Retinal changes in Alzheimer's disease— integrated prospects of imaging, functional and molecular advances

Alzheimer's Disease (AD) is a devastating neurodegenerative disorder of the brain, clinically characterised by cognitive deficits that gradually worsen over time. There is, at present, no established cure, or disease-modifying treatments for AD. As life expectancy increases globally, the number of individuals suffering from the disease is projected to increase substantially. Cumulative evidence indicates that AD neuropathological process is initiated several years, if not decades, before clinical signs are evident in patients, and diagnosis made. While several imaging, cognitive, CSF and blood-based biomarkers have been proposed for the early detection of AD; their sensitivity and specificity in the symptomatic stages is highly variable and it is difficult to justify their use in even earlier, pre-clinical stages of the disease. Research has identified potentially measurable functional, structural, metabolic and vascular changes in the retina during early stages of AD. Retina offers a distinctively accessible insight into brain pathology and current and developing ophthalmic technologies have provided us with the possibility of detecting and characterising subtle, disease-related changes. Recent human and animal model studies have further provided mechanistic insights into the biochemical pathways that are altered in the retina in disease, including amyloid and tau deposition. This information coupled with advances in molecular imaging has allowed attempts to monitor biochemical changes and protein aggregation pathology in the retina in AD. This review summarises the existing knowledge that informs our understanding of the impact of AD on the retina and highlights some of the gaps that need to be addressed. Future research will integrate molecular imaging innovation with functional and structural changes to enhance our knowledge of the AD pathophysiological mechanisms and establish the utility of monitoring retinal changes as a potential biomarker for AD

The Physiology and Proteomics of Drought Tolerance in Maize: Early Stomatal Closure as a Cause of Lower Tolerance to Short-Term Dehydration?

Understanding the response of a crop to drought is the first step in the breeding of tolerant genotypes. In our study, two maize (Zea mays L.) genotypes with contrasting sensitivity to dehydration were subjected to moderate drought conditions. The subsequent analysis of their physiological parameters revealed a decreased stomatal conductance accompanied by a slighter decrease in the relative water content in the sensitive genotype. In contrast, the tolerant genotype maintained open stomata and active photosynthesis, even under dehydration conditions. Drought-induced changes in the leaf proteome were analyzed by two independent approaches, 2D gel electrophoresis and iTRAQ analysis, which provided compatible but only partially overlapping results. Drought caused the up-regulation of protective and stress-related proteins (mainly chaperones and dehydrins) in both genotypes. The differences in the levels of various detoxification proteins corresponded well with the observed changes in the activities of antioxidant enzymes. The number and levels of up-regulated protective proteins were generally lower in the sensitive genotype, implying a reduced level of proteosynthesis, which was also indicated by specific changes in the components of the translation machinery. Based on these results, we propose that the hypersensitive early stomatal closure in the sensitive genotype leads to the inhibition of photosynthesis and, subsequently, to a less efficient synthesis of the protective/detoxification proteins that are associated with drought tolerance

Measurement of the Bottom-Strange Meson Mixing Phase in the Full CDF Data Set

We report a measurement of the bottom-strange meson mixing phase \beta_s using the time evolution of B0_s -> J/\psi (->\mu+\mu-) \phi (-> K+ K-) decays in which the quark-flavor content of the bottom-strange meson is identified at production. This measurement uses the full data set of proton-antiproton collisions at sqrt(s)= 1.96 TeV collected by the Collider Detector experiment at the Fermilab Tevatron, corresponding to 9.6 fb-1 of integrated luminosity. We report confidence regions in the two-dimensional space of \beta_s and the B0_s decay-width difference \Delta\Gamma_s, and measure \beta_s in [-\pi/2, -1.51] U [-0.06, 0.30] U [1.26, \pi/2] at the 68% confidence level, in agreement with the standard model expectation. Assuming the standard model value of \beta_s, we also determine \Delta\Gamma_s = 0.068 +- 0.026 (stat) +- 0.009 (syst) ps-1 and the mean B0_s lifetime, \tau_s = 1.528 +- 0.019 (stat) +- 0.009 (syst) ps, which are consistent and competitive with determinations by other experiments.Comment: 8 pages, 2 figures, Phys. Rev. Lett 109, 171802 (2012

A genomic catalog of Earth’s microbiomes

The reconstruction of bacterial and archaeal genomes from shotgun metagenomes has enabled insights into the ecology and evolution of environmental and host-associated microbiomes. Here we applied this approach to >10,000 metagenomes collected from diverse habitats covering all of Earth’s continents and oceans, including metagenomes from human and animal hosts, engineered environments, and natural and agricultural soils, to capture extant microbial, metabolic and functional potential. This comprehensive catalog includes 52,515 metagenome-assembled genomes representing 12,556 novel candidate species-level operational taxonomic units spanning 135 phyla. The catalog expands the known phylogenetic diversity of bacteria and archaea by 44% and is broadly available for streamlined comparative analyses, interactive exploration, metabolic modeling and bulk download. We demonstrate the utility of this collection for understanding secondary-metabolite biosynthetic potential and for resolving thousands of new host linkages to uncultivated viruses. This resource underscores the value of genome-centric approaches for revealing genomic properties of uncultivated microorganisms that affect ecosystem processes

Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)1.

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field

Analyze Of ZnO-Based Ethanol Bio-Sensor for Medical Processes

Abstract: It is well-established that ethanol sensors have wide applications in medical processes and food industries. Herein, ZnO nano-particles are synthesized and exposed to ethanol for gas sensing measurements. It is shown that their sensitivity and response time relates to how large they are. Transmission Electron Microscopy, X-ray Diffraction and UV-v is determined and differentiated the crystal morphology, crystallite size and the associated band gap of the nanoparticles depending on the constituents of the initial samples. The voltage-time graphs of sensors are obtained and the observed behavior is investigated. Key words: ZnOnano-particles Gas Bio-sensor Voltage-time relationshi

Proteomics

Gene expression analyses of embryonic stem cells (ESCs) will help to uncover or further define signaling pathways and molecular mechanisms involved in the maintenance of self-renewal and pluripotency. We employed a 2-DE-based proteomics approach to analyze human ESC line, Royan H5, in undifferentiated cells and different stages of spontaneous differentiation (days 3, 6, 12, and 20) by embryoid body formation. Out of 945 proteins reproducibly detected on gels, the expression of 96 spots changed during differentiation. Using MS, 87 ESC-associated proteins were identified including several proteins involved in cell proliferation, cell apoptosis, transcription, translation, mRNA processing, and protein folding. Transcriptional changes accompanying differentiation of Royan H5 were also analyzed using microarrays. We developed a comprehensive data set that shows the use of human ESC lines in vitro to mimic gastrulation and organogenesis. Our results showed that proteomics and transcriptomics data are complementary rather than duplicative. Although regulation of many genes during differentiation were observed only at transcript level, modulation of several proteins was revealed only by proteome analysis

Comparison of the proteome profiling of Iranian isolates of Leishmania tropica, L. major and L. infantum by two-dimensional electrophoresis (2-DE) and mass-spectrometry

Background: The mechanisms of virulence and species differences of Leishmania parasites are under the influence of gene expression regulations at posttranscriptional stages. In Iran, L. major and L. tropica are known as principal agents of cutaneous leishmaniasis, while L. infantum causes visceral leishmaniasis. Methods: As a preliminary study, we compared the proteome mapping of the above three Iranian isolates of Leishmania species through the 2-dimension electrophoresis (2-DE), and identified the prominent proteins by Liquid Chromatography (LC) mass spectrometry. Results: We reproducibly detected about 700 protein spots in each species by using the Melanie software. Totally, 264 proteins exhibited significant changes among 3 species. Forty nine protein spots identified in both L. tropica and L. major were similar in position in the gel, whereas only 35 of L. major proteins and 10 of L. tropica proteins were matched with those of L. infantum. Having identified 24 proteins in the three species, we sought to provide possible explanations for their differential expression patterns and discuss their relevance to cell biology. Conclusion: The comparison of proteome profiling pattern of the 3 species identified limit up and limit down regulated or absent /present proteins. In addition, the LC-MS data analysis showed that most of the protein spots with differential abundance in the 3 species are involved in cell motility and cytoskeleton, cell signaling and vesicular trafficking, intracellular survival / proteolysis, oxidative stress defense, protein synthesis, protein ubiquitination / proteolysis, and stress related proteins. Differentially proteins distributed among the species maybe implicated in host pathogenecity interactions and parasite tropism to cutaneous or visceral tissue macrophages

Draft Genome Sequence of Nesterenkonia sp. Strain F, Isolated From Aran-Bidgol Salt Lake in Iran

The draft genome of the aerobic, Gram-positive, halophilic chemoorganotroph Nesterenkonia sp. strain F consists of a 2,812,133-bp chromosome. This study is the first to report the shotgun-sequenced draft genome of a member of the genus Nesterenkonia