456 research outputs found
Small bowel stricture as a late sequela of superior mesenteric vein thrombosis
AbstractIntroductionThe increasing frequency of use of CT in patients with acute abdomen is likely to improve the diagnosis of rarely occurring conditions/causes such as superior mesenteric vein thrombosis (MVT). Despite its severe consequences, MVT often presents with nonspecific clinical features.Presentation of caseAD, a 64-year-old man was an emergency admission with vague abdominal discomfort of two weeks duration, acute upper abdominal pain, loose stools, fresh rectal bleeding and vomiting. A contrast enhanced abdominal CT showed thrombosis of the proximal portal vein and the entire length of the superior mesenteric vein (SMV) with small bowel ischaemia extending from the terminal ileum to the mid jejunal loops. Tests for paroxysmal nocturnal haemoglobinuria and Janus kinase 2 mutation yielded negative results. AD was readmitted seven months later with small bowel obstruction requiring segmental small bowel resection with end-to-end anastomosis. Abdominal CT had shown complete resolution of MVT but a small bowel stricture.DiscussionThrombosis limited to mesenteric veins results in earlier and more frequent development of infarction compared to portal combined with mesenteric venous thrombosis. Most patients may be successfully treated with anti-coagulation therapy alone. However, surgery may be required to deal with intestinal infarction or late sequela of MVT.ConclusionThis case demonstrates that MVT can be reversed by effective anticoagulation. However, the price paid for a mild to moderate effect on the bowel may be significant stricture later on. Patients escaping early bowel resection due to massive MVT leading to bowel infarction may still require resection later due to stricture
First systematic high-precision survey of bright supernovae
Rapid variability before and near the maximum brightness of supernovae has the potential to provide a better understanding of nearly every aspect of supernovae, from the physics of the explosion up to their progenitors and the circumstellar environment. Thanks to modern time-domain optical surveys, which are discovering supernovae in the early stage of their evolution, we have the unique opportunity to capture their intraday behavior before maximum. We present high-cadence photometric monitoring (on the order of seconds-minutes) of the optical light curves of three Type Ia and two Type II SNe over several nights before and near maximum light, using the fast imagers available on the 2.3 m Aristarchos telescope at Helmos Observatory and the 1.2 m telescope at Kryoneri Observatory in Greece. We applied differential aperture photometry techniques using optimal apertures and we present reconstructed light curves after implementing a seeing correction and the Trend Filtering Algorithm (TFA, KovΓ‘cs et al. 2005, MNRAS, 356, 557). TFA yielded the best results, achieving a typical precision between 0.01 and 0.04 mag. We did not detect significant bumps with amplitudes greater than 0.05 mag in any of the SNe targets in the VR-, R-, and I-bands light curves obtained. We measured the intraday slope for each light curve, which ranges between β0.37β0.36 mag dayβ1 in broadband VR, β0.19β0.31 mag dayβ1 in R band, and β0.13β0.10 mag dayβ1 in I band. We used SNe light curve fitting templates for SN 2018gv, SN 2018hgc and SN 2018hhn to photometrically classify the light curves and to calculate the time of maximum. We provide values for the maximum of SN 2018zd after applying a low-order polynomial fit and SN 2018hhn for the first time. We conclude that optimal aperture photometry in combination with TFA provides the highest-precision light curves for SNe that are relatively well separated from the centers of their host galaxies. This work aims to inspire the use of ground-based, high-cadence and high-precision photometry to study SNe with the purpose of revealing clues and properties of the explosion environment of both core-collapse and Type Ia supernovae, the explosion mechanisms, binary star interaction and progenitor channels. We suggest monitoring early supernovae light curves in hotter (bluer) bands with a cadence of hours as a promising way of investigating the post-explosion photometric behavior of the progenitor stars
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Response Modification Factors for Concrete Bridges in Europe
The paper presents a methodology for evaluating the actual response modification factors (q or R) of bridges and applies it to seven concrete bridges typical of the stock found in southern Europe. The usual procedure for analytically estimating the q-factor is through pushover curves derived for the bridge in (at least) its longitudinal and transverse directions. The shape of such curves depends on the seismic energy dissipation mechanism of the bridge; hence, bridges are assigned to two categories, those with inelastically responding piers and those whose deck is supported through bearings on strong, elastically responding piers. For bridges with yielding piers, the final value of the q-factor is found as the product of the overstrength-dependent component (qs) and the ductility-dependent component (qΞΌ), both estimated from the pertinent pushover curve. For bridges with bearings and nonyielding piers of the wall type, an equivalent q-factor is proposed, based on spectral accelerations at failure and at design level. In this paper, pushover curves are also derived for an arbitrary angle of incidence of seismic action using a procedure recently developed by the authors, to investigate the influence of the shape of the pushover curve on the estimation of q-factors. It is found that in all cases the available force reduction factors are higher than those used for design to either Eurocode 8 or AASHTO specifications
The actin-bundling protein fascin is overexpressed in colorectal adenomas and promotes motility in adenoma cells in vitro
Background:
Fascin is overexpressed in many cancers, including colorectal, but its role in the malignant transformation of benign colorectal adenomas is unclear.
Methods:
Immunohistochemical analysis of fascin expression was carried out in resected human colorectal adenoma specimens. The effects of forced overexpression of fascin on adenoma cell motility were also analysed.
Results:
We show fascin overexpression in adenomas increasing with tumour size, histological type, and degree of dysplasia and increased cell motility in adenoma cell lines following fascin transfection.
Conclusion:
These data suggest an important role for fascin in the malignant progression of colorectal tumours
Transcriptional down-regulation of the retinoblastoma protein is associated with differentiation and apoptosis in human colorectal epithelial cells
The aim of this study was to investigate the regulation of Rb protein expression in relation to increased differentiation and induction of apoptosis in colonic epithelial cells. In vivo, Rb protein expression was found to be down-regulated towards the top of the normal colonic crypt, coincident with the region of differentiation and apoptosis, but highly expressed in colonic carcinoma tissue. Using in vitro models to study the regulation of Rb expression in pre-malignant colonic epithelial cells, we have been able to show for the first time that Rb protein expression is transcriptionally down-regulated in differentiated pre-malignant cells (in post-confluent cultures) but not in malignant colorectal epithelial cells. Furthermore, suppression of rb protein function by the HPV-E7 viral oncoprotein increased both spontaneous and DNA damage-induced apoptosis. These results suggest that Rb is able to act as a survival factor in colonic epithelial cells by suppressing apoptosis, and that over-expression of pRb in colorectal tumour cells can cause a loss of sensitivity to apoptotic signalling, resulting in aberrant cell survival and resistance to therapy. Β© 2001 Cancer Research Campaign http://www.bjcancer.co
Surveillance of Bisphenol A and Phthalates in Materials in Contact with Food and Children Toys in Cyprus
In recent years a variety of chemicals have been found to disrupt the endocrine systems, and there is strong evidence that chemical exposure has been associated with adverse developmental and reproductive effects on fish and wildlife in particular locations. Bisphenol A (BPA) is one of a number of chemicals that may have the potential to interact with hormone systems in the body. BPA is an organic compound with two phenol functional groups used to make polycarbonate plastic and epoxy resins, along with other applications. Another class of chemicals are the phthalate esters and are mainly used as plasticizers (substances added to plastics to increase their flexibility, transparency, durability, and longevity). They are used primarily to soften PVC used in soft children toys
Gender Equity in Transplantation: A Report From the Women in Transplantation Workshop of The Transplantation Society of Australia and New Zealand
The exponential growth of young talented women choosing science and medicine as their professional career over the past decade is substantial. Currently, more than half of the Australian medical doctoral graduates and early career researchers are comprised of women, but less than 20% of all academic professorial staff are women. The loss of female talent in the hierarchical ladder of Australian academia is a considerable waste of government investment, productivity, and scientific innovation. Gender disparity in the professional workforce composition is even more striking within the field of transplantation. Women are grossly underrepresented in leadership roles, with currently no female heads of unit in any of the Australian and New Zealand transplanting centers. At the same time, there is also gender segregation with a greater concentration of women in lower-status academic position compared with their male counterparts. Given the extent and magnitude of the disparity, the Women in Transplantation Committee, a subcommittee of The Transplantation Society of Australia and New Zealand established a workshop comprising 8 female clinicians/scientists in transplantation. The key objectives were to (i) identify potential gender equity issues within the transplantation workforce; (ii) devise and implement potential strategies and interventions to address some of these challenges at a societal level; (iii) set realistic and achievable goals to enhance and facility gender equality, equity, and diversity in transplantation
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