Association of vitamin D receptor gene polymorphisms with susceptibility to bone and joint tuberculosis in Chinese Han population / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the association between vitamin D receptor (VDR) gene Apa I polymorphism and the susceptibility to bone and joint tuberculosis in Chinese Han population.</p><p><b>METHODS</b>Between May, 2015 and June, 2016, 100 patients with bone and joint tuberculosis and 100 healthy volunteers were recruited concomitantly in Heyuan Hospital of Traditional Chinese Medicine. Vitamin D receptor gene Apa I polymorphisms in these subjects were analyzed using SNaPshot.</p><p><b>RESULT</b>The genotype frequencies of Apa I-AA, Apa I-Aa and Apa I-aa were 51%, 41%, and 8% in the case group and 33%, 55%, and 12% in the control group, respectively, showing significant differences between the two groups (P<0.05). The genotype of Apa I-AA was significantly higher in the case group with an odds ratio (OR) of 2.073 (95% CI: 1.142-3.763).</p><p><b>CONCLUSION</b>The Apa I polymorphisms of the VDR gene are associated with the susceptibility to bone and joint tuberculosis in Chinese Han population, and individuals with a Apa I-AA genotype are at greater risks to develop bone and joint tuberculosis.</p>

Fabrication of a new composite scaffold material for delivering rifampicin and its sustained drug release in rats / 南方医科大学学报

<p><b>OBJECTIVE</b>To fabricate a new composite scaffold material as an implant for sustained delivery of rifampicin and evaluate its performance of sustained drug release and biocompatibility.</p><p><b>METHODS</b>The composite scaffold material was prepared by loading poly(lactic-co-glycolic) acid (PLGA) microspheres that encapsulated rifampicin in a biphasic calcium composite material with a negative surface charge. The in vitro drug release characteristics of the microspheres and the composite scaffold material were evaluated; the in vivo drug release profile of the composite scaffold material implanted in a rat muscle pouch was evaluated using high-performance liquid chromatography. The biochemical parameters of the serum and liver histopathologies of the rats receiving the transplantation were observed to assess the biocompatibility of the composite scaffold material.</p><p><b>RESULTS</b>The encapsulation efficiency and drug loading efficiency of microspheres were (56.05±5.33)% and (29.80±2.88)%, respectively. The cumulative drug release rate of the microspheres in vitro was (94.19±5.4)% at 28 days, as compared with the rate of (82.23±6.28)% of composite scaffold material. The drug-loaded composite scaffold material showed a good performance of in vivo drug release in rats, and the local drug concentration still reached 16.18±0.35 µg/g at 28 days after implantation. Implantation of the composite scaffold material resulted in transient and reversible liver injury, which was fully reparred at 28 days after the implantation.</p><p><b>CONCLUSION</b>The composite scaffold material possesses a good sustained drug release capacity and a good biocompatibility, and can serve as an alternative approach to conventional antituberculous chemotherapy.</p>

Biological characteristics of human degenerative vertebral endplate cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To observe the morphology and phenotypes of cells extracted from the endplate in the intervertebral discs and identify the factors affecting their biological characteristic.</p><p><b>METHODS</b>The intervertebral disc endplate were digested enzymatically, and the morphology of the obtained cells was examined under light microscope. Immunhistochemical analysis of collagen II and real-time PCR was carried out, and the morphologies, viability, cell growth, apoptosis and chondrocyte matrix production were compared between the cells isolated from the degenerative and normal vertebral endplates.</p><p><b>RESULTS</b>The cells in primary culture presented with spherical and oval morphology, and the cytoplasm was stained blue with toluidine blue. The morphologies of the cartilage endplate cells and the articular cells were almost identical. All the freshly isolated cells expressed collagen II. The degenerative vertebral endplate cells showed decreased expression of collagen II with increased apoptotic cells as compared with normal vertebral endplate cells.</p><p><b>CONCLUSION</b>The intervertebral disc endplate cells, like articular cartilage cells, express cartilage-specific matrix proteins. Degenerative vertebral endplate cells show decreased cell vitality with increases cell apoptosis.</p>

Expression of hypoxia-inducible factor-1alpha and matrix metalloproteinase-2 in degenerative lumbar intervertebral disc / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the expression of hypoxia-inducible factor-1alpha (HIF-1alpha) and matrix metalloproteinase-2 (MMP-2) in degenerative human intervertebral disc.</p><p><b>METHODS</b>Specimens of the nucleus pulposus of the degenerative discs were obtained from patients with lumbar disc herniation (experimental group), and those from young patients suffering thoracolumbal vertebral bursting fracture served as the control. The experimental group was divided into three subgroups according to the magnetic resonance imaging (MRI) results. The tissue specimens from all the groups were examined for HIF-1alpha and MMP-2 expressions using immunohistochemistry.</p><p><b>RESULTS</b>The tissues in the experimental group showed significantly higher expressions of HIF-1alpha and MMP-2 than those in the control group (P<0.05), and the expressions increased significantly with the severity of the degenerative changes of the intervertebral discs (P<0.05). A positive correlation was found between the expressions of the HIF-1alpha and MMP-2 in degenerative intervertebral discs.</p><p><b>CONCLUSION</b>HIF-1alpha and MMP-2 may participate in the degeneration of human intervertebral discs, in which process their expressions show a common pattern of enhancement with the progression of the condition.</p>

Complications of the anterior surgical approach for thoracolumbar spine tuberculosis: causes and countermeasures / 南方医科大学学报

<p><b>OBJECTIVE</b>To assess the effect of the anterior surgical approach for thoracolumbar spine tuberculosis and analyzed the causes of the surgical complications and the countermeasures.</p><p><b>METHODS</b>From Jan 1996 to Dec 2005, 120 patients with thoracolumbar spine tuberculosis underwent operations through the anterior approach either following the primary diagnosis (115 cases) or for recurrence (5 cases).</p><p><b>RESULTS</b>Intraoperative pleural rupture occurred in 4 cases, and rupture of the external iliac vein occurred 1 case. Three patients had damages of the T12 dorsal ramus. One patient developed venous embolism of the lower extremity after the operation, two had paralytic ileus and 1 had false diabetes insipidus. Of the 5 recurrent patients, 1 died due to alcoholic cirrhosis and acute liver failure, 1 received a third operation for loosened internal fixation, and 1 had recurrence due to extensive drug resistance (XDR).</p><p><b>CONCLUSION</b>Standardized antituberculous therapy is fundamental for preventing the recurrence of tuberculosis, and individualized antituberculous therapy adjustment according to the results of bacterial culture and drug sensitivity tests can be the most effective means for preventing drug resistance and reducing tuberculosis recurrence.</p>

Evaluation of the biocompatibility of pectin/poly vinyl alcohol composite hydrogel as a prosthetic nucleus pulposus material / 南方医科大学学报

<p><b>OBJECTIVE</b>To evaluate the biocompatibility of pectin/poly vinyl alcohol composite (CoPP) hydrogel for use as a prosthetic nucleus pulposus material.</p><p><b>METHODS</b>The in vitro cytotoxicity of CoPP hydrogel was tested in NCTC L929 cells, which were divided into normal control group, negative control group [treated with poly (vinyl alcohol) hydrogel, PVA], experimental group (treated with CoPP) and positive control group (0.64% phenol). The optical density of the cells on days 2, 4, and 7 of the corresponding treatments was determined and the relative growth rate calculated. For in vivo biocompatibility evaluation, dehydrated CoPP and PVA hydrogel were respectively implanted into the left and right gluteus of SD rats, and the wound healing and general status were observed. The muscular tissues containing the implants were taken 1, 4, and 12 weeks after the implantation for gross observation and microscopic observation of the inflammatory cell infiltration (ICI) and formation of the fibrous capsulation around the implants.</p><p><b>RESULTS</b>The L929 cells incubated with PVA and CoPP group both grew well, with relative growth rate over 80% and 75%, respectively. The cytotoxicity of PVA and CoPP was both lower than grade 1. In contrast, the relative growth rate in the positive control group was below 24%, with cytotoxicity over grade 4. In the SD rats, ICI of grade IV occurred in the muscular tissues around the PVA and CoPP implants at 1 week without formation of complete capsule, and at 4 weeks, ICI was lowered to grade 1 with grade 4 capsular reaction. Till week 12, the ICI and capsular reaction were both first grade.</p><p><b>CONCLUSION</b>CoPP hydrogel has in vitro grade 0 or 1 cytotoxicity and causes only mild inflammation after implantation in rats, suggesting good biocompatibility of the material.</p>

Effect of prosthetic nucleus pulposus replacement on stress distributions of lumbar disc endplate / 中华外科杂志

<p><b>OBJECTIVE</b>To determine the stress distribution on endplate after lumbar prosthetic disc nucleus (PDN) replacement.</p><p><b>METHODS</b>Six fresh lumbar vertebrae with normal Modic classification were harvested. The specimens were used to establish L4-5 intact, nucleotomy, prosthetic nucleus pulposus replacement models. Vertical compression tests were performed with MTS machine at the rate 50 N per second to maximum load of 1300 N. The stress under the endplate were measured directly with accurate pressure sensors.</p><p><b>RESULTS</b>For intact specimens, the stress on the endplate maintained higher in the central zone of the endplate, and decreased gradually to the periphery, and was well-distributed. After nucleotomy, the stress on the central zone of endplate was significantly decreased, and increased stress occurred in the periphery of endplate. After PDN replacement, the stress on the central zone of endplate was found more 15.1% higher than that in intact disc (P < 0.05), and the neighboring zone also showed higher stress measurements.</p><p><b>CONCLUSIONS</b>After lumbar prosthetic disc nucleus replacement, the stress concentration on endplate may occur in the central zone of prosthetic disc nucleus insertion. Therefore, the prosthetic nucleus pulposus with suitable shape, proper biomechanical functions and updated materials need further study.</p>

Perioperative complications of single-stage surgical management for spinal tuberculosis / 中华外科杂志

<p><b>OBJECTIVE</b>To analyze the causes of perioperative complications of single-stage surgical management for spinal tuberculosis.</p><p><b>METHODS</b>One hundred and twenty patients with thoracic, lumbar and lumbosacral spinal tuberculosis were treated by single-stage surgical management from January 1997 to January 2006 in our unit, including seventy-five males and forty-five females. The mean age was 34.5 (range 17 to 68) years old. The lesion ranged from T(6) to S(1). The anterior procedures of anterior debridement, interbody fusion and anterior fixation were carried out in sixty-five cases, posterior procedures in twenty-six cases, and combined anterior and posterior procedures in twenty-nine cases, respectively. The complications that occurred during surgical procedure and 1 month after operation were recorded. Underlying causes were analysed.</p><p><b>RESULTS</b>There were 10 cases (8.3%) were recorded of mild to severe complications during perioperative period in 120 patients. The complications and underlying causes were as follows: (1) A patient died from liver failure and blood coagulation dysfunction after operation due to inappropriate surgical timing (n = 1), in which case the patient with lumbosacral spinal tuberculosis also suffered from alcoholic liver sclerosis and dysfunction. (2) False diabetes insipidus (n = 1) and deep vein thrombosis of lower limbs (n = 1) occurred as result of surgical trauma. (3) Tear of iliac vein (n = 1) occurred with lumbosacral spinal tuberculosis because of unclear anatomical relationships when anterior debridement was performed. Injury of lumbar nerve roots (n = 3) and hemothorax (n = 1) also occurred due to mispractice of surgical procedures. (4) Paralysis intestinal obstruction and hypokalemia (n = 2) occurred after anterior procedures for lumbar spinal tuberculosis as a result of other reasons.</p><p><b>CONCLUSIONS</b>Improper perioperative care will lead to complications of single-stage surgical procedures for spinal tuberculosis. Emphasis should be put on preoperative evaluation, surgical planning, and postoperative caring for prevention of complications.</p>

Analysis of the long-term outcome of anterior approach surgery on cervical spondylotic myelopathy / 中华外科杂志

<p><b>OBJECTIVE</b>To investigate the long-term efficacy of anterior approach surgery on cervical spondylotic myelopathy and factors affecting prognosis.</p><p><b>METHODS</b>The data in 116 patients suffered from cervical spondylosis from January 1992 to December 2000 were reviewed, including 80 male cases and 36 female cases, whose age ranged from 36 to 76 years (mean, 51 years). The preoperative course of disease was 2 months to 20 years (mean, 19 months). There were 65 cases (56.0%) with single segments involved, 44 cases (37.9%) with two segments, 7 cases (6.0%) with three segments. Ninety-eight cases were onset slowly, 18 cases with no remote cause and aggravating quickly. Three kinds of surgeries were performed: anterior cervical decompression and autoiliac bone interbody fusion, anterior cervical decompression and fusion with threaded fusion cage, anterior cervical decompression and autoiliac bone interbody fusion with anterior screw-plate system. Improvement in spinal cord function was assessed using the Japanese Orthopaedic Association (JOA) scoring system, the long-term efficacy and influential factors were also analyzed.</p><p><b>RESULTS</b>The mean follow-up time was 7 years and three months (5 - 12 years). The mean preoperative JOA score was 9.34 +/- 1.81. The mean postoperative JOA score was 10.35 +/- 1.85. At the final follow-up, the JOA score was 14.09 +/- 1.90 and the recovery rate was 63.2%. Among the total patients, 27 cases were excellent, 47 cases were fine, 23 cases were good, 19 cases were poor, the fineness rate was 63.8%. The long-term efficacy of anterior approach surgery has close correlations with time of course, age of onset, preoperative spinal cord function and the number of affected segments, but has no correlations with modes of fusion and internal fixation.</p><p><b>CONCLUSIONS</b>The patients will be attentively observed while having a definite diagnosis of cervical spondylotic myelopathy. The good long-term results will be obtained after early anterior cervical decompression and fusion.</p>

Treatment of spondylolysis and spondylolisthesis with posterior STB thoracolumbar transpedicular screw-plate spine fixation system / 中华外科杂志

<p><b>OBJECTIVE</b>To observe the clinical effect of a self-designed posterior STB thoracolumbar transpedicular screw-plate system in the treatment of spondylolysis and spondylolisthesis.</p><p><b>METHODS</b>This STB screw-plate system is developed with titanium alloy (TC4, Ti6Al4V). During December, 1999 and January, 2001, this system was applied in 51 cases, including lumbar spondylolysis and spondylolisthesis (36 cases), degenerative lumbar instability (15 cases). The patients were aged 22 - 78 years, mean age: 47.5 - years; among them there were 14 male cases, 37 female cases; There were 15 cases degenerative spondylolisthesis with grade I-II slip, 36 cases of spondylolysis and spondylolisthesis, including 34 cases with grade I-II slips and 2 cases with grade III slips; single level of 33 cases, two levels 3 cases. Decompression was performed for the 43 cases with interbody fusion using iliac crest or bilateral-lateral fusion using demineralized bone matrix and 8 cases were fixed with demineralized bone matrix fusion without decompression.</p><p><b>RESULTS</b>All the operations heeded about 60 - 120 minutes, and during the operations bleeding amounts were 200 - 500 ml. The cases completely recovered to work or normal action after 3 months of surgeries. 46 of all cases were achieved to satisfactorily reduction and clinical effect, 5 cases of grade II-III remained incomplete reduction (grade I slip).</p><p><b>CONCLUSION</b>This STB system has advantages of biomechanical stability and reduction capability and its effect in clinical application is undoubtedly positive.</p>