Amphibian metamorphosis: an immunologic opportunity!

Anuran amphibian metamorphosis is an immunologically interesting period. For the investigator, it provides an unusual opportunity for analyzing both humoral regulation of the immune response and the development and maintenance of self-tolerance. Some of the questions one can ask are: Why don't immunocompetent larvae destroy antigenically disparate adult cells as they differentiate within them during metamorphosis? Do the dramatic hormonal changes occurring during this period regulate immunological function? How do animals in metamophorsis protect themselves from their immunologically hostile environment?     

The Social Impacts of Nanotechnology: an Ethical and Political Analysis

This paper attempts some predictions about the social consequences of nanotechnology and the ethical issues they raise. I set out four features of nanotechnology that are likely to be important in determining its impact and argue that nanotechnology will have significant social impacts in—at least—the areas of health and medicine, the balance of power between citizens and governments, and the balance of power between citizens and corporations. More importantly, responding to the challenge of nanotechnology will require confronting “philosophical” questions about the sort of society we wish to create and the role that technology might play in creating it. This in turn will require developing institutions and processes that allow the public to wield real power in relation to technological trajectories. My ultimate contention is that the immediate task established by the likely social impacts of nanotechnology is not so much to develop an ethics of nanotechnology as to facilitate an ethical conversation about nanotechnology.

Predatory prokaryotes: an emerging research opportunity

Predatory prokaryotes have evolved a unique strategy of obtaining energy and biosynthetic materials from their surroundings: acquiring them from other living bacterial cells. These types of microbes have been found in a diverse variety of environments, and may play an important role in modulating microbial population structure and dynamics, as has been hypothesized for marine viruses and possibly protists. Only one genus of predatory bacterium, Bdellovibrio, has been extensively described and studied, though several other examples have been reported in the literature. In this review, the four basic strategies used by currently described predatory prokaryotes will be discussed: "wolfpack" group predation, epibiotic attachment, direct cytoplasmic invasion, and periplasmic invasion. Special adaptations to each approach will be considered, and compared overall to the genetic and biochemical characteristics of symbiotic or pathogenic prokaryotes living within eukaryotic cells. Two specific examples of predatory microbes, Bdellovibrio and Ensifer, will be described in terms of predation strategy, association with host cells, and host range. The prospects for bringing to bear the tools of molecular microbial genetics to the study of predatory prokaryotes will be explored, using current research with Bdellovibrio and Ensifer as examples.     

Nanotechnology: an efficient approach for rejuvenation of aged seeds

Modern agricultural efforts are now in search of an efficient, eco-friendly and sustainable approach for enhanced crop production. Nearly 50–60% of seeds lost occurs due to improper technical handling. Seed deterioration manifests itself as reduction in the rate of germination and growth with increased susceptibility to biotic and abiotic stresses. Furthermore, seed ageing is another economic and scientific issue that is associated with an array of internal (structural, physiological and genetic) and external (storage temperature and relative humidity) factors. Reactive oxygen species (ROS) are believed to be a key player in ageing phenomenon. However, hydrated storage, or ROS blockers are a few of the conventionally used methods to minimize the ageing process. Recently, exogenous applications of different inorganic nanoparticles (metal and metal oxide) are suggested to revitalize and revive aged seeds. Owing to their special properties of nano-size with high surface area they easily penetrate the seed coat. Exposure of nanoparticles has been suggested to neutralize the excess of ROS to a level that initiates hormonal signaling to support early emergence of radicles from the seeds. Nanotechnology has been well explored to enhance the crops nutritional quality, livestock productivity, plant protection from various stressors and in enhancement of seed quality via nanopesticides and nanofertilizers. Aiming at sustainable agriculture practices with fewer inputs, maximum benefits, ecologically safe and compatible technique the nanotechnology is an efficient approach to counteract problems of seed ageing incurring during storage, which is relatively less explored and unresolved conventionally, in general.Keyword: Ageing, Deteriorative reactions, Nanoparticles, Oxidative stress, ROS     

Open access :an opportunity for biomedical research

Open access within the scientific community depends on the scientific context and the practices of the field. In the biomedical domain, the communication of research results is characterised by the importance of the peer reviewing process, the existence of a hierarchy among journals and the transfer of copyright to the editor. Biomedical publishing has become a lucrative market and the growth of electronic journals has not helped lower the costs. Indeed, it is difficult for today's public institutions to gain access to all the scientific literature. Open access is thus imperative, as demonstrated through the positions taken by a growing number of research funding bodies, the development of open access journals and efforts made in promoting open archives. This article describes the setting up of an Inserm portal for publication in the context of the French national protocol for open-access self-archiving and in an international context.     

Hereditary hemochromatosis: an opportunity for gene therapy

Levels of body iron should be tightly controlled to prevent the formation of oxygen radicals, lipoperoxidation, genotoxicity, and the production of cytotoxic cytokines, which result in damage to a number of organs. Enterocytes in the intestinal villae are involved in the apical uptake of iron from the intestinal lumen: iron is further exported from the cells into the circulation. The apical divalent metal transporter-1 (DMT1) transports ferrous iron from the lumen into the cells, while the basolateral transporter ferroportin extrudes iron from the enterocytes into the circulation. Patients with hereditary hemochromatosis display an accelerated transepithelial uptake of iron, which leads to body iron accumulation that results in cirrhosis, hepatocellular carcinoma, pancreatitis, and cardiomyopathy. Hereditary hemochromatosis, a recessive genetic condition, is the most prevalent genetic disease in Caucasians, with a prevalence of one in 300 subjects. The majority of patients with hereditary hemochromatosis display mutations in the gene coding for HFE, a protein that normally acts as an inhibitor of transepithelial iron transport. We discuss the different control points in the homeostasis of iron and the different mutations that exist in patients with hereditary hemochromatosis. These control sites may be influenced by gene therapeutic approaches; one general therapy for hemochromatosis of different etiologies is the inhibition of DMT1 synthesis by antisense-generating genes, which has been shown to markedly inhibit apical iron uptake by intestinal epithelial cells. We further discuss the most promising strategies to develop gene vectors and deliver them into enterocytes.     

Covalent inhibitors: an opportunity for rational target selectivity

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Reshaping of the tumor microenvironment by cellular senescence: An opportunity for senotherapies

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Optical imaging and tumor angiogenesis

Tumor angiogenesis is essential for tumor growth and progression. Therefore, targeting tumor blood vessels is a promising approach for cancer therapy. Angiogenesis, the formation of blood vessels, is a multistep process, and strongly influenced by the microenvironment. There are no in vitro assays that can resemble this dynamic process in vivo. For this reason, animal models and imaging technologies are critical for studying tumor angiogenesis, identifying therapeutic targets as well as validating the targets. Non-invasive molecular imaging in animal models presents an unprecedented opportunity and ability for us to perform repetitive observations and analysis of the biological processes underlying tumor angiogenesis and tumor progression in living animals in real time. As we gain a better understanding of the fundamental molecular nature of cancer, these techniques will be an important adjunct in translating the knowledge into clinical practice. This important information may elucidate how the tumor blood vessels behave and respond to certain treatments and therapies.     

Nanotechnology and biosensors

Nanotechnology is playing an increasingly important role in the development of biosensors. The sensitivity and performance of biosensors is being improved by using nanomaterials for their construction. The use of these nanomaterials has allowed the introduction of many new signal transduction technologies in biosensors. Because of their submicron dimensions, nanosensors, nanoprobes and other nanosystems have allowed simple and rapid analyses in vivo. Portable instruments capable of analyzing multiple components are becoming available. This work reviews the status of the various nanostructure-based biosensors. Use of the self-assembly techniques and nano-electromechanical systems (NEMS) in biosensors is discussed.     

Americans' Nanotechnology Risk Perception:

Although proposed nanotechnology applications hold great promise, little is known about the potential associated risks. This lack of clarity on the level of risk associated with nanotechnology has forced people to make decisions about consumption with incomplete information. A national random digit dialing telephone survey (N= 1014) was conducted in the United States to assess knowledge of nanotechnology and perception of risk in August 2006. This investigation looks critically at individuals' responses to questions about the balance of risks and benefits of nanotechnology, both at the outset of the survey and after respondents were given a brief introduction to the potential benefits and risks of the technology. Models were created to characterzise respondents who said they did not know how nanotechnology's risks and benefits balanced in the “preinformation” condition but who, in the postinformation condition, had a different opinion. Respondents who were highly educated, members of the Republican Party, or male were more likely to switch from “don't know” in the preinformation condition to “benefits outweigh risks” in the postinformation condition, whereas respondents who were less educated, members of the Democratic Party, or female were more likely to switch from “don't know” in the preinformation condition to “risks outweigh benefits” in the postinformation condition. This is the first study to our knowledge to develop a significant model of nanotechnology risk perception change, specifically with regard to gender differences. The power of information provision to sway opinions is also supported, highlighting the importance of developing educational efforts targeting vulnerable populations.     

Comment on David Roediger's seizing freedom: slave emancipation and liberty for all

ABSTRACT

David Roediger's important new book, Seizing Freedom, invites us to reconsider the possibilities of social change inspired by ‘slave self-emancipation’. Employing the concept of ‘revolutionary times’, the book makes the case for inspirational activism catalyzing broad social reform.     

Nanotechnology in Therapeutics: hydrogels and beyond

Nanotechnology in Therapeutics: Current Technology and Applications, Edited by Nicholas A. Peppas, J. Zach Hilt and J. Brock Thomas (Horizon Bioscience, 2007) contains seventeen chapters written by leading specialists in the field of polymeric materials for drug delivery and holds wealth of background as well as state of the art material divided into four sections: "Intelligent Therapeutics and Responsive Delivery Systems for Improved Absorption and Delivery", "Therapeutic Micro- and Nanodevices", "Nanostructured Therapeutic Materials" and "Nanoparticulate Systems in Intelligent Therapy". This newly published volume provides a stimulating read and a good point of reference to researchers wishing to explore the interdisciplinary fusion of nnanotechnology and medical therapeutics. The following gives brief summary and critically reviews the book.