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Homochirality, the phenomenon by which one of two virtually identical (non-superimposable mirror images) compounds is favored over the other in the chemistry of life, has been regarded as a requisite for the emergence of all living things on earth. Spontaneous mirror symmetry breaking has been proposed to produce the imbalance. Under this framework, Frank presented, in his foundational article "On spontaneous asymmetric synthesis", a simple chemical reaction network that displays spontaneous symmetry breaking for a specific set of reaction rates. Research has since focused on finding more complex and plausible models, each one with its advantages and disadvantages. Nevertheless, finding reaction rate values that make a model exhibit spontaneous symmetry breaking is a complex task, even for specially crafted models. LInear STability ANALysis of CHEmical Mechanism, Listanalchem, is a method and software for the search for appropriate reaction rates. It includes four different algorithms inspired by the analysis of Frank's network. Two classical algorithms are also included in Listanalchem: the Trace-Determinant plane and the Stoichiometric Network Analysis by Bruce Clarke. Listanalchem reads a chemical reaction network from plain text and runs one or more of the available algorithms according to the user selection. Listanalchem is tested and verified by studying classical, modified, and recent models proposed to explain the origin of biological homochirality.â¢Listanalchem allows a fast and reliable search for instability behavior in chemical mechanisms that pretend to explain spontaneous mirror symmetry breaking.â¢Listanalchem contains several model examples, including the most cited in the related literature.â¢Listanalchem is a tool that tests models that pretend to explain the origin of biological homochirality, helps find errors, and aids in designing new models.
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The search for new sources of high-quality non-crystalline silica as a construction material for high-performance concrete has attracted the interest of researchers for several decades. Numerous investigations have shown that highly reactive silica can be produced from rice husk, an agricultural waste that is abundantly available in the world. Among others, the production of rice husk ash (RHA) by chemical washing with hydrochloric acid prior to the controlled combustion process has been reported to provide higher reactivity because such a process removes alkali metal impurities from RHA and provides an amorphous structure with higher surface area. This paper presents an experimental work in which a highly reactive rice husk ash (TRHA) is prepared and evaluated as a replacement for Portland cement in high-performance concretes. The performance of RHA and TRHA was compared with that of conventional silica fume (SF). Experimental results showed that the increase in compressive strength of concrete with TRHA was clearly observed at all ages, generally higher than 20% of the strength obtained with the control concrete. The increase in flexural strength was even more significant, showing that concrete with RHA, TRHA and SF increased by 20%, 46%, and 36%, respectively. Some synergistic effect was observed when polyethylene-polypropylene fiber was used for concrete with TRHA and SF. The chloride ion penetration results also indicated that the use of TRHA had similar performance compared to that of SF. Based on the results of statistical analysis, the performance of TRHA is found to be identical to that of SF. The use of TRHA should be further promoted considering the economic and environmental impact that will be achieved by utilizing agricultural waste.
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Introducción. Las fugas anastomóticas son una complicación común y crítica en cirugía gastrointestinal, por lo que su identificación y tratamiento temprano son necesarios para evitar resultados adversos. El uso convencional con un valor límite de la proteína C reactiva ha demostrado una utilidad limitada. El objetivo de este estudio fue determinar la utilidad de la medición seriada de la proteína C reactiva en la detección de fugas anastomóticas. Métodos. Revisión prospectiva de base de datos retrospectiva de pacientes sometidos a cirugía abdominal mayor con al menos una anastomosis intestinal. Se midió la proteína C reactiva al tercer y quinto día posoperatorio. Las complicaciones se categorizaron según la clasificación de Clavien-Dindo. La precisión diagnóstica fue evaluada por el área bajo la curva. Resultados. Se incluyeron 157 pacientes, el 52 % mujeres. La edad promedio fue de 63,7 años. El mayor número de cirugías correspondió a gastrectomía (36,3 %), resección anterior de recto (15,3 %) y hemicolectomía derecha (13,4 %). El 25,5 % tuvieron alguna complicación postoperatoria y el 32,5 % (n=13) presentaron fuga en la anastomosis. El aumento de la proteína C reactiva tuvo un área bajo la curva de 0,918 con un punto de corte de aumento en 1,3 mg/L, sensibilidad de 92,3 % (IC95% 78 100) y una especificidad de 92,4 % (IC95% 88 96). Conclusiones. El aumento de 1,3 mg/L en la proteína C reactiva entre el día de la cirugía y el quinto día fue un predictor preciso de fugas anastomóticas en pacientes con cirugía abdominal mayor
Introduction. Anastomotic leaks are a common and critical complication in gastrointestinal surgery. Their identification and early treatment are necessary to avoid adverse results, and conventional use with a cutoff value of C-reactive protein has shown limited utility. The objective of this study was to determine the usefulness of serial measurement of C-reactive protein in the detection of anastomotic leaks. Methods. Prospective review of a retrospective database of patients undergoing major abdominal surgery with at least one intestinal anastomosis. C-reactive protein was measured on the third and fifth postoperative days. Complications were classified according to the Clavien-Dindo classification. Diagnostic accuracy was evaluated by the area under the curve.Results. 157 patients were included, 52% were females. The average age was 63.7 years. The largest number of surgeries corresponded to gastrectomies (36.3%), anterior resection of the rectum (15.3%) and right hemicolectomies (13.4%). 25.5% had some postoperative complication and 32.5% (n=13) had anastomosis leaks. The increase in C-reactive protein had an area under the curve of 0.918 with an increase cut-off point of 1.3 mg/L, sensitivity of 92.3% (95% CI 78-100) and specificity of 92.4%. (95% CI 88-96). Conclusions. The 1.3 mg/L increase in C-reactive protein between the day of surgery and the fifth day was an accurate predictor of anastomotic leaks in patients with major abdominal surgery
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Humanos , Proteína C , Anastomosis Quirúrgica , Fuga Anastomótica , Complicaciones Posoperatorias , Procedimientos Quirúrgicos del Sistema Digestivo , Evolución Clínica , GastrectomíaRESUMEN
Leishmaniasis may occur in three different clinical forms, namely, visceral, mucocutaneous and cutaneous, which are caused by different species of trypanosomatid protozoans of the genus Leishmania. Pentavalent antimonials are the leading treatment for cutaneous leishmaniasis despite the hepatic, renal, and cardiac toxicity. In addition, the response of some Leishmania species to pentavalent antimonials is increasingly poorer, and therefore new and more potent therapeutic alternatives are needed. Arnica montana L., Asteraceae, is a traditional medicinal plant of Europe and preparations of its flowers are commonly used externally to treat disorders of the musculoskeletal system as well as superficial inflammatory conditions. Previous studies have shown that Arnica tincture (AT), an ethanolic extract prepared from the flowerheads of Arnica montana as well as isolated Arnica sesquiterpene lactones (STLs) have antileishmanial activity in vitro against L. donovani and L. infantum, as well as in vivo against L. braziliensis. In this work, we studied the in vitro cytotoxicity and antileishmanial activity of AT and STLs against both L. braziliensis and L. tropica. The in vivo therapeutic effect of AT was studied in hamsters with cutaneous Leishmaniasis (CL) caused by experimental infection with L. braziliensis and L. tropica. Furthermore, various semisolid Arnica preparations were also evaluated against L. braziliensis. The STLs and the AT possess a very high in vitro activity against both Leishmania species with median effective concentrations (EC50) ranging from 1.9 to 5.9 µg/mL. The AT was not cytotoxic for human tissue macrophages, skin fibroblasts, and hepatic cells. The therapeutic response of hamsters infected with L. braziliensis to the topical treatment with AT was 87.5% at a dose of 19.2 µg STL/2× day/60 d, 72.7% at doses of 19.2 µg STL/1× d/60 d and 67% at a dose of 38.4 µg STL/2× d/60 d. In turn, the therapeutic response in hamsters infected with L. tropica was 100% when treated at a dose of 19.2 µg STL/2× day/60 d and 71% at a dose of 38.4 µg STL/2× d/60 d. On the other hand, the effectiveness of treatment with glucantime administered intralesionally at a dose of 200 mg/every three days for 30 days was 62.5% for L. braziliensis and 37.5% for L. tropica infection. These results are promising and encourage the implementation of clinical trials with AT in CL patients as a first step to using AT as a drug against CL.
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La rifampicina es un medicamento ampliamente utilizado para el tratamiento de diversas infecciones bacterianas con un amplio espectro de efectos adversos que varían desde reacciones leves hasta potencialmente fatales; la anemia hemolítica es un efecto adverso escasamente reportado en la literatura pero que puede tener un desenlace potencialmente fatal, reportamos así un caso de anemia hemolítica autoinmune asociada a lesión renal aguda en una paciente joven en segunda fase de tratamiento para tuberculosis pulmonar.
Summary Rifampicin is a widely used drug for the treatment of various infectious diseases with a broad spectrum of adverse reaction ranging from mild to life-threatening manifestations; hemolytic anemia is an adverse effect rarely reported in the literature, but it can have a potentially fatal outcome. Thus, we report a case of autoimmune hemolytic anemia associated with acute kidney injury in a young patient in the second phase of treatment for pulmonary tuberculosis.
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Humanos , Femenino , AdultoRESUMEN
Abstract Biological homochirality is modelled using chemical reaction mechanisms that include autocatalytic and inhibition reactions as well as input and output flows. From the mathematical point of view, the differential equations associated with those mechanisms have to exhibit bistability. The search for those bifurcations can be carried out using stoichiometric network analysis. This algorithm simplifies the mathematical analysis and can be implemented in a computer programme, which can help us to analyse chemical networks. However, regardless of the reduction to linear polynomials, which is made possible by this algorithm, in some cases, the complexity and length of the polynomials involved make the analysis unfeasible. This problem has been partially solved by extending the stoichiometric matrix with rows that code the duality relations between the different reactions occurring in the network given as input. All these facts allow us to analyse 28 different network models, highlighting the basic requirements needed by a chemical mechanism to have spontaneous mirror symmetry breaking.
Resumen El origen de la homoquiralidad biológica se ha modelado usando mecanismos de reacción con pasos autocatalíticos, de inhibición y flujos de entrada y salida. Desde el punto de vista de las matemáticas, las ecuaciones diferenciales asociadas a tales mecanismos deben exhibir biestabilidad. La búsqueda de tales bifurcaciones se puede hacer usando el análisis de redes estequiométricas. Tal algoritmo facilita el trabajo matemático y se puede implementar en un programa de computadora, con lo que se simplifica el análisis y ayuda a entender y mejorar los mecanismos de reacción. No obstante, y a pesar de la reducción en la complejidad que es alcanzada usando el análisis de redes estequiométricas, la dificultad y la longitud de los polinomios involucrados hacen que, en los casos más difíciles y de mayor envergadura, la solución de estos no sea posible. En este trabajo se ha superado parcialmente el problema, adicionando a la matriz estequiométrica un conjunto de filas que codifican la relación de dualidad entre las diferentes reacciones presentes en la red química dada como entrada al programa. Así, hemos logrado analizar 28 modelos diferentes de homoquiralidad biológica, extrayendo de ellos el conjunto de requisitos necesarios para tener un modelo cinética y termodinámicamente consistente.
Resumo A origem da homoquiralidade biológica foi modelada usando mecanismos de reação com etapas autocatalíticas, de inibição e fluxos de entrada e saída. Do ponto de vista da matemática, as equações diferenciais associadas a tais mecanismos devem ser instáveis. A instabilidade pode ser estudada usando o algoritmo de análise de redes estequiométricas. Tal algoritmo facilita o trabalho matemático e pode ser implementado num programa de computador, o que simplifica a análise e ajuda a entender e melhorar os mecanismos de reação. No entanto, e apesar da redução na complexidade que é alcançada usando a análise de redes estequiométricas, a complexidade e comprimento dos polinômios envolvidos fazem que, nos casos mais complexos e de maior envergadura, a solução dos mesmos não seja possível. Neste trabalho, o problema foi superado, parcialmente, adicionando à matriz estequiométrica um conjunto de linhas que codificam a relação de dualidade entre as diferentes reações presentes na rede química dada como entrada ao programa. Desta forma foi possível analisar 28 modelos diferentes de homoquiralidade biológica, extraindo deles o conjunto de requisitos necessários para ter um modelo cinético e termodinamicamente consistente.
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Abstract CHEMicalKINetics SimuLATOR (Chemkinlator) is a Graphical User Interface for the simulation of reaction mechanisms. The interface allows the user to see and change the parameters of a reaction network within a single window. Chemkinlator comes with built-in support for three types of kinetic simulations: Time Series, which computes the concentration of all species in an interval of time for the defined model; Bifurcation diagrams, which are the result of running several Time Series simulations over gradually different kinetic rate constants; and Flow/Temperature time series, which takes into account the effect of flow in the Continuous-flow well-Stirred Tank Reactor, and the effect of temperature on the rates constants according to the Arrhenius equation. In our research group, Chemkinlator has been the primary tool used to test the predictions made by algorithms that analyze homochirality phenomena. Chemkinlator is written in C++14 and Qt, and it uses the Fortran subroutine DLSODE to solve the differential equations associated with the reaction networks. Chemkinlator is open source software under the Apache 2.0 license and can be downloaded freely from https://gitlab.com/homochirality/chemkinlator.
Resumen CHEMical KINetics SimuLATOR (Chemkinlator) es una interfaz gráfica para realizar simulaciones de mecanismos de reacción. La interfaz le permite al usuario ver y cambiar los parámetros de una red de reacciones en una única ventana. Chemkinlator puede realizar tres tipos de simulaciones cinéticas: Time Series, calcula la concentración de cada especie en un intervalo de tiempo del modelo estudiado; Bifurcation, es el resultado de ejecutar varias veces las simulaciones del modo Time Series, cambiando gradualmente diferentes constantes de velocidad; y Flow/ Temperature es una serie de tiempo en la que se tiene en cuenta el efecto del flujo considerando un Reactor de Flujo Continuo bien Agitado y el efecto de la temperatura sobre las constantes de velocidad según la ecuación de Arrhenius. En nuestro grupo de investigación, Chemkinlator ha sido la herramienta principal para verificar las predicciones hechas por los algoritmos que analizan el fenómeno de homochiralidad. Chemkinlator está escrito en C++14 y Qt, y usa la subrutina de Fortran DLSODE para resolver las ecuaciones diferenciales relacionadas con los mecanismos de reacción. Chemkinlator es software de código abierto bajo la licencia Apache 2.0 y se puede descargar libremente de https://gitlab.com/homochirality/chemkinlator.
Resumo O CHEMical KINetics SimuLATOR (Chemkinlator) é uma interface gráfica para realizar simulações de mecanismos de reação. A interface permite ao usuário visualizar e alterar os parâmetros de uma rede de reação em uma única janela. O Chemkinlator pode realizar três tipos de simulações cinéticas: Time Series, calcula a concentração de cada espécie em um intervalo de tempo do modelo estudado; Bifurcation, é o resultado de executar várias vezes as simulações do modo Time Series, modificando gradualmente diferentes constantes de velocidade; e Flow/Temperature é uma serie de tempo que se considera o efeito do fluxo considerando um Reator de Fluxo Continuo bem Agitado e o efeito da temperatura sobre as constantes de velocidade pela equação de Arrhenius. No nosso grupo de investigação, o Chemkinlator tem sido a principal ferramenta para verificar as predições realizadas pelos algoritmos que analisam o fenómeno de homoquiralidade. O Chemkinlator está escrito em C++14 e Qt, e usa a sub-rotina de Fortran DLSODE para resolver as equações diferenciais relacionadas com os mecanismos de reação. O Chemkinlator é um software de código aberto baixo a licença Apache 2.0 e pode ser descarregado livremente em https://gitlab.com/homochirality/chemkinlator.
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American visceral leishmaniasis (VL) is a vector-borne disease caused by Leishmania infantum (syn. chagasi) and transmitted by Lutzomyia longipalpis and Lutzomyia evansi phlebotomine sand flies. Dogs not only are the main host reservoirs of the parasite but also suffer the disease; therefore, canine VL (CVL) has assumed an important role in public health. In Colombia, human and CVL are restricted to two transmission foci: one in the north region (Caribbean coast) and other in the central south region (middle Magdalena River Valley). We present a CVL case involving a 2-year-old male dog with a history of lack of appetite, general weakness, and progressive loss of weight. A diagnosis of CVL was obtained using the direct parasitological examination in spleen and bone marrow samples stained with Giemsa and RT-qPCR. The infecting Leishmania species was identified as L. infantum by PCR-restriction fragment length polymorphism amplifying the Hsp70 gene from bone marrow and spleen samples and confirming by sequencing. The patient responded favorably to treatment with intramuscular meglumine antimoniate at a dose of 100 mg/kg daily for 8 weeks and oral allopurinol at a dose of 10 mg/kg every 12 hours until new indication. This is the first report of urban CVL in the city of Cali, Colombia, highlighting the need for surveillance and control programs in the municipalities of the department of Valle del Cauca, a region where VL has not been informed before. The findings also indicate the need to reinforce the surveillance programs in other rural and urban regions of the country where favorable eco-epidemiological conditions exist.
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Enfermedades de los Perros/parasitología , Leishmania infantum/aislamiento & purificación , Leishmaniasis Visceral/veterinaria , Alopurinol/uso terapéutico , Animales , Antimetabolitos/uso terapéutico , Antiprotozoarios/uso terapéutico , Secuencia de Bases , Ciudades/epidemiología , Colombia/epidemiología , ADN Protozoario/genética , ADN Protozoario/aislamiento & purificación , Enfermedades de los Perros/epidemiología , Perros , Leishmania infantum/genética , Leishmaniasis Visceral/tratamiento farmacológico , Leishmaniasis Visceral/epidemiología , Masculino , Antimoniato de Meglumina/uso terapéuticoRESUMEN
La ingestión de nitrógeno líquido es una causa infrecuente de perforación gástrica, se conoce poco sobre como este compuesto afecta el tejido gastrointestinal, sus mecanismos de lesión y sus consecuencias clínicas. Cada vez es más frecuente el uso del nitrógeno líquido de forma comercial en productos de repostería y gastronomía, por lo que es importante reconocer sus potenciales efectos cuando la manipulación no es la adecuada. En este caso clínico describimos una perforación gástrica secundaria al consumo de helado preparado con nitrógeno líquido.
Liquid nitrogene ingestion is a frecuent cause of gastric perforation. It is unknown how this compound afects the gatrointestinal tissue, it mechanisisms of injury and the clinical consecuences. Nowadays, the use of liquid nitrogene in gastronomy is becoming a tendency, for this reason it is important to identify the potencial healt effects of this compound when is not correctly manipulated. The following article describes a secondary gastric perforation, as a consecuence of the consumption of ice cream prepared with liquid nitrogene.
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Humanos , Masculino , Persona de Mediana Edad , Estómago/lesiones , Helados/efectos adversos , Nitrógeno/efectos adversos , Neumoperitoneo/diagnóstico por imagen , Estómago/diagnóstico por imagen , Dolor Abdominal/etiología , Enfisema Mediastínico/diagnóstico por imagenRESUMEN
The goal of our research is the development of algorithmic tools for the analysis of chemical reaction networks proposed as models of biological homochirality. We focus on two algorithmic problems: detecting whether or not a chemical mechanism admits mirror symmetry-breaking; and, given one of those networks as input, sampling the set of racemic steady states that can produce mirror symmetry-breaking. Algorithmic solutions to those two problems will allow us to compute the parameter values for the emergence of homochirality. We found a mathematical criterion for the occurrence of mirror symmetry-breaking. This criterion allows us to compute semialgebraic definitions of the sets of racemic steady states that produce homochirality. Although those semialgebraic definitions can be processed algorithmically, the algorithmic analysis of them becomes unfeasible in most cases, given the nonlinear character of those definitions. We use Clarke's system of convex coordinates to linearize, as much as possible, those semialgebraic definitions. As a result of this work, we get an efficient algorithm that solves both algorithmic problems for networks containing only one enantiomeric pair and a heuristic algorithm that can be used in the general case, with two or more enantiomeric pairs.
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Hamsters are a suitable experimental model for visceral leishmaniasis (VL) because they mimic the features of the human disease. However, the infection after inoculation can only be verified after sacrifice of the animal or several months following infection, when obvious signs of the disease appear, compromising animal welfare in both cases. Unlike other studies, the present work used an inoculum of 5â¯×â¯108 promastigotes to induce Leishmania infantum infection, which are easier to produce than amastigotes, in in vitro culture. The infection in hamsters was detected using non-invasive methods such as ultrasound imaging (USG) and blood gases, in addition to alterations in hematological parameters and weight loss. USG imaging identified changes in the size and echogenicity of the spleen, liver, and kidney as early as week 9 (W9) after experimental inoculation. However, blood gases, specially lactate, was increased in response to the infection, with statistically significant differences between W9 and W0 (before infection) (pâ¯<â¯0.0001). The conventional hematological parameters showed progressive pancytopenia and weight loss of 15% and 10% in infected males and females respectively, at W9 versus W0 (pâ¯<â¯0.0001). Histological changes in the liver, kidney, and spleen correlated with changes detected by USG imaging and the number of parasites increased proportionately to the progression of infection, being higher at W24. In conclusion, USG imaging, lactate levels, hematocrit and hemoglobin parameters, along with weight loss allowed early detection of infection, which was then confirmed by the identification and quantification of parasites in the blood, liver, and spleen by qRT-PCR. In contrast, blood chemistry was not a useful tool in the early detection of VL infection because it did not correlate with alterations evident in other techniques. The use of non-invasive tools eliminates the need for animal sacrifice to confirm infection, thus reducing the number of animals required for a given study and eliminating the need to wait until the appearance of severe signs of infection, which affect animal welfare. These tools are therefore advantageous for use in preclinical studies, for studying pathogenesis as also for vaccine and drug development.
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Leishmania infantum/aislamiento & purificación , Leishmaniasis Visceral/diagnóstico , Animales , Análisis Químico de la Sangre , Análisis de los Gases de la Sangre , Cricetinae , Modelos Animales de Enfermedad , Femenino , Pruebas Hematológicas , Riñón/diagnóstico por imagen , Riñón/patología , Leishmania infantum/clasificación , Leishmaniasis Visceral/sangre , Leishmaniasis Visceral/diagnóstico por imagen , Hígado/diagnóstico por imagen , Hígado/parasitología , Hígado/patología , Masculino , Mesocricetus , Reacción en Cadena en Tiempo Real de la Polimerasa , Factores Sexuales , Bazo/diagnóstico por imagen , Bazo/parasitología , Bazo/patología , Ultrasonografía , Aumento de PesoRESUMEN
BACKGROUND: Leishmaniasis is a parasitic disease caused by more than 20 species of the Leishmania genus. The disease is globally distributed and is endemic in 97 countries and three territories in the tropical and subtropical regions. The efficacy of the current treatments is becoming increasingly low either due to incomplete treatment or resistant parasites. Failure of treatment is frequent, and therefore, the search for early biomarkers of therapeutic response in cutaneous leishmaniasis (CL) is urgently needed. OBJECTIVE: The aim of this study was to compare the proteomic profiles in patients with CL before and after 7 days of treatment and identify early biomarkers of curative response. METHODS: Four patients with a parasitological diagnosis of leishmaniasis with confirmation of species by PCR-RFLP were recruited. All patients had a single lesion, and a protein from the middle of the ulcer was quantified by liquid chromatography and mass spectrometry. RESULTS: A total of 12 proteins showed differential expression in the comparative LC-electrospray ionization MS/MS (LC-ESI-MS/MS) triplicate analysis. Seven of them were up-regulated and five of them were down-regulated. Calcium binding proteins A2, A8, and A9 and hemoglobin subunits alpha-2 and delta showed high correlation with epidermis development and immune response. CONCLUSION: We identified changes in the profiles of proteins that had a positive therapeutic response to the treatment. The proteins identified with differential expression are related to the reduction of inflammation and increased tissue repair. These proteins can be useful as biomarkers for early monitoring of therapeutic response in CL.
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Liquid nitrogene ingestion is a frecuent cause of gastric perforation. It is unknown how this compound afects the gatrointestinal tissue, it mechanisisms of injury and the clinical consecuences. Nowadays, the use of liquid nitrogene in gastronomy is becoming a tendency, for this reason it is important to identify the potencial healt effects of this compound when is not correctly manipulated. The following article describes a secondary gastric perforation, as a consecuence of the consumption of ice cream prepared with liquid nitrogene.
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Helados/efectos adversos , Nitrógeno/efectos adversos , Estómago/lesiones , Dolor Abdominal/etiología , Humanos , Masculino , Enfisema Mediastínico/diagnóstico por imagen , Persona de Mediana Edad , Neumoperitoneo/diagnóstico por imagen , Estómago/diagnóstico por imagenRESUMEN
Gaseous elemental Hg is stable enough to be transported over long distances. Some of the most important sources of Hg in the atmosphere are artisanal gold mining activities and forest fires. Both of these sources are particularly prevalent in the Amazonia region. Information regarding the capacity of soils for retaining Hg transported by the atmosphere is very important for understanding the metal cycle in the environment. The aim of this work was to study gaseous elemental Hg adsorption in soils with different physical and chemical characteristics. For this purpose, soils from different regions in Brazil and Colombia influenced or possibly influenced by gold mining activities and forest fires were studied. Hg adsorption tests were conducted by exposing soil samples to a gaseous elemental Hg atmosphere for 144â¯h. The total Hg concentration (THg) and Hg oxidation states were monitored using a direct Hg analyzer. Sample characterization analyses were performed. THg values obtained before the adsorption tests were 43-413 and 144-590⯵gâ¯kg-1 for grain size fractions below 2 and 0.063â¯mm, respectively. The predominant species found was Hg2+, with abundance levels from 68% to 99%. The results show a wide range of enhanced Hg retention capacities among the samples, ranging from 13 to 2236 times the initial concentration, and the speciation results demonstrate a decrease in the oxidized species range, from 21% to 78%. The statistical analysis indicated the importance of Mn-bearing minerals for the processes of adsorption/oxidation of gaseous elemental Hg in soils. These results contribute to the elucidation of the processes that occur with Hg at the soil/atmosphere interface and may help to explain the high concentrations of Hg found in Amazonian soils where no gold mining activities are practiced.
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Gases/química , Mercurio/química , Contaminantes del Suelo/química , Suelo/química , Adsorción , Brasil , Colombia , Monitoreo del Ambiente , Oro , Hierro/química , Manganeso/química , MineríaRESUMEN
La estrechez de uretra es definida como la disminución anormal en el calibre de la luz de la uretra que puede estar o no asociado a la fibrosis de los tejidos circundantes (uretra posterior), o del cuerpo esponjoso (uretra anterior). Esa patología es causada por diferentes condiciones como la inflamación, la infección, trauma o secundario a iatrogenia por diferentes mecanismos y en algunos casos en los cuales no se determina la etiología, se define como idiopática. La sintomatología no es específica y se puede sobreponer con otras condiciones que incluyen síntomas del tractor urinario inferior (LUTS) e infecciones del tracto urinario (ITU) que pueden confundir el diagnóstico.
Urethral stricture is defined as an abnormal decrease in the caliber of the urethral lumen that may or may not be associated with fibrosis of the surrounding tissues (posterior urethra), or of the corpus spongiosum (anterior urethra). This pathology is caused by different conditions such as inflammation, infection, trauma or secondary to iatrogenic by different mechanisms and in some cases in which the etiology is not determined, it is defined as idiopathic. The symptomatology is not specific and can be superimposed with other conditions including lower urinary tract symptoms (LUTS) and urinary tract infections (UTI) that can confuse the diagnosis.
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Humanos , Estrechez Uretral , Enfermedad Iatrogénica , Uretra , Infecciones Urinarias , Fibrosis , Colombia , Síntomas del Sistema Urinario InferiorRESUMEN
Introduction: In cutaneous leishmaniasis, the host immune response is responsible for the development of skin injuries but also for resolution of the disease especially after antileishmanial therapy. The immune factors that participate in the regulation of inflammation, remodeling of the extracellular matrix, cell proliferation and differentiation may constitute biomarkers of diseases or response to treatment. In this work, we analyzed the production of the growth factors EGF, TGFß1, PDGF, and FGF during the infection by Leishmania parasites, the development of the injuries and the early response to treatment. Methodology: Golden hamsters were infected with L. (V) braziliensis. The growth factors were detected in skin scrapings and biopsies every 2 weeks after infected and then at day 7 of treatment with different drug candidates by RT-qPCR. The parasitic load was also quantified by RT-qPCR in skin biopsies sampled at the end of the study. Results: The infection by L. (V) braziliensis induced the expression of all the growth factors at day 15 of infection. One month after infection, EGF and TGFß1 were expressed in all hamsters with inverse ratio. While the EGF and FGF levels decreased between day 15 and 30 of infection, the TGFß1 increased and the PGDF levels did not change. The relative expression of EGF and TGFß1 increased notably after treatment. However, the increase of EGF was associated with clinical cure while the increase of TGFß1 was associated with failure to treatment. The amount of parasites in the cutaneous lesion at the end of the study decreased according to the clinical outcome, being lower in the group of cured hamsters and higher in the group of hamsters that had a failure to the treatment. Conclusions: A differential profile of growth factor expression occurred during the infection and response to treatment. Higher induction of TGFß1 was associated with active disease while the higher levels of EGF are associated with adequate response to treatment. The inversely EGF/TGFß1 ratio may be an effective biomarker to identify establishment of Leishmania infection and early therapeutic response, respectively. However, further studies are needed to validate the utility of the proposed biomarkers in field conditions.
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Antiprotozoarios/uso terapéutico , Biomarcadores/análisis , Monitoreo de Drogas/métodos , Factor de Crecimiento Epidérmico/análisis , Leishmaniasis Cutánea/tratamiento farmacológico , Leishmaniasis Cutánea/patología , Factor de Crecimiento Transformador beta1/análisis , Animales , Biopsia , Modelos Animales de Enfermedad , Factores de Crecimiento de Fibroblastos/análisis , Perfilación de la Expresión Génica , Leishmania braziliensis/aislamiento & purificación , Mesocricetus , Carga de Parásitos , Factor de Crecimiento Derivado de Plaquetas/análisis , Reacción en Cadena en Tiempo Real de la Polimerasa , Piel/patologíaRESUMEN
Introducción Las roturas masivas del manguito de los rotadores representan una de las lesiones más complejas a las cuales se puede enfrentar el ortopedista especialista en hombro y son un gran reto cuando se desean lograr resultados clínicos satisfactorios. El objetivo del trabajo es describir los resultados clínicos de una nueva técnica quirúrgica para la reparación artroscópica de lesiones grandes y masivas del manguito de los rotadores (MR) utilizada en una clínica ortopédica especializada durante un período de 3 años. Materiales y métodos Se realizó un estudio descriptivo de una cohorte de pacientes con lesiones grandes y masivas del MR, diagnosticados mediante artrorresonancia directa y que cumplían criterios para reparación artroscópica, a los cuales se les realizó la reparación mediante una nueva técnica denominada doble MAC. Se analizaron como desenlaces la escala de Constant postoperatoria, la existencia de complicaciones y el grado de satisfacción de los pacientes con el procedimiento. Resultados Se evaluó a 21 pacientes (10 hombres y 11 mujeres) con una media de edad de 59,4 años (DE: 8,2) en el momento de la cirugía. Las roturas comprometieron el músculo supraespinoso en todos los casos y en el 42,8% el infraespinoso con un tamaño medio de rotura de 34,5 mm (DE: 11,2). El tiempo entre la cirugía y la evaluación fue, por término medio, de 9 meses. La escala de Constant postoperatoria fue, por término medio, de 77,4 (DE: 9,0). No se presentaron complicaciones en la cirugía o falla de los anclajes. Solo un paciente presentó capsulitis adhesiva temprana, que se trató con movilización articular, con la cual se logró normalizar todos los arcos de movilidad. Discusión La técnica doble MAC para la reparación artroscópica de las lesiones grandes y masivas del manguito de los rotadores es una técnica segura y efectiva, con buenos resultados funcionales evaluados a medio plazo y un porcentaje de satisfacción superior al 90%. Nivel de evidencia clínica Nivel IV.
Background Massive ruptures of the rotator cuff represent one of the most complex lesions that can be faced by the orthopaedic shoulder surgeon, and pose a great challenge to achieve satisfactory clinical results. The aim of this study is to describe the clinical outcomes of a new surgical technique for the repair of large and massive rotator cuff injuries used in a specialised orthopaedic clinic during a period of 3 years. Materials and methods A descriptive study was carried out on a cohort of patients with large and massive lesions of the rotator cuff, diagnosed by direct arthro-resonance, and who met criteria for arthroscopic repair. They underwent repair using a new technique called double MAC (Mason-Allen configuration). The post-surgical outcomes were measured using the Constant scale, and the presence of complications and the level of patient satisfaction with the procedure were analysed as outcomes. Results There were 21 patients (10 men and 11 women) with mean age of 59.4 (SD: 8.2) years at the time of surgery. A supraspinatus rupture was present in all (100%) of patients, and an infraspinatus rupture was present in 42.8%.. The mean size of the tear was 34.5 mm (SD: 11.2). Mean time between surgery and assessment was 9 months. Mean post-operative Constant score was 77.4 (SD: 9.0). There were no surgical complications or anchor failure. An early adhesive capsulitis was diagnosed and managed with articular mobilisation, with subsequent improvement in range of motion. Discussion Double MAC technique for arthroscopic repair of large and massive RCT is a safe and effective technique, with good clinical outcomes in the medium term and a patient satisfaction of over 90%. Evidence Level IV.
Asunto(s)
Humanos , Lesiones del Manguito de los Rotadores , Artroscopía , Hombro , Manguito de los RotadoresRESUMEN
Current chemotherapeutic agents for leishmaniasis have several disadvantages interfering with the effective treatment and therefore more and better antileishmanial drugs are needed. Discovery of candidates for leishmaniasis treatment requires not only accurate and precise methodologies but also well-known biological system to measure infectivity of parasites and antileishmanial activity of the new compounds. Significant variation in the in vitro and in vivo infectivity and sensitivity to established and experimental drugs in Leishmania strains are reported. This work reports the in vitro biological behavior and antileishmanial drugs sensitivity of different green fluorescent protein transfectant Leishmanias strains. The in vitro growth kinetic and infectivity to U937 cells vary slightly in the Leishmania transfectant strains in comparison with their correspondant wild-type. However, the insertion of the pIR3(-)-eGFP may affect the sensitivity of the parasites to meglumine antimoniate (MA) and miltefosine but not to amphotericin B (AMB) and pentamidine isethionate. In consequence, AMB or pentamidine isethionate but not MA or miltefosine should be used as antileishmanial control drugs during in vitro assays of antileishmanial activity. Furthermore, is recommended to test compounds against more than one Leishmania strain in order to verify that the antileihmanial activity of these compound is similar among species.
Asunto(s)
Antiprotozoarios/farmacología , Proteínas Fluorescentes Verdes/genética , Leishmania/efectos de los fármacos , Leishmaniasis/tratamiento farmacológico , Pruebas de Sensibilidad Parasitaria , Especificidad de la Especie , TransfecciónRESUMEN
Resumen: Introducción: La medición del engrosamiento diafragmático y el cambio de grosor en espiración e inspiración del mismo pueden utilizarse para predecir el éxito o fracaso en la extubación. Se evaluó la fracción de grosor diafragmático (FGD) por ultrasonido en pacientes de terapia intensiva y se comparó con índice de ventilación rápida superficial (VRS). Métodos: Los 65 pacientes con ventilación mecánica invasiva fueron reclutados prospectivamente en el Departamento de Medicina Crítica del Centro Médico ABC en un periodo de nueve meses, de agosto de 2015 a abril de 2016. La FGD se midió en la zona de aposición del diafragma al tórax en ambos hemitórax, utilizando un transductor de ultrasonido 4 MHz y el médico radiólogo realizó el procedimiento en todos los pacientes sin conocimiento de patologías. Los pacientes reclutados fueron sometidos a una prueba de respiración espontánea (PRE) cuando se reunieron los siguientes criterios: FiO2 <50%, la PEEP ≤ 5 cm de H2O, PaO2/FiO2 > 200, frecuencia respiratoria < 30 por minuto, ausencia de fiebre, neurológicamente alerta y sin el apoyo hemodinámico de vasopresores. Se calculó el porcentaje de cambio en FGD, siendo el final de la inspiración y el final de la espiración entre el final de la espiración en pacientes con ventilación mecánica invasiva en modalidad de ventilación presión soporte con progresión ventilatoria con fines de extubación. El éxito en la extubación se definió como respiración espontánea > 48 horas sin soporte ventilatorio después del retiro de tubo endotraqueal. Resultados: De los 65 pacientes reclutados, 23 (35.4%) fueron mujeres y 42 (64.6%) hombres, índice de masa corporal (IMC), de 25.83 (DE ± 4.19) todos fueron extubados en modalidad de ventilación presión soporte. La frecuencia de falla en la extubación fue de 21.5% y la mortalidad de 24.6%. Las variables asociadas a fracaso fueron valores de corte de FGD derecho 25.9%, FGD 23.1% izquierdo. Tiempo de ventilación mecánica en días con mediana de 4 (RIQ 3-6) versus 8.5 (RIQ 7-11), p < 0.001 y VRS con 68.2 ± 9.6 versus 53.9 ± 11.1, p < 0.001. Las variables obtenidas a partir de las mediciones USG fueron las siguientes: grosor diafragmático derecho al final de la espiración (RTEEx) 0.28 ± 0.05 cm, grosor diafragmático derecho al final de la inspiración (RTEI) 0.21 ± 0.05 cm, índice de grosor diafragmático derecho (RDTi) 0.76 ± 0.11 cm, índice de fracción diafragmática derecha (RDFi) 23.1 ± 10.7%. El valor predictivo positivo y el valor predictivo negativo fueron de 92 y 64%, respectivamente. El área bajo la curva ROC fue de 0.79 para FGD. Conclusiones: Las mediciones de grosor diafragmático por ultrasonido tanto VRS como de tiempo de ventilación mecánica son un parámetro útil para predecir el éxito o el fracaso de la extubación. Índice de ventilación rápida superficial (VRS) con una media de 57.0 ± 12.3 puntos. Este estudio demuestra que no hay relación entre falla a la extubación con EPOC, IMC y edad. La extubación es un procedimiento conjunto y entre más parámetros para extubación menor riesgo de presentar falla.
bstract: Introduction: By measuring diaphragmatic thickening and thickness change in expiration and inspiration, it can be used as a measure to predict the success or failure of extubation. The fraction of diaphragmatic thickness (FDT) was assessed by ultrasound in intensive care patients. Methods: 65 patients with invasive mechanical ventilation were recruited prospectively at the Department of Critical Care Medicine ABC Medical Center. The FDT was measured in the area of apposition of the diaphragm to the chest in both hemithorax, using an ultrasound transducer of 4 MHz. Patients underwent a spontaneous breathing trial (SBT) when they met all the following criteria are: FiO2 < 50%, PEEP ≤ 5 cmH2O, PaO2/FiO2 > 200, respiratory rate < 30 per minute, absence of fever, neurologically alert and without hemodynamic vasopressor support. The percentage change in FDT was calculated between the end of expiration and end of inspiration in patients with invasive mechanical ventilation with pressure support ventilation mode, all patients with ventilatory progression purposes extubation. A successful extubation was defined as spontaneous breathing > 48 hours without ventilatory support after removal of the endotracheal tube. Results: We included data obtained from 65 patients, 23 (35.4%) women and 42 (64.6%) men, mean Body Mass Index (BMI) of 25.83 (SD ± 4.19). The frequency of extubation failure was 21.5%, and mortality 24.6%. The variables associated with failure were cut-off values of DTF right 25.9%, DTF 23.1% left. Time of mechanical ventilation in days with a median of 4 (RIQ 3-6) versus 8.5 (RIQ 7-11), p <0.001 and RSBI with 68.2 ± 9.6 versus 53.9 ± 11.1, p < 0.001. The variables obtained from USG measurements were as follows: right thickness at end expiration (RTEEx) 0.28 ± .05 cm, right thickness at end inspiration (RTEIs) 0.21 ± .05 cm, right diaphragmal thickness (RDTi) 0.76 ± 0.11 cm, right diaphragmatic fraction index (RDFi) 23.1 ± 10.7%. The positive predictive value and negative predictive value were 92 and 64%, respectively. The area under the ROC curve was 0.79 for DTF. Conclusions: Diaphragmatic thickness measurements by ultrasound can be a useful parameter to predict the success or failure of extubation during ventilatory progression in patients with invasive mechanical ventilation. Rapid shallow breathing index (RSBI) with a mean of 57.0 ± 12.3 points. This study demonstrates that there is no relation between failure to extubation with COPD, BMI and age. Extubation is a joint procedure and the more parameters for extubation, the lower the risk of failure.
Resumo: Introdução: Ao medir o espessamento do diafragma e a mudança da espessura na exalação e inalação da mesma, pode ser usado como uma medida para prever o sucesso ou a falha da extubação. Avaliou-se a fração de espessamento do diafragma (FED) por meio de ultra-som em doentes na terapia intensiva e se comparou com o índice de respiração superficial e rápida (IRRS). Métodos: Os 65 pacientes com ventilação mecânica invasiva foram recrutados no departamento de medicina crítica do Centro Médico ABC em um período de 9 meses, agosto de 2015 abril de 2016. A FED foi medida na zona de aposição do diafragma ao tórax, em ambos hemitórax, usando um transdutor de ultra-som de 4 MHz e realizou-se por um radiologista em todos os doentes, sem saber as patologias do paciente. Os pacientes recrutados foram submetidos a teste de respiração espontânea (TRE) quando os seguintes critérios foram reunidos: FiO2 < 50%, PEEP ≤ 5 cmH2O, PaO2/FiO2 > 200, frequência respiratória < 30 por minuto, afebril, neurologicamente alerta e sem suporte hemodinâmico de vasopressores. Calculou-se a percentagem de alteração na FED, sendo o final da inspiração e o final da expiração entre o final da expiração, em pacientes com ventilação mecânica invasiva em modo ventilação de pressão suporte com progressão ventilatória com fins de extubação. A extubação bem sucedida foi definida como espontâneos de respiração > 48 horas sem suporte ventilatório após a remoção do tubo endotraqueal. Resultados: Dos 65 pacientes recrutados, 23 (35.4%) mulheres e 42 (64.6%) homens, índice de massa corporal (IMC) de 25.83 (± SD 4.19) todos foram extubados no modo ventilação de pressão suporte. A frequência de falha na extubação foi de 21.5% e mortalidade de 24.6%. As variáveis associadas ao fracasso foram valores de corte da FED direito 25.9%, FED 23.1% esquerdo. Tempo de ventilação mecânica em dias com uma mediana de 4 (IQR 3-6) vs. 8.5 (IQR 7-11), p < 0.001 e VRS com 68.2 ± 9.6 vs 53.9 ± vs 11.1, p < 0.001. Conclusões: As medições da espessura diafragmática por ultra-som tanto de RSV como o tempo de ventilação mecânica é um parâmetro útil para prever o sucesso ou a falha da extubação. Este estudo demonstra que não há relação entre pacientes com EPOC, IMC, idade e falha na extubação. A extubação é um procedimento conjunto e entre mais parâmetros para extubação menor o risco de apresentar falha.
RESUMEN
El Xantoastrocitoma Pleomórfico Espinal (XAPE) es una neoplasia primaria infrecuente del sistema nervioso central, descrita por primer vez en 1979. De estirpe astrocítica y aunque clasificada como grado II por la OMS, pueden existir variantes anaplásicas o malignas. Con localización usualmente temporal, pocos casos espinales se han descrito a la fecha, debido probablemente a un subdiagnóstico o un subregistro. El pronóstico es generalmente bueno y depende en gran medida del tipo histológico y extensión de la resección quirurgica. Describimos el caso de un hombre de 30 años de edad con dorsalgiay paresia del miembro inferior izquierdo. Se encontró en imágenes de resonancia magnética una lesión aparentemente intradural, extraaxial en los segmentos T8-T9 que se llevó a resección. Se confirmó por histopatología la presencia de un XAPE primario. En la presente publicación realizamos una revisión de la literatura disponible.
Spinal Pleomorphic Xanthoastrocytoma (SPXA) is a rare CNS primary neoplasm, first described in 1979. Although of astrocytic lineage and classified as a grade II neoplasm by the WHO, it may be have anaplastic or malignant variants. Usually located in the temporal lobe, few spinal cases have been described to date, probably due to underdiagnosis and underreporting. It usually has a good prognosis, but it depends on its histological type and extent of surgical resection. In this article, we describe the case of a 30-year old male who complained of low back pain and left lower limb paresis. The MRI showed an apparently intradural, extraaxial lesion at T8-T9 segments. The diagnosis of a primary SPXA was confirmed by histopathological studies. In this article, a review of the available literature is presented.