Tag: pubmed

Nat Commun. 2021 Apr 23;12(1):2463. doi: 10.1038/s41467-021-22613-2.

NO ABSTRACT

PMID:33893282 | DOI:10.1038/s41467-021-22613-2

Nat Commun. 2021 Apr 23;12(1):2435. doi: 10.1038/s41467-021-22757-1.

ABSTRACT

Antibiotic resistance spreads among bacteria through horizontal transfer of antibiotic resistance genes (ARGs). Here, we set out to determine predictive features of ARG transfer among bacterial clades. We use a statistical framework to identify putative horizontally transferred ARGs and the groups of bacteria that disseminate them. We identify 152 gene exchange networks containing 22,963 bacterial genomes. Analysis of ARG-surrounding sequences identify genes encoding putative mobilisation elements such as transposases and integrases that may be involved in gene transfer between genomes. Certain ARGs appear to be frequently mobilised by different mobile genetic elements. We characterise the phylogenetic reach of these mobilisation elements to predict the potential future dissemination of known ARGs. Using a separate database with 472,798 genomes from Streptococcaceae, Staphylococcaceae and Enterobacteriaceae, we confirm 34 of 94 predicted mobilisations. We explore transfer barriers beyond mobilisation and show experimentally that physiological constraints of the host can explain why specific genes are largely confined to Gram-negative bacteria although their mobile elements support dissemination to Gram-positive bacteria. Our approach may potentially enable better risk assessment of future resistance gene dissemination.

PMID:33893312 | DOI:10.1038/s41467-021-22757-1

J Contemp Dent Pract. 2020 Dec 1;21(12):1374-1378.

ABSTRACT

AIM AND OBJECTIVE: The present study compared the fracture strength and failure pattern of endodontically treated, bi-rooted, maxillary premolars with different number of coronal walls and postendodontic restoration (one vs double post).

MATERIALS AND METHODS: 105 premolars were divided into 3 groups according to the number of residual walls: control group (intact teeth; n = 15), group 1 (3 residual walls; n = 45), group 2 (2 residual walls; n = 45). Each test group was then divided into 3 subgroups (n = 15 each) according to postendodontic restoration: no post (A), 1 post (B) or 2 posts (C). A load was applied parallel to the longitudinal axis of the teeth, thus simulating physiological occlusion. ANOVA and Tukey’s tests were used to detect fracture strength differences among groups, while Chi-square test was used to check differences in fracture pattern.

RESULTS: No significant differences were observed between control group (intact teeth) and groups A1 (p = 0.999), B1 (p = 0.997) and C1 (p = 1.000); statistically significant differences were detected between control group and groups A2 (p < 0.001), B2 (p < 0.001) and C2 (p < 0.05). Different post placement techniques were non-significantly associated with fracture pattern in both groups 1 (p = 0.666) and 2 (p = 0.143) while, irrespective of the number of posts, the presence of the post was significantly associated with the fracture pattern in teeth with two residual walls. The double-post technique did not further improve the fracture resistance of hardly damaged endodontically treated maxillary bi-rooted premolars compared to single-post technique. Therefore, the insertion of a single post in the palatal canal could be a safer and more conservative choice.

CLINICAL SIGNIFICANCE: The double-post technique did not further improve the fracture resistance of severely structurally compromised endodontically treated maxillary premolars with two roots compared to the single-post technique. Therefore, the safer and less invasive treatment is the placement of a single post in the palatal canal.

PMID:33893261

J Contemp Dent Pract. 2020 Dec 1;21(12):1379-1383.

ABSTRACT

AIM AND OBJECTIVE: To compare the effectiveness of three irrigation systems, namely, Endovac system, Max I probe, and Navitip FX, in reduction of Enterococcus faecalis population from the root canal using agar diffusion method.

MATERIALS AND METHODS: Sixty extracted intact human permanent maxillary anterior teeth were selected for this study. In group I, root canals were irrigated using brush covered 30-gauge NaviTipFX. Ultradent in group II root canals was irrigated using brush covered 30-gauge Max-I-Probe Dentsply. In group III, root canals were irrigated using Endoactivator, Dentsply. In group IV, root canal was irrigated by using the Endovac system Sybronendo. The steps followed in the study include preparation of specimen, contamination of the samples followed by conduction of testing procedures with implementation of appropriate irrigation protocols, and sampling procedures.

RESULTS: Data were subjected to statistical analysis to interpret the significant differences among various irrigation systems. One-way analysis of variance, Post hoc Tukey tests were used for statistical analysis in the present study. Among the experimental groups, group IV showed statistically significant difference in reduction of E. faecalis. There were no statistical differences between them in reduction of E. faecalis in group I and group II compared and represented in Tables 1 and 2.

CONCLUSION: All four irrigation delivery systems have been found to be effective in the reduction of E. faecalis. Endovac showed comparable efficacy in reduction of colony-forming units to that of other delivery systems used in the study. The result has to be validated with in vivo studies and clinical trials of larger sample size.

CLINICAL SIGNIFICANCE: Selection of appropriate irrigation system capable of disinfection of canal complexities in apical third with less adverse effects is essential for good clinical success of endodontic treatment.

PMID:33893262

J Contemp Dent Pract. 2020 Dec 1;21(12):1368-1373.

ABSTRACT

AIM AND OBJECTIVE: To evaluate the marginal adaptation at the tooth-restoration interface at enamel and cementum margins using composite restoration reinforced with novel enamel inserts/biofillers.

MATERIALS AND METHODS: Standardized class V box-shaped cavities were prepared in 40 extracted maxillary first premolar teeth which were divided randomly into four experimental groups consisting of 10 samples each. Group I: Bulk placement. Groups II: Horizontal incremental technique. Group III: Restoration with precured composite balls (megafillers). Group IV: Restoration with biofillers. All the cavities were restored with visible light-activated direct restorative nanocomposite. The specimens were thermocycled for 24 hours. After thermocycling, the samples were immersed in a 1% methylene blue for 4 hours and subsequently evaluated for microleakage. Microleakage scores (0-4) were obtained from gingival margins of class V restorations and analyzed by statistical analysis. Evaluation of the data was performed by Kruskal-Wallis one-way analysis of variance (ANOVA), and Mann-Whitney U tests.

RESULTS: Microleakage scores have indicated restorations with biofillers showed best results followed by megafillers, incremental horizontal build-up, and bulk filling.

CONCLUSION: Biofillers provide a novel approach in improving microleakage and marginal adaptability of composite resin restorations.

CLINICAL SIGNIFICANCE: Incorporation of inserts, which are capable of adequate bonding to resin and tooth, may provide improved marginal adaptability and reduce microleakage around restorative margins.

PMID:33893260

Am J Transplant. 2021 Apr 23. doi: 10.1111/ajt.16622. Online ahead of print.

ABSTRACT

Normothermic Regional Perfusion (NRP) allows the in situ perfusion of organs with oxygenated blood in donation after the circulatory determination of death (DCDD). We aimed at evaluating the impact of NRP on the short-term outcomes of kidney transplants in controlled DCDD (cDCDD). This is a multicenter, nationwide, retrospective study comparing cDCDD kidneys obtained with NRP versus the standard rapid recovery (RR) technique. During 2012-2018, 2,302 cDCDD adult kidney transplants were performed in Spain using NRP (n=865) or RR (n=1,437). The study groups differed in donor and recipient age, warm and cold ischemic time and use of ex situ machine perfusion. Transplants in the NRP group were more frequently performed in high-volume centers (≥90 transplants/year). Through matching by propensity score, two cohorts with a total of 770 patients were obtained. After the matching, no statistically significant differences were observed between the groups in terms of primary non function (p=0.261) and mortality at one year (p=0.111). However, the RR of kidneys was associated with a significantly increased odds of delayed graft function (OR 1.97 [95%CI 1.43-2.72]; p<0.001) and 1-year graft loss (OR 1.77 [95%CI 1.01-3.17; p=0.034). In conclusion, compared with RR, NRP appears to improve the short-term outcomes of cDCDD kidney transplants.

PMID:33891793 | DOI:10.1111/ajt.16622

Anat Sci Educ. 2021 Apr 23. doi: 10.1002/ase.2093. Online ahead of print.

ABSTRACT

The state of alarm due to Covid-19 pandemic in Spain stopped all educational and most university research activities. The Spanish Anatomical Society (SAE) Consensus Expert Group on Body Donations piloted a study based on a questionnaire to know the status of body donations and dissection activities during the lockdown, as well as the future implications of Covid-19 pandemic for body donation programs and Anatomy teaching. The questionnaire results show that Spanish Universities refused body donations and stopped all dissection research and teaching. The Covid-19 expected influence on Anatomy teaching was referred to the increase of teaching workforce and resources required to apply the new safety measures to future practical activities, as well as to prepare and adapt teaching material for online-only programs. The application of reinforced safety measures was expected to be perceived by the respondent’s students as a gain in teaching quality, while the transformation of the anatomy courses in online-only programs will be perceived as a quality decrease. The respondent’s concerns about future institutional implications of the pandemic were related to increased costs of the adaptation of the facilities and the reinforced preventive measures, as well as the eventual decrease in donations. The complete lockdown applied on dissection rooms is not justified by scientific evidence and represents a break of the confidence deposed in the institutions by the donors. A consensus is required for the adoption of a renewed, comprehensive protocol for present and future body donations including the evidence Covid-19 pandemic has contributed to create.

PMID:33891806 | DOI:10.1002/ase.2093

Cancer. 2021 Apr 23. doi: 10.1002/cncr.33599. Online ahead of print.

ABSTRACT

BACKGROUND: Prior studies reveal a lack of illness understanding and prognostic awareness among patients with hematologic malignancies. Prognostic awareness and illness understanding among hospitalized patients with acute leukemia and multiple myeloma were evaluated, and patient-oncologist discordance was measured.

METHODS: Patients with acute leukemia and multiple myeloma hospitalized at Mount Sinai Hospital between February 2018 and February 2020 were enrolled. Patients were administered a survey assessing prognostic awareness, goals of care (GOC), and quality of life. Oncologists completed a similar survey for each patient. Discordance across the cohort of patients and oncologists using the likelihood-ratio χ² test and within patient-oncologist pairs using the κ statistic was assessed.

RESULTS: Sixty patients and 15 oncologists were enrolled. Among patients, 32 (53%) self-identified as White, 15 (25%) as self-identified as Black, and 9 (15%) self-identified as Hispanic. Across the entire cohort, patients were significantly more optimistic about treatment goals compared to oncologists (P < .001). Within patient-oncologist pairs, oncologists were significantly more optimistic than patients with respect to line of treatment (κ = 0.03). There was also a significant difference surrounding life expectancy (κ = 0.05), with 39 patients (65%) responding “don’t know” or deferring to a faith-based response compared to 18 oncologists (30%).

CONCLUSIONS: Significant discordance regarding prognosis and GOC among patients with hematologic malignancies and their oncologists was observed. These data support future interventions to improve prognostic understanding among this patient population to facilitate informed treatment choices.

LAY SUMMARY: Patients with blood cancer are known to have poor levels of illness understanding, and the role of patient-oncologist discordance is not well studied. We surveyed patients and oncologists about their understanding of disease prognosis, goals of care, and quality of life. We measured differences in patients’ and oncologists’ understanding of these key factors by comparing survey responses. There was significant disagreement between patients and oncologists surrounding prognosis and goals of care. Interventions are needed to improve patients’ understanding of prognosis, which will help them make more informed, value-aligned treatment choices.

PMID:33891716 | DOI:10.1002/cncr.33599

J Magn Reson Imaging. 2021 Apr 23. doi: 10.1002/jmri.27649. Online ahead of print.

ABSTRACT

BACKGROUND: Due to random motion of fetuses and maternal respirations, image quality of fetal brain MRIs varies considerably. To address this issue, visual inspection of the images is performed during acquisition phase and after 3D-reconstruction, and the images are re-acquired if they are deemed to be of insufficient quality. However, this process is time-consuming and subjective. Multi-instance (MI) deep learning methods (DLMs) may perform this task automatically.

PURPOSE: To propose an MI count-based DLM (MI-CB-DLM), an MI vote-based DLM (MI-VB-DLM), and an MI feature-embedding DLM (MI-FE-DLM) for automatic assessment of 3D fetal-brain MR image quality. To quantify influence of fetal gestational age (GA) on DLM performance.

STUDY TYPE: Retrospective.

SUBJECTS: Two hundred and seventy-one MR exams from 211 fetuses (mean GA ± SD = 30.9 ± 5.5 weeks).

FIELD STRENGTH/SEQUENCE: T₂ -weighted single-shot fast spin-echo acquired at 1.5 T.

ASSESSMENT: The T₂ -weighted images were reconstructed in 3D. Then, two fetal neuroradiologists, a clinical neuroscientist, and a fetal MRI technician independently labeled the reconstructed images as 1 or 0 based on image quality (1 = high; 0 = low). These labels were fused and served as ground truth. The proposed DLMs were trained and evaluated using three repeated 10-fold cross-validations (training and validation sets of 244 and 27 scans). To quantify GA influence, this variable was included as an input of the DLMs.

STATISTICAL TESTS: DLM performance was evaluated using precision, recall, F-score, accuracy, and AUC values.

RESULTS: Precision, recall, F-score, accuracy, and AUC averaged over the three cross validations were 0.85 ± 0.01, 0.85 ± 0.01, 0.85 ± 0.01, 0.85 ± 0.01, 0.93 ± 0.01, for MI-CB-DLM (without GA); 0.75 ± 0.03, 0.75 ± 0.03, 0.75 ± 0.03, 0.75 ± 0.03, 0.81 ± 0.03, for MI-VB-DLM (without GA); 0.81 ± 0.01, 0.81 ± 0.01, 0.81 ± 0.01, 0.81 ± 0.01, 0.89 ± 0.01, for MI-FE-DLM (without GA); and 0.86 ± 0.01, 0.86 ± 0.01, 0.86 ± 0.01, 0.86 ± 0.01, 0.93 ± 0.01, for MI-CB-DLM with GA.

DATA CONCLUSION: MI-CB-DLM performed better than other DLMs. Including GA as an input of MI-CB-DLM improved its performance. MI-CB-DLM may potentially be used to objectively and rapidly assess fetal MR image quality.

EVIDENCE LEVEL: 4 TECHNICAL EFFICACY: Stage 3.

PMID:33891778 | DOI:10.1002/jmri.27649

J Magn Reson Imaging. 2021 Apr 23. doi: 10.1002/jmri.27650. Online ahead of print.

ABSTRACT

BACKGROUND: According to the Liver Imaging Reporting and Data System (LI-RADS), the LI-RADS category M (LR-M), which are probably or definitely malignant but are not specific for hepatocellular carcinomas (HCCs), does not exclude HCCs. A gap in knowledge remains, including their characteristics and recurrence of HCCs categorized as LR-M.

PURPOSE: To compare the characteristics of HCCs categorized as LR-M with HCCs categorized as LR-4 or LR-5 (LR-4/5) using the LI-RADS version 2018 and evaluate the relationship of these categories with the risk of early recurrence after curative resections of single HCCs.

STUDY TYPE: Retrospective.

SUBJECTS: Two hundred and eighty-one patients (mean age, 57 years; 191 men and 90 women) who underwent curative resections for single HCCs and preoperative contrast-enhanced MRI between 2015 and 2017.

FIELD STRENGTH/SEQUENCE: 3T Dual gradient-echo T₁ WI with in- and opposed-phase, turbo spin-echo T₂ WI, diffusion-weighted echo-planar images, and three-dimensional gradient-echo T₁ WI before and after administration of contrast agent.

ASSESSMENT: MRI features according to the LI-RADS version 2018 were evaluated and LI-RADS category were assigned for each observation. Clinical, imaging, and histopathological features were compared based on LI-RADS categorization. Early recurrence rates (<2 years) and associated factors were also evaluated.

STATISTICAL TESTS: Fisher’s exact test, two-sample t test after satisfying assumption of normality through Shapiro-Wilk test, Fleiss κ coefficient, Cox proportional hazards regression analysis, Kaplan-Meier method, and log-rank test.

RESULTS: Forty-one HCCs (14.6%) were categorized as LR-M and 240 HCCs (85.4%) were categorized as LR-4/5. LR-M HCCs showed poorer differentiation than LR-4/5 HCCs. In the multivariate analysis, the LR-M category was an independent predictor for early recurrence (hazard ratio, 1.904; 95% confidence interval, 1.024-3.542; P < 0.05). Early recurrence rates were significantly higher in patients with LR-M HCCs than in patients with LR-4/5 HCCs (32.0% vs. 18.4%, respectively, P < 0 05).

DATA CONCLUSION: Compared to LR-4/5 HCCs, LR-M HCCs were associated with poorer tumor differentiation and higher early recurrence rates after curative resections of single HCCs.

LEVEL OF EVIDENCE: 3 Technical Efficacy Stage: 2.

PMID:33891790 | DOI:10.1002/jmri.27650