Biomedical subjects

M Derwahl

Publications and source records attributed to M Derwahl.

39 records · Page 3Linked to original sources

PubMed1989

Slow growth but intense hypertrophy of thyrocytes in long-standing Grave's goitres.

In order to evaluate the relative contribution of true cell replication, in comparison to mere cell hypertrophy, to the notoriously slow growth of toxic Graves' goitres persistently exposed to TSH receptor antibodies and requiring continuous thyrostatic treatment for more than one year, we have determined the fraction of dividing cells in 8 such goitres, using the monoclonal antibody Ki-67. This antibody identifies cells in late G1-, S-, G2- and M-phase. The fraction of Ki-67 positive cells ranged from 0.1 to 4.1% with a mean of 2.3 +/- 1.6. The apparently low absolute number of dividing cells is in full accordance with growth rates observed in multinodular goitres and in benign tumours of thyroidal and non-thyroidal origin. It is compatible with continuous, intense growth stimulation of the gland, particularly since thyrocytes may down-regulate their growth response when exposed to chronic stimulation. The observations account for the clinical observation that goitres, and in particular Graves' goitres, may take years to double their total mass of thyrocytes, whereas cell hyperplasia and functional overactivity (if untreated) continue unabated.

Adult↗

PubMed1987

Direct immunostaining of TSH receptor related autoantibodies in Graves' disease.

Ten thyroid specimens from patients with Graves' disease were investigated immunohistologically with respect to the localisation of thyrotropin (TSH) receptor related autoantibodies. After conventional preparation of formalin-fixed and paraffin-embedded thyroid slices for immunostaining, 3-5 micron tissue sections were incubated with a porcine thyrotropin receptor containing membrane preparation (pTSH-R). The TSH receptor containing membrane fragments bound to the thyroid tissue were revealed with a slightly modified unlabelled PAP technique according to Sternberger, using an antiserum to pTSH-R obtained from immunized rabbits. This technique resulted in a staining of a considerable portion of plasma cells within the lymphoplasmacellular infiltrates of all the Graves thyroids. No staining occurred if for negative control either pTSH-R or its antiserum from rabbit was omitted. In addition, the staining reaction was markedly reduced by pretreatment of pTSH-R with serum from patients with Graves' disease in order to occupy its binding sites for autoantibodies prior to the staining procedure. It is concluded that the staining of the intrathyroidal plasma cells is due to their synthesis of autoantibodies directed against TSH receptor related structures of thyroid epithelia. The results are in keeping with the concept that the thyroid as the target organ itself is the site of autoantibody synthesis in Graves' disease.

Autoantibodies↗

PubMed1987

Evidence of autoimmune pathogenesis in autonomous thyroid adenoma.

Using an immunohistochemical attempt to immunostain thyroid related autoantibodies, 30 specimens of autonomous adenomas of the thyroid were investigated. Twelve out of 23 inflammatory infiltrates surrounding the 'hot' nodules contained plasma cells, which gave a positive staining reaction for thyroid related autoantibodies. Seven adenomas showed no significant lymphoplasmacellular infiltration. It is concluded that this phenomenon might be due to an autoimmune pathogenesis in a part of patients with autonomous adenomas, indicating that there is no sharp line between autoimmune and non autoimmune thyroid disorder.

Adenoma↗