Myocardial steatosis across the spectrum of human health and disease.

Preclinical data strongly suggest that myocardial steatosis leads to adverse cardiac remodelling and left ventricular dysfunction. Using H cardiac magnetic resonance spectroscopy, similar observations have been made across the spectrum of health and disease. The purpose of this brief review is to summarize these recent observations.

Myocardial steatosis impairs left ventricular diastolic-systolic coupling in healthy humans.

Mounting evidence suggests that myocardial steatosis contributes to left ventricular diastolic dysfunction, but definitive evidence in humans is lacking due to confounding comorbidities. As such, we utilized a 48-h food restriction model to acutely increase myocardial triglyceride (mTG) content - measured by H magnetic resonance spectroscopy - in 27 young healthy volunteers (13 men/14 women). Forty-eight hours of fasting caused a more than 3-fold increase in mTG content (P < 0.

Plasma osteopontin relates to myocardial fibrosis and steatosis and to immune activation among women with HIV.

Objective: Women with HIV (WWH) have heightened heart failure risk. Plasma OPN (osteopontin) is a powerful predictor of heart failure outcomes in the general population. Limited data exist on relationships between plasma OPN and surrogates of HIV-associated heart failure risk.

Reduced myocardial perfusion is common among subjects with ischemia and no obstructive coronary artery disease and heart failure with preserved ejection fraction: a report from the WISE-CVD continuation study.

Aim: Women with evidence of ischemia and no obstructive coronary artery disease (INOCA) have an increased risk of major adverse cardiac events, including heart failure with preserved ejection fraction (HFpEF). To investigate potential links between INOCA and HFpEF, we examined pathophysiological findings present in both INOCA and HFpEF.

Methods: We performed adenosine stress cardiac magnetic resonance imaging (CMRI) in 56 participants, including 35 women with suspected INOCA, 13 women with HFpEF, and 8 reference control women.

1 Year HIIT and Omega-3 Fatty Acids to Improve Cardiometabolic Risk in Stage-A Heart Failure.

Objectives: This study aims to determine whether 1 year of high-intensity interval training (HIIT) and omega-3 fatty acid (n-3 FA) supplementation would improve fitness, cardiovascular structure/function, and body composition in obese middle-aged adults at high-risk of heart failure (HF) (stage A).

Background: It is unclear if intensive lifestyle interventions begun in stage A HF can improve key cardiovascular and metabolic risk factors.

Methods: High-risk obese adults (n = 80; age 40 to 55 years; N-terminal pro-B-type natriuretic peptide >40 pg/mL or high-sensitivity cardiac troponin T >0.

Hot Flashes and Cardiovascular Disease Risk Indices Among Women With HIV.

Unlabelled: Women with HIV (WWH) transitioning through menopause have heightened cardiovascular disease (CVD) risk. In the general population, hot flash burden relates to CVD risk indices. We found higher hot flash burden among women with vs without HIV.

Myocardial Steatosis Among Antiretroviral Therapy-Treated People With Human Immunodeficiency Virus Participating in the REPRIEVE Trial.

Background: People with human immunodeficiency virus (PWH) face increased risks for heart failure and adverse heart failure outcomes. Myocardial steatosis predisposes to diastolic dysfunction, a heart failure precursor. We aimed to characterize myocardial steatosis and associated potential risk factors among a subset of the Randomized Trial to Prevent Vascular Events in HIV (REPRIEVE) participants.

Brief Report: Vascular Dysfunction and Monocyte Activation Among Women With HIV.

Objective: Women with HIV (WHIV) on antiretroviral therapy (ART) face an increased risk of cardiovascular disease (CVD) in the context of heightened systemic immune activation. Aortic stiffness, a measure of vascular dysfunction and a robust predictor of CVD outcomes, is highly influenced by immune activation. We compared aortic stiffness among women with and without HIV and examined interrelationships between aortic stiffness and key indices of systemic immune activation.

Proton magnetic resonance spectroscopy in skeletal muscle: Experts' consensus recommendations.

H-MR spectroscopy of skeletal muscle provides insight into metabolism that is not available noninvasively by other methods. The recommendations given in this article are intended to guide those who have basic experience in general MRS to the special application of H-MRS in skeletal muscle. The highly organized structure of skeletal muscle leads to effects that change spectral features far beyond simple peak heights, depending on the type and orientation of the muscle.

Intramyocardial Triglycerides Among Women With vs Without HIV: Hormonal Correlates and Functional Consequences.

Context: Women with HIV (WHIV) on anti-retroviral therapy (ART) are living longer but facing heightened vulnerability to heart failure.

Objective: We investigated metabolic/hormonal/immune parameters relating to diastolic dysfunction-a precursor to heart failure-among WHIV without known cardiovascular disease (CVD).

Design And Outcome Measures: Nineteen ART-treated WHIV and 11 non-HIV-infected women without known CVD enrolled and successfully completed relevant study procedures [cardiac magnetic resonance spectroscopy (MRS) and cardiac MRI].

Immune Correlates of Diffuse Myocardial Fibrosis and Diastolic Dysfunction Among Aging Women With Human Immunodeficiency Virus.

Human immunodeficiency virus (HIV) imparts increased heart failure risk to women. Among women with HIV (WHIV), immune pathways relating to heart failure precursors may intimate targets for heart failure prevention strategies. Twenty asymptomatic, antiretroviral-treated WHIV and 14 non-HIV-infected women matched on age and body mass index underwent cardiac magnetic resonance imaging and immune phenotyping.

Deceptive strategy in Dactylorhiza orchids: multidirectional evolution of floral chemistry.

Background And Aims: The deception strategies of orchids remain poorly understood, especially in regard to the chemical compounds emitted from their flowers and their interaction with various taxonomic groups of pollinators. We investigated the phylogenetic relationships and compared the variation of floral chemical compounds between food-deceptive Dactylorhiza taxa (D. incarnata var.

Facultative slave-making ants Formica sanguinea label their slaves with own recognition cues instead of employing the strategy of chemical mimicry.

Slave-making ant species use the host workforce to ensure normal colony functioning. Slaves are robbed as pupae from their natal nest and after eclosion, assume the parasite colony as their own. A possible factor promoting the successful integration of slaves into a foreign colony is congruence with the slave-makers in terms of cuticular hydrocarbons, which are known to play the role of recognition cues in social insects.

Insulin access to skeletal muscle is impaired during the early stages of diet-induced obesity.

Objective: Insulin must move from the blood to the interstitium to initiate signaling, yet access to the interstitium may be impaired in cases of insulin resistance, such as obesity. This study investigated whether consuming a short- and long-term high-fat diet (HFD) impairs insulin access to skeletal muscle, the major site of insulin-mediated glucose uptake.

Methods: Male mongrel dogs were divided into three groups consisting of control diet (n = 16), short-term (n = 8), and long-term HFD (n = 8).

Transwomen and the Metabolic Syndrome: Is Orchiectomy Protective?

Male-to-female transsexual women or who undergo cross-sex hormone treatments experience increased health-related risks (e.g., increased rates of cardiovascular disease and premature death).

Stereochemistry of ring-opening/cross metathesis reactions of exo- and endo-7-oxabicyclo[2.2.1]hept-5-ene-2-carbonitriles with allyl alcohol and allyl acetate.

The ROCM reactions of exo- and endo-2-cyano-7-oxanorbornenes with allyl alcohol or allyl acetate promoted by different ruthenium alkylidene catalysts were studied. The stereochemical outcome of the reactions was established. The issues concerning chemo- (ROCM vs ROMP), regio- (1-2- vs 1-3-product formation), and stereo- (E/Z isomerism) selectivity of reactions under various conditions are discussed.

Increased pericardial fat accumulation is associated with increased intramyocardial lipid content and duration of highly active antiretroviral therapy exposure in patients infected with human immunodeficiency virus: a 3T cardiovascular magnetic resonance feasibility study.

Background: The aim of the current study was to examine whether the use of highly active antiretroviral therapy (HAART) in patients with HIV is associated with changes in pericardial fat and myocardial lipid content measured by cardiovascular magnetic resonance (CMR).

Methods: In this prospective case-control study, we compared 27 HIV seropositive (+) male subjects receiving HAART to 22 control male subjects without HIV matched for age, ethnicity and body mass index. All participants underwent CMR imaging for determination of pericardial fat [as volume at the level of the origin of the left main coronary artery (LM) and at the right ventricular free wall] and magnetic resonance spectroscopy (MRS) for evaluation of intramyocardial lipid content (% of fat to water in a single voxel at the interventricular septum).

Myocardial steatosis as a possible mechanistic link between diastolic dysfunction and coronary microvascular dysfunction in women.

Women with coronary microvascular dysfunction (CMD) and no obstructive coronary artery disease (CAD) have increased rates of heart failure with preserved ejection fraction (HFpEF). The mechanisms of HFpEF are not well understood. Ectopic fat deposition in the myocardium, termed myocardial steatosis, is frequently associated with diastolic dysfunction in other metabolic diseases.

Rapid development of cardiac dysfunction in a canine model of insulin resistance and moderate obesity.

Aims/hypothesis: The worldwide incidence of obesity and diabetes continues to rise at an alarming rate. A major cause of the morbidity and mortality associated with obesity and diabetes is heart disease, yet the mechanisms that lead to cardiovascular complications remain unclear.

Methods: We performed cardiac MRI to assess left ventricular morphology and function during the development of moderate obesity and insulin resistance in a well-established canine model (n = 26).

Elevated nocturnal NEFA are an early signal for hyperinsulinaemic compensation during diet-induced insulin resistance in dogs.

Aims/hypothesis: A normal consequence of increased energy intake and insulin resistance is compensatory hyperinsulinaemia through increased insulin secretion and/or reduced insulin clearance. Failure of compensatory mechanisms plays a central role in the pathogenesis of type 2 diabetes mellitus; consequently, it is critical to identify in vivo signal(s) involved in hyperinsulinaemic compensation. We have previously reported that high-fat feeding leads to an increase in nocturnal NEFA concentration.

Incomplete homogenization of chemical recognition labels between Formica sanguinea and Formica rufa ants (Hymenoptera: Formicidae) living in a mixed colony.

Formica sanguinea Latreille (Hymenoptera: Formicidae) is a slave-making species, i.e., it raids colonies of host species and pillages pupae, which are taken to develop into adult workers in a parasite colony.

Increase in visceral fat per se does not induce insulin resistance in the canine model.

Objectives: To determine whether a selective increase of visceral adipose tissue content will result in insulin resistance.

Methods: Sympathetic denervation of the omental fat was performed under general inhalant anesthesia by injecting 6-hydroxydopamine in the omental fat of lean mongrel dogs (n = 11). In the conscious animal, whole-body insulin sensitivity was assessed by the minimal model (SI ) and the euglycemic hyperinsulinemic clamp (SICLAMP ).

Is cardiorespiratory fitness a determinant of cardiomyopathy in the setting of type 2 diabetes?

Objective: The aim of this study was to determine whether high fitness attenuates the defects in left ventricular (LV) structure, function and triglyceride (TG) content in patients with type 2 diabetes mellitus (T2DM).

Materials And Methods: Patients (n = 74) with T2DM and ≥1 additional cardiac risk factor were recruited to participate in this cross-sectional study. Outcome measures of interest were LV structure and function by magnetic resonance imaging (MRI) and myocardial TG content by (1)H-magnetic resonance spectroscopy (MRS).