Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99


Any time

2019 ( 13 )

2018 ( 82 )

2017 ( 120 )

2016 ( 179 )

Custom range...

Search Results: 1 - 10 of 9497 matches for " PCR "
All listed articles are free for downloading (OA Articles)
Page 1 /9497
Display every page Item
Abdul Haque
The Professional Medical Journal , 1997,
Direct real-time PCR examination for Mycobacterium tuberculosis in respiratory samples can be cost effective  [PDF]
Bryan Joseph Renton, Patricia Denise Morrell, Richard Peter Davidson Cooke, Peter David Owen Davies
Health (Health) , 2009, DOI: 10.4236/health.2009.12011
Abstract: Aim: To assess whether the use of direct real- time polymerase chain reaction (PCR) on smear-positive sputa can be cost-effective, by speciating mycobacteria earlier than current methods and thereby preventing unnecessary screening tests as part of the contact tracing process. Methods: A retrospective study of all patients with smear-positive sputa in a Liverpool teach-ing hospital between 2004 and 2007. All the PCRs performed on these patients were re-viewed and compared them with their myco-bacterial culture results. Unit costs for PCR, chest X-ray (CXR), tuberculin skin test (TST), interferon-gamma (IFN-γ) and medical/nursing time were conservatively estimated at £50, £11, £10, £40 and £30 respectively. The total PCR costs were compared with the costs of unnec-essary follow up of patients, negative for My-cobacterium tuberculosis (MTB) by PCR, sub-sequently confirmed to be MTB culture nega-tive. Results: 203 smear-positive patients under-went direct PCR testing. 126 (62%) patients grew Mycobacterium tuberculosis (MTB), 74 (37%) had environmental mycobacterial infection (EMI) and 3 (1%) were culture negative. Of the 126 patients’ culture positive MTB patients, 123 were PCR positive and 3 PCR negative. Of the 77 pa-tients that were culture negative for MTB, 75 were PCR negative and 2 PCR positive The sensitivity, specificity, positive and negative predictive values for direct PCR versus MTB culture were 98%, 96%, 98% and 97% respec-tively. Total costs of all PCRs performed amounted to £10,150. The cost of contact pro-cedures for PCR-negative and MTB culture- negative index cases was estimated at £19,650. This equated to a total saving of £9,500 in contact tracing costs. Conclusions: Direct PCR examination testing of smear-positive patients can be cost-effective in areas where there is a high incidence of EMI.
Comparative Study of Different Methods for Analyzing Denitrifying Bacteria in Fresh Water Ecosystems  [PDF]
Kristina Rathsack, J?rg B?llmann, Marion Martienssen
Journal of Water Resource and Protection (JWARP) , 2014, DOI: 10.4236/jwarp.2014.66059

Bacteria capable of denitrification play a significant role in the nitrogen cycle of freshwater ecosystems. By metabolizing nitrogen compounds they e.g. counteract the eutrophication of natural waters. To get detailed insights into the in situ turnover rates of nitrogen a reliable tool of quantification for active microorganisms is essential. In the present investigation, quantification capabilities of a molecular tool (Polymerase Chain Reaction—PCR) and a cultivation based tool (Most probable number—MPN) were investigated and compared. The total bacterial concentration yielded by the molecular PCR approach was up to 6-fold higher compared to the results of the MPN approach. However, the portion of culturable denitrifying bacteria compared to the number of specific gene copies (nirS) was much lower. Depending on the environmental conditions, the difference between the PCR and the MPN approach was up to three orders of magnitude. From lab scale experiments with a pure P. aeroginosa strain it can be concludes, that these differences are not the result of inappropriate culture conditions but rather reflect the portion of so called viable but not culturable bacteria (VBNC). Low nitrate concentrations as found in many fresh water ecosystems induced a significant increase in the portion of non culturable denitrifying bacteria. Referred to the investigation of dynamic populations, the number of metabolic active bacteria is represented by the MPN rather than by the PCR approach.

Metals Complexes Formed with Oleanolic Acid  [PDF]
Nilton C. Ribeiro, Antonio J. Demuner, Marcelo H. dos Santos, Célia R. A. Maltha, Elson A. de Alvarenga, Slavko Komarnytsky
International Journal of Organic Chemistry (IJOC) , 2018, DOI: 10.4236/ijoc.2018.81011
Abstract: The oleanolic acid possesses diverse pharmacological properties, it is considered as a good starting material for creating new compounds. The oleanolic acid isolated of Plumeria obtusa leaves was used as raw material to obtained calcium, magnesium, zinc, nickel and copper complexes. The structures of complexes were confirmed by HRMS, 1H NMR, and 13C NMR. Five new compounds were synthesized to promote increased biological activity of oleanolic acid and PCR assays for the different type of cancer.
自然科学进展 , 2007,
Abstract: 聚合酶链式反应(PCR)在生命科学的研究领域已经得到了广泛的应用.文中对PCR技术的一些最新进展进行了简要的综述,其中包括定量PCR、纳米PCR、PCR芯片、原位PCR和免疫PCR的原理和应用.
Molecular Characterization of Echinococcus granulosus in South of Iran  [PDF]
Saeid Hosseinzadeh, Mehdi Fazeli, Arsalan Hosseini, Seyed Shahram Shekarforoush
Open Journal of Veterinary Medicine (OJVM) , 2012, DOI: 10.4236/ojvm.2012.24032
Abstract: The focus of present study was to determine the epidemiological and molecular aspects of different strains of cystic echinococcosis in Fars province, Iran. Liver and lung samples from 410 sheep, 206 goats and 315 cattle were collected. In cattle, the infestation rate was 18.1% (57/315), with 11.1% hepatic cysts and 7.0% pulmonary cysts. Out of all identified cysts, 31.4% of the hepatic and 31.8% of the pulmonary cysts were found fertile. Incidence rate of hydatid cyst infection in sheep was 15.5% (64/410) with 11.9% hepatic cysts and 3.6% pulmonary cysts, of which 24.5% and 20% of hepatic and pulmonary cysts were respectively identified as fertile. The infestation rate was 16.0% (33/206) in goat, in which 10.2% and 5.8% cysts were collected from liver and lung, correspondingly. The prevalence of fertile hepatic and pulmonary cysts was recorded as 23.8% and 16.7%, respectively. Genotyping the cystic materials using PCR showed that the most prominent strains responsible for cystic echinococcosis in the Fars province are G1 and G6/7, while no evidence of E. multilocularis was recorded. This information may give us some clues to find out more about strains distribution in different regions in Iran, which may finally use to find tools in the eradication program of the disease, here and elsewhere.
Clinical Presentations of HHV-6 Infection in Infants and Children in Kuwait: A Retrospective Study  [PDF]
Nada Madi, Haya Al-Tawalah, Widad Al-Nakib
Advances in Microbiology (AiM) , 2014, DOI: 10.4236/aim.2014.415119
Abstract: Clinical manifestations of human herpesvirus 6 (HHV-6) have not been clearly defined, and the role of HHV-6 in human disease among infants and children in Kuwait remains to be fully elucidated. A retrospective study covering the period between 2008 and 2014 was conducted on infants and children aged from 1 month to 5 years. Blood and CSF samples from infants and children who presented with symptoms suggestive HHV-6 infection were subjected to PCR test for HHV-6. Results showed that 9.3% (n = 42) of infants and children were positive for HHV-6. Fever was the most noticeable symptoms, presenting in 50% (n = 21) of the patients. Also, neutropenia was highly associated with HHV-6 infection, where it presented in 35.8% (n = 15) of infants and children. Our results provided important information about the clinical outcome of HHV-6 infection among infants and children in Kuwait.
Comparative Evaluation of Traditional Susceptibility Testing for MRSA with the PCR Approach  [PDF]
Tim Sandle, Ilya Azizov, Dmitriy Babenko, Antonella Chesca, Alena Lavrinenko
Advances in Microbiology (AiM) , 2014, DOI: 10.4236/aim.2014.416130
Abstract: Methicillin-resistant Staphylococcus aureus (MRSA) is a multi-drug resistant pathogen, which is responsible for increasing cases of serious diseases, including life-threatening diseases and nosocomial and community-acquired infections. Laboratory identification of MRSA is crucial and essential both for initiation of appropriate antimicrobial therapies and for effective infection control strategies that are designed to limit the spread of MRSA. In spite of the availability of commercial kits for MRSA detection in the market, the Clinical and Laboratory Standards Institute (CLSI) recommends the use of phenotypic methods, such as the disk diffusion method with oxacillin or with cefoxitin, as well as a serial dilution method with oxacillin. Nevertheless, some studies have shown that results obtained with such phenotypic methods are controversial. The aim of the study described in this paper was to comparatively evaluate the traditional susceptibility testing for MRSA with PCR as the gold standard assay. Analysis of collection (n = 68) isolates of Staphylococcus aureus revealed that the serial dilution method with oxacillin possessed the highest sensitivity (at 100%). In contrast, the disk diffusion methods with oxacillin and cefoxitin showed lower sensitivity (95.83%, 95% CI (78.81%-99.30%)). Furthermore, the borderline value of zone inhibition diameters for cefoxitin might be considered as a risk, and they may give false-susceptible result.
Rapid Screening of Recombinant Plasmids by Direct Colony Quantitative Real-Time PCR  [PDF]
Lei Hou, Xiuying Zhang, Yang Li, Shuai Chen, Hongyi Qu, Jiazhi Yu, Lianhai Zhang, Ziyi Fan
Advances in Bioscience and Biotechnology (ABB) , 2016, DOI: 10.4236/abb.2016.710041
Abstract: Quantitative real-time PCR (qPCR) was applied to rapid screening of positive plasmid clones. Insert-specific primer pairs were used in qPCR colony screening, and false positive colonies could easily be distinguished from true positive ones by comparing their Ct values. In addition, qPCR is particularly suitable when amplicon is small (<150 bp). This method is sensitive, simple and fast, obviates the need for gel electrophoresis, and is a cost-effective alternative to the traditional PCR approach.
Isolation of Moraxella sp. from Cases of Keratoconjunctivitis in an Organized Sheep Farm of India  [PDF]
Kumaragurubaran Karthik, Kaliyaperumal Manimaran, Ramalingam Mahaprabhu, Kulasekaran Shoba
Open Journal of Veterinary Medicine (OJVM) , 2017, DOI: 10.4236/ojvm.2017.710014
Abstract: Keratoconjunctivitis in sheep causes severe ocular irritation thereby reducing the production performance thus causing economic loss to the farmers. Bacterial cause of keratoconjunctivitis in sheep may be due to Listeria monocytogenes, Moraxella ovis, Mycoplasma conjunctivae, etc. An investigation carried out at Tirupathur, Sivagangai district, Tamil Nadu, India revealed keratoconjunctivitis in sheep (population 100 animals). Isolation and identification of eye swabs from ailing animals (n = 5) showed that the bacteria was Moraxella sp. Polymerase chain reaction (PCR) of the isolate was positive for Moraxella sp. Antimicrobial sensitivity testing of the isolate showed that it was sensitive to all antibiotics used in the study. This study reports the presence of Moraxella sp. infection in sheep warranting further studies to know the exact status of this organism so as to prevent keratoconjunctivitis in sheep.
Page 1 /9497
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.