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    White matter volume and microstructural integrity are associated with fatigue in relapsing multiple sclerosis
    (Springer Science and Business Media LLC, 2025-05-12)
    FIGUEROA VARGAS, ALEJANDRA MABEL  
    ;
    Sebastián Navarrete-Caro
    ;
    Claudia Cárcamo
    ;
    Ethel Ciampi
    ;
    Macarena Vásquez-Torres
      10
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    Methylated Reprimo Cell-Free DNA as a Non-Invasive Biomarker for Gastric Cancer
    (MDPI AG, 2025-04-03)
    María José Maturana
    ;
    Oslando Padilla
    ;
    Pablo M. Santoro
    ;
    Maria Alejandra Alarcón
    ;
    Wilda Olivares
    Restrictions resulting from the COVID-19 pandemic abruptly reversed the slow decline of the diagnosis and mortality rates of gastric cancer (GC). This scenario highlights the importance of developing cost-effective methods for mass screening and evaluation of treatment response. In this study, we evaluated a non-invasive method based on the circulating methylated cell-free DNA (cfDNA) of Reprimo (RPRM), a tumor suppressor gene associated with the development of GC. Methylated RPRM cfDNA was analyzed in three de-identified cohorts: Cohort 1 comprised 81 participants with GC and 137 healthy donors (HDs); Cohort 2 comprised 27 participants with GC undergoing gastrectomy and/or chemotherapy analyzed at the beginning and after three months of treatment; and Cohort 3 comprised 1105 population-based participants in a secondary prevention program who underwent esophagogastroduodenal (EGD) endoscopy. This cohort includes 180 normal participants, 845 participants with premalignant conditions (692 with chronic atrophic gastritis [AG] and 153 with gastric intestinal metaplasia/low-grade dysplasia [GIM/LGD]), 21 with high-grade dysplasia/early GC [HGD/eGC], and 59 with advanced GC [aGC]). A nested case-control substudy was performed using a combination of methylated RPRM cfDNA and pepsinogens (PG)-I/II ratio. The dense CpG island of the promoter region of the RPRM gene was bisulfite sequenced and analyzed to develop a fluorescence-based real-time PCR assay (MethyLight). This assay allows the determination of the absolute number of copies of methylated RPRM cfDNA. A targeted sequence of PCR amplicon products confirmed the gastric origin of the plasma-isolated samples. In Cohort 1, the mean value of GCs (32,240.00 copies/mL) was higher than that of the HD controls (139.00 copies/mL) (p < 0.0001). After dividing this cohort into training–validation subcohorts, we identified an area under the curve of 0.764 (95% confidence interval (CI) = 0.683–0.845) in the training group. This resulted in a cut-off value of 87.37 copies/mL (sensitivity 70.0% and specificity 80.2%). The validation subcohort predicted a sensitivity of 66.67% and a specificity of 83.33%. In Cohort 2 (monitoring treatment response), RPRM levels significantly decreased in responders (p = 0.0042) compared to non-responders. In Cohort 3 (population-based participants), 18.9% %, 24.1%, 30.7%, 47.0%, and 71.2% of normal, AG, GIM/LGD, HGD/eGC, and aGC participants tested positive for methylated RPRM cfDNA, respectively. Overall sensitivity and specificity in distinguishing normal/premalignant conditions vs. GC were 65.0% (95% CI 53.52% to 75.33%) and 75.9% (95% CI 73.16% to 78.49%), respectively, with an accuracy of 75.11% (95% CI 72.45% to 77.64%). Logistic regression analyses revealed an OR of 1.85 (95% CI 1.11–3.07, p = 0.02) and an odds ratio (OR) of 3.9 (95% CI 1.53–9.93, p = 0.004) for the risk of developing GIM/LGD and HGD/eGC, respectively. The combined methylated RPRM cfDNA and PG-I/II ratio reached a sensitivity of 78.9% (95% CI 54.43% to 93.95%) and specificity of 63.04% (95% CI 52.34% to 72.88%) for detecting HGD/eGC vs. three to six age- and sex-matched participants with premalignant conditions. Our results demonstrate that methylated RPRM cfDNA should be considered a direct biomarker for the non-invasive detection of GC and a predictive biomarker for treatment response.
      1Scopus© Citations 4
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      2
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    Quantitative Susceptibility Mapping MRI in Deep-Brain Nuclei in First-Episode Psychosis
    (2023)
    Marisleydis García Saborit
    ;
    Alejandro Jara
    ;
    Néstor Muñoz
    ;
    Carlos Milovic
    ;
    Angeles Tepper
    <jats:title>Abstract</jats:title> <jats:sec> <jats:title>Background</jats:title> <jats:p>Psychosis is related to neurochemical changes in deep-brain nuclei, particularly suggesting dopamine dysfunctions. We used an magnetic resonance imaging-based technique called quantitative susceptibility mapping (QSM) to study these regions in psychosis. QSM quantifies magnetic susceptibility in the brain, which is associated with iron concentrations. Since iron is a cofactor in dopamine pathways and co-localizes with inhibitory neurons, differences in QSM could reflect changes in these processes.</jats:p> </jats:sec> <jats:sec> <jats:title>Methods</jats:title> <jats:p>We scanned 83 patients with first-episode psychosis and 64 healthy subjects. We reassessed 22 patients and 21 control subjects after 3 months. Mean susceptibility was measured in 6 deep-brain nuclei. Using linear mixed models, we analyzed the effect of case-control differences, region, age, gender, volume, framewise displacement (FD), treatment duration, dose, laterality, session, and psychotic symptoms on QSM.</jats:p> </jats:sec> <jats:sec> <jats:title>Results</jats:title> <jats:p>Patients showed a significant susceptibility reduction in the putamen and globus pallidus externa (GPe). Patients also showed a significant R2* reduction in GPe. Age, gender, FD, session, group, and region are significant predictor variables for QSM. Dose, treatment duration, and volume were not predictor variables of QSM.</jats:p> </jats:sec> <jats:sec> <jats:title>Conclusions</jats:title> <jats:p>Reduction in QSM and R2* suggests a decreased iron concentration in the GPe of patients. Susceptibility reduction in putamen cannot be associated with iron changes. Since changes observed in putamen and GPe were not associated with symptoms, dose, and treatment duration, we hypothesize that susceptibility may be a trait marker rather than a state marker, but this must be verified with long-term studies.</jats:p> </jats:sec>
    Scopus© Citations 1  1
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    Outcomes of Total Ankle Arthroplasty in Postfracture Ankle Arthritis
    (2023)
    Jaeyoung Kim
    ;
    Ruben Radkievich
    ;
    Rami Mizher
    ;
    Isabel Shaffrey
    ;
    Martin O’Malley
    <jats:sec><jats:title>Background:</jats:title><jats:p> Ankle arthritis that develops after fracture accounts for a significant portion of ankle arthritis necessitating total ankle arthroplasty (TAA). It remains unknown whether TAA in postfracture patients produces equivalent outcomes to those without fracture history. The purpose of this study was to evaluate the medium-term outcomes of TAA in postfracture ankle arthritis compared to those without fracture history. </jats:p></jats:sec><jats:sec><jats:title>Methods:</jats:title><jats:p> This study reviewed 178 ankles from 171 consecutive patients who underwent TAA in our institution between 2007 and 2017 and completed a minimum 5-year follow-up. Four different TAA systems were utilized by 6 surgeons. Based on fracture history, patients were divided into 2 groups: the postfracture group (n = 63; median age 65.7 years; median follow-up 5.9 years) and the nonfracture group (n = 115; median age 64.4 years; median follow-up 6.2 years). Types and rates of complications including revision and reoperation were compared. Minimum 5-year Foot and Ankle Outcome Score (FAOS) and postoperative improvement were investigated. A subgroup analysis was performed to determine whether outcomes differ between intraarticular fracture patients (n = 43) and extraarticular fracture patients (n = 20). </jats:p></jats:sec><jats:sec><jats:title>Results:</jats:title><jats:p> Both groups exhibited comparable postoperative improvement and final FAOS scores. The postfracture group had a significantly higher reoperation rate than the nonfracture group (20 of 63, 31.7%, vs 17 of 115, 14.8%; P = .011), with gutter impingement being the most common cause. There were 3 revisions in each group. In the subgroup analysis, we found no evidence of statistical difference between the intraarticular fracture group and the extraarticular fracture group in terms of FAOS scores, revision, and reoperation rates. </jats:p></jats:sec><jats:sec><jats:title>Conclusion:</jats:title><jats:p> In this single-center, retrospective comparative study, we found total ankle arthroplasty in patients with a history of fractures around the ankle joint had no evidence of statistical difference in patient-reported outcomes and implant survivorship but led to a higher rate of nonrevision reoperation following surgery. In the much smaller subset of patients with previous fracture, we did not find that those with a history of intraarticular fracture had inferior outcomes after TAA when compared to those with a history of extraarticular fracture. </jats:p></jats:sec><jats:sec><jats:title>Level of Evidence:</jats:title><jats:p> Level III, case-control study. </jats:p></jats:sec>
      6Scopus© Citations 2
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    Scopus© Citations 11  3
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    Association between maternal obesity, essential fatty acids and biomarkers of fetal liver function
    (2023)
    Macarena Ortiz
    ;
    Francisca Sánchez
    ;
    Daniela Álvarez
    ;
    Cristian Flores
    ;
    Francisca Salas-Pérez
      7Scopus© Citations 5
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    Development and internal validation of a multifactorial risk prediction model for gallbladder cancer in a high‐incidence country
    (2023)
    Felix Boekstegers
    ;
    Dominique Scherer
    ;
    Carol Barahona Ponce
    ;
    Katherine Marcelain
    ;
    Valentina Gárate‐Calderón
    <jats:title>Abstract</jats:title><jats:p>Since 2006, Chile has been implementing a gallbladder cancer (GBC) prevention program based on prophylactic cholecystectomy for gallstone patients aged 35 to 49 years. The effectiveness of this prevention program has not yet been comprehensively evaluated. We conducted a retrospective study of 473 Chilean GBC patients and 2137 population‐based controls to develop and internally validate three GBC risk prediction models. The Baseline Model accounted for gallstones while adjusting for sex and birth year. Enhanced Model I also included the non‐genetic risk factors: body mass index, educational level, Mapuche surnames, number of children and family history of GBC. Enhanced Model II further included Mapuche ancestry and the genotype for rs17209837. Multiple Cox regression was applied to assess the predictive performance, quantified by the area under the precision‐recall curve (AUC‐PRC) and the number of cholecystectomies needed (NCN) to prevent one case of GBC at age 70 years. The AUC‐PRC for the Baseline Model (0.44%, 95%CI 0.42‐0.46) increased by 0.22 (95%CI 0.15‐0.29) when non‐genetic factors were included, and by 0.25 (95%CI 0.20‐0.30) when incorporating non‐genetic and genetic factors. The overall NCN for Chileans with gallstones (115, 95%CI 104‐131) decreased to 92 (95%CI 60‐128) for Chileans with a higher risk than the median according to Enhanced Model I, and to 80 (95%CI 59‐110) according to Enhanced Model II. In conclusion, age, sex and gallstones are strong risk factors for GBC, but consideration of other non‐genetic factors and individual genotype data improves risk prediction and may optimize allocation of financial resources and surgical capacity.</jats:p>
      5Scopus© Citations 16
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      20  1Scopus© Citations 6
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      10Scopus© Citations 7