Search PubMed⌕ Search

Biomedical subjects

C Diaconu

Publications and source records attributed to C Diaconu.

At least 19 recordsLinked to original sources

Spectral and interferometrical study of the interaction of haemin with glutathione.

The interaction of haemin with reduced glutathione (GSH) was investigated in vitro and the association constant was determined by both spectrophotometric and interferometric methods. In order to elucidate the nature of this interaction, the reaction of haemin with a typical reductive agent (sodium dithionite) and a typical chelating agent for hem-iron (histidine) was also studied. Haemin-induced haemolysis in the presence and absence of GSH was monitored spectrophotometrically. The results outline the role of GSH at physiological concentration in preventing erythrocyte damage by haemin.

Erythrocyte Membrane↗

[The diagnosis and treatment of benign tumors of the subdiaphragmatic digestive tract].

One hundred twenty-two benign tumors of subdiaphragmatic digestive tract admitted in the interval 1975-1988 at the III-rd Surgical Clinic of Iaşi are reported. Out of these patients 120 required surgical treatment, the remainder of 2 being treated conservatively (diffuse intestinal angiomatosis, Peutz-Jeghers' syndrome). The clinical evolution being atypical, the surgical intervention was required, in most of the cases, due to hemorrhagic and occlusive complications. Histologically, the polyps and schwannomas were prevalent. The diagnostic difficulties, especially in the cases with jejuno-ileal localization, are mentioned.

Diaphragm↗

[Cancer of the upper gastric pole--possibilities and limitations].

An analysis of the cases encountered over the last 5 years revealed a high frequency of gastric cancers located in the upper pole area of the stomach. These represented 23% of all gastric cancers. The low number of cases with this localization that could benefit from gastric resection (38,7%), in contrast with distal locations (65,4%) suggest either late detection or high invading potential of these cancers. Oeso-gastric resection - the only efficient curative or palliative treatment - was adapted according to site and extension of the tumour in both organs. In 6 cases partial resection of the thoracic oesophagus was necessary, and in another 4 cases total gastrectomy was performed. In 8 patients upper polar resection - including the oesophagus - was satisfactory from the oncologic viewpoint, and was well-tolerated by the patients.

Adult↗

Studies on the intermolecular forces involved in the antibody-antigen interactions, using V3 synthetic peptides and sera from HIV1 seropositive patients.

The nature of physical forces responsible for the antibody-antigen (Ab-Ag) reaction was analyzed in an original system, represented by synthetic peptides derived from the V3 consensus sequences of some HIV1 subtypes gp 120 and HIV1 positive human serum. For locating antigenic determines, flexibility, hydrophilicity and hydrophobicity profiles of the V3 peptides were analysed. The hydrophilicity indicates that V3 apex borders are involved in the first stage of the reaction. The flexibility and hydrophobicity suggest that the apex of the V3 loop (GPGR/Q) is involved in the stabilization of the complex by hydrophobic interactions. Further, we followed up the influence of the dielectric constant and of the pH upon the forces established between Ab and Ag. Modifications in the dielectric constant and pH reveal a significant contribution of electrostatic and van der Waals forces in securing the intermolecular complementarity. D2O produces the highest augmentation of the antibody affinity for the most hydrophilic peptides, while a very slight one was recorded for the most hydrophobic sequence. A high affinity of antibodies for the peptides MN, R and Z was registered at an acid pH, when their His residue was protonated. On the contrary, no influence was recorded in the case of the peptide A, which does not contain any His residue.

Amino Acid Sequence↗

[The action of amphiphilic drugs on human fibroblasts in vitro. Their possible use in antiviral and antitumor chemotherapy].

The LDH cytotoxicity test is able to emphasize the stabilisation of human embryo fibroblast membranes, in vitro, by two amphiphilic drugs: the metomidate and the thymolol. The membrane stabilisation is emphasized by the reduced LDH externalization as compared with the untreated cells. The use of the LDH test for the selection of some natural complexes or synthetic drugs with membrane stabilising and potential antiviral activity is proposed. The inhibition of LDH by metomidate was recorded, as decreasing of the enzyme activity with increasing metomidate concentration. This fact explains the known lactic acid accumulation, under metomidate treatment of human subjects. The use of metomidate in classical cancer treatment potentiation is proposed instead of lactate externalization inhibitors, already used for this aim.

Antineoplastic Agents↗