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Αλέξανδρος Γ. Σφακιανάκης

Sunday, July 24, 2022

Interferon‐gamma inducible protein 16 and type I interferon receptors expression in experimental apical periodontitis induced in wild type mice

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Abstract

Aim

The aim of this study was to evaluate the IFI16 and IFN-α/β receptors expression during the genesis and development of experimental apical periodontitis (AP) in mice teeth.

Methodology

AP was induced in the lower first molars of 40 C57BL/6 mice. They were divided according to the experimental periods 2, 7, 14, 21 and 42 days (n=8 per group). Five animals were used as a control group (without AP). Specimens were submitted to histological processing for description of the inflammatory process, immunostaining for the presence/absence and localization of IFI16 and IFN-α/β receptors (qualitative and semi-quantitative analysis), and tartrate-resistant acid phosphatase (TRAP) histoenzimology.

Results

The results showed a gradual development of AP over the experimental times. The expression of IFI16 was noticeably more exacerbated in the experimental early period (day 2) while the lowest expression was observed in the control group (p=0.02). For IFN-α/β receptors, a higher intensity staining was observed 42 days after AP induction, that was statistically different from the control group (p=0.02). Also, the number of TRAP positive cells was higher on the later periods (days 21 and 42) (p<0.001).

Conclusion

IFI16 protein expression was highest during the early periods after apical periodontitis induction in mice teeth, whilst IFN-α/β receptors expression was highest after apical periodontitis became established.

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Protective Effects of Cannabis sativa on chemotherapy‐induced nausea

alexandrossfakianakis shared this article with you from Inoreader

Abstract

Cyclophosphamide is an anticancer and immunosuppressive agent used in the treatment of various malignancies but causing gastrointestinal distress. Cannabis sativa (C. sativa) and its derivatives have been used for the treatment of human gastrointestinal disorders. A purpose of this study was to investigate the effect of C. sativa on nausea induced by cyclophosphamide in rats. The rats were divided into four groups (8 animals per group): Group 1: Normal control (saline i.p). Group 2: rats received cyclophosphamide (200 mg/kg i.p) 3 consecutive days. Group 3 and 4: Rats received cyclophosphamide (200 mg/kg ip) across days 1 – 7 and C. sativa (20 and 40 mg/kg sc) was administered on cyclophosphamide days 4 – 7. We examined intake of kaolin, normal food and changes in body weight, as an indicator of the emetic stimulus. Oxidative stress markers, antioxidant enzymes status, serotonin (5HT), dopamine, noradrenaline and CB1R levels were evaluated in the intestina l homogenate. Moreover, histopathological study was performed. Results showed that C. sativa ameliorates cyclophosphamide-induced emesis by increasing in body weight and normal diet intake with a decrease in kaolin diet intake after 7 days. Moreover, C. sativa significantly decreases (serotonin) 5HT, dopamine and noradrenaline, as well as, decreasing oxidative stress and inflammation. Administration of C. sativa significantly increased the expression of CB1R in intestinal homogenate. Treatment with C. sativa, also, improved the histological feature of an intestinal tissue. These results suggested that C. sativa possess antiemetic, antioxidant and anti-inflammatory effects in chemotherapy-induced nausea in rats by activating CB1R.

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Risk factor analysis for cytomegalovirus reactivation under prophylaxis with letermovir after allogeneic hematopoietic stem cell transplantation

alexandrossfakianakis shared this article with you from Inoreader

Abstract

Background

Letermovir has been approved as a novel cytomegalovirus (CMV) prophylactic agent after allogeneic hematopoietic stem cell transplantation (HSCT). However, there are still insufficient data to properly evaluate the real-world role of letermovir, and the risk factors for CMV reactivation under letermovir prophylaxis have not been clarified.

Methods

We performed a single-institution retrospective analysis of patients under prophylaxis with or without letermovir who underwent allogeneic HSCT between March 2012 and December 2019. In August 2018, letermovir was added to the clinical practice at our institution for the prophylaxis of CMV reactivation in allogeneic SCT recipients. Patients who underwent SCT without prophylactic letermovir from March 2012 until September 2018 served as a historical control.

Results

The cumulative incidence of clinically significant CMV infection (CS-CMVi) was significantly lower in the letermovir group than in the historical control group not receiving letermovir (30.2% vs 71.6%, P < 0.05, at 100 days). In addition, the cumulative incidence of non-relapse mortality (NRM) at day 500 was significantly lower in the letermovir group (4.7% vs 19.8%, P < 0.05). We then performed a risk factor analysis for developing CS-CMVi in the letermovir group. The only significant factor identified by this multivariable analysis was transplantation from a CMV seronegative donor to a seropositive recipient (HR = 2.76, 95% confidence interval 1.14 – 6.68, P < 0.05).

Conclusion

Our study showed that letermovir prophylaxis significantly reduced the incidence of CS-CMVi and NRM in a real-world setting and that the CMV serostatus of the donor remained as a risk factor for CS-CMVi even under letermovir prophylaxis.

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Thursday, July 21, 2022

Oral microbiome diversity – The curious case of Corynebacterium sp. isolation

alexandrossfakianakis shared this article with you from Inoreader

Abstract

Oral microbiome sequencing efforts revealed the presence of hundreds of different microbes. Interindividual differences at strain and species resolution suggests that microbiome diversity could lead to mechanistically distinct gene regulation as well as species related differences in phenotypes. Commonly, gene regulation and related phenotypes are studied in a few selected strains of a particular species with conclusions that are mostly generalized. The aim of this study was to isolate several species of Corynebacterium using an established protocol that led to the previous isolation of C. durum. Characterization of C. durum interspecies interactions revealed a specific mechanism for chain elongation in Streptococcus sanguinis that was the result of corynebacterial fatty acid production and secretion. While the protocol was successful applied to isolate what we presumed to be additional Corynebacterium based on several phenotypic traits that seem to be identical to C. durum, genome sequencing of the newly isolated strains placed them closer to Actinomyces. Both Corynebacterium and Actinomyces are sub-orders of the Actino-bacteridae and related species. Our study suggests to take several comprehensive strategies into consideration when taxonomically identifying closely related microorganisms. Furthermore, it seems to be important to test common core phenotypes in bacterial ecology to understand the behavior of specific groups of microbes, rather than simply relying upon genome sequence homology to establish relationships in the microbiome.

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Farnesol delivery via polymeric nanoparticle carriers inhibits cariogenic cross‐kingdom biofilms and prevents enamel demineralization

alexandrossfakianakis shared this article with you from Inoreader

Summary

Introduction

: Streptococcus mutans and Candida albicans are frequently detected together in the plaque from patients with early childhood caries (ECC) and synergistically interact to form a cariogenic cross-kingdom biofilm. However, this biofilm is difficult to control. Thus, to achieve maximal efficacy within the complex biofilm microenvironment, nanoparticle carriers have shown increased interest in treating oral biofilms in recent years.

Methods

: Here, we assessed the anti-biofilm efficacy of farnesol (Far), a hydrophobic antibacterial drug and repressor of Candida filamentous forms, against cross-kingdom biofilms employing drug delivery via polymeric nanoparticle carriers (NPCs). We also evaluated the effect of the strategy on teeth enamel demineralization.

Results

: The farnesol-loaded NPCs (NPC+Far) resulted in a 2-log CFU/mL reduction of S. mutans and C. albicans (hydroxyapatite disc biofilm model). High-resolution confocal images further confirmed a significant reduction in exopolysaccharides, smaller microcolonies of S. mutans, and no hyphal form of C. albicans after treatment with NPC+Far on human tooth enamel (HT) slabs, altering the biofilm 3D structure. Furthermore, NPC+Far treatment was highly effective in preventing enamel demineralization on HT, reducing lesion depth (79% reduction) and mineral loss (85% reduction) versus vehicle PBS-treated HT, while NPC or Far alone had no differences with the PBS.

Conclusion

: The drug delivery via polymeric NPCs has the potential for targeting bacterial-fungal biofilms associated with a prevalent and costly pediatric oral disease, such as ECC.

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Fall Risk and Functional Stability Before vs After Computerized Vestibular Retraining

alexandrossfakianakis shared this article with you from Inoreader

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This cohort study compares dynamic postural stability and risk of falls before and after computerized vestibular training among adults with unilateral vestibular deficits.
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Associations of Prior Head Injury With Olfaction in Older Adults

alexandrossfakianakis shared this article with you from Inoreader

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This cohort study investigates the associations of prior head injury, number of prior head injuries, and head injury severity with subjective and psychophysical olfactory function in older adults.
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