Nevin Manimala

Psychometrika. 2022 Nov 23. doi: 10.1007/s11336-022-09888-0. Online ahead of print.

ABSTRACT

The measurement of latent traits and investigation of relations between these and a potentially large set of explaining variables is typical in psychology, economics, and the social sciences. Corresponding analysis often relies on surveyed data from large-scale studies involving hierarchical structures and missing values in the set of considered covariates. This paper proposes a Bayesian estimation approach based on the device of data augmentation that addresses the handling of missing values in multilevel latent regression models. Population heterogeneity is modeled via multiple groups enriched with random intercepts. Bayesian estimation is implemented in terms of a Markov chain Monte Carlo sampling approach. To handle missing values, the sampling scheme is augmented to incorporate sampling from the full conditional distributions of missing values. We suggest to model the full conditional distributions of missing values in terms of non-parametric classification and regression trees. This offers the possibility to consider information from latent quantities functioning as sufficient statistics. A simulation study reveals that this Bayesian approach provides valid inference and outperforms complete cases analysis and multiple imputation in terms of statistical efficiency and computation time involved. An empirical illustration using data on mathematical competencies demonstrates the usefulness of the suggested approach.

PMID:36418780 | DOI:10.1007/s11336-022-09888-0

Int J Comput Assist Radiol Surg. 2022 Nov 23. doi: 10.1007/s11548-022-02792-z. Online ahead of print.

ABSTRACT

INTRODUCTION: Practicing endoscopic procedures is fundamental for the education of clinicians and the benefit of patients. Despite a diverse variety of model types, there is no system simulating anatomical restrictions and variations in a flexible and atraumatic way. Our goal was to develop and validate a new modelling approach for adhesion forces between colon and abdominal wall.

METHODS: An inlay for a standard mechanical trainer was designed and 3D printed. Colon specimens were fixed to the inlay along colon ascendens (CA) and colon descendens (CD) by a vacuum. Our system, which we refer to as Colonoscopy Vacuum Model (CoVaMo), was validated with 11 test persons with varying level of expertise. Each performed one colonoscopy and one polypectomy in the CoVaMo and in the Endoscopic Laparoscopic Interdisciplinary Training Entity (ELITE). Achieved adhesion forces, times required to fulfill different tasks endoscopically and a questionnaire, assessing proximity to reality, were recorded.

RESULTS: Mean adhesion forces of 37 ± 7 N at the CA and 30 ± 15 N at the CD were achieved. Test subjects considered CoVaMo more realistic than ELITE concerning endoscope handling and the overall anatomy. Participants needed statistically significantly more time to maneuver from anus to flexura sinistra in CoVaMo (377 s ± 244 s) than in ELITE (58 s ± 49 s).

CONCLUSION: We developed a training environment enabling anatomically and procedural realistic colonoscopy training requiring participants to handle all endoscope features in parallel. Fixation forces compare to forces needed to tear pig colon off the mesentery. Workflow and inlay can be adapted to any arbitrary ex vivo simulator.

PMID:36418762 | DOI:10.1007/s11548-022-02792-z

J Med Syst. 2022 Nov 24;46(12):102. doi: 10.1007/s10916-022-01891-3.

ABSTRACT

INTRODUCTION: Surgical skill assessment utilises direct observation and feedback by an expert which is potentially subjective, therefore obtaining objective data for hand and eye tracking is essential. Our aim was to evaluate a wearable mixed reality (MR) headset in these domains.

METHODS: Participants with differing levels of surgical expertise [novice (N), intermediate (I) & expert (E)] performed 4 simulated surgical tasks; 2 general dexterity (tasks 1&2) and 2 surgical skills (tasks 3&4) wearing the MR headset capturing their hand and eye movements (median & range). Metrics included hand path length and the speed of each index or thumb tip. Gaze data were also captured. Participant demographics, prior expertise and current experience were captured with an electronic survey. Data were analysed with a Shapiro-Wilk test or ANOVA as appropriate. A p-value of < 0.05 was significant.

RESULTS: Thirty-six participants were analysed (N = 18, I = 8, E = 8). Tasks 1&2 revealed 2 speed outcomes (left index and left-hand speed) which were significant. For tasks 3&4, various outcomes were significant: path length for left hand (N:45 cm vs. I:31 cm vs. E:27 cm, p = 0.03) and right hand (N:48 cm vs. I:29 cm vs. E:28 cm, p = 0.01) and total time (N:456s vs. I:292 vs. E: 245, p = 0.0002). With left-hand-tying, average path length (N:61 cm vs. I:39 vs. E:36, p = 0.04), average speed (N:11 cm/s vs. I:23 vs. E:24, p = 0.03), and total time (N:156s vs. I:43 vs. E:37, p = 0.003) were significant. The gaze-tracking was not statistically significant.

CONCLUSION: The MR headset can be utilised as a valid tool for surgical performance assessment. Outcomes including path length and speed can be valuable metrics captured by the MR Headset during the task completion for detecting surgical proficiency.

PMID:36418760 | DOI:10.1007/s10916-022-01891-3

Acta Neurochir (Wien). 2022 Nov 23. doi: 10.1007/s00701-022-05422-4. Online ahead of print.

ABSTRACT

OBJECTIVE: The purpose of the study was to investigate the feasibility and preliminary effects of unilateral biportal endoscopic extreme transforaminal lumbar interbody fusion(UBE-eXTLIF) with large cage combined with endoscopic unilateral pedicle screw fixation for lumbar degenerative diseases.

METHODS: Patients with lumbar degenerative diseases who received UBE-eXTLIF with large cage combined with endoscopic unilateral pedicle screw fixation from June 2022 to July 2022 were retrospectively analyzed, including 4 females and 1 males. The clinical symptoms and signs were consistent with the imaging changes. We recorded operation time, length of postoperative hospital stay, and complications. Visual Analogue Scale (VAS), Oswestry Disability Index (ODI), and modified Macnab scale was used to evaluate the clinical efficacy at preoperative, postoperative 1 month, and the last follow-up.

RESULTS: The operation was successfully completed in all cases. The operation time was 150-180 min, with an average of 164.60 ± 12.03 min. No serious complications such as dural tears and vascular and nerve injuries occurred during operation. All the patients got out of bed 1-3 days after surgery and were hospitalized 4-5 days after surgery, with an average of 4.20 ± 0.45 days. Preoperative VAS scores of low back pain were 6.20 ± 0.84 and respectively decreased to 2.20 ± 0.45 and 1.40 ± 0.55 at postoperative 1 month and at the last follow-up, and the difference was statistically significant (P < 0.05). Preoperative VAS scores of lower limb pain were 4.60 ± 2.61 and respectively decreased to 1.00 ± 0.71 and 0.60 ± 0.55 at postoperative 1 month and at the last follow-up, and the difference was statistically significant (P < 0.05). Preoperative ODI scores were 62.00 ± 3.16 and respectively decreased to 38.00 ± 1.41 and 32.40 ± 3.29 at postoperative 1 month and at the last follow-up, and the difference was statistically significant (P < 0.05). According to the modified Macnab criteria, the final outcome was excellent in 4 cases and good in 1 case. Five patients could return to normal activities within 3 weeks.

CONCLUSIONS: UBE-eXTLIF with large cage combined with endoscopic unilateral pedicle screw fixation can achieve excellent clinical results and may become a new minimally invasive endoscopic fusion method for lumbar degenerative diseases.

PMID:36418757 | DOI:10.1007/s00701-022-05422-4

J Med Syst. 2022 Nov 23;46(12):100. doi: 10.1007/s10916-022-01890-4.

ABSTRACT

In clinical practice, many drug therapies are associated with prolongation of the QT interval. In literature, estimation of the risk of prescribing drug-induced QT prolongation is mainly executed by means of logistic regression; only one paper reported the use of machine learning techniques. In this paper, we compare the performance of both techniques on the same dataset. High risk for QT prolongation was defined as having a corrected QT interval (QTc) ≥ 450 ms or ≥ 470 ms for respectively male and female patients. Both conventional statistical methods (CSM) and machine learning techniques (MLT) were used. All algorithms were validated internally and with a hold-out dataset of respectively 512 and 102 drug-drug interactions with possible drug-induced QTc prolongation. MLT outperformed the best CSM in both internal and hold-out validation. Random forest and Adaboost classification performed best in the hold-out set with an equal harmonic mean of sensitivity and specificity (HMSS) of 81.2% and an equal accuracy of 82.4% in a hold-out dataset. Sensitivity and specificity were both high (respectively 75.6% and 87.7%). The most important features were baseline QTc value, C-reactive protein level, heart rate at baseline, age, calcium level, renal function, serum potassium level and the atrial fibrillation status. All CSM performed similarly with HMSS varying between 60.3% and 66.3%. The overall performance of logistic regression was 62.0%. MLT (bagging and boosting) outperform CSM in predicting drug-induced QTc prolongation. Additionally, 19.2% was gained in terms of performance by random forest and Adaboost classification compared to logistic regression (the most used technique in literature in estimating the risk for QTc prolongation). Future research should focus on testing the classification on fully external data, further exploring potential of other (new) machine and deep learning models and on generating data pipelines to automatically feed the data to the classifier used.

PMID:36418746 | DOI:10.1007/s10916-022-01890-4

Methods Mol Biol. 2023;2583:63-79. doi: 10.1007/978-1-0716-2752-5_7.

ABSTRACT

Microcephaly often results from mitotic defects in neuronal progenitors, frequently by decreasing proliferation rates or shifting cell fates. During neurogenesis, oriented cell division-the molecular control of mitotic spindle positioning to control the axis of division-represents an important mechanism to balance expansion of the progenitor pool with generating cellular diversity. While mostly studied in the context of cortical development, more recently, spindle orientation has emerged as a key player in the formation of other brain regions such as the cerebellum. Here we describe methods to perform automated dual-color fluorescent immunohistochemistry on murine cerebellar sections using the mitotic markers phospho-Histone H3 and Survivin, and detail analytical and statistical approaches to display and compare division orientation datasets.

PMID:36418726 | DOI:10.1007/978-1-0716-2752-5_7

Updates Surg. 2022 Nov 23. doi: 10.1007/s13304-022-01427-x. Online ahead of print.

ABSTRACT

The objective is to explore the correlation between ultrasonic gallbladder length-width ratio (LTWR) and age, and the value of differential diagnosis between biliary atresia (BA) and other hepatic cholestasis. From January 2016 to June 2022, the data of 183 patients with jaundice who underwent abdominal ultrasound and surgical exploration in the Affiliated Hospital of Zunyi Medical University were analyzed retrospectively. The demographic data, liver function, and ultrasonic parameters were recorded and analyzed. There were statistically significant differences between BA group and non-BA group in maximum length, maximum width and LTWR of gallbladder (P < 0.001). In all age groups (I: ≤ 30 days; II: 31-60 days; III: 61-90 days; IV: 91-120 days; V: ≥ 121 days), in which group III (61-90 days) had the highest area under the curve (AUC) of 0.843, and group V (≥121 days) had the lowest AUC of 0.548. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of gallbladder LTWR > 3.26 for BA in group II (31-60 days) were 78.9%, 75.0%, 75.0%, 78.9% and 76.9%, respectively. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of gallbladder LTWR > 3.69 for BA in group III (61-90 days) were 76.6%, 84.6%, 92.5%, 59.5% and 78.9%, respectively. Ultrasonography LTWR of gallbladder has certain value in the diagnosis of BA. The diagnostic value of gallbladder LTWR in infants with different ages was quite different, and it was relatively high in infants with 31-90 days.

PMID:36418718 | DOI:10.1007/s13304-022-01427-x

Methods Mol Biol. 2023;2588:317-351. doi: 10.1007/978-1-0716-2780-8_19.

ABSTRACT

Today, -omics analyses, including the systematic cataloging of messenger RNA and microRNA sequences or DNA methylation patterns in a cell population, organ or tissue sample, allow for an unbiased, comprehensive genome-level analysis of complex diseases, offering a large advantage over earlier “candidate” gene or pathway analyses. A primary goal in the analysis of these high-throughput assays is the detection of those features among several thousand that differ between different groups of samples. In the context of oral biology, our group has successfully utilized -omics technology to identify key molecules and pathways in different diagnostic entities of periodontal disease.A major issue when inferring biological information from high-throughput -omics studies is the fact that the sheer volume of high-dimensional data generated by contemporary technology is not appropriately analyzed using common statistical methods employed in the biomedical sciences. Furthermore, machine learning methods facilitate the detection of additional patterns, beyond the mere identification of lists of features that differ between groups.Herein, we outline a robust and well-accepted bioinformatics workflow for the initial analysis of -omics data using open-source tools. We outline a differential expression analysis pipeline that can be used for data from both arrays and sequencing experiments, and offers the possibility to account for random or fixed effects. Furthermore, we present an overview of the possibilities for a functional analysis of the obtained data including subsequent machine learning approaches in form of (i) supervised classification algorithms in class validation and (ii) unsupervised clustering in class discovery.

PMID:36418696 | DOI:10.1007/978-1-0716-2780-8_19

Pharm Res. 2022 Nov 23. doi: 10.1007/s11095-022-03440-6. Online ahead of print.

ABSTRACT

PURPOSE: Long-acting formulations of the potent antiretroviral prodrug tenofovir alafenamide (TAF) hold potential as biomedical HIV prevention modalities. Here, we present a rigorous comparison of three animal models, C57BL/6 J mice, beagle dogs, and merino sheep for evaluating TAF implant pharmacokinetics (PKs).

METHODS: Implants delivering TAF over a wide range of controlled release rates were tested in vitro and in mice and dogs. Our existing PK model, supported by an intravenous (IV) dosing dog study, was adapted to analyze mechanistic aspects underlying implant TAF delivery.

RESULTS: TAF in vitro release in the 0.13 to 9.8 mg d^-1 range with zero order kinetics were attained. Implants with equivalent fabrication parameters released TAF in mice and sheep at rates that were not statistically different, but were 3 times higher in dogs. When two implants were placed in the same subcutaneous pocket, a two-week creep to C_max was observed in dogs for systemic drug and metabolite concentrations, but not in mice. Co-modeling IV and TAF implant PK data in dogs led to an apparent TAF bioavailability of 9.6 in the single implant groups (compared to the IV group), but only 1.5 when two implants were placed in the same subcutaneous pocket.

CONCLUSIONS: Based on the current results, we recommend using mice and sheep, with macaques as a complementary species, for preclinical TAF implant evaluation with the caveat that our observations may be specific to the implant technology used here. Our report provides fundamental, translatable insights into multispecies TAF delivery via long-acting implants.

PMID:36418671 | DOI:10.1007/s11095-022-03440-6

Hormones (Athens). 2022 Nov 22. doi: 10.1007/s42000-022-00421-7. Online ahead of print.

ABSTRACT

PURPOSE: Pain has always been a major concern in postoperative care. The aim of this study was to assess the impact of Mozart music on postoperative pain and physiological parameters in patients who underwent total thyroidectomy.

METHODS: Patients scheduled for total thyroidectomy were randomly assigned to a music group or a control group. The music intervention was applied immediately after surgery, whereas the control group received only usual care. Measurements of pain perception and physiological parameters were performed before, during, and after the music intervention in the music group and at the same time points in the control group. Pain was evaluated with the visual analog scale.

RESULTS: In a study population of 50 patients, a higher rate of decrease in pain was observed in the music group after the first 10 min of the music intervention compared to the control group (estimate = – 1.329; 95% CI [- 2.490, – 0.169]). Music also reduced respiratory rate by 1.31 rates/min more in the music group than in the control group at every assessment point (95% CI [- 2.171, – 0.451]). Changes in the remaining physiological parameters were not statistically significant between the music and the control group and within each group.

CONCLUSION: This study suggests that the use of music during immediate postoperative care after thyroidectomy could accelerate pain relief and lead to a greater decline of respiratory rate compared to that achieved in usual care.

TRIAL REGISTRATION NUMBER: NCT04699084, 30/12/2020.

PMID:36418659 | DOI:10.1007/s42000-022-00421-7