The Effect of Trabeculae Carneae on Left Ventricular Diastolic Compliance: Improvement in Compliance With Trabecular Cutting.

The role of trabeculae carneae in modulating left ventricular (LV) diastolic compliance remains unclear. The objective of this study was to determine the contribution of trabeculae carneae to the LV diastolic compliance. LV pressure-volume compliance curves were measured in six human heart explants from patients with LV hypertrophy at baseline and following trabecular cutting. The effect of trabecular cutting was also analyzed with finite-element model (FEM) simulations. Our results demonstrated that LV compliance improved after trabecular cutting (p < 0.001). Finite-element simulations further demonstrated that stiffer trabeculae reduce LV compliance further, and that the presence of trabeculae reduced the wall stress in the apex. In conclusion, we demonstrate that integrity of the LV and trabeculae is important to maintain LV stiffness and loss in trabeculae leads to more LV compliance.

Meta-Analysis of Genome-Wide Association Studies Reveals Genetic Mechanisms of Supraventricular Arrhythmias.

BACKGROUND: Substantial data support a heritable basis for supraventricular tachycardias, but the genetic determinants and molecular mechanisms of these arrhythmias are poorly understood. We sought to identify genetic loci associated with atrioventricular nodal reentrant tachycardia (AVNRT) and atrioventricular accessory pathways or atrioventricular reciprocating tachycardia (AVAPs/AVRT). METHODS: We performed multiancestry meta-analyses of genome-wide association studies to identify genetic loci for AVNRT (4 studies) and AVAP/AVRT (7 studies). We assessed evidence supporting the potential causal effects of candidate genes by analyzing relations between associated variants and cardiac gene expression, performing transcriptome-wide analyses, and examining prior genome-wide association studies. RESULTS: Analyses comprised 2384 AVNRT cases and 106 489 referents, and 2811 AVAP/AVRT cases and 1,483 093 referents. We identified 2 significant loci for AVNRT, which implicate NKX2-5 and TTN as disease susceptibility genes. A transcriptome-wide association analysis supported an association between reduced predicted cardiac expression of NKX2-5 and AVNRT. We identified 3 significant loci for AVAP/AVRT, which implicate SCN5A, SCN10A, and TTN/CCDC141. Variant associations at several loci have been previously reported for cardiac phenotypes, including atrial fibrillation, stroke, Brugada syndrome, and electrocardiographic intervals. CONCLUSIONS: Our findings highlight gene regions associated with ion channel function (AVAP/AVRT), as well as cardiac development and the sarcomere (AVAP/AVRT and AVNRT) as important potential effectors of supraventricular tachycardia susceptibility.

Prevalence and Phenotypic Burden of Monogenic Arrhythmias Using Integration of Electronic Health Records With Genetics.

BACKGROUND: Inherited primary arrhythmia syndromes and arrhythmogenic cardiomyopathies can lead to sudden cardiac arrest in otherwise healthy individuals. The burden and expression of these diseases in a real-world, well-phenotyped cardiovascular population is not well understood. METHODS: Whole exome sequencing was performed on 8574 individuals from the CATHGEN cohort (Catheterization Genetics). Variants in 55 arrhythmia-related genes (associated with 8 disorders) were identified and assessed for pathogenicity based on American College of Genetics and Genomics/Association for Molecular Pathology criteria. Individuals carrying pathogenic/likely pathogenic (P/LP) variants were grouped by arrhythmogenic disorder and matched 1:5 to noncarrier controls based on age, sex, and genetic ancestry. Long-term phenotypic data were annotated through deep electronic health record review. RESULTS: Fifty-eight P/LP variants were found in 79 individuals in 12 genes associated with 5 arrhythmogenic disorders (arrhythmogenic right ventricular cardiomyopathy, Brugada syndrome, hypertrophic cardiomyopathy, LMNA-related cardiomyopathy, and long QT syndrome). The penetrance of these P/LP variants in this cardiovascular cohort was 33%, 0%, 28%, 83%, and 4%, respectively. Carriers of P/LP variants associated with arrhythmogenic disorders showed significant differences in ECG, imaging, and clinical phenotypes compared with noncarriers, but displayed no difference in survival. Carriers of novel truncating variants in FLNC, MYBPC3, and MYH7 also developed relevant arrhythmogenic cardiomyopathy phenotypes. CONCLUSIONS: In a real-world cardiovascular cohort, P/LP variants in arrhythmia-related genes were relatively common (1:108 prevalence) and most penetrant in LMNA. While hypertrophic cardiomyopathy P/LP variant carriers showed significant differences in clinical outcomes compared with noncarriers, carriers of P/LP variants associated with other arrhythmogenic disorders displayed only ECG differences.

Patient Engagement With Urologists on Social Media in a Community Practice.

Background Based on the Boston Area Community Health Survey, 52 million adults in the United States will have lower urinary tract symptoms, urine leakage, painful bladder syndrome, and prostatitis, which may parallel the prevalence of cardiovascular disease. In the year 2000, benign prostatic hyperplasia (BPH) accounted for 117,000 emergency department visits and 105,000 hospitalizations. These numbers underscore the burden of urological conditions and highlight the importance of patient education in preventing unnecessary hospitalizations and emergency department visits. Certain factors that may alter the progression and severity of disease include physical activity and other lifestyle changes. Based on current trends, patient education via social media may be an invaluable tool in limiting the burden on urologists and the healthcare system in the future. Aims This study aims to determine whether patients in a community urology practice would engage with their urologists over social media and if the likelihood to engage was associated with various demographic factors. Furthermore, the likelihood to engage actively (defined as commenting/sharing) versus passively (defined as liking a post) on two different topics within the scope of urology was determined. The two topics used were erectile dysfunction (ED)/urinary incontinence and kidney stone prevention. Methods Participants were recruited from a community urologic clinic in Alabama. During the month of April 2021, 293 participants completed a survey that included basic demographic questions as well as questions with a visual analog 5-point Likert scale. Responses on the Likert scale were given a value of one (very unlikely) to five (very likely), and a two-tailed Mann-Whitney U test with an α of 0.05 was used to determine significance in differences of responses. In the case of ties, the mid-rank method was used to assign ranks. For analysis of the Likert scale responses, only those respondents who had social media accounts were included. Results Overall, respondents were more likely to interact with a post by their urologist passively engage rather than actively. They were also less likely to passively and actively engage on a topic concerning ED/urinary incontinence versus kidney stone prevention. On the topic of kidney stone prevention, respondents were less likely to engage actively than passively. There was no difference in the likelihood of actively or passively engaging on the topic of ED/urinary incontinence. Compared to men, women were more likely to actively and passively engage on social media. On the topic of ED/urinary incontinence, women were more likely than men to actively engage; however, there was no difference in passive engagement. On the topic of kidney stone prevention, women were more likely to actively and passively engage. When looking at the likelihood of engagement based on age, there was no difference in active or passive engagement between those 55 and under or older than 55. This held true when data were stratified by topic. Conclusion Based on these results, the maximum impact of a social media page from a urological practice would be gained by focusing on preventative practices for less sensitive urological conditions. Furthermore, the data suggests that as the population of social media users continues to age, physicians should not expect a change in engagement patterns anytime soon.

Differentiation of Human Induced Pluripotent Stem Cells into Epicardial-Like Cells.

The epicardium is a multipotent cell layer that is vital to myocardial development and regeneration. Epicardial cells contribute to cardiac fibroblast and smooth muscle populations of the heart and secrete paracrine factors that promote cardiomyocyte proliferation and angiogenesis. Despite a central role in cardiac biology, the mechanisms by which epicardial cells influence cardiac growth are largely unknown, and robust models of the epicardium are needed. Here, we review our protocol for differentiating induced pluripotent stem cells (iPSCs) into epicardial-like cells through temporal modulation of canonical Wnt signaling. iPSC-derived epicardial cells (iECs) resemble in vivo epicardial cells morphologically and display markers characteristic of the developing epicardium. We also review our protocol for differentiating iECs into fibroblasts and smooth muscle cells through treatment with bFGF and TGF-ß1, respectively. iECs provide a platform for studying fundamental epicardial biology and can inform strategies for therapeutic heart regeneration.

Beneficial effects of quercetin on sperm parameters in streptozotocin-induced diabetic male rats.

Quercetin (QR) is a strong antioxidant and has been shown to reduce oxidative stress in the long-term treatment of streptozotocin (STZ)-induced diabetes in animal models. Antioxidants have significant effects on spermatogenesis, sperm biology and oxidative stress, and changes in antioxidant capacity are considered to be involved in the pathogenesis of chronic diabetes mellitus. The present study aims to examine the influence of QR on spermatogenesis in STZ-induced diabetes in male Wistar rats. Animals (n = 50) were allocated into five groups: Group 1: Control rats given 0.5 ml of 20% glycerol in 0.9% normal saline. Group 2: Control rats given buffer (pH4.0).Group 3: diabetic controls. Group 4: rats given QR 15 mg/kg/day (i.p.). Group 5: STZ + QR rats. Animals were kept in standard conditions. At the end of the experiment (28th day), blood samples were taken for determination of testosterone, total antioxidant capacity, and levels of malondialdehyde and oxidized low-density lipoprotein. All rats were euthanized, testes were dissected out and spermatozoa were collected from the epididymis for analysis. Sperm numbers, percentages of sperm viability and motility, and total serum testosterone increased significantly in QR-treated diabetic rats (P < 0.05) compared with control groups. In histopathology, degeneration and inflammation in testes cells associated with diabetes were improved and testes weights in the QR-treated diabetic group decreased significantly in comparison with controls (P < 0.05). We conclude that QR has significant beneficial effects on the sperm viability, motility, and serum total testosterone and could be effective for maintaining healthy sperm parameters and male reproductive function in diabetic rats.

Coronary artery fistulas: CT findings.

Coronary artery fistulas are anomalous terminations of the coronary arteries. Most often, these fistulas are incidentally identified in the adult and pediatric populations. Many patients are asymptomatic; however, an awareness of these fistulas is important because they have been associated with various clinical features, including chest pain or heart failure in young patients. Correct diagnosis of coronary artery fistulas is important, and early surgical correction is indicated because of the high prevalence of late symptoms and complications. Traditionally, conventional angiography has been used for the diagnosis of coronary anomalies. With more frequent use of 64-row multi-detector computed tomography (CT) in chest and cardiac imaging, the number of incidentally found coronary artery fistulas has been increasing. CT angiography and conventional angiography can have additive value in diagnosis of this cardiac anomaly. In every CT study of the heart, special attention should be paid to the courses and terminations of the coronary arteries to detect these potentially fatal anomalies.

A Case of Rare Inherited Restrictive Cardiomyopathy With Severe Biatrial Enlargement.

We describe a case of inherited restrictive cardiomyopathy in a patient presenting with severe biatrial enlargement. We review the evaluation and management of restrictive cardiomyopathy with a focus on genetic etiologies. (Level of Difficulty: Intermediate.).

Structural characterization of an equilibrium unfolding intermediate in cytochrome c.

Although the denaturant-induced unfolding transition of cytochrome c was initially thought to be a cooperative process, recent spectroscopic studies have shown deviations from two-state behavior consistent with accumulation of an equilibrium intermediate. However, little is known about the structural and thermodynamic properties of this state, and whether it is stabilized by the presence of non-native heme ligands. We monitored the reversible denaturant-induced unfolding equilibrium of oxidized horse cytochrome c using various spectroscopic probes, including fluorescence, near and far-UV CD, heme absorbance bands in the Soret, visible and near-IR regions of the spectrum, as well as 2D NMR. Global fitting techniques were used for a quantitative interpretation of the results in terms of a three-state model, which enabled us to determine the intrinsic spectroscopic properties of the intermediate. A well-populated intermediate was observed in equilibrium experiments at pH 5 using either guanidine-HCl or urea as a denaturant, both for wild-type cytochrome c as well as an H33N mutant chosen to prevent formation of non-native His-heme ligation. For a more detailed structural characterization of the intermediate, we used 2D 1H-15N correlation spectroscopy to follow the changes in peak intensity for individual backbone amide groups. The equilibrium state observed in our optical and NMR studies contains many native-like structural features, including a well-structured alpha-helical sub-domain, a short Trp59-heme distance and solvent-shielded heme environment, but lacks the native Met80 sulfur-iron linkage and shows major perturbations in side-chain packing and other tertiary interactions. These structural properties are reminiscent of the A-state of cytochrome c, a compact denatured form found under acidic high-salt conditions, as well as a kinetic intermediate populated at a late stage of folding. The denaturant-induced intermediate also resembles alkaline forms of cytochrome c with altered heme ligation, suggesting that disruption of the native methionine ligand favors accumulation of structurally analogous states both in the presence and absence of non-native ligands.

A proposed role for all-trans retinal in regulation of rhodopsin regeneration in human rods.

In order to account for the multi-phasic dynamics of photopigment regeneration in human rods, we developed a new model of the retinoid cycle. We first examined the relative roles of the classical and channeling mechanisms of metarhodopsin decay in establishing these dynamics. We showed that neither of these mechanisms alone, nor a linear combination of the two, can adequately account for the dynamics of rhodopsin regeneration at all bleach levels. Our new model adds novel inhibitory interactions in the cycle of regeneration of rhodopsin that are consistent with the 3D structure of rhodopsin. Our analyses show that the dynamics of human rod photopigment regeneration can be accounted for by end-product regulation of the channeling mechanism where all-trans retinal (tral) inhibits the binding of 11-cis retinal to the opsin.tral complex.

Application of a Physiologically Based Pharmacokinetic Model to Study Theophylline Metabolism and Its Interactions With Ciprofloxacin and Caffeine.

Theophylline is a commonly used bronchodilator. However, due to its narrow therapeutic range, moderate elevation of serum concentration can result in adverse drug reactions (ADRs). ADRs occur because of interhuman pharmacokinetic variability and interactions with coprescribed medicines. We developed a physiologically based pharmacokinetic (PBPK) model of theophylline, caffeine, and ciprofloxacin metabolisms to: examine theophylline pharmacokinetic variability, and predict population-level outcomes of drug-drug interactions (DDIs). A simulation-based equation for personalized dosing of theophylline was derived. Simulations of DDI show that calculated personalized doses are safe even after cotreatment with large doses of strong inhibitors. Simulations of adult populations indicate that the elderly are most susceptible to ADRs stemming from theophylline-ciprofloxacin and theophylline-caffeine interactions. Females, especially Asians, due to their smaller average size, are more susceptible to DDI-induced ADRs following typical dosing practices. Our simulations also show that the higher adipose and lower muscle fractions in females significantly alter the pharmacokinetics of theophylline or ciprofloxacin.

The Karyote physico-chemical genomic, proteomic, metabolic cell modeling system.

Modeling approaches to the dynamics of a living cell are presented that are strongly based on its underlying physical and chemical processes and its hierarchical spatio-temporal organization. Through the inclusion of a broad spectrum of processes and a rigorous analysis of the multiple scale nature of cellular dynamics, we are attempting to advance cell modeling and its applications. The presentation focuses on our cell modeling system, which integrates data archiving and quantitative physico-chemical modeling and information theory to provide a seamless approach to the modeling/data analysis endeavor. Thereby the rapidly growing mess of genomic, proteomic, metabolic, and cell physiological data can be automatically used to develop and calibrate a predictive cell model. The discussion focuses on the Karyote cell modeling system and an introduction to the CellX and VirusX models. The Karyote software system integrates three elements: (1) a model-building and data archiving module that allows one to define a cell type to be modeled through its reaction network, structure, and transport processes as well as to choose the surrounding medium and other parameters of the phenomenon to be modeled; (2) a genomic, proteomic, metabolic cell simulator that solves the equations of metabolic reaction, transcription/translation polymerization and the exchange of molecules between parts of the cell and with the surrounding medium; and (3) an information theory module (ITM) that automates model calibration and development, and integrates a variety of data types with the cell dynamic computations. In Karyote, reactions may be fast (equilibrated) or slow (finite rate), and the special effects of enzymes and other minority species yielding steady-state cycles of arbitrary complexities are accounted for. These features of the dynamics are handled via rigorous multiple scale analysis. A user interface allows for an automated generation and solution of the equations of multiple timescale, compartmented dynamics. Karyote is based on a fixed intracellular structure. However, cell response to changes in the host medium, damage, development or transformation to abnormality can involve dramatic changes in intracellular structure. As this changes the nature of the cellular dynamics, a new model, CellX, is being developed based on the spatial distribution of concentration and other variables. This allows CellX to capture the self-organizing character of cellular behavior. The self-assembly of organelles, viruses, and other subcellular bodies is being addressed in a second new model, VirusX, that integrates molecular mechanics and continuum theory. VirusX is designed to study the influence of a host medium on viral self-assembly, structural stability, infection of a single cell, and transmission of disease.

Combined in vivo molecular and anatomic imaging for detection of ovarian carcinoma-associated protease activity and integrin expression in mice.

Most patients with epithelial ovarian cancer (EOC) experience drug-resistant disease recurrence. Identification of new treatments is a high priority, and preclinical studies in mouse models of EOC may expedite this goal. We previously developed methods for magnetic resonance imaging (MRI) for tumor detection and quantification in a transgenic mouse model of EOC. The goal of this study was to determine whether three-dimensional (3D) fluorescence molecular tomography (FMT) and fluorescent molecular imaging probes could be effectively used for in vivo detection of ovarian tumors and response to therapy. Ovarian tumor-bearing TgMISIIR-TAg mice injected with fluorescent probes were subjected to MRI and FMT. Tumor-specific probe retention was identified in vivo by alignment of the 3D data sets, confirmed by ex vivo fluorescent imaging and correlated with histopathologic findings. Mice were treated with standard chemotherapy, and changes in fluorescent probe binding were detected by MRI and FMT. Ovarian tumors were detected using probes specific for cathepsin proteases, matrix metalloproteinases (MMPs), and integrin α(v)ß(3). Cathepsin and integrin α(v)ß(3) probe activation and retention correlated strongly with tumor volume. MMP probe activation was readily detected in tumors but correlated less strongly with tumor volume. Tumor regression associated with response to therapy was detected and quantified by serial MRI and FMT. These results demonstrate the feasibility and sensitivity of FMT for detection and quantification of tumor-associated biologic targets in ovarian tumors and support the translational utility of molecular imaging to assess functional response to therapy in mouse models of EOC.

Patient opinion of the doctor-patient relationship in a public hospital in Qatar.

OBJECTIVE: To analyze the factors associated with the level of satisfaction of outpatients in their relationship with their doctor at the largest public hospital in Qatar. METHODS: This study was a cross-sectional survey of attitudes. Researchers surveyed 626 outpatients at Hamad General Hospital in Doha, Qatar from September 2009 to January 2010 using a novel questionnaire assessing satisfaction with patients' interaction(s) with their doctor (spent time with patient, took case seriously, maintained confidentiality, and the overall quality of visit). RESULTS: Mean responses on 4 Likert scale items (one to 5) were as follows: "spent enough time with patient" = 4.39; "doctor took case seriously" = 4.57; "satisfaction with doctor-patient confidentiality" = 4.71; "overall quality of visit" = 4.46. Age, gender, citizenship, level of education, and number of visits did not significantly impact the level of satisfaction. For 73.1% of patients, the physician's qualification was the most important factor in choosing a doctor. Of those surveyed, 40.7% of men and 28.1% of women preferred to see a doctor of their own gender. A positive correlation between perceived communication and satisfaction with the doctor-patient encounter was established. CONCLUSION: This study found that patients in the Out-Patient Department at Hamad Hospital were highly satisfied with their relationships with their doctors, and physician qualification was the most significant factor in choosing a doctor. A significant number of males and females preferred a physician of their own gender. Communication difficulty correlated with lower satisfaction.

Noncompaction syndrome of the myocardium: pathophysiology and imaging pearls.

Patients with noncompaction syndrome of the myocardium may present with cardiac arrhythmia, thromboembolic events, or left ventricular failure. Associations with other diseases, including neurologic or other cardiac syndromes, have been noted. Noncompaction syndrome of the myocardium is primarily diagnosed by echocardiography; however, CT scanning and magnetic resonance imaging are useful tools for determining severity and the patient's prognosis. With these methods, high-resolution images of the myocardium are obtained that enable better recognition of the areas over which the trabeculae are distributed. Early diagnosis can improve the patient's survival by premature heart transplantation or implantation of a defibrillator. Also, as there are many reports of occurrence of this syndrome in several members of the same family (mainly X-linked inheritance), upon accurate and early diagnosis, the patient's family can be further screened.

Gastric pneumatosis following nasogastric tube placement: a case report with literature review.

We report a case of gastric emphysema following placement of nasogastric (NG) tube. Gas in the wall of the stomach is a rare finding seen in various clinical situations. The reported cases fall into two different categories: "gastric emphysema" and "emphysematous gastritis". Differentiating these two entities is important, as the first one is usually a benign condition, but the second one carries a poor prognosis.

Jejunogastric intussusception: a case report with the review of literature.

Jejunogastric intussusception (JGI) is a rare but potentially lethal complication of gastrectomy or gastrojejunostomy. In the acute setting, early diagnosis and prompt surgical intervention are mandatory to avoid mortality. We present a case of JGI in a patient with a history of gastrojejunostomy who had increasing vomiting, hematemesis, and abdominal pain for 1 day.

The phosphatidylinositol 3-kinase signaling pathway exerts protective effects during sepsis by controlling C5a-mediated activation of innate immune functions.

The PI3K/Akt signaling pathway has been recently suggested to have controversial functions in models of acute and chronic inflammation. Our group and others have reported previously that the complement split product C5a alters neutrophil innate immunity and cell signaling during the onset of sepsis and is involved in PI3K activation. We report in this study that in vivo inhibition of the PI3K pathway resulted in increased mortality in septic mice accompanied by strongly elevated serum levels of TNF-alpha, IL-6, MCP-1, and IL-10 during sepsis as well as decreased oxidative burst activity in blood phagocytes. PI3K inhibition in vitro resulted in significant increases in TLR-4-mediated generation of various proinflammatory cytokines in neutrophils, whereas the opposite effect was observed in PBMC. Oxidative burst and phagocytosis activity was significantly attenuated in both neutrophils and monocytes when PI3K activation was blocked. In addition, PI3K inhibition resulted in strongly elevated TLR-4-mediated generation of IL-1beta and IL-8 in neutrophils when these cells were co-stimulated with C5a. C5a-induced priming effects on neutrophil and monocyte oxidative burst activity as well as C5a-induced phagocytosis in neutrophils were strongly reduced when PI3K activation was blocked. Our data suggest that the PI3K/Akt signaling pathway controls various C5a-mediated effects on neutrophil and monocyte innate immunity and exerts an overall protective effect during experimental sepsis.

Splenic rupture after diagnostic colonoscopy: a case report.

Colonoscopy is a commonly used diagnostic and therapeutic procedure. Splenic injury or rupture after this procedure is rare. We report a case of splenic rupture and hematoma in a middle-aged man who presented with symptoms of worsened anemia after diagnostic colonoscopy.