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Biomedical subjects

J A van der Donk

Publications and source records attributed to J A van der Donk.

9 recordsLinked to original sources

The histocompatibility complex GLA in the goat.

The current status of research on the major histocompatibility complex of the goat (GLA) is discussed, as well as its similarities to other species, although some of the results are preliminary.

Alleles

Common precursor molecule as origin for the ectopic-hormone-producing-tumour syndrome.

When messenger R.N.A. (m-R.N.A.) extracted from various hormone-secreting tumours was injected into Xenopus eggs, the translation products in all cases proved to be a protein of molecular weight 65 00. Analysis by polyacrylamide-gel electrophoresis and specific precipitation reactions with antibodies showed a striking similarity between the various proteins. When translation products of m-R.N.A. from calcitonin-secreting medullary thyroid carcinoma (M.T.C( and the non-secreting anaplastic form of M.T.C. were incubating with specific enzyme systems (the microsomal fraction) from both types of tumour, enzymes from anaplastic M.T.C. had no effect on the translation products, whereas enzymes from differentiated M.T.C. degraded the translation products from both differentiated and anaplastic M.T.C. The results support the hypothesis that the primary gene product of all the different types of carcinoma cell studied is a single large protein (a hormone precursor or prohormone) containing different specificities. The specific enzyme system in each carcinoma cell probably selects the specific hormone liberated from this primary protein.

Adenocarcinoma

Protein A reactivity of various mammalian immunoglobulins.

Serum samples and immunoglobulin fractions of eight mammalian species were applied to a Sepharose--protein A column. As with the human immunoglobulin subclasses IgG1, IgG2 and IgG4, all examined IgG classes and subclasses were bound to a greater or lesser extent to protein A. However, the binding of IgG1 of ruminants was very poor. Polyclonal IgM and IgA of the pig, the dog and the cat may be separated in protein A reactive and protein A non-reactive fractions. In addition, monoclonal canine IgM and IgA partially reacted with protein A. In combination with methods such as ammonium sulphate precipitation, ion exchange chromatography and gel-filtration, affinity chromatography with protein A is recommended for the rapid purification of certain Ig (sub)classes of a number of mammalian species.

Animals

Skin grafting and graft rejection in goats.

As part of a study to define the major histocompatibility complex of the goat and to show certain aspects of its biological function, a skin-grafting technique is described which might also be applicable for similar studies in other ruminant species.

Animals

Quantification of turkey immunoglobulins IgA, IgM and IgG in serum and secretions.

The immunoglobulins IgA, IgM and IgG of the turkey were quantitated in individual serum samples as well as in pooled sera. The variability of Ig levels in normal, healthy birds was quite high: IgA: mean value 0.633 mg/ml (4.0 -x - 2.5 -x); IgM: mean value 4.37 mg/ml (0.5 -x - 1.4 -x) and IgG: mean value 8.92 mg/ml (0.6 -x - 1.7 -x). Immunoglobulin levels in egg-yolk, egg-white, bile and some intraocular tissues were quantitated as well. An interesting finding was, that the forementioned variability was by far not so high with respect to IgG levels in 20 egg-yolk samples: mean value 5.1 mg/ml (0.86 x- - 1.17 -x). Though IgG and IgM could be detected in pooled turkey bile, IgA predominated in this secretion. In aqueous humor, iris tissue and vitreous body only IgG could be detected.

Animals