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C Cachera

Publications and source records attributed to C Cachera.

At least 19 recordsLinked to original sources
PubMed1998

Apo(a) phenotypes and lp(a) concentrations in renal transplant patients.

Plasma lipoprotein (a) (LP(a)) concentrations are increased in patients with end-stage renal disease. Considering the influence of the apolipoprotein (a) (Apo(a)) polymorphism and the mode of dialysis in this prospective longitudinal study, we compared Lp(a) concentrations before and after the first 6 months of a successful kidney transplantation in 125 recipient patients. Apo(a) phenotyping was performed by using SDS-PAGE and SDS-agarose, isoforms were classified into high molecular weight (HMW) and low molecular weight (LMW). Before the graft, the Lp(a) concentrations were significantly higher in CAPD than in hemodialysis patients (p = 0.021). Six months after transplantation, Lp(a) fell in both treatment groups. This decrease occurred within both LMW and HMW but to a different extent: median relative variations were -35 and -50%, respectively (p = 0. 048). Among patients with Lp(a) concentration >30 mg/dl 6 months after transplantation, 74% had LMW Apo(a) isoform while the remaining 26% had HMW isoform. Successful renal transplantation leads rapidly to a correction of Lp(a) concentrations, especially in patients treated with CAPD who have higher Lp(a) levels. The most important factor seems to be the LMW status corresponding to high Lp(a) levels.

Adolescent↗
PubMed1996

Alteration of the lipid and apolipoprotein contents of lipoprotein (a) in haemodialysis patients.

BACKGROUND: To examine the possible alteration in Lp(a) composition, protein and lipid contents of Lp(a) were determined in 10 haemodialysis patients (HD) matched with 10 controls (C) for apo(a) phenotypes. METHODS: All subjects (HD and C) had Lp(a) concentrations greater than 30 mg/dl (mean+/-SD : 82.3+/-41.4 vs 49. 3+22.5 mg/dl), a concentration which has been determined to be associated with an elevated cardiovascular risk. Apo(a)-containing particles were isolated by immunoaffinity chromatography using a monoclonal anti-apo(a) antibody. RESULTS: The molar concentrations of lipid and protein constituents of immunoaffinity isolated Lp(a) were expressed as number of moles per mole of apo(a). Lp(a) from HD patients were significantly richer in apo Cl11 (P<0.05) and triglycerides (TG) (P<0.05), compared to those of controls. Molar ratios of apo B, apo E, cholesterol and phospholipid s per apo(a)-containing particles were in the same range in both groups. CONCLUSION: Lp(a) from HD patients is characterized by an elevated content in TH and apo Cl11 in comparison with those of controls. Further studies are needed to evaluate in HD patients the contribution of changes in Lp(a) composition towards the metabolism of these particles.

Adult↗
PubMed1996

Apolipoprotein AI and apolipoprotein B containing particle analysis in normolipidemic hemodialyzed patients: evidence of free apolipoprotein E.

Whole plasma from 6 normolipidemic chronic renal failure (CRF) patients undergoing hemodialysis treatment was passed through the anti-apolipoprotein (Apo) AI immunosorbent column connected to the anti-Apo B immunoaffinity column. Apo AI and B containing particles were analyzed for lipid and Apo contents. The results were compared with findings obtained in age-matched normolipidemic healthy controls. Although plasma Apo AI and AII levels decreased in CRF patients, the concentrations of Apo CII, CIII, and E coeluted with Apo AI were similar to those of the controls. The slightly elevated plasma concentrations of Apo CII and CIII in the CRF patients studied were shown to be associated with Apo B containing particles. The nonretained fraction from both groups contains no Apo AI and no Apo B, but still contains lipids and other Apo such as Apo AII and Apo CII. The occurrence of approximately 29% of plasma Apo E in this fraction constitutes the main abnormality found in these patients (< 5% in controls). A two-phase electroimmunoassay shows that this Apo E did not correspond to the plasma E-AII complex. These findings show that the compositional alterations of Apo AI and Apo B containing particles in CRF patients were observed even in normolipidemic patients and suggest that the kidney may play a metabolic role in the removal of free forms of lipoprotein particles such as free Apo E.

Apolipoprotein A-I↗
PubMed1996

Neutral-lipid transfers and cholesteryl ester transfer protein in hemodialyzed patients.

Abnormalities in cholesteryl ester transfers may play a role in the development of atherosclerosis observed in patients with end-stage renal failure treated by chronic hemodialysis. Net neutral-lipid transfers and cholesteryl ester transfer protein activity and mass were investigated in 20 hemodialyzed patients, arbitrarily divided into two groups based on fasting triglyceride levels, and compared to triglyceride-matched control groups. In the hypertriglyceridemic subjects (plasma triglyceride values > 150 mg/dl), high-density lipoprotein cholesterol was decreased, and the net cholesteryl ester transfer rates were significantly higher than the rates in normolipidemic subjects. The comparison of subjects matched for plasma triglyceride and cholesterol levels showed no significant difference in cholesteryl ester or triglyceride transfer rates between patients and controls. Our results suggest that normal or elevated net neutral-lipid transfers are not related to the renal status of the subjects, but rather to their plasma triglyceride levels.

Aged↗
PubMed1993

Expression of apolipoprotein B epitopes in low density lipoproteins of hemodialyzed patients.

Serum and isolated low-density lipoprotein (LDL) composition abnormalities were investigated in 20 hemodialyzed patients with chronic renal failure and 15 healthy normolipidemic subjects for comparison. LDL apolipoprotein B (apo B) epitope accessibility was determined by the use of seven monoclonal antibodies (Mabs). These Mabs recognize fragments on the N-terminal part of apo B (Mabs B1, B4), on the middle part (Mab BL7), on the C-terminal (Mabs BA11, BL3), and the two remaining Mabs recognize conformational epitopes of apo B (BL5, DA7). Mab BA11 recognizes a fragment of apo B which interacts with the B/E receptor. In hemodialyzed patients, LDL content of triglycerides (P < 0.001) and apo CIII (P < 0.005) was increased, while cholesteryl esters (P < 0.005) were decreased. The accessibility of BL5 epitopes of LDL apo B was enhanced (P < 0.05), while BA11 epitope expression was decreased (P < 0.01). The conformation of patients' LDL (CRF-LDL) was probably abnormal and seemed to be related to some modification of the lipidic environment. It is important to consider a structural modification as it alters the B/E receptor recognition domain of apo B. These results confirm LDL abnormalities in hemodialyzed patients and suggest a possible modification of the recognition of the LDL by cells.

Adult↗
PubMed1993

Quantification of beta 2-microglobulin and albumin in plasma and peritoneal dialysis fluid by a noncompetitive immunoenzymometric assay.

An enzyme-linked immunosorbent assay (ELISA) was developed for measuring beta 2-microglobulin (beta 2m) and albumin in continuous ambulatory peritoneal dialysis (CAPD) fluid. Plasma concentrations of beta 2m were twofold greater in hemodialysis patients (41.3 +/- 13.3 mg/L) than in CAPD patients (23.6 +/- 5.5 mg/L) matched for duration of treatment. Measurement of beta 2m in CAPD fluid showed a substantial loss of this protein, approximately 31% of total body beta 2m, compared with a 5% loss of a protein of middle molecular mass (albumin). Because of the molecular sieving effects of the peritoneal membrane, peritoneal clearance of beta 2m was sixfold greater than that of albumin. Whether beta 2m losses prevent or delay the incidence of dialysis-induced amyloidosis in these patients remains to be established.

Dialysis Solutions↗
PubMed1992

Plasma level of lipoprotein Lp(a) is high in predialysis or hemodialysis, but not in CAPD.

Plasma Lp(a) lipoprotein level was determined in chronic renal failure (CRF) patients, 24 before initiation of dialysis, 18 undergoing hemodialysis, and 24 on continuous ambulatory peritoneal dialysis (CAPD). Eighteen healthy subjects were studied as controls. Median of Lp(a) level in both predialysis and dialysis patients was significantly increased: 23.5 mg/dl (range: 0 to 109) and 24.0 mg/dl (range: 1.4 to 90), respectively, as compared to healthy controls: 4.7 mg/dl (range: 1.8 to 27; P less than 0.001). By contrast, the median Lp(a) level in CAPD patients, 2.4 mg/dl (range: 0 to 39.5), was similar to the control group. Whether the CAPD procedure reduces the Lp(a) level in CRF patients has to be established in a prospective study.

Female↗
PubMed1992

Apo AIV in plasma and dialysate fluid of CAPD patients: comparison with other apolipoproteins.

Plasma lipids and apolipoproteins were determined in 18 patients with chronic renal failure on haemodialysis (HD), 18 patients on continuous ambulatory peritoneal dialysis (CAPD), and 18 healthy controls. Significant differences were observed between the two dialysis procedures, CAPD patients showed elevated plasma cholesterol, apo AI and apoB. No significant difference in plasma apo AIV concentration was observed between the two dialysis groups. Measurement of apolipoproteins in the dialysate fluid of five patients on CAPD showed losses of all apolipoproteins (AI, AII, AIV, B, CII, CIII and E). Although daily losses of apo AI and apo AIV were similar (255 and 221 mg/day respectively), the peritoneal clearance of apo AIV was threefold that of apo AI and 12-fold that of apo B. In view of the inverse correlation between peritoneal clearance and the molecular mass of proteins, about 13% of total plasma apo AIV was lost daily as lipoprotein-free form.

Adult↗
PubMed1991

Quantitative determination of different apolipoprotein B containing lipoproteins by an enzyme linked immunosorbent assay: apo B with apo C-III and apo B with apo E.

A non competitive enzyme-linked immunosorbent assay (ELISA) for total apolipoprotein (apo) B, apo B with apo C-III (LpC-III:B), and apo B with apo E (LpE:B), was developed. Microtiter plates were used as solid-phase, and subdivided into three parts, coated respectively with affinity purified antibodies to apo B, to apo C-III and to apo E. After incubating the antigen with coated plates, a horseradish peroxidase-labelled antibody to apo B was added to all the plates to estimate total apo B, LpC-III:B and LpE:B.

Apolipoprotein C-III↗
PubMed1991

Quantification of serum amyloid P by enzyme-linked immunosorbent assay.

This enzyme-linked immunosorbent assay procedure for quantifying serum amyloid P (SAP) in human plasma makes use of affinity-purified polyclonal antibodies to SAP in a "sandwich"-type format. The procedure is sensitive, reproducible, simple, and easily automatable. Results correlate well with those by a rocket immunoelectrophoresis method performed with the same antibodies. Sera from apparently normal individuals had a mean SAP content of 44.17 mg/L and increased with age.

Adolescent↗
PubMed1990

Lipoprotein particles in homozygous familial hypercholesterolemic patients treated with portacaval shunt and LDL apheresis.

Lipoprotein particles containing apolipoproteins (Apo) were studied by enzyme-linked-immunosorbent assay in two homozygous familial hypercholesterolemic patients (1 male and 1 female) with portacaval shunts, and in controls. Total Apo B, total cholesterol and LDL cholesterol were increased in both patients while complex Apo B containing particles, Lp CIII: B, were not increased in these FH patients. The dextran-sulfate cellulose columns (Liposorber LA-40) had an excellent adsorption selectivity and adsorption capacity for lipoprotein particles containing Apo B and a minimum adsorption capacity in Apo AI and Apo AII-containing particles. This apheresis technique selectively depleted plasma of atherogenic Apo B-containing particles with a minimal loss of antiatherogenic Apo AI-containing particles.

Adolescent↗
PubMed1990

[Application of the immunoenzyme technic in double determination of antibodies for the study of hyperlipoproteinemia].

Antibodies directed against designed apolipoprotein, were absorbed on microtiter plates, the other apolipoprotein present on the retained particles was evaluated by using corresponding peroxidase labeled antibodies. This differential antibody immunosorbent assay was applied to evaluate lipoprotein particles concentration in familial type IIa, IIb, III, IV, and in the type IV secondary to chronic renal failure. Type IIa and IIb, were characterized by the increasing plasma concentration of lipoprotein particles containing both apo B and apo E (LpE-B). Although type IIa have high level of apo CIII, the plasma concentration of lipoprotein containing both apo B and apo CIII was within the normal range. The high concentration of apo E in type III hyperlipoproteinemia, revealed the accumulation of LpB-CIII-E but mainly lipoproteins containing both apo B and apo E (LpE-B). The latter represents 0.94 +/- 0.51 g/l when compared to normolipidemic subjects: 0.29 +/- 0.06 g/l. The decrease concentration of apo AI affects essentially lipoprotein containing apo AI without apo AII (LpAI) in primary type IV hyperlipoproteinemic patients, while in chronic renal failure, both populations of apo AI (with and without apo AII) were affected. The differential antibody immunosorbent assay may be used in the future as a new approach to classify lipid transport disorders.

Apolipoproteins↗
PubMed1989

Antipeptide antibody against the human low-density-lipoprotein receptor. Characterization and cross-reactivity with bovine lymphocytes.

A dodecapeptide corresponding to the external N-terminal sequence of the human low-density-lipoprotein (LDL) receptor was synthesized. Antibodies raised in rabbits against the peptide were purified and were shown to react specifically with the peptide and with human LDL receptor of fibroblasts, HeLa cells and lymphocytes using binding studies and immunoblotting. By indirect immunogold analysis, antibodies bound to the LDL receptor of human lymphocytes could be revealed as clusters. Anti-receptor peptide immunoglobulins specifically bound to the human HeLa cell's LDL receptor with a lower affinity than LDL (Kd x 3). The anti-receptor peptide immunoglobulins and 125I-labelled-LDL competed with each other for the LDL-receptor sites. Antibodies failed to react with lymphocytes of subjects with the homozygous form of familial hypercholesterolaemia. Cross-reactivity with the dodecapeptide of the bovine LDL receptor was limited, but this cross-reactivity was confirmed by the binding of anti-receptor peptide immunoglobulins to the LDL receptor from bovine lymphocytes.

Amino Acid Sequence↗
PubMed1989

Apolipoprotein B immunochemical heterogeneity in dialysed patients with chronic renal failure and patients with coronary artery stenosis.

Serum cholesterol, triglyceride, apolipoprotein B (apo B) and the cholesterol and phospholipid content of apo-B-containing particles was determined in 41 male patients on dialysis for chronic renal failure, in 41 male patients with coronary artery disease selected on the basis of a total cholesterol level below 6.72 mmol/l and in 41 male control subjects of similar age. Apo B was assessed as total B protein determined using polyclonal antibodies and also by measuring the expression of epitopes recognized by three different monoclonal antibodies (BL3, BL5 and BL7). Triglyceride was increased (p less than 0.01) and cholesterol was decreased (p less than 0.01) in the dialysed patients with chronic renal failure. Total apo B was similar in the three tested groups while the expression of the BL7 epitope was increased in the group of dialysed patients with chronic renal failure (p less than 0.001). The expression of BL3 and BL5 epitopes was increased in patients with coronary artery disease (BL3: p less than 0.05; BL5: p less than 0.02) but not in dialysed patients with chronic renal failure. These results suggest an abnormal composition and an immunological heterogeneity of apo-B-containing lipoprotein particles in patients with coronary artery stenosis and in dialysed patients with chronic renal failure.

Antibodies, Monoclonal↗
PubMed1988

Antibodies of predetermined specificity to apolipoprotein C-II elicited with a synthetic peptide. Characterization and use for immunoassays.

Antibodies of predetermined specificity raised against a synthetic peptide corresponding to the C-terminal region of apolipoprotein C-II (Apo C-II) 63-79 were shown to be specific for the apolipoprotein by Western blot. The recognition by these antibodies of Apo C-II containing lipoprotein particles (both isolated and in plasma) was studied in a fluid-phase radioimmunoassay and the affinity constant for plasma was determined. The role of lipids in the expression of epitopes was studied by comparing the antigenicity of intact and delipidated Apo C-II containing fractions. The antibodies proved to be as suitable as conventional anti-protein antibodies in an immunoenzymometric assay and, moreover, were able to develop 'rockets' in an electroimmunoassay.

Antibodies↗
PubMed1988

Lipoprotein abnormalities in chronic haemodialysis patients.

Measurement of lipids, apolipoproteins A-I, A-II, B, C-III, Lp(a) and cholesterol, phospholipids, apo C-III in lipoprotein with and without apolipoprotein B was made in 49 patients (18 women and 31 men; mean age 50 +/- 15 years) undergoing maintenance haemodialysis for chronic renal failure. A group of 49 healthy people, matched for sex and age, acted as controls. In the haemodialysis group, special attention was placed upon the comparison of patients who had evident cardiovascular alterations (n = 17) with the residual group (n = 32). The concentration of apo C-III in apolipoprotein B containing lipoproteins was statistically higher in the patients with arterial disease than in the remaining subjects, whereas the ratio apo C-III from Lp no B/apo C-III from Lp B was decreased. Compared to controls, haemodialysis patients had significantly higher values of triglycerides, apolipoproteins C-III, Lp(a), and apolipoprotein C-III from apolipoprotein B-containing lipoproteins (LpB); in contrast, concentrations of phospholipids and cholesterol from lipoproteins without apolipoprotein B (Lp no B) and apolipoprotein A-II were significantly reduced in patients. Discriminant analysis indicated that the levels of apolipoprotein C-III and apolipoprotein C-III from LpB were the best indicators of deranged lipid transport in patients with chronic renal failure. Our data suggest that chronic haemodialysis patients tend to exhibit qualitative abnormalities of serum apolipoprotein-B triglyceride rich particles containing apolipoprotein C-III or (a).

Adolescent↗