Αρχειοθήκη ιστολογίου

Κυριακή 8 Ιανουαρίου 2023

Effect of sintering on the translucency of CAD‐CAM lithium disilicate restorations: a comparative in vitro study

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Abstract

Purpose

The available independent data on the translucency of novel pre and fully sintered chair-side computer-aided design and computer-aided manufacturing (CAD-CAM) lithium disilicate are limited. This comparative in vitro study evaluated the translucency degree of pre and fully sintered chairside CAD-CAM lithium disilicate crowns after optional, required, and additional firing processes.

Materials and Methods

One hundred and five maxillary left central incisor crowns manufactured by three different CAD-CAM lithium disilicate brands shade A1 were assigned into 7 groups as follows (n = 15): (1) n!ce Straumann without sintering; (2) n!ce Straumann with one additional sintering process; (3) n!ce Straumann with two additional sintering processes; (4) Amber Mill with one sintering process; (5) Amber Mill with two sintering processes; (6) IPS e.max CAD with one sintering process; (7) IPS e.max CAD with two sintering processes. The translucency of all crowns was evaluated with a color imaging spectrophotometer. All statistical analyses were performed using statistical software. A standard level of significance was set at α < 0.05.

Results

All the milled crowns presented different degrees of translucency, and additional sintering processes altered it. IPS E.max CAD with two (4.33 ± 0.26) and one (4.01 ± 0.15) sintering processes displayed the highest translucency, whereas n!ce Straumann with no sintering process provided the lowest value (2.82 ± 0.16).

Conclusions

The translucency of chairside lithium disilicate single-unit full-coverage restorations manufactured with subtractive technology was significantly influenced by the brand and the number of sintering processes. The traditional presintered IPS e.max CAD and the fully crystallized glass-ceramic n!ce Straumann considerably increased the translucency after one additional firing process, whereas Amber Mill decreased its translucency.

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Bioactive glass air‐abrasion promotes healing around contaminated implant surfaces surrounded by circumferential bone defects: An experimental study in the rat

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Abstract

Objectives

The present study aimed to evaluate the healing of experimentally induced bone defects around contaminated dental implants after air-abrasion using 45S5 or zinc oxide (ZnO)-containing bioactive glasses (BAGs).

Materials and Methods

One maxillary first molar was extracted from each Sprague–Dawley rat (n = 30). After 4-week healing, a titanium implant was placed in the extraction site with a circumferential bone defect. The rats were randomized into five different groups: (1) implants with Fusobacterium nucleatum and Porphyromonas gingivalis dual-species biofilm (IB); (2) implants with biofilm subjected to inert glass air-abrasion (inert); (3) sterile implants (S); (4) implants with biofilm subjected to 45S5 BAG air-abrasion (45S5); and (5) implants with biofilm subjected to ZnO-containing BAG air-abrasion (Zn4). After 8-week healing, maxillae were dissected, and histomorphometric analyses were performed.

Results

The first bone-to-implant contact was significantly shorter for the inert (1.58 ± 1.16 mm; p = 0.016), S (0.28 ± 0.13 mm; p < 0.001), 45S5 (0.41 ± 0.28 mm; p < 0.001), and Zn4 (0.26 ± 0.16 mm; p < 0.001) groups compared to IB group. Also, significantly more bone-to-implant contact was seen for S (72.35% ± 8.32%; p < 0.001), 45S5 (57.91% ± 24.10%; p = 0.002), and Zn4 (70.49% ± 12.74%; p < 0.001) groups than the IB group. The bone volume with the threads demonstrated significantly higher value for S (69.32% ± 9.15%; p < 0.001), 45S5 (58.93% ± 23.53%; p = 0.001), and Zn4 (68.65% ± 12.41%; p < 0.001) groups compared to the IB group. The bone volume within the defects was significantly higher for S (68.79% ± 11.77%; p < 0.001), 45S5 (62.51% ± 20.51%; p  = 0.002), and Zn4 (73.81% ± 15.07%; p < 0.001) groups compared to the IB group.

Conclusions

This study suggests that air-abrasion of contaminated moderately rough implant surfaces with either 45S5 or ZnO-containing BAGs enhances osseointegration and bone defect regeneration.

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Algorithmic dementia classification: promises and challenges

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Abstract
Dementia is a complex, progressive syndrome characterized by cognitive decline and disability. Gold-standard dementia diagnosis requires several hours of cognitive and clinical assessment and review by a panel of clinicians and is infeasible in large population-based cohort studies. Alternatively, algorithmic dementia classification methods, which use models that take measures of cognition and functional limitations into account or cognitive and functional limitation score cutoffs, have been developed to predict dementia status for participants in large studies. Developing accurate dementia classification algorithms is crucial for high-quality studies of the distribution and determinants of dementia. The article by Nichols et al. (Am J Epidemiol. XXXX;XXX(XX):XXXX–XXXX) assesses differences in associations of measures of cognition and functional limitations with prevalent versus incident dementia and discusses implications for algorithmic demen tia classification in research studies. This work highlights important opportunities for tailoring measures of cognition and functional limitations to study goals by selecting optimal measures and developing and validating algorithms specific to study needs. Combining efficient, high-quality assessments of cognition and functional limitations with innovative study designs will facilitate collection of higher quality measures in larger samples and support future development of accurate dementia classifications, ultimately leading to more impactful epidemiologic studies.
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Plasma Aβ42/Aβ40 ratios are not reduced in older people living with HIV

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Abstract
Background
As people with HIV (PWH) age, it remains unclear whether they are at higher risk for age-related neurodegenerative disorders, e.g., Alzheimer disease (AD), and if so, how to differentiate HIV-associated neurocognitive impairment from AD. We examined a clinically-available blood biomarker test for AD (plasma Aβ42/Aβ40 ratio), in cognitively-normal (CN) or cognitively-impaired (CI) PWH and people without HIV (PWoH) who were CN or with symptomatic AD.
Methods
66 PWH (age >40 years) (HIV RNA <50 copies/mL) and 195 PWoH provided blood samples, magnetic resonance imaging (MRI), and completed a neuropsychological battery or Clinical Dementia Rating scale (CDR). Participants were categorized by impairment (PWH_CN n = 43; PWH_CI n = 23; PWoH_CN n = 138; PWoH_AD n = 57). Plasma Aβ42 and Aβ40 concentrations were obtained using a liquid chromatography-tandem mass spectrometry method to calculate the PrecivityAD® Amyloid Probability Score (APS). The APS incorporates age and apolipoprotein E proteotype into a risk score for brain amyloidosis. Plasma Aβ42/Aβ40 and APS were compared between groups and assessed for relationships with hippocampal volumes or cognition and HIV clinical characteristics (PWH only).
Results
The plasma Aβ42/Aβ40 ratio was significantly lower, and APS higher, in PWoH_AD compared to other groups. A lower Aβ42/Aβ40 ratio and higher APS was associated with smaller hippocampal volumes for PWoH_AD. The Aβ42/Aβ40 ratio and APS were not associated with cognition or HIV clinical measures for PWH.
Conclusions
The plasma Aβ42/Aβ40 ratio can serve as a screening tool for AD and may help differentiate effects of HIV from AD within PWH, but larger studies with older PWH are needed.
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Nirmatrelvir‐ritonavir for the treatment of COVID‐19 patients: a systematic review and meta‐analysis

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Abstract

Nirmatrelvir-ritonavir (Paxlovid™) is an oral antiviral that has been approved for the treatment of mild-to-moderate COVID-19. We aimed to conduct a meta-analysis to evaluate the efficacy and safety of nirmatrelvir-ritonavir in COVID-19 patients. Various databases including PubMed, the Cochrane Library, medRxiv and Embase were searched from inception till 10 October 2022 and results from 12 studies (two randomized controlled trials (RCTs) and 10 observational studies) were pooled using a random-effects model with risk ratio (RR) as the effect measure. Nirmatrelvir-ritonavir reduced the risk of mortality (RR 0.24; 95% CI:0.15–0.37, I2=48%; moderate certainty) and hospitalization (RR 0.41; 95% CI:0.29–0.59, I2=90%; low certainty) in both patients with or without previous immunity to SARS-CoV-2 without an increased risk of adverse events. Our study provides encouraging evidence for nirmatrelvir-ritonavir as a safe and efficacious agent for COVID-19 but lar ge-scale RCTs are needed to confirm these findings.

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Outcomes of KTP Laser Ablation in Glottic Neoplasms: A Systematic Review and Meta‐Analysis

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Outcomes of KTP Laser Ablation in Glottic Neoplasms: A Systematic Review and Meta-Analysis

The aim of our review is to evaluate the safety and efficiency of transoral laser microsurgery (TLM) with potassium-titanyl-phosphate (KTP) laser ablation for glottic neoplasms. Eight studies were included. After an average follow-up of 3.3 years, the overall survival and disease-free survival for patients who underwent KTP. KTP is a safe and effective method for treating patients with early glottic neoplasms.


Objectives

To evaluate the safety and clinical effectiveness of transoral laser microsurgery (TLM) with potassium-titanyl-phosphate (KTP) laser ablation for glottic neoplasms.

Data Source

MEDLINE via PubMed, SCOPUS, Web of Science, and Cochrane Library.

Review Methods

A systematic review and meta-analysis of studies assessing the safety and efficacy of KTP laser therapy in patients with early-stage glottic neoplasms.

Results

Eight studies were included. After an average follow-up of 3.3 years, the overall survival and disease-free survival for patients who underwent KTP were 90.7% (95% CI 85%–96.5%) and 98.5% (95% CI 97.3%–99.8%), respectively. In the single-arm meta-analysis, the pooled estimate of recurrence was 7.7% (95% CI 3.4%–12%). The overall voice handicap index (VHI) estimate attributed to KTP in the single-arm meta-analysis was 6.76 (95% CI [3.05, 10.48]) and 5.21 (95% CI [2.86, 7.56]) within 6 months and after a one-year follow-up, respectively.

Conclusion

KTP laser ablation is a safe and effective method for treating patients with early glottic neoplasms. Laryngoscope, 2023

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Drug‐induced radiation recall reactions and non‐anticancer drugs: A descriptive analysis from VigiBase®

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Abstract

Background

Radiation recall reactions are inflammatory reactions confined to previously irradiated tissues, often of drug-induced etiology, particularly with anticancer therapies. Other drugs, in particular COVID-19 vaccines, may also be involved.

Objective

To describe radiation recall reactions under non-anticancer drugs more precisely.

Material and method

We extracted the cases of radiation recall reactions associated with non-anticancer drugs from WHO pharmacovigilance database VigiBase®. We performed two analyses from this extraction: a global analysis and an analysis focusing on vaccination-related issues.

Results

We extracted 120 cases corresponding to 269 drugs, of which 130 were non-anticancer (22 vaccines). Among the non-anticancer drugs, tozinameran was the most reported treatment (4.46% of cases), followed by levofloxacin (2.97%) and folinic acid (2.60%), dexamethasone (2.23), ChAdOx1 nCoV-19 vaccine and prednisone (1.86% each). Among vaccines, tozinameran (54.55% of cases) was the most reported, followed by ChAdOx1 nCoV-19 (22.73%), HPV & inactivated influenza vaccine (9.09% each), and elasomeran (4.55%).

Conclusion

Our study first describes the occurrence of radiation recall reactions during non-anticancer treatment. It also highlights a potential safety signal with COVID-19 vaccines.

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Temporal trends in the incidence of malignant and non-malignant primary brain and central nervous system tumors by method of diagnosis in England, 1993-2017

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Abstract
Background
Several studies report increasing incidence of primary CNS tumors. The reasons for this are unclear.
Methods
Data on all 188,340 individuals diagnosed with a primary CNS tumor in England (1993-2017) were obtained from the National Cancer Registry. Data on all CT head and MRI brain scans in England (2013-2017) were obtained from NHS Digital. Age-sex-standardized annual incidence rates per 100,000 population (ASR) were calculated by calendar year, tumor behavior, tumor location and method of diagnosis. Temporal trends were quantified using average annual percent change (AAPC).
Results
The ASR for all CNS tumors increased from 13.0 in 1993 to 18.6 in 2017 (AAPC: 1.5%, 95% CI: 1.3, 1.7). The ASR for malignant tumors (52% overall) remained stable (AAPC: +0.5%, 95% CI: -0.2, 1.3), while benign tumors (37% overall) increased (AAPC: +2.6%, 95% CI: 1.2, 4.0). Among the 66% of benign tumors that were microscopically c onfirmed, the ASR increased modestly (AAPC: 1.3%, 95% CI: 0.5, 2.1). However, among the 25% of benign tumors that were radiographically confirmed, the ASR increased substantially (AAPC: 10.2%, 95% CI: 7.9, 12.5), principally driven by large increases in those aged 65+. The rate of CT head scans in Accident & Emergency (A&E) increased during 2013-2017, with especially large increases in 65-84 and 85+ year olds (AAPCs: 18.4% and 22.5%).
Conclusion
Increases in CNS tumor incidence in England are largely attributable to greater detection of benign tumors. This could be the result of increasing use of neuroimaging, particularly CT head scans in A&E in people aged 65+.
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Upregulation of PD‐L1 by SARS‐CoV‐2 promotes immune evasion

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Abstract

Patients with severe COVID-19 often suffer from lymphopenia, which is linked to T cell sequestration, cytokine storm and mortality. However, it remains largely unknown how SARS-CoV-2 induces lymphopenia. Here, we studied the transcriptomic profile and epigenomic alterations involved in cytokine production by SARS-CoV-2-infected cells. We adopted a reverse time-order gene coexpression network (TO-GCN) approach to analyze time-series RNA-sequencing data, revealing epigenetic modifications at the late stage of viral egress. Furthermore, we identified SARS-CoV-2-activated NF-κB and IRF1 pathways contributing to viral infection and COVID-19 severity through epigenetic analysis of H3K4me3 ChIP-sequencing. Cross-referencing our transcriptomic and epigenomic datasets revealed that coupling NF-κB and IRF1 pathways mediate PD-L1 immunosuppressive programs. Interestingly, we observed higher PD-L1 expression in Omicron-infected cells than SARS-CoV-2 infected cells. Blocking PD-L1 at an earl y stage of virally-infected AAV-hACE2 mice significantly recovered lymphocyte counts and lowered inflammatory cytokine levels. Our findings indicate that targeting the SARS-CoV-2-mediated NF-κB and IRF1-PD-L1 axis may represent an alternative strategy to reduce COVID-19 severity.

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The third vaccine dose significantly reduces susceptibility to the B.1.1.529 (Ômicron) SARS‐CoV‐2 variant

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Abstract

The main COVID-19 vaccine formulations used today are mainly based on the wild-type SARS-CoV-2 spike glycoprotein as an antigen. However, new virus variants capable of escaping neutralization activity of serum antibodies elicited in vaccinated individuals have emerged. The Omicron (B.1.1.529) variant caused epidemics in regions of the world in which most of the population has been vaccinated. In this study, we aimed to understand what determines individual's susceptibility to Omicron in a scenario of extensive vaccination. For that purpose, we collected nasopharynx swab (n = 286) and blood samples (n = 239) from flu-like symptomatic patients, as well as their vaccination history against COVID-19. We computed the data regarding vaccine history, COVID-19 diagnosis, COVID-19 serology and viral genome sequencing to evaluate their impact on the number of infections. As main results, we showed that vaccination in general did not reduce the number of individuals infected by Omicron, even with an increased immune response found among vaccinated non-infected individuals. Nonetheless, we found that individuals who received the third vaccine dose showed significantly reduced susceptibility to Omicron infections. A relevant evidence that support this finding was the higher virus neutralization capacity of serum samples of most patients who received the third vaccine dose. In summary, this study shows that boosting immune responses after a third vaccine dose reduces susceptibility to COVID-19 caused by the Omicron variant. Results presented in this study are useful for future formulations of COVID-19 vaccination policies.

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