Critical Review of Synthesis, Toxicology and Detection of Acyclovir.

Acyclovir (ACV) is an effective and selective antiviral drug, and the study of its toxicology and the use of appropriate detection techniques to control its toxicity at safe levels are extremely important for medicine efforts and human health. This review discusses the mechanism driving ACV's ability to inhibit viral coding, starting from its development and pharmacology. A comprehensive summary of the existing preparation methods and synthetic materials, such as 5-aminoimidazole-4-carboxamide, guanine and its derivatives, and other purine derivatives, is presented to elucidate the preparation of ACV in detail. In addition, it presents valuable analytical procedures for the toxicological studies of ACV, which are essential for human use and dosing. Analytical methods, including spectrophotometry, high performance liquid chromatography (HPLC), liquid chromatography/tandem mass spectrometry (LC-MS/MS), electrochemical sensors, molecularly imprinted polymers (MIPs), and flow injection-chemiluminescence (FI-CL) are also highlighted. A brief description of the characteristics of each of these methods is also presented. Finally, insight is provided for the development of ACV to drive further innovation of ACV in pharmaceutical applications. This review provides a comprehensive summary of the past life and future challenges of ACV.

Association between metabolic syndrome and knee osteoarthritis: a cross-sectional study.

BACKGROUND: Osteoarthritis (OA) is the most prevalent chronic joint disease in China. The aim of this study was to examine the association between metabolic syndrome (MetS) and knee OA in a population-based Chinese study. METHODS: Data included in this analysis is from a cross-sectional study, i.e., the Xiangya Hospital Health Management Center Study. MetS was diagnosed according to the criteria defined by the Chinese Diabetes Society. Radiographic knee OA was defined as changes equivalent to Kellgren-Lawrence (K-L) grade 2 or above at least one side. Associations between MetS and its components with OA were evaluated by conducting multivariable adjusted logistic regression. RESULTS: A total of 5764 participants were included in the present study. The unadjusted OR (1.27, 95%CI: 1.10-1.47, P = 0.001), age-sex adjusted OR (1.17, 95%CI: 1.01-1.36, P = 0.041) and multivariable adjusted OR (1.17, 95%CI: 1.01-1.36, P = 0.043) all suggested a positive association between MetS and knee OA. Besides, its components (e.g., overweight, hypertension and dyslipidemia) were also associated with the prevalence of radiographic knee OA respectively, after adjusting for some confounding factors. In addition, with the accumulation of MetS components, the prevalence of knee OA increased. Furthermore, MetS as a whole was associated with the prevalence of knee osteophyte (OSP) (OR = 1.72, 95%CI: 1.42-2.09, P < 0.001), but not joint space narrowing (JSN) (OR = 1.06, 95%CI: 0.91-1.23, P = 0.449). CONCLUSIONS: The findings of the present study indicated that there was a positive association between the prevalence of MetS and knee OA. However, MetS as a whole was associated with the higher prevalence of knee OSP, but not JSN, which should shed light on our understanding the association between MetS and OA.

RANK pathway in giant cell tumor of bone: pathogenesis and therapeutic aspects.

Giant cell tumor is a relatively uncommon but painful tumor of bone, which can metastasize to the lungs. The RANK pathway is often reported to be involved in the pathogenesis of giant cell tumor of bone (GCTB). This pathway is a key signaling pathway of bone remodeling that plays a critical role in differentiation of precursors into multinucleated osteoclasts, and activation of osteoclasts leading to bone resorption. Dysregulation of RANK ligand (RANKL)-RANK-osteoprotegerin (OPG) signaling cascade induces the imbalance between bone formation and bone resorption, which leads to the changes in bone mass, increases osteoclast-mediated bone destruction, bone metastasis, and the progression of existing skeletal tumors. Recent evidences have shown that targeting the components of RANKL-RANK-OPG signaling pathway is a promising approach in the treatment of GCTB. This review study has focused on the association of RANKL-RANK-OPG pathway in the pathogenesis and progression of GCTB as well as discussed the possible therapeutic strategies by targeting this pathway.

Lipoic acid prevents steroid-induced osteonecrosis in rabbits.

The objective of this study was to investigate in vivo effects of lipoic acid (LA) in preventing steroid-induced osteonecrosis and the possible pathway in a rabbit model. Sixty rabbits were divided into 2 groups: rabbits were intraperitoneally injected with LA aqueous solution at 36 mg/kg of body weight per day for 4 weeks in Group A and rabbits were injected with physiologic saline (PS) as a control in Group B. At 2 weeks after starting treatment, they were intramuscularly injected once with 20 mg/kg of methylprednisolone acetate (MPSL). The femora were histopathologically examined for the presence of osteonecrosis. The plasma levels of total cholesterol (TC), low-density lipoprotein (LDL), high-density lipoprotein (HDL), glutathione (GSH), endothelin (ET) and malondialdehyde (MDA) were assayed at 2 weeks after the injection of MPSL. The incidence of osteonecrosis was significantly higher in Group B (73.1%) than in Group A (20.8%). The GSH level was higher in Group A than in Group B after the LA injection. The plasma MDA and ET levels were lower in Group A than in Group B at 2 weeks after the MPSL administration. Lipoic acid can prevent the development of steroid-induced osteonecrosis in rabbits. Inhibited oxidative stress and amendment of vascular endothelial dysfunction is a possible mechanism for this effect.

Which treatment is the best for giant cell tumors of the distal radius? A meta-analysis.

BACKGROUND: Intralesional excision and en bloc resection are used to treat giant cell tumors (GCTs) of the distal radius. However, it is unclear whether one provides lower rates of recurrences and fewer complications, and whether the use of polymethylmethacrylate (PMMA) after curettage reduces the risk of recurrence. QUESTIONS/PURPOSES: We examined whether curettage was associated with lower rates of recurrence and fewer major complications compared with en bloc excision, and whether PMMA resulted in lower rates of recurrence compared with a bone graft. METHODS: We systematically searched the literature using the criteria, "giant cell tumor" AND "curettage" OR "intralesional excision" OR "resection". Six relevant articles were identified that reported data for 80 curettage cases (PMMA, n = 49; bone graft, n = 26; no PMMA or bone grafts, n = 5) and 59 involving en bloc excision. A meta-analysis was performed using these data. RESULTS: Overall, patients in the intralesional excision group had a higher recurrence rate (relative risk [RR], 2.80; 95% CI, 1.17-6.71), especially for Campanacci grade 3 GCTs (RR, 4.90; 95% CI, 1.36-17.66), yet fewer major complications (RR, 0.21; 95% CI, 0.09-0.54) than the en bloc resection group. The use of PMMA versus bone graft did not affect the recurrence rate (RR, 0.98; 95% CI, 0.44-2.17). CONCLUSIONS: Based on data obtained from the limited number of studies available, intralesional excision appears to be more appropriate for the treatment of local lesions (e.g., grades 1 and 2) than grade 3 GCTs of the distal radius. Moreover, PMMA was not additionally effective as an adjuvant. LEVEL OF EVIDENCE: Level III, therapeutic study (systematic review). See Guidelines for Authors for a complete description of levels of evidence.

Effect of epimedium pubescen flavonoid on bone mineral status and bone turnover in male rats chronically exposed to cigarette smoke.

BACKGROUND: Epimedii herba is one of the most frequently used herbs in formulas that are prescribed for the treatment of osteoporosis in China and its main constituent is Epimedium pubescen flavonoid (EPF). However, it is unclear whether EPF during chronic exposure to cigarette smoke may have a protective influence on the skeleton. The present study investigated the effect of EPF on bone mineral status and bone turnover in a rat model of human relatively high exposure to cigarette smoke. METHODS: Fifty male Wistar rats were randomized into five groups: controls, passive smoking groups and passive smoking rats administered EPF at three dosage levels (75, 150 or 300 mg/kg/day) in drinking water for 4 months. A rat model of passive smoking was prepared by breeding male rats in a cigarette-smoking box. Bone mineral content (BMC), bone mineral density (BMD), bone turnover markers, bone histomorphometric parameters and biomechanical properties were examined. RESULTS: Smoke exposure decreased BMC and BMD, increased bone turnover (inhibited bone formation and stimulated its resorption), affected bone histomorphometry (increased trabecular separation and osteoclast surface per bone surface; decreased trabecular bone volume, trabecular thickness, trabecular number, cortical thickness, bone formation rate and osteoblast surface per bone surface), and reduced mechanical properties. EPF supplementation during cigarette smoke exposure prevented smoke-induced changes in bone mineral status and bone turnover. CONCLUSION: The results suggest that EPF can prevent the adverse effects of smoke exposure on bone by stimulating bone formation and inhibiting bone turnover and bone resorption.

Biomechanical evaluation of tenodesis reconstruction in ankle with deltoid ligament deficiency: a finite element analysis.

PURPOSE: Isolated deltoid ligament injuries are relatively uncommon but can be a significant source of pain and disability. Several approaches to deltoid reconstruction have been reported. However, there is no previous comparative study of Wiltberger, Deland, Kitaoka and Hintermann procedures with respect to biomechanical characteristics such as kinematics, ligaments and grafts stresses using finite element analysis. The purpose of this study was to evaluate the biomechanical results of those deltoid ligament reconstructions using finite element analysis. METHODS: A three-dimensional finite element model of the ankle including six bony structures, cartilage and nine principal ligaments surrounding the ankle joint complex was developed and validated. In addition to the intact model, superficial deltoid-deficient, deltoid-deficient, Wiltberger reconstruction, Deland reconstruction, Kitaoka reconstruction and Hintermann reconstruction models were simulated. Then, the forces in the ligaments and grafts and the kinematics of talus and calcaneus were predicted for an eversional or external torque through the range of ankle flexion. RESULTS: No reconstructions could completely restore the values for ankle flexibility and the stresses of the lateral ligaments to normality. The Kitaoka procedure was the most effective technique in eliminating external rotation displacement. The Deland procedure restored better the talar tilt than the other three reconstructions. CONCLUSION: This study showed that Kitaoka and Deland procedures have advantages with regard to rotational stabilities as well as ligaments stress in comparison with other methods.

Effect of Epimedium pubescen flavonoid on bone mineral density and biomechanical properties of femoral distal end and femoral diaphysis of passively smoking male rats.

BACKGROUND: Based on a rat model of human relatively high exposure to cigarette smoke, this study aimed to estimate whether Epimedium pubescen flavonoid (EPF) may prevent a smoke-induced decrease in bone mineral density (BMD) and weakening of the biomechanical properties of bone. METHODS: Fifty male Wistar rats were randomized into five groups: controls, passively smoking groups and passively smoking rats administered EPF at three dosage levels (75, 150 or 300 mg/kg/day) in drinking water for 4 months. A rat model of passive cigarette smoking was prepared by breeding male rats in a cigarette-smoking box for 4 months. Bone metabolic makers, BMD and biomechanical properties of the femoral distal end and femoral diaphysis were examined. RESULTS: Exposure to cigarette smoke decreased the BMD, affected bone turnover (inhibited bone formation and stimulated its resorption) and weakened the biomechanical properties of the femur at its distal end and diaphysis. EPF supplementation during cigarette smoke exposure prevented the decrease in BMD, accelerated bone turnover and weakened the biomechanical properties of bone. CONCLUSION: Our data suggest that EPF supplementation can prevent the adverse effects of smoke exposure on BMD and biomechanical properties by inhibiting bone turnover and preventing bone resorption, and in this way it can decrease the risk of bone fractures.

[Raman spectroscopy analysis of carbon structural evolution of diesel particulate matters with the treatment of nonthermal plasma].

Original and nonthermal plasma treated particulate matters (PM) samples of a diesel were obtained and characterized by Raman spectroscopy. A five-bands model was adopted for Raman spectrum curve fitting. As parameters involving most information about carbon structure, variation of FWHM of D1 band and D3 relative intensity were analyzed. It was found that original PM presented higher graphical structural order and lower chemical heterogeneity with the increase in the diesel load. After the treatment of NTP, the graphical structural order and chemical heterogeneity of PM kept at a relative stable level, affected very slightly by diesel load. Meanwhile, the amount of molecular carbon in PM increased. Further study for relation between structural evolution and chemical reactivity of PM with chemical kinetics would make Raman spectroscopy of great promise to become an important method for PM characterization, which could provide basis for more effective removal.

Bone turnover in passive smoking female rat: relationships to change in bone mineral density.

BACKGROUND: Many studies have identified smoking as a risk factor for osteoporosis, but it is unclear whether passive smoking has an effect on bone mineral density and bone turnover and if such an effect could cause osteoporosis.The purpose of the study was to investigate the effect of passive smoking on bone mineral density (BMD) and bone turnover and the relationship between BMD and bone turnover in female rat. METHODS: Forty-eight female Wistar rats were randomized into six groups: 2-month, 3-month,4-month smoke-exposed rats and their controls. A rat model of passive cigarette smoking was prepared by breeding female rats in a cigarette-smoking box for 2, 3 or 4 months. Serums were analyzed for levels of osteocalcin, bone-specific alkaline phosphatase (b-ALP) and Tartrate-resistant acid phosphatase 5b (TRACP 5b). BMD was assessed at lumbar vertebrae and femur by dual energy X-ray absorptiometry in passive smoking rats and in control rats. RESULTS: BMD of lumbar spine and femur was lower in 4-month smoke-exposed female rats than that in controls. However, there was no significant difference in serum osteocalcin levels between smoke-exposed rats and controls. Significantly lower b-ALP and higher TRACP 5b were found in the 3-month or 4-month smoke-exposed rats compared to controls. Subsequent analysis showed that b-ALP positively correlated with BMD of the lumbar vertebrae(r = 0.764, P = 0.027) and femur(r = 0.899, P = 0.002) in 4-month smoke-exposed female rats. Furthermore, TRACP 5b levels negatively correlated with BMD of lumbar vertebrae (r = -0.871, P = 0.005) and femur (r = -0.715, P = 0.046) in 4-month smoke-exposed female rats. CONCLUSION: Our data suggest that smoke exposure can inhibit bone formation and increase bone resorption. The hazardous effects of passive smoking on bone status are associated with increased bone turnover in female rat.

Finite element analysis of nonanatomic tenodesis reconstruction methods of combined anterior talofibular ligament and calcaneofibular ligament deficiency.

BACKGROUND: Nonanatomic tenodesis reconstruction procedures have been used for lateral ankle ligament reconstruction. However, there has been no comparison of Watson-Jones, Evans, and Chrisman-Snook procedures with respect to biomechanical characteristics such as kinematics, ligaments and grafts stresses using finite element analysis. METHODS: A three-dimensional finite element model of the ankle including seven bony structures, cartilage and nine principal ligaments surrounding the ankle joint complex was developed and validated. In addition to the intact model, combined anterior talofibular ligament (ATFL) and calcaneofibular ligament (CFL) deficient, Watson-Jones reconstruction, Evans reconstruction and Chrisman-Snook reconstruction models were simulated. Then, the forces in the ligaments and grafts and the kinematics of the talus and calcaneus were predicted for an inversion or internal torque of 1.7 Nom and an anterior drawer stress of 150 N through the range of ankle motion. RESULTS: All three operations were able to improve the stability of the ankle, but the effectiveness of each procedure was dependent on the direction of the stress applied and the position of the ankle in dorsiflexion-plantarflexion. CONCLUSION: This study showed that the Watson-Jones procedure has advantages with regard to anterior and rotational stabilities as well as ligaments and grafts stresses in comparison with other nonanatomic tenodesis reconstruction methods. CLINICAL RELEVANCE: The knowledge of stress inside the ligaments and reconstructed grafts could help to better understand the biomechanical behavior of the reconstructed joint.

Case report: severe melorheostosis involving the ipsilateral extremities.

Melorheostosis is a rare, noninheritable bone dysplasia characterized by its classic radiographic feature of flowing hyperostosis resembling dripping candle wax, generally on one side of the long bone. The condition originally was described by Leri and Joanny in 1922. Its etiology remains speculative, and treatment in most instances has been symptomatic. Melorheostosis usually affects one limb, more often the lower extremity, and rarely the axial skeleton. We report a rare case of severe melorheostosis in the ipsilateral upper and lower extremities with normal contralateral extremities. The plain radiographs revealed almost all the bones in the affected extremities, from clavicle and scapula to distal phalanges of the fingers and from femur to distal phalanges of the toes, presented extensive, dense hyperostosis and heterotopic ossification in the periarticular soft tissue. Physical examination showed considerable swelling and deformities of the left limbs, stiffness and distortion of the joints, and anesthesia in the left ulnar regions of the forearm and hand. The examination of the right side was normal. Computed tomography scans showed multiple areas of classic candle wax-like hyperostosis and narrowing or disappearance of the medullary cavity. Histologic analysis confirmed the clinical and imaging diagnosis and revealed extremely dense sclerotic bone of cortical pattern.

[Development of static three dimensional screw-plate system and the biomechanic features thereof, a comparative study].

OBJECTIVE: To develop a new internal fixation device and the matching tools for subtrochanteric fracture, investigate the biomechanical features thereof, and compare its effects with those of other instruments. METHODS: A new internal fixation device, static three dimensional screw-plate system: (STDSP) was developed based on the anatomical parameters and the biomechanical characteristics of proximal femur and combined with the biomechanical advantages of the model of three-dimensional plate and multiple-screws plate fixation. Sixteen paired cadaveric adult femurs were randomly divided into 2 equal groups: fracture healing group undergoing insertion of implant and then taking out thereof with a nail left, and fracture group with a trapezoid defect to mimic subtrochanteric fracture 4 of which were fixed with dynamic hip screw (DHS) and STDSP or Gamma nail and STDSP. All the specimens underwent A-P position four point bending test, axial compression test, torsion test, and destroyable test. RESULTS: (1) In the fracture group, A-P position four point bending test showed that the stretch displacement of STDSP group was (0.221 +/- 0.089) mm, significantly smaller than that of the Gamma nails group [(0.506 +/- 0.086) mm, t = 38.278 P = 0.000]; Axial compression test showed that the inferior displacement of the STDSP group was (2.804 +/- 0.585) mm, significantly larger than that of the Gamma nail group [(1.874 +/- 0.549) mm, t = -5.454, P = 0.012]; Torsion test showed that the torque values at 50 and 100 of the STDSP group were (3.78 +/- 0.84) J and (2.3 +/- 1.08) J, both significantly larger than those of the Gamma nail groups [(2.3 +/- 1.08) J and (4.35 +/- 1.81) J, t = -4.729 P = 0.018, and t = -3.227 P = 0.048] and those of the DHS group [(7.3 +/- 1.273) J and (4.325 +/- 0.88) J respectively, t = -3.242 P = 0.048]; and torsion destroyable test showed that the torque values at 200 of the STDSP group was (21.88 +/- 2.51) J, significantly larger than those of the Gamma nail and DHS groups, [(14.36 +/- 5.01) J and (15.475 +/- 1.924) J and (12.075 +/- 1.179) J, t = -3.323 P = 0.048, t = - 3.732 P = 0.034]. (2) In the fracture healing specimens, A-P position four point bending test showed that the radial degree displacement of the STDSP group was (1. 050 +/- 0.316) mm, significantly smaller than that of the DHS group [(1.261 +/- 0.364) mm, t = 3.4 P = 0.042]. CONCLUSIONS: More capable of resisting bending than DHS and less capable of resisting axial compression, STDSP is an excellent internal fixator with good biomechanical feature in treating subtrochanteric femoral fracture.

[Biomechanical analysis of artificial intervertebral disc in a 3-dimensional finite-element model].

OBJECTIVE: To evaluate the mechanical properties of artificial lumbar intervertebral disc by finite-element (FE) analysis, to predict the mechanical influence of loading on the prosthesis after placement, especially after the long-term employment,and to offer the mechanical basis and technological means for the design optimization. METHODS: A 3-dimensional solid model was built according to the geometry of the prosthesis; finite-element analysis was applied to determine the effect of the implanted artificial disc prosthesis on the biomechanical behavior; and the data of its mechanical responses were calculated in 3 compression modes which simulated its different load conditions in vivo. Simulations were conducted in a new specially designed manner, preferably simulated load conditions in vivo. RESULTS: A finite-element model was established by generating mesh out of the prosthesis geometry. The analysis was conducted in employing models of the disc prosthesis under 3 types of emulational realism loading conditions, obtaining the distributing characteristics and data of displacement-stress-strain-energy in the structure, which are difficult to measure exactly by conventional methods. CONCLUSION: Implanted loading strongly influences prosthesis in its internal distribution of displacement-stress-strain-energy in the structure, suggesting that the disc prosthesis allows correctly reproducing a profitable motion and cushion at the implanted level. Predictive wear may occur in special parts according to the designed prosthesis mechanical structure. When implanting an artificial disc, proper size should be taken in choosing disc and the higher core could provide better mechanical characteristics. The Results may assist in optimizing artificial lumbar disc replacement primarily from a biomechanical point of view.

[Internal fixation with T type titanium plate for volar Barton's fracture].

OBJECTIVE: To evaluate the operative method and the clinical efficacy of volar Barton's fracture treated by internal fixation with T type titanium plate. METHODS: We performed the operation of the open reduction and internal fixation with T type titanium plate in 18 patients with volar Barton's fracture. RESULTS: The 18 patients were followed up after the operation at the average time of 13 months (6 to 31 months). X radiographs showed that all patients achieved solid bone union. Mehara's evaluation for volar Barton's fracture revealed excellent outcome in 12 patients, good in 5 patients, and fair in 1 patients. The excellent and good rate of clinical results was 94.4%. X-radiographs showed that the volar tilting angle was 8-18 (mean=11.0) degree, and the ulnar inclining angle was 16-26 (mean=22.4) degree. There was no shortening of the radius. CONCLUSION: The operative treatment with titanium T type plate fixation for volar Barton's fracture is in favor of fracture anatomic reduction, solid internal fixation, and catagmatic concrescence. It is beneficial for functional recovery of the wrist at the utmost. The outcome in the near future is satisfactory. It is an ideal method for volar Barton's fracture.

[Design and manufacture of the static 3 dimensional screw-plate system and its matching tools].

OBJECTIVE: To design and manufacture a new type instrument and its matching tools for the proximal femur. METHODS: A new type instrument of subtrochanterical fracture-static 3-dimensional screw-plate system(STDSP)was designed and manufactured. The different types of accessory instruments which adapted to STDSP,the aiming guide, and the accessory tools were also designed and manufactured, and they were tested on bones. RESULTS: STDSP included 3 special lag screws and 1 anatomic plate. The lag screws distributed in femoral neck like "or"shape. There was 135 degree between the lag screws and femoral shaft. The shape of the plate was similar to the anatomic structure of the proximal thighbone. The posterior screw was stably connected to the plate. The plate was affixed crosswise to the lateral and anterior side by bicortical screws. The aiming guides and all kinds of accessory tools could help to install STDSP exactly and conveniently,which was verified on cadavers and X-ray photographs. CONCLUSION: STDSP has the function of dynamic compressing in 3-dimensional space, and can match with the structure of the proximal femur preferably. STDSP may be a suitable instrument to the subtrochanteric fractures. The accessory apparatus of STDSP has simple configuration,and can let the STDSP be installed accurately, conveniently and rapidly.

Construction of recombinant baculovirus Ac-CMV-hSox9 for gene therapy of intervertebral disc degeneration.

OBJECTIVE: To construct the recombinant baculovirus Ac-cytomegalovirus (CMV)-hSox9 for gene therapy of intervertebral disc degeneration. METHODS: Bac-to-Bac system was used for the construction of baculovirus Ac-CMV-hSox9. The cDNA of hSox9 was first cloned into a plasmid vector under the control of CMV promotor to generate the donor plasmid pFastBacDuljgreen fluorescene protein (GFP)-CMV (pFGC)-hSox9. The resultant plasmid was transformed into DH10Bac cells and then the transformation mixture was spread on Luria-Bertani (LB) agarose culture medium containing isopropyl-beta-D-thiogalactoside (IPTG), X-gal, gentamicin, kanamycin and tetracycline. The white colonies were selected and cultured for amplification, and the hSox9Bacmid DNA was extracted. After verification, recombinant baculovirus Ac-CMV-hSox9 was obtained through transfecting Sf 21 cells. The expression of hSox9 gene in the intervertebral disc cells in rabbits was determined by Western blotting and immunohistochemical staining. RESULTS: Polymerase chain reaction (PCR) confirmed the presence of hSox9 gene in the recombinant baculovirus and the Sf 21 cells transfected by the baculovirus showed the expression of fluorescence protein. Western blotting and immunohistochemical staining analysis indicated that exogenous hSox9 gene was expressed in the disc cells. CONCLUSIONS: The successful construction of the recombinant baculovirus Ac-CMV-hSox9 and the confirmation of the target gene expression provides a novel expression vector system for basic research and clinical treatment of intervertebral degenerative disc disease.

[Integrity of lumbar facet joint and curative effect after a lumbar intervertebral disc operation].

OBJECTIVE: To analyze the relation between the clinical outcome and the integrity of the facets after a lumbar operation,and to provide a reference for choosing operative method and clinical prognosis. METHODS: Forty-three patients with complete data underwent uni-segment discectomy were enrolled. There were 3 surgical interventions: open-window discectomy, full or semi-laminectomy. Groups were divided based on the integrity of the facets after the operation, and the clinical symptoms and signs were evaluated using the Japanese Orthopaedic Association Back (JOA) scores at 24-month follow-up. RESULTS: Preoperative JOA scores were not significantly different among the groups (P>0.05). Compared with the facet intact group at 24-month follow-up,JOA scores were descended statistically in total uni-facetectomy group and total uni-facetectomy plus partial opposite facetectomy group (P<0.01). CONCLUSION: Keeping facets integrated plays an important role in achieving good clinical results,and the damage of facet should be avoided in the lumbar operation.

[Denaturant gradient gel electrophoresis in the genetic diagnosis of hereditary multiple exostoses].

OBJECTIVE: To detect the mutations of EXT2 gene in hereditary multiple exostoses (HME) families and to investigate the sensitivity of denaturant gradient gel electrophoresis (DGGE) in screening the mutations in EXT2 gene. METHODS: Five HME families and 3 sporadic patients were screened for the mutation detection in all exons of EXT2 gene covering the coding sequence and the flanking intronic sequence by DGGE, and DNA sequencing was performed for products with abnormal conformation. RESULTS: Among these HME patients, we found 2 disease-causing mutations: A313T (nonsense mutation) and 319 insGT (frameshift mutation). CONCLUSION: Two mutations of EXT2 gene are identified in the sample. DGGE can be an ideal choice for gene diagnoses of HME.