Serum intact parathyroid hormone and ionised calcium concentration in children with renal insufficiency

We report our experience of the use of an immunoradiometric assay for intact parathyroid hormone (i-PTH) and the measurement of plasma ionised calcium concentration (PCa2+) in 73 children with chronic renal insufficiency (CRI); plasma creatinine concentration (PCr) 52-856 mumol/l. There was a poor correlation between i-PTH and PCr (r = 0.10, n = 552) compared with that for C-terminal PTH and PCr (r = 0.60, n = 248), suggesting that the i-PTH assay is independent of renal function in this group of treated children. A clear response of i-PTH to a low total plasma Ca (tPCa) and PCa2+ was observed. There was a significant positive correlation between both tPCa and PCa2+ (r = 0.50, n = 389) and the fraction of Ca2+ (the fraction of tCa which was ionised) and PCa2+ (r = 0.50, n = 389). The finding of a low or normal PCa2+ with a low calculated fraction of Ca2+ was frequently observed, i.e. the measured tPCa was unexpectedly high, suggesting complexing of Ca2+ by accumulated anions in CRI. There was a poor relationship between the plasma albumin concentration and both bound plus complexed Ca (tPCa minus PCa2+) and the fraction of Ca2+ (r = 0.15 and -0.17, respectively). The positive predictive value for a raised i-PTH of a tubular reabsorption of phosphate of less than 80% was 0.87, and of an alkaline phosphatase greater than 800 U/l was 0.37.(ABSTRACT TRUNCATED AT 250 WORDS)     

Processing optimization of solution derived PbZr1−xTixO3 thin films for piezoelectric applications

Abstract

Processing optimization allowed the sol-gel fabrication of 1 μm thick, phase pure perovskite thin films with identical grain size and controlled texture. This made it possible to fabricate stress compensated beams to measure the transverse piezoelectric coefficient over the whole composition range of PbZr_1?xTi_xO₃. The highest value of -12.1 C/m² was measured for (100)/(001) textured PZT53/47. For (111) textured films the maximum value of -8.7 C/m² was found to be in the tetragonal phase field at 55% Ti.     

IL-4-deficient Balb/c mice resist infection with Leishmania major

Mice with a genetically engineered deficiency for either IL-4 or IFN-gamma R1 (single mutants), and IL-4/IFN-gamma R1 (double mutants) on the Balb/c and 129Sv background were used to study the course of infection with Leishmania major. In contrast to genetically resistant 129Sv wildtype mice, IL-4/IFN-gamma R1 double mutant mice developed fetal disease with parasite dissemination to visceral organs similar to mice lacking IFN-gamma R1 only. Balb/c mice, which are exquisitely susceptible to L. major, were rendered resistant to infection by disruption of the IL-4 gene. As compared to homozygous IL-4+/- mice, heterozygous IL-4+/- mice, heterozygous IL-4+/- animals consistently developed smaller lesions with less ulceration and necrosis, indicating the likelihood of gene-dosage effects. This implicates that the magnitude of the IL-4 response determines the severity of disease. CD4+ T cells of IL-4-deficient mice showed impaired Th2 cell development, as assessed by quantitative RT-PCR of characteristic cytokines. Development of resistance is not explained by default Th1 development, because this was observed only at very late stages of infection. Moreover, the induction of inflammatory cytokines (e.g., IL-1 alpha, IL-1 beta, TNF-alpha, IL-12) together with iNOS in the lesion and draining lymph nodes was not altered in the absence of IL-4.     

Resistance of Fc receptor- deficient mice to fatal glomerulonephritis

Immune complex-mediated inflammation is a common mechanism of various autoimmune diseases. Glomerulonephritis (GN) is one of these diseases, and the main mechanism of the induction of GN has been unclear. We examined the contribution of Fc receptors in the induction of nephrotoxic GN by establishing and analyzing mice deficient in the Fc receptor gamma chain (FcRgamma). Whereas all wild-type mice died from severe glomerulonephritis with hypernitremia by administration of anti-glomerular basement membrane (GBM) antibodies, all FcRgamma-deficient mice survived. Histologically, wild-type mice showed glomerular hypercellularity and thrombotic changes, whereas the renal tissue in FcRgamma-deficient mice was almost intact. Deposition of anti-GBM antibody as well as complement components in the GBM were equally observed in both wild-type and knockout mice. These results demonstrate that the triggering of this type of glomerulonephritis is completely dependent on FcR+ cells.     

Mediation in dyadic data at the level of the dyads: A structural equation modeling approach.

An extended version of the Common Fate Model (CFM) is presented to estimate and test mediation in dyadic data. The model can be used for distinguishable dyad members (e.g., heterosexual couples) or indistinguishable dyad members (e.g., homosexual couples) if (a) the variables measure characteristics of the dyadic relationship or shared external influences that affect both partners; if (b) the causal associations between the variables should be analyzed at the dyadic level; and if (c) the measured variables are reliable indicators of the latent variables. To assess mediation using Structural Equation Modeling, a general three-step procedure is suggested. The first is a selection of a good fitting model, the second a test of the direct effects, and the third a test of the mediating effect by means of bootstrapping. The application of the model along with the procedure for assessing mediation is illustrated using data from 184 couples on marital problems, communication, and marital quality. Differences with the Actor-Partner Interdependence Model and the analysis of longitudinal mediation by using the CFM are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Iodine-131-MIBG therapy of a patient with carcinoid liver metastases

Iodine-13I-metaiodobenzylguanidine (MIBG) is highly concentrated by >60% of carcinoid metastases and thus provides a therapeutic opportunity. METHODS: A symptomatic patient with carcinoid liver metastases, unresponsive to chemotherapy combined with interferon-alpha, was subsequently treated with 131I-MIBG. RESULTS: Radionuclide therapy, which was without significant side effects, resulted in symptomatic improvement and reduced urinary 5-hydroxyindoleacetic acid levels. No new metastases were observed for 15 mo after 131I-MIBG therapy. Gross cystic change occurred in existing liver metastases, presumably as a result of ischemic necrosis. Surgical deroofing and aspiration of cysts led to regeneration of normal liver tissue. CONCLUSION: Iodine-131-MIBG therapy can provide prolonged symptomatic relief and improved quality of life in patients with metastatic carcinoid disease unresponsive to other therapies. The antitumor effect of 131I-MIBG was accompanied by few side effects, suggesting that this therapy should be considered in symptomatic patients with an early stage of disease.     

Piezoelectric micromachined ultrasonic transducers based on PZT thin films

This paper describes fabrication and characterization results of piezoelectric micromachined ultrasonic transducers (pMUTs) based on 2-microm-thick Pb(Zr0.53Ti0.47O3) (PZT) thin films. The applied structures are circular plates held at four bridges, thus partially unclamped. A simple analytical model for the fully clamped structure is used as a reference to optimize design parameters such as thickness relations and electrodes, and to provide approximate predictions for coupling coefficients related to previously determined thin film properties. The best coupling coefficient was achieved with a 270-microm plate and amounted to kappa2 = 5.3%. This value compares well with the calculated value based on measured small signal dielectric (epsilon = 1050) and piezoelectric (e3l,f = 15 Cm(-2)) properties of the PZT thin film at 100 kV/cm dc bias. The resonances show relatively large Q-factors, which can be partially explained by the small diameters as compared to the sound wavelength in air and in the test liquid (Fluorinert 77). A transmit-receive experiment with two quasi-identical pMUTs was performed showing significant signal transmission up to a distance of 20 cm in air and 2 cm in the test liquid.