[Increase in the incidence and risk of birth of children with Down's syndrome in Leningrad (1982-1989)].

Among 559,286 infants born in Leningrad in 1982-1989, there was revealed 744 infants (1.33/1000) with Down's syndrome (DS). The age distribution for their mothers as well as for 79,571 parturient women in the general population was investigated.

[Indicators of lipid metabolism and lipid peroxidation system in patients with different types of lesions of the vessels of the lower limbs].

A total of 66 patients were investigated with IR imager and television capillaroscopy for the blood circulation in the vessels of low extremities as well as for the values of lipid metabolism and the system of lipid peroxidation. According to the status of the vascular system in the low extremities the examinees were divided into the groups with the normal status of the vascular system, the groups with the signs of venous insufficiency, microcirculatory disorders and atherosclerosis of major vessels. With the disorders of microcirculation in low extremities staged increments in the atherogenic shifts in the exchange were demonstrated.

[Indicators of lipid metabolism and the blood lipid peroxidation system in men with regard to hereditary predisposition to atherosclerotic vascular pathology].

Lipid metabolism and the blood lipid peroxidation system were examined in 56 military males living in rather similar conditions. The parameters in question were compared in the following groups: (1) control subjects, including healthy individuals without a family history of atherosclerotic vascular abnormalities; (2) healthy subjects with a family history of atherosclerosis; (3) patients with coronary heart diseases. There were significant differences only in single cases between the groups.

[Indicators of lipid peroxidation in the blood in hereditary predisposition to arteriosclerosis].

In members of the families whose parents had atherosclerosis complicated by macrofocal myocardial infarction or stroke, the serum level of lipid peroxidation products was correlated to enzymatic activity of neutrophil and red blood cells oxidation-antioxidation. In persons with hereditary predisposition to atherosclerosis both with clinical signs of atherosclerosis and phenotypically healthy against the control group there was elevated content of plasma acylhydroperoxides and hypoactivity of neutrophil myeloperoxidase. Determination of lipid peroxidation products by malonic dealdehyde showed this parameter to be higher in members of the families of the study group and in those with cardiovascular disorders.

[Blood lipids and lipid peroxides in the families of patients with ischemic heart disease].

Levels of some fractions of blood neutral lipids and lipoperoxides were compared in the families of patients with coronary heart disease. The patients and their relatives (including healthy ones) were found to show a statistically significant increase in the atherogenic index, total cholesterol, low density lipoprotein cholesterol, triglyceride, total lipid, and lipoperoxide concentrations and a decrease in high density lipoprotein cholesterol levels as against controls. The changes in the values of lipids and lipoperoxides in the families of patients with coronary heart disease were homogenous and might be one of the pathogenetic links in the formation of hereditary predisposition to atherosclerotic cardiovascular diseases which might be detected in a prehospital period.

[Myeloperoxidase of neutrophils and its possible role in lipid peroxidation processes in arteriosclerosis].

Activity of blood plasma myeloperoxidase (MPO) of neutrophil leucocytes and acetyl hydroperoxides was studied in families of atherosclerosis patients. The neutrophil MPO activity was decreased and the blood plasma content of acetyl hydroperoxides was increased in subjects with hereditary predisposition to atherosclerosis. The role of MPO and its possible pathogenetic action as a generator of the active forms of oxygen in atherosclerosis and its complications has been discussed.

[Atherosclerosis and the process of lipid peroxidation].

Reported data on lipid peroxidation (LPO) in atherosclerotic cardiovascular diseases are summarized. Numerous evidences are presented in favor of the fact that atherosclerotic vascular lesions are accompanied with disordered blood LPO, resulting in the accumulation of excessive quantities of peroxide derivatives, an important pathogenetic sign of this disease, along with blood lipid and lipoprotein levels, and clinico-instrumental findings. Oxidation and antioxidation factors whose balanced interaction contributes to the control of LPO activity are described.

[The origin of an extra chromosome 21 in families of children with Down syndrome].

These are the first studies on the origin of nondisjunction of trisomy 21 in the USSR. Parental contribution was established in 84 of 140 families observed. In 66% cases the nondisjunction took place in oogenesis and in 34% cases - in spermatogenesis.

[Comparative study, using fluorescent methods, of cell membranes and their reconstituted liposomes].

Cell plasma membranes and proteoliposomes reconstituted from solubilized plasma membranes of thymocytes and Ehrlich ascites carcinoma cells have been studied by fluorescent methods. It has been shown that proteoliposomes are characterized by greater polarization and rigidity of microsurroundings in membrane proteins and greater microviscosity of membrane lipids. Proteoliposomes from thymocyte membranes contain less membrane proteins and express lower polarity of the lipid bilayer than proteoliposomes from Ehrlich ascites cells.

[Accumulation of DNA structural damages in human lymphocytes during aging].

Elastoviscosometric parameters of DNA from normal subjects of different age and patients with Down syndrome were assessed. Characteristics of DNA isolated from lymphocytes trisomic for chromosome 21 were studied to compare normal and pathological rates of ageing. Increased elastoviscosity was observed in normal subjects above 60.

[Serotonin concentration and transport in the blood platelets of ischemic stroke patients and their relatives].

Serotonin levels and transport were studied in patients with ischemic stroke (n = 31), their relatives (n = 50) and clinically healthy subjects (n = 45). A statistically significant difference was found in the absorption of exogenic serotonin in the patients and relatives. It has been shown that if judged by serotonin levels, the distribution curves in the control subjects patients with ischemic stroke and their relatives correspond to a model of the polygenic type of the heredity of the traits studied.

[Disorders in the lipid peroxidation system of the blood neutrophils of patients with the Shereshevskiĭ-Turner syndrome].

The neutrophil leukocyte test with the use of the antioxidant adrenaline was applied to study lipid peroxidation (LPO) in patients with Shereshevsky-Turner's syndrome. The data obtained point to the activation of LPO and reduction of the activity of the antioxidant system in neutrophil leukocytes.

[Specificity of liposome uptake from target cell lipids].

A more considerable uptake of liposomes (1.5-2 times greater) from lipids of target cells was revealed in the cells of ascites lympholeukemia NKLy/LL and Ehrlich's ascites carcinoma as compared with liposomes from other tumor lipids. NKLy/LL cells uptake liposomes from their own lipids 8 times as effective, whereas Ehrlich's carcinoma cells 3 times as effective as widely applied vesicles from egg lecithin.

[Relation between the prolongation of the anti-inflammatory activity of liposome-encapsulated hydrocortisone and liposome composition in experimental arthritis].

Experiments on rabbits with arthritis have demonstrated the possibility of a 10-fold decrease in the dose of hydrocortisone acetate incorporated into liposomes, administered intraarticularly as compared with a commercial drug in the form of suspension. The antiinflammatory effect was found to be appreciably prolonged (up to 5-6 days) upon the use of dipalmitoylphosphatidylcholine liposomes with 20 mol% cholesterol. Hydrocortisone had a prolongation effect (about 1-2 days) in the lipid phase of multilamellar liposomes from egg lecithin, dimyristoylphosphatidylcholine and distearoylphosphatidylcholine.

[Determination of the level of spontaneous damage in human and mammalian cell DNA].

A technique for registration of spontaneous DNA lesions in intact mammalian cells is proposed. Arabinosid cytosine and hydroxyurea were shown to inhibit the repair of gaps spontaneously formed and accumulated in DNA leading to the formation of double-strand DNA breaks and cell death. The rate of spontaneous lesions was different in cells from different animal species and different tissues.

[Comparative organ distribution of various sizes of liposomes during their intravenous administration].

Distribution after intravenous administration of unilamellar--0.025-0.030 micron, multilamellar--0.