Morphological features of allogenic nerve segment in rats after subcutaneous embedment

BACKGROUND ： Some studies demonstrate that allogenic peripheral nerve segment embedded subcutaneously significantly reduce the infiltration of lymphocyte and decrease immunological reaction.OBJECTIVE ： To observe the gross shape, optical and electron microscope results of allogenic nerve segment in rats 2 weeks after subcutaneous embedment, and compare with subcutaneous emdedment of autologous nerve segment. DESIGN ： A randomized and controlled experiment.SETTING ： Department of Orthopaedics of Fifth People＇s Hospital of Zhengzhou; Department of Orthopaedics,First Hospital Affiliated to Chongqing Medical University.MATERIALS ： Totally 30 adult healthy Wistar male rats, with body mass of （200±20） g, were enrolled. Ten rats were chosen as the donors of allogenic nerve transplantation. The other 20 rats were randomly divided into 2 groups： allogenic nerve embedment group and autologous nerve embedment group, with 10 rats in each one. JEM-1220 transmission electron microscope （Japan） and Olympus BX50 optical microscope （Japan） were used. METHODS ： This experiment was carried out at the laboratory of Orthopaedic Department, Chongqing Medical University from October 2000 to April 2002. ① Sciatic nerve of donor rats for allogenic nerve transplantation was cut off at 5 mm distant from pelvic strait.15 mm sciatic nerve segment was chosen from lateral part as graft, allogenic nerve embedment group： 15 mm sciatic nerve form the donor rats was embedded in the posterior part of right legs. Autologous nerve embedment group： 15 mm sciatic nerve segment of autologous left side was embedded in the posterior side of right legs. ② Nerve segment embedded subcutaneously was taken out at postoperative 2 weeks and performed gross observation; then 5 samples chosen randomly respectively from 2 groups and given haematoxylin-eosin staining and observation under optical microscope （×400）;The other 5 samples were made into ultrathin sections （0.5μm）and observed under transmission electron microscope（×17 000）. MAIN OUTCOME MEASURES ： Gross shape, optical and electron microscope results of nerve segments of rats between two groups at 2 weeks after subcutaneous embedment. RESULTS ： ① Results of gross observation： Appearance of nerve segment was similar between 2 groups. ② Results of optical observation： medullary sheath denaturation, axonotmesis, vascular engorgement, desmoplasia of adventitia and infiltration of inflammatory cells were all found in both 2 groups. Inflammatory reaction was a little more severe in the allogenic nerve embedment group than in the autologous nerve embedment groups.③Results of electron microscope ： Similar cataplasia and denaturation of medullary sheath and cataplasia of Schwann cell were all found in the 2 groups. CONCLUSION： Some inflammatory reaction occurs after allogenic nerve embedment, but the activity of Schwann cell is similar to that of peripheral nerve after autologous nerve embedment.

Ultrasound biomicroscopy in patients with unilateral pseudoexfoliation

·AIM: To compare the anterior segment morphology evaluated using ultrasound biomicroscopy(UBM) in patients with clinical pseudoexfoliation syndrome(XFS)in one eye and no clinical XFS in the fellow eye.·METHODS: Thirty patients with unilateral XFS were included in the study. All patients underwent evaluation of their anterior segment using UBM with and without dilatation with 1% cyclopentolate. The anterior chamber depth(ACD), lens thickness(LT), anterior chamber angle(ACA), ciliary body thickness(CBT), scleral thickness(ST), trabeculae-ciliary processes distance(T-CPD), and iris-ciliary processes distance(I-CPD) were measured using UBM scans. All results between the eyes with clinical XFS and their fellow eyes without clinical XFS were then compared.·RESULTS: Before dilatation the eyes with XFS(4.350±0.531 mm) were found to have a significantly thicker lens(P =0.002) than the eyes without XFS(4.238 ±0.540 mm).In addition after dilatation, the eyes with XFS(4.310 ±0.500 mm) were found to have a significantly thicker lens than the eyes without XFS(4.160±0.480 mm)(P=0.019).The average ACD, for the group with XFS, comparing pre-dilatation(2.616 ±0.349 mm) and post-dilatation measurements(2.714±0.413) was found to be statistically increased(P =0.014). The average ACD, comparing pre-dilatation to post-dilatation measurements in patients without XFS(2.680±0.360),(2.720±0.500) was found to be statistically unchanged(P =0.450).·CONCLUSION: Crystalline lenses tended to be thicker in the eyes with clinical pseudoexfoliation than their fellow eyes without pseudoexfoliation.

Synthesis and Structure of Butylene Terephthalate-ε-Caprolactone Copolyesters

A series of butylene terephthalate-E-caprolactone copolyesters (BCL) with different hard segment content were successfully synthesized and characterized by 1H-NMR. DSC. PLM and U viscometer, The sequence structure and crystallization characteristics of BCL copolyesters were carefully investigated.