Identification of human intestinal parasites affecting an asymptomatic peri-urban Argentinian population using multi-parallel quantitative real-time polymerase chain reaction

Background: In resource-limited countries, stool microscopy is the diagnostic test of choice for intestinal parasites (soil-transmitted helminths and/or intestinal protozoa). However, sensitivity and specificity is low. Improved diagnosis of intestinal parasites is especially important for accurate measurements of prevalence and intensity of infections in endemic areas. Methods: The study was carried out in Orán, Argentina. A total of 99 stool samples from a local surveillance campaign were analyzed by concentration microscopy and McMaster egg counting technique compared to the analysis by multi-parallel quantitative real-time polymerase chain reaction (qPCR). This study compared the performance of qPCR assay and stool microscopy for 8 common intestinal parasites that infect humans including the helminths Ascaris lumbricoides, Ancylostoma duodenale, Necator americanus, Strongyloides stercoralis, Trichuris trichiura, and the protozoa Giardia lamblia, Cryptosporidium parvum/hominis, and Entamoeba histolytica, and investigated the prevalence of polyparasitism in an endemic area. Results: qPCR showed higher detection rates for all parasites as compared to stool microscopy except T. trichiura. Species-specific primers and probes were able to distinguish between A. duodenale (19.1 %) and N. americanus (36.4 %) infections. There were 48.6 % of subjects co-infected with both hookworms, and a significant increase in hookworm DNA for A. duodenale versus N. americanus (119.6 fg/μL: 0.63 fg/μL, P∈<∈0.001) respectively. qPCR outperformed microscopy by the largest margin in G. lamblia infections (63.6 % versus 8.1 %, P∈<∈0.05). Polyparasitism was detected more often by qPCR compared to microscopy (64.7 % versus 24.2 %, P∈<∈0.05). Conclusions: Multi-parallel qPCR is a quantitative molecular diagnostic method for common intestinal parasites in an endemic area that has improved diagnostic accuracy compared to stool microscopy. This first time use of multi-parallel qPCR in Argentina has demonstrated the high prevalence of intestinal parasites in a peri-urban area. These results will contribute to more accurate epidemiological survey, refined treatment strategies on a public scale, and better health outcomes in endemic settings.Fil: Cimino, Rubén Oscar. Universidad Nacional de Salta; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Jeun, Rebecca. Baylor College Of Medicine; Estados UnidosFil: Juarez, Marisa. Universidad Nacional de Salta; ArgentinaFil: Cajal, Pamela S.. Universidad Nacional de Salta; ArgentinaFil: Vargas Flores, Paola Andrea. Universidad Nacional de Salta; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Echazú, Adriana. Universidad Nacional de Salta; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Bryan, Patricia E.. Baylor College Of Medicine; Estados UnidosFil: Nasser, Julio Rubén. Universidad Nacional de Salta; ArgentinaFil: Krolewiecki, Alejandro Javier. Universidad Nacional de Salta; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Mejia, Rojelio. Baylor College Of Medicine; Estados Unidos. Universidad Nacional de Salta; Argentin

Structural implications of the DFD-in domain in computer-aided molecular design of MAP kinase interacting kinase 2 inhibitors.

Protein translation is a key process on cell development and proliferation that is often deregulated in cancer. MAP kinase interacting kinases 1 and 2(Mnk1/2) play a pivotal role in regulating the capdependent translation through phosphorylation ofeIF4E transcription factor. Thus, Mnk1/2 targeting have been proposed as a novel therapeutic strategy that would minimize side-effects in contrast to other therapies. For this reason, there is a growing interestin designing in silico new Mnk1/2 inhibitors which demands from reliable structural models. Interestingly,the catalytic domain of Mnk proteins are characterized by a DFD motif instead of the characteristicDFG motif of other kinases. However, Mnk2 structural models described in literature are DFG mutated and do not contain the activation loop. Molecular design techniques have been applied to obtain a structural model of the full wild type Mnk2 protein including the activation loop. The effect of the loop on the interaction mechanism of well-known ligands has been evaluated. Obtained results suggest that the presence of the activation loop is determinant for the correct prediction of the active site and it is essential for the design of new inhibitors

Lipoma of the Uterine Corpus: Exceptional Eventuality Combined with an Ovarian Thecoma

Uterine lipomas are very uncommon with symptoms that are similar to leiomyomas. Their diagnosis is always histological although some radiological methods may suggest their existence prior to surgery. They are sometimes associated with endometrial pathology, but there are no previous reported cases related to ovarian thecoma. Their prognosis is excellent. Clinical, radiological, morphologic, and immunohistochemical findings are shown which correspond to uterine lipoma associated with endometrial polyps and ovarian thecoma

Role of transport performance on neuron cell morphology

The compartmental model is a basic tool for studying signal propagation in neurons, and, if the model parameters are adequately defined, it can also be of help in the study of electrical or fluid transport. Here we show that the input resistance, in different networks which simulate the passive properties of neurons, is the result of an interplay between the relevant conductances, morphology and size. These results suggest that neurons must grow in such a way that facilitates the current flow. We propose that power consumption is an important factor by which neurons attain their final morphological appearance.Comment: 9 pages with 3 figures, submitted to Neuroscience Letter

Model of Low-pass Filtering of Local Field Potentials in Brain Tissue

Local field potentials (LFPs) are routinely measured experimentally in brain tissue, and exhibit strong low-pass frequency filtering properties, with high frequencies (such as action potentials) being visible only at very short distances ($\approx$10~$\mu m$) from the recording electrode. Understanding this filtering is crucial to relate LFP signals with neuronal activity, but not much is known about the exact mechanisms underlying this low-pass filtering. In this paper, we investigate a possible biophysical mechanism for the low-pass filtering properties of LFPs. We investigate the propagation of electric fields and its frequency dependence close to the current source, i.e. at length scales in the order of average interneuronal distance. We take into account the presence of a high density of cellular membranes around current sources, such as glial cells. By considering them as passive cells, we show that under the influence of the electric source field, they respond by polarisation, i.e., creation of an induced field. Because of the finite velocity of ionic charge movement, this polarization will not be instantaneous. Consequently, the induced electric field will be frequency-dependent, and much reduced for high frequencies. Our model establishes that with respect to frequency attenuation properties, this situation is analogous to an equivalent RC-circuit, or better a system of coupled RC-circuits. We present a number of numerical simulations of induced electric field for biologically realistic values of parameters, and show this frequency filtering effect as well as the attenuation of extracellular potentials with distance. We suggest that induced electric fields in passive cells surrounding neurons is the physical origin of frequency filtering properties of LFPs.Comment: 10 figs, revised tex file and revised fig

Die Struktur der Synapsen im Nucleus dentatus des Menschen

The knowledge of the morphology of the synapse in the dentate nucleus is limited to the work of Cajal , who described the afferent fibers but not their end-formations. A. Jakob also described the afferent fibers in man with the Golgi method but was no more successful than Cajal . In this contribution the nature of the synapse was investigated with the unreduced variant of the silver carbonate technique of del Rio Hortega . The afferent fibers from the amiculum surround the neurons and their processes with a complicated network of fibers which contains numerous endbulbs and rings and form small plexus. There are three types of end-formations: a) those with an accentuation of the afferent fibers around the proximal segments of the dendrites; b) those with approximately even distribution of the afferent fibers around the pericaryon and the dendrites; c) those with numerous baskets which surround the processes.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47692/1/441_2004_Article_BF00345077.pd

Neuroglia at the crossroads of homoeostasis, metabolism and signalling: evolution of the concept

Ever since Rudolf Virchow in 1858 publicly announced his apprehension of neuroglia being a true connective substance, this concept has been evolving to encompass a heterogeneous population of cells with various forms and functions. We briefly compare the 19th–20th century perspectives on neuroglia with the up-to-date view of these cells as an integral, and possibly integrating, component of brain metabolism and signalling in heath and disease. We conclude that the unifying property of otherwise diverse functions of various neuroglial cell sub-types is to maintain brain homoeostasis at different levels, from whole organ to molecular

Beyond Hebb: Exclusive-OR and Biological Learning

A learning algorithm for multilayer neural networks based on biologically plausible mechanisms is studied. Motivated by findings in experimental neurobiology, we consider synaptic averaging in the induction of plasticity changes, which happen on a slower time scale than firing dynamics. This mechanism is shown to enable learning of the exclusive-OR (XOR) problem without the aid of error back-propagation, as well as to increase robustness of learning in the presence of noise.Comment: 4 pages RevTeX, 2 figures PostScript, revised versio

Update of the recommendations for the determination of biomarkers in colorectal carcinoma: National Consensus of the Spanish Society of Medical Oncology and the Spanish Society of Pathology

In this update of the consensus of the Spanish Society of Medical Oncology (Sociedad Española de Oncología Médica SEOM) and the Spanish Society of Pathology (Sociedad Española de Anatomía Patológica SEAP), advances in the analysis of biomarkers in advanced colorectal cancer (CRC) as well as susceptibility markers of hereditary CRC and molecular biomarkers of localized CRC are reviewed. Recently published information on the essential determination of KRAS, NRAS and BRAF mutations and the convenience of determining the amplifcation of human epidermal growth factor receptor 2 (HER2), the expression of proteins in the DNA repair pathway and the study of NTRK fusions are also evaluated. From the pathological point of view, the importance of analysing the tumour budding and poorly diferentiated clusters, and its prognostic value in CRC is reviewed, as well as the impact of molecular lymph node analysis on lymph node staging in CRC. The incorporation of pan-genomic technologies, such as next-generation sequencing (NGS) and liquid biopsy in the clinical management of patients with CRC is also outlined. All these aspects are developed in this guide, which, like the previous one, will remain open to any necessary revision in the future