In vivo construction of lymphoid node by implantation of adipose-derived stromal cells with hydroxypropyl methyl cellulose hydrogel in BALB/c nude mice.

Adipose-derived stromal cells have multilineage potential to differentiate into several specialized tissue types. Herein, we investigated whether ADSCs could differentiate into lymphoid node in vivo. Human ADSCs from routine liposuction were cultured in differentiation medium and were supplemented with transforming growth factor ß1 (TGF)-ß1 and basic fibroblast growth factor (bFGF). The induced hADSCs mixed with 13% (w/v) hydroxypropyl methylcellulose (HPMC) were injected into BALB/c nude mice subcutaneously. Eight weeks later, nodules were found under the injected sites. Histology, immunohistochemistry, and species identification analysis confirmed that the nodules were lymphoid nodes that were derived from the injected hADSCs. Our experiment demonstrated that the hADSCs could differentiate into lymphocyte-like cells and form lymphoid nodes in vivo. TGF-ß1 and bFGF might play important roles in the differentiation of hADSCs into lymphocyte-like cells. Our study might present an alternative approach for engineering immune organs and thus offer potential treatment for immunodeficiency diseases.

A Comparative Study on the Biological Characteristics of Human Adipose-Derived Stem Cells from Lipectomy and Liposuction.

PURPOSES: To compare the biological behaviors of human adipose-derived stem cells (ADSCs) isolated from adipose tissue by lipectomy and liposuction, with the purpose of providing the basis for clinical application. METHODS: The proliferation and apoptosis of ADSCs were analyzed by CCK-8 assay and flow cytometry. Cell migration was measured by a wound healing assay. An ELISA assay was used to evaluate paracrine functions. SOD and MDA were tested by xanthine oxidase and thiobarbituric acid reactions, respectively. In addition, we used a CCK-8, LDH assay and flow cytometry to analyze the proliferation and apoptosis of ADSCs treated with lidocaine or adrenaline. RESULTS: The viable ADSCs yield from liposuction was significantly lower than that from lipectomy, while the apoptosis of cells from liposuction was significantly higher than from lipectomy. The paracrine secretion of the two sources of ADSCs was highest when treated with 10-7 mol/L insulin and 10 ng/mL TGF-α, but there were no significant differences in VEGF, IL-6, IL-8 or HGF levels. The ADSCs from lipectomy migrated faster than those from liposuction, and SOD in the lipectomy group was higher than in the liposuction group, whereas MDA of the lipectomy group was lower than that of the liposuction group. The proliferation ADSCs treated with lidocaine or adrenaline was greatly decreased, while apoptosis was significantly increased, and cytotoxicity of lidocaine or adrenaline to ADSCs was dose-dependent. CONCLUSIONS: Compared with ADSCs from liposuction, the ADSCs from lipectomy have better biological characteristics. Lidocaine and adrenaline decreased the viability of ADSCs, and their cytotoxicity to ADSCs was dose-dependent.

Wound-healing improvement by resurfacing split-thickness skin donor sites with thin split-thickness grafting.

INTRODUCTION: Split-thickness skin graft (STSG) donor site dressing has been controversial until now. Our study aimed to assess the patient comfort and wound-healing efficacy with the application of thin split-thickness skin grafts regrafting on STSG donor sites. METHODS: One hundred ninety-two consecutive patients undergoing split-thickness skin grafting were included in the study, and the participants were randomly divided into the following three groups: group A was regrafted with thin STSGs and groups B and C were covered with occlusive hydrocellular dressing and paraffin gauze, respectively. The participants were compared according to the epithelialization time, pain and scar formation. RESULTS: The average time of epithelialization was 6.2 ± 1.1 days in group A, 11.1 ± 2.1 days in group B and 13.5 ± 2.5 days in group C. The pain scores on days 2 and 5 after operation were 2.3 ± 0.8 and 1.9 ± 0.8 in group A, 2.5 ± 1.1 and 3.9 ± 1.3 in group B, and 3.8 ± 1.4 and 5.9 ± 2.1 in group C. The scar scores at half a year and one year after operation were 4.3 ± 0.6 and 2.50 ± 0.6 in group A, 7.4 ± 0.6 and 6.2 ± 0.6 in group B, and 11.8 ± 0.4 and 10.9 ± 1.0 in group C, separately. The difference in the three groups was significant. CONCLUSION: Utilizing thin STSGs regrafting on donor sites could significantly shorten the epithelialization time, reduce pain and prevent hyperplastic scar formulation.

Association of CRR9 locus with elevated risk of squamous cell carcinoma and basal cell carcinoma.

BACKGROUND: Published studies have generated inconsistent results related to the contribution of CRR9 rs401681 C allele to the risk of developing non-melanoma skin cancer (NMSC), and it is the inconsistency that promoted us to undertake a meta-analysis to identify the degree of impact the C allele has on NMSC. METHOD: The PubMed, Science Direct, Embase and Cochrane Library were thoroughly searched from the start of November 2013 to the end of April 2014 by using CRR9, polymorphism, skin cancer and their synonyms. Based on a total of 44,036 subjects, we calculated ORs and 95% CIs to measure the influence of the C allele on NMSC predisposition. RESULTS: Overall, individuals carrying the risk C allele at rs401681 had 1.16 times (OR = 1.16, 95% CI: 1.10-1.21, heterogeneity: P = 0.298 and I2 = 0.166, Figure 2) greater risk of NMSC compared to the common T allele. In the further stratified analyses, we found a significant association between the C allele and BCC, Icelanders, and non-Icelanders. CONCLUSION: The results of this meta-analysis suggest that the C allele at rs401681 is likely to modify the genetic predisposition to NMSC.

Biomimetic LBL structured nanofibrous matrices assembled by chitosan/collagen for promoting wound healing.

This paper reports the fabrication of biomimetic nanofibrous matrices via co-electrospinning of polycaprolactone (PCL)/cellulose acetate (CA) and layer-by-layer self-assembly (LBL) of positively charged chitosan (CS) and negatively charged Type Ⅰ collagen on the nanofibrous matrix. FE-SEM images indicate that the average fiber diameter increased from 392 to 541 nm when the coating bilayers varied from 5 to 20.5. Besides, the excellent biocompatibility and enhanced attachment and spreading of normal human dermal fibroblasts (NHDFs) of prepared nanofibrous mats are confirmed by MTT and SEM results. Furthermore, the LBL structured (CS/collagen)n nanofibrous mats greatly improve the cell migration in vitro, promote re-epithelialization and vascularization in vivo, and up-regulate the expression of collagen Ⅳ and α-tubulin, as well as the Integrin ß1 and phosphorylation of focal adhesion kinase (FAK) at Tyr-397. The levels of expressed protein are significantly enhanced with increasing coating bilayers via immunohistochemistry and western blotting analyses. Collectively, these results suggest that the LBL structured biomimetic nanofibrous matrices may enhance cell migration and further promote the skin regeneration by up-regulating the secretion of ECM protein and triggering Integrin/FAK signaling pathway, which demonstrate the potential use of the nanofibrous mats to rapidly restore the structural and functional properties of wounded skin.

Human acellular dermal matrix allograft: A randomized, controlled human trial for the long-term evaluation of patients with extensive burns.

The potential of acellular dermal matrix (ADM) to improve cosmetic and functional outcomes has been demonstrated; however, there have been few clinical comparative studies assessing the long-term morphological, histological and functional changes after ADM placement. This study was designed to retrospectively evaluate the long-term outcomes of the cograft acellular dermal matrix with autologous thin split-thickness skin for the coverage of wounds in extensively burned patients. Thirty burn patients treated with a composite graft of ADM with autologous split-thickness skin from January 2007 to December 2009 were enrolled in this study. Another group of thirty patients who received only an autogenous split-thickness skin implant served as the control. Our study revealed that the collagen in the dermis treated with ADM were ordered, and the proportion of collagen III/I was much higher in the control group than in the ADM group. The basement membrane was prominent and continuous. Meanwhile, the VBSS (Vancouver Burn Skin Score) was used to evaluate skin quality, which shows a significant differences between the two group (P<0.001). Then the functional level was evaluated by the BI (Barthel Index), and the ADM group was much better than the control group (P=0.005). Based on these results, we concluded that the composite graft of ADM with autologous thin split-thickness skin was suitable for repairing the defects in functional areas after a burn. This technique might facilitate wound management with acceptable esthetic outcomes, good functional recovery and less scar hyperplasia at the donor site.

Zeolite-based hemostat QuikClot releases calcium into blood and promotes blood coagulation in vitro.

AIM: To examine the changes in electrolyte concentrations after addition of zeolite-based hemostat QuikClot in blood and the effects of zeolite on blood coagulation in vitro. METHODS: Fresh blood was taken from healthy adult volunteers and sheep, and the electrolyte concentrations in blood were measured using a blood electrolyte analyzer. Zeolite Saline Solution (ZSS) was prepared by addition of 2 g zeolite to 0.9% NaCl solution (4, 8, or 16 mL). The electrolytes in ZSS were measured using inductively coupled plasma atomic emission spectroscopy. The prothrombin time (PT) and activated partial thromboplastin time (APTT) of blood were measured using the test tube method. The activated clotting time (ACT) and clotting rate (CR) of blood were measured with Sonoclot Coagulation and Platelet Function Analyzer. RESULTS: Addition of zeolite (50 and 100 mg) in 2 mL human blood significantly increased Ca(2+) concentration, while Na(+) and K(+) concentrations were significantly decreased. Addition of zeolite (50 and 100 mg) in 0.9% NaCl solution (2 mL) caused similar changes in Ca(2+) and Na(+) concentrations. Si(4+) (0.2434 g/L) and Al(3+) (0.2575 g/L) were detected in ZSS (2 g/8 mL). Addition of ZSS in sheep blood shortened APTT in a concentration dependent manner, without changing PT. ZSS or aqueous solution of CaCl2 that contained Ca(2+) concentration identical to that of ZSS significantly shortened ACT in human blood without significantly changing CR, and the effect of ZSS on ACT was not significantly different from that of CaCl2. CONCLUSION: Zeolite releases Ca(2+) into blood, thus accelerating the intrinsic pathway of blood coagulation and shortening the clot formation time.

Treatment of infected soft tissue blast injury in swine by regulated negative pressure wound therapy.

OBJECTIVE: This study was designed to investigate the therapeutic potential of regulated negative pressure wound therapy (RNPT) in treating infected blast injuries in swine. BACKGROUND: Approximately 30% to 80% of blast injuries develop infection, which increases the morbidity and mortality of these casualties. RNPT has been used in US military operations in Iraq; however, no randomized controlled study has been conducted on the use of RNPT to treat infected war injuries. METHODS: Infected soft tissue blast injuries were treated with gauze dressings or RNPT with different pressures ranging from -5 to -35 kPa. To evaluate the wound healing process, the wound area, wound depth, the number of proliferative cells, and the vascular endothelial cells in the granulation tissue were measured at different time points. Furthermore, to evaluate the infection and inflammation of the blast injury, the bacterial load, bacterial species, and several inflammatory markers were detected. RESULTS: Compared with gauze dressing treatments, RNPT reduced bacterial load more efficiently, initiated granulation tissue formation earlier, and increased the inflammation faster. Negative pressures ranging from -10 to -25 kPa applied on the RNPT group showed beneficial effects in treating the infected soft tissue blast injury. RNPT did not significantly change both the aerobic and anaerobic bacterial composition compared with those of the gauze dressing group. CONCLUSIONS: RNPT clearly shows beneficial effects in treating the infected soft tissue blast injury in comparison with the gauze dressing therapy in swine.

Structure and properties of chitin/alginate blend membranes from NaOH/urea aqueous solution.

Chitin/alginate (CA) blend membranes were successfully prepared from 8 wt% NaOH/4 wt% urea aqueous solution by coagulating with 0.5M CaCl(2) aqueous solution containing 5 wt% HCl. Morphology, mechanical properties, thermal stability, and antimicrobial effects of the membranes were investigated by scanning electron microscopy, IR and UV spectroscopes, X-ray diffraction, tensile tests, thermogravimetric analysis, water swelling and antimicrobial tests. The CA blends were miscible when the content of alginate was range from 33 to 67 wt%. The crystallinity of the blend membranes decreased with an increase of alginate. Comparing with chitin membranes, the tensile strength and breaking elongation of the blend membranes were obviously improved in dry and wet states. The best values of the tensile strength and breaking elongation were 48 MPa and 27%, respectively. All the blend membranes still retained obvious antimicrobial effects toward S. aureus and E. coli. Therefore, they showed potential for biomedical application.

New swine model of infected soft tissue blast injury.

BACKGROUND: War injuries, especially blast injuries, have a high risk of infection. However, no animal models of infected war injuries have been built in large animals, which retards both the understanding and the treatment optimization of infected war injuries. METHODS: Soft tissue blast injuries were created by explosion of electric detonators in white domestic pigs. The ultra structure of the tissue around the wound was determined by transmission electron microscope. To develop infection of blast injury wounds, the pigs were housed in a standard animal house which was disinfected periodically, and the wounds were left untreated for 3 days. Wound specimens were collected daily to determine the bacterial load and bacterial components. To determine whether infection induces tissue necrosis in infected soft tissue blast injury wounds, uninfected blast injury wounds were created as controls of infected wounds by surgical debridement daily, and the wound area and wound depth of both wounds were measured. RESULTS: The wound area and the wound depth of the soft tissue blast injury created in this study fell in the range of human moderate soft tissue war injuries, and the ultra structure of the wounds was comparable with that of human blast injury wounds. The bacterial load of uninfected wounds was under 10 colony forming unit/g during the first 3 days of injury, while that of infected wounds was over 10 colony forming unit/g after 2 days of injury. The infected soft tissue blast injury wounds contained most of the bacteria frequently isolated in battlefield wounds. In addition, infection induced evident tissue necrosis in infected blast injury wounds. CONCLUSION: The infected soft tissue blast injury wounds mimic those in human, and they can be used to address key points of treatment optimization.

[Effectiveness evaluation of composite skin grafts in repairing deep burn wounds in functional regions].

OBJECTIVE: To evaluate the long-term effectiveness of composite grafts of acellular dermal matrix (ADM) and autologous split-thickness skin in repairing deep burn wounds. METHODS: Between June 2002 and December 2008, 30 patients (42 wound) were treated. There were 25 males and 5 females, aged 3-52 years with a median age of 31 years. Of them, 24 burned patients had 35 wounds, including 23 deep second degree and 12 third degree wounds with a mean disease duration of 24 days (range, 3-45 days); 6 patients with hyperplastic scar had 7 wounds with a mean disease duration of 16 days (range, 9-21 days). The wound locations were neck (2 wound), hand (4 wounds), forearm and elbow (8 wounds), shoulder (3 wounds), peoples (6 wounds), laps (4 wounds), ankle and legs (15 wounds), and the area of wounds ranged from 10 cm x 10 cm to 30 cm x 20 cm. After thorough debridement, tangential excision, and scar excision, ADM and autologous split-thickness skin graft were used to repair the wounds by one-step method. RESULTS: After operation, composite skin graft survived completely in 39 wounds of 27 patients, with a survival rate of 92.9%; partial necrosis occurred in 3 wounds of 3 patients (7.1%), and healed after dressing change and secondary skin graft. The patients were followed up 30-34 months (mean, 32 months) postoperatively. The appearance of the composite grafts were smooth and soft with good elasticity and low pigmentation. The activity and function of limbs recovered well. No scar hyperplasia was observed at the donor sites. CONCLUSION: It can achieve good outcomes in appearance and function to use ADM and autologous split-thickness skin graft for repairing deep burn wounds in functional regions.

The status of microRNA-21 expression and its clinical significance in human cutaneous malignant melanoma.

Dysregulation of microRNA-21 plays critical roles in tumor initiation and progression. The purpose of this study was to investigate the status of microRNA-21 expression in human cutaneous malignant melanoma and determine its clinical significance. TaqMan(®) real-time RT-PCR assay was performed to examine the expression of microRNA-21 in 10 cases of dysplastic nevi, 86 cases of primary cutaneous melanomas, 10 cases of melanoma metastases. The correlation of microRNA-21 expression with clinicopathological factors or prognosis of patients with cutaneous melanoma was statistically analyzed. Additionally, the effects of microRNA-21 expression on growth, apoptosis and chemo- or radiosensitivity of melanoma cells were also investigated by transfection of microRNA-21 inhibitor. We firstly showed that increased levels of microRNA-21 expression were shown from dysplastic nevi to primary cutaneous melanomas to melanoma metastases. Moreover, high miR-21 expression was found to be correlated with Breslow thickness and advanced clinical stage. Patients with high microRNA-21 expression showed shorter 5-year disease-free or overall survival than those with low microRNA-21 expression. Furthermore, multivariate regression analysis showed that the status of microRNA-21 expression was an independent prognostic factor for overall survival of patients. Antisense-mediated microRNA-21 inhibition could significantly suppress growth, increase apoptosis and enhance chemo- or radiosensitivity of human cutaneous melanoma cells by inducing the increased Bax/Bcl-2 ratio. Thus, the status of microRNA-21 might be an independent prognostic factor for patients with cutaneous melanoma, and microRNA-21 has the potential of being a novel molecular target for the treatment of human cutaneous melanoma.

Epidemiological studies of electrical injuries in Shaanxi province of China: a retrospective report of 383 cases.

A statistical survey was conducted at the Burn Unit of the Tangdu Hospital, Shaanxi, China, during the 10-year period from January 2000 to December 2009. In this retrospective study, 383 patients who admitted to our burn unit because of electrical trauma were included. Data including the patient's general condition, clinical presentation, complications and operation times was collected retrospectively and analyzed with epidemiological methods. Subjects in our collective were predominantly male (90.3%, n=346/383) and were composed by those who injured in work-related incidents (78.3%, n=300/383), rural individuals (58.2%, n=223/383) and students (9.4%, n=36/383). High voltage was directly correlated to severity clinical complications, and amputation. The percentage of myocardial impairment was 79.3% (n=92/116) among patients who suffered with electrical current through heart tissue. Along with the more developed east area of China, electrical injuries are becoming a growing concern of the developing West part in China as well. Electrical injuries induce serious tissue damage, need long hospital stay, and result in high rate of permanent disability and economic hardship for the afflicted families. A competent prevention program needs to be developed to address this problem.

Electrical injury alters ion channel expression levels and electrophysiological properties in rabbit dorsal root ganglia neurons.

The electrophysiological and morphological changes of nerve fibers induced by electrical injury have been widely addressed. However, the changes of ion channels in neurons after electrical shocks have not been systematically investigated yet. In this study, the sciatic nerves of rabbit were injured by 50 V 50 Hz, 110 V 50 Hz, and 220 V 50 Hz alternating current, respectively. One week later, the expression levels and electrophysiological changes of voltage-gated potassium (Kv) and sodium (Nav) channels in dorsal root ganglia (DRG) neurons were evaluated by RT-PCR, immunofluorescence staining and patch clamp technique. The Nav1.1 expression was decreased by 50V injury. The Kv1.2, Kv1.4, Nav1.1 and Nav1.7 expression levels and Kv current densities were reduced after 110 V injury. Under the 220 V injury circumstance, Kv1.2, Nav1.1, Nav1.7 expression levels, Kv current densities and TTX-R Na(+) current densities were significantly decreased, while TTX-S Na(+) current densities increased. These findings suggest that the expression levels, subunit compositions, and electrophysiological properties of Kv and Nav channels are altered after electrical injury, and the severity of injury gets worse as injury voltage increases.

Cell death-inducing DFF45-like effector, a lipid droplet-associated protein, might be involved in the differentiation of human adipocytes.

Cell death-inducing DFF45-like effector (CIDE) family proteins, including cell death-inducing DFF45-like effector A (CIDEA), cell death-inducing DFF45-like effector B (CIDEB) and cell death-inducing DFF45-like effector C (CIDEC) [fat-specific protein of 27 kDa in rodent (FSP27) in rodents], were originally identified by their sequence homology to the N-terminal region of DNA fragmentation factor DFF40/45. Recent reports have revealed that CIDE family proteins play important roles in lipid metabolism. Several studies involving knockdown mice revealed that FSP27 is a lipid droplet-targeting protein that can promote the formation of lipid droplets. However, the detailed roles of human CIDEC in the differentiation of human adipocytes remain unknown. In the present study, we found that the expression of CIDEC increased during the differentiation of fetal adipose tissues, but decreased during the de-differentiation of adipocytic tumors, suggesting that the expression of CIDEC should be positively correlated with the differentiation of adipocytes. Furthermore, we verified that human CIDEC was localized on the surface of lipid droplets. Using human primary pre-adipocytes, we confirmed that the expression of CIDEC was elevated during the differentiation of pre-adipocytes, and knockdown of CIDEC in human primary pre-adipocytes resulted in differentiation defects. These data demonstrate that CIDEC is essential for the differentiation of adipose tissue. Together with regulating adipocyte lipid metabolism, CIDEC should be a potential target for regulating adipocyte differentiation and reducing fat cell mass.

[Therapeutic effect of vacuum-assisted closure technology on infected explosion wound of pig].

OBJECTIVE: To investigate the effect of vacuum-assisted closure (V. A. C.) technology in the treatment of infected wound of skin and soft tissue as a result of explosion injury in pig. METHODS: Sixteen explosion wounds were established by electric detonators on the shoulders and hips on both sides of 4 small white domestic pigs ,and they were divided into A group [(without treatment and infection occurred on 1-2 post burn day (PBD), then treated with vaseline gauze on 3 (PBD)], and B group (with the same treatment as in A group, except for treatment of vacuum assisted closure (V. A. C) with pressure of - 15 kPa after 3 PBD). The data of wound depth, wound area, wound healing time were collected and analyzed at 3 PAD and 1, 3, 6, 9, 14, 19, 24 days after treatment. Specimens from wounds were collected for histopathology observation, including also cell proliferation index, the number of vascular endothelial cells, the activity of myeloperoxidase (MPO) and the number of bacteria. RESULTS: Compared with those in A group on land 3 days after treatment, wound area, wound depth were not enlarged or deepened in B group, while the number of inflammatory cells, vascular endothelial cells, proliferative cells were increased, the activity of MPO was enhanced and the number of bacteria was decreased. There were obvious differences between two groups in following indices: wound area ,wound depth, the number of vascular endothelial cells and bacteria during 1 to 19 days after treatment (P < 0.01)), the number of cell proliferation from 1 - 9 days after treatment (P < 0.01)), and the activity of MPO on 3, 6 days after treatment (P < 0. 01). The wound healing time was (32.8 +/- 1.6) d in A group, which was longer than that in B group (25.8 +/- 1.0 d, P < 0.01). CONCLUSION: Compared with conventional dressing change, V. A. C can decrease bacteria load, lessen secondary necrosis, prompt the inflammatory response, accelerate the formation of granulation tissue, shorten wound healing time in infectious wound of porcine skin and soft tissue resulted from explosion injury.

[The influence of vacuum-assisted drainage on the growth of capillaries in the wound produced by explosion in pig].

OBJECTIVE: To investigate the influence of vacuum-assisted closure (VAC) technique on the growth of capillaries in the wound of the pig produced by explosion. METHODS: Four small white pigs were inflicted with 16 explosion wounds [(7.3 +/- 1.0) cm2 in area] on both sides of the buttocks, shoulders and hips by detonation of a specific type of explosive, and the wounds were randomly divided into 2 groups, i. e, control (C, with conventional treatment from 2 post-injury day (PID) on and treatment (T, with VAC treatment after debridement from 2 PID on) groups, with 8 wounds in each group. Wound tissues of 2mm x 2mm x 2mm in size were harvested for pathological examination before treatment and on 1 and 3 post-treatment day (PTU). The differentiation of adventitial cells were examined with light microscope, and the pixel value of desmin positive particles and the luminal area of newly formed capillaries were assessed with Image C software. RESULTS: Most of vessels in the wound of both groups were in elliptic shape when observed in longitudinal section. In C group, few newly formed capillaries vessels with lack of pericytes were observed before treatment and on 1, 3 PTD, then the number began to increase on 6 PTD. In T group, the number of newly formed capillaries with pericytes was increased on 1 PTD, and it continued to increase thereafter. The pixel values of desmin positive particles in C group on 1, 3, and 6 PTD were (91 +/- 54), (199 +/- 85), and (1552 +/- 298), respectively, which were obviously higher than those in T group [(2569 +/- 330), (3984 +/- 377), (9611 +/- 960), P < 0.01]. The area of vessel lumen in C group was (59 +/- 36), (250 +/- 70), and (938 +/- 287) microm2, respectively on 1, 3, and 6 PTD, which was also smaller than those in T group [(818 +/- 234), (4518 +/- 1080), and (9058 +/- 1656) microm2, P < 0.01]. CONCLUSION: Compared with conventional therapy, VAC can not only accelerate the formation of new capillaries, but also enhance the differentiation of pericytes and the process of enwrapping them around the vessels, and increase the luminal area of newly formed capillaries.

[The changes in blood flow in sciatic nerve after electrical injury in rabbit].

OBJECTIVE: To study the changes in sciatic nerve blood flow and the expression of collagen type I after electric injury of rabbit nerve with different voltages. METHODS: Thirty-six healty rabbits were randomized into 3 groups before receiving injury with electricity in voltages, i.e. 50 v, 75 v, and 100 v groups. The changes in blood flow of sciatic nerve were observed with Laser Doppler Flowmeter immediately after injury and 1, 4, 8 weeks after injury. The changes in the expression of collagen type I was observed by immunohistochemical method, and the positive expression rate was calculated. RESULTS: The sciatic nerve blood flow increased in all groups immediately after electric injury. In the 75 v and 100v groups, the nerve blood flow [(53 +/- 3 ), (48 +/- 5) PU] was obviously lower than that of normal value [(62 +/- 4) PU, P < 0.05]. There was little collagen type I deposition in 50 v group, while brown collagenous fibers in epineurium and perineurium were observed in 75 v and 100v groups 4 and 8 weeks after injury. The expression of collagen type I in all groups were obviously higher than that of normal value, and that in 75v and 100 v groups were higher than that in 50 v group at bachl time-point (P < 0.01). CONCLUSION: The restoration of sciatic nerve blood flow is postponed following by the injury with increase of the electrical voltage. The collagen deposition after electrical injury may be one of the reasons for nerve blood flow decrease.

[Isolation, cultivation of adipose-derived mesenchymal stem cells and its chondrogenic ability].

AIM: To find a method for isolation and cultivation of human adipose-derived mesenchymal stem cells(ADSCs), and to investigate its chondrogenic ability. METHODS: Liposuction human adipose tissues were digested with collagenase type II. The obtained cells were primarily cultured in DMEM medium, and then changed into the induced medium. Alcian Blue stain, picrosirius red stain and the specific collagenase type II immunohistochemical staining were used to detect the results. RESULTS: After cultured in chondrogenic medium, the cells differentiated toward cartilage cells and secreted the specific cartilaginous matrices sulfated proteglycan and collagen type II. CONCLUSION: The human ADSCs have the potential ability to differentiate toward cartilage cells in the appropriated medium. The result provide a new method for the further research in cartilaginous tissue engineering.