MicroRNA-140-5p represses chondrocyte pyroptosis and relieves cartilage injury in osteoarthritis by inhibiting cathepsin B/Nod-like receptor protein 3.

Osteoarthritis (OA) is a degenerative joint disease. Dysregulated microRNA (miRNA) expressions are implicated in OA progression. Consequently, the current study set out to investigate the mechanism of miR-140-5p in OA cartilage injury. Firstly, the murine and cell models of OA were established, and cartilage tissues of OA mice were observed using hematoxylin and eosin staining and safranin O staining. Chondrocyte pyroptosis was further assessed using immunohistochemical and Calcein-AM/PI staining. The levels of gasdermin-D (GSDMD)-N, cleaved caspase-1, interleukin (IL)-1ß, and IL-18 in cartilage tissues and cells were determined using Western blot and enzyme-linked immunosorbent assay kits. The targeting relationship between miR-140-5p and cathepsin B (CTSB) was verified using a dual-luciferase assay. Moreover, the binding of CTSB and Nod-like receptor protein 3 (NLRP3) was detected using co-immunoprecipitation assay. Lastly, the effects of NLRP3 activation and CTSB overexpression on chondrocyte pyroptosis were documented. It was found that OA induction aggravated cartilage tissue injury and enhanced chondrocyte pyroptosis. miR-140-5p was poorly-expressed in OA models, and miR-140-5p over-expression alleviated chondrocyte pyroptosis, as evidenced by decreased GSDMD-N, cleaved caspase-1, IL-1ß, and IL-18 levels. miR-140-5p targeted the CTSB gene, whereas CTSB further bound to NLRP3 and activated the NLRP3 inflammasome. Additionally, CTSB over-expression or NLRP3 activation reversed the inhibitory effect of miR-140-5p on chondrocyte pyroptosis. Collectively, our findings revealed that miR-140-5p repressed chondrocyte pyroptosis and alleviated OA cartilage injury via inhibition of the CTSB/NLRP3. This study may confer a theoretical basis for the treatment of OA cartilage injury.

Anti-hyperuricemic and anti-gouty arthritis activities of polysaccharide purified from Lonicera japonica in model rats.

In this present study, we investigated the anti-hyperuricemic and anti-gouty arthritis effect of a puried water-soluble polysaccharide (LJP-1) obtained from Lonicera japonica. A series of characterization of the purified polysaccharide were carried out in this paper. Monosaccharide analysis showed that LJP-1 composed of glucuronic acid, glucose, galactose, arabinose, and xylose at the ratio of 2.43:1:2.09:1.95:1.96, respectively. The estimated molecular weight of LJP-1 was 17.5 kDa. LJP-1 belonged to pyranose and possessed α- and ß -glycosidic configurations. Congo red test showed that LJP-1 had a spatial triple helix structure. In pharmacodynamic experiments, the anti-hyperuricemic activity of LJP-1 was studied using hyperuricemic SD rat model induced via potassium oxonate and hypoxanthine. The result showed that LJP-1 could obviously decrease the serum uric acid level and suppress xanthine oxidase (XOD) activity. Moreover, in the gouty arthritis model established by sodium urate crystals, the degree of swelling of the ankle joint, IL-1ß, IL-6, TNF-α and COX-2-related inflammatory factors levels in murine serum all declined. Taken together, these results demonstrated that LJP-1 has anti-gouty arthritis effect. Therefore, LJP-1 could serve as a promising candidate for developing novel natural anti-gouty agent.

Potent Activity of the Bromodomain Inhibitor OTX015 in Multiple Myeloma.

Several studies demonstrate that the bromodomain inhibitor OTX015 has an antitumor activity in cancers. However, translation of these data to molecules suitable for clinical development has yet to be accomplished in multiple myeloma (MM). Here, we identified genes and biologic processes that substantiated the antimyeloma activity of OTX015 with global transcriptomics. OTX015 exerted a strong antiproliferative effect and induced cell cycle arrest in vitro. Gene expression profiling uncovered that OTX015 targeted NF-κB, EGFR, cell cycle regulation, and the cancer proliferation signaling pathway. Gene expression signatures displaying various levels of sensitivity to OTX015 were also identified. The data also showed that oral administration of OTX015 displayed significant antitumor activity in the mice model of disseminated human myeloma. In addition, our study provided the first evidence and rationale that OTX015 could promote osteoblast differentiation of mesenchymal stem cells (MSCs) and inhibited osteoclast formation and resorption in vivo experiments. Herein our results expanded the understanding of the mechanism for BET inhibitors OTX015 in MM. Our study provided an impressive basis for the clinical application of the novel antimyeloma agent OTX015 and uncovered signaling pathways that may play key roles in myeloma cell proliferation.

A new diterpenoid from the leaves of Platycladus orientalis.

A new diterpenoid, 17-methyl-8, 13-labdadien-15, 16-olid-19-oic acid methyl ester (1), along with two known compounds 2 and 3, were isolated from the leaves of Platycladus orientalis (L.) Franco. The structures were confirmed based on the analysis of HR-MS, 1D-NMR, and 2D-NMR spectra and the configuration of 1 was confirmed by the single-crystal X-ray diffraction.

[Comparison between external fixator and DVR system for the treatment of AO type C distal radial fractures].

OBJECTIVE: To compare the clinical effects of external fixator versus DVR system for the treatment of AO type C distal radius fractures. METHODS: 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. RESULTS: 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(P<0.05), while there was no significant difference in radial height and Gartland-Werley score(P>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. CONCLUSIONS: 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.

Distribution and alteration of lymphatic vessels in knee joints of normal and osteoarthritic mice.

OBJECTIVE: To investigate the distribution and alteration of lymphatic vessels and draining function in knee joints of normal and osteoarthritic mice. METHODS: For the mouse models of osteoarthritis (OA), we used mice with meniscal-ligamentous injury or mice with conditional knockout of the gene for cartilage transforming growth factor ß (TGFß) type II receptor. The severity of cartilage loss and joint destruction was assessed histologically. Capillary and mature lymphatic vessels were identified and analyzed using double immunofluorescence staining and a whole-slide digital imaging system. Lymphatic drainage of knee joints was examined using near-infrared lymphatic imaging. Patient joint specimens obtained during total knee or hip arthroplasty were evaluated to verify the content validity of the mouse findings. RESULTS: Lymphatic vessels were distributed in soft tissues (mainly around the joint capsule, ligaments, fat pads, and muscles of normal knees). The number of lymphatic vessels, particularly the number of capillaries, was significantly increased in joints of mice with mild OA, while the number of mature lymphatic vessels was markedly decreased in joints of mice with severe OA. OA knees exhibited significantly decreased lymph clearance. The number of both capillary and mature lymphatic vessels was significantly decreased in the joints of patients with OA. CONCLUSION: The whole-slide digital imaging system is a powerful tool, enabling the identification and assessment of lymphatic microvasculature in the entire mouse knee. Lymphatic capillaries and mature vessels are present in various soft tissues around articular spaces. Abnormalities of lymphatic vessels and draining function, including significantly reduced numbers of mature vessels and impaired clearance, are present in OA joints.

Thermal infrared emissivity spectrum and its characteristics of crude oil slick covered seawater.

Detecting oil slick covered seawater surface using the thermal infrared remote sensing technology exists the advantages such as: oil spill detection with thermal infrared spectrum can be performed in the nighttime which is superior to visible spectrum, the thermal infrared spectrum is superior to detect the radiation characteristics of both the oil slick and the seawater compared to the mid-wavelength infrared spectrum and which have great potential to detect the oil slick thickness. And the emissivity is the ratio of the radiation of an object at a given temperature in normal range of the temperature (260-320 K) and the blackbody radiation under the same temperature , the emissivity of an object is unrelated to the temperature, but only is dependent with the wavelength and material properties. Using the seawater taken from Bohai Bay and crude oil taken from Gudao oil production plant of Shengli Oilfield in Dongying city of Shandong Province, an experiment was designed to study the characteristics and mechanism of thermal infrared emissivity spectrum of artificial crude oil slick covered seawater surface with its thickness. During the experiment, crude oil was continuously dropped into the seawater to generate artificial oil slick with different thicknesses. By adding each drop of crude oil, we measured the reflectivity of the oil slick in the thermal infrared spectrum with the Fourier transform infrared spectrometer (102F) and then calculated its thermal infrared emissivity. The results show that the thermal infrared emissivity of oil slick changes significantly with its thickness when oil slick is relatively thin (20-120 µm), which provides an effective means for detecting the existence of offshore thin oil slick In the spectrum ranges from 8 to 10 µm and from 13. 2 to 14 µm, there is a steady emissivity difference between the seawater and thin oil slick with thickness of 20 µm. The emissivity of oil slick changes marginally with oil slick thickness and clearly below that of seawater in the spectrum range from 11. 7 to 14 µm, this spectrum range can be practically used to distinguish oil slick from seawater; Around the wavelength of 11.72, 12.2, 12.55, 13.48 and 13.8 µm, the emissivity of oil slick presents clearly increasing or decreasing trends with the increase of its thickness, which are one of the best wavelengths for observing the offshore oil slick and estimating its thickness.

[Monitoring the thermal plume from coastal nuclear power plant using satellite remote sensing data: modeling, and validation].

Thermal plume from coastal nuclear power plant is a small-scale human activity, mornitoring of which requires high-frequency and high-spatial remote sensing data. The infrared scanner (IRS), on board of HJ-1B, has an infrared channel IRS4 with 300 m and 4-days as its spatial and temporal resolution. Remote sensing data aquired using IRS4 is an available source for mornitoring thermal plume. Retrieval pattern for coastal sea surface temperature (SST) was built to monitor the thermal plume from nuclear power plant. The research area is located near Guangdong Daya Bay Nuclear Power Station (GNPS), where synchronized validations were also implemented. The National Centers for Environmental Prediction (NCEP) data was interpolated spatially and temporally. The interpolated data as well as surface weather conditions were subsequently employed into radiative transfer model for the atmospheric correction of IRS4 thermal image. A look-up-table (LUT) was built for the inversion between IRS4 channel radiance and radiometric temperature, and a fitted function was also built from the LUT data for the same purpose. The SST was finally retrieved based on those preprocessing procedures mentioned above. The bulk temperature (BT) of 84 samples distributed near GNPS was shipboard collected synchronically using salinity-temperature-deepness (CTD) instruments. The discrete sample data was surface interpolated and compared with the satellite retrieved SST. Results show that the average BT over the study area is 0.47 degrees C higher than the retrieved skin temperature (ST). For areas far away from outfall, the ST is higher than BT, with differences less than 1.0 degrees C. The main driving force for temperature variations in these regions is solar radiation. For areas near outfall, on the contrary, the retrieved ST is lower than BT, and greater differences between the two (meaning > 1.0 degrees C) happen when it gets closer to the outfall. Unlike the former case, the convective heat transfer resulting from the thermal plume is the primary reason leading to the temperature variations. Temperature rising (TR) distributions obtained from remote sensing data and in-situ measurements are consistent, except that the interpolated BT shows more level details (> 5 levels) than that of the ST (up to 4 levels). The areas with higher TR levels (> 2) are larger on BT maps, while for lower TR levels (≤ 2), the two methods perform with no obvious differences. Minimal errors for satellite-derived SST occur regularly around local time 10 a. m. This makes the remote sensing results to be substitutes for in-situ measurements. Therefore, for operational applications of HJ-1B IRS4, remote sensing technique can be a practical approach to monitoring the nuclear plant thermal pollution around this time period.

Association analysis of two candidate polymorphisms in the tumour necrosis factor-α gene with osteoarthritis in a Chinese population.

PURPOSE: The purpose of this study was to investigate the possible association between single nucleotide polymorphisms (SNPs) rs1800629 (TNF-α -308) and rs361525 (TNF-α -238) of the tumour necrosis factor (TNF)-α gene and susceptibility to osteoarthritis (OA) in the Han Chinese population. METHODS: The TNF-α -308 and -238 genotypes were determined by TaqMan assay in 200 OA cases and 305 controls. Odds ratios (ORs) for OA and 95% confidence intervals (CIs) from unconditional logistic regression models were used to evaluate relative risks. RESULTS: The frequencies of the allele 'A' of rs1800629 were 16% and 8.85% in OA cases and in controls, respectively, and thus the -308A allele had a 1.9612-fold (95% CI = 1.3323-2.8869, P < 0.001) increased risk for OA as compared to the -308G allele. However, no significant differences were found in the genotype and allele frequencies for rs361525 between OA and HC groups. CONCLUSIONS: In the Han Chinese population, the allele 'A' of TNF-α -308 may increase the risk for OA, whereas TNF-α -238 polymorphisms do not play a role in OA patients.

Atomic-level study of a thickness-dependent phase change in gold thin films heated by an ultrafast laser.

An ultrafast laser-induced phase change in gold thin films with different thicknesses has been simulated by the method of coupling the two-temperature model and the molecular dynamics, including transient optical properties. Numerical results show that the decrease of film thickness leads to faster melting in the early nonequilibrium time and a larger melting depth. Moreover, earlier occurrence and a higher rate of resolidification are observed for the thicker film. Further analysis reveals that the mechanism for the thickness-dependent phase change in the films is the fast electron thermal conduction in the nonequilibrium state.

[Study of neovascularization disturbance in deep partial-thickness scald in rats with diabetes mellitus].

OBJECTIVE: To study the relationship between the degree of neovascularization and non-healing wounds in scalded rats with diabetic mellitus. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

[An in vitro natural degeneration model of chondrocytes derived from endplate of intervertebral discs of rats].

OBJECTIVE: To set up a natural degeneration model of chondrocytes derived from endplate of intervertebral discs of rats in order to offer an appropriate carrier for the study on mechanism of intervertebral disc degeneration. METHODS: The method of enzyme digestion combined with natural subculture was used to set up the in vitro natural degeneration model of chondrocytes derived from the endplate of intervertebral disc of rats. The morphological appearances and microstructures of the chondrocytes of different generations were observed. The expression of collagen II in chondrocytes was detected by immunocytochemical method. RESULTS: The chondrocytes derived from the endplate of intervertebral disc expressed collagen II. After 13 days of culture, the chondrocytes of generation III showed that the ability of cell division descended, the nucleoli became unclear, the cells deformed obviously, fusiform shape with weak optical activity appeared, and the intercellular space was enlarged. There were vacuoles and lipid droplets in cytoplasm. The synthesis of collagen II, as well as the cell proliferation rate, descended notably. All results showed the natural degeneration process of the chondrocytes. CONCLUSION: The in vitro natural degeneration model of chondrocytes derived from endplate of intervertebral discs of rats was successfully established. This can offer the cytological basis for study on the mechanism of intervertebral disc degeneration.

[Influence of L-arginine supplementation on the plasma amino acid spectrum in burn patients].

OBJECTIVE: To explore the influence of L-arginine supplementation on the plasma amino acid spectrum in burn patients. METHODS: 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. RESULTS: 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). CONCLUSION: 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.

[The research progress of accelerating tendon healing and preventing tendon adhesion].

OBJECTIVE: To study the status quo of the methods and materials for accelerating the tendon healing and preventing the tendon adhesion as to provide an essential reference for future research and clinical application. METHODS: The recent articles on methods of accelerating tendon healing and preventing tendon adhesion were extensively reviewed. RESULTS: Tendon healing was decided by the co-effects of both endogenous and exogenous ways, and the former was more important. It was affected by the tendon sheath, vincula tendinum and synovial fluid as well. Tendon adhesion was mostly caused by excessive participation of exogenous healing factors and serious damage of the situations around the tendon. Tendon healing was accelerated by methods like repairing, reconstruction of peri-tendon tissues, electric stimulation, physiotherapy, adding herbs or growth factors, and gene intervention. Tendon adhesion was reduced or prevented by methods like the restoration of tendon sheath, using substitutions, adding herbs/drugs, and improving suturing techniques. CONCLUSION: Via the appropriate methods and techniques combining the Chinese traditional and modern medicine, tendon healing can be accelerated and the quality of tendon healing can be improved.

[Influence of dermal template on the biomechanical compliance of wound tissue].

OBJECTIVE: To investigate the influence of dermal template on the biomechanical compliance of wound tissue during wound repair. METHODS: 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. RESULTS: 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). CONCLUSION: Dermal template might affect the scar formation during wound healing, in improving wound healing quality by enhancing the biomechanical compliance of wound tissue.

[Study on the proliferation of epidermal cells of wound edge in deep partial thickness scald injury in rat].

OBJECTIVE: To investigate the rule and possible mechanism of epidermal proliferation in wound edge of deep partial thickness scald injury in rat. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

[Influence of tangential excision within 24 postburn hours on the local wound inflammatory response in patients with deep partial thickness burn].

OBJECTIVE: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

[Effects of dermal template on the biological behaviors of fibroblasts during wound healing].

OBJECTIVE: To study the effects of dermal template on the biological behaviors of fibroblasts during wound healing. METHODS: A total of 120 rats were made full-thickness wound modes on the dorsum and divided into 4 groups, in group 1, the wounds were allowed to heal by contraction(ConT); in group 2, the wounds covered with full-thickness skin grafts (FTSG); in group 3, the wounds were with split thickness skin grafts (STSG); and in group 4, the wounds were covered by dermal regeneration template with overlying thin split-thickness autograft (ADMT). The specimens were obtained at one week, two weeks, four weeks, six weeks, and twelve weeks respectively. The expressions of alpha smooth muscle actin(alpha-SMA, characteristic of MFB), fibronectin (FN), integrin alpha2 beta1 and transforming growth factor beta1 (TGF-beta1) were examined by immunohistochemical analysis. RESULTS: Positive expression of alpha-SMA, FN, integrin alpha2 beta1 and TGF-beta1 in ADMT groups was significantly lower than that in STSG group and ConT group, but higher than that in FTSG group (P < 0.05). CONCLUSION: Dermal regeneration template can inhibit the transformation of FB to MFB and restrain the expression of FN, integrin alpha2 beta1, and TGF-beta1 in fibroblasts which might reduce the possibility of hypertrophic scarring, and improve wound healing.

[The influence of L-arginine on the angiogenesis in burn wounds in diabetic rats].

OBJECTIVE: To investigate the possible mechanism of L-arginine supplementation on the angiogenesis of burn wounds in diabetic rats. METHODS: 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. RESULTS: 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. CONCLUSION: 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.