Integrative genome-centric metagenomics for surface water surveillance: Elucidating microbiomes, antimicrobial resistance, and their associations.

Surface water ecosystems are intimately intertwined with anthropogenic activities and have significant public health implications as primary sources of irrigation water in agricultural production. Our extensive metagenomic analysis examined 404 surface water samples from four different geological regions in Chile and Brazil, spanning irrigation canals (n = 135), rivers (n = 121), creeks (n = 74), reservoirs (n = 66), and ponds (n = 8). Overall, 50.25 % of the surface water samples contained at least one of the pathogenic or contaminant bacterial genera (Salmonella: 29.21 %; Listeria: 6.19 %; Escherichia: 35.64 %). Furthermore, a total of 1,582 antimicrobial resistance (AMR) gene clusters encoding resistance to 25 antimicrobial classes were identified, with samples from Brazil exhibiting an elevated AMR burden. Samples from stagnant water sources were characterized by dominant Cyanobacteriota populations, resulting in significantly reduced biodiversity and more uniform community compositions. A significant association between taxonomic composition and the resistome was supported by a Procrustes analysis (p < 0.001). Notably, regional signatures were observed regarding the taxonomic and resistome profiles, as samples from the same region clustered together on both ordinates. Additionally, network analysis illuminated the intricate links between taxonomy and AMR at the contig level. Our deep sequencing efforts not only mapped the microbial landscape but also expanded the genomic catalog with newly characterized metagenome-assembled genomes (MAGs), boosting the classification of reads by 12.85 %. In conclusion, this study underscores the value of metagenomic approaches in surveillance of surface waters, enhancing our understanding of microbial and AMR dynamics with far-reaching public health and ecological ramifications.

An intelligent climate monitoring system for hygrothermal virtual measurement in closed buildings using Internet-of-things and artificial hydrocarbon networks.

Studies analyzing indoor thermal environments comprising temperature and humidity may be insufficient when obtaining data from sensors, which may be susceptible to inaccurate or failed information from internal and external factors. Therefore, this study proposes an intelligent climate monitoring using a supervised learning method for virtual hygrothermal measurement in enclosed buildings used to predict temperature and relative humidity when a sensor failure is detected. The methodology comprises the data collection from a wireless sensor network, the building of the learning model for predicting the dynamics of environmental variables, and the implementation of a sensor failure detection model. We use an artificial hydrocarbon network as the learning model for their simplicity and effectiveness under uncertain and noisy data. The experiments use data acquired in two settings: (1) a laboratory office and (2) a museum storage room. The first scenario has multiple workstations, and the staff turns on or off the air conditioning depending on the feeling of comfort, generating an uncontrolled environment for the variables of interest. The second scenario has controlled temperature and humidity to ensure the conservation conditions of the museum pieces. Both scenarios used 12 sensors that acquired data for one month, providing an average of 58,300 values for each variable. Results of the proposed methodology provide 95% of accuracy in terms of sensor failure detection and identification, and less than 0.22% of tolerance variability in temperature and humidity after sensor accommodation in both scenarios.

Systemic Inflammation but not Oxidative Stress Is Associated with Physical Performance in Moderate Chronic Obstructive Pulmonary Disease.

Chronic obstructive pulmonary disease (COPD) patients manifest muscle dysfunction and impaired muscle oxidative capacity, which result in reduced exercise capacity and poor health status. The aim of this study was to compare the physical performance, systemic inflammation, and oxidative stress of patients with moderate COPD, and to associate physical performance with inflammatory and oxidative stress plasma markers. Twenty CONTROL (n = 10) and moderate COPD (n = 10) patients participated in this study. Systematic inflammation and oxidative stress plasma markers, maximal aerobic capacity (VO2peak), and maximal isometric strength (MVIC) of the knee extensor (KE) muscles were measured. VO2peak was 31.3% greater in CONTROL compared to COPD (P = 0.006). The MVIC strength of the KE was 43.9% greater in CONTROL compared to COPD (P = 0.002). Tumor necrosis factor-alpha (TNF-α) was 79.6% greater in COPD compared to CONTROL (P < 0.001). Glutathione peroxidase activity (GPx) activity was 27.5% lesser in COPD compared to CONTROL (P = 0.05). TNF-α concentration was correlated with KE MVC strength (R = -0.48; P = 0.045) and VO2peak (R = -0.58; P = 0.01). Meanwhile, malondialdehyde (MDA) and GPx activity were not associated with KE strength or VO2peak (P = 0.74 and P = 0.14, respectively). COPD patients showed lesser muscle strength and aerobic capacity than healthy control individuals. Furthermore, patients with COPD showed greater systemic inflammation and lesser antioxidant capacity than healthy counterparts. A moderate association was evident between levels of systemic inflammation and physical performance variables.

A Novel Traffic Prediction Method Using Machine Learning for Energy Efficiency in Service Provider Networks.

This paper presents a systematic approach for solving complex prediction problems with a focus on energy efficiency. The approach involves using neural networks, specifically recurrent and sequential networks, as the main tool for prediction. In order to test the methodology, a case study was conducted in the telecommunications industry to address the problem of energy efficiency in data centers. The case study involved comparing four recurrent and sequential neural networks, including recurrent neural networks (RNNs), long short-term memory (LSTM), gated recurrent units (GRUs), and online sequential extreme learning machine (OS-ELM), to determine the best network in terms of prediction accuracy and computational time. The results show that OS-ELM outperformed the other networks in both accuracy and computational efficiency. The simulation was applied to real traffic data and showed potential energy savings of up to 12.2% in a single day. This highlights the importance of energy efficiency and the potential for the methodology to be applied to other industries. The methodology can be further developed as technology and data continue to advance, making it a promising solution for a wide range of prediction problems.

Síndrome de Rapunzel asociado a perforación intestinal. Caso clínico / Rapunzel syndrome associated with intestinal perforation. Clinical case

Introducción. Los tricobezoares ocurren de forma frecuente en niñas y adolescentes, y se asocian a trastornos psicológicos como depresión, tricotilomanía o tricofagia. Caso clínico. Se presenta una paciente adolescente con síndrome de Rapunzel, con hallazgo adicional de perforación yeyunal debido al tricobezoar. Discusión. Dentro de las complicaciones de los tricobezoares se reporta invaginación intestinal (principalmente de yeyuno), apendicitis, obstrucción biliar, neumonía, pancreatitis secundaria y perforación, esta última como ocurrió en nuestra paciente. Conclusión. En pacientes mujeres adolescentes con dolor abdominal o abdomen agudo, se debe tener en cuenta el diagnóstico de síndrome de Rapunzel, así como sus probables complicaciones

Introduction. Trichobezoars occur frequently in young and adolescent girls, and are associated with psychological disorders such as depression, trichotillomania, or trichophagia. Clinical case. An adolescent patient with Rapunzel syndrome is presented, with an additional finding of jejunal perforation due to the trichobezoar. Discussion. Among the complications of trichobezoars, intussusception is reported (mainly of the jejunum), appendicitis, biliary obstruction, pneumonia, secondary pancreatitis, and perforation, the latter as occurred in our patient. Conclusion. In adolescent female patients with abdominal pain or acute abdomen, the diagnosis of Rapunzel syndrome should be taken into account, as well as its probable complications

Immunogenicity and reactogenicity of heterologous immunization against SARS CoV-2 using Sputnik V, ChAdOx1-S, BBIBP-CorV, Ad5-nCoV, and mRNA-1273.

Heterologous vaccination against coronavirus disease 2019 (COVID-19) provides a rational strategy to rapidly increase vaccination coverage in many regions of the world. Although data regarding messenger RNA (mRNA) and ChAdOx1 vaccine combinations are available, there is limited information about the combination of these platforms with other vaccines widely used in developing countries, such as BBIBP-CorV and Sputnik V. Here, we assess the immunogenicity and reactogenicity of 15 vaccine combinations in 1,314 participants. We evaluate immunoglobulin G (IgG) anti-spike response and virus neutralizing titers and observe that a number of heterologous vaccine combinations are equivalent or superior to homologous schemes. For all cohorts in this study, the highest antibody response is induced by mRNA-1273 as the second dose. No serious adverse events are detected in any of the schedules analyzed. Our observations provide rational support for the use of different vaccine combinations to achieve wide vaccine coverage in the shortest possible time.

Longitudinal Study after Sputnik V Vaccination Shows Durable SARS-CoV-2 Neutralizing Antibodies and Reduced Viral Variant Escape to Neutralization over Time.

Recent studies have shown a temporal increase in the neutralizing antibody potency and breadth to SARS-CoV-2 variants in coronavirus disease 2019 (COVID-19) convalescent individuals. Here, we examined longitudinal antibody responses and viral neutralizing capacity to the B.1 lineage virus (Wuhan related), to variants of concern (VOC; Alpha, Beta, Gamma, and Delta), and to a local variant of interest (VOI; Lambda) in volunteers receiving the Sputnik V vaccine in Argentina. Longitudinal serum samples (N = 536) collected from 118 volunteers obtained between January and October 2021 were used. The analysis indicates that while anti-spike IgG levels significantly wane over time, the neutralizing capacity for the Wuhan-related lineages of SARS-CoV-2 and VOC is maintained within 6 months of vaccination. In addition, an improved antibody cross-neutralizing ability for circulating variants of concern (Beta and Gamma) was observed over time postvaccination. The viral variants that displayed higher escape to neutralizing antibodies with respect to the original virus (Beta and Gamma variants) were the ones showing the largest increase in susceptibility to neutralization over time after vaccination. Our observations indicate that serum neutralizing antibodies are maintained for at least 6 months and show a reduction of VOC escape to neutralizing antibodies over time after vaccination. IMPORTANCE Vaccines have been produced in record time for SARS-CoV-2, offering the possibility of halting the global pandemic. However, inequalities in vaccine accessibility in different regions of the world create a need to increase international cooperation. Sputnik V is a recombinant adenovirus-based vaccine that has been widely used in Argentina and other developing countries, but limited information is available about its elicited immune responses. Here, we examined longitudinal antibody levels and viral neutralizing capacity elicited by Sputnik V vaccination. Using a cohort of 118 volunteers, we found that while anti-spike antibodies wane over time, the neutralizing capacity to viral variants of concern and local variants of interest is maintained within 4 months of vaccination. In addition, we observed an increased cross-neutralization activity over time for the Beta and Gamma variants. This study provides valuable information about the immune response generated by a vaccine platform used in many parts of the world.

Marco ético y jurídico en la investigación científica en chile: acreditación de comités ético científicos / Ethical and legal framework in scientific research from Chile: functioning of accredited scientific ethics committees

RESUMEN: La investigación científica en seres humanos es fundamental para el desarrollo y avance en la ciencia de la salud y para el bienestar de la sociedad. La necesidad de contar con principios éticos explícitos y un marco regulatorio, permitió en el año 2001 la aprobación de la Norma sobre Regulación de Ensayos Clínicos en Seres Humanos. La ley 20.120 (2006), norma la investigación científica en el ser humano, describe aspectos centrales para el desarrollo de la investigación, dando sustento legal a la creación de los Comités Éticos Científicos (CEC), entidades colegiadas que tienen por objeto velar por la protección de la vulneración de derechos y libertades de los participantes, pudiendo aprobar o rechazar los protocolos de los proyectos. En Chile al año 2021 se registran 62 CEC acreditados. La región Metropolitana concentra el 58,2 %, la zona Norte un 11,2 % y en el sur del país un 30,6 %, de ellos solo el 12,9 % están acreditados para evaluar ensayos clínicos aleatorizados (ECA). Los criterios éticos internacionales más utilizados son la Declaración de Helsinki, pautas éticas sobre la salud, bienestar y los derechos de los pacientes; El Consejo Internacional de Ciencias Médicas (CIOMS) que protege en entornos vulnerables de escasos recursos; y el Informe Belmont en la protección de los sujetos de investigación. Se concluye que las guías éticas nacionales e internacionales son pautas que guardan relación con la adecuada protección jurídica de los participantes, velando por el respeto a la autonomía, la justicia y la selección justa de los participantes, a través del consentimiento informado voluntario. El desarrollo de una cultura de conducta ética en la investigación se debe basar en tres dimensiones generales; el ambiente humano, ambiente político y mecanismos de la sociedad civil.

SUMMARY: Scientific research in human beings is essential for the development and advancement of health science and for the well-being of society. The need to have explicit ethical principles and a regulatory framework allowed in 2001 the approval of the Standard on the Regulation of Clinical Trials in Human Beings. Law 20,120 (2006), regulates scientific research in human beings and describes central aspects for the development of research, giving legal support to the creation of Scientific Ethics Committees (SEC), collegiate entities whose purpose is to ensure the protection of the vulnerability of rights and freedoms of the participants, being able to approve or reject the protocols of the projects. In Chile by 2021, 62 accredited CECs are registered. The Metropolitan region concentrates 58.2 %, the North zone 11.2 % and in the south of the country 30.6 %, of which only 12.9 % are accredited to evaluate randomized clinical trials (RCTs). The most widely used international ethical criteria are the Helsinki Declaration, ethical guidelines on health, well-being and the rights of patients; The International Council of Medical Sciences (CIOMS) that protects in vulnerability low-resource settings; and the Belmont Report on the protection of research subjects. It is concluded that the national and international ethical guidelines are appropriate legal ethical guidelines and risk-benefit ratio that protect the participants, ensuring respect for the autonomy, justice and fair selection of the participants, through voluntary informed consent. The development of a culture of ethical conduct in research must be based on three general dimensions; the human environment, political environment and mechanisms of civil society.

National Health Systems and COVID-19 Death Toll Doubling Time.

Coronavirus disease 2019 (COVID-19) has placed stress on all National Health Systems (NHSs) worldwide. Recent studies on the disease have evaluated different variables, namely, quarantine models, mitigation efforts, damage to mental health, mortality of the population with chronic diseases, diagnosis, use of masks and social distancing, and mortality based on age. This study focused on the four NHSs recognized by the WHO. These systems are as follows: (1) The Beveridge model, (2) the Bismarck model, (3) the National Health Insurance (NHI) model, and (4) the "Out-of-Pocket" model. The study analyzes the response of the health systems to the pandemic by comparing the time in days required to double the number of disease-related deaths. The statistical analysis was limited to 56 countries representing 70% of the global population. Each country was grouped into the health system defined by the WHO. The study compared the median death toll DT, between health systems using Mood's median test method. The results show high variability of the temporal trends in each group; none of the health systems for the three analyzed periods maintain stable interquartile ranges (IQRs). Nevertheless, the results obtained show similar medians between the study groups. The COVID-19 pandemic saturates health systems regardless of their management structures, and the result measured with the time for doubling death rate variable is similar among the four NHSs.

Diversity of Non-O157 Shiga Toxin-Producing Escherichia coli Isolated from Cattle from Central and Southern Chile.

Cattle are the main reservoir of Shiga toxin-producing Escherichia coli (STEC), one of the world's most important foodborne pathogens. The pathogen causes severe human diseases and outbreaks. This study aimed to identify and characterize non-O157 STEC isolated from cattle feces from central and southern Chile. We analyzed 446 cattle fecal samples and isolated non-O157 STEC from 12.6% (56/446); a total of 93 different isolates were recovered. Most isolates displayed ß-glucuronidase activity (96.8%; 90/93) and fermented sorbitol (86.0%; 80/93), whereas only 39.8% (37/93) were resistant to tellurite. A subgroup of 30 representative non-O157 STEC isolates was selected for whole-genome sequencing and bioinformatics analysis. In silico analysis showed that they grouped into 16 different sequence types and 17 serotypes; the serotypes most frequently identified were O116:H21 and O168:H8 (13% each). A single isolate of serotype O26:H11 was recovered. One isolate was resistant to tetracycline and carried resistance genes tet(A) and tet(R); no other isolate displayed antimicrobial resistance or carried antimicrobial resistance genes. The intimin gene (eae) was identified in 13.3% (4/30) of the genomes and 90% (27/30) carried the stx2 gene. A phylogenetic reconstruction demonstrated that the isolates clustered based on serotypes, independent of geographical origin. These results indicate that cattle in Chile carry a wide diversity of STEC potentially pathogenic for humans based on the presence of critical virulence genes.

Ética y jurisprudencia administrativa de los derechos de los sujetos de investigación en pandemia (COVID-19): función de los comités éticos científicos: Chile / Ethics and administrative jurisprudence of the rights of subjects of research in pandemic (COVID-19): role of the scientific ethics committees: Chile

RESUMEN: Todo gobierno debe reaccionar rápida y efectivamente ante cualquier pandemia, Chile no es la excepción y apoyado en el estado de Excepción Constitucional, ha tenido que implementar medidas que podrían involucrar poca información sobre las percepciones de las personas y las reacciones durante la implementación de las restricciones. Las instituciones internacionales de salud han determinado que es un deber moral realizar investigaciones que generen evidencia que promuevan y mejoren la atención de la salud y la mitigación de la pandemia, instando a reducir los "obstáculos" prácticos de la revisión ética. Los objetivos de este trabajo fueron analizar desde las perspectivas de las consideraciones éticas y jurídicas, el rol que cumplen los Comités Éticos Científicos en el manejo y la protección de las personas durante la pandemia de la COVID-19. La metodología de trabajo se basó en la recolección de la información de Instituciones nacionales e internacionales de Salud y luego analizarla según la jurisprudencia administrativa del gobierno de Chile. Se concluye que los cambios de criterios que deben observar los CECs en el proceso de revisión de los protocolos de los proyectos de investigación científica, deben velar por proteger los derechos de los pacientes y sujetos de investigación en cuanto puede involucrar información sensible, más aún, si se consideran las graves consecuencias de su transgresión, dar un sentido distinto al que corresponda a las normas sobre derechos de pacientes, puede resultar en "falta de servicio" y eventual vulneración en los derechos del sujeto de investigación. La labor de los CEC, debe realizarse siempre desde una interpretación restrictiva, reconociendo la función pública que cumplen como parte integrante de la labor ética encomendada por el legislador al efecto.

SUMMARY: Every government must react quickly and effectively to any pandemic, Chile is no exception and supported by the state of Constitutional Exception, it has had to implement measures that could involve little information about people's perceptions and reactions during the implementation of the restrictions. International health institutions have determined that it is a moral duty to carry out research that generates evidence that promotes and improves health care and the mitigation of the pandemic, urging to reduce the practical "obstacles" to ethical review. The objective of this study was to analyze from the perspectives of ethical and legal considerations, the role that Scientific Ethics Committees play in the management and protection of people during the COVID-19 pandemic. The methodology used was based on collecting information from national and international Health Institutions and then analyzing it according to the administrative jurisprudence of the Chilean government. It is concluded that the changes in criteria that the CECs must observe in the process of reviewing the protocols of scientific research projects, must ensure the protection of the rights of patients and research subjects insofar as it may involve sensitive information, even more if the serious consequences of its transgression are considered. Giving a different meaning to the one that corresponds may result in "lack of service" and eventual violation of the rights of the research subject. The task of the CEC, must always be carried out from a restrictive interpretation, recognizing the public function that they fulfill as an integral part of the ethical work entrusted by the legislators to that effect.

Whole-Genome Phylogenetic Analysis Reveals a Wide Diversity of Non-O157 STEC Isolated From Ground Beef and Cattle Feces.

Shiga toxin-producing Escherichia coli (STEC) causes foodborne outbreaks that can lead to complications such as hemolytic uremic syndrome. Their main reservoir is cattle, and ground beef has been frequently associated with disease and outbreaks. In this study, we attempted to understand the genetic relationship among STEC isolated in Chile from different sources, their relationship to STEC from the rest of the world, and to identify molecular markers of Chilean STEC. We sequenced 62 STEC isolated in Chile using MiSeq Illumina. In silico typing was determined using tools of the Center Genomic Epidemiology, Denmark University (CGE/DTU). Genomes of our local STEC collection were compared with 113 STEC isolated worldwide through a core genome MLST (cgMLST) approach, and we also searched for distinct genes to be used as molecular markers of Chilean isolates. Genomes in our local collection were grouped based on serogroup and sequence type, and clusters were formed within local STEC. In the worldwide STEC analysis, Chilean STEC did not cluster with genomes of the rest of the world suggesting that they are not phylogenetically related to previously described STEC. The pangenome of our STEC collection was 11,650 genes, but we did not identify distinct molecular markers of local STEC. Our results showed that there may be local emerging STEC with unique features, nevertheless, no molecular markers were detected. Therefore, there might be elements such as a syntenic organization that might explain differential clustering detected between local and worldwide STEC.

Liking Product Landscape: Going Deeper into Understanding Consumers' Hedonic Evaluations.

The use of graphical mapping for understanding the comparison of products based on consumers' perceptions is beneficial and easy to interpret. Internal preference mapping (IPM) and landscape segmentation analysis (LSA) have successfully been used for this propose. However, including all the consumers' evaluations in one map, with products' overall liking and attributes' perceptions, is complicated; because data is in a high dimensional space some information can be lost. To provide as much information as possible, we propose the liking product landscape (LPL) methodology where several maps are used for representing the consumers' distribution and evaluations. LPL shows the consumers' distribution, like LSA, and also it superimposes the consumers' evaluations. However, instead of superimposing the average overall liking in one map, this methodology uses different maps for each consumer's evaluation. Two experiments were performed where LPL was used for understanding the consumers' perceptions and compared with classic methodologies, IPM and cluster analysis, in order to validate the results. LPL can be successfully used for identifying consumers' segments, consumers' preferences, recognizing perception of product attributes by consumers' segments and identifying the attributes that need to be optimized.

Hypercholesterolemia Due to Lipoprotein X: Case Report and Thematic Review.

The liver is a key organ in lipid and lipoprotein metabolism, hence hepatic diseases often manifest as lipid disturbances. Cholestatic liver diseases are frequently associated with an important increase in total cholesterol at the expense of lipoprotein X (LpX), an abnormal lipoprotein isolated and characterized in the 1960s to 1970s in patients with obstructive jaundice. Lipoprotein X is rich in phospholipids, albumin, and free cholesterol, has a density similar to low-density lipoprotein (LDL), and a size similar to very low-density lipoprotein (VLDL), which has hampered its detection through routine laboratory tests. Unlike LDL, LpX has no apoB-100, so it is not removed from circulation via the LDL receptor, and it is not clear whether or not it can be atherogenic. Although LpX was initially described in patients with cholestasis, it has also been found in patients with genetic deficiency of lecithin-cholesterol acyltransferase (LCAT), in patients who receive lipid-rich parenteral nutrition and most recently in patients with graft versus host disease of the liver. In the presence of LpX, plasma total cholesterol can rise up to 1000 mg/dL, which may lead to the development of skin xanthomas and hyperviscosity syndrome. Treatment of LpX-dependent hypercholesterolemia with conventional hypolipidemic drugs is frequently ineffective, and definitive treatment relies on correction of the underlying cause of cholestasis. Here, we present the case of a patient with LpX-dependent hypercholesterolemia in the context of primary biliary cholangitis.

An Intelligent Failure Detection on a Wireless Sensor Network for Indoor Climate Conditions.

Wireless sensor networks (WSN) involve large number of sensor nodes distributed at diverse locations. The collected data are prone to be inaccurate and faulty due to internal or external influences, such as, environmental interference or sensor aging. Intelligent failure detection is necessary for the effective functioning of the sensor network. In this paper, we propose a supervised learning method that is named artificial hydrocarbon networks (AHN), to predict temperature in a remote location and detect failures in sensors. It allows predicting the temperature and detecting failure in sensor node of remote locations using information from a web service comparing it with field temperature sensors. For experimentation, we implemented a small WSN to test our sensor in order to measure failure detection, identification and accommodation proposal. In our experiments, 94.18% of the testing data were recovered and accommodated allowing of validation our proposed approach that is based on AHN, which detects, identify and accommodate sensor failures accurately.

Micro X-ray Fluorescence Study of Late Pre-Hispanic Ceramics from the Western Slopes of the South Central Andes Region in the Arica y Parinacota Region, Chile: A New Methodological Approach.

Archeological ceramic paste material typically consists of a mix of a clay matrix and various millimeter and sub-millimeter sized mineral inclusions. Micro X-ray fluorescence (XRF) is a standard compositional classification tool and in this work we propose and demonstrate an improved fluorescence map processing protocol where the mineral inclusions are automatically separated from the clay matrix to allow independent statistical analysis of the two parts. Application of this protocol allowed us to enhance the discrimination between different ceramic shards compared with the standard procedure of working with only the spatially averaged elemental concentrations. Using the new protocol, we performed an initial compositional classification of a set of 83 ceramic shards from the western slopes of the south central Andean region in the Arica y Parinacota region (Chile). Comparing the classifications obtained using the new versus the old (average concentrations only) protocols, we found that some samples were erroneously classified with the old protocol. From an archaeological perspective, a broad and heterogeneous regional sample set was used in this experimental study due to the fact that this was the first such analysis to be performed on ceramics from this region. This allowed a general overview to be obtained, however further work on more specific sample sets will be necessary to extract concrete archaeological conclusions.

Purificación y caracterización de lipopolisacáridos de Eikenella corrodens 23834 y Porphyromonas gingivalis W83 / Purification and characterization of lipopolysaccharide from Eikenella corrodens 23834 and Porphyromonas gingivalis W83

La purificación de lipopolisacáridos (LPS) o endotoxinas y su caracterización es un aspecto esencial para estudios que buscan aclarar el papel de estas biomoléculas de bacterias Gram negativas presentes en la cavidad oral y su relación con enfermedades locales periodontales y sistémicas. Este estudio implementa una metodología para la extracción, purificación y caracterización de LPS a partir de bacteria completa de Eikenella corrodens 23834 y Porphyromonas gingivalis W83, utilizando técnicas previamente descritas. La extracción cruda de LPS se realizó con fenol-agua caliente; la purificación se realizó con tratamiento enzimático con nucleasas y proteasa, seguido de cromatografía de exclusión por tamaño (Sephacryl S-200 HR) con deoxicolato de sodio como fase móvil. La caracterización de los extractos purificados se realizó por barrido espectrofotométrico, pruebas bioquímicas de electroforesis SDS-PAGE, ensayo Purpald y la prueba cromogénica de LAL. Como control para la identificación y caracterización de los extractos purificados se utilizaron LPS comerciales de Escherichia coli, Salmonella typhimurium, Rodobacter sphaeroides y Porphyromonas gingivalis. La metodología implementada permitió la obtención de LPS de elevada pureza con la identificación de KDO o heptosas, un quimiotipo de LPS-S (liso) para E. corrodens y LPS-SR (semi-rugoso) para P. gingivalis W83. Ambos LPS purificados mostraron capacidad endotóxica a bajas concentraciones. La metodología implementada en este estudio para la purificación y caracterización de LPS a partir de bacteria completa fue eficiente al compararla con los LPS comerciales.

Purification of lipopolysaccharide (LPS) or endotoxins and its characterization is an important aspect for studies aimed at clarify the role of these biomolecules from Gram negative bacteria present in the oral cavity and its relationship with periodontal and systemic diseases. This study describes an extraction, purification and characterization method of LPS from Eikenella corrodens 23834 and Porphyromonas gingivalis W83. LPS extraction was performed by using hot phenol-water; the purification was done with nuclease and protease enzymatic treatment, followed by size-exclusion chromatography (Sephacryl S-200 HR) with sodium deoxycholate as mobile phase. The characterization of the purified extracts was performed by spectrophotometric scanning, SDS-PAGE biochemical tests, Purpald assay and chromogenic LAL test. As control, commercial LPS from Escherichia coli, Salmonella typhimurium, P. gingivalis, and Rodobacter sphaeroides were used. The methodology mentioned above had allowed obtaining high purity LPS by identifying KDO or heptoses, a chemotype S-LPS (smooth) to E. corrodens; SR-LPS (semi-rough) for P. gingivalis W83. Both purified LPS showed endotoxic capacity at low concentrations. The methodology used in this study for purification and characterization of LPS from the whole bacteria was efficient when it was compared with commercial LPS.

Toward Tailor-Made Biocide Materials Based on Poly(propylene)/Copper Nanoparticles.

A set of poly(propylene) composites containing different amounts of copper nanoparticles (CNP) were prepared by the melt mixed method and their antimicrobial behavior was quantitatively studied. The time needed to reduce the bacteria to 50% dropped to half with only 1 v/v % of CNP, compared to the polymer without CNP. After 4 h, this composite killed more than 99.9% of the bacteria. The biocide kinetics can be controlled by the nanofiller content; composites with CNP concentrations higher than 10 v/v % eliminated 99% of the bacteria in less than 2 h. X-ray photoelectron spectroscopy did not detect CNP at the surface, therefore the biocide behavior was attributed to copper in the bulk of the composite.

[Celiac crisis: presentation as bleeding diathesis]. / Crisis celíaca: presentación con diátesis hemorrágica.

Celiac crisis is a severe and potentially fatal complication of celiac disease. Unusual at present, it has been described mainly in children younger than 2-years-old, but reports in adults do exist. We report a 26-years-old lady with tetany and bleeding diathesis at presentation. In spite of it rareness, it is important to consider celiac crisis among the multiple manifestations of celiac disease.