Saccharomyces cerevisiae chitin biosynthesis activation by N-acetylchitooses depends on size and structure of chito-oligosaccharides

<p>Abstract</p> <p>Background</p> <p>To explore chitin synthesis initiation, the effect of addition of exogenous oligosaccharides on <it>in vitro </it>chitin synthesis was studied. Oligosaccharides of various natures and lengths were added to a chitin synthase assay performed on a <it>Saccharomyces cerevisiae </it>membrane fraction.</p> <p>Findings</p> <p><it>N</it>-acetylchito-tetra, -penta and -octaoses resulted in 11 to 25% [¹⁴C]-GlcNAc incorporation into [¹⁴C]-chitin, corresponding to an increase in the initial velocity. The activation appeared specific to <it>N</it>-acetylchitooses as it was not observed with oligosaccharides in other series, such as beta-(1,4), beta-(1,3) or alpha-(1,6) glucooligosaccharides.</p> <p>Conclusions</p> <p>The effect induced by the <it>N</it>-acetylchitooses was a saturable phenomenon and did not interfere with free GlcNAc and trypsin which are two known activators of yeast chitin synthase activity <it>in vitro</it>. The magnitude of the activation was dependent on both oligosaccharide concentration and oligosaccharide size.</p

RT-GENE: Real-time eye gaze estimation in natural environments

In this work, we consider the problem of robust gaze estimation in natural environments. Large camera-to-subject distances and high variations in head pose and eye gaze angles are common in such environments. This leads to two main shortfalls in state-of-the-art methods for gaze estimation: hindered ground truth gaze annotation and diminished gaze estimation accuracy as image resolution decreases with distance. We first record a novel dataset of varied gaze and head pose images in a natural environment, addressing the issue of ground truth annotation by measuring head pose using a motion capture system and eye gaze using mobile eyetracking glasses. We apply semantic image inpainting to the area covered by the glasses to bridge the gap between training and testing images by removing the obtrusiveness of the glasses. We also present a new real-time algorithm involving appearance-based deep convolutional neural networks with increased capacity to cope with the diverse images in the new dataset. Experiments with this network architecture are conducted on a number of diverse eye-gaze datasets including our own, and in cross dataset evaluations. We demonstrate state-of-the-art performance in terms of estimation accuracy in all experiments, and the architecture performs well even on lower resolution images

Profound variation in dihydropyrimidine dehydrogenase activity in human blood cells: major implications for the detection of partly deficient patients

Dihydropyrimidine dehydrogenase (DPD) is responsible for the breakdown of the widely used antineoplastic agent 5-fluorouracil (5FU), thereby limiting the efficacy of the therapy. To identify patients suffering from a complete or partial DPD deficiency, the activity of DPD is usually determined in peripheral blood mononuclear cells (PBM cells). In this study, we demonstrated that the highest activity of DPD was found in monocytes followed by that of lymphocytes, granulocytes and platelets, whereas no significant activity of DPD could be detected in erythrocytes. The activity of DPD in PBM cells proved to be intermediate compared with the DPD activity observed in monocytes and lymphocytes. The mean percentage of monocytes in the PBM cells obtained from cancer patients proved to be significantly higher than that observed in PBM cells obtained from healthy volunteers. Moreover, a profound positive correlation was observed between the DPD activity of PBM cells and the percentage of monocytes, thus introducing a large inter- and intrapatient variability in the activity of DPD and hindering the detection of patients with a partial DPD deficiency. © 1999 Cancer Research Campaig

Genome-Wide Local Ancestry Approach Identifies Genes and Variants Associated with Chemotherapeutic Susceptibility in African Americans

Chemotherapeutic agents are used in the treatment of many cancers, yet variable resistance and toxicities among individuals limit successful outcomes. Several studies have indicated outcome differences associated with ancestry among patients with various cancer types. Using both traditional SNP-based and newly developed gene-based genome-wide approaches, we investigated the genetics of chemotherapeutic susceptibility in lymphoblastoid cell lines derived from 83 African Americans, a population for which there is a disparity in the number of genome-wide studies performed. To account for population structure in this admixed population, we incorporated local ancestry information into our association model. We tested over 2 million SNPs and identified 325, 176, 240, and 190 SNPs that were suggestively associated with cytarabine-, 5′-deoxyfluorouridine (5′-DFUR)-, carboplatin-, and cisplatin-induced cytotoxicity, respectively (p≤10−4). Importantly, some of these variants are found only in populations of African descent. We also show that cisplatin-susceptibility SNPs are enriched for carboplatin-susceptibility SNPs. Using a gene-based genome-wide association approach, we identified 26, 11, 20, and 41 suggestive candidate genes for association with cytarabine-, 5′-DFUR-, carboplatin-, and cisplatin-induced cytotoxicity, respectively (p≤10−3). Fourteen of these genes showed evidence of association with their respective chemotherapeutic phenotypes in the Yoruba from Ibadan, Nigeria (p<0.05), including TP53I11, COPS5 and GAS8, which are known to be involved in tumorigenesis. Although our results require further study, we have identified variants and genes associated with chemotherapeutic susceptibility in African Americans by using an approach that incorporates local ancestry information

Impact of volatile phenols and their precursors on wine quality and control measures of Brettanomyces/Dekkera yeasts

Volatile phenols are aromatic compounds and one of the key molecules responsible for olfactory defects in wine. The yeast genus Brettanomyces is the only major microorganism that has the ability to covert hydroxycinnamic acids into important levels of these compounds, especially 4-ethylphenol and 4-ethylguaiacol, in red wine. When 4-ethylphenols reach concentrations greater than the sensory threshold, all wine’s organoleptic characteristics might be influenced or damaged. The aim of this literature review is to provide a better understanding of the physicochemical, biochemical, and metabolic factors that are related to the levels of p-coumaric acid and volatile phenols in wine. Then, this work summarizes the different methods used for controlling the presence of Brettanomyces in wine and the production of ethylphenols

Analysis of the dihydropyrimidine dehydrogenase polymorphism in a British population

Subjects with low or absent dihydropyrimidine dehydrogenase activity (DPD) are at risk of excessive toxicity or death when undergoing fluoropyrimidine chemotherapy. The DPD polymorphism has not been well characterized in the general population and the frequency of the enzyme deficiency is not known. In preparation for a population multicentre analysis of DPD activity, a comparison of sample preparation methods and a pilot study in normal volunteer subjects was performed. The stability of peripheral blood mononuclear cell DPD activity at −70° C was determined in 35 mm sodium phosphate buffer with 10% glycerol, 100% fetal calf serum (FCS) or as a dry pellet. DPD activity declined in FCS and increased in glycerol buffer, both reaching a plateau value 14 days after blood sampling. The glycerol buffer method was then used to study DPD activity in 50 British subjects (36 M:14F; 20–56 years). A 8.4-fold range in DPD activity was observed (30.4–256 pmol min−1 mg−1 protein). DPD activity was not influenced by age or cigarette smoking. This information will facilitate analysis of the DPD polymorphism in populations from different countries and ethnic groups

Clinical, Imaging Characteristics and Long-Term Outcome Of Dogs with Intranasal Meningoencephalocele: A Case Series

No abstract available

Clinical, Imaging Characteristics and Long-Term Outcome Of Dogs with Intranasal Meningoencephalocele: A Case Series

No abstract available