Objective To establish the surgical landmarks of the endoscopic endonasal approach to the ventral region of middle-lower part of clivus and provide anatomic basis. Methods Twenty 10% formalin-fixed intact adult head specimens were used to dissect and observe the anatomic feature of this access in order to establish the surgical landmarks of the approach, and some relative anatomic data were measured. Five fresh and intact head specimens injected with colored latex were used, and completely analogical operation via endoscopic endonasal approach to the middle-lower part of clivus was performed in all cases. Results Anatomic landmarks of the approach included middle turbinate, choana narium, eustachian tube ostium, nasopharynx mucosa, longus capitis and longus colli, pharyngeal tubercle, and basi-on. To expose the ventral region of middle-lower part of clivus completely, the shortest distance was ( 89.60 ± 2. 52) mm. The ranges of stripping the inferior wall of sphenoid sinus and the lower clivus were bounded by pterygoid canal and foramen lacerum, and the distances from the median line were (9. 37 ± 0.59) mm and (10. 75 ± 0. 63 ) mm, respectively. Conclusions The structures of the ventral middle-lower part of clivus can be revealed sufficiently via an endoscopic endonasal approach.

The effect of morphine and naloxone on release of the excitatory amino acids (EAAs) of spinal astrocytes induced by TNF-α was studied. Astrocytes were purified from 2- to 3-day old SD rats and divided into 8 groups: group 1 (without any stimulatants); group 2 (10 ng/ml TNF-α);group3 (10 ng/ml TNF-α+0.5 μmol/L morphine); group 4 (10 ng/ml TNF-α+1. 0 μmol/L morphine); group 5 (10 ng/ml TNF-α+ 2. 0 μmol/L morphine) ; group 6 (10 ng/ml TNF-α+ 0. 5 μmol/L naloxone); group 7 (10 ng/ml TNF-α+ 1.0 μmol/L naloxone) ; group 8 (10 ng/ml TNF-α+2.0 μmol/L naloxone). In group 2, 3, 4 and 5, 0, 0.5, 1.0 or 2.0 μmol/Lmorphine was added to the cells cultured with serum-free Neurobasal/B27 medium containing 10 ng/ml TNF-α respec-tively, while in group 6, 7 and 8, 0.5, 1.0 or 2.0 μmol/Lnaloxone was added respectively to the cells cultured with serum-free Neurobasal/B27 medium containing 10 ng/ml TNF-α. After 30 min incubation, high-pressure liquid chromatography (HPLC) was used to measure the levels of EAAs in all cultured cells. The results showed the level of EAAs in group 2 was significant higher than in group 1 (P＜0.01). As compared with group 2, the levels of EAAs in group 3, 4 and 5 were decreased with the difference being significant between group 5 and group 2 (P＜0.01) or between group 4 and group 2 (P＜0.05). The levels of EAAs in group 6, 7 and group 8 was significantly lower than in group 2 (P＜0.05 or P＜0.01). It was concluded that TNF-α could promote the release of glutamate and aspartate from astrocytes, and morphine and naloxone might reduce the release of EAAs in cultured spinal astrocytes induced by TNF-α.