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W Huisman

Publications and source records attributed to W Huisman.

28 records · Page 2Linked to original sources
PubMed1980

Interference of imferon in colorimetric assays for iron.

Imferon (Merrell-National), an iron-dextran complex, is widely used in patients with iron deficiency. It is present in the circulation in appreciable amounts for two to three weeks after administration and interferes with all tested colorimetric iron assays, both with and without deproteinization. The amount of the plasma Imferon iron interference depends primarily on the choice of reductant. With dithionite it is essentially 100%. In the presence of ascorbic acid and hydroxylamine, the interference depends also on assay conditions, especially temperature, but also incubation time and pH. The minimum interference in a homogeneous assay was about 3%. The relative amount of interference from hemoglobin iron under the various assay conditions is different from that of Imferon iron. In the presence of a reducing agent, the dextran-iron complex decomposes--instantaneously with dithionite, and gradually with sulfite, ascorbic acid, and hydroxylamine. The freed iron becomes dialyzable, can react with bathophenanthroline, and elutes on a Sephadex G-50 or G-15 column in the same fractions as an ammonium ferrous sulfate.

Ascorbic Acid↗
PubMed1970

The regulation of synthesis and storage of chymotrypsin inhibitor I in leaves of potato and tomato plants.

The synthesis and accumulation of chymotrypsin inhibitor I in tomato leaflets is induced by detachment, or by destruction of petiole phloem by steam when followed by incubation of the leaflets in light. The induction process with detached tomato leaflets is similar to that found with detached potato leaflets. The large amount of inhibitor I synthesized per leaflet cell per unit time suggests either that the structural gene is redundant or that an unusually stable messenger RNA is present. In both tomato and potato leaflets the accumulation of inhibitor I is potently inhibited by actinomycin D, puromycin, and cycloheximide, but not by chloramphenicol. Indoleacetic acid is moderately inhibitory, as is 3-(3,4-dichlorophenyl)-1,1-dimethylurea. Glutamine and asparagine are both markedly stimulating. The cumulative data suggest that inhibitor I is a major depot or interim storage protein and that its existence in any particular tissue is under complex controls by both the internal and external environments of the plants.

Chymotrypsin↗
PubMedDate not supplied

Feline immunodeficiency virus subunit vaccines that induce virus neutralising antibodies but no protection against challenge infection.

Three experimental vaccines against feline immunodeficiency virus (FIV), all based on viral antigens presented via immune stimulating complexes (iscoms), were tested for their capacity to induce protection in cats from FIV infection. The respective vaccines consisted of FIV propagated in Crandell feline kidney (CrFK) cells (FIV-iscoms); FIV-iscoms spiked with recombinant vaccinia virus expressed FIV envelope glycoprotein incorporated into iscoms (FIV-iscoms + vGR657x15-iscoms) and vGR657x15-iscoms spiked with recombinant FIV Gag protein incorporated into iscoms (vGR657x15-iscoms + FIV-Gag-iscoms). Simian immunodeficiency virus envelope glycoprotein incorporated into iscoms, iscoms prepared with uninfected CrFK cells, and PBS served as controls. All cats vaccinated with vGR657x15-iscoms combined with FIV-iscoms or FIV-Gag-iscoms developed Env-specific plasma antibody responses. These antibodies neutralised FIV infection in CrFK cells, but failed to neutralise FIV infection in primary feline thymocytes. FIV-iscoms induced poor Env-specific responses and only one out of six cats developed antibodies that neutralised FIV in the CrFK cell based assay. Four weeks after challenge all cats proved to be infected, showing that none of the vaccine preparations provided protection. In contrast, 2 weeks after infection, virus infected peripheral blood mononuclear cells were only observed in cats vaccinated with FIV-iscoms + vGR657x15-iscoms or CrFK-iscoms and to a lesser extent in cats vaccinated with FIV-iscoms and vGR657x15-iscoms + FIV-Gag-iscoms, but not in cats vaccinated with SIV-iscoms or PBS. The differences found in cell associated virus loads amongst the respective groups are discussed in the light of antibody mediated enhancement of infectivity and protective effects provided by Gag-specific T cell responses.

Animals↗