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Growth-promoting effect of Rh(D) antibody on human pancreatic islet cells

2012-11-29T00:14:43Z

Growth-promoting effect of Rh(D) antibody on human pancreatic islet cells Feller John; Simpson Ann; Nelson Margaret; Swan M; O'Connell Philip; Hawthorne Wayne; Tao Chang; O'Brien Bronwyn Context/Objective: Hyperinsulinism with islet cell hyperplasia is a frequent complication, of unknown cause, in hemolytic disease of the newborn, occurring in Rh(D)-positive infants of Rh-isoimmunized Rh(D)-negative mothers, but not in infants with other hemolytic disorders. We investigated the possibility that trans-placentally acquired anti-D Ig is the cause of both conditions. Design: Monolayer cultures of human islet cells were exposed to sera from Rh-isoimmunized mothers and newborns, where jaundice, hyperinsulinism, and hypoglycemia in the infant had ensued. Parallel cultures with anti-D, specific anti-D monoclonal antibodies, normal human Ig (15 Î¼g/ml), and serum controls were also undertaken. Islet cell proliferation was determined by [ 3H]thymidine incorporation. Insulin storage and chronic and acute insulin secretion to glucose were analyzed by RIA. Rh(D) surface antigen expression was determined on islet cells by flow cytometric analysis. Results: Islet cell proliferation and insulin secretion were significantly greater in coculture with test sera (P < 0.01; n = 8) and with anti-D (P < 0.001; n = 8), compared with either controls or Ig. After 8 d of growth, the static incubation experiment showed a 3.5-fold response to glucose stimulus in all sera. Rh(D) antigen expression was detected on the islet cell surface by flow cytometry, and islet cell morphology was normal. Colocalization of the proliferation marker Ki67 with insulin by immunofluorescent staining further indicated that Rh(D) antibody promoted islet growth. Conclusions: The anti-Rh(D) islet cell proliferative effect generates neonatal hyperinsulinism in Rh isoimmunization. Anti-Rh(D) may have application for islet cell proliferation in diabetes mellitus treatment for Rh(D)-positive subjects. Further analysis is required. Copyright © 2008 by The Endocrine Society.

Southern Roles in Global Nanotechnology Innovation: Perspectives from Thailand and Australia

2012-11-05T03:36:18Z

Southern Roles in Global Nanotechnology Innovation: Perspectives from Thailand and Australia Maclurcan Donald The term `nano-divide¿ has become a catch-phrase for describing various kinds of global nanotechnology inequities. However, there has been little in-depth exploration as to what the global nano-divide really means, and limited commentary on its early nature. Furthermore, the literature often presents countries from the Global South as `passive¿ agents in global nanotechnology innovation¿without the ability to develop endogenous nanotechnology capabilities. Yet others point to nanotechnology providing opportunities for the South to play new roles in the global research and development process. In this paper I report on the findings of a qualitative study that involved the perspectives of 31 Thai and Australian key informants, from a broad range of fields. The study was supplemented by a survey of approximately 10% of the Thai nanotechnology research community at the time. I first explore how the global nano-divide is understood and the implication of the divide¿s constructs in terms of the roles to be played by various countries in global nanotechnology innovation. I then explore the potential nature of Southern passivity and barriers and challenges facing Southern endogenous innovation, as well as an in-depth consideration of the proposition that Southern countries could be `active¿ agents in the nanotechnology process. I argue that it is the nano-divide relating to nanotechnology research and development capabilities that is considered fundamental to nanotechnology¿s Southern outcomes. The research suggests that Southern countries will encounter many of the traditional barriers to engaging with emerging technology as well as some new barriers relating to the nature of nanotechnology itself. Finally, the research suggests that nanotechnology may offer new opportunities for Southern countries to enter the global research and development picture.

Thin films of ruthenium phthalocyanine complexes

2013-03-25T04:14:49Z

Thin films of ruthenium phthalocyanine complexes Rawling Tristan; Austin Christine; Hare Dominic; Doble Philip; Zareie Hadi; Mcdonagh Andrew Four new ruthenium phthalocyanine complexes bearing axial ligands with thioacetate groups that facilitate thin film formation on gold surfaces are presented. Scanning tunnelling microscopy (STM) images and surface coverage data obtained by solution inductively coupled plasma mass spectrometry (ICP-MS) experiments show that peripheral and axial ligand substituents on the complexes have a significant effect on their surface coverage. A laser ablation ICP-MS technique that provides information about thin films across macro-sized areas is described here for the first time. Using the technique, the maximum surface coverage of a ruthenium phthalocyanine complex was found to occur within one minute of gold substrate immersion in the complex-containing solution.

Plasmon resonance and electric field amplification of crossed gold nanorods

2012-09-18T02:37:54Z

Plasmon resonance and electric field amplification of crossed gold nanorods Cortie Michael; Stokes Nicholas; Mcdonagh Andrew Here we explore the unusual plasmon resonances of crossed gold nanorod structures of varying geometries. Using numerical simulations, we show that the resonances of simple rods are hybridized and blue-shifted in the composite structures and that these structures are surrounded by spatially extended and high intensity electric fields. This attribute suggests several potential uses for these shapes, for example as a nano-antenna for the generation of two-photon fluorescence.