迷迭香酸对人表皮黑素细胞黑素生成的影响

目的探讨迷迭香酸(rosmarinic acid)对体外培养的人表皮黑素细胞黑素生成的影响。方法取对数生长期的人表皮黑素细胞,分别加入不同浓度的迷迭香酸进行实验。MTT法测定体外培养的人黑素细胞活力,NaOH裂解法测定黑素含量,体外氧化多巴反应方法测定酪氨酸酶活性。结果与对照组相比,10～80μmol/L迷迭香酸对黑素细胞活力无明显影响,而100μmol/L迷迭香酸抑制黑素细胞活力(P0.01);10～80μmol/L迷迭香酸呈浓度依赖性促进黑素细胞黑素合成;10～80μmol/L迷迭香酸对蘑菇酪氨酸酶活性无明显影响(P0.05);20～80μmol/L迷迭香酸对黑素细胞酪氨酸酶活性有促进作用(P0.01)。结论迷迭香酸具有促进人表皮黑素细胞黑素生成的作用。     

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.     

甲氧沙林脂质体对小鼠黑素瘤细胞黑素生成影响的研究

目的:探讨甲氧沙林脂质体(8-MOPL)对小鼠B16F黑素瘤细胞增殖、黑素含量、酪氨酸酶活性的影响。方法:采用体外培养的小鼠B16F黑素瘤细胞株,以等浓度的甲氧沙林(8-MOP)为对照,用四甲基偶氮唑蓝(MTT)法测定细胞增殖情况;NaOH裂解法测定黑素合成;多巴氧化法测定酪氨酸酶活性。结果:与等浓度8-MOP相比,低浓度8-MOPL(10-25μmol/L)能显著提高酪氨酸酶活性和黑素含量(P<0.05)。高浓度8-MOPL(100-200μmol/L)对细胞的抑制作用更显著(P<0.05)。结论:用脂质体作为8-MOP的载体可以显著提高8-MOP对靶细胞的作用,为8-MOPL制剂治疗白癜风的临床应用提供了实验依据。     

甲氧沙林对体外培养的人毛囊外根鞘无色素黑素细胞的激活作用

目的:观察甲氧沙林(8-MOP)对体外培养的人毛囊外根鞘无色素黑素细胞黑素合成相关酶的影响。方法:3种浓度(10、50、100μmol/L)的8-MOP作用于体外培养的人毛囊外根鞘无色素黑素细胞,经免疫荧光染色后,采用激光共聚焦显微镜观察不同浓度、不同作用时间的8-MOP对无色素黑素细胞形态的影响,荧光定量分析酪氨酸酶、酪氨酸相关蛋白(TRP)1、TRP2表达量的变化。结果:50、100μmol/L8-MOP作用于人毛囊外根鞘无色素黑素细胞3d能显著促进酪氨酸酶的表达(P<0.01)熏作用7d后TRP1、TRP2的表达也增加(P<0.05)。结论:8-MOP在体外能直接刺激毛囊外根鞘无色素黑素细胞的活化。     

8－甲氧补骨脂素对小鼠黑素瘤细胞黑素生成的调节及相关信号转导研究

目的研究光化疗法中光敏剂8 -甲氧补骨脂素(8 -MOP)在诱导白癜风色素减退皮损复色过程中所起的作用及其分子机制。方法用体外培养的B16F10鼠黑素瘤细胞作模型 ,观察了不同浓度(10～500μmol/L)8 -MOP对B16F10细胞的形态、酪氨酸酶活性和黑素含量的影响。结果50或100μmol/L浓度的8 -MOP处理细胞48h后 ,B16F10细胞的树状突明显增多延长 ,胞浆内出现较多的棕褐色颗粒。8 -MOP并能以浓度依赖方式提高酪氨酸酶活性和黑素含量 ,较对照组高2～3倍(P<0.01),且在50、100μmol/L浓度时这种作用呈现最强。此外还发现8 -MOP尚能浓度依赖地抑制细胞生长 ,100μmol/L时与对照组相比细胞抑制高达60 % ,500μmol/L时细胞几乎不能生长。用蛋白激酶A或C的激活剂 ,异丁基甲基黄嘌呤 (IBMX)和佛波酯 (TPA)与8 -MOP联合处理细胞发现8 -MOP诱导黑素生成作用能被IBMX加强 ,被长时程作用的TPA抑制。结论8 -MOP能以浓度依赖方式提高酪氨酸酶活性和黑素含量,在体外直接诱导鼠黑素瘤细胞黑素生成 ,蛋白激酶A和蛋白激酶C信号途径参与8 -MOP诱导黑素生成作用的调节。     

姜黄素对正常人表皮黑素细胞黑素生成的影响

目的研究姜黄素对体外培养的正常人表皮黑素细胞黑素生成及酪氨酸酶活性的影响。方法采用MTT法测定姜黄素对人表皮黑素细胞的活力的影响,体外氧化DOPA反应方法测定酪氨酸酶活性,NaOH法测定黑素生成量。结果姜黄素在浓度小于或等于10μmol/L时无明显细胞毒性。姜黄素在浓度大于或等于2.5μmol/L时呈剂量依赖性抑制酪氨酸酶活性,减少黑素生成,差异具有统计学意义(P<0.01)。结论姜黄素抑制培养的人表皮黑素细胞的黑素生成,可能具有开发成为美白产品的前景。     

芦荟素抑制人表皮黑素细胞酪氨酸酶的最佳浓度选择

目的:研究抑制人表皮黑素细胞酪氨酸酶的芦荟素最佳浓度。方法:选择不同浓度的中药单体芦荟素(分别为0.010、0.001、0.100、1.000和10.000mmol/L),作用于体外培养的人表皮黑素细胞,测定黑素细胞增殖率、酪氨酸酶活性和黑素含量。结果:10.000mmol/L芦荟素组导致黑素细胞死亡;与正常对照组相比,芦荟素浓度大于0.100mmol/L的黑素细胞增殖率明显下降(P<0.05);所有实验组黑素细胞的酪氨酸酶活性和黑素含量都显著降低(P<0.001)。结论:低浓度的芦荟素(0.001～0.010mmol/L)在不影响黑素细胞增殖的情况下可以显著抑制酪氨酸酶活性和黑素的合成。     

山柰素与熊果苷对体外培养人正常黑素细胞的作用

目的比较山柰素与熊果苷对体外培养人正常黑素细胞增殖、黑素合成及其酪氨酸酶活性的影响,为探索色素沉着性皮肤病的发病机制以及筛选新的治疗药物提供理论依据。方法以不同浓度(1～100μmol/L)山柰素与熊果苷干预体外培养的人正常黑素细胞,比较两者对黑素细胞的黑素含量、细胞增殖及其酪氨酸酶活性的影响。结果对于黑素细胞酪氨酸酶活性和黑素含量的抑制作用,山柰素在各个浓度均优于熊果苷,差异有统计学意义(P<0.05),山柰素对细胞增殖抑制率无明显影响,而熊果苷在各浓度对细胞增殖抑制作用显著,且随其浓度增加,抑制率逐渐增强。结论山柰素对黑素细胞酪氨酸酶活性及黑素合成的抑制作用强于熊果苷,并对黑素细胞的增殖及形态无明显的负面影响,是一种有良好应用前景的酪氨酸酶抑制剂。     

欧前胡素抑制人表皮黑素细胞黑素生成

目的：评价欧前胡素对培养人表皮黑素细胞黑素生成的作用。方法：体外分离、纯化培养人表皮黑素细胞。随机分为空白组、熊果苷组和欧前胡素组（12．5μM,25μM和50μM）,作用48h,观察黑素细胞形态．检测黑素细胞活力、酪氨酸酶活性和黑素含量,免疫荧光显微镜观察欧前胡素对黑素细胞酪氨酸酶的影响。结果：不同浓度（0、12．5μM、25μM和50μM）欧前胡素作用于黑素细胞48h后,细胞活力分别为100％、107．8％、87．5％和59．7％。低浓度欧前胡素不影响黑素细胞形态,高浓度（50μM）对黑素细胞活力、酪氨酸酶活性、黑素含量有抑制作用,呈剂量依赖性。欧前胡素对酪氨酸酶蛋白在细胞内定位未见明显影响,但酪氨酸酶荧光强度降低。结论：欧前胡素抑制体外培养人表皮黑素细胞酪氨酸酶活性而降低黑素生成。     

吡美莫司对人黑素细胞黑素合成的影响

目的:评价吡美莫司在体外对人表皮黑素细胞酪氨酸酶活性及黑素生成的影响.方法:培养人原代表皮黑素细胞,利用四甲基偶氮唑蓝(MTT)还原法测定细胞活力,采用酶学方法测定酪氨酸酶活性,氢氧化钠法测定黑素含量.结果:随着剂量的增高,1 nmol/L、10 nmol/L、100 nmol/L及1μmol/L吡美莫司对黑素细胞的酪氨酸酶活性(分别为112.87%,117.29%,120.49%和123.97%)和黑素生成(分别为118.92%,122.55%,128.25%和134.48%)的促进作用逐渐增强,10 nmol/L、100 nmol/L及1μmol/L吡美莫司与对照组相比差异有统计学意义(P<0.01).结论:吡美莫司对人表皮黑素细胞的酪氨酸酶活性和黑素生成有较强的促进作用.     

New fillers for the new man

ABSTRACT:  Two new collagen-based lidocaine-containing dermal fillers, ArteSense™/ArteFill™ (Artes Medical, San Diego, CA) and Evolence® (Colbar LifeScience Ltd., Herzliya, Israel), have proved to be of particular interest to men, many of whom seek a long-lasting or permanent correction. ArteFill™ has been available in the United States since 2006, and it is expected that Evolence® will reach the American market in 2008. The properties of the two products will be described, and experience based on the administration of many hundreds of syringes of both products by a Canadian dermatologist will be detailed here, with tips and precautions to optimize patient outcomes.     

Outcomes and adverse effects of ablative vs nonablative lasers for skin resurfacing: A systematic review of 1093 patients

It is generally believed that ablative laser therapies result in prolonged healing and greater adverse events when compared with nonablative lasers for skin resurfacing. To evaluate the efficacy of ablative laser use for skin resurfacing and adverse events as a consequence of treatment in comparison to other modalities, a PRISMA‐compliant systematic review (Systematic Review Registration Number: 204016) of twelve electronic databases was conducted for the terms “ablative laser” and “skin resurfacing” from March 2002 until July 2020. Studies included meta‐analyses, randomized control trials, cohort studies, and case reports to facilitate evaluation of the data. All articles were evaluated for bias. The search strategy produced 34 studies. Of 1093 patients included in the studies of interest, adverse events were reported in a total of 106 patients (9.7%). Higher rates of adverse events were described in nonablative therapies (12.2% ± 2.19%, 31 events) when compared with ablative therapy (8.28% ± 2.46%, 81 events). 147 patients (13.4%) reported no side effects, 68 (6.22%) reported expected, transient self‐resolving events, and five (0.046%) presented with hypertrophic scarring. Excluding transient events, ablative lasers had fewer complications overall when compared with nonablative lasers (2.56% ± 2.19% vs 7.48% ± 3.29%). This systematic review suggests ablative laser use for skin resurfacing is a safe and effective modality to treat a range of pathologies from photodamage and acne scars to hidradenitis suppurativa and posttraumatic scarring from basal cell carcinoma excision. Further studies are needed, but these results suggest that ablative lasers are a superior, safe, and effective modality to treat damaged skin.     

Genetic alterations in RAS‐regulated pathway in acral lentiginous melanoma

Studies integrating clinicopathological and genetic features have revealed distinct patterns of genomic aberrations in Melanoma. Distributions of BRAF or NRAS mutations and gains of several oncogenes differ among melanoma subgroups, while 9p21 deletions are found in all melanoma subtypes. In the study, status of genes involved in cell cycle progression and apoptosis was evaluated in a panel of 17 frozen primary acral melanomas. NRAS mutations were found in 17% of the tumors. In contrast, BRAF mutations were not found. Gains of AURKA gene (20q13.3) were detected in 37.5% of samples, gains of CCND1 gene (11q13) or TERT gene (5p15.33) in 31.2% and gains of NRAS gene (1p13.2) in 25%. Alterations in 9p21 were identified in 69% of tumors. Gains of 11q13 and 20q13 were mutually exclusive, and 1p13.2 gain was associated with 5p15.33. Our findings showed that alterations in RAS‐related pathways are present in 87.5% of acral lentiginous melanomas.     

Self‐resolving superficial primary cutaneous mucormycosis in a 7‐week‐old infant

A 7‐week‐old girl, born at 30 weeks' gestational age, presented to clinic for evaluation of a crop of vesicular lesions that were noted after removal of a bandage that had been in place for 4 days. A punch biopsy of the lesion revealed fungal elements that were later identified as Rhizopus spp. The lesion began to self‐resolve, and no further treatment was needed, with full resolution of the lesion by 1 month after presentation. Clinicians should be aware of the variable presentations of mucormycosis and consider fungal infection in the differential diagnosis when evaluating vulnerable patients with skin eruptions.     

Multiple New-Onset Subcutaneous Nodules of the Upper Extremity Digits: Giant Cell Tumor of Tendon Sheath and Lipoma

A black woman with the concurrent onset of two subcutaneous nodules located on the digits of her upper extremities is described. Initially, a single systemic disorder was considered; yet, the lesions differed in morphology and consistency. Microscopic examination of the nodules showed a giant cell tumor of tendon sheath and a lipoma. Although Occam's “razor” suggests that multiple lesions in the same person are more likely to represent variable manifestations of a single disorder than several different diseases in that individual, the simultaneously appearing lesions in this patient represented two different conditions.