Vergleich der systemischen Konzentration von MMP-8 und Surfactant Protein D vor und nach der nicht-chirurgischen Therapie der chronischen Parodontitis

Diese Studie untersuchte die Wertigkeit der systemischen Expression von SP-D und MMP-8 zur Verlaufskontrolle der Parodontitis. Dazu wurden in venösen Blutproben die Konzentrationen von SP-D und MMP-8 vor und sechs Monate nach einer indikationsgerechten parodontologischen Behandlung von 150 Patienten bestimmt. Die Diagnose der Parodontitis wurde nach einer standardisierten klinischen und radiologischen Untersuchung aller Patienten an Hand von definierten Kriterien gestellt. Zusätzlich erfolgte eine mikrobiologische Untersuchung der parodontalen Taschen. In der Gesamtpopulation zeigten die klinischen Befunde im Vergleich der initialen zur ersten Nachuntersuchung eine signifikante Verbesserung der gemessenen Werte. Sowohl die Sondierungstiefen als auch die Blutungsneigung nach Sondierung nahmen durch die Therapie signifikant ab. Gleichzeitig konnte für Bakterien der Spezies Treponema denticola eine signifikante Reduktion der Infektion nachgewiesen werden nicht aber für die übrigen fünf getesteten parodontalpathogenen Bakterien. Die systemische Expression von MMP-8 war in der Gesamtpopulation vor und sechs Monate nach der parodontalen Therapie nicht unterschiedlich. Die Konzentration des SP-D zeigte nach der parodontalen Therapie tendenziell eine Verringerung. Nach der statistischen Analyse der Ergebnisse erreichte dieser Unterschied jedoch ebenfalls keine Signifikanz. Auch nach Stratifikation der Studienkohorte nach dem Geschlecht und dem Rauchverhalten, konnte keine signifikant unterschiedliche systemische Expression der beiden Markermoleküle MMP-8 und SP-D vor und nach der Parodontaltherapie angetroffen werden. Zusammenfassend führte die Therapie der Parodontitis nach sechs Monaten zur erwarteten signifikanten Verbesserung der klinischen Befundparameter gleichzeitig aber nicht zu einer Veränderung der systemischen Expression von MMP-8 und SP-D. Die Bestimmung der systemischen Konzentrationen dieser beiden Markermoleküle scheint deshalb zur Kontrolle des parodontalen Erkrankungsverlaufs im Zeitraum von sechs Monaten nicht ausreichend zuverlässig zu sein

Vergleich der systemischen Konzentration von MMP-8 und Surfactant Protein D vor und nach der nicht-chirurgischen Therapie der chronischen Parodontitis

Diese Studie untersuchte die Wertigkeit der systemischen Expression von SP-D und MMP-8 zur Verlaufskontrolle der Parodontitis. Dazu wurden in venösen Blutproben die Konzentrationen von SP-D und MMP-8 vor und sechs Monate nach einer indikationsgerechten parodontologischen Behandlung von 150 Patienten bestimmt. Die Diagnose der Parodontitis wurde nach einer standardisierten klinischen und radiologischen Untersuchung aller Patienten an Hand von definierten Kriterien gestellt. Zusätzlich erfolgte eine mikrobiologische Untersuchung der parodontalen Taschen. In der Gesamtpopulation zeigten die klinischen Befunde im Vergleich der initialen zur ersten Nachuntersuchung eine signifikante Verbesserung der gemessenen Werte. Sowohl die Sondierungstiefen als auch die Blutungsneigung nach Sondierung nahmen durch die Therapie signifikant ab. Gleichzeitig konnte für Bakterien der Spezies Treponema denticola eine signifikante Reduktion der Infektion nachgewiesen werden nicht aber für die übrigen fünf getesteten parodontalpathogenen Bakterien. Die systemische Expression von MMP-8 war in der Gesamtpopulation vor und sechs Monate nach der parodontalen Therapie nicht unterschiedlich. Die Konzentration des SP-D zeigte nach der parodontalen Therapie tendenziell eine Verringerung. Nach der statistischen Analyse der Ergebnisse erreichte dieser Unterschied jedoch ebenfalls keine Signifikanz. Auch nach Stratifikation der Studienkohorte nach dem Geschlecht und dem Rauchverhalten, konnte keine signifikant unterschiedliche systemische Expression der beiden Markermoleküle MMP-8 und SP-D vor und nach der Parodontaltherapie angetroffen werden. Zusammenfassend führte die Therapie der Parodontitis nach sechs Monaten zur erwarteten signifikanten Verbesserung der klinischen Befundparameter gleichzeitig aber nicht zu einer Veränderung der systemischen Expression von MMP-8 und SP-D. Die Bestimmung der systemischen Konzentrationen dieser beiden Markermoleküle scheint deshalb zur Kontrolle des parodontalen Erkrankungsverlaufs im Zeitraum von sechs Monaten nicht ausreichend zuverlässig zu sein

Evaluation of the nanotube intrinsic resistance across the tip-carbon nanotube-metal substrate junction by Atomic Force Microscopy

Using an atomic force microscope (AFM) at a controlled contact force, we report the electrical signal response of multi-walled carbon nanotubes (MWCNTs) disposed on a golden thin film. In this investigation, we highlight first the theoretical calculation of the contact resistance between two types of conductive tips (metal-coated and doped diamond-coated), individual MWCNTs and golden substrate. We also propose a circuit analysis model to schematize the «tip-CNT-substrate» junction by means of a series-parallel resistance network. We estimate the contact resistance R of each contribution of the junction such as Rtip-CNT, RCNT-substrate and Rtip-substrate by using the Sharvin resistance model. Our final objective is thus to deduce the CNT intrinsic radial resistance taking into account the calculated electrical resistance values with the global resistance measured experimentally. An unwished electrochemical phenomenon at the tip apex has also been evidenced by performing measurements at different bias voltages with diamond tips. For negative tip-substrate bias, a systematic degradation in color and contrast of the electrical cartography occurs, consisting of an important and non-reversible increase of the measured resistance. This effect is attributed to the oxidation of some amorphous carbon areas scattered over the diamond layer covering the tip. For a direct polarization, the CNT and substrate surface can in turn be modified by an oxidation mechanism

Investigation of Luminescent Triplet States in Tetranuclear Cu-I Complexes : Thermochromism and Structural Characterization

To develop new and flexible Cu-I containing luminescent substances, we extend our previous investigations on two metal-centered species to four metal-centered complexes. These complexes could be a basis for designing new organic light-emitting diode (OLED) relevant species. Both the synthesis and in-depth spectroscopic analysis, combined with high-level theoretical calculations are presented on a series of tetranuclear Cu-I complexes with a halide containing Cu4X4 core (X=iodide, bromide or chloride) and two 2-(diphenylphosphino)pyridine bridging ligands with a methyl group in para (4-Me) or ortho (6-Me) position of the pyridine ring. The structure of the electronic ground state is characterized by X-ray diffraction, NMR, and IR spectroscopy with the support of theoretical calculations. In contrast to the para system, the complexes with ortho-substituted bridging ligands show a remarkable and reversible temperature-dependent dual phosphorescence. Here, we combine for the first time the luminescence thermochromism with time-resolved FTIR spectroscopy. Thus, we receive experimental data on the structures of the two triplet states involved in the luminescence thermochromism. The transient IR spectra of the underlying triplet metal/halide-to-ligand charge transfer (M-3/XLCT) and cluster-centered ((CC)-C-3) states were obtained and interpreted by comparison with calculated vibrational spectra. The systematic and significant dependence of the bridging halides was analyzed.Peer reviewe

Atrial fibrosis heterogeneity is a risk for atrial fibrillation in pigs with ischaemic heart failure

Background Atrial fibrillation (AF) is the most common arrhythmia and is associated with considerable morbidity and mortality. Ischaemic heart failure (IHF) remains one of the most common causes of AF in clinical practice. However, ischaemia-mediated mechanisms leading to AF are still incompletely understood, and thus, current treatment approaches are limited. To improve our understanding of the pathophysiology, we studied a porcine IHF model. Methods In pigs, IHF was induced by balloon occlusion of the left anterior descending artery for 90 min. After 30 days of reperfusion, invasive haemodynamic measurements and electrophysiological studies were performed. Masson trichrome and immunofluorescence staining were conducted to assess interstitial fibrosis and myofibroblast activation in different heart regions. Results After 30 days of reperfusion, heart failure with significantly reduced ejection fraction (left anterior obique 30°, 34.78 ± 3.29% [IHF] vs. 62.03 ± 2.36% [control], p < .001; anterior–posterior 0°, 29.16 ± 3.61% vs. 59.54 ± 1.09%, p < .01) was observed. These pigs showed a significantly higher susceptibility to AF (33.90% [IHF] vs. 12.98% [control], p < .05). Histological assessment revealed aggravated fibrosis in atrial appendages but not in atrial free walls in IHF pigs (11.13 ± 1.44% vs. 5.99 ± .86%, p < .01 [LAA], 8.28 ± .56% vs. 6.01 ± .35%, p < .01 [RAA]), which was paralleled by enhanced myofibroblast activation (12.09 ± .65% vs. 9.00 ± .94%, p < .05 [LAA], 14.37 ± .60% vs. 10.30 ± 1.41%, p < .05 [RAA]). Correlation analysis indicated that not fibrosis per se but its cross-regional heterogeneous distribution across the left atrium was associated with AF susceptibility (r = .6344, p < .01). Conclusion Our results suggest that left atrial cross-regional fibrosis difference rather than overall fibrosis level is associated with IHF-related AF susceptibility, presumably by establishing local conduction disturbances and heterogeneity

HCC biomarkers – state of the old and outlook to future promising biomarkers and their potential in everyday clinical practice

Hepatocellular carcinoma (HCC) is one of the most common and deadly tumors worldwide. Management of HCC depends on reliable biomarkers for screening, diagnosis, and monitoring of the disease, as well as predicting response towards therapy and safety. To date, imaging has been the established standard technique in the diagnosis and follow-up of HCC. However, imaging techniques have their limitations, especially in the early detection of HCC. Therefore, there is an urgent need for reliable, non/minimal invasive biomarkers. To date, alpha-fetoprotein (AFP) is the only serum biomarker used in clinical practice for the management of HCC. However, AFP is of relatively rather low quality in terms of specificity and sensitivity. Liquid biopsies as a source for biomarkers have become the focus of clinical research. Our review highlights alternative biomarkers derived from liquid biopsies, including circulating tumor cells, proteins, circulating nucleic acids, and exosomes, and their potential for clinical application. Using defined combinations of different biomarkers will open new perspectives for diagnosing, treating, and monitoring HCC

Genomic assessment of quarantine measures to prevent SARS-CoV-2 importation and transmission

Mitigation of SARS-CoV-2 transmission from international travel is a priority. We evaluated the effectiveness of travellers being required to quarantine for 14-days on return to England in Summer 2020. We identified 4,207 travel-related SARS-CoV-2 cases and their contacts, and identified 827 associated SARS-CoV-2 genomes. Overall, quarantine was associated with a lower rate of contacts, and the impact of quarantine was greatest in the 16-20 age-group. 186 SARS-CoV-2 genomes were sufficiently unique to identify travel-related clusters. Fewer genomically-linked cases were observed for index cases who returned from countries with quarantine requirement compared to countries with no quarantine requirement. This difference was explained by fewer importation events per identified genome for these cases, as opposed to fewer onward contacts per case. Overall, our study demonstrates that a 14-day quarantine period reduces, but does not completely eliminate, the onward transmission of imported cases, mainly by dissuading travel to countries with a quarantine requirement

Genomic assessment of quarantine measures to prevent SARS-CoV-2 importation and transmission

Mitigation of SARS-CoV-2 transmission from international travel is a priority. We evaluated the effectiveness of travellers being required to quarantine for 14-days on return to England in Summer 2020. We identified 4,207 travel-related SARS-CoV-2 cases and their contacts, and identified 827 associated SARS-CoV-2 genomes. Overall, quarantine was associated with a lower rate of contacts, and the impact of quarantine was greatest in the 16–20 age-group. 186 SARS-CoV-2 genomes were sufficiently unique to identify travel-related clusters. Fewer genomically-linked cases were observed for index cases who returned from countries with quarantine requirement compared to countries with no quarantine requirement. This difference was explained by fewer importation events per identified genome for these cases, as opposed to fewer onward contacts per case. Overall, our study demonstrates that a 14-day quarantine period reduces, but does not completely eliminate, the onward transmission of imported cases, mainly by dissuading travel to countries with a quarantine requirement

Evaluating the Effects of SARS-CoV-2 Spike Mutation D614G on Transmissibility and Pathogenicity.

Global dispersal and increasing frequency of the SARS-CoV-2 spike protein variant D614G are suggestive of a selective advantage but may also be due to a random founder effect. We investigate the hypothesis for positive selection of spike D614G in the United Kingdom using more than 25,000 whole genome SARS-CoV-2 sequences. Despite the availability of a large dataset, well represented by both spike 614 variants, not all approaches showed a conclusive signal of positive selection. Population genetic analysis indicates that 614G increases in frequency relative to 614D in a manner consistent with a selective advantage. We do not find any indication that patients infected with the spike 614G variant have higher COVID-19 mortality or clinical severity, but 614G is associated with higher viral load and younger age of patients. Significant differences in growth and size of 614G phylogenetic clusters indicate a need for continued study of this variant

Exponential growth, high prevalence of SARS-CoV-2, and vaccine effectiveness associated with the Delta variant

SARS-CoV-2 infections were rising during early summer 2021 in many countries associated with the Delta variant. We assessed RT-PCR swab-positivity in the REal-time Assessment of Community Transmission-1 (REACT-1) study in England. We observed sustained exponential growth with average doubling time (June-July 2021) of 25 days driven by complete replacement of Alpha variant by Delta, and by high prevalence at younger less-vaccinated ages. Unvaccinated people were three times more likely than double-vaccinated people to test positive. However, after adjusting for age and other variables, vaccine effectiveness for double-vaccinated people was estimated at between ~50% and ~60% during this period in England. Increased social mixing in the presence of Delta had the potential to generate sustained growth in infections, even at high levels of vaccination