2,751 research outputs found
Growth Hormone (GH)-Releasing Peptide Stimulation of GH Release from Human Somatotroph Adenoma Cells: Interaction with GH-Releasing Hormone, Thyrotropin- Releasing Hormone, and Octreotide.
No full textThe synthetic hexapeptide GH-releasing peptide (GHRP; His-D-Trp-Ala-Trp-D-Phe-Lys-NH2) specifically stimulates GH secretion in humans in vivo and in animals in vitro and in vivo via a still unknown receptor and mechanism. To determine the effect of GHRP on human somatotroph cells in vitro, we stimulated cell cultures derived from 12 different human somatotroph adenomas with GHRP alone and in combination with GH-releasing hormone (GHRH), TRH, and the somatostatin analog octreotide. GH secretion of all 12 adenoma cultures could be stimulated with GHRP, whereas GHRH was active only in 6 adenoma cultures. In GHRH-responsive cell cultures, simultaneous application of GHRH and GHRP had an additive effect on GH secretion. TRH stimulated GH release in 4 of 7 adenoma cultures; in TRH-responsive cell cultures there was also an additive effect of GHRP and TRH on GH secretion. In 5 of 9 adenoma cultures investigated, octreotide inhibited basal GH secretion. In these cell cultures, GHRP-induced GH release was suppressed by octreotide. In 5 of 5 cases, the protein kinase-C inhibitor phloretin partly inhibited GHRP-stimulated GH release, but not basal GH secretion. In summary, GH secretion was stimulated by GHRP in all somatotroph adenomas investigated, indicating that its unknown receptor and signaling pathway are expressed more consistently in somatotroph adenoma cells than those for GHRH, TRH, and somatostatin. Our data give further evidence that GHRP-stimulated GH secretion is mediated by a receptor different from that for GHRH or TRH, respectively, and that protein kinase-C is involved in the signal transduction pathway. Because human somatotroph adenoma cell cultures respond differently to various neuropeptides (GHRH, TRH, somatostatin, and others), they provide a model for further investigation of the mechanism of action of GHRP-induced GH secretion
The End of "Made in Hong Kong"? : De-industrialisation and Industrial Promotion Policy in Hong Kong
No full textThis article explores spatial aspects of Hong Kong's deindustrialisation, related both to the development of closer cross-border ties and to Hong Kong's evolution as a global city. Industrial promotion has always had its place in the generally non-interventionist economic policy ofthe government. However, under the new political and economical conditions industrial promotion has moved up on the agenda. In particular, the promotion of high-tech industries is given special governmental attention. The author wams that the plans for re-industrialising Hong Kong may be based on an obsolete view of the city: the city as an isolated entity rather than as the cross-border economic agglomeration that it is growing into. The aim should be to develop a strong and productive industrial base with intraregional co-operation for the whole agglomeration instead of just for Hong Kong
Traceless solid-phase synthesis of cyclopenta[c]quinolines and cyclopenta[c]chromenes via hetero [6+3] cycloadditions of fulvene. A facile approach to the 11-heterosteroids framework
No full textIntramolecular [2+2] photocycloaddition-fragmentation: Facile entry to a novel tricyclic 5-6-7 ring system
No full textMulti-way Spatial Joins Using R-Trees: Methodology and Performance Evaluation
No full textAdvances in Spatial Databases, 6th International Symposium, SSD'99, Hong Kong, China, July 20-23, 199
Mechanical properties of WC-10Co cemented carbides sintered from nanocrystalline spray conversion processed powders
No full textIntramolecular Diels-Alder cycloadditions of fulvenes: Synthesis of the Kigelinol, Neoamphilectane and Kempanes skeletons
No full textIntramolecular Diels-Alder cycloadditions of fulvenes. Application to the kigelinol, neoamphilectane, and kempane skeletons
No full textHetero [6+3] cycloaddition of fulvenes with N-alkylidene glycine esters: A facile synthesis of the delavayine and incarvillateine framework
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