On Some Nuisance Parameter Free Uniformly Most Powerful Tests

TAKEUCHI (1969) provides a uniformly most powerful (UMP) one side test for testing the location parameter of the two parameters exponential model when the scale parameter is unknown. The power of his similar size α test depends, however, on the unknown scale parameter. In this case and in more general situations when there exists a sufficient statistic for the nuisance parameter, the theory of generalized THOMPSON's distributions, more specifically, the Thompsonization of a test statistic, LAURENT (1959, 1972) provides a UMP test whose power does not depend on the nuisance parameter. Examples of application of the general nuisance parameter free test procedure include here the truncated exponential, the inverse Gaussian, and the geometric distributions.     

Effect of carboxyl-reduced heparin on the growth inhibition of bovine pulmonary artery smooth muscle cells

Heparin (HP) inhibits the proliferation of bovine pulmonary artery smooth muscle cells (BPASMC’s), among other cell types in vitro. In order to develop a potential therapeutic agent to reverse vascular remodeling, we are involved in deciphering the relationship between the native HP structure and its antiproliferative potency. We have previously reported the influence of the molecular size and the effects of various O-sulfo and N-acetyl groups of HP on growth-inhibitory activity. In this study, to understand the influence of carboxyl groups in the HP structure required for endogenous activity, a chemically modified derivative of native HP was prepared by converting the carboxyl groups of hexuronic acid residues in HP to primary hydroxyl groups. This modification procedure involves the treatment of HP with N-(3-dimethylaminopropyl)-N-ethylcarbodiimide followed by reduction with NaBH₄ to yield carboxyl-reduced heparin (CR-HP). When compared to the antiproliferative potency of native HP on cultured BPASMC’s at three dose levels (1, 10, and 100 μg/mL), the CR-HP showed significantly less potency at all the doses. These results suggest that hexuronic acid residues in both major and variable sequences in HP are essential for the antiproliferative properties of native HP.     

Apical Scaffolding Protein NHERF2 Modulates the Localization of Alternatively Spliced Plasma Membrane Ca2+ Pump 2B Variants in Polarized Epithelial Cells

The membrane localization of the plasma membrane Ca²⁺-ATPase isoform 2 (PMCA2) in polarized cells is determined by alternative splicing; the PMCA2w/b splice variant shows apical localization, whereas the PMCA2z/b and PMCA2x/b variants are mostly basolateral. We previously reported that PMCA2b interacts with the PDZ protein Na⁺/H⁺ exchanger regulatory factor 2 (NHERF2), but the role of this interaction for the specific membrane localization of PMCA2 is not known. Here we show that co-expression of NHERF2 greatly enhanced the apical localization of GFP-tagged PMCA2w/b in polarized Madin-Darby canine kidney cells. GFP-PMCA2z/b was also redirected to the apical membrane by NHERF2, whereas GFP-PMCA2x/b remained exclusively basolateral. In the presence of NHERF2, GFP-PMCA2w/b co-localized with the actin-binding protein ezrin even after disruption of the actin cytoskeleton by cytochalasin D or latrunculin B. Surface biotinylation and fluorescence recovery after photobleaching experiments demonstrated that NHERF2-mediated anchorage to the actin cytoskeleton reduced internalization and lateral mobility of the pump. Our results show that the specific interaction with NHERF2 enhances the apical concentration of PMCA2w/b by anchoring the pump to the apical membrane cytoskeleton. The data also suggest that the x/b splice form of PMCA2 contains a dominant lateral targeting signal, whereas the targeting and localization of the z/b form are more flexible and not fully determined by intrinsic sequence features.     

The likelihood of persistent arthritis increases with the level of anti-citrullinated peptide antibody and immunoglobulin M rheumatoid factor: a longitudinal study of 376 patients with very early undifferentiated arthritis

Introduction  

We wanted to assess the importance of the levels of anti-citrullinated peptide antibody (anti-CCP) and immunoglobulin M (IgM) rheumatoid factor (RF) in predicting development of persistent arthritis from undifferentiated arthritis (UA), and to investigate whether there is an added predictive value for persistent arthritis in testing for both anti-CCP and IgM RF.     

Akt activity protects rheumatoid synovial fibroblasts from Fas-induced apoptosis by inhibition of Bid cleavage

Introduction  

Synovial hyperplasia is a main feature of rheumatoid arthritis pathology that leads to cartilage and bone damage in the inflamed joints. Impaired apoptosis of resident synoviocytes is pivotal in this process. Apoptosis resistance seems to involve defects in the extrinsic and intrinsic apoptotic pathways. The aim of this study was to investigate the association of PI3Kinase/Akt and the mitochondrial apoptotic pathway in the resistance of rheumatoid arthritis (RA) fibroblast like synovial cells (FLS) to Fas-mediated apoptosis.     

Synthesis of positively charged galactose-bearing surfactants

An approach to the synthesis of cationic carbohydrate surfactants with potential antimicrobial and transfecting activities is proposed.     

Gold nanoparticles disturb nuclear chromatin decondensation in mouse sperm in vitro

The effect of gold nanoparticles on mouse epididymal sperm has been studied using the model system of nuclear chromatin decondensation in vitro. It is shown that the treatment of gametes, preliminary membrane-freed by sodium dodecyl sulfate, in the mediums containing gold nanoparticles (with diameter ∼2.5 nm) in concentrations 1.0 × 10¹⁵ or 0.5 × 10¹⁵ particles/ml and following incubation in dithiothreitol solution (DTT) resulted in failure of chromatin decondensation process and nucleus structure. We conclude that gold nanoparticles possess spermatotoxicity. The mechanism of cytotoxic effect of gold nanoparticles may be related with their interaction with molecules of double-helix DNA. The model system studied in this research is applicable for further investigations of cytotoxic effects of nanoparticles of different origin and made of different metals.     

Presence, richness and extinction of birds of prey in the Mediterranean and Macaronesian islands

Aim We analyse modern patterns of richness, presence and extinction of birds of prey (Accipitriforms and Falconiforms) in the Mediterranean and Macaronesian islands, using an integrated approach involving both biogeographical and human‐induced factors. Location Forty‐three islands grouped into nine Mediterranean and Macaronesian archipelagos. Methods Information about 25 species breeding during the past century and their fate (permanence or extinction) was compiled from the literature and regional reports. Jaccard's similarity index and cluster analyses were applied to define island assemblages. In order to detect the factors driving richness, presence and extinction, generalized linear models (GLM) were applied to 32 explanatory variables, evaluating location, physiography, isolation of island, taxonomic affinities and life‐history patterns of the raptor species. Results Islands belonging to the same archipelago clustered when raptor assemblages were compared, revealing a marked biogeographical signal. Species richness was influenced by island area and accessibility from the continent (explained deviance of 51% in the GLM). Models of the probability of presence (explained deviance of 32%) revealed positive influences of migratory patterns (maximum for partial migrants), size of distribution areas and proximity to main migration routes. The model for probability of extinction explained only 8% of the deviance. It revealed that populations living on islands with a high density of human population were more prone to disappear. Also, raptors depending on human resources had more risk of extinction. Main conclusions Basic predictions of island biogeography can explain current patterns of raptor richness in the study area despite millennia of intense humanization processes. Colonization success appears to depend on life‐history traits linked to migratory and dispersal strategies, whereas body‐size constraints are not influential. Additionally, our results reveal the importance of species‐based analyses in studies of island biogeography.