New Implications (new + implication)

Distribution by Scientific Domains

Selected Abstracts

The Yale Report of 1828: A New Reading and New Implications

Michael S. Pak
First page of article [source]

New implications for the QUAKING RNA binding protein in human disease

Carol Anne Chénard
Abstract The use of spontaneously occurring mouse models has proved to be a valuable tool throughout the years to delineate the signals required for nervous system development. This is especially true in the field of myelin biology, with a large number of different models available. The quaking viable mouse models dysmyelination in the nervous system and links the QUAKING RNA binding proteins to myelination and cell fate decisions. In this Mini-Review, we highlight the biological functions attributed to this KH-type RNA binding protein and the recent achievements linking it to human disorders. © 2007 Wiley-Liss, Inc. [source]

Recent insights into R gene evolution

SUMMARY Plants are under strong evolutionary pressure to maintain surveillance against pathogens. Resistance (R) gene-dependent recognition of pathogen avirulence (Avr) determinants plays a major role in plant defence. Here we highlight recent insights into the molecular mechanisms and selective forces that drive the evolution of NB-LRR (nucleotide binding-leucine-rich repeat) resistance genes. New implications for models of R gene evolution have been raised by demonstrations that R proteins can detect cognate Avr proteins indirectly by ,guarding' virulence targets, and by evidence that R protein signalling is regulated by intramolecular interactions between different R functional domains. Comparative genomic surveys of NB-LRR diversity in different species have revealed ancient NB-LRR lineages that are unequally represented among plant taxa, consistent with a Birth and Death Model of evolution. The physical distribution of NB-LRRs in plant genomes indicates that tandem and segmental duplication are important factors in R gene proliferation. The majority of R genes reside in clusters, and the frequency of recombination between clustered genes can vary strikingly, even within a single cluster. Biotic and abiotic factors have been shown to increase the frequency of recombination in reporter transgene-based assays, suggesting that external stressors can affect genome stability. Fitness penalties have been associated with some R genes, and population studies have provided evidence for maintenance of ancient R allelic diversity by balancing selection. The available data suggest that different R genes can follow strikingly distinct evolutionary trajectories, indicating that it will be difficult to formulate universally applicable models of R gene evolution. [source]

Commentary on: return of the cycad hypothesis , does the amyotrophic lateral sclerosis/Parkinsonism dementia complex (ALS/PDC) of Guam have new implications for global health?

P. A. Cox
First page of article [source]

Return of the cycad hypothesis , does the amyotrophic lateral sclerosis/parkinsonism dementia complex (ALS/PDC) of Guam have new implications for global health?

P. G. Ince
Recently published work provides evidence in support of the cycad hypothesis for Lytico,Bodig, the Guamanian amyotrophic lateral sclerosis/parkinsonism dementia complex (ALS/PDC), based on a new understanding of Chamorro food practices, a cyanobacterial origin of ,-methylaminoalanine (BMAA) in cycad tissue, and a possible mechanism of biomagnification of this neurotoxic amino acid in the food chain. BMAA is one of two cycad chemicals with known neurotoxic properties (the other is cycasin, a proven developmental neurotoxin) among the many substances that exist in these highly poisonous plants, the seeds of which are used by Chamorros for food and medicine. The traditional diet includes the fruit bat, a species that feeds on cycad seed components and reportedly bioaccumulates BMAA. Plant and animal proteins provide a previously unrecognized reservoir for the slow release of this toxin. BMAA is reported in the brain tissue of Guam patients and early data suggest that some Northern American patients dying of Alzheimer's disease (AD) have detectable brain levels of BMAA. The possible role of cyanobacterial toxicity in sporadic neurodegenerative disease is therefore worthy of consideration. Recent neuropathology studies of ALS/PDC confirm understanding of this disorder as a ,tangle' disease, based on variable anatomical burden, and showing biochemical characteristics of ,AD-like' combined 3R and 4R tau species. This model mirrors the emerging view that other neurodegenerative disease spectra comprise clusters of related syndromes, owing to common molecular pathology, with variable anatomical distribution in the nervous system giving rise to different clinical phenotypes. Evidence for ,ubiquitin-only' inclusions in ALS/PDC is weak. Similarly, although there is evidence for ,-synucleinopathy in ALS/PDC, the parkinsonian component of the disease is not caused by Lewy body disease. The spectrum of sporadic AD includes involvement of the substantia nigra and a high prevalence of ,incidental',-synucleinopathy in sporadic AD is reported. Therefore the pathogenesis of Lytico,Bodig appears still to have most pertinence to the ongoing investigation of the pathogenesis of AD and other tauopathies. [source]

Communicating quality: a unified model of disclosure and signalling

Andrew F. Daughety
Firms communicate product quality to consumers through a variety of channels. Economic models of such communication take two alternative forms when quality is exogenous: (i),disclosure of quality through a credible direct claim; or (ii),signalling of quality via producer actions that influence buyers' beliefs about quality. In general, these two literatures have ignored one another. We argue that firms should be viewed as choosing which means of communication they will employ. We show that integration of these two alternatives leads to new implications about disclosure, signalling, firm preferences over type, and the social efficiency of the channel of communication employed. [source]

2134: Arachnoid cell changes following elevated pressure and oxidative stress: new implications for optic nerve degeneration

Purpose The study of meningothelial cells (MCs) and their connection to optic nerve function. MCs line the arachnoid layer of the meninges and form a barrier between the CSF and the blood circulation. A previous study revealed a significantly increased proliferation of MCs in the arachnoid surrounding the optic nerve glaucoma patients. Methods To explore a possible role of these cells in the pathogenesis of diseases of the optic nerve, we studied the effect of elevated hydrostatic pressure and oxidative stress on MCs using rotenone to inhibit mitochondrial function and compared them to untreated control cells. Cell viability and proliferation were measured using a MTS-based assay. As a measure of barrier function, we assessed the endocytotic activity of MCs by fluorescence and confocal microscopy following fluorescent-latex bead uptake. Results Exposure of MCs to elevated hydrostatic pressure caused significant cellular proliferation and a dramatic decrease in endocytotic activity. Furthermore, mild oxidative stress severely inhibited endocytosis, thus negatively impacting MC barrier function. Conclusion MCs surround the optic nerve, thereby shielding it from but also conditioning the microenvironment of this sensitive area. As elevated pressure and oxidative stress occur in patients with increased intracranial pressure who have papilledema and probably in some cases of normal-tension glaucoma, these phenomena may impact the function of MCs and thus, contribute to the loss of retinal ganglion cells in the course of these and, perhaps, other optic nerve diseases. [source]