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Biomedical subjects

G Ghyka

Publications and source records attributed to G Ghyka.

47 records · Page 3Linked to original sources

Ginterferon (human leukocyte interferon) efficiency in the treatment of viral diseases. 1. Efficiency in viral keratoconjunctivitis.

Ginterferon is a human leukocyte interferon (IFN) produced in the "V. Babes" Institute by in vitro culture of leukocytes separated from neonatal cord blood. Ginterferon (50,000 IU/ml) was administered to 40 patients who suffered for at least two weeks of a hepatic keratoconjunctivitis resistant to treatment with conventional regimens of human immunoglobulins, Iduviran or topical antiinflammatory drugs. In 35 cases (87%) complete recovery (total epithelialization and disappearance of all symptoms) occurred in a significantly shorter time (10-14 days) as compared to similar cases which recovered after 30-40 days by conventional treatment. Local or general untoward effects were not observed in any of the patients. Recovery in the remaining 5 cases was slower, 28-30 days. This slow response may have been due to unusual weakness of the general immunobiological condition in these patients (myocardial infarction or repeated stress) which might have favoured repeated waves of virus spreads from foci of viral latency which are not attained by the topically administered IFN.

Drug Evaluation↗

The use of differential staining of sister chromatid to estimate the in vitro effect of human alpha interferon on cell division in normal and tumour cells.

Concentration of 10, 100 and 1000 I.U./ml of human leukocyte alpha interferon (IFN) were added into peripheral human blood (PBL) cultures and in KB cell cultures in the presence of 5-bromdeoxyuridine (BrdU) at 10 micrograms/ml. After 72 hours the differential staining of sister chromatid (harlequin) technique was applied in order to differentiate among the metaphases of successive cell generations occurring in the presence of IFN. The frequency of the first (M1), second (M2) and third (M3) metaphases was recorded and the replication index (RI) as well as the average generation time (AGT) was calculated for untreated controls and for each of the IFN concentrations used, both in the blood cultures and in the KB cells. In the PBL cultures a clear dose-related inhibitory effect of IFN on cell division was observed, the RI values being lessened whereas the AGT concomitantly increased by increasing the IFN concentrations. An increase in M1 metaphase frequency was observed concomitantly with a diminished number of M3 cells. In KB cells the division kinetics was not influenced by IFN as indicated by similar RI and AGT values observed in controls and in IFN treated cells. However, the frequencies of both M1 and M3 cells were slightly diminished concomitantly with a discrete augmentation of M2 cell number. The differential staining of sister chromatid thus proved a highly useful technique to investigate the different sensitivity of the normal and malignant cells to the growth inhibitory effect induced by alpha IFN in vitro.

Bromodeoxyuridine↗

Significance of some immunochemical data for the viral pathogeny of multiple sclerosis.

Cerebrospinal fluid (CSF) samples from 124 patients with different neurological diseases (35 having an ascertained diagnosis of multiple sclerosis (MS) and 20--of subacute sclerosing panencephalitis (SSPE)) were investigated by immunoelectrophoresis. The correlation between the "secretory" immunoelectrophoretic pattern of CSF proteins in MS and SSPE patients and the incidence of antimeasles HI antibodies in the CSF is analysed. The results point to a different pathogenic significance of the presence of antimeasles antibodies : a) persistent measles virus infection in SSPE and b) a particular genetic constitution, coincident with a hyperreactivity to measles virus, in MS.

Antibodies, Viral↗

Interleukin-2 (IL-2) in the treatment of malignant brain tumors (glioblastomas).

The present study is aimed to provide a new possible approach to the treatment of glioblastomas, in an effort to control the extremely severe evolution of these tumors. Thus, from May 28, 1991, we started the administration of IL-2 (produced at the "Victor Babeş" Institute, Bucharest) in 9 glioblastoma patients (operated on at the Neurosurgery department VII of the "G. Marinescu" Hospital, Bucharest) by repeated intraoperative and postoperative local injections. The survival period from the first IL-2 administration was 7 months (1 case), 8 months (2 cases), 11 months (2 cases), 14 months (1 case) and 17 months (1 case). There are only 2 survivors: one 4 months and the other 23 months following the first injection of IL-2. The survivor whose condition 23 months following introduction of IL-2 therapy is very good, demonstrates that IL-2 offers some chance to these hopeless patients.

Brain Neoplasms↗

Tumoral infiltrate after local treatment with interferon in squamous cell carcinoma.

Using monoclonal antibodies UCHL-1 (T lymphocytes), MT-1 (pan T) and L-26 (B lymphocytes) in the study of the tumoral infiltrate after local treatment with alpha interferon (Roferon) in patients with squamous cell carcinoma of the lower lip, it was observed that: the proportion of UCHL-1 positive cells was between 30% and 80%, the proportion of MT-1 positive cells was of 85% and that of the L-26 positive cells was of 30% of all the cells in the infiltrate. In the area in which after treatment with interferon the tumoral structures had disappeared, the proportion of T lymphocytes was smaller than in the areas in which the tumoral structures were still present. The therapeutic effect of interferon is due both to the direct effects on the tumoral cell and also to the indirect effects, namely the activation of the cytotoxic T lymphocytes and of other cells in the tumoral infiltrate.

Adult↗

An antigen for the diagnosis of M. pneumoniae infections by passive hemagglutination.

The authors establish the optimal conditions (protein concentration, temperature) for the coupling of purified mycoplasma antigen to sheep red blood cells, in order to obtain an antigenic complex stable for at least 1 year. This comples allows specific determination by passive hemagglutination--a simple and rapid technique--of anti-mycoplasma antibodies in the sera of men or animals suspected of mycoplasma infections. Under the stated experimental conditions, antibody titers equal to or higher than 1/128 indicate an infection with M. pneumoniae.

Animals↗

Preliminary investigations on the diagnostic value of passive hemagglutination and complement fixation tests in infections with Mycoplasma pneumoniae.

In order to evaluate the efficiency of passive hemagglutination (PHA) and complement fixation (CF) tests for the diagnosis of M. pneumoniae infections, 144 serum samples--out of which 81 from patients with respiratory and cutaneous infections and 63 from subjects with other diseases (controls)--were comparatively investigated by the two methods. The PHA test made evident a positivity index of 65% in the case of mixed pneumonias, as against 17% in controls, while the results obtained by CF were almost identical in the two groups investigated. The high specificity and sensitivity of the PHA reaction recommend this method for the diagnosis of acute M. pneumoniae infections.

Antibodies, Bacterial↗