The effect of exogenous nerve growth factor(NGF) examined on the neural repair of adult rabbit sciatic nerve was evaluated in the present study. A nerve regeneration chamber was created by suturing the proximal and distal ends of a transected sciatic nerve into a silicone chamber, A gap of 6 mm in chamber was left after removal of a 3mm piece of nerve in the distal ends and insertion of the proximal andl distal stumps into the chamber. Animals were operated on bilaterally, one side of the chamber was filled with a 1 mg/ml NGF/normal saline(NS) (experimental)and the contralateral side with NS(control). The regenerated nerves from within the silicone chamber were dissected and fixed 1 to 5 weeks following surgery for histological studies at both the light microscopic and ultrastructural levels. The NGF chamber showed a more mature regenerated nerve based on a larger diameter of the regenerated nerve trunk, a great number of axons, and thicker myelin sheaths.
In order to evaluate the value of impedance rheopneumogram (IRP) in predicting pulmonary arterial pressure (PAP) and pulmonary arterial hypertension (PAH) noninvasively and quantitatively, 150 patients with chronic obstructive pulmonary disease (COPD) were examined by IRP and right heart catheterization simultaneously. It was found that some parameters derived from IRP correlated well with PAP, the strongest correlation being demonstrated by Q-B/B-Y ratio (γ = 0.74,P<0.001) and Hs (γ = −0.56,P<0.001). We made a multi-stepwise regressional analysis and, obtained an equation to predict PAP from IRP parameters: PAP (kPa) = [−2.26−5.05xlnHs+27.02 × (Q-B/B-Y)] × 0.133 (γ = 0.78,P<0.001) Other 30 COPD patients were selected to assess the effectiveness of the equation, We found that the sensitivity and specificity of the equation in identifying PAH were 83% and 93% respectively.