Validation of an analytical method for determining nitrites in meat samples

According to FAO, global food demand is increasing as a consequence of population, economic and urbanization growth, particularly in developing countries. Therefore, food industry must develop conservation methods that allow the food to last longer and in better conditions. In the case of meat, sodium nitrite (nitrite) is used in preservation processes. This is because nitrites have the ability to inhibit the anaerobic development of microorganisms. In addition, it is usually used because of  its ability to fix the color in red meats and to improve the organoleptic characteristics of the food, making its texture, flavor and color are more attractive to the consumer. However, its use is regulated by the Commission Regulation (EU) No 1129/2011 of 11 November 2011 amending Annex II to Regulation (EC) No 1333/2008 of the European Parliament and of the Council which establish a list of food additives with relevance. Nitrites are included among these additives because they are important precursors of the formation of the N-nitrosamines, which are carcinogenic and mutagenic compounds. These additives, when consumed in processed food, has been linked to the risk of gastric cancer in humans. Therefore, it is essential to develop analytical methods that help to determine adequately nitrites concentration in foods at levels required by legislation.The analytical method selected was based on the reaction of the nitrite present in foods with a sulfanilic acid reagent (α-naphthylamine). This results in a colorimetric reaction that forms a pink compound that can be measured spectrophotometrically. We prepared the sample to homogenization with an electric mixer to get a better extraction of de nitrite. Later, the sample was added with a known concentration of a reference material.Several assays were done for determine the reproducibility, replicability and accuracy of the method. Recovery results (70-80%) show that the selected method is adequate to carry out nitrite determination in meats. Moreover, during the startup of the method it was observed that this methodology is influenced by the homogenization of the sample and the conservation time of the reagents, revealing the importance to control and standardized the procedure.

Predicting Subclinical Atherosclerosis in Low-Risk Individuals: Ideal Cardiovascular Health Score and Fuster-BEWAT Score.

BACKGROUND: The ideal cardiovascular health score (ICHS) is recommended for use in primary prevention. Simpler tools not requiring laboratory tests, such as the Fuster-BEWAT (blood pressure [B], exercise [E], weight [W], alimentation [A], and tobacco [T]) score (FBS), are also available. OBJECTIVES: The purpose of this study was to compare the effectiveness of ICHS and FBS in predicting the presence and extent of subclinical atherosclerosis. METHODS: A total of 3,983 participants 40 to 54 years of age were enrolled in the PESA (Progression of Early Subclinical Atherosclerosis) cohort. Subclinical atherosclerosis was measured in right and left carotids, abdominal aorta, right and left iliofemoral arteries, and coronary arteries. Subjects were classified as having poor, intermediate, or ideal cardiovascular health based on the number of favorable ICHS or FBS. RESULTS: With poor ICHS and FBS as references, individuals with ideal ICHS and FBS showed lower adjusted odds of having atherosclerotic plaques (ICHS odds ratio [OR]: 0.41; 95% confidence interval [CI]: 0.31 to 0.55 vs. FBS OR: 0.49; 95% CI: 0.36 to 0.66), coronary artery calcium (CACS) ≥1 (CACS OR: 0.41; 95% CI: 0.28 to 0.60 vs. CACS OR: 0.53; 95% CI: 0.38 to 0.74), higher number of affected territories (OR: 0.32; 95% CI: 0.26 to 0.41 vs. OR: 0.39; 95% CI: 0.31 to 0.50), and higher CACS level (OR: 0.40; 95% CI: 0.28 to 0.58 vs. OR: 0.52; 95% CI: 0.38 to 0.72). Similar levels of significantly discriminating accuracy were found for ICHS and FBS with respect to the presence of plaques (C-statistic: 0.694; 95% CI: 0.678 to 0.711 vs. 0.692; 95% CI: 0.676 to 0.709, respectively) and for CACS ≥1 (C-statistic: 0.782; 95% CI: 0.765 to 0.800 vs. 0.780; 95% CI: 0.762 to 0.798, respectively). CONCLUSIONS: Both scores predict the presence and extent of subclinical atherosclerosis with similar accuracy, highlighting the value of the FBS as a simpler and more affordable score for evaluating the risk of subclinical disease

Identificación mediante la huella del pabellón auricular

Desarrollo del actual protocolo para el tratamiento de huellas de oreja y análisis tanto de la técnica como de la validez jurídica actual de la identificación por este métodoUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Activation of innate and specific immune responses in hemolytic uremic syndrome (HUS)- patients

La función primaria del sistema inmunológico es preservar al individuo sano frente a infinidad de agentes microbianos patógenos o injuriantes. Sin embargo, en determinadas circunstancias los mecanismos agresores normalmente montados contra un agente invasor, pueden tornarse altamente injuriantes para el propio individuo. Hay importantes evidencias tanto clínicas como experimentales, de que la reacción inflamatoria inducida por los distintos componentes de las bacterias Escherichia coli productoras de toxina Shiga (Stx) (STEC), fundamentalmente la Stx y los lipopolisacáridos (LPS), contribuye decisivamente en la evolución a la forma completa de SUH Así los pacientes al ser diagnosticados de SUH, presentan evidencias de haber sufrido un proceso de activación del sistema inmune innato, o reacción inflamatoria muy aguda y temprana en la evolución de la enfermedad. Algunas de estas evidencias pueden resumirse como: una neutrofilia marcada, leucocitos neutrófilos (PMN) circulantes que se encuentran “agotados o exhaustos”, los monocitos diferenciados hacia un fenotipo inflamatorio (menor expresión de CD14 y aumento de CD16), y se encuentra un significativo descenso en los leucocitos que presentan el receptor para la quimioquina Fractalquina (FKN, CX3CL1)) (CX3CR1): los. monocitos clásicos y células Natural Killer (NK). Estas células tienen un alto potencial citotóxico. La FKN se expresa en endotelio y epitelio renal y ha sido involucrada en los mecanismos patogénicos en distintas nefropatías. Llamativamente, encontramos una correlación significativa entre la severidad del cuadro renal y las alteraciones mencionadas. Por último se discute el papel protector que la respuesta inmune específica podría ejercer, fundamentalmente a través de la producción de anticuerpos neutralizantes de la Stx.The central role of the immune system is the preservation of the health against several pathogenic microbes and injury agents. However, on special conditions defensive mechanisms triggered towards the foreign agent can damage the host. Clinical and experimental evidence indicate that inflammatory reaction triggered by the main components of Shiga toxin (Stx)- producing Escherichia coli (STEC), participate in the evolution to the complete form of HUS. When children are diagnosed of HUS, they present evidence that have suffered a very strong and early inflammatory response. These features include: the presence of a marked neutrophilia, the polymorfonuclear leucocytes (PMN) are “deactivated or exhausted” and the monocytes are differentiated towards an inflammatory phenotype (CD14-reduced and CD16-enhanced membrane expression). In addition, HUS-patients show a marked reduction in the absolute and relative number of leucocytes carrying the receptor (CX3CR1) for the chemokine “Fractalkine” (FKN, CX3 CL1), which are the classic monocytes and Natural Killer cells (NK). All these cells express a high cytotoxic potencial. The chemokine FKN is expressed in endothelial and epithelial renal cells, and is involved in the pathogenic mechanism of different nephropathies. Noteworthy, we found a significant correlation between the severity of the renal damage (as days of anuria) and the alterations described above. Finally, the protective role of specific immune response, mainly through the antibody production with Stx-neutralizing capacity, is discussed.Fil: Palermo, Marina Sandra. Academia Nacional de Medicina de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Fernandez, Gabriela C.. Academia Nacional de Medicina de Buenos Aires; ArgentinaFil: Ramos, Maria Victoria. Academia Nacional de Medicina de Buenos Aires; ArgentinaFil: Bentancor, Leticia. Academia Nacional de Medicina de Buenos Aires; ArgentinaFil: Fernández Brando, Romina Jimena. Academia Nacional de Medicina de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Dran, Graciela I.. Academia Nacional de Medicina de Buenos Aires; ArgentinaFil: Isturiz, Martín Amadeo. Academia Nacional de Medicina de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; Argentin

Spectrophotometric color measurement to assess temperature of exposure in cortical and medullar of heated human bones: a preliminary study

Heated-bone color changes may provide information about temperature of exposure, with interest for anthropologists and forensic experts. The aim of this study was to assess heat-induced color changes by spectrophotometry in cortical and medullar human bones heated at different temperatures and times. CIELAB (International Commission on Illumination-LAB) color parameters (L*, a*, and b*) and whiteness (WI) and yellowness (YI) indexes were obtained by spectrophotometry in the cortical and medullar zones of 36 bone sections exposed at 200, 400, 600, and 800 °C for 30 and 60 min. The accuracy of color-based temperature estimations was evaluated by Receiver Operating Characteristics (ROC) analysis. Chromaticity a* showed the best significant discrimination power with the area under the ROC curve (AUC) values ranged from 0.9 to 1.0 in cortical zones and 0.7 to 1.0 in medullar zones for all temperatures of exposures and both time of exposures. Chromaticity b*, and WI and YI indexes showed an AUC of 1.0 at 400, 600, and 800 °C for 30 and 60 min in the cortical and medullar zones. The spectrophotometric color parameters provided a highly accurate estimation of the temperature of exposure to discriminate between temperatures and exposure times in the cortical and medullar zones. Spectrophotometric bone color measurement in cortical and medullar zones can be an objective and reproducible method to estimate the temperature of exposition, and it can be considered useful for forensic and anthropological purposes.This research was funded by Universidad de Málaga. J.S. (CPII17/00024) holds a ‘’Miguel Servet II’’ research contract from the National System of Health (Spain), EU-ERDF-Instituto de Salud Carlos III, and Instituto de Investigación Biomédica de Málaga (IBIMA)

Impact of Gastrointestinal Digestion In Vitro Procedure on the Characterization and Cytotoxicity of Reduced Graphene Oxide

The growing interest in graphene derivatives is a result of their variety of applications in many fields. Due to their use, the oral route could be a potential way of entrance for the general population. This work assesses the biotransformation of reduced graphene oxide (rGO) after an in vitro digestion procedure (mouth, gastric, intestinal, and colon digestion), and its toxic effects in different cell models (HepG2, Caco-2, and 3D intestinal model). The characterization of rGO digestas evidenced the agglomeration of samples during the in vitro gastrointestinal (g.i.) digestion. Internalization of rGO was only evident in Caco-2 cells exposed to the colonic phase and no cellular defects were observed. Digestas of rGO did not produce remarkable cytotoxicity in any of the experimental models employed at the tested concentrations (up to 200 µg/mL), neither an inflammatory response. Undigested rGO has shown cytotoxic effects in Caco-2 cells, therefore these results suggest that the digestion process could prevent the systemic toxic effects of rGO. However, additional studies are necessary to clarify the interaction of rGO with the g.i. tract and its biocompatibility profile.Fondo Europeo de Desarrollo Regional US-1259106, P18-RT1993Junta de Andalucía POSTDOC_21_0013

Optimización del diseño de elementos de máquinas utilizando el software CES Edupack

Memoria ID-117. Ayudas de la Universidad de Salamanca para la innovación docente, curso 2018-2019

Structure and function of the N-terminal extension of the formin INF2

In INF2—a formin linked to inherited renal and neurological disease in humans—the DID is preceded by a short N-terminal extension of unknown structure and function. INF2 activation is achieved by Ca2+-dependent association of calmodulin (CaM). Here, we show that the N-terminal extension of INF2 is organized into two α-helices, the first of which is necessary to maintain the perinuclear F-actin ring and normal cytosolic F-actin content. Biochemical assays indicated that this helix interacts directly with CaM and contains the sole CaM-binding site (CaMBS) detected in INF2. The residues W11, L14 and L18 of INF2, arranged as a 1-4-8 motif, were identified as the most important residues for the binding, W11 being the most critical of the three. This motif is conserved in vertebrate INF2 and in the human population. NMR and biochemical analyses revealed that CaM interacts directly through its C-terminal lobe with the INF2 CaMBS. Unlike control cells, INF2 KO cells lacked the perinuclear F-actin ring, had little cytosolic F-actin content, did not respond to increased Ca2+ concentrations by making more F-actin, and maintained the transcriptional cofactor MRTF predominantly in the cytoplasm. Whereas expression of intact INF2 restored all these defects, INF2 with inactivated CaMBS did not. Our study reveals the structure of the N-terminal extension, its interaction with Ca2+/CaM, and its function in INF2 activatio