Biomedical subjects
K Olander
Publications and source records attributed to K Olander.
False precursors of melanin as selective melanoma seekers.
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Management of pterygia: should thiotepa be used?
Pterygium, a common source of morbidity throughout the world, may appear to be an innocuous, easily excised lesion, yet it plagues the ophthalmologist by its high rate of recurrence, ranging from 20% to 30% after simple excision. Beta irradiation has been used by ophthalmic surgeons for many years. Another method of stemming the high percentage of pterygium recurrence is through local application of thiotepa, a radiomimetic drug that inhibits rapidly proliferating cells. The following report is a review of the literature from 1960 to 1977 on the role of thiotepa in treatment of pterygium, with emphasis on the complications of thiotepa administration. The recurrence rate after topical postoperative use of thiotepa ranges from 0 to 8%, with disturbing variance in results, depending on each investigator's definition of "recurrence", the length of follow-up, the type of pterygium, and the number of patients. The main reported complication from thiotepa's use has been depigmentation of skin around several patients' eyes, sometimes precipitated by exposure to the sun's rays.
Uptake of [131I]thiouracil in tumours of patients with disseminated malignant melanoma. A pilot study.
Previous studies on mice carrying melanoma have shown that 5-iodo-2-thiouracil (ITU) is accumulated in the tumours due to its specific incorporation into melanin during its synthesis. ITU is also selectively localized in murine melanoma metastases and in cultured human melanoma cells. Progressive formation of melanin is, however, a prerequisite for the incorporation. Four patients with disseminated melanoma were injected intravenously with 39-62 MBq [131I]TU. Blood and urine samples were gradually collected, and 3-7 days postinjection tumours were biopsied and examined by impulse counting. The patients were scanned with a gamma camera over the total body daily for 3-4 days. The radioactivity was rapidly excreted. Poor melanin pigmentation of the tumours and low proliferation rate (possibly induced by chemotherapy) decreased the uptake of radioactivity by the tumors, and no imaging was possible. One of the patients, however, had clearly progressive disease with darkly pigmented metastases which contained considerably higher levels of radioactivity than the surrounding skin. Calculations indicated that a doubling of the radioiodine dose would probably make visualization of the tumours possible.