The Combination of Neutrophil-Lymphocyte Ratio and Platelet-Lymphocyte Ratio with Liquid Biopsy Biomarkers Improves Prognosis Prediction in Metastatic Pancreatic Cancer.

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive cancer with a highly inflammatory microenvironment and liquid biopsy has emerged as a promising tool for the noninvasive analysis of this tumor. In this study, plasma was obtained from 58 metastatic PDAC patients, and neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), circulating cell-free DNA (cfDNA) concentration, and circulating RAS mutation were determined. We found that NLR was significantly associated with both overall survival (OS) and progression-free survival. Remarkably, NLR was an independent risk factor for poor OS. Moreover, NLR and PLR positively correlated, and combination of both inflammatory markers significantly improved the prognostic stratification of metastatic PDAC patients. NLR also showed a positive correlation with cfDNA levels and RAS mutant allelic fraction (MAF). Besides, we found that neutrophil activation contributed to cfDNA content in the plasma of metastatic PDAC patients. Finally, a multi-parameter prognosis model was designed by combining NLR, PLR, cfDNA levels, RAS mutation, RAS MAF, and CA19-9, which performs as a promising tool to predict the prognosis of metastatic PDAC patients. In conclusion, our study supports the idea that the use of systemic inflammatory markers along with circulating tumor-specific markers may constitute a valuable tool for the clinical management of metastatic PDAC patients.

Phestilla subodiosus sp. nov. (Nudibranchia, Trinchesiidae), a corallivorous pest species in the aquarium trade.

Phestilla subodiosus sp. nov. (Nudibranchia: Trinchesiidae) is a novel species that feeds on corals in the genus Montipora (Scleractinia: Acroporidae) which are economically important in the aquarium industry. Nuclear-encoded H3, 28SC1-C2, and mitochondrial-encoded COI and 16S markers were sequenced. Phylogenetic analysis, Automatic Barcode Gap Discovery (ABGD), morphological data, and feeding specialization all support the designation of Phestilla subodiosus sp. nov. as a distinct species. Although new to science, Phestilla subodiosus sp. nov. had been extensively reported by aquarium hobbyists as a prolific pest over the past two decades. The species fell into a well-studied genus, which could facilitate research into its control in reef aquaria. Our phylogenetic analysis also revealed Tenellia chaetopterana formed a well-supported clade with Phestilla. Based upon a literature review, its original morphological description, and our phylogenetic hypothesis, we reclassified this species as Phestilla chaetopterana comb. nov.

Circulating Cell-Free DNA-Based Liquid Biopsy Markers for the Non-Invasive Prognosis and Monitoring of Metastatic Pancreatic Cancer.

Liquid biopsy may assist in the management of cancer patients, which can be particularly applicable in pancreatic ductal adenocarcinoma (PDAC). In this study, we investigated the utility of circulating cell-free DNA (cfDNA)-based markers as prognostic tools in metastatic PDAC. Plasma was obtained from 61 metastatic PDAC patients, and cfDNA levels and fragmentation were determined. BEAMing technique was used for quantitative determination of RAS mutation allele fraction (MAF) in cfDNA. We found that the prognosis was more accurately predicted by RAS mutation detection in plasma than in tissue. RAS mutation status in plasma was a strong independent prognostic factor for both overall survival (OS) and progression-free survival (PFS). Moreover, RAS MAF in cfDNA was also an independent risk factor for poor OS, and was strongly associated with primary tumours in the body/tail of the pancreas and liver metastases. Higher cfDNA levels and fragmentation were also associated with poorer OS and shorter PFS, body/tail tumors, and hepatic metastases, whereas cfDNA fragmentation positively correlated with RAS MAF. Remarkably, the combination of CA19-9 with MAF, cfDNA levels and fragmentation improved the prognostic stratification of patients. Furthermore, dynamics of RAS MAF better correlated with patients' outcome than standard CA19-9 marker. In conclusion, our study supports the use of cfDNA-based liquid biopsy markers as clinical tools for the non-invasive prognosis and monitoring of metastatic PDAC patients.

Accidentes biológicos en estudiantes de medicina de una universidad peruana: prevalencia, mecanismos y factores de riesgo / Biological accidents in a Peruvian university medical students: prevalence, mechanisms and risk factors

Introducción: Una de las más serias amenazas que enfrentan los estudiantes de medicina durante su práctica clínica es la posibilidad de exposición a accidentes biológicos, debido en la mayoría de los casos a la inexperiencia y el escaso desarrollo de las habilidades manuales. Objetivos: Establecer la frecuencia, mecanismos, circunstancias y factores de riesgo de los accidentes biológicos ocurridos entre estudiantes de medicina. Diseño: Estudio descriptivo observacional de corte transversal. Institución: Facultad de Medicina, Universidad Nacional Mayor de San Marcos, Lima, Perú. Participantes: Estudiantes de medicina. Metodología: Se aplicó una encuesta estructurada anónima, voluntaria y autoadministrada.Principales medidas de resultados: Accidentes biológicos. Resultados: En total fueron 307 entrevistados. La prevalencia de accidentes biológicos en la población estudiada fue de 51,5 por ciento (158/307). La media de accidentes biológicos en el último año fue de 1,06. El 91,1 por ciento de los estudiantes del último año presentó al menos un accidente biológico, versus 11,9 por ciento en los estudiantes del primer año. Los estudiantes del último año informaron con más frecuencia accidentes de riesgo alto para transmisión de infecciones, siendo 47,6 por ciento por pinchazo con objeto punzocortante, y 80,6 por ciento tuvo exposición a sangre; los accidentes de riesgo alto son mucho más frecuentes en quirófanos y sala de partos (51,9 por ciento). Conclusiones: La prevalencia de accidentes biológicos fue 51,5 por ciento, siendo el pinchazo la forma más frecuente. Es necesario desarrollar estrategias que permitan velar por la bioseguridad de los estudiantes de medicina.

Introduction: One of the most serious problems of medical students is occupational exposure during their clinical training as they lack experience and limited development of hand skills. Objectives: To establish the frequency, mechanisms, circumstances and risk factors of biological accidents reported in medical students. Design: Descriptive observational transversal type study. Setting: Faculty of Medicine, Universidad Nacional Mayor de San Marcos, Lima, Peru. Participants: Medical students. Methodology: A retrospective anonymous and voluntary survey was conducted. Study participants were randomly chosen. Main outcome measures: Biological accidents. Results: In a sample of 307 students 51,5 per cent had at least one accident (158/307); median of biological accidents in the last year was 1,06; 91,1 per cent of senior students had at least one biological accident last year versus 11,9 per cent of first-year students. Senior students inform more often about high-risk infection-transmission accidents, 47,6 per cent caused by pinching with a sharp object while 80,6 per cent were exposed to blood; high-risk accidents are far more often in surgical and delivery rooms (51,9 per cent). Conclusions: It is necessary to develop strategies that allow medical students to enforce biosecurity concepts.