Immunological characterization of chromogranins A and B and secretogranin II in the bovine pancreatic islet

Antisera against chromogranin A and B and secretogranin II were used for analysing the bovine pancreas by immunoblotting and immunohistochemistry. All three antigens were found in extracts of fetal pancreas by one dimensional immunoblotting. A comparison with the soluble proteins of chromaffin granules revealed that in adrenal medulla and in pancreas antigens which migrated identically in electrophoresis were present. In immunohistochemistry, chromogranin A was found in all pancreatic endocrine cell types with the exception of most pancreatic polypeptide-(PP-) producing cells. For chromogranin B, only a faint immunostaining was obtained. For secretorgranin II, A-and B-cells were faintly positive, whereas the majority of PP-cells exhibited a strong immunostaining for this antigen. These results establish that chromogranins A and B and secretogranin II are present in the endocrine pancreas, but that they exhibit a distinct cellular localization

Enzymatic surface hydrolysis of PET enhances bonding in PVC coating

The effect of polyesterase preparations from Thermomyces lanuginosus and Beauveria brongniartii on the hydrophilicity of PET materials was assessed. As a result of polyesterase treatment the hydrophilicity of PET fabrics was increased by up to 8 cm in terms of rising height with increases in surface tension from 6.2 mNm (heat-inactivated control samples) to above 8 mNm. Both enzymes were able to increase the amount of hydroxyl groups on PET from 90 to a maximum of 182 mmol kg-1, while only the B. brongniartii polyesterase released significant amounts of terephthalic acid from PET. Enzymatic surface hydrolysis of PET increased the bonding strength in PVC coating to 13.40 daN 5cm-1 using 0.5% adhesive compared to 11.5 daN 5cm-1 obtained without enzyme pretreatment and 6% of adhesive.The research was financed by the SFG, the FFG, the city of Graz and the province of Styria and by European Commission within the project GRD 2000-30110 Biosynte

On the topology and area of higher dimensional black holes

Over the past decade there has been an increasing interest in the study of black holes, and related objects, in higher (and lower) dimensions, motivated to a large extent by developments in string theory. The aim of the present paper is to obtain higher dimensional analogues of some well known results for black holes in 3+1 dimensions. More precisely, we obtain extensions to higher dimensions of Hawking's black hole topology theorem for asymptotically flat ($\Lambda=0$) black hole spacetimes, and Gibbons' and Woolgar's genus dependent, lower entropy bound for topological black holes in asymptotically locally anti-de Sitter ($\Lambda<0$) spacetimes. In higher dimensions the genus is replaced by the so-called $\sigma$-constant, or Yamabe invariant, which is a fundamental topological invariant of smooth compact manifolds.Comment: 15 pages, Latex2e; typos corrected, a convention clarified, resulting in the simplification of certain formulas, other improvement

Parabolic stable surfaces with constant mean curvature

We prove that if u is a bounded smooth function in the kernel of a nonnegative Schrodinger operator $-L=-(\Delta +q)$ on a parabolic Riemannian manifold M, then u is either identically zero or it has no zeros on M, and the linear space of such functions is 1-dimensional. We obtain consequences for orientable, complete stable surfaces with constant mean curvature $H\in\mathbb{R}$ in homogeneous spaces $\mathbb{E}(\kappa,\tau)$ with four dimensional isometry group. For instance, if M is an orientable, parabolic, complete immersed surface with constant mean curvature H in $\mathbb{H}^2\times\mathbb{R}$, then $|H|\leq 1/2$ and if equality holds, then M is either an entire graph or a vertical horocylinder.Comment: 15 pages, 1 figure. Minor changes have been incorporated (exchange finite capacity by parabolicity, and simplify the proof of Theorem 1)

A classification theorem for Helfrich surfaces

In this paper we study the functional \SW_{\lambda_1,\lambda_2}, which is the the sum of the Willmore energy, $\lambda_1$-weighted surface area, and $\lambda_2$-weighted volume, for surfaces immersed in $\R^3$. This coincides with the Helfrich functional with zero `spontaneous curvature'. Our main result is a complete classification of all smooth immersed critical points of the functional with $\lambda_1\ge0$ and small $L^2$ norm of tracefree curvature. In particular we prove the non-existence of critical points of the functional for which the surface area and enclosed volume are positively weighted.Comment: 21 page

Differentiation in Neuroblastoma: Diffusion-Limited Hypoxia Induces Neuro-Endocrine Secretory Protein 55 and Other Markers of a Chromaffin Phenotype

Background: Neuroblastoma is a childhood malignancy of sympathetic embryonal origin. A high potential for differentiation is a hallmark of neuroblastoma cells. We have previously presented data to suggest that in situ differentiation in tumors frequently proceeds along the chromaffin lineage and that decreased oxygen ( hypoxia) plays a role in this. Here we explore the utility of Neuro-Endocrine Secretory Protein 55 ( NESP55), a novel member of the chromogranin family, as a marker for this process.Methodology/Principal Findings: Immunohistochemical analyses and in situ hybridizations were performed on human fetal tissues, mouse xenografts of human neuroblastoma cell lines, and on specimens of human neuroblastoma/ganglioneuroma. Effects of anaerobic exposure on gene expression by cultured neuroblastoma cells was analyzed with quantitative real-time PCR. Fetal sympathetic nervous system expression of NESP55 was shown to be specific for chromaffin cell types. In experimental and clinical neuroblastoma NESP55 immunoreactivity was specific for regions of chronic hypoxia. NESP55 expression also correlated strikingly with morphological evidence of differentiation and with other chromaffin-specific patterns of gene expression, including IGF2 and HIF2 alpha. Anaerobic culture of five neuroblastoma cell lines resulted in an 18.9-fold mean up-regulation of NESP55.Conclusions/Significance: The data confirms that chronic tumor hypoxia is a key microenvironmental factor for neuroblastoma cell differentiation, causing induction of chromaffin features and NESP55 provides a reliable marker for this neuronal to neuroendocrine transition. The hypoxia-induced phenotype is the predominant form of differentiation in stroma-poor tumors, while in stroma-rich tumors the chromaffin phenotype coexists with ganglion cell-like differentiation. The findings provide new insights into the biological diversity which is a striking feature of this group of tumors

Electrospinning polypropylene with an amino acid as a strategy to bind the antimicrobial peptide Cys-LC-LL-37

Hospital isolation gowns are increasingly competitive, with brands and manufacturers contesting consumer preferences. The textile materials in contact with the skin can acquire secretions and multiresistant microorganisms, causing discomfort and health risks, respectively. A new nanofibrous substrate---polypropylene grafted with l-Cys---was developed with an increased crystallinity, providing its surface with --SH hooks necessary to efficiently cross-link the antimicrobial peptide Cys-LC-LL-37 in order to protect against nosocomial pathogens and their spread to community. Furthermore, this application does not require environmental control of humidity, and it is not susceptible to enzyme and microorganism degradation.The authors acknowledge the Fundação para a Ciência e Tecnologia (FCT) for the PhD Grant SFRH/ BD/91444/2012 and Programa Operacional Capital Humano (POCH) and European Union for co-funding the work.info:eu-repo/semantics/publishedVersio

Misfit-dislocation generation by dissociated dislocations in quantum-well heterostructures

The mechanisms whereby 60° misfit dislocations are generated from dissociated threading dislocations in quantum-well heterostructures are considered. The two partial dislocations experience different misfit stresses, resulting in each partial having a different critical thickness. As a consequence, a number of different dislocation configurations are predicted, including the possibility of producing stacking faults of infinite width. © 1994 The American Physical Societ

The phosphatase and tensin homologue deleted on chromosome 10 mediates radiosensitivity in head and neck cancer

BACKGROUND: For locally advanced squamous cell carcinoma of the head and neck (HNSCC), the recurrence rate after surgery and postoperative radiotherapy is between 20 and 40%, and the 5- year overall survival rate is similar to 50%. Presently, no markers exist to accurately predict treatment outcome. Expression of proteins in the human epidermal growth factor receptor (EGFR) pathway has been reported as a prognostic marker in several types of cancer. METHODS: The aim of this study was to investigate the prognostic value of proteins in the EGFR pathway in HNSCC. For this purpose, we collected surgically resected tissue of 140 locally advanced head and neck cancer patients, all treated with surgery and postoperative radiotherapy. RESULTS: In a multivariate analysis, expression of the phosphatase and tensin homologue deleted on chromosome 10 (PTEN) was significantly related to worse locoregional control (LRC; HR: 2.2, 95% CI: 1.1-4.6; P = 0.03), independent of lymph node metastases (HR: 5.6, 95% CI: 1.2-27.4; P = 0.03) and extranodal spread (HR: 2.7; 95% CI: 1.2- 6.5; P = 0.02). In vitro clonogenic radiosensitivity assays confirmed that overexpression of PTEN resulted in increased radioresistance. CONCLUSION: Our study is the first report showing that expression of PTEN mediates radiosensitivity in vitro and that increased expression in advanced HNSCC predicts worse LRC. British Journal of Cancer (2010) 102, 1778-1785. doi: 10.1038/sj.bjc.6605707 www.bjcancer.com Published online 25 May 2010 (C) 2010 Cancer Research U

Effects of IKAP/hELP1 Deficiency on Gene Expression in Differentiating Neuroblastoma Cells: Implications for Familial Dysautonomia

Familial dysautonomia (FD) is a developmental neuropathy of the sensory and autonomous nervous systems. The IKBKAP gene, encoding the IKAP/hELP1 subunit of the RNA polymerase II Elongator complex is mutated in FD patients, leading to a tissue-specific mis-splicing of the gene and to the absence of the protein in neuronal tissues. To elucidate the function of IKAP/hELP1 in the development of neuronal cells, we have downregulated IKBKAP expression in SHSY5Y cells, a neuroblastoma cell line of a neural crest origin. We have previously shown that these cells exhibit abnormal cell adhesion when allowed to differentiate under defined culture conditions on laminin substratum. Here, we report results of a microarray expression analysis of IKAP/hELP1 downregulated cells that were grown on laminin under differentiation or non-differentiation growth conditions. It is shown that under non-differentiation growth conditions, IKAP/hELP1 downregulation affects genes important for early developmental stages of the nervous system, including cell signaling, cell adhesion and neural crest migration. IKAP/hELP1 downregulation during differentiation affects the expression of genes that play a role in late neuronal development, in axonal projection and synapse formation and function. We also show that IKAP/hELP1 deficiency affects the expression of genes involved in calcium metabolism before and after differentiation of the neuroblastoma cells. Hence, our data support IKAP/hELP1 importance in the development and function of neuronal cells and contribute to the understanding of the FD phenotype