Biological conduit small gap sleeve bridging method for peripheral nerve injury: regeneration law of nerve fibers in the conduit.

The clinical effects of 2-mm small gap sleeve bridging of the biological conduit to repair peripheral nerve injury are better than in the traditional epineurium suture, so it is possible to replace the epineurium suture in the treatment of peripheral nerve injury. This study sought to identify the regeneration law of nerve fibers in the biological conduit. A nerve regeneration chamber was constructed in models of sciatic nerve injury using 2-mm small gap sleeve bridging of a biodegradable biological conduit. The results showed that the biological conduit had good histocompatibility. Tissue and cell apoptosis in the conduit apparently lessened, and regenerating nerve fibers were common. The degeneration regeneration law of Schwann cells and axons in the conduit was quite different from that in traditional epineurium suture. During the prime period for nerve fiber regeneration (2-8 weeks), the number of Schwann cells and nerve fibers was higher in both proximal and distal ends, and the effects of the small gap sleeve bridging method were better than those of the traditional epineurium suture. The above results provide an objective and reliable theoretical basis for the clinical application of the biological conduit small gap sleeve bridging method to repair peripheral nerve injury.

Biodegradable chitin conduit tubulation combined with bone marrow mesenchymal stem cell transplantation for treatment of spinal cord injury by reducing glial scar and cavity formation.

We examined the restorative effect of modified biodegradable chitin conduits in combination with bone marrow mesenchymal stem cell transplantation after right spinal cord hemisection injury. Immunohistochemical staining revealed that biological conduit sleeve bridging reduced glial scar formation and spinal muscular atrophy after spinal cord hemisection. Bone marrow mesenchymal stem cells survived and proliferated after transplantation in vivo, and differentiated into cells double-positive for S100 (Schwann cell marker) and glial fibrillary acidic protein (glial cell marker) at 8 weeks. Retrograde tracing showed that more nerve fibers had grown through the injured spinal cord at 14 weeks after combination therapy than either treatment alone. Our findings indicate that a biological conduit combined with bone marrow mesenchymal stem cell transplantation effectively prevented scar formation and provided a favorable local microenvironment for the proliferation, migration and differentiation of bone marrow mesenchymal stem cells in the spinal cord, thus promoting restoration following spinal cord hemisection injury.

Mortality of HIV infected clients treated with methadone maintenance treatment in Yili Kazakh autonomous prefecture / 中华预防医学杂志

<p><b>OBJECTIVE</b>To investigate the mortality of HIV infected clients from methadone maintenance treatment (MMT) clinics in Yili Kazakh autonomous prefecture as well as the factors associated with mortality of HIV infected clients.</p><p><b>METHODS</b>A retrospective cohort study was performed. Data of 860 cases were collected from National Methadone Maintenance Treatment database, National AIDS/HIV database and antiretroviral therapy (ART) treatment database for adults. Information collected included demographic information of HIV infected clients, methadone daily treatment information, CD4 testing information, ART treatment information and death information. Recruiting began from August, 2005 through May, 2011. Cox proportional regression was used to identify factors associated with mortality. The proportional hazard assumption was assessed using Schoenfeld's residuals test. Missing values were imputed using the multiple linear regression method. R software (version 2.13.0) was used to perform data analysis.</p><p><b>RESULTS</b>A total of 860 HIV positive MMT clients were analyzed. The methadone dose for study subjects was (38.2 ± 20.7) mg/d. 27.8% (239/860) of study subjects participated in ART treatment, 38.7% (333/860) had never tested for CD4 count. The age for study subjects was (32.9 ± 6.4) years old. Among all these subjects, 67.3% (579/860) were married. During the observation period, 151 deaths were observed in 2192.9 person years. The average observation time was 2.6 year for each subject. The all-cause mortality rate was 68.9‰. Cox proportion model showed that ART treatment (HR = 0.53, 95%CI: 0.32 - 0.88), baseline CD4 count at 200 - 350 cells/µl (HR = 0.35, 95%CI: 0.20 - 0.60), baseline CD4 count more than 350 cells/µl (HR = 0.16, 95%CI: 0.09 - 0.29), and marriage (HR = 0.55, 95%CI: 0.37 - 0.82) were associated with less mortality compared with control group. Age (more than 45 years old) (HR = 5.20, 95%CI: 2.60 - 10.20) and sharing needles (HR = 1.40, 95%CI: 1.02 - 2.00) were risk factors associated with death.</p><p><b>CONCLUSION</b>High mortality rate was observed among HIV infected clients. Methadone clinic should provide ART treatment or ART referral services.</p>

Comparison of carcinoembryonic antigen prognostic value in serum and tumour tissue of patients with colorectal cancer.

OBJECTIVE: Carcinoembryonic antigen (CEA) in the serum and the tumour tissue of colorectal cancer (CRC) patients is the most commonly used tumour marker for the diagnosis and evaluation of prognosis or recurrence after treatment, but the role remains controversial. The objective of this study was to compare the prognostic value of CEA both in serum and tumour tissue in CRC. METHOD: A total of 173 patients with CRC in stages I-III were retrospectively assessed with the endpoint of recurrence or metastasis after curative operation. CEA was assessed both in serum and tumour tissue. RESULTS: 37.0% (64/173) patients had a high level of CEA in serum (S-CEA) while 39.3% (68/173) had high CEA in tumour tissue (T-CEA). There were no significant differences in clinico-pathological features between the low and high S-CEA or T-CEA groups. The high S-CEA group had a worse prognosis than the low S-CEA group but the difference was not significant. The high T-CEA group had a significantly poorer prognosis than the low T-CEA group (P = 0.028) in the univariate analysis. The multivariate analysis demonstrated that the T-CEA was an independent prognosis factor in CRC. Because many factors would affect the concentration of S-CEA, there was no correlation between S-CEA and T-CEA directly. CONCLUSION: Our study suggests that a high T-CEA concentration may be a useful and independent predictor for poor outcome after surgery in CRC patients. It may be stronger than a high preoperative serum CEA level.

[Cloning, expression and purification of human heat shock protein GP96 gene in Escherichia coli].

Heat shock protein gp96 is a member of HSP90 families. It can elicits both innate and adaptive immune responses. Generally it is essential to obtain enough amounts of pure gp96 to meet the needs of study and application. But the recombinant gp96 in E. coli is easy to degrade and form aggregates in certain conditions. In the experiment, first cloned human gp96 gene into pET-30a vector and expressed the recombinant in E. coli Blstar. Then purified gp96 by Ni-affinity column, anion exchange column and Gel-filtration in turn. In the end, removes most degraded fragments, aggregates and obtains certain amount of soluble gp96, which make an foundation for further investigations of the protein.