677 research outputs found

    Conversion of the death inhibitor ARC to a killer activates pancreatic β cell death in diabetes

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    Loss of insulin-secreting pancreatic β cells through apoptosis contributes to the progression of type 2 diabetes, but underlying mechanisms remain elusive. Here, we identify a pathway in which the cell death inhibitor ARC paradoxically becomes a killer during diabetes. While cytoplasmic ARC maintains β cell viability and pancreatic architecture, a pool of ARC relocates to the nucleus to induce β cell apoptosis in humans with diabetes and several pathophysiologically distinct mouse models. β cell death results through the coordinate downregulation of serpins (serine protease inhibitors) not previously known to be synthesized and secreted by β cells. Loss of the serpin α1-antitrypsin from the extracellular space unleashes elastase, triggering the disruption of β cell anchorage and subsequent cell death. Administration of α1-antitrypsin to mice with diabetes prevents β cell death and metabolic abnormalities. These data uncover a pathway for β cell loss in type 2 diabetes and identify an FDA-approved drug that may impede progression of this syndrome

    The Use of a Compression Device as an Alternative to Hand-Sewn and Stapled Colorectal Anastomoses: Is Three a Crowd?

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    BackgroundThe NiTi CAR™ 27 is a newer device that uses compression to create an anastomosis. An analysis of this device in the creation of colorectal anastomoses in humans has yet to be reported in the USA.MethodsA non-randomized, prospective pilot study of the NiTi CAR™ 27 device in patients undergoing a left-sided colectomy between March 2008 and August 2009 was performed.ResultsTwenty-three patients (9 men and 14 women) underwent a left-sided colectomy and compression anastomosis with the CAR™ 27 device. Minor morbidities, 3 of 23 (13%) patients, included one small postoperative abscess requiring antibiotics alone and two postoperative anastomotic strictures requiring balloon dilation. Major morbidities, 1 of 23 (4%) patients, included a partial anastomotic dehiscence/leak requiring surgical dismantling of the anastomosis and diversion.ConclusionThe CAR™ 27 device shows promise as a safe and effective alternative for the creation of colorectal anastomoses. However, studies in a larger patient population are warranted to demonstrate equivalence of this device

    Current treatment options for recurrent nasopharyngeal cancer

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    Loco-regional control rate of nasopharyngeal carcinoma (NPC) has improved significantly in the past decade. However, local recurrence still represents a major cause of mortality and morbidity in advanced stages, and management of local failure remains a challenging issue in NPC. The best salvage treatment for local recurrent NPC remains to be determined. The options include brachytherapy, external radiotherapy, stereotactic radiosurgery, and nasopharyngectomy, either alone or in different combinations. In this article we will discuss the different options for salvage of locally recurrent NPC. Retreatment of locally recurrent NPC using radiotherapy, alone or in combination with other treatment modalities, as well as surgery, can result in long-term local control and survival in a substantial proportion of patients. For small-volume recurrent tumors (T1–T2) treated with external radiotherapy, brachytherapy or stereotactic radiosurgery, comparable results to those obtained with surgery have been reported. In contrast, treatment results of advanced-stage locally recurrent NPC are generally more satisfactory with surgery (with or without postoperative radiotherapy) than with reirradiation

    WNP: A Novel Algorithm for Gene Products Annotation from Weighted Functional Networks

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    Predicting the biological function of all the genes of an organism is one of the fundamental goals of computational system biology. In the last decade, high-throughput experimental methods for studying the functional interactions between gene products (GPs) have been combined with computational approaches based on Bayesian networks for data integration. The result of these computational approaches is an interaction network with weighted links representing connectivity likelihood between two functionally related GPs. The weighted network generated by these computational approaches can be used to predict annotations for functionally uncharacterized GPs. Here we introduce Weighted Network Predictor (WNP), a novel algorithm for function prediction of biologically uncharacterized GPs. Tests conducted on simulated data show that WNP outperforms other 5 state-of-the-art methods in terms of both specificity and sensitivity and that it is able to better exploit and propagate the functional and topological information of the network. We apply our method to Saccharomyces cerevisiae yeast and Arabidopsis thaliana networks and we predict Gene Ontology function for about 500 and 10000 uncharacterized GPs respectively

    Reirradiation of head and neck cancer focusing on hypofractionated stereotactic body radiation therapy

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    Reirradiation is a feasible option for patients who do not otherwise have treatment options available. Depending on the location and extent of the tumor, reirradiation may be accomplished with external beam radiotherapy, brachytherapy, radiosurgery, or intensity modulated radiation therapy (IMRT). Although there has been limited experience with hypofractionated stereotactic radiotherapy (hSRT), it may have the potential for curative or palliative treatment due to its advanced precision technology, particularly for limited small lesion. On the other hand, severe late adverse reactions are anticipated with reirradiation than with initial radiation therapy. The risk of severe late complications has been reported to be 20- 40% and is related to prior radiotherapy dose, primary site, retreatment radiotherapy dose, treatment volume, and technique. Early researchers have observed lethal bleeding in such patients up to a rate of 14%. Recently, similar rate of 10-15% was observed for fatal bleeding with use of modern hSRT like in case of carotid blowout syndrome. To determine the feasibility and efficacy of reirradiation using modern technology, we reviewed the pertinent literature. The potentially lethal side effects should be kept in mind when reirradiation by hSRT is considered for treatment, and efforts should be made to minimize the risk in any future investigations

    Risk factors for breast cancer in postmenopausal Caucasian and Chinese-Canadian women

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    Abstract Introduction Striking differences exist between countries in the incidence of breast cancer. The causes of these differences are unknown, but because incidence rates change in migrants, they are thought to be due to lifestyle rather than genetic differences. The goal of this cross-sectional study was to examine breast cancer risk factors in populations with different risks for breast cancer. Methods We compared breast cancer risk factors among three groups of postmenopausal Canadian women at substantially different risk of developing breast cancer - Caucasians (N = 413), Chinese women born in the West or who migrated to the West before age 21 (N = 216), and recent Chinese migrants (N = 421). Information on risk factors and dietary acculturation were collected by telephone interviews using questionnaires, and anthropometric measurements were taken at a home visit. Results Compared to Caucasians, recent Chinese migrants weighed on average 14 kg less, were 6 cm shorter, had menarche a year later, were more often parous, less often had a family history of breast cancer or a benign breast biopsy, a higher Chinese dietary score, and a lower Western dietary score. For most of these variables, Western born Chinese and early Chinese migrants had values intermediate between those of Caucasians and recent Chinese migrants. We estimated five-year absolute risks for breast cancer using the Gail Model and found that risk estimates in Caucasians would be reduced by only 11% if they had the risk factor profile of recent Chinese migrants for the risk factors in the Gail Model. Conclusions Our results suggest that in addition to the risk factors in the Gail Model, there likely are other factors that also contribute to the large difference in breast cancer risk between Canada and China

    ADC Histograms from Routine DWI for Longitudinal Studies in Cerebral Small Vessel Disease: A Field Study in CADASIL.

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    Diffusion tensor imaging (DTI) histogram metrics are correlated with clinical parameters in cerebral small vessel diseases (cSVD). Whether ADC histogram parameters derived from simple diffusion weighted imaging (DWI) can provide relevant markers for long term studies of cSVD remains unknown. CADASIL patients were evaluated by DWI and DTI in a large cohort study overa6-year period. ADC histogram parameters were compared to those derived from mean diffusivity (MD) histograms in 280 patients using intra-class correlation and Bland-Altman plots. Impact of image corrections applied to ADC maps was assessed and a mixed effect model was used for analyzing the effects of scanner upgrades. The results showed that ADC histogram parameters are strongly correlated to MD histogram parameters and that image corrections have only limited influence on these results. Unexpectedly, scanner upgrades were found to have major effects on diffusion measures with DWI or DTI that can be even larger than those related to patients' characteristics. These data support that ADC histograms from daily used DWI can provide relevant parameters for assessing cSVD, but the variability related to scanner upgrades as regularly performed in clinical centers should be determined precisely for longitudinal and multicentric studies using diffusion MRI in cSVD
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