112 research outputs found

    Gold nanoparticles-based sensors for detection of mycobacterium tuberculosis genomic DNA

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    Tuberculosis (TB) caused by Mycobacterium tuberculosis (MTB), is an airborne disease that strikes one third of the globe’s population. In addition to infection of 9.6 million patients, TB claimed the lives of 1.5 million people in 2014 only. The majority of TB patients are present in the third world where the balance between cost-effective diagnostic method and prevalence of TB is difficult to achieve. Accurate diagnosis of TB is necessary to timely initiation of treatment. The available diagnostic tools are slow, while the rapid methods are either inaccurate or relatively unaffordable. So, sometimes the diagnosis is presumptive based on the clinical findings and the treatment is empiric. The treatment is lengthy and demands the administration of multiple antibiotics. However, the emergence of drug resistance threatened the global control programs of TB. The objective of this work is to develop cheap, fast and accurate detection methods. Two gold nanoparticles (AuNPs) based sensors were developed for colorimetric and fluorometric detection of MTB. Seventy two anonymous sputum samples were cultured then DNA was extracted. MTB H37Ra was the positive control while M. smegmatis and 8 non-MTB and negative controls. Characterization of the samples was achieved by multiplex PCR using MTB and NTM specific primers. Random samples were amplified by 16S-23S ITS primers and sequenced. Drug resistance associated mutations of MDR-TB were identified by MAS-PCR. The colorimetric assay aim was the detection of amplified MTB DNA by cationic AuNPs. The samples were amplified by IS6110 and rpoB primers. Only MTB samples yielded amplicons. So the negatively charged dsDNA attracted the positively charged AuNPs inducing their aggregation and the color turned blue. While the negative samples did not yield any amplicons and the AuNPs remained dispersed so the color was red. The sensitivity and specificity was 100% and the detection limit was 5.4 ng/μl of MTB DNA. The fluorometric assay exploited the quenching property of 40 nm AuNPs. The unamplified DNA was fragmented in the presence of 16s rDNA specific probe tagged with the fluorophore CY-3 by sonication and denatured for 3 min at 95 ºC followed by annealing at 52ºC for 45 sec. Then AuNPs were added and the fluorescence was measured. By FRET, the relative fluorescence was calculated revealing a cut-off value of 3. In MTB samples, the CY3-16s rDNA specific probe hybridized with its target and became spaced from the AuNPs allowing high fluorescence to be detected. Due to the lack of target-probe hybridization in the negative samples, the AuNPs were adsorbed on the probe and thus the fluorescence is quenched. Thirteen samples were chosen randomly, amplified and sequenced. Sequencing confirmed that 12/13 samples were MTB with 100% concordance with the multiplex PCR and FRET. The assay had sensitivity and specificity of 98.6% and 90% respectively and concordance of 98% with multiplex PCR. The detection limited was calculated to be 10 ng/ul. In conclusion, two AuNPs based sensors were developed to allow low cost and rapid detection of MTB on low source settings. The assays are rapid, sensitive and can have great potential in clinical practice for TB diagnosis

    Study of Treg FOXP3 in childhood bronchial asthma in relation to corticosteroid therapy

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    Background: T cells are considered the main cells responsible for production of suppressive cytokines, and play a key role in balancing the immune responses to maintain the peripheral tolerance against allergens. Objective: The present study investigates T regulatory (Treg) forkheadwinged helix protein 3 FOXP3 expression in childhood asthma and its relation to corticosteroid therapy. Methods: In this case control study, Treg FOXP3 was measured in blood of 60 children using real time polymerase chain reaction (RT-PCR) technique. Two asthmatic groups were included, one on corticosteroid therapy (20 patients) and the other not on corticosteroid treatment (20 patients). They were compared to 20 healthy children as controls. Results: FOXP3 concentration was significantly elevated in asthmatic patients (90 ± 77.4) compared to healthy children (12.844 ± 10.6) (p= 0.000). FOXP3 was significantly more elevated in asthmatics on corticosteroids (161.158 ± 63.9) than steroid naive asthmatics (36.038 ± 23.4) (p=0.000). Levels of Treg FOXP3 in asthmatics with inhaled corticosteroids (mean 151.16 ± 53.79) were almost similar to FOXP3 in asthmatics with systemic corticosteroids (161.49±72.5) (p>0.05). FOXP3 levels did not differ with smoking, asthma severity or disease control and did not correlate with age, FEV1, blood lymphocytes percentage or eosinophils percentage. Conclusion: Asthmatics have increased expression of FOXP3, and corticosteroid therapy –whether oral or inhaled - enhances FOXP3 expression.Keywords: FOXP3, Treg, Corticosteroids, Bronchial asthma, Transcription factors, CytokinesEgypt J Pediatr Allergy Immunol 2012;10(1):39-43

    A single tube system for the detection of Mycobacterium tuberculosis DNA using gold nanoparticles based FRET assay

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    The global combat against MTB is limited by challenges in accurate affordable detection. In this study, a rapid, affordable, single tube system for detection of unamplified MTB16s rDNA was developed. Utilizing a AuNP based FRET system, this assay achieved a sensitivity and specificity of 98.6% and 90% respectively.This report was made possible by a NPRP award [NPRP 4-1215-3-317] from the Qatar National Research Fund (a member of The Qatar Foundation). The statements made herein are solely the responsibility of the authors

    Paclitaxel and Sorafenib: The Effective Combination of Suppressing the Self-Renewal of Cancer Stem Cells

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    Combination therapy, which is a treatment modality combining two or more therapeutic agents, is considered a cornerstone of cancer therapy. The combination of anticancer drugs, of which functions are different from the other, enhances the efficiency compared to the monotherapy because it targets cancer cells in a synergistic or an additive manner. In this study, the combination of paclitaxel and sorafenib in low concentration was evaluated to target cancer stem cells, miPS-BT549cmP and miPS-Huh7cmP cells, developed from mouse induced pluripotent stem cells. The synergistic effect of paclitaxel and sorafenib on cancer stem cells was assessed by the inhibition of proliferation, self-renewal, colony formation, and differentiation. While the IC(50)values of paclitaxel and sorafenib were approximately ranging between 250 and 300 nM and between 6.5 and 8 mu M, respectively, IC(50)of paclitaxel reduced to 20 and 25 nM, which was not toxic in a single dose, in the presence of 1 mu M sorafenib, which was not toxic to the cells. Then, the synergistic effect was further assessed for the potential of self-renewal of cancer stem cells by sphere formation ability. As a result, 1 mu M of sorafenib significantly enhanced the effect of paclitaxel to suppress the number of spheres. Simultaneously, paclitaxel ranging in 1 to 4 nM significantly suppressed not only the colony formation but also the tube formation of the cancer stem cells in the presence of 1 mu M sorafenib. These results suggest the combination therapy of paclitaxel and sorafenib in low doses should be an attractive approach to target cancer stem cells with fewer side effects

    Hematopoietic Cells Derived from Cancer Stem Cells Generated from Mouse Induced Pluripotent Stem Cells

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    Cancer stem cells (CSCs) represent the subpopulation of cancer cells with the ability to differentiate into other cell phenotypes and initiated tumorigenesis. Previously, we reported generating CSCs from mouse induced pluripotent stem cells (miPSCs). Here, we investigated the ability of the CSCs to differentiate into hematopoietic cells. First, the primary cells were isolated from malignant tumors that were formed by the CSCs. Non-adherent cells (NACs) that arose from adherent cells were collected and their viability, as well as the morphology and expression of hematopoietic cell markers, were analyzed. Moreover, NACs were injected into the tail vein of busulfan conditioned Balb/c nude mice. Finally, CSCs were induced to differentiate to macrophages while using IL3 and SCF. The round nucleated NACs were found to be viable, positive for hematopoietic lineage markers and CD34, and expressed hematopoietic markers, just like homing to the bone marrow. When NACs were injected into mice, Wright-Giemsa staining showed that the number of white blood cells got higher than those in the control mice after four weeks. CSCs also showed the ability to differentiate toward macrophages. CSCs were demonstrated to have the potential to provide progenies with hematopoietic markers, morphology, and homing ability to the bone marrow, which could give new insight into the tumor microenvironment according to the plasticity of CSCs

    Knowledge about Autism Spectrum Disorder (ASD) predicts motivation to volunteer : a cross-sectional survey among psychology students

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    Children with Autism Spectrum Disorder (ASD) and their parents require support from the community, and could profit from volunteer work involving the family. At the same time, university students demonstrate a high willingness to volunteer in community initiatives such as work involving children with ASD. This study aims to examine the relationship between ASD knowledge and the motivation to volunteer among university students. Students (N=150) from a private university in the Klang Valley, Malaysia, participated in this study. Instruments utilized in this study were the Stone Autism Survey and Volunteer Functions Inventory. The results indicated that a higher level of ASD knowledge was the strongest predictor of higher motivation to volunteer after adjusting for relevant demographic factors and exposure to ASD children. Meanwhile, female and Hindu participants reported a significantly higher motivation to volunteer. This study emphasizes the need to increase factual knowledge about ASD among university students, and any effort to encourage students to volunteer in helping individuals with ASD should include knowledge sharing about this population

    Managing infectious diarrhea among young children in community pharmacies in Saudi Arabia and the implications for AMR

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    Introduction: Diarrhea remains a major global health issue for children under five, contributing substantially to morbidity and mortality. Community pharmacists play a pivotal role in the management of these children; however, their competence in managing childhood diarrhea in Saudi Arabia is under-researched. This is important to ensure optimal patient care. Method: Simulated patients (SPs) presenting with three pediatric diarrhea scenarios were used to evaluate pharmacists’ practice in terms of their counselling, history taking, over-the-counter (OTC) prescribing, medication instructions, diet/fluid advice, and/or information provision. Pharmacists’ practice was categorized into adequate, less adequate, and poor. Results: 182 community pharmacists, primarily male and non-Saudi, participated in the study, of which 60% were in chain pharmacies. Only 5% showed adequate practice in currently managing pediatric diarrhea. Of the 182 simulated patient visits, 62% received medication in all three scenarios and 20% were referred to physicians, with 16% of pharmacists failing to provide any form of intervention. The main medications recommended were kaolin (34%), pectin (34%) and metronidazole (11%). While most pharmacists (86%) asked about the patient's identity and age, 15% provided incorrect management information, 16% failed to provide guidance on the prescribed medicines, and 18% dispensed antimicrobials without a valid prescription. Conclusion: A high level of inadequate management of pediatric diarrhea in Saudi Arabia was observed. This highlights the need for extensive training to improve community pharmacists’ practice in service delivery including providing counselling and advice on the appropriate management of childhood diarrhea. The latter is particularly important to reduce antimicrobial resistance

    A new cineol derivative, polyphenols and norterpenoids from Saharan myrtle tea (Myrtus nivellei): Isolation, structure determination, quantitative determination and antioxidant activity

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    Abstract The phytochemical profile of decoction and infusion, obtained from the dried leaves of M. nivellei, consumed as tea in Saharan region, was characterized by UHPLC-PDA-HRMS. Fourteen compounds were characterized and, to confirm the proposed structures a preparative procedure followed by NMR spectroscopy was applied. Compound 3 (2-hydroxy-1,8-cineole disaccharide) was a never reported whereas a bycyclic monoterpenoid glucoside (2), two ionol glucosides (1 and 12), a tri-galloylquinic acid (4), two flavonol glycosides (5 and 9), and a tetra-galloylglucose (7), were reported in Myrtus spp. for the first time. Five flavonol O-glycosides (6, 8, 10–11, and 14) togheter a flavonol (13) were also identified. Quantitative determination of phenolic constituents from decoction and infusion has been performed by HPLC-UV-PDA. The phenolic content was found to be 150.5 and 102.6 mg/g in decoction and infusion corresponding to 73.8 and 23.6 mg/100 mL of a single tea cup, respectively. Myricetin 3-O-β-d-(6″-galloyl)glucopyranoside (5), isomyricitrin (6) and myricitrin (8) were the compounds present in the highest concentration. The free-radical scavenging activities of teas and isolated compounds was measured by the DPPH assay and compared with the values of other commonly used herbal teas (green and black teas). Decoction displayed higher potency in scavenging free-radicals than the infusion and green and black teas

    Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

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    BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London
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