Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 18 de 18
Filtrar
1.
MethodsX ; 12: 102519, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38226357

RESUMEN

Fabric analysis is essential for understanding the evolution of volcaniclastic deposits. Here we present a comprehensive and efficient methodology, called "Clast shape-fabric analysis," which is part of the Quantitative Textural Analysis (QTA). This methodology combines high-resolution image analysis techniques with geospatial data processing tools. The fabric of a deposit refers to the three-dimensional orientation of the particles with respect to space, where the degree of iso-orientation of the major axes of the particles is taken into account. The process begins with the collection of oriented samples in the field. Then, in the laboratory, the samples are processed to obtain high-resolution images. The final stage involves the analysis of these images using the FabricS program, which combines image processing techniques and circular statistics. An application of the method was made at the Joya Honda Maar in Mexico, where shape-fabric analysis was used to identify the emission centers of pyroclastic materials. In summary, the "Clast shape-fabric analysis" is a reliable, low-cost and high-potential methodology that can be applied in several geoscientific disciplines and other areas of scientific research.•New Methodology for shape-fabric analysis is presented.•The methodology involves field work, laboratory work and image analysis.•Identification of particle orientations in volcaniclastic deposits.

2.
Gut Pathog ; 15(1): 65, 2023 Dec 14.
Artículo en Inglés | MEDLINE | ID: mdl-38098020

RESUMEN

BACKGROUND: Eimeria genus belongs to the apicomplexan parasite phylum and is responsible for coccidiosis, an intestinal disease with a major economic impact on poultry production. Eimeria tenella is one of the most virulent species in chickens. In a previous study, we showed a negative impact of caecal microbiota on the physiopathology of this infection. However, the mechanism by which microbiota leads to the physiopathology remained undetermined. Macrophages play a key role in inflammatory processes and their interaction with the microbiota during E. tenella infection have never been investigated. We therefore examined the impact of microbiota on macrophages during E. tenella infection. Macrophages were monitored in caecal tissues by immunofluorescence staining with KUL01 antibody in non-infected and infected germ-free and conventional chickens. Caecal cells were isolated, stained, analyzed and sorted to examine their gene expression using high-throughput qPCR. RESULTS: We demonstrated that microbiota was essential for caecal macrophage recruitment in E. tenella infection. Furthermore, microbiota promoted a pro-inflammatory transcriptomic profile of macrophages characterized by increased gene expression of NOS2, ACOD1, PTGS2, TNFα, IL1ß, IL6, IL8L1, IL8L2 and CCL20 in infected chickens. Administration of caecal microbiota from conventional chickens to germ-free infected chickens partially restored macrophage recruitment and response. CONCLUSIONS: Taken together, these results suggest that the microbiota enhances the physiopathology of this infection through macrophage recruitment and activation. Consequently, strategies involving modulation of the gut microbiota may lead to attenuation of the macrophage-mediated inflammatory response, thereby limiting the negative clinical outcome of the disease.

3.
BMC Public Health ; 23(1): 1054, 2023 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-37264338

RESUMEN

BACKGROUND: The COVID-19 pandemic has affected the world in multiple ways and has been a challenge for the health systems of each country. From the beginning, risk factors for the severity and mortality of the disease were considered, as the spread of the virus was related to the living conditions of each population. METHODS: In this ecological study we have evaluated the role of geography, precisely the altitude above sea level in the incidence and mortality of COVID-19 in Peru. Incidence and mortality data were taken from the open-access database of the government of Peru until March 2021. COVID-19 cases and COVID-19 mortality were treated as cases/density population and 1000 x cases/inhabitants while altitude was treated as continuous and as a categorical variable divided in 7 categories. The relationship between COVID-19 cases or deaths for COVID-19 and altitude as continuous variable was determined using Spearman correlation test. Meanwhile when altitude was considered as a categorical variable, Poisson regression or negative binomial analyses were applied. RESULTS: A significant inverse correlation was found between COVID-19 cases by population density and altitude (r=-0.37 p < 0.001). By altitude categories, the lowest risk for infection was observed between 3,000 and 3,500 m (IRR 0.08; 95% CI 0.05,0.12). Moreover, we found an inverse correlation between altitude and COVID-19 mortality (r=-0.39 p < 0.001). Also, the lowest risk for mortality was observed between 3,000 and 3,500 m (IRR 0.12; 95%CI 0.08; 0.18). Similar results were found when analyses were adjusted for inhabitants and stratified by sex. CONCLUSION: This study reports an inverse relationship between COVID-19 incidence and mortality with respect to the altitude of residence, particularly, a u-shaped protection is shown, with a highest benefit between 3000 and 3500 m. The possibility of using hypoxia as an alternative treatment requires more complex studies that should allow knowing the physiological and environmental mechanisms of the protective role.


Asunto(s)
COVID-19 , Humanos , COVID-19/epidemiología , Altitud , Perú/epidemiología , Pandemias/prevención & control , Factores de Riesgo
4.
J Chem Phys ; 156(15): 154502, 2022 Apr 21.
Artículo en Inglés | MEDLINE | ID: mdl-35459318

RESUMEN

In this work, we studied the effect of Li+, Na+, K+, Mg2+, and Ca2+ chlorides and sulfates on the temperature of maximum density (TMD) of aqueous solutions at room pressure. Experiments at 1 molal salt concentration were carried out to determine the TMD of these solutions. We also performed molecular dynamics simulations to estimate the TMD at 1 and 2 m with the Madrid-2019 force field, which uses the TIP4P/2005 water model and scaled charges for the ions, finding an excellent agreement between experiment and simulation. All the salts studied in this work shift the TMD of the solution to lower temperatures and flatten the density vs temperature curves (when compared to pure water) with increasing salt concentration. The shift in the TMD depends strongly on the nature of the electrolyte. In order to explore this dependence, we have evaluated the contribution of each ion to the shift in the TMD concluding that Na+, Ca2+, and SO4 2- seem to induce the largest changes among the studied ions. The volume of the system has been analyzed for salts with the same anion and different cations. These curves provide insight into the effect of different ions upon the structure of water. We claim that the TMD of electrolyte solutions entails interesting physics regarding ion-water and water-water interactions and should, therefore, be considered as a test property when developing force fields for electrolytes. This matter has been rather unnoticed for almost a century now and we believe it is time to revisit it.

5.
J Virol ; 94(4)2020 01 31.
Artículo en Inglés | MEDLINE | ID: mdl-31776281

RESUMEN

A novel genus within the Orthomyxoviridae family was identified in the United States and named influenza D virus (IDV). Bovines have been proposed to be the primary host, and three main viral lineages (D/OK-like, D/660-like, and D/Japan-like) have been described. Experimental infections had previously been performed in swine, ferrets, calves, and guinea pigs in order to study IDV pathogenesis. We developed a murine experimental model to facilitate the study of IDV pathogenesis and the immune response. DBA/2 mice were inoculated with 105 50% tissue culture infective dose (TCID50) of D/bovine/France/5920/2014 (D/OK-like). No clinical signs or weight loss were observed. Viral replication was observed mainly in the upper respiratory tract (nasal turbinates) but also in the lower respiratory tract of infected mice, with a peak at 4 days postinfection. Moreover, the virus was also detected in the intestines. All infected mice seroconverted by 14 days postinfection. Transcriptomic analyses demonstrated that IDV induced the activation of proinflammatory genes, such as gamma interferon (IFN-γ) and CCL2. Inoculation of NF-κB-luciferase and Ifnar1-/- mice demonstrated that IDV induced mild inflammation and that a type I interferon response was not necessary in IDV clearance. Adaptation of IDV by serial passages in mice was not sufficient to induce disease or increased pathogenesis. Taken together, present data and comparisons with the calf model show that our mouse model allows for the study of IDV replication and fitness (before selected viruses may be inoculated on calves) and also of the immune response.IMPORTANCE Influenza D virus (IDV), a new genus of Orthomyxoviridae family, presents a large host range and a worldwide circulation. The pathogenicity of this virus has been studied in the calf model. The mouse model is frequently used to enable a first assessment of a pathogen's fitness, replication, and pathogenesis for influenza A and B viruses. We showed that DBA/2 mice are a relevant in vivo model for the study of IDV replication. This model will allow for rapid IDV fitness and replication evaluation and will enable phenotypic comparisons between isolated viruses. It will also allow for a better understanding of the immune response induced after IDV infection.


Asunto(s)
Especificidad del Huésped/inmunología , Infecciones por Orthomyxoviridae/inmunología , Thogotovirus/patogenicidad , Animales , Anticuerpos Antivirales/inmunología , Modelos Animales de Enfermedad , Femenino , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Endogámicos DBA , Orthomyxoviridae/inmunología , Infecciones por Orthomyxoviridae/virología , Infecciones del Sistema Respiratorio/virología , Seroconversión , Replicación Viral/inmunología
6.
Br J Cancer ; 99(7): 1050-5, 2008 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-18797464

RESUMEN

To determine whether molecular parameters could be partly responsible for resistance or sensitivity to oxaliplatin (OX)-based chemotherapy used as first-line treatment in advanced colorectal cancer (CRC). We studied the usefulness of the excision repair cross-complementing 1 (ERCC1), xeroderma pigmentosum group D (XPD), XRCC1 and GSTP1 polymorphisms as predictors of clinical outcome in these patients. We treated 126 CRC patients with a first-line OX/5-fluorouracil chemotherapeutic regimen. Genetic polymorphisms were determined by real-time PCR on an ABI PRISM 7000, using DNA from peripheral blood. Clinical response (CR), progression-free survival (PFS) and overall survival (OS) were evaluated according to each genotype. In the univariate analysis for CR, ERCC1-118 and XPD 751 polymorphisms were significant (P=0.02 and P=0.05, respectively). After adjustment for the most relevant clinical variables, only ERCC1-118 retained significance (P=0.008). In the univariate analysis for PFS, ERCC1-118 and XPD 751 were significant (P=0.003 and P=0.009, respectively). In the multivariant analysis, only the XPD 751 was significant for PFS (P=0.02). Finally, ERCC1-118 and XPD 751 polymorphisms were significant in the univariate analysis for OS (P=0.006 and P=0.015, respectively). Both genetic variables remained significant in the multivariate Cox survival analysis (P=0.022 and P=0.03). Our data support the hypothesis that enhanced DNA repair diminishes the benefit of platinum-based treatments.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Neoplasias Colorrectales/tratamiento farmacológico , Farmacogenética , Adulto , Anciano , Anciano de 80 o más Años , Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/patología , Proteínas de Unión al ADN/genética , Supervivencia sin Enfermedad , Endonucleasas/genética , Femenino , Fluorouracilo/administración & dosificación , Glutatión Transferasa/genética , Humanos , Neoplasias Hepáticas/secundario , Neoplasias Hepáticas/cirugía , Masculino , Persona de Mediana Edad , Compuestos Organoplatinos/administración & dosificación , Oxaliplatino , Reacción en Cadena de la Polimerasa , Resultado del Tratamiento , Proteína 1 de Reparación por Escisión del Grupo de Complementación Cruzada de las Lesiones por Rayos X
7.
Rev Med Chil ; 136(6): 789-92, 2008 Jun.
Artículo en Español | MEDLINE | ID: mdl-18769838

RESUMEN

Pregnancy of an anencephalic fetus generates deep thoughts about its diagnosis, treatment and management of maternal risk, having in mind the irreversibility of the fetal situation. At the present moment, there are no guidelines for labor care in these cases, probably because in most developed countries in which abortion is legal, these pregnancies are interrupted earlier. In Chile, where abortion is illegal we must deal with these situations at the end of the pregnancy period. Of 35,682 labors attended at our hospital, 14 were anencephalic fetuses. In 50% of these a cesarean section was done and in one, a hysterectomy was required due to uterine inertia.


Asunto(s)
Anencefalia/cirugía , Discusiones Bioéticas , Parto Obstétrico , Feto/anomalías , Aborto Inducido/ética , Aborto Inducido/legislación & jurisprudencia , Anencefalia/diagnóstico , Comienzo de la Vida Humana/ética , Ética Médica , Femenino , Humanos , Embarazo , Diagnóstico Prenatal
8.
Rev. méd. Chile ; 136(6): 789-792, jun. 2008.
Artículo en Español | LILACS | ID: lil-490767

RESUMEN

Pregnancy of an anencephalic fetus generates deep thoughts about its diagnosis, treatment and management of maternal risk, having in mind the irreversibility of the fetal situation. At the present moment, there are no guidelines for labor care in these cases, probably because in most developed countries in which abortion is legal, these pregnancies are interrupted earlier. In Chile, where abortion is illegal we must deal with these situations at the end of the pregnancy period. Of 35,682 labors attended at our hospital, 14 were anencephalic fetuses. In 50 percent of these a cesarean section was done and in one, a hysterectomy was required due to uterine inertia.


Asunto(s)
Femenino , Humanos , Embarazo , Anencefalia/cirugía , Discusiones Bioéticas , Parto Obstétrico , Feto/anomalías , Aborto Inducido , Aborto Inducido/legislación & jurisprudencia , Anencefalia/diagnóstico , Comienzo de la Vida Humana , Ética Médica , Diagnóstico Prenatal
9.
Pharmacogenomics J ; 8(5): 315-20, 2008 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-17684476

RESUMEN

The identification of clinical and genetic parameters to predict the outcome in advanced colorectal cancer is a key issue in the management of this disease. We ascertained whether the clinical determinants of survival defined in a large cohort of patients treated with 5-fluorouracil (5-FU) (European Organization for the Research and Treatment of Cancer, EORTC model) also apply to 109 colorectal cancer patients receiving a therapy including oxaliplatin/5-FU as their first-line treatment. Our results confirm the considerable discriminatory power of the clinical model proposed in patients treated with a combined chemotherapy regimen. With the aim of identifying additional genetic prognostic parameters, we determined whether the polymorphisms in the promoter region of the thymidylate synthase (TS) gene that modifies the number of operative binding sites of a transcription factor (USF) could predict the clinical outcome of our patients and complement the EORTC clinical model. Our results indicate that this new genetic parameter (the number of USF-binding sites) could be considered when evaluating the role of TS genotype in the efficacy of the 5-FU-based regimens. Further, confirmatory studies aimed at evaluating the effect of the number of binding sites of transcription factors for selecting 5-FU-treated patients are warranted.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Neoplasias Colorrectales/tratamiento farmacológico , Timidilato Sintasa/genética , Factores de Transcripción/metabolismo , Adulto , Anciano , Anciano de 80 o más Años , Sitios de Unión , Estudios de Cohortes , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/patología , Femenino , Fluorouracilo/administración & dosificación , Humanos , Masculino , Persona de Mediana Edad , Compuestos Organoplatinos/administración & dosificación , Oxaliplatino , Regiones Promotoras Genéticas , Análisis de Regresión , Resultado del Tratamiento
10.
Rev. sanid. mil ; 54(5): 227-34, sept.-oct. 2000. tab, CD-ROM
Artículo en Español | LILACS | ID: lil-292193

RESUMEN

La hiperplasia prostática benigna (HPB) es un problema común en el varón senil. La HPB es el crecimiento prostático estromal-glandular en varones con un efecto testicular hormonal asociado con la edad y que produce obstrución urinaria conocida como prostatismo. 50 por ciento de varones con evidencia histológica de HPB evolucionarán a una obstrucción clínica y 25 por ciento tendrá que recibir algún tipo de tratamiento para sus síntomas. Este estudio valoró hombres con prostatismo asociado a HPB con un bajo volumen de zona transicional (ZT), y la utilidad de la incisión transuretral de próstata (ITUP), al compararse con varones en vigilancia y otros que recibieron tratamiento con bloqueadores alfa. Material y métodos. Doce hombres fueron sometidos a ITUP después de evaluación con la puntuación de la AUA, índice de calidad de vida y tasa de flujo máximo y se compararon los resultados con 10 pacientes que recibieron bloqueadores alfa y otro grupo de 10 pacientes que se vigilaron en un tiempo de 24 semanas, cada grupo con una ZT prostática de 15 cc o menor. Resultados. Los pacientes sometidos a ITUP obtuvieron los beneficios de esta modalidad incrementando la tasa de flujo máximo 4.93 ml/s, los pacientes con bloqueadores alfa incrementaron 4.36 ml/s, y los pacientes vigilados sólo incrementaron 1.8 ml/s, la puntuación de la AUA disminuyó 10.4 puntos en los pacientes sometidos a ITUP, en los pacientes con bloqueadores alfa disminuyó 3.8 puntos y en los pacientes vigilados se incrementó 1.5, el índice de calidad de vida disminuyó 2.5 puntos en los pacientes sometidos a ITUP, 1.6 en los que recibieron bloqueadores alfa y 0.2 en los pacientes vigilados. Conclusiones. La ITUP es una excelente alternativa de tratamiento de la BPB con bajo volumen de ZT (< de 15 cc), con buenos resultados a mediano plazo valorando lo anterior con la puntuación de síntomas de la AUA, índice de calidad de vida y tasa de flujo máximo


Asunto(s)
Humanos , Masculino , Persona de Mediana Edad , Hiperplasia Prostática/cirugía , Obstrucción Uretral/cirugía , Obstrucción Uretral/diagnóstico , Procedimientos Quirúrgicos Mínimamente Invasivos/métodos , Enfermedades de la Próstata/tratamiento farmacológico , Resección Transuretral de la Próstata
11.
Rev. chil. obstet. ginecol ; 63(3): 173-6, 1998. tab
Artículo en Español | LILACS | ID: lil-242616

RESUMEN

Presentamos dos casos de esta rara miopatía durante el embarazo, enfatizando su condición de alto riesgo obstétrico perinatal, resaltamos el muy mal pronóstico gestacional dejadas evolucionar espontaneamente y la probable relación de este mal pronóstico con la concomitancia de anticuerpos anticardiolipinas


Asunto(s)
Humanos , Femenino , Embarazo , Dermatomiositis/complicaciones , Polimiositis/complicaciones , Complicaciones del Embarazo/tratamiento farmacológico , Anticuerpos Anticardiolipina , Creatina Quinasa , Dermatomiositis/diagnóstico , Dermatomiositis/tratamiento farmacológico , Muerte Fetal , Trabajo de Parto Inducido , Oligohidramnios , Polimiositis/diagnóstico , Polimiositis/tratamiento farmacológico , Prednisona/uso terapéutico , Diagnóstico Prenatal
12.
Rev. chil. obstet. ginecol ; 58(4): 262-70, 1993. ilus, tab
Artículo en Español | LILACS | ID: lil-136946

RESUMEN

Se analizan las muertes fetales (MF) mayores de 22 semanas durante un año en un Servicio de aproximadamente 12.000 partos anuales. Hubo 118 MF y se logró completar el estudio en 97 embarazos (100 óbitos), se diseñaron dos grupos controles. Las patologías más relacionadas con la MF fueron la rotura prematura de membranas, infección ovular y parto prematuro. Seguidas por la patología funicular, desprendimiento prematuro de placenta, preeclampsia y colestasia intrahepática del embarazo. La educación de la madre y el control prenatal fueron significativamente mejores en el grupo control. La mayoría de los óbitos ocurrieron fuera del hospital (70 por ciento). El estudio anatomopatológico se logró realizar en pocos casos (34 por ciento). Concluímos que un porcentaje apreciable de estas MF es prevenible con un acertado control prenatal y que un estudio anatomopatológico completo y moderno, que incluya los anexos ovulares disminuiría el alto número de MF (26 por ciento) que persiste sin diagnóstico


Asunto(s)
Humanos , Femenino , Embarazo , Muerte Fetal/epidemiología , Desprendimiento Prematuro de la Placenta/complicaciones , Estudios de Casos y Controles , Colestasis Intrahepática/complicaciones , Consumo de Bebidas Alcohólicas/epidemiología , Rotura Prematura de Membranas Fetales/complicaciones , Mortalidad Fetal , Trabajo de Parto Prematuro/complicaciones , Preeclampsia/complicaciones , Fumar/epidemiología
13.
Rev. chil. obstet. ginecol ; 57(5): 327-33, 1992. tab
Artículo en Español | LILACS | ID: lil-119263

RESUMEN

Se presenta la experiencia en 7 pacientes con antecedentes de pérdida recurrente del embarazo (x=3,7 rango 2-6) con AACL(+) en las cuales se descartó otra etiología; éstas pacientes totalizaban 26 gestaciones no tratadas concluidas en 24 pérdidas fetales (constando en 9 la muerte fetal in útero) y 2 RN vivos. La duración promedio de esas gestaciones fue 17,4 semanas (rango 8-37). Fueron tratadas con prednisona 20 mg/día y ASA 100 mg/día obteniéndose 7 RN vivos y 1 mortinato. En todas las pacientes se obtuvo descenso de los AACL. La duración promedio de las gestaciones tratadas fue de 31,7 semanas (rango 26-28). Se concluye que la presencia de AACL se correlaciona con alta mortalidad y bajo peso fetal y que con el tratamiento se obtiene gestaciones significativamente más largas que en las no tratadas y mayor relación de niños vivos respecto al número de embarazos


Asunto(s)
Humanos , Femenino , Embarazo , Adulto , Aborto Habitual/diagnóstico , Aspirina/uso terapéutico , Prednisona/uso terapéutico , Síndrome Antifosfolípido/diagnóstico , Aborto Habitual/etiología , Síndrome Antifosfolípido/complicaciones
14.
Rev. chil. obstet. ginecol ; 57(1): 23-6, 1992. tab, ilus
Artículo en Español | LILACS | ID: lil-112262

RESUMEN

1. Se estudiaron 202 pacientes embarazadas portadoras de colestasia intrahepática del embarazo (CIE) que fueron atendidas en la Unidad de Feto de Alto Riesgo (FAR) de la Maternidad del Hospital del Salvador. Se compararon con un grupo control compuesto por 404 pacientes con embarazo de evolución normal. 2. Las pacientes portadoras de CIE presentaron tres veces más riesgo de tener un recién nacido (RN) de pretérmino con respecto a los controles (p < 0,01), descartando la cesárea como factor confundente. 3. Las pacientes con CIE sin patología asociada no presentaron mayor riesgo que los controles de tener un RN de bajo peso de nacimiento (< 2.500 g) o con Apgar al minuto < 7, a cualquier edad gestacional y vía del parto. 4. El riesgo de presentar meconio fue tres veces mayor en las pacientes portadoras de CIE, y éste aumentó aún más (Odds ratio = 4,87 con p < 0,01) al presentar una patología asociada. 5. Analizando separadamente el grupo de pacientes colestásicas con meconio y comparándolas con el 2.500 g), Apgar < 7 al minuto y extrañámente para parto de pretérmino. 6. Se postula que la presencia de meconio en portadores de CIE sin patología asociada, disponiéndose de monitorización adecuada de embarazo y parto, no se relaciona con mal pronóstico perinatal


Asunto(s)
Embarazo , Recién Nacido , Humanos , Femenino , Colestasis Intrahepática/complicaciones , Meconio , Estudios de Casos y Controles , Trabajo de Parto Prematuro , Factores de Riesgo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...