Simple-to-use and portable device for free chlorine determination based on microwave-assisted synthesized carbon dots and smartphone images.

A new portable and simple 3D printed device was designed for free chlorine determination in water samples. The analytical method was based on the quenching caused by free chlorine on the fluorescence emission of the carbon dots (CD) synthesized from citric acid and urea. The fluorescence was captured through the camera of a smartphone, which was coupled to the 3D printed device, and the images were processed using the RGB system by the ImageJ 1.51q software. The proposed method was selective and precise (RSD% 4.6, for n = 6), and the trueness of the results was evaluated by comparing the results obtained with those recovered by the spectrophotometric method 4500-Cl G (standard method), with good agreement between them. Moreover, the remarkable correlation between the CD signal and the free chlorine concentration resulted in a determination with low detection limits (limit of detection of 6 µg L-1 and limit of quantification of 20 µg L-1). Therefore, the new method and the related portable device could be considered a fast, economical and reliable alternative for the on-site determination of free chlorine in water samples.

Dispersive micro solid-phase extraction (DµSPE) with graphene oxide as adsorbent for sensitive elemental analysis of aqueous samples by laser induced breakdown spectroscopy (LIBS).

In this work, the combination of dispersive micro solid-phase extraction (DµSPE) with laser-induced breakdown spectroscopy (LIBS) was evaluated for simultaneous preconcentration and detection of Zn, Cd, Mn, Ni, Cr and Pb in aqueous samples. Two adsorbent materials were tested in the microextraction step, namely graphene oxide and activated carbon. In both cases, the microextraction process consisted in the dispersion of a small quantity of adsorbent in the sample solution containing the analytes. However, while the use of activated carbon required a previous chelation of the metals, this step was avoided with the use of graphene oxide. After extraction, the analytes retained in the adsorbents were analysed by LIBS. Several experimental factors affecting the extraction of the metals (adsorbent amount, pH and extraction time) were optimized by means of the traditional univariate approach. Under optimum microextraction conditions, the analytical features of the proposed DµSPE-LIBS methods were assessed, leading to limits of detection below 100 µg kg-1 and 50 µg kg-1 with the use of activated carbon and graphene oxide, respectively, as adsorbents in the DµSPE process. Trueness evaluation of the most sensitive procedure was carried out by spike and recovery experiments in a real sample of tap water, leading to recovery values in the range 98-110%.

First-time-in-human randomized clinical trial in healthy volunteers and haemodialysis patients with SNF472, a novel inhibitor of vascular calcification.

AIMS: SNF472 is a calcification inhibitor being developed for the treatment of cardiovascular calcification in haemodialysis (HD) and in calciphylaxis patients. This study investigated the safety, tolerability and pharmacokinetics (PK) of intravenous (IV) SNF472 in healthy volunteers (HV) and HD patients. METHODS: This is a first-time-in-human, double-blind, randomized, placebo-controlled Phase I study to assess the safety, tolerability and PK of SNF472 after ascending single IV doses in HV and a single IV dose in HD patients. A pharmacodynamic analysis was performed to assess the capability of IV SNF472 to inhibit hydroxyapatite formation. RESULTS: Twenty HV and eight HD patients were enrolled. The starting dose in HV was 0.5 mg kg-1 and the dose ascended to 12.5 mg kg-1 . The dose selected for HD patients was 9 mg kg-1 . Safety analyses support the safety and tolerability of IV SNF472 in HD patients and HV. Most treatment-emergent adverse events were mild in intensity. No clinically significant effects were observed on vital signs or laboratory tests. PK results were similar in HD patients and HV and indicate a lack of significant dialysability. Pharmacodynamic analyses demonstrated that SNF472 administration reduced hydroxyapatite crystallization potential in HD patients who received IV SNF472 9 mg kg-1 by 80.0 ± 2.4% (mean ± standard error of the mean, 95% CI, 75.3-84.8) compared to placebo (8.7 ± 21.0%, P < 0.001, 95% CI, -32.4 to 49.7). CONCLUSION: The results from this study showed acceptable safety and tolerability, and lack of significant dialysability of IV SNF472. It is a potential novel treatment for cardiovascular calcification in end-stage renal disease and calciphylaxis warranting further human studies.

Portable electrochemical sensor based on 4-aminobenzoic acid-functionalized herringbone carbon nanotubes for the determination of ascorbic acid and uric acid in human fluids.

A new portable electrochemical sensor based on 4-aminobenzoic acid-modified herringbone carbon nanotubes (hCNTs-4ABA/Au-IDA) has been developed for the simultaneous determination of ascorbic acid (AA) and uric acid (UA) in physiological fluids. AA and UA were quantified by chronoamperometry at 0.1 and 0.32 V, respectively, in phosphate buffer solution (PBS 0.25 M, pH 7.0). Significant results were obtained for the separate quantification of AA and UA, with a limit of detection (LOD) of 0.65 µM for both analytes, and sensitivities of (9.0 ±â€¯0.4) A g-1 mM-1 and (8.8 ±â€¯0.3) A g-1 mM-1 for AA and UA, respectively. Repeatability was studied at 50 µM for AA and UA, providing relative standard deviations (RSD) lower than 9%. Additions of glucose, dopamine and epinephrine did not interfere with the AA and UA determination. Furthermore, UA did not interfere with AA determination at 0.1 V, although AA additions increased the current recorded at 0.32 V. The method has been successfully applied to human urine, perspiration and serum samples, without significant matrix effects, which allows for the use of an external calibration and the analysis of all the matrices investigated.

A stretchable and screen-printed electrochemical sensor for glucose determination in human perspiration.

Here we present two types of all-printable, highly stretchable, and inexpensive devices based on platinum (Pt)-decorated graphite for glucose determination in physiological fluids. Said devices are: a non-enzymatic sensor and an enzymatic biosensor, the latter showing promising results. Glucose has been quantified by measuring hydrogen peroxide (H2O2) reduction by chronoamperometry at -0.35V (vs pseudo-Ag/AgCl) using glucose oxidase immobilized on Pt-decorated graphite. The sensor performs well for the quantification of glucose in phosphate buffer solution (0.25M PBS, pH 7.0), with a linear range between 0 mM and 0.9mM, high sensitivity and selectivity, and a low limit of detection (LOD). Thus, it provides an alternative non-invasive and on-body quantification of glucose levels in human perspiration. This biosensor has been successfully applied on real human perspiration samples and results also show a significant correlation between glucose concentration in perspiration and glucose concentration in blood measured by a commercial glucose meter.

Niche modelling of the Chilean recluse spider Loxosceles laeta and araneophagic spitting spider Scytodes globula and risk for loxoscelism in Chile.

In Chile, all necrotic arachnidism is attributed to the Chilean recluse spider Loxosceles laeta (Nicolet) (Araneae: Sicariidae). It is predated by the spitting spider Scytodes globula (Nicolet) (Araneae: Scytodidae). The biology of each of these species is not well known and it is important to clarify their distributions. The aims of this study are to elucidate the variables involved in the niches of both species based on environmental and human footprint variables, and to construct geographic maps that will be useful in estimating potential distributions and in defining a map of estimated risk for loxoscelism in Chile. Loxosceles laeta was found to be associated with high temperatures and low rates of precipitation, whereas although S. globula was also associated with high temperatures, its distribution was associated with a higher level of precipitation. The main variable associated with the distribution of L. laeta was the human footprint (48.6%), which suggests that this is a highly invasive species. Similarly to other species, the distribution of L. laeta reaches its southern limit at the Los Lagos region in Chile, which coincides with high levels of precipitation and low temperatures. The potential distribution of L. laeta in Chile corresponds to the distribution of cases of loxoscelism.

Niche modelling of the Chilean recluse spider Loxosceles laeta and araneophagic spitting spider Scytodes globula and risk for loxoscelism in Chile

In Chile, all necrotic arachnidism is attributed to the Chilean recluse spider Loxosceles laeta (Nicolet) (Araneae: Sicariidae). It is predated by the spitting spider Scytodes globula (Nicolet) (Araneae: Scytodidae). The biology of each of these species is not well known and it is important to clarify their distributions. The aims of this study are to elucidate the variables involved in the niches of both species based on environmental and human footprint variables, and to construct geographic maps that will be useful in estimating potential distributions and in defining a map of estimated risk for loxoscelism in Chile. Loxosceles laeta was found to be associated with high temperatures and low rates of precipitation, whereas although S.globula was also associated with high temperatures, its distribution was associated with a higher level of precipitation. The main variable associated with the distribution of L.laeta was the human footprint (48.6%), which suggests that this is a highly invasive species. Similarly to other species, the distribution of L.laeta reaches its southern limit at the Los Lagos region in Chile, which coincides with high levels of precipitation and low temperatures. The potential distribution of L.laeta in Chile corresponds to the distribution of cases of loxoscelism

An entomological and seroepidemiological study of the vectorial-transmission risk of Chagas disease in the coast of northern Chile.

Four species of triatomines are known from Chile: Triatoma infestans Klug, Mepraia spinolai Porter, M. gajardoi Frías, Henry & González, and M. parapatrica Frías (Hemiptera: Reduviidae), the last three are endemic. The geographical distribution of M. gajardoi includes the coastal areas in the north of Chile between 18° and 21°S, an area with both a resident workforce and summer-season visitors. A study was developed to assess the risk of vectorial transmission of Chagas disease by M. gajardoi in hut settlements on the coast of the Tarapacá Region, in particular in Caleta San Marcos and Caleta Río Seco. The study comprised fingerstick sampling of 95 persons, venous samples from 29 domestic dogs and capture of 52 triatomines, from both fishing coves. The samples were analysed by enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR) techniques. The results show that, of the total number of persons studied, 100% were negative for Trypanosoma cruzi Chagas (Trypanosomatida: Trypanosomatidae) antibodies, 10.34% of canids were positive for the antibody and 5.8% of M. gajardoi were infected to the PCR technique. The presence of this species in areas close to human settlements constitutes a risk to human populations established on the coast of northern Chile.

Calidad de vida en pacientes con cáncer de próstata: Validación de un instrumento para la práctica clínica / Quality of life in patients with prostate cancer: validation of an instrument for clinical practice

OBJETIVO: Actualmente existen instrumentos para evaluar los distintos aspectos en el impacto sobre la calidad de vida en aquellos pacientes portadores de cáncer de próstata que son sometidos a algún tipo de tratamiento, pero la mayoría son de 50 o más preguntas y de difícil aplicación en la práctica clínica. Recientemente se ha publicado la validación en inglés de una versión acortada del instrumento más utilizado para medir la calidad de vida en pacientes con cáncer de próstata: EPIC (Expanded Prostate Cancer Composite). Esta versión denominada EPIC-CP (Expanded Prostata Cancer Composite-Clinical Practice) consiste en 16 preguntas dispuestas en una página, de fácil y rápida aplicación clínica. El objetivo primario de este trabajo fue desarrollar y validar el cuestionario EPIC-CP en español como instrumento de evaluación de calidad de vida en pacientes con cáncer de próstata (CaP). Un objetivo secundario fue la observación de las diferencias de los aspectos que impactan en la calidad de vida entre los pacientes tratados y los candidatos a tratamiento. MÉTODOS: Se realizó una traducción inversa-directa al español de la versión original de la encuesta. Se aplicaron 128 cuestionarios de calidad de vida EPIC-CP y EQ5D (cuestionario de salud del EuroQuol Group Association) a 46 (40%) pacientes candidatos a ser sometidos a diferentes tratamientos - Prostatectomía abierta (PA), Prostatectomía robótica (PR), Braquiterapia (Br) o Radioterapia Conformacional (RC)- y a 82 (64%) pacientes ya tratados (9 PA, 13 PR, 7 Br y 4 RC). Para evaluar la confiabilidad se evaluó la consistencia interna a través del Coeficiente Alfa de Cronbach para cada categoría de la EPIC-CP. Para valorar la sensibilidad al cambio se compararon las puntuaciones en pacientes tratados y no tratados con el test de Suma de Rangos de Wilcoxon. RESULTADOS: En todos los dominios de la EPIC-CP, se obtuvo un consistencia interna elevada (alfa de Cronbach 0,66-0,9). No se encontraron diferencias significativas en la edad ni en el nivel educacional entre pacientes tratados y no tratados. Se encontraron diferencias significativas en la puntuación total de la EPIC CP entre pacientes tratados y no tratados en los dominios incontinencia urinaria (p = 0,0002), función intestinal (p = 0,04), sexual (p < 0,0001) y función hormonal (p = 0,002). CONCLUSIÓN: La versión en del EPIC-CP es confiable y válida, por lo que resulta una herramienta útil para medir la calidad de vida en pacientes con CaP, así como el impacto de distintos tratamientos en ella

OBJECTIVES: Currently there are instruments to evaluate the different features of the impact on quality of life in those patients with prostate cancer undergoing any type of treatment, but most of them have 50 or more questions and they are difficult to apply in clinical practice. An English validation of a shortened version of the EPIC (Expanded Prostate Cancer Composite), the most used instrument to measure the quality of life in patients with prostate cancer, has been published recently. This version called EPIC-CP (Expanded Prostate Cancer Composite-Clinical Practice) consists of 16 questions arranged in a page, for easy and rapid clinical application. The objective of this work is to validate a Spanish version of the EPIC-CP. METHOD: An inversa-directa Spanish translation of the original version was performed. The EPIC-CP and EQ5D questionnaires were applied to 46 patients eligible to be subjected to different treatments - open prostatectomy (OP), Robotic Prostatectomy (RP), brachytherapy (Br) or conformational radiotherapy (CR) - and 82 patients already treated (9 OP, 13 RP, 7 Br, 4 CR). For reliability evaluation, the Cronbach's alpha was used to test the internal consistency for each domain of the EPIC-CP. Treated and untreated patients' scores were compared with the Wilcoxon range sum test to assess the sensitivity to change. RESULTS: Cronbach's alpha was elevated in all the EPIC-CP domains (near or greater than 0.7), indicating a high internal consistency. There was no significant difference in age and educational level between treated and untreated patients. We found significant differences between treated and untreated patients in the total EPIC CP score, in the domains of urinary incontinence, bowel function, sexual function and hormonal function. CONCLUSIÓN: The Spanish version of the EPIC-CP is reliable and valid, so it is a useful tool to measure the quality of life in patients with prostate cancer, as well as the impact of different treatments

Dispersive liquid-liquid microextraction for metals enrichment: a useful strategy for improving sensitivity of laser-induced breakdown spectroscopy in liquid samples analysis.

A rapid and efficient Dispersive Liquid-Liquid Microextraction (DLLME) followed by Laser-Induced Breakdown Spectroscopy detection (LIBS) was evaluated for simultaneous determination of Cr, Cu, Mn, Ni and Zn in water samples. Metals in the samples were extracted with tetrachloromethane as pyrrolidinedithiocarbamate (APDC) complexes, using vortex agitation to achieve dispersion of the extractant solvent. Several DLLME experimental factors affecting extraction efficiency were optimized with a multivariate approach. Under optimum DLLME conditions, DLLME-LIBS method was found to be of about 4.0-5.5 times more sensitive than LIBS, achieving limits of detection of about 3.7-5.6 times lower. To assess accuracy of the proposed DLLME-LIBS procedure, a certified reference material of estuarine water was analyzed.

Diagnóstico de la isquemia cerebral tardía y el vasoespasmo en la hemorragia subaracnoidea: ¿hasta cuándo monitorizar? / Diagnosis of delayed cerebral ischaemia and vasospasm in subarrachnoid haemorrhage: How long should they be monitored?

No disponible

Vasoespasmo cerebral tardio posterior a hemorragia subaracnoidea. Correlación por Dopplertranscraneal y TAC de perfusión / No disponible

No disponible

Valoración dinámica de la habilidad narrativa: aplicación en un caso de trastorno específico del lenguaje / Dynamic Assessment of the Narrative Ability: its use in a specific language impairment diagnosed child

La evaluación desde un modelo interactivo, como esel caso de la valoración dinámica, permite observare interpretar el proceso de aprendizaje de los niños ala vez que aporta criterios para definir los objetivos yestrategias a trabajar durante la intervención. Esteprocedimiento es realmente valioso en el marco de laintervención en narración con alumnos diagnosticadosde trastorno específico de lenguaje debido a lacomplejidad lingüística y cognitiva del aprendizajenarrativo. La valoración dinámica se convierte en estecaso en un instrumento útil ya que permite a loslogopedas conocer cómo el niño aprende, cómo usala nueva información y la transfiere o generaliza ennuevas habilidades. En este trabajo se quiere destacarla utilidad de este modelo

The evaluation from an interactive model, as it isthat of the Dynamic Assessment, allows both toobserve and to interpret the learning processes usedby a child and to give useful information in order todefine the goals and strategies to teach during languageintervention. This interactive assessment isreally powerful during narrative work in childrenwith Specific Language Impairment because of thecognitive and linguistic complexity of the narrativelearning. The Dynamic Assessment becomesthen an useful instrument as it allows speech therapiststo realize how that child learns, how he usesthe new information, and how he transfers or generalizesit into new abilities, This paper wants tounderline the usefulness of this model

[Study of renal function and compensatory changes in children with single kidney]. / Determinación de función renal y cambios compensadores en niños con riñón único.

INTRODUCTION: It has always been thought that a reduction of renal tissue in childhood sometimes causes some irreversible injury in the remnant kidney as the years go by. The aim of this paper is to look over the presence of these changes and identify the risk of nephropaty throughout several parameters. MATERIAL AND METHODS: We reviewed 38 children, 23 males and 15 females, aged between 1 and 15 years, who had lost unilateral renal mass because of congenital or adquired diseases. We made two groups of patients on the basis of having born without any unilateral renal function -group I- or having lost unilateral renal function after the second year of life. We measured: Somatometry, arterial pressure, glomerular filtration, microalbuminuria, renal volume and gammagraphic studies were also made. We also considered the presence of contralateral anomalies. RESULTS: Body weight and height were within normal percentiles. Arterial pressure increased in 5 patients. Seric creatinine was normal, creatinine clearance (Ccr) was higher than normal in all patients of both groups, and urinary excretion of protein was normal. Renal volume of remnant kidney was similar in both groups, and no relation with renal function level was found, but it increased through the years. Isotopic studies showed ectatic drainage in all urinary systems. Contralateral anomalies were seen in 7 patients, and they consisted in hydronephrosis and vesico-ureteral reflux. CONCLUSIONS: Hypertension was not related to the cause of renal absence nor the pathology of remnant kidney. Ccr was higher than normal, showing an hyperfiltration status, not confirmed by the values of isotopic filtrate. Renal volume reached by the single kidney was affected by the time after the renal loss, and apparently has been slowed down in cases with contralateral anomalies.

Determinación de función renal y cambios compensadores en niños con riñón único / Study of renal function and compensatory changes in children with single kidney

Introducción. Se ha considerado siempre que la reducción de la masa renal durante la infancia, causa una serie de cambios funcionales que eventualmente pueden conducir a un daño irreversible en el riñón remanente con el paso de los años. Objetivos. La evidencia de estas lesiones en múltiples publicaciones nos movió a revisar a un grupo de 38 pacientes monorrenos en la edad infantil y a intentar determinar el riesgo de aparición de las mismas a través de parámetros como la función renal, la tensión arterial, la presencia de proteinuria y el volumen renal. Material y métodos. Se estudiaron 38 pacientes, 23 de ellos varones y 15 mujeres, de edades entre 1 y 13 años, que habían sufrido pérdida de masa renal por causas congénitas o adquiridas. Se separaron en dos grupos de enfermos: Grupo I: Ausencia congénita unilateral de riñón funcionante (25 casos). Grupo II: Nefrectomizados por pérdida de un riñón(con función previa normal) después del segundo año de vida (13 casos). Se midió la somatometría, la tensión arterial (TA), el filtrado glomerular (FG), la proteinuria, el volumen renal (VR) y se consideró la presencia de anomalías contralaterales (AC). Resultados. El peso y la talla se encontró en percentiles normales. La TA se encontró elevada en 5 pacientes. La creatinina sérica sólo estaba elevada en 1 paciente con severa afectación del riñón remanente, el aclaramiento de creatinina (Ccr) resultó elevado de forma generalizada y se observó microalbuminuria en 2 pacientes. El volumen renal fue similar en ambos grupos. El estudio isotópico evidenció ectasia sin obstrucción en el 80% de todos los casos y el FG según el método de Inoue (corregido para niños) resultó en ambos grupos dentro de valores normales. Conclusiones. No encontramos diferencias significativas en la función renal entre los dos grupos de pacientes ni tampoco indicios de nefropatía por hiperfiltración. El Ccr evidenció una situación de hiperfiltrado en todos los casos. El filtrado glomerular calculado por estudio isotópico no confirmó estasituación. El volumen renal no se observó relacionado con la edad a la que se produjo la pérdida renal, y sí con el tiempo transcurrido postpérdida. La existencia de anomalías en el riñón contralateral influye en el grado de hipertrofia que desarrolla (AU)

Introduction. It has always been thought that a reduction of renal tissue in childhood sometimes causes some irreversible injury in the remnant kidney as the years go by. The aim of this paper is to look over the presence of these changes and identify the risk of nephropaty throughout several parameters. Material and methods. We reviewed 38 children, 23 males and 15 females, aged between 1 and 15 years, who had lost unilateral renal mass because of congenital or adquired diseases. We made two groups of patients on the basis of having born without any unilateral renal function –group I– or having lost unilateral renal function after the second year of life. We measured: Somatometry, arterial pressure, glomerular filtration, microalbuminuria, renal volume and gammagraphic studies were also made. We also considered the presence of contralateral anomalies. Results. Body weight and height were within normal percentiles. Arterial pressure increased in 5 patients. Seric creatinine was normal, creatinine clearance (Ccr) was higher than normal in all patients of both groups, and urinary excretion of protein was normal. Renal volume of remnant kidney was similar in both groups, and no relation with renal function level was found, but it increased through the years. Isotopic studies showed ectatic drainage in all urinary systems. Contralateral anomalies were seen in 7 patients, and they consisted in hydronephrosis and vesico-ureteral reflux. Conclusions. Hypertension was not related to the cause of renal absence nor the pathology of remnant kidney. Ccr was higher than normal, showing an hyperfiltration status, not confirmed by the values of isotopic filtrate. Renal volume reached by the single kidney was affected by the time after the renal loss, and apparently has been slowed down in cases with contralateral anomalies Introduction. It has always been thought that a reduction of renal tissue in childhood sometimes causes some irreversible injury in the remnant kidney as the years go by. The aim of this paper is to look over the presence of these changes and identify the risk of nephropaty throughout several parameters. Material and methods. We reviewed 38 children, 23 males and 15 females, aged between 1 and 15 years, who had lost unilateral renal mass because of congenital or adquired diseases. We made two groups of patients on the basis of having born without any unilateral renal function –group I– or having lost unilateral renal function after the second year of life. We measured: Somatometry, arterial pressure, glomerular filtration, microalbuminuria, renal volume and gammagraphic studies were also made. We also considered the presence of contralateral anomalies. Results. Body weight and height were within normal percentiles. Arterial pressure increased in 5 patients. Seric creatinine was normal, creatinine clearance (Ccr) was higher than normal in all patients of both groups, and urinary excretion of protein was normal. Renal volume of remnant kidney was similar in both groups, and no relation with renal function level was found, but it increased through the years. Isotopic studies showed ectatic drainage in all urinary systems. Contralateral anomalies were seen in 7 patients, and they consisted in hydronephrosis and vesico-ureteral reflux. Conclusions. Hypertension was not related to the cause of renal absence nor the pathology of remnant kidney. Ccr was higher than normal, showing an hyperfiltration status, not confirmed by the values of isotopic filtrate. Renal volume reached by the single kidney was affected by the time after the renal loss, and apparently has been slowed down in cases with contralateral anomalies (AU)

Relative vs. absolute statistical analysis of compositions: a comparative study of surface waters of a Mediterranean river.

Most hydrogeological research includes some sort of statistical study, which is generally conducted on the raw measures of chemical variables, though there are several theoretical and practical studies warning against this practice. Arguments refer mainly to the positive character of this type of data, and to the fact that they carry only information about the relative abundance of each component on the whole, what makes techniques based on correlation, like the widely used Principal Component Analysis (PCA), loose their meaning. The solution proposed by Aitchison (1982, Journal of the Royal Statistical Society, Series B 44(2), 139-177)-based on working with log-ratios of observations-is equivalent to define a new distance between compositions and to adapt usual statistical techniques to it. To illustrate its effect, our study compares the performance of the biplot-a PCA graphical technique-according to the usual Euclidean and to the Aitchison distance. The study is conducted on a set of 14 molarities measured monthly through the years 1997-1999 at 30 different stations along the Llobregat River and its tributaries (Barcelona, NE Spain). Ordinary analysis, implicitly based on an Euclidean distance, presents some deficiencies, mainly because it only captures major ion variations and the inferred relationship between them actually depends on other non-relevant variables, such as water mass. An analysis based on compositional distances captures variations of all the ions; it is robust against the inclusion of non-relevant variables in the analysis; and it offers a way to build factors expressed as equilibrium equations. In our case, two promising factors are extracted, showing the different anthropogenic and geological pollution sources of the rivers.

Comparison between Haemophilus parasuis infection in colostrums-deprived and sow-reared piglets.

The aim of this study was to compare the development of Glasser's disease in sow-reared and colostrum-deprived piglets. Ninety piglets from a commercial pig farm in Spain were used. The farm was positive for Haemophilus parasuis. Fifty-two pigs were sow-reared (SR) and 38 were colostrum-deprived (CD) piglets. The animals were intratracheally inoculated with H. parasuis serovar 5 and sacrificed at 1, 2 and 3 days post-infection. To assess the development of disease, antibody titers, clinical signs, pathological lesions, microbiological isolation and PCR amplification were compared between the groups. Inoculation of SR pigs did not cause clinical signs or lesions of Glasser's disease. In SR pigs, H. parasuis isolation and specific PCR amplification from tissues showed a very low number of positive samples. In contrast, in CD pigs, inoculation resulted in the typical signs and lesions of Glasser's disease. Positive microbiological isolation and specific PCR products were obtained from the majority of the tissues tested, and no antibodies against H. parasuis were detected. The experimental infection using CD pigs describes a successful method to study this microorganism and confirms the important role that maternal antibodies play in protection against clinical signs and disease.

Expression at mRNA level of cytokines and A238L gene in porcine blood-derived macrophages infected in vitro with African swine fever virus (ASFV) isolates of different virulence.

Porcine macrophage cultures were infected with two ASFV isolates of variable virulence and mRNA levels of several relevant macrophage-derived cytokines were quantified by real time PCR. At six hours post infection, a clear enhancement of mRNA expression of TNFalpha, IL6, IL12 and IL15 was observed in macrophages infected with the low virulent ASFV/NH/P68 (NHV) when compared to those infected with the highly virulent ASFV/L60 (L60). The sequence of the A238L gene homologue to the cellular IkappaB was found identical in both viral isolates and its expression at mRNA level was higher in macrophages infected with NHV when compared to macrophages infected with L60. Furthermore our results suggest a negative correlation between the mRNA expression of A238L gene and the mRNA expression of the above mentioned cytokines (with the exception of IL10) in L60 infected macrophages in opposition to the positive correlation (with exception of the IL1) suggested in NHV infection. Overall, our data strongly emphasize that virulence of ASFV isolates may depend on their capacity to regulate the expression of macrophage-derived cytokines relevant for the development of host protective responses by yet unknown mechanisms triggered by the virus at early stages of the cellular infection.