Fibroblast morphology,growth rate and gene expression in facial melasma

BackgroundIn addition to melanocytic hyperfunction, changes are observed in the upper dermis of melasma, and fibroblasts play a central role in collagen synthesis and pigmentation induction.ObjectiveTo explore the morphology, growth rate, and gene expression profile of fibroblasts from the skin with melasma in comparison to fibroblasts from the adjacent healthy skin.MethodsTen women with facial melasma were biopsied (lesion and adjacent healthy skin), and the fragments were processed for fibroblast culture. Samples from five participants were seeded to evaluate growth (days 2, 5 and 8) and senescence (SA-β-gal) curves. The samples from the other participants were submitted to real-time PCR to comparatively evaluation of the expression of 39 genes.ResultsCultured fibroblasts from melasma skin were morphologically less fusiform in appearance and on average a 34% (95% CI 4%?63%) greater proportion of cells labeled with SA-β-gal than the fibroblasts from the adjacent skin. The cell growth rate was lower for the melasma samples after eight days (p < 0.01). TheWNT3A, EDN3, ESR2, PTG2, MMP1, and SOD2 genes were up-regulated, whereas the COL4A1, CSF2, DKK3, COL7A1, TIMP4, CCL2, and CDH11 genes were down-regulated in melasma skin fibroblasts when compared to the ones from adjacent healthy skin.Study limitationsSmall sample size; absence of functional tests.ConclusionsFibroblasts from the skin with melasma showed a lower growth rate, less fusiform morphology and greater accumulation of SA-β-gal than those from adjacent photo exposed skin. Moreover, their gene expression profile comprised factors that may contribute to upper dermis damage and sustained melanogenesis.     

Hypomelanosis of Ito with Multiple Congenital Anomalies

Hypomelanosis of Ito (HI) is a neurocutaneous disorder, also known as incontinentia pigmenti achromians. HI has been associated with chromosomal abnormalities, especially mosaicism. Herein, we report a case of HI with multiple congenital anomalies. A 2-month-old girl presented with multiple linear and whorling hypopigmentation on the face, trunk, and both extremities and patch alopecia on the scalp. Moreover, she had conical teeth, aniridia of the both eyes, and multiple musculoskeletal problems, including syndactyly and coccyx deviation. Cytogenetic analysis on peripheral blood was normal 46, XX, and no mutation was found in IKBKG gene test.     

Acquired hyperpigmentations

Cutaneous hyperpigmentations are frequent complaints, motivating around 8.5% of alldermatological consultations in our country. They can be congenital, with differentpatterns of inheritance, or acquired in consequence of skin problems, systemicdiseases or secondary to environmental factors. The vast majority of them are linkedto alterations on the pigment melanin, induced by different mechanisms. This reviewwill focus on the major acquired hyperpigmentations associated with increasedmelanin, reviewing their mechanisms of action and possible preventive measures.Particularly prominent aspects of diagnosis and therapy will be emphasized, withfocus on melasma, post-inflammatory hyperpigmentation, periorbital pigmentation,dermatosis papulosa nigra, phytophotodermatoses, flagellate dermatosis, erythemadyschromicum perstans, cervical poikiloderma (Poikiloderma of Civatte), acanthosisnigricans, cutaneous amyloidosis and reticulated confluent dermatitis     

Mechanisms regulating melanogenesis

Skin pigmentation is an important human phenotypic trait whose regulation, in spiteof recent advances, has not yet been fully understood. The pigment melanin isproduced in melanosomes by melanocytes in a complex process called melanogenesis. Themelanocyte interacts with endocrine, immune, inflammatory and central nervoussystems, and its activity is also regulated by extrinsic factors such as ultravioletradiation and drugs. We have carried out a review of the current understanding ofintrinsic and extrinsic factors regulating skin pigmentation, the melanogenesisstages and related gene defects. We focused on melanocyte-keratinocyte interaction,activation of melanocortin type 1 receptor (MC1-R) by peptides(melanocyte-stimulating hormone and adrenocorticotropic hormone) resulting fromproopiomelanocortin (POMC) cleavage, and mechanisms of ultraviolet-induced skinpigmentation. The identification and comprehension of the melanogenesis mechanismfacilitate the understanding of the pathogenesis of pigmentation disorders and thedevelopment of potential therapeutic options.     

Influence of ethanol dose and pigmentation on the incorporation of ethyl glucuronide into rat hair

Ethyl glucuronide (EtG) is a minor and specific metabolite of ethanol. It is incorporated into growing hair, allowing a retrospective detection of alcohol consumption. However, the suitability of quantitative EtG measurements in hair to determine the quantity of alcohol consumed has not clearly been demonstrated yet. The purpose of this study was to evaluate the influence of ethanol dose and hair pigmentation on the incorporation of EtG into rat hair. Ethanol and EtG kinetics in blood were investigated after a single administration of ethanol.Eighteen rats were divided into four groups receiving 0 (control group), 1, 2, or 3 g ethanol/kg body weight. Ethanol was administered on 4 consecutive days per week for 3 weeks by intragastric route. Twenty-eight days after the initial ethanol administration, newly grown hair was shaved. Pigmented and nonpigmented hair were analyzed separately by gas chromatography coupled to tandem mass spectrometry. Blood samples were collected within 12 h after the ethanol administration. EtG and ethanol blood levels were measured by liquid chromatography coupled to tandem mass spectrometry and headspace gas chromatography-flame ionization detector, respectively. No statistically significant difference was observed in EtG concentrations between pigmented and nonpigmented hair (Spearman's rho = 0.95). Thus, EtG incorporation into rat hair was not affected by hair pigmentation. Higher doses of ethanol resulted in greater blood ethanol area under the curve of concentration versus time (AUC) and in greater blood EtG AUC. A positive correlation was found between blood ethanol AUC and blood EtG AUC (Spearman's rho = 0.84). Increased ethanol administration was associated with an increased EtG concentration in hair. Blood ethanol AUC was correlated with EtG concentration in hair (Pearson's r = 0.89). EtG concentration in rat hair appeared to reflect the EtG concentration in blood. Ethanol was metabolized at a median rate of 0.22 g/kg/h, and the median elimination half-life of EtG was 1.21 h. This study supports that the bloodstream is likely to display a major role in the hair EtG incorporation.     

点阵铒激光治疗面部皮肤老化

目的探讨点阵铒激光治疗面部皮肤老化的有效性和安全性。方法面部皮肤老化患者150例,以点阵铒激光垂直扫描照射面部皮肤老化区。激光能量600～1000 mJ,光斑直径3.5或7 mm。照射至被照射区皮肤出现点状出血为止,共照射2次。以治疗后皮肤的肤色、毛细血管扩张、毛孔粗大、色素沉着和皮肤变化的改善程度判断疗效。结果治疗后肤色、毛细血管扩张、毛孔粗大、色素沉着及皮肤质地5项指标的症状积分均有较显著下降,治疗前症状积分均在中度,治疗后均达轻度,其中色斑评分下降最多,最少的是毛细血管扩张。结论点阵铒激光治疗面部皮肤老化安全性较高,疗效较好,副作用小,不影响患者的学习及工作。     

Pigmentation and the chemcial basis of schizophrenia.

Using a Lovibond flexible fibro-optic tintometer, no differences of skin pigmentation were found between chronic male schizophrenic patients untreated with phenothiazines, and non-schizophrenics. No differences were found between chronic male schizophrenics receiving phenothiazines and those not so treated. This latter comparison may however be questioned on the grounds that the treatment had consisted not of chlorpromazine alone (which is particularly associated with pigmentation), but of a variety of drugs, including fluphenazine. An ideal, chronically treated group proved impossible to assemble. No support is thus provided for the hypothesis proposed by Greiner & Nicholson linking the supposed chemical basis of schizophrenia with pigmentation.     

Characterization of the brown pigment of the mucosa of the urinary tract

Summary The brownish discoloration of the mucosa of the urinary tract which is present in 10–42% of the patients with chronic abuse of analgesics containing phenacetin is, like the discoloration of liver, skin and cartilage, due to lipids similar in type to those in the lipid component of lipofuscin. Offprint requests to: M.J. Mihatsch at the above address     

Pigmentation after single and multiple UV-exposures depending on UV-spectrum

Minimal pigmentation dose (MMD) after a single UV-exposure is well investigated. Whereas only few studies have established MMD after multiple UV-exposures and mainly in fair-skinned persons. The purpose of this study was to establish MMD 1 week after, respectively, one and five UV-exposures in volunteers with a large variation in constitutive pigmentation. A total of 52 volunteers (skin Types II–V) had skin pigmentation quantified by reflectance spectroscopy. They were UV-exposed on the back for 1 and 5 days using a Solar Simulator, narrowband UVB, broadband UVA and UVA1. For all sources a higher dose was needed the more pigmented the skin, except for UVA1. After one UV-exposure, we found a significant positive linear correlation between UV-dose to one MMD, skin type and pre-exposure skin pigmentation. After five UV-exposures the positive linear correlation between UV-dose and MMD and skin type was only significant for narrow band UVB, pre-exposure skin pigmentation was significant also for Solar Simulator. For UVA and particularly UVA1 the MMD was independent of pre-exposure pigmentation. The number of SED to MMD is therefore almost the same for very fair-skinned and dark-skinned persons. Pre-exposure pigmentation was clearly more predictive of MMD than skin type. 50% of MMD equals a pigmentation increase of 1%. The shorter the wavelengths the higher the SED to produce MMD. Solar was the least melanogenic and UVA1 the most melanogenic. For the UVB-sources a higher dose was needed the more pigmented the skin. For UVA the MMD was independent of pre-exposure pigmentation.     

The utility of surface reflectance for the recognition of upright and inverted faces

The variation among faces can be partitioned into two sources: (a) shape and (b) surface reflectance. To compare the utility of shape and reflectance for face recognition, we created two sets of faces, with individual exemplars differing only by shape in one set and only by reflectance in the other set. Grayscale and full color versions of the stimuli were used in separate experiments; the physical variation between exemplars was equated across the two sets with the grayscale but not the full color stimuli. Subjects performed a matching task in which both the target and distractor were drawn from the same set, so that only shape or only reflectance information could be used to perform the task. With the grayscale stimuli, performance was better in the shape condition, but with the color stimuli, performance was better in the reflectance condition. Inversion of the faces disrupted performance with the shape and reflectance sets about equally, suggesting that the inversion effect is not caused specifically by the spacing of facial features, or even by shape information more generally. These results provide evidence that facial identity is a function of reflectance as well as shape, and place important constraints on explanations of why inversion impairs face recognition.