Amorphous calcific tumor of the mitral annulus echocardiographically mimicking a vegetation

We describe echocardiographic findings in an elderly patient with histologically proven amorphous tumor involving the posterior mitral annulus, mimicking a vegetation.     

Role for proteasome activator PA200 and postglutamyl proteasome activity in genomic stability

Proteasome activator PA200 enhances proteasome-mediated cleavage after acidic residues in vitro; however, its role within cells is not known. Here, we show that, in response to ionizing radiation, PA200 forms hybrid proteasomes with 19S caps and 20S core proteasomes that accumulate on chromatin, leading to an increase in proteolytic activity. Unlike many other proteins that respond to DNA damage, the response of PA200 appears to be independent of Ataxia Telangiectasia Mutated and p53, but dependent on DNA-dependent protein kinase activity. Nonetheless, PA200 is critical because PA200-knockdown cells show genomic instability and reduced survival after exposure to ionizing radiation. This phenotype is reproduced by specific inhibition of postglutamyl activity of proteasomes, but combined treatment with PA200 siRNA and postglutamyl inhibitor does not show additive effects on survival. Together, these data suggest a unique role for PA200 in genomic stability that is likely mediated through its ability to enhance postglutamyl cleavage by proteasomes.     

Immunoradiometric assay measurements of insulin-like growth factor-I (IGF-I): Comparison with radioimmunoassays using native or des (1–3) IGF-I as radioligands

Insulin-like growth-factor-binding proteins (BPs) in serum interfere with the measurement of insulin-like growth factor-I (IGF-I). Various assays have been developed to overcome this interference. We evaluated an immunoradiometric (IRMA) assay and compared it with the radioimmunoassay (RIA) using both native IGF-I and a truncated form of IGF-I [des (1–3) IGF-I] as radioligands. The IRMA was simpler (one step assay) and faster (3 hr incubation) than RIA(s) (overnight incubation). Sera were extracted with acid ethanol (AE) before all three assays. Analysis of serum samples (n = 78) performed by use of the two different radioligands in the RIA assays were highly correlated (r = 0.967, P < 0.0001). Measurements of serum IGF-I by IRMA in same samples were also highly correlated with those of the RIA assays (r = 0.952 for RIA and 0.947 for trIGF-I RIA, P < 0.0001 for both). To assess the effect of binding protein-3 (BP-3) levels (after AE extraction) on these assays, BP-3 levels were measured in sera from 36 healthy women. The mean BP-3 level was 3.6 ± 0.79 (S.D.) mg/L (range 1.3–5.0), and there was no significant difference in IGF-I levels measured by the three assays. Also, BP-3 levels were inversely correlated with IGF-I levels as measured by all three methods (r = 0.73 for IRMA, 0.71 for trIGF-I, and 0.75 for IGF-I RIA). To assess the effect of binding protein-1 (BP-1) levels on these assays, IGF-I was also measured by IRMA and trIGF-I RIA in 19 women with advanced breast cancer. Women with breast cancer had significantly higher (P < 0.001) BP-1 levels than age matched healthy women. IGF-I levels measured by IGF-I IRMA were slightly lower than those measured by trIGF-I RIA in breast cancer patients. However, this difference was not statistically significant (P = 0.56). These findings suggest that variations in BP-3 or BP-1 levels after AE extraction have no significant effect in any of these assays. We conclude that trIGF-I as a radioligand provides no added advantage over the standard IGF-I RIA. We also conclude that the IRMA assay is valid for measuring IGF-I and is faster and more convenient than RIA. © 1996 Wiley-Liss, Inc.     

Serum anti-Müllerian hormone and inhibin B in disorders of spermatogenesis

This study investigates circulating concentrations of AMH and inhibin B in men with azoospermia. Serum AMH and inhibin B are significantly lower in the men with nonobstructive azoospermia compared to the controls and the men with obstructive azoospermia, suggesting that these hormones could be markers of nonobstructive azoospermia.     

Identification of phospholipids in human meibum by nano-electrospray ionisation tandem mass spectrometry

Meibum is believed to be the major source of tear film lipids, which are vital in the prevention of excess evaporation of the aqueous phase. The complete lipid composition of meibum has yet to be established. While earlier studies reported the presence of phospholipids in human meibum, recent mass spectrometric studies have not detected them. In this study we use electrospray ionisation tandem mass spectrometry to investigate the presence of phospholipids in meibum and provide comparison to the phospholipid profile of tears.Lipids were extracted from human meibum and tear samples using standard biphasic methods and analysed by nano-electrospray ionisation tandem mass spectrometry using targeted ion scans. A total of 35 choline-containing phospholipids were identified in meibum and the profile of these was similar to that observed in tears, suggesting tear lipids are derived from meibum. The results shown here highlight the need for a combination of optimised techniques to enable the identification of the large range of lipid classes in meibum.