外源性透明质酸对创面愈合组织的影响

目的：研究外源性透明质酸对创面愈合组织中生化组分的影响，以期探索外源性HA在创伤愈合中的作用及其机制。方法：在小型猪背部的去中厚皮创面上应用不同浓度和剂型的外源性HA，并于术后第3、7、14、21、28天切取创面组织及正常皮肤，测定其糖胺多糖、HA及Ⅲ型胶原的含量变化。结果：愈合过程中，实验组创面愈合组织中的GAG、HA含量逐渐升高，1周时达峰值并能维持3周；创面对照组术后3天也见增高，但随后即迅速下降。实验组的Ⅲ型胶原含量也始终明显高于对照组，其中又以1．0％、2．0％HA组最高。结论：外源性HA能显著增高愈合组织中HA、Ⅲ型胶原含量并能维持较长时间，从而有利于创伤愈合及减轻瘢痕形成。     

Fetal wound healing using a genetically modified murine model: the contribution of P-selectin

Purpose

During early gestation, fetal wounds heal with paucity of inflammation and absent scar formation. P-selectin is an adhesion molecule that is important for leukocyte recruitment to injury sites. We used a murine fetal wound healing model to study the specific contribution of P-selectin to scarless wound repair.

Methods

Linear excisional wounds were created on the dorsa of E15.5 and E17.5 gestation fetuses in wild-type and P-selectin (-/-) mice (term = 19 days). Wounds were harvested at various time-points after wounding and analyzed using histology and immunohistochemistry.

Results

The E15.5 wounds in both wild-type and P-selectin (-/-) fetuses healed scarlessly and with minimal inflammation, whereas E17.5 wounds healed with fibrosis and inflammation. However, the scars of the P-selectin (-/-) wounds appeared slightly different than wild-type. There were significantly more inflammatory cells in E17.5 wild-type wounds 6 hours after injury (P < .001), but the difference was no longer significant by 24 hours. Finally, reepithelialization was slower in the E15.5 knockout wounds compared to their wild-type counterparts.

Conclusions

Absence of P-selectin delays inflammatory cell recruitment and reepithelialization of fetal wounds; however, scar formation still occurs in late gestation wounds. The contribution of specific molecules to fetal wound healing can be elucidated using murine knockout or transgenic models.     

The effect of colchicine on the peritoneal membrane

Peritoneal dialysis (PD) is a treatment modality for patients with renal failure. Peritoneal fibrosis is one of the most serious complications after long-term continuous ambulatory peritoneal dialysis (CAPD). Histological studies in both humans and animals show that chronic peritoneal dialysis results in fibrosis of the peritoneal membrane. In our study, we investigated the effect of colchicine on peritoneal alterations induced by hypertonic PD solution in rats. Sprague-Dawley rats intraperitoneally received saline (control group) once daily, for 28 days, or 3.86% glucose (PDF group), or 3.86% glucose plus colchicine (colchicine group). Animals from each group were sacrificed after 28 days with anesthetized ketamine (60 mg/kg BW). For the PD fluid assessment, 1 h before the sacrifice of animals, 10 mL PD fluid of 2.27% glucose was given, and this fluid was obtained after the sacrifice. The levels of transforming endothelial growth factor beta (TGF-beta), tumor necrosis factor alpha (TNF-alpha) and albumin were investigated both in the peritoneal dialysate and blood, and the levels of malondialdehyde (MDA) were investigated only in peritoneal dialysate. The peritoneal membrane was evaluated histologically by light microscopy. When groups were compared in terms of body weight change, the colchicine group significantly lost weight compared to controls and PDF group (-4.7% + 4.5, 3.5% +/- 7.2, 3.0% +/- 1.3, respectively, p = 0.018). Also, the blood albumin level was significantly lower for these in the colchicine group compared to those in the PDF group (2.7 +/- 0.35 versus 3.2 +/- 0.3 g/dL, respectively, p = 0.048). The blood TGF-beta level was significantly lower in the control group, and no difference was observed between the PDF and colchicine groups (294.4 +/- 67.5 versus 787.4 +/- 237.4 versus 615.3 +/- 235.1 pg/mL, respectively, p = 0.004). The mesothelial thickness found in groups was as follows: control group 102 +/- 18.9 microm, PDF group 128.33 +/- 33.1 microm, colchicine group 117 +/- 35.6 microm (p = 0.34). In conclusion, a rat model for peritoneal dialysis associated peritoneal derangement without fibrosis could be induced. Colchicine could not prevent peritoneal derangement in this model.     

Simple organ cornea culture model for re-epithelialization after in vitro excimer laser ablation

BACKGROUND AND OBJECTIVE: Most of the in vitro work to characterize the effects of clinical laser surgery on corneal tissues has concentrated on the effects on stromal keratocytes and endothelium with little attention being paid to corneal epithelium. Our purpose is to describe the epithelial healing rates observed in freshly cultured rabbit corneas treated with phototherapeutic keratectomy (PTK). STUDY DESIGN/MATERIALS AND METHODS: Corneas were placed in a simple organ culture system, with media change every 2 days. A clinical excimer laser was used to perform a 6 mm diameter, 100 microm depth transepithelial PTK on 24 cultured rabbit corneas, 1 day after culture initiation. For each post-treatment day, one experimental and one control cornea were removed from culture and stained with fluorescein, photographed, and fixed for histology. Epithelial defect area was measured with digital imaging software and analyzed statistically to assess the re-epithelialization rate. RESULTS: Control corneas, maintained in culture for 1-4 days, had no epithelial defects. Those corneas treated with PTK exhibited an immediate epithelial defect that slowly healed over 3 days. This was confirmed on histopathological analysis. A significant linear trend in re-epithelialization across the time points studied was found (F = 80.48, P = 0.0029). The slope of the linear regression model showed an estimate rate of re-epithelialization of -6.70 over the 3 days. CONCLUSION: We have described the development of a simple, whole organ, rabbit cornea culture model for re-epithelialization after PTK. Our rates of epithelial healing resemble those found in the literature in live rabbit models. Therefore, this model may possibly be used to monitor epithelial wound healing in different corneal diseases or injuries.     

Keratinocyte protein expression in rapidly regenerating epidermis following laser-induced thermal injury

We examined 20 punch biopsies taken from five patients at varying intervals following CO2 laser-induced thermal injury. The regenerating epidermis was studied with monoclonal antibodies AE1 and AE3 (directed against low and high molecular weight keratins), and involucrin, a protein found within the cellular envelope of the most mature keratinocytes. Twenty-four hours following thermal damage, there was extensive spillage of keratins and involucrin into the papillary dermis and disarray of all constituents of the necrotic keratinocytes. Early ingrowth of basaloid keratinocytes weakly expressed AE1. By 1 week, keratinocytes expressed AE1 in varying intensities throughout the epidermis. AE3 was present in its normal distribution, staining all but the most basaloid keratinocytes. Involucrin stained cells deep within the epidermis. Six weeks following the initial injury, the staining pattern within the epidermis had returned to normal. Thus, it appears that the regenerating epidermis produces low molecular weight keratins in cells at all levels and forms premature cellular envelopes, perhaps as a protective measure, before expression of these constituents reverts to the normal pattern. These findings suggest that keratinocyte differentiation in wound-healing following laser-induced thermal injury is similar to that seen in other types of injury. Observed clinical differences may be attributable to differences in keratinocyte proliferative or migratory capabilities.     

甲壳质套管在大鼠脊髓横断损伤修复中的应用

目的：探讨甲壳质生物套管在大鼠脊髓完全横断损伤中的应用价值。方法：16只雄性SD大鼠随机分为2组，行T8—9节段脊髓完全横断损伤，A组单纯横断脊髓作为对照，B组用甲壳质生物套管套接横断脊髓断端，术后1个月时处死取材，行HE、尼氏染色及免疫组织化学染色（NF200、GFAP）检查。结果：大鼠对甲壳质套管无明显排斥反应；B组可见断端脊髓纤维向套管间隙内生长，且脊髓头侧断端前角运动细胞数量明显多于A组（P〈0．05），细胞处于活跃功能相，GFAP染色阳性面积A组明显大于B组（P〈0．05），B组套管间隙内可见神经纤维丝（NF200）及GFAP染色阳性胶质细胞框架存在，A组断端间为较大空洞，无神经纤维及胶质细胞的存在。结论：甲壳质生物套管在大鼠脊髓损伤的修复过程中可为断端脊髓神经纤维生长提供间隙，这种套接材料及方式可作为研究和治疗脊髓损伤的模型和方法。     

The effect of sepsis on wound healing.

BACKGROUND: Normal wound healing is a regulated sequence of events that successfully restore tissue integrity. Previous studies have suggested that wound healing is impaired in a septic host. The current study examines the effect of sepsis on the inflammatory and proliferative phases of wound healing at a remote site of secondary injury. METHODS: Polyvinyl alcohol sponges, either inoculated with a standard dose of Pseudomonas aeruginosa (experimental) or soaked in normal saline (control), were placed subcutaneously in the anterior abdominal region of male B6D2F1 mice. Immediately following sponge placement, full thickness excisional dermal wounds were created on the dorsum. Wound healing was examined at days 3, 5, and 7 postinjury. The infiltration of neutrophils and macrophages into wounds was quantified, and the reepithelialization rate and collagen content were measured. RESULTS: Peripheral neutrophil counts were significantly elevated in infected mice, yet neutrophil content of the remote wound of infected animals was significantly reduced (5% of control, P < 0.05). Wounds of infected mice also showed a 30% reduction in the macrophage content. Wounds of infected animals exhibited delayed reepithelialization (76 +/- 3 vs 97 +/- 3% at day 5, P < 0.05) and collagen synthesis (55.3 +/- 9.5 vs 105 +/- 13.0 microg/wound, P < 0.05). CONCLUSION: Systemic infection alters both the inflammatory and the proliferative processes at remote sites of injury. Multiple factors seem likely to contribute to the increased incidence of wound complications in septic patients.     

The effect of oral sodium taurocholate on endotoxemia and intestinal anastomotic wound healing in rats with obstructive jaundice

The effect of sodium taurocholate (ST) on endotoxemia and intestinal anastomotic wound healing in obstructive jaundice was evaluated in a rat model. A total of 108 Wistar rats were divided into three main groups. Thus, 36 animals were given ileal anastomosis (IA) alone (IA group), 36 were given IA with bile duct ligation (BDL) (IA+BDL group), and 36 were given IA with BDL and oral sodium taurocholate (ST) (IA+BDL+ST group). These three main groups were then divided into three equal subgroups, A, B, and C, which were killed on postoperative days (POD), 3, 5, and 9, respectively. In the IA+BDL+ST group, ST was administrated perioperatively and ceased from POD 5 onwards. The anastomotic hydroxyproline level and bursting pressure were significantly lower in the IA+BDL animals compared with the others on POD 3, 5, and 9 (P<0.008). Endotoxemia was prominent in the IA+BDL group from POD 3 (P=0.011). After ST was stopped, 42% of the AI+BDL+ST animals developed endotoxemia by POD 9 (P=0.008). Anastomotic wound healing was better in the IA+BDL+ST group (P<0.01). These findings suggest that endotoxemia and its adverse effects on wound healing in obstructive jaundice can be prevented by the oral administration of ST.     

The effect of stromal vascular fraction in an experimental frostbite injury model

BackgroundDespite current treatment modalities, frostbite remains an injury with a poor prognosis which may cause functional morbidities. Several experimental and clinical studies have demonstrated that stromal vascular fraction is an autologous mixture, which can improve wound healing and vasculogenesis. The aim of this study was to show the beneficial effects of stromal vascular fraction on experimental frostbite healing.Material and methodsStromal vascular fraction (SVF) was harvested from 5 rats after excision of the inguinal fat pads. Another 20 rats were separated into 2 groups of 10 as the SVF group and the control group. A frostbite injury was created on each rat using a cryoprobe frozen with liquid nitrogen (?196 °C). SVF was applied to the SVF group and phosphate-buffered saline to the control group. All injections were performed subcutaneously within the frostbite injury area. Biopsies were performed on days 5 and 14 for histopathological and immunochemical evaluations. The tissue perfusion rates of both groups were assessed on day 14 using indocyanine green angiography (SPY system).ResultsThe increase in mean tissue perfusion was 373.3% ( ± 32.1) in the SVF group and 123.8% ( ± 16.3) in the control group (p < 0.001). The macroscopic wound reduction rates of the SVF and control groups were 25.5% ( ± 19.1) and 18.0% ( ± 5.9), respectively on day 5%, and 78.2% ( ± 9.2) and 57.3% ( ± 16.7) on day 14 (p = 0.007; p = 0.003). Acute inflammation and the fibrosis gradient were significantly decreased in the SVF group compared to the control group (p = 0.004, p = 0.054 respectively on day 14). Granulation tissue amount, re-epithelialization score and neovascularization were significantly increased in the SVF group (p = 0.006, p = 0.010 and p = 0.021, respectively on day 14).ConclusionsThe study results demonstrated that SVF increases frostbite wound healing by increasing tissue perfusion rate, neovascularization and re-epithelialization, and modulating acute inflammation and fibrosis.     

康复新联合赛肤润治疗大鼠急性放射性皮肤损伤效果观察

目的 观察康复新联合赛肤润治疗大鼠急性放射性皮肤损伤的疗效。 方法 取40只SD大鼠，用放射性核素32P敷贴固定于大鼠背部皮肤以制备急性放射性皮肤损伤模型。建模后，将大鼠随机分为模型组、康复新组、赛肤润组、康复新联合赛肤润组（联合组），各10只。模型组用生理盐水擦拭皮损处；康复新组用康复新涂抹皮损处；赛肤润组用赛肤润喷涂皮损处；联合组先涂抹康复新液，待干后喷涂赛肤润，2次/d。各组均在8：00及16:00固定时间涂抹药液。观察创面局部变化及愈合时间。治疗第2周、4周、8周时取皮损创面组织进行苏木精-伊红染色和Masson染色。 结果 与模型组比较，康复新组、赛肤润组、联合组的愈合时间显著缩短（均P＜0.05）；联合组的愈合时间显著短于康复新组及赛肤润组（均P＜0.05）；组织病理学检测结果显示，联合组创面组织炎性细胞浸润、水肿程度显著低于其他组，新生毛细血管数量及胶原纤维含量显著高于其他组，胶原纤维排列更整齐，表皮结构更加完整。与模型组比较，治疗第2周、4周、8周时康复新组、赛肤润组、联合组的胶原纤维含量较高（均P＜0.05）；与康复新组、赛肤润组相比，联合组的胶原纤维含量较高（均P＜0.05）。 结论 康复新联合赛肤润能够减轻放射性皮肤损伤创面早期炎症反应，促进创面血管新生与胶原纤维形成，缩短创面愈合时间，加快创面修复。     

A randomised controlled trial of amniotic membrane in the treatment of a standardised burn injury in the merino lamb

Burn injury is associated with disabling scar formation which impacts on many aspects of the patient's life. Previously we have shown that the fetus heals a deep dermal burn in a scarless fashion. Amniotic membrane (AM) is the outermost fetal tisue and has beeen used as a dressing in thermal injuries, though there is little data to support this use. To assess the efficacy of AM in scar minimisation after deep dermal burn wound, we conducted a randomised controlled study in the 1-month lamb. Lambs were delivered by caesarian section and the amniotic membranes stored after which lambs were returned to their mothers post-operatively. At 1 month, a standardised deep dermal burn was created under general anaesthesia on both flanks of the lamb. One flank was covered with unmatched AM, the other with paraffin gauze. Animals were sequentially euthanased from Day 3–60 after injury and tissue analysed for histopathology and immunohistochemically for α-smooth muscle actin (αSMA) content. AM resulted in reduced scar tissue as assessed histopathologically and reduced αSMA content. This study provides the first laboratory evidence that AM may reduce scar formation after burn injury.     

The external microenvironment of healing skin wounds

The skin wound microenvironment can be divided into two main components that influence healing: the external wound microenvironment, which is outside the wound surface; and the internal wound microenvironment, underneath the surface, to which the cells within the wound are exposed. Treatment methods that directly alter the features of the external wound microenvironment indirectly affect the internal wound microenvironment due to the exchange between the two compartments. In this review, we focus on the effects of temperature, pressure (positive and negative), hydration, gases (oxygen and carbon dioxide), pH, and anti‐microbial treatment on the wound. These factors are well described in the literature and can be modified with treatment methods available in the clinic. Understanding the roles of these factors in wound pathophysiology is of central importance in wound treatment.     

体表神经纤维瘤的手术治疗探讨

目的：探讨体表神经纤维瘤的切除及创面修复的方法。方法：24例患者均行手术,其中切除后直接缝合13例,皮瓣转移6例,皮片移植4例,1例行肿瘤切除术同时行截肢术。术中采用肿胀麻醉技术,控制性降压技术等治疗方法。结果：20例患者Ⅰ期愈合,4例部分伤口裂开,经换药而愈。有两例巨大神经纤维瘤术中予以输血,其余病人未予输血。结论：对体表神经纤维瘤行切除手术,术中采用合适技术,可显著减少术中出血,降低手术风险,创面修复应根据瘤体大小及部位选择不同的修复方法。     

Modeling early thermal injury using an ex vivo human skin model of contact burns

BackgroundEarly mechanisms underlying the progressive tissue death and the regenerative capability of burn wounds are understudied in human skin. A clinically relevant, reproducible model for human burn wound healing is needed to elucidate the early changes in the human burn wound environment. This study reports a reproducible contact burn model on human skin that explores the extent of tissue injury and healing over time, and defines the inter-individual variability in human skin to enable use in mechanistic studies on burn wound progression and healing.MethodsUsing a customized burn device, contact burns of various depths were created on human skin by two operators and were evaluated for histologic depth by three raters to determine reproducibility. Early burn wound progression and wound healing were also evaluated histologically after the thermally injured human skin was cultured ex vivo for up to 14 days.ResultsBurn depths were reproducibly generated on human skin in a temperature- or time-dependent manner. No significant difference in operator-created or rater-determined depth was observed within each patient sample. However, significant inter-individual variation was identified in burn depth in ten patient samples. Burn-injured ex vivo human skin placed into culture demonstrated differential progression of cell death and collagen denaturation for high and low temperature contact burns, while re-epithelialization was observed in superficial burn wounds over a period of 14 days.ConclusionThis model represents an invaluable tool to evaluate the inter-individual variability in early burn wound progression and wound healing to complement current animal models and enhance the translation of preclinical research to improvements in patient care.     

The effect of thalidomide on spinal cord ischemia/reperfusion injury in a rabbit model

STUDY DESIGN: Randomized study. OBJECTIVES: To evaluate the effects of thalidomide on spinal cord ischemia/reperfusion injury via reduced TNF-alpha production. SETTING: Animal experimental laboratory, Clinical Research Institute of Seoul National University Hospital, Seoul, Korea. METHODS: Spinal cord ischemia was induced in rabbits by occluding the infrarenal aorta. Rabbits in group N did not undergo ischemic insult, but rabbits in groups C (the untreated group), THA, and THB underwent ischemic insult for 15 min. The THA and THB groups received thalidomide (20 mg/kg) intraperitoneally (i.p.) before ischemia, but only the THB group received thalidomide (i.p., 20 mg/kg) after 24 and 48 h of reperfusion. After evaluating neurologic functions at 1.5 h, 3, and 5 days of reperfusion, rabbits were killed for histopathologic examination and Western blot analysis of TNF-alpha. RESULTS: The THA and THB groups showed significantly less neurologic dysfunction than the C group at 1.5 h, 3, and 5 days of reperfusion. The number of normal spinal motor neurons in ventral gray matter was higher in THA and THB than in C, but no difference was observed between THA and THB. Western blot analysis showed a significantly higher level of TNF-alpha in C than in THA and THB at 1.5 h of reperfusion, but no difference was observed between C, THA, or THB at 3 or 5 days of reperfusion. CONCLUSION: Thalidomide treatment before ischemic insult reduces early phase ischemia/reperfusion injury of the spinal cord in rabbits.     

甲壳素涂层PGLA神经导管修复兔面神经缺损的实验研究

目的:探讨甲壳素涂层PGLA神经导管修复兔面神经缺损的效果。方法:成年雄性新西兰兔24只,无菌条件下切断双侧面神经下颊支,制成15mm的兔面神经下颊支缺损模型。左侧用甲壳素涂层聚丙交脂-乙交脂共聚物[poly(L-lactide-co-glycolide),PGLA]神经导管修复;右侧用翻转自体神经修复作为对照。术后5周、10周和14周行大体观察、电生理检查、组织学、电镜观察评价修复效果。结果:术后5周观察到神经导管中有新生轴索通过,再生神经发育不成熟;右侧自体神经修复近段有髓神经纤维均匀疏散分布,远段未见明显再生神经束形成。术后14周左侧再生神经已通过神经导管长入远端,电生理检查结果表明自体神经修复侧再生神经质量优于神经导管修复侧,差异有统计学意义(P<0.01)。自体神经修复再生纤维密度优于神经导管修复侧,差异有统计学意义(P<0.01),但自体神经修复侧近段神经髓鞘部分空泡样变性及脱髓鞘改变,远段再生神经纤维束形成少,面肌联带运动程度较导管修复侧严重。结论:甲壳素涂层PGLA神经导管能有效修复周围神经缺损,有望替代自体神经移植。     

Local application of a transcutaneous carbon dioxide paste prevents excessive scarring and promotes muscle regeneration in a bupivacaine-induced rat model of muscle injury

In postoperative patients with head and neck cancer, scar tissue formation may interfere with the healing process, resulting in incomplete functional recovery and a reduced quality of life. Percutaneous application of carbon dioxide (CO₂) has been reported to improve hypoxia, stimulate angiogenesis, and promote fracture repair and muscle damage. However, gaseous CO₂ cannot be applied to the head and neck regions. Previously, we developed a paste that holds non-gaseous CO₂ in a carrier and can be administered transdermally. Here, we investigated whether this paste could prevent excessive scarring and promote muscle regeneration using a bupivacaine-induced rat model of muscle injury. Forty-eight Sprague Dawley rats were randomly assigned to either a control group or a CO₂ group. Both groups underwent surgery to induce muscle injury, but the control group received no treatment, whereas the CO₂ group received the CO₂ paste daily after surgery. Then, samples of the experimental sites were taken on days 3, 7, 14, and 21 post-surgery to examine the following: (1) inflammatory (interleukin [IL]-1β, IL-6), and transforming growth factor (TGF)-β and myogenic (MyoD and myogenin) gene expression by polymerase chain reaction, (2) muscle regeneration with haematoxylin and eosin staining, and (3) MyoD and myogenin protein expression using immunohistochemical staining. Rats in the CO₂ group showed higher MyoD and myogenin expression and lower IL-1β, IL-6, and TGF-β expression than the control rats. In addition, treated rats showed evidence of accelerated muscle regeneration. Our study demonstrated that the CO₂ paste prevents excessive scarring and accelerates muscle regeneration. This action may be exerted through the induction of an artificial Bohr effect, which leads to the upregulation of MyoD and myogenin, and the downregulation of IL-1β, IL-6, and TGF-β. The paste is inexpensive and non-invasive. Thus, it may be the treatment of choice for patients with muscle damage.