Journal of endocrinological investigation
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J. Endocrinol. Invest. · Jan 2005
ReviewPre-clinical and clinical experiences with novel somatostatin ligands: advantages, disadvantages and new prospects.
Since the cloning and characterization of the five human somatostatin receptor (SSTR) subtypes, our understanding of the expression and functional role of the five SSTR subtypes in human (neuro-)endocrine tumors has increased significantly. The majority of human (neuro-)endocrine tumors express multiple SSTR. GH-secreting pituitary adenomas preferentially express SSTR2 and SSTR5, prolactinomas SSTR1 and SSTR5, and corticotroph adenomas express SSTR2 (low number) and predominantly SSTR5s. ⋯ However, every advantage has its disadvantage. Targeting multiple SSTR potentially induces more adverse effects as well. Especially, glucose homeostasis might induce new problems in the long-term use of universal ligands.
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J. Endocrinol. Invest. · Jan 2005
Review Comparative StudyHormonal cut-offs of partial androgen deficiency: a survey of androgen assays.
While the typical symptomatology of severe hypogonadism in young adults permits the clinical diagnosis of hypoandrogenism, the diagnosis of partial androgen deficiency of the aging male (PADAM), as occurs relatively frequently in elderly males, is much more difficult. This is due to its clinical picture being subtle and aspecific, and to the fact that both clinical and biochemical evidence of androgen deficiency are required for the diagnosis. In the absence of a practical, clinical useful parameter of androgen activity, we have to rely upon bio-active plasma testosterone levels. ⋯ As even when using the same kits, values for plasma testosterone and SHBG may differ significantly between laboratories, each laboratory should define its own normal values. As to the methodology, neither direct measurement of free testosterone by analog assay, nor the FT index (T/ SHB) can be recommended, only values obtained by dialysis, ammoniumsulfate precipitation or calculation yielding reliable estimates of androgen bio-activity. Dialysis and ammoniumsulfate precipitation are however work intensive and not widely used.
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J. Endocrinol. Invest. · Jan 2005
ReviewSomatostatin analogs in the treatment of neuroendocrine gastroenteropancreatic and intrathoracic tumors.
Somatostatin is a peptide hormone that posses several biological functions of which inhibition of hormone secretion from endocrine cells is one. Neuroendocrine tumors usually express somatostatin receptors (SSTRs), although the subtypes and number of SSTRs expressed in a certain tumor is very variable. ⋯ By this approach, it is possible to select patients suitable for treatment. Among patients with functioning neuroendocrine tumors expressing SSTR, more than 80% respond with symptomatic relief during somatostatin analog treatment, while treatment of non-functioning tumors still remains somewhat controversial.