2,339 research outputs found

    Invertebrate carcasses as a resource for competing Aedes albopictus and Aedes aegypti (Diptera : Culicidae)

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    However, little is known of the role of these carcasses in other containers, which also receive leaf fall and stemflow inputs. This experiment investigated effects of accumulated invertebrate carcasses as a resource for two competing mosquitoes, Aedes albopictus (Skuse) and Aedes aegypti (L.) whether either species differentially benefited from accumulated carcasses, and if such a benefit affected interspecific competition. First, we measured accumulation of invertebrate carcasses in standard containers at a field site. We then used a replacement series with five different species ratios at the same total density: and varied the input of invertebrate carcasses [dead Drosophila melanogaster (Meigen) ] in three levels: none, the average input from our field site, or the maximum input recorded at our field site. Survivorship, development time, and mass were measured for each mosquito species as correlates of population growth, and were used to calculate a population performance index, lambda\u27. There were strong positive effects of invertebrate carcass additions on all growth correlates and lambda\u27. Differences in performance between species were pronounced in small or no carcass additions and absent in large inputs of invertebrate carcasses, but there was little evidence that inputs of invertebrate carcasses altered the competitive advantage in this system. These results suggest that terrestrial invertebrate carcasses may be an important resource for many types of container communities, and large accumulations of dead invertebrates may: reduce resource competition between these mosquitoes. thus favoring coexistence. We propose that the total amount of resource, including accumulated invertebrate carcasses, may explain observed patterns of replacement involving these mosquitoes

    Iron deficiency in heart failure patients

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    A anemia é uma comorbidade frequente nos pacientes com insuficiência cardíaca (IC) e sua presença parece estar associada à pior evolução, sendo descrita em alguns estudos como fator de prognóstico independente tanto na IC sistólica quanto na diastólica. Entretanto, ainda não sabemos se a anemia causa pior evolução ou se é apenas um marcador do maior comprometimento cardíaco nos portadores de IC. A etiologia da anemia na IC é multifatorial e parece variar conforme a população estudada. Os fatores como a deficiência nutricional de ferro, presença de insuficiência renal, intensa atividade inflamatória sistêmica, uso de medicações que inibem a produção de eritropoetina ou que causam perda sanguínea são os mais frequentes causadores de anemia na IC. A prevalência de anemia citada nos estudos de IC é muito variável (de 9% a 79,1%) e isto é dependente da população estudada, da fase da cardiopatia, do método e referências hematimétricas utilizadas para diagnóstico. A deficiência de ferro é um importante fator etiológico e está presente em um número significativo de pacientes com anemia e IC associada. Em estudo realizado em nosso grupo, a incidência de deficiência de ferro nos pacientes com anemia foi de 61,8%. Portanto, a anemia é um achado frequente, sua presença acentua as manifestações clínicas da IC e está associada a piora do prognóstico. Conhecer a causa da anemia facilita o seu tratamento e, apesar da sua correção ainda não ser consenso, os pacientes sem anemia têm melhor evolução.Anemia is common in heart failure (HF) patients with its presence apparently associated to a worse prognosis, and as such is described in some studies as an independent predictor of death and hospitalization of patients suffering from systolic and diastolic dysfunction. It remains unknown whether anemia causes the worse evolution of HF patients or whether it is only one marker of a worse heart disease stage. The etiology of anemia is multifactorial and seems to change dependent on the studied population. Factors such as nutritional iron deficiency, presence of kidney failure, intense systematic inflammatory activity, medication use that inhibits the production of erythropoietin or that results in blood loss are the most frequent causes of anemia in heart disease. The prevalence of anemia reported in studies of HF is very variable (from 9 to 79.1%) and is dependent of the studied population, stage of heart disease and method and references used for diagnosis. Iron deficiency is an important etiologic factor which is present in a significant number of patients with the association of anemia and HF. In a study carried out by our group, the incidence of iron deficiency in anemic patients was 61.8%. Hence, anemia is a frequent finding; its presence accentuates the clinical manifestations of HF and is associated to a worse prognosis. An understanding of the cause of anemia makes treatment easier and although there is no consensus on its correction, patients without anemia have a better evolution

    Further notes on the capture of a Carcharhinus leucas, in a northeastern Atlantic oceanic insular shelf, the Azores archipelago, Portugal

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    Copyright © 2006 Société Française d’Ichtyologie.In March 1993, a specimen of Carcharhinus leucas was captured by fishermen on the south coast of Te rceira Island, the Azores Archipelago. Its head was recovered and its jaws were preserved. This is the first capture of this species on an oceanic insular shelf in the Atlantic. The distribution of C. leucas in this ocean is commented.RÉSUMÉ: Note complémentaire sur la capture de Carcharhinus leucas (Carcharhinidae) dans une île océanique de l’Atlantique nord-est, l’archipel des Açores, Portugal. En mars 1993, un spécimen de Carcharhinus leucas a été capturé par des pêcheurs sur la côte sud de l’île Terceira dans l’archipel desAçores. Sa tête a été récupérée et ses mâchoires préservées. Il s’agit de la première capture de cette espèce sur une plateforme océanique de l’Atlantique. La distribution de C. leucas dans cet océan est commentée

    THE INFLUENCE OF COLD IN PROPRIOCEPTION OF THE NORMAL KNEE JOINT

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    The objective of this study was to determine whether the therapeutic use of cold, affects proprioception when applied to the knee joint. Cryotherapy decreases sensory and motor nerve conduction velocities, which are necessary for a normal proprioceptive acuity. Normal proprioceptive acuity is necessary in order to avoid injuries of the musculoskelectal system. Sixty-four healthy volunteers, aged 18-25, moderately active men and women were recruited from a large sample of University students. Subjects were randomly assigned to either the control or the experimental group. The subjects of the experimental group were subjected to 20 min of temperature at constant (5ºC), with an ice application to the knee joint. The results showed that cold does not affect the joint position sense in a normal knee

    Characterization of thimet oligopeptidase and neurolysin activities in B16F10-Nex2 tumor cells and their involvement in angiogenesis and tumor growth

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    <p>Abstract</p> <p>Background</p> <p>Angiogenesis is a fundamental process that allows tumor growth by providing nutrients and oxygen to the tumor cells. Beyond the oxygen diffusion limit from a capillary blood vessel, tumor cells become apoptotic. Angiogenesis results from a balance of pro- and anti-angiogenic stimuli. Endogenous inhibitors regulate enzyme activities that promote angiogenesis. Tumor cells may express pro-angiogenic factors and hydrolytic enzymes but also kinin-degrading oligopeptidases which have been investigated.</p> <p>Results</p> <p>Angiogenesis induced by B16F10-Nex2 melanoma cells was studied in a co-culture with HUVEC on Matrigel. A stimulating effect on angiogenesis was observed in the presence of B16F10-Nex2 lysate and plasma membrane. In contrast, the B16F10-Nex2 culture supernatant inhibited angiogenesis in a dose-dependent manner. This effect was abolished by the endo-oligopeptidase inhibitor, JA-2. Thimet oligopeptidase (TOP) and neurolysin activities were then investigated in B16F10-Nex2 melanoma cells aiming at gene sequencing, enzyme distribution and activity, influence on tumor development, substrate specificity, hydrolytic products and susceptibility to inhibitors. Fluorescence resonance energy transfer (FRET) peptides as well as neurotensin and bradykinin were used as substrates. The hydrolytic activities in B16F10-Nex2 culture supernatant were totally inhibited by <it>o</it>-phenanthrolin, JA-2 and partially by Pro-Ile. Leupeptin, PMSF, E-64, Z-Pro-Prolinal and captopril failed to inhibit these hydrolytic activities. Genes encoding M3A enzymes in melanoma cells were cloned and sequenced being highly similar to mouse genes. A decreased proliferation of B16F10-Nex2 cells was observed in vitro with specific inhibitors of these oligopeptidases. Active rTOP but not the inactive protein inhibited melanoma cell development in vivo increasing significantly the survival of mice challenged with the tumor cells. On Matrigel, rTOP inhibited the bradykinin – induced angiogenesis. A possible regulation of the homologous tumor enzyme in the perivascular microenvironment is suggested based on the observed rTOP inhibition by an S-nitrosothiol NO donor.</p> <p>Conclusion</p> <p>Data show that melanoma cells secrete endo-oligopeptidases which have an important role in tumor proliferation in vitro and in vivo. rTOP inhibited growth of subcutaneously injected B16F10-Nex2 cells in mice. TOP from tumor cells and bradykinin in endothelial cells are two antagonist factors that may control angiogenesis essential for melanoma growth. A regulatory role of NO or S-nitrosothiols is suggested.</p

    Eficácia da imunoterapia no tratamento de pitiose facial em equino.

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    Pythiosis in horses is a proliferative and ulcerative disease that primarily affects the skin and subcutaneous tissue of limbs, thoracic-abdominal region and head. This disease sometimes can also affect limb bones or cause tumoral masses in abdomen. Usually, the cutaneous cases are confused with habronemiasis. The disease is more common in marshy areas, places with formation of slow drainage ponds and aquatic vegetation under high temperatures. The aim of this study was to describe the development of facial lesions in a horse caused by pythiosis in Cuiaba, Mato Grosso, and, additionally to discuss relevant issues regarding the diagnosis, clinical course and response to immunotherapy treatment.Publicação 955. Hospital Forum

    Metastatic squamous cell carcinoma to the colon arising from a mature cystic ovarian teratoma

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    Malignant transformation of a mature cystic teratoma is extremely rare, occurring in 0.17-2% of cases.1 The most common malignant degeneration is squamous cell carcinoma (SCC) arising from the ectoderm. Approximately half of all cases of SCC of the ovary are confined to the ovary at time diagnosis.1,2 Secondary to its absolute rarity and the relative infrequency of cases with metastatic spread the optimal treatment of advanced stage disease is unknown. Outcomes for locally advanced and widespread disease have historically been very poor. Ford and Timmons recently reported on a patient with stage IIC SCC arising in a mature cystic teratoma treated with multimodal therapy who has been free of disease for more than five years.3 Herein we report on a woman with stage IIIC SCC arising within a mature cystic teratoma treated with directed chemoradiation who subsequently developed metastatic SCC to the colon

    Characterization of the LysR-type transcriptional regulator YcjZ-like from Xylella fastidiosa overexpressed in Escherichia coli

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    AbstractThe Xylella fastidiosa 9a5c strain is a xylem-limited phytopathogen that is the causal agent of citrus variegated chlorosis (CVC). This bacterium is able to form a biofilm and occlude the xylem vessels of susceptible plants, which leads to significant agricultural and economic losses. Biofilms are associated with bacterial pathogenicity because they are very resistant to antibiotics and other metal-based chemicals that are used in agriculture. The X. fastidiosa YcjZ-like (XfYcjZ-like) protein belongs to the LysR-type transcriptional regulator (LTTR) family and is involved in various cellular functions that range from quorum sensing to bacterial survival. In the present study, we report the cloning, expression and purification of XfYcjZ-like, which was overexpressed in Escherichia coli. The secondary folding of the recombinant and purified protein was assessed by circular dichroism, which revealed that XfYcjZ-like contains a typical α/β fold. An initial hydrodynamic characterization showed that XfYcjZ-like is a globular tetramer in solution. In addition, using a polyclonal antibody against XfYcjZ-like, we assessed the expression profile of this protein during the different developmental phases of X. fastidiosa in in vitro cultivated biofilm cells and demonstrated that XfYcjZ-like is upregulated in planktonic cells in response to a copper shock treatment. Finally, the ability of XfYcjZ-like to interact with its own predicted promoter was confirmed in vitro, which is a typical feature of LysR. Taken together, our findings indicated that the XfYcjZ-like protein is involved in both the organization of the architecture and the maturation of the bacterial biofilm and that it is responsive to oxidative stress
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