Search PubMed⌕ Search

Biomedical subjects

H Rorsman

Publications and source records attributed to H Rorsman.

At least 109 records · Page 6Linked to original sources

Glutathionedopa in malignant melanoma.

A human melanoma metastasis was found to contain a substance identical with synthetic glutathionedopa when examined by means of an automatic amino acid analyser, chromatography on a Dowex-50 column, thin-layer electrophoresis, and by fluorimetry. The presence of glutathionedopa in melanoma tissue and of enzymes capable of hydrolysing the glutathione moiety of the molecule, together with the absence of glutathionedopa in the urine, suggest that glutathionedopa is an intermediate substance in the formation of 5-S-cysteinyldopa.

Cysteinyldopa↗

Phaeomelanic pigments from a human melanoma.

The pigments in melanomas from 2 patients were studied with regard to solubility and chemical composition. Melanoma pigment from a patient with red-blonde hair was alkali-soluble and contained 9 or 10% sulfur and was thus of phaeomelanic type. Melanoma pigment from a patient with red-brown hair was insoluble in 0.2 N NaOH. Its sulfur content was 6%. This pigment was eumelanic with regard to solubility characteristics but the sulfur content was higher than previously observed for eumelanin.

Adult↗

Demonstration of 3-methoxytyrosine in the urine of melanoma patients.

With the aid of gas chromatography and mass spectrometry a metabolite of dopa, 3-methoxytyrosine, has been demonstrated in the urine of 2 patients with melanoma metastases, the amounts excreted being 4.0 mg and 8.5 mg/24 hours, respectively. 3-Methoxytyrosine could not with certainty be identified in the urines of two normal subjects.

Chromatography, Gas↗

Ultrastruct and biochemical chantes in cultured human malignant melanoma cells after heterotransplantation into nude mice.

Cells from three lines of cultured human malignant melanomas were heterotransplanted into nude mice and then recultered. The shape of the cells, the aspect of the melanosomes, and the content of 5-S-cyteinyldopa showed pronounced changes induced by the transplantation. Such results indicate that this experimental model should be used with great caution. A relationship was found between the shape of the melanosomes and the content of 5-S-cysteinyldopa in the cells.

Animals↗

Differentiation of melanocytes in cultures of primary malignant melanoma indicated by 5-S-cysteinyldopa formation.

The dedifferentiation of cultured primary human malignant melanocytes was not accompanied by disappearance of 5-S-cysteinyldopa formation. The addition of conditioned medium from undifferentiated fibroblast-like cells brought about the reappearance of pigmented melanocytes and the increase of the metabolite in the cells and culture medium. The presence of 5-S-cysteinyldopa in cultured cells indicated the melanocytic origin of undifferentiated cells, and the increase of this metabolite was characteristic of differentiation.

Cell Differentiation↗

Formation of cysteinyldopa from glutathionedopa in melanoma.

Glutathionedopa injected intravenously into mice is metabolized and excreted in the urine as a compound with the fluorescence characteristics of cysteinyldopa. Glutathionedopa incubated with a guinea-pig kidney homogenate is metabolized to a compound with the fluorescence characteristics of cysteinyldopa. Boiling of the kidney homogenate prevents the metabolism of glutathionedopa. Incubation of glutathionedopa with a homogenate of a melanoma metastasis led to the formation of a compound with the fluorescence characteristics of cysteinyldopa. Boiling of the melanoma homogenate prevented the metabolism of glutathionedopa. Large amounts of glutathione added to the incubate inhibited the reaction. Lung tissue and blood plasma had no detectable ability to metabolize glutathionedopa. The results show that human melanoma contains one or several enzymes capable of metabolizing glutathionedopa to a smaller dopathioether, probably cysteinyldopa. Such enzymes seem to be normally present in mice and guinea-pigs and have been demonstrated in the guinea-pig kidney.

Animals↗

Excretion of 5-S-cysteinyldopa in the urine of healthy subjects.

Seventy-six Caucasians, 30 men and 46 women, were investigated for the 24-hour excretion of 5-S-cysteinyl dopa in the urine during the months of September to November, 1973. No subject had had strong sun exposure for at least 4 weeks prior. A preliminary finding of a variation of 5-S-cysteinyldopa with season necessitated this precaution. The excretion varied between 9.0 and 242 mug/24 hours. The mean value in men was 100 mug/24 hours and in women 77.8 mug/24 hours. Subjects with white hair had lower values than those with pigmented hair, but there was no other difference between the excreted amounts in subjects with differing hair colour. There was no variation with age when the subjects with white hair were excluded. No variation with weight or body surface was found. Excretion of dopa and dopamine determined together did not correlate with the excretion of 5-S-cysteinyldopa.

Adolescent↗

Urinary excretion of 5-S-cysteinyldopa in patients with primary melanoma or melanoma metastasis.

Urinary excretion of 5-S-cysteinyldopa was studied in 9 patients with primary melanoma. All had 5-S-cysteinyldopa excretion in the normal range. In 8 of the patients excretion values decreased after removal of the tumour. Twenty-four patients with clinical signs of melanoma metastasis were examined for 5-S-cysteinyldopa and dopa+dopamine in the urine. 16 of the 24 had pathologically increased excretion of 5-S-cysteinyldopa and 7 of the 24 had pathological excretion of dopa+dopamine. Six of the latter belonged to the group with increased 5-S-cysteinyldopa excretion and one patient had a borderline value of 5-S-cysteinyldopa. Determination of 5-S-cysteinyldopa seems to be of value in the follow-up of patients operated on for primary melanoma.

Adult↗