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Τετάρτη 23 Νοεμβρίου 2022

Implant deformation and implant–abutment fracture resistance after standardized artificial aging: An in vitro study

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Abstract

Background and purpose

Zirconia abutments have been widely adopted in clinical implant practice. The unique mechanical properties of zirconia may significantly affect the long-term prognosis of implant treatments. The purpose of this study was to investigate the influence of abutment material on implant deformation and fracture resistance of internal conical connection implant–abutment complexes of two diameters after standardized artificial aging.

Materials and methods

Thirty original abutments (one-piece titanium, one-piece zirconia, zirconia with alloy base) with two diameters (regular, narrow) were connected to internal conical connection implants and subjected to a standardized artificial aging process consisting of thermal cycling and mechanical cyclic loading. Microcomputed tomography (μCT) scans of implant bodies were performed before and after aging. 3-dimensional images of implant bodies were generated from the μCT scans and aligned for before and after aging to calculate the volumetric deformation amount. Finally, fracture resistance was measured using a mechanical static loading test for the surviving aged and 30 brand-new specimens.

Results

All specimens survived artificial aging. No significant difference in implant deformation was found in the regular groups (p = 0.095). In narrow groups, the one-piece zirconia group showed significantly less deformation (p < 0.0001). For fracture resistance, no significant decrease was observed after aging in any group (p > 0.05). One-piece zirconia abutments showed significantly lower strength than the other two materials for both diameters (p < 0.0001).

Conclusions

In the regular diameter system, abutment material had no significant influence on the tested mechanical property degradation after simulated long-term oral use. The mechanical performance of narrow diameter one-piece zirconia abutments differed from the other two materials. For optimal performance, one-piece zirconia abutments should be adopted only in anterior regions.
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Characterization of FA1654: a putative DPS protein in Filifactor alocis

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Abstract

The survival/adaptation of Fillifactor alocis, a fastidious gram positive asaccharolytic anaerobe, to the inflammatory environment of the periodontal pocket requires an ability to overcome oxidative stress. Moreover, its pathogenic characteristics are highlighted by its capacity to survive in the oxidative-stress microenvironment of the periodontal pocket and a likely ability to modulate the microbial community dynamics. There is still a significant gap in our understanding of its mechanism of oxidative stress resistance and its impact on the virulence and pathogenicity of the microbial biofilm. Coinfection of epithelial cells with F.alocis and P.gingivalis, resulted in the upregulation of several genes including HMPREF0389_01654(FA1654). Bioinformatics analysis indicates that FA1654 has a "di-iron binding domain", and could function as a DNA Starvation and Stationary Phase Protection (DPS) protein. We have further characterized the FA1654 protein to deter mine its role in oxidative stress resistance in F.alocis. In the presence of hydrogen peroxide induced oxidative stress there was a ∼1.3 fold upregulation of the FA1654 gene in F.alocis. Incubation of the purified FA1654 protein with DNA in the presence of hydrogen peroxide and iron resulted in the protection of the DNA from Fenton-mediated degradation. Circular Dichroism (CD) and Differential Scanning Flourimetry (DSF) studies have documented the intrinsic ability of rFA1654 protein to bind iron, however the rFA1654 protein is missing the intrinsic ability to reduce hydrogen peroxide. Collectively, the data may suggest that FA1654 in F.alocis is involved in oxidative stress resistance via an ability to protect against Fenton-mediated oxidative stress-induced damage.

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Auricular Reconstruction for Relapsing Polychondritis

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This case report describes woman in her early 20s presented to the hospital with an acquired auricular deformity after an ear piercing and was diagnosed with recurrent polychondritis that required total auricular reconstruction.
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Use of the Toxicity Index in Evaluating Adverse Events in Anal Cancer Trials: Analysis of RTOG 9811 and RTOG 0529

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imageNovel toxicity metrics that account for all adverse event (AE) grades and the frequency of may enhance toxicity reporting in clinical trials. The Toxicity Index (TI) accounts for all AE grades and frequencies for categories of interest. We evaluate the feasibility of using the TI methodology in 2 prospective anal cancer trials and to evaluate whether more conformal radiation (using Intensity Modulated Radiation Therapy) results in improved toxicity as measured by the TI. Patients enrolled on NRG/RTOG 0529 or nonconformal RT enrolled on the 5-Fluorouracil/Mitomycin arm of NRG/RTOG 9811 were compared using the TI. Patients treated on NRG/RTOG 0529 had lower median TI compared with patients treated with nonconformal RT on NRG/RTOG 9811 for combined GI/GU/Heme/Derm events (3.935 vs 3.996, P=0.014). The TI methodology is a feasible method to assess all AEs of interest and may be useful as a composite metric for future efforts aimed at treatment de-escalation or escalation
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Redefining the costal margin: A pilot study

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imageBACKGROUND Classical teaching of rib anatomy contends that the false ribs (7th to 10th) fuse anteriorly to form the costal margin of the chest. Slipped rib syndrome consists of false rib subluxation into the thorax with symptomatic impingement of the intercostal nerve. We sought to determine the incidence of this anatomic finding through anatomic study of the costal margin. METHODS Cadavers were evaluated for mobility and attachment of the ninth and tenth ribs. Experienced anatomists and chest wall surgeons conducted a standardized dissection and assessed rib tip mobility using predefined criteria. Videos of dissections were submitted to a single investigator who reviewed the findings. RESULTS Costal margins of 40 cadavers (45% male) were evaluated bilaterally. The average age was 83 years ± 11 years. The ninth rib was found to be attached to the eighth rib 100% of the time by an interchondral cartilaginous attachment along the body of the eighth and ninth ribs. Internal subluxation was noted in 19% (15 of 80), and the tip of the rib was mobile in 86% (69 of 80) evaluations. The tenth rib was attached to the ninth rib in 18%(14/80). A "floating" 10th rib was noted in 59% (47 of 80) of specimens. Subluxation was noted in 33% (26 of 60). Half of the ribs that subluxed moved medially to the ninth rib and half moved externally. An upwardly hooked tip was noted in 10% (8 of 80). Ribs with a hooked tip subluxed in 63% (5 of 8), and all of these ribs (5 of 5) moved to the interior of the chest (p = 0.020). CONCLUSION The ninth rib is commonly attached to the eighth rib, but the tenth rib is often not attached to the ninth rib. Most commonly, the tenth rib is a "floating" rib. Internal subluxation of the tenth rib as well as the presence of a hooked tip may predispose individuals to the development of "slipped rib syndrome." LEVEL OF EVIDENCE Diagnostic Tests or Criteria; Level III.
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Surgical stabilization of rib fractures versus nonoperative treatment in patients with multiple rib fractures following cardiopulmonary resuscitation: An international, retrospective matched case-control study

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imageBACKGROUND The presence of six or more rib fractures or a displaced rib fracture due to cardiopulmonary resuscitation (CPR) has been associated with longer hospital and intensive care unit (ICU) length of stay (LOS). Evidence on the effect of surgical stabilization of rib fractures (SSRF) following CPR is limited. This study aimed to evaluate outcomes after SSRF versus nonoperative management in patients with multiple rib fractures after CPR. METHODS An international, retrospective study was performed in patients who underwent SSRF or nonoperative management for multiple rib fractures following CPR between January 1, 2012, and July 31, 2020. Patients who underwent SSRF were matched to nonoperative controls by cardiac arrest location and cause, rib fracture pattern, and age. The primary outcome was ICU LOS. RESULTS Thirty-nine operatively treated patient were matched to 66 nonoperatively managed controls with comparable CPR-related characteristics. Patients who underwent SSRF more often had displaced rib fractures (n = 28 [72%] vs. n = 31 [47%]; p = 0.015) and a higher median number of displaced ribs (2 [P25–P75, 0–3] vs. 0 [P25–P75, 0–3]; p = 0.014). Surgical stabilization of rib fractures was performed at a median of 5 days (P25–P75, 3–8 days) after CPR. In the nonoperative group, a rib fixation specialist was consulted in 14 patients (21%). The ICU LOS was longer in the SSRF group (13 days [P25–P75, 9–23 days] vs. 9 days [P25–P75, 5–15 days]; p = 0.004). Mechanical ventilator-free days, hospital LOS, thoracic complications, and mortality were similar. CONCLUSION Despite matching, those who underwent SSRF over nonoperative management for multiple rib fractures following CPR had more severe consequential chest wall injury and a longer ICU LOS. A benefit of SSRF on in-hospital outcomes could not be demonstrated. A low consultation rate for rib fixation in the nonoperative group indicates that the consideration to perform SSRF in this population might be associated with other nonradiographic or injury-related variables. LEVEL OF EVIDENCE Therapeutic/Care Management; Level III.
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Τρίτη 22 Νοεμβρίου 2022

Asparaginase‐related diabetic ketoacidosis: Analysis of the FDA Adverse Event Reporting System (FAERS) data and literature review

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Asparaginase-related diabetic ketoacidosis: Analysis of the FDA Adverse Event Reporting System (FAERS) data and literature review

This study investigated the association between asparaginase and diabetic ketoacidosis from the perspective of adverse reaction signal detection and literature review. The reporting odd ratio (ROR) of diabetic ketoacidosis (DKA) caused by l-asparaginase was statistically significant, but there was not a statistical association for DKA caused by pegaspargase. Combined with the results of literature review, we speculated that the asparaginase dosage form may affect the occurrence of DKA.


Abstract

What is Known and Objective

Diabetic ketoacidosis (DKA) may occur during asparaginase use. However, limited by the study population, the association between asparaginase and DKA has not been elucidated. The purpose of this study was to determine the potential association between asparaginase and DKA and analyse related clinical characteristics and possible risk factor.

Methods

Disproportionality analysis with the reporting odd ratio (ROR) was used to detect the adverse reaction signals of asparaginase-associated DKA in Food and Drug Administration Adverse Event Reporting System (FAERS). A literature review was conducted to further analyse clinical characteristics, possible risk factor and something noteworthy in asparaginase-associated DKA.

Results and Discussion

A total of 12 reports of DKA associated with l-asparaginase (l-asp) and 6 reports associated with pegaspargase (PEG-asp) were extracted in FAERS, more than 50% of the cases were classified as serious adverse events. DKA was a positive signal of l-asp (ROR = 2.397, 95% CI 1.360–4.226), while not closely related to the use of PEG-asp (ROR = 1.602, 95% CI 0.719–3.570). Searched in PubMed, Embase and Web of Science, a total of eight patients were collected. The patients were mainly adolescent patients, aged between 11 and 25 years old with a median age of 16 years. Drug dosage form distribution is unbalanced, 7 patients received l-asp and only 1 received PEG-asp.

What is New and Conclusions

The ROR of KDA caused by l-asp was statistically significant, but there was not a statistical association for DKA caused by PEG-asp. Asparaginase dosage form may affect the occurrence of DKA, but further research is needed.
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Relapse after non‐metastatic rhabdomyosarcoma: The impact of routine surveillance imaging on early detection and post‐relapse survival

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Abstract

Background

Patients with rhabdomyosarcoma (RMS) whose disease relapses have little chance of being cured, so front-line treatments are usually followed up with surveillance imaging in an effort to detect any recurrences as early as possible, and thereby improve post-relapse outcomes. The real benefit of such routine surveillance imaging in RMS remains to be demonstrated, however. This retrospective, single-center study examines how well surveillance imaging identifies recurrent tumors and its impact on post-relapse survival.

Methods

The analysis concerned 79 patients <21 years old treated between 1985 and 2020 whose initially localized RMS relapsed. Clinical findings, treatment modalities, and survival were analyzed, comparing patients whose relapse was first suspected from symptoms they developed (clinical symptoms group) with those whose relapse was identified by radiological surveillance (routine imaging group).

Results

Tumor relapses came to light because of clinical symptoms in 42 cases, and on routine imaging in 37. The time to relapse was much the same in the two groups. The median overall survival (OS) and 5-year OS rate were, respectively, 10 months and 12.6% in the clinical symptoms group, and 11 months and 27.5% in the routine imaging group (p-value .327). Among patients with favorable prognostic scores, survival was better for those in the routine imaging group (5-year OS 75.0% vs. 33.0%, p-value .047).

Conclusion

It remains doubtful whether surveillance imaging has any real impact on RMS relapse detection and patients' post-relapse survival. Further studies are needed to establish the most appropriate follow-up recommendations, taking the potentially negative effects of regular radiological exams into account.
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The fate of interneurons, GABAA receptor sub‐types and perineuronal nets in Alzheimer's disease

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Abstract

Alzheimer's disease (AD) is the most common neurological disease, which is associated with gradual memory loss and correlated with synaptic hyperactivity and abnormal oscillatory rhythmic brain activity that precedes phenotypic alterations and is partly responsible for the spread of the disease pathology. Synaptic hyperactivity is thought to be because of alteration in the homeostasis of phasic and tonic synaptic inhibition, which is orchestrated by the GABAA inhibitory system, encompassing subclasses of interneurons and GABAA receptors, which play a vital role in cognitive functions, including learning and memory. Furthermore, the extracellular matrix, the perineuronal nets (PNNs) which often go unnoticed in considerations of AD pathology, encapsulate the inhibitory cells and neurites in critical brain regions and have recently come under the light for their crucial role in synaptic stabilisation and excitatory-inhibitory balance and when disrupted, serve as a potential trigger for AD-associated synaptic imbalance. Therefore, in this review, we summarise the current understanding of the selective vulnerability of distinct interneuron subtypes, their synaptic and extrasynaptic GABAAR subtypes as well as the changes in PNNs in AD, detailing their contribution to the mechanisms of disease development. We aim to highlight how seemingly unique malfunction in each component of the interneuronal GABA inhibitory system can be tied together to result in critical circuit dysfunction, leading to the irreversible symptomatic damage observed in AD.
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FACE-Q satisfaction following upper third facial gender-affirming surgery using custom bone-section guides

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Postoperative satisfaction after facial gender-affirming surgery (FGAS) has not yet been assessed using a validated questionnaire. There is currently no postoperative satisfaction questionnaire specific to transgender patients concerning facial surgery. The contributions of three-dimensional planning in fronto-orbital surgery in trans women and the use of bone cutting guides for facial feminization surgery have been demonstrated. The primary objective of this study was to evaluate postoperative satisfaction with the upper third of the face in trans women using a validated questionnaire – FACE-Q – after fronto-orbital surgery using custom-made bone cutting guides. (Source: International Journal of Oral and Maxillofacial Surgery)
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