Search PubMed⌕ Search

Biomedical subjects

D Georgescu

Publications and source records attributed to D Georgescu.

29 records · Page 2Linked to original sources
PubMedDate not supplied

The entrapment of biological active substances into liposomes. II. Effects of oral administration of liposomally entrapped insulin in normal and alloxanized rats.

Insulin (I) was entrapped into liposomes of various lipid compositions. After oral administration, some of the normal rats treated with neutral liposomes (c) and (d) having egg yolk lecithin, prepared with 2 or 4 mg I/ml respectively, showed a decrease in blood glucose at 2 and 4 hrs. In alloxanized rats (75 mg alloxan/kg body weight) the positive liposomes (f) have induced in some animals a decrease in blood glucose at both time intervals after oral treatment. When neutral liposomes (c) were administered to diabetic rats (125 mg alloxan/kg body) the blood glucose decreased in 9 of 12 animals from 391 to 125 mg/100 ml blood, at 3 hrs after oral treatment. At 1 h, the effect had appeared in 3 of 14 animals. The neutral liposomes (g) having synthetic lecithin, induced a decrease in blood glucose in 5 of 10 animals. A good correlation was observed between decreased glucose and increased insulin levels with the same variability throughout the treated group. No increased insulin levels were observed in diabetic control and normal rats. By the RIA method, the insulin entrapment was 8%. Histological studies have shown that at 35 min after oral administration, neutral liposomes (c) penetrate deeply into the intestinal wall of alloxanized rats as compared both to the neutral liposomes with synthetic lecithin (g) or to the positive ones (f).

Administration, Oral↗
PubMedDate not supplied

Amino acid content of the brain in rats focal penicillin induced epilepsy.

The initial objective of the present study was to investigate the role of excitatory and inhibitory amino acids in generalized as compared to focal epilepsy, both forms being induced by the same convulsant agent, i.e. penicillin. Our attempts to obtain in the rat the generalized epilepsy, constantly induced in cats by systemic administration of penicillin, were unsuccessful. This is probably due to the rudimentary development of the cerebral cortex in rodents as compared to the feline cortex. The tentative conclusion was drawn that the cortex is the brain structure mainly involved in the genesis of petit mal seizures. Penicillin was applied to the cortex of 40 white Wistar rats and the electrical cortical activity was registered. The concentrations of glutamate, aspartate, glycine, GABA and serine were determined in the cerebral cortex, the brain stem and the cerebellum. The same amino acids were determined in the brain of 20 controls. No significant changes in the amino acid contents were obtained in the cerebral cortex. In the brain stem the glutamate level was significantly increased while the glycine content was markedly decreased. These findings are consistent with the involvement of the brain stem structures in seizure activity.

Amino Acids↗
PubMedDate not supplied

The cerebral content of excitatory and inhibitory amino acids in rats following withdrawal of antiepileptic drugs.

The aim of the present study was to investigate the role of amino acids in the increased seizure susceptibility induced by withdrawal of antiepileptic drugs (AEDs). Fifty white Wistar rats treated with AEDs and 30 controls were used. The animals were previously exposed to the acoustic stimulus and only the non responsive were used. The administered AEDs were morphosuximide, ethosuximide, phenobarbital, valproate and gluthetimide. The treatment was discontinued after 2 weeks. The acoustic stimulation was repeated after 2-4 days of abstention. The animals were sacrificed and the amino acids glutamate, aspartate, GABA, glycine and serine were determined in the cortex and the brain stem. The withdrawal of AEDs induced seizure susceptibility in 71% of the rats treated with phenobarbital and in 76% of those receiving morphosuximide. A significant increase of glutamate levels was found in the brain stem following withdrawal of both morphosuximide and ethosuximide. The level of GABA was elevated in the brain stem after valproate and morphosuximide withdrawal. The increase of glutamate concentration can be correlated with the increased seizure susceptibility. The unexpected rise of the GABA level could be interpreted as a compensatory inhibitory mechanism.

Acoustic Stimulation↗
PubMedDate not supplied

Comparative study on some systemic humoral and cellular immune markers in only HIV or HIV and hepatitis B infected children.

Three different groups of asymptomatic children, aged from 12 to 24 months (30 subjects per each group), i.e. controls, only HIV, or HIV/hepatitis B virus (HBV) double infected, were studied, as concerned the following systemic immune parameters: immunoglobulin (IgG, IgM, IgA, IgD) levels; absolute numbers of blood CD+4, CD+8, CD+16 and CD+19 cells; phytohaemagglutinin (PHA)-blast responsiveness of T lymphocytes; natural killer (NK) cell activity--as tested by means of cytotoxicity assays; per cent suppression of PHA-dependent T cell blastogenesis in the presence of concanavalin A (Con A) selected T suppressor (Ts) cells. On the other hand, in 15 ARC-shifting cases belonging to HIV, and HIV/HBV groups, respectively, a second serum sample was collected and searched comparatively with the corresponding first serum sample, as regarded: presence of total and anti-p24 HIV antibodies, patterns of Western Blot (WB), as well as amounts of free p24-HIV antigen. In asymptomatic double HIV/HBV infected subjects, some immune disorders occurred, at a more significant degree, as compared to only HIV-infected. Once the shift toward ARC being installed, in both infected groups a decrease of anti-p24 HIV antibody presence, disappearance of corresponding band in WB confirmation test, as well as presence of free p24 antigen in serum, were noticed. However, greater amounts of p24 antigen in HIV/HBV infected, as compared to only HIV infected patients, were found. Some considerations about diagnostic and predictive value of presented data are discussed.

AIDS-Related Complex↗
PubMedDate not supplied

[Therapy with large doses of methylprednisolone in Basedow's ophthalmopathy].

Up to now there is no satisfactory therapeutical method in Graves' ophthalmopathy (GO). Recently, several authors have published the results of the so-called "pulse" method of corticotherapy, using intravenous methylprednisolone (MP) 1 g dissolved in 200 ml isotonic NaCl solution. We have treated with this method 4 patients (3 women and 1 man, aged between 35-62 years) with severe GO (III-V class after AMT Classification). Although the number of perfusions varied between 1 (2 patients) and 8, the results are encouraging: 3 improvements, 1 stationary evolution (after a single "pulse"). We have not noticed important side-effects. In conclusion we consider that the "pulse" method have proved its efficiency, recommendable in severe GO.

Adult↗
PubMedDate not supplied

Comparative study on some systemic humoral and cellular immune markers in only HIV or HIV and hepatitis B infected children.

Three different groups of asymptomatic children, aged from 12 to 24 months (30 subjects per each group), i.e. controls, only HIV, or HIV/hepatitis B virus (HBV) double infected, were studied, as concerned the following systemic immune parameters: immunoglobulin (IgG, IgM, IgA, IgD) levels; absolute numbers of blood CD+4, CD+8, CD+16 and CD+19 cells; phytohaemagglutinin (PHA)-blast responsiveness of T lymphocytes; natural killer (NK) cell activity--as tested by means of cytotoxicity assays; per cent suppression of PHA-dependent T cell blastogenesis in the presence of concanavalin A (Con A) selected T suppressor (Ts) cells. On the other hand, in 15 ARC-shifting cases belonging to HIV, and HIV/HBV groups, respectively, a second serum sample was collected and searched comparatively with the corresponding first serum sample, as regarded: presence of total and anti-p24 HIV antibodies, patterns of Western Blot (WB), as well as amounts of free p24-HIV antigen. In asymptomatic double HIV/HBV infected subjects, some immune disorders occurred, at a more significant degree, as compared to only HIV-infected. Once the shift toward ARC being installed, in both infected groups a decrease of anti-p24 HIV antibody presence, disappearance of corresponding band in WB confirmation test, as well as presence of free p24 antigen in serum, were noticed. However, greater amounts of p24 antigen in HIV/HBV infected, as compared to only HIV infected patients, were found. Some considerations about diagnostic and predictive value of presented data are discussed.

AIDS-Related Complex↗
PubMedDate not supplied

[An endoscopic treatment alternative in vesico-ureteral reflux (VUR)].

Vesicoureteral reflux (VUR) represent an important pathology (surgical treatment was until recently the "gold standard" therapy) in urology. Between September 1995 and October 1997 we used endoscopic Romanian collagen injection in 21 cases with VUR (3 cases grade II, 14 cases grade III, 4 cases grade IV). The collagen solution (1/1 with distilled water) was injected at the 6 hour of the ureteral large ostium (15/35 ml). In some cases we obtained the perfect occlusion of the incompetent ureteral ostium by complementary injections at 3 and 9 hours. It was necessary to reinject collagen twice in 8 cases and three times in 3 cases. Success rate appeared in 66.66% cases. We did not confront ourselves with postoperative complications. Hospitalization period was 3.2 days. The mean follow-up period was 12 months (range 6 to 28). Our results prove that endoscopic collagen injection applied in VUR is a simple, efficient, without complications method, minimally invasive.

Adolescent↗