphies groups Notharctus tenebrosus and Darwinius masillae with extant strepsirrhines rather than haplorhines suggesting that the form of pedal digit II reflects substantial homoplasy during the course of early primate evolution

Nanoscale Mobility of the Apo State and TARP Stoichiometry Dictate the Gating Behavior of Alternatively Spliced AMPA Receptors.

Neurotransmitter-gated ion channels are allosteric proteins that switch on and off in response to agonist binding. Most studies have focused on the agonist-bound, activated channel while assigning a lesser role to the apo or resting state. Here, we show that nanoscale mobility of resting α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-type ionotropic glutamate receptors (AMPA receptors) predetermines responsiveness to neurotransmitter, allosteric anions and TARP auxiliary subunits. Mobility at rest is regulated by alternative splicing of the flip/flop cassette of the ligand-binding domain, which controls motions in the distant AMPA receptor N-terminal domain (NTD). Flip variants promote moderate NTD movement, which establishes slower channel desensitization and robust regulation by anions and auxiliary subunits. In contrast, greater NTD mobility imparted by the flop cassette acts as a master switch to override allosteric regulation. In AMPA receptor heteromers, TARP stoichiometry further modifies these actions of the flip/flop cassette generating two functionally distinct classes of partially and fully TARPed receptors typical of cerebellar stellate and Purkinje cells

Use of tocilizumab and sarilumab alone or in combination with corticosteroids for covid-19: systematic review and network meta-analysis

Objective: To compare the effects of interleukin 6 receptor blockers, tocilizumab and sarilumab, with or without corticosteroids, on mortality in patients with covid-19. Design: Systematic review and network meta-analysis. Data sources: World Health Organization covid-19 database, a comprehensive multilingual source of global covid-19 literature, and two prospective meta-analyses (up to 9 June 2021). Review methods: Trials in which people with suspected, probable, or confirmed covid-19 were randomised to interleukin 6 receptor blockers (with or without corticosteroids), corticosteroids, placebo, or standard care. The analysis used a bayesian framework and assessed the certainty of evidence using the GRADE approach. Results from the fixed effect meta-analysis were used for the primary analysis. Results: Of 45 eligible trials (20 650 patients) identified, 36 (19 350 patients) could be included in the network meta-analysis. Of 36 trials, 27 were at high risk of bias, primarily due to lack of blinding. Tocilizumab, in combination with corticosteroids, suggested a reduction in the risk of death compared with corticosteroids alone (odds ratio 0.79, 95% credible interval 0.70 to 0.88; 35 fewer deaths per 1000 people, 95% credible interval 52 fewer to 18 fewer per 1000; moderate certainty of evidence), as did sarilumab in combination with corticosteroids, compared with corticosteroids alone (0.73, 0.58 to 0.92; 43 fewer per 1000, 73 fewer to 12 fewer; low certainty). Tocilizumab and sarilumab, each in combination with corticosteroids, appeared to have similar effects on mortality when compared with each other (1.07, 0.86 to 1.34; eight more per 1000, 20 fewer to 35 more; low certainty). The effects of tocilizumab (1.12, 0.91 to 1.38; 20 more per 1000, 16 fewer to 59 more; low certainty) and sarilumab (1.07, 0.81 to 1.40; 11 more per 1000, 38 fewer to 55 more; low certainty), when used alone, suggested an increase in the risk of death. Conclusion: These findings suggest that in patients with severe or critical covid-19, tocilizumab, in combination with corticosteroids, probably reduces mortality, and that sarilumab, in combination with corticosteroids, might also reduce mortality. Tocilizumab and sarilumab, in combination with corticosteroids, could have similar effectiveness. Tocilizumab and sarilumab, when used alone, might not be beneficial.This project is supported by two Canadian Institutes of Health Research grants (VR4-172738; MM1-174897). The funders had no role in considering the study design or in the collection, analysis, interpretation of data, writing of the report, or decision to submit the article for publication.publishedVersio