31例成年男性头发生长特性的初步观察

目的 探讨中国成年男性头发的生长特性.方法 将31名志愿者头皮顶部及颞部各剃去约1.2 cm×1.2 cm范围内的头发;间隔7天后对上述部位微距照相,分析图像,得到头发密度及头发生长速度;拔取观察部位的头发,显微镜下测量头发尖端、中部及根部的直径.结果 31例成年男性头发密度为(132±42)根/cm²,顶部的头发密度显著高于颞部(P<0.001).头发生长速度为(461±44)μm/d,颞部的头发生长速度显著高于顶部(P<0.01).头发直径为(97±9)μm,顶部和颞部之间头发直径差异无统计学意义(P>0.05),头发尖端、中部及根部之间直径的差异亦无统计学意义(P>0.05).结论 与白人和非洲人相比,中国成年男性头发的密度较低,但头发生长速度较快.     

何首乌、女贞子等中药煎剂对体外培养的猪毛囊毛发生长的影响

目的 探讨何首乌、女贞子等中药混合煎剂对体外培养的猪毛囊毛发生长的影响。方法 将离体培养的猪毛囊分为对照组(Williams E培养基)和中药组(Williams E培养基+中药煎剂),显微镜下观察各组毛囊毛发生长和毛球部形态变化,并用末端脱氧核苷酸转移酶介导dUTP缺口末端标记法(TUNEL)检测各组毛囊中的凋亡细胞。结果 培养第7天,对照组毛囊毛发生长长度低于中药组(P<0.001);对照组毛囊TUNEL阳性细胞数明显高于中药组(P<0.001);毛球形态观察,对照组毛囊出现退行性变化,而中药组毛囊仍维持生长期毛囊形态。结论 何首乌、女贞子等中药煎剂能在一定程度上抑制猪毛囊细胞内凋亡,延缓生长期毛囊进入退行期。     

米诺地尔对培养鼠触须毛囊生长的影响

目的 体内米诺地尔临床应用引起多毛, 局部外用治疗秃发有效 方法 采用C₅₇BL/6J近交系乳鼠触须毛囊培养、毛囊显微形态观察及³H-TdR同位素标记掺入等技术, 研究在体外不同浓度米诺地尔在不同培养时间条件下对毛囊生长的影响.结果 米诺地尔浓度70μg/ml, 培养24小时, 毛囊生长较快.毛囊形态学改变示毛乳头松散, 毛球部扩大, 毛母质细胞增生活跃, 培养48小时, 毛囊生长明显减慢.培养30小时, ³H-TdR摄入率明显增高.结论 米诺地尔对体外培养鼠触须毛囊有直接促生长作用, 且与米诺地尔浓度及培养时间有一定关系.     

毛囊黏蛋白沉积症与蕈样肉芽肿T细胞受体基因重排的对比研究

目的 研究毛囊黏蛋白沉积症与蕈样肉芽肿的关系.方法 从8例特发性毛囊黏蛋白沉积症、3例毛囊黏蛋白沉积症合并蕈样肉芽肿和1例蕈样肉芽肿患者获得病变组织,将其埋于石蜡中.设计T淋巴细胞受体(TCR)可变区引物Vγ1-8/A,Vγ10,Vγ11及β,利用PCR方法分析了12例患者组织中T淋巴细胞受体基因重排的情况.结果 8例特发性毛囊黏蛋白沉积症中1例,3例毛囊黏蛋白沉积症合并蕈样肉芽肿和1例蕈样肉芽肿患者皮损TCR Vγ1-8/A呈单克隆性.结论 对于年龄较大、病程较长的毛囊黏蛋白沉积症患者,应行TCRγ基因重排检查,以排除淋巴瘤.     

毛囊闭锁性三联征一例及家系分析

目的 探讨毛囊闭锁性三联征的临床和遗传学特点。方法 对1例毛囊闭锁性三联征继发鳞状细胞癌的特殊病例,在临床检查的基础上,进行了家系调查和系谱分析。结果 此家系共有13例,于20岁左右发病,先证者临床特点及实验室检查符合毛囊闭锁性三联征的诊断。结论 遗传因素是不可忽视的主要因素,本病可能为常染色体显性遗传病。     

黄芩苷对人毛囊生长和毛乳头细胞分泌血管内皮生长因子的影响

目的 探讨黄芩苷对体外培养的人毛囊生长、毛乳头细胞增殖和分泌血管内皮生长因子(VEGF)的影响.方法 选择不同浓度黄芩苷作用于体外培养的人头皮毛囊8天,观察人毛囊生长及形态变化:作用于人毛乳头细胞72h,四甲基偶氮唑监(MTF)法测定细胞增殖活性,ELISA法检测细胞分泌的VEGF水平.结果 7.5.15,30,45μg/mL的黄芩苷对体外培养的人头皮毛囊有明显促生长作用;3.75,7.5,15,30μg/mL的黄芩苷对毛乳头细胞增殖无明显影响,但促进细胞分泌VEGF,与阴性对照组相比,差异有统计学意义.结论 黄芩苷促进体外培养的人头皮毛囊生长,部分可能是通过增加毛乳头细胞分泌VEGF促使毛发生长.     

甲氧沙林对人毛囊黑素细胞增殖、活化和黑素合成作用的研究

目的 研究甲氧沙林对人毛囊黑素细胞活化、增殖和黑素合成的影响.方法 体外培养正常人毛囊黑素细胞,观察不同浓度甲氧沙林(10～500μmol/L)对毛囊黑素细胞形态、增殖、酪氨酸酶活性和黑素合成的影响.结果 50μmol/L甲氧沙林处理细胞7d后,毛囊黑素细胞树突明显增多延长,胞浆内出现较多棕褐色颗粒,酪氨酸酶活性和黑素含量增加显着高于对照组(P<0.01).结论 甲氧沙林能诱导毛囊黑素细胞树突增多延长,酪氨酸酶活性和黑素含量增加.     

毛囊内无色素黑素细胞的超微结构特点

目的 探讨来自人毛发的毛囊内无色素黑素细胞的超微结构特点.方法 胶原酶V消化正常人头皮,获取毛囊.游离毛囊用0.1mol/LPBS冲洗,胰酶消化,得细胞悬液.将细胞悬液接种到适合黑素细胞生长的培养基.细胞传第3代后,收集细胞,电镜观察摄片.结果 透射电镜下可见此细胞为单核圆形或椭圆形细胞,核大,核膜双层,核内常染色体丰富,而异染色质很少.胞质中充满黑素体,多为Ⅱ和Ⅲ期,极少为Ⅰ、Ⅳ期.黑素体内的电子密度颗粒多排列成同心圆形,少数排列呈线状.胞质内高尔基复合体不明显.结论 毛囊内无色素黑素细胞超微结构不同于表皮黑素细胞,这种结构变化导致功能上的不成熟,无色素黑素细胞是成熟黑素细胞的贮库.     

拉坦前列素对体外培养的猪毛囊生长的影响

目的探讨拉坦前列素对体外培养的猪毛囊生物学特性的影响。方法采用猪毛囊体外培养模型,记录体外培养的猪毛囊生长速度和毛球部形态学改变,评价拉坦前列素对毛发生长的作用。结果与阴性对照组比较,拉坦前列素质量浓度达到0.8ng/mL时即能使培养的猪毛囊生长速度加快(P<0.05),并持续生长达8d,且毛囊毛球部仍然呈现生长期样形态,而对照组则表现为退行期/休止期样外观。结论拉坦前列素对体外培养的猪毛囊生长具有明显的促进作用。能够延长毛囊的生长期。     

女贞子等中药对小鼠毛囊生长周期中生长因子mRNA表达的影响

目的 探讨女贞子等中药促毛囊生长的机制。方法 我们应用RT-PCR技术和凝胶密度扫描分析技术,对正常生长周期中毛囊肝细胞生长因子(HGF)和血管内皮细胞生长因子(VEGF) mRNA表达水平,以及女贞子等中药对体外培养小鼠触须毛囊HGF和VEGFmRNA表达水平的影响进行了深入的研究。结果 我们的研究发现正常毛囊生长周期中,生长期毛囊有明显的HGF和VEGF mRNA表达,而退行/休止期毛囊则很难检测出上述因子mRNA的表达。在毛囊生长发育的过程中,HGF和VEGF mRNA表达也逐渐减弱。与女贞子混合培养的毛囊,在培养的第6天仍有相当量的HGF和VEGF mRNA表达,而相应的对照组则未能测到这些因子的表达。而与齐敦果酸培养的毛囊在培养的第6天仅有HGFmRNA表达,而无VEGF mRNA的表达。结论 女贞子及齐敦果酸可促进体外培养的毛囊对HGF和(或)VEGFmRNA的表达。从而从分子生物学水平揭示了上述药物促进毛囊生长的可能机制。     

T-oligos as differential modulators of human scalp hair growth and pigmentation: a new “time lapse system” for studying human skin and hair follicle biology in vitro?

Small DNA oligonucleotides homologous to the 3′ overhang of human telomeres, called T-oligos, stimulate pigmentation in human epidermal melanocytes in vitro and in vivo. They induce UV-mimetic effects in the absence of DNA-damage, however, it is unknown how T-oligos affect human hair follicle keratinocyte and melanocyte functions in situ. Here, we present the first evidence that these oligonucleotides are powerful modulators of pigmentation and growth of microdissected, organ-cultured human scalp hair follicles. Hair follicles were incubated with T-oligo or vehicle control and were then assessed for changes in hair shaft length, follicle morphology, pigmentation, proliferation and apoptosis. After only 48 h, T-oligos induced a fourfold increase in pigmentation of human anagen VI hair bulbs, while hair matrix keratinocyte proliferation was reduced by 65%, without apparent changes in hair bulb cell apoptosis. This corresponded well with a significant inhibition of hair shaft elongation, which was not accompanied by premature catagen induction in anagen VI hair follicles. These diametrically opposed effects of T-oligos on human hair follicle melanocytes (stimulation of melanogenesis) versus human hair bulb keratinocytes (inhibition of proliferation) in situ illustrate that human hair follicle organ culture offers an excellent tool for T-oligo research. They suggest that T-oligos deserve to be further explored for the management of clinical hair growth and pigmentation disorders, and raise the possibility that this model may offer a unique “time lapse system” for studying skin and hair follicle biology and DNA repair strategies under physiologically relevant conditions.     

Quantification of hair follicle parameters using computer image analysis: A comparison of androgenetic alopecia with normal scalp biopsies

Computer image analysis enables large numbers of hairs to be measured in an automated fashion. In this study, we examined horizontal scalp biopsies from 10 patients with a histological diagnosis of androgenetic alopecia and 10 normal control subjects. The density of hair follicles and the ratio of terminal to vellus hairs were determined. Hair shaft, hair canal and hair follicle diameter, inner root sheath width and outer root sheath area were measured using the Chromatic Colour Image Analysis program. This study showed a statistically significant progressive decrease in size of hair canal diameters from normal terminal hairs (85.93 ± 10.07 μm) through to androgenetic alopecia terminal (68.83 ± 13.60 μm) and vellus hairs (28.67 ± 5.60 μm). This pattern is also seen with hair follicle diameters; normal terminal (268.41 ± 24.88 μm), androgenetic alopecia terminal (236.34 ± 17.23 μm), and vellus hairs (130.88 ± 19.96 μm). Outer root sheath areas, hair shaft diameters and ratio of terminal to vellus hairs were significantly larger in normal (18500 ± 4222 μm²; 82.71 ± 13.79 μm; 36:1; respectively) compared with androgenetic alopecia scalp biopsies (8403 ± 3322 μm²; 61.11 ± 14.42 μm; 3:1; respectively), whereas inner root sheath width and density did not vary significantly. Computer image analysis can be adapted for use in clinical trials where large numbers and objectivity are critical in determining the efficacy of hair growth promoters.     

Human hair greying is linked to a specific depletion of hair follicle melanocytes affecting both the bulb and the outer root sheath

BACKGROUND: Although hair greying is a very common phenomenon characterized by loss of pigment in the hair shaft, the events that cause and control natural hair whitening with age in humans are still unclear. OBJECTIVES: To decipher the origin of natural hair whitening. METHODS: Human hair melanocytes were immunohistochemically characterized at different stages of whitening. RESULTS: Loss of hair shaft melanin was found to be associated with a decrease in both bulb melanin content and bulb melanocyte population. Although few melanocytes were present in the bulbs of grey hair, they still expressed tyrosinase and tyrosinase-related protein-1, synthesized and transferred melanins to cortical keratinocytes as seen by the presence of melanin granules. In white hair bulbs, no melanocytes could be detected either with pMel-17 or vimentin labelling. Pigmented hair follicles are known to contain inactive melanocytes in the outer root sheath (ORS), and grey and white hairs were also found to contain some of these quiescent melanocytes. However, their population was decreased compared with pigmented hair follicles, ranging from small to nil. This depletion of melanocytes in the different areas of white hairs was detected throughout the hair cycle, namely at telogen and early anagen stages. In contrast, the infundibulum and sebaceous gland of both pigmented and white hairs showed a similar distribution of melanocytes. Furthermore, other distinct cell populations located in the ORS, namely putative stem cells, Merkel cells and Langerhans cells were equivalently identified in pigmented and white hairs. CONCLUSIONS: Thus, hair greying appears to be a consequence of an overall and specific depletion of bulb and ORS melanocytes of human hair.     

Reduction of regrowing hair shaft size and pigmentation after ruby and diode laser treatment

Laser pulses which selectively damage pigmented hair follicles are a useful treatment for hypertrichosis. Clinically, regrowing hairs are often thinner and lighter after treatment. In this study, hair shaft diameter and optical transmission (700 nm) were measured before and after ruby (694 nm) and diode (800 nm) laser irradiation. Hair was collected from 47 and 41 subjects treated with ruby (0.3 ms and 3 ms) and diode (10-20 ms) lasers, respectively. "Responders" were defined as subjects with significant long-term hair loss as determined by hair counts at 9 and/or 12 months after treatment. In ruby laser responders (34/47), regrowing hairs were significantly both thinner (decreased diameter) and lighter (increased transmission). In "nonresponders" (13/47), regrowing hairs were lighter, but not thinner. The regrowing hair shaft absorption coefficient (as calculated assuming Beer's law) was significantly decreased by 0.3 ms ruby laser treatment, but was not changed by 3 ms ruby laser or diode laser treatment. After diode laser treatment, 38 of the 41 subjects were responders and regrowing hairs were both thinner and lighter. These results show that laser treatments can affect structural recovery (size of hair), follicular pigmentation (hair absorption coefficient), or both. Regrowth of thinner hair (decreased shaft diameter) occurs in conjunction with actual loss of hair. After long pulses (3 ms ruby; diode), regrowing hair was thinner and also lighter to an extent related to the decrease in hair diameter. In contrast, short ruby laser pulses (0.3 ms) appeared to be capable of inhibiting follicular pigmentation per se, in addition to affecting the hair diameter. This may account for the complete regrowth of lighter hair in "nonresponders" treated with 0.3 ms pulses. Laser-induced reduction in hair diameter and/or pigmentation are both long-term responses which confer cosmetic benefits in addition to actual hair loss.     

Expression Pattern and Role of Klotho in Human Hair Follicles

BackgroundKlotho protein plays a pivotal role in aging regulation. However, it is unclear whether klotho is expressed in human hair follicles and is correlated with hair growth.ObjectiveThe purpose of this study was to determine the expression pattern and role of klotho in human hair follicles.MethodsWe examined the klotho expression patterns in human hair follicles from young and aged donors. Furthermore, we examined the functional roles of klotho on human hair growth using klotho siRNA and klotho recombinant protein.ResultsInterestingly, klotho was expressed in human hair follicles at both gene and protein levels. In hair follicles, prominent klotho expression was mainly observed in the outermost regions of the outer root sheath and hair bulb matrix cells. Quantification of klotho protein expression in young and aged donors showed that klotho expression decreased with aging. In human hair follicle organ culture, klotho silencing promoted premature catagen induction and inhibited human hair growth. Otherwise, klotho protein prolonged human hair growth.ConclusionThese results indicate that klotho might be an important regulatory factor for human hair growth and hair cycle change.     

Hair shaft abnormalities in alopecia areata evaluated by optical coherence tomography

Background/purpose: Optical coherence tomography (OCT) is able to provide highly reproducible measurements of hair shaft thickness, including hair shaft diameter, cross‐sectional surface area and hair shape, similar to histology but in vivo. Variations in the caliber of hair shafts have been described in patchy hair loss like alopecia areata (AA) using electron microscopy. The aim of this study was to evaluate whether OCT is useful for the evaluation of hair shaft abnormalities in AA. Methods: The measurements were performed on patients with AA (n=9), aged 2–66 years. Fifty hairs from the border of an alopecic area and 50 hairs from an unaffected area without hair loss were examined using the OCT technique. The hair parameters were characterized by the cross‐section (CS) and the form factor. The ratio of the maximal and minimal diameters of the hair at a fixed measuring distance from the scalp surface determined the form factor (d_max/d_min). Results: In all cases, the CS of hairs from an AA patch was significantly lower compared with hairs of an unaffected area. However, the form factor did not indicate any disturbances in hair growth. Conclusions: The results demonstrate that structural abnormalities of hair shafts are found in active lesions of AA, but not in clinically unaffected hairs. The OCT technique is a promising method to gain more insight into the pathogenesis of AA in a non‐invasive way.     

Physiology of the vellus hair follicle: hair growth and sebum excretion

The growth of vellus hair and the secretion of sebum from vellus hair follicles were measured on the forehead, cheek, chest, shoulder and back of healthy men and women aged 15-30 years. Hair growth was assessed by computerized image-analysis of photographs and sebum excretion by the use of Sebutape followed by image analysis. The density of vellus hairs and the percentage of growing hairs were higher on the face than on the thorax (439 hairs/cm2 with 49% growing hairs on the forehead compared with 85 hairs/cm2 with 31.5% growing hairs on the back). The rate of growth ranged from 0.03 mm/day on the forehead to 0.13 mm/day on the back. The maximum length of vellus hair significantly decreased with age; otherwise hair growth was not affected by age or sex. Some variations in hair growth and sebum secretion were observed over a period of 3 months, but no consistent rhythms were detected. There was no obvious link between vellus hair growth and sebum excretion.     

毛囊色素

毛发的颜色主要取决于毛囊色素(优黑素/褐黑素)的合成与表达,黑素颗粒由黑素细胞合成,并向皮质及角质形成细胞转运,最终沉积于毛干内,上述过程主要包括了毛囊黑素细胞的发育,黑素颗粒在毛囊中的合成和转运,黑素细胞的调控,黑素颗粒在毛干上的沉积以及毛囊色素单元的老化。