Fluorimetric determination of DNA interstrand crosslinks

It has been found that phosphoric acid decreases the first excitation maximum of Ce(III) at 256 nm, increases the second excitation maximum at 297 nm and shifts the fluorescence maximum from 350 to 346 nm. Under optimum conditions, with λexc = 297 nm and λem = 346 nm, Ce(III) can be determined fluorimetrically with a detection limit of 1.2 ng ml-1 in 12M-H3PO4 medium. No interference was observed from a 20-200 fold excess of HCl, H2SO4, Na, K, NH4+, Al and the rare earth elements. HNO3 interferes and Ce(IV) and Fe(III) interfere strongly. It follows from the stereofluorograms of Ce and Tb that the spectra of the two elements are practically independent. The detection limit for Tb(III) in 0.02-2.5M-H2SO4 medium for λexc = 222 nm and λem = 494 nm is 33 ng ml-1. No interference was observed from a 5-20 fold excess of Al3+ and the other rare earth elements. The determination is slightly less sensitive in H3PO4 or HCl medium. The relative standard deviation of the measurement for 10 ng ml-1 Ce(III) or 50 ng ml-1 Tb(III) is about 3%.

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Solid-Phase Fluorimetric Determination of Tetracyclines in Medicinal Preparations on Cellulose Paper and in Thin-Layer Silica Gel Using a Smartphone

Pharmaceutical Chemistry Journal ◽

10.1007/s11094-021-02416-x ◽

2021 ◽

Author(s):

V. G. Amelin ◽

Z. A. C. Shogah ◽

D. S. Bol’shakov

Keyword(s):

Thin Layer ◽

Silica Gel ◽

Solid Phase ◽

Fluorimetric Determination ◽

Cellulose Paper ◽

Medicinal Preparations

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Fluorimetric determination of sphingosine and its application to natural mixtures of glycosphingolipids

The Journal of Lipid Research ◽

10.1016/s0022-2275(20)43008-1 ◽

1970 ◽

Vol 11 (2) ◽

pp. 164-166

Author(s):

L. Coles ◽

G.M. Gray

Keyword(s):

Fluorimetric Determination

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trans-Fatty acids promote p53-dependent apoptosis triggered by cisplatin-induced DNA interstrand crosslinks via the Nox-RIP1-ASK1-MAPK pathway

Scientific Reports ◽

10.1038/s41598-021-89506-8 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Yusuke Hirata ◽

Miki Takahashi ◽

Yuto Yamada ◽

Ryosuke Matsui ◽

Aya Inoue ◽

...

Keyword(s):

Fatty Acids ◽

Mapk Pathway ◽

Regulatory Protein ◽

Strand Break ◽

Mitogen Activated Protein Kinase ◽

Ros Generation ◽

Apoptotic Pathway ◽

Interstrand Crosslinks ◽

Pathway Activation ◽

Dna Interstrand Crosslinks

Abstracttrans-Fatty acids (TFAs) are food-derived fatty acids associated with various diseases including cardiovascular diseases. However, the underlying etiology is poorly understood. Here, we show a pro-apoptotic mechanism of TFAs such as elaidic acid (EA), in response to DNA interstrand crosslinks (ICLs) induced by cisplatin (CDDP). We previously reported that TFAs promote apoptosis induced by doxorubicin (Dox), a double strand break (DSB)-inducing agent, via a non-canonical apoptotic pathway independent of tumor suppressor p53 and apoptosis signal-regulating kinase (ASK1), a reactive oxygen species (ROS)-responsive kinase. However, here we found that in the case of CDDP-induced apoptosis, EA-mediated pro-apoptotic action was reversed by knockout of either p53 or ASK1, despite no increase in p53 apoptotic activity. Upon CDDP treatment, EA predominantly enhanced ROS generation, ASK1-p38/c-Jun N-terminal kinase (JNK) mitogen-activated protein kinase (MAPK) pathway activation, and ultimately cell death, all of which were suppressed either by co-treatment of the NADPH oxidase (Nox) inhibitor Apocynin, or by knocking out its regulatory protein, receptor-interacting protein 1 (RIP1). These results demonstrate that in response to CDDP ICLs, TFAs promote p53-dependent apoptosis through the enhancement of the Nox-RIP1-ASK1-MAPK pathway activation, providing insight into the diverse pathogenetic mechanisms of TFAs according to the types of DNA damage.

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