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Nevin Manimala Statistics

Ordinal Classification with Distance Regularization for Robust Brain Age Prediction

IEEE Winter Conf Appl Comput Vis. 2024 Jan;2024:7867-7876. doi: 10.1109/wacv57701.2024.00770. Epub 2024 Apr 9.

ABSTRACT

Age is one of the major known risk factors for Alzheimer’s Disease (AD). Detecting AD early is crucial for effective treatment and preventing irreversible brain damage. Brain age, a measure derived from brain imaging reflecting structural changes due to aging, may have the potential to identify AD onset, assess disease risk, and plan targeted interventions. Deep learning-based regression techniques to predict brain age from magnetic resonance imaging (MRI) scans have shown great accuracy recently. However, these methods are subject to an inherent regression to the mean effect, which causes a systematic bias resulting in an overestimation of brain age in young subjects and underestimation in old subjects. This weakens the reliability of predicted brain age as a valid biomarker for downstream clinical applications. Here, we reformulate the brain age prediction task from regression to classification to address the issue of systematic bias. Recognizing the importance of preserving ordinal information from ages to understand aging trajectory and monitor aging longitudinally, we propose a novel ORdinal Distance Encoded Regularization (ORDER) loss that incorporates the order of age labels, enhancing the model’s ability to capture age-related patterns. Extensive experiments and ablation studies demonstrate that this framework reduces systematic bias, outperforms state-of-art methods by statistically significant margins, and can better capture subtle differences between clinical groups in an independent AD dataset. Our implementation is publicly available at https://github.com/jaygshah/Robust-Brain-Age-Prediction.

PMID:38606366 | PMC:PMC11008505 | DOI:10.1109/wacv57701.2024.00770

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Nevin Manimala Statistics

Evaluating cardiovascular disease risk stratification using multiple-polygenic risk scores and pooled cohort equations: insights from a 17-year longitudinal Korean cohort study

Front Genet. 2024 Mar 28;15:1364993. doi: 10.3389/fgene.2024.1364993. eCollection 2024.

ABSTRACT

Cardiovascular disease (CVD) remains the leading cause of mortality worldwide, caused by a complex interplay of genetic and environmental factors. This study aimed to evaluate the combined efficacy of multi-polygenic risk scores and pooled cohort equations (PCE) for predicting future CVD risks in the Korean population. In this longitudinal study, 7,612 individuals from the Ansan and Ansung cohorts were analyzed over a 17-year follow-up period. The participants were genotyped using the Korea Biobank Array, and quality-controlled genetic data were subjected to imputation analysis. The weighted sum of the PRSs (wPRSsum) was calculated using PRS-CS with summary statistics from myocardial infarction, ischemic stroke, coronary artery disease, and hypertension genome-wide association studies. The recalibrated PCE was used to assess clinical risk, and the participants were stratified into risk groups based on the wPRSsum and PCE. Associations between these risk scores and incident CVD were evaluated using Cox proportional hazards models and Kaplan-Meier analysis. The wPRSsum approach showed a significant association with incident CVD (HR = 1.15, p = 7.49 × 10-5), and the top 20% high-risk genetic group had an HR of 1.50 (p = 5.04 × 10-4). The recalibrated PCE effectively differentiated between the low and high 10-year CVD risk groups, with a marked difference in survival rates. The predictive models constructed using the wPRSsum and PCE demonstrated a slight improvement in prediction accuracy, particularly among males aged <55 years (C-index = 0.640). We demonstrated that while the integration of wPRSsum with PCE did not significantly outperform the PCE-only model (C-index: 0.703 for combined and 0.704 for PCE-only), it provided enhanced stratification of CVD risk. The highest risk group, identified through the combination of high wPRSsum and PCE scores, exhibited an HR of 4.99 for incident CVD (p = 1.45 × 10-15). These findings highlight the potential of integrating genetic risk assessments with traditional clinical tools for effective CVD risk stratification. Although the addition of wPRSsum to the PCE provided a marginal predictive improvement, it proved valuable in identifying high-risk individuals and supporting personalized treatment strategies. This study reinforces the utility of multi-PRS in conjunction with clinical risk assessment tools, paving the way for more tailored approaches for CVD prevention and management in diverse populations.

PMID:38606355 | PMC:PMC11007088 | DOI:10.3389/fgene.2024.1364993

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Nevin Manimala Statistics

National Trends in Utilization of Normothermic Machine Perfusion in DCD Liver Transplantation

Transplant Direct. 2024 Apr 9;10(5):e1596. doi: 10.1097/TXD.0000000000001596. eCollection 2024 May.

ABSTRACT

BACKGROUND: In liver transplantation, advances in ex situ normothermic machine perfusion (NMP) have improved outcomes compared with traditional static cold storage (SCS) in donation after circulatory death (DCD) organs. We aimed to characterize trends in the utilization of NMP versus SCS in DCD liver transplantation in the United States.

METHODS: This retrospective cohort study used data from the United Network for Organ Sharing database to identify recipient-donor adult liver transplant pairs from DCD donors from January 2016 to June 2022. Utilization of NMP and changes in donor risk index (DRI) and components between NMP and SCS were assessed across transplant year eras (2016-2018, 2019-2020, and 2021-2022). Statistical comparisons were made using the Kruskal-Wallis test or the chi-square test.

RESULTS: A total of 3937 SCS and 127 NMP DCD donor transplants were included. Utilization of NMP ranged from ~0.4% to 3.5% from 2016 to 2021 and rose significantly to 11.2% in early 2022. Across transplant eras, median DRI increased significantly for SCS and NMP, but the magnitude of the increase was larger for NMP. With NMP DCDs, there were significant increases in median donor age, national share proportion, and “cold ischemic time” over time. Finally, there was a shift toward including higher DRI donors and higher model for end-stage liver disease score transplant recipients with NMP in later transplant eras.

CONCLUSIONS: In recent years, NMP utilization has increased and expanded to donors with higher DRI and recipients with higher model for end-stage liver disease score at transplant, suggesting increasing familiarity and risk tolerance with NMP technology. As NMP remains a relatively new technique, ongoing study of patient outcomes, organ allocation practices, and utilization patterns is critical.

PMID:38606351 | PMC:PMC11005893 | DOI:10.1097/TXD.0000000000001596

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Nevin Manimala Statistics

Physician reported outcomes of hip arthroscopy without a perineal post: an international survey

J Hip Preserv Surg. 2022 Jul 26;11(1):3-7. doi: 10.1093/jhps/hnac038. eCollection 2024 Jan.

ABSTRACT

Although the current literature reports an acceptable rate of complications with the use of a perineal post in hip arthroscopy, they are still possible and preventable. The purpose of this study was to survey International Society for Hip Arthroscopy (ISHA) members on their use of postless distraction in hip arthroscopy. A 19-question survey was emailed to hip preservation surgeons that are members of ISHA. The questions examined surgeons’ location, experience, utilization of a perineal post or postless distraction and any complications they may have encountered. In all, 145 respondents completed the survey. Regarding complications encountered when using a perineal post, the most frequent responses were temporary nerve damage (115, 80.6%), temporary genitourinary complications (39, 27%), temporary genital skin injury (35, 24%) and permanent nerve injury (12, 8%). Regarding the postless technique, of the 60 respondents who noted they have utilized postless distraction, 9 (15%) reported complications, with 7 (12%) reporting temporary nerve damage being the most common and 0 reporting cases of permanent nerve injury. These were statistically significantly less than those reported with a perineal post. Ninety-seven percent reported that after utilizing postless distraction, their patients were recovering better than or the same as when using a perineal post. This survey had excellent international participation by experienced hip arthroscopists. There were a statistically significantly decreased number of complications reported by the surgeons utilizing postless distraction. This survey highlights that postless distraction is being done successfully with lower reported complications and excellent patient recovery.

PMID:38606336 | PMC:PMC11005764 | DOI:10.1093/jhps/hnac038

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Nevin Manimala Statistics

Intraoperative traction has a negligible time-dependent influence on patient-reported outcomes after hip arthroscopy: a cohort study

J Hip Preserv Surg. 2023 Nov 15;11(1):38-43. doi: 10.1093/jhps/hnad034. eCollection 2024 Jan.

ABSTRACT

The aim of this study is to determine if post-operative patient-reported outcome measures (PROMs) are influenced by hip arthroscopy traction duration. Patients from a local prospective hip arthroscopy database were retrospectively analyzed. Four hip-specific PROMs were utilized: modified Harris Hip Score (mHHS), Hip Outcome Score-Activities of Daily Living (HOS-ADL), Hip Outcome Score-Sports Specific (HOS-SS), and international Hip Outcome Tool (iHOT). PROMs were collected pre-operatively and 6 months, 1 year and 2 years post-operatively. Two cohorts were created based on a cut-off corresponding to the 66th percentile for our patient cohort. Analyses were completed for each PROM at each post-operative interval with univariable statistics. Multivariable statistics were examined to identify the variables that were predictive of achieving post-operative minimal clinically important difference (MCID) at the 2-year follow-up. Overall, 222 patients met the inclusion criteria. The mean age was 32.4 ± 9.4 years, and 116 (52.3%) were female. The average traction time of the study population was 46.1 ± 12.9 min. A total of 145 patients were included in the short traction cohort (65%) with traction times of <50 min (66th percentile). No significant differences were found regarding PROM scores or MCID achievement rates between both cohorts at any post-operative period. In multivariable analyses, achievement of MCID was predicted by a decrease in traction time for all PROMs and pincer-type resection for mHSS, HOS-ADL and iHOT. There was no difference in PROMs and MCID achievement between longer and shorter traction time cohorts. On multivariable analysis, a decrease in traction time is predictive of MCID for all PROM scores and pincer-type resection was predictive of MCID for most PROM scores. Level of evidence: Level III, cohort study.

PMID:38606333 | PMC:PMC11005777 | DOI:10.1093/jhps/hnad034

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Nevin Manimala Statistics

The role of iliopsoas fractional lengthening in hip arthroscopy: a systematic review

J Hip Preserv Surg. 2023 Nov 15;11(1):67-79. doi: 10.1093/jhps/hnad039. eCollection 2024 Jan.

ABSTRACT

Arthroscopic iliopsoas fractional lengthening (IFL) is a surgical option for the treatment of internal snapping hip syndrome (ISHS) after failing conservative management. Systematic review. A search of PubMed central, National Library of Medicine (MEDLINE) and Scopus databases were performed by two individuals from the date of inception to April 2023. Inclusion criteria were ISHS treated with arthroscopy. Sample size, patient-reported outcomes and complications were recorded for 24 selected papers. Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed and registered on PROSPERO database for systematic reviews (CRD42023427466). Thirteen retrospective case series, ten retrospective comparative studies, and one randomized control trial from 2005 to 2022 were reported on 1021 patients who received an iliopsoas fractional lengthening. The extracted data included patient satisfaction, visual analogue scale, the modified Harris hip score and additional outcome measures. All 24 papers reported statistically significant improvements in post-operative patient-reported outcome measures after primary hip arthroscopy and iliopsoas fractional lengthening. However, none of the comparative studies found a statistical benefit in performing IFL. Existing studies lack conclusive evidence on the benefits of Iliopsoas Fractional Lengthening (IFL), especially for competitive athletes, individuals with Femoroacetabular Impingement (FAI), and borderline hip dysplasia. Some research suggests IFL may be a safe addition to hip arthroscopy for Internal Snapping Hip Syndrome, but more comprehensive investigations are needed. Future studies should distinguish between concurrent procedures and develop methods to determine if the psoas muscle is the source of pain, instead of solely attributing it to the joint.

PMID:38606331 | PMC:PMC11005755 | DOI:10.1093/jhps/hnad039

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Nevin Manimala Statistics

Mechanistic Modeling of Longitudinal Shape Changes: Equations of Motion and Inverse Problems

SIAM J Appl Dyn Syst. 2022;21(1):80-101. doi: 10.1137/21m1423099.

ABSTRACT

This paper examines a longitudinal shape evolution model in which a three-dimensional volume progresses through a family of elastic equilibria in response to the time-derivative of an internal force, or yank, with an additional regularization to ensure diffeomorphic transformations. We consider two different models of yank and address the long time existence and uniqueness of solutions for the equations of motion in both models. In addition, we derive sufficient conditions for the existence of an optimal yank that best describes the change from an observed initial volume to an observed volume at a later time. The main motivation for this work is the understanding of processes such as growth and atrophy in anatomical structures, where the yank could be roughly interpreted as a metabolic event triggering morphological changes. We provide preliminary results on simple examples to illustrate, under this model, the retrievability of some attributes of such events.

PMID:38606305 | PMC:PMC11008764 | DOI:10.1137/21m1423099

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Nevin Manimala Statistics

Sequential Memory with Temporal Predictive Coding

Adv Neural Inf Process Syst. 2023;36:44341-44355.

ABSTRACT

Forming accurate memory of sequential stimuli is a fundamental function of biological agents. However, the computational mechanism underlying sequential memory in the brain remains unclear. Inspired by neuroscience theories and recent successes in applying predictive coding (PC) to static memory tasks, in this work we propose a novel PC-based model for sequential memory, called temporal predictive coding (tPC). We show that our tPC models can memorize and retrieve sequential inputs accurately with a biologically plausible neural implementation. Importantly, our analytical study reveals that tPC can be viewed as a classical Asymmetric Hopfield Network (AHN) with an implicit statistical whitening process, which leads to more stable performance in sequential memory tasks of structured inputs. Moreover, we find that tPC exhibits properties consistent with behavioral observations and theories in neuroscience, thereby strengthening its biological relevance. Our work establishes a possible computational mechanism underlying sequential memory in the brain that can also be theoretically interpreted using existing memory model frameworks.

PMID:38606302 | PMC:PMC7615819

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Nevin Manimala Statistics

Analysis of risk factors related to the progression rate of hemifacial spasm

Front Neurol. 2024 Mar 28;15:1357280. doi: 10.3389/fneur.2024.1357280. eCollection 2024.

ABSTRACT

INTRODUCTION: Although there have been many researches on the etiology and risk factors with the onset of hemifacial spasm, researches on the risk factors related to progression rate are limited. This study aims to analyze the risk factors related to the progression rate of hemifacial spasm.

METHODS: The study enrolled 142 patients who underwent microvascular decompression for hemifacial spasm. Based on the duration and severity of symptoms, patients were classified into rapid progression group and slow progression group. To analyze risk factors, univariate and multivariate logistic regression analyses were conducted. Of 142 patients with hemifacial spasm, 90(63.3%) were classified as rapid progression group, 52(36.7%) were classified as slow progression group.

RESULTS: In the univariate analysis, there were significant statistical differences between the two groups in terms of age of onset (P = 0.021), facial nerve angle (P < 0.01), hypertension (P = 0.01), presence of APOE ε4 expression (P < 0.01) and different degrees of brainstem compression in the Root Entry Zone (P < 0.01). In the multivariable analyses, there were significant statistical differences between the two groups in terms of age of symptom onset (P < 0.01 OR = 6.591), APOE ε4 (P < 0.01 OR = 5.691), brainstem compression (P = 0.006 OR = 5.620), and facial nerve angle (P < 0.01 OR = 5.758). Furthermore, we found no significant correlation between the severity of facial spasms and the progression rate of the disease (t = 2.47, P = 0.12>0.05).

CONCLUSION: According to our study, patients with facial nerve angle ≤ 96.5°, severer compression of the brainstem by offending vessels, an onset age > 45 years and positive expression of APOE ε4, may experience faster progression of hemifacial spasm.

PMID:38606273 | PMC:PMC11007217 | DOI:10.3389/fneur.2024.1357280

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Nevin Manimala Statistics

Evaluation of the efficacy and safety of intravenous infusion of ferric derisomaltose in the treatment of iron deficiency anemia: a single-center retrospective analysis

Zhonghua Xue Ye Xue Za Zhi. 2024 Feb 14;45(2):178-183. doi: 10.3760/cma.j.cn121090-20230718-00009.

ABSTRACT

Objective: To investigate the clinical efficacy and safety of ferric derisomaltose injection versus iron sucrose injection in the treatment of iron deficiency anemia (IDA) . Methods: A total of 120 patients with iron deficiency anemia admitted from June 2021 to March 2023 were given intravenous iron supplementation with ferric derisomaltose to assess the efficacy and safety of hemoglobin (HGB) elevation before and after treatment. Simultaneously, the clinical effects of iron supplementation with iron sucrose were compared to those of inpatient patients during the same period. Results: Baseline values were comparable in both groups. Within 12 weeks of treatment, the elevated HGB level in the ferric derisomaltose group was higher than that of the iron sucrose group, with a statistical difference at all time points, and the proportion of HGB increased over 20 g/L in the patients treated for 4 weeks was higher (98.7%, 75.9% ). During the treatment with ferric derisomaltose and iron sucrose, the proportion of mild adverse reactions in the ferric derisomaltose group was slightly lower than that of the iron sucrose group, and neither group experienced any serious adverse reactions. The patients responded well to the infusion treatment, with no reports of pain or pigmentation at the injection site. Conclusion: The treatment of IDA patients with ferric derisomaltose has a satisfactory curative effect, with the advantages of rapidity, accuracy, and safety. Therefore, it is worthy of widespread clinical use.

PMID:38604795 | DOI:10.3760/cma.j.cn121090-20230718-00009