40 research outputs found

    S. Enteritidis and S. Typhimurium Harboring SPI-1 and SPI-2 Are the Predominant Serotypes Associated With Human Salmonellosis in Saudi Arabia

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    Non-typhoidal Salmonella (NTS) strains are Gram negative bacterial pathogens that are associated with foodborne illness worldwide. During the process of infection, Salmonella uses two molecular injectisomes known as Type 3 Secretion Systems (T3SS) to secrete virulence factors that are encoded by Salmonella Pathogenicity Island-1 (SPI-1) and SPI-2 into host cells. These secretion systems play a major role in virulence, as shown in various animal models, but little is known about their role in human infections. In Saudi Arabia, NTS strains frequently cause human infections but data regarding these pathogenic strains is fairly limited. The aim of this study was to characterize Salmonella human clinical isolates in Riyadh, Saudi Arabia, by determining their serotype, testing for the presence of SPI-1 and SPI-2 genes and to determine the antibiotic resistance profiles of these strains. Using the rapid Check and Trace Salmonella™ (CTS) system our results demonstrate that S. Enteritidis and S. Typhimurium were the predominant serovars, followed by S. Livingstone, S. Kentucky and S. Poona among a list of 36 serovars reported for the first time in the country. In addition, SPI-1 genes were detected in 99% of the isolates, while the sifA gene (SPI-2) was not detected in 13.5% of the isolates. These results suggest that both the SPI-1 and SPI-2 virulence determinants are important for human infection. Moreover, we report the presence of a Multi-Drug (MDR) carbapenem resistant S. Kentucky isolate harboring the blaOXA−48 gene not reported previously in Saudi Arabia

    Licenciar para silenciar: o papel da Inquisição numa comédia de equívocos (1649)

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    Considerações sobre a acção da Inquisição em Portugal: o caso do mestre-escola Manuel Antunes.info:eu-repo/semantics/publishedVersio

    Echinacoside ameliorates hepatic fibrosis and tumor invasion in rats with thioacetamide-induced hepatocellular carcinoma

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    Hepatocellular carcinoma (HCC) affects approximately 800,000 individuals globally each year. Despite advancements in HCC treatments, there is still a pressing need to identify new drugs that can combat resistance. One potential option is echinacoside, a natural caffeic acid glycoside with antioxidant, anti-inflammatory, antidepressant, and antidiabetic properties. Therefore, we aimed to investigate the ability of echinacoside to exhibit antitumor activity against HCC in rats through ameliorating hepatic fibrosis and tumor invasion. Rats were given thioacetamide to induce HCC, and some were given 30 mg/kg of echinacoside twice a week for 16 weeks. The liver impairment was assessed by measuring serum α-fetoprotein (AFP) and examining liver sections stained with Masson trichrome or anti-transforming growth factor (TGF)-β1 antibodies. The hepatic expression of mRNA and protein levels of TGF-β1, β-catenin, SMAD4, matrix metalloproteinase-9 (MMP9), phosphoinositide 3-kinases (PI3K), mammalian target of rapamycin (mTOR), connective tissue growth factor 2 (CCN2), E-Cadherin, platelets derived growth factor (PDGF)-B and fascin were also analyzed. Echinacoside improved the survival rate of rats by decreasing serum AFP and the number of hepatic nodules. Examination of micro-images indicated that echinacoside can reduce fibrosis. It also significantly decreased the expression of TGF-β1, β-catenin, SMAD4, MMP9, PI3K, mTOR, CCN2, PDGF-B, and fascin while enhancing the expression of E-Cadherin. In conclusion, echinacoside exhibits a protective effect against HCC by increasing survival rates and decreasing tumor growth. It also acts as an inhibitor of the hepatic tissue fibrosis pathway by reducing the expression of TGF-β1, β-catenin, SMAD4, PI3K, CCN2, PDGF-B and mTOR. Additionally, it prevents tumor invasion by suppressing MMP9 and fascin, and increasing the expression of E-Cadherin

    Abstracts from the 3rd International Genomic Medicine Conference (3rd IGMC 2015)

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    Peptidomimetic inhibitors of L-plastin reduce the resorptive activity of osteoclast but not the bone forming activity of osteoblasts in vitro.

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    Sealing ring formation is a requirement for osteoclast function. We have recently identified the role of an actin-bundling protein L-plastin in the assembly of nascent sealing zones (NSZs) at the early phase of sealing ring formation in osteoclasts. TNF-α signaling regulates this actin assembly by the phosphorylation of L-plastin on serine -5 and -7 residues at the amino-terminal end. These NSZs function as a core for integrin localization and coordinating integrin signaling required for maturation into fully functional sealing rings. Our goal is to elucidate the essential function of L-plastin phosphorylation in actin bundling, a process required for NSZs formation. The present study was undertaken to determine whether targeting serine phosphorylation of cellular L-plastin would be the appropriate approach to attenuate the formation of NSZs. Our approach is to use TAT-fused small molecular weight amino-terminal L-plastin peptides (10 amino acids) containing phospho- Ser-5 and Ser-7. We used peptides unsubstituted (P1) and substituted (P2- P4) at serine-to-alanine residues. Immunoblotting, actin staining, and dentine resorption analyses were done to determine cellular L-plastin phosphorylation, NSZ or sealing ring formation, and osteoclast function, respectively. Immunoblotting for bone formation markers, Alizarin red staining and alkaline phosphatase activity assay have been done to determine the effect of peptides on the mineralization process mediated by osteoblasts. Transduction of unsubstituted (P1) and substituted peptides at either Serine 5 or Serine 7 with Alanine (P3 and P4) demonstrated variable inhibitory effects on the phosphorylation of cellular L-plastin protein. Peptide P1 reduces the following processes substantially: 1) cellular L-plastin phosphorylation; 2) formation of nascent sealing zones and sealing rings; 3) bone resorption. Substitution of both Serine-5 and -7 with Alanine (P2) had no effects on the inhibitory activities described above. Furthermore, either the L-plastin (P1-P5) or (P6) control peptides had a little or no impact on the a) assembly/disassembly of podosomes and migration of osteoclasts; b) mineralization process mediated by osteoblasts in vitro. Small molecular weight peptidomimetics of L-plastin inhibits bone resorption by osteoclasts via attenuation of NSZ and sealing ring formation but not bone formation by osteoblasts in vitro. The L-plastin may be a valuable therapeutic target to treat and prevent diseases associated with bone loss without affecting bone formation

    Identification of sequence-specific interactions of the CD44-intracellular domain with RUNX2 in the transcription of matrix metalloprotease-9 in human prostate cancer cells

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    Aim: The Cluster of differentiation 44 (CD44) transmembrane protein is cleaved by γ-secretase, the inhibition of which blocks CD44 cleavage. This study aimed to determine the biological consequence of CD44 cleavage and its potential interaction with Runt-related transcription factor (RUNX2) in a sequence-specific manner in PC3 prostate cancer cells.Methods: Using full-length and C-terminal deletion constructs of CD44-ICD (D1-D5) expressed as stable green fluorescent protein-fusion proteins in PC3 cells, we located possible RUNX2-binding sequences.Results: Chromatin immunoprecipitation assays demonstrated that the C-terminal amino acid residues between amino acids 671 and 706 in D1 to D3 constructs were indispensable for sequence-specific binding of RUNX2. This binding was minimal for sequences in the D4 and D5 constructs. Correspondingly, an increase in matrix metalloprotease-9 (MMP-9) expression was observed at the mRNA and protein levels in PC3 cells stably expressing D1–D3 constructs.Conclusion: These results provide biochemical evidence for the possible sequence-specific CD44-ICD/RUNX2 interaction and its functional relationship to MMP-9 transcription in the promoter region

    Engineering of L-Plastin Peptide-Loaded Biodegradable Nanoparticles for Sustained Delivery and Suppression of Osteoclast Function In Vitro

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    We have recently demonstrated that a small molecular weight amino-terminal peptide of L-plastin (10 amino acids; “MARGSVSDEE”) suppressed the phosphorylation of endogenous L-plastin. Therefore, the formation of nascent sealing zones (NSZs) and bone resorption are reduced. The aim of this study was to develop a biodegradable and biocompatible PLGA nanocarrier that could be loaded with the L-plastin peptide of interest and determine the efficacy in vitro in osteoclast cultures. L-plastin MARGSVSDEE (P1) and scrambled control (P3) peptide-loaded PLGA-PEG nanoparticles (NP1 and NP3, respectively) were synthesized by double emulsion technique. The biological effect of nanoparticles on osteoclasts was evaluated by immunoprecipitation, immunoblotting, rhodamine-phalloidin staining of actin filaments, and pit forming assays. Physical characterization of well-dispersed NP1 and NP3 demonstrated ~130-150 nm size, < 0.07 polydispersity index, ~-3 mV ζ-potential, and a sustained release of the peptide for three weeks. Biological characterization in osteoclast cultures demonstrated the following: NP1 significantly reduced (a) endogenous L-plastin phosphorylation; (b) formation of NSZs and sealing rings; (c) resorption. However, the assembly of podosomes which are critical for cell adhesion was not affected. L-plastin peptide-loaded PLGA-PEG nanocarriers have promising potential for the treatment of diseases associated with bone loss. Future studies will use this sustained release of peptide strategy to systematically suppress osteoclast bone resorption activity in vivo in mouse models demonstrating bone loss

    Genomic Characterization of Uropathogenic <i>Escherichia coli</i> Isolates from Tertiary Hospitals in Riyadh, Saudi Arabia

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    Uropathogenic Escherichia coli (UPEC) is the most common cause of urinary tract infections (UTIs) in hospitalised and non-hospitalised patients. Genomic analysis was used to gain further insight into the molecular characteristics of UPEC isolates from Saudi Arabia. A total of 165 isolates were collected from patients with UTIs between May 2019 and September 2020 from two tertiary hospitals in Riyadh, Saudi Arabia. Identification and antimicrobial susceptibility testing (AST) were performed using the VITEK system. Extended-spectrum β-lactamase (ESBL)-producing isolates (n = 48) were selected for whole genome sequencing (WGS) analysis. In silico analysis revealed that the most common sequence types detected were ST131 (39.6%), ST1193 (12.5%), ST73 (10.4%), and ST10 (8.3%). Our finding showed that blaCTX-M-15 gene was detected in the majority of ESBL isolates (79.2%), followed by blaCTX-M-27 (12.5%) and blaCTX-M-8 (2.1%). ST131 carried blaCTX-M-15 or blaCTX-M-27, and all ST73 and ST1193 carried blaCTX-M-15. The relatively high proportion of ST1193 in this study was notable as a newly emerged lineage in the region, which warrants further monitoring

    Effects of irritable bowel syndrome on the health-related quality of life among the Saudi population

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    Background: Irritable bowel syndrome (IBS) is a digestive system disorder. Patients with IBS have a significantly lower quality of life (QoL). In this study, we aimed to assess how IBS affects the Saudi Arabian population's health-related (HR)-QoL. Methods: A cross-sectional Web-based survey was conducted with a representative sample (n = 1346) of patients who met the Rome IV criteria for IBS from all regions of the country between February and May 2021. The questionnaire surveyed participants' socio-demographic data (nationality, sex, age, region, marital status, level of education, and occupation) and included 24 questions on IBS divided into four categories: (1) diagnosis; (2) symptoms; (3) impact on patients' lives; and (4) management methods. The HR-QoL score was calculated using a five-point Likert scale, with higher scores indicating worse QoL. Results: Most patients (83.3%) were diagnosed by a physician, and 66.7% had a family member or a friend with IBS. Mixed IBS was the most common type of IBS (26.4%). Factors associated with poor QoL and significantly associated with IBS included female sex, initial diagnosis by a general physician, intermittent symptoms, and being asymptomatic for weeks to months. Conclusions: Greater attention to the QoL of patients with IBS is required to help them deal with IBS and create supportive environments to reduce its psychological effects
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