571 research outputs found
Pulmonary hypertension is a manifestation of congestive heart failure and left ventricular diastolic dysfunction in octogenarians with severe aortic stenosis
Previous studies have suggested that pulmonary hypertension (PH) in severe aortic stenosis (AS) is a risk factor for operative mortality with aortic valve replacement (AVR). Conversely, others have shown that patients with AS and PH extract a large symptomatic and survival benefit from AVR compared with those patients not treated surgically. We sought to evaluate the prevalence, severity, and mechanism of PH in an elderly patient cohort with severe AS. We prospectively evaluated 41 patients aged ≥80 years with severe AS. All patients underwent cardiac catheterization and transthoracic echocardiography within 24 hours. We found that PH was common in this cohort: 32 patients (78%) had PH; however, the predominant mechanism of PH was left heart congestion. Patients with PH had nearly double the pulmonary artery wedge pressure of patients without PH (23 vs. 13 mmHg; P ≤ 0.001). In patients with PH compared with those without, pulmonary vascular resistance was higher yet still under 3 Wood units (WU; 2.9 vs. 1.5 WU; P = 0.001), and the transpulmonary gradient (11 vs. 7 mmHg; P = 0.01) and diastolic pulmonary gradient (DPG; 3.0 vs. 2.7 mmHg; P = 0.74) were in normal range. Left ventricular diastolic abnormalities were more common in patients with severe AS and PH. Right ventricular (RV) dysfunction was common (13/41 patients, 32%), but the PH and non-PH groups had similar tricuspid annular plane systolic excursion (2.0 vs. 2.3 cm; P = 0.15). Only 2 subjects had both RV dysfunction and an elevated DPG. In conclusion, PH is common in elderly patients with severe AS. This occurs largely due to left heart congestion, with a relative absence of pulmonary vascular disease and RV dysfunction, and as such, PH may serve as a heart failure equivalent in these patients
Developing a clinical trial unit to advance research in an academic institution
AbstractResearch, clinical care, and education are the three cornerstones of academic health centers in the United States. The research climate has always been riddled with ebbs and flows, depending on funding availability. During a time of reduced funding, the number and scope of research studies have been reduced, and in some instances, a field of study has been eliminated. Recent reductions in the research funding landscape have led institutions to explore new ways to continue supporting research. Mayo Clinic in Rochester, MN has developed a clinical trial unit within the Department of Medicine, which provides shared resources for many researchers and serves as a solution for training and mentoring new investigators and study teams. By building on existing infrastructure and providing supplemental resources to existing research, the Department of Medicine clinical trial unit has evolved into an effective mechanism for conducting research. This article discusses the creation of a central unit to provide research support in clinical trials and presents the advantages, disadvantages, and required building blocks for such a unit
Detection of Multiple Variants of Grapevine Fanleaf Virus in Single Xiphinema index Nematodes
Grapevine fanleaf virus (GFLV) is responsible for a widespread disease in vineyards
worldwide. Its genome is composed of two single-stranded positive-sense RNAs, which both show
a high genetic diversity. The virus is transmitted from grapevine to grapevine by the ectoparasitic
nematode Xiphinema index. Grapevines in diseased vineyards are often infected by multiple genetic
variants of GFLV but no information is available on the molecular composition of virus variants
retained in X. index following nematodes feeding on roots. In this work, aviruliferous X. index were
fed on three naturally GFLV-infected grapevines for which the virome was characterized by RNAseq.
Six RNA-1 and four RNA-2 molecules were assembled segregating into four and three distinct
phylogenetic clades of RNA-1 and RNA-2, respectively. After 19 months of rearing, single and pools
of 30 X. index tested positive for GFLV. Additionally, either pooled or single X. index carried multiple
variants of the two GFLV genomic RNAs. However, the full viral genetic diversity found in the leaves
of infected grapevines was not detected in viruliferous nematodes, indicating a genetic bottleneck.
Our results provide new insights into the complexity of GFLV populations and the putative role of X.
index as reservoirs of virus diversity
Advances in the treatment of hereditary transthyretin amyloidosis: A review
Introduction: Amyloid transthyretin amyloidosis (ATTR) is a progressive and often fatal disease caused by the buildup of mutated (hereditary ATTR [hATTR]; also known as ATTR variant [ATTRv]) or normal transthyretin (wild-type ATTR) throughout the body. Two new therapies-inotersen, an antisense oligonucleotide therapy, and patisiran, an RNA interference therapy-received marketing authorization and represent a significant advance in the treatment of amyloidosis. Herein, we describe the clinical presentation of ATTR, commonly used procedures in its diagnosis, and current treatment landscape for ATTR, with a focus on hATTR.
Methods: A PubMed search from 2008 to September 2018 was conducted to review the literature on ATTR.
Results: Until recently, there have been few treatment options for polyneuropathy of hATTR. Inotersen and patisiran substantially reduce the amyloidogenic precursor protein transthyretin and have demonstrated efficacy in patients with early- and late-stage disease and in slowing or improving neuropathy progression. In contrast, established therapies, such as liver transplantation, typically reserved for patients with early-stage disease, and tafamidis, indicated for the treatment of early-stage disease in Europe, or diflunisal, a nonsteroidal anti-inflammatory drug that is used off-label, are associated with side effects and/or unclear efficacy in certain patient populations. Thus, inotersen and patisiran are positioned to be the preferred therapeutic modalities.
Conclusions: Important differences between inotersen and patisiran, including formulation, dosing, requirements for premedications, and safety monitoring, require an understanding and knowledge of each treatment for informed decision making.info:eu-repo/semantics/publishedVersio
Butler enables rapid cloud-based analysis of thousands of human genomes.
We present Butler, a computational tool that facilitates large-scale genomic analyses on public and academic clouds. Butler includes innovative anomaly detection and self-healing functions that improve the efficiency of data processing and analysis by 43% compared with current approaches. Butler enabled processing of a 725-terabyte cancer genome dataset from the Pan-Cancer Analysis of Whole Genomes (PCAWG) project in a time-efficient and uniform manner
A case of muscular bridge resulting in myocardial infraction following heavy effort: a case report
Muscular bridge (MB) is transient systolic coronary blockage occurring due to exposure of a portion of epicardial coronary arteries to compression during systole as a result of tunneling into the myocardium. Although rare, these patients may develop angina pectoris, severe arrhythmia and myocardial infraction (MI). A 30-year-old male patient presented to the emergency with severe pain with an onset at the front part of the chest followed by spreading to the back and arms, during a football match. The investigations performed revealed anterior wall infraction and thus thrombolytic treatment was administered. Patient's history was normal except for smoking. The patient was detected to play football occasionally since his childhood; however, we learnt that he had started playing without warm-up exercises at the last football match. Coronary angiography detected a lesion with an onset in the left anterior descending artery following the 1st diagonal and extending to the 2nd diagonal and exhibiting a significant contraction during systole. The patient was considered to have myocardial infraction secondary to myocardial bridge. Sudden deaths frequently occur in competitive sports requiring heavy effort
A Novel Unsupervised Method to Identify Genes Important in the Anti-viral Response: Application to Interferon/Ribavirin in Hepatitis C Patients
Background: Treating hepatitis C with interferon/ribavirin results in a varied response in terms of decrease in viral titer and ultimate outcome. Marked responders have a sharp decline in viral titer within a few days of treatment initiation, whereas in other patients there is no effect on the virus (poor responders). Previous studies have shown that combination therapy modifies expression of hundreds of genes in vitro and in vivo. However, identifying which, if any, of these genes have a role in viral clearance remains challenging. Aims: The goal of this paper is to link viral levels with gene expression and thereby identify genes that may be responsible for early decrease in viral titer. Methods: Microarrays were performed on RNA isolated from PBMC of patients undergoing interferon/ribavirin therapy. Samples were collected at pre-treatment (day 0), and 1, 2, 7, 14 and 28 days after initiating treatment. A novel method was applied to identify genes that are linked to a decrease in viral titer during interferon/ribavirin treatment. The method uses the relationship between inter-patient gene expression based proximities and inter-patient viral titer based proximities to define the association between microarray gene expression measurements of each gene and viral-titer measurements. Results: We detected 36 unique genes whose expressions provide a clustering of patients that resembles viral titer based clustering of patients. These genes include IRF7, MX1, OASL and OAS2, viperin and many ISG's of unknown function. Conclusion: The genes identified by this method appear to play a major role in the reduction of hepatitis C virus during the early phase of treatment. The method has broad utility and can be used to analyze response to any group of factors influencing biological outcome such as antiviral drugs or anti-cancer agents where microarray data are available. © 2007 Brodsky et al
Biochemical and aggregation analysis of Bence Jones proteins from different light chain diseases
Deposition of immunoglobulin light chains is a result of clonal proliferation of monoclonal plasma cells that secrete free immunoglobulin light chains, also called Bence Jones proteins (Bence Jones proteins). These Bence Jones proteins are present in circulation in large amounts and excreted in urine in various light chain diseases such as light chain amyloidosis (AL), light chain deposition disease (LCDD) and multiple myeloma (MM). BJP from patients with AL, LCDD and MM were purified from their urine and studies were performed to determine their secondary structure, thermodynamic stability and aggregate formation kinetics. Our results show that LCDD and MM proteins have the lowest free energy of folding while all proteins show similar melting temperatures. Incubation of the BJP at their melting temperature produced morphologically different aggregates: amyloid fibrils from the AL proteins, amorphous aggregates from the LCDD proteins and large spherical species from the MM proteins. The aggregates formed under in vitro conditions suggested that the various proteins derived from patients with different light chain diseases might follow different aggregation pathways
Gene–Environment Interactions at Nucleotide Resolution
Interactions among genes and the environment are a common source of phenotypic variation. To characterize the interplay between genetics and the environment at single nucleotide resolution, we quantified the genetic and environmental interactions of four quantitative trait nucleotides (QTN) that govern yeast sporulation efficiency. We first constructed a panel of strains that together carry all 32 possible combinations of the 4 QTN genotypes in 2 distinct genetic backgrounds. We then measured the sporulation efficiencies of these 32 strains across 8 controlled environments. This dataset shows that variation in sporulation efficiency is shaped largely by genetic and environmental interactions. We find clear examples of QTN:environment, QTN: background, and environment:background interactions. However, we find no QTN:QTN interactions that occur consistently across the entire dataset. Instead, interactions between QTN only occur under specific combinations of environment and genetic background. Thus, what might appear to be a QTN:QTN interaction in one background and environment becomes a more complex QTN:QTN:environment:background interaction when we consider the entire dataset as a whole. As a result, the phenotypic impact of a set of QTN alleles cannot be predicted from genotype alone. Our results instead demonstrate that the effects of QTN and their interactions are inextricably linked both to genetic background and to environmental variation
The Evolution of Single Cell-derived Colorectal Cancer Cell Lines is Dominated by the Continued Selection of Tumor Specific Genomic Imbalances, Despite Random Chromosomal Instability
Intratumor heterogeneity is a major challenge in cancer treatment. To decipher patterns of chromosomal heterogeneity, we analyzed six colorectal cancer cell lines by multiplex interphase FISH (miFISH). The mismatch repair deficient cell lines DLD-1 and HCT116 had the most stable copy numbers, whereas aneuploid cell lines (HT-29, SW480, SW620 and H508) displayed a higher degree of instability. We subsequently assessed the clonal evolution of single cells in two CRC cell lines, SW480 and HT-29, which both have aneuploid karyotypes but different degrees of chromosomal instability. The clonal compositions of the single cell-derived daughter lines, as assessed by miFISH, differed for HT-29 and SW480. Daughters of HT-29 were stable, clonal, with little heterogeneity. Daughters of SW480 were more heterogeneous, with the single cell-derived daughter lines separating into two distinct populations with different ploidy (hyper-diploid and near-triploid), morphology, gene expression and tumorigenicity. To better understand the evolutionary trajectory for the two SW480 populations, we constructed phylogenetic trees which showed ongoing instability in the daughter lines. When analyzing the evolutionary development over time, most single cell-derived daughter lines maintained their major clonal pattern, with the exception of one daughter line that showed a switch involving a loss of APC. Our meticulous analysis of the clonal evolution and composition of these colorectal cancer models shows that all chromosomes are subject to segregation errors, however, specific net genomic imbalances are maintained. Karyotype evolution is driven by the necessity to arrive at and maintain a specific plateau of chromosomal copy numbers as the drivers of carcinogenesis
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