Bioaccumulation of inorganic elements in dreissena polymorpha from the Ebro river, Spain: could zebra mussels be used as a bioindicator of the impact of human activities?

Dreissena polymorpha is among the top 100 most harmful invasive species in aquatic habitats. European Directive 2013/39/UE establishes Environmental Quality Standards for biota because it has been demonstrated that pollutants bioaccumulate in aquatic organisms. This study evaluated bioaccumulation of inorganic elements in the soft tissues of D. polymorpha in order to assess the usefulness of zebra mussels as a bioindicator of contaminant presence in super fi cial waters. Concentrations of 66 elements were measured in order to evaluate their relation- ship with nearby anthropogenic activity and to the values recommended by Environmental Quality Standards for biota. Bivalves were col- lected from four sample points along the Ebro River Basin (Spain), where diverse human activities are carried out. Zebra mussels accumulate toxins in soft tissue during their life cycle, including Al, Cr, Fe, Hg, Pb, Th, Cd and U. The highest levels of accumulation corresponded to elements associated with human activity in the area, showing the impact of anthropogenic actions on biota. D. polymorpha not only supplies information about current water quality but also acts as a witness of past water quality by bioconcentrating toxic elements present in the environment and providing relevant results about historical water contamination. In conclusion, D. polymorpha is a harmful and dangerous invasive species, but its pervasiveness means that it can be used as a bioindicator to assess current and past presence of elements in water

Inhibición del crecimiento y enquistamiento de <i>Entamoeba histolytica</i> por liofilizados de factores difusibles de <i>Lactobacillus plantarum</i> y <i>Bifidobacterium longum</i>

Entamoeba histolytica es el agente causal de la amibiasis, la cual presenta dos estadios en su ciclo de vida: el trofozoíto y el quiste; el trofozoíto representa la fase invasiva, el quiste representa la fase infestiva y de resistencia. La droga para el tratamiento de la amibiasis es el metronidazol; sin embargo esta droga presenta múltiples efectos secundarios indeseables; por lo que es necesaria la búsqueda de nuevas alternativas terapéuticas. La Organización Mundial de la Salud ha propuesto el empleo de microorganismos para el diseño de terapias de interferencia microbiana. Entre los microorganismos recomendados se encuentran los lactobacillus y bifidobacterias.Universidad Nacional de La Plat

Inhibición del crecimiento y enquistamiento de <i>Entamoeba histolytica</i> por liofilizados de factores difusibles de <i>Lactobacillus plantarum</i> y <i>Bifidobacterium longum</i>

Entamoeba histolytica es el agente causal de la amibiasis, la cual presenta dos estadios en su ciclo de vida: el trofozoíto y el quiste; el trofozoíto representa la fase invasiva, el quiste representa la fase infestiva y de resistencia. La droga para el tratamiento de la amibiasis es el metronidazol; sin embargo esta droga presenta múltiples efectos secundarios indeseables; por lo que es necesaria la búsqueda de nuevas alternativas terapéuticas. La Organización Mundial de la Salud ha propuesto el empleo de microorganismos para el diseño de terapias de interferencia microbiana. Entre los microorganismos recomendados se encuentran los lactobacillus y bifidobacterias.Universidad Nacional de La Plat

Aflatoksin M1 u mliječnim međuproduktima nastalim u proizvodnji Manchego sira: razdioba i postojanost

Aflatoxin M1 (AFM1) distribution in curd, whey, Manchego cheese, the traditional Spanish whey cheese Requesón and Requesón whey, and its stability during two different cold treatments, have been studied. Raw ewe’s milk was artificially contaminated with AFM1 in a final concentration of 50 and 100 ng kg-1, and was used to produce Manchego cheese. AFM1 determinations were carried out by HPLC with fluorimetric detection after immunoaffinity clean-up. The mean AFM1 concentrations in the produced curd and Manchego cheese were approximately 2- and 3-fold higher than the initial milk they were made from, and the levels of this toxin remaining in whey were 42.3 % and 51.3 % of the initial concentrations. In the Requesón samples, the mean AFM1 values were 1.7 times higher than those in the corresponding whey, while 33.7 % and 44.4 % of the AFM1 concentration detected in milk also appeared in the Requesón whey. Short refrigeration and freezing periods did not affect the toxin levels in either curd or Requesón samples. When ewe’s milk destined for Manchego cheese-making is AFM1-contaminated at the EU limit level (50 ng kg-1) or double, a concentration of this toxin will appear in the manufactured products, but values will be considerably below the toxic doses (Tolerable Daily Intake = 2 ng kg-1 body weight per day), which poses a human health problem.U istraživanju je utvrđivana razdioba aflatoksina M1 (AFM1) u grušu, sirutki, Manchego siru, tradicionalnom španjolskom Requesón siru načinjenom od sirutke i Requesón sirutki te njegova stabilnost tijekom dva različita tretmana hlađenja. Svježe ovčje mlijeko je “umjetno” kontaminirano s AFM1 u završnoj koncentraciji od 50 i 100 ng kg-1 i korišteno je u proizvodnji Manchego sira. Koncentracije AFM1 mjerene su HPLC fluorometrijskom detekcijom nakon potpunog pročišćavanja imunoafinitetnim postupkom. Srednje vrijednosti koncentracija AFM1 u proizvedenom grušu i Manchego siru bile su oko 2 do 3 puta veće od prvotnog mlijeka od kojeg su načinjeni, a razine toksina zaostale u sirutki bile su 42,3 % i 51,3 % od početne koncentracije. U Requesón uzorcima srednje AFM1 vrijednosti bile su 1,7 puta veće od onih u uzorcima sirutke, dok su AFM1 koncentracije 33,7 % i 44,4 % utvrđene u mlijeku, također utvrđene i u odgovarajućim uzorcima Requesón sirutke. Kratka razdoblja hlađenja i zamrzavanja nisu utjecala na razinu toksina u grušu i Requesón uzorcima. U slučaju kada je ovčje mlijeko namijenjeno za proizvodnju Manchego sira kontaminirano s AFM1 na razini EU-propisa (50 ng kg-1), ili dvostruko većom od te granice, određena koncentracija tog toksina pojavit će se u prerađevinama, ali će vrijednosti biti znatno niže od toksičnih doza (podnošljive dnevne doze = 2 ng kg-1 tjelesne mase dnevno), što predstavlja određeni problem za ljudsko zdravlje

Association between preoperative levels of 25-hydroxyvitamin D and hospital-acquired infections after hepatobiliary surgery: A prospective study in a third-level hospital

Introduction Evidence implicates vitamin D deficiency in poorer outcomes and increased susceptibility to hospital-acquired infections (HAIs). This study examined the association between serum vitamin D levels and HAIs in a population of hepatobiliary surgery patients. Methods Participants in this prospective analytical observational study were patients who underwent hepatobiliary surgery in a tertiary hospital in Aragon, Spain, between February 2018 and March 2019. Vitamin D concentrations were measured at admission and all nosocomial infections during hospitalization and after discharge were recorded. Results The mean 25-hydroxyvitamin D concentration of the study population (n = 301) was 38.56 nmol/L, which corresponds to vitamin D deficiency. Higher vitamin D concentrations were associated with a decreased likelihood of developing a HAI in general (p = 0.014), and in particularly surgical site infection (p = 0.026). The risk of HAI decreased by 34% with each 26.2-nmol/L increase in serum vitamin D levels. Conclusions Vitamin D levels may constitute a modifiable risk factor for postoperative nosocomial infections in hepatobiliary surgery patients

Amebas de vida libre en aguas residuales y fangos: Su papel como reservorio natural de bacterias potencialmente patógenas

Las amebas de vida libre (AVL) son protozoos ubicuos, presentes en suelos y en ecosistemas acuáticos naturales y artificiales. Participan en los procesos de depuración desarrollados en las Estaciones Depuradoras de Aguas Residuales (EDAR), convirtiéndolas en un nicho ecológico idóneo para la proliferación de AVL, que las colonizan e instauran en ellas su hábitat, ya que se alimentan de bacterias presentes en el medio. Los procesos de depuración biológica no están diseñados con el fin de eliminar la contaminación microbiológica, aunque ayudan a reducir algunas poblaciones bacterianas. Hasta la fecha, sólo algunas especies y géneros de AVL han sido descritos como patógenos, pero todas ellas suponen un riesgo como reservorio de bacterias patógenas. Su forma quística, les confiere resistencia frente a las condiciones adversas y desinfectantes comunes, permitiéndoles superar los procesos de depuración y potabilización y colonizar sistemas artificiales de agua. En este trabajo, se estudió la presencia de AVL en aguas y fangos de 5 EDAR que vierten sus aguas a la cuenca del Ebro, analizando un total de 20 puntos de muestreo. Para ello, se llevó a cabo el aislamiento AVL y la posterior identificación de género y especie, así como de las bacterias endosimbiontes, mediante la reacción en cadena de la polimerasa (PCR). De las 41 amebas aisladas en el 85 % de las muestras, 21 fueron identificadas genéticamente. Trece de ellas, pertenecieron al género Acanthamoeba spp., 6 a Naegleria spp. y 2 se identificaron como Vermamoeba vermiformis. El 53,66 % de las AVL albergaba en su interior Mycobacterium spp., el 29,27 % Legionella pneumophila y el 14,63 % Pseudomonas spp. Free-living amoebae (FLA) are ubiquitous protozoa, present in soils and in natural and artificial aquatic ecosystems. They take part in the purification processes that take place in Wastewater Treatment Plants (WWTPs), thereby turning these plants into ecological niches suitable for proliferation of FLAs, which they colonize and in which they establish their habitat, since they feed on bacteria present in the environment. Biological purification processes are not designed to remove microbiological contamination, although they help to reduce some microbial populations. At present only some genera and species of FLAs have been described as pathogenic, but all of them pose a risk as reservoirs of pathogenic bacteria. Their cystic stage gives them resistance to adverse conditions and common disinfectants, allowing them to withstand water purification processes and colonize artificial water systems. The presence of FLAs in waters and sludges from 5 WWTPs that discharge their waters into the Ebro river basin has been studied in this work. To this end, a total of 20 sample points were analysed by isolating the FLAs and subsequently identifying their genus and species. The same was done for endosymbiotic bacteria, by Polymerase Chain Reaction (PCR). Out of 41 FLAs that were isolated in 85 % of the samples, 21 were genetically identified. Thirteen belonged to the genus Acanthamoeba spp., 6 to Naegleria spp. and 2 were identified as Vermamoeba vermiformis. 53.66 % of FLAs hosted Mycobacterium spp., 29.27 % Legionella pneumophila, and 14.63 % Pseudomonas spp

Ligand-independent oligomerization of TACI is controlled by the transmembrane domain and regulates proliferation of activated B cells.

In mature B cells, TACI controls class-switch recombination and differentiation into plasma cells during T cell-independent antibody responses. TACI binds the ligands BAFF and APRIL. Approximately 10% of patients with common variable immunodeficiency (CVID) carry TACI mutations, of which A181E and C172Y are in the transmembrane domain. Residues A181 and C172 are located on distinct sides of the transmembrane helix, which is predicted by molecular modeling to spontaneously assemble into trimers and dimers. In human B cells, these mutations impair ligand-dependent (C172Y) and -independent (A181E) TACI multimerization and signaling, as well as TACI-enhanced proliferation and/or IgA production. Genetic inactivation of TACI in primary human B cells impaired survival of CpG-activated cells in the absence of ligand. These results identify the transmembrane region of TACI as an active interface for TACI multimerization in signal transduction, in particular for ligand-independent signals. These functions are perturbed by CVID-associated mutations

Identification and validation of common molecular targets of hydroxytyrosol

Hydroxytyrosol (HT) is involved in healthful activities and is beneficial to lipid metabolism. Many investigations focused on finding tissue-specific targets of HT through the use of different omics approaches such as transcriptomics and proteomics. However, it is not clear which (if any) of the potential molecular targets of HT reported in different studies are concurrently affected in various tissues. Following the bioinformatic analyses of publicly available data from a selection of in vivo studies involving HT-supplementation, we selected differentially expressed lipid metabolism-related genes and proteins common to more than one study, for validation in rodent liver samples from the entire selection. Four miRNAs (miR-802-5p, miR-423-3p, miR-30a-5p, and miR-146b-5p) responded to HT supplementation. Of note, miR-802-5p was commonly regulated in the liver and intestine. Our premise was that, in an organ crucial for lipid metabolism such as the liver, consistent modulation should be found for a specific target of HT even if different doses and duration of HT supplementation were used in vivo. Even though our results show inconsistency regarding differentially expressed lipid metabolism-related genes and proteins across studies, we found Fgf21 and Rora as potential novel targets of HT. Omics approaches should be fine-tuned to better exploit the available databases

Aharonov-Bohm spectral features and coherence lengths in carbon nanotubes

The electronic properties of carbon nanotubes are investigated in the presence of disorder and a magnetic field parallel or perpendicular to the nanotube axis. In the parallel field geometry, the $\phi_{0}(=hc/e)$-periodic metal-insulator transition (MIT) induced in metallic or semiconducting nanotubes is shown to be related to a chirality-dependent shifting of the energy of the van Hove singularities (VHSs). The effect of disorder on this magnetic field-related mechanism is considered with a discussion of mean free paths, localization lengths and magnetic dephasing rate in the context of recent experiments.Comment: 22 pages, 6 Postscript figures. submitted to Phys. Rev.

El gen tpi como herramienta en los estudios epidemiolo´gicos de la giardiosis

Giardia duodenalis es un protozoo que causa infección en humanos y animales, que se puede transmitir por vía hídrica, de persona a persona o por contacto con animales, siendo una de las infecciones intestinales más frecuentes en nuestro país, por lo que supone una preocupación de Salud Pública. Su estudio epidemiológico, requiere la caracterización molecular de los parásitos, utilizando genes con gran variabilidad como el que codifica la triosafosfatoisomerasa (tpi) y analizando la homología entre aislamientos. El objetivo del trabajo es establecer el criterio de identidad que permita la comparación epidemiológica de los aislamientos de Giardia. Se recogieron 2-3 muestras de heces en días alternos, de 26 pacientes con giardiosis. Tras la extracción de ADN, se amplificaron por técnicas de PCR, un fragmento del gen tpi y un fragmento del gen de la beta-giardina (bg), que se utilizó como comparación. Los fragmentos obtenidos fueron secuenciados y las secuencias analizadas con los programas BioEdit y DnaSP v.5.0. Las secuencias del gen tpi mostraron una elevada divergencia, con valores de diversidad ¿ entre 0 y 0, 21219. La aparición de picos múltiples en el cromatograma, indicaron la presencia de varios clones en la misma muestra. Las diferencias entre aislamientos del mismo paciente fueron iguales o mayores que las encontradas para el conjunto de todas las muestras. La variabilidad del gen tpi no permite establecer unos criterios de identidad, necesarios para la identificación de aislamientos. Las infecciones mixtas intragenotipo ocurren de una forma muy frecuente, sugiriendo una implicación de la vía ambiental como principal fuente de transmisión o una variación genética muy elevada. Giardia duodenalis is a protozoon that causes infection in humans and animals. It can be transmitted by contaminated water, from person to person or by contact with animals; it being the cause one of the most common intestinal infections in our country, so it is a public health concern. The epidemiological study thereof requires the molecular characterization of parasites, using genes with great variability, such as the one that codes triosephosphate isomerase (tpi), and analizing the homology between isolates. The purpose of this work is to establish the identity criterion for epidemiological comparison of Giardia isolates. 2-3 stool samples were collected in alternate days from 26 patients with giardiasis. After DNA extraction, a fragment of the tpi gene and a fragment of the beta-giardin (bg) gene-used for comparison purposes-were amplified by means of PCR techniques. The obtained fragments were sequenced and the sequences analyzed with the BioEdit and DnaSP v.5.0 software. The tpi gene sequences showed a high divergence, with values of diversity ¿ ranging from 0 to 0.21219. The appearance of multiple peaks in the chromatogram points to the presence of various clones in the same sample. The differences between isolates from the same patient where equal or higher than those found for the collection of all samples. The variability of the tpi gene does not allow identity criteria to be established, which are necessary for isolate identification. Mixed intragenotype infections occur very frequently, which suggests the environmental path is the principal path of transmission and/or there is very high genetic variability