A tunable gelatin-hyaluronan dialdehyde/methacryloyl gelatin interpenetrating polymer network hydrogel for additive tissue manufacturing.

Methacryloyl gelatin (GelMA) is a versatile material for bioprinting because of its tunable physical properties and inherent bioactivity. Bioprinting of GelMA is often met with challenges such as lower viscosity of GelMA inks due to higher methacryloyl substitution and longer physical gelation time at room temperature. In this study, a tunable interpenetrating polymer network (IPN) hydrogel was prepared from gelatin-hyaluronan dialdehyde (Gel-HDA) Schiff's polymer, and 100% methacrylamide substituted GelMA for biofabrication through extrusion based bioprinting.

The development of a 3D printable chitosan-based copolymer with tunable properties for dentoalveolar regeneration.

Dentoalveolar tissue engineering is an emerging yet challenging field, considering the lack of suitable materials and difficulty to produce patient-specific hydrogel scaffolds. The present paper aims to produce a 3D printable and tuneable biomaterial by copolymerizing a synthesized water-soluble chitosan derivative called maleic anhydride grafted chitosan (MA-C) with gelatin using genipin, a natural crosslinking agent. Development and testing of this material for 3D printing, degradation, and swelling demonstrated the ability to fabricate scaffolds with controlled physical properties based on pre-determined designs.

Limitations in the Assessment of Prosthesis-Patient Mismatch.

Background: Prosthesis-patient mismatch (PPM) after aortic valve replacement (AVR) may affect survival but data are conflicting. It is assessed by relating effective orifice area (EOA) to body surface area (EOAi). EOA is patient-specific as the result of flow-velocity times area at the individual patient's outflow tract levels (LVOT) divided by trans-prosthetic flow velocity.

Increased Protein Tyrosine Phosphatase 1B (PTP1B) Activity and Cardiac Insulin Resistance Precede Mitochondrial and Contractile Dysfunction in Pressure-Overloaded Hearts.

Background: Insulin resistance in diabetes mellitus has been associated with mitochondrial dysfunction. Defects at the level of mitochondria are also characteristic of heart failure. We assessed changes in cardiac insulin response and mitochondrial function in a model of pressure overload-induced heart failure.

GLP-1 Improves Diastolic Function and Survival in Heart Failure with Preserved Ejection Fraction.

Heart failure with preserved ejection fraction (HFpEF) has emerged as a public health burden with currently no effective medication. We assessed the treatment effects of the incretin hormone glucagon-like peptide-1 (GLP-1) on cardiac metabolism and function in a model of HFpEF. Following aortic banding, rats developed HFpEF characterized by diastolic dysfunction, pulmonary congestion, and poor survival (38%).

Percutaneous cannulation for cardiopulmonary bypass in minimally invasive surgery is associated with reduced groin complications.

Objectives: Femoral cutdown is standard in most centres if groin cannulation is used for cardiopulmonary bypass in minimally invasive cardiac surgery (MICS). Arterial closure devices (ACDs) allow placement of larger cannulas percutaneously, but its benefit in MICS is unclear. We assessed our results with percutaneous groin cannulation using ACDs in comparison with conventional surgical access in patients undergoing MICS.

Risk factors for mortality after pericardiectomy for chronic constrictive pericarditis in a large single-centre cohort.

Objectives: Constrictive pericarditis (CP) is an uncommon disease with multiple causes and unclear clinical outcomes. To date, few publications have clearly defined risk factors of poor outcomes after surgery for CP. We performed a retrospective analysis of almost 100 patients undergoing surgical treatment for CP at a single institution in order to identify risk factors for perioperative and long-term mortality.

Triheptanoin Alleviates Ventricular Hypertrophy and Improves Myocardial Glucose Oxidation in Rats With Pressure Overload.

Objective: Cardiac hypertrophy is characterized by changes in substrate utilization and activity of the Krebs cycle. We assessed the effects of triheptanoin, an odd-chain fat that might support the Krebs cycle, on cardiac metabolism and function in a model of cardiac hypertrophy.

Methods And Results: Rats were subjected to aortic banding (AoB) to induce pressure overload (PO).

Novel thoughts on patient-prosthesis mismatch in aortic valve replacement: the rationale for the PAR I trial.

The hemodynamic performance of prosthetic tissue valves is influenced by valve design and valve-specific sizing strategies. Design determines the actual geometric opening area (GOA) of the prosthetic valve and sizing strategy its actual chosen size. Currently, hemodynamic performance is assessed by determining the effective orifice area (EOA; derived from the continuity equation by relating flow velocities with the area of the left ventricular outflow tract [LVOTA]).

Glucagon-like peptide-1 reduces contractile function and fails to boost glucose utilization in normal hearts in the presence of fatty acids.

Unlabelled: GLP-1 and exendin-4, which are used as insulin sensitizers or weight reducing drugs, were shown to improve glucose uptake in the heart. However, the direct effects of GLP-1 or exendin-4 on normal hearts in the presence of fatty acids, the main cardiac substrates, have never been investigated. We therefore assessed the effects of GLP-1 or exendin-4 on myocardial glucose uptake (GU), glucose oxidation (GO) and cardiac performance (CP) under conditions of fatty acid utilization.

Not all porcelain is the same: classification of circular aortic calcifications (porcelain aorta) according to the impact on therapeutic approach.

Severe aortic calcification, also known as "porcelain aorta," has a major impact on patient outcome. Its presence also influences the choice of procedure depending on where it is located. However, to date there is no clear definition on how this term should be employed, being often used as an exclusion criteria for conventional surgery where aortic clamping and/or cannulation is required.

Echocardiography alone allows the determination of heart failure stages in rats with pressure overload.

Background: There is currently no standard for the assessment of contractile function in animals. We aimed to determine whether transthoracic echocardiography in rats with chronic pressure overload allows determining the stage of hypertrophy and heart failure (HF).

Methods: Pressure overload was created by placement of a metal clip around the thoracic aorta at a weight of 40 to 50 g.

Pressure overload differentially affects respiratory capacity in interfibrillar and subsarcolemmal mitochondria.

Years ago a debate arose as to whether two functionally different mitochondrial subpopulations, subsarcolemmal mitochondria (SSM) and interfibrillar mitochondria (IFM), exist in heart muscle. Nowadays potential differences are often ignored. Presumably, SSM are providing ATP for basic cell function, whereas IFM provide energy for the contractile apparatus.

Biphasic response of skeletal muscle mitochondria to chronic cardiac pressure overload - role of respiratory chain complex activity.

Pressure overload induced heart failure affects cardiac mitochondrial function and leads to decreased respiratory capacity during contractile dysfunction. A similar cardiac mitochondrial dysfunction has been demonstrated by studies which induce heart failure through myocardial infarction or pacing. These heart failure models differ in their loading conditions to the heart and show nevertheless the same cardiac mitochondrial changes.

Where is the common sense in aortic valve replacement? A review of hemodynamics and sizing of stented tissue valves.

Heated debates revolve around the hemodynamic performance of stented aortic tissue valves. Because the opening area strongly influences the generation of a pressure gradient over the prosthesis, and the outer diameter determines which valve actually fits into the aortic root, it would seem logical that the valve with the greatest opening area in relation to its outer diameter should allow the best hemodynamic performance. Interestingly, neither of these 2 parameters is reflected by the manufacturing companies' size labels or suggested sizing strategies.

Myocardial infarction in rats causes partial impairment in insulin response associated with reduced fatty acid oxidation and mitochondrial gene expression.

Objective: Myocardial infarction leads to contractile dysfunction. In patients with diabetes, impaired contractility has been associated with the loss of insulin effects and mitochondrial dysfunction. We assessed cardiac insulin sensitivity and mitochondrial and contractile function in rats after ligation of the left coronary artery.

Proteomic remodelling of mitochondrial oxidative pathways in pressure overload-induced heart failure.

Aims: Impairment in mitochondrial energetics is a common observation in animal models of heart failure, the underlying mechanisms of which remain incompletely understood. It was our objective to investigate whether changes in mitochondrial protein levels may explain impairment in mitochondrial oxidative capacity in pressure overload-induced heart failure.

Methods And Results: Twenty weeks following aortic constriction, Sprague-Dawley rats developed contractile dysfunction with clinical signs of heart failure.

Clinical follow-up of a pregnant woman with cor triatriatum.

Cor triatriatum (CT) is a rare congenital cardiac anomaly that usually becomes symptomatic in the first years of life. If the condition is not associated with other cardiac defects, and depending on the degree of communication between the upper chamber and left atrium (LA), patients may reach adulthood. We report a case of an asymptomatic, adult, female patient with CT diagnosed by transthoracic echocardiogram (TTE) and followed-up during pregnancy.