FGF signalling is critical for normal embryonic development. Sulf1 has been shown to inhibit FGF activity. The role of FGF4 in Sulf1 regulation was investigated during digital development of the quail autopod. Implantation of FGF4 beads in both the interdigit and at the tip of digit III differentially up-regulated Sulf1 as also confirmed in micromass cultures. FGF4 inhibited interdigital mesodermal apoptosis in a concentration dependent manner. The FGF inhibitor, SU5402, inhibited Sulf1 expression when placed in the interdigital mesoderm. However, when placed at the digital tip, SU5402 induced an ectopic domain of Sulf1 expression and inhibited further phalange formation. (+info)
A pseudohypoparathyroidism type Ia patient with normocalcemia.
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Pseudohypoparathyroidism type Ia (PHP-Ia), one of 4 types of PHP, is a genetic disease characterized by clinical hypoparathyroidism caused by parathyroid hormone (PTH) resistance. In addition, patients with PHP-Ia show resistance to other hormones as well as Albright's hereditary osteodystrophy (AHO), a constellation of features including short stature, obesity, brachydactyly, ectopic ossifications, and/or mental retardation. Hypocalcemia is one of the hallmarks of PHP-Ia, but several PHP-Ia patients have been described to have normocalcemia. We encountered a 10-year-old girl with typical Albright's hereditary osteodystrophy with round face, short stature, brachydactyly, and obesity. Biochemical examination showed normocalcemia and increased PTH levels. Ellsworth-Howard test did not show any responses of urinary cAMP and phosphate. Based on these findings, she was diagnosed as having PHP-Ia with normocalcemia. Sequencing analysis of the GNAS gene identified a heterozygous missense mutation in exon 13 (R385H), which was previously reported in a PHP-Ia patient. The exact reason for her normocalcemia is not determined, but we must recognize heterogeneous biochemical findings even in PHP-Ia. (+info)
Avian hind-limb digit length ratios measured from radiographs are sexually dimorphic.
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