Adriamycin dose and time effects on cell cycle, cell death, and reactive oxygen species generation in leukaemia cells.

We investigate the relative importance of the different mechanisms of Adriamycin, an anthracycline, and their interrelations, in particular the link between cell cycle arrest, cell death, and generation of reactive oxygen species (ROS) that is suspected to be the origin of cardiotoxic side-effects. We introduced a lifetime fluorescence based technology and used videomicrofluorometry, two efficient analytical methods. We show that depending on the doses and time after incubation, ADR will not reach the same compartments (nucleus, mitochondria, cytosol) in the cells, having consequences on the production of ROS, growth arrest pathways and cell death pathways.

New method for the detection of reactive oxygen species in anti-tumoural activity of adriamycin: a comparison between hypoxic and normoxic cells.

Tumour hypoxia plays a role in chemoresistance in several human tumours. However, how hyperbaric oxygen leads to chemotherapeutic gain is unclear. This study investigates the relation of reactive oxygen species (ROS) generation with anti-tumoural effect of adriamycin (ADR) on CCRF-CEM cells under hypoxic (2% O(2)) and normoxic (21% O(2)) conditions.

Measurements of calcium with a fluorescent probe Rhod-5N: Influence of high ionic strength and pH.

We describe a new method for the spectroscopic determination of high calcium concentration using a fluorescent probe Rhod-5N. This method was investigated in order to be utilized in high ionic strength solution, such as seawater. The probe is fluorescent when bound to calcium, LM, but not as the free form L.

Variation of 1-pyrenebutyric acid fluorescence lifetime in single living cells treated with molecules increasing or decreasing reactive oxygen species levels.

1-Pyrenebutyric acid (PBA) is a fluorescent probe whose fluorescence lifetime depends on local oxygen and free radical concentrations. We propose to use PBA fluorescence lifetime to quantify reactive oxygen species (ROS) in biological samples. Time-resolved microfluorimetry was used to record the fluorescence decay of single living cells loaded with this probe.

Effect of adriamycin treatment on the lifetime of pyrene butyric acid in single living cells.

We investigated the fluorescence lifetime of pyrene butyric acid (PBA) using various O2 concentrations in cells. Both in living and freshly fixed cells, PBA lifetime decreased with oxygen concentration. We recorded decay curves in single cells and measured PBA lifetime and NAD(P)H intensity values.

Cytotoxic effect of Laxaphycins A and B on human lymphoblastic cells (CCRF-CEM) using digitised videomicrofluorometry.

Laxaphycin A (laxa A) and Laxaphycin B (laxa B), cyclic peptides isolated from the terrestrial blue-green alga Anabaena laxa or the marine cyanobacterium Lyngbya majuscula have antifungal and cytotoxic activities. We used numerical videomicrofluorometry and a protocol of multiple labelling with Hoescht 33342 (nuclear DNA), Rhodamine 123 (mitochondria) and Nile Red (plasma membrane) to study the cytotoxicity of these substances in human lymphoblastic cells sensitive (CEM-WT) or resistant (CEM-VLB and CEM-VM1) to anticancer agents. The results indicate a low resistance index of 2 for CEM-VLB cells treated with laxa B or laxa A + lava B.

Lifetime of fluorescent pyrene butyric acid probe in single living cells for measurement of oxygen fluctuation.

We study the fluorescence lifetime of the well-known 1-pyrene butyric acid (PBA) to assess oxygen concentrations in living cells. The behavior of the probe is first studied in water, ethanol, protein solution and liposome suspension. The Stern-Volmer plot of these solutions is linear, and the bimolecular reaction rate constant agrees with previous observations.

Microfluorometric study of oxygen dependence of (1"-pyrene butyl)-2-rhodamine ester probe in mitochondria of living cells.

The access to oxygen concentration is of importance in various organelles of living cells, especially in mitochondria. A new probe, (1"-pyrene butyl)-2-rhodamine ester, was designed to target this organelle. We present here the properties of the probe in such an environment.