290 research outputs found
Analysis and automated classification of images of blood cells to diagnose acute lymphoblastic leukemia
Analysis of white blood cells from blood can help to detect Acute Lymphoblastic Leukemia, a potentially fatal blood cancer if left untreated. The morphological analysis of blood cells images is typically performed manually by an expert; however, this method has numerous drawbacks, including slow analysis, low precision, and the results depend on the operator’s skill. We have developed and present here an automated method for the identification and classification of white blood cells using microscopic images of peripheral blood smears. Once the image has been obtained, we propose describing it using brightness, contrast, and micro-contour orientation histograms. Each of these descriptions provides a coding of the image, which in turn provides n parameters. The extracted characteristics are presented to an encoder’s input. The encoder generates a high-dimensional binary output vector, which is presented to the input of the neural classifier. This paper presents the performance of one classifier, the Random Threshold Classifier. The classifier’s output is the recognized class, which is either a healthy cell or an Acute Lymphoblastic Leukemia-affected cell. As shown below, the proposed neural Random Threshold Classifier achieved a recognition rate of 98.3 % when the data has partitioned on 80 % training set and 20 % testing set for. Our system of image recognition is evaluated using the public dataset of peripheral blood samples from Acute Lymphoblastic Leukemia Image Database. It is important to mention that our system could be implemented as a computational tool for detection of other diseases, where blood cells undergo alterations, such as Covid-1
Functional, immunological and three-dimensional analysis of chemically synthesisedsporozoite peptides as components of a fully-effective antimalarial vaccine
Our ongoing search for a fully-effective vaccine against the Plasmodium falciparum parasite (causing the most lethal form ofhuman malaria) has been focused on identifying and characterising proteins' amino acid sequences (high activity binding peptides orHABPs) involved in parasite invasion of red blood cells (RBC) by the merozoite and hepatocytes by the sporozoite. Many such merozoiteHABPs have been recognised and molecularly and structurally characterised; however, native HABPs are immunologically silentsince they do not induce any immune response or protection against P. falciparum malaria infection and they have to be structurallymodified to allow them to fit perfectly into immune system molecules.A deeply structural analysis of these conserved merozoite HABPs and their modified analogues has led to rules or principles becomingrecognised for constructing a logical and rational methodology for a minimal subunit-based, multi-epitope, multi-stage, chemicallysynthesisedvaccine. The same in-depth analysis of the most relevant sporozoite proteins involved in sporozoite cell-traversal and hepatocyteinvasion as well as the hepatic stage is shown here.Specifically modifying these HABPs has resulted in a new set of potential pre-erythrocyte targets which are able to induce high, longlastingantibody titres in Aotus monkeys, against their corresponding recombinant proteins and the complete parasite native molecules.This review shows how these rules may be applied against the first stage of parasite invasion (i.e. the sporozoite) to mount the first line ofdefence against the malarial parasite, which may indeed be the most effective one. Our results strongly support including some of thesemodified sporozoite HABPs in combination with the previously-described modified merozoite HABPs for obtaining the aforementionedfully-protective, multiepitope, multi-stage, minimal subunit-based, chemically-synthesized, antimalarial vaccine. © 2011 Bentham Science Publishers
Parasite-related genetic and epigenetic aspects and host factors influencing plasmodium falciparum invasion of erythrocytes
Malaria, a disease caused by Plasmodium parasites, is widespread throughout tropical and sub-tropical regions worldwide; it mostly affects children and pregnant woman. Eradication has stalled despite effective prevention measures and medication being available for this disease; this has mainly been due to the parasite's resistance to medical treatment and the mosquito vector's resistance to insecticides. Tackling such resistance involves using renewed approaches and techniques for accruing a deep understanding of the parasite's biology, and developing new drugs and vaccines. Studying the parasite's invasion of erythrocytes should shed light on its ability to switch between invasion phenotypes related to the expression of gene sets encoding proteins acting as ligands during target cell invasion, thereby conferring mechanisms for evading a particular host's immune response and adapting to changes in target cell surface receptors. This review considers some factors influencing the expression of such phenotypes, such as Plasmodium's genetic, transcriptional and epigenetic characteristics, and explores some host-related aspects which could affect parasite phenotypes, aiming at integrating knowledge regarding this topic and the possible relationship between the parasite's biology and host factors playing a role in erythrocyte invasion. © 2019 Ararat-Sarria, Patarroyo and Curtidor. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms
Efecto de ácido giberélico (AG3), nitrato de potasio (KNO3) y rizobacterias promotoras del crecimiento vegetal (PGPRs), sobre el desarrollo temprano de Solanum sessiliflorum (COCONA)
En este trabajo se realizaron pruebas de germinación a semillas de Solanum sessiliflorum para conocer los requerimientos generales que presenta esta especie para llevar a cabo este proceso y producir plantas viables en etapas tempranas de crecimiento bajo condiciones diferentes a las de su área de distribución habitual. En las pruebas se determinaron porcentajes de viabilidad, porcentajes de germinación, tiempos de germinación y respuesta al estímulo de la luz. Por otro lado, se evalúo el efecto de diferentes tratamientos pre-siembra con los promotores de crecimiento AG3 (ácido giberélico), KNO3 (nitrato de potasio) y PGPRs (rizobacterias promotoras de crecimiento) de los géneros Bacillus sp y Pseudomonas sp, sobre el desarrollo de S. sessiliflorm. Adicionalmente se obtuvo una descripción de los estadios de desarrollo de la especie. El estudio se realizó en la Universidad Militar Nueva Granada, Cajicá, Colombia, a una temperatura media de 18ºC y 2558 m.s.n.m, con semillas tomadas de frutos maduros de S. sessiliflorum provenientes de Caquetá, Colombia (temperatura media anual de 27ºC y 242 m.s.n.m). Se determinó que las PGPRs no tuvieron efecto positivo sobre el desarrollo de ésta especie, mientras que los tratamientos con AG3 y KNO3 tanto en presencia como en ausencia de luz, presentaron disminución de tiempos de germinación e incremento en los porcentajes de germinaciónThis study tested Solanum sessiliflourm for seed germination in order to know the general requirements for this species to carry out this process and to produce viable plants under different conditions from its customary distribution area. In tests, we determined viability percentages, germination percentages, germination times and response to the stimulus of light. Furthermore, we evaluated the effect of pre-sowing treatments with growth promoters GA3 (gibberellic acid), KNO3 (potassium nitrate) and PGPRs (growth promoting rhizobacteria) from the genera Bacillus sp and Pseudomonas sp, over S. sessiliflorum development at early growth stages. Additionally, we obtained a description of phenological stages for the species. The study was conducted at Nueva Granada Military University, Cajicá, Colombia, with an average temperature of 18ºC and 2558 m.a.s.l, with seeds from ripe fruits of S. sessiliflorum native from Caquetá, Colombia (average annual temperature of 27ºC and 242 m.a.s.l). We found PGPRs provided no positive effect on this species development, while treatments with GA3 and KNO3 in presence and absence of light, had decreased time germination and increased germination percentages significantly, according with statistic testPregrad
Identificación y caracterización de la proteína del cuello de las roptrias 5 (RON5) en Plasmodium falciparum y determinación de las regiones de unión a glóbulos rojos humanos
87 páginasIn this research, advanced control strategies were designed under the Active Disturbance Rejection Control (ADRC) approach to increase the biomass production in microalgae cultures. For the above, from a control frame of reference, the development was envisaged into two stages, control and optimization. The first stage resulted in three different controllers designs: two ADRC strategies assisted by observer and a Model-Free Control (MFC). In each case, the aim was to guarantee the tracking of the reference signal. In the second stage, the design of two optimization strategies were achieves to increase the biomass production, offline and on-line. Comparing, at a simulation level, these strategies with other existing proposals, the following was found: 1) the ADRC strategies assisted by observer had a few dependence on the model, letting us to work with an approximate model that only required knowing of the system order and the input gain; 2) the off-line optimization, despite maximizing the biomass production, required knowing the model and 3) the proposal that combines MFC with on-line optimization, may act on any microalgae culture since it does not need a model. All the proposals are robust front to disturbances and variation of parameters allowing to increase the biomass production when an optimization strategy is used.La malaria es una de las enfermedades infecciosas más prevalentes y mortales a nivel mundial. Cinco especies de Plasmodium (protozoario intracelular obligado del filo Apicomplexa) infectan al humano, siendo Plasmodium falciparum la especie responsable de las manifestaciones clínicas más severas, con amplia distribución en las zonas tropicales y subtropicales del África Subsahariana. Según los estimados de la Organización Mundial de la Salud (OMS), en el año 2010 se presentaron alrededor de 216 millones de casos de malaria y cerca de un millón de muertes, principalmente de niños menores de 5 años. Esta cifra se ha incrementado en los últimos años, luego de la aparición de variantes del parásito que son resistentes a drogas antimaláricas y por la resistencia a los insectidas por parte del mosquito. Es por lo tanto urgente el desarrollo de medidas de control efectivas que permitan la erradicación de esta parasitosis.Doctorado en BiocienciasDoctor en Biociencia
PvRON2, a new Plasmodium vivax rhoptry neck antigen
<p>Abstract</p> <p>Background</p> <p>Rhoptries are specialized organelles from parasites belonging to the phylum <it>Apicomplexa</it>; they secrete their protein content during invasion of host target cells and are sorted into discrete subcompartments within rhoptry neck or bulb. This distribution is associated with these proteins' role in tight junction (TJ) and parasitophorous vacuole (PV) formation, respectively.</p> <p>Methods</p> <p><it>Plasmodium falciparum </it>RON2 amino acid sequence was used as bait for screening the codifying gene for the homologous protein in the <it>Plasmodium vivax </it>genome. Gene synteny, as well as identity and similarity values, were determined for <it>ron2 </it>and its flanking genes among <it>P. falciparum</it>, <it>P. vivax </it>and other malarial parasite genomes available at PlasmoDB and Sanger Institute databases. <it>Pvron2 </it>gene transcription was determined by RT-PCR of cDNA obtained from the <it>P. vivax </it>VCG-1 strain. Protein expression and localization were assessed by Western blot and immunofluorescence using polyclonal anti-<it>Pv</it>RON2 antibodies. Co-localization was confirmed using antibodies directed towards specific microneme and rhoptry neck proteins.</p> <p>Results and discussion</p> <p>The first <it>P. vivax </it>rhoptry neck protein (named here <it>Pv</it>RON2) has been identified in this study. <it>Pv</it>RON2 is a 2,204 residue-long protein encoded by a single 6,615 bp exon containing a hydrophobic signal sequence towards the amino-terminus, a transmembrane domain towards the carboxy-terminus and two coiled coil α-helical motifs; these are characteristic features of several previously described vaccine candidates against malaria. This protein also contains two tandem repeats within the interspecies variable sequence possibly involved in evading a host's immune system. <it>Pv</it>RON2 is expressed in late schizonts and localized in rhoptry necks similar to what has been reported for <it>Pf</it>RON2, which suggests its participation during target cell invasion.</p> <p>Conclusions</p> <p>The identification and partial characterization of the first <it>P. vivax </it>rhoptry neck protein are described in the present study. This protein is homologous to <it>Pf</it>RON2 which has previously been shown to be associated with <it>Pf</it>AMA-1, suggesting a similar role for <it>Pv</it>RON2.</p
Implementación de un Sistema de Medición de la Conductividad del Agua con Transmisión de Datos en Tiempo Real
This document shows the implementation of a water conductivity measurement system with the special attribute of data transmission in real time through Wi-Fi and Bluetooth devices. For the development of the proposed work, an evolutionary methodology was used, which is developed phase by phase, with the possibility of returning to a previous phase to make the pertinent adjustments. Within the development, the KEYESTUDIO sonda measurement sensor TDS V1 sensor module with XH2.54-3 was used, which connects to the ESP8266 data acquisition card together with the DS18B20 temperature sensor, being the IoT platform and a LabVIEW® interface monitoring panels for transmitted data of electrical conductivity and temperature of the chosen environment. It is important to mention that the implemented system provides effective monitoring of water conductivity from a remote location, yielding reliable values, without user intervention in the chosen environment.El presente documento muestra la implementación de un sistema de medición de la conductividad del agua con el atributo especial de transmisión de datos en tiempo real por medio de dispositivos wifi y bluetooth. Para el desarrollo del trabajo propuesto se hizo uso de una metodología de tipo evolutivo, la cual se va desarrollando fase por fase, con la posibilidad de regresar a una fase anterior para realizar los ajustes pertinentes. Dentro del desarrollo se hizo uso del sensor KEYESTUDIO sonda de medición TDS V1 módulo de sensor con XH2.54-3, el cual se conecta a la tarjeta de adquisición de datos ESP8266 junto con el sensor de temperatura DS18B20, siendo la plataforma IoT y una interfaz de LabVIEW® los paneles de monitoreo para los datos transmitidos de conductividad eléctrica y temperatura del entorno escogido. Es importante mencionar que el sistema implementado brinda monitoreo efectivo desde un lugar remoto sobre conductividad del agua, arrojando valores fiables, sin intervención del usuario en el entorno escogido
Los contratos laborales ocultos en los contratos de prestación de servicios en la gobernación del Meta en secretaria de educación
El ordenamiento jurídico contempla unos parámetros y reglas para la contratación estatal y contratación laboral, por desconocimiento o por mala fe, se ha distorsionado la aplicabilidad de ambos contratos, generando de esta manera una vulneración a los derechos mínimos fundamentales de los individuos involucrados. Por lo tanto, se expondrá las diferencias de cada contrato, los pronunciamientos de las Cortes sobre este flagelo y las afectaciones y vulneraciones que recaen en los contratistas de los entes estatales, en específico, de la secretaria de educación de la Gobernación del Meta.Universidad Libre - Especialización en derecho laboral y seguridad socialThe legal system contemplates certain parameters and rules for state contracting and labor contracting, but due to ignorance or bad faith, the applicability of both contracts has been distorted, thus generating a violation of the minimum fundamental rights of the individuals involved. Therefore, the differences of each contract, the pronouncements of the High Courts on this scourge and the affectations and violations that fall on the contractors of the state entities, specifically, of the Secretary of Education of the Governorate of Meta, will be exposed
Conserved binding regions provide the clue for peptide-based vaccine development: A chemical perspective
Synthetic peptides have become invaluable biomedical research and medicinal chemistry tools for studying functional roles, i.e., binding or proteolytic activity, naturally-occurring regions' immunogenicity in proteins and developing therapeutic agents and vaccines. Synthetic peptides can mimic protein sites; their structure and function can be easily modulated by specific amino acid replacement. They have major advantages, i.e., they are cheap, easily-produced and chemically stable, lack infectious and secondary adverse reactions and can induce immune responses via T- and B-cell epitopes. Our group has previously shown that using synthetic peptides and adopting a functional approach has led to identifying Plasmodium falciparum conserved regions binding to host cells. Conserved high activity binding peptides' (cHABPs) physicochemical, structural and immunological characteristics have been taken into account for properly modifying and converting them into highly immunogenic, protection-inducing peptides (mHABPs) in the experimental Aotus monkey model. This article describes stereo-electron and topochemical characteristics regarding major histocompatibility complex (MHC)-mHABP-T-cell receptor (TCR) complex formation. Some mHABPs in this complex inducing long-lasting, protective immunity have been named immune protection-inducing protein structures (IMPIPS), forming the subunit components in chemically synthesized vaccines. This manuscript summarizes this particular field and adds our recent findings concerning intramolecular interactions (H-bonds or-interactions) enabling proper IMPIPS structure as well as the peripheral flanking residues (PFR) to stabilize the MHCII-IMPIPS-TCR interaction, aimed at inducing long-lasting, protective immunological memory. © 2017 by the authors. Licensee MDPI, Basel, Switzerland.1
Parasite-Related Genetic and Epigenetic Aspects and Host Factors Influencing Plasmodium falciparum Invasion of Erythrocytes
Malaria, a disease caused by Plasmodium parasites, is widespread throughout tropical and sub-tropical regions worldwide; it mostly affects children and pregnant woman. Eradication has stalled despite effective prevention measures and medication being available for this disease; this has mainly been due to the parasite's resistance to medical treatment and the mosquito vector's resistance to insecticides. Tackling such resistance involves using renewed approaches and techniques for accruing a deep understanding of the parasite's biology, and developing new drugs and vaccines. Studying the parasite's invasion of erythrocytes should shed light on its ability to switch between invasion phenotypes related to the expression of gene sets encoding proteins acting as ligands during target cell invasion, thereby conferring mechanisms for evading a particular host's immune response and adapting to changes in target cell surface receptors. This review considers some factors influencing the expression of such phenotypes, such as Plasmodium's genetic, transcriptional and epigenetic characteristics, and explores some host-related aspects which could affect parasite phenotypes, aiming at integrating knowledge regarding this topic and the possible relationship between the parasite's biology and host factors playing a role in erythrocyte invasion
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