PubMed Health⌕ Search

Biomedical subjects

D Raichvarg

Publications and source records attributed to D Raichvarg.

85 records · Page 5Linked to original sources
PubMed1979

[Comparative study of digoxin determination by E.L.I.S.A. and radioimmunoassay techniques (author's transl)].

This study is based on a double blind interlaboratory comparison between radioimmunoassay and E.L.I.S.A. digoxin determination. The correlation between digoxin values found with these two methods is good (r = 0.96 for therapeutic and toxic ranges 1,0 ng/ml - 5,5 ng/ml). The results indicate good repeatability, reproducibility and precision. The determination by E.L.I.S.A. can be performed with sera or plasma. The presence of haemolysis makes no appreciable difference in results. No variation is observed when different kits are used from an identical lot. However digoxin gives an important cross reactivity with digitoxin in Enzymeimmunoassay. Therefore it is necessary to know exactly the digitalis glycoside before the determination in order to avoid significant error.

Digoxin↗
PubMed1979

[Estimation of serum lipids: method without extraction adapted to autoanalysis (author's transl)].

An entirely automatic method, without prior extraction, is described for the determination of total serum lipids by a nephelemetric method. The results are compared with those obtained by Canal's method. There is a good correlation between the two technics. With a similar concentration of lipid the respective quantities of cholesterol and triglyceride do not intervene in the flocculation. The respective influence of the bilirubin concentration, hemolysis, and the concentration and nature of the serum proteins is considered. This method should permit simultaneous autoanalysis of the three parameters of classical lipid investigation: total lipids, triglycerides and cholesterol.

Autoanalysis↗
PubMed1978

[Demonstration and semi-automatic assay of gelatin in serum].

We suggest a semi-automatic method for the determination of gelatin. The measured concentration of gelatin is not dependant for the amino-acid composition of that plasma substitute preparation. Plasmatic proteins are separated previously from gelatin by precipitation using trichloracetic acid (5 p. cent; vol/vol). Modified gelatin lower in molecular weight than proteins can be found in the supernatant. It is determined by Lowry method with an automatic continuous flow system. Standardization must be realized using gelatin's solution since the developped coloration intensity with proteins is stronger. At electrophoresis, gelatin migrates essentially towards beta-globulins. beta-globulins increased with the gelatin level in serum. Percentage of variation for beta globulins and other fractions must be determinated in function of the protein level before perfusion. So it is possible to study the percentage of variation of these electrophoretic fractions independantly of the altered protein level.

Autoanalysis↗
PubMed1975

[Lymphocytes. Roles in cellular immunity and humoral immunity].

The lymphocytes are now considered as ubiquitous cells which play a role in delayed hypersensitivity, the rejection of grafts and antibody synthesis. The lymphocytes are essential in the immune process, for they may both recognise the antibody and initiate the response. They act either by themselves or after differentiation into specialised cells and, usually, in coordination with other cells with phagocytic functions. After briefly recalling the morphology, localisation, circulation, sites of production and heterogeneity of the lymphocytes, the authors discuss their function, describe lymphocytic transformation, and the role of T lymphocytes in delayed hypersensitivity, in the rejection of grafts and the direct cytotoxic effect. Antibody synthesis with B lymphocytes and the intervention of mononucleated cells with phagocytic activity, the cooperation of T lymphocytes are developed. The exploration of lymphocytic functions includes the recognition of an antigen by the lymphocyte, fixation of marked antigens, rosette formation, the demonstration of delayed hypersensitivity (inhibition of macrophage migration, cytotoxicity, skin tests), the estimation of antibodies and measurement of lymphocyte transformation. Certain factors, due to antigen-host reaction, regulate the lymphocytic immune reaction. One may experimentally intervene by immunostimulation and immunosuppression.

Antibody Formation↗
PubMedDate not supplied

Direct phenotyping of human apolipoprotein E in plasma: application to population frequency distribution in Paris (France).

Apolipoprotein E (Apo E) is a component of VLDL and HDL and plays a significant role in the regulation of cholesterol concentration. An improvement in isoelectric focusing for Apo E phenotyping is presented: the plasma Apo E was dissociated from lipoproteins by the use of Tween 20; the optimal concentration of type V neuraminidase was determined (1 U/ml); up to 48 samples were analyzed per plate and revealed by immunoblotting. Using this method, we have determined Apo E phenotypes and estimated their association with total cholesterol and Apo B levels in 498 healthy blood donors in Paris (France). The relative frequencies of Apo E alleles epsilon 2, epsilon 3 and epsilon 4 in this population were 0.079, 0.801 and 0.120, respectively. The association between Apo E phenotypes and concentration of Apo B-containing lipoproteins was confirmed (Apo B (g/l): E4/E3 subjects, 1.10 +/- 0.29; E3/E2 subjects, 0.93 +/- 0.22; both significantly different from E3/E3 subjects, 0.99 +/- 0.28). Total cholesterol (mmol/l): E4/E3 subjects, 5.43 +/- 1.15; E3/E2 subjects, 4.79 +/- 0.83; both significantly different from E3/E3 subjects, 5.03 +/- 1.11.

Adult↗
PubMedDate not supplied

Effect of recombinant human interleukin-1 beta and tumor necrosis factor alpha on liver cytochrome P-450 and serum alpha-1-acid glycoprotein concentrations in the rat.

Two hepatocyte-related effects of recombinant human interleukin-1 beta and tumor necrosis factor alpha alone or in association were tested following iv administration to Fischer 344 rats. Within 24 hr, both monokines induced a dose-dependent decrease in cytochrome P-450 levels, whereas serum alpha-1-acid glycoprotein concentrations were strongly increased. The largest variation of both parameters was observed using a combination of the two monokines. Dexamethasone, which possesses anti-interleukin-1 properties and is known to stimulate alpha-1-acid glycoprotein synthesis in rats, also depressed cytochrome P-450 levels, suggesting that alpha-1-acid glycoprotein might mediate the monokine-related inhibition of drug metabolism. Nevertheless, at the lowest doses of monokines tested, only cytochrome P-450 levels were modified. The transfer of a post-dexamethasone serum to normal rats did not change cytochrome P-450 levels.

Animals↗
PubMedDate not supplied

Blood polymorphonuclear behavior in patients with ankylosing spondylitis.

The oxidative metabolism and chemotaxis of polymorphonuclear leukocytes (PMNs) collected from patients with ankylosing spondylitis and healthy subjects were studied in parallel. The responses to opsonized zymosan were significantly lowered considering oxygen consumption and release of superoxide anions, whereas no modification of these parameters to phorbol myristate acetate and calcium ionophore (A 23187) stimulations were observed. A seric factor was not involved but the characterization of a specific intrinsic abnormality of the PMNs needs further investigations. PMN chemotaxis, assessed by two methods performed in parallel, remained unchanged.

Adult↗
PubMedDate not supplied

Type IV hyperlipoproteinemia in patients with algodystrophy.

The present work studies lipid metabolism in patients with algodystrophy (AD). A correct positive correlation (r = 0.75) between the triglyceride levels and low density lipoprotein (LDL)/very low density lipoprotein (VLDL) ratio and the VLDL increase observed by gel disk electrophoresis confirm that a type IV hyperlipoproteinemia is associated with AD. In contrast, the degree of high density lipoprotein (HDL) saturation in cholesterol (HDL-cholesterol/HDL-phospholipids) and the classical atherogenous index (cholesterol/HDL-cholesterol) were not modified. The decrease of plasma post-heparin lipolytic activities (PHLA) was not significant but further studies should be performed to correlate PHLA with a reduced activity of the adipose tissue lipoprotein lipase.

Cholesterol↗
PubMedDate not supplied

Superoxide dismutases in polymorphonuclear leukocytes from patients with ankylosing spondylitis or rheumatoid arthritis.

The activity of cyanide-sensitive and cyanide-insensitive superoxide dismutase (CNs- and CNi-SOD) was measured in polymorphonuclear neutrophils isolated from the blood of patients with ankylosing spondylitis (A.S.) or adults with rheumatoid arthritis (R.A.). Our purpose was to detect alterations in the protecting activity of these enzymes that might cause rheumatic lesions secondary to superoxide anion generation in the inflammatory loci. There was no difference in total SOD activity (CNs + CNi) in either A.S. or R.A. when compared to the control group. In contrast, CNi-SOD activity decreased in R.A. and A.S. and CNs-SOD activity rose significantly in A.S. only. None of the changes observed in SOD activity correlated with patient's age, erythrocyte sedimentation rate, clinical evolution of the disease or the drug doses administered. It is concluded that the reduced activity of CNi-SOD might be partly responsible for the reduced protection of the joints against oxygen-free radicals in patients with A.S. or R.A. Other factors however appear to have greater effects on the clinical evolution of these diseases.

Arthritis, Rheumatoid↗
PubMedDate not supplied

[A colorimetric method for the evaluation of phagocytosis by mouse peritoneal macrophages (author's transl)].

In this study, a technique for the evaluation of circulating leukocyte phagocytosis has been adapted to mouse peritoneal macrophages. This quantitative determination was performed by the spectrophotometric measurement of the reduced nitroblue tetrazolium (NBT) fixed on bacteria or latex spherules. Capacity of phagocytosis was thus correlated with the intensity of the NBT intracellular reduction by macrophages. This method is technically simple and requires no expensive materials. The phagocytosis of latex did not significantly differ, neither in the presence of autologous or heterologous serum (X +/- G = 0.100 +/- 0.014/2.5 X 10(6) cells) nor in the absence of serum (X +/- G = 0.088 +/- 0.007/2.5 X 10(6) cells). The use of macrophages suspended in the culture medium highly decreased the phagocytic activity (X +/- G = 0.021 +/- 0.002/2.5 X 10(6) cells) and confirmed thus the role played by the support in endocytosis. A specific antiserum weakly enhanced the phagocytic process for Escherichia coli. The mean values with and without serum were 0.065 +/- 0.005/2.5 X 10(6) cells and 0.050 +/- 0.005, respectively. Heating of the serum (56 degrees C, 30 min) and inhibition of both complement activation pathways by EDTA showed that complement plays the major role in this weak enhancement of bacterial phagocytosis by peritoneal mouse macrophages. Bacterial phagocytic stimulation of macrophages was not induced by addition of CA+++ or Mg++ into the culture medium.

Animals↗
PubMedDate not supplied

[Enzyme-immuno assay for total estrogens and human placental lactogen. Comparison with radio-immuno-assay in normal pregnancy-monitoring (author's transl)].

The concentrations of estrogens (E) and human placental lactogen (HLP) are estimated in sera by radio immuno-assay (RIA) and enzyme-immuno-assay (EIA). Statistical data indicate mean intra-assay variation coefficients of 7% and 12% for E and HLP tests, respectively. The correlation coefficient (RIA/EIA) are found higher than 0,9% for both hormonal assays. The dilution curves obtained by RIA and EIA are similar. However, Student'test gives a significant difference for E determination. In fact, total E and E 3 only are measured by EIA and RIA, respectively. In most cases biological interferences are negligible except for HLP in presence of higher protein or haemoglobin levels. RIA and EIA are performed to study serum HLP and E levels throughout normal pregnancies. Results allow to use EIA for HLP and E evaluations in pregnancy-monitoring.

Adolescent↗