To reconstruct 3 D images of microstructure and ultrastructure of regenerated sciatic nerve of rats with serial cross sections. The 6 mm defects of the sciatic nerve of 90 Wistar rats were bridge connected with silicone tube and were sampled at 3, 7, 15, 30, 60, 90 days respectively after injury. The images of optical and electronic microscope were taken by micro photograph system and scanner, then they were input into the computer, by which the image registration and segmentation were completed. The direct volume rendering model was used to realize the 3 D reconstruction and display. The results showed the morphological changes in degenerated and regenerated sciatic nerve fibres and their appendicular structures could be observed with the 3 D images. It is suggested that the reconstructing results could reveal the differences between the regenerated and normal sciatic nerve fibres of rats intuitively and visually, so it could be used as a new method in the study of peripheral nerve injury.

Objective To evaluate the regional cerebral metabolic changes in different episodes by magnetic resonance spectroscopy (MRS) after explosive brain injury in rabbits. Methods Fortyfive New Zealand white rabbits were randomly divided into eight groups, ie, normal control group( 10 rabbits) and trauma group (35 rabbits). The explosive injury in trauma group was induced by explosion of 600 mg TNT equivalent of paper detonators at 6.5 cm above the rabbit brain. The rabbits in trauma group was divided into 1,6, 12, 24 hours, 3, 7, 14 days subgroups (6 rabbits per group). The survival rate was observed at different time points after explosive injury. The MRS was used to detect the regional cerebral metabolic changes including N-acetylaspartate (NAA)/creatine (Cr) ratio and choline(Cho)/Cr ratio as well as evolution of blast injuries over time. Results The rabbits survived for overseven days in the trauma groups, with typical brain contusion manifested by pathological and conventional MRI. Compared with the normal control group, the NAA/Cr ratio was markedly decreased at one hour after injury, slightly rose again at 24 hours and fell again after seven days. The Cho/Cr ratio was markedly increased at one hour after injury, slightly fell again at 12 hours and rose again at three days after injury.Conclusions MRS can manifest the regional cerebral metabolic changes of rabbits with explosive injury at different time points and hence provide a theoretical basis for understanding the local tissue changes and determining the type of tissue damage after blast injury.

Objective To study the value of pre-surgery computed tomography(CT)scan on post-surgery pathological risk grades of gastrointestinal stromal tumor(GIST).Methods Forty-one patients of GIST were retrospectively evaluated and confirmed by histological diagnosis. Tumor size, density, margin, contour, location, growth pattern, degree and pattern of lesion enhancement was analyzed. Results Based on pathological results, the total diagnosis accuracy of location and character on CT is 95.1%(39/41)and 92.6%(38/41), respectively.Tumors size of low risk group was smaller than that in the other two groups(P>0.05).There was no significant difference in tumor size between moderate and high risk groups. Using Chi-test analysis, tumor density, margin, contour, growth pattern was statistically different among different pathological risk grades (P < 0.05). CT features of enhancement were not significantly different among the pathological risk groups (P > 0.05). Conclusions CT plays an important role not only in the detection and localizing GIST but also in the evaluation of the extension and characteristics of these tumors. CT imaging can predict the invasive behaviors through tumor density, size, shape, contour, growth pattern and enhanced pattern.

OBJECTIVETo explore the characteristics of mutations 4 common deafness-related genes among 216 patients from Shanghai area with non-syndromic hearing impairment (NSHI).

METHODSThirteen mutation sites in the four genes, namely GJB2 (c.35delG, c.176del16, c.235delC, c.299delAT, and c.155delTCTG), SLC26A4 (c.IVS7-2A>G, c.2168A>G, and c.1229C>T), mtDNA 12SrRNA (m.1494C>T, m.1555A>G, m.7445A>G, and m.12201T>C) and GJB3 (c.538C>T) were detected among the 216 patients and 41 individuals with normal hearing. The frequency and types of mutations were compared between the two groups.

RESULTSAmong the 216 NSHI patients, the total detection rate was 16.20% (35/216). GJB2 mutations were found in 17(7.87%) of the 216 patients, which included 5 cases with homozygous c.235delC mutation, 5 with homozygous c.235delC mutation, 1 with homozygous c.299delAT mutation, and 1 with homozygous c.299delAT mutation. c.235delC and 299delAT mutations were found in 5 cases. SLC26A4 mutation was found in 12(5.56%) of the 216 patients, which included 2 cases with homozygous c.IVS7-2A>G mutation, 9 with homozygous c.IVS7-2A>G mutation, and 1 with homozygous c.2168A>G mutation. Homogeneous mtDNA 12SrRNA m.1555A>G mutation was found in 6(2.78%) of the 216 patients. No GJB3 gene mutation was detected. No mutation of the 4 genes were detected in the 41 individuals with normal hearing. In 2 cases of the 12 patients with SLC26A4 gene mutation, CT scan of the temporal bone has confirmed expansion of vestibular aqueduct.

CONCLUSIONAbove results indicated that GJB2 and SLC26A4 were the major genes involved with hearing loss in Shanghai area.