133 research outputs found

    Infección experimental por herpesvirus bovino 1 en conejas gestantes

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    Natural infection with Bovine herpesvirus 1 (BoHV-1) produces several clinical manifestations including conjunctivitis, respiratory signs, genital diseases and abortion. The rabbit is a good model for studying of latency, pathogenicity of BoHV-5 and other bovine herpesviruses. This study was conducted in order to analyze the response to experimental infection with BoHV-1 in rabbits during different periods of pregnancy. The results obtained could be useful for better understanding of the infection in cattle. A new method of infection was used. The rabbits developed clinical signs. The virus was recovered from nasal swabs and histological lesions were found in the analyzed samples. The humoral response was demonstrated and viral DNA was detected from the placentas. This work showed for the first time the arrival of BoHV-1 to blood after intranasal infection with the virus. It also provides a useful tool that can be used to evaluate the pathogenicity of by BoHV-1 strains, the immune response and to study viral latency and reactivation.La infección natural por Herpesvirus bovino 1 (BoHV-1) se manifiesta por conjuntivitis, signos respiratorios (rinotraqueitis), lesiones genitales (vulvovaginitis pustular infecciosa o balanopostitis) y abortos. El conejo, hasta el momento, ha resultado ser el mejor modelo experimental para estudiar los diferentes aspectos de la infección por BoHV-1, el fenómeno de latencia, la neuropatogenicidad de BoHV-5 y el comportamiento de diferentes cepas virales. Este trabajo se desarrolló con el objetivo de estudiar la respuesta de conejas infectadas con BoHV-1 en diferentes períodos de la gestación para que los datos resultantes puedan ser utilizados para la mejor comprensión de la infección en el bovino. Se utilizó un nuevo método de infección intranasal. Los animales desarrollaron signos clínicos. Se recuperó virus a partir de hisopados nasales, se observaron lesiones histopatológicas en las muestras analizadas, se demostró la respuesta inmune humoral y se detectó ADN viral a partir de placentas de los animales gestantes infectados. En este trabajo se evidenció por primera vez en el modelo conejo la llegada del virus al torrente sanguíneo luego de la infección intranasal. Además se aporta una herramienta de utilidad que puede ser utilizada para evaluar la virulencia de diferentes cepas de BoHV-1 y la respuesta inmune a distintos inmunógenos como también para realizar estudios de latencia y reactivación

    Nut production in Bertholletia excelsa across a logged forest mosaic: implications for multiple forest use

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    Although many examples of multiple-use forest management may be found in tropical smallholder systems, few studies provide empirical support for the integration of selective timber harvesting with non-timber forest product (NTFP) extraction. Brazil nut (Bertholletia excelsa, Lecythidaceae) is one of the world’s most economically-important NTFP species extracted almost entirely from natural forests across the Amazon Basin. An obligate out-crosser, Brazil nut flowers are pollinated by large-bodied bees, a process resulting in a hard round fruit that takes up to 14 months to mature. As many smallholders turn to the financial security provided by timber, Brazil nut fruits are increasingly being harvested in logged forests. We tested the influence of tree and stand-level covariates (distance to nearest cut stump and local logging intensity) on total nut production at the individual tree level in five recently logged Brazil nut concessions covering about 4000 ha of forest in Madre de Dios, Peru. Our field team accompanied Brazil nut harvesters during the traditional harvest period (January-April 2012 and January-April 2013) in order to collect data on fruit production. Three hundred and ninety-nine (approximately 80%) of the 499 trees included in this study were at least 100 m from the nearest cut stump, suggesting that concessionaires avoid logging near adult Brazil nut trees. Yet even for those trees on the edge of logging gaps, distance to nearest cut stump and local logging intensity did not have a statistically significant influence on Brazil nut production at the applied logging intensities (typically 1–2 timber trees removed per ha). In one concession where at least 4 trees ha-1 were removed, however, the logging intensity covariate resulted in a marginally significant (0.09) P value, highlighting a potential risk for a drop in nut production at higher intensities. While we do not suggest that logging activities should be completely avoided in Brazil nut rich forests, when a buffer zone cannot be observed, low logging intensities should be implemented. The sustainability of this integrated management system will ultimately depend on a complex series of socioeconomic and ecological interactions. Yet we submit that our study provides an important initial step in understanding the compatibility of timber harvesting with a high value NTFP, potentially allowing for diversification of forest use strategies in Amazonian Perù

    Urinary tract infections in children after renal transplantation

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    Urinary tract infections (UTI) after pediatric kidney transplantation (KTX) are an important clinical problem and occur in 15–33% of patients. Febrile UTI, whether occurring in the transplanted kidney or the native kidney, should be differentiated from afebrile UTI. The latter may cause significant morbidity and is usually associated with acute graft dysfunction. Risk factors for (febrile) UTI include anatomical, functional, and demographic factors as well as baseline immunosuppression and foreign material, such as catheters and stents. Meticulous surveillance, diagnosis, and treatment of UTI is important to minimize acute morbidity and compromise of long-term graft function. In febrile UTI, parenteral antibiotics are usually indicated, although controlled data are not available. As most data concerning UTI have been accumulated retrospectively, future prospective studies have to be performed to clarify pathogenetic mechanisms and risk factors, improve prophylaxis and treatment, and ultimately optimize long-term renal graft survival

    Differential expression of 12 histone deacetylase (HDAC) genes in astrocytomas and normal brain tissue: class II and IV are hypoexpressed in glioblastomas

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    <p>Abstract</p> <p>Background</p> <p>Glioblastoma is the most lethal primary malignant brain tumor. Although considerable progress has been made in the treatment of this aggressive tumor, the clinical outcome for patients remains poor. Histone deacetylases (HDACs) are recognized as promising targets for cancer treatment. In the past several years, HDAC inhibitors (HDACis) have been used as radiosensitizers in glioblastoma treatment. However, no study has demonstrated the status of global <it>HDAC </it>expression in gliomas and its possible correlation to the use of HDACis. The purpose of this study was to evaluate and compare mRNA and protein levels of class I, II and IV of HDACs in low grade and high grade astrocytomas and normal brain tissue and to correlate the findings with the malignancy in astrocytomas.</p> <p>Methods</p> <p>Forty-three microdissected patient tumor samples were evaluated. The histopathologic diagnoses were 20 low-grade gliomas (13 grade I and 7 grade II) and 23 high-grade gliomas (5 grade III and 18 glioblastomas). Eleven normal cerebral tissue samples were also analyzed (54 total samples analyzed). mRNA expression of class I, II, and IV <it>HDACs </it>was studied by quantitative real-time polymerase chain reaction and normalized to the housekeeping gene <it>β-glucuronidase</it>. Protein levels were evaluated by western blotting.</p> <p>Results</p> <p>We found that mRNA levels of class II and IV <it>HDACs </it>were downregulated in glioblastomas compared to low-grade astrocytomas and normal brain tissue (7 in 8 genes, <it>p </it>< 0.05). The protein levels of class II HDAC9 were also lower in high-grade astrocytomas than in low-grade astrocytomas and normal brain tissue. Additionally, we found that histone H3 (but not histone H4) was more acetylated in glioblastomas than normal brain tissue.</p> <p>Conclusion</p> <p>Our study establishes a negative correlation between <it>HDAC </it>gene expression and the glioma grade suggesting that class II and IV <it>HDACs </it>might play an important role in glioma malignancy. Evaluation of histone acetylation levels showed that histone H3 is more acetylated in glioblastomas than normal brain tissue confirming the downregulation of <it>HDAC </it>mRNA in glioblastomas.</p

    Assessing the Effects of Climate on Host-Parasite Interactions: A Comparative Study of European Birds and Their Parasites

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    [Background] Climate change potentially has important effects on distribution, abundance, transmission and virulence of parasites in wild populations of animals. [Methodology/Principal Finding] Here we analyzed paired information on 89 parasite populations for 24 species of bird hosts some years ago and again in 2010 with an average interval of 10 years. The parasite taxa included protozoa, feather parasites, diptera, ticks, mites and fleas. We investigated whether change in abundance and prevalence of parasites was related to change in body condition, reproduction and population size of hosts. We conducted analyses based on the entire dataset, but also on a restricted dataset with intervals between study years being 5–15 years. Parasite abundance increased over time when restricting the analyses to datasets with an interval of 5–15 years, with no significant effect of changes in temperature at the time of breeding among study sites. Changes in host body condition and clutch size were related to change in temperature between first and second study year. In addition, changes in clutch size, brood size and body condition of hosts were correlated with change in abundance of parasites. Finally, changes in population size of hosts were not significantly related to changes in abundance of parasites or their prevalence. [Conclusions/Significance] Climate change is associated with a general increase in parasite abundance. Variation in laying date depended on locality and was associated with latitude while body condition of hosts was associated with a change in temperature. Because clutch size, brood size and body condition were associated with change in parasitism, these results suggest that parasites, perhaps mediated through the indirect effects of temperature, may affect fecundity and condition of their hosts. The conclusions were particularly in accordance with predictions when the restricted dataset with intervals of 5–15 years was used, suggesting that short intervals may bias findings.The Academy of Finland is acknowledged for a grant to TE (project 8119367) and EK (project 250709). PLP was supported by a research grant (TE_291/2010) offered by the Romanian Ministry of Education and Science. T. Szép received funding from OTKA K69068 and JT from OTKA 75618. JMP was supported by a JAE grant from Consejo Superior de Investigaciones Científicas. SM-JM, FdL-AM, JF, JJS and FV were respectively supported by projects CGL2009-09439, CGL2012-36665, CGL2009- 11445, CGL2010-19233-C03-01 and CGL2008-00562 by the Spanish Ministry of Science and Innovation and FEDER and project EVITAR by the Spanish Ministry of Health. FV was also supported by the European Regional Development Fund. MACT was funded by a predoctoral FPU grant from the Spanish Ministry of Education (AP20043713). PM was supported by grant from the Polish Ministry of Science and Higher Education (project 2P04F07030), and the Foundation for Polish Science
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