Comparison of short-term estrogenicity tests for identification of hormone-disrupting chemicals.

The aim of this study was to compare results obtained by eight different short-term assays of estrogenlike actions of chemicals conducted in 10 different laboratories in five countries. Twenty chemicals were selected to represent direct-acting estrogens, compounds with estrogenic metabolites, estrogenic antagonists, and a known cytotoxic agent. Also included in the test panel were 17beta++-estradiol as a positive control and ethanol as solvent control.

Semen analysis performed by different laboratory teams: an intervariation study.

Some recent studies have indicated that sperm concentration has decreased during the last 50 years. However, comparisons between laboratories have revealed that geographical differences seem to exist and that any decrease may not be global. One point of criticism concerning comparison of results from different laboratories has been that some of the discrepancies detected could reflect the lack of standardized methods used in the different laboratories.

Metabolic effects of GH: a rationale for continued GH treatment of GH-deficient adults after cessation of linear growth.

GH deficiency in children has been treated for decades with GH in order to normalize growth and final height. After cessation of linear growth GH treatment has traditionally been stopped. However, adults with GH deficiency have increased mortality due to cardiovascular disease and share several clinical signs, such as reduced muscle strength, reduced exercise capacity, reduced sweating ability and thermoregulation, subnormal kidney function, reduced myocardial function, reduced energy expenditure, abnormal thyroid hormone metabolism, impaired psychosocial well-being, decreased lean body mass and decreased bone mineral content.

Effects of growth hormone on body composition in adults.

GH replacement therapy in GH-deficient adults has recently been shown to increase (normalize) muscle volume and decrease adipose tissue volume as measured by means of CT scan and skinfold thickness. Also in adults with acquired GH deficiency in adulthood, GH replacement has been shown to significantly influence body composition with an increase in lean body mass and a reduction in skinfold thickness. Preliminary results from an open long-term trial indicate that 12 months of GH substitution result in a further normalization of the muscle/fat ratio.