scholarly journals ADP-ribosyl transferase activity and gamma radiation cytotoxicity of Pseudomonas aeruginosa exotoxin A

AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Radwa N. Morgan ◽  
Sarra E. Saleh ◽  
Khaled M. Aboshanab ◽  
Hala A. Farrag
Keyword(s):  
Gamma Radiation ◽  
Cultured Cells ◽  
Uv Spectroscopy ◽  
Detection Methods ◽  
Transferase Activity ◽  
Exotoxin A ◽  
Protein Extract ◽  
Intracellular Enzyme ◽  
Adp Ribosyltransferase ◽  
The Impact

AbstractThis work explores the ADP-ribosyltransferase activity of Pseudomonas (P.) aeruginosa exotoxin A using the guanyl hydrazone derivative, nitrobenzylidine aminoguanidine (NBAG) and the impact of gamma radiation on its efficacy. Unlike the conventional detection methods, NBAG was used as the acceptor of ADP ribose moiety instead of wheat germ extract elongation factor 2. Exotoxin A was extracted from P. aeruginosa clinical isolates and screened for toxA gene using standard PCR. NBAG was synthesized using aminoguanidine bicarbonate and 4-nitrobenzaldehyde and its identity has been confirmed by UV, FTIR, Mass and 13C-NMR spectroscopy. The ADP-ribosyl transferase activity of exotoxin A on NBAG in the presence of Nicotinamide adenine dinucleotide (NAD+) was recorded using UV spectroscopy and HPLC. In vitro ADP-ribosyl transferase activity of exotoxin A protein extract was also explored by monitoring its cytotoxicity on Hep-2 cells using sulforhodamine B cytotoxicity assay. Bacterial broths were irradiated at 5, 10, 15, 24 Gy and exotoxin A protein extract activity were assessed post exposure. Exotoxin A extract exerted an ADP-ribosyltransferase ability which was depicted by the appearance of a new ʎmax after the addition of exotoxin A to NBAG/NAD+ mixture, fragmentation of NAD+ and development of new peaks in HPLC chromatograms. Intracellular enzyme activity was confirmed by the prominent cytotoxic effects of exotoxin A extract on cultured cells. In conclusion, the activity of Exotoxin A can be monitored via its ADP-ribosyltransferase activity and low doses of gamma radiation reduced its activity. Therefore, coupling radiotherapy with exotoxin A in cancer therapy should be carefully monitored.

DNA nick end labeling: a reliable marker for apoptosis?

1995 ◽  
Vol 53 ◽  
pp. 962-963
Author(s):  
Anne F. Bushnell ◽  
Sarah Webster ◽  
Lynn S. Perlmutter
Keyword(s):  
Cell Death ◽  
Cultured Cells ◽  
Apoptotic Cell ◽  
Morphological Characteristics ◽  
Detection Methods ◽  
Tissue Preparation ◽  
Preparation Methods ◽  
Dna Laddering ◽  
Disease States ◽  
Reliable Marker

Apoptosis, or programmed cell death, is an important mechanism in development and in diverse disease states. The morphological characteristics of apoptosis were first identified using the electron microscope. Since then, DNA laddering on agarose gels was found to correlate well with apoptotic cell death in cultured cells of dissimilar origins. Recently numerous DNA nick end labeling methods have been developed in an attempt to visualize, at the light microscopic level, the apoptotic cells responsible for DNA laddering.The present studies were designed to compare various tissue processing techniques and staining methods to assess the occurrence of apoptosis in post mortem tissue from Alzheimer's diseased (AD) and control human brains by DNA nick end labeling methods. Three tissue preparation methods and two commercial DNA nick end labeling kits were evaluated: the Apoptag kit from Oncor and the Biotin-21 dUTP 3' end labeling kit from Clontech. The detection methods of the two kits differed in that the Oncor kit used digoxigenin dUTP and anti-digoxigenin-peroxidase and the Clontech used biotinylated dUTP and avidinperoxidase. Both used 3-3' diaminobenzidine (DAB) for final color development.

scholarly journals A Systematic Review of Landsat Data for Change Detection Applications: 50 Years of Monitoring the Earth

2021 ◽  
Vol 13 (15) ◽  
pp. 2869
Author(s):  
MohammadAli Hemati ◽  
Mahdi Hasanlou ◽  
Masoud Mahdianpari ◽  
Fariba Mohammadimanesh
Keyword(s):  
Time Series ◽  
Change Detection ◽  
Policy Development ◽  
Atmospheric Correction ◽  
Open Data ◽  
Detection Methods ◽  
Landsat 8 ◽  
Landsat Images ◽  
Detection Analysis ◽  
The Impact

With uninterrupted space-based data collection since 1972, Landsat plays a key role in systematic monitoring of the Earth’s surface, enabled by an extensive and free, radiometrically consistent, global archive of imagery. Governments and international organizations rely on Landsat time series for monitoring and deriving a systematic understanding of the dynamics of the Earth’s surface at a spatial scale relevant to management, scientific inquiry, and policy development. In this study, we identify trends in Landsat-informed change detection studies by surveying 50 years of published applications, processing, and change detection methods. Specifically, a representative database was created resulting in 490 relevant journal articles derived from the Web of Science and Scopus. From these articles, we provide a review of recent developments, opportunities, and trends in Landsat change detection studies. The impact of the Landsat free and open data policy in 2008 is evident in the literature as a turning point in the number and nature of change detection studies. Based upon the search terms used and articles included, average number of Landsat images used in studies increased from 10 images before 2008 to 100,000 images in 2020. The 2008 opening of the Landsat archive resulted in a marked increase in the number of images used per study, typically providing the basis for the other trends in evidence. These key trends include an increase in automated processing, use of analysis-ready data (especially those with atmospheric correction), and use of cloud computing platforms, all over increasing large areas. The nature of change methods has evolved from representative bi-temporal pairs to time series of images capturing dynamics and trends, capable of revealing both gradual and abrupt changes. The result also revealed a greater use of nonparametric classifiers for Landsat change detection analysis. Landsat-9, to be launched in September 2021, in combination with the continued operation of Landsat-8 and integration with Sentinel-2, enhances opportunities for improved monitoring of change over increasingly larger areas with greater intra- and interannual frequency.

scholarly journals Screening for Melanoma and Other Skin Cancer Shows a Higher Early Melanoma Incidence: Social Educational Program “Life Fear-Free”

2021 ◽  
Vol 8 (1) ◽  
pp. 54-68
Author(s):  
Lev Demidov ◽  
Igor Samoylenko ◽  
Nina Vand ◽  
Igor Utyashev ◽  
Irina Shubina ◽  
...  
Keyword(s):  
Skin Cancer ◽  
Screening Program ◽  
Excisional Biopsy ◽  
Skin Lesions ◽  
Detection Methods ◽  
Non Melanoma Skin Cancer ◽  
The Social ◽  
Educational Campaign ◽  
Skin Cancer Detection ◽  
The Impact

Background: The screening program Life Fear-Free (LFF) aimed at early diagnosis of cutaneous melanoma (CM) was introduced in Samara, Chelyabinsk, Yekaterinburg, and Krasnodar (Russia) in 2019. Objectives: To analyze the impact of the program on early CM and non-melanoma skin cancer (NMSC) detection. Methods: According to the social educational campaign, people were informed about CM risk factors and symptoms and were invited for skin examination. The program planned to involve 3200 participants in total. Participants with suspicious lesions were invited for excisional biopsy. Results: 3143 participants, including 75.4% women, were examined for skin lesions. The average age of the participants was 43.7 years. Mostly skin phototypes II and III were registered (48.2% and 41.0%, respectively); 3 patients had CM, 15 had basal cell carcinoma, and 1 had Bowen’s disease, which were confirmed histologically. All detected melanomas had Breslow’s thickness of 1 mm. Conclusion: The participants showed high interest in early skin cancer detection programs. The incidence rate of CM and NMSCs among the program participants was higher than in general public. The early disease grade was proven for the detected CMs and NMSCs. The study has shown that it is important to continue such programs.

A noise reduction method for semi-supervised community detection based on harmonic function

2018 ◽  
Vol 32 (14) ◽  
pp. 1850166 ◽  
Author(s):  
Lilin Fan ◽  
Kaiyuan Song ◽  
Dong Liu
Keyword(s):  
Harmonic Function ◽  
Prior Knowledge ◽  
Community Detection ◽  
Detection Methods ◽  
Detection Process ◽  
Knowledge Based ◽  
Detection Approach ◽  
Series Of Experiments ◽  
Novel Strategy ◽  
The Impact

Semi-supervised community detection is an important research topic in the field of complex network, which incorporates prior knowledge and topology to guide the community detection process. However, most of the previous work ignores the impact of the noise from prior knowledge during the community detection process. This paper proposes a novel strategy to identify and remove the noise from prior knowledge based on harmonic function, so as to make use of prior knowledge more efficiently. Finally, this strategy is applied to three state-of-the-art semi-supervised community detection methods. A series of experiments on both real and artificial networks demonstrate that the accuracy of semi-supervised community detection approach can be further improved.

The Impact of Accurate Distances on UV Spectroscopy of White Dwarfs and Cataclysmic Variables

2009 ◽  
Author(s):  
Paul E. Barrett ◽  
Patrick Godon ◽  
Michael E. Van Steenberg ◽  
George Sonneborn ◽  
H. Warren Moos ◽  
...  
Keyword(s):  
White Dwarfs ◽  
Uv Spectroscopy ◽  
Cataclysmic Variables ◽  
The Impact

Magnetische Monopole in vereinheitlichten Eichtheorien

1986 ◽  
Vol 41 (6) ◽  
pp. 777-787
Author(s):  
Eckehard W. Mielke
Keyword(s):  
Elementary Particle ◽  
Particle Physics ◽  
Detection Methods ◽  
Elementary Particle Physics ◽  
Gauge Models ◽  
Empirical Success ◽  
Long Time ◽  
The Impact ◽  
Magnetic North

Although refuted for a long time as a monstrosity, today’s concepts in elementary particle physics necessitate it on theoretical grounds: The existence of isolated elementary magnetic north- or south poles. If compared with a proton, the mass of such a monopole is estimated to be gigantic; comparable to that of an amoeba. Under the impact of the empirical success of unified gauge models, the search for monopoles has been steadily enforced with the aid of new detection methods.

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