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Objective@#To construct and identify a mouse model with conditional knockout (cKO) of p75 neurotrophin receptor (p75NTR-cKO) gene in epidermis cells by Cre-loxP system.@*Methods@#Five p75NTRflox/flox transgenic C57BL/6J mice (aged 6-8 weeks, male and female unlimited, the age and sex of mice used for reproduction were the same below) and five keratin 14 promotor-driven (KRT14-) Cre+ /- transgenic C57BL/6J mice were bred and hybridized via Cre-loxP system. Five p75NTRflox/+ ·KRT14-Cre+ /- mice selected from the first generation of mice were mated with five p75NTRflox/flox mice to obtain the second generation hybrids. After the second generation mice were born 20-25 days, the parts of the mice tail were cut off to identify the genotype by polymerase chain reaction method. Four p75NTR gene complete cKO mice (6 weeks old) and 4 wild-type mice (6 weeks old) were selected and sacrificed respectively. The abdominal skin tissue and brain tissue were excised to observe the expression of p75NTR in the two tissue of two types of mice by immunohistochemical staining. The abdominal skin tissue of two types of mice was obtained to observe the histomorphological changes by hematoxylin and eosin staining.@*Results@#(1) Twenty second generation mice were bred. The genotype of 4 mice was p75NTRflox/flox·KRT14-Cre+ /-(p75NTR-/-), i. e. p75NTR gene complete cKO mice; the genotype of 5 mice was p75NTRflox/+ ·KRT14-Cre+ /-, i. e. p75NTR gene partial cKO mice; the genotype of 5 mice was p75NTRflox/flox·KRT14-Cre-/-, and that of 6 mice was p75NTRflox/+ ·KRT14-Cre-/-, all of which were wild-type mice. (2) The expression of p75NTR was negative in skin epidermis tissue of p75NTR gene complete cKO mice, while numerous p75NTR positive expression was observed in skin epidermis tissue of wild-type mice. Abundant p75NTR positive expression was observed in brain tissue of both wild-type mice and p75NTR gene complete cKO mice. (3) There was no abnormal growth of skin epidermis tissue in both wild-type mice and p75NTR gene complete cKO mice, with intact hair follicle structure.@*Conclusions@#Applying Cre-loxP system can successfully construct a p75NTR-cKO mice model in epidermis cells without obvious changes in skin histomorphology.
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The process of burn wounds healing includes the removal of necrotic tissue, the hyperplasia of granulation tissue and epithelialization. The removal of necrotic tissue is the first step in dealing with burn wounds. Although there are a variety of adjuvant drugs for removing necrotic tissue, surgical debridement is still the main way of debridement of burn wounds. Surgical debridement of burn wounds includes escharectomy, tangential excision and dermabrasion. Escharectomy and tangential excision have been widely used in clinical practice, while dermabrasion has not been known to the majority of burns colleagues. This article summarizes the clinical application and progress of dermabrasion in burn wounds.
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Objective@#To investigate the application of high-frequency ultrasound in dermabrasion of patients with deep partial-thickness burns.@*Methods@#Twenty-six patients with deep partial-thickness burns conforming to the study criteria were hospitalized in our unit from March 2015 to March 2016. Patients were all performed with dermabrasion. The structure of skin tissue and blood flow signals of uninjured side and wounds before dermabrasion, and those of wounds immediately post dermabrasion and on post dermabrasion day (PDD) 1, 3, 5, 7, 10, 14, and 21 were detected with high-frequency ultrasound, and the percentage of blood flow signals was calculated. According to the results of comparison between percentage of blood flow signals of wounds and that of normal skin before dermabrasion, patients were divided into no significant decrease group (NSD, n=19) and significant decrease group (SD, n=7). Wound healing time of patients in two groups was recorded. Data were processed with analysis of variance of repeated measurement, LSD test, t test and Chi-square test. The correlation between the percentage of blood flow signals of wounds before dermabrasion and wound healing time of 26 patients were analyzed by Spearman correlation analysis.@*Results@#(1) Epidermis of normal skin of patients in two groups before dermabrasion showed continuous smooth linear hyperecho, which was stronger than that of dermis, and boundary of dermis and subcutaneous tissue showed stronger discontinuous linear echo than that of dermis, which gradually transited to subcutaneous tissue. In group NSD, epidermis of wound of patients before dermabrasion showed intermittent rough linear echo, which was weaker than that of normal skin epidermis, and there was no obvious abnormity of boundary between dermis and subcutaneous tissue. Immediately post dermabrasion and on PDD 1, no linear hyperecho of epidermis was observed, showing complete attrition of epidermis, and the echo of dermis and subcutaneous tissue had no obvious change as compared with that before dermabrasion, with flat surface of dermis and partly abraded superficial-dermis but relatively well preserved dermal tissue in whole. The epidermis showed discontinuous linear hyperecho, and epidermis was discontinuously regenerated on PDD 3 and 5. Partial continuous linear hyperecho was detected in the epidermis, showing partial continuous regeneration of epidermis on PDD 7 and 10. The regenerated epidermis was thicker than normal skin epidermis and showed rough linear hyperecho with non-uniform thickness on PDD 14. The regenerated epidermis was thicker than normal skin epidermis and showed rather smooth linear hyperecho with uniform thickness on PDD 21. In group SD, the structure of epidermis and dermis of wound of patients before dermabrasion, immediately post dermabrasion, and on PDD 1 was similar to that in group NSD, but the echo of boundary of dermis and subcutaneous tissue was weakened in different degrees. There was no linear hyperecho of epidermis, showing no epidermis was regenerated on PDD 3 and 5. Intermittent regeneration of epidermis appeared on PDD 7 and 10 with intermittent linear hyperecho. Partial continuous linear hyperecho was detected in the epidermis, showing partial continuous regeneration of epidermis on PDD 14 and 21. (2) The percentages of blood flow signals of wounds of patients in group NSD before dermabrasion, immediately post dermabrasion, and on PDD 1 were (3.1±1.3)%, (6.5±2.0)%, and (5.3±1.9)% respectively, higher than those in group SD [(0.9±1.1)%, (3.5±1.3)%, and (3.6±0.9)% respectively, P<0.05 or P<0.01]. The percentages of blood flow signals of wounds of patients in two groups were similar at the other time points (with P values above 0.05). Compared with the percentage of normal skin in the same group [(3.2±0.7)%], the percentages of blood flow signals of wounds of patients in group NSD were significantly increased immediately post dermabrasion and on PDD 1 (with P values below 0.01) but had no significant change at the other time points (with P values above 0.05). The percentage of blood flow signals of wounds of patients before dermabrasion in group SD was significantly lower than that of normal skin in the same group [(2.8±0.6)%, P<0.01]. The percentage of blood flow signals of wounds of patients in group SD was close to that of normal skin in the same group at each time point post dermabrasion (with P values above 0.05). (3) The wound healing time of patients in group NSD was (16.2±2.5) d, lower than that in group SD [(30.9±2.9) d, t=12.67, P<0.01]. There was obvious negative correlation between the percentage of blood flow signals of wounds before dermabrasion and wound healing time of 26 patients (r=-0.77, P<0.01).@*Conclusions@#High-frequency ultrasound is a good way to observe the imaging features of wounds in patients with deep partial-thickness burns before and after dermabrasion, and it can provide objective imaging evidence for the performance of dermabrasion in patients with deep partial-thickness burns.
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Objective To summarized the projects received and funded in the fields of emergency and intensive care medicine/trauma/burns/plastic surgery from National Natural Science Foundation of China (NSFC) during 2010-2013,put forward the thinking and perspective of this future trend in these fields.Methods The number of the funded project and total funding in the fields of emergency and intensive care medicine/trauma/burns/plastic surgery from NSFC during 2010-2013 had been statistical analyzed,in the meantime,the overview situation of various branches in basic research and further preliminary analysis the research frontier and hot issues have been analyzed.Results ① The number of funded project were 581 in H 15 of NSFC during 2010-2013,total funding reached to 277.13 million RMB,including 117 projects in H 1511 (emergency and intensive care medicine/trauma/burns/plastic surgery and other science issue),96 projects in H1507 (wound healing and scar),88 projects in H1502 (multi-organ failure),71 projects in H 1505 (burn),61 projects in H 1504 (trauma) ② The top 10 working unit for project funding in the field of Emergency and intensive care medicine/trauma/burns/plastic surgery present as Third Military Medical University (70),Shanghai Jiao tong University (69),Second Military Medical University (40),Chinese PLA General Hospital (36),Forth Military Medical University (35),Zhejiang University (22),Sun Yat-Sen University (18),Southern Medical University (14),China Medical University (11),Capital Medical University (11) respectively,the number of funded project positive correlated with funding.③ The funded research field in H15 covered almost all important organs and system injury or repair research,our scientists reached a fairly high level in some research field,for example,sepsis,trauma,repair,et al.Sepsis was funded 112 projects in H15 for 4 years,the growth rate became rapid and stable comparing to shock,burns and cardiopulmonary resuscitation funded projects' number.emergency and intensive care medicine/trauma/burns research fields related to heart,lung,bone/cartilage/muscle,stomach/intestinal/liver,brain/spinal cord/peripheral nerve and other tissues/organs.The number of funded projects in plastic surgery related research fields in angioma and flap related projects were down below to 3 projects,but the number of funded project in wounds,scar repair related research field were more than other fields relatively.④ In frontier and research hot issue,the funded rate represent as 23.8％,21.4％,19.0％ and 23.9％ in stem cell related research fields in 4 years respectively.The funded rate average to 20.9％ in epigenetic related research fields for four years,the funded rate achieved to break through zero in autophagy related research fields,the total rate raised to 32.6％ from 2011 to 2013.Conclusions The funded number and funding were raised rapidly in the fields of emergency and intensive care medicine/trauma/burns/plastic surgery from NSFC.The application for each proposal should be focus on concise or upgrade the scientific issues to improve the quality.The depth or systematic in content and interdisciplinary research fields (e.g.immunology) should be paid attention to.Sepsis,trauma and burns will be the main stream direction in future in the fields of emergency and intensive care medicine/trauma/burns/plastic surgery.The fields of wound healing and scar,surface organ defects,damage,repair and regeneration,surface tissue/organ transplantation and reconstruction,craniofacial deformities and correction are important develop directions in future work.
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Pulsed dye laser [PDL] is an important treatment for superficial infantile hemangioma, but few studies report on its cellular mechanism. The aim of this study was to evaluate alterations of serum vascular endothelial growth factor [VEGF] level in infantile hemangioma [IH] patients after laser treatment and effects of PDL irradiation on human umbilical vein endothelial cells [HUVECs] in vitro, as well as to explore the biomolecular mechanisms and ultrastructure changes of the PDL effect. 74 children with infant hemangioma including 45 patients in proliferating phase, 18 patients in involuting phase, 11 patients in involuted phase and 10 healthy children were engaged in this study. The plasma VEGF levels of children were measured with the enzyme-linked immunosorbent assay [ELISA]. 24 hours after, HUVECs cultured in vitro were irradiated with PDL, cell apoptosis, mRNA levels of VEGF, and changes of ultrastructure were evaluated using flow cytometry, real-time reverse transcriptase polymerase chain reaction [RT-PCR], and transmission electron microscopy, respectively. The serum VEGF concentrations in children with proliferating hemangiomas were significantly higher than in patients with involuting / involved hemangiomas and healthy patients. After receiving 3 laser treatments, the plasma VEGF levels of IH patients in proliferating hemangiomas decreased significantly. PDL irradiation could down-regulate VEGF mRNA expression of HUVECs, and increase cell apoptosis rate. The present study demonstrates that PDL irradiation imparts apoptosis induction effects on HUVECs in vitro. Furthermore, our results suggest that vascular endothelial growth factor may be of particular importance in pathophysiology and PDL treatment of hemangiomas, also serum VEGF levels may be used as an aid in the follow up of IH. This provides valuable evidence of the PDL effect on infantile hemangioma