China
Africa
Explore chapters and articles related to this topic
Breast Imaging with Radiolabeled Antibodies
Published in Raymond Taillefer, Iraj Khalkhali, Alan D. Waxman, Hans J. Biersack, Radionuclide Imaging of the Breast, 2021
Lamk M. Lamki, Bruce J. Barron
Biodistribution depends on the antibody used; e.g., anti-CEA antibody shows a distribution half-life is about 1 hour, and the elimination half-life is about 13 hours, with 27% of the radiolabeled substance excreted via the urine in the first 24 hours postinjection. This is typical for a Fab' fragment, but much larger for (Fab')2 and intact IgG. In the case of In-111-labeled B72.3 (IgG), we found the plasma half-life to be between 33.3 and 41.2 hours, depending on the dosage of antibody used. Biodistribution of all Mabs depends on whether IgG or fragments are used and also what radiolabel is used, as already discussed. Typically Fab' fragments go more to kidneys, because of their small size, while IgG goes more to the liver, where it is metabolized with orthoproteins. The relative distribution of the Mab is also influenced by the isotope used, e.g., when Tc-99 was used to label antimelanoma Fab' fragment, there was a significant myocardial uptake not seen with other isotopes labeling of the same Fab' fragment [11,28].
Clearance Pathways and Tumor Targeting of Imaging Nanoparticles *
Published in Valerio Voliani, Nanomaterials and Neoplasms, 2021
Since both nanoprobes and small molecular probes have unique strengths in cancer imaging, integration of these strengths into a single probe is expected to lead to significant improvements in clinically translatable nanomedicines for early cancer diagnosis and therapy. A list of these properties includes: Size-dependent properties;Multimodality;Strong EPR effect;Long-term circulation in blood (prolonged elimination half-life);High physiological stability;Efficient renal clearance;Minimum accumulation in nontargeted tissues and organs;Rapid distribution to various organs and tissues (short distribution half-life);Low perturbation on the labeled biomolecules (binding affinity, cellular dynamics, etc.).
Cardiovascular Medications in Pregnancy
Published in Afshan B. Hameed, Diana S. Wolfe, Cardio-Obstetrics, 2020
All medications can enter breast milk, but how readily the drug passes into mature milk depends on several factors including: Drug molecular weightLipid solubilityProtein bindingVolume of distributionHalf-lifeAcid dissociation constant (pKa)
Liquid chromatography/tandem mass spectrometric analysis of penicillamine for its pharmacokinetic evaluation in dogs
Published in Toxicology Mechanisms and Methods, 2020
Andreas F. Lehner, Levent Dirikolu, Margaret Johnson, John P. Buchweitz, Daniel K. Langlois
The pharmacokinetic parameters were calculated using Phoenix Winnonlin (Version 8.1, Certara USA, Inc., Princeton, NJ). The compartmental model used following IV administration is represented by the general equation (a) where Cp is the plasma concentration of compound at any time (t), A and B are the Y intercepts associated with distribution and elimination phases, respectively, and α and β represent the rate constant of distribution and terminal elimination phase, respectively (Riviere 1997). The rate constant of distribution (α), and distribution half-life (t1/2 α) were determined using the method of residuals (Gibaldi and Perrier 1975). The terminal half-life (t1/2 β) (Martinez 1998a) was calculated according to Equation (1).
Albumin-based cancer therapeutics for intraperitoneal drug delivery: a review
Published in Drug Delivery, 2020
Leen Van de Sande, Sarah Cosyns, Wouter Willaert, Wim Ceelen
After IV administration, MTX is rapidly and efficiently cleared from the circulation. The mean distribution half-life ranges from 1.5 to 3.5 h in patients with normal total body clearance (Evans et al., 1986). Consequently, tumor exposure time of MTX is short, and a HSA-MTX conjugate was introduced to prolong exposure. A comparative in vivo study examined the antitumor activity of HSA-MTX (12.5 mg/kg) after IP administration versus IV administration of unbound MTX (100 mg/kg) (Burger et al., 2001). A soft tissue sarcoma xenograft (SXF 1301) and a prostate-cancer xenograft (PRXF PC3M) were used. Tumor fragments of 25 mg were subcutaneously (SC) implanted in both flanks of outbred nude mice. When tumors were clearly palpable and had reached a volume of 100–200 mm3, mice were randomly allocated into treatment groups and were weekly treated for 3 weeks. In the soft tissue sarcoma xenograft, a single IP injection of MTX-HSA was sufficient to cause complete tumor remission for more than 119 days (end of experiment) after treatment was initiated. Therefore, injections on days 8 and 15 were not given. IV MTX was less effective and resulted in only short-lasting partial tumor regression. In the prostate-cancer xenograft, MTX-HSA showed tumor growth inhibition of 92.8% compared to the control mice, while injection of MTX showed growth inhibition of 20.8% compared to the control mice.
Investigation of disposition for TAK-448, a synthetic peptide of kisspeptin analog, in rats and dogs using the radiolabeled TAK-448 suitable for pharmacokinetic study
Published in Xenobiotica, 2019
Yuu Moriya, Akifumi Kogame, Yoshihiko Tagawa, Akio Morohashi, Takahiro Kondo, Satoru Asahi
The concentrations of total radioactivity and metabolite in the biological samples were expressed as TAK-448F equivalent values. Data are denoted as the mean values or mean values ± standard deviation (S.D.). The metabolic profiles of plasma and feces were determined using pooled samples from three rats and four dogs. Maximum concentration (Cmax) and time to reach Cmax (Tmax) were established directly from plasma concentration data. The distribution half-life (t1/2α), elimination half-life (t1/2β) and the area under the plasma concentration-time curve (AUC) were calculated by linear regression analysis and the trapezoidal method, respectively. The apparent absorption ratio of the total radioactivity (Fapp) and bioavailability (F%) were calculated by the following equation: