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find Author "ZHANG Chen" 18 results
  • Effect of B Vitamins Supplementation on Cardiovascular and Cerebrovascular Disease by Lowering Plasma Homocysteine Concentration: A Meta-analysis

    Objective To assess the effect of B vitamins supplementation on cardiovascular and cerebrovascular diseases, and also to evaluate the relationship between homocysteine and risk of cardiovascular and cerebrovascular diseases. Methods Using the words ‘homocysteine’, ‘cardiovascular disease’, ‘cerebrovascular disease’, ‘B vitamins’, and ‘randomized controlled trial’, we searched PubMed, Ovid, and Springer. We also hand searched relevant journals and conference proceedings. Randomized controlled trials published between 1998 and July 2008 which evaluated the effect of B vitamins supplementation on vascular diseases were collected. Two reviewers independently screened trials, extracted data, and evaluated the quality of included trials. The Cochrane Collaboration’s RevMan 4.2 software was used for statistical analysis. Results Sixteen trials involving 27,043 patients with vascular disease were included. Results of meta-analyses showed that no significant differences were identified between the B vitamins group and the control group for each of the four endpoints, including the risk of cardiovascular events (RR 0.98, 95%CI 0.94 to 1.03), the risk of coronary heart disease (RR 0.99, 95%CI 0.92 to 1.07), the risk of stroke (RR 0.90, 95%CI 0.80 to 1.02), and the total mortality (RR 0.98, 95%CI 0.92 to 1.05). Sensitivity analyses conducted by a random effect model or with the exclusion of low-quality trials did not change the overall results. Conclusion  The trials currently available cannot confirm the causal relationship between homocysteine and risk of cardiovascular and cerebrovascular diseases. More evidence from large-scale randomized controlled trials is needed to confirm this. There is not sufficient evidence to show that B vitamins supplementation can lower the risk of cardiovascular and cerebrovascular diseases. B vitamins supplementation should not be recommended for the secondary prevention of such diseases.

    Release date:2016-08-25 03:36 Export PDF Favorites Scan
  • NEUROPROTECTIVE EFFECTS OF RECOMBINANT ADENO-ASSOCIATED VIRUS EXPRESSING VASCULAR ENDOTHELIAL GROWTH FACTOR ON RAT TRAUMATIC SPINAL CORD INJURY AND ITS MECHANISM

    Objective To investigate the neuroprotective effects of recombinant adeno-associated virus (rAAV) expressing vascular endothel ial growth factor (VEGF) on traumatic spinal cord injury (SCI) of rat and its mechanisms. Methods The 144 male Sprague Dawley rats were randomly divided into 4 groups, and each group contained 36 rats. The rats in sham group (group A) received dorsal laminectomy without SCI and microinjection, the rats in model control group (group B), rAAV-green fluorescent protein (GFP) group (group C), and rAAV-hVEGF165-GFP group (group D) received dorsallaminectomy with SCI and injection of 20 μL sal ine, rAAV-GFP viruses, or rAAV-hVEGF165-GFP viruses, respectively. At 3 and 7 days after operation, Basso-Beattie-Bresnahan (BBB) score was used to evaluate the neurologic function. At 7 days after operation, Nissl’s body staining was used to evaluate the histopathological changes; apoptosis was confirmed by transmission electron microscope examination and TUNEL staining; the expression of aquaporin 4 (AQP-4) was detected by Western blot assay. At 1, 3, 5, and 7 days, ELISA assay was used to detect the VEGF165 protein expression. Results According to BBB scores, the neurologic function in group D was significantly better than those in groups B and C at 3 and 7 days after operation (P lt; 0.05). Nissl’s body staining showed that tissue damage in group D was significantly milder than those in groups B and C at 7 days after operation (P lt; 0.05). ELISA results showed that VEGF165 protein expression was slowly-released in low dose in group D, and the expression in group D was significantly higher than that in groups A, B, and C at 3, 5, and 7 days after operation (P lt; 0.05). The results of transmission electron microscope and TUNEL staining showed that apoptosis rate of spinal cord neurons in group D was significantly lower than that in groups B and C at 7 days after operation (P lt; 0.05). The results of Western blot showed that AQP-4 expression in group D was significantly decreased when compared with that in groups B and C at 7 days after operation (P lt; 0.05). Conclusion TherAAV expressing VEGF has neuroprotective effects by inhibiting apoptosis of spinal cord neurons and relieving spinal cord edema.

    Release date:2016-08-31 04:23 Export PDF Favorites Scan
  • STUDY ON TIME EFFECT OF GENE EXPRESSION OF RECOMBINANT ADENO-ASSOCIATED VIRUS VECTOR CO-EXPRESSING HUMAN VASCULAR ENDOTHELIAL GROWTH FACTOR 165 AND HUMAN BONE MORPHOGENETIC PROTEIN 7 GENES

    Objective To study the time effect of the gene expression of recombinant adeno-associated virus (rAAV) vector co-expressing human vascular endothel ial growth factor 165 (hVEGF165) and human bone morphogenetic protein 7 (hBMP-7) genes so as to lay a theoretical foundation for gene therapy of osteonecrosis. Methods The best multipl icity of infection (MOI) of BMSCs transfected with rAAV was detected by fluorescent cell counting. The 3rd generation rabbit bone mesenchymal stem cells (BMSCs) were transfected with rAAV-hVEGF165-internal ribosome entry site (IRES)-hBMP-7 (experimental group) and green fluorescent protein (GFP) labeled rAAV-IRES-GFP (control group), respectively. The expression of GFP was observed by inverted fluorescent microscope. The expressions of hVEGF165 and hBMP-7 were assessed by RT-PCR assay and Western blot assay in vitro. The transfected cells in 2 groups were prepared into suspension with 5 × 106 cells/mL, and injected into the rabbit thigh muscles of experimental group 1 (n=9) and control group 1 (n=9), respectively. The muscle injected with rAAV-IRES-GFP was sl iced by frozen section method and the expression of GFP protein was observed by inverted fluorescent microscope. The expressions of hVEGF165 and hBMP-7 were assessed by Western blot assay and ELISA assay in vivo. Results The best MOI of BMSCs transfected with rAAV was 5 × 104 v.g/cell. In vitro, the expressions of GFP, hVEGF165, and hBMP-7 genes started at 1 day after transfection, the expressions obviously increased at 14 days after transfection, and the expression maintained the b level at 28 days after transfection. In vivo, the expressions of GFP, hVEGF165, and hBMP-7 genes could be detected at 2 weeks after injection, and b expressions were shown at 6 to 8 weeks after injection. The values of hVEGF165 and hBMP-7 were (248.67 ± 75.58) pg/mL and (4.80 ± 0.61) ng/mL respectively in experimental group 1, and were (32.28 ± 8.42) pg/mL and (0.64 ± 0.42) ng/mL respectively in control group 1; showing significant differences between 2 groups (P lt; 0.05). Conclusion The rAAV-hVEGF165-IRES-hBMP-7 has efficient gene expression ability.

    Release date:2016-08-31 05:49 Export PDF Favorites Scan
  • ALLOGRAFT ANTIGENICITY OF HUMAN EAR CARTILAGE AND EFFECT OF CELL EXTRACTION ON ANTIGENICITY

    OBJECTIVE: To study the allograft antigenicity of human ear cartilage and the effect of the cell extraction on antigenicity. METHODS: The human ear cartilage was acellular by cell extraction with Triton X-100. Then the cartilage and the acellular cartilage were analyzed by anti-MHC-I immunohistochemical staining, the reaction of the peripheral blood mononuclear(PBM) cells to the cartilage and the acellular cartilage and the migration of the PBM cells toward the cartilage and the acellular cartilage. RESULTS: The result of human ear cartilage was positive for the anti-MHC-I immunohistochemical staining, whereas that of the acellular cartilage was negative for the staining. The reactive proliferation of the PBM cells was more when they were co-cultured with human ear cartilage than that when they were cultured alone in vitro(P lt; 0.05), but the acellular cartilage did not show the same phenomena (P gt; 0.05); when the cartilage and the acellular cartilage were co-cultured with the PBM cells, the PBM cells migrated to the cartilage much more than that to acellular cartilage(P lt; 0.01). CONCLUSION: Human ear cartilage has allograft antigenicity and its antigenicity can be removed by cell extraction with Triton X-100.

    Release date:2016-09-01 09:35 Export PDF Favorites Scan
  • Facial nerve-sublingual nerve parallel bridge anastomosis for facial nerve injury caused by closed temporal bone fractures

    Objective To investigate the effectiveness of facial nerve-sublingual nerve parallel bridge anastomosis for facial nerve injury resulting from closed temporal bone fractures. Methods Between January 2017 and December 2019, 9 patients with facial nerve injury resulting from closed temporal bone fracture caused by head and face trauma were treated. Among them, 5 patients were treated with facial nerve-sublingual nerve parallel bridge anastomosis (operation group), and 4 patients were treated with neurotrophic drugs combined with rehabilitation exercise (conservative group). There was no significant difference in gender, age, side, cause of injury, duration of facial nerve injury before surgery, House-brackmann grading (hereinafter referred to as HB grading) of facial nerve injury, and other general information between 2 groups (P>0.05). HB grading was used to evaluate the improvement of facial nerve function before and after treatment. At the same time, facial nerve neuroelectrophysiological test was performed to evaluate the electrical activity of facial muscles before and after treatment. Tongue function, atrophy, and tongue deviation were evaluated after nerve anastomosis according to the tongue function scale proposed by Martins et al. Results Patients in both groups were followed up 12-30 months, with an average of 25 months. None of the 5 patients in the operation group showed symptoms such as tongue muscle atrophy, tongue extension deviation, hypoglossal nerve dysfunction (mainly including slurred speech, choking with water), postoperative infection, bleeding, lower limb muscle atrophy or lower limb motor dysfunction after sural nerve injury. Postoperative skin sensory disturbance in lateral malleolus area was found, but gradually recovered to normal. During the follow-up, facial nerve and sublingual motor neurons were innervated to paralyzed facial muscle in the operation group. At last follow-up, the HB grading of 5 patients in the operation group improved from preoperative grade Ⅴ in 2 cases, grade Ⅵ in 3 cases to grade Ⅱ in 3 cases, grade Ⅲ in 1 case, and grade Ⅳ in 1 case. And in the conservative group, there were 1 patient with grade Ⅴ and 3 patients with grade Ⅵ before operation, facial asymmetry continued during follow-up, and only 2 patients improved from grade Ⅵ to grade Ⅴ at last follow-up. There was significant difference in prognosis HB grading between the two groups (t=5.693, P=0.001). In the operation group, the amplitude and frequency of F wave were gradually improved, and obvious action potential could be collected when the facial muscle was vigorously contracted. On the contrary, there was no significant difference in neuroelectrophysiological results before and after treatment in the conservative group. ConclusionFacial nerve-sublingual nerve parallel bridge anastomosis can effectively retain the integrity of the facial nerve, while introducing the double innervation of the sublingual nerve opposite nerve, which is suitable for the treatment of severe incomplete facial nerve injury caused by closed fracture.

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  • EXPERIMENTAL STUDY ON THREE REPAIRING METHODS FOR FEMORAL NERVE INJURY AFTER LIGATION IN RATS

    Objective To investigate the effects of 3 methods (suture removal, suture removal with epineurium neurolysis, and l igated femoral nerve resection with end-end suture) in repairing femoral nerve injury after l igation in different periods so as to provide a reference for cl inical use of repairing iatrogenic l igation injury of the peri pheral nerve. Methods A total of 120 adult female Sprague Dawley rats, weighing (200 ± 20) g, were used to prepare the animal models of left femoralnerve l igation, and were divided into groups A (n=40), B (n=40), and C (n=40) according different repairing methods. Atimmediate, 1, 3, and 5 months (10 rats each time point) after l igation, suture removal was performed in group A, suture removal with epineurium neurolysis in group B, and l igated femoral nerve resection with end-end suture in group C. At 3 months after operation, the foot-base angle (FBA) and the heels-tail angle (HTA), action potential and conduction velocity of femoral nerve, and wet weight of quadriceps femoris muscle (QFM) were measured; the samples of quadriceps femoris and femoral nerve were harvested for histological observation, muscle fiber count, and nerve fiber passing rate measuring. Results The FBA in group A was significant smaller than that in group C at immediate, 1, 3, and 5 months (P lt; 0.05), but there was no significant difference between groups A and B (P gt; 0.05). The HTA in group A was significantly smaller than that in group C at immediate, 1, 3, and 5 months (P lt; 0.05), and the THA in group B was significantly smaller than that in group C at 1, 3, and 5 months (P lt; 0.05). The wet weight of QFM in group B was significantly higher than that in group C at immediate, 3, and 5 months (P lt; 0.05), and the wet weight of QFM in group A was significantly higher than that in group C at immediate and 3 months (P lt; 0.05), but no significant difference was found between groups A and B at immediate, 1, and 3 months (P gt; 0.05). There was significant difference in the action potential of femoral nerve between group A and groups B and C at immediate and 1 month (P lt; 0.05), but there was no significant difference between other groups at 3 and 5 months (P gt; 0.05) except between groups A and C at 5 months (P lt; 0.05). The conduction velocity of femoral nerve in group A was significantly faster than that in group C at immediate, 1, and 5 months (P lt; 0.05), and it was significantly faster in group A than in group B at immediate and 1 month (P lt; 0.05), but no significant difference was found between groups A and B at 3 and 5 months (P gt; 0.05), between groups B and C at other time points (P gt; 0.05) except at immediate (P lt; 0.05). The count of muscle fibre of the quadriceps femoris was significantly more in groups A and B than in group C at immediate (P lt; 0.05); it was significantly more in group A than in group B at 5 months (P lt; 0.05). The passing rate of the femoral nerve fiber was significantly higher in group A than in groups B and C at 3 months (P lt; 0.05), but no significant difference was found between the other groups (P gt; 0.05). Conclusion After femoral nerve l igation, suture removal method has the best effect at early term, the next is epineurium neurolysis method, and the worst is the l igation femoral nerve resection with end-end suture repair.

    Release date:2016-08-31 04:23 Export PDF Favorites Scan
  • EXPERIMENTAL STUDY ON OSTEOGENIC DIFFERENTIATION OF ADIPOSE-DERIVED STEM CELLS TREATED WITH DIFFERENT CONCENTRATIONS OF DEXAMETHASONE

    Objective Dexamethasone is one of the basic agents which could induce osteogenic differentiation of mesenchymal stem cells. To investigate the optimal concentration of dexamethasone in osteogenic differentiation of adiposederivedstem cells (ADSCs) so as to provide the theoretical basis for further bone tissue engineering researches. Methods FiveNew Zealand rabbits (2-3 kg) of clean grade, aged 3 months and male or female, were obtained. ADSCs were isolated from the subcutaneous adipose tissue of inguinal region, and cultured with collagenase digestion, then were detected and identified by CD44, CD106 immunofluorescence staining and adi pogenic differentiation. ADSCs at passage 3 were used and the cell density was adjusted to 1 × 105 cells/mL, then the cells were treated with common cultural medium (group A) and osteogenic induced medium containing 0 (group B), 1 × 10-9 (group C), 1 × 10-8 (group D), 1 × 10-7 (group E), 1 × 10-6 (group F), and 1 × 10-5 mol/ L (group G) dexamethasone, respectively. The cell prol iferation and the mRNA expressions of osteocalcin (OC) and core binding factor α1 (Cbfα1) were detected by MTT and RT-PCR, respectively. The activity of alkal ine phosphatase (ALP) was measured, and the percentage of mineral area was calculated. The mineral nodules were also detected by al izarin red staining. Results ADSCs mostly presented fusiform and polygon shape with positive expression of CD44 and negative expression of CD106. The result of oil red O staining was positive after ADSCs treated with adipogenic induced medium. The result of MTT revealed that the absorbance (A) value decl ined with the ascending of the concentration of dexamethasone, and there was significant difference in A value between groups D and E at 5 and 7 days after osteogenic induction (P lt; 0.05). The mRNA expressions of OC and Cbfα1 reached the peak in groups E and D at 7 days after osteogenic induction, respectively. The activity of ALP and the percentage of mineral area had the maximum value in group D at 14 days, then decl ined gradually. There was no significant difference in the mRNA expressions of OC and Cbfα1, the activity of ALP, and the percentage ofmineral area between groups D and E (P gt; 0.05), but significant differences were found between groups D and E and other groups (P lt; 0.05). After 14 days, the cells of group G died, and the result of al izarin red staining was positive in groups B, C, D, E, and F. Conclusion When the concentration of dexamethasone in osteogenic medium is 1 × 10-8 mol/L, it could not only reduce the inhibitive effect on cells prol iferation, but also induce osteogenic differentiation of ADSCs more efficiently.

    Release date:2016-08-31 05:42 Export PDF Favorites Scan
  • Anatomy of mortis corona vascular and its clinical significances in laparoscopic total extraperitoneal hernia repair

    Objective To study anatomy of mortis corona vascular and analyze its characteristics and clinical significances in laparoscopic total extraperitoneal hernia repair (TEP). Method The clinical data of 45 patients with inguinal hernia underwent laparoscopic TEP from July 2013 to October 2015 in the Fourth People’s Hospital of Zigong City were collected. Results ① There were 45 patients with inguinal hernia a total of 52 bilateral inguinal hernias (15 direct hernias, 37 oblique hernias). The total appear rate of corona mortis vascular was 61.5% (32/52). The appear rate of corona mortis artery was significantly higher than that of the corona mortis vein〔46.2% (24/52)versus 34.6% (18/52),P<0.05〕, the diameter of the corona mortis artery was significantly smaller than that of the corona mortis vein〔(3.2±0.3) mmversus (3.4±0.4) mm,t=2.231,P<0.05〕. ② The appear rates of corona mortis artery and vein in the male patients were significantly higher than those of the female patients (P<0.05). Compared with the female patients, the age of onset was older (P<0.05), thickness of abdominal wall was thinner (P<0.05), diameter of corona mortis vascular was bigger (P<0.05) in the male patients. ③ The total appear rate of corona mortis vascular in the patients with direct hernia was significantly lower than that of the patients with oblique hernia (P<0.05). The age of onset of the patients with direct hernia was significantly older than that of the patients with oblique hernia (P<0.05). Conclusions There is a higher appear rate of corona mortis vascular in patients with oblique hernia, which in male patients is higher as compared with female patients. Age of onset of male patient with inguinal hernia is older than that of female patient with inguinal hernia. It suggests that appear of corona mortis vascular might be associated with degeneration of abdominal wall. It has a certain role for localization and avoidance of corona mortis vascular in TEP.

    Release date:2017-02-20 06:43 Export PDF Favorites Scan
  • STUDY ON EFFECT OF RECOMBINANT ADENO-ASSOCIATED VIRUS VECTOR CO-EXPRESSING HUMAN VASCULAR ENDOTHELIAL GROWTH FACTOR 165 AND HUMAN BONE MORPHOGENETIC PROTEIN 7 GENES ON BONE REGENERATION AND ANGIOPOIESIS IN VIVO

    Objective To study the effect of recombinant adeno-associated virus (rAAV) vector co-expressing human vascular endothel ial growth factor 165 (hVEGF165) and human bone morphogenetic protein 7 (hBMP-7) genes on bone regeneration and angiopoiesis in vivo so as to provide a theoretical basis for the gene therapy of avascular necrosis of thefemoral head (ANFH). Methods Twenty-four male adult New Zealand rabbits were made the ischemic hind l imb model and divided into 4 groups (n=6). The 3rd generation rabbit bone marrow mesenchymal stem cells (BMSCs) were transfected with the following 4 virus and were administered intramuscularly into the ischemic thigh muscle of 4 groups, respectively: rAAVhVEGF165- internal ribosome entry site (IRES)-hBMP-7 (group A), rAAV-hVEGF165-green fluorescent protein (GFP) (group B), rAAV-hBMP-7-GFP (group C), and rAAV-IRES-GFP (group D). At 8 weeks after injection, the blood flow of anterior tibial artery in the rabbit hind l imb was detected by ultrasonographic image. Immunohistochemical staining for CD34 was performed to identify the prol iferation of capillary. Another 24 male adult New Zealand rabbits were made the femur muscle pouch model and divided into 4 groups (n=6). The above 4 BMSCs transfected with rAAV were administered intramuscularly into the muscle pouch. At 8 weeks after injection, X-ray radiography was used to assess orthotopic bone formation, and von Kossa staining to show mineral ization. Results No symptoms of local or systemic toxicity were observed after rAAV injection. At 8 weeks after injection, the ratio of ischemic to normal blood flow and the number of capillaries in group A were the highest among 4 groups (P lt; 0.05). The ratio of ischemic to normal blood flow and the number of capillaries in group B were significantly higher than those in group C and group D (P lt; 0.05). However, there was no significant difference between group C and group D (P gt; 0.05). At 8 weeks after injection, orthotopic ossification and mineral ization were evidently detected in group A and group C, and group A was ber than group C. No obvious evidence of orthotopic ossification and mineral ization were observed in group B and group D. Conclusion rAAV-hVEGF165-IRES-hBMP-7 vector has the biological activities of inductive bone regeneration and angiopoiesis in vivo.

    Release date:2016-09-01 09:04 Export PDF Favorites Scan
  • Clinical prospective comparative study on short-term effectiveness of arthroscopic treatment of popliteal cyst between cyctectomy and internal drainage combined with cyctectomy

    ObjectiveTo compare the short-term effectiveness between arthroscopic cystectomy and internal drainage combined with cystectomy in popliteal cyst.MethodsBetween March 2014 and March 2017, 56 patients with symptomatic popliteal cyst were enrolled in the study, randomized block design was used to divided the patients into trial group (arthroscopic cystectomy combined with internal drainage group, n=28) and control group (arthroscopic internal drainage group, n=28). Excluding those who had incomplete follow-up and received surgery for other diseases postoperatively, 26 patients in the experimental group and 27 patients in the control group were finally enrolled in the study. There was no significant difference in gender, age, side, course of disease, maximum diameter and grade of popliteal cyst, and associated diseases between two groups (P>0.05). The operation time, duration of popliteal ecchymosis and the middle back of calf tenderness were observed postoperatively. The circumference of calf at 1 day, 1 week, and 2 weeks after operation were measured and the differences were calculated with the measurement before operation. Lower extremity venous thrombosis was observed by color doppler ultrasonography at 1 week after operation. The effectiveness was evaluated by Rauschning and Lindgren grading criteria. And MRI was used to observe whether the popliteal cyst disappeared or decreased and measured its maximum diameter at 1 year after operation.ResultsPatients in both groups were followed up 12-14 months, with an average of 12.5 months. The operation time, duration of popliteal ecchymosis, and the middle back of calf tenderness of the trial group were all longer than those in the control group (P<0.05), the differences of circumference of calf at 1 day, 1 week, and 2 weeks after operation of the trial group were greater than those in the control group (P<0.05). Color doppler ultrasonography of the lower extremity at 1 week after operation found that the intermuscular venous thrombosis occurred in 2 cases of the trial group, while no lower extremity thrombosis was found in the control group; and the difference between two groups was not significant (P=0.236). According to the Rauschning and Lindgren grading criteria, there were 16 cases of grade 0, 6 cases of grade 1, and 4 cases of grade 2 in the trial group, and 17 cases of grade 0, 4 cases of grade 1, and 6 cases of grade 2 in the control group at 1 year after operation. There was no significant difference between 2 groups (Z=–1.872, P=0.078). Nine cases (34.62%) of the trial group and 13 cases (48.15%) of the control group still have residual cysts by MRI, the maximum diameter of which was less than 2 cm. The cysts disappeared in the remaining patients in both groups, and there was no recurrence during the follow-up. There was no significant difference in cyst residual rate between 2 groups (χ2=2.293, P=0.852).ConclusionCompared with arthroscopic internal drainage, the short-term effectiveness of the arthroscopic internal drainage combined with cystectomy had no significant improvement, and the operation time was prolonged, the postoperative complications were obviously increased.

    Release date:2018-10-09 10:34 Export PDF Favorites Scan
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