Quantitative and morphological differences of nerve fibers between proliferative and mature scars in two-and three-dimensional spaces

BACKGROUND： Numerous studies use fluorescent microscopy to obtain two-dimensional optical images of the morphology of nerve fibers in hypertrophic scars. In addition, current confocal microscopy studies have focused on normal, not pathological, cutaneous nerves. However, laser scanning confocal microscopy results in a three-dimensional structure of the nerve fibers. OBJECTIVE： To observe quantitative and morphological differences in nerve fibers from the proliferative and mature stage in hypertrophic scars using fluorescent and confocal microscopy. DESIGN, TIME AND SETTING： Neuropathological, comparison study was conducted at the Provincial Hospital Affiliated to Shandong University, China from June 2006 to July 2007. PARTICIPANTS： Specimens were selected from 30 patients undergoing scar restoration at the Provincial Hospital Affiliated to Shandong University of China at 1 month to 23 years following wound healing. The study comprised 20 males and 10 females. The scars were fibrous lesions, erythematous, tough, confined to skin lesions, did not exhibit ulceration or infection, exhibited telangiectasia, with or without itching and pain, and were not locally treated. Samples were equally assigned to two groups according to course of disease： proliferative group （〈 6 months） and mature group （6-24 months）. Control samples were collected from full-thickness skin from donor sites （n = 10）. METHODS： Nerve fiber morphology was observed using fluorescent and confocal microscopy following immunofluorescence of the skin specimens. The microscopic images were semi-quantitatively analyzed to acquire a positive area ratio of neurofilament protein-positive nerve fibers. MAIN OUTCOME MEASURES： Morphology and positive area ratio of neurofilament protein/positive nerve fibers was measured. RESULTS： The positive area ratio of neurofilament protein-positive nerve fibers was significantly greater in the proliferative group compared to the normal control group （P 〈 0.05）. Nerve fibers were irregularly distributed and exhibited local swelling, twisting, and disconnection. However, the positive area ratio of neurofilament protein-positive nerve fibers was significantly less in the mature group compared with the normal control group （P 〈 0.05）. The nerve fibers were arranged in an orderly manner, with intact inner and stereoscopic structures similar to normal skin. CONCLUSION： Compared with mature scars, hypertrophic scars exhibited a greater number of nerve fibers, with more serious pathologies.

Remodeling of skin nerve fibers during burn wound healing

Burn wound healing involves a complex sequence of processes. Recent studies have revealed that skin reinnervation may have an impact on physiological wound repair. Few studies have addressed the process of reinnervation and morphological changes in regenerated nerve fibers. The regeneration of neurites during full-thickness burn wound healing was determined by immunofluorescent staining using an anti-neurofilament protein monoclonal antibody, and three-dimensional morphology was observed under a laser scanning confocal microscope. Morphology and the volume fraction of collagen and nerve fibers were measured. Skin reinnervation increased during wound healing, peaked during the proliferative scar stage, and then decreased to lower levels during the maturation period. The results from the skin nerve fibers correlated with those from collagen using semi-quantitative analysis. Disintegration and fragmentation were observed frequently in samples from the proliferative stage, and seldom occurred during the maturation stage. There was a remodeling process of regenerated nerve fibers during wound healing, which comprised changed innervation density and topical morphology. The mechanism of remodeling for nerve fibers requires further investigation.

Compound graft with acellular exoge-nous dennis and autogenous thin skin reducing formation of scar

BACKGROUND: Autogenous skin graft is a common method in treatment of deep bum, late survive effect of grafted skin flap is directly related to its thickness. In clinic, therapeutic effect of full thickness graft is the best. However, due to large skin-providing area that can't be sutured directly and survive rate of graft at infected wound surface is very low, its clinical application is limited, especially in deep burn with large area. This study is to search a best material repairing wound surface of deep burn, reduce proliferation of scar and protect limbs function.

The application of acellular dermal matrix allograft in functional position of patients with post-barns plastic operation

AIM：To investigate the effect of allogeneic acellular dermal matrix(ADM) on cograft in joint functional positions of patients with post-burn plastic operation.METHODS:9 patients with hypertrophic acar and joint dysfunction after severe burns were used.After pre-treating with trypsin and TritonX-100,13 reticulated ADM were overlapped with autogenous ultrathin split-thickness skin grafts(USTS),and were transplanted to the acar excision wounds in the joints of four limbs at the same time.The neighbouring autogenous thin split-thickness skin grafts(TSTS) were used as control.RESULTS:The composite skin grafts as well as the controls were all survived.The rejection and hypertrophic scars were not found during (1-5) years follow-up studies.The apearance,fiber and function of composite skin grafts were near to normal skins.CONCLUSION;The ADM could be used to joint functional positions of patients with post-burn hypertrophicscare and could produce satisfactory plastic results as dermal substitute.

Pretreatment with Dingnaofang reduces vascular endothelial cell apoptosis induced by cerebral ischemia/perfusion injury

BACKGROUND： Vascular endothelial cell apoptosis participates in cerebral ischemia/reperfusion injury, and the method of Qi-supplementation and blood-activation has remarkable neuroprotective effects against cerebral ischemia/reperfusion injury. OBJECTIVE： To explore the molecular mechanism that Dingnaofang （Chinese herbs for supplementing Qi and activating blood circulation） inhibits vascular endothelial cell apoptosis induced by cerebral ischemia/reperfusion injury. DESIGN, TIME AND SETFING： A randomized controlled animal experiment was performed at the Department of Central Laboratory, Third Xiangya Hospital, Central South University, China, between October 2007 and December 2008. MATERIALS： Dingnaofang consisted of Huangqi （Milkvetch Root; Radix Astragah）, Chuanxiong （Szechwan Lovage Rhizome; Rhizoma Chuanxiong）, Yinxingye （ginkgo leaf; Fofium Ginkgo）, Dilong （earthworm; Pheretima）, Danggui （Chinese Angelica; Radix Angelicae Sinensis）, Tianqi （Radix Notoginseng）, and Gancao （Radix Glycyrrhizae; Radix Glycytthizae）, with a proportion of 5：2：2： 1： 1： 1： 1. METHODS： A total of 130 Sprague Dawley rats were randomly divided into sham-surgery （n = 10）, cerebral ischemia/reperfusion （n = 40）, cerebral ischemia pretreatment （n = 40） and Dingnaofang pretreatment groups （n = 40）. Middle cerebral artery occlusion was used to induce cerebral ischemic injury. The bilateral common carotid artery in the cerebral ischemia pretreatment group was blocked for 10 minutes on days 7, 3 and 1 prior to ischemia/reperfusion injury, while rats in Dingnaofang pretreatment group were intragastrically administrated with 4 g Dingnaofang 1 week prior to cerebral ischemia once per day, for 7 successive days. MAIN OUTCOME MEASURES： Apoptosis ratios in vascular endothelial cells were measured using Hoechst 33258 staining and flow cytometry; apoptosis was detected by monitoring DNA gradient bands and the activation of caspase-3, 8, 9 and Bid using Western blot. RESULTS： Following cerebral ischemiaJreperfusion injury, the number of apoptotic vascular endothelial cells in the middle cerebral artery significantly increased （P 〈 0.01）; however, cerebral ischemia pretreatment and Dingnaofang pretreatment groups significantly reduced apoptosis induced by cerebral ischemia/reperfusion injury （P 〈 0.01）. In particular, DNA gradient bands were not observed following Dingnaofang pretreatment. At 24 hours after cerebral ischemia/reperfusion injury, cleaved fragments of caspase-3, 8 and 9 were detected at 11 kD （P 11）, 20 kD （P 20） and 10 kD （P 10）, respectively, following Western blot. Bid was also cleaved into its truncated form （tBid; 15 kD）. Gray scale analysis indicated that P 11, P 20, P 10 and tBid band values in the Dingnaofang pretreatment group were significantly less than in the cerebral ischemia/reperfusion and cerebral ischemia pretreatment groups （P 〈 0.01 or P 〈 0.05）. CONCLUSION： Dingnaofang inhibits vascular endothelial cell apoptosis induced by cerebral ischemia/reperfusion injury via inhibition of apoptotic signal transduction pathways.

Experience of rehabilitation treatment on 234 cases of burn

BACKGROUND: At present, treatment of bum is not only to save life and promote healing of wound surface, but lateral rehabilitation and problems about returning to society are included. Rehabilitation treatment of bum should be performed through the entire therapeutic course.OBJECTIVE: To explore the effects of rehabilitation treatment on burn.UNIT: Department of Burn, Affiliated Second Hospital of Kunming Medical CollegeSUBJECTS: From October 1985 to October 2001,234 patients with burn received rehabilitation including 146 males and 88 females aged 10 months to 68 years (mean: 23. 4 years). Among all cases, comprehensive therapy was performed for 230 times, support and slit therapy was performed for 141 times.INTERVENTION: Affected limbs were laid at function posi-

Dipeptide transport: an active process with energy-and proton-dependence in the human intestinal cell line,Caco-2

Objective: To determine the active process on dipeptide transport with proton-and energy-dependence in Caco-2 cells.Methods: A human intestinal cell monolayer(Caco-2) was used as the in vitro model of human small intestine and cephalexin as the model substrate for dipeptide transporter(PepT1).Caco-2 cells grown on multiwell dishes(24 wells) and Transwell membrane filters were incubated in the culture medium. The transport and uptake experiments of cephalexin across apical membranes were then conducted with different temperature and different pH values.Uptake of cephalexin in Caco-2 cells gsown on multiple well dishes with addition of energy inhibitors(sodium azide,SA and 2,4-dinitrophenol,DNP) were then measured. Results: The accumulation of cephalexin into Caco-2 monolayers increased with the duration of culture.The uptake from the apical surface was markedly influenced by the pH of the apical medium,and the maximal uptake was achieved at pH 5.5;further acidification of the incubation medium may decrease transport of cephalexin despite an increase inward H+ gradient.Cephalexin uptake was linear over the concentration range when the cells were incubated at 4℃ while the uptake rate was enhanced and tended to be saturated as the cephalexin concentration increased when the cells were incubated at 37℃.The kinetic parameters for the cephalexin transport carrier were determined to be: Vmax of(22.173±1.9) nmol/min per mg protein,Km of(2.069±0.9)mol/L,the Kd was estimated to be(0.07±0.02) nmol/min per mg protein per mmol/L.Uptake of cephalexin was markedly inhibited by sodium azide(SA) and 2,4-dinitrophenol(DNP). Conclusion: Cephalexin was transported actively across Caco-2 cells,and the transport process was proton-and energy-dependent.In addition, Caco-2 cells taked up cephalexin by dipeptide transporters that closely resembled the transporters present in the intestine.Caco-2 cells represented an ideal cellular model for future studies of the dipeptide transporter.

Randomized controlled trial of the absorbency of four dressings and their effects on the evaporation of burn wounds

Background Wound dressings are divided into traditional and new types. The new dressings are thought to accelerate wound healing. The purpose of this study was to supplement the scanty data on the absorbency of the new dressings and their effects on evaporation from the burn surface.Methods The water absorption rate of four dressings （carbon fiber dressing, hydrogel dressing, silver nanoparticle dressing, and vaseline gauze） were measured by the immersion-weight gain method. A total of 120 inpatients with 10% superficial partial-thickness burn wounds were randomly assigned to four groups, each with 30 participants. Carbon fiber dressing, hydrogel dressing, and silver nanoparticle dressing were used in groups A, B, and C as the primary dressing, and traditional vaseline gauze was used in group D as the control. Multi-spot evaporation from normal skin and naked wound, and from wounds covered with each of the four dressings was measured post-burn on days 1, 3, 5, and 7 by an EP-I evaporimeter under conditions of 21℃ -22℃ ambient temperature and 74%-78% humidity.Results The absorption rates of the four dressings were 988% with carbon fiber dressing, 96% with silver nanoparticle, 41% with vaseline gauze, and 6% with hydrogel. Evaporation from the naked burn wounds was about 1/3 higher than from normal skin （P〈0.01）. Compared with wounds without applied dressing, evaporation from dressed wounds decreased and was time-dependent （P〈0.01）. The evaporation of wounds with carbon fiber dressing was the lowest （（13.40 ± 2.82） ml·h^-1·m^-2, P〈0.01） on day 1 post-burn, compared with the other groups. Conclusion All four dressings have water retention capacity while carbon fiber dressing has the highest absorption rate and shows the best containment and evaporation from the burn wound.

Current surgical practices of robotic-assisted tissue repair and reconstruction

This paper systematically reviewed and analyzed the recent publications of robotic-assisted surgeries in the field of tissue repair and reconstruction.Surgical robots can elevate skin flap more accurately and shorten the time of tissue harvest.In addition,robotic-assisted surgery has the advantage of minimal tissue trauma and thus forms minimal scar.The utilization of surgical robots reduces the occurrence of complications after oral radical tumor resection while achieving cosmetic sutures.Robotic-assisted radical mastectomy could radically remove invasive breast cancer lesions and achieve breast reconstruction in the first stage through the small incisions in the operation areas.Surgical robots enable precise microvascular anastomosis and reduce tissue edema in the surgical field.Robotic-assisted technology can help appropriately locate the target tissues at different angles during sinus and skull base surgeries and accurately place tissues during urethroplasty.The robotic-assisted technology provides a new platform for surgical innovation in the field of tissue repair and reconstruction.However,the uncertainty in the survival rate after tumor radical surgery,the increase of operating time,and the high costs are barriers for its clinical application in tissue repair and reconstructive surgery.Nevertheless,robotic-assisted technology has already demonstrated an impact on the field of tissue repair and reconstruction in a meaningful way.

Prediction of key transcription factors during skin regeneration by combining gene expression data and regulatory network information analysis

Burn is one of the most common injuries in clinical practice. The use of transcription factors (TFs) has been reported to reverse the epigenetic rewiring process and has great promise for skin regeneration. To better identify key TFs for skin reprogramming, we proposed a predictive system that conjoint analyzed gene expression data and regulatory network information. Methods: Firstly, the gene expression data in skin tissues were downloaded and the LIMMA package was used to identify differential-expressed genes (DEGs). Then three ways, including identification of TFs from the DEGs, enrichment analysis of TFs by a Fisher’s test, the direct and network-based influence degree analysis of TFs, were used to identify the key TFs related to skin regeneration. Finally, to obtain most comprehensive combination of TFs, the coverage extent of all the TFs were analyzed by Venn diagrams. Results: The top 30 TFs combinations with higher coverage were acquired. Especially, TFAP2A, ZEB1, and NFKB1 exerted greater regulatory influence on other DEGs in the local network and presented relatively higher degrees in the protein–protein interaction (PPI) networks. Conclusion: These TFs identification could give a deeper understanding of the molecular mechanism of cell trans-differentiation, and provide a reference for the skin regeneration and burn treatment.