PubMed · 7704804
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
H B Burch, L Wartofsky. 1994. Hyperthyroidism.. https://pubmed.ncbi.nlm.nih.gov/7704804/
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
The high mobility group As (HMGAs) belong to a family of nonhistone nuclear proteins that orchestrate the assembly of nucleoprotein complexes. Through a complex network of protein-DNA and protein-protein interaction, they play important roles in gene transcription, recombination, and chromatin structure. This protein family is involved, through different mechanisms, in both benign and malignant neoplasias. We have recently reported that transgenic mice carrying the Hmga1 or Hmga2 genes under transcriptional control of the cytomegalovirus promoter develop pituitary adenomas secreting prolactin and growth hormone. We have shown that the mechanism of the HMGA2-induced pituitary adenoma is based on the increased E2F1 activity. The expression profile of mouse normal pituitary glands and adenomas induced in HMGA transgenic mice revealed an increased expression of the ccnb2 gene, coding for the cyclin B2 protein, in the neoplastic tissues compared with the normal pituitary gland. Here, we show, by electrophoretic mobility shift assay and chromatin immunoprecipitation, a direct binding of HMGA proteins to the promoter of ccnb2 gene, whereas luciferase assays showed that HMGAs are able to up-regulate ccnb2 promoter activity. Finally, we report an increased CCNB2 expression in human pituitary adenomas of different histotypes that is directly correlated with HMGA1 and HMGA2 expression. Because cyclin B2 is involved in the regulation of the cell cycle, these results taken together indicate that HMGA-induced cyclin B2 overexpression gives an important contribution to experimental and human pituitary tumorigenesis.
A patient with hypercalcaemia had persistently suppressed serum intact parathyroid hormone levels (measured by immunochemiluminometric assay). However, other biochemical tests and open-neck exploration confirmed a diagnosis of primary hyperparathyroidism.
BACKGROUND: Recent attention has focused on calcium and certain vitamins as potential protective agents against colorectal neoplasia. METHODS: Two case-control studies were conducted on patients who underwent colonoscopy between 1986 and 1988, comparing 297 patients with newly diagnosed adenomas with 505 controls (without current or prior history of neoplasia), and 198 patients with recurrent adenomas with 347 recurrent controls (with no current neoplasia, but with a history of polypectomy). Subjects were interviewed regarding their regular usage of supplementation with vitamins A, C, D, and E, or with calcium, multivitamins, or any vitamin supplements. RESULTS: No consistent associations were observed with the use of any of these supplements. CONCLUSIONS: More studies are necessary to confirm these findings. It may be necessary to develop other chemopreventive agents, such as aspirin, for colorectal neoplasia.