Implementation of the 2015 European Society of Cardiology guidelines for the management of infective endocarditis in the Netherlands.

Because the occurrence of infective endocarditis (IE) continues to be associated with high mortality, a working group was created by the Dutch Society of Cardiology to examine how the most recent European Society of Cardiology (ESC) guidelines for IE management could be implemented most effectively in the Netherlands. In order to investigate current Dutch IE practices, the working group conducted a country-wide survey. Based on the results obtained, it was concluded that most ESC recommendations could be endorsed, albeit with some adjustments. For instance, the suggested pre-operative screening and treatment of nasal carriers of Staphylococcus aureus as formulated in the ESC guideline was found to be dissimilar to current Dutch practice, and was therefore made less restrictive. The recently adapted ESC diagnostic criteria for IE were endorsed, while the practical employment of the relevant diagnostic techniques was simplified in an adapted flowchart. In addition, the presence of a multidisciplinary, so-called 'endocarditis team' in tertiary centres was proposed as a quality indicator. An adapted flowchart specifically tailored to Dutch practice for microbiological diagnostic purposes was constructed. Lastly, the working group recommended the Stichting Werkgroep Antibioticabeleid (SWAB; Dutch Working Party on Antibiotic Policy) guidelines for IE treatment instead of the antibiotic regimens proposed by the ESC.

Excess mortality after hip fracture in elderly persons from Europe and the USA: the CHANCES project.

BACKGROUND: Hip fractures are associated with diminished quality of life and survival especially amongst the elderly. OBJECTIVE: All-cause mortality after hip fracture was investigated to assess its magnitude. METHODS: A total of 122 808 participants from eight cohorts in Europe and the USA were followed up for a mean of 12.6 years, accumulating 4273 incident hip fractures and 27 999 deaths. Incident hip fractures were assessed through telephone interviews/questionnaires or national inpatient/fracture registries, and causes of death were verified with death certificates. Cox proportional hazards models and the time-dependent variable methodology were used to assess the association between hip fracture and mortality and its magnitude at different time intervals after the injury in each cohort. We obtained the effect estimates through a random-effects meta-analysis. RESULTS: Hip fracture was positively associated with increased all-cause mortality; the hazard ratio (HR) in the fully adjusted model was 2.12, 95% confidence interval (CI) 1.76-2.57, after adjusting for potential confounders. This association was stronger amongst men [HR: 2.39, 95% CI: 1.72-3.31] than amongst women [HR: 1.92, 95% CI: 1.54-2.39], although this difference was not significant. Mortality was higher during the first year after the hip fracture [HR: 2.78, 95% CI: 2.12-3.64], but it remained elevated without major fluctuations after longer time since hip fracture [HR (95% CI): 1.89 (1.50-2.37) after 1-4 years; 2.15 (1.81-2.55) after 4-8 years; 1.79 (1.57-2.05) after 8 or more years]. CONCLUSION: In this large population-based sample of older persons across eight cohorts, hip fracture was associated with excess short- and long-term all-cause mortality in both sexes.

Dynamic and differential Oct-1 expression during early Xenopus embryogenesis: persistence of Oct-1 protein following down-regulation of the RNA.

As a first step towards the elucidation of the role of the transcription factor Oct-1 in development, we prepared a monoclonal antibody to study the spatio-temporal distribution of Oct-1 protein in vivo. Here we report differential expression of the Oct-1 gene in the Xenopus embryo both at the RNA and the protein level. Transcripts and protein are detected in ectodermal and mesodermal cell lineages, in which the expression exhibits a pattern of progressive spatial restriction in the course of development. The Oct-1 expression as reported here is not correlated with cell density or cell proliferation in the embryo. Our results suggest a role of Oct-1 in the specification and differentiation of neuronal and neural crest cells. In many other cells, the developmental decision to down regulate Oct-1 is delayed, probably due to a high stability of the protein.

Comparative analysis of Engrailed-1 and Wnt-1 expression in the developing central nervous system of Xenopus laevis.

Expression of the Engrailed-1 (XEn-1) gene was studied in Xenopus embryogenesis by Northern blot analysis and whole-mount in situ hybridization. One transcript of 2.2 kb was detected from stage 17 (midneurula) onwards, until stage 47 (swimming tadpole). The expression pattern of the XEn-1 gene as revealed by in situ hybridization can be divided in three regions. The first domain of transient expression appears at the midneurula stage (st. 17) in the anterior part of the neural fold, forming a complete ring of positive cells at the mid/hindbrain border after neural tube closure. A second region of transient expression is detected as groups of ventro-lateral cells in the spinal cord and the hindbrain from late-neurula till tadpole stages. A third area of transient expression of XEn-1 is formed by the anterior part of the developing pronephros. Comparison of XEn-1 expression at the mid/hindbrain border with that of the Xenopus wnt-1 and engrailed-2 genes reveals that XEn-1 and Xwnt-1, in contrast to XEn-2, are both detected in a narrow stripe of positive cells in this region. Analysis in exogastrulated embryos reveals that expression of XEn-1 and Xwnt-1, but not XEn-2, is induced by planar signaling in the presumptive midbrain. Of the three genes only XEn-1 is expressed in the floorplate at the mid/hindbrain border, while Xwnt-1 is expressed in adjacent cells in the neural ectoderm. The results suggest that in vertebrates at the interface between cells in the floorplate and in the paraxial neuroectoderm, at the limited region of the mid/hindbrain border, En-1 interacts with wnt-1 in a signaling pathway analogous to the engrailed/wingless signaling in the parasegments of the Drosophila embryo.

Insulin-like growth factor (IGF) II induced changes in expression of IGF binding proteins in lymphoid tissues of hIGF-II transgenic mice.

Overexpression of human insulin-like growth factor II (IGF-II) in transgenic mice does not result in increased overall body growth. The IGF-II overexpression, however, specifically causes growth of the thymus and not of the spleen. We address the question whether the observed differences in growth induction in lymphoid tissues by IGF-II can be related to differences in local IGF binding protein (IGFBP) production, using nonradioactive in situ hybridization and Northern blot analysis. IGFBP-2, -4, and -5 are expressed in both lymphoid tissues of normal mice. The spleen additionally expresses IGFBP-3 and IGFBP-6. IGFBP-1 expression was not detected. Although the expression pattern of the IGFBPs did not change upon IGF-II overexpression, the level of expression changed in a specific manner for each IGFBP. In both the thymus and the spleen of transgenic mice, IGFBP-2 and -5 gene expression was slightly increased, whereas the level of IGFBP-4 expression was not altered. In the spleen, IGFBP-6 expression was not altered by IGF-II overexpression, whereas IGFBP-3 expression was strongly increased. The differences in IGFBP expression, and the difference in response of these IGFBPs to IGF-II overexpression in thymus and spleen suggests an important role of these proteins in growth regulation of both lymphoid tissues. We speculate that an increase of IGFBP-3 expression together with changes in expression of other IGFBPs, inhibits IGF-II stimulated growth in the spleen by an autocrine-/paracrine pathway.

Combined pituitary hormone deficiency caused by compound heterozygosity for two novel mutations in the POU domain of the Pit1/POU1F1 gene.

The POU homeodomain containing transcriptional activator POU1F1, formerly called Pit1 or GHF-1, is required for the embryological determination and postnatal secretory function of the GH-, PRL-, and TSH-producing cells in the anterior pituitary. Several mutations in the gene encoding POU1F1 have been described, resulting in a syndrome of combined pituitary hormone deficiency involving these three hormones. Most of the patients with this phenotype have either a dominant negative mutation in codon 271 (R271W) or are homozygous for a recessive mutation in the POU1F1 gene; to date only one case has been reported with compound heterozygosity for two point mutations. Here, we describe a boy with severe deficiencies of GH, PRL, and TSH who had compound heterozygosity for two novel point mutations in the POU1F1 gene: a 1-bp deletion frameshift mutation (747delA), the first one described to date in this gene, which leads to a nonfunctional truncated protein lacking the entire DNA recognition helix of the POU homeodomain, and a missense mutation in the C-terminal end of the fourth alpha-helix of the POU-specific domain (W193R),which causes a 500-fold reduction in the ability to bind to DNA and activate transcription.

A comparison of in vitro bioassays to determine cellular glucocorticoid sensitivity.

An altered cellular glucocorticoid (GC) sensitivity is associated with several pathophysiological conditions such as asthma, diabetes, or rheumatoid arthritis. Several bioassays have been developed and employed to assess cellular GC sensitivity of peripheral blood mononuclear cells (PBMC), but correlations between these have rarely been investigated. We have compared four mitogen-based assays and an FK506 binding protein 51 (FKBP51) mRNA induction assay, using ten controls and a GC-resistant patient. The mitogen-based assays were performed using either diluted whole blood or isolated PBMC, and showed relatively large assay variations for the parameters maximal effect and half-maximal effect concentration. The FKBP51 assay showed smaller intra-assay and within-individual variation compared with the mitogen-based assays. The whole blood-based mitogen assays and the FKBP51 assay clearly discriminated the GC-resistant patient from the controls but, in contrast to expectations, both PBMC-based mitogen assays did not. The GC-induced FKBP51 mRNA increase in PBMC may be an alternative to determine an altered individual GC sensitivity with several advantages as compared with mitogen-based assays, such as the use of unstimulated PBMC, and a better intra- and inter-individual reproducibility.

An additional PII in Escherichia coli: a new regulatory protein in the glutamine synthetase cascade.

The PII protein in the glutamine synthetase cascade transduces the nitrogen signal, as sensed by uridylyltransferase, both to the NRII/NRI two-component system and to adenylyltransferase, to regulate the activity of glutamine synthetase. Here we describe the amplification of a chromosomal DNA fragment from Escherichia coli which contains the sequence of a PII homologue. The derived amino acid sequence of this DNA fragment is 67% identical to E. coli PII. It contains the conserved tyrosine residue which is known to be the site of uridylylation in PII. E. coli is the first organism in which two different PII proteins have been detected.

Sex hormone-binding globulin levels are not causally related to venous thrombosis risk in women not using hormonal contraceptives.

BACKGROUND: Oral contraceptive use increases the risk of venous thrombosis as well as sex hormone-binding globulin (SHBG) levels. Furthermore, increased SHBG levels are positively associated with activated protein C (APC) resistance and thrombotic risk in oral contraceptive users. OBJECTIVES: To determine whether increased SHBG levels are causally related to venous thrombosis in women not using hormonal contraceptives. METHODS: Premenopausal women were selected from a case-control study on venous thrombosis, the Multiple Environmental and Genetic Assessment of risk factors for venous thrombosis (MEGA) study (23 patients; 258 controls). Women using hormonal contraceptives were excluded. First, the risk of venous thrombosis with SHBG levels above the normal reference range (70 nm) was determined. Second, because multiple regulatory factors affect SHBG levels and residual confounding may remain, we determined six single-nucleotide polymorphisms (SNPs) in the SHBG gene and assessed the risk of venous thrombosis in a different case-control study, the Leiden Thrombophilia Study (LETS) (20 patients; 74 controls), and in the MEGA study. Finally, the association between SHBG levels and the normalized activated partial thromboplastin time-based APC resistance (an intermediate endpoint for venous thrombosis) was determined. RESULTS: Elevated SHBG levels (> 70.0 nm) were associated with venous thrombosis (odds ratio 1.92; 95% confidence interval [CI] 0.74-5.00). However, this finding can be explained by residual confounding. Two SNPs in the SHBG gene affected SHBG levels, but not venous thrombosis risk. Furthermore, SHBG levels in controls were not associated with APC resistance (SHBG level, > 70.0 vs. ≤ 70.0 nm: mean difference in normalized APC sensitivity ratio, 0.03; 95% CI -0.05 to 0.10). Exclusion of women with FV Leiden did not materially change these results. CONCLUSIONS: Increased SHBG levels are not causally related to the risk of venous thrombosis.

GR transcripts are localized during early Xenopus laevis embryogenesis and overexpression of GR inhibits differentiation after dexamethasone treatment.

We have studied the spatial expression of the Xenopus GR in early embryos by whole-mount in situ hybridization. At the gastrula stage, GR mRNA is localized in the dorsal ectoderm. By the early neurula stage, GR transcripts were detected along the notoplate. Between mid and late neurula stages, GR mRNA was not detectable. At the tailbud stage, GR mRNA was found in the anterior part of the embryo, including the cement gland, eyes, brain, the foregut, stomodeal-hypophyseal anlage, the olfactory placodes, head mesenchyme and somites. Injection of Xenopus GR RNA into zygotes followed by treatment dexamethasone from the blastula stage onwards inhibits early differentiation. Expression of Xbra, gsc and histone H3 genes in these embryos is not inhibited, indicating that the GR effects are not due to a general squelching effect on transcription.

A novel nonsense mutation of the KAL gene in two brothers with Kallmann syndrome.

Kallmann syndrome (KS), defined by the association of hypogonadotropic hypogonadism and anosmia or hyposmia, can be caused by mutations in the KAL gene on Xp 22.3. This gene encodes an extracellular matrix glycoprotein called anosmin-1, which belongs to the class of cell adhesion molecules. In the absence of a functional KAL protein, migration of both olfactory and gonadotropin-releasing hormone neurons is arrested. A defective anosmin-1 molecule may also play a role in the development of synkinesia and renal agenesis, which are exclusively seen in the X-linked form of KS. We describe the clinical presentation and molecular diagnosis of the defect in two brothers with KS. An X-linked mode of transmission was assumed on the basis of synkinesia and the presence of oligomenorrhoea in the mother. A novel nonsense mutation was found in exon 13 of the KAL gene, encoding the region of the fourth fibronectin type III repeat of anosmin-1, which results in an apparently nonfunctional truncated protein.

Analysis of Wnt/Engrailed signaling in Xenopus embryos using biolistics.

We adapted the Biolistics Particle Delivery System for the introduction of DNA into Xenopus embryos, allowing us to modulate the expression of different genes at specific time points during development. In the present study we applied the Biolistics method to the study of the wnt-engrailed signaling cascade in the developing Xenopus embryo. We show that ectopic expression of Xwnt-1 and Xwnt-5C is sufficient to activate specifically XEn-1 and not XEn-2.

An alternative PII protein in the regulation of glutamine synthetase in Escherichia coli.

The PII protein has been considered pivotal to the dual cascade regulating ammonia assimilation through glutamine synthetase activity. Here we show that PII, encoded by the glnB gene, is not always essential; for instance upon ammonia deprivation of a glnB deletion strain, glutamine synthetase can be deadenylylated as effectively as in the wild-type strain. We describe a new operon, glnK amtB, which encodes a homologue of PII and a putative ammonia transporter. We cloned and overexpressed glnK and found that the expressed protein had almost the same molecular weight as PII, reacted with polyclonal PII antibody, and was 67% identical in terms of amino acid sequence with Escherichia coli PII. Like PII, purified GlnK can activate the adenylylation of glutamine synthetase in vitro, and, in vivo, the GlnK protein is uridylylated in a glnD-dependent fashion. Unlike PII, however, the expression of glnK depends on the presence of UTase, nitrogen regulator I (NRI), and absence of ammonia. Because of a NRI and a sigma N (sigma 54) RNA polymerase-binding consensus sequence upstream from the glnK gene, this suggests that glnK is regulated through the NRI/NRII two-component regulatory system. Indeed, in cells grown in the presence of ammonia, glutamine synthetase deadenylylation upon ammonia depletion depended on PII. Possible regulatory implications of this conditional redundancy of PII are discussed.

A novel specific bioassay for the determination of glucocorticoid bioavailability in human serum.

OBJECTIVE: Some patients develop side-effects even on relatively low doses of topically administered glucocorticoids (GCs), while others appear to be less sensitive to GCs. We have developed and validated a bioassay which can measure glucocorticoid bioavailability directly from small amounts of human serum to help elucidate underlying mechanisms. METHODS: We have stably transfected the human embryonic kidney cell line HEK293 with a plasmid expressing the glucocorticoid receptor, and a plasmid containing the luciferase gene preceded by three concatenated steroid response elements, bringing luciferase expression under control of the liganded glucocorticoid receptor. RESULTS: The assay, with an intra- and interassay coefficient of variance (CV) better than 10%, showed the expected difference in potency between different GCs (fluticasone propionate > budesonide > dexamethasone > hydrocortisone). No cross-reactivity was detected with other steroid hormones such as progesterone, testosterone and oestradiol. The bioassay easily detects the rise and subsequent fall of bioavailable GCs in human serum following ingestion of only 0.5 mg dexamethasone, and clearly reflects the diurnal cortisol rhythm. Moreover, systemic availability following inhalation of 2 x 250 micro g fluticasone propionate using a pressure dose inhaler could be demonstrated. CONCLUSIONS: This assay can be used to determine levels of bioavailable GCs in serum, both endogenous and administered, and thus may help in optimizing treatment regimens. The small amount of serum needed to perform an analysis makes this assay applicable even to infants.