870 research outputs found
Niveles de acrilamida en hojuelas de papas fritas comercializadas en Lima Metropolitana en el año 2018 y valores de referencia
Analiza los niveles de acrilamida en hojuela de papas fritas comercializadas en el año 2018 y comparar su situación frente a los valores de referencia establecidos internacionalmente. Fueron evaluadas 16 marcas de hojuelas de papas fritas (M1 a M16) provenientes de 9 productores. Fueron analizadas por cromatografía HPLC con columna HILIC, usando el método QUECHERS para su extracción y limpieza con factor de recuperación de 77,9%. Los niveles de acrilamida fueron expresados en μg/kg y comparados con los valores establecidos de la Unión Europea. Resultados: 12 de las 16 marcas, presentaron niveles promedio de acrilamida entre 868 y 2591 μg/kg; 2 de los 9 productores (fabricante de marcas M3, M6, M11 y M12) presentaron los más bajos niveles de acrilamida, con una media entre 386 y 540 μg/kg. Las muestras M1 y M8, de mayor distribución y probablemente mayor consumo, presentaron niveles de acrilamida >1033 μg/kg. Este trabajo encontró un promedio de contenido de acrilamida de 1234,18 μg/kg y que el 75 % de las marcas de hojuela de papas fritas comercializadas en Lima Metropolitana superaron los valores de referencia de 750 μg/kg
Estandarización de un protocolo para obtención de inóculo inactivado de adenovirus aviar serotipos 4 y 8b en células LMH = Protocol standardization for obtaining inactivated inoculum of avian adenovirus serotypes 4 and 8b in LMH cells
Adenovirus aviar tipo 1 (FAdV) es considerado un patógeno de importancia para la industria avícola. Los serotipos 4 (FAdV-4) y 8b (FAdV-8b) son responsables de hepatitis por cuerpos de inclusión (IBH) y síndrome de hidropericardio (HHS) en pollos y son prevalentes en el Perú. El objetivo del presente trabajo fue establecer un protocolo estandarizado de obtención de inóculos virales inactivados de FAdV-4 y FAdV-8b producidos en células de hepatoma de pollo (LMH). Para ello, células LMH al 70 % de confluencia,crecidas en medio DMEM con 10 % de suero fetal bovino, fueron infectadas con FAdV-4 o FAdV-8b para evaluar el valor de multiplicidad de infección (MOI) y tiempo de cosecha óptimos. Luego, se realizó la producción de 1L de ambos serotipos considerando un MOI de 10 y tiempo de cosecha de 96 h post-infección (hpi). Seguidamente, ambas cosechas virales fueron clarificadas y concentradas mediante ultrafiltración tangencial (UFT) en membrana de 100kDa e inactivadas con 30mM de etilenimina binaria (BEI) a 37°C por 18 h. La pérdida de infectividad fue corroborada por el cálculo de dosis infecciosa del 50 % de cultivo de células (TCID50). Nuestros resultados mostraron que con un MOI de 10 y cosecha de 96 hpi se alcanzó el mayor título viral (> 1x108 TCID50/mL). Además, se mostró que la UFT permitió concentrar 10 veces la cantidad de virus con una recuperación del 91% y que la inactivación con BEI fue eficiente. Los inóculos inactivados obtenidos pueden ser utilizados en la formulación de una vacuna para prevenir IBH y HHS en pollos de forma segura.Avian adenovirus type 1 (FAdV) is considered an important pathogen for the poultry industry. Serotypes 4 (FAdV4) and 8b (FAdV-8b) are responsible for Inclusion Body Hepatitis (IBH) and Hydropericardium Syndrome (HHS) in chickens and are prevalent in Perú. The objective of this work was to establish a standardized protocol for obtaining inactivated viral inoculum of FAdV-4 and FAdV-8b produced in chicken hepatoma (LMH) cells. For this, LMH cells at 70 % confluence, grown in DMEM
medium with 10 % fetal bovine serum, were infected with FAdV-4 or FAdV-8b to evaluate the optimal multiplicity of infection (MOI) value and harvest time. Then, the production of 1L of both serotypes was carried out considering an MOI of 10 and a harvest time of 96 h postinfection (hpi). Next, both viral harvests were clarified and concentrated by tangential ultrafiltration (UFT) on a 100kDa membrane and inactivated with 30mM Binary Ethyleneimine (BEI) at 37°C for 18 h. Loss of infectivity was corroborated by calculating the 50 % cell culture infectious dose (TCID50). Our results showed that with an MOI of 10 and a harvest time of 96 hpi, the highest viral titer was reached (> 1x108 TCID50/mL). In addition, it was shown that UFT allowed concentrating 10 times the amount of virus with a 91% recovery rate and that inactivation with BEI was efficient. The inactivated inoculum obtained can be used in the formulation of a vaccine to safely prevent IBH and HHS in chickens.EEA BalcarceFil: Flores Santos, Juan Carlos. Quimtia, Desarrollo e investigación; Perú.Fil: Quispe, Juana. Quimtia, Desarrollo e investigación; Perú.Fil: Huberman, Yosef Daniel. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina.Fil: Mendoza Espinoza, Alfredo. Quimtia, Desarrollo e investigación; Perú.Fil: Caballero García, Melani. Quimtia, Desarrollo e investigación; Perú
"Antarctic yeasts as a source of L-asparaginase: Characterization of a glutaminase-activity free L-asparaginase from psychrotolerant yeast Leucosporidium scottii L115"
"Microorganisms from extreme environments, such as the Antarctic ecosystems, have a great potential to produce
enzymes with novel characteristics. Within this context, L-asparaginase (ASNase) obtained from yeast species has
been poorly studied. In this study, yeasts isolated from samples collected at Admiralty Bay (King George Island,
Antarctica) were tested to produce ASNase. From an initial screening of 40 strains, belonging to 13 different
species, Leucosporidium scottii L115 produced an ASNase activity (LsASNase activity: 6.24 U g-1 of dry cell weight)
with the lowest glutaminase activity. The LsASNase was purified 227-fold, with a specific activity of 137.01 U
mg-1 at 37 ◦C, without glutaminase activity. Moreover, the maximum enzyme activity was observed at pH 7.5
and at a temperature of 55 ◦C. The enzyme is a multimer of 462 kDa, presenting a single band of 53 kDa molecular mass in reduced conditions; after PGNase F treatment, a single band of 45 kDa was observed. The
enzymatic kinetic evaluation revealed an allosteric regulation of the enzyme and the kinetic parameters were
determined at 37 ◦C, pH 7.0 as substrate affinity constant, K0.5 = 233 μM, kcat = 54.7 s
− 1 and Hill coefficient, nH
= 1.52, demonstrating positive cooperativity by the enzyme and the substrate. This is the first study to report L.
scottii as a source of glutaminase-activity free L-asparaginase, an acute lymphoblastic leukemia drug feature
suitable for the treatment of asparagine synthetase negative cancer cells.
Bacteria producing L-asparaginase isolated from Peruvian saline environments
L-asparaginase (EC 3.5.1.1) hydrolyzes L-asparagine in L-aspartic acid and ammonia. Its efficiency is subject to its kinetics and specificity on the substrate, characteristics that vary from one source to another. Thus, microorganisms from saline environments constitute a phylogenetic and metabolically heterogeneous group for the search of new enzymes. Therefore, the objective of this study was the phenotypic and genotypic characterization of bacteria with L-asparaginase activity isolated from Maras, Pilluana and Chilca salterns. The 24 evaluated bacteria were classified as 38% Gram-negative bacilli and 54% positive; and 8% Gram-positive cocci. The majority grew in 5% salt water, pH 7.0 and 37 °C, all assimilated glucose. Of the 24 bacteria that produced L-asparaginase in solid medium, enzymatic activity was determined in submerged cultures by the Nessler method in 14 of them. The CH11, M62, M64, M68, and P19 strains identified as Bacillus sp., by partial sequencing of the 16S ribosomal gene, presented higher L-asparaginase activity and instability due to the presence of proteases. Saline environments bacteria are potential sources for the prospective production of L-asparaginase to use them as a therapeutic agent and in the food industry
The Interplay between Natural Selection and Susceptibility to Melanoma on Allele 374F of SLC45A2 Gene in a South European Population
We aimed to study the selective pressures interacting on SLC45A2 to investigate the interplay between selection and susceptibility to disease. Thus, we enrolled 500 volunteers from a geographically limited population (Basques from the North of Spain) and by resequencing the whole coding region and intron 5 of the 34 most and the 34 least pigmented individuals according to the reflectance distribution, we observed that the polymorphism Leu374Phe (L374F, rs16891982) was statistically associated with skin color variability within this sample. In particular, allele 374F was significantly more frequent among the individuals with lighter skin. Further genotyping an independent set of 558 individuals of a geographically wider population with known ancestry in the Spanish population also revealed that the frequency of L374F was significantly correlated with the incident UV radiation intensity. Selection tests suggest that allele 374F is being positively selected in South Europeans, thus indicating that depigmentation is an adaptive process. Interestingly, by genotyping 119 melanoma samples, we show that this variant is also associated with an increased susceptibility to melanoma in our populations. The ultimate driving force for this adaptation is unknown, but it is compatible with the vitamin D hypothesis. This shows that molecular evolution analysis can be used as a useful technology to predict phenotypic and biomedical consequences in humans
PATOLOGIA DO QUADRIL DAS CRIANÇAS: UMA REVISÃO INTEGRATIVA
Many of the pathologies that affect the hip in adults have their origins in childhood, making the early diagnosis of these conditions through specific pediatric orthopedic evaluation extremely important. Research shows that late diagnoses are associated with a considerable increase in the number of sequelae. This article consists of an integrative review, which aims to analyze and discuss the main hip pathologies in children, in order to expand the knowledge of students and professionals in the area about the subject in question. The work consists of an integrative literature review, in which a basic, qualitative, exploratory and bibliographic research was carried out in the databases. Hip pathology in children is a field of medical study and treatment that encompasses a variety of conditions and problems that affect the hip joint in younger individuals. These conditions can range from congenital problems to disorders acquired over time. It is critical to understand that healthy hip development is crucial for children's mobility and quality of life, and any issues in this area must be addressed with care and attention. In summary, hip pathologies in children encompass a variety of conditions, from developmental dysplasia of the hip to proximal epiphysis of the femur. Early diagnosis and adequate treatment are essential to avoid complications and long-term sequelae.Muitas das patologias que afetam o quadril de adultos têm suas origens na infância, tornando o diagnóstico precoce dessas condições por meio de avaliação ortopédica pediátrica específica de extrema importância. Pesquisas demonstram que diagnósticos tardios estão associados a um aumento considerável no número de sequelas. O presente artigo consiste em uma revisão integrativa, no qual tem como objetivo analisar e discutir acerca das principais patologias de quadril das crianças, no intuito de ampliar os conhecimentos de estudantes e profissionais da área acerca do tema em questão. O trabalho consiste em uma revisão de literatura do tipo integrativa, na qual foi realizada uma pesquisa dos tipos básica, qualitativa, exploratória e bibliográfica, nas bases de dados. A patologia do quadril em crianças é um campo de estudo e tratamento médico que abrange uma variedade de condições e problemas que afetam a articulação do quadril em indivíduos mais jovens. Essas condições podem variar desde problemas congênitos até distúrbios adquiridos ao longo do tempo. É fundamental entender que o desenvolvimento saudável do quadril é crucial para a mobilidade e a qualidade de vida das crianças e qualquer problema nessa área deve ser abordado com cuidado e atenção. Em suma, as patologias do quadril em crianças abrangem uma variedade de condições, desde a displasia do desenvolvimento do quadril até a epifisiólise proximal do fêmur. O diagnóstico precoce e o tratamento adequado são fundamentais para evitar complicações e sequelas a longo prazo
Humans with inherited MyD88 and IRAK-4 deficiencies are predisposed to hypoxemic COVID-19 pneumonia
X-linked recessive deficiency of TLR7, a MyD88- and IRAK-4–dependent endosomal ssRNA sensor, impairs SARS-CoV-2 recognition and type I IFN production in plasmacytoid dendritic cells (pDCs), thereby underlying hypoxemic COVID-19 pneumonia with high penetrance. We report 22 unvaccinated patients with autosomal recessive MyD88 or IRAK-4 deficiency infected with SARS-CoV-2 (mean age: 10.9 yr; 2 mo to 24 yr), originating from 17 kindreds from eight countries on three continents. 16 patients were hospitalized: six with moderate, four with severe, and six with critical pneumonia, one of whom died. The risk of hypoxemic pneumonia increased with age. The risk of invasive mechanical ventilation was also much greater than in age-matched controls from the general population (OR: 74.7, 95% CI: 26.8–207.8, P < 0.001). The patients’ susceptibility to SARS-CoV-2 can be attributed to impaired TLR7-dependent type I IFN production by pDCs, which do not sense SARS-CoV-2 correctly. Patients with inherited MyD88 or IRAK-4 deficiency were long thought to be selectively vulnerable to pyogenic bacteria, but also have a high risk of hypoxemic COVID-19 pneumonia
Ciencias de la Biología y Agronomía
Este volumen I contiene 17 capítulos arbitrados que se ocupan de estos asuntos en Tópicos Selectos de Ciencias de la Biología y Agronomía, elegidos de entre las contribuciones, reunimos algunos investigadores y estudiantes. Se presenta un Estudio Comparativo de los Recursos Hidrológico-Forestales de la Microcuenca de la Laguna de Epatlan, Pue. (1993 a 2014); la Situación Actual de la Mancha de Asfalto en Maíz (Zea mays L.) en los Municipios de Jiquipilas y Ocozocoautla, Chiapas, México; las poblaciones sobresalientes de maíz de la raza Zapalote Chico, en la Región Istmeña de Oaxaca; Se indica el índice de área foliar de cultivo de Chile Poblano mediante dos métodos en condiciones protegidas; Esquivel, Urzúa y Ramírez exploran el efecto de la biofertilización con Azospirillum en el crecimiento y producción de Jitomate; esbozan su artículo sobre la determinación del nivel de Heterosis en híbridos de Maíz para la Comarca Lagunera; una investigación sobre la estabilización de semilla de Solanum lycopersicum durante el almacenamiento y estimulación de la germinación; acotan sobre el CTAB como una nueva opción para la detección de Huanglongbing en cítricos, plantean su evaluación sobre el aluminio y cómo afecta la vida de florero de Heliconia psittacorum; indican sobre el impacto del H-564C, como un híbrido de maíz con alta calidad de proteina para el trópico húmedo de México; presetan su investigación sobre la producción de Piña Cayena Lisa y MD2 (Ananas comosus L.) en condiciones de Loma Bonita, en Oaxaca; acotan sobre el efecto de coberteras como control biológico por conservación contra áfidos en Nogal Pecanero; esbozan sobre la caracterización de cuatro genotipos de Frijol Negro en Martínez de la Torre, Veracruz, México; presentan una caracterización hidroecológica de la microcuenca de Arroyo Prieto, Yuriría, Gto., y alternativas para su restauración ambiental; presentan su investigación sobre el efecto del hongo Beauveria bassiana sobre solubilización de fosfatos y la disponibilidad de fósforo en el suelo; plantean su investigación sobre la Germinación y regeneración in vitro de Epidendrum falcatum LINDL; esbozan su artículo sobre genotipos de frijol negro y su tolerancia a sequía terminal en Veracruz, México
PERSPECTIVA PSICOSOCIAL DE LOS DERECHOS HUMANOS
Hoy en día es imprescindible abordar el problema de los derechos desde una perspectiva holística que integre la posición que el individuo ocupa en la sociedad y el impacto de los hechos sociales sobre su persona. Esta perspectiva va por lo tanto más allá del enfoque clásico de las violaciones a los derechos civiles y políticos de los ciudadanos sino, también incluye sus derechos económicos, sociales y culturales. Cualquier enfoque de tipo holístico debe entender al ser humano en su ambiente, social, cultural, natural y en función a todas las estructuras existentes, por más sutiles que sean o invisibles que parezcan. Precisamente este libro permite apreciar la dimensión amplia y compleja del ser en sociedad y las interacciones que de ambas partes se generan y las ramificaciones que producen. No es un ejercicio fácil y los editores de este volumen han logrado un salto cuántico al poder congregar en un solo espacio miradas que en otras circunstancias podrían haber sido opuestas y hasta contrarias a nuestra comprensión de problemas que, en efecto, tienen raíces comunes.
El libro está dividido en 5 secciones, El espíritu de los tiempos actuales y los Derechos Humanos, Construcción ciudadana y ejercicio de los Derechos Humanos, Violaciones a Derechos Humanos, victimizaciones y su atención, Ejercicio de los Derechos Humanos y situaciones disruptivas y Defensa y defensores de Derechos Humanos.Manuel Gutiérrez Romero
Jessica Ruiz Magañ
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