Τετάρτη 5 Οκτωβρίου 2022

Oral biofilm dysbiosis during experimental periodontitis

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Abstract

Objectives

We have previously characterized the main osteoimmunological events that occur during ligature periodontitis. This study aims to determine the polymicrobial community shifts that occur during disease development.

Methods

Periodontitis was induced in C57BL/6 mice using the ligature-induced periodontitis model. Healthy oral mucosa swabs and ligatures were collected every 3-days from 0 to 18 days post-ligature placement. Biofilm samples were evaluated by 16SrRNA gene sequencing (Illumina MiSeq) and QIIME. Timecourse changes were determined by relative abundance, diversity, and rank analyses (PERMANOVA, Bonferroni-adjusted).

Results

Microbial differences between health and periodontal inflammation were observed at all phylogenic levels. An evident microbial community shift occurred in 25 genera during the advancement of "gingivitis" (3-6d) to periodontitis (9-18d). From day 0–18, dramatic changes were identified Streptococcus levels, with an overall decrease (54.04-0.02%) as well an overall increase of Enterococcus and Lactobacillus (23.7-73.1% and 10.1%-70.2%, respectively). Alpha-diversity decreased to its lowest at 3d, followed by an increase in diversity as disease advancement. Beta-diversity increased after ligature placement, indicating that bone loss develops in response to a greater microbial variability (p = 0.001). Levels of facultative and strict anaerobic bacteria augmented over the course of disease progression, with a total of 8 species significantly different during the 18-day period.

Conclusion

The data supports that murine gingival inflammation and alveolar bone loss develop in response to microbiome shifts. Bacterial diversity increased during progression to bone loss. These findings further support the utilization of the periodontitis ligature model for microbial shift analysis under different experimental conditions.

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Τρίτη 4 Οκτωβρίου 2022

Afatinib triggers a Ni2+‐resistant Ca2+ influx pathway in A549 non‐small cell lung cancer cells

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Abstract

Afatinib is used to treat non-small cell lung cancer cells (NSCLC), and its mechanism involves irreversible inhibition of epidermal growth factor receptor (EGFR) tyrosine kinase. In this study, we examined if afatinib had cytotoxic action against NSCLC other than inhibition of tyrosine kinase. Afatinib (1-30 μM) caused apoptotic death in A549 NSCLC in a concentration-dependent manner. Afatinib triggered Ca2+ influx without causing Ca2+ release, and the Ca2+ influx was not unaffected by sodium orthovanadate (SOV, an inhibitor of tyrosine phosphatase), suggesting that afatinib-triggered Ca2+ response was unrelated to its inhibition of tyrosine kinase. Addition of afatinib also promoted Mn2+ influx. Ca2+ influx triggered by afatinib was resistant to SKF96365 and ruthenium red (two general blockers of TRP channels) and, unexpectedly, Ni2+ (a non-specific Ca2+ channel blocker). Afatinib caused an i ncrease in mitochondrial Ca2+ level, an initial mitochondrial hyperpolarization (4 h) and followed by mitochondrial potential collapse (24-48 h). Afatinib-induced cell death was slightly but significantly alleviated in low extracellular Ca2+ condition or under pharmacological block of mitochondrial permeability transition pore (MPTP) opening by cyclosporin A. Therefore, in addition to tyrosine kinase inhibition as a major anti-cancer mechanism of afatinib, stimulation of an atypical Ca2+ influx pathway, mitochondrial Ca2+ overload and potential collapse in part contribute to afatinib-induced cell death.

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Bupivacaine inhibits the TLR4 ‐ and TLR2 ‐ Myd88/NF‐κB pathways in human leukocytes

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Abstract

Background

Local anesthetics have anti-inflammatory effects. Because most previous experiments were performed with supra-therapeutic concentrations, we measured the effects of clinically relevant concentrations of bupivacaine on the TLR4- and TLR2-MyD88-NF-κB pathways.

Methods

We measured TNF-α and PGE2 release, p38 MAP-kinase phosphorylation and translocation of NF-κB in human peripheral blood mononuclear cells (hPBMC) and human monocytes challenged with LPS (lipopolysaccharide) or Pam3CSK4 (tripalmitoylated lipopeptide Pam3CysSerLys4) in the presence or absence of bupivacaine. Similarly, we measured the effect of bupivacaine on HEK293 cells expressing the hTLR4 and the hTLR2 genes and challenged with LPS or Pam3CSK4. Finally, molecular docking simulations of R(+)- and S(-)-bupivacaine binding to the TLR4-MD-2 complex and to the TLR2/TLR1 heterodimer were performed.

Results

In PBMCs, bupivacaine from 0.1 to 100 μM inhibited LPS-induced TNF-α and PGE2 secretion, phosphorylation of p38 and nuclear translocation of NF-κB in monocytes. Bupivacaine similarly inhibited the effects of Pam3CSK4 on TNF-α secretion. Bupivacaine inhibited the effect of LPS on HEK293 cells expressing the human TLR4 receptor and the effect of Pam3CSK4 on HEK293 cells expressing the human TLR2 receptor. Molecular docking showed that bupivacaine binds to the MD-2 co-receptor of TLR4 and to the TLR2 receptor.

Conclusions

Contrary to numerous experiments performed with supratherapeutic doses, our results were obtained with concentrations of bupivacaine as low as 0.1 μM. We conclude that bupivacaine modulates the inflammatory reactions such as those observed after surgery or trauma, at least partly by inhibiting the TLR4- and TLR2-NF-κB pathways.

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Estimation of the time-varying incremental effect of low dose aspirin on incidence of pregnancy

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Background. In many research settings, the intervention implied by the average causal effect of a time-varying exposure is impractical or unrealistic, and we might instead prefer a more realistic target estimand. Instead of requiring all individuals to be always exposed vs. unexposed, incremental effects quantify the impact of merely shifting each individual's probability of being exposed. Methods. We demonstrate estimation of incremental effects in the time-varying setting, using data from the Effects of Aspirin in Gestation and Reproduction trial, which assessed the effect of preconception low-dose aspirin on pregnancy outcomes. Compliance to aspirin or placebo was summarized weekly and was affected by time-varying confounders such as bleeding or nausea. We sought to estimate what the incidence of pregnancy by 26 weeks post-randomization would have been if we shifted each participant's probability of taking aspirin or placebo in each week by odds ratios (OR) between 0.30 and 3.00. Results. Under no intervention (OR=1), the incidence of pregnancy was 77% (95% CI: 74%, 80%). Decreasing women's probability of complying with aspirin had little estimated effect on pregnancy incidence. When we increased women's probability of taking aspirin, estimated incidence of pregnancy increased, from 83% (95% CI: 79%, 87%) for OR=2 to 89% (95% CI: 84%, 93%) for OR=3. We observed similar results when we shifted women's probability of complying with placebo. Conclusions. These results estimated that realistic interventions to increase women's probability of taking aspirin would have yielded little to no impact on the incidence of pregnancy, relative to similar interventions on placebo. Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.
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Magnetic Resonance Imaging Directed Surgical Decision Making for Lateral Pelvic Lymph Node Dissection in Rectal Cancer After Total Neoadjuvant Therapy (TNT)

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imageObjective: Lateral pelvic lymph node (LPLN) metastases are an important cause of preventable local failure in rectal cancer. The aim of this study was to evaluate clinical and oncological outcomes following magnetic resonance imaging (MRI)-directed surgical selection for lateral pelvic lymph node dissection (LPLND) after total neoadjuvant therapy (TNT). Methods: A retrospective consecutive cohort analysis was performed of rectal cancer patients with enlarged LPLN on pretreatment MRI. Patients were categorized as LPLND or non-LPLND. The main outcomes were lateral local recurrence rate, perioperative and oncological outcomes and factors associated with decision making for LPLND. Results: A total of 158 patients with enlarged pretreatment LPLN and treated with TNT were identified. Median follow-up was 20 months (interquartile range 10–32). After multidisciplinary review, 88 patients (56.0%) underwent LPLND. Mean age was 53 (SD±12) years, and 54 (34.2%) were female. Total operative time (509 vs 429 minutes; P=0.003) was greater in the LPLND group, but median blood loss (P=0.70) or rates of major morbidity (19.3% vs 17.0%) did not differ. LPLNs were pathologically positive in 34.1%. The 3-year lateral local recurrence rates (3.4% vs 4.6%; P=0.85) did not differ between groups. Patients with LPLNs demonstrating pretreatment heterogeneity and irregular margin (odds ratio, 3.82; 95% confidence interval: 1.65–8.82) or with short-axis ≥5 mm post-TNT (odds ratio 2.69; 95% confidence interval: 1.19–6.08) were more likely to undergo LPLND. Conclusions: For rectal cancer patients with evidence of LPLN metastasis, the appropriate selection of patients for LPLND can be facilitated by a multidisciplinary MRI-directed approach with no significant difference in perioperative or oncologic outcomes.
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Polyethylenglycol – Freund oder Feind?

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Laryngorhinootologie 2022; 101: 784-786
DOI: 10.1055/a-1861-7047

Anaphylaktische Reaktionen nach Impfungen sind selten. Zwei Fälle von Reaktionen nach der Pfizer-BioNTech-Covid-19-Vakzine, BNT162b2, wurden aus dem UK berichtet, weitere 19 aus den USA. Als möglicher Auslöser wurde Polyethylenglycol (PEG) angeschuldigt. Pegylierung ist ein üblicher Vorgang in der Impfstoffherstellung, um die Substanzen vor schnellem immunologischem Abbau zu schützen. PEG ist ein Polyether (Synonyme z. B. Laureth-9, Polidocanol, Thesit, Macrogol) und findet sich in Kosmetika, Körperpflegeprodukten, Nahrungsmitteln, Liposomen und Nanopartikeln als Drug-Delivery-Systeme für Medikamente und als osmotisches Laxans vor Gastro-/Koloskopien. IgM-Antikörper auf PEG werden bei 70% der Bevölkerung nachgewiesen. Bei 2 Fällen von Soforttyp-Reaktionen auf PEG fanden sich IgE-Antiköper, bei anderen Medikamentengaben mit PEG geht man von pseudoallergischen Reaktionen über die Komplement-Aktivierungs-related Pseudoallergie (CARPA) aus. In Relation zum weit verbreiteten Einsatz von PEG sind die Impfreaktionen sehr selten und aktuell kein Grund, Allergiker oder Menschen mit Anaphylaxien bei entsprechenden Vorsichtsmaßnahmen auf bekannte Auslöser auszuschließen. Aufgrund der Meldepflicht (Gesundheitsamt und Arzneimittelkommission der deutschen Ärzteschaft) ist bald mit weiteren Erkenntnissen zu rechnen.
[...]

Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, Germany

Article in Thieme eJournals:
Table of contents  |  Abstract  |  Full text

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Δευτέρα 3 Οκτωβρίου 2022

Viral load decrease in SARS‐CoV‐2 BA.1 and BA.2 Omicron sublineages infection after treatment with monoclonal antibodies and direct antiviral agents

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ABSTRACT

Background

The efficacy on the Omicron variant of the approved early- coronavirus disease 2019 (COVID-19) therapies, especially monoclonal antibodies, has been challenged by in vitro neutralization data, while data on in vivo antiviral activity are lacking.

Materials and methods

We assessed potential decrease from day1 to day7 viral load (VL) in nasopharyngeal swabs of outpatients receiving Sotrovimab, Molnupiravir, Remdesivir, or Nirmatrelvir/ritonavir for mild-to-moderate COVID-19 due to sublineages BA.1 or BA.2, and average treatment effect (ATE) by weighted marginal linear regression models.

Results

A total of 521 patients [378 BA.1 (73%),143 (27%) BA.2] received treatments (Sotrovimab 202, Molnupiravir 117, Nirmatrelvir/ritonavir 84, and Remdesivir 118): median age 66 years, 90% vaccinated, median time from symptoms onset 3 days. Day1 mean viral load was 4.12 log2 (4.16 for BA.1 and 4.01 for BA.2). The adjusted analysis showed that Nirmatrelvir/ritonavir significantly reduced VL compared to all the other drugs, except vs. Molnupiravir in BA.2. Molnupiravir was superior to Remdesivir in both BA.1 and BA.2, and to Sotrovimab in BA.2. Sotrovimab had better activity than Remdesivir only against BA.1.

Conclusions

Nirmatrelvir/ritonavir showed the greatest antiviral activity against Omicron variant, comparable to Molnupiravir only in the BA.2 subgroup. VL decrease could be a valuable surrogate of drug activity in the context of the high prevalence of vaccinated people and low probability of hospital admission.

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