Αρχειοθήκη ιστολογίου

Αλέξανδρος Γ. Σφακιανάκης
ΩτοΡινοΛαρυγγολόγος
Αναπαύσεως 5
Άγιος Νικόλαος Κρήτη 72100
2841026182
6032607174

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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Immunomodulatory effect of IL‐1RA in LPS activated macrophage/dental pulp stem cells co‐culture

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Abstract

Aims:

Lipopolysaccharides (LPS) activated human dental pulp stem cells (hDPSCs) and macrophage co-cultures showed downregulated TNF-α secretion that is modulated by hDPSCs through IDO axis, whereas the secretory levels of IL-1β remained unchanged. Therefore, sustained production of IL-1β could contribute to progressive dental pulp inflammation. However, the role of IL-1 receptor antagonists (IL-1RA) in downregulating the secretion of IL-1β and TNF-α in LPS activated M0/M1/M2 macrophage and hDPSCs co-culture has not been studied yet. Therefore, the aim of the present study is to determine the immunomodulatory role of blocking IL-1 receptors in DPSCs macrophage co-culture activated with LPS.

Methodology:

Human monocytic cell line THP-1 was polarised to M0, M1, and M2 macrophages and co-cultured with hDPSCs. The viability of the co-cultured cells was assessed by apoptosis assay. Co-cultures were activated with LPS followed by the assessment of gene expression and protein levels of IL-1β and TNF-α with and without IL-1RA blocking via qRT-PCR and cytokine flex assay by flow cytometry. Data from three separate experiments was analysed using One-way ANOVA followed by Tukey's Post-hoc test and a p value of <0.05 was considered statistically significant.

Results:

THP-1 derived M0, M1, and M2 macrophages co-cultured with hDPSCs showed spindle and round-shaped cells, with > 90% viability when assessed by apoptosis assay. Inflammatory TNF-α and IL-1β profile in stimulated co-cultures showed upregulated IL-1β whereas TNF-α was downregulated (p< 0.05). Anti-inflammatory gene expression levels of IL-10, TGF-β were downregulated (p< 0.05). Blocking with IL-1RA resulted in remarkable decrease of IL-1β at the gene expression and protein production levels while TNF-α levels remained low (p< 0.05). Levels of anti-inflammatory cytokine IL-10 showed no significant difference.

Conclusion:

Blocking the IL-1 receptor in hDPSCs and macrophage (M0, M1, M2) co-cultures activated with LPS resulted in down regulation of inflammatory cytokines IL-1β and TNF-α. These findings highlight the immunomodulatory effect of IL-1RA in inflammatory conditions of dental pulp infections.

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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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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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Investigating a possible causal relationship between maternal serum urate concentrations and offspring birthweight: a Mendelian randomization study

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Abstract
Background
Higher urate levels are associated with higher systolic blood pressure (SBP) in adults, and in pregnancy with lower offspring birthweight. Mendelian randomization (MR) analyses suggest a causal effect of higher urate on higher SBP and of higher maternal SBP on lower offspring birthweight. If urate causally reduces birthweight, it might confound the effect of SBP on birthweight. We therefore tested for a causal effect of maternal urate on offspring birthweight.
Methods
We tested the association between maternal urate levels and offspring birthweight using multivariable linear regression in the Exeter Family Study of Childhood Health (EFSOCH; n =872) and UK Biobank (UKB; n =133 187). We conducted two-sample MR to test for a causal effect of maternal urate [114 single-nucleotide polymorphisms (SNPs); n =288 649 European ancestry] on offspring birthweight (n =406 063 European ancestry; maternal SNP effect estimates adjusted for fetal effects). We assessed a causal relationship between urate and SBP using one-sample MR in UKB women (n =199 768).
Results
Higher maternal urate was associated with lower offspring birthweight with similar confounder-adjusted magnitudes in EFSOCH [22 g lower birthweight per 1-SD higher urate (95% CI: –50, 6); P =0.13] and UKB [–28 g (95% CI: –31, –25); P = 1.8 × 10–75]. The MR causal effect estimate was directionally consistent, but smaller [–11 g (95% CI: –25, 3); PIVW=0.11]. In women, higher urate was causally associated with higher SBP [1.7 mmHg higher SBP per 1-SD higher urate (95% CI: 1.4, 2.1); P =7.8 × 10–22], consistent with that previously published in women and men.
Conclusion
The marked attenuation of the MR result of maternal urate on offspring birthweight compared with the multivariable regression result suggests previous observational associations may be confounded. The 95% CIs of the MR result included the null but suggest a possible small effect on birthweigh t. Maternal urate levels are unlikely to be an important contributor to offspring birthweight.
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