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Artigo em Inglês | MEDLINE | ID: mdl-30790450


BACKGROUND: Over 2,000 people a year in the United Kingdom need a bone marrow or blood stem cell transplant. It is important to accurately quantify the hematopoietic stem cells to predict whether the transplant will be successful in replenishing the immune system. However, they are present at low frequency, which complicates accurate quantification. The current gold standard method is single-platform flow cytometry using internal reference counting beads to determine the concentration of CD34 cells. However, volumetric flow cytometers have the ability to measure the acquisition volume, which removes the need for reference beads for calculation of cell concentrations. METHOD: In this study, we compared both methods for calculating CD34 cell concentrations in volumetric cytometers, using either the volume reading or the number of reference beads for calculation. In addition, the uncertainty of measurement for each method was estimated. RESULTS: The results show that both methods have similar uncertainties of measurement. Regression analysis showed low to no statistical difference in CD34 cell concentrations obtained with each method. CONCLUSIONS: Overall, this study suggests that the volumetric method is a valid approach but that the adoption of this technology may be hindered without some form of external calibration of volume readings to increase confidence in the measurement. © 2019 The Authors. Cytometry Part B: Clinical Cytometry published by Wiley Periodicals, Inc. on behalf of International Clinical Cytometry Society.

Phytochem Anal ; 28(6): 541-549, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28722248


INTRODUCTION: Salvia, an important and widely available member of Lamiaceae family. Although comparative analysis on secondary metabolites in several Salvia species from Turkey has been reported, their hallucinogenic chemicals have not been screened thoroughly. OBJECTIVE: This study provides LC-MS/MS analysis of 40 Salvia species for screening their psychoactive constituents of salvinorin A and salvinorin B. 5S-rRNA gene non-coding region of Salvia plants was sequenced, aligned and compared with that sequence of Salvia divinorum plant. METHODOLOGY: Targeted molecules of salvinorin A and salvinorin B were quantified, using LC-MS/MS, from all aerial parts of 40 Salvia species, collected from different parts of Turkey. Regions of 5S-rRNA gene from different species were amplified by polymerase chain reaction and DNA sequences were aligned with Salvia divinorum DNA sequences. RESULTS: Very few of the Salvia species (S. recognita, S. cryptantha and S. glutinosa) contained relatively high levels of salvinorin A (212.86 ± 20.46 µg/g, 51.50 ± 4.95 µg/g and 38.92 ± 3.74 µg/g, respectively). Salvinorin B was also found in Salvia species of S. potentillifolia, S. adenocaulon and S. cryptantha as 2351.99 ± 232.22 µg/g, 768.78 ± 75.90 µg/g and 402.24 ± 39.71 µg/g, respectively. The sequences of 5S-rRNA gene of 40 different Salvia species were presented and it was found that none of the Salvia species in Turkey had similar DNA sequence to Salvia divinorum plant. CONCLUSION: This is the first report of screening 40 Salvia species in Turkey according to their psychoactive constituents, salvinorin A and salvinorin B and their genomic structures. It is possible that some of these Salvia species may exhibit some psycho activity. Thus, they need to be screened further. Copyright © 2017 John Wiley & Sons, Ltd.

Alucinógenos/química , Salvia/química , Salvia/genética , Cromatografia Líquida/métodos , DNA de Plantas/genética , Regulação da Expressão Gênica de Plantas , Genoma de Planta , Filogenia , Especificidade da Espécie , Espectrometria de Massas em Tandem/métodos , Turquia
Food Chem ; 221: 1253-1257, 2017 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-27979086


Preventing adulteration of meat and meat products with less desirable or objectionable meat species is important not only for economical, religious and health reasons, but also, it is important for fair trade practices, therefore, several methods for identification of meat and meat products have been developed. In the present study, ten different DNA extraction methods, including Tris-EDTA Method, a modified Cetyltrimethylammonium Bromide (CTAB) Method, Alkaline Method, Urea Method, Salt Method, Guanidinium Isothiocyanate (GuSCN) Method, Wizard Method, Qiagen Method, Zymogen Method and Genespin Method were examined to determine their relative effectiveness for extracting DNA from meat samples. The results show that the salt method is easy to perform, inexpensive and environmentally friendly. Additionally, it has the highest yield among all the isolation methods tested. We suggest this method as an alternative method for DNA isolation from meat and meat products.

DNA/isolamento & purificação , Produtos da Carne/análise , Carne/análise , Compostos de Cetrimônio/química , DNA/análise , Reação em Cadeia da Polimerase , Espectrometria de Fluorescência
BMC Infect Dis ; 16: 366, 2016 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-27487852


BACKGROUND: Real-time PCR (qPCR) based methods, such as the Xpert MTB/RIF, are increasingly being used to diagnose tuberculosis (TB). While qualitative methods are adequate for diagnosis, the therapeutic monitoring of TB patients requires quantitative methods currently performed using smear microscopy. The potential use of quantitative molecular measurements for therapeutic monitoring has been investigated but findings have been variable and inconclusive. The lack of an adequate reference method and reference materials is a barrier to understanding the source of such disagreement. Digital PCR (dPCR) offers the potential for an accurate method for quantification of specific DNA sequences in reference materials which can be used to evaluate quantitative molecular methods for TB treatment monitoring. METHODS: To assess a novel approach for the development of quality assurance materials we used dPCR to quantify specific DNA sequences in a range of prototype reference materials and evaluated accuracy between different laboratories and instruments. The materials were then also used to evaluate the quantitative performance of qPCR and Xpert MTB/RIF in eight clinical testing laboratories. RESULTS: dPCR was found to provide results in good agreement with the other methods tested and to be highly reproducible between laboratories without calibration even when using different instruments. When the reference materials were analysed with qPCR and Xpert MTB/RIF by clinical laboratories, all laboratories were able to correctly rank the reference materials according to concentration, however there was a marked difference in the measured magnitude. CONCLUSIONS: TB is a disease where the quantification of the pathogen could lead to better patient management and qPCR methods offer the potential to rapidly perform such analysis. However, our findings suggest that when precisely characterised materials are used to evaluate qPCR methods, the measurement result variation is too high to determine whether molecular quantification of Mycobacterium tuberculosis would provide a clinically useful readout. The methods described in this study provide a means by which the technical performance of quantitative molecular methods can be evaluated independently of clinical variability to improve accuracy of measurement results. These will assist in ultimately increasing the likelihood that such approaches could be used to improve patient management of TB.

DNA Bacteriano/isolamento & purificação , Mycobacterium tuberculosis/genética , Reação em Cadeia da Polimerase em Tempo Real/métodos , Tuberculose Pulmonar/diagnóstico , Adulto , Feminino , Humanos , Masculino , Microscopia , Técnicas de Diagnóstico Molecular , Patologia Molecular , Sensibilidade e Especificidade