936 resultados para Janus kinase-signal transducer and activator of transcription signal pathway
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In this study, we investigated the potential role of high-mobility group box 1 (HMGB1) in severe acute pancreatitis (SAP) and the effects of growth hormone (G) and somatostatin (S) in SAP rats. The rats were randomly divided into 6 groups of 20 each: sham-operated, SAP, SAP+saline, SAP+G, SAP+S and SAP+G+S. Ileum and pancreas tissues of rats in each group were evaluated histologically. HMGB1 mRNA expression was measured by reverse transcription-PCR. Levels of circulating TNF-α, IL-1, IL-6, and endotoxin were also measured. In the SAP group, interstitial congestion and edema, inflammatory cell infiltration, and interstitial hemorrhage occurred in ileum and pancreas tissues. The levels of HMGB1, TNF-α, IL-1, IL-6 and endotoxin were significantly up-regulated in the SAP group compared with those in the sham-operated group, and the 7-day survival rate was 0%. In the SAP+G and SAP+S groups, the inflammatory response of the morphological structures was alleviated, the levels of HMGB1, TNF-α, IL-1, IL-6, and endotoxin were significantly decreased compared with those in the SAP group, and the survival rate was increased. Moreover, in the SAP+G+S group, all histological scores were significantly improved and the survival rate was significantly higher compared with the SAP group. In conclusion, HMGB1 might participate in pancreas and ileum injury in SAP. Growth hormone and somatostatin might play a therapeutic role in the inflammatory response of SAP.
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Recent studies have revealed that an intrinsic apoptotic signaling cascade is involved in vascular hyperpermeability and endothelial barrier dysfunction. Propofol (2,6-diisopropylphenol) has also been reported to inhibit apoptotic signaling by regulating mitochondrial permeability transition pore (mPTP) opening and caspase-3 activation. Here, we investigated whether propofol could alleviate burn serum-induced endothelial hyperpermeability through the inhibition of the intrinsic apoptotic signaling cascade. Rat lung microvascular endothelial cells (RLMVECs) were pretreated with propofol at various concentrations, followed by stimulation with burn serum, obtained from burn-injury rats. Monolayer permeability was determined by transendothelial electrical resistance. Mitochondrial release of cytochrome C was measured by ELISA. Bax and Bcl-2 expression and mitochondrial release of second mitochondrial-derived activator of caspases (smac) were detected by Western blotting. Caspase-3 activity was assessed by fluorometric assay; mitochondrial membrane potential (Δψm) was determined with JC-1 (a potential-sensitive fluorescent dye). Intracellular ATP content was assayed using a commercial kit, and reactive oxygen species (ROS) were measured by dichlorodihydrofluorescein diacetate (DCFH-DA). Burn serum significantly increased monolayer permeability (P<0.05), and this effect could be inhibited by propofol (P<0.05). Compared with a sham treatment group, intrinsic apoptotic signaling activation - indicated by Bax overexpression, Bcl-2 downregulation, Δψm reduction, decreased intracellular ATP level, increased cytosolic cytochrome C and smac, and caspase-3 activation - was observed in the vehicle group. Propofol not only attenuated these alterations (P<0.05 for all), but also significantly decreased burn-induced ROS production (P<0.05). Propofol attenuated burn-induced RLMVEC monolayer hyperpermeability by regulating the intrinsic apoptotic signaling pathway.
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We investigated whether 6-gingerol affects the maturation and proliferation of osteoblast-like MG63 cells in vitro. Osteoblast-like MG63 cells were treated with 6-gingerol under control conditions, and experimental inflammation was induced by tumor necrosis factor-α (TNF-α). Expression of different osteogenic markers and cytokines was analyzed by real-time PCR, Western blotting, and enzyme-linked immunosorbent assay. In addition, alkaline phosphatase (ALP) enzyme activity and biomineralization as markers for differentiation were measured. Treatment with 6-gingerol resulted in insignificant effects on the proliferation rate. 6-Gingerol induced the differentiation of osteoblast-like cells with increased transcription levels of osteogenic markers, upregulated ALP enzyme activity, and enhanced mineralized nodule formation. Stimulation with TNF-α led to enhanced interleukin-6 and nuclear factor-κB expression and downregulated markers of osteoblastic differentiation. 6-Gingerol reduced the degree of inflammation in TNF-α-treated MG-63 cells. In conclusion, 6-gingerol stimulated osteoblast differentiation in normal physiological and inflammatory settings, and therefore, 6-gingerol represents a promising agent for treating osteoporosis or bone inflammation.
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Foodborne disease caused by microorganisms is a problem of public health. Minas soft cheese is a national product manufactured using simple technology; it has high level of acceptance in the country making its production an important economic activity. Many microorganisms may be present in foods including the bacterium Escherichia coli (E. coli). Overall, E. coli is a harmless commensal bacterium; however, some strains may have a pathogenic potential. Several outbreaks of foodborne diseases associated with consumption of contaminated cheese have been reported, and the presence of pathogenic strains of E. coli has increased. The objective of this study was to isolate, evaluate the antimicrobial susceptibility, and characterize, by Multiplex PCR, the pathogenic E. coli strains isolated from Minas cheese commercialized in Rio de Janeiro. Thirty samples were analyzed and five strains of E. coli (EPEC) were identified. The assessment of antimicrobial susceptibility revealed 40% of the isolates resistant to ampicillin and 40% with intermediate resistance to ampicillin-sulbactam combination. These findings are a warning signal to health authorities since Minas cheese is a ready to eat food product, and therefore should not pose health risks to the population.
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Abstract Peripheral nerves have the unique capability to regenerate after injury. Insights into regeneration of peripheral nerves after injury may have implications for neurodegenerative diseases of the nervous system. We investigated the ability of polysaccharide from Hericium erinaceus mushroom in the treatment of nerve injury following peroneal nerve crush in Sprague-Dawley rats by daily oral administration. In sensory functional recovery test, the time taken for the rats to withdraw its hind limb from contact with the hot plate was measured. The test revealed acceleration of sensory recovery in the polysaccharide group compared to negative controls. Further, peripheral nerve injury leads to changes at the remotely located DRG containing cell bodies of sensory neurons. Immunofluorescence studies showed that Akt and p38 MAPK were expressed in DRG and strongly upregulated in polysaccharide group after peripheral nerve injury. The intensity of endothelial cells antigen-1 that recognized endothelial cells in the blood vessels of distal segments in crushed nerves was significantly higher in the treated groups than in the negative control group. Our findings suggest that H. erinaceus is capable of accelerating sensory functional recovery after peripheral nerve injury and the effect involves the activation of protein kinase signaling pathways and restoration of blood-nerve barrier.
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Prostate cancer (PCa) has emerged as the most commonly diagnosed lethal cancer in European men. PCa is a heterogeneous cancer that in the majority of the cases is slow growing: consequently, these patients would not need any medical treatment. Currently, the measurement of prostate-specific antigen (PSA) from blood by immunoassay followed by digital rectal examination and a pathological examination of prostate tissue biopsies are the most widely used methods in the diagnosis of PCa. These methods suffer from a lack of sensitivity and specificity that may cause either missed cancers or overtreatment as a consequence of over-diagnosis. Therefore, more reliable biomarkers are needed for a better discrimination between indolent and potentially aggressive cancers. The aim of this thesis was the identification and validation of novel biomarkers for PCa. The mRNA expression level of 14 genes including AMACR, AR, PCA3, SPINK1, TMPRSS2-ERG, KLK3, ACSM1, CACNA1D, DLX1, LMNB1, PLA2G7, RHOU, SPON2, and TDRD1 was measured by a truly quantitative reverse transcription PCR in different prostate tissue samples from men with and without PCa. For the last eight genes the function of the genes in PCa progression was studied by a specific siRNA knockdown in PC-3 and VCaP cells. The results from radical prostatectomy and cystoprostatectomy samples showed statistically significant overexpression for all the target genes, except for KLK3 in men with PCa compared with men without PCa. Statistically significant difference was also observed in low versus high Gleason grade tumors (for PLA2G7), PSA relapse versus no relapse (for SPON2), and low versus high TNM stages (for CACNA1D and DLX1). Functional studies and siRNA silencing results revealed a cytotoxicity effect for the knock-down of DLX1, PLA2G7, and RHOU, and altered tumor cell invasion for PLA2G7, RHOU, ACSM1, and CACNA1D knock-down in 3D conditions. In addition, effects on tumor cell motility were observed after silencing PLA2G7 and RHOU in 2D monolayer cultures. Altogether, these findings indicate the possibility of utilizing these new markers as diagnostic and prognostic markers, and they may also represent therapeutic targets for PCa.
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Phascolomyces articulosus genomic DNA was isolated from 48 h old hyphae and was used for amplification of a chitin synthase fragment by the polymerase chain reaction method. The primers used in the amplification corresponded to two widely conserved amino acid regions found in chitin synthases of many fimgi. Amphfication resulted in four bands (820, 900, 1000 and 1500 bp, approximately) as visualized in a 1.2% agarose gel. The lowest band (820 bp) was selected as a candidate for chitin synthase because most amplified regions from other fimgi so far exhibited similar sizes (600-750 bp). The selected fragment was extracted from the gel and cloned in the Hinc n site of pUC19. The derived plasmid and insert were designated ^\5C\9'PaCHS and PaCHS respectively. The plasmid pUC19-PaC/fS was digested by several restriction enzymes and was found to contain BamHl and HincU sites. Sequencing of PaCHS revealed two intron sequences and a total open reading frame of 200 amino acids. The derived polypeptide was compared with other related sequences from the EMBL database (Heidelberg, Germany) and was matched to 36 other fiilly or partially sequenced fimgal chitin synthase genes. The closest resemblance was with two genes (74.5% and 73.1% identity) from Rhizopus oligosporus. Southern hybridization with the cloned fragment as a probe to the PCR reaction showed a strong signal at the fragment selected for cloning and weaker signals at the other two fragments. Southern hybridization with partially digested Phascolomyces articulosus genomic DNA showed a single band. The amino acid sequence was compared with sequences from other chitin synthase gene classes using the CLUSTALW program. The chitin synthase fragment from Phascolomyces articulosus was initially grouped in class n along with chitin synthase fragments from Rhizopus oligosporus and Phycomyces blakesleeanus which also belong to the same class, Zygomycetes. Bootstrap analysis using the neighbor-joining method available by CLUSTALW verified such classification. Comparison of PaCHS revealed conservation of intron positions that are characteristic of chitin synthase gene fragments of zygomycetous fungi.
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Adenoviruses are nonenveloped icosahedral shaped particles. The double stranded DNA viral genome is divided into 5 major early transcription units, designated E1 A, E1 B, and E2 to E4, which are expressed in a regulated manner soon after infection. The gene products of the early region 3 (E3), shown to be nonessential for viral replication in vitro, are believed to be involved in counteracting host immunosurveillance. In order to sequence the E3 region of Bovine adenovirus type 2 (BAV2) it was necessary to determine the restriction map for the plasmid pEA48. A physical restriction endonuclease map for BamHl, Clal, Eco RI, Hindlll, Kpnl, Pstt, Sail, and Xbal was constructed. The DNA insert in pEA48 was determined to be viral in origin using Southern hybridization. A human adenovirus type 5 recombinant plasmid, containing partial DNA fragments of the two transcription units L4 and L5 that lie just outside the E3, was used to localize this region. The recombinant plasmid pEA was subcloned to facilitate sequencing. The DNA sequences between 74.8 and 90.5 map units containing the E3, the hexon associated protein (pVIII), and the fibre gene were determined. Homology comparison revealed that the genes for the hexon associated pV11I and the fibre protein are conserved. The last 70 amino acids of the BAV2 pV11I were the most conserved, showing a similarity of 87 percent with Ad2 pV1I1. A comparison between the predicted amino acid sequences of BAV2 and Ad40, Ad41 , Ad2 and AdS, revealed that they have an identical secondary structure consisting of a tail, a shaft and a knob. The shaft is composed of 22, 15 amino acid motifs, with periodic glycines and hydrophobic residues. The E3 region was found to consist of about 2.3 Kbp and to encode four proteins that were greater than 60 amino acids. However, these four open reading frames did not show significant homology to any other known adenovirus DNA or protein sequence.
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Recombinant Adenoviruses (Ads) have been shown to have potential applications in three areas: gene therapy, high level protein expression and recombinant vaccines.' At least three different locations within the Ad genome can be deleted and subsequently used for the insertion of foreign sequences. These include the Early 3 (E3), Early 1 (E1) and Early 4 (E4) regions. Viral vectors of this type have been well studied in Human Ads 2 and 5, however one has not yet been constructed for Bovine Adenovirus Type 2 (BAV2). The E3 region is located between 76.6 and 86 m.u. on the r-strand and is transcribed in a rightward direction. The gene products of the Early 3 region (E3) have been shown to be non-essential for viral replication, in vitro, but are required for host immunosurveillance. This study represents the cloning and reconstitution of a BAV2 E3 deletion mutant. A deletion of 1800bp was made within the E3 region of BAV2 and the thymidine kinase gene was subsequently inserted in the deleted area . . The plasmid pdlE3-4tk1 (23.4Kbp) was constructed and used to to facilitate homologous recombination with the wild type BAV2 to produce a mutant. Southern Blotting and Hybridization results suggest the presence of a BAV2 E3 deletion mutant with thymidine kinase sequences present. The E4 region of Human Adenovirus types 2 and 5 is located at the extreme right end of the genome (91.3 map units - 99.1 map units) and is transcribed in a leftward direction giving rise to a complicated set of differentially spliced mRNAs. Essentially there are 7 open reading frames (ORFs) encoding for at least 7 polypeptides. The gene products encoded by the E4 region have been shown to be essential for the expression of late viral genes, host cell shutoff and normal viral growth. We have cloned and sequenced the right end segment between 90.5 map units and 100 map units of the BAV2 genome. The results show several open reading frames which encode polypeptides exhibiting homology to three polypeptides encoded by the E4 region of human adenovirus type 2. These include the 14kDa protein encoded by ORF1, the 34kDa protein encoded by ORF6 and the 13kDa protein encoded by ORF3. The nucleotide sequence, restriction enzyme map, and ORF map of the E4 region could be very useful in future molecular manipulation of this region and could possibly explain the slow growth rate of BAV2 in MDBK cells.
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A simple, low-cost concentric capillary nebulizer (CCN) was developed and evaluated for ICP spectrometry. The CCN could be operated at sample uptake rates of 0.050-1.00 ml min'^ and under oscillating and non-oscillating conditions. Aerosol characteristics for the CCN were studied using a laser Fraunhofter diffraction analyzer. Solvent transport efficiencies and transport rates, detection limits, and short- and long-term stabilities were evaluated for the CCN with a modified cyclonic spray chamber at different sample uptake rates. The Mg II (280.2nm)/l\/lg 1(285.2nm) ratio was used for matrix effect studies. Results were compared to those with conventional nebulizers, a cross-flow nebulizer with a Scott-type spray chamber, a GemCone nebulizer with a cyclonic spray chamber, and a Meinhard TR-30-K3 concentric nebulizer with a cyclonic spray chamber. Transport efficiencies of up to 57% were obtained for the CCN. For the elements tested, short- and long-term precisions and detection limits obtained with the CCN at 0.050-0.500 ml min'^ are similar to, or better than, those obtained on the same instrument using the conventional nebulizers (at 1.0 ml min'^). The depressive and enhancement effects of easily ionizable element Na, sulfuric acid, and dodecylamine surfactant on analyte signals with the CCN are similar to, or better than, those obtained with the conventional nebulizers. However, capillary clog was observed when the sample solution with high dissolved solids was nebulized for more than 40 min. The effects of data acquisition and data processing on detection limits were studied using inductively coupled plasma-atomic emission spectrometry. The study examined the effects of different detection limit approaches, the effects of data integration modes, the effects of regression modes, the effects of the standard concentration range and the number of standards, the effects of sample uptake rate, and the effect of Integration time. All the experiments followed the same protocols. Three detection limit approaches were examined, lUPAC method, the residual standard deviation (RSD), and the signal-to-background ratio and relative standard deviation of the background (SBR-RSDB). The study demonstrated that the different approaches, the integration modes, the regression methods, and the sample uptake rates can have an effect on detection limits. The study also showed that the different approaches give different detection limits and some methods (for example, RSD) are susceptible to the quality of calibration curves. Multicomponents spectral fitting (MSF) gave the best results among these three integration modes, peak height, peak area, and MSF. Weighted least squares method showed the ability to obtain better quality calibration curves. Although an effect of the number of standards on detection limits was not observed, multiple standards are recommended because they provide more reliable calibration curves. An increase of sample uptake rate and integration time could improve detection limits. However, an improvement with increased integration time on detection limits was not observed because the auto integration mode was used.
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The last will and testament of Peter Wright dated December 18, 1812. Transcription of will is below.
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Prior to September 11 2011, Canada was recognized as a leading advocate of international refugee protection and the third largest settlement country in the world. University educated refugees were admitted to the country in part on the basis of their education, but once in Canada their credentials were often ignored. The purpose of this study was to explore, through a transnational feminist lens, immigrant and settlement experiences of refugee female teachers from Yugoslavia who immigrated to Canada during and after the Yugoslav wars; to document the ways in which socially constructed categories such as gender, race, and refugee status have influenced their post-exile experiences and identities; and to identify the government's role in creating conditions where the women were either able or unable to continue in their profession. In this study, I employed both a transnational feminist methodology and narrative inquiry. The analysis process included an emphasis on the storying stories model, poetic transcription, and concentric storying. The women’s voices are represented in various forms throughout the document including individual and collective narratives. Each narrative contributed to a detailed picture of immigration and settlement processes as women spoke of continuing their education, knowing or learning the official language, and contributing to Canadian society and the economy. The findings challenge the image of a victimized and submissive refugee woman, and bring to the centre of discourse the image of the refugee woman as a skilled professional who often remains un- or underemployed in her new country. The dissertation makes an important contribution to an underdeveloped area in the research literature, and has the potential to inform immigration, settlement, and teacher education policies and practices in Canada and elsewhere.
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The Madagascar periwinkle [Catharanthus roseus (L.) G. Don] is a commercially important horticultural flower species and is the only source for several pharmaceutically valuable monoterpenoid indole alkaloids (MIAs), including the powerful antihypertensive ajmalicine and the antineoplastic agents vincristine and vinblastine. While biosynthesis of MIA precursors has been elucidated, conversion of the common MIA precursor strictosidine to MIAs of different families, for example ajmalicine, catharanthine or vindoline, remains uncharacterized. Deglycosylation of strictosidine by the key enzyme Strictosidine beta-glucosidase (SGD) leads to a pool of uncharacterized reaction products that are diverted into the different MIA families, but the downstream reactions are uncharacterized. Screening of 3600 EMS (ethyl methane sulfonate) mutagenized C. roseus plants to identify mutants with altered MIA profiles yielded one plant with high ajmalicine, and low catharanthine and vindoline content. RNA sequencing and comparative bioinformatics of mutant and wildtype plants showed up-regulation of SGD and the transcriptional repressor Zinc finger Catharanthus transcription factor (ZCT1) in the mutant line. The increased SGD activity in mutants seems to yield a larger pool of uncharacterized SGD reaction products that are channeled away from catharanthine and vindoline towards biosynthesis of ajmalicine when compared to the wildtype. Further bioinformatic analyses, and crossings between mutant and wildtype suggest a transcription factor upstream of SGD and ZCT1 to be mutated, leading to up-regulation of Sgd and Zct1. The crossing experiments further show that biosynthesis of the different MIA families is differentially regulated and highly complex. Three new transcription factors were identified by bioinformatics that seem to be involved in the regulation of Zct1 and Sgd expression, leading to the high ajmalicine phenotype. Increased cathenamine reductase activity in the mutant converts the pool of SGD reaction products into ajmalicine and its stereoisomer tetrahydroalstonine. The stereochemistry of ajmalicine and tetrahydroalstonine biosynthesis in vivo and in vitro was further characterized. In addition, a new clade of perakine reductase-like enzymes was identified that reduces the SGD reaction product vallesiachotamine in a stereo-specific manner, characterizing one of the many reactions immediately downstream of SGD that determine the different MIA families. This study establishes that RNA sequencing and comparative bioinformatics, in combination with molecular and biochemical characterization, are valuable tools to determine the genetic basis for mutations that trigger phenotypes, and this approach can also be used for identification of new enzymes and transcription factors.
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This thesis investigated the modulation of dynamic contractile function and energetics of work by posttetanic potentiation (PTP). Mechanical experiments were conducted in vitro using software-controlled protocols to stimulate/determine contractile function during ramp shortening, and muscles were frozen during parallel incubations for biochemical analysis. The central feature of this research was the comparison of fast hindlimb muscles from wildtype and skeletal myosin light chain kinase knockout (skMLCK-/-) mice that does not express the primary mechanism for PTP: myosin regulatory light chain (RLC) phosphorylation. In contrast to smooth/cardiac muscles where RLC phosphorylation is indispensable, its precise physiological role in skeletal muscle is unclear. It was initially determined that tetanic potentiation was shortening speed dependent, and this sensitivity of the PTP mechanism to muscle shortening extended the stimulation frequency domain over which PTP was manifest. Thus, the physiological utility of RLC phosphorylation to augment contractile function in vivo may be more extensive than previously considered. Subsequent experiments studied the contraction-type dependence for PTP and demonstrated that the enhancement of contractile function was dependent on force level. Surprisingly, in the absence of RLC phosphorylation, skMLCK-/- muscles exhibited significant concentric PTP; consequently, up to ~50% of the dynamic PTP response in wildtype muscle may be attributed to an alternate mechanism. When the interaction of PTP and the catchlike property (CLP) was examined, we determined that unlike the acute augmentation of peak force by the CLP, RLC phosphorylation produced a longer-lasting enhancement of force and work in the potentiated state. Nevertheless, despite the apparent interference between these mechanisms, both offer physiological utility and may be complementary in achieving optimal contractile function in vivo. Finally, when the energetic implications of PTP were explored, we determined that during a brief period of repetitive concentric activation, total work performed was ~60% greater in wildtype vs. skMLCK-/- muscles but there was no genotype difference in High-Energy Phosphate Consumption or Economy (i.e. HEPC: work). In summary, this thesis provides novel insight into the modulatory effects of PTP and RLC phosphorylation, and through the observation of alternative mechanisms for PTP we further develop our understanding of the history-dependence of fast skeletal muscle function.
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BACKGROUND: The role of ss-catenin signaling in mesodermal lineage formation and differentiation has been elusive. METHODOLOGY: To define the role of ss-catenin signaling in these processes, we used a Dermo1(Twist2)(Cre/+) line to target a floxed beta-catenin allele, throughout the embryonic mesenchyme. Strikingly, the Dermo1(Cre/+); beta-catenin(f/-) conditional Knock Out embryos largely phenocopy Pitx1(-/-)/Pitx2(-/-) double knockout embryos, suggesting that ss-catenin signaling in the mesenchyme depends mostly on the PITX family of transcription factors. We have dissected this relationship further in the developing lungs and find that mesenchymal deletion of beta-catenin differentially affects two major mesenchymal lineages. The amplification but not differentiation of Fgf10-expressing parabronchial smooth muscle progenitor cells is drastically reduced. In the angioblast-endothelial lineage, however, only differentiation into mature endothelial cells is impaired. CONCLUSION: Taken together these findings reveal a hierarchy of gene activity involving ss-catenin and PITX, as important regulators of mesenchymal cell proliferation and differentiation.