内置小室毛发重建模型

目的:建立一个高效、可重复的毛发重建模型,观察其诱导毛发的效果,探讨毛发发育的机制并为脱发的细胞学治疗提供实验基础.方法:制做假体小室置于裸鼠背部皮下,制备新生C57BL/6鼠真皮和表皮细胞混悬液,注射于裸鼠背部预置的小室内.7d后剪开表皮拆除小室,创面旷置,观察创面皮肤的愈合及毛发生长情况.结果:通过内置小室模型成功构建了毛发组织,新生毛发长出体表并具有良好方向性与生长密度,组织学检测其毛囊结构与正常组织无异.结论:内置小室是更为优化的毛发重建模型,成功诱导形成了正常结构的毛发组织,特别是毛发发育的早期,在有效避免外部因素的影响下,建立了类似于机体的内环境,更加有利于毛发的发育形成.     

聚丙烯材料假发移植物的组织相容性及可移植假发的外观效果

目的:以聚丙烯为基础材料制作假发移植物,通过动物实验观察其组织相容性及可移植假发的外观仿真效果。方法:实验于2005-08/2006-08在南方医科大学动物实验中心完成。运用聚丙烯材料设计并加工成侧面呈锯齿状锚刺,顶端固定假发的移植物。移植物主干和锚刺均使用医用聚丙烯单丝线(购自上海浦东金环医疗用品有限公司)制作;发束由单根或多根真人毛发或其他动物毛发组成,根部插在主干端头的埋入孔内,加压融合。取10只新西兰白兔(南方医科大学动物实验中心提供),每只白兔头皮采用毛囊单位移植技术,植入20根假发移植物,10只白兔头皮共移植200根。将10只白兔按随机数字表法分为两组,即大体观察组和组织学观察组,每组5只。大体观察组主要观察1年内移植物脱落情况并计数;组织学观察组分别于移植后第1周、第2周及其后1年内每个月在无菌条件下,每只兔分次采集包含有1根移植物的头皮组织条,进行组织学观察。结果:10只白兔全部进入结果分析,无脱失。①移植物的组织形态学观察结果:移植后1周移植物周围组织炎症反应轻微;移植后2周移植物周围有大量胶原纤维形成,炎症细胞局部稍有增多,移植物的主干和锚刺间已有胶原纤维长入;移植1个月后,成熟的纤维组织形成包膜于移植物及锚刺周围,无明显炎症反应。移植2个月后至1年,移植物周围组织无明显不良反应。②移植物脱落情况:5只白兔头皮共移植100根移植物。移植后第1周共脱落4根,第2周脱落2根,第3周￣第12个月无脱落,总结1年内脱落率为6%,并集中于最初2周。结论:以聚丙烯为基础材料的假发移植物可以较稳固地锚定于头皮,具有良好的组织相容性,可获得较佳仿真效果,是运用毛发修复外科技术治疗秃发的一种新的探索。但移植术后早期要注意保护创面,防止牵拉移植物。     

毛乳头细胞诱导毛囊形成的可能性研究

背景：毛囊在伤口愈合，肿瘤发生等过程中起主导作用，由于其在活体内影响因素较多，故难以研究其生物学作用机制。目的：利用培养的毛乳头细胞观察体内外条件下诱导毛囊形成的可能。设计：非随机非对照的实验研究。地点和对象：实验在第三军医大学大坪医院野战外科研究所完成。对象为正常人头皮中获取毛乳头细胞、真皮鞘细胞、毛囊上、下段及球部细胞。干预：将毛乳头细胞、真皮鞘细胞分别与毛囊上、下段上皮细胞进行体外三维培养重建，用游离细胞混合移植于裸鼠，组织学观察毛囊形成情况。主要观察指标：毛囊毛乳头细胞、真皮鞘细胞对分段毛囊上皮细胞的诱导分化作用。结果：毛囊间表皮细胞、毛囊上段上皮细胞、下段上皮细胞和球部细胞在间质细胞凝胶上均可形成双层结构的组织工程皮肤，在真皮鞘细胞胶原凝胶上毛囊的上、下段上皮细胞形成了毛囊结构，移植于裸鼠后毛乳头细胞胶原凝胶诱导毛囊上、下段细胞形成了毛囊。低代毛乳头细胞与毛囊上皮细胞混合移植形成了数量较多、结构典型的毛囊，并有肉眼可见的毛发纤维产生。结论：毛囊的真皮成分细胞即毛乳头细胞、真皮鞘细胞在体内、外均具有诱导毛囊形成的能力，通过与毛囊上皮细胞之间的相互作用，诱导毛囊形成。     

一种复合头皮营养液对小鼠毛发生长的影响

目的 观察复合头皮营养液对雄激素型脱发模型小鼠毛发生长的影响。方法 利用丙酸睾酮诱导建立雄激素型脱发小鼠模型,随机分为正常组、模型组、2%米诺地尔组、5%米诺地尔组和复合头皮营养液组,每日在脱毛区涂抹2次,连续30 d。观察小鼠毛发生长情况。结果与正常组比较,模型组小鼠毛发生长评分显著降低（P<0.01）,与模型组比较,2%米诺地尔组、5%米诺地尔组和复合头皮营养液组毛发生长评分显著升高（P<0.01）,同时,5%米诺地尔组和复合头皮营养液组毛囊较多,分布比较密集。结论 复合头皮营养液可显著增加雄激素型小鼠脱毛区新生毛发生长,毛囊形态数量得到改善,具有促进毛发生长的作用,效果优于2%米诺地尔,与5%米诺地尔相当。     

毛乳头细胞诱导毛囊形成的可能性研究

背景毛囊在伤口愈合,肿瘤发生等过程中起主导作用,由于其在活体内影响因素较多,故难以研究其生物学作用机制.目的利用培养的毛乳头细胞观察体内外条件下诱导毛囊形成的可能.设计非随机非对照的实验研究.地点和对象实验在第三军医大学大坪医院野战外科研究所完成.对象为正常人头皮中获取毛乳头细胞、真皮鞘细胞、毛囊上、下段及球部细胞.干预将毛乳头细胞、真皮鞘细胞分别与毛囊上、下段上皮细胞进行体外三维培养重建,用游离细胞混合移植于裸鼠,组织学观察毛囊形成情况.主要观察指标毛囊毛乳头细胞、真皮鞘细胞对分段毛囊上皮细胞的诱导分化作用.结果毛囊间表皮细胞、毛囊上段上皮细胞、下段上皮细胞和球部细胞在间质细胞凝胶上均可形成双层结构的组织工程皮肤,在真皮鞘细胞胶原凝胶上毛囊的上、下段上皮细胞形成了毛囊结构,移植于裸鼠后毛乳头细胞胶原凝胶诱导毛囊上、下段细胞形成了毛囊.低代毛乳头细胞与毛囊上皮细胞混合移植形成了数量较多、结构典型的毛囊,并有肉眼可见的毛发纤维产生.结论毛囊的真皮成分细胞即毛乳头细胞、真皮鞘细胞在体内、外均具有诱导毛囊形成的能力,通过与毛囊上皮细胞之间的相互作用,诱导毛囊形成.     

骨髓基质干细胞复合煅烧骨的皮下成骨

背景：研究证明骨髓基质干细胞与煅烧骨支架材料结合后可形成组织工程化骨,但在动物体内的生物相容性及皮下诱导成骨的能力国内报道较少. 目的：观察骨髓基质细胞复合异种煅烧骨植入BALB/c裸鼠背部皮下的成骨性能及煅烧骨材料作为组织工程骨支架材料的可行性. 方法：选用经脱脂及脱蛋白处理后高温煅烧形成的骨支架材料与梯度密度离心法分离培养至第3代的羊骨髓基质干细胞构建细胞-煅烧骨复合物植入 BALB/c 裸鼠背部皮下,选同期对侧背部皮下植入单纯煅烧骨为对照组. 结果与结论：煅烧后的松质骨块为白垩色,表面呈蜂窝状多孔结构,保留了天然松质骨的多孔状空间结构.骨小梁结构完整,孔隙相互连通.骨髓基质干细胞接种到煅烧骨后24 h可见大量细胞黏附于支架上,7 d后细胞分泌大量细胞外基质,细胞与基质分界不清,细胞能在材料上良好地黏附、增殖与生长,细胞活性未受到支架材料的影响.植入4周后,两组均可见煅烧骨边缘出现少量残片,细胞-煅烧骨复合物组煅烧骨孔隙周边可发现骨细胞,对照组煅烧骨表面可见纤维结缔组织包绕.植入后8周,两组均可见到煅烧骨部分降解为片状类骨质,周围有成纤维细胞包绕,排列紧密,形态多样,细胞-煅烧骨复合物组煅烧骨孔隙内可见煅烧骨表面有排列成行的成骨细胞,孔隙间有散在淋巴细胞浸润.对照组标本可见孔隙内有大量结缔组织长入,未见明显成骨迹象.结果说明,经高温煅烧后的松质骨材料,具有良好的生物相容性和生物安全性,可作为骨髓基质干细胞的良好载体,复合后植入体内能够诱导新生骨组织形成,可作为骨缺损组织工程修复的支架材料.     

血管内皮细胞生长因子(VEGF) 能使小鼠的毛发变粗

美国马萨诸塞州总医院和哈佛大学医学院的研究人员发现 ,血管内皮细胞生长因子 (VEGF)能使小鼠的毛发变粗或增厚 ,而有希望为男性脱发提供一种新的治疗方法。男性秃发或脱发是一种遗传性疾病 ,能引起许多中年男性头发脱落。科学家发现 VEGF能促使毛囊处的血管增大 ,为毛发提供更多的营养 ,而促进其生长。科学家建立了一株基因工程小鼠 ,这种小鼠的毛囊细胞能持续产生 VEGF,使毛囊周围的血管增大 ,血管周围的发根变粗 ,导致毛发变厚。研究还观察到小鼠并不能长出更多毛发 ,只是使毛发变粗。当剃去毛发后 ,小鼠的毛发会更快的长出来。研…     

小鼠毛囊单位移植修复创面中真皮成分生长情况的研究

目的:建立雄性鼠须的毛囊单位移植雌性小鼠背部的创面模型,观察毛囊单位移植修复创面中真皮成分的生长情况。方法:32只近交系C57雌性小鼠麻醉后,在背部形成15 mm×15 mm的创面,然后将其随机分为4组:空白对照组(A组)、毛囊单位移植组(B组)、微粒皮移植组(C组)、限制创面收缩毛囊单位移植组(D组),每组8只,分别进行相应的移植操作。采用显色原位杂交(chromogenic in situ hybridization,CISH)检测愈合创面中真皮组织来源的成分。结果:A、B、C 3组小鼠术后1周的创面愈合率分别为(45.24±3.16)%、(60.95±2.48)%、(54.18±2.44)%,术后创面愈合时间分别为(27.13±1.25)d、(21.25±1.67)d、(23.13±1.96)d。对3组小鼠术后1周的创面愈合率及术后创面愈合时间进行两两比较,差异均有统计学意义(P均<0.01)。D组小鼠创面中的毛囊单位持续存活,并形成"皮岛"样结构。CISH实验证实,创面修复过程中雄性鼠须的毛囊单位细胞成分出现在真皮组织中。结论:毛囊单位移植可以促进小鼠创面的愈合,鼠须毛囊单位在限制创面收缩的情况下移植于鼠背创面可以形成岛状皮肤。     

用脱发素硬膏治疗黄癣的护理

黄癣俗称癞痢头或秃疮,是由黄癣菌属所引起,如不积极治疗,可造成永久性继发性秃发。黄癣主要发生于头皮部,初起时为围绕毛发的表皮下黄红色小点,以后发展成为黄癣痂,呈蝶状,边椽翘起,中心微凹,富于粘着性,不易脱落,有一至数根头发穿过,有鼠臭味。在疾病过程中由于毛囊被破坏,痊愈后可形成瘢痕,使毛发不能再生。本病的传染途径为用黄癣患者理发后未消     

改良单根毛囊分离法在眉部和会阴部毛发缺失治疗中的应用初探

目的：探讨改良单根毛囊分离法治疗毛发缺失的临床疗效。方法：对眉毛稀疏16例、会阴毛发稀疏9例患者,采用改良的单根毛囊分离法分离出单根毛囊后植入,每例单侧全眉种植约150~200个移植体,会阴部种植约500~600个移植体。随访其疗效。结果：25例患者随访3~12个月,毛发成活率达90%~95%,植入区外观自然,瘢痕不明显。结论：眉部和会阴部单根毛发移植术中采用改良的单根毛囊分离法,能便捷得到更多完整单根毛囊,从而提高供区毛发的使用率。     

人体毛囊单位移植裸鼠背部创面效果的研究

目的:研究人体毛囊单位修复裸鼠创面的效果以及人体毛囊单位在裸鼠创面中的生长情况.方法:40只裸鼠随机分为5组,空白对照组(A组,n=8)、毛囊单位移植组(B组,n=8)、微粒皮移植组(C组,n=8)、脱细胞真皮加毛囊单位移植组(D组,n=8)、限制创面收缩毛囊单位移植组(E组,n=8),分别进行相关移植操作结果:A、B、C、D组术后2周的创面愈合率分别为(51.50±1.07)％、(64.49±0.75)％、(58.66±1.56)％、(46.25±2.27)％.A、B、C、D组创面愈合时间分别为(24.00±1.31)d、(18.63±1.69)d、(21.75±1.28)d、(27.13±1.46)d.B、C两组在愈合率和愈合速度方面均优于A、D两组,差异有统计学意义(P＜0.0001);而B组愈合率和愈合速度方面又由于C组,差异有统计学意义(P＜0.0001).结论:人体毛囊单位移植可以促进裸鼠创面愈合.人体毛囊单位在限制裸鼠创面收缩情况下,无法发挥创面修复作用.     

Control of hair growth and follicle size by VEGF-mediated angiogenesis

The murine hair follicle undergoes pronounced cyclic expansion and regression, leading to rapidly changing demands for its vascular support. Our study aimed to quantify the cyclic changes of perifollicular vascularization and to characterize the biological role of VEGF for hair growth, angiogenesis, and follicle cycling. We found a significant increase in perifollicular vascularization during the growth phase (anagen) of the hair cycle, followed by regression of angiogenic blood vessels during the involution (catagen) and the resting (telogen) phase. Perifollicular angiogenesis was temporally and spatially correlated with upregulation of VEGF mRNA expression by follicular keratinocytes of the outer root sheath, but not by dermal papilla cells. Transgenic overexpression of VEGF in outer root sheath keratinocytes of hair follicles strongly induced perifollicular vascularization, resulting in accelerated hair regrowth after depilation and in increased size of hair follicles and hair shafts. Conversely, systemic treatment with a neutralizing anti-VEGF antibody led to hair growth retardation and reduced hair follicle size. No effects of VEGF treatment or VEGF blockade were observed in mouse vibrissa organ cultures, which lack a functional vascular system. These results identify VEGF as a major mediator of hair follicle growth and cycling and provide the first direct evidence that improved follicle vascularization promotes hair growth and increases hair follicle and hair size.     

Hair follicle stem cells combined with human allogeneic acellular amniotic membrane for repair of full thickness skin defects in nude mice

Repair of large skin defects caused by burns, trauma, or tumor operations is a clinical challenge. Hair follicle stem cells (HFSCs) are involved in epithelialization of wounds, formation of new hair follicles and promote vascularization in the newly formed skin, and human acellular amniotic membrane (hAAM) is a promising scaffold for skin substitute. Here, we investigated the ability of rat HFSCs (rHFSCs) combined with an hAAM to repair full thickness skin defects in nude mice. The effect of the rHFSC‐hAAM composite on the repair of skin defects in nude mice was assessed by hematoxylin and eosin staining, immunohistochemistry, and EdU‐labeled cell tracking. Isolated and cultured rHFSCs had strong cloning and proliferation potentials. Immunofluorescence staining and flow cytometry assays showed that rHFSCs expressed high levels of integrin α6, CK15, p63, and Sox9. Cells cultured in hAAM showed flaky and cluster‐like morphology and were able to adhere and grow effectively. After transplantation, the rHFSC‐hAAM composite promoted wound healing in nude mice. Moreover, cells in the rHFSC‐hAAM composite were directly involved in hair follicle formation and angiogenesis of tissue around the hair follicle. These results provide an experimental and theoretical basis for the clinical application of HFSCs in repair of human skin defects and a new approach for skin tissue engineering.     

Autoimmune hair loss (alopecia areata) transferred by T lymphocytes to human scalp explants on SCID mice.

Alopecia areata is a tissue-restricted autoimmune disease of the hair follicle, which results in hair loss and baldness. It is often psychologically devastating. The role of T lymphocytes in this disorder was investigated with cell transfer experiments. Scalp explants from patients were transplanted to severe combined immunodeficiency (SCID) mice and injected with autologous T lymphocytes isolated from involved scalp. T lymphocytes which had been cultured with hair follicle homogenate along with antigen-presenting cells were capable of inducing the changes of alopecia areata, including hair loss and perifollicular infiltrates of T cells, along with HLA-DR and ICAM-1 expression of the follicular epithelium. Similar changes were not noted in grafts injected with scalp-derived T cells that had not been cultured with follicular homogenate. These data indicate that alopecia areata is mediated by T cells which recognize a follicular autoantigen.     

枸杞多糖对胎儿卵巢组织冷冻保存的影响

背景：抗氧化剂的应用对于提高卵巢组织冻存后的活力起着很重要的作用。目的：通过观察冷冻保存的胎儿卵巢组织异种移植到裸鼠肾被膜下的发育情况,探索枸杞多糖在卵巢组织冷冻保存中的作用。方法：实验分为4组。①新鲜移植组：取材后的新鲜胎儿卵巢组织直接进行移植。②冻存对照组：冷冻保护液为基液。③β-巯基乙醇组：冷冻保护液为基液添加100μmol/Lβ-巯基乙醇。④枸杞多糖组：冷冻保护液为基液添加400mg/L枸杞多糖。对冷冻复温后的胎儿卵巢皮质块进行祼鼠的肾被膜下移植,并于移植后12周取材。结果与结论：各组在移植物的存活率上差异无显著性意义（P〉0.05）。在卵泡计数上冷冻对照组最低（P〈0.05）。在卵泡的存活率上,各组间差异均有显著性意义,其中以冷冻对照组最低,枸杞多糖组最高。β-巯基乙醇组和枸杞多糖组卵巢超微结构较冷冻对照组保存的好。提示400mg/L的枸杞多糖和100μmol/L的β-巯基乙醇有利于卵巢组织的冷冻保存,并可显著提高冷冻卵巢组织移植后的存活率。     

Reconstructed human skin shows epidermal invagination towards integrated neopapillae indicating early hair follicle formation in vitro

Application of reconstructed human Skin (RhS) is a promising approach for the treatment of extensive wounds and for drug efficacy and safety testing. However, incorporating appendages, such as hair follicles, into RhS still remains a challenge. The hair follicle plays a critical role in thermal regulation, dispersion of sweat and sebum, sensory and tactile functions, skin regeneration, and repigmentation. The aim of this study was to determine whether human neopapilla could be incorporated into RhS (differentiated epidermis on fibroblast and endothelial cell populated dermis) and whether the neopapillae maintain their inductive follicular properties in vitro. Neopapillae spheroids, constructed from expanded and self‐aggregating dermal papilla cells, synthesized extracellular matrix typically found in follicular papillae. Compared with dermal fibroblasts, neopapillae showed increased expression of multiple genes (Wnt5a, Wnt10b, and LEF1) known to regulate hair development and also increased secretion of CXCL1, which is a strong keratinocyte chemoattractant. When neopapillae were incorporated into the dermis of RhS, they stimulated epidermal down‐growth resulting in engulfment of the neopapillae sphere. Similar to the native hair follicle, the differentiated invaginating epidermis inner side was keratin 10 positive and the undifferentiated outer side keratin 10 negative. The outer side was keratin 15 positive confirming the undifferentiated nature of these keratinocytes aligning a newly formed collagen IV, laminin V positive basement membrane within the hydrogel. In conclusion, we describe a RhS model containing neopapillae with hair follicle‐inductive properties. Importantly, epidermal invagination occurred to engulf the neopapillae, thus demonstrating in vitro the first steps towards hair follicle morphogenesis in RhS.     

Analysis of epidermal entry in experimental cutaneous Bacillus anthracis infections in mice

Cutaneous infection is the most common form of human anthrax, but little is known of Bacillus anthracis-epidermal interactions. To study the latter, we used experimental inoculations of B. anthracis Sterne spores onto mouse flank skin. In DBA/2 mice (a sensitive strain) 10(7) spores injected intradermally or applied under occlusive dressings to abraded skin produced ipsilateral inguinal edema and rapid death. Epicutaneous application to shaved-only skin produced edema and death in most animals, but at longer times. Mortality after inoculation onto abraded skin was less in C57BL/6 mice (a relatively resistant strain). Inoculations onto shaved-only skin immunized C57BL/6 mice, and they survived later intradermal spore injections. Histology revealed massive organism proliferation in remaining epidermis and hair follicles of inoculated abraded skin, but less growth in the dermis itself. Conversely, no foci could be located by microscopic examination after inoculation onto shaved-only skin. High-dose nonocclusive dressing inoculations onto unshaved skin in DBA/2 mice revealed small numbers of infective foci, all in hair follicles. These results suggest that epidermal damage may increase infection susceptibility to B. anthracis of hair follicle contents and remaining epidermal remnants; the findings also indicate that access may occur through hair follicles and the denuded dermis.     

Gene expression profiling gets to the root of human hair follicle stem cells

Hair follicle stem cells sustain growth and cycling of the hair follicle and are located in the permanent portion of the follicle known as the bulge. In this issue of the JCI, Ohyama et al. report the characterization of global gene expression patterns of human hair follicle stem cells after their isolation using sophisticated laser capture techniques to microdissect out bulge cells. They discovered a panel of cell surface markers useful for isolating living hair follicle stem cells, a finding with potential therapeutic implications since isolated stem cells in mice can generate new hair follicles when transplanted to other mice. The findings of Ohyama et al. validate the use of the mouse for studying hair follicle biology but also underscore critical differences between mouse and human stem cell markers. In particular, CD34, which delineates hair follicle stem cells in the mouse, is not expressed by human hair follicle stem cells, while CD200 is expressed by stem cells in both species. Ultimately, this information will assist efforts to develop cell-based and cell-targeted treatments for skin disease.