Search Results Heading

MBRLSearchResults

mbrl.module.common.modules.added.book.to.shelf
Title added to your shelf!
View what I already have on My Shelf.
Oops! Something went wrong.
Oops! Something went wrong.
While trying to add the title to your shelf something went wrong :( Kindly try again later!
Are you sure you want to remove the book from the shelf?
Oops! Something went wrong.
Oops! Something went wrong.
While trying to remove the title from your shelf something went wrong :( Kindly try again later!
    Done
    Filters
    Reset
  • Discipline
      Discipline
      Clear All
      Discipline
  • Is Peer Reviewed
      Is Peer Reviewed
      Clear All
      Is Peer Reviewed
  • Item Type
      Item Type
      Clear All
      Item Type
  • Subject
      Subject
      Clear All
      Subject
  • Year
      Year
      Clear All
      From:
      -
      To:
  • More Filters
46 result(s) for "Huggins, Gordon S."
Sort by:
Distinct Phenotypes Induced by Three Degrees of Transverse Aortic Constriction in Mice
Transverse aortic constriction (TAC) is a well-established model of pressure overload-induced cardiac hypertrophy and failure in mice. The degree of constriction “tightness” dictates the TAC severity and is determined by the gauge (G) of needle used. Though many reports use the TAC model, few studies have directly compared the range of resulting phenotypes. In this study adult male mice were randomized to receive TAC surgery with varying degrees of tightness: mild (25G), moderate (26G) or severe (27G) for 4 weeks, alongside sham-operated controls. Weekly echocardiography and terminal haemodynamic measurements determined cardiac remodelling and function. All TAC models induced significant, severity-dependent left ventricular hypertrophy and diastolic dysfunction compared to sham mice. Mice subjected to 26G TAC additionally exhibited mild systolic dysfunction and cardiac fibrosis, whereas mice in the 27G TAC group had more severe systolic and diastolic dysfunction, severe cardiac fibrosis, and were more likely to display features of heart failure, such as elevated plasma BNP. We also observed renal atrophy in 27G TAC mice, in the absence of renal structural, functional or gene expression changes. 25G, 26G and 27G TAC produced different responses in terms of cardiac structure and function. These distinct phenotypes may be useful in different preclinical settings.
Individualized interactomes for network-based precision medicine in hypertrophic cardiomyopathy with implications for other clinical pathophenotypes
Progress in precision medicine is limited by insufficient knowledge of transcriptomic or proteomic features in involved tissues that define pathobiological differences between patients. Here, myectomy tissue from patients with obstructive hypertrophic cardiomyopathy and heart failure is analyzed using RNA-Seq, and the results are used to develop individualized protein-protein interaction networks. From this approach, hypertrophic cardiomyopathy is distinguished from dilated cardiomyopathy based on the protein-protein interaction network pattern. Within the hypertrophic cardiomyopathy cohort, the patient-specific networks are variable in complexity, and enriched for 30 endophenotypes. The cardiac Janus kinase 2-Signal Transducer and Activator of Transcription 3-collagen 4A2 (JAK2-STAT3-COL4A2) expression profile informed by the networks was able to discriminate two hypertrophic cardiomyopathy patients with extreme fibrosis phenotypes. Patient-specific network features also associate with other important hypertrophic cardiomyopathy clinical phenotypes. These proof-of-concept findings introduce personalized protein-protein interaction networks (reticulotypes) for characterizing patient-specific pathobiology, thereby offering a direct strategy for advancing precision medicine. Understanding patient-specific pathobiological pathways is a critical step for advancing precision medicine. Here the authors show that individualized protein-protein interaction networks provide key insight on patient-level pathobiology and clinically relevant pathophenotypic characteristics in a complex disease.
Altered intercellular communication and extracellular matrix signaling as a potential disease mechanism in human hypertrophic cardiomyopathy
Hypertrophic cardiomyopathy (HCM) is considered a primary disorder of the sarcomere resulting in unexplained left ventricular hypertrophy but the paradoxical association of nonmyocyte phenotypes such as fibrosis, mitral valve anomalies and microvascular occlusion is unexplained. To understand the interplay between cardiomyocyte and nonmyocyte cell types in human HCM, single nuclei RNA-sequencing was performed on myectomy specimens from HCM patients with left ventricular outflow tract obstruction and control samples from donor hearts free of cardiovascular disease. Clustering analysis based on gene expression patterns identified a total of 34 distinct cell populations, which were classified into 10 different cell types based on marker gene expression. Differential gene expression analysis comparing HCM to Normal datasets revealed differences in sarcomere and extracellular matrix gene expression. Analysis of expressed ligand-receptor pairs across multiple cell types indicated profound alteration in HCM intercellular communication, particularly between cardiomyocytes and fibroblasts, fibroblasts and lymphocytes and involving integrin β1 and its multiple extracellular matrix (ECM) cognate ligands. These findings provide a paradigm for how sarcomere dysfunction is associated with reduced cardiomyocyte secretion of ECM ligands, altered fibroblast ligand-receptor interactions with other cell types and increased fibroblast to lymphocyte signaling, which can further alter the ECM composition and promote nonmyocyte phenotypes.
Cardiometabolic deaths attributable to poor diet among Kuwaiti adults
Nutrition transition towards a Western diet is happening in parallel with the rapidly increasing rates of cardiovascular disease and its risk factors in Kuwait. The cardiometabolic deaths attributable to poor diet have not been quantified among Kuwaiti adults. Using a Comparative Risk Assessment model that incorporated dietary intake data from Kuwait's first national nutrition survey, number of cardiometabolic deaths from the World Health Organization, and estimated associations of diet with cardiometabolic deaths from the Global Burden of Disease project, we estimated the number and proportion of cardiometabolic deaths attributable to suboptimal intake of 10 dietary factors among Kuwaiti adults ages 25+ years, and by population subgroups. An estimated 1,308 (95% uncertainty interval [UI] = 1,228-1,485) cardiometabolic deaths were attributed to suboptimal diet, accounting for 64.7% (95% UI = 60.7%-73.4%) of all cardiometabolic deaths in Kuwait in 2009. The low intake of nuts/seeds was associated with the highest estimated number and proportion of cardiometabolic deaths (n = 380, 18.8%), followed by high intake of sodium (n = 256, 12.6%), low intake of fruits (n = 250, 12.4%), low intake of vegetables (n = 236, 11.7%), low intake of whole grains (n = 201, 9.9%), and high intake of sugar-sweetened beverages (n = 201, 9.9%). The estimated proportions of cardiometabolic deaths attributable to suboptimal diet were higher in men (67.7%) than women (57.8%) and in younger adults aged 25-34 years (84.5%) than older adults aged ≥55 years (55.6%). Suboptimal dietary intake was associated with a very substantial proportion of cardiometabolic deaths among Kuwaiti adults in 2009, with young adults and men experiencing the largest proportion of diet-associated cardiometabolic deaths in Kuwait.
Transcriptome analysis of pig intestinal cell monolayers infected with Cryptosporidium parvum asexual stages
Background Human cryptosporidiosis is caused primarily by two species of apicomplexan protozoa, Cryptosporidium parvum and C. hominis . In cultured cell monolayers, the parasite undergoes two generations of asexual multiplication (merogony). However, the proportion of parasites completing the life-cycle is low and insufficient to sustain continuous propagation. Due to the intracellular location of meronts and later life-cycle stages, oocyst and sporozoites are the only forms of the parasite that can readily be isolated. Results Research on the replicating forms of Cryptosporidium parasites and their interaction with the host cell remains challenging. Based on an RNA-Seq analysis of monolayers of pig epithelial cells infected with C. parvum , here we report on the impact of merogony on the host’s gene regulation. Analysis of the transcriptome of infected and uninfected monolayers demonstrates a significant impact of the infection on host cell gene expression. A total of 813 genes were differentially expressed. Functional terms significantly altered in response to infection include phosphoprotein, RNA binding and acetylation. Upregulation of cell cycle pathways indicates an increase in mitosis. Notably absent from differentially enriched functional categories are stress- and apoptosis-related functions. The comparison of the combined host-parasite transcriptome reveals that C. parvum gene expression is less diverse than the host cell transcriptome and is highly enriched for genes encoding ribosomal functions, such as ribosomal proteins. Conclusions These results indicate that C. parvum infection significantly changes host biological functions and provide new insight into gene functions driving early C. parvum intracellular development.
Specialized Pro-Resolving Mediators Reduce Scarring After Cleft Lip Repair
Residual scarring after cleft lip repair surgery remains a challenge for both surgeons and patients and novel therapeutics are critically needed. The objective of this preclinical experimental study was to evaluate the impact of the methyl-ester of pro-resolving lipid mediator lipoxin A (LXA -ME) on scarring in a novel rabbit model of cleft lip repair. A defect of the lip was surgically created and repaired in eight six-week old New Zealand white rabbits to simulate human cleft lip scars. Rabbits were randomly assigned to topical application of PBS (control) or 1 ug of LXA -ME (treatment). 42 days post surgery all animals were euthanized. Photographs of the cleft lip area defect and histologic specimens were evaluated. Multiple scar assessment scales were used to compare scarring. Animals treated with LXA -ME exhibited lower Visual Scar Assessment scores compared to animals treated with PBS. Treatment with LXA -ME resulted in a significant reduction of inflammatory cell infiltrate and density of collagen fibers. Control animals showed reduced 2D directional variance (orientation) of collagen fibers compared to animals treated with LXA -ME demonstrating thicker and more parallel collagen fibers, consistent with scar tissue. These data suggest that LXA -ME limits scarring after cleft lip repair and improves wound healing outcomes in rabbits favoring the resolution of inflammation. Further studies are needed to explore the mechanisms that underlie the positive therapeutic impact of LXA -ME on scarring to set the stage for future human clinical trials of LXA -ME for scar prevention or treatment after cleft lip repair.
Diagnostic accuracy of point-of-care ultrasound with artificial intelligence-assisted assessment of left ventricular ejection fraction
Focused cardiac ultrasound (FoCUS) is becoming standard practice in a wide spectrum of clinical settings. There is limited data evaluating the real-world use of FoCUS with artificial intelligence (AI). Our objective was to determine the accuracy of FoCUS AI-assisted left ventricular ejection fraction (LVEF) assessment and compare its accuracy between novice and experienced users. In this prospective, multicentre study, participants requiring a transthoracic echocardiogram (TTE) were recruited to have a FoCUS done by a novice or experienced user. The AI-assisted device calculated LVEF at the bedside, which was subsequently compared to TTE. 449 participants were enrolled with 424 studies included in the final analysis. The overall intraclass coefficient was 0.904, and 0.921 in the novice (n = 208) and 0.845 in the experienced (n = 216) cohorts. There was a significant bias of 0.73% towards TTE (p = 0.005) with a level of agreement of 11.2%. Categorical grading of LVEF severity had excellent agreement to TTE (weighted kappa = 0.83). The area under the curve (AUC) was 0.98 for identifying an abnormal LVEF (<50%) with a sensitivity of 92.8%, specificity of 92.3%, negative predictive value (NPV) of 0.97 and a positive predictive value (PPV) of 0.83. In identifying severe dysfunction (<30%) the AUC was 0.99 with a sensitivity of 78.1%, specificity of 98.0%, NPV of 0.98 and PPV of 0.76. Here we report that FoCUS AI-assisted LVEF assessments provide highly reproducible LVEF estimations in comparison to formal TTE. This finding was consistent among senior and novice echocardiographers suggesting applicability in a variety of clinical settings.
Perinatal Natural History of the Ts1Cje Mouse Model of Down Syndrome: Growth Restriction, Early Mortality, Heart Defects, and Delayed Development
The Ts1Cje model of Down syndrome is of particular interest for perinatal studies because affected males are fertile. This permits affected pups to be carried in wild-type females, which is similar to human pregnancies. Here we describe the early natural history and growth profiles of Ts1Cje embryos and neonates and determine if heart defects are present in this strain. Pups were studied either on embryonic (E) day 15.5, or from postnatal (P) day 3 through weaning on P21. PCR amplification targeting the neomycin cassette (present in Ts1Cje) and Sry (present in males) was used to analyze pup genotypes and sex ratios. Body weights and lengths, as well as developmental milestones, were recorded in Ts1Cje mice and compared to their wild-type (WT) littermates. Histological evaluations were performed at E15.5 to investigate the presence or absence of heart defects. Pups were divided into two groups: Ts1Cje-I pups survived past weaning and Ts1Cje-II pups died at some point before P21. Ts1Cje mouse embryos showed expected Mendelian ratios (45.8%, n = 66 for Ts1Cje embryos; 54.2%, n = 78 for WT embryos). Histological analysis revealed the presence of ventricular septal defects (VSDs) in 21% of Ts1Cje E15.5 embryos. After weaning, only 28.2% of pups were Ts1Cje (185 Ts1Cje out of 656 total pups generated), with males predominating (male:female ratio of 1.4:1). Among the recovered dead pups (n = 207), Ts1Cje (63.3%, n = 131, p<0.01) genotype was found significantly more often than WT (36.7%, n = 76). Retrospective analysis of Ts1Cje-II (pre-weaning deceased) pups showed that they were growth restricted compared to Ts1Cje-I pups (post-weaning survivors). Growth restriction correlated with statistically significant delays in achieving several neonatal milestones between P3 and P21 compared to Ts1Cje-I (post-weaning survivors) neonates and WT littermates. Ts1Cje genotype is not associated with increased early in utero mortality. Cardiac defects, specifically VSDs, are part of the phenotype in this strain. There is increased neonatal mortality in Ts1Cje pups, with sex differences observed. Ts1Cje mice that died in the neonatal period were more likely to be growth restricted and delayed in achieving neonatal developmental milestones.