ABSTRACT
Due to their amphiphilic properties, detergents readily disrupt cellular membranes and cause rapid cytolysis. In this study we demonstrate that treatment of cells with sublytic concentrations of detergents such as Triton X-100, Nonidet P-40, n-octylglucoside and the bile salt sodium deoxycholate induce typical signs of apoptosis including DNA fragmentation and cleavage of poly(ADP-ribose) polymerase molecules. The detergent concentration required for apoptosis was below the critical micellar concentration. Induction of apoptosis was not restricted to human cells but similarly occurred in a variety of other vertebrate cell lines. Unstimulated peripheral blood mononuclear cells were susceptible to apoptosis induction by detergent suggesting that apoptosis in this circumstance is not mediated by CD95. Cell death was not due to influx of calcium from the medium. Apoptosis was blocked and cytolysis prevented by treatment with peptide inhibitors of caspases. These findings suggest a process of apoptosis that is initiated upon nonspecific alterations at the cell membrane level. Physiologic correlates of this process still have to be defined.
Subject(s)
Apoptosis/drug effects , Caspases/metabolism , Deoxycholic Acid/pharmacology , Detergents/pharmacology , Glucosides/pharmacology , Octoxynol/pharmacology , Polyethylene Glycols/pharmacology , Amino Acid Chloromethyl Ketones/pharmacology , Calcium/metabolism , Cations, Monovalent , Cell Death/drug effects , Cell Line, Transformed , Culture Media , Cysteine Proteinase Inhibitors/pharmacology , Enzyme Activation , Humans , Jurkat CellsABSTRACT
Injection of electric field pulses of high intensity (kV/cm) and short duration (microsecond range) into a cell suspension results in a temporary increase of the membrane permeability due to a reversible electric breakdown of the cell membrane. Here we demonstrate that application of supercritical field pulses between 4. 5 and 8.1 kV/cm strength and 40 microsec duration induce typical features of apoptosis in Jurkat T-lymphoblasts and in HL-60 cells including DNA fragmentation and cleavage of the poly(ADP ribose) polymerase. Apoptosis induction did not depend on the presence of any particular electrolyte in the extracellular medium. However, no apoptosis was observed in solutions without a minimum amount of salt. Apoptotic DNA fragmentation was prevented by the caspase inhibitor zVAD.
Subject(s)
Apoptosis , Electric Stimulation , Caspases/metabolism , Culture Media , DNA Fragmentation , Electroporation , Enzyme Activation , HL-60 Cells , Humans , Ions , Jurkat CellsSubject(s)
Anesthesia, Dental/methods , Anesthetics, Local/administration & dosage , Facial Pain/prevention & control , Bupivacaine/administration & dosage , Facial Pain/etiology , Humans , Hydrogen-Ion Concentration , Injections/adverse effects , Mandibular Nerve , Nerve Block , Prilocaine/administration & dosageSubject(s)
Dental Porcelain/therapeutic use , Dental Veneers , Dental Bonding/methods , Esthetics, Dental , Humans , Incisor , Maxilla , Models, DentalABSTRACT
This article presents a recently developed porcelain-fused-to-metal dental material, which combines strength and durability with aesthetics and can be used in the anterior as well as posterior regions. Developed in Europe, this system is now available in the United States and can be used in conjunction with all conventional restorations. In the case presented, this material was used with a gold-casted premachined plastic screw-type attachment, and a case report is used to illustrate the clinical procedure.
