Characterisation of global and regional mitral annular strains in an acute porcine model.

Objectives: This study aimed to explore regional mitral annular strain using a novel computational method.

Methods: Eight pigs underwent implantation with piezoelectric transducers around the mitral annulus. Interventions of pre- and afterload were performed by inferior vena cava constriction and endovascular balloon occlusion of the descending aorta.

Mitral annular dynamics are influenced by left ventricular load and contractility in an acute animal model.

The purpose of this study was to investigate the effects of loading conditions and left ventricular (LV) contractility on mitral annular dynamics. In 10 anesthetized pigs, eight piezoelectric transducers were implanted equidistantly around the mitral annulus. High-fidelity catheters measured left ventricular pressures and the slope of the end-systolic pressure-volume relationship (E ) determined LV contractility.

Left ventricular venting during extracorporeal membrane oxygenation; the effects on cardiac performance in a porcine model of critical post-cardiotomy failure.

Introduction: Left ventricular distension is a major concern with postcardiotomy veno-arterial extracorporeal membrane oxygenation (VA-ECMO) supporting a critical heart failure after cardiac surgery. This porcine study evaluates the effects of left ventricular venting on cardiac function during ECMO-supported circulation and after weaning from ECMO.

Methods: Twenty anaesthetised open-chest pigs were put on cardiopulmonary bypass with aortic cross-clamping and suboptimal cardioplegic arrest for 40 min.

Effects of Add-On Left Ventricular Assist Device to Extracorporeal Membrane Oxygenation During Refractory Cardiac Arrest in a Porcine Model.

This study evaluated the effects of extracorporeal membrane oxygenation (ECMO) in combination with a percutaneous adjunctive left ventricular assist device (LVAD) in a porcine model during 60 minutes of refractory cardiac arrest (CA). Twenty-four anesthetized swine were randomly allocated into three groups given different modes of circulatory assist: group 1: ECMO 72 ml/kg/min and LVAD; group 2: ECMO 36 ml/kg/min and LVAD; and group 3: ECMO 72 ml/kg/min. During CA and extracorporeal cardiopulmonary resuscitation (ECPR), mean left ventricular pressure (mLVP) was lower in group 1 (p = 0.

Balanced Biventricular Assist Versus Extracorporeal Membrane Oxygenation in Cardiac Arrest.

Mechanical assist devices in refractory cardiac arrest are increasingly employed. We compared the hemodynamics and organ perfusion during cardiac arrest with either veno-arterial extracorporeal membrane oxygenation (ECMO) or biventricular assisted circulation combining left- and right-sided impeller devices (BiPella) in an acute experimental setting. Twenty pigs were randomized in two equal groups receiving circulatory support either by ECMO or by BiPella during 40 minutes of ventricular fibrillation (VF) followed by three attempts of cardioversion, and if successful, 60 minute observation with spontaneous, unsupported circulation.

An experimental study on intraoperative recovery of recurrent laryngeal nerve function.

Objective: If bilateral thyroid surgery is planned and staged thyroidectomy considered in case of loss of neuromonitoring signal (LOS), a waiting time of 20 minutes is suggested for evaluation of early nerve recovery. This recommendation is based on clinical observations and has not been thoroughly validated experimentally.

Methods: Sixteen pigs were randomly studied, and electromyogram (EMG) was continuously recorded during traction injury until an amplitude decrease of 70% from baseline (BL) (16 nerves) or LOS (16 nerves), and further during 40-minute recovery time.

Myocardial perfusion and cardiac dimensions during extracorporeal membrane oxygenation-supported circulation in a porcine model of critical post-cardiotomy failure.

Introduction: Venoarterial extracorporeal membrane oxygenation is widely used as mechanical circulatory support for severe heart failure. A major concern with this treatment modality is left ventricular distension due to inability to overcome the afterload created by the extracorporeal membrane oxygenation circuit. The present porcine study evaluates coronary circulation, myocardial perfusion and ventricular distension during venoarterial extracorporeal membrane oxygenation.

Vocal cord function during recurrent laryngeal nerve injury assessed by accelerometry and EMG.

Objective: Gradual impairment of nerve conduction is expected to be tightly associated with simultaneous gradual loss of vocal cord contractility, related to the fact that injured axons are connected to a defined number of muscle cells. In clinical studies, there is a time gap between observed adverse electromyographic (EMG) changes and examination of vocal cord function. This study evaluates the impact of intraoperative EMG changes on synchronous vocal cord contractility by simultaneous use of continuous intraoperative neuromonitoring (C-IONM) and accelerometry for registration of actual vocal cord function at a given change of EMG amplitude.

Left ventricular dysfunction after two hours of polarizing or depolarizing cardioplegic arrest in a porcine model.

Introduction: This experimental study compares myocardial function after prolonged arrest by St. Thomas' Hospital polarizing cardioplegic solution (esmolol, adenosine, Mg) with depolarizing (hyperkalaemic) St. Thomas' Hospital No 2, both administered as cold oxygenated blood cardioplegia.

Injury mechanisms and electromyographic changes after injury of the recurrent laryngeal nerve: Experiments in a porcine model.

Background: Recurrent laryngeal nerve (RLN) injury during surgery may reveal differences in electromyographic (EMG) changes after sustained compression or traction.

Methods: In 20 pigs with the NIM-FLEX EMG-endotracheal tube, EMG was recorded at baseline, during sustained RLN compression, or traction until 70% amplitude decrease and during 30 minutes of recovery.

Results: Seventy percent amplitude decrease from baseline was reached after 110 ± 98 seconds (compression group) and 2034 ± 2108 seconds (traction group).

Microvascular fluid exchange during CPB with deep hypothermia circulatory arrest or low flow.

Objective: Use of deep hypothermic low-flow (DHLF) cardiopulmonary bypass (CPB) has been associated with higher fluid loading than the use of deep hypothermia circulatory arrest (DHCA). We evaluated whether these perfusion strategies influenced fluid extravasation rates and edema generation differently per-operatively.

Materials And Methods: Twelve anesthetized pigs, randomly allocated to DHLF (n = 6) or DHCA (n = 6), underwent 2.

Myocardial energy metabolism and ultrastructure with polarizing and depolarizing cardioplegia in a porcine model.

Objectives: This study investigated whether the novel St. Thomas' Hospital polarizing cardioplegic solution (STH-POL) with esmolol/adenosine/magnesium offers improved myocardial protection by reducing demands for high-energy phosphates during cardiac arrest compared to the depolarizing St. Thomas' Hospital cardioplegic solution No 2 (STH-2).

The influence of acute unloading on left ventricular strain and strain rate by speckle tracking echocardiography in a porcine model.

Noninvasive measurements of myocardial strain and strain rate by speckle tracking echocardiography correlate to cardiac contractile state but also to load, which may weaken their value as indices of inotropy. In a porcine model, we investigated the influence of acute dynamic preload reductions on left ventricular strain and strain rate and their relation to the pressure-conductance catheter-derived preload recruitable stroke work (PRSW) and peak positive first derivative of left ventricular pressure (LV-dP/dtmax). Speckle tracking strain and strain rate in the longitudinal, circumferential, and radial directions were measured during acute dynamic reductions of end-diastolic volume during three different myocardial inotropic states.

Myocardial function after polarizing versus depolarizing cardiac arrest with blood cardioplegia in a porcine model of cardiopulmonary bypass.

Objectives: Potassium-based depolarizing St Thomas' Hospital cardioplegic solution No 2 administered as intermittent, oxygenated blood is considered as a gold standard for myocardial protection during cardiac surgery. However, the alternative concept of polarizing arrest may have beneficial protective effects. We hypothesize that polarized arrest with esmolol/adenosine/magnesium (St Thomas' Hospital Polarizing cardioplegic solution) in cold, intermittent oxygenated blood offers comparable myocardial protection in a clinically relevant animal model.

Haemodynamic differences between pancuronium and vecuronium in an experimental pig model.

Objective: To compare baseline cardiovascular function in anesthetised pigs using either pancuronium or vecuronium as a neuromuscular blocker.

Study Design: Retrospective, non-randomized comparison.

Animals: Norwegian Land Race pigs (Sus scrofa domesticus) weighing mean 42 ± SD 3 kg.

DNA methylation of the CYP1A1 enhancer is associated with smoking-induced genetic alterations in human lung.

CYP1A1 (cytochrome P4501A1) catalyze the conversion of polycyclic aromatic hydrocarbons into reactive metabolites, which may induce DNA damage. We hypothesized that DNA methylation of the CYP1A1 enhancer could be involved in inter-individual differences in mRNA levels of CYP1A1 or affect the smoking-induced DNA damage in human lung. Using DNA bisulfite conversion and pyrosequencing, we show that DNA methylation of the CYP1A1 enhancer is affected by smoking.

Antiapoptotic intervention in repeated blood cardioplegia: a porcine study of myocardial function.

Background: Lethal reperfusion injury has been associated with apoptotic cell death. Insulin and insulin-like growth factors (IGF-I/IGF-II) may modulate this cell death when administered at the onset of reperfusion after ischemia. We explored if antiapoptotic treatment with IGF-II could influence left ventricular function in an experimental model with cardiopulmonary bypass and repeated oxygenated blood cardioplegia.

A specific interleukin-1B haplotype correlates with high levels of IL1B mRNA in the lung and increased risk of non-small cell lung cancer.

Epidemiological evidence suggests a relationship between chronic inflammation and lung cancer. Inflammation in the lung may be modulated by host genetic factors such as polymorphisms in inflammatory genes. Identification of polymorphisms in inflammatory genes may help understanding interindividual differences in susceptibility to lung cancer.

A comprehensive analysis of phase I and phase II metabolism gene polymorphisms and risk of non-small cell lung cancer in smokers.

Lung cancer is a leading cause of cancer mortality worldwide with smoking and occupational exposure to carcinogenic compounds as the major risk factors. Susceptibility to lung cancer is affected by existence of polymorphic genes controlling the levels of metabolic activation and detoxification of carcinogens. We have investigated 105 single nucleotide polymorphisms (SNPs) in 31 genes from the phase I and phase II metabolism genes and antioxidant defense genes for association with the risk of non-small cell lung cancer (NSCLC) in a Norwegian population-based study.

Frequency of TP53 mutations in relation to Arg72Pro genotypes in non small cell lung cancer.

Mutations in the TP53 gene are important events during human lung carcinogenesis. The TP53 gene harbors several polymorphisms, and functional studies have shown that the Arg72Pro polymorphism alters both wild-type and mutant p53 protein activity. Thus, we hypothesized that certain Arg72Pro genotypes may influence the frequency and pattern of somatic mutations in TP53.

Sex differences in risk of lung cancer: Expression of genes in the PAH bioactivation pathway in relation to smoking and bulky DNA adducts.

It is controversial whether women have a higher lung cancer susceptibility compared to men. We previously reported higher levels of smoking-related bulky DNA adducts in female lungs. In a pilot study (27 cases), we also found a higher level of female lung cytochrome P4501A1 (CYP1A1) gene expression.

Polymorphisms of DNA repair genes and risk of non-small cell lung cancer.

Lung cancer is a leading cause of cancer mortality with an inter-individual difference in susceptibility to the disease. The inheritance of low-efficiency genotypes involved in DNA repair and replication may contribute to the difference in susceptibility. We investigated 44 single nucleotide polymorphisms (SNPs) in 20 DNA repair genes including nucleotide excision repair (NER) genes XPA, ERCC1, ERCC2/XPD, ERCC4/XPF and ERCC5/XPG; base excision repair (BER) genes APE1/APEX, OGG1, MPG, XRCC1, PCNA, POLB, POLiota, LIG3 and EXO1; double-strand break repair (DSB-R) genes XRCC2, XRCC3, XRCC9, NBS1 and ATR; and direct damage reversal (DR) gene MGMT/AGT.

The female gender has a positive effect on survival independent of background life expectancy following surgical resection of primary non-small cell lung cancer: a study of absolute and relative survival over 15 years.

Surgical resection is the treatment of choice for non-advanced lung cancer, but is encumbered with an overall relative poor long time prognosis. The purpose of this study was to examine if long time survival for patients operated for non-small cell lung cancer have changed over a 15 years period. We retrospectively studied hospital records of the 351 patients operated, with the intention to cure, for a primary non-small cell carcinoma (NSCLC) in our department between 1 January 1988 and 31 December 2002.