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Biomedical subjects

F Niculescu

Publications and source records attributed to F Niculescu.

52 records · Page 3Linked to original sources
PubMedDate not supplied

Isolation of anti-carcinoembryonic antigen (CEA), specific immunoglobulins and their use in immunocytochemical and enzyme-immunoassays (ELISA).

Anti-carcinoembryonic (CEA) polyclonal antibodies in sheep and rabbits were raised using purified CEA from acid extracts of human colon adenocarcinoma. CEA was purified by gel filtration on Sepharose 4B CL and chromatography on DEAE-Sephadex A50. The antiserum was adsorbed with human serum and perchloric acid extract from normal colon. Anti-CEA IgG was purified from monospecific antiserum by ion-exchange chromatography and its specificity was tested on cryostat sections from colon adenocarcinoma by the indirect immunoperoxidase technique. The specific reaction was compared with that obtained by using a similar technique and two CEA specific monoclonal antibodies. An anti-CEA IgG peroxidase conjugate was obtained allowing to establish a "sandwich" ELISA-CEA system with two antibodies. CEA determinations were made in a group of 15 normal controls (mean value 4.8 +/- 0.4 ng/ml) and in 30 colorectal tumor patients (mean value 26.6 +/- 2.15 ng/ml). The anti-CEA antibodies are proven useful in immunocytochemical and ELISA techniques and may be further used in radioimaging of tumors.

Adenocarcinoma↗
PubMedDate not supplied

[The isolation of anti-carcinoembryonic antigen (CEA) immunoglobulins and their use in immunocytochemical and immunoenzyme (ELISA) technics].

Carcinoembryonic anti-antigen (CEA) polyclonal antibodies were obtained in ram and rabbit using as antigen source the extracts with perchloric acid from the human colon adenocarcinomas. CEA was purified by gel filtration on Sepharose 4BCL and ion-exchange chromatography (DEAE-Sephadex A50). The total antiserum was absorbed with human serum and perchloric acid extract from the normal colon. IgG anti-CEA was purified by chromatography of the monospecific antiserum, then tested for bonding specificity, at cryostat on sections of colon adenocarcinoma, by indirect immunoperoxidase. The specific reaction was compared with that obtained by the same technique, using two monoclonal antibodies specific to the CEA molecule (MAb-26/3/13 and MAb-26/5/1 respectively). IgG anti-CEA was also used for obtaining some IgG-peroxidase conjugates, with an immunoenzymatic system, ELISA type, with two antibodies according to the model of the ELISA kits produced by the Cantacuzino Institute (ELISA-AFP). The ELISA-CEA kit was standardized using an international CEA standard. CEA was quantitatively determined with this immunoenzymatic system (ELISA-CEA) on a group of 15 healthy subjects (average: 4.8 +/- 0.12 ng/ml) and on 30 patients with colorectal tumours (average: 26.6 +/- 0.15 ng/ml). ELISA-CEA kit, sensitive and reproducible, allow the usual quantitative determination of CEA, a useful marker in diagnosing and monitoring tumour evolution.

Antibody Specificity↗
PubMedDate not supplied

[Heterophile antibodies].

After a short history and definition of the heterophile antibodies (antibodies in the IgM class, reacting to the antigenic determinants common to several species of animals) the paper reports on the antigens generating heterophile antibodies: the Forssman antigen, the Hanganutziu-Deicher antigen, the Paul-Brunnell antigen, respectively. Data are presented on the structure of these antigens and the important in diagnosing the heterophile antibodies in a series of diseases: malignant tumours, lymphomas, leukemias, infections mononucleosis, rheumatoid polyarthritis, Kawasaki's disease, Marek's disease.

Animals↗
PubMedDate not supplied

Lupus anticoagulant and transient severe bleeding tendency in a girl aged nine years.

A 9-year old girl admitted in our clinic for severe hemorrhagic syndrome was found to display a high level of lupus anticoagulant (LA) leading to an important prolongation of phospholipid-dependent coagulation. Positive antinuclear and anti DNA antibodies, as well as very low levels of complement C3 and C4 proteins confirmed the diagnosis of systemic lupus erythematosus. Therapy with cortisone and cyclophosphamide led to normalization of the clotting tests but could not arrest the development of renal and hepatic lesions. The patient is one of the few cases with presence of lupus anticoagulant associated with severe hemorrhagic diathesis, in opposition to the more frequently reported thrombotic tendency connected with antiphospholipid antibodies.

Acute Disease↗
PubMedDate not supplied

C5b-9 deposition in children with glomerular diseases.

Kidney biopsies were obtained in 28 children with glomerular diseases and studied using indirect immunofluoreoscence and immunoperoxidase for the detection of IgG, IgA, IgM, Clq, C3c, C4, Fibrinogen and the neoantigens of the terminal C5b-9 complement complex. An affinity-purified rabbit IgG was used to recognize the neoantigens of the assembled terminal components of the complement system into the C5b-9 complex. The immunohistochemical studies were correlated to the clinical data and laboratory investigations. Fourteen of the 28 patients presented specific C5b-9 glomerular deposits; they were also present at the tubular sites in 8 patients and at the vascular sites in 12 patients. An unfavourable evolution was observed for patients presenting C5b-9 deposits in contrast to those without such deposits, even of the same histopathological pattern of glomerulonephritis. The presence of C5b-9 complex at the site of glomerular injury suggests a pathological involvement of the "in situ" complement activation and could be a marker in the prognosis of the glomerular diseases.

Adolescent↗
PubMedDate not supplied

Immunohistochemical localization of the terminal C5b-9 complement complexes associated to S-protein and macrophage immunoreactive deposits in human damaged myocardial areas.

The indirect and double-labelling immunoperoxidase techniques were used to localize the C5b-9 neoantigens, S-protein and macrophage immunoreactive deposits in myocardial areas with necrosis and sclerosis. Granular masses of C5b-9 neoantigens, diffuse areas of S-protein and nucleated and anucleated immunoreactive deposits of macrophage origin were localized in damaged myocardial areas but not in areas free of lesion. The presence of C5b-9 neoantigens associated to S-protein and macrophage deposits is suggestive for a local complement activation in the complex heterolytic events of myocardial injury.

Complement Membrane Attack Complex↗
PubMedDate not supplied

Quantitative determinations of immunoglobulins and complement components in human aortic atherosclerotic wall.

Saline and acid eluates of intima with only fatty streaks, fibrous plaque and intima surrounding the fibrous plaque were obtained from 42 human aortae. IgG, IgA, IgM, C1q, C3c, C4, C9, C3A, C-reactive protein, alpha-1-antitrypsin, alpha-2-macroglobulin, albumin, transferrin and fibrinogen were quantitatively determined in these eluates using the radial immunodiffusion technique. Saline extracted IgG and IgA were significantly higher in the fibrous plaque and adjacent tissue than in the fatty streak intima, where IgM was the highest. IgG and IgA were only present in acid eluates. The complement components were present in all saline eluates, but only traces of C3c and C1q in some acid eluates. Statistically significant differences were found for C1q and C9. C-reactive protein was present in 23 samples. The results could suggest an involvement of immune mechanisms in the progression of the atherosclerotic lesion.

Adolescent↗
PubMedDate not supplied

Immunologic alterations associated with chronic hemodialysis.

Parameters of humoral immunity were studied in 18 patients with chronic renal failure undergoing hemodialysis. IgG, IgA and IgM serum levels presented no differences compared with healthy donors. High immunoglobulins levels were found in 40 patients with chronic renal failure and conservative treatment. Complement components C1q, C4, C9, were normal, but C3 and C3A were significantly low prior to dialysis. During hemodialysis, the complement system showed an activation by the alternative pathway (AP). The cuprophan membrane was proved to be an important factor in this activation. The circulating immune complexes (CIC) were also high. Seven patients presented autoantibodies, 2 against smooth muscle and 5 against gastric parietal cells. Our results suggested a certain humoral immune alteration during chronic hemodialysis.

Antibody Formation↗