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Nevin Manimala Statistics

MRI-based random survival Forest model improves prediction of progression-free survival to induction chemotherapy plus concurrent Chemoradiotherapy in Locoregionally Advanced nasopharyngeal carcinoma

BMC Cancer. 2022 Jul 6;22(1):739. doi: 10.1186/s12885-022-09832-6.

ABSTRACT

BACKGROUND: The present study aimed to explore the application value of random survival forest (RSF) model and Cox model in predicting the progression-free survival (PFS) among patients with locoregionally advanced nasopharyngeal carcinoma (LANPC) after induction chemotherapy plus concurrent chemoradiotherapy (IC + CCRT).

METHODS: Eligible LANPC patients underwent magnetic resonance imaging (MRI) scan before treatment were subjected to radiomics feature extraction. Radiomics and clinical features of patients in the training cohort were subjected to RSF analysis to predict PFS and were tested in the testing cohort. The performance of an RSF model with clinical and radiologic predictors was assessed with the area under the receiver operating characteristic (ROC) curve (AUC) and Delong test and compared with Cox models based on clinical and radiologic parameters. Further, the Kaplan-Meier method was used for risk stratification of patients.

RESULTS: A total of 294 LANPC patients (206 in the training cohort; 88 in the testing cohort) were enrolled and underwent magnetic resonance imaging (MRI) scans before treatment. The AUC value of the clinical Cox model, radiomics Cox model, clinical + radiomics Cox model, and clinical + radiomics RSF model in predicting 3- and 5-year PFS for LANPC patients was [0.545 vs 0.648 vs 0.648 vs 0.899 (training cohort), and 0.566 vs 0.736 vs 0.730 vs 0.861 (testing cohort); 0.556 vs 0.604 vs 0.611 vs 0.897 (training cohort), and 0.591 vs 0.661 vs 0.676 vs 0.847 (testing cohort), respectively]. Delong test showed that the RSF model and the other three Cox models were statistically significant, and the RSF model markedly improved prediction performance (P < 0.001). Additionally, the PFS of the high-risk group was lower than that of the low-risk group in the RSF model (P < 0.001), while comparable in the Cox model (P > 0.05).

CONCLUSION: The RSF model may be a potential tool for prognostic prediction and risk stratification of LANPC patients.

PMID:35794590 | DOI:10.1186/s12885-022-09832-6

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Nevin Manimala Statistics

Distal tibial tubercle osteotomy can lessen change in patellar height post medial opening wedge high tibial osteotomy? A systematic review and meta-analysis

J Orthop Surg Res. 2022 Jul 6;17(1):341. doi: 10.1186/s13018-022-03231-0.

ABSTRACT

OBJECTIVE: Medial opening wedge high tibial osteotomy (MOWHTO) is a mainstream surgical method for treating early medial compartment knee osteoarthritis. Undesirable sequelae such as patella infera may happen following tuberosity osteotomy. We conducted this systematic review and meta-analysis to compare the change in patellar position after proximal tibial tubercle osteotomy (PTO) versus distal tibial tubercle osteotomy (DTO) intervention.

METHODS: The 11 studies were acquired from PubMed, Medline, Embase and Cochrane Library. The data were extracted by two of the coauthors independently and were analyzed by RevMan5.3. Mean differences, odds ratios and 95% confidence intervals were calculated. Cochrane Collaboration’s Risk of Bias Tool and Newcastle-Ottawa Scale were used to assess risk of bias.

RESULTS: Eleven observational studies were assessed. The methodological quality of the trials ranged from moderate to high. The pooled results of postoperative patellar height (Caton-Deschamps index and Blackburne-Peel index) and postoperative complications showed that the differences were statistically significant between PTO and DTO interventions. Patellar index ratios decreased significantly in the PTO groups, and 12 (9.2%) complications under DTO surgery and 2 (1.6%) complications under PTO surgery were reported. The differences of postoperative posterior tibial slope (angle) was not statistically significant, but postoperative posterior tibial slope of both groups increased. Sensitivity analysis proved the stability of the pooled results and the publication bias was not apparent.

CONCLUSIONS: DTO in MOWHTO maintained the postoperative patellar height, and clinically, for patients with serious patellofemoral osteoarthritis, DTO can be preferred. Postoperative complications are easily preventable with caution. In view of the heterogeneity and small sample size, whether these conclusions are applicable should be further determined in future studies.

PMID:35794572 | DOI:10.1186/s13018-022-03231-0

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Nevin Manimala Statistics

Three-dimensional assessment of palatal area changes after posterior crossbite correction with tooth-borne and tooth bone-borne rapid maxillary expansion

Angle Orthod. 2022 Jul 6. doi: 10.2319/012822-85.1. Online ahead of print.

ABSTRACT

OBJECTIVES: To assess and compare the three-dimensional treatment changes in palatal surface area and volume using either tooth-borne (TB) or tooth bone-borne (TBB) rapid maxillary expanders and to evaluate the long-term effects of the two devices and the incidence of the relapse between the groups.

MATERIALS AND METHODS: A total of 52 consecutive patients who met the eligibility criteria were recruited and allocated to either the TB group, mean age 9.3 years (standard deviation [SD], 1.3), or the TBB group, mean age 9.5 years (SD, 1.2). Study casts were taken before, directly after, 1 year after, and 5 years after expansion. Study casts were digitized, superimposed, and evaluated. Participants were randomly allocated in blocks of different sizes using the concealed allocation principle in a 1:1 ratio.

RESULTS: Changes in palatal volume, palatal surface area, and palatal projection area within and between the groups up to 5 years after expansion followed the same pattern and did not show any statistically significant differences between the groups. Relapse was seen in 15% of the patients. It seemed that open-bite and a Class III growth pattern could be assumed as prognosis-deteriorating factors in regard to stability of the treatment.

CONCLUSIONS: There were no significant differences between the TB and TBB groups in palatal volume, palatal shell area, or palatal projection area directly after expansion or at 1 year and 5 years after expansion, which implies that the two devices gave rise to the same immediate and long-term outcomes.

PMID:35793528 | DOI:10.2319/012822-85.1

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Nevin Manimala Statistics

Shared Differential Expression-Based Distance Reflects Global Cell Type Relationships in Single-Cell RNA Sequencing Data

J Comput Biol. 2022 Jul 6. doi: 10.1089/cmb.2021.0652. Online ahead of print.

ABSTRACT

Unsupervised cell clustering on the basis of meaningful biological variation in single-cell RNA sequencing (scRNA seq) data has received significant attention, as it assists with ontological subpopulation identification among the data. A key step in the clustering process is to compute distances between the cells under a specified distance measure. Although particular distance measures may successfully separate cells into biologically relevant clusters, they may fail to retain global structure of the data, such as relative similarity between the cell clusters. In this article, we modify a biologically motivated distance measure, SIDEseq, for use of aggregate comparisons of cell types in large single-cell assays, and demonstrate that, across simulated and real scRNA seq data, the distance matrix more consistently retains global cell type relationships than commonly used distance measures for scRNA seq clustering. We call the modified distance measure “SIDEREF.” We explore spectral dimension reduction of the SIDEREF distance matrix as a means of noise filtering, similar to principal components analysis applied directly to expression data. We utilize a summary measure of relative cell type distances to better display the cell group relationships. SIDEREF visualizations more consistently reflect global structures in the data than other commonly considered distance measures. We utilize relative cell type distances and the SIDEREF distance measure to uncover compositional differences between annotated leukocyte cell groups in a compendium of Mus musculus scRNA seq assays comprising 12 tissues. SIDEREF and associated analysis is openly available on GitHub.

PMID:35793527 | DOI:10.1089/cmb.2021.0652

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Nevin Manimala Statistics

Acid-base balance in hemodialysis patients in everyday practice

Ren Fail. 2022 Dec;44(1):1090-1097. doi: 10.1080/0886022X.2022.2094805.

ABSTRACT

INTRODUCTION: Abnormalities in blood bicarbonates (HCO3) concentration are a common finding in patients with chronic kidney disease, especially at the end-stage renal failure. Initiating of hemodialysis does not completely solve this problem. The recommendations only formulate the target concentration of ≥22 mmol/L before hemodialysis but do not guide how to achieve it. The aim of the study was to assess the acid-base balance in everyday practice, the effect of hemodialysis session and possible correlations with clinical and biochemical parameters in stable hemodialysis patients.

MATERIAL AND METHODS: We enrolled 75 stable hemodialysis patients (mean age 65.5 years, 34 women), from a single Department of Nephrology. We assessed blood pressure, and acid-base balance parameters before and after mid-week hemodialysis session.

RESULTS: We found significant differences in pH, HCO3 pCO2, lactate before and after HD session in whole group (p < 0.001; p < 0.001; p < 0.001; p = 0.001, respectively). Buffer bicarbonate concentration had only statistically significant effect on the bicarbonate concentration after dialysis (p < 0.001). Both pre-HD acid-base parameters and post-HD pH were independent from buffer bicarbonate content. We observed significant inverse correlations between change in the serum bicarbonates and only two parameters: pH and HCO3 before hemodialysis (p = 0.013; p < 0.001, respectively).

CONCLUSIONS: Despite the improvement in hemodialysis techniques, acid-base balance still remains a challenge. The individual selection of bicarbonate in bath, based on previous single tests, does not improve permanently the acid-base balance in the population of hemodialysis patients. New guidelines how to correct acid-base disorders in hemodialysis patients are needed to have less ‘acidotic’ patients before hemodialysis and less ‘alkalotic’ patients after the session.

PMID:35793495 | DOI:10.1080/0886022X.2022.2094805

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Nevin Manimala Statistics

Complete Blood Counts and Blood Smear Analyses in 312 Diabetic Dogs (2007-2017)

J Am Anim Hosp Assoc. 2022 Jul 1;58(4):180-188. doi: 10.5326/JAAHA-MS-7230.

ABSTRACT

Diabetes mellitus is a common endocrinopathy in dogs that has been associated with various biochemical changes and comorbid diseases, but hematologic abnormalities have been rarely reported. The aim of this retrospective study was to evaluate complete blood count and blood smear alterations and to describe their relationship with, and incidence of comorbid diseases in, diabetic dogs. Three-hundred twelve diabetic dogs, 286 dogs diagnosed with systemic, nondiabetic illnesses, and 506 healthy dogs were identified during the study period. Groups were compared using contingency tables and logistic regression. Associations between statistically significant complete blood count and blood smear alterations and comorbidities were evaluated using multivariable analysis. High-grade codocytosis and anisocytosis were identified more frequently in diabetic dogs, whereas high-grade reactive lymphocytosis and keratocytosis were identified less frequently (P < .001). Diabetic dogs with high-grade codocytosis had lower red blood cell, hemoglobin, hematocrit and higher white blood cell counts (P < .001). Diabetic ketoacidosis was diagnosed more frequently in diabetic dogs with high-grade codocytosis when compared with those with low-grade codocytosis (P < .001) or when compared with any other cell morphologic alterations. This study suggests that blood smear analysis should be a routine part of the evaluation of diabetic dogs.

PMID:35793489 | DOI:10.5326/JAAHA-MS-7230

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Nevin Manimala Statistics

A general framework for subgroup detection via one-step value difference estimation

Biometrics. 2022 Jul 6. doi: 10.1111/biom.13711. Online ahead of print.

ABSTRACT

Recent statistical methodology for precision medicine has focused on either identification of subgroups with enhanced treatment effects or estimating optimal treatment decision rules so that treatment is allocated in a way that maximizes, on average, predefined patient outcomes. Less attention has been given to subgroup testing, which involves evaluation of whether at least a subgroup of the population benefits from an investigative treatment, compared to some control or standard of care. In this work, we propose a general framework for testing for the existence of a subgroup with enhanced treatment effects based on the difference of the estimated value functions under an estimated optimal treatment regime and a fixed regime that assigns everyone to the same treatment. Our proposed test does not require specification of the parametric form of the subgroup and allows heterogeneous treatment effects within the subgroup. The test applies to cases when the outcome of interest is either a time-to-event or a (uncensored) scalar, and is valid at the exceptional law. To demonstrate the empirical performance of the proposed test, we study the type I error and power of the test statistics in simulations and also apply our test to data from a Phase III trial in patients with hematological malignancies.

PMID:35793474 | DOI:10.1111/biom.13711

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Nevin Manimala Statistics

Infection risk in psoriatic patients receiving tumor necrosis factor inhibitors: A 20-year systematic review and meta-analysis of randomized controlled trials

J Eur Acad Dermatol Venereol. 2022 Jul 6. doi: 10.1111/jdv.18407. Online ahead of print.

ABSTRACT

Tumor necrosis factor inhibitors (TNFis) are commonly used for treating psoriatic diseases; however, the risk of infection while receiving TNFis remains uncertain. The aim of this study was to investigate the infection risk in patients with psoriatic disease receiving TNFis. A prospectively registered systematic literature search was conducted in Medline (PubMed), Cochrane Central Register of Controlled Trials (CENTRAL), EMBASE, and the ClinicalTrials.gov databases from inception to December 31, 2021. We included double-blind randomized controlled trials that compared TNFis or other biologics with placebo in adults with psoriasis or psoriatic arthritis. The primary outcomes included overall and serious infection risks, and secondary outcomes included upper respiratory infections and nasopharyngitis risks. The risk ratio of the dichotomous outcome was calculated using the Mantel-Haenszel method with random effects, and heterogeneity was assessed using Cochran’s Q statistic and quantified using the I-squared statistic. A total of 48 studies with 15464 patients with psoriatic diseases were included. The meta-analysis demonstrated a slightly increased overall infection risk (risk ratio =1.09; 95% confidence interval,1.02 to 1.15) but not serious infection risk (risk ratio =0.95; 95% confidence interval, 0.61 to 1.49) among patients receiving TNFis. There was also no increased risks of upper respiratory infections (risk ratio =1.10; 95% confidence interval, 0.94 to 1.28) or nasopharyngitis (risk ratio =1.14; 95% confidence interval, 1.00 to 1.30). In subgroup analyses using the fixed effects model, only etanercept and certolizumab pegol were respectively associated with an increased risk of overall infection (RR = 1.14, 95% CI, 1.03 to 1.27) and upper respiratory infections (RR=1.42, 95% CI, 1.02 to 1.98). In conclusion, evidence to date suggests an increased overall infection risk that is generally tolerable in patients with psoriatic diseases receiving TNFis. There are no increased risks of serious infections, upper respiratory infections, or nasopharyngitis.

PMID:35793472 | DOI:10.1111/jdv.18407

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Nevin Manimala Statistics

Same Storm, Different Boat: The Global Impact of COVID-19 on Palliative Care

Psychooncology. 2022 Jul 6. doi: 10.1002/pon.5995. Online ahead of print.

ABSTRACT

The COVID-19 pandemic has had a complex and profound impact on the provision of palliative care globally. To support learning from palliative care providers and researchers worldwide, the Education Subcommittee of International Psycho-Oncology Society (IPOS) Palliative Care Special Interest Group developed a webinar with presentations by and discussion with eight international palliative care leaders. Presentations were content rich; the speakers used both quantitative (e.g., sharing recent statistical findings) and qualitative (e.g., narrative storytelling, anecdotal experiences) approaches to portray the effect of COVID-19 in their region. Subsequent to the webinar, the committee collectively identified five themes conveyed by the presenters through consensus. The themes included: 1) altered accessibility to palliative care, with socio-economic status impacting virtual health availability; 2) reduced opportunities to preserve dignity, as survival has been prioritized over preserving the humanity of patients and their loved ones; 3) complicated grief and bereavement arising from social distancing requirements; 4) greater awareness of the importance of sustaining health provider well-being; and 5) the development of valuable innovations across nations, institutions, disciplines, and communities. Overall, the webinar facilitated valuable connection for global learning and identified opportunities for research and clinical interventions. This article is protected by copyright. All rights reserved.

PMID:35793431 | DOI:10.1002/pon.5995

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Nevin Manimala Statistics

Unraveling the Structural Sensitivity of CO2 Electroreduction at Facet-Defined Nanocrystals via Correlative Single-Entity and Macroelectrode Measurements

J Am Chem Soc. 2022 Jul 6. doi: 10.1021/jacs.2c02001. Online ahead of print.

ABSTRACT

The conversion of CO2 into value-added products is a compelling way of storing energy derived from intermittent renewable sources and can bring us closer to a closed-loop anthropogenic carbon cycle. The ability to synthesize nanocrystals of well-defined structure and composition has invigorated catalysis science with the promise of nanocrystals that selectively express the most favorable sites for efficient catalysis. The performance of nanocrystal catalysts for the CO2 reduction reaction (CO2RR) is typically evaluated with nanocrystal ensembles, which returns an averaged system-level response of complex catalyst-modified electrodes with each nanocrystal likely contributing a different (unknown) amount. Measurements at single nanocrystals, taken in the context of statistical analysis of a population, and comparison to macroscale measurements are necessary to untangle the complexity of the ever-present heterogeneity in nanocrystal catalysts, achieve true structure-property correlation, and potentially identify nanocrystals with outlier performance. Here, we employ environment-controlled scanning electrochemical cell microscopy to isolate and investigate the electrocatalytic CO2RR response of individual facet-defined gold nanocrystals. Using correlative microscopy approaches, we conclusively demonstrate that {110}-terminated gold rhombohedra possess superior activity and selectivity for CO2RR compared with {111}-terminated octahedra and high-index {310}-terminated truncated ditetragonal prisms, especially at low overpotentials where electrode kinetics is anticipated to dominate the current response. The methodology framework described here could inform future studies of complex electrocatalytic processes through correlative single-entity and macroscale measurement techniques.

PMID:35793438 | DOI:10.1021/jacs.2c02001