Performing a Multicenter Retrospective Study.

Multicenter retrospective studies can provide a pragmatic approach to evaluating uncommon pediatric conditions and are less expensive than prospective research. A well-executed retrospective multicenter study, with rigorous study design, systematic data collection, and robust statistical analysis, can produce clinically important and generalizable findings A variety of observational designs can be employed, including cross-sectional, cohort, and case-control studies. Selection bias, ascertainment bias, and confounding are common issues in retrospective research.

External Validation of Two Clinical Prediction Models for Pediatric Pneumonia.

Objective: To externally validate two prediction models for pediatric radiographic pneumonia.

Methods: We prospectively evaluated the performance of two prediction models (Pneumonia Risk Score [PRS] and Catalyzing Ambulatory Research in Pneumonia Etiology and Diagnostic Innovations in Emergency Medicine [CARPE DIEM] models) from a prospective convenience sample of children 90 days - 18 years of age from a pediatric emergency department undergoing chest radiography for suspected pneumonia between January 1, 2022, and December 31st, 2023. We evaluated model performance using the original intercepts and coefficients and evaluated for performance changes when performing recalibration and re-estimation procedures.

[Prophylactic surgery for hepatic and biliary tumors].

Benign tumors of the liver and biliary tract are rare entities, and some of them require surgical management to prevent their malignant transformation. Tumors from the biliary tract with malignant potential are treated either by hepatic resection, for mucinous cystic neoplasm and ciliated hepatic foregut cysts, or by biliary resections, for biliary papillary neoplasm and type I and IV choledochal cysts. The pathologies requiring prophylactic cholecystectomy are polyps larger than 10 mm, porcelain gallbladder and pancreaticobiliary maljunction.

Aberrant Methylation of the Imprinted C19MC and MIR371-3 Clusters in Patients with Non-Small Cell Lung Cancer.

Epigenetic mechanisms have emerged as an important contributor to tumor development through the modulation of gene expression. Our objective was to identify the methylation profile of the imprinted C19MC and MIR371-3 clusters in patients with non-small cell lung cancer (NSCLC) and to find their potential target genes, as well as to study their prognostic role. DNA methylation status was analyzed in a NSCLC patient cohort ( = 47) and compared with a control cohort including COPD patients and non-COPD subjects ( = 23) using the Illumina Infinium Human Methylation 450 BeadChip.