Tag: pubmed

J Hand Surg Am. 2021 Sep 7:S0363-5023(21)00478-0. doi: 10.1016/j.jhsa.2021.07.028. Online ahead of print.

ABSTRACT

PURPOSE: The etiology of Kienböck disease remains unclear, although mechanical, vascular, and metabolic risk factors have been suggested. We aimed to investigate the association of the angle between the curvatures of the distal radius and the development of Kienböck disease.

METHODS: The lunate facet inclination (LFI), scaphoid facet inclination, and interfacet angle (IFA) values were measured using posteroanterior plain radiographs of 82 patients diagnosed with Kienböck disease. The results were compared with normative angular reference values published based on an analysis of 400 wrists of Caucasian patients aged between 20 and 45 years. The posteroanterior radiographs were divided into 3 categories: negative, neutral, and positive based on ulnar variance, and the relationship between ulnar variance and facet angles was evaluated.

RESULTS: The IFA value was significantly higher than the normative angular reference value in the patients with Kienböck disease. Conversely, the LFI values were significantly lower in the Kienböck patient group. There were no statistically significant differences in the IFA and LFI values among the ulnar variance groups.

CONCLUSIONS: Measuring IFA and LFI allows the evaluation of the bifacet curvature of the distal radius articular surface in the coronal plane. Steep IFA and shallow LFI are associated with Kienböck disease. Increased IFA may lead to abnormal load transmission to the intermediate column, which might eventually lead to increased stress on the lunate.

TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic IV.

PMID:34507867 | DOI:10.1016/j.jhsa.2021.07.028

Pancreatology. 2021 Aug 18:S1424-3903(21)00527-5. doi: 10.1016/j.pan.2021.08.004. Online ahead of print.

ABSTRACT

BACKGROUND & AIMS: Increased intrapancreatic fat is associated with pancreatic diseases; however, there are no established objective diagnostic criteria for fatty pancreas. On non-contrast computed tomography (CT), adipose tissue shows negative Hounsfield Unit (HU) attenuations (-150 to -30 HU). Using whole organ segmentation on non-contrast CT, we aimed to describe whole gland pancreatic attenuation and establish 5th and 10th percentile thresholds across a spectrum of age and sex. Subsequently, we aimed to evaluate the association between low pancreatic HU and risk of pancreatic ductal adenocarcinoma (PDAC).

METHODS: The whole pancreas was segmented in 19,456 images from 469 non-contrast CT scans. A convolutional neural network was trained to assist pancreas segmentation. Mean pancreatic HU, volume, and body composition metrics were calculated. The lower 5th and 10th percentile for mean pancreatic HU were identified, examining the association with age and sex. Pre-diagnostic CT scans from patients who later developed PDAC were compared to cancer-free controls.

RESULTS: Less than 5th percentile mean pancreatic HU was significantly associated with increase in BMI (OR 1.07; 1.03-1.11), visceral fat (OR 1.37; 1.15-1.64), total abdominal fat (OR 1.12; 1.03-1.22), and diabetes mellitus type 1 (OR 6.76; 1.68-27.28). Compared to controls, pre-diagnostic scans in PDAC cases had lower mean whole gland pancreatic HU (-0.2 vs 7.8, p = 0.026).

CONCLUSION: In this study, we report age and sex-specific distribution of pancreatic whole-gland CT attenuation. Compared to controls, mean whole gland pancreatic HU is significantly lower in the pre-diagnostic phase of PDAC.

PMID:34507900 | DOI:10.1016/j.pan.2021.08.004

Geriatr Nurs. 2021 Aug 20:S0197-4572(21)00280-9. doi: 10.1016/j.gerinurse.2021.08.012. Online ahead of print.

ABSTRACT

BACKGROUND: There are known significant relationships between greater physical activity and less depression, and greater social isolation and greater depression; therefore, it is important to understand these relationships among older adults during COVID-19.

METHODS: The Physical Activity Scale for Elders, Geriatric Depression Scale, and PROMIS Social Isolation were administered. Path analysis was performed to evaluate the relationship between physical activity, social isolation, and depression.

RESULTS: Of 803 surveys received, Consistent with our a-priori model, higher social isolation predicted greater depression. (p<0.001).

CONCLUSION: Older adults may suffer a high emotional price during times of imposed social distancing.

PMID:34507833 | DOI:10.1016/j.gerinurse.2021.08.012

Int J Nurs Educ Scholarsh. 2021 Sep 10. doi: 10.1515/ijnes-2021-0056. Online ahead of print.

ABSTRACT

OBJECTIVES: There is limited knowledge about students’ experiences with virtual simulation when using a video conferencing system. Therefore, the aim of this study was to explore how second-year undergraduate nursing students experienced learning through virtual simulations during the COVID-19 pandemic.

METHODS: The study had an exploratory design with both quantitative and qualitative approaches. In total, 69 nursing students participated in two sessions of virtual simulation during spring 2020, and 33 students answered online questionnaires at session 1. To further explore students’ experiences, one focus group interview and one individual interview were conducted using a video conferencing system after session 2. In addition, system information on use during both sessions was collected.

RESULTS: Changes in the students’ ratings of their experiences of virtual simulation with the Body Interact™ system were statistically significant. The virtual simulation helped them to bridge gaps in both the teaching and learning processes. Four important aspects of learning were identified: 1) learning by self-training, 2) learning from the software (Body Interact™), 3) learning from peers, and 4) learning from faculty.

CONCLUSIONS: We conclude that virtual simulation through a video conferencing system can be useful for student learning and feedback from both peers and faculty is important.

PMID:34506698 | DOI:10.1515/ijnes-2021-0056

J Neuroimaging. 2021 Sep 10. doi: 10.1111/jon.12926. Online ahead of print.

ABSTRACT

BACKGROUND AND PURPOSE: The gold standard for imaging of meningiomas is MRI with gadolinium-based contrast agent. Due to increased costs, time, and uncertain chronic effects of gadolinium exposure, use of noncontrast T2-weighted imaging (T2WI) in lieu of contrast-enhanced MRI has been an increasing focus of research across various diagnostic scenarios. The purpose of this study was to evaluate the diagnostic accuracy of T2WI in detecting changes in meningioma tumor volume.

METHODS: Imaging and clinical data were reviewed for 82 consecutive patients undergoing MR-surveillance of intracranial meningioma. Using volumetric-T2WI, two neuroradiologists independently calculated tumor volumes. Measurements were compared to a baseline study contrast-enhanced T1 tumor volume. Using contrast-enhanced sequences as the reference standard, statistical analysis was performed to determine the accuracy of T2WI in detecting changes of meningioma volume.

RESULTS: Using only T2WI, readers detected meningioma volume change ≥ 20% in 19/82 patients and volume change <20% in 63/82 patients. Reader accuracy for detecting change in tumor volume on T2WI ≥ 20% was 0.85, sensitivity 0.65, specificity 0.93, positive predictive value (PPV) 0.79, and negative predictive value (NPV) 0.87. For meningiomas >1 ml, reader accuracy for detecting change in tumor volume on T2WI ≥20% was 0.90, sensitivity 0.78, specificity 0.95, PPV 0.88, and NPV 0.91. Change in tumor volume on T2WI ≥20% was detected with 100% accuracy for posterior fossa meningiomas. Inter-reader agreement for all meningiomas was moderate (κ = 0.45) improving to substantial agreement (κ = 0.77) with tumor volumes >1 ml.

CONCLUSION: Volumetric-T2WI detects changes in meningioma volume with comparable accuracy to gold standard T1 postcontrast imaging, particularly with higher tumor volumes and posterior fossa locations.

PMID:34506680 | DOI:10.1111/jon.12926

Oncologist. 2021 Sep 10. doi: 10.1002/onco.13969. Online ahead of print.

ABSTRACT

BACKGROUND: We externally validated Fujimoto’s Post-Transplant Lymphoproliferative Disorder (PTLD) scoring system for risk prediction by using the Taiwan Blood and Marrow Transplant Registry Database (TBMTRD), and aimed to create a superior scoring system using machine learning methods.

MATERIALS AND METHODS: Consecutive allogeneic hematopoietic cell transplant (HCT) recipients registered in the TBMTRD from 2009 to 2018 were included in this study. The Fujimoto PTLD score was calculated for each patient. The machine learning algorithm, LASSO, was used to construct a new score system, which was validated using the 5-fold cross validation method.

RESULTS: We identified 2,148 allogeneic HCT recipients, of which 57 (2.65%) developed PTLD in the TBMTRD. In this population, the probability for PTLD development by Fujimoto score at five years for patients in the low, intermediate, high and very high-risk groups were 1.15%, 3.06%, 4.09%, 8.97%, respectively. The score model had acceptable discrimination with a C-statistic of 0.65 and a near-perfect moderate calibration curve (HL test P of 0.81). Using LASSO regression analysis, a four-risk-group model was constructed and the new model showed better discrimination in the validation cohort when compared with The Fujimoto PTLD score (C-statistic: 0.75 vs. 0.65).

CONCLUSION: Our study demonstrated a more comprehensive model when compared with Fujimoto’s PTLD scoring system, which included additional predictors identified through machine learning that may have enhanced discrimination. The widespread use of this promising tool for risk stratification of patients receiving HCT allows identification of high-risk patients that may benefit from preemptive treatment for PTLD.

IMPLICATIONS FOR PRACTICE: We validated the Fujimoto score for the prediction of PTLD development following HSCT in an external, independent, and nationally representative population. We also developed a more comprehensive model with enhanced discrimination for better risk stratification of patients receiving HSCT, potentially changing clinical managements in certain risk groups. Previously unreported risk factors associated with the development of PTLD after HSCT were identified using the machine learning algorithm, LASSO, including pre-HSCT medical history of mechanical ventilation, and the chemotherapy agents used in conditioning regimen.

PMID:34506688 | DOI:10.1002/onco.13969

Oncologist. 2021 Sep 10. doi: 10.1002/onco.13965. Online ahead of print.

ABSTRACT

BACKGROUND: Breast cancer is the most common cancer among women worldwide, and the second leading cause of brain metastases (BrM). We assessed the treatment patterns and outcomes of women treated for breast cancer BrM at our institution in the modern era of stereotactic radiosurgery (SRS).

MATERIALS AND METHODS: We conducted a retrospective analysis of women (≥ 18 years old) with metastatic breast cancer who were treated with surgery, whole brain radiotherapy (WBRT) or SRS to the brain at the Sunnybrook Odette Cancer Center, Toronto, Canada between 2008 and 2018. Patients with a history of other malignancies and those with an uncertain date of diagnosis of BrM were excluded. Descriptive statistics were generated and survival analyses were performed, with subgroup analyses by breast cancer subtype.

RESULTS: Among 683 eligible patients, 153 (22.4%) had triple negative (TNBC), 188 (27.5%) had HER2+, 246 (36.0%) had hormone receptor (HR)+/HER2-, and 61 (13.3%) had breast cancer of unknown subtype. The majority of patients received fist line WBRT (n=459, 67.2%) or SRS (n=126, 18.4%). The median brain-specific progression-free survival and median overall survival (OS) were 4.1 months (IQR 1.0-9.6 months) and 5.1 months (IQR 2.0-11.7 months) in the overall patent population, respectively. Age >60 years, presence of neurological symptoms at BrM diagnosis, first line WBRT and HER2- subtype were independently prognostic for shorter OS.

CONCLUSION: Despite the use of SRS, outcomes among patients with breast cancer BrM remain poor. Strategies for early detection of BrM and central nervous system-active systemic therapies warrant further investigation.

IMPLICATIONS FOR PRACTICE: Although triple negative and HER2+ breast cancer have a predilection for metastasis to the central nervous system (CNS), patients with hormone receptor (HR)+/HER2- breast cancer represent a high proportion of patients with breast cancer brain metastases (BrM). Hence, clinical trials should include patients with BrM and evaluate CNS-specific activity of novel systemic therapies when feasible, irrespective of breast cancer subtype. In addition, given that symptomatic BrM are associated with shorter survival, we propose that screening programs for the early detection and treatment of breast cancer BrM warrant further investigation in an era of minimally toxic stereotactic radiosurgery.

PMID:34506676 | DOI:10.1002/onco.13965

J Neuroimaging. 2021 Sep 10. doi: 10.1111/jon.12929. Online ahead of print.

ABSTRACT

BACKGROUND AND PURPOSE: Super-resolutionreconstruction (SRR) can be used to reconstruct 3-dimensional (3D) high-resolution (HR) volume from several 2-dimensional (2D) low-resolution (LR) stacks of MRI slices. The purpose is to compare lengthy 2D T2-weighted HR image acquisition of neonatal subjects with 3D SRR from several LR stacks in terms of image quality for clinical and morphometric assessments.

METHODS: LR brain images were acquired from neonatal subjects to reconstruct isotropic 3D HR volumes by using SRR algorithm. Quality assessments were done by an experienced pediatric radiologist using scoring criteria adapted to newborn anatomical landmarks. The Wilcoxon signed-rank test was used to compare scoring results between HR and SRR images. For quantitative assessments, morphology-based segmentation was performed on both HR and SRR images and Dice coefficients between the results were computed. Additionally, simple linear regression was performed to compare the tissue volumes.

RESULTS: No statistical difference was found between HR and SRR structural scores using Wilcoxon signed-rank test (p = .63, Z = .48). Regarding segmentation results, R² values for the volumes of gray matter, white matter, cerebrospinal fluid, basal ganglia, cerebellum, and total brain volume including brain stem ranged between .95 and .99. Dice coefficients between the segmented regions from HR and SRR ranged between .83 ± .04 and .96 ± .01.

CONCLUSION: Qualitative and quantitative assessments showed that 3D SRR of several LR images produces images that are of comparable quality to standard 2D HR image acquisition for healthy neonatal imaging without loss of anatomical details with similar edge definition allowing the detection of fine anatomical structures and permitting comparable morphometric measurement.

PMID:34506677 | DOI:10.1111/jon.12929

Biometrics. 2021 Sep 10. doi: 10.1111/biom.13552. Online ahead of print.

ABSTRACT

Many large-scale surveys collect both discrete and continuous variables. Small area estimates may be desired for means of continuous variables, proportions in each level of a categorical variable, or for domain means defined as the mean of the continuous variable for each level of the categorical variable. In this paper, we introduce a conditionally specified bivariate mixed-effects model for small area estimation, and provide a necessary and sufficient condition under which the conditional distributions render a valid joint distribution. The conditional specification allows better model interpretation. We use the valid joint distribution to calculate empirical Bayes predictors and use the parametric bootstrap to estimate the mean squared error. Simulation studies demonstrate the superior performance of the bivariate mixed-effects model relative to univariate model estimators. We apply the bivariate mixed-effects model to construct estimates for small watersheds using data from the Conservation Effects Assessment Project (CEAP), a survey developed to quantify the environmental impacts of conservation efforts. We construct predictors of mean sediment loss, the proportion of land where the soil loss tolerance is exceeded, and the average sediment loss on land where the soil loss tolerance is exceeded. In the data analysis, the bivariate mixed-effects model leads to more scientifically interpretable estimates of domain means than those based on two independent univariate models.

PMID:34506632 | DOI:10.1111/biom.13552

J Med Virol. 2021 Sep 10. doi: 10.1002/jmv.27331. Online ahead of print.

ABSTRACT

SARS-CoV-2 is a newly discovered beta coronavirus at the end of 2019, which is highly pathogenic and poses a serious threat to human health. In this paper, 1,875 SARS-CoV-2 whole genome sequences and the sequence coding spike protein (S gene) sampled from the United States were used for the bioinformatics analysis to study the molecular evolutionary characteristics of its genome and spike protein. The MCMC method was used to calculate the evolution rate of the whole genome sequence and the nucleotide mutation rate of S gene. The results showed that the nucleotide mutation rate of the whole genome was 6.677×10^-4 substitution per site per year, and the nucleotide mutation rate of S gene was 8.066×10^-4 substitution per site per year, which was at a medium level compared with other RNA viruses. Our findings confirmed the scientific hypothesis that the rate of evolution of the virus gradually decreases over time. We also found 13 statistically significant positive selection sites in SARS-CoV-2 genome. In addition, the results showed that there were 101 non-synonymous mutation sites in the amino acid sequence of S protein, including seven putative harmful mutation sites. This paper preliminarily clarified the evolutionary characteristics of SARS-CoV-2 in the United States, providing a scientific basis for future surveillance and prevention of virus variants. This article is protected by copyright. All rights reserved.

PMID:34506640 | DOI:10.1002/jmv.27331