Identification of over- and undertreatment in the Dutch national cervical cancer screening program: A data linkage study at the hospital level.

Research into the quality of cancer screening programs often lacks the perspective of clinicians, missing insights into the performance of individual hospitals. This retrospective cohort study aimed to identify guideline deviation (specifically, overtreatment and undertreatment) related to the cervical cancer screening program in Dutch hospitals by deterministically linking nationwide insurance data with pathology data for cervical intraepithelial neoplasia (CIN). We then constructed quality indicators using the Dutch CIN guideline and National Health Care Institute recommendations to assess compliance with CIN management, treatment outcomes, and follow-up, using an empirical Bayes shrinkage model to correct for case-mix variation and hospitals with few observations.

Disparities in cancer-related healthcare among people with intellectual disabilities: A population-based cohort study with health insurance claims data.

Background: Concerns have been raised about the accessibility and quality of cancer-related care for people with intellectual disabilities (ID). However, there is limited insight into cancer incidence and the utilization of cancer care at the ID population level to inform targeted cancer control strategies. Therefore, we aimed to examine differences in the utilization of cancer-related care between people with and without ID, identified through diagnostic codes on health insurance claims.

Data on uncoupling protein-3 levels, hypoxia, low flow ischemia, and insulin stimulation in dystrophin-deficient mouse hearts.

The data contain body weights, plasma free fatty acids concentrations and cardiac uncoupling protein-3 protein levels for wild-type and mice. The data provide heart rates, left ventricular contractile functions, coronary flow, phosphocreatine concentrations, and adenosine 5'-triphosphate (ATP) concentrations throughout hypoxia in mouse hearts. This data article also provides left ventricular contractile functions after low flow ischemia with and without glucose, glycogen levels before ischemia or hypoxia, glucose uptake rates during low flow ischemia and insulin stimulation, and insulin-stimulated phospho-Akt protein levels, a protein in insulin signaling, in mouse hearts.

Data on triiodothyronine treated peroxisome proliferator-activated receptor-alpha-null mouse hearts using magnetic resonance imaging and magnetic resonance spectroscopy.

This data contain left ventricular end-diastolic volumes, end-systolic volumes, stroke volumes, ejection fractions, cardiac outputs, heart rates, phosphocreatine concentrations, adenosine 5'-triphosphate (ATP) concentrations, total creatine concentrations, citrate synthase activities and heart weights for wild-type and peroxisome proliferator-activated receptor-alpha-null mouse hearts without and with triiodothyronine treatment.

Impaired cardiac contractile function in arginine:glycine amidinotransferase knockout mice devoid of creatine is rescued by homoarginine but not creatine.

Aims: Creatine buffers cellular adenosine triphosphate (ATP) via the creatine kinase reaction. Creatine levels are reduced in heart failure, but their contribution to pathophysiology is unclear. Arginine:glycine amidinotransferase (AGAT) in the kidney catalyses both the first step in creatine biosynthesis as well as homoarginine (HA) synthesis.

Living without creatine: unchanged exercise capacity and response to chronic myocardial infarction in creatine-deficient mice.

Rationale: Creatine is thought to be involved in the spatial and temporal buffering of ATP in energetic organs such as heart and skeletal muscle. Creatine depletion affects force generation during maximal stimulation, while reduced levels of myocardial creatine are a hallmark of the failing heart, leading to the widely held view that creatine is important at high workloads and under conditions of pathological stress.

Objective: We therefore hypothesised that the consequences of creatine-deficiency in mice would be impaired running capacity, and exacerbation of heart failure following myocardial infarction.

Moderate elevation of intracellular creatine by targeting the creatine transporter protects mice from acute myocardial infarction.

Aims: Increasing energy storage capacity by elevating creatine and phosphocreatine (PCr) levels to increase ATP availability is an attractive concept for protecting against ischaemia and heart failure. However, testing this hypothesis has not been possible since oral creatine supplementation is ineffectual at elevating myocardial creatine levels. We therefore used mice overexpressing creatine transporter in the heart (CrT-OE) to test for the first time whether elevated creatine is beneficial in clinically relevant disease models of heart failure and ischaemia/reperfusion (I/R) injury.

MR spectroscopy in heart failure.

Magnetic resonance spectroscopy (MRS) is an established technique for the non-invasive assessment of myocardial metabolism. MRS is ideal for the evaluation of heart failure, as it allows quantification of the primary energy source for all myocardial cellular functions (ATP), the energy reserve phosphocreatine (PCr), and the creatine kinase reaction, which maintains cellular energy equilibrium. PCr forms the primary ATP buffer in the cell via the creatine kinase (CK) reaction and is involved in transporting the chemical energy from the ATP-producing mitochondria to the ATP-consuming contractile proteins.

Evaluation of infarcted murine heart function: comparison of prospectively triggered with self-gated MRI.

Measurement of cardiac function is often performed in mice after, for example, a myocardial infarction. Cardiac MRI is often used because it is noninvasive and provides high temporal and spatial resolution for the left and right ventricle. In animal cardiac MRI, the quality of the required electrocardiogram signal is variable and sometimes deteriorates over time, especially with infarcted hearts or cardiac hypertrophy.

Changes in creatine transporter function during cardiac maturation in the rat.

Background: It is well established that the immature myocardium preferentially utilises non-oxidative energy-generating pathways. It exhibits low energy-transfer capacity via the creatine kinase (CK) shuttle, reflected in phosphocreatine (PCr), total creatine and CK levels that are much lower than those of adult myocardium. The mechanisms leading to gradually increasing energy transfer capacity during maturation are poorly understood.

Characterization and in vitro and in vivo testing of CB2-receptor- and NGAL-targeted paramagnetic micelles for molecular MRI of vulnerable atherosclerotic plaque.

Purpose: Atherosclerotic plaque macrophages express the peripheral cannabinoid receptor (CB2-R) and promote fibrous cap degradation by secretion of neutrophil gelatinase-associated lipocalin 2 (NGAL). In this study, we report the preparation, characterization, and in vitro and in vivo testing of double-labeled (MR and fluorescent) CB2-R- and NGAL-targeted micelles.

Procedures/results: Specific CB2-R agonists or antibodies directed to 24p3 (mouse homolog of NGAL) were incorporated into di-oleoyl-polyethylene glycol-phosphatidylethanolamine 1000 (DOPE-PEG1000) micelles or di-stearoyl-polyethylene glycol-phosphatidylethanolamine 2000 (DSPE-PEG2000) micelles.

Negative MR contrast caused by USPIO uptake in lymph nodes may lead to false positive observations with in vivo visualization of murine atherosclerotic plaque.

Objective: USPIOs are used clinically as contrast agent for magnetic resonance imaging (MRI) of lymph nodes, and in research settings for MRI of macrophages in atherosclerotic lesions. However, T2* weighted (T2*w) imaging can lead to "blooming" with overestimation of the area occupied by USPIOs. In this study, plaque uptake of USPIOs in atherosclerotic mice was investigated in the presence and absence of circulating monocytes.

Mice over-expressing the myocardial creatine transporter develop progressive heart failure and show decreased glycolytic capacity.

The metabolic phenotype of the failing heart includes a decrease in phosphocreatine and total creatine concentration [Cr], potentially contributing to contractile dysfunction. Surprisingly, in 32- week-old mice over-expressing the myocardial creatine transporter (CrT-OE), we previously demonstrated that elevated [Cr] correlates with left ventricular (LV) hypertrophy and failure. The aim of this study was to determine the temporal relationship between elevated [Cr] and the onset of cardiac dysfunction and to screen for potential molecular mechanisms.

Abnormal cardiac morphology, function and energy metabolism in the dystrophic mdx mouse: an MRI and MRS study.

Patients with muscular dystrophy have abnormal cardiac function and decreased high-energy phosphate metabolism. Here, we have determined whether the 8 month old mdx mouse, an animal model of muscular dystrophy, also has abnormal cardiac function and energetics. In vivo cardiac MRI revealed 33% and 104% larger right ventricular end-diastolic and end-systolic volumes, respectively, and 17% lower right ventricular ejection fractions in mdx mice compared with controls.

The application of NMR spectroscopy for the study of heart failure.

Magnetic resonance spectroscopy (MRS) has been used for several decades to examine the biochemistry of the myocardium in a non destructive manner. (31)P MRS, in particular, has been used to study heart failure. (31)P MRS allows for the detection of adenosine triphosphate (ATP), the primary energy source for all energy consuming processes in cardiomyocytes, and phosphocreatine (PCr).

Creatine uptake in mouse hearts with genetically altered creatine levels.

Creatine plays an important role in energy metabolism in the heart. Cardiomyocytes accumulate creatine via a specific creatine transporter (CrT), the capacity of which is reduced in the failing heart, resulting in lower myocardial creatine concentration. Therefore, to gain insight into how the CrT is regulated, we studied two mouse models of severely altered myocardial creatine levels.

Cardiac structure and function during ageing in energetically compromised Guanidinoacetate N-methyltransferase (GAMT)-knockout mice - a one year longitudinal MRI study.

Background: High-resolution magnetic resonance imaging (cine-MRI) is well suited for determining global cardiac function longitudinally in genetically or surgically manipulated mice, but in practice it is seldom used to its full potential. In this study, male and female guanidinoacetate N-methyltransferase (GAMT) knockout, and wild type littermate mice were subjected to a longitudinal cine-MRI study at four time points over the course of one year. GAMT is an essential enzyme in creatine biosynthesis, such that GAMT deficient mice are entirely creatine-free.

The creatine kinase energy transport system in the failing mouse heart.

Characteristic alterations of the creatine kinase (CK) system occur in heart failure and may contribute to contractile dysfunction. We examined two mouse models of chronic cardiac stress, transverse aortic constriction (TAC) and coronary artery ligation (CAL), and examined the relationship of CK system changes with hypertrophy and heart failure development. C57Bl/6 mice were subjected to TAC or sham surgery and sacrificed after 2-10 weeks according to echocardiographic criteria of myocardial hypertrophy and function to create four groups representing progressive dysfunction from normal, through compensated hypertrophy, to heart failure.

MR spectroscopy in heart failure--clinical and experimental findings.

Magnetic resonance spectroscopy (MRS) allows for the non-invasive detection of a wide variety of metabolites in the heart. To study the metabolic changes that occur in heart failure, (31)P- and (1)H-MRS have been applied in both patients and experimental animal studies. (31)P-MRS allows for the detection of phosphocreatine (PCr), ATP, inorganic phosphate (Pi) and intracellular pH, while (1)H-MRS allows for the detection of total creatine.

Combined blockade of the Na+ channel and the Na+/H+ exchanger virtually prevents ischemic Na+ overload in rat hearts.

Blocking either the Na(+) channel or the Na(+)/H(+) exchanger (NHE) has been shown to reduce Na(+) and Ca(2+) overload during myocardial ischemia and reperfusion, respectively, and to improve post-ischemic contractile recovery. The effect of combined blockade of both Na(+) influx routes on ionic homeostasis is unknown and was tested in this study. [Na(+)](i), pH(i) and energy-related phosphates were measured using simultaneous (23)Na- and (31)P-NMR spectroscopy in isolated rat hearts.

Supranormal myocardial creatine and phosphocreatine concentrations lead to cardiac hypertrophy and heart failure: insights from creatine transporter-overexpressing transgenic mice.

Background: Heart failure is associated with deranged cardiac energy metabolism, including reductions of creatine and phosphocreatine. Interventions that increase myocardial high-energy phosphate stores have been proposed as a strategy for treatment of heart failure. Previously, it has not been possible to increase myocardial creatine and phosphocreatine concentrations to supranormal levels because they are subject to tight regulation by the sarcolemmal creatine transporter (CrT).

Serial high resolution 3D-MRI after aortic banding in mice: band internalization is a source of variability in the hypertrophic response.

Transverse aortic constriction (TAC) is used as a model of left ventricular hypertrophy and failure; however, there is extensive variability in the hypertrophic response. In 43 mice that underwent TAC with a 7-0 polypropylene suture, 13 were identified by echocardiography with initial LV hypertrophy that halted or regressed over time. Post-mortem examination on 7 of these mice found the constricting band to be intact, but partially internalized into the aortic lumen, allowing blood flow around the stenosis.

Reduced inotropic reserve and increased susceptibility to cardiac ischemia/reperfusion injury in phosphocreatine-deficient guanidinoacetate-N-methyltransferase-knockout mice.

Background: The role of the creatine kinase (CK)/phosphocreatine (PCr) energy buffer and transport system in heart remains unclear. Guanidinoacetate-N-methyltransferase-knockout (GAMT-/-) mice represent a new model of profoundly altered cardiac energetics, showing undetectable levels of PCr and creatine and accumulation of the precursor (phospho-)guanidinoacetate (P-GA). To characterize the role of a substantially impaired CK/PCr system in heart, we studied the cardiac phenotype of wild-type (WT) and GAMT-/- mice.

Mechanisms of creatine depletion in chronically failing rat heart.

The failing myocardium is characterised by energetic imbalance, reflected by reduced phosphocreatine and creatine content. These changes may contribute to cardiac dysfunction, yet mechanisms of creatine and phosphocreatine depletion are poorly understood. Creatine is taken up by the heart via the creatine transporter.

Long-term stability of cardiac function in normal and chronically failing mouse hearts in a vertical-bore MR system.

We previously demonstrated stability of ventricular volumes and cardiac function in normal and in chronically failing mouse hearts in MR systems with a vertical-bore magnet for up to 1 h. However, in order to exploit the benefits of an increased magnetic field strength of these MR systems in more time-consuming studies required by, for example MR spectroscopy, we investigated whether cardiac function and ventricular volumes of healthy and infarcted mice would be affected in vertical position over a prolonged period. We applied high-resolution MR cine imaging on an 11.