scholarly journals Can a Quantitative Assessment of SARS-CoV-2 PCR Predict Degree of Severity and Outcomes in Critical Care Patients with COVID-19

2021 ◽  
Author(s):  
Rosalind Stonham ◽  
Chantelle Monck ◽  
Laurence Orchard ◽  
Laurence Baker ◽  
Nusreen Ahmad-Saeed ◽  
...  
Keyword(s):  
Kidney Injury ◽  
Infection Cycle ◽  
Chain Reaction ◽  
Icu Stay ◽  
Heating And Cooling ◽  
Target Nucleic Acid ◽  
Polymerase Chain ◽  
The Impact ◽  
Degree Of Severity ◽  
Critical Care Patients

Abstract Real-Time polymerase chain reaction (qPCR) is the gold standard diagnostic method for acute SARS-CoV-2 infection. Cycle threshold (Ct) is defined as the number of heating and cooling cycles required during the PCR process. Ct-values are inversely proportional to the amount of target nucleic acid in a sample. Our aim in this retrospective study was to determine the impact of serial SARS-CoV-2 qPCR Ct-values, among critically ill COVID-19 patients both prior and during intensive care unit (ICU) stay, on: mortality, need for mechanical ventilation (MV) and development of acute kidney injury (AKI). There was a continuous increment in Ct-values over the ICU stay from 1st-week through to 3rd-week. Although not significant, lower ICU 1st-week Ct-values were associated with Black ethnicity, increased need for MV and mortality. However, patients who had developed AKI at any stage of their illness had significantly lower Ct-values compared to those with normal renal function. When ICU 1st-week Ct-values are subcategorised as <20, 20-30 and >30 the 28-day survival probability was less for patients with Ct-values of <20.To our knowledge this is the first report showing the impact of Ct-values and outcomes, especially AKI, among patients at different time point’s prior to and during ICU stay.

PCR BY THERMAL CONVECTION

2004 ◽  
Vol 18 (16) ◽  
pp. 775-784 ◽  
Author(s):  
DIETER BRAUN
Keyword(s):  
Polymerase Chain Reaction ◽  
Thermal Convection ◽  
Dna Amplification ◽  
Reaction Vessel ◽  
Cold Region ◽  
Chain Reaction ◽  
Heating And Cooling ◽  
Highly Sensitive ◽  
Specific Amplification ◽  
Polymerase Chain

The Polymerase Chain Reaction (PCR) allows for highly sensitive and specific amplification of DNA. It is the backbone of many genetic experiments and tests. Recently, three labs independently uncovered a novel and simple way to perform a PCR reaction. Instead of repetitive heating and cooling, a temperature gradient across the reaction vessel drives thermal convection. By convection, the reaction liquid circulates between hot and cold regions of the chamber. The convection triggers DNA amplification as the DNA melts into two single strands in the hot region and replicates into twice the amount in the cold region. The amplification progresses exponentially as the convection moves on. We review the characteristics of the different approaches and show the benefits and prospects of the method.

scholarly journals Amplification of human beta-actin gene by the reverse transcriptase-polymerase chain reaction: implications for assessment of RNA from formalin-fixed, paraffin-embedded material.

1996 ◽  
Vol 44 (10) ◽  
pp. 1205-1207 ◽  
Author(s):  
A Dakhama ◽  
V Macek ◽  
J C Hogg ◽  
R G Hegele
Keyword(s):  
Polymerase Chain Reaction ◽  
Pcr Amplification ◽  
Housekeeping Gene ◽  
Chain Reaction ◽  
Viral Genomes ◽  
Negative Results ◽  
Beta Actin ◽  
Target Nucleic Acid ◽  
Formalin Fixed Paraffin Embedded ◽  
Polymerase Chain

The polymerase chain reaction (PCR) is a powerful method that allows enzymatic amplification of rate target nucleic acid sequences. It has been applied to the amplification of viral genomes from paraffin-embedded pathology specimens. However, interpretation of negative results requires amplification of a housekeeping gene such as beta-actin. In the present study we used specific oligonucleotide primers previously designed to amplify both the genomic DNA and the mRNA transcript from paraffin-embedded tissue. These products have predicted sizes of 250 BP and 154 BP, respectively, but our results showed that PCR amplification only (without reverse transcription) unexpectedly generated the 154-BP product. Further investigation of the nature of this product demonstrated that it originated from the amplification of DNA, not RNA. We conclude that the 154-BP product generated by these primers cannot be exclusively considered as beta-actin RNA product and should not be used to assess successful extraction of RNA, to ascertain its integrity, or to normalize for the total amount of RNA assayed by RT-PCR from paraffin-embedded tissue.

scholarly journals Clinical outcomes of concomitant use of enteral and intravenous sedatives and analgesics in mechanically ventilated patients with COVID-19

2021 ◽  
Author(s):  
Nayoung Kang ◽  
Mohammed A Alrashed ◽  
Eric M Place ◽  
Phuongthao T Nguyen ◽  
Stephen J Perona ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
Invasive Mechanical Ventilation ◽  
Institutional Review Board ◽  
Chain Reaction ◽  
Mechanically Ventilated ◽  
Ventilation Time ◽  
Institutional Review ◽  
Significant Difference ◽  
Polymerase Chain ◽  
The Impact

Abstract Disclaimer In an effort to expedite the publication of articles related to the COVID-19 pandemic, AJHP is posting these manuscripts online as soon as possible after acceptance. Accepted manuscripts have been peer-reviewed and copyedited, but are posted online before technical formatting and author proofing. These manuscripts are not the final version of record and will be replaced with the final article (formatted per AJHP style and proofed by the authors) at a later time. Purpose To evaluate potential differences in days on mechanical ventilation for patients with coronavirus disease 2019 (COVID-19) based on route of administration of analgesic and sedative medications: intravenous (IV) alone vs IV + enteral (EN). Summary This institutional review board–approved study evaluated ventilation time and fentanyl or midazolam requirements with or without concurrent EN hydromorphone and lorazepam. Patients were included in the study if they were 18 to 89 years old and were admitted to the intensive care unit with a positive severe acute respiratory syndrome coronavirus 2 reverse transcription and polymerase chain reaction or antigen test and respiratory failure requiring invasive mechanical ventilation for more than 72 hours. In total, 100 patients were evaluated, 60 in the IV-only group and 40 in the IV + EN group. There was not a significant difference in ventilation time between the groups (mean [SD], 19.6 [12.8] days for IV + EN vs 15.6 [11.2] days for IV only; P = 0.104). However, fentanyl (2,064 [847] μg vs 2,443 [779] μg; P &lt; 0.001) and midazolam (137 [72] mg vs 158 [70] mg; P = 0.004) requirements on day 3 were significantly higher in the IV-only group, and the increase in fentanyl requirements from day 1 to day 3 was greater in the IV-only group than in the IV + EN group (378 [625] μg vs 34 [971] μg; P = 0.033). Conclusion Addition of EN analgesic and sedative medications to those administered by the IV route did not change the duration of mechanical ventilation in patients with COVID-19, but the combination may reduce IV opioid requirements, decreasing the impact of IV medication shortages.

scholarly journals Циклостойкие миниатюрные термоэлектрические модули

2019 ◽  
Vol 53 (5) ◽  
pp. 604
Author(s):  
М.П. Волков ◽  
И.А. Драбкин ◽  
Л.Б. Ершова ◽  
А.А. Назаренко
Keyword(s):  
Polymerase Chain Reaction ◽  
Test Data ◽  
Medical Equipment ◽  
Dna Analysis ◽  
Heat Fluxes ◽  
Chain Reaction ◽  
Periodic Heating ◽  
Thermoelectric Modules ◽  
Heating And Cooling ◽  
Polymerase Chain

AbstractIn the paper the test data on new cycle-resistant thermoelectric modules are presented and discussed. These modules can be applied in medical equipment for polymerase chain reaction (PCR) to carry out DNA analysis with the help of rapid periodic heating and cooling of biological probes. However, high density of heat fluxes and, as a result, significant mechanical stresses in miniature thermoelectric modules involve special requirements to their reliability. The company RMT Ltd. has developed a technology for the production of highly reliable miniature thermoelectric modules that allowed them to withstand more than 500 thousand heating-cooling cycles (from 20 to 100°C) with a rate of 20°C/s and more.

Detection of Aspergillus fumigatus by Polymerase Chain Reaction (PCR)

2019 ◽  
Vol 10 (04) ◽  
pp. 655-661
Author(s):  
Zainab H Abood AL-Asadi
Keyword(s):  
Polymerase Chain Reaction ◽  
Aspergillus Fumigatus ◽  
Oligonucleotide Primer ◽  
Rrna Gene ◽  
Fungal Culture ◽  
Chain Reaction ◽  
Isolation And Identification ◽  
Internal Transcribed Spacer Region ◽  
Polymerase Chain ◽  
The Impact

Aspergillosis refers to fungi infections of the respiratory tract caused by Aspergillus species, especially Aspergillus fumigatus. Infection of A. fumigatus was increased in the last few years due to either resistances to antibiotics or the influence of other factors such as other fungal infections. The present study aimed to review the impact of Aspergillus fumigatus in Aspergillosis cases, and study the role of Singleplex PCR for amplification of ITS1, ITS4 of rRNA gene in the detection of fungal isolate. In this study, One hundred sputum samples were collected from patients admitted to the specialize chest and respiratory diseases center / Baghdad who were suffering from respiratory problems. During these studied, molds were isolation and identification based on Conventional method (Direct microscopy by using 10% KOH, and fungal culture was done on Sabouraud Dextrose agar supplemented with chloramphenicol and on Czapek-Dox agar incubated at 37°C and examined for 3-7 days then macroscopic, microscopic examination of the colony by(lactophenol cotton blue stain )and molecular methods by using Polymerase chain reaction (PCR)technique for identification. The 10% KOH examination was positive for 35 cases, while laboratory culturing was positive for 53 cases. Aspergillus sp were isolated from 44(83%) patients; A. fumigatus was isolated in 23 (42. 4%) patients while A. flavus, A. niger, and A. terreus were isolated from 11 (20. 08%), (13. 2%) and 3 (5. 7%) patients respectively, also isolated Penicillium spp. at percentage 1(1. 9%). In this study. The ages of participants ranged from 10-70years with a mean age of 34years, the males were more susceptible to fungal infection, were recorded 35/53 (66. 3), compared to females were 18/53 (33. 96). The infection of fungi was more prevalent in ages 30-40recorded 26(53. 06%) followed by ages 40-50, 13(26. 5), while the lowest infection recorded in the age group 10- 20 years was 2(2. 04%). DNA isolated from twenty-three A. fumigatus isolates was used as a template, and the specific of oligonucleotide primer sequences were used in conventional PCR to detect the presence of internal transcribed spacer region ( ITS) region of the rRNA gene for Aspergillus fumigates. The results of the PCR amplification of the rRNA gene showed that this gene was present in 19 samples out 23 positive samples which isolation with a PCR product size of approximated 385 bp, while 4 samples out 23 positive samples showed negative results for the presence of this gene as indicated by the absence of the PCR products in their relevant lanes. Statistical analysis revealed that the PCR to have a sensitivity of 95. 1% in the detection of Aspergillus fumigatus in Aspergillosis cases. Polymerase chain reaction (PCR) is a rapid, specific, and sensitive method to detect Aspergillus fumigatus in aspergillosis cases of humans.

scholarly journals The impact of COL1A1 and COL6A1 expression on hypospadias and penile curvature severity

BMC Urology ◽  
2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Prahara Yuri ◽  
Gunadi ◽  
Rahmadani Puji Lestari ◽  
Firly Putri Fardilla ◽  
Wiwit Ananda Wahyu Setyaningsih ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Polymerase Chain Reaction ◽  
External Genitalia ◽  
Penile Curvature ◽  
Moderate Correlation ◽  
Chain Reaction ◽  
Polymerase Chain ◽  
Distal Hypospadias ◽  
Male External Genitalia ◽  
The Impact

Abstract Background Hypospadias, the most frequent congenital male external genitalia abnormality, is usually associated with curvature of the ventral penis, i.e. chordee. Abnormality of darto tissue has been suggested as the pathophysiology of chordees. Collagen is one of the most abundant fibrous proteins within the extracellular matrix. In this study, we determined the expression of collagen 1 (COL1A1) and COL6A1 in patients with hypospadias and associated them with the severity of penile curvature. Methods We included 60 children < 18 years old, consisting of 20 distal hypospadias, 20 proximal hypospadias patients, and 20 controls in our institution from 2017 – 2020. The expression of COL1A1 and COL6A1 in darto tissue was determined by reverse-transcriptase polymerase chain reaction (qPCR). The penile curvature severity was classified as mild (< 30 degrees), moderate (30–60 degrees), and severe (> 60 degrees). Results qPCR showed that COL1A1 and COL6A1 expression was significantly downregulated in the distal (0.88 (0.38–2.53) and 0.54 (0.16–4.35), respectively) and proximal 0.76 (0.33–2.57) and 0.57 (0.18–1.38), respectively) hypospadias groups compared to controls (1.85 (0.24–4.61) and 0.93 (0.17–4.06), respectively) with p-values of 0.024 and 0.018, respectively. Furthermore, there was a moderate correlation between COL1A1 and COL6A1 expression (r = 0.458, p < 0.0001). Interestingly, COL1A1 and COL6A1 were also significantly downregulated in the moderate and severe chordee groups compared to the mild chordee groups, with p-values of 0.003 and 0.037, respectively. Conclusions Aberrant COL1A1 and COL6A1 expression might affect abnormalities in darto tissue and penile curvature severity in hypospadias patients.

Mo1852 The Impact of Polymerase Chain Reaction on Clostridium difficile Detection and Clinical Outcomes

2015 ◽  
Vol 148 (4) ◽  
pp. S-726-S-727
Author(s):  
Mona Akbari ◽  
Victor Novack ◽  
Ciaran P. Kelly ◽  
Daniel A. Leffler
Keyword(s):  
Polymerase Chain Reaction ◽  
Clostridium Difficile ◽  
Clinical Outcomes ◽  
Chain Reaction ◽  
Polymerase Chain ◽  
The Impact

Savitzky–Golay smoothing and differentiation for polymerase chain reaction quantification

2018 ◽  
Vol 96 (3) ◽  
pp. 380-389 ◽  
Author(s):  
Charles Gaudreault ◽  
Joanny Salvas ◽  
Joël Sirois
Keyword(s):  
Relative Error ◽  
Logistic Model ◽  
Data Sets ◽  
Threshold Method ◽  
Chain Reaction ◽  
Quantification Method ◽  
Curve Modeling ◽  
Polymerase Chain ◽  
The Impact ◽  
Inter Assay Variation

In quantitative PCR (qPCR), replicates can minimize the impact of intra-assay variation; however, inter-assay variations must be minimized to obtain a robust quantification method. The method proposed in this study uses Savitzky–Golay smoothing and differentiation (SGSD) to identify a derivative-maximum-based cycle of quantification. It does not rely on curve modeling, as is the case with many existing techniques. PCR fluorescence data sets challenged for inter-assay variations (different thermocycler units, different reagents batches, different operators, different standard curves, and different labs) were used for the evaluation. The algorithm was compared with a four-parameter logistic model (4PLM) method, the Cy0 method, and the threshold method. The SGSD method compared favourably with all methods in terms of inter-assay variation. SGSD was statistically different from the 4PLM (P = 0.03), Cy0 (P = 0.05), and threshold (P = 0.004) methods on relative error comparison basis. For intra-assay variations, SGSD outperformed the threshold method (P = 0.005) and equalled the 4PLM and Cy0 methods (P > 0.05) on relative error basis. Our results demonstrate that the SGSD method could potentially be an alternative to sigmoid modeling based methods (4PLM and Cy0) when PCR data are challenged for inter-assay variations.

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