Invariance under the combined transformations of CPT (in any order) is guaranteed in Quantum Field Theory in flat space times due to a basic theorem (CPT Theorem). The currently used formalism of particle physics phenomenology is based on this theorem. However, there may be violations of the basic underlying assumptions of this theorem in models of quantum gravity, namely Lorentz covariance, un...

Serotonin immunoreactive (5-HT-IR) neurons identified as cerebropleural ganglion triplets (CPTs) in Hermissenda may be homologues of 5-HT-IR neurons identified in other opisthobranch molluscs. In studies of isolated nervous systems and semi-intact preparations we used a combination of immunohistochemical techniques and fluorescent labeling with Lucifer yellow to identify 5-HT-IR CPT neurons aft...

BACKGROUND CPT-11 is hydrolyzed to its active metabolite SN-38, which is mainly eliminated through conjugation by hepatic uridine diphosphate glucuronosyl transferases (UGTs) to the glucuronide (SN-38G) derivative. Preclinical studies showed that UGT*1.1 is the isozyme responsible for SN-38 glucuronidation. Patients with Gilbert's syndrome have deficient UGT*1.1 activity, therefore may have an ...

PKG activator 8-(4-chlorophenylthio)-guanosine 3',5'-cyclic monophosphate (CPT) at reperfusion protects ischemic hearts, but the mechanism is unknown. We recently proposed that in preconditioned hearts PKC lowers the threshold for adenosine to initiate signaling from low-affinity A2b receptors during early reperfusion thus allowing endogenous adenosine to activate survival kinases phosphatidyli...

To identify mechanisms of camptothecin (CPT) resistance and the relationship between CPT-resistant cells and other anticancer agents, a CPT-resistant cell line (CPT30) and its partial revertant cell line (CPT30R) were established from a human nasopharyngeal carcinoma cell line (HONE-1). CPT30 and CPT30R cells displayed a 14- and 3.5-fold resistance to CPT compared with HONE-1 cells, respectivel...

Camptothecin (CPT) is a specific topoisomerase I (top1) poison which traps top1 cleavable complexes; e.g. top1-linked DNA single-strand breaks with 5'-hydroxyl and 3'-top1 linked termini. CPT is also a potent anticancer agent and several of its derivatives have recently shown activity in the chemotherapy of solid tumors. Our aim was to apply the ligation-mediated polymerase chain reaction (LM-P...

This study was conducted to investigate developmental changes in the kinetics of carnitine palmitoyltransferase (CPT) within hepatic and skeletal muscle tissues of the canine species. Carnitine concentrations, CPT activity and the apparent K(m) for carnitine were measured in tissue homogenates from dogs in six age categories: newborn; 24-h-old; 3-, 6- and 9-wk-old; and adult. Hepatic CPT activi...

O(6)-Methylguanine-DNA methyltransferase (MGMT) is a DNA repair protein that removes alkyl-adducts from the O(6)-guanine in DNA and is a crucial defense against O(6)-alkylating agent-induced cytotoxicity. We demonstrated here that two camptothecin (CPT)-resistant cell lines (CPT30 and KB100) were more sensitive to N,N'-bis(2-chloroethyl)-N-nitrosurea (BCNU) than their parental cells. Enhanced s...

BACKGROUND Camptothecin (CPT) has recently attracted increasing attention as a promising anticancer agent for a variety of tumors. But the clinical application is largely hampered by its extreme water insolubility and unpredictable side effect. It is essential to establish an efficient and safe protocol for the administration of CPT versus melanoma. METHODS Camptothecin was encapsulated with ...

Nanoparticle (NP)-based combination chemotherapy has been proposed as an effective strategy for achieving synergistic effects and targeted drug delivery for colon cancer therapy. Here, we fabricated a series of hyaluronic acid (HA)-functionalized camptothecin (CPT)/curcumin (CUR)-loaded polymeric NPs (HA-CPT/CUR-NPs) with various weight ratios of CPT to CUR (1 : 1, 2 : 1 and 4 : 1). The resulta...