Temporal and spatial expression of genes involved in DNA methylation during reproductive development of sexual and apomictic Eragrostis curvula.

Recent reports in model plant species have highlighted a role for DNA methylation pathways in the regulation of the somatic-to-reproductive transition in the ovule, suggesting that apomixis (asexual reproduction through seeds) likely relies on RdDM downregulation. Our aim was therefore to explore this hypothesis by characterizing genes involved in DNA methylation in the apomictic grass Eragrostis curvula. We explored floral transcriptomes to identify homologs of three candidate genes, for which mutations in Arabidopsis and maize mimic apomixis (AtAGO9/ZmAGO104, AtCMT3/ZmDMT102/ZmDMT105, and AtDDM1/ZmCHR106), and compared both their spatial and temporal expression patterns during reproduction in sexual and apomictic genotypes. Quantitative expression analyses revealed contrasting expression patterns for the three genes in apomictic vs sexual plants. In situ hybridization corroborated these results for two candidates, EcAGO104 and EcDMT102, and revealed an unexpected ectopic pattern for the AGO gene during germ line differentiation in apomicts. Although our data partially support previous results obtained in sexual plant models, they suggest that rather than an RdDM breakdown in the ovule, altered localization of AtAGO9/ZmAGO104 expression is required for achieving diplospory in E. curvula. The differences in the RdDM machinery acquired during plant evolution might have promoted the emergence of the numerous apomictic paths observed in plants.

Where to next with animal health in Latin America? The transition from endemic to disease-free status.

The Latin American and Caribbean region (LAC) is a leading global producer and exporter of animal products. Its livestock production systems are diverse, ranging from large-scale commercial enterprises to family farms. Countries in this region have sought to improve their animal health status through both public and private efforts. Despite significant advances in eradicating such diseases as foot and mouth disease and classical swine fever, other animal health challenges remain; constraining exports, causing negative economic impacts and threatening food security. Obtaining certification of disease-free status is only the first step towards gaining benefits from improvements in animal health. Increasing international trade means that countries must manage the sustainability of their disease-free status in conjunction with trade partners and must comply with additional food safety and animal welfare standards. This paper comments on the challenges created by this new scenario in relation to the epidemiology and economics of animal health, when seeking to improve decisionmaking for animal health management. The authors characterise the current LAC livestock landscape and animal health situation, describing transitions in disease control and the use of economics in improving animal health. They conclude with remarks on the challenges presented by decision-making, economic rationality, sources of benefits, distribution and incentives.

La région Amérique latine et Caraïbes est l'une des principales régions productrices et exportatrices de produits d'origine animale dans le monde. Les systèmes de production du secteur de l'élevage y sont très diversifiés, depuis les petites exploitations familiales jusqu'aux élevages commerciaux à grande échelle. Les pays de la région ont cherché à améliorer la situation de la santé animale sur leur territoire en y consacrant les efforts de leur secteur public et privé. Malgré les avancées considérables réalisées dans l'éradication de maladies comme la fièvre aphteuse et la peste porcine classique, la santé animale est encore confrontée à des problèmes qui freinent les exportations et ont un impact économique négatif, tout en menaçant la sécurité de l'approvisionnement alimentaire. La reconnaissance officielle du statut indemne de maladie ne représente qu'une première étape dans le processus visant à générer des bénéfices grâce à une meilleure santé animale. L'intensification des échanges internationaux impose aux pays de s'assurer de la durabilité de leur statut indemne aux côtés de leurs partenaires commerciaux et de respecter de nouvelles normes relatives à la sécurité sanitaire des aliments et au bien-être animal. Les auteurs analysent les conséquences de ce scénario sur l'épidémiologie et l'économie de la santé animale ainsi que ses enjeux dans la recherche d'une meilleure prise de décisions dans la gestion de la santé animale. Ils définissent ensuite le paysage actuel de l'élevage et la situation de la santé animale en Amérique latine et dans les Caraïbes et décrivent les évolutions à l'oeuvre en matière de lutte contre les maladies animales et d'utilisation de l'économie dans l'amélioration de la santé animale. Ils concluent sur quelques remarques concernant les difficultés qui se présentent en matière de prise de décision, de rationalité économique, de sources de profit, de distribution et d'incitation.

La región de América Latina y el Caribe es uno de los principales productores y exportadores de productos animales del mundo. Sus sistemas de producción ganadera exhiben gran heterogeneidad, pues van desde las grandes empresas de dimensión industrial hasta las pequeñas explotaciones familiares. Apoyándose en la iniciativa tanto pública como privada, los países de la región vienen tratando de mejorar su situación zoosanitaria. Pese a los importantes progresos registrados en la erradicación de enfermedades como la fiebre aftosa o la peste porcina clásica, subsisten otros problemas de sanidad animal que restringen las exportaciones, lastran la economía y amenazan la seguridad alimentaria. La certificación de «ausencia de enfermedad¼ es solo el primer paso para beneficiarse de las mejoras conseguidas en el terreno de la sanidad animal. Habida cuenta de la intensificación del comercio internacional, los países deben gestionar la continuidad a largo plazo de su estatuto de «libres de enfermedad¼ conjuntamente con sus socios comerciales y, para ello, cumplir normas adicionales en material de inocuidad de los alimentos y bienestar animal. Los autores exponen las dificultades que se plantean en esta nueva coyuntura de la epidemiología y la economía de la sanidad animal a la hora de mejorar los procesos decisorios en materia de gestión zoosanitaria. Tras caracterizar el actual paisaje de la ganadería y la situación zoosanitaria en América Latina y el Caribe, describen la transición que se está operando en cuanto al control de enfermedades y al uso de la economía para mejorar la sanidad animal y concluyen con una serie de observaciones sobre los problemas que surgen en relación con la adopción de decisiones, la racionalidad económica, las fuentes de beneficios y las cuestiones ligadas a la distribución y los incentivos.

Evaluation of the non-catalytic binding function of Ts26GST a glutathione transferase isoform of Taenia solium.

Taenia solium glutathione transferase isoform of 26.5 kDa (Ts26GST) was observed to bind non-catalytically to porphyrins, trans-trans-dienals, bile acids and fatty acids, as assessed by inhibition kinetics, fluorescence spectroscopy and competitive fluorescence assays with 8-anilino-1-naphthalene sulfonate (ANS). The quenching of Ts26GST intrinsic fluorescence allowed for the determination of the dissociation constants (KD) for all ligands. Obtained data indicate that Ts26GST binds to all ligands but with different affinity. Porphyrins and lipid peroxide products inhibited Ts26GST catalytic activity up to 100% in contrast with only 20-30% inhibition observed for bile acids and two saturated fatty acids. Non-competitive type inhibition was observed for all enzyme inhibitor ligands except for trans-trans-2,4-decadienal, which exhibited uncompetitive type inhibition. The dissociation constant value KD = 0.7 µM for the hematin ligand, determined by competitive fluorescence assays with ANS, was in good agreement with its inhibition kinetic value Ki = 0.3 µM and its intrinsic fluorescence quenching KD = 0.7 µM. The remaining ligands did not displace ANS from the enzyme suggesting the existence of different binding sites. In addition to the catalytic activity of Ts26GST the results obtained suggest that the enzyme exhibits a ligandin function with broad specificity towards nonsubstrate ligands.

First identification of Mycobacterium avium paratuberculosis sheep strain in Argentina

We here identified for the first time the presence of Mycobacterium avium paratuberculosis (MAP) sheep (S) strain in Argentina. IS900 polymerase chain reaction (PCR) was positive. The S strain was compared with MAP cattle (C) strains by using IS1311 PCR-restriction endonuclease analysis (PCR-REA), multiplex PCR and restriction fragment length polymorphism (RFLP) analysis.

First identification of Mycobacterium avium paratuberculosis sheep strain in Argentina.

We here identified for the first time the presence of Mycobacterium avium paratuberculosis (MAP) sheep (S) strain in Argentina. IS900 polymerase chain reaction (PCR) was positive. The S strain was compared with MAP cattle (C) strains by using IS1311 PCR-restriction endonuclease analysis (PCR-REA), multiplex PCR and restriction fragment length polymorphism (RFLP) analysis.

Using Ant Programming Guided by Grammar for Building Rule-Based Classifiers.

The extraction of comprehensible knowledge is one of the major challenges in many domains. In this paper, an ant programming (AP) framework, which is capable of mining classification rules easily comprehensible by humans, and, therefore, capable of supporting expert-domain decisions, is presented. The algorithm proposed, called grammar based ant programming (GBAP), is the first AP algorithm developed for the extraction of classification rules, and it is guided by a context-free grammar that ensures the creation of new valid individuals. To compute the transition probability of each available movement, this new model introduces the use of two complementary heuristic functions, instead of just one, as typical ant-based algorithms do. The selection of a consequent for each rule mined and the selection of the rules that make up the classifier are based on the use of a niching approach. The performance of GBAP is compared against other classification techniques on 18 varied data sets. Experimental results show that our approach produces comprehensible rules and competitive or better accuracy values than those achieved by the other classification algorithms compared with it.

Catalytic Reduction of Noble Metal Salts by Sodium Hypophosphite Promoted by the Film Poly-(p-Allyl Ether Benzenesulfonic Acid).

Glassy carbon electrodes were coated with the film poly-(p-allyl ether benzenesulfonic acid) by an anodic procedure. Nickel, platinum, and palladium ions were introduced into the film by ion exchange of H(+) with the corresponding salts. These ions were catalytically reduced to their corresponding metals using the known electroless reducing agent sodium hypophosphite. Scanning electron microcopy and energy dispersive X-ray spectroscopy were carried out to demonstrate the occurrence of the catalytic process. To compare this method with another one carried out in our laboratory, the electrocatalytic reduction of H(+) was studied using the same modified electrodes. A suggested mechanism for the catalysis is proposed.

Pediatric group B coxsackievirus infections.

The CVB have long been recognized as significant pathogens of infants and children. Although the major route for transmission of the CVB is fecal-oral, vertical transmission from mother to infant is also possible. This review will focus on the more common or clinically relevant CVB-related syndromes, their diagnosis, treatment, and prevention.

Dynamics of Eimeria oocyst excretion in dairy calves in the Province of Buenos Aires (Argentina), during their first 2 months of age.

Clinical coccidiosis is associated with high fecal contamination and stress situations, mainly in animals under 1 year of age. Artificially fed dairy calves are one of the categories most prone to suffer from this parasitic disease. The study was carried out in a commercial dairy farm. Feces samples of heifer calves between 2 and 8 weeks old were taken monthly for oocyst counts and Eimeria spp. identification. Of the 862 feces samples analyzed, 48% presented oocysts. When grouping the results of monthly samplings of each age group, it was observed that this percentage increased in the group of calves between 20 and 40 days of life, reaching the peak average of 85% of infection prevalence in the group with between 26 and 30 days of age. The discharge of oocysts observed between 21 and 35 days of age was superior to the rest (p<0.05). This trend appeared every month throughout the whole year. However, during March, April, June, September and November, the curves in the group categories were higher than in the remaining months (p<0.05). Twelve Eimeria species were identified, being E. ellipsoidalis, E. bovis, E. zuernii and E. auburnensis those in highest numbers. E. ellipsoidalis had an important predominance in the opg composition, >75% up to 25 days of life (p<0.05). E. bovis reached peak values in the 26 and 30 days group (p<0.05), remaining without significant variations in the last stage of the artificial milk feeding period (approximately 60 days of life), when the oocyst counts were significantly low. Oocysts of E. auburnensis appeared in great proportion (46%) in the cultures later than the previous species (p<0.05), in calves of the age groups of between 46 and 50 days of age. Oocysts of E. zuernii showed no trend associated with age. The highest prevalence of infection and of oocyst values appeared during the periods with better environmental conditions for sporulation, survival and dispersion of oocysts (spring and autumn), coincident with the highest birth rates and an elevated number of calves in the paddock. Calves developed a process of natural "vaccination" against coccidiosis. This was demonstrated by the decrease in the quantity of animals shedding oocysts and in the number of oocysts eliminated at the end of the artificial milk feeding period.

[Metastasis in maxilar sinus as only manifestation of disseminate renal adenocarcinoma]. / Metástasis en seno maxilar como única manifestación de adenocarcinoma renal diseminado.

Paranasal sinuses and nose metastasis are very uncommon. About 50 have been reported. Renal cell carcinoma is the primary neoplasm which most frequently metastasizes in the nasosinusal region, followed by breast and lug. Symptoms are unspecific, but the epistaxis constitutes the most common sign due to the significant vascularizations of the tumor. Prognosis is poor. The survival rate fluctuates between 15-30% at 5 years. Surgery is the elective treatment.

Metástasis en seno maxilar como única manifestación de adenocarcinoma renal diseminado / Metastasis in maxilar sinus as only manifestation of disseminate renal adenocarcinoma

Los tumores metastásicos en senos paranasales y fosas son excepcionales. Se han descrito en la literatura unos 50 casos localizados en seno maxilar. El adenocarcinoma ranal es la neoplasia primaria que más frecuentemente metastatiza en la región nasosinusal, seguido de tumores mamarios y pulmonares. Presenta una sintomatología inespecífica siendo la epistaxis el síntoma más frecuente debido a la gran vascularización tumoral. Tienen un pronóstico pobre con una tasa de supervivencia en torno al 15-30% a lso 5 años. El tratamiento de elección es la cirugía

Paranasal sinuses and nose metastasis are very uncommon. About 50 have been reported. Renal cell carcinoma is the primary neoplasm which most frequently metastasizes in the nasosinusal region, followed by breast and lug. Symptoms are unspecific, but the epistaxis constitutes the most common sign due to the significant vascularizations of the tumor. Prognosis is poor. The survival rate fluctuates between 15-30% at 5 years. Surgery is the elective treatment

Ganciclovir population pharmacokinetics in neonates following intravenous administration of ganciclovir and oral administration of a liquid valganciclovir formulation.

Cytomegalovirus (CMV) is the most common viral congenital infection, producing both sensorineural hearing loss and mental retardation. Our objective was to assess the population pharmacokinetics of a research-grade oral valganciclovir solution in neonates with symptomatic congenital CMV disease. Twenty-four neonates received 6 weeks of antiviral therapy. Ganciclovir and valganciclovir were measured by liquid chromatography/tandem mass spectroscopy. NONMEM version VI beta was used for population analyses. All profiles were consistent with a one-compartment model. Postnatal age, body surface area, and gender did not improve the model fit after body weight was taken into account. The typical value of clearance (l/h), distribution volume (l), and bioavailability of ganciclovir were 0.146 x body weight (WT)(1.68), 1.15 x WT, and 53.6%, respectively. Although these results cannot be extrapolated to extemporaneously compounded valganciclovir preparations, they provide the foundation on which a commercial-grade valganciclovir oral solution may be a viable option for administration to neonates.

[Maxillary sinus metastasis of renal cell carcinoma]. / Adenocarcinoma renal metastásico en seno maxilar.

Paranasal sinuses and nose metastasis are very uncommon tumors, about 50 have been reported. Renal cell carcinoma is the primary neoplasm which most frequently metastasizes in the nasosinusal region, followed by breast and lung. Symptoms are unspecific, but the epistaxis constitutes the most common sign due to the significant vascularizations of the tumor. Prognosis is poor. The survival rate fluctuates between 15-30% at 5 years. Surgery is the elective treatment.

Adenocarcinoma renal metastásico en seno maxilar / Maxillary sinus metastasis of renal cell carcinoma

Los tumores metastásicos en senos paranasales y fosas son excepcionales. Se han descrito en la literatura unos 50 casos localizados en seno maxilar. El adenocarcinoma renal es la neoplasia primaria que más frecuentemente metastatiza en la región nasosinusal, seguido de tumores mamarios y pulmonares. Presenta una sintomatología inespecífica siendo la epistaxis el síntoma más frecuente debido a la gran vascularización tumoral. Tienen un pronóstico pobre con una tasa de supervivencia en torno al 15-30% a los 5 años. El tratamiento de elección es la cirugía

Paranasal sinuses and nose metastasis are very uncommon tumors, about 50 have been reported. Renal cell carcinoma is the primary neoplasm which most frequently metastasizes in the nasosinusal region, followed by breast and lug. Symptoms are unspecific, but the epistaxis constitutes the most common sign due to the significant vascularizations of the tumor. Prognosis is poor. The survival rate fluctuates between 15-30% at 5 years. Surgery is the elective treatment

Management strategies for a eutrophic water supply reservoir--San Roque, Argentina.

Possible management strategies to improve water quality in a eutrophic water supply reservoir in Argentina were evaluated using the one-dimensional coupled hydrodynamics and water quality model DYRESM-CAEDYM. The model was used to determine the effects of several different artificial destratification system designs (including both bubble plume diffusers and surface impellers with draft tubes, both separately and in combination), on the biomass of the potentially toxic cyanobacteria Microcystia aeruginosa. The best results were found by using a combination of a deep and shallow diffuser, to break down the seasonal thermocline and therefore limit sediment nutrient release and anoxia, and to enhance vertical mixing in the surface mixed layer, respectively.

Toward testing the hypothesis that group B coxsackieviruses (CVB) trigger insulin-dependent diabetes: inoculating nonobese diabetic mice with CVB markedly lowers diabetes incidence.

Insulin-dependent (type 1) diabetes mellitus (T1D) onset is mediated by individual human genetics as well as undefined environmental influences such as viral infections. The group B coxsackieviruses (CVB) are commonly named as putative T1D-inducing agents. We studied CVB replication in nonobese diabetic (NOD) mice to assess how infection by diverse CVB strains affected T1D incidence in a model of human T1D. Inoculation of 4- or 8-week-old NOD mice with any of nine different CVB strains significantly reduced the incidence of T1D by 2- to 10-fold over a 10-month period relative to T1D incidences in mock-infected control mice. Greater protection was conferred by more-pathogenic CVB strains relative to less-virulent or avirulent strains. Two CVB3 strains were employed to further explore the relationship of CVB virulence phenotypes to T1D onset and incidence: a pathogenic strain (CVB3/M) and a nonvirulent strain (CVB3/GA). CVB3/M replicated to four- to fivefold-higher titers than CVB3/GA in the pancreas and induced widespread pancreatitis, whereas CVB3/GA induced no pancreatitis. Apoptotic nuclei were detected by TUNEL (terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling) assay in CVB3/M-infected pancreata but not in CVB3/GA-infected pancreata. In situ hybridization detected CVB3 RNA in acinar tissue but not in pancreatic islets. Although islets demonstrated inflammatory infiltrates in CVB3-protected mice, insulin remained detectable by immunohistochemistry in these islets but not in those from diabetic mice. Enzyme-linked immunosorbent assay-based examination of murine sera for immunoglobulin G1 (IgG1) and IgG2a immunoreactivity against diabetic autoantigens insulin and HSP60 revealed no statistically significant relationship between CVB3-protected mice or diabetic mice and specific autoimmunity. However, when pooled sera from CVB3/M-protected mice were used to probe a Western blot of pancreatic proteins, numerous proteins were detected, whereas only one band was detected by sera from CVB3/GA-protected mice. No proteins were detected by sera from diabetic or normal mice. Cumulatively, these data do not support the hypothesis that CVB are causative agents of T1D. To the contrary, CVB infections provide significant protection from T1D onset in NOD mice. Possible mechanisms by which this virus-induced protection may occur are discussed.

Increased red cell sodium-lithium countertransport and lymphocyte cytosolic calcium are separate phenotypes in patients with essential hypertension.

Increased red blood cell sodium-lithium countertransport (SLC) activity and elevated intracellular calcium have been observed in hypertensive patients. The association of these ion transport abnormalities with each other and with another phenotype, insulin resistance, has been suggested. We investigated whether elevated SLC activity and increased lymphocyte cytosolic calcium (Ca(cyt)) occur in the same individuals and whether either is associated with hyperinsulinaemia. We measured SLC activity, lymphocyte Ca(cyt)and fasting insulin levels in hypertensive patients and normal subjects. Consistent with prior studies, SLC activity was significantly and positively correlated with fasting insulin levels (r = 0.45, P < 0.01). However, SLC activity and lymphocyte Ca(cyt) were significantly but inversely correlated (r = -0.42, P < 0.01) and lymphocyte Ca(cyt) was also inversely correlated with fasting insulin (r = -0.55, P < 0.001). When the study participants were instead separated into two groups based on fasting insulin levels, those above the median (15 microU/ml) had significantly higher SLC activity and significantly lower Ca(cyt). When separated by lymphocyte Ca(cyt) levels (above or below 120 nM) those patients with low lymphocyte Ca(cyt) had significantly higher SLC activity and significantly higher insulin levels. Multiple linear regression showed that fasting insulin was significantly predictive of SLC activity (P = 0.05) and Ca(cyt) (P < 0.01). Thus, elevated SLC activity and increased lymphocyte Ca(cyt) are separate and distinct ion transport phenotypes in hypertensive patients, linked through a relationship to hyperinsulinaemia that is direct with SLC activity and inverse with lymphocyte Ca(cyt).

Transcranial magnetic stimulation coregistered with MRI: a comparison of a guided versus blind stimulation technique and its effect on evoked compound muscle action potentials.

INTRODUCTION AND METHODS: Compound muscle action potentials (CMAPs) elicited by transcranial magnetic stimulation (TMS) are characterized by enormous variability, even when attempts are made to stimulate the same scalp location. This report describes the results of a comparison of the spatial errors in coil placement and resulting CMAP characteristics using a guided and blind TMS stimulation technique. The former uses a coregistration system, which displays the intersection of the peak TMS induced electric field with the cortical surface. The latter consists of the conventional placement of the TMS coil on the optimal scalp position for activation of the first dorsal interossei (FDI) muscle. RESULTS: Guided stimulation resulted in significantly improved spatial precision for exciting the corticospinal projection to the FDI compared to blind stimulation. This improved precision of coil placement was associated with a significantly increased probability of eliciting FDI responses. Although these responses tended to have larger amplitudes and areas, the coefficient of variation between guided and blind stimulation induced CMAPs did not significantly differ. CONCLUSION: The results of this study demonstrate that guided stimulation improves the ability to precisely revisit previously stimulated cortical loci as well as increasing the probability of eliciting TMS induced CMAPs. Response variability, however, is due to factors other than coil placement.

Un paciente con fibrilación auricular

La fibrilación auricular es una de las arritmias más frecuentes que el clínico se puede encontrar en la práctica médica habitual. En esta revisión se intenta hacer un análisis de su etiología, clínica y abordaje terapéutico, tanto en fase aguda como en fase crónica. Por otra parte, definiremos el concepto de fibrilación auricular solitaria y el de fibrilación auricular paroxística.Finalmente se establece un algoritmo básico terapéutico de abordaje de esta entidad (AU)