Fluorescence Polarization as a Functional Parameter in Monitoring Living Cells: Theory and Practice

The use of fluorescence polarization as a functional parameter in monitoring cellular activation calls for the reliable and accurate measurement of the fluorescence intensity and polarization (FI and FP) of microscopic objects. The relevant experimental parameters that enter such measurements are thoroughly discussed. The possibility of executing FP measurements properly by flow-through systems is compared with that of static cytometry. Remarks on the effects of high-power excitation on markers and cells conclude the paper.     

Spectrum of the effect of laser radiation on hemoglobin of the blood vessels of skin

We suggested and consider the primary mechanism of biostimulation and of the therapeutic effect of low-level laser radiation caused by a local increase in the effectiveness of oxygen transfer by oxyhemoglobin of the blood vessels of skin. The spectra of the effect of laser radiation on oxyhemoglobin and hemoglobin of the blood vessels of skin are presented which were obtained using a method of numerical simulation with allowance for the optical characteristics of skin and for the depth of penetration into it of radiation of different wavelengths. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 65, No. 6, pp. 877–860, November–December, 1998.     

Theoretical and experimental basis of biostimulation by laser irradiation

A physical model is described to explain the biostimulating effect of a laser beam. It is proposed that polarization is responsible, with the unidirectional electromagnetic field reorienting the lipid bilayer in the cell membrane. A light source which emits linearly polarized light has been made and used in clinical trials.     

Role of coherence in interaction of opticalradiation with macromolecules

Based on analysis of the properties of macromolecules in a coherent optical radiation field and taking into account experimentally established data on the specificity of the interaction between laser radiation and biomolecules (the dependence of the efficacy of the interaction on the coherence length, the presence of an effect in a region of the spectrum far away from the absorption band), we propose a mechanism for wave interaction of coherent optical radiation with macromolecules, and we construct a very simple mathematical model for such interaction. Using the mathematical model, we calculate the dependence of the vibrational energy of the macromolecule in a coherent radiation field on the coherence time and the intramolecular relaxation rate. We show that the increase in the vibrational energy of the macromolecules strongly depends on the radiation coherence length. When exposed to incoherent radiation, the vibrational energy of the biomolecules remains practically constant, while when exposed to laser radiation (coherence length ≈3 cm), the vibrational energy of the atoms increases by 2–4 orders of magnitude, leading to a change in the conformation of the biomolecules and the activity of enzymes. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 2, pp. 225–231, March–April, 2006.