130 research outputs found
Use of Animal Models in the Study of Colitis
Inflammatory bowel diseases (IBDs) relate to chronic inflammations in different parts of the gastrointestinal (GI) tract involving both ulcerative colitis (UC) and Crohn’s disease (CD). Ulcerative colitis begins in the rectum and extends continuously up the colon. Notably, CD may affect any area of the GIT, from the mouth to the anus. Various conditions may influence the genesis of the disease, such as genetics, environment, intestinal microbiota and the presence of agents of enteric infections. Experimental models are therefore suitably used to investigate the various etiological factors; similarly colitis can be induced by genetic modification, cell transfer, spontaneous inflammation and chemical agents. The objective of this chapter is to present current concept on animal models of inflammatory bowel diseases. These models are crucial for the understanding of inflammatory bowel diseases, development of alternative treatments and more effective therapeutic agents thus contributing to the control of the disease
Alluvial xenotime and heavy minerals assemblage from the northern edge of Nisa-Albuquerque Batholith, eastern Portugal : provenance and geochemical implications
Alluvial xenotime and heavy minerals assemblage from the northern edge of Nisa-Albuquerque Batholith, eastern Portugal : provenance and geochemical
implications / Rute Salgueiro... [et al.]. - Amsterdam : Elsevier, 2014. - [18] p. : il., 13 figuras e 8 tabelas ; 30 cm
The xenotime-bearing heavy mineral assemblages present in the alluvial samples from Vila Velha de Ródão, Nisa, Póvoa e Meadas and Sto. António das
Areias, localized in the northern edge of Nisa-Albuquerque Batholith, Eastern Portugal, were studied in detail. The insights for mineral provenance came from
the analysis of the drainage network and from the composition of the regional alluvial samples and outcropping lithologies. Since xenotime is a mineral with
economic interest, the motivation of the current work is its contribution for exploration studies, considering the potential information contained in the alluvial
samples. In the study region, the alluvial heavy minerals and their morphology reflect clearly the mineralogy and relative distance to their source,
respectively. In alluvial samples with direct provenance from the Nisa granite (late Carboniferous), the increase in xenotime concentration and decrease in
monazite, apatite, zircon, ilmenite and iron oxide concentration, from W (Nisa) to E (Sto. António das Areias), matches the increase in P2O5 and decrease in
REE, CaO, Zr, TiO2, and Fe2O3 contents in granite rocks.
The geochemical signature of xenotime studied reveals an igneous source, characterized by the characteristic strong Eu negative anomaly in REE patterns.
Their YPO4 values (72–78 mol%) are similar to xenotime from Erzgebirge (Germany) granites. The high values of Y/Ho (50–71) and, in some cases, downward
kinks at Ho in REE plots, suggest generation in late stages of crystallization and association with a siliceous evolved magmatic system. The slight decrease in
HREE contents in xenotime, from W to E, and Ho anomalies in the normalized REE pattern are similar to those identified in the Nisa granite, which supports
the sourcing of xenotime from these granitic rocks. The genetic development of the batholith chemical zonation (more evolved to E) seems to have favoured
the generation of xenotime instead of apatite, monazite and zircon, in the eastern end area (Sto. António das Areias).
Supporting the geochemical signature, the alluvial zircons also display morphological typologies that are compatible with provenance from peraluminous
granites formed at temperatures of 600–700 °C, possibly from the Nisa granite. Since all xenotime grains show the same magmatic affinity, this leads to the
hypothesis that the xenotime from the Vila Velha de Ródão sample, with provenance from Cenozoic sedimentary rocks, has been transported to this northern
area, after been disaggregated from Nisa batholith granites, most probably by braided anastomosing and erratically sandy channels, that explains its actual
position in the opposite bank of the Tagus river. This phosphate has been deposited with other sediments in tectonic depressions and subsequently included
in the formation of sedimentary rocks. The greater development of Ca, Th and U phosphate inclusions/substitutions in these xenotime grains can be explained
by the chemical mobility provided during all the geological processes
Public health and epidemiology journals published in Brazil and other Portuguese speaking countries
It is well known that papers written in languages other than English have a great risk of being ignored simply because these languages are not accessible to the international scientific community. The objective of this paper is to facilitate the access to the public health and epidemiology literature available in Portuguese speaking countries. It was found that it is particularly concentrated in Brazil, with some few examples in Portugal and none in other Portuguese speaking countries. This literature is predominantly written in Portuguese, but also in other languages such as English or Spanish. The paper describes the several journals, as well as the bibliographic databases that index these journals and how to access them. Most journals provide open-access with direct links in the indexing databases. The importance of this scientific production for the development of epidemiology as a scientific discipline and as a basic discipline for public health practice is discussed. To marginalize these publications has implications for a more balanced knowledge and understanding of the health problems and their determinants at a world-wide level
Fulfillment of the Brazilian Agenda of Priorities in Health Research
This commentary describes how the Brazilian Ministry of Health's (MoH) research support policy fulfilled the National Agenda of Priorities in Health Research (NAPHR). In 2003, the MoH started a democratic process in order to establish a priority agenda in health research involving investigators, health managers and community leaders. The Agenda was launched in 2004 and is guiding budget allocations in an attempt to reduce the gap between scientific knowledge and health practice and activities, aiming to contribute to improving Brazilian quality of life. Many strategies were developed, for instance: Cooperation Agreements between the Ministry of Health and the Ministry of Science and Technology; the decentralization of research support at state levels with the participation of local Health Secretariats and Science and Technology Institutions; Health Technology Assessment; innovation in neglected diseases; research networks and multicenter studies in adult, women's and children's health; cardiovascular risk in adolescents; clinical research and stem cell therapy. The budget allocated by the Ministry of Health and partners was expressive: US$419 million to support almost 3,600 projects. The three sub-agenda with the higher proportion of resources were "industrial health complex", "clinical research" and "communicable diseases", which are considered strategic for innovation and national development. The Southeast region conducted 40.5% of all projects and detained 59.7% of the resources, attributable to the concentration of the most traditional health research institutes and universities in the states of São Paulo and Rio de Janeiro. The second most granted region was the Northeast, which reflects the result of a governmental policy to integrate and modernize this densely populated area and the poorest region in the country. Although Brazil began the design and implementation of the NAPHR in 2003, it has done so in accordance with the 'good practice principles' recently published: inclusive process, information gathering, careful planning and funding policy, transparency and internal evaluation (an external independent evaluation is underway). The effort in guiding the health research policy has achieved and legitimated an unprecedented developmental spurt to support strategic health research. We believe this experience is valuable and applicable to other countries, but different settings and local political circumstances will determine the best course of action to follow
Atrial fibrillation ablation : the added value of adenosine test in confirming pulmonary vein isolation
© The European Society of Cardiology 2018. All rights reserved.Introduction: Adenosine test has been increasingly used to confirm pulmonary vein isolation (PVI) in patients undergoing ablation of atrial fibrillation (AF). However, its impact on the success of ablation remains unknown.
Purposes: To evaluate the results of the adenosine triphosphate (ATP) test in patients undergoing PVI and assess the success of ablation related to the use of this test (adenosine-guided PVI versus conventional PVI).
Methods: Single-center prospective study of consecutive patients undergoing first AF ablation procedure, started at January 2013. After ablation, the persistence of PVI was tested with adenosine triphosphate administration (15–30mg by intravenous route). When adenosine triphosphate-induced pulmonary vein conduction (termed as reconduction) was observed, additional energy applications of radiofrequency were applied to obtain persistent isolation on retesting. Cardiac event recorder was performed at 7 days, 3, 6 and 12 months after ablation and annually from the 2nd year.
The adenosine triphosphate-induced reconduction rate was evaluated depending on the pulmonary vein involved. The impact of adenosine test implementation in the success of the ablation at 365 days (recurrence of AF or supraventricular tachycardia) was determined by analysis of overall survival using Kaplan-Meier method.
Results: Adenosine test was performed on 151 patients, with reconduction detected on at least one of the pulmonary veins in 11 patients (33.8%) and in 17.6% of the 641 pulmonary veins evaluated, with no statistically significant difference between the different veins. The overall success rate of AF ablation at 365 days was 72% and did not differ significantly between adenosine-guided PVI versus conventional PVI (74.3% versus 70.8%, P = NS), although the duration of follow-up had been shorter in the first group (median of 13.0 vs. 38.3 months; p<0.001).
Conclusion: The adenosine-induced reconduction occurs in about one third of the patients. However, the additional adenosine-guided energy applications do not seem to increase the overall success of ablation. We found no significant reduction in the 1 year incidence of recurrent atrial tachyarrhythmias by ATP-guided PVI compared with conventional PVI.info:eu-repo/semantics/publishedVersio
Iron age genomic data from Althiburos – Tunisia renew the debate on the origins of African taurine cattle
The Maghreb is a key region for understanding the dynamics of cattle dispersal and admixture with local aurochs following their earliest domestication in the Fertile Crescent more than 10,000 years ago. Here, we present data on autosomal genomes and mitogenomes obtained for four archaeological specimens of Iron Age (∼2,800 cal BP–2,000 cal BP) domestic cattle from the Eastern Maghreb, i.e. Althiburos (El Kef, Tunisia). D-loop sequences were obtained for an additional eight cattle specimens from this site. Maternal lineages were assigned to the elusive R and ubiquitous African-T1 haplogroups found in two and ten Althiburos specimens, respectively. Our results can be explained by post-domestication hybridization of Althiburos cattle with local aurochs. However, we cannot rule out an independent domestication in North Africa considering the shared ancestry of Althiburos cattle with the pre-domestic Moroccan aurochs and present-day African taurine cattle.info:eu-repo/semantics/publishedVersio
XIST-promoter demethylation as tissue biomarker for testicular germ cell tumors and spermatogenesis quality
Background: The event of X chromosome inactivation induced by XIST, which is physiologically observed in females, is retained in testicular germ cell tumors (TGCTs), as a result of a supernumerary X chromosome constitution. X chromosome inactivation also occurs in male germline, specifically during spermatogenesis. We aimed to analyze the promoter methylation status of XIST in a series of TGCT tissues, representative cell lines, and testicular parenchyma. Methods: Two independent cohorts were included, comprising a total of 413 TGCT samples, four (T)GCT cell lines, and 86 testicular parenchyma samples. The relative amount of methylated and demethylated XIST promoter fragments was assessed by quantitative methylation-specific PCR (qMSP) and more sensitive high-resolution melting (HRM) methylation analyses. Results: Seminomas showed a lower amount of methylated XIST fragments as compared to non-seminomas or normal testis (p < 0.0001), allowing for a good discrimination among these groups (area under the curve 0.83 and 0.81, respectively). Seminomas showed a significantly higher content of demethylated XIST as compared to non-seminomas. The percentage of demethylated XIST fragment in cell lines reflected their chromosomal constitution (number of extra X chromosomes). A novel and strong positive correlation between the Johnsen’s score and XIST demethylation was identified (r = 0.75, p < 0.0001). Conclusions: The X chromosome inactivation event and demethylated XIST promoter are promising biomarkers for TGCTs and for assessing spermatogenesis quality
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