Biomedical subjects

W van der Pol

Publications and source records attributed to W van der Pol.

3 recordsLinked to original sources

PubMed2000

Pneumococcal capsular polysaccharide-specific IgA triggers efficient neutrophil effector functions via FcalphaRI (CD89).

Specific anti-capsular polysaccharide IgG is believed to be important for protection against infection by Streptococcus pneumoniae. Significant IgA responses have been observed after vaccination with pneumococcal vaccines, but the role of this isotype in anti-pneumococcal host defense is unclear. Here, it is shown that purified serum IgA specific for pneumococcal capsular polysaccharides can initiate efficient cellular effector functions, such as phagocytosis, via interaction with the myeloid IgA receptor, FcalphaRI (CD89). The efficiency of FcalphaR-triggered granulocyte effector functions was comparable to that of FcgammaRIIa (CD32), as shown in experiments with bispecific antibodies. These results support a role for polysaccharide-specific IgA in antipneumococcal cellular effector function and suggest that FcalphaRI represents an important leukocyte receptor for immunity against S. pneumoniae.

Antibodies, Bacterial↗

PubMed1998

IgG receptor polymorphisms: risk factors for disease.

Two groups of receptors for immunoglobulin G (FcgammaR) can be distinguished. Endothelial cells and placental syncytiotrophoblasts express an MHC class I-like FcgammaR important for regulation of IgG half-life and IgG transport, respectively. FcgammaR expressed on leukocytes constitute a heterogeneous family of membrane bound and soluble proteins. The various FcgammaR (sub) classes of this family differ in ligand affinity and specificity, which is determined by primary structure, glycosylation, association with signaling subunits, and environmental factors (such as serine proteases). The finding that polymorphisms of FcgammaRIIa, FcgammaRIIIa, and FcgammaRIIIb critically affect interaction with antibodies has prompted analysis in patients which provided tantalizing evidence for the relevance of FcgammaR polymorphisms as risk factors for a number of infectious and autoimmune diseases.

Antibodies, Monoclonal↗

PubMedDate not supplied

Identification of diuron and four of its metabolites in human postmortem plasma and urine by LC/MS with a moving-belt interface.

Unknown compounds that were not amenable to GC/MS were found during routine benzodiazepine HPLC screening in a postmortem case. The apparent thermolability made the application of liquid chromatography with mass spectrometry mandatory. The moving-belt interface was used because of its value for identification based on the use of both electron impact and chemical ionization, which provided information on both structure and molecular weight. The herbicide diuron and four of its metabolites were identified in plasma and urine and had a total concentration as high as 100 mg/L. Metabolism via demethylation and hydroxylation appeared to be the major routes.

Chromatography, High Pressure Liquid↗