Cochlear outer sulcus cells (OSC) and vestibular transitional cells (VTC) are part of the parasensory epithelium in the inner ear and are located in homologous positions between the sensory hair cells and the cation secretory epithelial cells in the cochlea and the vestibular labyrinth. OSC are known to sustain a reabsorptive transepithelial current and to contain an immunoreactivity for P2X(2) purinergic receptors. This study addresses whether OSC and VTC share functional similarities and extends this hypothesis to the question of whether both cell types contain functional P2X(2) receptors. The current density (I(sc)) was recorded with the vibrating probe technique and was found to be similar in VTC and OSC. Both gadolinium and flufenamic acid reduced I(sc) in VTC, as reported previously for OSC. I(sc) was stimulated by extracellular ATP but not by selective agonists of P2Y receptors. Purinergic receptor agonists increased I(sc) with a potency order of ATP > 2'- and 3'-O-(4-benzoyl-benzoyl)adenosine 5'-triphosphate alpha,beta-methyleneadenosine 5'-triphosphate in both OSC and VTC. In the presence of suramin (100 micrometer) or gadolinium (100 micrometer), the responses of ATP were inhibited significantly in both OSC and VTC. This pharmacological profile is consistent with that of the P2X(2) receptor. These results demonstrate that VTC participate in vestibular parasensory cation absorption and that both OSC and VTC regulate their parasensory cation flux via P2X(2) receptors, which would regulate the endolymphatic concentration of the current-carrying ion species in auditory and vestibular transduction.

Intrahepatic bile ducts are patent in the liver of patients with biliary atresia in early infancy. Small bile ducts at the porta hepatis continuing to the intrahepatic ducts usually terminate in fibrous tissue replacing the hepatic radicles, which does not extend to the common hepatic duct. Therefore, the level of transection of the fibrous tissue at the porta hepatis is of prime importance for successful hepatic portoenterostomy. Transection should be done at the level of the posterior surface of the portal vein. The overall cure rate of surgery for biliary atresia was 30%. In our recent series, however, the results have markedly improved and the cure rate has been increased to 55%. There are 47 patients living without jaundice, 22 of them for more than 5 years. The longest survivors are 23 years old. All the longterm survivors are leading a normal life for their age, although 6 of them have some physical or mental handicap. Early operation, adequate surgical technique, and prevention of postoperative cholangitis are requisites for successful hepatic portoenterostomy.

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