Osteoclast activity of MG63 cells on silicon doped zirconia films prepared by cathodic arc deposition / 中国组织工程研究

BACKGROUND:Various surface modification techniques have been utilized as an attempt to improve the osteointegration of Ti-based implants, which is a hotspot research concerning the artificial joint prosthesis. OBJECTIVE:To evaluate the effect of silicon doped zirconia film on the titanium surface on relevant factors of osteoblast-like MG63 cells. METHODS:Silicon doped zirconia and zirconia films were respectively prepared on the titanium surface by cathodic arc deposition. Osteoblast-like MG63 cells were cultured on silicon doped zirconia film, zirconia film and pure titanium, respectively. After 1, 4, 7, 10 days of incubation, samples were collected for assay. Osteoprotegerin (OPG) and receptor activator of nuclear factor κB ligand (RANKL) at mRNA and protein levels were detected using real-time PCR and ELISA, respectively. RESULTS AND CONCLUSION:(1) At 1 day of inoculation, there was no significant difference in the OPG mRNA and protein expression among the three groups. At 4 days of inoculation, the expression of OPG mRNA and protein in the silicon doped zirconia film and zirconia film groups was significantly higher than that in the pure titanium group (P<0.05), but there was no significant difference between the former two groups. At 7 and 10 days of inoculation, the expression of OPG mRNA and protein in the silicon doped zirconia film growp was highest among the three groups (P<0.05). (2) At 1 day of inoculation, there was no significant difference in the RANKL mRNA and protein expression among the three groups. At 4 and 7 days of inoculation, the expression of RANKL mRNA and protein in the silicon doped zirconia film group was significantly lower than that in the other two groups (P<0.05). At 10 days of inoculation, the expression of OPG mRNA and protein in the silicon doped zirconia film and zirconia film groups was significantly higher than that in the pure titanium group (P<0.05), but there was no significant difference between the former two groups. To conclude, silicon doped zirconia film fabricated by cathodic arc deposition can enhance the expression of OPG and reduce the expression of RANKL at the same time.

Comparison between external fixator and DVR system for the treatment of AO type C distal radial fractures / 中国骨伤

<p><b>OBJECTIVE</b>To compare the clinical effects of external fixator versus DVR system for the treatment of AO type C distal radius fractures.</p><p><b>METHODS</b>The clinical data of 52 patients with type C distal radial fractures treated with external fixator or DVR system respectively from January 2009 to December 2013 were analyzed retrospectively. In DVR system group, 31 patients were treated by open reduction and internal fixation with DVR system, involved 11 males and 20 females, with an average age of(47.3±10.9) years ranging from 24 to 65 years;according to AO/ASIF classification, 12 cases were type C1, 15 cases were type C2, 4 cases were type C3. In external fixator group, 21 patients were treated by closed reduction and cross wrist external fixation, involved 8 males and 13 females, with an average age of (48.1±12.1) years ranging from 26 to 69 years; according to AO/ASIF classification, 7 cases were type C1, 11 cases were type C2, 3 cases were type C3. The postoperative images, wrist joint functions and Gartland-Wetley scores were evaluated and compared.</p><p><b>RESULTS</b>Thirty-one patients in DVR system group were followed up for 20.4 months(ranged from 13 to 36 months) and in external fixator group 21 patients were followed up for 17.1 months (ranged from 11 to 33 months) respectively. X-rays showed all fractures healed. The palm dip and radial inclination in the DVR system group were significantly better than in the external fixator group(<0.05), while there was no significant difference in radial height and Gartland-Werley score(>0.05). There was 1 case of wrist stiffness in the DVR system group; 2 cases of pin tract infection, 1 case of fixator loosening and 2 cases of wrist stiffness in the external fixator group.</p><p><b>CONCLUSIONS</b>Clinical outcomes of DVR system fixation for type C distal radial fractures are better than that of external fixator fixation. However, DVR system fixation costs more and requires a secondary surgery to remove the internal fixation. The choices of surgical method depend on the clinical conditions of the patients.</p>

Study of neovascularization disturbance in deep partial-thickness scald in rats with diabetes mellitus / 中华烧伤杂志

<p><b>OBJECTIVE</b>To study the relationship between the degree of neovascularization and non-healing wounds in scalded rats with diabetic mellitus.</p><p><b>METHODS</b>Sixty Sprague-Dawley rats were randomly divided into control group (C, n = 30, with treatment of isotonic saline) and streptozocin (STZ)-induced diabetic group (D, n = 30, with treatment of STZ), and then they were inflicted with 20% TBSA deep partial thickness scald. Wound specimens were harvested immediately after scald and on 1, 3, 7, 10, 14, 21 post scald days (PSD) to observe histological changes, and wound healing rates were calculated. Degree of neovascularization in wound (labeled with blue microsphere) and the quantity of vascular endothelial cells (labeled with red CD31) were also measured by double-labeling immunofluorescence.</p><p><b>RESULTS</b>Compared with those in C group, Wound healing rate and histological value scores were lowered, and the degree of neovascularization was abated markedly at each time point. The degree of neovascularization in D group (12.00 +/- 1.40) was obviously lower than that in C group on 7 PSD (60.00 +/- 3.00, P <0.01). There was no obvious difference in the number of vascular endothelial cells in both groups, however, the majority of endothelial cells had not formed functional capillaries in D group.</p><p><b>CONCLUSION</b>Vascular endothelial cell can proliferate actively with poor blood supply in diabetic nonhealing with deep partial-thickness scald wounds, but it is still poor in blood supply due to lack of functional capillaries.</p>

Influence of tangential excision within 24 postburn hours on the local wound inflammatory response in patients with deep partial thickness burn / 中华烧伤杂志

<p><b>OBJECTIVE</b>To investigate the influence of early tangential excision within 24 postburn hours on local wound inflammatory response and tissue injury in patients with deep partial thickness burn.</p><p><b>METHODS</b>Twelve patients with deep partial thickness burn were enrolled in the study. Tangential excision was performed within 24 postburn hours. The same wound of a patient was divided into three areas for harvesting tissue samples, i.e. pre-operation, post-operation and non-operation areas. For each patient, the biopsies from the pre-operation area were harvested before tangential excision, while those from post-operation and non-operation areas were harvested during 5 to 7 postburn days (PBDs). The contents of IL-8, MPO and MDA in wound tissue were determined by tissue culture and chemical colorimetry, respectively. HE and Mason's staining were employed to assess the degree of necrosis of the wound tissue.</p><p><b>RESULTS</b>The IL-8, MPO and MDA contents in the local wound tissue after tangential excision were 6.83 +/- 1.85 microg/L, 4.07 +/- 0.87 U/g, and 8.94 +/- 5.66 micromol/g, respectively, which were significantly lower than those from non-operation area (P < 0.01). The inflammatory response in the non-operative wound area was distinct with expansion of necrotic tissue area. In contrast, the local inflammatory response of the wound after tangential excision was ameliorated without the enlargement of necrotic tissue area.</p><p><b>CONCLUSION</b>Tangential excision within 24 postburn hours could be beneficial in ameliorating local inflammatory response, and in preventing progressive deepening of the burn wounds, thus it could accelerate wound healing in patients with deep partial thickness burn.</p>

Influence of dermal template on the biomechanical compliance of wound tissue / 中华烧伤杂志

<p><b>OBJECTIVE</b>To investigate the influence of dermal template on the biomechanical compliance of wound tissue during wound repair.</p><p><b>METHODS</b>One hundred and forty-four SD rats subjected to full-thickness skin loss on the dorsum were enrolled in the study, and they were randomly divided into A (n = 6, without grafting on wound), B (n = 6, with full thickness skin grafting on wound), C (n = 6, with razor thin skin grafting on wound) and D [n = 6, with acellular dermal matrix (ADM) and razor thin skin grafting on wound] groups. The tissue samples from the wounds were harvested 1, 2, 4, 6, 12 and 20 weeks after the operation. The biomechanical compliance of the wound was assessed by Instron biomechanics tensiometer. The expression of alpha-SMA in the dermal fibroblasts of each group was determined by immunohistochemistry (ABC) method.</p><p><b>RESULTS</b>The biomechanical compliance of the wound in D group was higher than that in A and C groups (P < 0.05), but lower than that in B group during 4 to 20 weeks after operation (P < 0.05). The expression of alpha-SMA in D group (7.53 +/- 0.98)% was lower than that in A (26.99 +/- 2.90)% and C (2.18 +/- 2.79)% groups (P < 0.01), but higher than that in B group at 4 weeks after operation (P < 0.05).</p><p><b>CONCLUSION</b>Dermal template might affect the scar formation during wound healing, in improving wound healing quality by enhancing the biomechanical compliance of wound tissue.</p>

Study on the proliferation of epidermal cells of wound edge in deep partial thickness scald injury in rat / 中华烧伤杂志

<p><b>OBJECTIVE</b>To investigate the rule and possible mechanism of epidermal proliferation in wound edge of deep partial thickness scald injury in rat.</p><p><b>METHODS</b>Twenty-four Sprague-Dawley rats inflicted with deep partial thickness scald were randomized into pre-scalding, 3 post-scalding day (PSD), 7PSD and 14PSD groups, with 6 rats in each group. Skin specimens from the wound edge were harvested for the observation of the histological characteristics of the epidermis. Cell cycles of epidermal cells were analyzed with flow cytometry. The expressions of cyclin D1, cyclin B1, cdk4 and the histone H1 kinase activity of MPF in epidermal cells were determined by Western blotting.</p><p><b>RESULTS</b>Augmentation of nuclei and nucleoli was found in the epidermal cells from the wound edge in 3PSD group, while increased number of epidermal cells with obviously augmented nuclei and nucleoli were found in 14PSD group. The percentage of the cells in S phase increased in 14 PSD group. The percentage of epidermal cells in G2/M phase began to increase in 3PSD group, and that in 7PSD (4.5 +/- 0.6) and 14PSD (5.4 +/- 1.0) groups were obviously higher than that in pre-scalding group (2.9 +/- 1.1, P < 0.05). The expression of cyclin D1 increased significantly in 3PSD group. The expression of cdk4 decreased in 3PSD group, but began to increase in 14PSD group. There was no difference in the expression of cyclin B1 among groups. The MPF activity was significantly increased in 14PSD group.</p><p><b>CONCLUSION</b>There was enhanced DNA synthesis and mitosis in epidermal cells of rats with deep partial scald during early post-scald stage, and active proliferation of epidermal cells was observed on 14PSD. The expression of cyclinD1/cdk4 complex and the activity of MPF increased since 14PSD, indicating that there was a special regulative pattern during wound healing.</p>

Influence of L-arginine supplementation on the plasma amino acid spectrum in burn patients / 中华烧伤杂志

<p><b>OBJECTIVE</b>To explore the influence of L-arginine supplementation on the plasma amino acid spectrum in burn patients.</p><p><b>METHODS</b>Ten burn patients were randomly divided into burn control (n = 5, with compound 14 amino acid injection accounting for 2% of the total caloric value), and experimental (n = 5, with intravenous injection of L-arginine which accounted for 2% of total caloric value) groups. The intake of other nutrients for these two groups of patients was the same. The nutrient regimen was begun on the 3 PBD, with one quarter of the daily supply. On 4 and 5 PBD, one half of the daily supply was given, and from 6 to 21 PBD full supplementation was given. Venous blood samples were collected on 3, 7, 14, 21 and 28 PBD for the determination of plasma levels of amino acids. Ten normal volunteers served as normal control.</p><p><b>RESULTS</b>The plasma level of citrulline in both groups was significantly lower than normal value (P < 0.05) on 3 PBD before L-arginine supplementation. There was no obvious difference in plasma levels of ornithine and arginine in the two groups on 3 PBD compared with normal value (P > 0.05). The plasma level of ornithine, citrulline and arginine in burn control group declined on 3 PBD. The plasma level of arginine in experimental group on 14, 21 and 28 PBD were 280 +/- 121 micromol/L, 223 +/- 106 micromol/L and 110 +/- 44 micromol/L, respectively, which were significantly higher than those in burn control group (124 +/- 21 micromol/L, 59 +/- 15 micromol/L, 50 +/- 26 micromol/L). The plasma level of ornithine (30 +/- 5 micromol/L) and citrulline (162 +/- 44 micromol/L) on 21 PBD in experimental group were markedly higher than those in burn control group (8 +/- 7 micromol/L, 66 +/- 4 micromol/L, P < 0.05 or 0.01). There was no difference in the plasma levels of other amino acids at all postburn time points between the two groups (P > 0.05).</p><p><b>CONCLUSION</b>The production process of L-arginine from citrulline was accelerated after burns. The plasma levels of L-arginine, ornithine and citrulline were increased markedly after L-arginine supplementation, while that of other amino acids was not influenced. The pharmacological effects of L-arginine may be related to the promotion of ornithine cycle.</p>

The influence of L-arginine on the angiogenesis in burn wounds in diabetic rats / 中华烧伤杂志

<p><b>OBJECTIVE</b>To investigate the possible mechanism of L-arginine supplementation on the angiogenesis of burn wounds in diabetic rats.</p><p><b>METHODS</b>One hundred male Sprague-Dawley (SD) rats were used in the study and were randomly divided into A (scalding control, n = 25), B (scalding of the rats with diabetes, n = 25), C (L-glycine control, n = 25) and D (L-arginine supplementation, n = 25) groups. Diabetes was produced by intra-peritoneal injection of streptozotocin (STZ) in B, C and D groups. The rats in C and D groups were gavaged with L-glycine and L-arginine in dose of 200 mg.kg(-1).d(-1), respectively. The glucose content of the back skin tissue was determined for five rats in each group eight weeks after STZ administration. Deep partial thickness scalding of 20% TBSA was engendered on the back in the other 80 rats. The wound area, wound healing rate, and microvascular density with CD34 immunohistochemistry staining were determined on 3rd, 7th, 14th, and 21st post scalding days (PSDs), In addition, the amount of nitric oxide (NO) released from the wound tissue and the tissue contents of vascular endothelial growth factor (VEGF) and transforming growth factor beta1 (TGF-beta1) from wound were determined at the above time points.</p><p><b>RESULTS</b>Compared to those in group B, the wound healing rate in group D increased significantly since the 7th PSD [(44.10 +/- 3.50)%, P < 0.05], and the wound MVD value was increased significantly at all postburn time points. Furthermore, the levels of VEGF, NO and TGF-beta1 in the wound tissue was also increased significantly, while the glucose content in the cutaneous tissue was decreased to (1.380 +/- 0.120) mg/g.</p><p><b>CONCLUSION</b>L-arginine supplementation could be beneficial to the angiogenesis in the burn wound of the rats with diabetes, as well as to wound healing by increasing the synthesis and the release of VEGF, NO and TGF-beta1 from burn wound and by decreasing the glucose content in the cutaneous tissue of diabetic rats.</p>

Experimental study on the role of cytokines and keratinocytes in the survival mechanism of auto and allogeneic mixed skin grafting / 中华烧伤杂志

<p><b>OBJECTIVE</b>To explore the role of cytokines and keratinocytes in the survival mechanism of mixed auto and allogeneic skin grafting.</p><p><b>METHODS</b>Thirty-six SD rats were employed in the study. The rat model with mixed auto and allogeneic skin grafting and mixed human epithelial and lymphocytic culture (MELC) model were established. The change of IL-10 in the serum and the supernatant of the cultured tissue sample from the local wound was observed after the mixed skin grafting in scalded rats. And the role of epithelium in the induction of immunosuppression in vitro was monitored.</p><p><b>RESULTS</b>The serum IL-10 content in the rats with mixed skin grafting (25.89 +/- 2.82 ng/L) at 7 postoperative day (POD) was evidently higher than that in normal rats (14.20 +/- 2.43 ng/L) (P < 0.05). The IL-10 content in the culture supernatant of rat tissue samples exhibited evident different during 4-14 PODs (P < 0.05-0.01), while which was no difference to that in normal rat on 21st and 28th POD. The inhibiting effects of autologous epithelia and keratinocytes in MELC system were correlated with their dosage. After the adding of autologous keratinocytes to MELC system the cytokines secreted from Th1 could induce the secretion of cytokines from Th2 by IL-10 mediation. This effect could be corrected by the addition of monoclonal antibody of IL-10.</p><p><b>CONCLUSION</b>The keratinocytes inlayed in the autoskin during mixed grafting could increase the local IL-10 level by activating Th2 cells, which might be one of the important reasons of the survival of mixed skin grafting.</p>

An experimental study on the effects of postburn dietary supplementation of enhanced nutrients / 中华烧伤杂志

<p><b>OBJECTIVE</b>To evaluate the effects of postburn dietary supplementation of arginine (Arg), omega-3 polyunsaturated fatty acid (omega-3PUFA) and glutamine (Glu) on the metabolism, immunology and wound healing in scalded rats.</p><p><b>METHODS</b>Thirty Sprague-Dawley (SD) rats inflicted with 30% total body surface area deep partial thickness scald on the back after the gastrostomy catheter was placed were employed as the model. The rats were randomly divided into A and B groups, and all of them received continuous isonitrogenous (25% protein, 12% fat, 63% carbohydrate), isocaloric (175 kcal/kg/day), and isovolemic intragastric tube feedings. The contents of Arg, omega-3PUFA, Glu in the dietary of B group were enriched. The parameters were measured on the 10th day after injury, including the response of spleen cells to ConA, the plasma levels of PGE(2), IL-2, albumin, transferrin, glucagons, cortisol in blood, the urinary content of vanillylmandelic acid (VAM) in 24-hour urine, the content of hydroxyproline, the ratio of type I to type III collagen in burn wounds, and the nitrogen content in the liver and in the jejunal mucosa, as well as the weight changes, skin delayed hypersensitivity test, and wound healing time.</p><p><b>RESULTS</b>It was revealed that the serum level of albumin, the nitrogen content in the liver and in the jejunal mucosa were obviously higher in B than those in A group. At the same time, there was no statistical difference in the plasma levels of cortisol and glucagons and urinary content of VAM between the two groups, nor in body weight changes. Meanwhile, the response of spleen cells to ConA and the skin delayed hypersensitivity induced by DNFB 14 days after injury in group B were also enhanced compared with those in group A. Although the expression of PGE2 from peritoneal macrophages was lower, the content of hydroxyproline from burn wounds in group B was significantly higher than that in group A, and the ratio of type l to type III collagen in group B was significantly lower than that in group A. Compared with group A, the wound healing time in group B was significantly shortened (P < 0.05).</p><p><b>CONCLUSION</b>The low-fat and high-protein feeding diet with enriched arginine, omega-3 PUFA, glutamine could benefit the nutritional status after burn injury, thus improve the immunological function and promote wound healing.</p>

Clinical observation of the effect of tangential excision within 24 postburn hours on the patients with deep partial thickness burn / 中华烧伤杂志

<p><b>OBJECTIVE</b>To investigate the safety and the clinical effect of the tangential excision of the patients with deep partial thickness burn within 24 postburn hours (PBHs).</p><p><b>METHODS</b>Twelve patients with deep partial thickness burn with the indication for tangential excision, the operation was carried out within 24 PBHs. These patients were designated as group A. Another group of fourteen patients with similar conditions undergoing tangential excision during 4 - 6 PBDs were designated as group B. The amount of fluid infusion during shock stage, the shock signs, the vital signs during recovery period, the urine output, as well as the healing time were compared between the two groups.</p><p><b>RESULTS</b>There was no obvious difference in the amount of fluid infusion and the shock signs between the two groups. There were evident differences in the body temperature and heart rate during recovery period, with the urine output increased dramatically during shock stage in group A when compared with those in group B (P < 0.05-0.01). The average wound healing days in group A were less than that in group B (P < 0.01).</p><p><b>CONCLUSION</b>Tangential excision within 24 PBHs was applicable and safe for the patients with deep partial thickness burn, and wound healing time was thus shortened.</p>