Pleiotropic patterning response to activation of Shh signaling in the limb apical ectodermal ridge.

Sonic hedgehog (Shh) signaling in the limb plays a central role in coordination of limb patterning and outgrowth. Shh expression in the limb is limited to the cells of the zone of polarizing activity (ZPA), located in posterior limb bud mesoderm. Shh is not expressed by limb ectoderm or apical ectodermal ridge (AER), but recent studies suggest a role for AER-Shh signaling in limb patterning.

Configurations of the segmental and subsegmental bronchi and arteries in the right upper lobe of the human lung with special reference to their concomitant relations and double subsegmental arterial supply.

The basic, concomitant topographical relation between the segmental bronchus and artery shows derived figures in the dorsolateral part of the cranial portion of the mammalian lung, especially in humans. However, the pulmonary arterial supply has not been investigated well in the subsegmental level, even in humans. One or two subsegments of S2 received a double arterial supply from both the superior and inferior pulmonary trunks in 39.

Individual variations in aging of the male urethral rhabdosphincter in Japanese.

Although the degenerative changes with aging of the male urethral rhabdosphincter (URS) have been investigated, its individual morphological variations are still unclear. To provide an anatomical basis for clinical evaluation of the individual URS function in the aged, we investigated the structural differences in the URS of 25 elderly Japanese men using semiserial sections stained immunohistochemically and by hematoxylin-eosin. Before removal of the histological specimens, we dissected the ischioanal fossa and labeled several structures by carbon particles to allow proper orientation during the histological observations.