Nanomechanical and topographical imaging of living cells by Atomic Force Microscopy with colloidal probes

Atomic Force Microscopy (AFM) has a great potential as a tool to characterize mechanical and morphological properties of living cells; these properties have been shown to correlate with cells' fate and patho-physiological state in view of the development of novel early-diagnostic strategies. Although several reports have described experimental and technical approaches for the characterization of cell elasticity by means of AFM, a robust and commonly accepted methodology is still lacking. Here we show that micrometric spherical probes (also known as colloidal probes) are well suited for performing a combined topographic and mechanical analysis of living cells, with spatial resolution suitable for a complete and accurate mapping of cell morphological and elastic properties, and superior reliability and accuracy in the mechanical measurements with respect to conventional and widely used sharp AFM tips. We address a number of issues concerning the nanomechanical analysis, including the applicability of contact mechanical models and the impact of a constrained contact geometry on the measured elastic modulus (the finite-thickness effect). We have tested our protocol by imaging living PC12 and MDA-MB-231 cells, in order to demonstrate the importance of the correction of the finite-thickness effect and the change in cell elasticity induced by the action of a cytoskeleton-targeting drug.Comment: 51 pages, 12 figures, 3 table

Evaluation of heart attack admissions pre- and post-implementation of a smoke-free indoor air policy [abstract]

Multiple laboratory and epidemiological studies find secondhand smoke exposure causes adverse health outcomes. Additionally, an increasing number of studies at community, state and national levels identify significant reductions in hospital admission rate of acute myocardial infarction (AMI) after implementation of a smoke-free indoor air law. A more complete understanding of the health and other benefits related to implementation of community-wide smoke-free ordinances will increase evidence to support policy change in additional communities. Purpose: This project examines changes in hospital admissions for AMI before and after implementation of the comprehensive indoor air ordinance in Columbia, MO. Method: The Hospital Industry Data Institute (HIDI) and Harry S. Truman Memorial Veterans' Hospital provided incidence data for AMI admissions in Columbia, surrounding areas and a regional comparison city without a comprehensive smoke-free indoor air ordinance (Jefferson City, MO) for three years before and two years after implementation of Columbia's smoke-free policy. Poisson analyses tested differences in population-adjusted AMI rates before and after implementation in each population. Results: Implementation of a smoke-free ordinance in Columbia was associated with a 25% reduction in the rate of acute myocardial infarction (p<0.05), compared to an 18% decrease in areas surrounding Columbia (p<0.05) and a non-significant 11% decline in Jefferson City. Conclusion: Implementation of a smoke-free ordinance in Columbia, MO is associated with a significant reduction in hospital admissions for AMI among those residing in city limits and surrounding areas

Edmund Husserl: The objects as units of sense

El presente trabajo se propone elucidar distintas aristas y consecuencias de la noción de objeto en la fenomenología de Husserl, tomando como referencia principal las lecciones de 1907, publicadas con el título: Ding und Raum (Cosa y Espacio). El trabajo busca dar cuenta del reconocimiento de la dimensión de sentido que dicha noción involucra, y de como la misma pretende distanciarse de las visiones clásicas, tanto realistas como idealistas. Para ello, se analizan las siguientes cuestiones: 1) el modo de darse (Gegebenheitsweise) del objeto a la percepción y el conocimiento, 2) la manera de entender los conceptos de identidad y trascendencia, 3) la manera de entender el vínculo objeto-propiedad.The aim of this work is to elucidate the different angles and consequences of the notion of object in Husserl´s phenomenology (considering the 1907 lections Ding und Raum). This work tries to account for the recognition of the dimension of sense that is involved in that notion, and how it seeks to distance itself from such classic visions as realism and idealism. To accomplish this aim, the following matters are analyzed: 1) the mode of givenness (Gegebenheitsweise) of the object to perception and knowledge, 2) the way in which the concepts of identity and transcendence are understood, 3) the way in which the relationship between object and property is understood

Review of the literature regarding visual-perceptual motor skills, their relationship to reading, and to the disadvantaged child

The writer set out to investigate the literature which discussed the visual-perceptual-motor skills fundamental to reading readiness. More specifically, the writer wished to investigate the literature which pertained to the inner-city child and to the deficiencies he has in this area. The writer is interested in ascertaining whether all incoming primary children would benefit from a perceptual-motor program and if such a program would be especially feasible in an inner-city school

Modelo de la dinámica poblacional de Anoda cristata en un cultivo de soja resistente a glifosato bajo diferentes sistemas de manejo

Se desarrolló un modelo de simulación de la dinámica del banco de semillas de Anoda cristata (L.) Schlecht en un cultivo de soja. El modelo considera distintas estrategias de manejo: ausencia de control, control con la dosis recomendada y con la mitad de dicha dosis y dos espaciamientos entre filas del cultivo de soja (35 y 70 cm). El modelo fue evaluado usando datos de experiencias previas realizadas durante 4 años consecutivos. El modelo reprodujo ajustadamente la dinámica del banco de semillas. El banco de semillas decreció más cuando no se produjeron semillas; en ausencia de control, alcanzó una densidad de equilibrio. Cuando se produjeron semillas todos los años, el modelo fue más sensible a cambios en la tasa de predación pero cuando no se produjeron semillas, la mortalidad de éstas fue el proceso más importante. La simulación muestra que puede ocurrir erradicación a largo plazo con el uso continuo de glifosato a la dosis recomendada, o con la combinación de soja sembrada a 35 cm entre filas y la mitad de la dosis recomendada.A computer simulation model was developed to describe Anoda cristata (L.) Schlecht seedbank dynamics in soybeans. The model considers different weed management strategies: absence of control, control with the recommended rate and with glyphosate at half the recommended rate, and two soybean row spacings (35 and 70 cm). The model was evaluated using data from previous experiments obtained for four consecutive years. The model accurately reproduced the seedbank dynamics. The seedbank decreased more in weed management strategies without seed production. In absence of control, the seedbank reached an equilibrium density. When seeds were produced every year, the model output was more sensitive to changes in the rate of predation; but without seed production, seed mortality was the most important process. Simulation demonstrated that long-term eradication may occur with continuous use of glyphosate at the recommended rate or with the combination of soybean at 35 cm between rows and glyphosate at half the recommended rate.Fil: Puricelli, E.. Universidad Nacional de Rosario; ArgentinaFil: Vitta, Javier Ignacio. Universidad Nacional de Rosario; ArgentinaFil: Sabbatini, Mario Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; ArgentinaFil: Orioli, Gustavo Adolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; Argentin

Intubación orotraqueal con vía submandibular en Cirugía yTraumatología Bucomaxilofacial

Introduction: Submandibular tracheal intubation is a technique that can be applied in Oral and Maxillofacial Surgery and Traumatology,as well asother surgical specialties. Its main advantages are helpingin the surgical manipulation of the middle facial skeleton and jaw and allowing the intraoperative control of dental occlusion. The technique is analternative to elective tracheostomy. Objective and case report: The article presents the treatment of an adult patient, with sequelae of multiple fractures in the face due to a car accident, with endotracheal intubation using submandibular approach.Final considerations: In large surgical manipulations of the face, the submandibular approach for tracheal intubation allows a faster, facilitated anatomical access with a lower risk of damage to adjacent structures when compared to other pathways. It also guarantees excellent cervical mobility, the possibility of wide manipulation and the use of occlusion as a guide for surgical intervention.Introdução:A intubação orotraqueal com trajeto submandibular é uma técnica que pode ser aplicada em Cirurgia e Traumatologia Buco-maxilo-faciais e outras especialidades cirúrgicas. Tem sua indicação diante da necessidade de manipulação cirúrgica do esqueleto fixo da face e mandíbula, permitindo o estabelecimentoda oclusão trans-operatória. A técnica é uma alternativa à realização da traqueostomia eletiva. Objetivo e relato do caso: O artigo tem por objetivo apresentar a intubação orotraqueal com trajeto submandibular, que foi aplicada em um paciente adulto, vítima de acidente automobilístico, com sequela de múltiplas fraturas em face. Considerações finais:Nas grandes manipulações cirúrgicas da face, o trajeto cirúrgico submandibular, para a passagem do tubo de anestesia, permite um acesso anatômico mais rápido, facilitado e com menor risco de danos às estruturas adjacentes, quando comparado com outras vias. Garante ainda, excelente mobilidade cervical, possibilidade de ampla manipulação e utilização da oclusão como guia para intervenção cirúrgica.Introdución:La intubación orotraqueal con vía submandibular es una técnica que se puede aplicar en Cirugía y Traumatología Buccomaxilofacial y otras especialidades quirúrgicas. Está indicado por la necesidad de manipulación quirúrgica del esqueleto fijo de rostro y mandíbula, permitiendo el establecimiento de oclusión intraoperatoria. La técnica es una alternativa a la realización de una traqueotomía electiva. Objetivo y relato de caso: El artículotiene como objetivo presentar la intubación orotraqueal con vía submandibular, la cual se aplicó a un paciente adulto, víctima de un accidente automovilístico, con secuelas de múltiples fracturas en la cara. Consideraciones finales: En manipulaciones quirúrgicas mayores del rostro, la vía quirúrgica submandibular, para el paso del tubo de anestesia, permite unacceso anatómico más rápido, más fácil y con menor riesgo de daño a las estructuras adyacentes, en comparación con otras vías. También garantiza unaexcelente movilidad cervical, posibilidad de amplia manipulación y uso de la oclusión como guía para la intervención quirúrgica

Thirty-eight-year follow-up of the first patient of mandibular reconstruction with free vascularized fibula flap

Background: The mandible is responsible for vital functions of the stomatognathic system, and its loss results in functional and aesthetic impairment. Mandibular reconstruction with free fibula flap is considered the gold standard for mandibular reconstruction. Case presentation: We describe here the 38-year follow-up of the patient who was the first case of mandibular reconstruction with free fibula flap reported in the literature. The original report describes a 27-year-old woman who had undergone extensive mandibulectomy due to an osteosarcoma. A microvascularized fibula flap was used for mandibular reconstruction in 1983. Two years later, a vestibulo-lingual sulcoplasty with skin graft was performed to allow the construction of a total dental prosthesis. Fifteen years after the initial treatment, an autologous iliac crest graft was placed in the fibula flap, aimed at increasing bone thickness and height for rehabilitation with implant supported prosthesis. In 2015, a rib graft was positioned in the mental region, enhancing the support to the soft tissues of the face and improving the oral function. A recent review of the patient shows well-balanced facial morphology and optimal functional results of the procedure. Conclusions: The fibula flap method, described in 1975 and first reported for mandibular reconstruction in 1985, continues to be applied as originally described, especially where soft tissue damage is not extensive. Its use in reconstructive surgery was expanded by advancements in surgery and techniques such as virtual surgical planning. However, there is still a lack of evidence related to the long-term evaluation of outcomes. The present work represents the longest-term follow-up of a patient undergoing mandibular reconstruction with free vascularized fibula flap, presenting results showing that, even after 38 years, the procedure continues to provide excellent results

Public Oncologic Serum Biobank

The Public Oncologic Serum Biobank is a not for-profit organization that has been established within the academia setting since 2009, which aims to prospectively collect and store serum samples from cancer patients and volunteers and their associated clinical and epidemiological data, with the ultimate goal to distribute them to the local and international research community focusing in understanding and improving cancer diagnosis and treatment.Fil: Rondot Radío, Pedro. Public Oncologic Serum Biobank; ArgentinaFil: Puricelli, Lydia Ines. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncologia "Angel H. Roffo"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Public Oncologic Serum Biobank; Argentin

Applied mechanics of the Puricelli osteotomy: a linear elastic analysis with the finite element method

<p>Abstract</p> <p>Background</p> <p>Surgical orthopedic treatment of the mandible depends on the development of techniques resulting in adequate healing processes. In a new technical and conceptual alternative recently introduced by Puricelli, osteotomy is performed in a more distal region, next to the mental foramen. The method results in an increased area of bone contact, resulting in larger sliding rates among bone segments. This work aimed to investigate the mechanical stability of the Puricelli osteotomy design.</p> <p>Methods</p> <p>Laboratory tests complied with an Applied Mechanics protocol, in which results from the Control group (without osteotomy) were compared with those from Test I (Obwegeser-Dal Pont osteotomy) and Test II (Puricelli osteotomy) groups. Mandible edentulous prototypes were scanned using computerized tomography, and digitalized images were used to build voxel-based finite element models. A new code was developed for solving the voxel-based finite elements equations, using a reconditioned conjugate gradients iterative solver. The Magnitude of Displacement and von Mises equivalent stress fields were compared among the three groups.</p> <p>Results</p> <p>In Test Group I, maximum stress was seen in the region of the rigid internal fixation plate, with value greater than those of Test II and Control groups. In Test Group II, maximum stress was in the same region as in Control group, but was lower. The results of this comparative study using the Finite Element Analysis suggest that Puricelli osteotomy presents better mechanical stability than the original Obwegeser-Dal Pont technique. The increased area of the proximal segment and consequent decrease of the size of lever arm applied to the mandible in the modified technique yielded lower stress values, and consequently greater stability of the bone segments.</p> <p>Conclusion</p> <p>This work showed that Puricelli osteotomy of the mandible results in greater mechanical stability when compared to the original technique introduced by Obwegeser-Dal Pont. The increased area of the proximal segment and consequent decrease of the size of lever arm applied to the mandible in the modified technique yield lower stress values and displacements, and consequently greater stability of the bone segments.</p

Apicotomy: a root apical fracture for surgical treatment of impacted upper canines

Impacted canines, due to systemic or local factors, represent a frequent problem in most populations. Surgical intervention usually involves exposure for spontaneous eruption, exposure for orthodontic traction or extraction. The author presents the apicotomy technique, which has been successfully used during the past twenty years for conservative intervention in cases of impacted upper canines with dilaceration or apical root-ankylosis. This original method involves surgical fracture of the root apex, followed by orthodontic traction of the corono-radicular region