[Stimulation of proliferation by carnosine: cellular and transcriptome approaches].

Concentration of endogenous dipeptide carnosine in human muscle tissue reaches tens of millimoles. For more than 100 years of research, a lot of data concerning carnosine functions were accumulated, among which anti-aging effects are regarded most important. Heire, effect of carnosine in cell cultures was studied.

[Experimental morphological study of posttraumatic proliferative vitreoretinopathy prevention by cell adhesion peptide Arg-Gly-Asp-Ser].

Proliferative vitreoretinopathy (PVR) was induced in 25 rabbits by injection of autologous adenosine phosphate-activated platelets in the vitreous. Injury to the internal interface retinal membrane as a result of adhesion of aggregated platelets to it, followed by the formation of an epiretinal membrane, underlies the morphogenesis of experimental PVR. Proliferative processes in the retina were paralleled by destructive atrophic changes in it, which might be due to active physiological substances released in the course of aggregation.

[Potentiation by promethazine of hypotensive effects of adrenergic drugs on intraocular pressure].

Experiments including previous installations of promethazine (pipolphen) into the conjunctival sac followed by the topical administration of beta-adrenergic blocker timolol or a sympathomimetic drug isoptoepinal (adrenaline) have been performed on 24 rabbits (48 eyes). The substantial changes in the action mode of the mentioned drugs as the enhancement of their hypotensive effect on the intraocular pressure (IOP) have been demonstrated under the performance of the above mentioned procedure. When applied after promethazine instillations, timolol induced significantly increased outflow facility of the aqueous humor that was not usually noted in the cases of timolol topical instillations without a pretreatment of the eye with promethazine.

[Diffusion properties of water in the human crystalline lens during cataract development].

Normal and cataractal decapsulated lenses of man were studied by NMR method-spin echo to obtain information concerning efficient coefficients of self diffusion, times of spin-spin relaxation of water protons (T2) and water content in the lens (c) at 25 degrees C in the course of cataractogenesis. It has been found that the values T2 and c at 25 degrees C are much higher in the nuclei of completely turbid lenses than in the transparent ones; the self-diffusion coefficients in the turbid lenses were also higher. At -9 degrees C a significant decrease of the content of undestroyed by frost (bound) water was observed at the stage of mature cataract as compared to transparent lenses.

[Oligomerization of water soluble proteins of rabbit crystalline lens under the action of diamide].

The study has examined the effects of the SH-oxidizing agent diamide (Diazane dicarboxylic acid bis-(N,N-dimethyl-amide)) on the water-soluble portion of proteins from rabbit lenses. The dialyzed protein extracts were incubated for 1-1.5 hrs with various concentrations of diamide.

[Results of combined use of taufon and timolol in the treatment of patients with open-angle glaucoma].

The effect of taufon and timolol maleate combination on intraocular pressure and ocular hemodynamics was studied in 44 patients (63 eyes) with primary open-angle glaucoma. Combined administration of these agents elevated almost twofold the fluid discharge efficacy coefficient and normalized Becker's coefficient in 68.6 percent of patients.

[Extracellular glycoproteins of the ocular trabecular zone in patients with primary open-angle glaucoma].

The content of fibronectin, an extracellular glycoprotein, in the drainage out-flow system of human eyes was measured by the indirect immunoperoxidase staining technique. The degree of fibronectin accumulation in ocular tissues was evaluated by quantitative morphometric analysis. Fibronectin level in the ocular drainage system of humans grows with ageing and rapidly increases at different stages of primary open-angle glaucoma development.

[Photo damage to the eye in exposure to the radiation from a Nd:YAG Q-switching laser: the physicochemical structural changes to the crystalline lens and the vitreous body].

Structural changes in the lens and vitreous body exposed to short-pulse Nd:YAG Q-switching laser were under study. The laser was focussed in the lens nucleus or vitreous center plane. A pulse energy was 7.

[Oxidation of pyridine nucleotides in injuries of the cornea].

NADH fluorescence may serve a convenient test indicating the tissue redox status. Rabbit cornea has been incubated at ambient temperature in media of different compositions with 5.10(-5) M NADH at pH 7.

[Morphometric analysis of lens opacification].

A method of classifying cataractous changes in excised human cataracts that was based on separate and independent photographic documentation with subsequent quantitative evaluation of lens opacification has been proposed. The degree of lens clouding was evaluated quantitatively by measuring the optical density index and the area of clouding with certain optical density parameters (equidensities) by use of a texture analyzer system apparatus. This technique made it possible to obtain the contrast image of the lens clouding areas in the frontal projection and to determine their share in the total area of the lens surface.

[Molecular organization of protein-lipid components of the crystalline lens].

Lens transparency is primarily a physical phenomenon and is a manifestation of the lens structural organization. Traditionally the lens is considered as a "sac filled with proteins uniformly". Such studies have described overall average properties of the lens but have dealt with neither structural nor functional inhomogeneities in the lens tissue.

[Spectral characteristics of intraocular lenses and injury to the retina caused by visible light].

It has been shown that intraocular lenses (IOL) prepared from polymethylmethacrylate and silicon let pass the light of short-wave visible and long-wave spectrum regions. Unlike natural lens, IOL have no yellowish coloration, which results in the appearance of chromatic aberrations and brightness of IOL during implantation. Mechanisms of damaging effects of visible light on the retina were studied.

[Effect of carnosine on intraocular pressure].

It has been demonstrated in experiments on non-anesthetized rabbits that conjunctival injection of carnosine (beta-alanyl 1-histidine) caused a decrease in normal intraocular pressure and reduced prostaglandin-induced ocular hypertension. The rapid onset of the pressure response and the absence of papillary dilation in rabbits treated with carnosine were observed. It is concluded that L-carnosine can be used as a potent drug for the prevention of reactive hypertension syndrome.

The antioxidative properties of carnosine, a natural histidine containing dipeptide.

The experimental results suggest that the antioxidative function of carnosine is one of the most important manifestations of its biological role. The ability of carnosine to interact directly with lipid peroxidation products was demonstrated. The effects of carnosine on partial restoration of lens transparency in dog eyes with senile cataract which is known to be caused by lipid peroxidation were demonstrated "in vitro" and "in vivo".

[Mechanisms of retinal damage in chloroquine retinopathy].

The paper presents the results of comparative electron microscopic, electrophysiological and biochemical studies of chloroquine effect on lipid peroxidation (LPO) both in vitro and in vivo (rabbits and rats). It has been shown that the progress of chloroquine retinopathy was not accompanied by the increment of the initial LPO level, and the use of ionol antioxidant did not protect the retina from the adverse effect of chloroquine. Besides, chloroquine was shown to suppress LPO in vitro.

[The chemical nature of the fluorescing products accumulating in the lipids of the crystalline lenses of mice with hereditary cataract].

The content of diene conjugates (lipid hydroperoxides) was shown to be significantly higher in lipids extracted from the lenses of mice with hereditary cataract than in the controls. The same holds true for characteristics of fluorescence of the end-product of lipid peroxidation. Two (low- and high-molecular weight) peaks were detected in chromatographic lipid profile of cataract lenses measured by fluorescence on Sephadex LH-20 column, whereas only one (high-molecular weight) peak was found in lipids from normal lenses.

[Modification of membrane structures in cataract].

Early alterations relating to lenticular opacity occurred long before large protein aggregates formation in the lens and in plasma membranes of lens fibres. At the first step of human cataract development membranes contained typical knobs, sockets and fragments. Then, with development of cataract, further fragmentation and undulation of lens membranes were observed; surface of the fibre membranes was increased.

[Antioxidative enzyme activity and metabolism of peroxide compounds in the crystalline lens during cataractogenesis].

Lens antioxidative enzyme activity (catalase, superoxide dismutase, glutathione peroxidase) in cataract as well as the possibility of cataract induction by the lipid peroxidation products and their influence on the content of reduced thiols (oxy-red balance) were studied. It was shown that the rate of the H2O2 decomposition by the human cataract lenses is lowered in comparison with the normal lenses. This is not due to the lowered catalase or glutathione-peroxidase 1 activity, but depends on the deficiency of reduced glutathione in the lens.

[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.

[Cataract induction by products of lipid peroxidation].

Liposome suspension prepared from the unsaturated phospholipids exposed to lipid peroxidation (LPO) induced posterior subcapsular cataracts after injection into the posterior vitreous of rabbit eyes. In the background of this model lies a type of lens opacity formed during retinal degeneration when toxic peroxide substances diffuse anteriorly through the vitreous body resulting in vitreous opacities and complicated cataracts. Saturated liposomes (prepared from beta-oleoyl-gamma-palmitoyl) L-alpha-lecithin) did not induce lens opacities, which is the evidence that a lipid peroxidation mechanism may be responsible for the posterior cataracts.

[Crystalline lens induction of lipid peroxidation].

The level of lipid peroxidation products (LPP) was determined in the aqueous humor from the anterior chamber of patients with cataract and donor eyes. The content of LPP in senile cataract aqueous humor was shown to be significantly increased. To determine the possible mechanism of LPP increase in aqueous humor, human lenses at different stages of cataract as well as transparent human and rabbit lenses were incubated for 3 hours in 3.