[Application of heated oxygen-helium mixture for combined treatment of community-acquired pneumonia].

Community-acquired pneumonia (CAP) is the commonest infectious disease characterized by the high lethality rate. The aim of this work was to estimate the efficacy of introducing inhalation of heated oxygen-helium mixture (thermoheliox) into standard therapy of CAP. The study included 50 patients with moderately severe CAP 25 patients of group 1 were given standard therapy plus thermoheliox, those of group 2 were treated by standard method.

[Role of optical properties of the venous wall for endovenous laser obliteration].

Presented herein are the results of studying the optical density of water, blood, and venous-wall tissue for various-wavelength laser radiation, with determining the peaks of absorption of radiation by the above-mentioned media. The absorption peaks in water and blood correspond to wavelengths of 1,450 and 1,935 nm, respectively. Peaks of absorption in the venous-wall tissue are within the intervals equaling 650-950 nm, 1,445-1,455 nm, and more than 1,900 nm.

[Mechanism of photosensitized luminescence of singlet oxygen dimols in air-saturated pigment solutions].

Luminescence of singlet oxygen dimols (1O2)2 with the main spectral maximum at 703-706 nm and much weaker bands at 640 and 770-780 nm was studied using mechanical phosphoroscopes in aerobic solutions of the nonfluorescent photosensitizer phenalenone in CCl4 and C6F6 at relatively low radiant power. The spectrum of this luminescence resembles that of dimol luminescence, which we had detected previously in solutions of porphyrins and other compounds. It was shown that, in phenalenone solutions, the mechanism of dimol luminescence involves reaction of two 1O2 molecules and one ground-state pigment molecule.

[Phosphorescence analysis of the chlorophyll triplet state in preparations of photosystem II].

The low-temperature (77 K) phosphorescence of chlorophyll (Chl) in the reaction centres (D1D2-cyt b559-particles) and the core complexes of photosystem II isolated from higher plants was studied. Two phosphorescence spectral bands with the emission maxima at 950 and 977 nm, excitation maxima at 666 and 675-680 nm, and the lifetimes equal to 2 and 1.5 ms, respectively, were registered.

[Photodynamic activity and singlet oxygen].

The primary mechanisms for the photodynamic action of pigments and dyes, the principles of their division into mechanisms of type I and type II, and the role of these processes in biological systems are reviewed. Singlet oxygen is considered to be an indicator of the mechanisms of photodynamic reactions. The methods of its detection are described, which are based on the use of chemical traps, measurements of infrared phosphorescance at 1270 nm, and the registration singlet oxygen-sensitized delayed fluorescence caused by the summation of the energy of two singlet oxygen molecules by one dye molecule.

[Study of kinetic parameters of singlet molecular oxygen in aqueous porphyrin solutions. Effect of detergents and the quencher sodium azide].

The kinetic parameters of porphyrin-photosensitized formation and deactivation of singlet molecular oxygen (1O2) and their dependence on the concentration of the 1O2 quencher sodium azide were investigated in air-saturated water, ethanol, and aqueous micellar solutions of detergents using time-resolved measurements of oxygen phosphorescence under pulsed laser excitation. The lifetimes of 1O2 formation and deactivation and the rate constants of 1O2 quenching by sodium azide were determined. It was shown that, with no azide in the solutions, the rise in phosphorescence intensity after the laser flash corresponded to the kinetics of energy transfer from the porphyrin triplet molecules to oxygen, while the decay kinetics corresponded to the kinetics of 1O2 deactivation.

[Photosensitized formation of singlet oxygen in water solutions of covalent porphyrin-antibody conjugates].

The effective photogeneration of singlet molecular oxygen (1O2) by porphyrins (coproporphyrin I; 2,4-bi (alpha-methoxyethyl) deuteroporphyrin IX and cyclopanten-coproporphyrin I) conjugated with antibodies (mouse monoclonal IgG and IgM and human gamma-globulin) have been observed with the direct luminescence method of 1O2 detection. Absolute quantum yields of 1O2 formation by the conjugates have been determined. The data suggest that porphyrin-antibody conjugates are promising for the use as drugs in photodynamic tumor treatment.

Photodestruction in vitro of tumour cells sensitized by porphyrins and their conjugates with specific antibodies.

The photodynamic action of a number of carboxylic porphyrins and their covalent conjugates with specific monoclonal IgM antibodies on a human lung adenocarcinoma cell line was studied. All the conjugates showed strong phototoxicity which did not correspond with the phototoxicity of the free porphyrins. Absolute quantum yields of singlet oxygen photogeneration by the porphyrins and their conjugates were obtained and compared with the phototoxicity of the compounds.

[Photogeneration of singlet molecular oxygen by the components of hematoporphyrin IX derivative].

The photosensitized luminescence of singlet molecular oxygen has been studied in aqueous and alcoholic solutions of hematoporphyrin IX (HP) and di- and oligomeric components of "hematoporphyrin derivative" (photofrin II) which is known to be used as a drug in photodynamic tumor therapy. The quantum yields of 1O2 generation (gamma delta) by these compounds have been determined. It was found that the highest gamma delta values are characteristic of alcoholic and micellar detergent aqueous solutions.

[Sensibilized dimer luminescence of singlet molecular oxygen in solutions].

With the use of mechanical phosphoroscope the "universal" delayed emission has been found in aerobic solutions of different sensitizers in CCl4. The spectrum of this emission has the main maximum at 703 nm. The luminescence intensity is proportional to the square of the intensity of the exciting light.

[Quenching of singlet molecular oxygen by screening pigments-- melanins and ommochromes].

Synthetic DOPA-melanin and natural screening pigments--sepiomelanin and ommochromes are shown to quench the luminescence of singlet molecular oxygen (1O2) in aqueous (D2O, pD = 7.5-8.1) solutions.

[Photosensitized generation of singlet molecular oxygen by endogenous substances of the eye lens].

It is shown that kinurenine derivatives, harmane (beta-carboline) and tetracycline hydrochloride known as photosensitizers of cataractogenesis in lens produce luminescence of singlet molecular oxygen (1O2) under photoexcitation in air saturated aqueous (D2O) solution. The quantum yields of the 1O2 generation by these substances are determined. The data obtained by this direct 1O2 determination technique suggest that 1O2 might take part in cataractogenesis.

[Molecular organization of pheophytin a in aqueous solutions of detergents].

Absorption, fluorescence and excitation fluorescence spectra of pheophytin a have been measured in aqueous solutions of nonionic (Triton X-100), anionic (sodium lauryl sulphate) and cationic (Cetyl pyridinium chloride) detergents at different concentrations and pH after system relaxation. By measuring the second derivative and differential spectra, it has been shown, that if detergent concentrations are lower than critical micelles concentration, or if the detergent is completely absent, the pigment forms conglomerates containing both dimeric and monomeric forms with an efficient energy transfer between them. If detergent concentrations are higher than critical micelles concentration, pheophytin a localizes in detergent micelle in monomeric form at neutral and acidic pH, and allomerizes at alkaline pH.

[Photochemistry of phycobilisomes: photosensitized reduction of methylviologen].

The ability of phycobilisomes (PBS) to photosensitize the reduction of methylviologen by dithiothreitol has been shown. This reaction has been studied in dependence on the structural integrity of PBS, nature and pH of the medium, and concentration of reagents. The action spectrum of the reaction has been measured, and its quantum yield has been detected.

[Fractionation of phycobilisomes from the blue-green alga Nostoc muscorum].

Phycobilisomes (PBS) isolated from Nostoc muscorum contain eight spectral forms of phycobiliproteins. PBS partially dissociated by osmotic or temperature shock, were separated into 42S and 34S particles by centrifugation in sucrose density gradient. The 42S particles are enriched with phycocyanin, the 34S ones--with allophycocyanin.

[Photogeneration of singlet oxygen by psoralens].

Photosensitized luminescence of singlet (1 delta g) molecular oxygen with the maximum at 1272 nm has been found in solutions of psoralen, angelicin and 8-methoxypsoralen in CCl4. The luminescence excitation spectra, quantum yields of generation (gamma g) and rate constants of quenching (Kq) of 1 delta g by psoralens have been measured. The gamma g values 0,0055, 0,0026, 0,002 and Kq values 9 X 10(3), 11 X 10(3) and 12 X X 10(3) have been obtained for psoralen, angelicin and 8-methoxypsoralen, respectively.

[Magnetic interaction of manganese with pheophytin anion-radical and chlorophyll cation-radical in reaction centers of the photosystem II].

The influence of Mn on saturation curves of ESR spectra of Ph(-) and P(+)(680) at 1-200K in samples with different content of Mn has been studied. An analysis of these data and those on photoinduced changes of fluorescence yield of chlorophyll leads to the conclusion that the Mn-containing centre in Photosystem 2 is a cluster of 4 Mn atoms, two of which can be replaced by Mg(2+) or any other divalent metal. The distances between Mn Na Ph as well as between Mn and P(680) have been estimated.

[Estimation of the number of manganese atoms functioning in the donating side of photosystem 2].

Comparison of theoretically expected and experimental dependence of reactivation of the donor side of photosystem 2 (PS-2) on concentration of exogenic MnCl2 that was observed in PS-2 preparation after complete extraction of manganese was made. It is shown that in the absence of Mg2+ or bivalent cations of other metals (Me2+) the reactivation corresponds to the filling of a tetranuclear Mn-containing active center; in the presence of 3 microM Mg2+ or other Me2+ the reactivation takes place as a result of binding of two manganese atoms in the center. It is suggested that a tetranuclear manganese complex (which probably is responsible for the photosynthetic oxidation of water) functions in the donor side of PS-2; two of these four manganese atoms can be substituted by Mg2+ or other Me2+ without changing activity of the center.

[Quenching of singlet oxygen with chlorophylls and porphyrins].

The rate constants (kox) of irreversible oxidation of chlorophylls and porphyrins by 1 delta g state of oxygen (1O2) have been determined. It has been shown that kox values are 1-5 orders of magnitude lower than the values of rate constants of quenching 1O2 (kq) with the same pigments. The correlation between kox and kq has been found.

[Formation of free radicals at photoreduction of allophycocyanin B].

A photoinduced ESR signal is detected in the presence of 10(-2) M of dithionine in phycobilisomes and in fractions enriched in allophycocyanin B. The signal is characterized by the line width of 12G and g-factor of 2.004.

[Effects of pyridazinones and cerulenin on the biosynthesis and functional state of photosystem 2 in barley leaves].

The effects of pyridazinones and cerulenin on the formation of photosystem 2 in etiolated barley leaves and its functional state in green leaves were studied. It was shown that the reaction centers of photosystem 2 in greening leaves are formed after 2.5--3.

[Reversible effect of intensive light on photobiochemical properties of Rhodospirillum rubrum chromatophores].

The effect of high intensity (photosynthesis-saturating) light on the optical properties of the bacteriochlorophyll and the light-induced H+ uptake by R. rubrum chromatophores was studied. It was shown that under aerobic conditions illumination causes reversible inhibition (in the dark) of the chromatophore ability for the light-induced uptake of H+, a reversible inhibition of the photosynthetical reaction center function and irreversible bleaching of the antennal bacteriochlorophyll.

[Molecular arrangement of protochlorophyll aggregated forms in solid films].

The conditions were found for the successive self-assembly of two protochlorophyll aggregated forms in solid films with absorption maxima at 647 (+/-1) nm (PChl 647) and 651 (+/-1) nm (PChl 651) and fluorescence maxima at 653-655 nm and 654-657 nm, respectively. These forms model the native photochemically active form of the precursor of chlorophyll (chlorophyllide) in plants (P650). The investigation of infrared spectra (in the region 1800-1600 cm-1), CD-spectra and fluorescence, carried out in this study, permitted in between the indicated forms to distinguish the type of the molecular arrangement of aggregated structures, PChl 647 is supposed to consist of unstable dimers formed without the participation of keto groups of the cyclopentanone rings, while the structure of PChl 651 includes the dimers to bind more firmly by the intermolecular bonds formed at the expense of keto groups and a central magnesium atom.

[Pheophytin participation in primary processes of electron transfer in photosystem II reaction centers].

Reversible photoreduction of pheophytin "a" was found in preparations of the Photosystem 2 of green plants, the "primary" electron acceptor of PS-2, Q, being reduced in the dark. Study of this photoreaction showed that pheophytin functions in PS-2 reaction centres (r. c.