A novel deep learning-based method for automatic stereology of microglia cells from low magnification images.

Microglial cells mediate diverse homeostatic, inflammatory, and immune processes during normal development and in response to cytotoxic challenges. During these functional activities, microglial cells undergo distinct numerical and morphological changes in different tissue volumes in both rodent and human brains. However, it remains unclear how these cytostructural changes in microglia correlate with region-specific neurochemical functions. To better understand these relationships, neuroscientists need accurate, reproducible, and efficient methods for quantifying microglial cell number and morphologies in histological sections. To address this deficit, we developed a novel deep learning (DL)-based classification, stereology approach that links the appearance of Iba1 immunostained microglial cells at low magnification (20×) with the total number of cells in the same brain region based on unbiased stereology counts as ground truth. Once DL models are trained, total microglial cell numbers in specific regions of interest can be estimated and treatment groups predicted in a high-throughput manner (<1 min) using only low-power images from test cases, without the need for time and labor-intensive stereology counts or morphology ratings in test cases. Results for this DL-based automatic stereology approach on two datasets (total 39 mouse brains) showed >90% accuracy, 100% percent repeatability (Test-Retest) and 60× greater efficiency than manual stereology (<1 min vs. ∼ 60 min) using the same tissue sections. Ongoing and future work includes use of this DL-based approach to establish clear neurodegeneration profiles in age-related human neurological diseases and related animal models.

An Overview of Nano Multilayers as Model Systems for Developing Nanoscale Microstructures.

The microstructural transformations of binary nanometallic multilayers (NMMs) to equiaxed nanostructured materials were explored by characterizing a variety of nanoscale multilayer films. Four material systems of multilayer films, Hf-Ti, Ta-Hf, W-Cr, and Mo-Au, were synthesized by magnetron sputtering, heat treated at 1000 °C, and subsequently characterized by transmission electron microscopy. Binary systems were selected based on thermodynamic models predicting stable nanograin formation with similar global compositions around 20-30 at.%. All NMMs maintained nanocrystalline grain sizes after evolution into an equiaxed structure, where the systems with highly mobile incoherent interfaces or higher energy interfaces showed a more significant increase in grain size. Furthermore, varying segregation behaviors were observed, including grain boundary (GB) segregation, precipitation, and intermetallic formation depending on the material system selected. The pathway to tailored microstructures was found to be governed by key mechanisms and factors as determined by a film's initial characteristics, including global and local composition, interface energy, layer structure, and material selection. This work presents a global evaluation of NMM systems and demonstrates their utility as foundation materials to promote tailored nanomaterials.

Alanino aminotrasferasa en pancreatitis aguda de origen biliar / Alanine aminotransferase in biliary acute pancreatitis

La pancreatitis aguda (PA) es una enfermedad de alta prevalencia e impacto socioeconómico. En nuestro medio la causa principal es la patología biliar. La ultrasonografía endoscópica no siempre está disponible dado su alto costo. Los niveles de alaninoaminotransferasa (ALT) mayores de 150 UI/l se han relacionado con patología obstructiva de la vía biliar. Objetivo: determinar las características de la ALT en nuestra población para diagnosticar el origen biliar de la PA. Materiales y métodos: estudio de corte transversal en el Hospital de San José de Bogotá DC. Se revisaron historias clínicas con diagnóstico de PA de agosto 2010 a marzo 2012. Se analizaron datos sociodemográficos, clínicos, de laboratorio, imagenológicos, hallazgos intraoperatorios y diagnóstico etiológico. Resultados: se reclutaron 106 pacientes, 67% mujeres. Se estableció por análisis ROC que los niveles de ALT mayores de 74 UI/l fueron más sensibles y específicos que los de 150 UI/l. Se encontró la relación de ALT mayor de 74 UI/l con hiperbilirrubinemia, ictericia y hallazgos ecográficos compatibles con etiología biliar. Conclusión: existe significancia estadística para ALT mayor a 74 UI/l con etiología biliar (sensibilidad 89%, especificidad 71%) con p <0.001. Se requieren estudios que comparen esta prueba diagnóstica con ultrasonografía endoscópica...

Acute pancreatitis (AP) exhibits high prevalence and high social and economic impact. It is mainly of biliary etiology in our setting. Endoscopic ultrasonography is not always available due to its high costs. Alanine aminotransferase (ALT) levels greater than 150 UI/l have been related to biliary duct obstruction. Objective: to determine ALT features among our population to establish biliary etiology. Materials and Methods: a cross sectional study at Hospital de San José, Bogotá DC. The medical records of all patients with AP from August 2010 to March 2012 were reviewed. Social, demographic, clinical, laboratory, imaging, intraoperative findings and etiologic diagnosis data were analyzed. Results: 106 patients were recruited, 67% females. An ROC analysis established that at ALT levels greater than 74 IU/l there was greater sensibility and specificity than at ALT levels of 150 IU/l. The relation between greater than 74 UI/l ALT levels with hyperbilirrubinemia, jaundice and ultrasonographic findings compatible with biliary etiology was found. Conclusion: there is statistically significant correlations between ALT levels greater than 74UI/l and biliary etiology (sensibility 89%, specificity 71%), p <0.001. Further studies comparing this diagnostic test with endoscopic ultrasonography are required...

Cuándo operar un paciente con sepsis en estado crítico / When to operate a septic critically ill patient

La infección intraabdominal de cualquier origen es la segunda causa de muerte por sepsis en los pacientes en estado crítico y continúa siendo un reto para el médico tratante, dado que existen muchos factores que afectan el enfoque del manejo racional. La creciente tasa de resistencia de los gérmenes intrahospitalarios a las terapias antibióticas convencionales, las diferentes visiones que existen sobre cómo dilucidar el dilema de definir una conducta médica o quirúrgica y la falta de ensayos clínicos con suficiente validez que nos proporcionen una guía que cambie el curso de la enfermedad, hacen de este problema un objeto de constante discusión y discrepancia entre los especialistas que intervienen en su solución. Esta revisión actualiza los conceptos de grupos multidisciplinarios que ayudarán a definir la conducta para el manejo apropiado de esta grave situación clínica.

Regardless its origin, intra-abdominal infection is the second cause of death due to sepsis in critically ill patients and remains a challenge for the treating physician due to the many factors affecting the approach of a rational management. The increase of the resistance rate to conventional antimicrobial therapy of nosocomial organisms, different opinions on how to work out the dilemma of defining a medical or surgical treatment and the lack of valid clinical trials providing guidelines which change the disease´s course, makes this problem a subject of constant discussion and discrepancy between intervening specialists. This review updates the concepts of various multidisciplinary groups which will help define the conduct for appropriate handling of this serious clinical condition.