Endurance Exercise Training Mitigates Diastolic Dysfunction in Diabetic Mice Independent of Phosphorylation of Ulk1 at S555.

Millions of diabetic patients suffer from cardiovascular complications. One of the earliest signs of diabetic complications in the heart is diastolic dysfunction. Regular exercise is a highly effective preventive/therapeutic intervention against diastolic dysfunction in diabetes, but the underlying mechanism(s) remain poorly understood. Studies have shown that the accumulation of damaged or dysfunctional mitochondria in the myocardium is at the center of this pathology. Here, we employed a mouse model of diabetes to test the hypothesis that endurance exercise training mitigates diastolic dysfunction by promoting cardiac mitophagy (the clearance of mitochondria via autophagy) via S555 phosphorylation of Ulk1. High-fat diet (HFD) feeding and streptozotocin (STZ) injection in mice led to reduced endurance capacity, impaired diastolic function, increased myocardial oxidative stress, and compromised mitochondrial structure and function, which were all ameliorated by 6 weeks of voluntary wheel running. Using CRISPR/Cas9-mediated gene editing, we generated non-phosphorylatable Ulk1 (S555A) mutant mice and showed the requirement of p-Ulk1at S555 for exercise-induced mitophagy in the myocardium. However, diabetic Ulk1 (S555A) mice retained the benefits of exercise intervention. We conclude that endurance exercise training mitigates diabetes-induced diastolic dysfunction independent of Ulk1 phosphorylation at S555.

Foreign Body Ingestion: An Unusual Case in a Patient with Dementia.

Foreign body ingestion is a problem seen frequently in the emergency department, particularly in children. In this case report, we present an uncommon example: foreign body ingestion in an elderly patient with a history of dementia. This patient's symptoms of dysphagia, cough, and pooling secretions in the posterior oral cavity suggested food impaction, and after further investigation, coins were found in the upper and middle esophagus. Most of the coins were removed, the patient was monitored, and outpatient follow-up was organized to ensure the safe elimination of all the coins. This case illustrates the importance of having a high pretest probability for certain diagnoses based upon how specific patient populations present.

Obesity-Induced Coronary Microvascular Disease Is Prevented by iNOS Deletion and Reversed by iNOS Inhibition.

Coronary microvascular disease (CMD) caused by obesity and diabetes is major contributor to heart failure with preserved ejection fraction; however, the mechanisms underlying CMD are not well understood. Using cardiac magnetic resonance applied to mice fed a high-fat, high-sucrose diet as a model of CMD, we elucidated the role of inducible nitric oxide synthase (iNOS) and 1400W, an iNOS antagonist, in CMD. Global iNOS deletion prevented CMD along with the associated oxidative stress and diastolic and subclinical systolic dysfunction. The 1400W treatment reversed established CMD and oxidative stress and preserved systolic/diastolic function in mice fed a high-fat, high-sucrose diet. Thus, iNOS may represent a therapeutic target for CMD.

Developing Topics.

BACKGROUND: This study aims to detect direct cost savings with early detection of Alzheimer's disease (AD) and related dementias. We hypothesize that earlier diagnosis of AD can reduce direct healthcare costs and unnecessary utilization. A retrospective case-control study is conducted using Optum Market Clarity Claims/EHR linked dataset on Medicare Advantage population from Jan 1 2011 to Dec 31 2020. METHOD: Based on whether the patient was diagnosed with prior Mild Cognitive Impairment (MCI) before progressing to an AD diagnosis per ICD-9/10 cm diagnosis codes, AD patients are categorized into early vs. late diagnosis (for those who were identified in the MCI stage vs not). Both groups are compared on annual all-cause healthcare costs and frequency of encounters longitudinally spanning across 6 years pre-index period and 3 years post-index with AD diagnosis date as the index date. To understand the impact of early diagnosis, we estimated total cost, medical service cost and drug cost post-index within the first 3 years by risk adjustment on baseline demographics, comorbidities, procedures, lab tests, and visits prior to AD diagnosis using propensity score weighting. RESULT: Early-diagnosed patients (N = 421) have a lower utilization rate of inpatient skilled nursing facility, nursing home and hospitalization than late-diagnosed patients (N = 2817) after being diagnosed with AD. We also observed average medical service cost savings in all 3 years post-index, ranging from $320 to $2556 per patient per year. Per cost allocation analysis, medical service cost savings are observed in inpatient, emergency room, inpatient SNF, urgent care, nursing home/assisted living, and observation unit. Risk adjusted cost savings with statistical significance are observed in year 3 post-index. The mean cost difference between late and early diagnoses: total cost ($15472.11), medical service ($15013.7) and medication cost ($1601.61). CONCLUSION: The study highlights opportunities for earlier diagnosis and suggests long-term healthcare savings for AD patients who have been diagnosed at MCI stage compared to patients who were directly diagnosed with AD. Further research is needed to drill down into the driver of cost savings and whether it is attributable to disease management of MCI or other complications.

Accelerated fatty acid composition MRI of epicardial adipose tissue: Development and application to eplerenone treatment in a mouse model of obesity-induced coronary microvascular disease.

PURPOSE: To develop an accelerated MRI method to quantify the epicardial adipose tissue (EAT) fatty acid composition (FAC) and test the hypothesis that eplerenone (EPL) shifts the EAT FAC toward unsaturation in obese mice. METHODS: Undersampled multi-echo gradient echo imaging employing a dictionary-based compressed-sensing reconstruction and iterative decomposition with echo asymmetry and least-squares-based mapping (IDEAL) was developed, validated, and used to study EAT in obese mice scanned at 7T. Fully sampled and rate 2, 2.5, 3, and 3.5 undersampled image data were acquired, reconstructed, and assessed using RMSE and structural similarity (SSIM). Two groups of mice were studied: untreated (control, n = 10) and EPL-treated (n = 10) mice fed a high-fat high-sucrose diet. MRI included imaging of EAT FAC, EAT volume, and myocardial perfusion reserve. RESULTS: Rate 3 acceleration provided RMSE <5% and structural similarity >0.85 for FAC MRI. After 6 weeks of diet, EPL-treated compared to untreated mice had a reduced EAT saturated fatty acid fraction (0.27 ± 0.09 vs. 0.39 ± 0.07, P < 0.05) and increased EAT unsaturation degree (4.37 ± 0.32 vs. 3.69 ± 0.58, P < 0.05). Also, EAT volume in EPL-treated compared to untreated mice was reduced (8.1 ± 0.6 mg vs. 11.4 ± 0.7 mg, P < 0.01), and myocardial perfusion reserve was improved (1.83 ± 0.15 vs. 1.61 ± 0.17, P < 0.05). CONCLUSION: Rate 3 accelerated FAC MRI enabled accurate quantification of EAT FAC in mice. EPL treatment shifted the EAT FAC toward increased unsaturation and was associated with improvement of coronary microvascular function.

Novel Smooth Muscle Ca2+-Signaling Nanodomains in Blood Pressure Regulation.

BACKGROUND: Ca2+ signals in smooth muscle cells (SMCs) contribute to vascular resistance and control blood pressure. Increased vascular resistance in hypertension has been attributed to impaired SMC Ca2+ signaling mechanisms. In this regard, transient receptor potential vanilloid 4 (TRPV4SMC) ion channels are a crucial Ca2+ entry pathway in SMCs. However, their role in blood pressure regulation has not been identified. METHODS: We used SMC-specific TRPV4-/- (TRPV4SMC-/-) mice to assess the role of TRPV4SMC channels in blood pressure regulation. We determined the contribution of TRPV4SMC channels to the constrictor effect of α1 adrenergic receptor (α1AR) stimulation and elevated intraluminal pressure: 2 main physiologic stimuli that constrict resistance-sized arteries. The contribution of spatially separated TRPV4SMC channel subpopulations to elevated blood pressure in hypertension was evaluated in angiotensin II-infused mice and patients with hypertension. RESULTS: We provide first evidence that TRPV4SMC channel activity elevates resting blood pressure in normal mice. α1AR stimulation activated TRPV4SMC channels through PKCα (protein kinase Cα) signaling, which contributed significantly to vasoconstriction and blood pressure elevation. Intraluminal pressure-induced TRPV4SMC channel activity opposed vasoconstriction through activation of Ca2+-sensitive K+ (BK) channels, indicating functionally opposite pools of TRPV4SMC channels. Superresolution imaging of SMCs revealed spatially separated α1AR:TRPV4 and TRPV4:BK nanodomains in SMCs. These data suggest that spatially separated α1AR-TRPV4SMC and intraluminal pressure-TRPV4SMC-BK channel signaling have opposite effects on blood pressure, with α1AR-TRPV4SMC signaling dominating under resting conditions. Furthermore, in patients with hypertension and a mouse model of hypertension, constrictor α1AR-PKCα-TRPV4 signaling was upregulated, whereas dilator pressure-TRPV4-BK channel signaling was disrupted, thereby increasing vasoconstriction and elevating blood pressure. CONCLUSIONS: Our data identify novel smooth muscle Ca2+-signaling nanodomains that regulate blood pressure and demonstrate their impairment in hypertension.

Acquired tracheo-esophageal fistula in adult-a classical case of 'what not to do'.

Acquired tracheo-esophageal fistulas (TEFs) are challenging. The most common causes are prolonged intubation, malignancy, and trauma whereas granulomatous infections like tuberculosis are rare. Endoscopic intervention with esophageal or tracheal stenting or clipping is of unproven benefit in the management of such lesions, where surgical repair is almost invariably required. We report a case of a 32-year-old man, with a case of multidrug-resistant pulmonary tuberculosis. He had no history of malignancy or trauma. The patient developed spontaneous TEF probably due to mediastinal lymph node necrosis. Multiple attempts were made using staplers, clips, and atrial septal defect (ASD) device closure but were unsuccessful. The nuanced complication leads to very individualized course of treatment which was optimal for this patient.

Endothelial pannexin 1-TRPV4 channel signaling lowers pulmonary arterial pressure in mice.

Pannexin 1 (Panx1), an ATP-efflux pathway, has been linked with inflammation in pulmonary capillaries. However, the physiological roles of endothelial Panx1 in the pulmonary vasculature are unknown. Endothelial transient receptor potential vanilloid 4 (TRPV4) channels lower pulmonary artery (PA) contractility and exogenous ATP activates endothelial TRPV4 channels. We hypothesized that endothelial Panx1-ATP-TRPV4 channel signaling promotes vasodilation and lowers pulmonary arterial pressure (PAP). Endothelial, but not smooth muscle, knockout of Panx1 increased PA contractility and raised PAP in mice. Flow/shear stress increased ATP efflux through endothelial Panx1 in PAs. Panx1-effluxed extracellular ATP signaled through purinergic P2Y2 receptor (P2Y2R) to activate protein kinase Cα (PKCα), which in turn activated endothelial TRPV4 channels. Finally, caveolin-1 provided a signaling scaffold for endothelial Panx1, P2Y2R, PKCα, and TRPV4 channels in PAs, promoting their spatial proximity and enabling signaling interactions. These results indicate that endothelial Panx1-P2Y2R-TRPV4 channel signaling, facilitated by caveolin-1, reduces PA contractility and lowers PAP in mice.

Molecular Mechanisms of Adenosine Stress T1 Mapping.

BACKGROUND: Adenosine stress T1 mapping is an emerging magnetic resonance imaging method to investigate coronary vascular function and myocardial ischemia without application of a contrast agent. Using gene-modified mice and 2 vasodilators, we elucidated and compared the mechanisms of adenosine myocardial perfusion imaging and adenosine T1 mapping. METHODS: Wild-type (WT), A2AAR-/- (adenosine A2A receptor knockout), A2BAR-/- (adenosine A2B receptor knockout), A3AR-/- (adenosine A3 receptor knockout), and eNOS-/- (endothelial nitric oxide synthase knockout) mice underwent rest and stress perfusion magnetic resonance imaging (n=8) and T1 mapping (n=10) using either adenosine, regadenoson (a selective A2AAR agonist), or saline. Myocardial blood flow and T1 were computed from perfusion imaging and T1 mapping, respectively, at rest and stress to assess myocardial perfusion reserve and T1 reactivity (ΔT1). Changes in heart rate for each stress agent were also calculated. Two-way ANOVA was used to detect differences in each parameter between the different groups of mice. RESULTS: Myocardial perfusion reserve was significantly reduced only in A2AAR-/- compared to WT mice using adenosine (1.06±0.16 versus 2.03±0.52, P<0.05) and regadenoson (0.98±026 versus 2.13±0.75, P<0.05). In contrast, adenosine ΔT1 was reduced compared with WT mice (3.88±1.58) in both A2AAR-/- (1.63±1.32, P<0.05) and A2BAR-/- (1.55±1.35, P<0.05). Furthermore, adenosine ΔT1 was halved in eNOS-/- (1.76±1.46, P<0.05) versus WT mice. Regadenoson ΔT1 was approximately half of adenosine ΔT1 in WT mice (1.97±1.50, P<0.05), and additionally, it was significantly reduced in eNOS-/- mice (-0.22±1.46, P<0.05). Lastly, changes in heart rate was 2× greater using regadenoson versus adenosine in all groups except A2AAR-/-, where heart rate remained constant. CONCLUSIONS: The major findings are that (1) although adenosine myocardial perfusion reserve is mediated through the A2A receptor, adenosine ΔT1 is mediated through the A2A and A2B receptors, (2) adenosine myocardial perfusion reserve is endothelial independent while adenosine ΔT1 is partially endothelial dependent, and (3) ΔT1 mediated through the A2A receptor is endothelial dependent while ΔT1 mediated through the A2B receptor is endothelial independent.

Nitroxide-enhanced MRI of cardiovascular oxidative stress.

BACKGROUND: In vivo imaging of oxidative stress can facilitate the understanding and treatment of cardiovascular diseases. We evaluated nitroxide-enhanced MRI with 3-carbamoyl-proxyl (3CP) for the detection of myocardial oxidative stress. METHODS: Three mouse models of cardiac oxidative stress were imaged, namely angiotensin II (Ang II) infusion, myocardial infarction (MI), and high-fat high-sucrose (HFHS) diet-induced obesity (DIO). For the Ang II model, mice underwent MRI at baseline and after 7 days of Ang II (n = 8) or saline infusion (n = 8). For the MI model, mice underwent MRI at baseline (n = 10) and at 1 (n = 8), 4 (n = 9), and 21 (n = 8) days after MI. For the HFHS-DIO model, mice underwent MRI at baseline (n = 20) and 18 weeks (n = 13) after diet initiation. The 3CP reduction rate, Kred , computed using a tracer kinetic model, was used as a metric of oxidative stress. Dihydroethidium (DHE) staining of tissue sections was performed on Day 1 after MI. RESULTS: For the Ang II model, Kred was higher after 7 days of Ang II versus other groups (p < 0.05). For the MI model, Kred , in the infarct region was significantly elevated on Days 1 and 4 after MI (p < 0.05), whereas Kred in the noninfarcted region did not change after MI. DHE confirmed elevated oxidative stress in the infarct zone on Day 1 after MI. After 18 weeks of HFHS diet, Kred was higher in mice after diet versus baseline (p < 0.05). CONCLUSIONS: Nitroxide-enhanced MRI noninvasively quantifies tissue oxidative stress as one component of a multiparametric preclinical MRI examination. These methods may facilitate investigations of oxidative stress in cardiovascular disease and related therapies.

Health Impact Assessment of Sulfolane on Embryonic Development of Zebrafish (Danio rerio).

Sulfolane is a widely used polar, aprotic solvent that has been detected by chemical analysis in groundwater and creeks around the world including Alberta, Canada (800 µg/mL), Louisiana, USA (2900 µg/mL) and Brisbane, Australia (4344 µg/mL). Previous research provided information on adverse effects of sulfolane on mammals, but relatively little information is available on aquatic organisms. This study tested the effects of sulfolane (0-5000 µg/mL) on early development of zebrafish larvae, using various morphometric (survival, hatching, yolk sac and pericardial oedema, haemorrhaging, spinal malformations, swim bladder inflation), growth (larval length, eye volume, yolk sac utilisation), behavioural (touch response, locomotor activity and transcript abundance parameters (ahr1a, cyp1a, thraa, dio1, dio2, dio3, 11ßhsd2, gr, aqp3a, cyp19a1b, ddc, gria2b and hsp70) for 120 h. Embryos were chronically exposed to sulfolane throughout the experimental period. For locomotor activity, however, we also investigated acute response to 2-h sulfolane treatment. Sulfolane sensitivity causing significant impairment in the observed parameters were different depending on parameters measured, including survival (concentrations greater than 800 µg/mL), morphometric and growth (800-1000 µg/mL), behaviour (500-800 µg/mL) and transcript abundance (10 µg/mL). The overall results provide novel information on the adverse health impacts of sulfolane on an aquatic vertebrate species, and an insight into developmental impairments following exposure to environmental levels of sulfolane in fish embryos.

Measurement of Equilibration Time of Dry Goods Loads in Autoclaves.

The equilibration time of an autoclave is defined as the period of time that elapses between the attainment of the sterilization temperature at the reference measurement point of the autoclave chamber and the attainment of the sterilization temperature at all measurement probes within the dry goods load placed within the autoclave during a sterilization cycle.The equilibration time is an indicator of the ability of the autoclave to remove air from and to subsequently sterilize the dry goods load placed within the autoclave chamber. Therefore, the equilibration time is an indicator of the performance of an autoclave. Periodic measurements of the equilibration time and evaluation of the equilibration time data can assure continued performance of the autoclave.For autoclaves that support biopharmaceutical manufacturing plants, the equilibration time is generally measured by placing heat penetration probes within the dry goods load items placed within the autoclave during a sterilization cycle. However, measurement of the equilibration time in this fashion yields results that are highly variable and difficult to replicate.This paper presents a study that attempts to understand the impact of the following autoclave variables on the consistent measurement of the equilibration time and on the reduction of the equilibration time: type of dry goods load item placed inside the autoclave, location of the heat penetration probe placed within the dry goods load item, location of the dry goods load item inside the autoclave chamber, orientation of the dry goods load item inside the autoclave chamber, number of coils of the tubing elements of a dry goods load item, total thermal mass of the dry goods load items placed inside the autoclave, temperature of the dry goods load items at the start of the sterilization cycle, presence of residual moisture in the dry goods load items at the start of the sterilization cycle, number of steam and vacuum pulses used for preconditioning in the autoclave recipe, depth of the steam and vacuum pulses used for preconditioning in the autoclave recipe, and hold time of the steam and vacuum pulses used for preconditioning in the autoclave recipe.The focus of this paper is on tests performed to evaluate these variables followed by analysis and interpretation of the test data to identify key variables that have the highest impact on the measurement of the equilibration time. The conclusion of this paper presents a process to achieve shorter equilibration times in autoclaves through control of the key variables identified.LAY ABSTRACT: The equilibration time is an indicator of the performance of an autoclave. Periodic measurements of the equilibration time and evaluation of the equilibration time data of an autoclave can assure continued performance of said autoclave.This paper presents a study performed to develop a general guideline for consistent measurement of the equilibration time of an autoclave through identification and control of key sources of variability that impact the measurement. The focus of this paper is the testing and data analysis performed to identify these key sources of variability observed in a typical autoclave load sterilized through a typical autoclave cycle in a biopharmaceutical manufacturing plant. The conclusion of this paper presents a process to achieve shorter equilibration times in autoclaves through control of the key variables identified.

Changes in cell fate determine the regenerative and functional capacity of the developing kidney before and after release of obstruction.

Congenital obstructive nephropathy is a major cause of chronic kidney disease (CKD) in children. The contribution of changes in the identity of renal cells to the pathology of obstructive nephropathy is poorly understood. Using a partial unilateral ureteral obstruction (pUUO) model in genetically modified neonatal mice, we traced the fate of cells derived from the renal stroma, cap mesenchyme, ureteric bud (UB) epithelium, and podocytes using Foxd1Cre, Six2Cre, HoxB7Cre, and Podocyte.Cre mice respectively, crossed with double fluorescent reporter (membrane-targetted tandem dimer Tomato (mT)/membrane-targetted GFP (mG)) mice. Persistent obstruction leads to a significant loss of tubular epithelium, rarefaction of the renal vasculature, and decreased renal blood flow (RBF). In addition, Forkhead Box D1 (Foxd1)-derived pericytes significantly expanded in the interstitial space, acquiring a myofibroblast phenotype. Degeneration of Sine Oculis Homeobox Homolog 2 (Six2) and HoxB7-derived cells resulted in significant loss of glomeruli, nephron tubules, and collecting ducts. Surgical release of obstruction resulted in striking regeneration of tubules, arterioles, interstitium accompanied by an increase in blood flow to the level of sham animals. Contralateral kidneys with remarkable compensatory response to kidney injury showed an increase in density of arteriolar branches. Deciphering the mechanisms involved in kidney repair and regeneration post relief of obstruction has potential therapeutic implications for infants and children and the growing number of adults suffering from CKD.

Diagnostic Accuracy of a Rapid Biparametric MRI Protocol for Detection of Histologically Proven Prostate Cancer.

OBJECTIVE: To evaluate the performance of a rapid, low cost, noncontrast MRI examination as a secondary screening tool in detection of clinically significant prostate cancer. METHODS: In this prospective single institution study, 129 patients with elevated prostate-specific antigen levels or abnormal digital rectal examination findings underwent MRI with an abbreviated biparamatric MRI protocol consisting of high-resolution axial T2- and diffusion-weighted images. Index lesions were classified according to modified Prostate Imaging - Reporting and Data System (mPI-RADS) version 2.0. All patients underwent standard transrectal ultrasound-guided biopsy after MRI with the urologist being blinded to MRI results. Subsequently, all patients with suspicious lesions (mPI-RADS 3, 4, or 5) underwent cognitively guided targeted biopsy after discussion of MRI results with the urologist. Sensitivity and negative predictive value for identification of clinically significant prostate cancer (Gleason score 3+4 and above) were determined. RESULTS: Rapid biparametric MRI discovered 176 lesions identified in 129 patients. Rapid MRI detected clinically significant cancers with a sensitivity of 95.1% with a negative predictive value of 95.1% and positive predictive value of 53.2%, leading to a change in management in 10.8% of the patients. False negative rate of biparametric (bp) MRI was 4.7%. CONCLUSION: We found that a bp-MRI examination can detect clinically significant lesions and changed patient management in 10.8% of the patients. A rapid MRI protocol can be used as a useful secondary screening tool in men presenting with suspicion of prostate cancer.

Multimodal imaging of the tricuspid valve: normal appearance and pathological entities.

The tricuspid valve, which is the atrioventricular valve attached to the morphological right ventricle, is affected by a wide range of pathological processes. Tricuspid valve diseases are now increasingly recognized as a significant cause of morbidity and mortality. Echocardiography is the most widely available and, hence, the first-line imaging modality used in the evaluation of tricuspid valve disorders; however, CT and MRI are also increasingly used for further evaluation and characterization of these entities. In this article, we first review the normal anatomy and embryology of the tricuspid valve, followed by a discussion of the role of multiple imaging modalities in the evaluation of tricuspid valve abnormalities. We then review and illustrate the imaging appearance of several congenital and acquired tricuspid valve abnormalities. Main Messages • Tricuspid valve diseases have a significant impact on morbidity and mortality. • CT and MRI are increasingly used in the evaluation of tricuspid disorders. • CT and MRI help in diagnosis, functional evaluation, pre-surgical planning and post-surgical follow-up. • The most common cause of tricuspid regurgitation is functional.

Single coronary artery with a pre-pulmonic dual left anterior descending artery and a retro-aortic left circumflex artery.

We present two cases of an unusual coronary artery anomaly, namely, a single coronary artery with retro-aortic course of the left circumflex artery and pre-pulmonic course of the left anterior descending artery, and one of which showed a dual left anterior descending artery as well - a combination that has not yet been reported in the literature.

Imaging Cardiovascular Manifestations of Genetic Syndromes.

Congenital structural cardiovascular defects are commonly associated and found concurrently with many different types of genetic diseases and syndromes. Understanding these cardiovascular manifestations is essential for diagnosing these genetic syndromes without delay and provides prompt attention and repair of life-threatening defects without complications. Computed tomography and magnetic resonance imaging are increasingly used in the evaluation of cardiovascular abnormalities, and it is imperative for radiologists to be cognizant of the syndromes associated with these abnormalities. In this article, we review the cardiovascular manifestations of the common genetic syndromes and illustrate the role of computed tomography and magnetic resonance imaging in the evaluation of these abnormalities.