透明质酸含量在兔正常皮肤及皮肤创伤愈合过程的变化

目的　分析透明质酸在创伤愈合过程中的含量变化以及胎儿型愈合和成人型愈合的机理。方法　通过胎兔创伤模型及皮肤均化的方法，提取游离及结合的透明质酸（ＨＡ） ，应用透明质酸结合蛋白（ ＨＡＢＰ） 技术，对胚胎兔、成年兔皮肤在正常及创伤愈合过程中用放射免疫法测定游离、结合及ＨＡ 的总量。结果　⑴不同孕期正常胎兔皮肤的游离ＨＡ 及ＨＡ 总量的差异均无显著意义，结合ＨＡ 有显著的波动，而且均比正常成兔增高（ Ｐ＜ ０ ．０１） ；⑵胎兔皮肤创伤后不同愈合时间的游离ＨＡ 及ＨＡ 总量的差异均无显著意义，结合ＨＡ 的组成亦有显著变化；⑶创伤胎兔与正常胎兔相比，各组分ＨＡ 均增高（ Ｐ＜ ０ ．０５） ；⑷创伤成年兔游离ＨＡ 及ＨＡ 总量均比正常成年兔显著增高（ Ｐ＜ ０ ．０１） ，而在创伤成年兔内部游离ＨＡ 及ＨＡ 总量呈“山峰型”变化；⑸胎兔、成年兔皮肤创伤后对应比较发现，ＨＡ 总量均为胎兔高（ Ｐ＜ ０ ．０１） ，而游离ＨＡ 则第２ 、３ 天差异无显著意义。结论　ＨＡ 的增高是胎儿型愈合不可缺少的内部机制，其中游离ＨＡ 起主导作用，但结合ＨＡ 随孕期的延长以及在创伤后不同愈合时间所发生的显著变化，对于临床控制瘢痕形成具有很重要的意义     

胎兔、孕兔、成年兔伤口愈合中肿瘤坏死因子和表皮生长因子含量分析

目的：探索胎兔伤口无瘢痕愈合的可能机理及条件。方法：采用孕22－23d的母兔及所孕胎兔皮肤伤口无瘢痕愈合的动物模型及成年兔皮肤伤口愈合模型，以放射免疫法测定其表皮生长因子（EGF）和肿瘤坏死因子（TNF）含量。结果：胎儿伤口中的EGF和TNF术后3d明显升高（P＜0．05），并维持至术后7d；孕兔及成年兔仅在术后3d升高（P＜0．05），术后7d降到接近正常水平。结论：胎兔皮肤伤口中特有的细胞因子水平是胎儿伤口无瘢痕愈合的重要因素。     

一氧化氮在成兔与胚胎兔创面愈合过程中含量的比较

目的:分析胚胎无瘢痕愈合的潜在原因,研究NO(一氧化氮)在成人型和胚胎型愈合过程中的差别.方法:在已建立的胎兔创伤模型的基础上,用一氧化氮酶法试剂盒检测胚胎兔和成兔皮肤匀浆液中NO的含量,并对结果进行比较.结果:①正常胎兔不同孕期皮肤中NO含量无差别.②正常胎兔皮肤中NO含量高于正常成兔皮肤中NO含量(P＜0.01).③创伤胎兔皮肤中NO含量高于正常胎兔皮肤中NO含量(P＜0.01).④创伤成兔皮肤中NO含量高于正常成兔皮肤中NO含量(P＜0.01).⑤创伤胎兔皮肤中NO含量高于创伤成兔皮肤中NO含量(P＜0.01).结论:NO参与了胚胎和成年动物的创面愈合过程,并在两种愈合过程中存在差别.     

一氧化氮在成兔与胚胎兔创面愈合过程中含量的比较

目的 :分析胚胎无瘢痕愈合的潜在原因 ,研究NO(一氧化氮 )在成人型和胚胎型愈合过程中的差别。方法 :在已建立的胎兔创伤模型的基础上 ,用一氧化氮酶法试剂盒检测胚胎兔和成兔皮肤匀浆液中NO的含量 ,并对结果进行比较。结果 :①正常胎兔不同孕期皮肤中NO含量无差别。②正常胎兔皮肤中NO含量高于正常成兔皮肤中NO含量 (P <0 .0 1)。③创伤胎兔皮肤中NO含量高于正常胎兔皮肤中NO含量 (P <0 .0 1)。④创伤成兔皮肤中NO含量高于正常成兔皮肤中NO含量 (P <0 .0 1)。⑤创伤胎兔皮肤中NO含量高于创伤成兔皮肤中NO含量 (P <0 .0 1)。结论 :NO参与了胚胎和成年动物的创面愈合过程 ,并在两种愈合过程中存在差别     

胎兔皮肤伤口中糖胺多糖及透明质酸含量分析

目的探讨胎兔皮肤伤口无瘢痕愈合机理。方法 取胎兔,孕兔,成年兔切口及其周围组织,用阿利新蓝比色法,醋酸纤维素膜电脉分离法测定糖胺多糖（GAG）和透明质酸（HA）含量。结果 （1）胎兔正常皮肤（GAG及HA的含量均明显高于孕兔及成年兔（P＜0．01）,手术区,胎兔,孕兔,成年兔在术后3天时GAG及HA均升高（P＜0．05）。但术后第7天,胎兔GAG含量仍维持在高水平,而孕兔及成年兔其含量下降到接近正常水平,。结论 高浓度的HA在胎兔伤口间质的持续存在对胎兔伤口无瘢痕愈合起很重要的作用。     

胎兔伤口无瘢痕愈合的形态学和胶原构成研究

目的：探讨胎兔伤口无瘢痕愈合的可能机理及条件。方法：用22－23d的孕兔建立胎兔伤口无瘢痕愈合的动物模型,并与孕兔、成年兔伤口愈合进行比较,对各组兔皮肤切口组织进行光镜和透射电镜检查,胶原含量测定（羟脯氨酸法）及分型。结果：①胎兔切口无急性炎症反应,成纤维细胞（FB）出现早,伤口无瘢痕一期愈合。②胎兔伤口中胶原含量及构成变化不显著;孕兔、成年兔胶原在术后7d时升高（P＜0．05）。结论：无急性炎症反应、皮肤中的FB及胶原构成是胎兔伤口无瘢痕愈合的重要因素。     

一氧化氮在成兔与胚胎兔创面愈合过程中含量的比较

目的；分析胚胎无瘢痕愈合的潜在原因，研究ＮＯ（一氧化氮）在成人型和胚胎型愈合过程中的差别。方法：在已瓣胎兔创伤模型的基础上。用一氧化氮酶法试剂盒检测胚胎兔和成兔皮肤匀浆液中ＮＯ的含量，并对结果进行比较。     

胎兔及成兔耳软骨创伤愈合的形态学观察

软骨创伤愈合是整形外科的一个重要问题。关节软骨破坏后依靠纤维组织愈合 ,直接影响到关节的抗压性能及关节活动 ,甚至造成关节强直。我们从胎儿皮肤无瘢痕愈合现象得到启示 ,在怀孕 2 3ｄ的胎兔耳上制作了胎兔软骨创伤愈合模型 ,并比较观察了胎兔和成兔耳软骨创伤愈合的过程。1　材料和方法1 1　动物选择　选择怀孕 2 3ｄ(孕期为 31ｄ)的日本大耳白兔 15只 ,成兔 15只。孕兔随机分为 5组 ,每组 3只。每只孕兔取两只胎兔于其左耳部做切口 ,右耳作对照。第 1,2 ,3组分别于创伤后第 1,3,6ｄ取材 ,第 4 ,5组于创伤后 14 ,2 1ｄ取材。成兔随…     

胚胎兔和成年兔伤口愈合中肌成纤维细胞的表达

胚胎动物与成年动物的创伤愈合存在差别 ,表现在炎症反应轻、创面不收缩和无瘢痕形成[1,2 ] 。本实验在光镜和电镜下观察胚胎兔和成年兔伤口愈合过程中肌成纤维细胞(ｍｙｏｆｉｂｒｏｂｌａｓｔ,ＭＦＢ)的表达 ,以期探讨胎兔伤口不收缩的原因以及胎兔无瘢痕愈合的机制。材　料　和　方　法1.动物模型及分组 :选择怀孕 2 3ｄ的日本大耳白兔 6只 ,随机分为两组 ,每组 3只 ,每只孕兔取两只胎兔做创伤 ,分别于创伤后 3、6ｄ行剖宫产手术取出创伤胎兔 ,在取出创伤胎兔的同时 ,每只孕兔还剖取两只正常胎兔作对照。另取普通成年日本大耳白兔 12只 ,…     

胎兔皮肤无瘢痕愈合相关蛋白的筛选与初步分析

目的：筛选胎兔皮肤组织无瘢痕愈合相关蛋白，并初步分析其在无瘢痕愈合过程中的作用。方法：建立胎兔背部切割伤模型，运用蛋白质组双向电泳技术筛选胎兔皮肤伤后差异表达的蛋白质，并进行质谱和数据库检索分析。结果：筛选出20个在伤后胎兔皮肤组织中特异高表达的蛋白质点，经过质谱和数据库检索分析后确定：伴侣素或线粒体蛋白P1前体、弹性蛋白（Vimentin，Vim）、微管蛋白β多肽、核不均一核糖核蛋白H（异质性胞核核糖核蛋白H）、α-烯醇酶（α-磷酸丙酮酸水合酶）等无瘢痕愈合相关蛋白在胎兔皮肤伤后表达增加。结论：上述无瘢痕愈合相关蛋白可能通过对基因转录和翻译的调控，促进胶原蛋白等的合成和正确的折叠、装配，以及促进细胞的增殖、分化和发育等，促进胎兔皮肤创伤的修复，参与其无瘢痕愈合过程。     

Fetal wound healing. The ontogeny of scar formation in the non-human primate.

OBJECTIVE: This study determined how scar formation develops in a non-human primate model of fetal skin repair. SUMMARY BACKGROUND DATA: A transition from healing scarlessly to healing with scar formation characterizes skin repair in rat and sheep fetuses. New knowledge of the regulatory processes occurring in the fetal wound at the initial stages of scar formation may provide insights into the early mechanisms of scar formation. METHODS: Full-thickness wounds were made in fetal rhesus monkey lips from 75 through 114 days gestation (n = 6, term = 165 days). Wounds were harvested at 14 days postwounding and processed for histology (hematoxylin & eosin, Masson's trichrome) as well as immunohistochemistry (human type I or type III collagen). RESULTS: Wounds healed with complete restoration of normal tissue architecture in the 75-day gestation fetus. However in the 85-100 day gestation fetuses, wounds healed with an absence of hair follicles and sebaceous glands, but the dermal collagen pattern remained reticular and similar to that in unwounded dermis. At 107 days, a thin scar was present in the wound, thereby demonstrating a transition to scar formation between 100 and 107 days gestation (early 3rd trimester) in the non-human primate. CONCLUSIONS: In the non-human primate fetus, a transition from scarless repair to adult-type repair with scar formation occurs in the early third trimester. These data provide insight into the transition process; the ontogeny of scar formation is characterized initially by wounds healing without the presence of epidermal appendages but with a normal reticular dermal collagen pattern, which we term the "transition wound."     

Analysis of transforming growth factor beta receptor binding in embryonic, fetal, and adult rabbit fibroblasts

Adult wound repair traits including inflammation, fibroplasia, and collagen deposition are not seen at fetal wound sites. This observation raised questions about regulatory mechanisms extant in fetal healing. Transforming growth factor beta (TGF-beta) is an important regulatory polypeptide known to orchestrate fibroplasia and collagen synthesis during adult wound repair. Previous studies have suggested that the wounded rabbit fetus is capable of responding with these adult characteristics if provided with exogenous TGF-beta. In order to test whether the observed in vivo effects of TGF-beta in the rabbit fetus might be due to a direct effect on the fibroblast, TGF-beta receptor binding characteristics of early passage cultured embryonic (14 days' gestation), fetal (24 days' gestation), and adult rabbit fibroblasts were studied by flow cytometry. Experiments were carried out using fluorescein-conjugated TGF-beta (F-TGF-beta) with analysis on an EPICS V flow cytometer. F-TGF-beta was incubated with each of the three fibroblast types at 37 degrees C after which time the cells were washed twice and analyzed with a minimum of 10(5) cells for each data point. F-TGF-beta bound rapidly and reversibly to the embryonic, fetal, and adult fibroblasts with saturation being achieved at 1 nmol/L for fetal and adult cells, and 8 nmol/L in the embryonic fibroblasts. Saturating concentrations of F-TGF-beta yielded mean channel numbers (a function of relative amounts of F-TGF-beta-bound) of 172, 114, and 97 for embryonic, fetal, and adult cells, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)     

Transition from fetal to adult repair occurring in mouse forelimbs maintained in organ culture.

In previous wound healing experiments with the use of midgestation murine fetal forelimb explants, wounds were made before or immediately after amputation from the fetus. This experimental technique allows one to ask the question: Do circulatory elements initiate or sustain the repair process in vitro? The hypotheses tested in the current study were that repair occurs in organ culture in the absence of systemic influences and that the in vivo transition from fetal-like to adult-type repair persists in an unperfused in vitro system. Gestational day-14 mouse forelimbs were harvested and placed in serum-free culture medium. Before amputation, control forelimbs received linear full-incision microscalpel wounds that were closed primarily. The animals in the other group were not immediately wounded but cultured for 4 days and then wounded with primary wound closure. All limbs were cultured for 7 days after wounding and then processed for histologic analysis. In the immediately wounded limbs, scarless healing occurred with collagen fibers deposited in a reticular form. In contrast, the delay-wounded limbs had collagen organized in parallel arrays (disordered), constituting repair by scarring. Wound repair proceeded as a local phenomenon in the absence of systemic mediators. We conclude that day-14 gestation forelimbs undergo maturation in culture, causing a transition from scarless to adult scar repair.     

Wound healing in a fetal,adult, and scar tissue model: A comparative study

Early gestation fetal wounds heal without scar formation. Understanding the mechanism of this scarless healing may lead to new therapeutic strategies for improving adult wound healing. The aims of this study were to develop a human fetal wound model in which fetal healing can be studied and to compare this model with a human adult and scar tissue model. A burn wound (10 × 2 mm) was made in human ex vivo fetal, adult, and scar tissue under controlled and standardized conditions. Subsequently, the skin samples were cultured for 7, 14, and 21 days. Cells in the skin samples maintained their viability during the 21‐day culture period. Already after 7 days, a significantly higher median percentage of wound closure was achieved in the fetal skin model vs. the adult and scar tissue model (74% vs. 28 and 29%, respectively, p<0.05). After 21 days of culture, only fetal wounds were completely reepithelialized. Fibroblasts migrated into the wounded dermis of all three wound models during culture, but more fibroblasts were present earlier in the wound area of the fetal skin model. The fast reepithelialization and prompt presence of many fibroblasts in the fetal model suggest that rapid healing might play a role in scarless healing.     

胎儿和成人皮肤及其创面愈合过程中碱性成纤维细胞生长因子的表达及意义

目的　探讨胎儿和成人皮肤及其创面愈合过程中碱性成纤维细胞生长因子 (b FGF)的表达及其意义。方法　将孕龄 2 0～ 2 4周胎儿皮肤移植至 BAL B/ C裸鼠背部皮下 ,皮片成活后制造创面 ,建立胎儿无瘢痕愈合动物模型 ,定期获取相应标本。对临床所取正常成人皮肤及创面愈合皮肤标本 ,采用免疫组织化学染色方法 ,观察 b FGF的表达情况。　结果　正常胎儿皮肤及创伤后胎儿皮肤中均未见明显的 b FGF阳性表达。正常成人皮肤中血管周围可见阳性表达 ;创伤后成人皮肤也可见阳性表达 ,尤其成纤维细胞和血管内皮细胞创伤后表达明显增强。高倍镜视野随机观察计数b FGF阳性表达细胞数 ,正常胎儿皮肤为 2 .1± 0 .1,创伤后 12小时 ,1、3天和 1周胎儿皮肤分别为 2 .2± 0 .1、2 .1± 0 .3、2 .1± 0 .3和 2 .0± 0 .1;正常成人皮肤为 2 3.2± 4 .2 ,创伤后成人皮肤为 4 0 .5± 3.6 ,胎儿正常皮肤和创伤皮肤 b FGF表达与正常成人皮肤和创伤后皮肤 b FGF表达比较 ,差异有统计学意义 (P<0 .0 1)。　结论　 b FGF的阴性表达可能是胎儿皮肤无瘢痕愈合的重要原因之一。     

胎儿皮肤免疫细胞CD68、CD3的表达与无瘢痕愈合的关系

目的探讨人胎儿皮肤、正常成人皮肤及增生性瘢痕(HS)组织免疫细胞CD68、CD3与无瘢痕愈合的关系。方法选择笔者单位引产的16~33周胎龄的10例胎儿皮肤、7例正常成人皮肤以及18例HS标本,用免疫组织化学的方法分别检测其巨噬细胞、T淋巴细胞的表面标志CD68、CD3的表达。结果胎儿皮肤中CD68[(5±6)个/400倍视野]显著少于成人[(23±4)个/400倍视野,P<0.01],成人皮肤中CD68又显著少于HS[(38±16)个/400倍视野,P<0·01].随胎龄增加,CD68逐渐增多,在24~28周胎龄时迅速上升,28周以后上升缓慢。发育各期胎儿皮肤中均未见CD3;成人皮肤中可见少量CD3[(24±8)个/400倍视野],主要分布于表皮基底层;HS组织中CD3较多[(69±25)个/400倍视野],常聚集成片状,主要分布于真皮乳头层,在小血管周围呈袖套状分布,数量和染色强度大于成人皮肤(P<0.01).结论胎儿皮肤中CD68数量少可能与无瘢痕愈合存在一定的关系;同时胎儿皮肤无瘢痕愈合可能与胎儿皮肤中缺乏CD3有关。     

人创面愈合过程中同源异形框基因的表达及意义

目的 探讨人胎儿及成人皮肤创面愈合过程中，几种同源异形框基因的表达及在胎儿无瘢痕愈合中的作用。方法 采用原位杂交方法，对正常成人和胎儿皮肤及创面愈合过程中PRX—2、H0XBl3、H0X2．2和H0X2．3的表达进行观察。结果 (1)在正常胎儿和成人皮肤中可见PRX—2阳性表达，以前阳性程度为强。分布部位有所不同，在正常胎儿皮肤中，阳性表达主要见于真皮乳头层毛干部周围细胞，表皮中也可见阳性表达；而在正常成人皮肤中，表皮基底层细胞呈弱阳性表达，真皮组织中未见阳性表达。胎儿皮肤创伤后，接近切口的组织中阳性表达明显增强，而成人皮肤创伤后，阳性表达未见明显变化，仍局限于表皮基底层细胞；(2)在正常胎儿及成人皮肤均可见H0XBl3阳性表达，真皮部分主要集中在毛囊细胞，表皮部分主要集中在基底层细胞，创伤后其表达明显减弱，尤其是胎儿皮肤；(3)在正常胎儿皮肤中H0X2．2和H0X2．3阳性表达主要见于表皮全层，表皮基底层阳性表达比较强，真皮中可见弱阳性表达，创伤后近切口的组织中，表达增强。在正常成人皮肤及其创面，未见到阳性表达。结论 同源异形框基因作为与发育生物学密切相关的基因，在人胎儿及成人皮肤创面愈合过程中的表达有所不同，这可能是二创面愈合差异的根本原因。