Health Services Use and Costs in Individuals with Autism Spectrum Disorder in Germany: Results from a Survey in ASD Outpatient Clinics

Journal of Autism and Developmental Disorders - Autism spectrum disorders (ASD) are associated with high services use, but European data on costs are scarce. Utilisation and annual costs of 385...     

Short-Term Functional Adaptation of Aquaporin-1 Surface Expression in the Proximal Tubule,a Component of Glomerulotubular Balance

Transepithelial water flow across the renal proximal tubule is mediated predominantly by aquaporin-1 (AQP1). Along this nephron segment, luminal delivery and transepithelial reabsorption are directly coupled, a phenomenon called glomerulotubular balance. We hypothesized that the surface expression of AQP1 is regulated by fluid shear stress, contributing to this effect. Consistent with this finding, we found that the abundance of AQP1 in brush border apical and basolateral membranes was augmented >2-fold by increasing luminal perfusion rates in isolated, microperfused proximal tubules for 15 minutes. Mouse kidneys with diminished endocytosis caused by a conditional deletion of megalin or the chloride channel ClC-5 had constitutively enhanced AQP1 abundance in the proximal tubule brush border membrane. In AQP1-transfected, cultured proximal tubule cells, fluid shear stress or the addition of cyclic nucleotides enhanced AQP1 surface expression and concomitantly diminished its ubiquitination. These effects were also associated with an elevated osmotic water permeability. In sum, we have shown that luminal surface expression of AQP1 in the proximal tubule brush border membrane is regulated in response to flow. Cellular trafficking, endocytosis, an intact endosomal compartment, and controlled protein stability are the likely prerequisites for AQP1 activation by enhanced tubular fluid shear stress, serving to maintain glomerulotubular balance.     

Comparison of the roll-plate and sonication techniques in the diagnosis of microbial ureteral stent colonisation: results of the first prospective randomised study

Background

Microbial ureteral stent colonisation (MUSC) is one leading risk factor for complications associated with ureteral stent placement. As MUSC remains frequently undetected by standard urine cultures, its definitive diagnosis depends on microbiological investigation of the stent. However, a standard reference laboratory technique for studying MUSC is still lacking.

Materials and methods

A total of 271 ureteral stents removed from 199 consecutive patients were investigated. Urine samples were obtained prior to device removal. Stents were divided into four parts. Each part was separately processed by the microbiology laboratory within 6 h. Ureteral stents were randomly allocated to roll-plate or sonication, respectively, and analysed using standard microbiological techniques. Demographic and clinical data were prospectively collected using a standard case-report form.

Results

Overall, roll-plate showed a higher detection rate of MUSC compared with sonication (35 vs. 28 %, p < 0.05) and urine culture (35 vs. 8 %, p < 0.05). No inferiority of Maki’s technique was observed even when stents were stratified according to indwelling time below or above 30 days. Compared with roll-plate, sonication commonly failed to detect Enterococcus spp., coagulase-negative staphylococci (CoNS) and Enterobacteriaceae. In addition, sonication required more hands-on time, more equipment and higher training than roll-plate in the laboratory.

Conclusions

This prospective randomised study demonstrates the superiority of Maki’s roll-plate technique over sonication in the diagnosis of MUSC and that urine culture is less sensitive than both methods. The higher detection rate, simplicity and cost-effectiveness render roll-plate the methodology of choice for routine clinical investigation as well as basic laboratory research.     

SPAK Differentially Mediates Vasopressin Effects on Sodium Cotransporters

Activation of the Na⁺-K⁺-2Cl⁻-cotransporter (NKCC2) and the Na⁺-Cl⁻-cotransporter (NCC) by vasopressin includes their phosphorylation at defined, conserved N-terminal threonine and serine residues, but the kinase pathways that mediate this action of vasopressin are not well understood. Two homologous Ste20-like kinases, SPS-related proline/alanine-rich kinase (SPAK) and oxidative stress responsive kinase (OSR1), can phosphorylate the cotransporters directly. In this process, a full-length SPAK variant and OSR1 interact with a truncated SPAK variant, which has inhibitory effects. Here, we tested whether SPAK is an essential component of the vasopressin stimulatory pathway. We administered desmopressin, a V2 receptor–specific agonist, to wild-type mice, SPAK-deficient mice, and vasopressin-deficient rats. Desmopressin induced regulatory changes in SPAK variants, but not in OSR1 to the same degree, and activated NKCC2 and NCC. Furthermore, desmopressin modulated both the full-length and truncated SPAK variants to interact with and phosphorylate NKCC2, whereas only full-length SPAK promoted the activation of NCC. In summary, these results suggest that SPAK mediates the effect of vasopressin on sodium reabsorption along the distal nephron.The furosemide-sensitive Na⁺-K⁺-2Cl⁻-cotransporter (NKCC2) of the thick ascending limb (TAL) and the thiazide-sensitive Na⁺-Cl⁻-cotransporter (NCC) of the distal convoluted tubule (DCT) are key regulators of renal salt handling and therefore participate importantly in BP and extracellular fluid volume homeostasis.¹ Loss-of-function mutants in the SLC12A1/ A3 genes encoding NKCC2 and NCC cause salt-losing hypotension and hypokalemic alkalosis in Bartter’s and Gitelman’s syndromes,^2,3 whereas their overactivity may contribute to essential hypertension.^4,5 Recently, attention has been focused on the two closely related STE20-like kinases, SPS-related proline/alanine-rich kinase (SPAK) and oxidative stress responsive kinase 1 (OSR1), which can phosphorylate NKCC2 and NCC at their N-terminal conserved threonine or serine residues (T96, T101, and T114 of mouse NKCC2 and T53, T58, and S71 of mouse NCC) and thereby activate the transporters.^6–8 Despite the high homology between SPAK and OSR1 and their overlapping renal expression patterns, distinct roles along the nephron have been suggested based on data from SPAK-deficient and kidney-specific OSR1-deficient mice: deletion of SPAK primarily impairs the function of NCC, whereas deletion of OSR1 negatively affects NKCC2.^9–11 The complex functional properties of a WNK-SPAK/OSR1-N(K)CC interaction cascade are currently being defined.¹² Recently, arginine vasopressin (AVP), signaling via the V2 receptor (V2R), has been identified as an efficient activator of both cotransporters, affecting their luminal trafficking and phosphorylation.^13–18 Because plasma AVP levels may vary not only with the sleep-wake cycle or long-term physiologic challenges, but also with pulsatile changes over the short term, distinct, time-dependent responses may occur.¹⁹ SPAK and OSR1 are well placed to regulate distal NaCl reabsorption in response to AVP. Here we tested the role of SPAK in AVP-induced activation of NKCC2 and NCC, acutely and during long-term treatment. The results suggest that SPAK is an essential kinase that modulates distal nephron function in response to AVP stimulation.     

Tissue-type plasminogen activator increases the binding of glu-plasminogen to clots.

Porcine tissue-type plasminogen activator (t-PA) increases the binding of 125I-glu-plasminogen to clots made from human plasma or purified fibrinogen in a time and t-PA concentration dependent fashion. The accumulation of plasminogen was faster and greater on noncrosslinked plasma clots than on clots which had been crosslinked by Factor XIIIa. Furthermore, the uptake of plasminogen to crosslinked fibrin clots occurred at a slower rate in the presence of alpha 2-plasmin inhibitor (alpha 2 PI) than in its absence. The kinetics of the uptake of 125I-plasminogen were analyzed using SDS-polyacrylamide gel electrophoresis and radioautography of solubilized plasma clots formed in the presence of t-PA. During the initial phase there was a decrease of clot-bound glu-plasminogen; simultaneously, there was a slight increase in clot-bound glu-plasmin and in plasmin complexed to alpha 2 PI that was crosslinked to alpha-chain polymers of fibrin. This was followed by a marked increase in clot-bound plasminogen having glutamic acid as NH2-terminal (glu-plasminogen) and gluplasmin. t-PA-induced enhancement of glu-plasminogen uptake appears to be mediated by plasmin but does not require the conversion of glu-plasminogen to plasminogen having lysine or methionine as NH2-terminal. The described mechanism assures an adequate supply of clot-bound plasmin, which is the enzyme ultimately involved in the degradation of fibrin.     

The FNTB promoter polymorphism rs11623866 as a potential predictive biomarker for lonafarnib treatment of ovarian cancer patients

Aim

Despite promising preclinical findings regarding clinical utility of farnesyltransferase inhibitors (FTI), such as lonafarnib, success of clinical trials is limited. A multicentre AGO-OVAR-15 phase II trial reported an unfavourable effect of lonafarnib on the outcome of patients with advanced ovarian cancer. This study was performed as a genetic subgroup analysis of the AGO-OVAR-15 trial, and investigated the utility of the promoter polymorphism rs11623866 of the farnesyltransferase ß-subunit gene (FNTB) in predicting the clinical effectiveness of lonafarnib.

Methods

The influence of rs11623866 (c.-609G > C) on FNTB promoter activity was investigated by electrophoretic-mobility-shift assay, luciferase-reporter assay and RT-qPCR. A total of 57 out of 105 patients from the AGO-OVAR-15 trial, treated with carboplatin and paclitaxel ± lonafarnib, was genotyped for rs11623866 by restriction fragment length polymorphism analysis. Genotype-dependent survival analysis was performed by Kaplan–Meier analysis.

Results

The presence of the G allele was associated with increased FNTB promoter activity compared with the C allele. An unfavourable effect of lonafarnib was limited to patients carrying a GG genotype (HR_PFS 6.2, 95%CI = 2.01, 19.41, P = 0.002; HR_OS 9.6, 95%CI = 1.89, 48.54, P = 0.006). Median progression free survival (PFS) for patients with the GG genotype in the lonafarnib treated arm was 10 months, whereas median PFS without FTI-treatment was 40 months. Median overall survival (OS) in the lonafarnib-treated group was 19 months, whereas median OS was not reached in the untreated group.

Conclusions

Discrepancies between preclinical success and clinical failure may be due to the patients'' genetic variability of FNTB. Therefore, our results may encourage retrospective evaluation of FNTB polymorphisms in previous FTI studies, especially those reporting positive FTI response.