Tag: pubmed

Magn Reson Med. 2021 Dec 27. doi: 10.1002/mrm.29125. Online ahead of print.

ABSTRACT

PURPOSE: Multicomponent analysis of MRI T₂ relaxation time (mcT₂ ) is commonly used for estimating myelin content by separating the signal at each voxel into its underlying distribution of T₂ values. This voxel-based approach is challenging due to the large ambiguity in the multi-T₂ space and the low SNR of MRI signals. Herein, we present a data-driven mcT₂ analysis, which utilizes the statistical strength of identifying spatially global mcT₂ motifs in white matter segments before deconvolving the local signal at each voxel.

METHODS: Deconvolution is done using a tailored optimization scheme, which incorporates the global mcT₂ motifs without additional prior assumptions regarding the number of microscopic components. The end results of this process are voxel-wise myelin water fraction maps.

RESULTS: Validations are shown for computer-generated signals, uniquely designed subvoxel mcT₂ phantoms, and in vivo human brain. Results demonstrated excellent fitting accuracy, both for the numerical and the physical mcT₂ phantoms, exhibiting excellent agreement between calculated myelin water fraction and ground truth. Proof-of-concept in vivo validation is done by calculating myelin water fraction maps for white matter segments of the human brain. Interscan stability of myelin water fraction values was also estimated, showing good correlation between scans.

CONCLUSION: We conclude that studying global tissue motifs prior to performing voxel-wise mcT₂ analysis stabilizes the optimization scheme and efficiently overcomes the ambiguity in the T₂ space. This new approach can improve myelin water imaging and the investigation of microstructural compartmentation in general.

PMID:34958690 | DOI:10.1002/mrm.29125

J Biopharm Stat. 2021 Dec 27:1-17. doi: 10.1080/10543406.2021.2011902. Online ahead of print.

ABSTRACT

In this paper, we develop a methodology for leveraging real-world data into single-arm clinical trial studies. In recent years, the idea of augmenting randomized clinical trials data with real-world data has emerged as a particularly attractive technique for health organizations and drug developers to accelerate the drug development process. Major regulatory authorities such as the Food and Drug Administration and European Medicines Agency have recognized the potential of utilizing real-world data and are advancing toward making regulatory decisions based on real-world evidence. Several statistical methods have been developed in recent years for borrowing data from real-world sources such as electronic health records, product and disease registries, as well as claims and billing data. We propose a novel approach to augment single-arm clinical trials with the real-world data derived from single or multiple data sources. Furthermore, we illustrate the proposed method in the presence of missing data and conduct simulation studies to evaluate its performance in diverse settings.

PMID:34958629 | DOI:10.1080/10543406.2021.2011902

Vascular. 2021 Dec 27:17085381211062747. doi: 10.1177/17085381211062747. Online ahead of print.

ABSTRACT

OBJECTIVES: Thoracic outlet syndrome (TOS) is a group of disorders caused by impingement of the neurovascular structures at the thoracic outlet. Neurogenic TOS (nTOS), which is thought to be caused by a compression of the brachial plexus, accounts for more than 90% of the cases. Although treatment for nTOS is successful through physiotherapy and/or surgical decompression, little is known about the impact of psychosocial factors, namely, major depressive disorder (MDD), on postoperative outcomes such as non-routine discharge (NRD). Here, we assess whether MDD predicts the type of discharge following nTOS surgical intervention.

METHODS: A retrospective analysis of the National Inpatient Sample database from the years 2005-2018 was performed. Using the International Classification of Diseases Clinical Modification, Ninth and Tenth revisions, patients who underwent a surgical intervention for nTOS were identified. Our primary outcome was to investigate the effects of MDD on nTOS patient disposition status after surgical management; secondary outcomes included analysis of total hospital charges and length of stay. NRD was defined as anything beyond discharge home without healthcare services. Univariate and multivariable logistic regression analyses were conducted to assess MDD and other potential independent predictors of NRD and prolonged hospital stay (> 2 days) following surgical intervention.

RESULTS: A total of 6099 patients were identified: 596 (9.77%) patients with MDD and 5503 (90.23%) without MDD. On average, patients with MDD were older (39.6 ± 12.0 years vs. 36.0 ± 13.0 years; p < 0.001), female (80.7% vs. 63.5%; p < 0.001), white (89.6% vs. 85.6%; p = 0.030), and on Medicare (9.6% vs 5.2%; p < 0.001). Univariate and multivariable logistic regression models identified MDD as an independent risk factor associated with a higher risk of NRD (adjusted odds ratio [aOR], 1.50; 95% confidence interval [CI], 1.0-2.2). Additionally, chronic kidney disease (aOR, 2.60; 95% CI, 1.2-5.4), postoperative complications (aOR, 1.87; 95% CI, 1.2-2.9), and Medicare (aOR, 2.95; 95% CI, 1.9-4.7) were statistically significant predictors for higher risk of NRD. However, MDD was not associated with prolonged hospital stay (aOR, 1.00; 95% CI, 0.8-1.2) or higher median of total charges (MDD group: $27,867 vs. non-MDD group: $28,123; p = 0.799).

CONCLUSION: Comorbid MDD was strongly associated with higher NRD rates following nTOS surgical intervention. MDD had no significant impact on length of hospital stay or total hospital charges. Additional prospective research is necessary in order to better evaluate the impact of MDD in patients with nTOS.

PMID:34958613 | DOI:10.1177/17085381211062747

J Speech Lang Hear Res. 2021 Dec 27:1-14. doi: 10.1044/2021_JSLHR-21-00306. Online ahead of print.

ABSTRACT

PURPOSE: We proposed and tested a causal instantiation of the World Health Organization’s International Classification of Functioning, Disability and Health (ICF) framework, linking acoustics, intelligibility, and communicative participation in the context of dysarthria.

METHOD: Speech samples and communicative participation scores were collected from individuals with dysarthria (n = 32). Speech was analyzed for two acoustic metrics (i.e., articulatory precision and speech rate), and an objective measure of intelligibility was generated from listener transcripts. Mediation analysis was used to evaluate pathways of effect between acoustics, intelligibility, and communicative participation.

RESULTS: We observed a strong relationship between articulatory precision and intelligibility and a moderate relationship between intelligibility and communicative participation. Collectively, data supported a significant relationship between articulatory precision and communicative participation, which was almost entirely mediated through intelligibility. These relationships were not significant when speech rate was specified as the acoustic variable of interest.

CONCLUSION: The statistical corroboration of our causal instantiation of the ICF framework with articulatory acoustics affords important support toward the development of a comprehensive causal framework to understand and, ultimately, address restricted communicative participation in dysarthria.

PMID:34958608 | DOI:10.1044/2021_JSLHR-21-00306

Chin Med J (Engl). 2021 Dec 21. doi: 10.1097/CM9.0000000000001864. Online ahead of print.

ABSTRACT

BACKGROUND: Hepatectomy for hepatocellular carcinoma (HCC) beyond the Milan criteria is shown to be beneficial. However, a high rate of post-operative HCC recurrence hinders the long-term survival of the patients. This study aimed to investigate and compare the impacts of tenofovir (TDF) and entecavir (ETV) on the recurrence of hepatitis B viral (HBV)-related HCC beyond the Milan criteria.

METHODS: Data pertaining to 1532 patients who underwent hepatectomy and received antiviral therapy between January 2014 and January 2019 were collected from five centers. Recurrence-free survival (RFS) analysis was performed using the Kaplan-Meier method. Cox proportional hazards regression analysis was performed to determine prognostic factors for HCC recurrence.

RESULTS: The analysis incorporates 595 HBV-related HCC patients. The overall 5-year RFS was 21.3%. Among them, 533 and 62 patients received ETV and TDF treatment, respectively. The 1-, 3-, and 5-year RFS rates were 46.3%, 27.4%, and 19.6%, respectively, in the ETV group compared with 65.1%, 41.8%, and 37.2%, respectively, in the TDF group (P < 0.001). Multivariate analysis showed that TDF treatment (hazard ratio [HR]: 0.604, P = 0.005), cirrhosis (HR: 1.557, P = 0.004), tumor size (HR: 1.037, P = 0.008), microvascular invasion (MVI) (HR: 1.403, P = 0.002), portal vein tumor thrombus (PVTT) (HR: 1.358, P = 0.012), capsular invasion (HR: 1.228, P = 0.040), and creatinine levels (CREA) (HR: 0.993, P = 0.031) were statistically significant prognostic factors associated with RFS.

CONCLUSIONS: Patients with HCC beyond the Milan criteria exhibited a high rate of HCC recurrence after hepatectomy. Compared to the ETV therapy, TDF administration significantly lowered the risk of HCC recurrence.

PMID:34958539 | DOI:10.1097/CM9.0000000000001864

J Phys Chem Lett. 2021 Dec 27:91-97. doi: 10.1021/acs.jpclett.1c03813. Online ahead of print.

ABSTRACT

We apply chirped-pulse uniform flow millimeterwave (CPUF-mmW) spectroscopy to study the complex multichannel reaction dynamics in the reaction between the propargyl and amino radicals (C₃H₃ + NH₂/ND₂), a radical-radical reaction of importance in the gas-phase chemistry of astrochemical environments and combustion systems. The photolytically generated radicals are allowed to react in a well-characterized quasi-uniform supersonic flow, and mmW rotational spectroscopy (70-93 GHz) is used for simultaneous detection of the reaction products: HCN, HNC, HC₃N, DCN, DNC, and DC₃N, while spectral intensities of the measured pure-rotational lines allow product branching to be quantified. High-level electronic structure calculations were used for theoretical prediction of the reaction pathways and branching. Experimentally deduced product branching fractions were compared with the results from statistical simulations based on the RRKM theory. Product branching was found to be strongly dependent on the excess internal energy of the C₃H₃ and NH₂/ND₂ reactants.

PMID:34958581 | DOI:10.1021/acs.jpclett.1c03813

J Environ Qual. 2021 Dec 27. doi: 10.1002/jeq2.20318. Online ahead of print.

ABSTRACT

Variability of dairy process wastewater (PWW) nitrogen (PWW-N) content makes precise fertilizing of forage challenging. Our objective was to improve measurement accuracy of PWW-N. We characterized PWW-N and quantified its variability using over 1000 PWW samples from 91 lagoons on commercial California dairies. We used statistical modeling and stochastic simulations to compare the accuracy of various protocols for measuring PWW-N applied to forage crops. Electrical Conductivity (EC) was positively correlated with N concentration within a lagoon (conditional R² = 69%, mixed model). Simulations compared the accuracy of N application rates when lagoon samples for N analyses were collected more frequently and from more homogenous lagoons. When sampled quarterly, the N application measurement error was ±50%. Homogenizing PWW and sampling weekly reduced measurement error to ±42% and ±30%, respectively. Simulations using EC as an N concentration proxy within an automated irrigation system reduced N application measurement error to ±5%. More accurate automated N concentration measurements allow for precision N management that meets yield goals and reduces environmental impacts. This article is protected by copyright. All rights reserved.

PMID:34958489 | DOI:10.1002/jeq2.20318

Int Endod J. 2021 Dec 27. doi: 10.1111/iej.13676. Online ahead of print.

ABSTRACT

AIM: To identify factors that are predictive of short-term professional and societal impact of research within the specialty of Endodontology, and to identify the top-10 articles that achieved the greatest societal impact and describe their characteristics.

METHODOLOGY: Research articles in the field of Endodontology published in 2019 were eligible for inclusion, with the sample identified using Medline. Following screening of titles and abstracts, bibliometric data of the identified articles were exported into a spreadsheet, where further data related to continental origin, type of article, type of journal (endodontic or non-endodontic) and grant-funding were collated, with additional data concerning presence of journal impact factor, citations, news mentions and Altmetric-tracked-mentions and scores compiled using Clarivate, Scopus, ProQuest and Altmetric Explorer, respectively. Data analysis comprised descriptive statistics, frequency distributions, cross-tabulations and un/adjusted negative binomial regression models (P<0.05).

RESULTS: The search retrieved 30,443 articles; 951 were included for analysis. Most articles originated from Asia (43.2%) with over 51.5% of articles published in endodontic journals and 80% published in a journal with an impact factor. Over three-quarters of articles were primary research, 141 were grant-funded, 165 had a news mention, 338 achieved an Altmetric Attention Score and 808 were cited. The five-highest ranked articles were mentioned in general news bulletins, five of the top-10 articles were primary research and six of the top-10 were published in endodontic journals. The highest Altmetric Attention Score and citation count were 100 and 87, respectively. Adjusted models demonstrated that the type of article, publication in a journal with an impact factor, absence of grant-funding and coverage within general news bulletins predicted the Altmetric Attention Scores (P<0.001). Article type, publication in an impact-factor journal and presence of an Altmetric Attention Score were predictive of citations (P<0.001).

CONCLUSIONS: Article type and publication in a journal with an impact factor were significant predictors of both societal and professional impact of research articles within Endodontology in the short-term. Non grant-funded research and coverage in general news bulletins achieved greater societal impact, whereas an article achieving an Altmetric Attention Score was also strongly related to professional impact.

PMID:34958490 | DOI:10.1111/iej.13676

Abdom Radiol (NY). 2021 Dec 27. doi: 10.1007/s00261-021-03387-z. Online ahead of print.

ABSTRACT

PURPOSE: Reports on the future liver remnant (FLR) hypertrophy rate in patients undergoing portal vein embolization (PVE) before left trisectionectomy are sparse. This study aimed to assess the FLR hypertrophy rate in patients undergoing PVE before left trisectionectomy.

METHODS: Between January 2010 and June 2021, 30 patients (22 men and eight women; mean age, 65.7 years) underwent PVE, mainly using gelatin sponge, before left trisectionectomy. The preoperative diagnosis was cholangiocarcinoma in 28 patients and colorectal liver metastases in two patients. The FLR hypertrophy rate, increase in the FLR volume (FLRV) ratio (the ratio of the FLRV to the total liver volume), and complications were evaluated. The patients were further divided into two groups: one group of patients with left portal vein stenosis or occlusion before PVE (n = 12) and another without left portal vein stenosis or occlusion before PVE (n = 18). The FLR hypertrophy rate and increase in the FLRV ratio were compared between the two groups.

RESULTS: The FLR hypertrophy rate and increase in the FLRV ratio were 31.3% and 6.9%, respectively. One major complication, cholangitis, developed; however, its association with PVE was unclear. The difference in the FLR hypertrophy rate and the increase in the FLRV ratio between the two groups of patients was statistically insignificant.

CONCLUSION: PVE before left trisectionectomy is effective in achieving FLR hypertrophy. PVE before left trisectionectomy was equally effective in patients with left portal vein stenosis or occlusion as compared to those without. The complication rates were acceptable.

PMID:34958405 | DOI:10.1007/s00261-021-03387-z

BJS Open. 2021 Nov 9;5(6):zrab107. doi: 10.1093/bjsopen/zrab107.

ABSTRACT

BACKGROUND: Anorectal melanoma is a rare neoplasm with a poor prognosis. The surgical approaches for anorectal melanoma can be categorized into local excision (procedures without lymph node removal and preservation of the rectum) and extensive resection (procedures with rectum and pararectal lymph node removal). The aim of this systematic review and meta-analysis was to compare the survival of patients who underwent extensive resection with that of patients who underwent local excision, stratifying patients according to tumour stage.

METHODS: A literature review was performed according to PRISMA guidelines by searching MEDLINE/PubMed for manuscripts published until March 2021. Studies comparing survival outcomes in patients with anorectal melanoma who underwent local excision versus extensive resection were screened for eligibility. Meta-analysis was performed for overall survival after the different surgical approaches, stratified by tumour stage.

RESULTS: There were 347 studiesidentified of which 34 were included for meta-analysis with a total of 1858 patients. There was no significant difference in overall survival between the surgical approaches in patients per stage (stage I odds ratio 1.30 (95 per cent c.i. 0.62 to 2.72, P = 0.49); stage II odds ratio 1.61 (95 per cent c.i. 0.62 to 4.18, P = 0.33); stage I-III odds ratio 1.19 (95 per cent c.i. 0.83 to 1.70, P = 0.35). Subgroup analyses were conducted for the time intervals (<2000, 2001-2010 and 2011-2021) and for continent of study origin. Subgroup analysis for time interval and continent of origin also showed no statistically significant differences in overall survival.

CONCLUSION: No significant survival benefit exists for patients with anorectal melanoma treated with local excision or extensive resection, independent of tumour stage.

PMID:34958352 | DOI:10.1093/bjsopen/zrab107