Utilidad de la ecografía a pie de cama en la punción lumbar: un análisis del rendimiento diagnóstico basado en la evidencia disponible

Los avances en la tecnología de la ciencia biomédica han permitido incrementar la tasa de éxito de las intervenciones gracias a las mejoras en seguridad y eficacia. Durante la evaluación del paciente con un trastorno neurológico agudo que requiere una punción lumbar, existen algunas condiciones que pueden dificultar la realización de este procedimiento, tales como la infección en el lugar de la punción o las anomalías óseas que puedan causar una lesión medular. El uso de la ecografía a pie de cama es una buena alternativa para acompañar a la punción debido a su capacidad para explorar estructuras que no pueden ser evaluadas mediante la exploración física. En los centros hospitalarios de baja complejidad, donde pueden existir barreras de acceso a herramientas de imagen costosas, la ecografía es una opción rentable para el abordaje de patologías urgentes. Con base en lo anterior, el objetivo de este manuscrito consiste en revisar conceptos relevantes basados en la evidencia más reciente, que están relacionados con el uso de la ecografía para la realización de la punción lumbar.

Advances in biomedical technology have increased the success rate of medical procedures due to improvements in safety and efficacy. During the assessment of patients with acute neurological disorder who require a lumbar puncture, some conditions may hinder its performance, such as infection at the puncture site or bone abnormalities that may cause spinal cord injury. Bedside ultrasound is a good alternative to assist in the performance of a puncture, due to its ability to examine structures that cannot be assessed by physical examination. In primary health care centers, where there may be obstacles that prevent access to expensive imaging tools, ultrasound is a cost-effective option in the approach to urgent pathologies. In view of the foregoing, this paper aims to review important recent evidence-based concepts related to the use of ultrasound for the performance of a lumbar puncture.

La biopsia líquida en el diagnóstico y monitoreo de pacientes oncológicos: Oportunidades y retos en Latinoamérica / Liquid biopsy in the diagnosis and monitoring of cancer patients: opportunities and challenges in Latin America

Resumen En los últimos años el estudio de los ácidos nucleicos circulantes ha tenido grandes avances en el campo de la oncología, lo que ha permitido avanzar de forma importante en las aplicaciones clínicas de la biopsia líquida en diferentes áreas como el pronóstico, la estadificación, la predicción de recurrencia, la selección y monitorización de tratamientos, entre otros. Lo anterior se debe en gran parte al desarrollo de nuevas y mejores tecnologías, algunas de las cuales incluso han sido autorizadas para el diagnóstico y seguimiento clínico de ciertos tipos de cáncer. No obstante, la utilización de la biopsia líquida como herramienta de apoyo clínico sigue siendo objeto de estudio. Debido a la importancia que ha cobrado este avance tecnológico a nivel mundial, se realizó una revisión de literatura con el fin de establecer el estado actual del uso de biopsia líquida en oncología, así como sus aplicaciones clínicas actuales, con un énfasis en Latinoamérica.

Abstract In recent years, the study of circulating nucleic acids has made great progress in the field of oncology, allowing for significant advances in clinical applications of liquid biopsy in diverse areas such as prognosis, staging, recurrence prediction, selection and monitoring of treatments, among others. This advance is largely due to the development of new and better technologies, some of which have even been validated for the diagnosis and clinical follow-up of certain types of cancer. However, the use of liquid biopsy as an additional tool in clinical oncology remains under study. Given the worldwide importance of this technological advance, a literature review was conducted to establish the current status of the use of liquid biopsy in oncology, as well as its current clinical applications, with a particular focus on Latin America.

Identifying new potential genetic biomarkers for HELLP syndrome using massive parallel sequencing.

BACKGROUND: Preeclampsia (PE) is a frequently occurring multisystemic disease affecting ~5% of pregnancies. PE patients may develop HELLP syndrome (haemolysis, elevated liver enzymes, and low platelet), a mother and foetus life-threatening condition. Research into HELLP's genetic origin has been relatively unsuccessful, mainly because normal placental function and blood pressure regulation involve the fine-regulation of hundreds of genes. OBJECTIVE: To identify new genes and mutations constituting potential biomarkers for HELLP syndrome. STUDY DESIGN: The present case-control study involved whole-exome sequencing of 79 unrelated HELLP women. Candidate variants were screened in a control population constituted by 176 individuals. Stringent bioinformatics filters were used for selecting potentially etiological sequence variants in a subset of 487 genes. We used robust in silico mutation modelling for predicting the potential effect on protein structure. RESULTS: We identified numerous sequence variants in genes related to angiogenesis/coagulation/blood pressure regulation, cell differentiation/communication/adhesion, cell cycle and transcriptional gene regulation, extracellular matrix biology, lipid metabolism and immunological response. Five sequence variants generated premature stop codons in genes playing an essential role in placental physiology (STOX1, PDGFD, IGF2, MMP1 and DNAH11). Six variants (ERAP1- p.Ile915Thr, ERAP2- p.Leu837Ser, COMT-p.His192Gln, CSAD-p.Pro418Ser, CDH1- p.Ala298Thr and CCR2-p.Met249Lys) led to destabilisation of protein structure as they had significant energy and residue interaction-related changes. We identified at least two mutations in 57% of patients, arguing in favour of a polygenic origin for the HELLP syndrome. CONCLUSION: Our results provide novel evidence regarding PE/HELLP's genetic origin, leading to new biomarkers, having potential clinical usefulness, being proposed.

Corrigendum to "In Vivo Resistance to Ceftolozane/Tazobactam in Pseudomonas aeruginosa Arising by AmpC- and Non-AmpC-Mediated Pathways".

[This corrects the article DOI: 10.1155/2018/9095203.].

In Vivo Resistance to Ceftolozane/Tazobactam in Pseudomonas aeruginosa Arising by AmpC- and Non-AmpC-Mediated Pathways.

Two pairs of ceftolozane/tazobactam susceptible/resistant P. aeruginosa were isolated from 2 patients after exposure to ß-lactams. The genetic basis of ceftolozane/tazobactam resistance was evaluated, and ß-lactam-resistant mechanisms were assessed by phenotypic assays. Whole genome sequencing identified mutations in AmpC including the mutation (V213A) and a deletion of 7 amino acids (P210-G216) in the Ω-loop. Phenotypic assays showed that ceftolozane/tazobactam resistance in the strain with AmpCV213A variant was associated with increased ß-lactamase hydrolysis activity. On the other hand, the deletion of 7 amino acids in the Ω-loop of AmpC did not display enhanced ß-lactamase activity. Resistance to ceftolozane/tazobactam in P. aeruginosa is associated with changes in AmpC; however, the apparent loss of ß-lactamase activity in AmpC∆7 suggests that non-AmpC mechanisms could play an important role in resistance to ß-lactam/ß-lactamase inhibitor combinations.

Genomic and Molecular Characterization of Clinical Isolates of Enterobacteriaceae Harboring mcr-1 in Colombia, 2002 to 2016.

Polymyxins are last-resort antimicrobial agents used to treat infections caused by carbapenem-resistant Enterobacteriaceae Due to the worldwide dissemination of polymyxin resistance in animal and human isolates, we aimed to characterize polymyxin resistance associated with the presence of mcr-1 in Enterobacteriaceae and nonfermenter Gram-negative bacilli, using isolates collected retrospectively in Colombia from 2002 to 2016. A total of 5,887 Gram-negative clinical isolates were studied, and 513 were found to be resistant to the polymyxins. Susceptibility to colistin was confirmed by broth microdilution for all mcr-1-positive isolates, and these were further subjected to whole-genome sequencing (WGS). The localization of mcr-1 was confirmed by S1 pulsed-field gel electrophoresis (S1-PFGE) and CeuI-PFGE hybridization. Transferability was evaluated by mating assays. A total of 12 colistin-resistant isolates recovered after 2013 harbored mcr-1, including 8 Escherichia coli, 3 Salmonella enterica serovar Typhimurium, and 1 Klebsiella pneumoniae isolate. E. coli isolates were unrelated by PFGE and belonged to 7 different sequence types (STs) and phylogroups. S Typhimurium and K. pneumoniae isolates belonged to ST34 and ST307, respectively. The mcr-1 gene was plasmid borne in all isolates but two E. coli isolates which harbored it on the chromosome. Conjugation of mcr-1 was successful in 8 of 10 isolates (8.2 × 10-5 to 2.07 × 10-1 cell per recipient). Plasmid sequences showed that the mcr-1 plasmids belonged to four different Inc groups (a new IncP-1 variant and the IncFII, IncHI1, and IncH families). Our results indicate that mcr-1 is circulating in clinical isolates of colistin-resistant Enterobacteriaceae in Colombia and is mainly harbored in transferable plasmids.

[Evaluation in 18 hours of Cardiac Dynamics with the Mathematical Law of Dynamic Systems] / Evaluación en 18 horas de la dinámica cardiaca con la ley matemática de los sistemas dinámicos.

Introduction: an exponential law has been found for chaotic dynamic cardiac systems, making it possible to quantify the differences between normal and pathological cardiac dynamics. Methodology: 120 electrocardiographic records were analyzed, 40 corresponded to subjects within the limits of normality and 80 with different pathologies. For each holter the attractors generated with the data during 18 hours and throughout the dynamics were analyzed. The fractal dimension of the attractor and its spatial occupation were calculated. To these measures was applied the diagnosis mathematical evaluation previously developed, comparing the evaluation for 18 hours and for the whole registry; sensitivity, specificity and Kappa coefficient were finally calculated. Results: For the normal dynamics, the occupancy spaces in the Kp grid were between 200 and 381 for the evaluation of the whole holter, and between 201 and 384 in the evaluation during 18 hours, showing the closeness in the measurements, which allows that the decrease in the time of the evaluation is consistent, this same proximity was observed for the diseased and acute dynamics. Conclusion: It was evidenced the clinical applicability in 18 hours of the exponential law in the chaotic cardiac dynamics associated with arrhythmias showing to be useful for the prediction of the evolution towards acute states of the dynamics

Introducción: una ley exponencial se ha hallado para los sistemas dinámicos caóticos cardiacos, logrando cuantificar las diferencias entre dinámicas cardiacas normales y patológicas. Metodología: Se analizaron 120 registros electrocardiográficos, 40 correspondían a sujetos dentro de los límites de normalidad y 80 con diferentes patologías. Para cada holter se analizaron los atractores generados con los datos durante 18 horas y durante toda la dinámica. Se calculó la dimensión fractal del atractor y su ocupación espacial. A estas medidas se aplicó la evaluación matemática diagnostica desarrollada previamente, comparando la evaluación para 18 horas y para todo el registro; finalmente se calculó la sensibilidad, especificidad y coeficiente Kappa. Resultados: Para las dinámicas normales los espacios de ocupación en la rejilla Kp estuvieron entre 200 y 381 en la evaluación de la totalidad del holter, y entre 201 y 384 en la evaluación durante 18 horas, mostrando la cercanía en las medidas, lo que permite que la disminución en el tiempo de la evaluación sea consistente, esta misma cercanía se observó para las dinámicas enfermas y agudas. Conclusión: Se evidenció la aplicabilidad clínica en 18 horas de la ley exponencial en la dinámica cardiaca caótica asociada a arritmias mostrando ser de utilidad para la predicción de la evolución hacia estados agudos de la dinámica.

The Plasmodium vivax Pv41 surface protein: identification and characterization.

Recently, Plasmodium vivax has been related to nearly 81% of malaria cases reported in Central America and the Mediterranean. Due to the difficulty of culturing this parasite species in vitro, most studies on P. vivax have focused on the identification of new antigens by homology comparison with P. falciparum vaccine candidate proteins. In this study, we have identified and characterized a Pf41 homologue in P. vivax, hence named Pv41, by following such approach and using web-available bioinformatics databases, molecular techniques and immunochemistry assays. Pv41 protein is a 384-amino-acid-long antigen encoded by a single exon that exhibits two s48/45 domains characteristic of gametocyte surface proteins. We have also demonstrated Pv41 transcription and expression during late intra-erythrocytic parasite stages and defined its subcellular localization on the parasite surface.

Concordancia entre el diagnóstico clínico y paraclínico de las cervico-vaginitis más frecuentes / Concordance between the clinical and paraclinical diagnosis of the most frequent cervico-vaginitis

Se realizó un estudio multicéntrico (Hospital Universitario de San Ignacio, Hospital San José e Instituto Materno Infantil de Bogotá), seleccionando secuencialmente 301 pacientes de la consulta general de ginecología con o sin sintomatología de cervico-vaginitis que cumplieran los criterios de inclusión y de exclusión. El objetivo general del estudio fue establecer la concordancia entre el diagnóstico clínico de la secreción vaginal y el diagnóstico hecho mediante los exámenes para-clínico considerados como estándar de oro. Dentro de los objetivos específicos se consideraron establecer las cervico vaginitis tanto sintomáticas asintomáticas, establecer la sensibilidad y especificidad del examen clínico frente al método diagnóstico para cada germen en particular y establecer la frecuencia con que las cervico-vaginitis se presentan en nuestro medio. A cada paciente se le practicó inicialmente examen con especuloscopia realizando clínico correspondiente a los hallazgos encontrados, y posteriormente se le tomó muestra de flujo específicamente para Cultivo de Gardenerella vaginalis, Trichomona Vaginalis, Candida albicans, Neisseria gonorreae y prueba de ELISA para Clamydia trachomatis. (truncado 2500 caracteres)