NF-kappaB inhibits sodium transport via down-regulation of SGK1 in renal collecting duct principal cells.

Tubulointerstitial inflammation is a common feature of renal diseases. We have investigated the relationship between inflammation and Na(+) transport in the collecting duct (CD) using the mCCD(cl1) and mpkCDD(cl4) principal cell models. Lipopolysaccharide (LPS) decreased basal and aldosterone-stimulated amiloride-sensitive transepithelial current in a time-dependent manner. This effect was associated with a decrease in serum and glucocorticoid-regulated kinase 1 (SGK1) mRNA and protein levels followed by a decrease in epithelial sodium channel (ENaC) alpha-subunit mRNA levels. The LPS-induced decrease in SGK1 expression was confirmed in isolated rat CD. This decreased expression of either SGK1 or the ENaC alpha-subunit was not due to enhanced degradation of mRNA. In contrast, LPS inhibited transcriptional activity of the SGK1 promoter measured by luciferase-reporter gene assay. The effect of LPS was not mediated by inhibition of mineralocorticoid or glucocorticoid receptor, because expression of both receptors was unchanged and blockade of either receptor by spironolactone or RU486, respectively, did not prevent the down-regulation of SGK1. The effect of LPS was mediated by the canonical NF-kappaB pathway, as overexpression of a constitutively active mutant, IKKbeta (inhibitor of nuclear factor kappaB kinase-beta) decreased SGK1 mRNA levels, and knockdown of p65 NF-kappaB subunit by small interfering RNA increased SGK1 mRNA levels. Chromatin immunoprecipitation showed that LPS increased p65 binding to two NF-kappaB sites along the SGK1 promoter. In conclusion, we show that activation of the NF-kappaB pathway down-regulates SGK1 expression, which might lead to decreased ENaC alpha-subunit expression, ultimately resulting in decreased Na(+) transport.

Trabecular Bone Score: A Noninvasive Analytical Method Based Upon the DXA Image.

The trabecular bone score (TBS) is a gray-level textural metric that can be extracted from the two-dimensional lumbar spine dual-energy X-ray absorptiometry (DXA) image. TBS is related to bone microarchitecture and provides skeletal information that is not captured from the standard bone mineral density (BMD) measurement. Based on experimental variograms of the projected DXA image, TBS has the potential to discern differences between DXA scans that show similar BMD measurements. An elevated TBS value correlates with better skeletal microstructure; a low TBS value correlates with weaker skeletal microstructure. Lumbar spine TBS has been evaluated in cross-sectional and longitudinal studies. The following conclusions are based upon publications reviewed in this article: 1) TBS gives lower values in postmenopausal women and in men with previous fragility fractures than their nonfractured counterparts; 2) TBS is complementary to data available by lumbar spine DXA measurements; 3) TBS results are lower in women who have sustained a fragility fracture but in whom DXA does not indicate osteoporosis or even osteopenia; 4) TBS predicts fracture risk as well as lumbar spine BMD measurements in postmenopausal women; 5) efficacious therapies for osteoporosis differ in the extent to which they influence the TBS; 6) TBS is associated with fracture risk in individuals with conditions related to reduced bone mass or bone quality. Based on these data, lumbar spine TBS holds promise as an emerging technology that could well become a valuable clinical tool in the diagnosis of osteoporosis and in fracture risk assessment. © 2014 American Society for Bone and Mineral Research.

A morphological grading of spinal stenosis: a radiological study on LSS and LBP patients : P173

Introduction: Clinical symptoms and degree of spinal stenosis based on cross sectional dural sac area correlate only weakly in lumbar spinal stenosis (LSS) patients. We conceived a four grade classification system (A, B, C & D) based on the morphology of the dural sac and its contents as seen on T2 axial MRI images. The categories take into account the rootlet/CSF ratio. We applied this grading to three patient groups: LSS scheduled for surgery; LSS following conservative treatment and patients with low back pain (LBP) without leg pain. Materials/Methods: A total of 346 T2 axial MRI images taken from LSS and LBP patients were included in this retroperspective study. 37 patients had decompressive surgery (132 MRI images), 31 conservative treatment (116 MRI images) and 27 patients had unspecific LBP (98 MRI images). Dural sac cross-sectional surface area and morphological grading of the canal were measured digitally both at disc and pedicle level. Intra- and inter-observer reliability were assessed (weighted Cohen's kappa statistics) from 50 MRI images taken from the surgery group. Results: At the most severe disc level, grade A (mild stenosis) was found in 3% of MRI images of the surgical group as opposed to 51% in the conservatively treated group and 85% in the LBP group. Grade B occurred in 8% of the surgical, 20% of the conservative and was negligible in LBP group (below 1%). Grade C and D (severe stenosis) was found in 89% of the surgical group, as opposed to 30% in conservative group and 11% in LBP group. The grades of all groups were comparable at the pedicle levels, exhibiting in 94% a grade A with a maximum at the A1 grade. Pedicle and disc level cross-sectional area were smallest in the surgery group and smaller in the conservative group as compared to the LBP group at the levels L2, L3 and L4. According to cross-sectional area measurements patients from the surgery group seems to have smaller vertebral canal although this was not related to smaller stature. Validation of grading: Average intra-and inter observer kappas were 0.76 and 0.69 respectively, for physicians working in the study originating institution. Combining all observers the kappa values were 0.57 +/- 0.19. and 0.44 +/- 0.19 respectively. Dural sac cross-sectional area measurements showed no statistically significant differences between observers. Conclusion: Since no specific measurement tools are needed the grading suits everyday clinical practice and favours communication of degree of stenosis between practising physicians. In our institution Grade A stenosis was less likely to require surgical treatment. This grading can therefore be an aid in surgical patient selection in teaching units.

The heterotetrameric architecture of the epithelial sodium channel (ENaC).

The epithelial sodium channel (ENaC) is a key element for the maintenance of sodium balance and the regulation of blood pressure. Three homologous ENaC subunits (alpha, beta and gamma) assemble to form a highly Na+-selective channel. However, the subunit stoichiometry of ENaC has not yet been solved. Quantitative analysis of cell surface expression of ENaC alpha, beta and gamma subunits shows that they assemble according to a fixed stoichiometry, with alpha ENaC as the most abundant subunit. Functional assays based on differential sensitivities to channel blockers elicited by mutations tagging each alpha, beta and gamma subunit are consistent with a four subunit stoichiometry composed of two alpha, one beta and one gamma. Expression of concatameric cDNA constructs made of different combinations of ENaC subunits confirmed the four subunit channel stoichiometry and showed that the arrangement of the subunits around the channel pore consists of two alpha subunits separated by beta and gamma subunits.

Identification of corticosteroid-regulated genes in cardiomyocytes by serial analysis of gene expression.

Corticosteroids (aldosterone, cortisol/corticosterone) exert direct functional effects on cardiomyocytes. However, gene networks activated by corticosteroids in cardiomyocytes, as well as the involvement of the mineralocorticoid receptor (MR) vs the glucocorticoid receptor (GR) in these effects, remain largely unknown. Here we characterized the corticosteroid-dependent transcriptome in primary culture of neonatal mouse cardiomyocytes treated with 10(-6) M aldosterone, a concentration predicted to occupy both MR and GR. Serial analysis of gene expression revealed 101 aldosterone-regulated genes. The MR/GR specificity was characterized for one regulated transcript, namely ecto-ADP-ribosyltransferase-3 (Art3). Using cardiomyocytes from GR(null/null) or MR(null/null) mice we demonstrate that in GR(null/null) cardiomyocytes the response is abrogated, but it is fully maintained in MR(null/null) cardiomyocytes. We conclude that Art3 expression is regulated exclusively via the GR. Our study identifies a new set of corticosteroid-regulated genes in cardiomyocytes and demonstrates a new approach to studying the selectivity of MR- vs GR-dependent effects.

Malaria prevention in travelers.

A common approach to malaria prevention is to follow the "A, B, C, D" rule: Awareness of risk, Bite avoidance, Compliance with chemoprophylaxis, and prompt Diagnosis in case of fever. The risk of acquiring malaria depends on the length and intensity of exposure; the risk of developing severe disease is primarily determined by the health status of the traveler. These parameters need to be assessed before recommending chemoprophylaxis and/or stand-by emergency treatment. This review discusses the different strategies and drug options available for the prevention of malaria during and post travel.

The transmembrane serine protease (TMPRSS3) mutated in deafness DFNB8/10 activates the epithelial sodium channel (ENaC) in vitro.

TMPRSS3 encodes a transmembrane serine protease that contains both LDLRA and SRCR domains and is mutated in non-syndromic autosomal recessive deafness (DFNB8/10). To study its function, we cloned the mouse ortholog which maps to Mmu17, which is structurally similar to the human gene and encodes a polypeptide with 88% identity to the human protein. RT-PCR and RNA in situ hybridization on rat and mouse cochlea revealed that Tmprss3 is expressed in the spiral ganglion, the cells supporting the organ of Corti and the stria vascularis. RT-PCR on mouse tissues showed expression in the thymus, stomach, testis and E19 embryos. Transient expression of wild-type or tagged TMPRSS3 protein showed a primary localization in the endoplasmic reticulum. The epithelial amiloride-sensitive sodium channel (ENaC), which is expressed in many sodium-reabsorbing tissues including the inner ear and is regulated by membrane-bound channel activating serine proteases (CAPs), is a potential substrate of TMPRSS3. In the Xenopus oocyte expression system, proteolytic processing of TMPRSS3 was associated with increased ENaC mediated currents. In contrast, 6 TMPRSS3 mutants (D103G, R109W, C194F, W251C, P404L, C407R) causing deafness and a mutant in the catalytic triad of TMPRSS3 (S401A), failed to undergo proteolytic cleavage and activate ENaC. These data indicate that important signaling pathways in the inner ear are controlled by proteolytic cleavage and suggest: (i) the existence of an auto-catalytic processing by which TMPRSS3 would become active, and (ii) that ENaC could be a substrate of TMPRSS3 in the inner ear.

A novel neutrophil elastase inhibitor prevents elastase activation and surface cleavage of the epithelial sodium channel expressed in Xenopus laevis oocytes.

The amiloride-sensitive epithelial sodium channel (ENaC) constitutes a limiting step in sodium reabsorption across distal airway epithelium and controlling mucociliary clearance. ENaC is activated by serine proteases secreted in the extracellular milieu. In cystic fibrosis lungs, high concentrations of secreted neutrophil elastase (NE) are observed. hNE could activate ENaC and contribute to further decreased mucociliary clearance. The aims of this study were (i) to test the ability of an engineered human neutrophil elastase inhibitor (EPI-hNE4) to specifically inhibit the elastase activation of ENaC-mediated amiloride-sensitive currents (I(Na)) and (ii) to examine the effect of elastase on cell surface expression of ENaC and its cleavage pattern (exogenous proteolysis). Oocytes were exposed to hNE (10-100 microg/ml) and/or trypsin (10 microg/ml) for 2-5 min in the presence or absence of EPI-hNE4 (0.7 microm). hNE activated I(Na) 3.6-fold (p < 0.001) relative to non-treated hENaC-injected oocytes. EPI-hNE4 fully inhibited hNE-activated I(Na) but had no effect on trypsin- or prostasin-activated I(Na). The co-activation of I(Na) by hNE and trypsin was not additive. Biotinylation experiments revealed that cell surface gamma ENaC (but not alpha or beta ENaC) exposed to hNE for 2 min was cleaved (as a 67-kDa fragment) and correlated with increased I(Na). The elastase-induced exogenous proteolysis pattern is distinct from the endogenous proteolysis pattern induced upon preferential assembly, suggesting a causal relationship between gamma ENaC cleavage and ENaC activation, taking place at the plasma membrane.

Virushepatitis [Viral hepatitis].

Viral hepatitis is associated with significant morbidity and mortality worldwide. Hepatitis A and E viruses are enterally transmitted and lead to usually self-limited acute hepatitis. Hepatitis B, C and D viruses are transmitted by parenteral routes and can lead to chronic hepatitis with progression to liver cirrhosis and hepatocellular carcinoma. Here, we briefly review current understanding and new developments in the virology and epidemiology, diagnosis, natural history, therapy and prevention of viral hepatitis.

Comparison of 2 frailty indexes for prediction of falls, disability, fractures, and death in older women.

BACKGROUND: Frailty, as defined by the index derived from the Cardiovascular Health Study (CHS index), predicts risk of adverse outcomes in older adults. Use of this index, however, is impractical in clinical practice. METHODS: We conducted a prospective cohort study in 6701 women 69 years or older to compare the predictive validity of a simple frailty index with the components of weight loss, inability to rise from a chair 5 times without using arms, and reduced energy level (Study of Osteoporotic Fractures [SOF index]) with that of the CHS index with the components of unintentional weight loss, poor grip strength, reduced energy level, slow walking speed, and low level of physical activity. Women were classified as robust, of intermediate status, or frail using each index. Falls were reported every 4 months for 1 year. Disability (> or =1 new impairment in performing instrumental activities of daily living) was ascertained at 4(1/2) years, and fractures and deaths were ascertained during 9 years of follow-up. Area under the curve (AUC) statistics from receiver operating characteristic curve analysis and -2 log likelihood statistics were compared for models containing the CHS index vs the SOF index. RESULTS: Increasing evidence of frailty as defined by either the CHS index or the SOF index was similarly associated with an increased risk of adverse outcomes. Frail women had a higher age-adjusted risk of recurrent falls (odds ratio, 2.4), disability (odds ratio, 2.2-2.8), nonspine fracture (hazard ratio, 1.4-1.5), hip fracture (hazard ratio, 1.7-1.8), and death (hazard ratio, 2.4-2.7) (P < .001 for all models). The AUC comparisons revealed no differences between models with the CHS index vs the SOF index in discriminating falls (AUC = 0.61 for both models; P = .66), disability (AUC = 0.64; P = .23), nonspine fracture (AUC = 0.55; P = .80), hip fracture (AUC = 0.63; P = .64), or death (AUC = 0.72; P = .10). Results were similar when -2 log likelihood statistics were compared. CONCLUSION: The simple SOF index predicts risk of falls, disability, fracture, and death as well as the more complex CHS index and may provide a useful definition of frailty to identify older women at risk of adverse health outcomes in clinical practice.

The molecular signature of the stroma response in prostate cancer-induced osteoblastic bone metastasis highlights expansion of hematopoietic and prostate epithelial stem cell niches.

The reciprocal interaction between cancer cells and the tissue-specific stroma is critical for primary and metastatic tumor growth progression. Prostate cancer cells colonize preferentially bone (osteotropism), where they alter the physiological balance between osteoblast-mediated bone formation and osteoclast-mediated bone resorption, and elicit prevalently an osteoblastic response (osteoinduction). The molecular cues provided by osteoblasts for the survival and growth of bone metastatic prostate cancer cells are largely unknown. We exploited the sufficient divergence between human and mouse RNA sequences together with redefinition of highly species-specific gene arrays by computer-aided and experimental exclusion of cross-hybridizing oligonucleotide probes. This strategy allowed the dissection of the stroma (mouse) from the cancer cell (human) transcriptome in bone metastasis xenograft models of human osteoinductive prostate cancer cells (VCaP and C4-2B). As a result, we generated the osteoblastic bone metastasis-associated stroma transcriptome (OB-BMST). Subtraction of genes shared by inflammation, wound healing and desmoplastic responses, and by the tissue type-independent stroma responses to a variety of non-osteotropic and osteotropic primary cancers generated a curated gene signature ("Core" OB-BMST) putatively representing the bone marrow/bone-specific stroma response to prostate cancer-induced, osteoblastic bone metastasis. The expression pattern of three representative Core OB-BMST genes (PTN, EPHA3 and FSCN1) seems to confirm the bone specificity of this response. A robust induction of genes involved in osteogenesis and angiogenesis dominates both the OB-BMST and Core OB-BMST. This translates in an amplification of hematopoietic and, remarkably, prostate epithelial stem cell niche components that may function as a self-reinforcing bone metastatic niche providing a growth support specific for osteoinductive prostate cancer cells. The induction of this combinatorial stem cell niche is a novel mechanism that may also explain cancer cell osteotropism and local interference with hematopoiesis (myelophthisis). Accordingly, these stem cell niche components may represent innovative therapeutic targets and/or serum biomarkers in osteoblastic bone metastasis.

The glucocorticoid-induced leucine zipper (gilz/tsc22d3-2) gene locus plays a crucial role in male fertility.

The glucocorticoid-induced leucine zipper (Tsc22d3-2) is a widely expressed dexamethasone-induced transcript that has been proposed to be important in immunity, adipogenesis, and renal sodium handling based on in vitro studies. To address its function in vivo, we have used Cre/loxP technology to generate mice deficient for Tsc22d3-2. Male knockout mice were viable but surprisingly did not show any major deficiencies in immunological processes or inflammatory responses. Tsc22d3-2 knockout mice adapted to a sodium-deprived diet and to water deprivation conditions but developed a subtle deficiency in renal sodium and water handling. Moreover, the affected animals developed a mild metabolic phenotype evident by a reduction in weight from 6 months of age, mild hyperinsulinemia, and resistance to a high-fat diet. Tsc22d3-2-deficient males were infertile and exhibited severe testis dysplasia from postnatal d 10 onward with increases in apoptotic cells within seminiferous tubules, an increased number of Leydig cells, and significantly elevated FSH and testosterone levels. Thus, our analysis of the Tsc22d3-2-deficient mice demonstrated a previously uncharacterized function of glucocorticoid-induced leucine zipper protein in testis development.

After-hours paediatric telephone triage and advice : the Neuchâtel experience

Résumé Introduction : Plusieurs études américaines et australiennes ont décrit des systèmes de tri téléphonique des urgences pédiatriques. En Europe, les services publics d'urgences pédiatriques ont peu de données épidémiologiques sur lesquelles s'appuyer pour répondre à la demande de soins. Depuis 1996, le département de pédiatrie de l'hôpital Pourtalès, Neuchâtel, offre, en dehors des heures ouvrables, mi tri téléphonique infirmier gratuit. Le présent travail analyse : 1) la situation suisse de l'offre en tri téléphonique infirmier pour les urgences pédiatriques ; 2) une partie des données épidémiologiques de l'expérience neuchâteloise. Méthode : 1) Un questionnaire a été envoyé aux 35 services d'urgences pédiatriques publics de Suisse pour Savoir si un tel tri était utilisé ; 2) une analyse rétrospective de tous les appels reçus, consignés sur fiches standardisées, en 1997 et 2000 a été menée. Résultats : 1) La majorité des services (27/35) ont effectivement un système de tri infirmier. Peu offrent une formation spécifique pour ce travail (14/27) ; 2) Au total, 7870 appels ont été analysés (3242 en 1997; 4628 en 2000, ± 43%). En semaine, la majorité ont été reçus entre 18h et 23h et le week-end en milieu de matinée. Septante-cinq % des appels ont concerné des enfants de 5 ans ou moins. La fièvre, les otalgies et la toux ont représenté 42% des plaintes. Vingt-sept % des appels ont été pris en charge uniquement par les conseils infirmiers, 15 % ont été transmis à l'interne de garde et 50% ont conduit à un rendez-vous dans le service le jour même. Conclusion : Nos données peuvent aider d'autres services d'urgences pédiatriques à planifier au mieux la mise en place d'un tel système de tri téléphonique. Abstract Delivery of paediatric primary care by call centres has emerged as a satisfactory system. It been reported in the literature in the United States and Australia. European public-funded paediatric emergency departments (ED) have little epidemiological data to rely on to match the demand in care. Since 1996, we have run a free nurse-led after-hours paediatric telephone triage and advice (TTA) system, To determine wether other Swiss public paediatric departments practiced formal TTA, we conducted a nation-wide postal survey. To delineate who used our call centre and for what reasons, we embarked on a retrospective study of ail the 1997/2000 calls. Most of the units run a TTA (27/35) but few specifically train their staff (14/27). A 43% increase in call numbers was seen between 1997 (3242) and 2000 (4628). During week-days, most of the calls were between 6 and 11 pm and at weekends, a mid morning activity peak was seen. Some 75% of calls were for children aged 5 years or less. Fever, earache and cough accounted for 42% of the main complaints. Of all calls, 27% were dealt by nurses' advice only. About 15% of the calls were transferred to the on-call resident. About 50% led to a same day ED appointment. Conclusion: Nurse-led paediatric telephone triage and advice is common in Switzerland where training seems to be irregular. Our data can help units to better plan an eventual paediatric telephone triage and advice service. After-hours; Paediatric; Telephone advice; Telephone triage

Control of hair follicle cell fate by underlying mesenchyme through a CSL-Wnt5a-FoxN1 regulatory axis.

Epithelial-mesenchymal interactions are key to skin morphogenesis and homeostasis. We report that maintenance of the hair follicle keratinocyte cell fate is defective in mice with mesenchymal deletion of the CSL/RBP-Jkappa gene, the effector of "canonical" Notch signaling. Hair follicle reconstitution assays demonstrate that this can be attributed to an intrinsic defect of dermal papilla cells. Similar consequences on hair follicle differentiation result from deletion of Wnt5a, a specific dermal papilla signature gene that we found to be under direct Notch/CSL control in these cells. Functional rescue experiments establish Wnt5a as an essential downstream mediator of Notch-CSL signaling, impinging on expression in the keratinocyte compartment of FoxN1, a gene with a key hair follicle regulatory function. Thus, Notch/CSL signaling plays a unique function in control of hair follicle differentiation by the underlying mesenchyme, with Wnt5a signaling and FoxN1 as mediators.