ABSTRACT
Objective To study the effect of subarachnoid hemorrhage (SAH) on voltagedependent potassium channels (Kv) currents of smooth muscle cells,which is hypothesized to be different between cerebral pial arteries and penetrating arteries.Methods Smooth muscle cells from cerebral pial arteries and penetrating arteries in rats were enzymatically isolated 72 h after SAH,and patch clamp was used to test the relative cell size,resting potential and Kv currents.Results Resting potential of either pial ((45.63 ±1.18) mV) or penetrating artery ((41.55-± 1.19) mV) was shifted positively by SAH,even more significantly in latter (F =8.24,P ＜ 0.05 ; F =9.36,P ＜ 0.01) ; Resting potential of pial artery of control ((38.76 ± 1.03) mV),penetrating artery of control ((38.53 ± 0.67) mV),pial artery of SAH ((36.87 ± 1.49) mV) and penetrating artery of SAH((37.89 ± 1.24) mV) were shifted positively to the same level by 1 μmol/L 4-aminopyridine (4AP; F =3.08,P ＞0.05).Maximum Current Density (Imax) of either pial ((20.82 ±0.59) pA/pF) or penetrating artery ((15.15 ±0.37) pA/pF) was compromised by SAH,also more significantly in latter (F =6.22,P ＜ 0.05) ; Imax of pial artery of control (9.15 ± 0.16),penetrating artery of control (9.04 ± 0.36),pial artery of SAH (8.77 ± 0.26) and penetrating artery of SAH (9.12 ± 0.17) were decreased to the same level by 1 μmol/L 4AP (F =2.96,P ＞ 0.05).Conclusions SAH probably shares the similar pathway with Kv blocker (4AP) in Kv currents inhibition.Further,SAH differently inhibits smooth muscle cells Kv currents and resting potential of cerebral pial arteries and penetrating arteries,which may be related with their different sensitivity towards cerebral vasospasm following SAH.
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AIM: The aim of this study was to explore the expression of nerve growth factor(NGF) in spinal dorsal horn following crushed spinal cord injury. METHODS: The adult Srague-Dawley rat model of crushed spinal cord injury was established by the method in our laboratory, and intact spinal cord was used as control. The rats were sacrificed respectively after 24 hours, 7 days, and 21 days of operation, and the L3 spinal segments were removed out and fixed in 4% polyformaldehyde. The segments were sectioned into sections of 20 μm in thickness. The sections were stained with anti-NGF antibody by ABC method of immunohistochemistry technique. The immunoreactive intensity of NGF and the number of positive neurons as well as glial cells in dorsal horn were observed and counted under light microscope. RESULTS: The number of positive cells and immunoreactive intensity of NGF increased gradually in the dorsal horn at 24 hours, 7 days and 21 days following crushed spinal cord injury compared with control group (P＜0.01). CONCLUSION: These results indicated that NGF plays an important role in the postoperative reaction during the early period of the crushed spinal cord injury.
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AIM: It is well known that different injuries will result in different consequences. In this paper, we investigated the morphological change of spinal cord following crushed, hemi-sectioned and transected injury. METHODS: Sixty Wistar rats were randomly divided into 4 groups: intact group, crushed spinal cord injury group (cSCI), hem-sectioned SCI group (hSCI) and transitioned SCI group (tSCI). The models of SCI were established by the method in our laboratory. The animals in each group were sacrificed respectively at 24 hours, 7 and 24 days after operation. The L2 spinal cord which located in the caudal of injury site was taken respectively from each animal in each group and sectioned into frozen sections (20 μm). The sections were stained by hematoxylin and observed under light microscope. The number of neurons in dorsal and ventral horn was also counted. RESULTS: In cSCI group, some neurons appear to atrophy compared with that of intact group, but the number of neurons did not decrease apparently than that of intact group (P＞0.05). Comparatively, some cavities were observed in dorsal and ventral horn in hemi-sectioned and transitioned SCI group. And the number of neurons in dorsal horn and ventral horn decreased greatly at 24 hours, 7 and 21 days compared with intact group (P＜0.05). The results indicated that the decrease of neuronal number in dorsal horn and ventral horn after injury resulted from hSCI and tSCI, but not from cSCI. As a result, some different strategies should be considered for different injuries. For example, some neurotrophic factors may be useful in cSCI, but, many neurons have disappeared following hSCI and tSCI, therefore, other strategies that increase the number of neurons should be considered too. CONCLUSION: Our results provide the important morphological evidences on the change of spinal cord following cSCI, hSCI and tSCI. The data will be useful in treatment of SCI in the future.
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Objective To summarize the experience of the trans-unilateral nasal and sphenoidal approach to pituitary denomas.Methods 20 cases of pituitary adenomas were removed by the trans-unilateral nasal and sphenoid approach under operating microscope,of which there were 2 microadenoma patients,16 macroadenoma patients;2 giant pituitary adenoma patients.Results Of all the 20 patients,12 had total resection of tumor;4 had subtotal resection of tumor and 4 had part resection of tumor.All cases showed improvement.After the operation,3 had diabetes insipidus and 2 had CSF rhinorrhea,which had been cured by the time they left the hospital.Conclusion this method is minimally invasive with short operative distance,time and fewer complications.