scholarly journals Nucleic acid detection systems for enteroviruses.

1991 ◽  
Vol 4 (2) ◽  
pp. 156-168 ◽  
Author(s):  
H A Rotbart
Keyword(s):  
Nucleic Acid ◽  
Slow Growth ◽  
Acid Synthesis ◽  
In Vitro Transcription ◽  
Nucleic Acid Detection ◽  
Human Pathogens ◽  
Detection Systems ◽  
The Past ◽  
Polymerase Chain

The enteroviruses comprise nearly 70 human pathogens responsible for a wide array of diseases including poliomyelitis, meningitis, myocarditis, and neonatal sepsis. Current diagnostic tests for the enteroviruses are limited in their use by the slow growth, or failure to grow, of certain serotypes in culture, the antigenic diversity among the serotypes, and the low titer of virus in certain clinical specimens. Within the past 6 years, applications of molecular cloning techniques, in vitro transcription vectors, automated nucleic acid synthesis, and the polymerase chain reaction have resulted in significant progress toward nucleic acid-based detection systems for the enteroviruses that take advantage of conserved genomic sequences across many, if not all, serotypes. Similar approaches to the study of enteroviral pathogenesis have already produced dramatic advances in our understanding of how these important viruses cause their diverse clinical spectra.

scholarly journals A low-cost fluorescence reader for in vitro transcription and nucleic acid detection with Cas13a

PLoS ONE ◽  
2019 ◽  
Vol 14 (12) ◽  
pp. e0220091 ◽  
Author(s):  
Florian Katzmeier ◽  
Lukas Aufinger ◽  
Aurore Dupin ◽  
Jorge Quintero ◽  
Matthias Lenz ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Low Cost ◽  
In Vitro Transcription ◽  
Nucleic Acid Detection

scholarly journals 8-AZAGUANINE RESISTANCE IN MAMMALIAN CELLS I. HYPOXANTHINE-GUANINE PHOSPHORIBOSYLTRANSFERASE

Genetics ◽  
1972 ◽  
Vol 72 (2) ◽  
pp. 239-252 ◽  
Author(s):  
F D Gillin ◽  
D J Roufa ◽  
A L Beaudet ◽  
C T Caskey
Keyword(s):  
Nucleic Acid ◽  
Mammalian Cells ◽  
Chinese Hamster ◽  
Acid Synthesis ◽  
Ethyl Methanesulfonate ◽  
Nucleic Acid Synthesis ◽  
Wild Type ◽  
Chinese Hamster Cells ◽  
Hypoxanthine Guanine Phosphoribosyltransferase

ABSTRACT Chinese hamster cells were treated with ethyl methanesulfonate or N-methyl-N'-nitro-N-nitrosoguanidine, and mutants resistant to 8-azaguanine were selected and characterized. Hypoxanthine-guanine phosphoribosyltransferase activity of sixteen mutants is extremely negative, making them suitable for reversion to HGPRTase+. Ten of the extremely negative mutants revert at a frequency higher than 10-7 suggesting their point mutational character. The remaining mutants have demonstrable HGPRTase activity and are not useful for reversion analysis. Five of these mutants have < 2% HGPRTase and are presumably also HGPRTase point mutants. The remaining 14 mutants utilize exogenous hypoxanthine for nucleic acid synthesis poorly, and possess 20-150% of wild-type HGPRTase activity in in vitro. Their mechanism of 8-azaguanine resistance is not yet defined.

Regulation der Chlorophyllbiosynthese. Lidit- und entwicklungsbedingte Aktivitätsänderungen von vier aufeinander folgenden Enzymen der Porphyrin- und Chlorophyllbiosynthesekette / Regulation of Chlorophyll Biosynthesis. Changes in Activity of Four Consecutive Enzymes in the Porphyrin and Chlorophyll Biosynthesis Chain during Development and Illumination

1973 ◽  
Vol 28 (1-2) ◽  
pp. 45-58 ◽  
Author(s):  
Hansjörg A. W. Schneider
Keyword(s):  
Nucleic Acid ◽  
Chlorophyll Biosynthesis ◽  
Acid Synthesis ◽  
Chlorophyll Synthesis ◽  
The Other ◽  
Tissue Cultures ◽  
Leaf Tissues ◽  
Porphyrin Synthesis

The activities of enzymes related with chlorophyll and porphyrin synthesis have been examined during development and greening of young corn leaves. The enzymes succinyl-CoA-synthetase (SCoAS), δ-amino-levulinate synthetase (ALAS), δ-amino-levulinate dehydratase (ALAD) and the enzymes involved in porphobilinogenase (PBGA) were under investigaton. When leaves are illuminated and chlorophyll synthesis begins the activity of ALAD is not influenced. The activity of PBGA and SCoAS are slightly higher than in darkness, but the changes are below the range affecting chlorophyll biosynthesis. ALA, however, is only synthetized in the light. Synthesis ceases immediately when illuminiation ist stopped, indicating'that in darkness ALAS is not active. On the other hand ALAS is active in dark grown roots, tubers and other non-leaf tissues. Feeding the plant with succinate, glycine or α-keto-glutarate has no effect on chlorophyll synthesis, but the amount of ALA is reduced, whereas sucrose promotes its accumulation. The results are discussed with completely antitethaal results obtained with tissue cultures of tobacco and are integrated into a scheme which excludes the contrariety of hypotheses deduced from experi- ments with inhibitors of protein and nucleic acid synthesis. It is suggested that the varying results are caused by the action of light on different stages in differentiation of plastids and cells. In contrast to the enzymes SCoAS, ALAD and PBGA whose activities were determined in vitro, ALAS was assayed in vivo by means of the accumulation of (5-amino-levulinate (ALA) after blocking the enzyme ALAD by levulinate (LA). Optimum accumulation is observed when the concentration is about 2 · 10-2 м. LA is not converted to ALA in appreciable amounts. This could be proved by feeding the plants with 14C-LA which was prepared from uniformly labeled 14C-fructose.

Fuel-mediated teratogenesis: biochemical effects of hypoglycemia during neurulation in mouse embryos in vitro

1989 ◽  
Vol 257 (2) ◽  
pp. E269-E276 ◽  
Author(s):  
E. S. Hunter ◽  
T. W. Sadler
Keyword(s):  
Nucleic Acid ◽  
Glucose Metabolism ◽  
Severe Hypoglycemia ◽  
Acid Synthesis ◽  
Mouse Embryos ◽  
Nucleic Acid Synthesis ◽  
Glycolytic Metabolism ◽  
Whole Embryo Culture ◽  
Altered Glucose

Hypoglycemia has been reported to induce congenital malformations and growth retardation in rodent embryos during the period of neural tube closure in vitro. However, the biochemical alterations responsible for the production of the dysmorphogenic effects have not been evaluated. Therefore, the rates of glucose metabolism by glycolysis, citric acid cycle, oxidative pentose phosphate pathway (PPP), and anabolic utilization were evaluated in mouse embryos and extraembryonic membranes using the whole embryo culture technique. Altered glucose metabolism by glycolysis and oxidative PPP, as well as altered anabolic synthesis, were produced by exposure to hypoglycemia. In embryos exposed to mild hypoglycemia (80 mg/dl) altered metabolism by the PPP and an associated effect on nucleic acid synthesis were in part responsible for the dysmorphogenic effects of this treatment. In contrast, severe hypoglycemia (40 mg/dl) appeared to have an immediate effect on glycolytic metabolism in addition to effects on the PPP and nucleic acid synthesis. Therefore, a multifactorial biochemical mechanism contributes to the induction of malformations by severe hypoglycemia in mouse embryos in vitro. Furthermore, the differential effects of moderate vs. severe hypoglycemia on glycolytic metabolism, and possibly energy production, may account for the differences in the severity of these treatments on embryonic growth and the incidence of malformations.

scholarly journals Inhibition of microRNA-21 via locked nucleic acid-anti-miR suppressed metastatic features of colorectal cancer cells through modulation of programmed cell death 4

Tumor Biology ◽  
2017 ◽  
Vol 39 (3) ◽  
pp. 101042831769226 ◽  
Author(s):  
Reza Nedaeinia ◽  
Mohammadreza Sharifi ◽  
Amir Avan ◽  
Mohammad Kazemi ◽  
Abdolreza Nabinejad ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Polymerase Chain Reaction ◽  
Cell Death ◽  
Nucleic Acid ◽  
Locked Nucleic Acid ◽  
Chain Reaction ◽  
Programmed Cell Death 4 ◽  
Polymerase Chain ◽  
Novel Therapeutic

Colorectal cancer is among the most lethal of malignancies, due to its propensity to metastatic spread and multifactorial-chemoresistance. The latter property supports the need to identify novel therapeutic approaches for the treatment of colorectal cancer. MicroRNAs are endogenous non-coding small RNA molecules that function as post-transcriptional regulators of gene expression. Recently, programmed cell death 4 has been identified as a protein that increases during apoptosis. This gene is among the potential targets of miR-21 (OncomiR). Locked nucleic acid–modified oligonucleotides have recently emerged as a potential therapeutic option for targeting microRNAs. The aim of this study was to explore the functional role of locked nucleic acid-anti-miR-21 in the LS174T cell line in vitro and in vivo models. LS174T cells were treated with locked nucleic acid-anti-miR-21 for 24, 48, and 72 h in vitro. The expression of miR-21 and PDCD4 at messenger RNA (mRNA) level was evaluated by quantitative real-time polymerase chain reaction, while the protein level of PDCD4 was determined by Western blotting. Cell migratory behavior and the cluster-forming ability of cells were assessed before and after therapy. The disseminated tumor cells were assessed in the chick chorioallantoic membrane model by Alu quantitative polymerase chain reaction. Locked nucleic acid-anti-miR-21 was transfected successfully into the LS174T cells and inhibited the expression of miR-21. Locked nucleic acid-anti-miR-21 inhibited the migration and the number of cells forming clusters. Moreover, we found that locked nucleic acid-anti-miR-21 transfection was associated with a significant reduction in metastatic properties as assessed by the in ovo model. Our findings demonstrated the novel therapeutic potential of locked nucleic acid-anti-miR-21 in colon adenocarcinoma with high miR-21 expression.

Pineal effects upon pituitary protein and nucleic acid synthesis in vitro

1976 ◽  
Vol 2 (4) ◽  
pp. 207-210
Author(s):  
Nancy S. Peress ◽  
Gollapudi G. Murthy ◽  
Robert J. Balcom
Keyword(s):  
Nucleic Acid ◽  
Acid Synthesis ◽  
Nucleic Acid Synthesis

scholarly journals A Chemical-Enhanced System for CRISPR-Based Nucleic Acid Detection

2021 ◽  
Author(s):  
Zihan Li ◽  
Wenchang Zhao ◽  
Shixin Ma ◽  
Zexu Li ◽  
Yingjia Yao ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Detection System ◽  
Point Of Care ◽  
Detection Sensitivity ◽  
Nucleic Acid Detection ◽  
Chemical Additives ◽  
Lateral Flow Strip ◽  
Viral Pathogens ◽  
Detection Systems ◽  
System Robustness

The CRISPR-based nucleic acid detection systems such as SHERLOCK, DETECTR and HOLMES have shown great potential for point-of-care testing of viral pathogens, especially in the context of COVID-19 pandemic. Here we optimize several key parameters of reaction chemistry and develop a Chemical Enhanced CRISPR Detection system for nucleic acid (termed CECRID). For the Cas12a/Cas13a-based signal detection phase, we determine buffer conditions and substrate range for optimal detection performance. By comparing several chemical additives, we find that addition of L-proline can secure or enhance Cas12a/Cas13a detection capability. For isothermal amplification phase with typical LAMP and RPA methods, inclusion of L-proline can also enhance specific target amplification as determined by CRISPR detection. Using SARS-CoV-2 pseudovirus, we demonstrate CECRID has enhanced detection sensitivity over chemical additive-null method with either fluorescence or lateral flow strip readout. Thus, CECRID provides an improved detection power and system robustness towards practical application of CRISPR-based diagnostics.

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