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Biomedical subjects

B Teisner

Publications and source records attributed to B Teisner.

At least 163 records · Page 9Linked to original sources
PubMed1982

Influence of time, temperature and coagulation on the measurement of C3, C3 split products and C4.

Quantitative and qualitative immunoelectrophoretic analyses of circulating C3, C3 split products and C4 were performed in matched EDTA plasma and serum obtained from 5 normal subjects and stored for up to 48 h at room temperature (18 degrees C-22 degrees C) and 4 degrees C. Fluctuations in apparent levels of C3 were greater in serum than plasma stored at room temperature, a fall in levels seen by 24 h being followed by a significant increase. By contrast, levels of C3 did not alter if stored at 4 degrees C. C4 levels in both EDTA plasma and serum remained unchanged for 24 h, a slight decrease being seen at 48 h. Levels of C4 remained constant if samples were stored at 4 degrees C. Crossed immunoelectrophoresis revealed a significant progressive decrease in C3 levels and a simultaneous increase in C3c occurring after 4 h in serum and 8 h in EDTA plasma, stored at room temperature. In studies conducted at 4 degrees C, similar but delayed fluctuations were seen. A progressive and significant increase in C3d levels was seen in both plasma and serum samples stored at room temperature, levels rising to 276% (plasma) and 308% (serum) of levels seen at zero time. At 4 degrees C marginal increases in C3d levels only were observed. These results suggest that in vitro degradation of C3 and C4 are readily facilitated by temperature, time and coagulation, and that conditions of collection and storage of samples must be optimized for the accurate definition of activation of the complement cascade.

Adult↗
PubMed1982

Pregnancy specific beta 1-glycoprotein (SP1) conversion of SP1 beta to SP1 alpha by "acidification": an artefact.

Late pregnancy serum and plasma were examined in rocket immunoelectrophoresis (RIE) and crossed immunoelectrophoresis (XIE) before and after "acid treatment" (pH 2.5, 10 min). The analysis revealed changes in the precipitation morphology in the majority of circulating proteins extending from the albumin to the gamma-region. In RIE, the precipitation pattern of SP1 was altered, this change being independent of polyethylene glycol. In addition, XIE analysis of SP1 revealed a change in the precipitation morphology with no change in electrophoretic mobility. The results can be explained by non-specific aggregation and denaturation due to "acid treatment", and are therefore unlikely to be of any biological or immunochemical importance.

Acids↗
PubMed1982

Comparative assays in three laboratories of serum specimens containing pregnancy-specific beta 1 glycoprotein with different proportions of the alpha variant.

Following several reports that the alpha component of pregnancy-specific beta 1 glycoprotein (SP1) gives dose-response curves that are flatter than those of the beta component when assayed by radioimmunoassay of the competitive type, a collaborative study was carried out by 3 laboratories to examine whether radial immunodiffusion or rocket immunoelectrophoresis give similar result. Five sera from pregnant women at the 34-39th week of gestation with beta : alpha ratios of 0.8-4.7 were assayed by both the latter methods against either the IARC 78 610 reference preparation of the SP1 Behring standard. When preparations were assayed by rocket immunoelectrophoresis (two laboratories), the dose-response curves were parallel. When preparations were assayed by radial immunodiffusion (two laboratories), parallelism was observed (one laboratory) after the addition of polyethylene glycol, the presence of which is necessary to visualize immune precipitates in which alpha is involved. Discrepancies observed when methodologies such as competitive radioimmunoassay are used, in which there are limited amounts of antibodies, are explained, at least partially, but the fact that the beta component has a greater relative affinity for the antibody as higher concentrations of beta : alpha mixtures are assayed. However, when antibody is present in excess, as in radial immunodiffusion and rocket immunoelectrophoresis, no such difference in affinity seems to occur.

Australia↗
PubMed1982

Demonstration of antigenic determinants specific for the split products of the third complement factor, C3.

Crossed anti-C3c immunoelectrophoresis of a plasma sample with in vivo complement activation revealed a pronounced 'spur' formation towards the cathodic region of immunochemical interaction between native C3 and C3c. In situ absorption of the antibody preparation against C determinants of the 3rd complement factor using fresh normal EDTA plasma as antigen demonstrated the presence of C3 split product specific determinants.

Antibody Formation↗
PubMed1982

Circulating antithrombins in pregnancy.

In a cross-sectional study circulating levels of antithrombins, antithrombin III, alpha 1-antitrypsin and alpha 2-macroglobulin were measured in groups of 20 women before pregnancy, during each trimester and post partum. Blood levels of antithrombin III were significantly lower, alpha 1-antitrypsin higher and alpha 2-macroglobulin no different when compared with those of the non-pregnant and puerperal states. These findings suggest that there may be not only an increase in total antithrombin production, but also a qualitative change in antithrombin 'activity', the principal protein during pregnancy being alpha 1-antitrypsin.

Alpha-Globulins↗
PubMed1982

Circulating C3, C4, and C3 split products (C3c and C3d) during normal pregnancy.

The plasma concentrations of the complement components C3 and C4, as well as the split products C3c and C3d, were measured before, during, and after normal pregnancy. Significantly increased values were observed in the C3 and C3d levels in the second and third trimesters of pregnancy. The level of C4 was not significantly affected by pregnancy and C3c could not be detected using electroimmunoassays. These results suggest that the increased C3 split-product levels observed reflected an increased turnover of native C3 rather than activation of the complement cascade.

Complement C3↗
PubMed1982

Radioimmunoassay for pregnancy-associated plasma protein A.

A specific and highly sensitive radioimmunoassay for determination of pregnancy-associated plasma protein A in human serum is described. The minimum detection limit for this protein was 2.9 micrograms/L. The within- and between-assay coefficients of variation were 4.0 and 4.5%, respectively. The circulating protein was detected within 32 days of conception in eight normal pregnancies and within 21 days in a twin pregnancy. Circulating concentrations in the mother at term were consistently higher (10-fold) than in matched amniotic fluid; none was detected in the umbilical circulation. This protein was also detected in the circulation of patients with hydatiform mole. This assay will permit investigations into the clinical evaluation of measurements of the protein during early pregnancy and trophoblastic disease.

Amniotic Fluid↗
PubMed1981

Specific interaction between placental protein 5 and thrombin.

The affinity of placental protein 5 (PP5) for thrombin was examined by the application of placental homogenate, late pregnancy serum, plasma and amniotic fluid to thrombin-Sepharose column chromatography. A specific interaction between PP5 in these fluids and thrombin was seen, revealing heterogeneity of PP5 with respect to thrombin affinity. Placental homogenate contained non-binding (species I), interacting (species II) and strongly binding (species III) subpopulations of PP5. By contrast, serum contained predominantly the strongly binding form (species III) and a minor proportion of the non-binding form (species I). The interacting form (species II) was the major form in plasma and amniotic fluid. These observations imply that the interacting form (species II) is the dominant form produced by the placenta and secreted into the circulation, but is converted to species III, i.e. high affinity for thrombin during coagulation. These results suggest that PP5 may be involved locally in the regulation of the coagulation system during pregnancy.

Amniotic Fluid↗
PubMed1981

Pregnancy-associated plasma protein A: circulating levels during normal pregnancy.

The development of specific and sensitive electroimmunoassays for a recently identified high molecular weight alpha-2 mobile pregnancy-specific protein (pregnancy-associated plasma protein A, PAPP-A or SP4) is described. These assays have permitted the detection of circulating levels of PAPP-A (10 microgram/L) as early as the fifth week of pregnancy. In all 18 subjects studied, the levels of PAPP-A rose from first detection in the first trimester until delivery at term. The development of these assays now permit the evaluation of PAPP-A measurement as a diagnostic test of early pregnancy and as an index of fetal well-being throughout gestation.

Female↗
PubMed1981

Circulating levels of pregnancy zone protein: normal range and the influence of age and gender.

Serum levels of pregnancy zone protein (PZP) were measured in 506 apparently normal males and 329 normal non-pregnant females, the age range being 18 to 70 years. The estimations of PZP were performed by sensitive radio-rocket-line immunoelectrophoresis. The distribution of the data had a marked positive skew in both sexes which was reduced following logarithmic transformation. Serum concentrations in both men and women were found to increase significantly with advancing age. This increase and the mean concentrations were significantly higher in females.

Adolescent↗
PubMed1981

Double-decker rocket immunoelectrophoresis for direct quantitation of complement C3 split products with C3d specificities in plasma.

A double-decker rocket immunoelectrophoresis (DD-RIE) method for direct quantitation of complement split products with C3d determinants in human plasma is described. The usefulness of the DD-RIE method for monitoring C3 activation has been assessed and compared with conventional crossed immunoelectrophoresis (CIE) for C3c determination in a patient with iatrogenic septic shock and patients with rheumatoid arthritis. In contrast with CIE the DD-RIE method is quantitative by reference to a standard curve based on an internal reference C3d preparation and its sensitivity and assay capacity are superior to CIE. All reagents and antibody preparation are commercially available and the production of standards is easy. No overlapping was observed between C3d values in plasma from healthy persons and patients with active classical rheumatoid arthritis. The DD-RIE is highly suitable for routine use in laboratories of clinical immunology.

Complement C3↗
PubMed1981

Comparison of pregnancy-associated murine protein-1 and human pregnancy zone protein.

Immunological cross-reaction between human pregnancy zone protein (PZP, SP-3, alpha 2-PAG) and pregnancy-associated murine protein-1 (PAMP-1) was demonstrated by countercurrent line immunoelectrophoresis using antibodies against the proteins raised in hens. The levels of PZP and PAMP-1 were measured during pregnancy and found to be very similar in the first half of pregnancy. Both proteins were found to be heterogeneous and separable according to surface properties. It is suggested that the murine PAMP-1 can be used to study the physiology of human PZP.

Animals↗