RESUMO
Parathyroid hormone (PTH) stimulates osteoblasts to produce the proinflammatory cytokine interleukin-6 (IL-6), causing bone resorption. In patients with primary hyperparathyroidism, elevated serum levels of IL-6 normalize after resection of parathyroid tumours. Because IL-6 is also expressed in normal parathyroids and in other endocrine cells (adrenal and islet), we hypothesized that parathyroid tumours might contribute directly to the elevated serum IL-6 levels in patients with hyperparathyroidism. Immunohistochemistry identified IL-6, PTH, and chromogranin-A (an endocrine and neuroendocrine tumour marker) in normal, adenomatous and hyperplastic parathyroids. Using immunofluorescence and confocal microscopy, IL-6 co-localized with PTH and with chromogranin-A in parathyroid cells. All cultured parathyroid tumours secreted IL-6 at levels markedly higher than optimally stimulated peripheral blood mononuclear cells. Supernates from cultured parathyroids stimulated proliferation of an IL-6-dependent cell line, and anti-IL-6 MoAb abolished this stimulatory effect. IL-6 mRNA was documented in cultured parathyroid tumours, cultured normal parathyroids, fresh operative parathyroid tumours and fresh operative normal specimens. In conclusion, these data show that parathyroid tumours and normal parathyroids contain, produce and secrete IL-6. Our findings present a novel pathway by which human parathyroids may contribute markedly to IL-6 production and elevation of serum IL-6 levels in patients with hyperparathyroidism. The physiological relevance of IL-6 production by human parathyroids remains to be determined, but IL-6 secretion by parathyroid tumours may contribute to bone loss and to other multi-system complaints observed in these patients.
Assuntos
Interleucina-6/biossíntese , Glândulas Paratireoides/metabolismo , Neoplasias das Paratireoides/metabolismo , Células Cultivadas , Cromogranina A , Cromograninas/metabolismo , Humanos , Hiperparatireoidismo/etiologia , Hiperparatireoidismo/metabolismo , Microscopia Confocal , Osteoblastos/metabolismo , Hormônio Paratireóideo/metabolismo , Neoplasias das Paratireoides/complicações , Lesões Pré-Cancerosas/metabolismo , RNA Mensageiro/genética , Fator de von Willebrand/metabolismoRESUMO
Formal preparation of allied health instructors for responsibilities of teaching and educational leadership has been encouraged through substantial federal grants, institutional funds and university programming. A review of the literature reveals very little regarding formal measurements of outcomes in terms of career progress of the graduates their professional activities and their level of satisfaction with the educational content and preparation as a teacher. This study focuses on the achievements and opinions of 106 graduates of a master's degree teacher preparation program. Graduates were found to be employed in positions commensurate with their preparation, and rewarded by their employers with career advancement, salary increases and promotions. The graduates believed that they had gained the skills needed. They also identified the strengths and weaknesses of the program. Implications of the findings are discussed.