Biomedical subjects
Publications and source records attributed to M Georgescu.
In a scanning electron microscope study evaluating the effects of a 10% carbamide peroxide gel on stained enamel and dentin, no surface morphologic changes were observed after 72 hours of contact with the bleaching gel.
Oxidative modification of genetic material has been implicated as a factor in carcinogenesis, particularly during promotion and progression, and therefore there is a need for sensitive detection of oxidized DNA bases. We developed a method that can be applied to DNA isolated from any source and used to simultaneously quantify oxidized nucleosides without a need to prelabel the DNA or use destructive hydrolytic procedures. This method is based on: (a) enzymatic DNA digestion; (b) HPLC separation of the resultant nucleosides; (c) acetylation of the oxidized nucleosides with [3H]Ac2O (acetic anhydride); (d) removal of the radioactive debris; and (e) quantitative analysis of tritiated nucleoside acetates by HPLC. Enzymatic DNA digestion was optimized using DNase I in the presence of Mg2+ (pH 7), followed by nuclease P1 in the presence of Zn2+ (pH 5.1) and alkaline phosphatase (pH 7.5). Analysis of DNA oxidized with H2O2 in the presence of Fe2+/EDTA for 30 min showed that the levels of 8-OHdG (8-hydroxy-2'-deoxyguanosine) were increased 2.7-fold, HMdU (5-hydroxymethyl-2'-deoxyuridine) 3.15-fold, and FdU (5-formyl-2'-deoxyuridine) 2.5-fold. Although the (-)-isomer of cis-dTG (cis-thymidine glycol) was enhanced 2.3 times, the (+)-isomer remained virtually unchanged. Analysis of DNA isolated from epidermal cells of mice treated in vivo with the tumor promoter TPA (12-O-tetradecanoylphorbol 13-acetate) showed 4.8-, 2.7-, and 8.7-fold increases in the levels of total cis-dTG, 8-OHdG, and HMdU, respectively, and of some unknown DNA oxidation products. These results prove applicability of the 3H-postlabeling method to the analysis of DNA (and potentially RNA) isolated from many sources, including animals and humans.
Using a two stages screening method the prevalence in the general population of hyperlipoproteinemias (HLP), separated in the five types proposed by Fredrickson, Levy and Lees, and adopted by WHO has been studied. The study included 7,085 subjects of both sexes, aged 25-65 years, representing 84,52 % of a population taken at random within a district of Bucarest. HLP was found in 1,013 cases, i.e. 14,29 % of the investigated population. 48.37 % were men and 51.63 % women. The prevalence of HLP was lowest in the first decace of age studied (25-35 years) and highest in the last two decades (45-65 years). Overweight was more frequently encountered in these patients (64.46 %) than in the total population (32.3 %). Of the 1,013 cases with HLP, 42.35 % (6.05 % of the total population) were of type IV, 27.05 % (3.86 % of the total population) of type II-b, 22.80 % (3.26 % of the total population) of type II-a, 4.74 % (0.67 % of the total population) of the type III and 3.06 % (0.43 % of the total population) of the type V. 22.70 % of the HLP patients were considered primary familial HLP, 66.54 % primary non-familial HLP and 10.76 % secondary HLP; IN 109 secondary HLP, the most frequently encountered disease was diabetes mellitus (42.20 %), followed by hypothyroidism (24.77 %), alcoholism (12.84 %), obstructive liver diseases (9.17 %), pancreatitis (5.50 %), nephrotic syndrome (2.75 %) and treatment with estrogens and steroids (2.75 %).
Explore the source record for details and available documents.
Transversal epidemiologic investigations carried out in different populations from several regions of Romania : Gurghiu Valley (lumberjacks from a mountain region), Danube Delta and Razelm lagoon complex (fishermen), and Bucharest have shown that, in spite of the high caloric value of food and even of a high intake of saturated fats, mean serum cholesterol is lower in the rural areas than in Bucharest, probably owing to the strenuous physical work. However, except myocardial infarction, more frequent in the urban than in the rural regions, the other forms of coronary heart disease have a relatively higher frequency in villages, particularly atrial fibrillation and ECG signs of ischemia. These findings might be explained by a greater prevalence of hypertension in these populations. It is concluded that the risk factors, which act synergically, depend on the complex structure of the "ecologic niche".
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Four patients with infantile familial sudanophilic leucodystrophy confirmed histologically and biochemically were investigated by E.E.G. and E.M.G. The E.E.G. showed a severe, non-specific slow wave abnormality, of moderate voltage and disorganized in 2 cases, with some critical' tonic' discharge. E.M.G. study was normal in relaxed muscle; peripheral nerve stimulation, however, revealed marked slowing of motor conduction velocities favouring a segmental demyelinisation process, which was ultimately confirmed histologically. This study underlines the value of investigation of infantile encephalopathies.