The qnr genes are plasmid-borne fluoroquinolone-resistance determinants widespread in Enterobacteriaceae. Three families of qnr determinants (qnrA, B and S) have been described, but little is known about their expression and regulation. Two new determinants, qnrC and qnrD, have been found recently. Here, we describe the characterization of the qnrB2 promoter and the identification of a LexA-bin...

Temozolomide (TMZ), an alkylating agent, is widely used for treating primary and recurrent high-grade gliomas. However, the efficacy of TMZ is often limited by the development of resistance. Recently, studies have found that TMZ treatment could induce autophagy, which contributes to therapy resistance in glioma. To enhance the benefit of TMZ in the treatment of glioblastomas, effective combinat...

Although significant advances have been made in treating malignant pediatric central nervous system tumors such as medulloblastoma, no effective therapy exists for diffuse pontine glioma or intramedullary spinal astrocytoma. Biology of these 2 tumors is poorly understood, in part because diffuse pontine gliomas are not treated surgically, and tumor specimens from intramedullary spinal astrocyto...

The anti-diabetic drug metformin targets pancreatic cancer stem cells (CSCs), but not their differentiated progenies (non-CSCs), which may be related to distinct metabolic phenotypes. Here we conclusively demonstrate that while non-CSCs were highly glycolytic, CSCs were dependent on oxidative metabolism (OXPHOS) with very limited metabolic plasticity. Thus, mitochondrial inhibition, e.g., by me...

The characteristics of inducer binding to lactose repressor protein in the presence of a small (29 base pair) operator DNA fragment have been examined. The presence of operator DNA fragments decreases the affinity of the protein for inducer molecules. The maximum change observed is a 20-fold increase in the concentration of inducer necessary for half-saturation of the protein. The non-linearity...

Two mixed-NH3/amine platinum (II) complexes of 3-dichoroacetoxylcyclobutane-1, 1-dicarboxylate have been prepared in the present study and characterized by elemental analysis and IR, HPLC-MS and (1)H, (13)C-NMR. The complexes exist in equilibrium between two position isomeric forms and undergo hydrolysis reaction in aqueous solution, releasing the platinum pharmacophores and dichloroacetate whi...

Whole cell biocatalysis is an important tool for pharmaceutical intermediates synthesis, although it is hindered by some shortcomings, such as high cost and toxicity of inducer, mass transfer resistance caused by cell membrane and side reactions. Whole-cell catalysis using N-acetyl-d-glucosamine 2-epimerase (EC 5.1.3.8) and N-acetyl-d-neuraminic acid (Neu5Ac) aldolase (EC 4.1.3.3) is a promisin...

DL-beta-aminobutyric acid (BABA) is a non-protein amino acid that is an effective inducer of resistance against a variety of plant pathogens. However, examples of BABA-induced resistance against insect herbivores have not been reported. We applied BABA as a soil drench to legumes and monitored its effects on the pea aphid Acyrthosiphon pisum (Harris). On tic bean (Vicia faba var. minor), BABA i...

Plant resistance inducers, also called elicitors, could be useful to reduce the use of pesticides. However, their performance in controlling diseases in the field remains unsatisfactory due to lack of specific knowledge of how they can integrate crop protection practices. In this work, we focused on apple crop and acibenzolar-S-methyl (ASM), a well-known SAR (systemic acquired resistance) induc...

Systematic crosses between various strains of Drosophila melanogaster lead in some cases to partly sterile F1 females. Two main classes of strains, inducer and reactive, may be recognized on the basis of the fertility of F1 female progeny. Females which may show incomplete sterilty (SF female) arise only when reactive females are crossed with inducer males, other crosses, including the reciproc...