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Autoradiography
Published in Joan Gil, Models of Lung Disease, 2020
Autoradiography is the method of recording a picture or pattern from a radiographic source in which the source of the radioactivity is contained within the tissue or specimen. Autoradiography is an old technique that preceded and ultimately contributed to the discovery of radioactivity by the combined efforts of Niepce de St. Victor in 1867, Henry Becquerel in 1896, (1896a,b,c,d); and the Curies in 1898. It was not until the 1940s that autoradiography was transformed from a curiosity to a legitimate scientific technology, when Leblond (1943) demonstrated the distribution of radioactive iodine in thyroid tissue.
Biochemical Methods of Studying Hepatotoxicity
Published in Robert G. Meeks, Steadman D. Harrison, Richard J. Bull, Hepatotoxicology, 2020
Prasada Rao S. Kodavanti, Harihara M. Mehendale
It would be more confirmative if in vivo3H-thymidine incorporation is followed by autoradiographic examination of liver sections for 3H-thymidine label. The most useful isotope for autoradiography is tritium, an unstable isotope of hydrogen which emits weak beta radiation. The half-life of tritium is 12.5 years and the mean beta-particle energy is 0.018 MeV. In biological materials, the approximate range of the tritium beta particle is around 1 μm although 1 or 2% of the beta particles do have ranges up to 3 μm. The principle in autoradiography is that the label in the samples emits radiation. When the emulsion is exposed to this radiation, it gives spots in the form of black grains. These are called silver grains. The number of silver grains in a cell and the number of cells containing these silver grains will give an index of cell division. The procedure described here is liquid emulsion dipping method outlined by Gude (1968). Critical care should be taken by not exposing the reagents or slides to light during critical steps. We have indicated this in the procedure.
A Survey of Newer Gene Probing Techniques
Published in Victor A. Bernstam, Pocket Guide to GENE LEVEL DIAGNOSTICS in Clinical Practice, 2019
The main advantage of using radioactive labels in ISH is the high level of sensitivity that can be attained, making it capable of identifying DNA sequences a few hundred base pairs in length. The disadvantages are associated with handling of radioactive materialsneed for autoradiography and lengthy exposure timeslimited shelf life of radioisotopesfrequently extensive background
Salidroside Inhibits Ganglion Cell Apoptosis by Suppressing the Müller Cell Inflammatory Response in Diabetic Retinopathy
Published in Current Eye Research, 2023
Jing Li, Wenqiang Liu, Yufei Wang, Anqi Liu, Shengxue Yu, Hongdan Yu, Zhongfu Zuo, Xuezheng Liu
Total protein was extracted using lysis buffer containing 20 mM HEPES (pH 7.6), 150 mM NaCl, 1 mM EDTA, 1% Triton X-100, phosphatase inhibitor cocktail (Sigma–Aldrich), and protease inhibitor cocktail (Roche). The protein concentration was measured using the Bradford assay reagent (Bio-Rad). Equal amounts of protein were resolved on a 10% SDS–PAGE gel and then transferred to a nitrocellulose membrane by electrophoresis. The following antibodies were purchased from Cell Signaling and used to blot for the proteins of interest: anti-Rabbit glial fibrillary acidic protein, GFAP (GFAP) (1:4000, Abcam), anti-Rabbit IL-22 (1:2000, Bioss), anti-Rabbit p-STAT3 (1:2000, affinity), and anti-Rabbit c-caspase3 (1:2000, Abcam). Anti- Rabbit-β-actin (1:4000, Abcam) was used as an internal control for the total protein extracts. Signals were visualized with autoradiography using an ECL system (Thermo Fisher Scientific). The data were analyzed using ImageJ software.
Potential application of mass spectrometry imaging in pharmacokinetic studies
Published in Xenobiotica, 2022
Chukwunonso K. Nwabufo, Omozojie P. Aigbogun
Several molecular imaging platforms that can be used to visualise and quantify drugs at disease target tissues are available, but each has its disadvantages as previously described (Willmann et al. 2008). Optical imaging has limited clinical translation, low depth of penetration, and the probes utilised (e.g. fluorescent probe) could affect the drug PK profile. Magnetic resonance imaging (MRI) is costly and has a high imaging time while imaging using ultrasound technique is limited to the vasculature. Other sophisticated imaging modalities such as positron emission tomography and single-photon-emission computed tomography are limited by the high cost and low spatial resolution (Nwabufo and Aigbogun 2022). On the other hand, computed tomography lacks target specificity and has low soft-tissue contrast. Similarly, autoradiography is costly, has a long imaging time, and suffers from specificity issues due to challenges with distinguishing the radioactivity coming from parent compound and their associated degradation products or metabolites (Spruill et al. 2022). Given that many of these molecular imaging techniques including positron-emission tomography and single-photon-emission computed tomography require the use of radioactive isotopes, it is prone to numerous health and environmental hazards.
Absorption, metabolism, and excretion of [14C]-sebetralstat (KVD900) following a single oral dose in healthy male participants
Published in Xenobiotica, 2022
Peter Mutch, Mohammad Bashir, Bonnie Jung, Ping Yi, Matt Iverson
Sebetralstat and [14C]-sebetralstat were combined in solution prior to recrystallisation, so the radiolabelled and non-radiolabelled materials were equivalent in their physical characteristics. The chemical and radiochemical stability of the dose material was determined in the radio-diluted solid material. All dose preparation was performed to good manufacturing practice. On day 1 of the trial, all participants received a single oral dose of 600 mg containing ∼540 µCi of [14C]-sebetralstat administered in two capsules with 240 mL of room temperature water. The structure of [14C]-sebetralstat and the position of the radiolabel are shown in Figure 1. The radioactive dose was established by dosimetry calculations based on quantitative whole-body autoradiography in pigmented and non-pigmented rats. The overall whole-body radiation dose in a male participant after a dose of 540 µCi was calculated to be 8.08 and 8.35 mrem (based on data from albino and pigmented rats, respectively), well below the US Food and Drug Administration exposure limit of 3000 mrem after a single dose for human isotope studies (per 21 Code of Federal Regulations 361). During the trial, participants received a standardised high-fibre diet at scheduled times. All participants fasted overnight (≥10 h) and refrained from water for 1 h before dosing and 2 h post-dose.