Search PubMed⌕ Search

Biomedical subjects

D Roelcke

Publications and source records attributed to D Roelcke.

At least 91 records · Page 5Linked to original sources
PubMed1982

Rapid detection of Treponema pallidum and cytomegalovirus specific IgM antibodies with the passive haemagglutination.

For the detection of Treponema pallidum-specific IgM antibodies in patients' serum samples four simple and rapid methods are compared and evaluated. They show decreasing sensitivity and specificity in the row listed: (1) Treponema pallidum haemagglutination (TPHA) after IgM separation by affinity chromatography on controlled-pore glass heads (anti-IgM-CPG), or (2) by ion exchange chromatography on DEAE-cellulose; (3) solid-phase haemagglutination (SPHA) in glass microvials or (4) on polysterene microplates. The latter tests have found to be inferior, although they can be considerably improved by the use of affinity chromatography--purified catch antibodies. The commercially available DEAE-cellulose microcolumn delivers a simple method for IgM separation, and in spite of a relatively high IgA contamination it proved to be useful also for CMV-specific IgM haemagglutination tests, as compared to ELISA results.

Antibodies, Bacterial↗
PubMed1981

New antigenic determinant (Sa) on human lymphocytes and phagocytes.

Presence of antigenic determinants reacting with homogeneous IgM/kappa cold agglutinin (CA) of a new specificity, tentatively called Sa, was investigated by bithermic cytotoxicity assay and by immunofluorescence. CA Sa killed on average 38% allogeneic peripheral blood lymphocytes (PBL) and up to 74% of autologous PBL. There was preferential kill of B-PBL compared to T-PBL. Some preference toward B cells was also noted using tonsillary B and T lymphocytes. Cytotoxic activity of CA Sa against chronic lymphocytic leukemia cells of B-type was almost equal to that of potent anti-I CA and much stronger than anti-i CA. Presence of additional B-cytotoxic factor in the serum was excluded by the use of red blood cell eluate composed solely of homogeneous CA. Thymocytes and helper-type T cells from a patient with T cell chronic lymphocytic leukemia were very susceptible to the cytotoxic action of Sa. CA Sa killed 39% of monocytes, but there was almost no kill of polymorphonuclear leukocytes. Lymphocytotoxicity of CA Sa was abolished by sialyllactose and was not influenced by I-active glycoproteins. Comparison of CA Sa to CA of other specificities showed marked differences, supporting the view that Sa has new, previously unrecognized specificity.

Aged↗
PubMed1981

A further cold agglutinin, F1, recognizing a N-acetylneuraminic acid-determined antigen.

A cold agglutinin, F1, reacted with an erythrocyte antigen, which was inactivated by neuraminidase. It resembled anti-I antibodies in reacting more strongly with erythrocytes of adults than with cord blood cells. However, unlike I, this 'new' antigen is destroyed by neuraminidase treatment. This antigen is also distinct from Pr, Gd and Sa type antigens which are equally expressed on cord and adult erythrocytes.

Aged↗
PubMed1981

[Determinations of immunoglobulin from the blood of the umbilical vein after pathological course of pregnancy and in foetal growth retardation (author's transl)].

Serum-IgM and serum-IgA concentrations of 561 unselected samples of umbilical cord were determined by the radial immunodiffusion method (Mancini's technique). The mean IgM value of all blood samples was 13.8 mg%. In 9.9% of all cases only we found measurable IgA values, the average IgA concentration being 4.5 mg%. Elevated IgM values (greater than 30 mg%) - pointing to an intrauterine infection - were found to be more frequent (12.1%) in foetal of growth retardation than with newborn of normal body weight, where the incidence of increased IgM values was 5.5% of the examined cases only (however, without a statistically significant difference). In preceding infections during pregnancy, elevated IgM values (greater than 30 mg%) were also found more frequently than in cases without infections (11.8% vs. 5.7%, respectively). Basing on these results, we can suspect that intrauterine infection is one of the possible causes of foetal growth retardation, but not one of the main ones.

Adult↗
PubMed1980

[Improvement of symphilis screening in blood donors by TPHA test (author's transl)].

The introduction of the TPHA test in syphilis screening of blood units donated at the Heidelberg University blood bank resulted in an increase of positive test results from 0.16 precent to 0.64 percent at the first donation. Due to the high specificity of the TPHA and (FTA-Abs) test the number of doubtful and unspecific reaction results was significantly reduced. The result "TPHA and CMT reactive" indicates syphilis to be treated. From 1967--1978 this figure (0.06%--0.07%) has remained unaltered, indicating that the incidence of syphilis among blood donors has not increased. Using the TPHA test it was possible to detect blood donors with a history of syphilis, a group which could not be identified in the past. It is characterized by the reaction pattern "TPHA reactive, CMT not reactive" and is three times as frequent among our donors as the seroreactive group identified by CMT only. If fresh or unsufficiently treated cases of syphilis can be excluded, these results indicate that the individual has had a syphilis sometimes in the past. Application of the TPHA test in blood donor care reduces the risks of blood transfusion and improves the control of venereal diseases as required by law.

Blood Donors↗
PubMed1980

Failure of IgA cold agglutinin to activate C.

No complement (C) activation was observed when IgA cold agglutinin was reacted with its antigen on RBC. Neither C-consumption (CH50) nor C1 binding (classical pathway) nor conversion of factor B or C3 (alternative pathway) could be detected. In contrast, IgM cold agglutinins under the same conditions did activate the classical pathway. If the IgA was heat aggregated it was able to activate the alternative pathway as evidenced by factor B and C3 conversion. The result is consistent with the absence of in vivo hemolysis in patients with IgA cold agglutinins.

Autoantibodies↗
PubMed1980

A new human monoclonal cold agglutinin Sa recognizing terminal N-acetylneuraminyl groups on the cell surface.

A human homogeneous IgM/K cold agglutinin (CA) Sa is described, whose corresponding antigen on erythrocytes (RBC) was abolished by neuraminidase. This indicated that the antigen was related to N-acetylneuraminic acid, similar to Pr and Gd antigens. In contrast, this antigen was only partially destroyed by proteases, whereas Pr antigens are completely destroyed and Gd antigens are not influenced by proteases. Sa antibody activity was inhibited by sialyllactose NeuAc (alpha 2 leads to 3) (alpha 2 leads to 6) Gal (beta, 1 leads to 4) Glc like anti-Gd but in contrast to anti-Pr. The corresponding antigen was associated with an RBC membrane glycoprotein fraction like Pr, Sa is one of a spectrum of human monoclonal CA against cell surface neuraminyl groups.

Aged↗
PubMed1979

Human cold agglutinins against "cryptic" erythrocyte antigens.

Two examples of human IgM cold agglutinins agglutinated human RBC only after enzyme treatment in vitro. Proteases were optimally effective, neuraminidase was also effective. The cold agglutinins did not coat native RBC but were directed against "cryptic" RBC determinants. The cold agglutinins belonged to the anti -I/-i complex indicating a "new" type of I/i determinants. They were strongly accessible to cold agglutinin interaction on native RBC of a patient with congenital dyserythropoietic anaemia. Enzyme treatment of RBC was shown to be not only suited for defining cold agglutinin specificities but also essential for detecting the "new" type of cold agglutinins, obviously causing autoimmune haemolytic anaemia in vivo.

Aged↗
PubMed1979

The Lewis antigen system and its relevance for clinical transplantation.

The influence of the Lewis blood group system on transplant survival was studied retrospectively in 161 kidney transplantations. Le (a-b+) recipients had significantly higher graft survival rates than Le (a+b-) or Le (a-b-) recipients. From the known distribution of the Lewis blood groups among the European population, a high percentage of Lewis-compatible transplants would be expected among Le (a-b+) recipients in contrast to the Le (a+b-) and Le (a-b-) recipients. Other factors which are known to influence transplant prognosis such as HLA-match between donor and recipient, ischemic time of the transplants and pretransplant blood transfusions did not differ significantly in any of the three groups studied. Our data again suggest the relevance of the Lewis blood group system for clinical kidney transplantation. The findings should be confirmed by prospective typing of donor and recipient for Lewis antigens.

Graft Survival↗
PubMed1979

Influence of the Lewis blood group system on clinical kidney transplantation.

The different Lewis phenotypes were determined retrospectively in 201 kidney transplant recipients. Transplant survival rates in Lewis compatible recipients were significantly higher (p less than 0.0005) than in Lewis incompatible recipients. The improvement of transplant prognosis by matching for Lewis antigens was confirmed by a prospective study comprising 55 donor/recipient combinations. HLA matching had little benefit on transplant survival whereas survival rates are strikingly increased by Lewis compatibility. In the Lewis compatible but HLA mismatched group, graft survival was definitely higher than in the HLA matched but Lewis mismatched group. Our data indicate that Lewis antigens play an important role in transplant prognosis. Compatibility in the Lewis system should therefore be considered when recipients are selected.

ABO Blood-Group System↗
PubMed1978

Variable-region subgroup and specificity of cold agglutinins.

The variable-region subgroup determined by amino acid sequence analysis of heavy and light chains of two monoclonal cold agglutinins with the new anti-Gd specificity is reported. Both proteins belong to the VHIII subgroup of heavy chains; one light chain falls into the V kappaI subgroup, the other has a blocked N-terminus which so far has not been observed in human kappa chains. The comparison of anti-Gd with anti-I/-i or anti-Pr cold agglutinins indicates that anti-Gd differs from other cold agglutinins with respect to variable-region subgroup. The data extend previous findings on the restriction of certain antibodies to distinct variable-region subgroups.

Agglutinins↗
PubMed1978

Inhibition of human anti-Gd cold agglutinins by sialyllactose.

Two examples of IgM kappa-monotopic cold agglutinins occurring in patients with non-Hodgkin lymphomas, reacted with erythrocyte autoantigens, which were protease-resistant but were inactivated by neuraminidase. The cold agglutinins were inhibited by the trisaccharide sialyllactose [NeuNAc(alpha,2 leads to 3) Gal (beta, 1 leads to 4)Glc], which is not related to oligosaccharides known to inhibit anti-I/-i cold agglutinins, Anti-Pr cold agglutinins are not inhibited by sialyllactose, although N-acetylneuraminic acid (NeuNAc) is an essential component not only of Gd but also of Pr determinants. Gd determinants are not bound to erythrocyte membrane glycoproteins, but are apparently bound to membrane glycolipids (gangliosides).

Agglutinins↗
PubMed1978

Identification of I/i, Pr1-3 and Gd antigens in the human kidney: possible relevance to hyperacute graft rejection induced by cold agglutinins.

Human cold agglutinins (CA) with I/i, Pr1--3 and Gd specificities were tested for reactivity against kidney tissue by immunofluorescent techniques. I/i antigens were found on the epithelia of the Henle's loops and distal tubules. Pr1--3 antigens were demonstrated on the glomerular capillaries. Gd antigens were localized on the endothelia of the glomerular and peritubular capillaries as well as in the kidney interstitium. From these results, it is suggested that hyperacute rejection of renal transplants in recipients with high-titre CA may not only be caused by intravascular erythrocyte agglutination but also by direct cytotoxic damage of the transplant. Since CA occur frequently in potential kidney recipients, pre-operative determinations of CA in these patients should be recommended.

Adult↗