Tissue Preparation for Liquid Scintillation and Gamma Counting — the Counting Processes
Lelio G. Colombetti in Principles of Radiopharmacology, 2019
Self-absorption is also dependent on the energy of the emitted beta radiation, the more energetic the radiation the less the self-absorption. For tritium the self-absorption losses may be so large that this counting technique may be of little value. One of the most important applications of suspension counting is the counting of carbon-14 barium carbonate. When large quantities of sample must be used, the carbon dioxide resulting from combustion can be bubbled through barium solutions to convert it to barium carbonate. The carbonate formed is of uniform particle size and has a constant self-absorbance factor. Thus there is a linear relationship between observed activity and sample sizes, a phenomenon not common to other carbon-14-labeled compounds. Quench correction of gels containing barium carbonate can therefore be made.36 The impracticality of quench correction by the internal standards method has also been shown.37 Despite these limitations liquid scintillation gel supension counting has been used to count a variety of samples that could not be counted easily by other techniques. To list only a few examples, successful counting of large volumes of sodium hydroxide tissue digests, radioactivity on silica adsorbents from thin-layer chromatography, the assay of metallic precipitates of calcium-45, strontium-89, iron-55, and −59, and the counting of plasma samples in dimethyl sulfoxide (75% efficiency)38 have been reported. The use of dimethyl sulfoxide as a primary solvent should probably be further investigated because of its exceptional solubilizing properties. Other applications of suspension counting have been reviewed by Rapkin.39
The urinary bladder
Professor Sir Norman Williams, Professor P. Ronan O’Connell, Professor Andrew W. McCaskie in Bailey & Love's Short Practice of Surgery, 2018
On cystoscopy the characteristic ulcer is found in the fundus, but it may be absent. This area bleeds readily as the bladder is decompressed. Treatment is difficult and unsatisfactory. Hydrostatic dilatation under anaesthesia may give relief for some months. Instillation of dimethylsulfoxide results in improvement in some patients. Other drugs that have been tried include intravesical heparin, oral ranitidine and steroid therapy. Patients with severe symptoms may well require cystectomy and orthotopic bladder substitution. In patients with severe inflammation involving the trigone and urethra, this operation may not result in complete relief and some type of urinary diversion may be needed.
Preparation of Samples for Liquid Scintillation and Gamma Counting
Howard J. Glenn, Lelio G. Colombetti in Biologic Applications of Radiotracers, 2019
Self-absorption is also dependent on the energy of the emitted beta radiation; the more energetic the radiation, the less the self-absorption. For tritium, the self-absorption losses may be so large that this counting technique may be of little value. One of the most important applications of suspension counting is the counting of 14C barium carbonate. When large quantities of sample must be used, the carbon dioxide resulting from combustion can be bubbled through barium solutions to convert it to barium carbonate. The carbonate formed is of uniform particle size and has a constant self-absorbance factor. Thus, there is a linear relationship between observed activity and sample sizes, a phenomenon not common to other 14C-labeled compounds. Quench correction of gels containing barium carbonate can therefore be made.42 The impracticality of quench correction by the internal standards method has also been shown.43 Despite these limitations, liquid scintillation gel suspension counting has been used to count a variety of samples that could not be counted easily by other techniques. To list only a few examples, successful counting of large volumes of sodium hydroxide tissue digests, radioactivity on silica adsorbents from thin-layer chromatography, the assay of metallic precipitates of 45Ca, 89Sr, 55Fe and 59Fe, and the counting of plasma samples in dimethylsulfoxide (75% efficiency)44 have been reported. The use of dimethyl sulfoxide as a primary solvent should probably be further investigated because of its exceptional solubilizing properties. Other applications of suspension counting have been reviewed by Rapkin.45
Protease-activated receptor-2 activation enhances epithelial wound healing via epidermal growth factor receptor
Published in Tissue Barriers, 2022
Mahesha Bandara, Wallace K. MacNaughton
Concentrations of 1.0 µM to 10.0 µM 2fLI were used in the concentration-response curve in 10% serum and serum-free media conditions. Dimethyl sulfoxide (DMSO, Sigma-Aldrich; 0.1%) was used as the solvent for pharmacological inhibitors. The effect of COX-1 and COX-2 enzymes on wound healing were investigated using a COX-2 selective inhibitor NS-398 (Cayman Chemical, Ann Arbor, MI; 10 µM) and a nonselective COX inhibitor, indomethacin (Sigma-Aldrich; 10 µM). The involvement of EGFR activation in PAR2-induced wound healing was assessed using the EGFR tyrosine kinase inhibitor, PD153035 (4-[(3-bromophenyl)amino]-6,7-dimethoxyquinazoline hydrochloride, Tocris Bioscience, Oakville, ON, Canada) in wound healing assays. Human epidermal growth factor (EGF, 5 and 10 nM; GF-010-8 Cedarlane, Burlington, ON) was used as the positive control for EGFR activation. Cells were pre-treated with 10 nM PD153035 or the vehicle (0.02% DMSO) for 30 min before treatments and 10 nM of PD153035 was used in combination with 10 µM 2fLI or 5 ng/ml EGF. PP2 (Biomol, Hamburg, Germany: AG-CR1-3563-M005) was used as a Src tyrosine kinase inhibitor and GM6001 (Cayman Chemical: 14,533) was used as a broad-spectrum MMP inhibitor. Cells were pre-treated with 10 µM GM6001, 100 nM PP2 or the vehicle (0.02% DMSO) for 30 min. Inhibitors were used in combination with 10 µM 2fLI.
Harpagoside-induced anaphylactic reaction in an IgE-independent manner both in vitro and in vivo
Published in Immunopharmacology and Immunotoxicology, 2018
Delu Che, Jiao Cao, Rui Liu, Jue Wang, Yajing Hou, Tao Zhang, Nan Wang
HAR and compound 48/80 (C48/80, C2313, Lot: 073M4050V) were obtained from Sigma-Aldrich (St. Louis, MO) and purified to ≥98%. Fluo-3, AM ester, and Pluronic F-127 were from Biotium (Fremont, CA). TM buffer was prepared on the day of the experiments (6.954 g/L NaCl, 0.353 g/L KCl, 0.282 g/L CaCl2, 0.143 g/L MgSO4, 0.162 g/L KH2PO4, 2.383 g/L HEPES, 0.991 g/L glucose, and 1 g/L bovine serum albumin, pH 7). Metoprolol tartrate (Lot: 100084–201102), 3–(4,5-dimethylthiazol-2-l)-2,5-diphenyltetrazolium bromide (MTT; CAS: 298–93-1), and Triton X-100 were obtained from Amresco (Solon, OH). Dimethyl sulfoxide (analytical reagent, Sigma-Aldrich, MO Lot: MFCD00002089). All ELISA kits were obtained from KYM Bio-tech (Beijing, China). All aqueous solutions were prepared using ultrapure water produced by the MK-459 Millipore Milli-Q Plus ultra-pure water system (Billerica, MA).
Liposome quercetin enhances the ablation effects of microwave ablation in treating the rabbit VX2 liver tumor model
Published in International Journal of Hyperthermia, 2022
Hao Li, Pengfei Chen, Manzhou Wang, Wenhui Wang, Fangzheng Li, Xinwei Han, Jianzhuang Ren, Xuhua Duan
Quercetin (3,3,4,5,7-pentahydroxflavone), a kind of natural nontoxic flavonoid compound, has the functions of anti-proliferation and antitumour, inhibiting the synthesis of biomacromolecule, affecting the activity of many enzymes, and promoting apoptosis [17,18]. Quercetin is difficult to dissolve in water. As a common cosolvent of quercetin, dimethyl sulfoxide can cause hemolysis and damage to liver and kidney functions which limited its clinical application [19]. Yuan et al. had confirmed that liposomes can change the water solubility of quercetin and prolong the half-life of quercetin in vivo, reduce drug toxicity and significantly enhance the solubility and bioavailability of quercetin. Thus, liposomes could effectively play the role of inhibiting the expression of HSP70 in tumor cells, inhibiting tumor microvascular formation and promoting tumor cell apoptosis [10].
Related Knowledge Centers
- Methyl Group
- Nitrogen Dioxide
- Sulfoxide
- Organosulfur Chemistry
- Chemical Formula
- Chemical Polarity
- Trigonal Pyramidal Molecular Geometry
- Tetrahedral Molecular Geometry
- Dimethyl Sulfide
- Kraft Process