Incidence and outcome of prosthetic valve endocarditis after transcatheter aortic valve replacement in the Netherlands.

BACKGROUND: Transcatheter aortic valve replacement (TAVR) is increasingly being used as an alternative to conventional surgical valve replacement. Prosthetic valve endocarditis (PVE) is a rare but feared complication after TAVR, with reported first-year incidences varying from 0.57 to 3.1%. This study was performed to gain insight into the incidence and outcome of PVE after TAVR in the Netherlands. METHODS: A multicentre retrospective registry study was performed. All patients who underwent TAVR in the period 2010-2017 were screened for the diagnosis of infective endocarditis in the insurance database and checked for the presence of PVE before analysis of general characteristics, PVE parameters and outcome. RESULTS: A total of 3968 patients who underwent TAVR were screened for PVE. During a median follow-up of 33.5 months (interquartile range (IQR) 22.8-45.8), 16 patients suffered from PVE (0.4%), with a median time to onset of 177 days (IQR 67.8-721.3). First-year incidence was 0.24%, and the overall incidence rate was 0.14 events per 1000 person-years. Overall mortality during follow-up in our study was 31%, of which 25% occurred in hospital. All patients were treated conservatively with intravenous antibiotics alone, and none underwent a re-intervention. Other complications of PVE occurred in 5 patients (31%) and included aortic abscess (2), decompensated heart failure (2) and cerebral embolisation (1). CONCLUSION: PVE in patients receiving TAVR is a relatively rare complication and has a high mortality rate.

Arcuate nucleus neuropeptide coexpression and connections to gonadotrophin-releasing hormone neurones in the female rhesus macaque.

The underlying hypothalamic neurocircuitry by which metabolism and feeding regulates reproductive function has been well-studied in the rodent; however, recent data have demonstrated significant neuroanatomical differences in the human brain. The present study had three objectives, centred on arcuate nucleus neuropeptides regulating feeding and reproduction: (i) to characterise coexpression patterns in the female nonhuman primate; (ii) to establish whether these neuronal populations make potential contacts with gonadotophin-releasing hormone (GnRH) neurones; and (iii) to determine whether these contacts differ between the low and high GnRH-releasing states of pre-puberty and adulthood, respectively. Female nonhuman primates have several coexpression patterns of hypothalamic neuropeptides that differ from those reported in rodents. Cocaine- and amphetamine-regulated transcript (CART) is not coexpressed with pro-opiomelanocortin but instead with neuropeptide Y (NPY). CART is also expressed in a subpopulation of kisspeptin cells in the nonhuman primate, similar to observations in humans but diverging from findings in rodents. Very few GnRH-expressing neurones received close appositions from double-labelled kisspeptin/CART fibres; however, both single-labelled kisspeptin and CART fibres were in frequent apposition with GnRH neurones, with no differences between prepubertal and adult animals. NPY/agouti-related peptide (AgRP) coexpressing fibres contacted significantly more GnRH neurones in prepubertal animals than adults, consistent with increased NPY and AgRP mRNA observed in prepubertal animals. The findings of the present study detail significant differences in arcuate nucleus neuropeptide coexpression in the monkey compared to the rodent and are consistent with the hypothesis that arcuate nucleus NPY/AgRP neurones play an inhibitory role in controlling GnRH neuronal regulation in the prepubertal primate.

Perpetuating effects of androgen deficiency on insulin resistance.

BACKGROUND/OBJECTIVES: Androgen deprivation therapy (ADT) is commonly used for treatment of prostate cancer but is associated with side effects, such as sarcopenia and insulin resistance. The role of lifestyle factors such as diet and exercise on insulin sensitivity and body composition in testosterone-deficient males is poorly understood. The aim of the present study was to examine the relationships between androgen status, diet and insulin sensitivity. SUBJECTS/METHODS: Middle-aged (11-12 years old) intact and orchidectomized male rhesus macaques were maintained for 2 months on a standard chow diet and then exposed for 6 months to a Western-style, high-fat/calorie-dense diet (WSD) followed by 4 months of caloric restriction (CR). Body composition, insulin sensitivity, physical activity, serum cytokine levels and adipose biopsies were evaluated before and after each dietary intervention. RESULTS: Both intact and orchidectomized animals gained similar proportions of body fat, developed visceral and subcutaneous adipocyte hypertrophy and became insulin resistant in response to the WSD. CR reduced body fat in both groups but reversed insulin resistance only in intact animals. Orchidectomized animals displayed progressive sarcopenia, which persisted after the switch to CR. Androgen deficiency was associated with increased levels of interleukin-6 and macrophage-derived chemokine (C-C motif chemokine ligand 22), both of which were elevated during CR. Physical activity levels showed a negative correlation with body fat and insulin sensitivity. CONCLUSIONS: Androgen deficiency exacerbated the negative metabolic side effects of the WSD such that CR alone was not sufficient to improve altered insulin sensitivity, suggesting that ADT patients will require additional interventions to reverse insulin resistance and sarcopenia.

Vasoconstrictor eicosanoids and impaired microvascular function in inactive and insulin-resistant primates.

The inability to augment capillary blood volume (CBV) in response to insulin or glucose is thought to contribute to insulin resistance (IR) by limiting glucose uptake in key storage sites. Understanding the mechanisms that contribute to impaired CBV augmentation early in the onset of IR may lead to new future therapies. We hypothesized that inactivity alters the balance of vasoactive eicosanoids and contributes to microvascular IR. In ten activity-restricted (AR) and six normal activity adult male rhesus macaques, contrast-enhanced ultrasound of skeletal muscle blood flow and CBV was performed at baseline and during intravenous glucose tolerance test (IVGTT). Plasma was analyzed for vasoconstrictor hydroxyeicosatetraenoic acids (HETEs) and the ratio of vasodilatory epoxyeicosatrienoic acids (EETs) to their less biologically active dihydroxyeicosatrienoic acids (DHETs) as an indirect measure of soluble epoxide hydrolase activity. AR primates were IR during IVGTT and had a 45% lower glucose-stimulated CBV response. Vasoconstrictor 18-HETE and 19-HETE and the DHET/EET ratio were markedly elevated in the AR group and correlated inversely with the CBV response. In addition, levels of 18-HETE and 19-HETE correlated directly with microvascular IR. We conclude that a shift toward increased eicosanoid vasoconstrictor tone correlates with abnormal skeletal muscle vascular recruitment and may contribute to IR.

Effect of dipyridamole on myocardial reperfusion injury: A double-blind randomized controlled trial in patients undergoing elective coronary artery bypass surgery.

Dipyridamole reduces reperfusion-injury in preclinical trials and may be beneficial in patients undergoing coronary angioplasty, but its effect on patients undergoing coronary artery bypass grafting (CABG) is unknown. We hypothesized that dipyridamole limits myocardial reperfusion-injury in patients undergoing CABG. The trial design was a double-blind trial randomizing between pretreatment with dipyridamole or placebo. In all, 94 patients undergoing elective on-pump CABG were recruited between February 2010 and June 2012. The primary endpoint was plasma high-sensitive (hs-) troponin-I at 6, 12, and 24 hours after reperfusion. Secondary endpoints were the occurrence of bleeding, arrhythmias, need for inotropic support, and intensive care unit length of stay. Finally, 79 patients (33 dipyridamole) were included in the per-protocol analysis. Dipyridamole did not significantly affect postoperative hs-troponin-I (change in plasma hs-troponin I -3% [95% confidence interval -23% to 36%]; P > 0.1). Secondary endpoints did not differ between groups. Dipyridamole prior to CABG does not significantly reduce postoperative hs-troponin release.

Increased fibroblast growth factor 21 expression in high-fat diet-sensitive non-human primates (Macaca mulatta).

OBJECTIVE: Fibroblast growth factor 21 (FGF21) is a metabolic regulator of glucose and lipid metabolism. The physiological role of FGF21 is not yet fully elucidated, however, administration of FGF21 lowers blood glucose in diabetic animals. Moreover, increased levels of FGF21 are found in obese and diabetic rodents and humans compared with lean/non-diabetic controls. METHODS: Adult male rhesus macaque monkeys were chronically maintained on a high-fat diet (HFD) or a standard diet (control, CTR). Plasma levels of FGF21, triglycerides and cholesterol were measured and body weight was record. Glucose-stimulated insulin secretion (GSIS) and glucose clearance was determined during an intravenous glucose tolerance test. Furthermore, expression of FGF21 and its receptors were determined in liver, pancreas, three white adipose tissues (WATs) and two skeletal muscles. RESULTS: A cohort of the high-fat fed monkeys responded to the HFD with increasing body weight, plasma lipids, total cholesterol, GSIS and decreased glucose tolerance. These monkeys were termed HFD sensitive. Another cohort of monkeys did not become obese and maintained normal insulin sensitivity. These animals were defined as HFD resistant. Plasma FGF21 levels were significantly increased in all HFD fed monkeys compared with the CTR group. The HFD-sensitive monkeys showed a significant increase in FGF21 mRNA expression in all examined tissues compared with CTR, whereas FGF21 expression in the HFD-resistant group was only increased in the liver, pancreas and the retroperitoneal WAT. In the WAT, the co-receptor ß-klotho was downregulated in the HFD-sensitive monkeys compared with the HFD-resistant group. CONCLUSION: This study demonstrates that HFD changes FGF21 and FGF21 receptor expression in a tissue-specific manner in rhesus monkeys; differential regulation is moreover observed between HFD-sensitive and -resistant monkeys. Monkeys that maintain normal levels of the FGF21 co-receptor ß-klotho in the WAT on HFD were protected toward development of dyslipidemia and hyperglycemia.

Antithrombotic therapy in patients undergoing TAVI: an overview of Dutch hospitals.

PURPOSE: To assess current antithrombotic treatment strategies in the Netherlands in patients undergoing transcatheter aortic valve implantation (TAVI). METHODS: For every Dutch hospital performing TAVI (n = 14) an interventional cardiologist experienced in performing TAVI was interviewed concerning heparin, aspirin, thienopyridine and oral anticoagulation treatment in patients undergoing TAVI. RESULTS: The response rate was 100 %. In every centre, a protocol for antithrombotic treatment after TAVI was available. Aspirin was prescribed in all centres, concomitant clopidogrel was prescribed 13 of the 14 centres. Duration of concomitant clopidogrel was 3 months in over two-thirds of cases. In 2 centres, duration of concomitant clopidogrel was based upon type of prosthesis: 6 months versus 3 months for supra-annular and intra-annular prostheses, respectively. CONCLUSIONS: Leaning on a small basis of evidence and recommendations, the antithrombotic policy for patients undergoing TAVI is highly variable in the Netherlands. As a standardised regimen might further reduce haemorrhagic complications, large randomised clinical trials may help to establish the most appropriate approach.

Plasma sphingolipids are biomarkers of metabolic syndrome in non-human primates maintained on a Western-style diet.

BACKGROUND: The intake of a Western diet enriched in animal fat has been shown to be a major risk factor for Type 2 diabetes and obesity. Previous rodent studies have indicated that these conditions may be triggered by the accumulation of the sphingolipid ceramide in insulin-sensitive tissues. However, data are lacking in this regard from both humans and non-human primates. OBJECTIVE: Here we have investigated the relationship between plasma ceramides and metabolic syndrome in Rhesus macaques fed a high-fat and high-fructose (HFFD) 'western' diet. METHODS: We investigated this relationship in cohorts of monkeys fed a HFFD for a period of 8 months to 5 years. Animals were classified as control, pre-diabetic or diabetic based on fasting plasma parameters and insulin sensitivity. RESULTS: HFFD treatment produced significant increases in body weight and body fat and also resulted in a decline in insulin sensitivity. In parallel to the reduction in insulin sensitivity, significant increases in both plasma ceramide and dihydroceramide levels were observed, which further increased as animals progressed to the diabetic state. Plasma levels of the rare sphingolipid C18:0 deoxysphinganine, a marker of increased metabolic flux through serine palmitoyl transferase (SPT), were also elevated in both pre- and diabetic animals. Furthermore, plasma serine levels were significantly elevated in diabetic monkeys, which may indicate a shift in SPT substrate selectivity from serine to alanine or glycine. In contrast, branch chain amino acids were unchanged in pre-diabetic non-human primates, and only plasma valine levels were elevated in diabetic animals. CONCLUSION: Together, these data indicate that HFFD induces de novo synthesis of ceramides in non-human primates, and that increased production of plasma ceramides is significantly correlated with the decline in insulin sensitivity.

Cardiac operative risk evaluation: The EuroSCORE II, does it make a real difference?

BACKGROUND: The EuroSCORE, worldwide used as a model for prediction of mortality after cardiac surgery, has recently been renewed. Since October 2011, the EuroSCORE II calculator is available at the EuroSCORE website and recommended for clinical use. The intention of this paper is to compare the use of the initial EuroSCORE and EuroSCORE II as a risk evaluation tool. METHODS: 100 consecutive patients who underwent combined mitral valve and coronary bypass surgery (MVR + CABG) and 100 consecutive patients undergoing combined aortic valve surgery and coronary bypass surgery (AVR + CABG) at the Radboud University Nijmegen Medical Center before 10 October 2011 were included. For both groups the initial EuroSCORE and the EuroSCORE II model were used for risk calculation and based on the calculated risks, cumulative sum charts (CUSUM) were constructed to evaluate the impact on performance monitoring. RESULTS: For the MVR + CABG group the calculated risk using the initial logistic EuroSCORE was 9.95 ± 8.47 (1.51-45.37) versus 5.08 ± 4.03 (0.67-19.76) for the EuroSCORE II. For the AVR + CABG group 9.50 ± 8.6 (1.51-69.5) versus 4.77 ± 6.6 (0.96-64.24), respectively. For both groups the calculated risk by the EuroSCORE II was statistically lower compared with the initial EuroSCORE (p < 0.001). This lower expected risk has influence on performance monitoring, using risk-adjusted CUSUM analysis. CONCLUSION: The EuroSCORE II, based on a recently updated database, reduces the overestimation of the calculated risk by the initial EuroSCORE. This difference is statistically significant and the EuroSCORE II may also reflect better current surgical performance.

Leptin is not the critical signal for kisspeptin or luteinising hormone restoration during exit from negative energy balance.

Low levels of the adipocyte hormone leptin are considered to be the key signal contributing to inhibited gonadotrophin-releasing hormone (GnRH) release and reproductive acyclicity during negative energy balance. Hypoleptinaemia-induced inhibition of GnRH may be initiated with upstream inhibition of the secretagogue kisspeptin (Kiss1) because GnRH neurones do not express leptin receptors. The present study aimed to determine whether eliminating the hypoleptinaemia associated with caloric restriction (CR), by restoring leptin to normal basal levels, could reverse the suppression of the reproductive neuroendocrine axis. Fifty percent CR resulted in significant suppression of anteroventral periventricular Kiss1 mRNA, arcuate nucleus (ARH) Kiss1 and neurokinin B (NKB) mRNA levels and serum luteinising hormone (LH). Restoring leptin to normal basal levels did not restore Kiss1 or NKB mRNA or LH levels. Surprisingly, leptin did not activate expression of phosphorylated signal-transducer and activator of transcription-3 in ARC Kiss1 neurones, indicating that these neurones may not relay leptin signalling to GnRH neurones. Previous work in fasting models showing restoration of LH used a pharmacological dose of leptin. Therefore, in a 48-h fast study, replacement of leptin to pharmacological levels was compared with replacement of leptin to normal basal levels. Maintaining leptin at normal basal levels during the fast did not prevent inhibition of LH. By contrast, pharmacological levels of leptin did maintain LH at control values. These results suggest that, although leptin may be a permissive signal for reproductive function, hypoleptinaemia is unlikely to be the critical signal responsible for ARC Kiss1 and LH inhibition during negative energy balance.

Evaluation of quality in adult cardiac surgery: let us speak the same language.

Over the last years, measurements of quality of care have become more and more a public product, used by providers, purchasers and consumers, and patients. This information serves as an important guide for improvement, as well as a decision support tool for everybody taking part in medical treatment. This evolution can be compared with advertising and as in commercials it is important to use the right information. In this report we focus on the quality of adult cardiac surgery. Honest information is of course essential, but in this article attention is asked for the variables used to evaluate the quality of cardiac surgery. (Neth Heart J 2010;18:365-9.).

Critical determinants of hypothalamic appetitive neuropeptide development and expression: species considerations.

Over the last decade there has been a striking increase in the early onset of metabolic disease, including obesity and diabetes. The regulation of energy homeostasis is complex and involves the intricate integration of peripheral and central systems, including the hypothalamus. This review provides an overview of the development of brain circuitry involved in the regulation of energy homeostasis as well as recent findings related to the impact of both prenatal and postnatal maternal environment on the development of these circuits. There is surprising evidence that both overnutrition and undernutrition impact the development of these circuits in a similar manner as well as having similar consequences of increased obesity and diabetes later in life. There is also a special focus on relevant species differences in the development of hypothalamic circuits. A deeper understanding of the mechanisms involved in the development of brain circuitry is needed to fully understand how the nutritional and/or maternal environments impact the functional circuitry as well as the behavior and physiological outcomes.

Sensitive and rapid immunoassay for parathyroid hormone using magnetic particle labels and magnetic actuation.

A rapid method for the sensitive detection of proteins using actuated magnetic particle labels, which are measured with a giant magneto-resistive (GMR) biosensor, is described. The technique involves a 1-step sandwich immunoassay with no fluid replacement steps. The various assay binding reactions as well as the bound/free separation are entirely controlled by magnetic forces induced by electromagnets above and below the sensor chip. During the assay, particles conjugated with tracer antibodies are actuated through the sample for target capture, and rapidly brought to the sensor surface where they bind to immobilized capture antibodies. Weakly or unbound labels are removed with a magnetic force oriented away from the GMR sensor surface. For the measurement of parathyroid hormone (PTH), a detection limit in the 10 pM range is obtained with a total assay time of 15 min when 300 nm particles are used. The same sensitivity can be achieved in 5 min when 500 nm particles are used. If 500 nm particles are employed in a 15-minute assay, then 0.8 pM of PTH is detectable. The low sample volume, high analytical performance and high speed of the test coupled with the compact GMR biosensor make the system especially suitable for sensitive testing outside of laboratory environments.

Llama-derived phage display antibodies in the dissection of the human disease oculopharyngeal muscular dystrophy.

Functional analysis of the estimated 30,000 genes of the human genome requires fast and reliable high-throughput methods to study spatio-temporal protein dynamics. To explore the suitability of heavy-chain antibodies (HCAbs) for studying mechanisms underlying human disease, we used oculopharyngeal muscular dystrophy (OPMD) as a paradigm for the expanding group of protein aggregation disorders that is characterized by subcellular dislocalization and aggregation of mutant protein. OPMD is caused by a moderate alanine expansion in the poly-A binding protein nuclear 1 (PABPN1) and is associated with intranuclear PABPN1 deposition exclusively in muscle. An experimental approach was designed in which the primary sequence of the PABPN1 gene was employed for generating a prokaryotic expression construct that permitted its expression in the host Escherichia coli. The purified product was used for immunization of a llama as well as for the selection of an antigen-specific antibody fragment from the derived phage display library. This single-domain antibody was able to recognize the native gene product in mammalian cell lines and in human muscle tissue by immunocytochemical, immunohistochemical and immunoblot analysis. Our results suggest that phage display derived heavy-chain antibodies can be used in proteomics to study the localization and function of hypothetical gene products, relevant to human disease.

Analysis of the role of the mitogen-activated protein kinase in mediating cyclic-adenosine 3',5'-monophosphate effects on prolactin promoter activity.

The mechanisms mediating cAMP effects to stimulate transcription of the PRL gene have been examined. Treatments that elevate intracellular cAMP concentrations were found to stimulate the mitogen-activated protein kinase (MAPK) in GH(3) cells. Elevated cAMP was also found to stimulate activation of the GTP-binding protein, Rap1. Rap1GAP1 reduced cAMP-induced phosphorylation of MAPK, offering evidence that Rap1 may play a role in mediating activation of MAPK. Treatment of GH(3) cells with PD98059, an inhibitor of the MAPK pathway, reduced the ability of forskolin to activate a PRL reporter gene, providing evidence that MAPK contributes to cAMP-mediated effects on the PRL promoter. As previous studies have implicated Ets factor binding sites within the PRL promoter in mediating responses to MAPK, we expected that the Ets sites would also play a role in cAMP responsiveness. Surprisingly, mutation of all of the consensus Ets factor binding sites in the proximal PRL promoter greatly reduced responsiveness to epidermal growth factor (EGF) and TRH but did not reduce cAMP responsiveness. Experiments using an expression vector for adenovirus 12S E1a provided evidence that the coactivators, CREB binding protein and/or p300, probably play a role in cAMP responsiveness of the PRL promoter. Interestingly, the ability of a GAL4-p300 fusion protein to enhance reporter gene activity was stimulated by cAMP in a MAPK-dependent manner. These findings provide evidence for a model for cAMP-induced PRL transcription involving Rap1-induced MAPK activity leading to stimulation of the transcriptional coactivators, CBP and p300.

[Diagnostic image (26). Pneumopericardium due to leaking drainage system]. / Diagnose in beeld (26). Pneumopericardium door een lekkend drainagesysteem.

A 55-year-old man with pleuropericarditis carcinomatosa was treated with pericardiocentesis and drainage. Because of leakage in the drainage system a pressure pneumopericardium developed.

Complete allele information in the diagnosis of facioscapulohumeral muscular dystrophy by triple DNA analysis.

Facioscapulohumeral muscular dystrophy is caused by partial deletion of the D4Z4 repeat array on chromosome 4q35. Genetic diagnosis is based on sizing of this repeat array, which is complicated by cross-hybridization of a homologous polymorphic repeat array on chromosome 10 and by the frequent exchanges between these chromosomal regions. The restriction enzyme XapI optimizes the diagnosis of facioscapulohumeral muscular dystrophy by uniquely digesting 4-derived repeat units and leaving 10-derived repeat units undigested, thus complementing BlnI, which uniquely digests 10-derived repeat units. A triple analysis with EcoRI, EcoRI/BlnI, and XapI unequivocally allows characterization of each of the four alleles, whether homogeneous or hybrid. This is particularly useful in the case of identical sized 4-derived and 10-derived arrays, in situations of suspected facioscapulohumeral muscular dystrophy with nonstandard allele configurations, and for assignment of hybrid fragments to their original alleles.

Regulation of proliferation and apoptosis by epidermal growth factor and protein kinase C in human ovarian surface epithelial cells.

Epidermal growth factor (EGF) is produced in the ovary and influences proliferation of the malignant ovarian surface epithelium (OSE); yet its role in malignancy or in regulating the normal surface epithelium is unclear. In human OSE cells derived from primary cultures of normal tissue transfected with SV40 large T antigen (IOSE cells), EGF promoted survival but not proliferation. This survival effect was reversed by acute treatment with the phorbol ester, 12-0-tetradecanoyl-13-phorbol acetate (TPA) which alone markedly inhibited IOSE proliferation. We tested whether the activities of the mitogen-activated protein kinases (ERK1/2 and JNK1) varied in response to EGF, TPA, or combinations of these agonists and if the same treatments altered patterns of immediate early gene expression. Alone, EGF activated ERK1/2, increased and sustained levels of c-jun mRNA, but had almost no effect on JNK1 activation. Conversely, PKC activation resulted in a rapid, but transient induction of c-fos RNA and of both kinases, JNK1 and ERK2. When combined, EGF and TPA further enhanced the phosphorylation of both enzymes despite inhibiting survival. Though JNKs and ERKs are thought to transduce opposing cellular responses, in IOSE cells, robust costimulation of the JNK and ERK pathways may redirect the survival message.