scholarly journals Standardization of SYBR Green-Based Real-Time PCR Through the Evaluation of Different Thresholds for Different Skin Layers: An Accuracy Study and Track of the Transmission Potential of Multibacillary and Paucibacillary Leprosy Patients

2021 ◽  
Vol 12 ◽  
Author(s):  
Lais Sevilha-Santos ◽  
Selma Regina Penha Silva Cerqueira ◽  
Ciro Martins Gomes
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Sybr Green ◽  
Molecular Techniques ◽  
Contrast Threshold ◽  
Control Group ◽  
Transmission Potential ◽  
Household Contacts ◽  
Nasal Swabs ◽  
Leprosy Patients

The development of new molecular techniques is essential for the early diagnosis of leprosy. Studies in the field have failed to elucidate the performance of these tests in clinical practice. We aimed to design a new primer pair for the repetitive element (RLEP) target of Mycobacterium leprae and to test the accuracy of SYBR green-based real-time PCR through the evaluation of different thresholds for different skin layers. We also aimed to track the transmission potential of multibacillary and paucibacillary leprosy patients. The in vitro validation of our reaction resulted in a quantification limit of 0.03 bacilli. We then conducted a cross-sectional/cohort-based study of diagnostic accuracy. Patients were included, and skin samples were divided into four layers: epidermis, superior dermis, inferior dermis, and hypodermis. We also quantified M. leprae in nasal swabs of the included patients and compared the results to the number of household contacts also diagnosed with leprosy. One hundred patients with a clinical presentation compatible with leprosy were allocated to the leprosy or control group. Although the parasite load was greater in the superior and inferior dermis, M. leprae DNA was found in all skin layers. The best sensitivity was observed for the superior dermis using the presence of any quantifiable bacillus DNA as the threshold [sensitivity=59.26% (95% CI=45.97–71.32)]. In the epidermis, setting 1 quantifiable bacillus as the threshold resulted in 100% specificity (95% CI=92.29–100). The number of bacilli found in nasal swabs was not significantly related to the number of household contacts also diagnosed with leprosy. Paucibacillary patients tested positive only for bacillus fragments in nasal swabs but not for the entire bacilli. We can conclude that superficial biopsies might result in sensitivity loss, although different skin sample types will have little influence on the final accuracy. In contrast, threshold changes greatly influence these properties. Paucibacillary patients may not be a relevant source of disease transmission.

scholarly journals Recruitment of cyanobacteria by reverse transcription quantitative real-time PCR based on expression of Microcystis gene

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7188
Author(s):  
Long Yu ◽  
Xiaofei Wu ◽  
Yang Yu ◽  
Limei Shi ◽  
Min Zhang
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Lake Taihu ◽  
Rna Extraction ◽  
Sybr Green ◽  
Quantitative Detection ◽  
Control Group ◽  
Quantitative Real Time Pcr ◽  
Total Rna ◽  
Pcr Method

In this study, a SYBR Green quantitative real-time PCR method was established and applied. Relative expression of the synthetic genes from Microcystis gas vesicles (gvpC), algal toxin genes (mcyA), and polysaccharides (espL) from water and sediments of Meiliang Bay and from the center of Lake Taihu were tested from January to June, 2017. Indoor Microcystis aeruginosa was used as the control group. The kit for total RNA extraction in Microcystis was optimized. Results showed that the optimized kit extracted high-concentrations and high-quality total RNA from Microcystis. The extraction purity and concentration were significantly higher than those extracted by the original kit. The transcription level of gvpC increased gradually until a peak was reached in March. However, expression of gvpC decreased continuously at the proliferating and floating stages of Cyanobacterial biomass. The maximum level of expression of gvpC in April in comparison to expression of mcyA in March occurred first. We found that the SYBR Green qRT-PCR method, which is characterized by high specificity, repeatability, is rapid, and can be used for quantitative detection of expression of gvpC, mcyA, and espL. The recruitment of cyanobacteria is the process in which cyanobacteria in the sediment began to regain their activity, started to grow and migrated to the water column.

scholarly journals Detection of Uncommon Enteric Bacterial Pathogens from Acute Diarrheal Specimens Using SYBR-Green Real Time PCR

2019 ◽  
Vol 72 (2) ◽  
pp. 88-93 ◽  
Author(s):  
Goutam Chowdhury ◽  
Oscar C. Stine ◽  
Krishnan Rajendran ◽  
Asish K. Mukhopadhyay ◽  
Keinosuke Okamoto ◽  
...  
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Bacterial Pathogens ◽  
Sybr Green

scholarly journals Detection of Peanut Allergen Traces with a Real Time PCR Assay - The Challenge to Protect Food-Allergic Consumers

2017 ◽  
Vol 7 (1) ◽  
pp. 32 ◽  
Author(s):  
Dimitra Houhoula ◽  
Stamatios Koussissis ◽  
Vladimiros Lougovois ◽  
John Tsaknis ◽  
Dimitra Kassavita ◽  
...  
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Rapid Detection ◽  
Food Products ◽  
Molecular Techniques ◽  
Food Allergens ◽  
Pcr Assay ◽  
Peanut Allergen ◽  
Pcr Method ◽  
Detection And Quantification

The aim of the present study was the implementation of molecular techniques in the detection and quantification of allergic substances of peanut in various kinds of food products, e.g., breakfast cereals, chocolates and biscuits that are frequently related to allergies. In some cases, the presence of peanuts can be due to contamination during production and are not declared on the label. A total of 152 samples were collected from supermarkets and were analysed by a Real Time PCR method. The results indicated that 125 samples (83,3%) were found positive in peanut traces but the most important finding is that from the 84 samples that had no allergen declaration for peanuts, 48 (57,1%) of them were found positive. In conclusion, Real Time PCR can be a very important tool for the rapid detection and quantification of food allergens.

scholarly journals The association of male infertility with telomere length: A case control study

2021 ◽  
Vol 8 (4) ◽  
pp. 325-332
Author(s):  
Kate Deepali Rajesh ◽  
Puranam Vatsalaswamy ◽  
Manvikar Purshotam Rao
Keyword(s):  
Male Infertility ◽  
Telomere Length ◽  
Real Time ◽  
Real Time Pcr ◽  
Case Control Study ◽  
Case Control ◽  
Control Group ◽  
Significant Difference ◽  
Control Study ◽  
Sperm Telomere Length

To study the relevance of sperm telomere length and infertility in men. : Our case-control study included twenty-five males in couple with sub-fertility/infertility (test group) and twenty five healthy males (control group) with proven paternity in the age group 25 to 35 years. The Absolute Sperm Telomere length (aSTL) was measured by real-time PCR. We investigated whether any significant difference in the aSTL value existed between the groups and analysed the relationship between aSTL and other sperm parameters.The mean (SE) aSTL recorded in the infertile cases was significantly shorter than for the control group being 140.60 (6.66) Kb/genome and 239.63 (12.32) Kb/genome respectively (p <0.001) A weak correlation was eminent between aSTL kb/genome and the total sperm count mil/ml (rho= 0.04, p - 0.86), progressive sperm motility (rho= - 0.02, p=0.934) and sperm viability (rho= - 0.07 p=0.741) in the infertile group. The measurement of aSTL by real-time PCR is a simple and rapid method that offers further paramount information with respective to the quality of sperm. It is befitted for epidemiological studies, hence opening new perspectives in the evaluation of male infertility. Limitations - Our study was confined to men aged between 25 and 35 years. Further comparative studies are needed to explore the significance of STL and infertility in older males. Additional studies will help illumine the significance of aSTL as a prognostic biomarker in assisted reproduction.

scholarly journals Astragaloside positively regulated osteogenic differentiation of pre-osteoblast MC3T3-E1 through PI3K/Akt signaling pathway

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Wei Bing Jing ◽  
Hongjuan Ji ◽  
Rui Jiang ◽  
Jinlong Wang
Keyword(s):  
Western Blot ◽  
Osteogenic Differentiation ◽  
Real Time ◽  
Signaling Pathway ◽  
Real Time Pcr ◽  
Akt Signaling ◽  
Calcium Deposition ◽  
Control Group ◽  
Akt Signaling Pathway ◽  
Western Blot Assay

Abstract Background Osteoporosis is a widespread chronic disease characterized by low bone density. There is currently no gold standard treatment for osteoporosis. The aim of this study was to explore the role and mechanism of Astragaloside on osteogenic differentiation of MC3T3-E1 cells. Methods MC3T3-E1 cells were divided into control and different dose of Astragaloside (10, 20, 40, 50, and 60 μg/ml). Then, ALP and ARS staining were performed to identify the effects of Astragaloside for early and late osteogenic capacity of MC3T3-E1 cells, respectively. Real-time PCR and western blot were performed to assess the ALP, OCN, and OSX expression. PI3K/Akt signaling pathway molecules were then assessed by Western blot. Finally, PI3K inhibitor, LY294002, was implemented to assess the mechanism of Astragaloside in promoting osteogenic differentiation of MC3T3-E1 cells. Results Astragaloside significantly increased the cell viability than the control group. Moreover, Astragaloside enhanced the ALP activity and calcium deposition than the control groups. Compared with the control group, Astragaloside increased the ALP, OCN, and OSX expression in a dose-response manner. Western blot assay further confirmed the real-time PCR results. Astragaloside could significantly increase the p-PI3K and p-Akt expression than the control group. LY294002 partially reversed the promotion effects of Astragaloside on osteogenic differentiation of MC3T3-E1 cells. LY294002 partially reversed the promotion effects of Astragaloside on ALP, OCN, and OSX of MC3T3-E1 cells. Conclusion The present study suggested that Astragaloside promoted osteogenic differentiation of MC3T3-E1 cells through regulating PI3K/Akt signaling pathway.

scholarly journals Estimating Clinically Relevant Cut-Off Values for a High-Throughput Quantitative Real-Time PCR Detecting Bacterial Respiratory Pathogens in Cattle

2021 ◽  
Vol 8 ◽  
Author(s):  
Alicia F. Klompmaker ◽  
Maria Brydensholt ◽  
Anne Marie Michelsen ◽  
Matthew J. Denwood ◽  
Carsten T. Kirkeby ◽  
...  
Keyword(s):  
Real Time ◽  
High Throughput ◽  
Real Time Pcr ◽  
Pasteurella Multocida ◽  
Age Groups ◽  
Therapeutic Interventions ◽  
Respiratory Pathogens ◽  
Logistic Regression Models ◽  
Histophilus Somni ◽  
Nasal Swabs

Bovine respiratory disease (BRD) results from interactions between pathogens, environmental stressors, and host factors. Obtaining a diagnosis of the causal pathogens is challenging but the use of high-throughput real-time PCR (rtPCR) may help target preventive and therapeutic interventions. The aim of this study was to improve the interpretation of rtPCR results by analysing their associations with clinical observations. The objective was to develop and illustrate a field-data driven statistical method to guide the selection of relevant quantification cycle cut-off values for pathogens associated with BRD for the high-throughput rtPCR system “Fluidigm BioMark HD” based on nasal swabs from calves. We used data from 36 herds enrolled in a Danish field study where 340 calves within pre-determined age-groups were subject to clinical examination and nasal swabs up to four times. The samples were analysed with the rtPCR system. Each of the 1,025 observation units were classified as sick with BRD or healthy, based on clinical scores. The optimal rtPCR results to predict BRD were investigated for Pasteurella multocida, Mycoplasma bovis, Histophilus somni, Mannheimia haemolytica, and Trueperella pyogenes by interpreting scatterplots and results of mixed effects logistic regression models. The clinically relevant rtPCR cut-off suggested for P. multocida and M. bovis was ≤ 21.3. For H. somni it was ≤ 17.4, while no cut-off could be determined for M. haemolytica and T. pyogenes. The demonstrated approach can provide objective support in the choice of clinically relevant cut-offs. However, for robust performance of the regression model sufficient amounts of suitable data are required.

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