Photosensitized inactivation of HeLa tumor cells by phthalocyanines

The combined effect of tetrasulfonated phthalocyanine (TSPC, 1.0 microM) or chloroaluminum phthalocyanine (CAPC, 1.0 microM) and copper vapour laser radiation (lambda = 670 nm) causes a dose dependent decrease in the survival rate of HeLa cells at exponential and stationary growth phases estimated by the trypan blue exclusion test or colony-forming ability test. TSPC is two times and CAPC seven times more effective, with regard to lethality, than the known photosensitizer, a hematoporphyrin derivative.     

Is the coherence of low-intensity laser light essential for its effect on biological objects?

Low-intensity laser light coherence is considered in relation to biological objects under normal physiological conditions. Estimations show that the excitation rate (the rate of coherent states generation) of typical biomolecules in visible range (sigma abs = 10(-17) cm2, I = 10(-3) W/cm2) is 10(12)-10(13) times lower than that of their phase relaxation. It means that the role of coherent interaction processes is negligible. This conclusion is confirmed by the experimental results obtained with living cells of different types.     

Lethal and mutagenic effect of the XeCl laser on Escherichia coli

The survival rate and reversions to tryptophan-independence of Escherichia coli after XeCl laser irradiation (lambda = 308 nm) within the dose range from 10(3) to 10(5) J/m2 have been studied to show that LD37 is 10(4) J/m2, the survival rate at a maximum dose of 10(5)J/m2 is 1 per cent, and the number of mutants per 10(6) cells survived is 100.     

Comparison of the action of powerful pulses of ultrashort UV on the DNA replication and transcription functions in proliferating and resting HeLa cells

It was established that the response of proliferating and resting HeLa cells to irradiation with single powerful UV-pulses (lambda = 266 nm, the pulse duration 3.10(-11) sec) is different. In the proliferating cells, the rate of DNA synthesis is markedly changed (accelerated or retarded) while the rate of RNA synthesis changes slightly. In the resting cells, RNA synthesis is stimulated while DNA synthesis remains at the control level. In all cases, the processes observed depend upon the intensity and the number of pulses.     

Interaction of hybridoma antibodies with normal and mutant forms of Escherichia coli recA protein

We have prepared hybridomas which secrete antibodies against E. coli recA protein, by fusing spleen lymphocytes from immunized mice with P3X63-AG8 myeloma cells. This paper describes a preliminary survey of properties of antibody from a hybridoma population designated 156, which inhibits the strand pairing, strand assimilation, repressor cleavage, and DNA-dependent ATPase activities of recA protein. The 156 antibody consists of one or two species which have been tentatively identified as IgG2b. 156 Globulin reacts 4.6-fold more efficiently with denatured recA protein, and it reacts partially with the native tif-1, lexB30, recA44, and recA629 proteins, as well as with peptide fragments which are not common to all four proteins.