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Biomedical subjects

L Valenta

Publications and source records attributed to L Valenta.

At least 19 recordsLinked to original sources

Immunosuppressive and immunizing activities in human tumor cell-free extract.

Cell-free extracts (CFE) from cultured human tumor cells, when used to sensitize lymphocytes, were capable of inducing distinct lymphocyte-mediated cytotoxicity (LMC) at low dose and had relatively low or no activity at a high dose. The higher dose of CFE suppressed markedly the induction of LMC when added to the mixed lymphocyte tumor cell cultures. The ability to induce LMC was associated most with 10,000 g fractions. All fractions, 1,000, 20,000 and 100,000 g, were able to suppress the induction of LMC, but 100,000 g fractions had the most suppressive activity. The supernatants of 100,000 g fractions were only slightly suppressive. Lymphocytes activated with tumor cell fractions were also cytotoxic to K-562 cells.

Cell-Free System

A TSH secreting pituitary tumour causing hyperthyroidism: presentation of a case and review of the literature.

A 45 year old male with a 12 year history of mild hyperthyroidism and a pituitary tumour is presented. He had both clinical and laboratory evidence of hyperthyroidism and his serum TSH was persistently and markedly elevated. A TRH test resulted in no further rise in serum TSH. No evidence of pituitary or peripheral endocrine deficiencies existed and prolactin levels were normal. Craniotomy was performed and a pituitary adenoma was removed. On light microscopy, it was mostly composed of chromophobes. However, occasional granulated cells were observed, and on electron microscopy, most of the cells contained fine granules, which suggested possible thyrotroph origin of the tumour. One week post-operatively the patient's serum TSH returned to normal. Again, TRH produced no response in TSH. The patient became hypothyroid by clinical and laboratory findings and is currently on thyroid replacement therapy. The previously reported TSH secreting tumours associated with hyperthyroidism are reviewed.

Adenoma, Chromophobe