Flow-Through Free Anterolateral Thigh Flap in Reconstruction of Severe Limb Injury.

OBJECTIVE: This study aimed to present the use of flow-through free anterolateral thigh (ALT) flap for the reconstruction of severe limb injury. PATIENTS AND METHODS: Four patients (2 male and 2 female subjects), with an average age of 26 (9-39) years, were included. These injuries referred to upper and lower limbs, including bone, soft tissue, nerve, and arterial segments. Two patients experienced large soft tissue defects in the lower limb and were repaired by double flow-through ALT flaps. The sizes of damaged soft tissues in the remaining 2 patients were 14 × 10 cm and 21 × 13 cm, respectively. Three patients had bone fractures, in which one of them experienced bone shortening during operation. The arterial injury was observed in 2 patients and the lengths of defects were 5 and 12 cm, respectively. Flow-through free ALT flap was applied for all 4 patients. RESULTS: Patients were followed up for 18 months. All the flaps have survived successfully without any vascular crisis or infection. All incision wounds were under primary healing stage, without any severe complications. The flaps showed better appearance, color, texture, and satisfactory sensation. All patients had satisfactory functional recovery of their injured limbs. CONCLUSIONS: The flow-through free ALT flap assists in overcoming complex traumatic injuries with severe soft tissue and arterial defects in the limbs. This flow-through ALT flap can be an effective alternative for reconstruction of severe limb injury.

Impact of MDM2 gene polymorphism on sarcoma risk.

A T>G single nucleotide polymorphism (SNP, rs2279744) of the MDM2 gene has been investigated in sarcoma community, but the findings are conflicting. This study was designed to well define the relationship between SNP rs2279744 and sarcoma risk. We did a systematic computerized search of the PubMed, Web of Science, and Science Direct databases to identify the human case-control studies investigating the relationship between SNP rs2279744 and sarcoma risk with complete genetic data. Pooled odds ratios (ORs) were calculated with the Mantel-Haenszel fixed-effect model or the DerSimonian and Laird random effects model to estimate the risk of sarcoma. Overall analysis included five independent studies. On the whole, the T/G genotype or the combined G/G and T/G genotypes appeared to be associated with approximately 1.40-fold higher risk of sarcoma relative to the T/T genotype (T/G vs. T/T: OR 1.33, 95% CI 1.00-1.77; G/G + T/G vs. T/T: OR 1.42, 95% CI 1.08-1.85). We noted that the Caucasian populations showed a similarly increased risk of sarcoma ascribed to the carriage of the same genotypes (T/G vs. T/T: OR 1.41, 95% CI 1.05-1.90; G/G + T/G vs. T/T: OR 1.49, 95% CI 1.13-1.97). This meta-analysis provides evidence that MDM2 SNP rs2279744 may be significantly associated with increased risk of sarcoma in Caucasian individuals.

The effects of Cordyceps sinensis phytoestrogen on estrogen deficiency-induced osteoporosis in ovariectomized rats.

BACKGROUND: Isoflavones are naturally occurring plant chemicals belonging to the "phytoestrogen" class. The aim of the present study was to examine the effects of isoflavones obtained from Cordyceps sinensis (CSIF) on development of estrogen deficiency-induced osteoporosis in ovariectomized rats. METHODS: After the rats were treated orally with CSIF, serum alkaline phosphatase (ALP), tartarate resistant acid phosphatase (TRAP), serum osteocalcin (OC), homocysteine (HCY), C-terminal crosslinked telopeptides of collagen type I (CTX), estradiol and interferonγ (IFN-γ) level were examined. At the same time, the urine calcium, plasma calcium, plasma phosphorus and the mass of uterus, thymus and body were also examined. RESULTS: The beneficial effects of CSIF on improvement of osteoporosis in rats were attributable mainly to decrease ALP activity, TRAP activity, CTX level and IFN-γ level. At the same time, CSIF also increase the OC and estradiol level in ovariectomized osteopenic rats. The histological examination clearly showed that dietary CSIF can prevent bone loss caused by estrogen deficiency. CONCLUSION: The significant estrogenic activity of CSIF demonstrated that CSIF has significant estrogenic effects in OVX rats.

Bright luminol electrochemiluminescence mediated by a simple TEMPO radical for visualized multiplex detection.

In this work, a series of 2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPO) radicals bearing different functional groups were exploited as a simple catalyst to promote electrochemiluminescence (ECL) generation in luminol/H2O2 system. These TEMPO radicals were found to facilitate the electrochemical oxidation of H2O2 and luminol through different catalytic mechanisms, as well as the subsequent ECL generation of luminol/H2O2 system. The electrochemical oxidation and luminol ECL generation could be tuned by the functional group on the para-position of TEMPO, for which the structure/activity relationship was revealed. Finally, with the combination of enzymatic system, luminol ECL enhancement up to 9.6-fold was obtained through the catalysis of 4-hydroxyl-TEMPO. The enhanced luminol ECL allows acquiring brighter ECL images in a single-electrochemical system (SEES) for multiplex detection of cholesterol, H2O2 and glucose.

Comparing clinical outcomes of patients with severe lower limb trauma undergoing orthoplastic and orthopedic surgeries: A long-term study protocol.

This long-term study protocol aims to compare the clinical outcomes of patients with severe lower limb trauma undergoing orthoplastic and orthopedic surgeries, focusing on their physical and psychological status. Patients with lower limb injuries and open fractures have been recruited since October 2019 and will be followed up until October 2024. The patients will be divided into two groups: (1) Orthoplastic group, where single-stage debridement, fixation, and soft tissue repair will be performed, and (2) Orthopedic group, where soft tissue repair will be done in a delayed-stage. The follow-up period will be one year, during which clinical data, limb function recovery, psychological scores, and health-related quality of life (HRQOL) will be evaluated to assess postoperative recovery and clinical outcomes. Additional clinical data, such as socio-demographic information, baseline features, Enneking score, Visual Analogue Scale (VAS) score, two-point discrimination score, and blood test parameters will also be collected. The 36-Item Short Form Health Survey (SF-36) will be used to evaluate HRQOL, while the Post-traumatic Stress Disorder Checklist (PCL) will assess the severity of self-reported post-traumatic stress disorder. The results of this study will provide valuable insights into prognostically relevant targets and contribute to improving the management and outcomes of patients with lower limb injuries and open fractures, who often face challenges related to limb disability and potential amputation postoperatively, significantly impacting their psychological and physical well-being.

Comminuted lunate fracture combined with distal radius fracture and scaphoid fracture: A case report.

RATIONALE: Incidence of lunate fractures is very low, less than 1% of all fractures. Lunate fractures generally come from high-energy injuries, often combined with other wrist fractures. Simple lunate fractures can be fixed with screws or Kirschner wires. However, Comminuted lunate fractures are difficult to reduce and fixe by conventional methods. PATIENT CONCERNS: Here we report a 42-year-old male construction worker who was crushed by an excavator bucket and presented with comminuted lunate fracture combined with distal radius fracture and scaphoid fracture. DIAGNOSES: Comminuted lunate fracture, distal radius fracture, and scaphoid fracture. INTERVENTIONS: The posterior approach was used to reconstruct the radial lunate bone with polymethylmethacrylate cement, and cannulated screws were used to fix the scaphoid and distal radius fractures. OUTCOMES: At the 3rd month after surgery, the movement of the right wrist joint improved. At the sixth month after surgery, the patient returned to the building site and began working at the same intensity as before the injury. LESSONS: Although the incidence of comminuted lunate fractures is very low, they occur sometimes. For comminuted lunate fractures, early identification and intervention can preserve most of the function of the wrist joint.

Meta-analysis of neoadjuvant immunotherapy for non-metastatic colorectal cancer.

Background: Immunotherapy has been approved for the treatment of metastatic colorectal cancer. The efficacy and safety of neoadjuvant immunotherapy for the treatment of non-metastatic colorectal cancer remains unclear. We tried to explore clinical effect of neoadjuvant immunotherapy in the treatment of non-metastatic colorectal cancer. Methods: We searched the databases (PubMed, Wanfang Embase, Cochrane Library and China National Knowledge Infrastructure databases) to obtain suitable articles up to September 2022. The primary outcomes of pathological complete response (pCRs), major pathological response (MPR), objective response rate (ORR), R0-resection and anus preserving rate were collected and evaluated. Secordary outcomes (pCRs and MPR) of subgroup analysis between deficient mismatch repair/microsatellite instability-high group (dMMR/MSI-H) and proficient mismatch repair/microsatellite stable group (pMMR/MSS) and outcomes for rectal cancer were analyzed for the final results. Results: We included ten articles and 410 cases of non-metastatic colorectal cancer with neoadjuvant immunotherapy. There were 113 (27.5%) cases with the dMMR/MSI-H status and 167 (40.7%) cases with the pMMR/MSS status. pCRs was found in 167/373 (44.6%) patients (ES: 0.49, 95% CI: 0.36 to 0.62, P<0.01, chi2 = 65.3, P<0.01, I 2 = 86.2%) and MPR was found in 194/304 (63.8%) patients (ES: 0.66, 95% CI: 0.54 to 0.78, P<0.01, chi2 = 42.55, P<0.01, I 2 = 81.2%) with the random-effects model and huge heterogeneity. In the subgroup analysis, pCRs was higher in the dMMR/MSI-H group than the pMMR/MSS group in the fixed-effects model with minimal heterogeneity (OR: 3.55, 95% CI: 1.74 to 7.27, P<0.01, chi2 = 1.86, P=0.6, I 2 = 0%). pCRs was found in 58/172 (33.9%) rectal cancer patients (ES: 0.33, 95% CI: 0.26 to 0.40, P<0.01, chi2 = 3.04, P=0.55, I 2 = 0%) with the fixed-effects model and little heterogeneity. Conclusion: Neoadjuvant immunotherapy could increase pCRs and MPR rate for non-metastatic colorectal cancer. Neoadjuvant immunotherapy could achieve better pCRs rate in dMMR/MSI-H group than in the pMMR/MSS group. Neoadjuvant immunotherapy could be another treatment option for non-metastatic colorectal cancer. Systematic review registration: https://www.crd.york.ac.uk/prospero/#myprospero, identifier CRD42022350523.

Universal screening for Lynch syndrome in operated colorectal cancer by immunohistochemistry: a cohort of patients in Liaoning province, China.

OBJECTIVE: Lynch syndrome (LS) is the most common hereditary colorectal cancer syndrome worldwide. Due to the decreasing family size in Liaoning province. The Bethesda and Amsterdam II criteria have lower sensitivity and specificity and are not suitable for the local population. Immunohistochemistry screening for mutations in DNA mismatch repair (MMR) in newly diagnosed colorectal cancer can improve the detection rate of LS. METHODS: All newly diagnosed colorectal cancer patients who underwent surgery between January 2018 and June 2020 at Cancer Hospital of China Medical University and Shengjing Hospital of China Medical University from Liaoning China were included retrospectively, and the ratio of universal LS screening by immunohistochemistry, MMR protein deficiency (dMMR) ratio, MLH1 loss, MSH2 loss, MSH6 loss, and PMS2 loss was analyzed. The clinicopathological characteristics of patients with pMMR and dMMR were analyzed. RESULTS: A total of 7019 colorectal cancer patients underwent surgery and 4802 (68.41%) patients were screened by immunohistochemistry for MMR, 258 (5.37%) cases were reported to have a loss of MMR expression. In the dMMR group, a higher number of patients were under 50 years old, more tumors were located at the right colon, less patients have lymph node metastasis, more tumors were stage II, and histological types of mucinous carcinoma or signet ring carcinoma were more common, compared with the pMMR group. Only 2.71% dMMR patients meet Amsterdam criteria II, 2.71% of patients meet Revised Bethesda guidelines, and 17.83% meet Chinese LS criteria. Twenty-five dMMR patients were confirmed by next-generation sequencing and five families were confirmed as Lynch family. CONCLUSION: These data imply that universal screening for LS by immunohistochemistry may be effective in Liaoning province.

Using untargeted metabolomics to profile the differences of the fruits of Lycium barbarum in different geographical origins.

An ultra-high performance liquid chromatography system coupled with the Q-Exactive mass spectrometry (UHPLC-QE-MS) approach combined with multivariate statistical analysis was used to investigate the metabolic profiles of the fruits of Lycium barbarum in different geographical origins in China. Several classes of compounds such as sugars, amino acids, organic acids, fatty acids, polyphenols and alkaloid were identified in hydroalcoholic extracts, and ten differential metabolites including amino acids, organic acids and vitamins were identified by multivariate statistical method. It was discussed that the differences between organic acids and amino acids in the samples may be caused by environmental factors such as ultraviolet radiation, soil and altitude. A total of 119 metabolic pathways were involved in the differential metabolites and 17 of them were retained for enrichment analysis. It was found that alanine, aspartate and glutamate metabolism, arginine biosynthesis, glutathione metabolism, glyoxylate and dicarboxylate metabolism, purine metabolism, histidine metabolism and aminoacyl-tRNA biosynthesis were the most important pathways. These findings play an important role in the origin tracing of the Lycium barbarum fruit.

Radical treatment of severe open fractures of extremities by orthoplastic surgery: a 10-year retrospective study.

OBJECTIVE: This study aimed to retrospectively analyze clinical data of a series of patients with severe open fractures of extremities (Gustilo IIIb or IIIc), who achieved a satisfactory outcome through radical orthoplastic surgery, so as to provide a reference for determining the treatment of severe open fractures of extremities. METHODS: The clinical data of 41 consecutive patients with severe open fracture (Gustilo IIIb or IIIc) of the limb, who underwent successful surgical debridement, fixation, and soft tissue reconstruction in one stage between January 2008 and January 2019, were retrospectively reviewed. Postoperative indicators, including infection rate and union time, were acquired by a regular follow-up and analyzed. RESULTS: The mean (±SD) age of the patients was 38 ± 16 years. A total of 90 open fractures and severe soft tissue damages were analyzed. The soft tissue cover was achieved within 72 h. The overall rate of infection was 14.6% (6/41). Sex and the Mangled Extremity Severity Score were associated with infection. The median union time of 40 patients (one amputation) was 32 weeks. CONCLUSION: The overall rate of infection exhibited a lower tendency in this study compared with previous studies on high-grade open fractures following a two-stage orthopedic approach. The consequence of infection rate and union time was similar to that in previous studies. These results indicated that the single-stage radical orthoplastic treatment was an effective and reliable option for reconstructing severe open fractures.

Orthopedic trauma of limbs associated with vascular injuries.

OBJECTIVE: To evaluate the treatment for patients with major vascular injuries associated with traumatic orthopedic injuries. METHODS: A total of 196 patients, aged from 4-67 years with the mean age of 29.88 years, had major vascular injuries associated with traumatic orthopedic injuries and were treated in our hospital in a period of 44 years. The most common mechanism of trauma was blunt trauma (67.3%), open injuries accounted for 32.4% and 54.5% of the injuries were located in the lower extremities. The vascular injury frequently happened in the femoral artery (26.7%) and popliteal artery (20.3%). The treatment principle consisted of aggressive resuscitation, Doppler imaging and stable bone internal fixation with subsequent vascular repair and debridement. The vascular repair for injuries included end-to-end anastomosis (80 cases, 39.6%), interpositional vein graft (94, 46.5%), vascular decompression through fracture distraction (18, 8.9%), arterial ligation (6, 3.0%), vein patch (2, 1.0%), bypass graft (2, 1.0%), venous repair including autogenous vein graft (9, 24.3%) and ligation (28, 75.7%) and prophylactical fasciotomy (15, 7.4%). Postoperative amputation was performed in 16 cases (16.3%). RESULTS: No intraoperative death was observed and all fractures united within 6 months. Limbs were salvaged in 180 patients (91.8%). Among these patients, early complications were found in 19 patients (9.7%) and late complications were observed in 8 patients (4.1%). CONCLUSIONS: A well-organized approach, based on a specific treatment principle, not only improves clinical outcome but also does good to excellent functional recovery for patients with severe orthopedic injuries and concomitant vascular lesion.

Modified human uterus transplantation using ovarian veins for venous drainage: the first report of surgically successful robotic-assisted uterus procurement and follow-up for 12 months.

OBJECTIVE: To report the 12-month results of the first human uterus transplantation case using robot-assisted uterine retrieval. This type of transplantation may become a treatment for permanent uterine factor infertility. DESIGN: Case study. SETTING: University hospital. PATIENT(S): A 22-year-old woman with complete müllerian agenesis who underwent a previous surgery for vaginal reconstruction. The live uterine donor was her mother. INTERVENTION(S): The uterus transplantation procedure consisted of robot-assisted uterine procurement, orthotopic replacement and fixation of the retrieved uterus, revascularization, and end-to-side anastomoses of bilateral hypogastric arteries and ovarian-uterine vein to the bilateral external iliac arteries and veins. MAIN OUTCOME MEASURE(S): Data from preoperative investigations, surgery, and follow-up (12 months). RESULT(S): The duration of the donor and recipient surgeries were 6 and 8 hours, 50 minutes, respectively. No immediate perioperative complications occurred in the recipient or donor. The recipient experienced menarche 40 days after transplant surgery, and she has had 12 menstrual cycles since the surgery. No rejection episodes occurred in the recipient. CONCLUSION(S): These results demonstrate the feasibility of live-donor uterine transplantation with a low-dose immunosuppressive protocol and the role of DaVinci robotic assistance during human uterine procurement. CLINICAL TRIAL REGISTRATION NUMBER: XJZT12Z06.

MiR-210 inhibits NF-κB signaling pathway by targeting DR6 in osteoarthritis.

Osteoarthritis (OA) is characterized by degradation of articular cartilage and joint inflammation. MicroRNAs have been proved to play an important role in the regulation of chondrogenesis. Previous study showed that microRNA-210 (miR-210) was probably associated with osteoarthritis, while the function of miR-210 in osteoarthritis still remains unknown. The aim of the present study was to investigate the protective effect of miR-210 on osteoarthritis. In the in vitro study, miR-210 level in chondrocytes was decreased after treatment with lipopolysaccharide (LPS). Transfection with miR-210 mimic inhibited LPS-induced pro-inflammatory cytokines production, cell viability reduction and cell apoptosis. Results of luciferase activity assay showed that miR-210 targeted 3'-UTR of death receptor 6 (DR6) to inhibit its expression. MiR-210 mimic and DR6 siRNA transfection inhibited the activation of NF-κB pathway and cell apoptosis of chondrocytes. For the in vivo study, OA model was established on rats by anterior cruciate ligament transection (ACLT). MiR-210 expression is reduced in OA rats. MiR-210 over-expressing lentivirus was injected into the OA rats. Cytokines production, and NF-κB and DR6 expression in OA rats was inhibited by miR-210 overexpression. The results demonstrated that miR-210 decreased inflammation in articular cavity in OA rats by targeting DR6 and inhibiting NF-κB signaling pathway.

Osteoprotective effect of cordycepin on estrogen deficiency-induced osteoporosis in vitro and in vivo.

The purpose of this study was to verify the effect of cordycepin on ovariectomized osteopenic rats. Fifty Wistar female rats used were divided into 5 groups: (1) sham-operation rats (control), (2) ovariectomized (OVX) rats with osteopenia, and (3) OVX'd rats with osteopenia treated with cordycepin (5 mg, 10 mg, and 20 mg) for 8 weeks. After the rats were treated orally with cordycepin, serum alkaline phosphatase (ALP), tartrate resistant acid phosphatase (TRAP), serum osteocalcin (OC), homocysteine (HCY) , C-terminal crosslinked telopeptides of collagen type I (CTX) level, and oxidative stress were examined, respectively. The femoral neck was used for mechanical compression testing. At the same time, we further investigated the effect of cordycepin in vitro assay. The beneficial effects of cordycepin on improvement of osteoporosis in rats were attributable mainly to decrease ALP activity, TRAP activity, and CTX level. At the same time, cordycepin also increases the OC level in ovariectomized osteopenic rats. The histological examination clearly showed that dietary cordycepin can prevent bone loss caused by estrogen deficiency. These experimental results suggest that complement cordycepin is protective after ovariectomized osteopenic in specific way.

Preparation and assessment of heterotopic osteoinduction of beta-TCP/rhBMP-2 composite.

OBJECTIVE: To search for ideal bone graft substitute. METHODS: The beta TCP/rhBMP-2 composite was constructed by combining beta-Tricalcium phosphat (beta-TCP) that was prepared by the authors with recombinant human morphogenetic protein-2 (rhBMP-2) and was implanted into the muscle pouches in the thigh of mice. beta-TCP alone was implanted on the opposite side as controls. At intervals of 1,3,7,14 and 28 days after the implantation, the specimens were obtained, and histologic study and alkaline phosphatase assay (7,14,28 days) were performed. RESULTS: There was a large amount of cartilage and bone formation within the composite, increasing with time; whereas there was no new bone formation where beta-TCP alone was implanted. Besides, the levels of alkaline phosphatase in the beta-TCP/rhBMP-2 implants also were increasing with time and were higher than those in controls. CONCLUSIONS: The results indicate that beta-TCP/rhBMP-2 composite possesses heterotopic osteoinductive potential.

Cordycepin (3'-deoxyadenosine) down-regulates the proinflammatory cytokines in inflammation-induced osteoporosis model.

The effect of cordycepin (3'-deoxyadenosine) on inflammation-induced osteoporosis (IMO) was studied in this paper. After the rats were treated orally with cordycepin (20 mg/kg), serum osteocalcin (OC), homocysteine (HCY), C-terminal cross-linked telopeptides of collagen type I (CTX), maleic dialdehyde (MDA), polymorphonuclear cells (PMN), interleukin-1ß (IL-1ß), and tumor necrosis factor-α (TNF-α), they were examined by ELISA or immunohistochemistry. The specimens from the liver were also processed for light microscopic examination. The IMO rats showed a significant increase in plasma CTX, MDA, PMN, IL-1ß, TNF-α, and nitrate levels as well as a significant decrease in plasma OC. These changes were attenuated by cordycepin (20 mg/kg) supplementation in the IMO rats. Examination of the liver specimens revealed mononuclear cell infiltration in the portal areas in the IMO rats which was not detected in the cordycepin (20 mg/kg) rats. These results suggest that cordycepin may act as an anti-inflammatory agent in magnesium silicate-induced inflammation in osteoporosis.

Modified uterine allotransplantation and immunosuppression procedure in the sheep model.

OBJECTIVE: To develop an orthotopic, allogeneic, uterine transplantation technique and an effective immunosuppressive protocol in the sheep model. METHODS: In this pilot study, 10 sexually mature ewes were subjected to laparotomy and total abdominal hysterectomy with oophorectomy to procure uterus allografts. The cold ischemic time was 60 min. End-to-end vascular anastomosis was performed using continuous, non-interlocking sutures. Complete tissue reperfusion was achieved in all animals within 30 s after the vascular re-anastomosis, without any evidence of arterial or venous thrombosis. The immunosuppressive protocol consisted of tacrolimus, mycophenolate mofetil and methylprednisolone tablets. Graft viability was assessed by transrectal ultrasonography and second-look laparotomy at 2 and 4 weeks, respectively. RESULTS: Viable uterine tissue and vascular patency were observed on transrectal ultrasonography and second-look laparotomy. Histological analysis of the graft tissue (performed in one ewe) revealed normal tissue architecture with a very subtle inflammatory reaction but no edema or stasis. CONCLUSION: We have developed a modified procedure that allowed us to successfully perform orthotopic, allogeneic, uterine transplantation in sheep, whose uterine and vascular anatomy (apart from the bicornuate uterus) is similar to the human anatomy, making the ovine model excellent for human uterine transplant research.

[Induction of axial vascularization in processed bovine cancellous bone scaffold using arteriovenous loop].

OBJECTIVE: To explore the method of inducing axial vascularization in a processed bovine cancellous bone scaffold by using an arteriovenous loop, and to evaluate its effect of vascularization. METHODS: Custom-made processed bovine cancellous bone discs were processed into cylinder with circular grooves. Thirty male SD rats weighing 300-350 g (3-4 months old) were randomly divided into 2 groups (n = 15 per group): experimental group in which the femoral veins in the groin of rats were separated and transplanted to the contralateral femoral artery and vein stump, the processed bovine cancellous bone scaffold was inserted into the arteriovenous loop, which was placed into the annular groove. Control group, in which the blood vessels in the groin of rats were cut, no anastomosis was conducted, and the processed bovine cancellous bone scaffold was planted. At 2, 4 and 8 weeks after operation, gross observation, ink infusion histology observation and microvessel bulk density detection were conducted. RESULTS: At each postoperative time point, the samples in the experimental group were fresh red, the circulation of blood vessels were smooth bidirectionally, while the samples in the control group were dark red soft, and flexible. Ink infusion histology observation showed the processed bovine cancellous bone scaffold in the experimental group had obvious vascularization, the blood vessels tended to be mature and integrated into network, and neovascular sprouts originated from arteriovenous loop were evident, especially at 8 weeks after operation; while there was no vascularization in the control group. At 2, 4 and 8 weeks after operation, the bulk density of the microvessels in the experimental group was (3.59 +/- 1.84), (16.61 +/- 10.23) and (39.04 +/- 13.46) microm3/microm3, respectively, and it was (2.43 +/- 0.97), (6.79 +/- 2.92) and (25.31 +/- 10.98) microm3/microm3, respectively, in the control group. Significant differences was noted between two groups at 4 and 8 weeks after operation (P < 0.05), and no significant difference was evident at 2 weeks after operation (P > 0.05). CONCLUSION: Inducing vascularization in a processed bovine cancellous bone using an arteriovenous loop is a new strategy of revascularization and may provide valuable clues for the preparation of functional artificial bone.

[Preparation of rhBMP-2/BCB reconstituted bone xenograft and assay of its osteoinductivity].

OBJECTIVE: To investigate a new grafting material of bone xenograft with strong bone inductive and conductive capacity. METHODS: Based on successful clinical application of the reconstituted bone xenograft (RBX), a new xenograft was made by combining recombinant human bone morphogenetic protein-2 (rhBMP-2) with antigen-free bovine cancellous bone (BCB). Sixty male BALB/C mice aged 4 weeks were divided into study group of 30 and control group of 30 randomly. rhBMP-2/BCB was implanted in the left thigh muscle pouch in the study group and BCB in the control group. The mice were sacrificed at 7 d, 14 d and 21 d after implantation. Inductivity of rhBMP-2/BCB was detected by histological observation and biochemical determination of the samples. RESULTS: Histological examination showed that rhBMP-2/BCB induced chondrogenesis on the 7th day, with woven bone formed on the 14th day, and lamellar bone and marrow on the 21st day, while BCB failed to induce chondrogenesis or osteogenesis on the 7th, 14th and 21st days. The alkaline phosphatase activities and calcium content in study group were higher than those in control group with significant difference (P < 0.01). CONCLUSION: rhBMP-2/BCB is an ideal grafting material with strong bone inductive and conductive capacity without evoking immune reaction.