448 research outputs found

    Should expectations about the rate of new antiretroviral drug development impact the timing of HIV treatment initiation and expectations about treatment benefits?

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    Background: Many analyses of HIV treatment decisions assume a fixed formulary of HIV drugs. However, new drugs are approved nearly twice a year, and the rate of availability of new drugs may affect treatment decisions, particularly when to initiate antiretroviral therapy (ART). Objectives: To determine the impact of considering the availability of new drugs on the optimal initiation criteria for ART and outcomes in patients with HIV/AIDS. Methods: We enhanced a previously described simulation model of the optimal time to initiate ART to incorporate the rate of availability of new antiviral drugs. We assumed that the future rate of availability of new drugs would be similar to the past rate of availability of new drugs, and we estimated the past rate by fitting a statistical model to actual HIV drug approval data from 1982-2010. We then tested whether or not the future availability of new drugs affected the model-predicted optimal time to initiate ART based on clinical outcomes, considering treatment initiation thresholds of 200, 350, and 500 cells/mm 3. We also quantified the impact of the future availability of new drugs on life expectancy (LE) and quality-adjusted life expectancy (QALE). Results: In base case analysis, considering the availability of new drugs raised the optimal starting CD4 threshold for most patients to 500 cells/mm 3. The predicted gains in outcomes due to availability of pipeline drugs were generally small (less than 1%), but for young patients with a high viral load could add as much as a 4.9% (1.73 years) increase in LE and a 8% (2.43 QALY) increase in QALE, because these patients were particularly likely to exhaust currently available ART regimens before they died. In sensitivity analysis, increasing the rate of availability of new drugs did not substantially alter the results. Lowering the toxicity of future ART drugs had greater potential to increase benefit for many patient groups, increasing QALE by as much as 10%. Conclusions: The future availability of new ART drugs without lower toxicity raises optimal treatment initiation for most patients, and improves clinical outcomes, especially for younger patients with higher viral loads. Reductions in toxicity of future ART drugs could impact optimal treatment initiation and improve clinical outcomes for all HIV patients. © 2014 Khademi et al

    Use of sutureless and rapid deployment prostheses in challenging reoperations

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    Sutureless and rapid-deployment bioprostheses have been introduced as alternatives to traditional prosthetic valves to reduce cardiopulmonary and aortic cross-clamp times during aortic valve replacement. These devices have also been employed in extremely demanding surgical settings, as underlined in the present review. Searches on the PubMed and Medline databases aimed to identify, from the English-language literature, the reported cases where both sutureless and rapid-deployment prostheses were employed in challenging surgical situations, usually complex reoperations sometimes even performed as bailout procedures. We have identified 25 patients for whom a sutureless or rapid-deployment prosthesis was used in complex redo procedures: 17 patients with a failing stentless bioprosthesis, 6 patients with a failing homograft, and 2 patients with the failure of a valve-sparing procedure. All patients survived reoperation and were reported to be alive 3 months to 4 years postoperatively. Sutureless and rapid-deployment bioprostheses have proved effective in replacing degenerated stentless bioprostheses and homografts in challenging redo procedures. In these settings, they should be considered as a valid alternative not only to traditional prostheses but also in selected cases to transcatheter valve-in-valve solutions

    The value of multi-slice-computed tomography coronary angiography for risk stratification

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    Multi-slice-computed tomography coronary angiography (CTA) provides direct non-invasive anatomic assessment of the coronary arteries allowing for early identification of coronary artery disease (CAD). This information is useful for diagnosis of CAD, particularly the rule out of CAD. In addition, early identification of CAD with CTA may also be useful for risk stratification. The purpose of this review is to provide an overview of the current literature on the prognostic value of CTA and to discuss how the prognostic information obtained with CTA can be used to further integrate the technique into clinical practice. Non-invasive anatomic assessment of plaque burden, location, composition, and remodeling using CTA may provide prognostically relevant information. This information has been shown to be incremental to the Framingham risk score, coronary artery calcium scoring, and myocardial perfusion imaging. Characterization of atherosclerosis non-invasively has the potential to provide important prognostic information enabling a more patient-tailored approach to disease management. Future studies assessing outcome after CTA-based risk adjustments are needed to further understand the value of detailed non-invasive anatomic imaging

    Mitral paravalvular abscess with left ventriculo-atrial fistula in a patient on dialysis

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    Background: Infective endocarditis in hemodialysis patients is challenging but is becoming more common recently. Case report: A 64-year-old man with end-stage renal disease on hemodialysis presented with infective endocarditis of mitral valve and coronary artery disease after commencing training for home hemodialysis. During a course of antibiotic treatment the patient developed left ventriculo-atrial fistula due to mitral paravalvular abscess. Abscess debridement followed by reconstruction of the mitral annulus with fresh autologous pericardial patch and mitral valve replacement using a mechanical prosthesis with concomitant coronary artery bypass grafting was performed successfully. Conclusion: Timely diagnosis, proper antibiotic treatment and early surgical intervention including aggressive debridement should improve the outcome of this high-risk disease. © 2009 Kitamura et al; licensee BioMed Central Ltd.Tadashi Kitamura, James Edwards, Suchi Khurana and Robert G Stukli

    Enzyme based soil stabilization for unpaved road construction

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    Enzymes as soil stabilizers have been successfully used in road construction in several countries for the past 30 years. However, research has shown that the successful application of these enzymes is case specific, emphasizing that enzyme performance is dependent on subgrade soil type, condition and the type of enzyme used as the stabilizer. A universal standard or a tool for road engineers to assess the performance of stabilized unbound pavements using well-established enzymes is not available to date. The research aims to produce a validated assessment tool which can be used to predict strength enhancement within a generalized statistical framework. The objective of the present study is to identify new materials for developing the assessment tool which supports enzyme based stabilization, as well as to identify the correct construction sequence for such new materials. A series of characterization tests were conducted on several soil types obtained from proposed construction sites. Having identified the suitable soil type to mix with the enzyme, a trial road construction has been performed to investigate the efficiency of the enzyme stabilization along with the correct construction sequence. The enzyme stabilization has showed significant improvement of the road performance as was evidenced from the test results which were based on site soil obtained before and after stabilization. The research will substantially benefit the road construction industry by not only replacing traditional construction methods with economical/reliable approaches, but also eliminating site specific tests required in current practice of enzyme based road construction

    Atrophin-1, the Dentato-Rubral and Pallido-Luysian Atrophy Gene Product, Interacts with Eto/Mtg8 in the Nuclear Matrix and Represses Transcription

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    Dentato-rubral and pallido-luysian atrophy (DRPLA) is one of the family of neurodegenerative diseases caused by expansion of a polyglutamine tract. The drpla gene product, atrophin-1, is widely expressed, has no known function or activity, and is found in both the nuclear and cytoplasmic compartments of neurons. Truncated fragments of atrophin-1 accumulate in neuronal nuclei in a transgenic mouse model of DRPLA, and may underlie the disease phenotype

    AA amyloidosis. A single institution cohort study.

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    There is limited epidemiological information on AA amyloidosis in Argentina, so the objective of this study was to describe the epidemiological characteristics of this disease in a tertiary hospital in our country. We designed a prospective clinical cohort of all consecutive patients with AA amyloidosis confirmed by immunohistochemistry in tissue from the Institutional Registry of Amyloidosis of the Hospital Italiano de Buenos Aires, in the period 04/01/2012- 12/31/2017. Of the 121 patients in the registry, 18 were included with AA for the analysis. Of the total included, 50% (9) were female, with a median age of 53.5 (interquartile range, RII 46-61) years. The 88.9% (16) of cohort presented renal compromise, all had proteinuria, and 6 required dialysis. Six had amyloid infiltration of the digestive system. The latency between the onset of the underlying disease and the diagnosis of AA had a median of 27 (RII 8-35) years. The underlying disease was of inflammatory origin in 6 cases. In 50% (9) of the patients the cause of AA amyloidosis was unknown. In the remaining 50%, these causes resemble those observed in developed countries. Furthermore, our results highlight the importance of their differential diagnosis to identify the most appropriate treatment or follow-up according to the situation presented by each patient

    Severe neurological phenotypes of Q129 DRPLA transgenic mice serendipitously created by en masse expansion of CAG repeats in Q76 DRPLA mice

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    We herein provide a thorough description of new transgenic mouse models for dentatorubral–pallidoluysian atrophy (DRPLA) harboring a single copy of the full-length human mutant DRPLA gene with 76 and 129 CAG repeats. The Q129 mouse line was unexpectedly obtained by en masse expansion based on the somatic instability of 76 CAG repeats in vivo. The mRNA expression levels of both Q76 and Q129 transgenes were each 80% of that of the endogenous mouse gene, whereas only the Q129 mice exhibited devastating progressive neurological phenotypes similar to those of juvenile-onset DRPLA patients. Electrophysiological studies of the Q129 mice demonstrated age-dependent and region-specific presynaptic dysfunction in the globus pallidus and cerebellum. Progressive shrinkage of distal dendrites of Purkinje cells and decreased currents through α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid and γ-aminobutyrate type A receptors in CA1 neurons were also observed. Neuropathological studies of the Q129 mice revealed progressive brain atrophy, but no obvious neuronal loss, associated with massive neuronal intranuclear accumulation (NIA) of mutant proteins with expanded polyglutamine stretches starting on postnatal day 4, whereas NIA in the Q76 mice appeared later with regional specificity to the vulnerable regions of DRPLA. Expression profile analyses demonstrated age-dependent down-regulation of genes, including those relevant to synaptic functions and CREB-dependent genes. These results suggest that neuronal dysfunction without neuronal death is the essential pathophysiologic process and that the age-dependent NIA is associated with nuclear dysfunction including transcriptional dysregulations. Thus, our Q129 mice should be highly valuable for investigating the mechanisms of disease pathogenesis and therapeutic interventions

    The Oncoprotein EVI1 and the DNA Methyltransferase Dnmt3 Co-Operate in Binding and De Novo Methylation of Target DNA

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    EVI1 has pleiotropic functions during murine embryogenesis and its targeted disruption leads to prenatal death by severely affecting the development of virtually all embryonic organs. However, its functions in adult tissues are still unclear. When inappropriately expressed, EVI1 becomes one of the most aggressive oncogenes associated with human hematopoietic and solid cancers. The mechanisms by which EVI1 transforms normal cells are unknown, but we showed recently that EVI1 indirectly upregulates self-renewal and cell-cycling genes by inappropriate methylation of CpG dinucleotides in the regulatory regions of microRNA-124-3 (miR-124-3), leading to the repression of this small gene that controls normal differentiation and cell cycling of somatic cells. We used the regulatory regions of miR-124-3 as a read-out system to investigate how EVI1 induces de novo methylation of DNA. Here we show that EVI1 physically interacts with DNA methyltransferases 3a and 3b (Dnmt3a/b), which are the only de novo DNA methyltransferases identified to date in mouse and man, and that it forms an enzymatically active protein complex that induces de novo DNA methylation in vitro. This protein complex targets and binds to a precise region of miR-124-3 that is necessary for repression of a reporter gene by EVI1. Based on our findings, we propose that in cooperation with Dnmt3a/b EVI1 regulates the methylation of DNA as a sequence-specific mediator of de novo DNA methylation and that inappropriate EVI1 expression contributes to carcinogenesis through improper DNA methylation

    Long term prognostic importance of late gadolinium enhancement in first-presentation non-ischaemic dilated cardiomyopathy

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    © 2019 Elsevier B.V. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/ This author accepted manuscript is made available following 12 month embargo from date of publication (January 2019) in accordance with the publisher’s archiving policyBackground Presence of myocardial fibrosis in well-established non-ischaemic dilated cardiomyopathy (NIDCM) is associated with adverse clinical outcomes. However, the impact of myocardial fibrosis at first presentation in NIDCM, and its long-term association with left ventricular (LV) dysfunction, heart failure (HF) and ventricular arrhythmia (VA) remains unclear. We investigated whether the presence of myocardial fibrosis quantified by late gadolinium enhancement cardiovascular magnetic resonance (LGE-CMR) at presentation, is independently associated with long-term major adverse cardiovascular events (MACE) in patients with first presentation NIDCM. Methods Consecutive patients with a first diagnosis of NIDCM were recruited. Patients underwent LGE-CMR at baseline. Replacement myocardial fibrosis by LGE-CMR was quantified by experienced observers blinded to patient outcome. MACE was defined as a composite end-point including cardiac death, HF rehospitalisation and the occurrence of sustained VA. Results Fifty-one patients with first presentation NIDCM were included, of which 49 (96%) had follow up and outcome data. Median follow up was 8.2 years. Both the LGE positive and LGE negative groups had similar clinical characteristics at follow up. In univariate Cox regression analysis, positive LGE was associated with MACE (HR:3.44; 95% CI:1.89 to 6.24, p-value < 0.001) and HF rehospitalisation (HR:2.89; 95% CI:1.42 to 5.85, p-value = 0.003). In multivariate Cox regression, positive LGE-CMR was independently associated with MACE (HR:3.53; 95% CI:1.51 to 8.27, p-value = 0.004) and HF rehospitalisation (HR:3.07; 95% CI:1.24 to 7.59, p-value = 0.015). Conclusions The presence of myocardial fibrosis in first presentation NIDCM is independently associated with an increased risk of HF rehospitalisation, at long term follow-up
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