1000 resultados para GIK13305-1
Resumo:
Critical cellular decisions such as should the cell proliferate, migrate or differentiate, are regulated by stimulatory signals from the extracellular environment, like growth factors. These signals are transformed to cellular responses through their binding to specific receptors present at the surface of the recipient cell. The epidermal growth factor receptor (EGF-R/ErbB) pathway plays key roles in governing these signals to intracellular events and cell-to-cell communication. The EGF-R forms a signaling network that participates in the specification of cell fate and coordinates cell proliferation. Ligand binding triggers receptor dimerization leading to the recruitment of kinases and adaptor proteins. This step simultaneously initiates multiple signal transduction pathways, which result in activation of transcription factors and other target proteins, leading to cellular alterations. It is known that mutations of EGF-R or in the components of these pathways, such as Ras and Raf, are commonly involved in human cancer. The four best characterized signaling pathways induced by EGF-R are the mitogen-activated protein kinase cascades (MAPKs), the lipid kinase phosphatidylinositol 3 kinase (PI3K), a group of transcription factors called Signal Transducers and Activator of Transcription (STAT), and the phospholipase Cγ; (PLCγ) pathways. The activation of each cascade culminates in kinase translocation to the nucleus to stimulate various transcription factors including activator protein 1 (AP-1). AP-1 family proteins are basic leucine zipper (bZIP) transcription factors that are implicated in the regulation of a variety of cellular processes (proliferation and survival, growth, differentiation, apoptosis, cell migration, transformation). Therefore, the regulation of AP-1 activity is critical for the decision of cell fate and their deregulated expression is widely associated with many types of cancers, such as breast and prostate cancers. The aims of this study were to characterize the roles of EGF-R signaling during normal development and malignant growth in vitro and in vivo using different cell lines and tissue samples. We show here that EGF-R regulates cell proliferation but is also required for regulation of AP-1 target gene expression in fibroblasts in a MAP-kinase mediated manner. Furthermore, EGF-R signaling is essential for enterocyte proliferation and migration during intestinal maturation. EGF-R signaling network, especially PI3-K-Akt pathway mediated AP-1 activity is involved in cellular survival in response to ionizing radiation. Taken together, these results elucidate the connection of EGF-R and AP-1 in various cellular contexts and show their importance in the regulation of cellular behaviour presenting new treatment cues for intestinal perforations and cancer therapy.
Resumo:
A multiplex real-time PCR was developed for the detection and differentiation of two closely related bovine herpesviruses 1 (BoHV-1) and 5 (BoHV-5). The multiplex real-time PCR combines a duplex real-time PCR that targets the DNA polymerase gene of BoHV-1 and BoHV-5 and a real-time PCR targeting mitochondrial DNA, as a house-keeping gene, described previously by Cawthraw et al. (2009). The assay correctly identified 22 BoHV-1 and six BoHV-5 isolates from the Biosecurity Sciences Laboratory virus collection. BoHV-1 and BoHV-5 were also correctly identified when incorporated in spiked semen and brain tissue samples. The detection limits of the duplex assay were 10 copies of BoHV-1 and 45 copies of BoHV-5. The multiplex real-time PCR had reaction efficiencies of 1.04 for BoHV-1 and 1.08 for BoHV-5. Standard curves relating Ct value to template copy number had correlation coefficients of 0.989 for BoHV-1 and 0.978 for BoHV-5. The assay specificity was demonstrated by testing bacterial and viral DNA from pathogens commonly isolated from bovine respiratory and reproductive tracts. The validated multiplex real-time PCR was used to detect and differentiate BoHV-1 and BoHV-5 in bovine clinical samples with known histories.
Resumo:
A detailed analysis of the 1H and 13C NMR spectra of C-2 aryl and alkyl/desalkyl substituted isomeric exo- and endo-5-methylbicyclo[3.2.1]octane-6,8-diones is presented. The chemical shift of the C-5 angular methyl, the C-2 alkyl/olefinic (C-10)/C-2 methine protons, the aromatic proton shieldings and the characteristic AMX and ABX spectral pattern of the ketomethylene and bridgehead protons were found to be sensitive to the phenyl ring orientation (anisotropy). These distinctive features could be used for configurational distinction for this class of compounds. With increasing ortho-methoxy substitution on the phenyl ring, considerable deshilelding of the bridgehead proton was observed (ca. 0.6 ppm). Absence of the C-2 alkyl group in the desalkyl isomers resulted in substantial changes in the chemical shifts of different protons. A study of the NMR spectra of the corresponding bicyclic compounds with C-2 methoxy/hydroxy substitution instead of the aryl group revealed that the anisotropy of the phenyl ring and the electronegative oxygen substituents have opposite effects. The 13C NMR spectral assignment of each carbon resonance of C-2 aryl and alkyl/desalkyl substituted isomeric exo- and endo-5-methylbicyclo[3.2.1]octane-6,8-diones and the corresponding C-2 methoxy/hydroxy/chloro and methyl bicyclic compounds are reported. Additional ortho-methoxy substitution on the phenyl ring was found to produce considerable high field shifts of the C-10 and C-1 carbon resonances. A high-field shift was observed for the C-6 and C-8 carbonyl carbons, presumably due to 1,3-dicarbonyl interactions. The chemical shifts of C-1 aromatic, C-10 alkyl and C-2 carbons, which are sensitive to exo/endo isomerism, could be utilized in differentiating a pair of isomers.
Resumo:
It is shown that a leaky aquifer model can be used for well field analysis in hard rock areas, treating the upper weathered and clayey layers as a composite unconfined aquitard overlying a deeper fractured aquifer. Two long-duration pump test studies are reported in granitic and schist regions in the Vedavati river basin. The validity of simplifications in the analytical solution is verified by finite difference computations.
Resumo:
The effects of the herbicide, 3-amino-1,2,4-triazole, an inhibitor of heme synthesis in rat liver, have been examined in the mold Neurospora crassa. The drug is a potent inhibitor of the growth of the mold and produces biochemical changes identical to those produced by chloramphenicol. 3-Amino-1,2,4-triazole, like chloramphenicol, is a direct and specific inhibitor of protein synthesis on mitoribosomes. A decrease in the levels of mitochondrial proteins which are completely or partly made on mitoribosomes and an accumulation in the levels of mitochondrial proteins of cytosolic origin have been observed. Both drugs depress porphyrin and heme levels, but there is actually an elevation in the levels of δ-aminolevulinate dehydratase, the rate-limiting enzyme of the heme-biosynthetic pathway in Neurospora crassa. In liver the enzyme is present in non-limiting amounts and the levels are depressed under conditions of 3-amino-1,2,4-triazole treatment. In Neurospora crassa the ‘derepression’ of δ-aminolevulinate dehydratase under conditions of 3-amino-1,2,4-triazole or chloramphenicol treatment is only partial because the drugs inhibit protein synthesis on mitoribosomes. It is concluded that an optimal rate of protein synthesis on mitoribosomes is necessary to maintain an adequate rate of heme synthesis.
Resumo:
Crystal structures of the title compounds, (I) and (II), have been determined by three-dimensional diffraction methods. Crystals of CsHIoN 4 (I) are monoclinic, space group P21/a with Z = 4, Mr= 162, a = 7.965 (1), b = 16.232 (2), c = 7.343 (1) A, fl = 113.54 (1) °, V = 890.7 A 3, D,n = 1.218, D x = 1.208 gcm -3, g(Cu Ka, 2 = 1.5418/~) = 6.47 em -1, F(000) = 344. The crystals of C9H12N4 (II) are orthorhombic, space group P21en, with Z = 4, Mr = 176, a = 7.983 (3), b = 8.075 (2), c = 14.652 (3) ./k, V = 944.43/~3, Dm= 1.219, D x = 1.237 g cm -3, #(Mo Ka, ). = 0.7107 ,/k) = 0.868 cm -1, F(000) = 376. Both structures were solved by direct methods and refined to R = 5.8% for (I) and 5.3 % for (II). The C-C double-bond distances are 1.407 (3) in (I) and 1.429 (6)/~ in (II), appreciably longer than normal. The steric and push-pull effects result in rotation about the C=C bond, the rotation angles being 20.2 (3) in (I) and 31.5 (6) o in (II).
Reinvestigation of the structure of Feist's acid 3-methylene-trans-1,2-cyclopropanedicarboxylic acid
Resumo:
C6H604, Mr = 142, triclinic, P[, a = 4.842(1), b = 7.607(1), c = 9.168 (3) A, ~ = 98.41(2), fl = 99.89(2), y = 77.74(1) ° , V = 320.9/k 3, Z = 2, Dm= 1.45 (flotation), D x = 1.470 g cm -3, p(Mo Ktt, 2 = 0.7107 A) = 0.63 cm -~, F(000) = 148. The structure was solved by direct methods and refined to an R value of 0.038 for 723 intensity measurements. The geometrical changes in the cyclopropane ring are discussed in the light of substituent effects. In the crystal structure the carboxylic groups are disordered.
Resumo:
Migraine is a common episodic neurological disorder, typically presenting with recurrent attacks of severe headache and autonomic dysfunction. Apart from rare monogenic subtypes, no genetic or molecular markers for migraine have been convincingly established. We identified the minor allele of rs1835740 on chromosome 8q22.1 to be associated with migraine (P = 5.38 x 10(-)(9), odds ratio = 1.23, 95% CI 1.150-1.324) in a genome-wide association study of 2,731 migraine cases ascertained from three European headache clinics and 10,747 population-matched controls. The association was replicated in 3,202 cases and 40,062 controls for an overall meta-analysis P value of 1.69 x 10(-)(1)(1) (odds ratio = 1.18, 95% CI 1.127-1.244). rs1835740 is located between MTDH (astrocyte elevated gene 1, also known as AEG-1) and PGCP (encoding plasma glutamate carboxypeptidase). In an expression quantitative trait study in lymphoblastoid cell lines, transcript levels of the MTDH were found to have a significant correlation to rs1835740 (P = 3.96 x 10(-)(5), permuted threshold for genome-wide significance 7.7 x 10(-)(5). To our knowledge, our data establish rs1835740 as the first genetic risk factor for migraine.
Resumo:
Three distinct coordination complexes, viz., [Co(imi)(2)(tmb)(2)] (1) [where imi = imidazole], {[Ni(tmb)(2)(H2O)(3)]center dot 2H(2)O}(n) (2) and [Cu-2(mu-tmb)(4)(CH3OH)(2)] (3), have been synthesized hydrothermally by the reactions of metal acetates,2,4,6-trimethylbenzoic acid (Htmb) and with or without appropriate amine. The Ni analogue of 1 and the Co analogue of 2 have also been synthesized. X-ray single-crystal diffraction suggests that complex 1 represents discrete mononuclear species and complex 2 represents a 1D chain coordination polymer in which the Ni(H) ions are connected by the bridging water molecules. Complex 3 represents a neutral dinuclear complex. In 1, the central metal ions are associated by the carboxylate moiety and imidazole ligands, whereas the central metal atom is coordinated to the carboxylate moiety and the respective solvent molecules in 2 and 3. In 3, the four 2,4,6-trimethylbenzoate moieties act as a bridge connecting two copper (11) ions and the 0 atoms of methanol coord geometry, with the methanol molecule at the apical position. In all the three structures the central metal atom sits on a crystallographic inversion centre. In all the cases, the coordination entities are further organized via hydrogen bonding interactions to generate multifarious supramolecular networks. Complexes 1, 2 and 3 have also been characterized by spectroscopic (UV/Vis and IR) and thermal analysis (TGA). In addition, the complexes were found to exhibit antimicrobial activity. The magnetic susceptibility measurements, measured from 8 to 300 K, revealed antiferromagnetic interactions between the Co(II) ions in compound 1 and the Ni(II) ions in la, respectively.
Resumo:
OBJECTIVE: The study of ethnically homogeneous populations may help to identify schizophrenia risk loci. The authors conducted a genomewide linkage scan for schizophrenia in an Indian population. METHOD: Participants were 441 individuals (262 affected probands and siblings) who were recruited primarily from one ethnically homogeneous group, the Tamil Brahmin caste, although individuals from other geographically proximal castes also participated. Genotyping of 124 affected sibling pair pedigrees was performed with 402 short tandem repeat polymorphisms. Linkage analyses were conducted using nonparametric exponential LOD (logarithm of the odds ratio for linkage) scores and parametric heterogeneity LOD scores. Parametric heterogeneity scores were calculated using simple dominant and recessive models, correcting for multiple statistics. The data were examined for evidence of consanguinity. Genomewide significance levels were determined using 10,000 gene dropping simulations. RESULTS: These findings revealed genomewide significant linkage to chromosome 1p31.1, through the use of both exponential and heterogeneity LOD scores, incorporating correction for multiple statistics and mild consanguinity. The estimated sibling recurrence risk associated with this putative locus was 1.95. Analysis for heterogeneity LOD scores also detected suggestive linkage to chromosomes 13q22.1 and 16q12.2. Using 117 tag single nucleotide polymorphisms (SNPs), family-based association analyses of phosphodiesterase 4B (PDE4B), the closest schizophrenia candidate gene, detected no convincing evidence of association, suggesting that the chromosome 1 peak represents a novel risk locus. CONCLUSIONS: This is the first study-to the authors' knowledge-to report significant linkage of schizophrenia to chromosome 1p31.1. Further investigation of this chromosome region in diverse populations is warranted to identify underlying sequence variants.
Resumo:
The distribution and density of the ampullary electroreceptors in the skin of elasmobranchs are influenced by the phylogeny and ecology of a species. Sensory maps were created for 4 species of pristid sawfish. Their ampullary pores were separated into pore fields based on their innervation and cluster formation. Ventrally, ampullary pores are located in 6 areas (5 in Pristis microdon), covering the rostrum and head to the gills. Dorsally, pores are located in 4 areas (3 in P. microdon), which cover the rostrum, head and may extend slightly onto the pectoral fins. In all species, the highest number of pores is found on the dorsal and ventral sides of the rostrum. The high densities of pores along the rostrum combined with the low densities around the mouth could indicate that sawfish use their rostrum to stun their prey before ingesting it, but this hypothesis remains to be tested. The directions of ampullary canals on the ventral side of the rostrum are species specific. P. microdon possesses the highest number of ampullary pores, which indicates that amongst the study species this species is an electroreception specialist. As such, juvenile P. microdon inhabit low-visibility freshwater habitats.
Resumo:
The Parechoviruses (HPEV) belong to the family Picornaviridae of positive-stranded RNA viruses. Although the parechovirus genome shares the general properties of other picornaviruses, the genus has several unique features when compared to other family members. We found that HPEV1 attaches to αv integrins on the cell surface and is internalized through the clathrin-mediated endocytic pathway. During he course of the infection, the Golgi was found to disintegrate and the ER membranes to swell and loose their ribosomes. The replication of HPEV1 was found to take place on small clusters of vesicles which contained the trans-Golgi marker GalT as well as the viral non-structural 2C protein. 2C was additionally found on stretches of modified ER-membranes, seemingly not involved in RNA replication. The viral non-structural 2A and 2C proteins were studied in further detail and were found to display several interesting features. The 2A protein was found to be a RNA-binding protein that preferably binds to positive sense 3 UTR RNA. It was found to bind also duplex RNA containing 3 UTR(+)-3 UTR(-), but not other dsRNA molecules studied. Mutagenesis revealed that the N-terminal basic-rich region as well as the C-terminus, are important for RNA-binding. The 2C protein on the other hand, was found to have both ATP-diphosphohydrolase and AMP kinase activities. Neither dATP nor other NTP:s were suitable substrates. Furthermore, we found that as a result of theses activities the protein is autophosphorylated. The intracellular changes brought about by the individual HPEV1 non-structural proteins were studied through the expression of fusion proteins. None of the proteins expressed were able to induce membrane changes similar to those seen during HPEV1 infection. However, the 2C protein, which could be found on the surface of lipid droplets but also on diverse intracellular membranes, was partly relocated to viral replication complexes in transfected, superinfected cells. Although Golgi to ER traffic was arrested in HPEV1-infected cells, none of the individually expressed non-structural proteins had any visible effect on the anterograde membrane traffic. Our results suggest that the HPEV1 replication strategy is different from that of many other picornaviruses. Furthermore, this study shows how relatively small differences in genome sequence result in very different intracellular pathology.
Resumo:
This manual is a guide to establishing a set of operations to achieve high grade results in product quality and recovery, flexibility, innovation, cost, and competitiveness. The manual outlines: - economic and feasible technologies for increasing recovery and reducing avoidable loss during processing, from the log to the finished board, and - mechanisms that allow production value to be optimised in different sized mills. Part 1 covers sections 1 to 7: Drying overview and strategy, coupe, log yard, green mill, green pack, bioprotection, rack timber. Part 2 Link: http://era.deedi.qld.gov.au/3137 Includes sections 8 to 17: Air drying, pre-drying, reconditioning, controlled final drying, dry milling, storage, information assessment, drying quality assessment, moisture content monitoring, glossary.