1,163 research outputs found

    Development of a PCR-RFLP marker to genetically distinguish Prosorhynchus crucibulum and Prosorhynchus aculeatus

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    The cercariae stages of Prosorhynchus crucibulum and Prosorhynchus aculeatus are morphologically indistinguishable. However, the differentiation of these two species is crucial to understand the transmission dynamics between these primary hosts (mussels) and the secondary hosts (fish). In this way, the objective of this study is to develop an accurate molecular identification too] to differentiate the cercariae stage of P. crucibulum and P. aculeatus. We targeted the 18S nuclear ribosomal DNA region by PCR amplification and sequenced this amplicon. By generating these sequences, we developed a RFLP tool with the use of the enzymes Hincll and FokI that produced different restriction profiles between P. crucibulum and P. aculeatus. Each enzyme generated different-sized fragments specific to the species examined and no cross-reaction between the species was detected in their restriction pattern. By sequencing, no intraspecific-polymorphism was detected since there is 100% homology among A aculeatus or A crucibulum. These results indicate that PCR-linked restriction analysis of the 18S rDNA region provided us with rapid and reliable molecular tools for distinction of the cercariae of these species. The sequences generated were deposited in GenBank accession numbers for P. crucibulum cercariae (FJ463407, FJ463408 and FJ463409) and adult worm (FJ429096, FJ429097), and for A aculeatus adult (FJ429094 and FJ429095). (C) 2009 Elsevier Ireland Ltd. All rights reserved

    In Vivo Analysis of Trypanosoma cruzi Persistence Foci at Single-Cell Resolution

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    Infections with Trypanosoma cruzi are usually lifelong despite generating a strong adaptive immune response. Identifying the sites of parasite persistence is therefore crucial to understanding how T. cruzi avoids immune-mediated destruction. However, this is a major technical challenge, because the parasite burden during chronic infections is extremely low. Here, we describe an integrated approach involving comprehensive tissue processing, ex vivo imaging, and confocal microscopy, which allowed us to visualize infected host cells in murine tissue with exquisite sensitivity. Using bioluminescence-guided tissue sampling, with a detection level of 200 parasites, which we term mega-nests. In contrast, during the acute stage, when the total parasite burden is considerably higher and many cells are infected, nests containing >50 parasites are rarely found. In C3H/HeN mice, but not BALB/c mice, we identified skeletal muscle as a major site of persistence during the chronic stage, with most parasites being found in large mega-nests within the muscle fibers. Finally, we report that parasites are also frequently found in the skin during chronic murine infections, often in multiple infection foci. In addition to being a site of parasite persistence, this anatomical reservoir could play an important role in insect-mediated transmission and have implications for drug development.IMPORTANCETrypanosoma cruzi causes Chagas disease, the most important parasitic infection in Latin America. Major pathologies include severe damage to the heart and digestive tract, although symptoms do not usually appear until decades after infection. Research has been hampered by the complex nature of the disease and technical difficulties in locating the extremely low number of parasites. Here, using highly sensitive imaging technology, we reveal the sites of parasite persistence during chronic-stage infections of experimental mice at single-cell resolution. We show that parasites are frequently located in smooth muscle cells in the circular muscle layer of the colon and that skeletal muscle cells and the skin can also be important reservoirs. This information provides a framework for investigating how the parasite is able to survive as a lifelong infection, despite a vigorous immune response. It also informs drug development strategies by identifying tissue sites that must be accessed to achieve a curative outcome

    Morphological and molecular analysis of metacercariae of Diphtherostomum brusinae (Stossich, 1888) Stossich, 1903 from a new bivalve host Mytilus galloprovincialis

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    DOI: 10.1017/S0022149X10000428The digenean trematode Diphtherostomum brusinae (Stossich, 1888) Stossich, 1903 presents a complex life cycle that may involve more than one intermediate host. The present study represents the first description of the metacercariae from D. brusinae infecting the labial palps of a new intermediate host, Mytilus galloprovincialis, in the Aveiro estuary, Portugal. The morphology of this parasitic stage was studied by light (LM) and scanning electron microscopy (SEM) and some differences were reported (body and sucker sizes, and spine distribution and shape). In this work, the 18S partial region of the ribosomal DNA was sequenced from D. brusinae metacercariae isolated from M. galloprovincialis collected in different localities of the Aveiro estuary. In addition, sequences from the same region of the 18S rDNA were obtained from D. brusinae cercariae and metacercariae, hosted by Nassarius reticulatus and Cerastoderma edule, respectively. No intraspecific polymorphism was detected in the 18S partial region, since there was 100% homology among all the sequences analysed. The same comparison was made for the ITS1, and we observed intraspecific polymorphism in this region. To our knowledge, this is the first report of D. brusinae metacercariae infecting the mussel M. galloprovincialis with support from morphological and molecular data

    A comparison of hepatitis B viral markers of patients in different clinical stages of chronic infection

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    Hepatitis B viral markers may be useful for predicting outcomes such as liver-related deaths or development of hepatocellular carcinoma. We determined the frequency of these markers in different clinical stages of chronic hepatitis B infection. We compared baseline hepatitis B viral markers in 317 patients who were enrolled in a prospective study and identified the frequency of these tests in immune-tolerant (IT) patients, in inactive carriers , and in patients with either hepatitis B e antigen ( HBeAg)- positive or HBeAg-negative chronic hepatitis or cirrhosis. IT patients were youngest (median age 27 years) and HBeAg- negative patients with cirrhosis were oldest (median age 58 years) (p = 0.03 to < 0.0001). The male to female ratio was similar both in IT patients and in inactive carriers, but there was a male preponderance both in patients with chronic hepatitis and in patients with cirrhosis (p < 0.0001). The A1896 precore mutants were most prevalent in inactive carriers (36.4%) and HBeAg- negative patients with chronic hepatitis (38.8%; p < 0.0001), and the T 1762/A1764 basal core promoter mutants were most often detected in HBeAg- negative patients with cirrhosis (65.1%; p = 0.02). Genotype A was detected only in 5.3% of IT patients, and genotype B was least often detected in both HBeAg-Positive patients with chronic hepatitis and cirrhosis (p = 0.03). The hepatitis B viral DNA levels were lowest in inactive carriers (2.69 log(10) IU/mL) and highest in IT patients (6. 80 log(10) IU/mL; p = 0.02 to < 0.0001). At follow-up, HBeAg-positive and HBeAg-negative patients with cirrhosis accounted for 57 of 64 (89.1%) liver-related deaths (p < 0. 0001). Differences in baseline hepatitis B viral markers were detected in patients in various clinical stages of hepatitis B virus infection. HBeAg-positive and HBeAg- negative patients with cirrhosis accounted for the majority of the liver-related fatalities

    Manual lymphatic drainage therapy in patients with breast cancer related lymphoedema

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    <p>Abstract</p> <p>Background</p> <p>Lymphoedema is a common and troublesome condition that develops following breast cancer treatment. The aim of this study is to analyze the effectiveness of Manual Lymphatic Drainage in the treatment of postmastectomy lymphoedema in order to reduce the volume of lymphoedema and evaluate the improvement of the concomitant symptomatology.</p> <p>Methods</p> <p>A randomized, controlled clinical trial in 58 women with post-mastectomy lymphoedema. The control group includes 29 patients with standard treatment (skin care, exercise and compression measures, bandages for one month and, subsequently, compression garnments). The experimental group includes 29 patients with standard treatment plus Manual Lymphatic Drainage. The therapy will be administered daily for four weeks and the patient's condition will be assessed one, three and six months after treatment.</p> <p>The primary outcome parameter is volume reduction of the affected arm after treatment, expressed as a percentage. Secondary outcome parameters include: duration of lymphoedema reduction and improvement of the concomitant symptomatology (degree of pain, sensation of swelling and functional limitation in the affected extremity, subjective feeling of being physically less atractive and less feminine, difficulty looking at oneself naked and dissatisfaction with the corporal image).</p> <p>Discussion</p> <p>The results of this study will provide information on the effectiveness of Manual Lymphatic Drainage and its impact on the quality of life and physical limitations of these patients.</p> <p>Trial registration</p> <p>ClinicalTrials (NCT): <a href="http://www.clinicaltrials.gov/ct2/show/NCT01152099">NCT01152099</a></p

    Persistent inequalities in unplanned hospitalisation among colon cancer patients across critical phases of their care pathway, England, 2011-13.

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    BACKGROUND: Reducing hospital emergency admissions is a key target for all modern health systems. METHODS: We analysed colon cancer patients diagnosed in 2011-13 in England. We screened their individual Hospital Episode Statistics records in the 90 days pre-diagnosis, the 90 days post-diagnosis, and the 90 days pre-death (in the year following diagnosis), for the occurrence of hospital emergency admissions (HEAs). RESULTS: Between a quarter and two thirds of patients experience HEA in the three 90-day periods examined: pre-diagnosis, post-diagnosis and before death. Patients with tumour stage I-III from more deprived backgrounds had higher proportions of HEAs than less deprived patients during all studied periods. This remains even after adjusting for differing distributions of risk factors such as age, sex, comorbidity and stage at diagnosis. CONCLUSIONS: Although in some cases HEAs might be unavoidable or even appropriate, the proportion of HEAs varies by socioeconomic status, even after controlling for the usual patient factors, suggestive of remediable causes of excess emergency healthcare utilisation in patients belonging to higher deprivation groups. Future inquiries should address the potential role of clinical complications, sub-optimal healthcare administration, premature discharge or a lack of social support as potential explanations for these patterns of inequality

    What explains ethnic organizational violence? Evidence from Eastern Europe and Russia

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    Why do some ethnopolitical organizations use violence? Research on substate violence often uses the state level of analysis, or only analyzes groups that are already violent. Using a resource mobilization framework drawn from a broad literature, we test hypotheses with new data on hundreds of violent and non-violent ethnopolitical organizations in Eastern Europe and Russia. Our study finds interorganizational competition, state repression and strong group leadership associated with organizational violence. Lack of popularity and holding territory are also associated with violence. We do not find social service provision positively related to violence, which contrasts with research on the Middle East

    HERMES: Towards an Integrated Toolbox to Characterize Functional and Effective Brain Connectivity

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    The analysis of the interdependence between time series has become an important field of research in the last years, mainly as a result of advances in the characterization of dynamical systems from the signals they produce, the introduction of concepts such as generalized and phase synchronization and the application of information theory to time series analysis. In neurophysiology, different analytical tools stemming from these concepts have added to the ‘traditional’ set of linear methods, which includes the cross-correlation and the coherency function in the time and frequency domain, respectively, or more elaborated tools such as Granger Causality. This increase in the number of approaches to tackle the existence of functional (FC) or effective connectivity (EC) between two (or among many) neural networks, along with the mathematical complexity of the corresponding time series analysis tools, makes it desirable to arrange them into a unified-easy-to-use software package. The goal is to allow neuroscientists, neurophysiologists and researchers from related fields to easily access and make use of these analysis methods from a single integrated toolbox. Here we present HERMES (http://hermes.ctb.upm.es), a toolbox for the Matlab® environment (The Mathworks, Inc), which is designed to study functional and effective brain connectivity from neurophysiological data such as multivariate EEG and/or MEG records. It includes also visualization tools and statistical methods to address the problem of multiple comparisons. We believe that this toolbox will be very helpful to all the researchers working in the emerging field of brain connectivity analysis
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