¿Qué te pica cuando te pica al salir del agua?

La dermatitis cercarial es una reacción alérgica cutánea que afecta a los bañistas de lagos infectados con cercarias de la familia Schistosomatidae, parásitos cuyo ciclo de vida incluye caracoles y aves. Las personas se contagian cuando la cercaria penetra por error en la piel mientras se encuentran en el agua. La cercaria muere en la piel y los síntomas que causa en la persona son hormigueo y picazón que puede llegar a ser muy intensa y durar una semana, además de la aparición de ronchas que se van con el tiempo. Se han detectado brotes en casi todo el mundo, en América del Sur han sido citados casos en Chile y en Argentina. Se considera que los factores de riesgo para los bañistas son: bañarse cerca de la costa; durante la mañana, y haber sido infectado en el pasado. Las medidas de prevención como bañarse con ropa, pueden reducir el riesgo de contraer la dermatitis cercarial, pero la única totalmente efectiva es evitar bañarse en aguas donde está presente este parásito

¿Qué te pica cuando te pica al salir del agua?

La dermatitis cercarial es una reacción alérgica cutánea que afecta a los bañistas de lagos infectados con cercarias de la familia Schistosomatidae, parásitos cuyo ciclo de vida incluye caracoles y aves. Las personas se contagian cuando la cercaria penetra por error en la piel mientras se encuentran en el agua. La cercaria muere en la piel y los síntomas que causa en la persona son hormigueo y picazón que puede llegar a ser muy intensa y durar una semana, además de la aparición de ronchas que se van con el tiempo. Se han detectado brotes en casi todo el mundo, en América del Sur han sido citados casos en Chile y en Argentina. Se considera que los factores de riesgo para los bañistas son: bañarse cerca de la costa; durante la mañana, y haber sido infectado en el pasado. Las medidas de prevención como bañarse con ropa, pueden reducir el riesgo de contraer la dermatitis cercarial, pero la única totalmente efectiva es evitar bañarse en aguas donde está presente este parásito.Fil: Veleizán, Aylen A. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche; Argentina.Fil: Flores, Verónica R. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche; Argentina

Marine invertebrates as proxies for early kelp use along the western coast of South America

Coastal societies have lived at the seaward edge of the Atacama Desert since at least 12,000 years ago. Kelp forest ecosystems provide evidence for important subsistence activity along the entire Chilean coast through fishing and gathering. Despite their importance, especially in hyperarid contexts with limited plant abundance, there is scarce evidence of kelp in archaeological contexts, hampering the study of kelp use in the past. In the present study, we use the presence of small marine invertebrates, inhabitants of stipes and holdfasts of macroalgae, as proxies that indicate past kelp presence. We analyze samples of three species of snails (Tegula atra, Tegula tridentata, and Diloma nigerrima) and one limpet (Scurria scurra) from nine archaeological sites dated between 7,000 and 500 cal years before present located around the area of Taltal (25°Lat S). Modern samples of these species were collected to reconstruct the size of fragmented archaeological shells and subsequently estimate the size of harvested kelps. Through this approach, we estimated the size and relative abundance of kelp used by coastal groups that inhabited the southern part of the Atacama Desert for around 6,500 years. Our results are a contribution to the scarce information on the presence and use of kelp in the prehistory of the Americas and contribute to comparative perspectives with other areas of the world where the use of kelp by humans in the past has already been explored

A global assessment of parasite diversity in galaxiid fishes

Free-living species often receive greater conservation attention than the parasites they support, with parasite conservation often being hindered by a lack of parasite biodiversity knowl edge. This study aimed to determine the current state of knowledge regarding parasites of the Southern Hemisphere freshwater fish family Galaxiidae, in order to identify knowledge gaps to focus future research attention. Specifically, we assessed how galaxiid–parasite knowledge differs among geographic regions in relation to research effort (i.e., number of studies or fish individuals examined, extent of tissue examination, taxonomic resolution), in addition to ecological traits known to influ ence parasite richness. To date, ~50% of galaxiid species have been examined for parasites, though the majority of studies have focused on single parasite taxa rather than assessing the full diversity of macro- and microparasites. The highest number of parasites were observed from Argentinean galaxiids, and studies in all geographic regions were biased towards the highly abundant and most widely distributed galaxiid species, Galaxias maculatus. Parasite diversity generally increased with the number of studies and individual fish examined, however studies which examined parasites from all body tissues could overcome the effects of low study effort. In order to promote further understanding of galaxiid–parasite biodiversity, we provide a series of recommendations, including the use of molecular techniques to verify parasite identity, and highlight the future roles both fish biologists and parasitologists can plapublishedVersio

Utilidad del Cobas® Taqman® Ct Test, v2.0 para la detección de cepas de Chlamydia Trachomatis circulantes en México

Objective: This study aimed to evaluate the usefulness of the qPCR de COBAS® TaqMan® CT test to detect circulating strains in Mexico. Materials and Methods: Descriptive and transversal study. We analyzed 413 endocervical cases for the COBAS® system of patients with infertility, with the diagnosis of C. trachomatis. that acudieron has the Clínica ETS del Instituto Nacional de Perinatología (INPer) in the Ciudad de México. Las muestras positivas también analizaron por el sistema Abbot Real-time CT / NG, y por PCR de punto final para la detección de plásmido. Las variables de estudio fueron: Infertilidad, diagnóstico de Chlamydia trachomatis, infección por Chlamydia y otras variables. To determine the association between CT infection and clinical data, Fisher's no parametric exact test was used. A value p<0.05 was considered significant. Results: Of the 413 deaths, 276 female patients with primary infertility and 137 with secondary infertility, they ranged from 20 to 42 years. The main cause of primary infertility is endocrine-ovarian factor and secondary infertility is tuboperitoneal factor. Of 22 positive cases, a significant association between infertility by tubárico factor and infection by C. trachomatis (RR = 2.47 95% CI 1.1-5.5, p <0.05) was demonstrated by COBAS prueba ® TaqMan® CT. De éstas solo 5 fueron identificadas por el sistema Abbott (p <0.011). Conclusion. El sistema de COBAS® TaqMan® CT de Roche Molecular Diagnostic mostró mayor utilidad para identificar las cepas de CT que están circulando en México. Conclusion: The COBAS® TaqMan® CT test from Roche Molecular Diagnostic showed more utility in identifying the CT strains that circulate in Mexico.Objetivo: Evaluar la utilidad de la prueba de qPCR de COBAS® TaqMan® Chlamydia trachomatis (CT) para la detección de cepas circulantes en México. Materiales y Métodos: Estudio descriptivo y transversal. Se analizaron 413 muestras endocervicales por el sistema COBAS® de pacientes con infertilidad, con el diagnóstico de C. trachomatis. que acudieron a la Clínica ETS del Instituto Nacional de Perinatología (INPer) en la Ciudad de México. Las muestras positivas también analizaron por el sistema Abbot Real-time CT / NG, y por PCR de punto final para la detección de plásmido. Las variables de estudio fueron: Infertilidad, diagnóstico de Chlamydia trachomatis, infección por Chlamydia y otras variables. Para determinar la asociación entre la infección por CT y los datos clínicos se utilizó la prueba no paramétrica exacta de Fisher. Un valor p<0.05 fue considerado como significativo. Resultados: De las 413 muestras, 276 pacientes femeninas con infertilidad primaria y 137 de infertilidad secundaria, con edades de 20 a 42 años. La principal causa de infertilidad primaria fue factor endocrino-ovárico y de infertilidad secundaria fue el factor tuboperitoneal. De 22 muestras fueron positivas, una asociación significativa entre la infertilidad por factor tubárico y la infección por C. trachomatis (RR = 2,47 IC95% 1,1-5,5, p <0,05) fue demostrada por la prueba COBAS® TaqMan® CT. De éstas solo 5 fueron identificadas por el sistema Abbott (p <0.011). Conclusión: El sistema de COBAS® TaqMan® CT de Roche Molecular Diagnostic mostró mayor utilidad para identificar las cepas de CT que están circulando en México

Overexpression of wild type RRAS2, without oncogenic mutations, drives chronic lymphocytic leukemia

[Background]: Chronic lymphocytic leukemia (CLL) is the most frequent, and still incurable, form of leukemia in the Western World. It is widely accepted that cancer results from an evolutionary process shaped by the acquisition of driver mutations which confer selective growth advantage to cells that harbor them. Clear examples are missense mutations in classic RAS genes (KRAS, HRAS and NRAS) that underlie the development of approximately 13% of human cancers. Although autonomous B cell antigen receptor (BCR) signaling is involved and mutations in many tumor suppressor genes and oncogenes have been identified, an oncogenic driver gene has not still been identified for CLL. [Methods]: Conditional knock-in mice were generated to overexpress wild type RRAS2 and prove its driver role. RT-qPCR analysis of a human CLL sample cohort was carried out to measure RRAS2 transcriptional expression. Sanger DNA sequencing was used to identify a SNP in the 3’UTR region of RRAS2 in human CLL samples. RNAseq of murine CLL was carried out to identify activated pathways, molecular mechanisms and to pinpoint somatic mutations accompanying RRAS2 overexpression. Flow cytometry was used for phenotypic characterization and shRNA techniques to knockdown RRAS2 expression in human CLL. [Results]: RRAS2 mRNA is found overexpressed in its wild type form in 82% of the human CLL samples analyzed (n = 178, mean and median = 5-fold) as well as in the explored metadata. A single nucleotide polymorphism (rs8570) in the 3’UTR of the RRAS2 mRNA has been identified in CLL patients, linking higher expression of RRAS2 with more aggressive disease. Deliberate overexpression of wild type RRAS2 in mice, but not an oncogenic Q72L mutation in the coding sequence, provokes the development of CLL. Overexpression of wild type RRAS2 in mice is accompanied by a strong convergent selection of somatic mutations in genes that have been identified in human CLL. R-RAS2 protein is physically bound to the BCR and mediates BCR signals in CLL. [Conclusions]: The results indicate that overexpression of wild type RRAS2 is behind the development of CLL.This work was supported by grants from the Spanish Association against Cancer (GC16173472GARC), PID2019-104935RB-I00 from the ‘Comision Interministerial de Ciencia y Tecnología’, the ‘Fundación Ramón Areces’, and by the European Research Council ERC 2013-Advanced Grant 334763 “NOVARIPP”, Instituto de Salud Carlos III (ISCIII) (CIBERONC – groups CB16/12/00233, CB16/12/00351), the Health Council of the Junta de Castilla y León (GRS 2036/A/19) and private Gilead (GLD15/00348). Juan de la Cierva (FJCI-2016-28756)

Virtual Reality as a Tool for Evaluation of Repetitive Rhythmic Movements in the Elderly and Parkinson's Disease Patients

This work presents an immersive Virtual Reality (VR) system to evaluate, and potentially treat, the alterations in rhythmic hand movements seen in Parkinson's disease (PD) and the elderly (EC), by comparison with healthy young controls (YC). The system integrates the subjects into a VR environment by means of a Head Mounted Display, such that subjects perceive themselves in a virtual world consisting of a table within a room. In this experiment, subjects are presented in 1st person perspective, so that the avatar reproduces finger tapping movements performed by the subjects. The task, known as the finger tapping test (FT), was performed by all three subject groups, PD, EC and YC. FT was carried out by each subject on two different days (sessions), one week apart. In each FT session all subjects performed FT in the real world (FTREAL) and in the VR (FTVR); each mode was repeated three times in randomized order. During FT both the tapping frequency and the coefficient of variation of inter-tap interval were registered. FTVR was a valid test to detect differences in rhythm formation between the three groups. Intra-class correlation coefficients (ICC) and mean difference between days for FTVR (for each group) showed reliable results. Finally, the analysis of ICC and mean difference between FTVR vs FTREAL, for each variable and group, also showed high reliability. This shows that FT evaluation in VR environments is valid as real world alternative, as VR evaluation did not distort movement execution and detects alteration in rhythm formation. These results support the use of VR as a promising tool to study alterations and the control of movement in different subject groups in unusual environments, such as during fMRI or other imaging studies

Genetic manipulation of LKB1 elicits lethal metastatic prostate cancer

Gene dosage is a key defining factor to understand cancer pathogenesis and progression, which requires the development of experimental models that aid better deconstruction of the disease. Here, we model an aggressive form of prostate cancer and show the unconventional association of LKB1 dosage to prostate tumorigenesis. Whereas loss of Lkbl alone in the murine prostate epithelium was inconsequential for tumorigenesis, its combination with an oncogenic insult, illustrated by Pten heterozygosity, elicited lethal metastatic prostate cancer. Despite the low frequency of LKB1 deletion in patients, this event was significantly enriched in lung metastasis. Modeling the role of LKB1 in cellular systems revealed that the residual activity retained in a reported kinase-dead form, LKB1(K781), was sufficient to hamper tumor aggressiveness and metastatic dissemination. Our data suggest that prostate cells can function normally with low activity of LKB1, whereas its complete absence influences prostate cancer pathogenesis and dissemination

Plant trait and vegetation data along a 1314 m elevation gradient with fire history in Puna grasslands, Perú

Alpine grassland vegetation supports globally important biodiversity and ecosystems that are increasingly threatened by climate warming and other environmental changes. Trait-based approaches can support understanding of vegetation responses to global change drivers and consequences for ecosystem functioning. In six sites along a 1314 m elevational gradient in Puna grasslands in the Peruvian Andes, we collected datasets on vascular plant composition, plant functional traits, biomass, ecosystem fluxes, and climate data over three years. The data were collected in the wet and dry season and from plots with different fire histories. We selected traits associated with plant resource use, growth, and life history strategies (leaf area, leaf dry/wet mass, leaf thickness, specific leaf area, leaf dry matter content, leaf C, N, P content, C and N isotopes). The trait dataset contains 3,665 plant records from 145 taxa, 54,036 trait measurements (increasing the trait data coverage of the regional flora by 420%) covering 14 traits and 121 plant taxa (ca. 40% of which have no previous publicly available trait data) across 33 families

Full-Exon Pyrosequencing Screening of BRCA Germline Mutations in Mexican Women with Inherited Breast and Ovarian Cancer

Hereditary breast cancer comprises 10% of all breast cancers. The most prevalent genes causing this pathology are BRCA1 and BRCA2 (breast cancer early onset 1 and 2), which also predispose to other cancers. Despite the outstanding relevance of genetic screening of BRCA deleterious variants in patients with a history of familial cancer, this practice is not common in Latin American public institutions. In this work we assessed mutations in the entire exonic and splice-site regions of BRCA in 39 patients with breast and ovarian cancer and with familial history of breast cancer or with clinical features suggestive for BRCA mutations by massive parallel pyrosequencing. First we evaluated the method with controls and found 41–485 reads per sequence in BRCA pathogenic mutations. Negative controls did not show deleterious variants, confirming the suitability of the approach. In patients diagnosed with cancer we found 4 novel deleterious mutations (c.2805_2808delAGAT and c.3124_3133delAGCAATATTA in BRCA1; c.2639_2640delTG and c.5114_5117delTAAA in BRCA2). The prevalence of BRCA mutations in these patients was 10.2%. Moreover, we discovered 16 variants with unknown clinical significance (11 in exons and 5 in introns); 4 were predicted as possibly pathogenic by in silico analyses, and 3 have not been described previously. This study illustrates how massive pyrosequencing technology can be applied to screen for BRCA mutations in the whole exonic and splice regions in patients with suspected BRCA-related cancers. This is the first effort to analyse the mutational status of BRCA genes on a Mexican-mestizo population by means of pyrosequencing