Biomedical subjects

C Alibeu

Publications and source records attributed to C Alibeu.

10 recordsLinked to original sources

PubMed1994

Non-coordinated biosynthesis of early complement components in a deficiency of complement proteins C1r and C1s.

We report on a 60-year-old woman with systemic lupus erythematosus and a total (95%) C1r and a partial (36%) C1s deficiency. The patient complained about cutaneous lesions on forearms and legs without other systemic involvement. Elevated anti-nuclear, anti-native DNA and anti-SSA antibodies were present. The finding of persistently depressed levels of haemolytic complement activity (CH50) on both serum and plasma, associated with normal levels of C3, C4 and C2 components, and normal alternative pathway haemolytic activity showed a deficiency of an early component of the classical pathway. Indeed C1r component was below the limits of detection whereas C1s component was lowered (36%). The depressed CH50 was only corrected by purified C1r. Biosynthesis of C1r and C1s by patient's monocytes was spontaneously normal but not up-regulated by interferon-gamma for C1r alone, whereas the biosynthesis of C1s, but also of interleukin-6, was increased, indicating a specific disregulation of C1r. The deficiency was associated with a lupus syndrome and a fatal assumed septic shock. This is in agreement with other reported cases.

Cells, Cultured↗

PubMed1990

[Evaluation of the bactericidal effect of the membrane attack complex of serum complement].

The bactericidal activity of serum complement and particularly of the membrane attack complex (MAC-C5b-C9) was studied on E. coli C600 with a simple functional test. The test evaluates the in vitro kinetics of the bactericidal effect and the subsequent counting of surviving germs. Homozygous deficiency of a particular membrane attack complex protein was easily detected from a total loss of bactericidal activity. These results were confirmed on Neisseriae meningitidis A and C, but in this case a more complex protocol was required. Deficits of proteins of the membrane attack complex sequence of complement are often found in sera of patients suffering from recurrent Neisseriae infections. This simple test, adapted to family studies, appears, thus, as a valuable basis for a detection of relatives at risk.

Blood Bactericidal Activity↗

PubMed1988

A sensitive method to assay blood complement C1- inhibitor activity.

Hereditary angioneurotic edema results from deficiency of complement protein C1- inhibitor. Using a new spectrophotometric assay for C1-s esterase activity on the N-alpha-benzoyl-L-arginine ethyl ester, we describe a routinely available method for quantifying low C1- Inhibitor functional activities in EDTA-treated plasma of hereditary angioneurotic edema patients. C1- Inhibitor activity is deduced from the residual esterase activity of C1-s incubated with 20-80 microliters plasma samples. Arbitrary units (volume of sample inhibiting 50% of C1-s activity) were used to express C1- Inhibitor normal activity which was estimated as 22,500 +/- 5,000 (SD) U/l in 45 healthy individuals. The correlation with C1- Inhibitor antigen in these healthy individuals and 89 patients with varying concentrations of C1 Inhibitor ranging from 0.05-1.05 g/l was r = 0.91. Levels down to 2,000 U/l could be estimated. Specific inhibitory activity is an absolute requirement to distinguish between type I and type II hereditary angioneurotic edema.

Complement C1 Inactivator Proteins↗

PubMed1986

Evaluation and tolerance of a new polycarbonate membrane in elderly patients. Preliminary results.

We studied the performance and tolerance of a new capillary hemodialyzer using a polycarbonate membrane (Gambrane PCD 1000) in a group of 5 elderly patients (mean age 68 years). The ultrafiltration coefficient is 6 (justifying the monitoring control of weight loss) and clearances for small molecules are comparable with cellulosic membranes. A good tolerance during 300 sessions was observed; nevertheless, an important neutropenia was noted in 2 out of 5 patients. The complement activation measured by the dosage of the C3a Desarg fraction existed in all the patients, reaching an average 6 times the initial level compared to 40 times for Cuprophan. Complement activation and neutropenia are considerably reduced by the reuse of the hemodialyzer as it was described for the cellulosic membranes.

Age Factors↗

PubMed1983

[Serum immune complexes in rheumatoid arthritis (a study of 100 cases). Comparison of the results obtained by four different detection techniques].

The detection of serum immune complexes in cases of rheumatoid arthritis (RA) was performed using four different detection techniques: cryoglobuline (CG), the polyethylene glycol C1q test (PEGC1q), the 125I labelled C1q test (C1qBA) and the detection of anticomplement power (ACP). CG, PEGC1q, and C1qBA are more often positive in cases of sero-positive RA than in sero-negative RA (p less than 0,001 for each test). There are significant and relatively concordant correlations between the positivity of these three tests and certain clinical and laboratory parameters in particular, the level of rheumatoid factor (p less than 0,001) and the presence of extra-articular manifestations. When ACP is found in cases of RA of recent onset, it is associated, in sero-positive cases of RA, with the presence of immune complexes and a more severe form of the disease.

Adult↗

PubMed1980