Home About us Contact
|
Home About us Contact | ||
|
|
||
Epidermal Thickness (epidermal + thickness)
Selected AbstractsIntrinsic aging vs. photoaging: a comparative histopathological, immunohistochemical, and ultrastructural study of skinEXPERIMENTAL DERMATOLOGY, Issue 5 2002M. El-Domyati Abstract: Cutaneous aging is a complex biological phenomenon affecting the different constituents of the skin. To compare the effects of intrinsic and extrinsic aging processes, a total of 83 biopsies were collected from sun-exposed and protected skin of healthy volunteers representing decades from the 1st to the 9th (6,84 years of age). Routine histopathology coupled with computer-assisted image analysis was used to assess epidermal changes. Immunoperoxidase techniques with antibodies against type I and type III collagens and elastin were used to quantitatively evaluate changes in collagen and elastic fibers and their ultrastructure was examined by transmission electron microscopy. Epidermal thickness was found to be constant in different decades in both sun-exposed and protected skin; however, it was significantly greater in sun-exposed skin (P = 0.0001). In protected skin, type I and III collagen staining was altered only after the 8th decade, while in sun-exposed skin the relative staining intensity significantly decreased from 82.5% and 80.4% in the 1st decade to 53.2% and 44.1% in the 9th decade, respectively (P = 0.0004 and 0.0008). In facial skin the collagen fiber architecture appeared disorganized after the 4th decade. The staining intensity of elastin in protected skin significantly decreased from 49.2% in the 1st decade to 30.4% in the 9th decade (P = 0.05), whereas in sun-exposed skin the intensity gradually increased from 56.5% in the 1st decade to 75.2% in the 9th decade (P = 0.001). The accumulated elastin in facial skin was morphologically abnormal and appeared to occupy the areas of lost collagen. Collectively, the aging processes, whether intrinsic or extrinsic, have both quantitative and qualitative effects on collagen and elastic fibers in the skin. [source] Effects of moisturization on epidermal homeostasis and differentiationCLINICAL & EXPERIMENTAL DERMATOLOGY, Issue 1 2007R. W. Short Summary Moisturizers are commonly used for routine skin care. This study assessed the effects of a moisturizer on barrier function, epidermal architecture, keratinocyte proliferation, and physiological regulation of the epidermis in photoaged but otherwise normal skin. Fifteen women with moderately photoaged forearms were treated twice a day for 4 weeks with a moisturizer containing dimethicone and glycerine. Baseline and post-treatment transepidermal water loss (TEWL) and ipsilateral forearm biopsies were obtained. Epidermal thickness, melanin levels, keratinocyte proliferation, and expression of keratins were evaluated. Induction of keratins 6 and 16, commonly associated with keratinocyte proliferation and wound healing, was observed. Epidermal thickness increased by 0.019 mm (P = 0.005), barrier function improved (TEWL decreased by 13%) and melanin intensity decreased (P = 0.004). Even nonxerotic, photoaged skin may appear younger, benefiting structurally and functionally from routine use of moisturizers containing dimethicone and glycerine. [source] Effect of Laser Resurfacing on p53 Expression in Photoaged Facial SkinDERMATOLOGIC SURGERY, Issue 6 2007MOETAZ M. EL-DOMYATI MD BACKGROUND p53 overexpression has been reported in photoaged skin. Meanwhile, p53 gene mutations have been implicated as an important factor in the pathogenesis of ultraviolet (UV) light,induced skin cancer. OBJECTIVE The objective was to evaluate the effect of laser resurfacing on the epidermal thickness and expression of p53 in photoaged skin. METHODS Specimens were obtained from the facial skin of 10 patients before and after 3 months and 1 year of treatment using CO2 (five cases) and erbium (Er):YAG (five cases) lasers. Specimens were also obtained from six age-matched controls. These biopsies were used for routine histopathology, histometry, and p53 immunoperoxidase staining. RESULTS Both CO2 and Er:YAG lasers were found to induce a significant decrease in p53 expression in biopsies obtained after 3 months (p=.0004 and .002, respectively) followed by gradual increase (p=.01 in both groups). A significant increase (p<.01) in epidermal thickness was also observed after 1 year of resurfacing. This increase, however, is inversely correlated with the level of p53 expression in such patients. CONCLUSION The decrease in epidermal p53 expression after CO2 and Er:YAG lasers may account for some of the benefits of resurfacing on the epidermis, as well as prevention of actinic neoplasia by adjusting any disturbance in the proliferation/apoptosis balance observed in photoaged facial skin. [source] Gross and Microscopic Findings in Patients Submitted to Nonablative Full-Face Resurfacing Using Intense Pulsed Light: A Preliminary StudyDERMATOLOGIC SURGERY, Issue 8 2002Enrique Hernández-Pérez MD background. Intense pulsed light (IPL) is a noncoherent, nonlaser, filtered flashlamp emitting a broadband visible light that has been shown to be effective in photoepilation, as well as in a number of vascular and pigmented lesions of the skin. Their efficacy has also been reported recently in the treatment of photodamaged facial skin. In the last condition, however, there are few studies showing the clinical and microscopic changes produced by IPL. objective. To assess the gross and microscopic changes that occur in photodamaged skin submitted to nonablative full-face resurfacing (NAFFR) using IPL. methods. Five women were submitted to five NAFFR sessions using IPL, one every 2 weeks. Skin biopsies and photographs were taken on all of the patients before the first procedure and after the last one, as well as weekly clinical assessment. Data concerning skin features (wrinkles, oiliness, thickness, dilated pores, and general appearance) were all assessed. Microscopic improvement of the aging features in the epidermis and dermis were all assessed. For the statistical analysis a t test for small samples was used. results. All the patients showed clinical and microscopic improvement in every one of the parameters assessed. The t test for small samples showed a statistically significant difference (P < 0.01) in epidermal thickness. conclusion. Facial photodamage was clinically and microscopically improved using IPL. Use of IPL as a rejuvenating method seems to be promising, with minimal side effects, a wide safety margin, and minimal downtime. [source] Gastrin-Releasing Peptide, a Bombesin-like Neuropeptide, Promotes Cutaneous Wound HealingDERMATOLOGIC SURGERY, Issue 4 2002Yuji Yamaguchi MD Background. Little is known about the effects of neuropeptides on wound healing. Objective. To investigate the effect of gastrin-releasing peptide (GRP), one of the bombesin-like neuropeptides, on wound healing. Methods. The effects of GRP on cultured keratinocyte proliferation and migration were measured by BrdU uptake and in vitro scratch assay, respectively. Various concentrations of GRP ointments (0, 10,9, 10,8, 10,7, 10,6 M) were topically applied to 1.0 mm wounds on porcine flanks. Results. GRP stimulated keratinocyte growth and locomotion in a dose-dependent manner. Topical administration of GRP accelerated macroscopic epidermal regeneration in a dose-dependent manner, as measured by planimetry. Histologic studies also showed that GRP promoted reepithelialization, including epidermal thickness as well as superficial skin coverage. conclusion. Topical use of GRP may clinically accelerate wound healing of burns, injuries, chronic ulcers, and skin graft donor sites through the enhancement of keratinocyte growth and spreading. [source] Topical treatment with thiazolidinediones, activators of peroxisome proliferator-activated receptor-,, normalizes epidermal homeostasis in a murine hyperproliferative disease modelEXPERIMENTAL DERMATOLOGY, Issue 3 2006Marianne Demerjian Abstract:, In a murine model of epidermal hyperplasia reproducing some of the abnormalities of several common skin disorders, we previously demonstrated the antiproliferative and pro-differentiating effects of peroxisome proliferator-activated receptor (PPAR),, PPAR,/,, and liver X receptor activators. Unlike other subgroups of PPAR activators, thiazolidinediones (TZDs), a family of PPAR, ligands, did not inhibit keratinocyte proliferation in normal murine skin. Here, we studied the effects of two TZDs, namely ciglitazone (10 mM) and troglitazone (1 mM), in the same murine model where epidermal hyperproliferation was reproduced by repeated barrier abrogation with tape stripping. Topical treatment with ciglitazone and troglitazone resulted in a marked and significant decrease in epidermal thickness. Furthermore, in all TZD-treated groups, we observed a significant decrease in keratinocyte proliferation using proliferating cell nuclear antigen, 5-bromo-2,-deoxyuridine, and tritiated thymidine incorporation. However, using the terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling assay, we found no difference in apoptosis between different treatments, emphasizing that it is the antiproliferative role of these activators that accounts for the decrease of epidermal thickness. Finally, using immunohistochemical methods, we determined the effects of ciglitazone on keratinocyte differentiation in this hyperproliferative model. We observed an increased expression of involucrin and filaggrin following ciglitazone treatment, suggesting a pro-differentiating action of TZDs in this model. In summary, topical TZDs significantly reduce epidermal keratinocyte proliferation while promoting differentiation in a murine model of hyperproliferative epidermis. Together, these results suggest that in addition to their metabolic effects currently in use in the treatment of type 2 diabetes, topical TZDs could be considered as potential alternative therapeutic agents in hyperproliferative skin diseases such as psoriasis. [source] Defining the transcriptome of accelerated and replicatively senescent keratinocytes reveals links to differentiation, interferon signaling, and Notch related pathways,JOURNAL OF CELLULAR BIOCHEMISTRY, Issue 2 2006Ranjan J. Perera Abstract Epidermal keratinocytes (KCs) undergo highly orchestrated morphological and molecular changes during transition from proliferative compartment into growth arrested early and late differentiation layers, prior to dying in outermost cornified layers of normal skin. Creation of stratum corneum is vital to barrier function protecting against infection. Transcriptional events in KCs regulating complex processes of differentiation and host defense required to maintain constant epidermal thickness and resistance to infection in either young or aged skin are largely unknown. Furthermore, as terminal differentiation is characterized by irreversible loss of replicative potential culminating in dead layers at the skin surface, this process may be viewed as a form of senescence. However, a complete transcriptional profile of senescent (SN) human KCs has not been previously defined to permit delineation of molecular boundaries involving differentiation and senescence. To fill this void, we utilized global transcriptional analysis of KCs maintained in vitro as either cultures of proliferating (PR) cells, early and late confluent (LC) (accelerated senescence) cultures, or KCs undergoing replicative senescence. Global gene expression profiling revealed early confluent (EC) KCs were somewhat similar to PR KCs, while prominent differences were evident when compared to LC KCs; which were also distinct from replicatively SN KCs. While confluent KCs have in common several genes regulating differentiation with replicatively SN KCs, the latter cells expressed elevated levels of genes involved in interferon signaling and inflammatory pathways. These results provide new insights into cell autonomous transcriptional-based programs operative within KCs contributing to replicative senescence, with partial sharing of genes involved in differentiation. In addition, regulation of KC senescence may involve participation of interferon signaling pathways derived from the important role of KCs in protecting skin from infection. Integrating all of the transcriptional data revealed a key role for Notch receptor mediated signaling in the confluency induced differentiation phenotype using this model system. J. Cell. Biochem. 98: 394,408, 2006. © 2006 Wiley-Liss, Inc. [source] Acute effect of solar-simulated radiation on epidermal thickness assessed by confocal laser scanning microscopy in vivoJOURNAL OF THE EUROPEAN ACADEMY OF DERMATOLOGY & VENEREOLOGY, Issue 5 2004T Gambichler [source] Cyclooxygenase-2 deficiency increases epidermal apoptosis and impairs recovery following acute UVB exposureMOLECULAR CARCINOGENESIS, Issue 5 2007Jacqueline K. Akunda Abstract The cyclooxygenases, COX-1 and COX-2, are involved in cutaneous responses to both acute and chronic UV exposure. In the present study, wild-type (WT), COX-1,/, and COX-2,/, mice were used to determine the influence of the individual isoform on mouse skin responses to acute UVB treatment. Immunohistochemistry and Western analysis indicated that COX-2, and not COX-1, was induced by UVB (2.5 or 5.0 kJ/m2), but that COX-1 remained the major source of prostaglandin E2 production. UVB exposure significantly increased epidermal apoptosis in all genotypes compared to untreated mice. However, while the number of apoptotic cells in WT and COX-1,/, mice were about equal, the number of apoptotic cells was 2.5-fold greater in COX-2,/, mice. Apoptosis in WT and COX-2,/, mice peaked at 24 h post-exposure. The increased apoptosis and reduced proliferation in COX-2,/, mice resulted in about a 50% decrease in epidermal thickness at 24,48 h post-exposure compared to about a 50% increase in epidermal thickness in WT mice. UVB-induced cell replication, as measured by BrdU labeling, was reduced in COX-2,/, compared to WT mice at 24,96 h. However, by 96 h post-exposure, both WT and COX-2,/, mice showed epidermal hyperplasia. The data indicate that COX-2 induction initially protects against the acute sunburn effects of UVB, but that continuous induction of COX-2 may contribute to skin cancer in chronic UVB exposure. © 2007 Wiley-Liss, Inc. [source] Infant Skin Microstructure Assessed In Vivo Differs from Adult Skin in Organization and at the Cellular LevelPEDIATRIC DERMATOLOGY, Issue 2 2010Georgios N. Stamatas Ph.D. The purpose of this study was to examine infant skin microstructure in vivo and to compare it with that of adult skin. The lower thigh area of 20 healthy mothers (ages 25,43) and their biological children (ages 3,24 months) was examined using in vivo noninvasive methods including fluorescence spectroscopy, video microscopy, and confocal laser scanning microscopy. Stratum corneum and supra-papillary epidermal thickness as well as cell size in the granular layer were assessed from the confocal images. Adhesive tapes were used to remove corneocytes from the outer-most layer of stratum corneum and their size was computed using image analysis. Surface features showed differences in glyph density and surface area. Infant stratum corneum was found to be 30% and infant epidermis 20% thinner than in adults. Infant corneocytes were found to be 20% and granular cells 10% smaller than adult corneocytes indicating a more rapid cell turnover in infants. This observation was confirmed by fluorescence spectroscopy. Dermal papillae density and size distribution also differed. Surprisingly, a distinct direct structural relationship between the stratum corneum morphology and the dermal papillae was observed exclusively in infant skin. A change in reflected signal intensity at ,100 ,m indicating the transition between papillary and reticular dermis was evident only in adult skin. We demonstrate in vivo qualitative and quantitative differences in morphology between infant and adult skin. These differences in skin microstructure may help explain some of the reported functional differences. [source] Anti-wrinkling effects of the mixture of vitamin C, vitamin E, pycnogenol and evening primrose oil, and molecular mechanisms on hairless mouse skin caused by chronic ultraviolet B irradiationPHOTODERMATOLOGY, PHOTOIMMUNOLOGY & PHOTOMEDICINE, Issue 5 2007Ho-Song Cho Background: Naturally occurring antioxidants were used to regulate the skin damage caused by ultraviolet (UV) radiation because several antioxidants have demonstrated that they can inhibit wrinkle formation through prevention of matrix metalloproteinases (MMPs) and/or increase of collagen synthesis. Objective: We examined the effect of oral administration of the antioxidant mixture of vitamin C, vitamin E, pycnogenol, and evening primrose oil on UVB-induced wrinkle formation. In addition, we investigated the possible molecular mechanism of photoprotection against UVB through inhibition of collagen-degrading MMP activity or through enhancement of procollagen synthesis in mouse dorsal skin. Methods: Female SKH-1 hairless mice were orally administrated the antioxidant mixture (test group) or vehicle (control group) for 10 weeks with UVB irradiation three times a week. The intensity of irradiation was gradually increased from 30 to 180 mJ/cm2. Microtopographic and histological assessment of the dorsal skins was carried out at the end of 10 weeks to evaluate wrinkle formation. Western blot analysis and EMSA were also carried out to investigate the changes in the balance of collagen synthesis and collagen degradation. Results: Our antioxidant mixture significantly reduced UVB-induced wrinkle formation, accompanied by significant reduction of epidermal thickness, and UVB-induced hyperplasia, acanthosis, and hyperkeratosis. This antioxidant mixture significantly prevented the UVB-induced expressions of MMPs, mitogen-activated protein (MAP) kinase, and activation of activator protein (AP)-1 transcriptional factor in addition to enhanced type I procollagen and transforming growth factor-,2 (TGF-,2) expression. Conclusion: Oral administration of the antioxidant mixture significantly inhibited wrinkle formation caused by chronic UVB irradiation through significant inhibition of UVB-induced MMP activity accompanied by enhancement of collagen synthesis. [source] Wet-wrap treatment using dilutions of tacrolimus ointment and fluticasone propionate cream in human APOC1 (+/+) mice with atopic dermatitisBRITISH JOURNAL OF DERMATOLOGY, Issue 1 2009A.P. Oranje Summary Background, Wet-wrap treatment (WWT) with diluted topical steroids is widely used in atopic dermatitis (AD). Mice with transgenic overexpression of human apolipoprotein C1 (APOC1) in the liver and the skin are not only characterized by hyperlipidaemia and raised IgE levels, but also by pruritic dermatitis and a disturbed skin barrier function, providing a novel in vivo mouse model for AD. Objectives, We investigated an adapted WWT method in the AD model in APOC1 mice in order to establish its efficacy. Methods, The effect of topical 0·1% and 0·03% tacrolimus ointment, tacrolimus base ointment, different dilutions of 0·05% fluticasone propionate (FP) cream and emollient on the development of dermatitis in APOC1 mice was investigated. WWT was performed with 0·03% tacrolimus ointment or 0·017% FP cream. Results, AD in APOC1 mice responded to topical treatment with tacrolimus or FP. In contrast to tacrolimus treatment, FP treatment was associated with loss of body weight. WWT reinforced several therapeutic aspects, notably improvements in transepidermal water loss and in epidermal thickness. WWT using tacrolimus 0·03% ointment was more effective than WWT using FP 0·017% cream. Conclusions, AD in APOC1 mice responds to treatment with (diluted) tacrolimus or FP; treatment with FP cream, but not tacrolimus ointment, was associated with weight loss. In this study, the adapted WWT using tacrolimus or FP in mice had a limited improving effect as compared with open application of tacrolimus or FP. [source] Evaluation of the atrophogenic potential of different glucocorticoids using optical coherence tomography, 20-MHz ultrasound and profilometry; a double-blind, placebo-controlled trialBRITISH JOURNAL OF DERMATOLOGY, Issue 4 2006M. Coßmann Summary Background, Skin atrophy is one of the main side-effects of topical corticosteroid therapy. Although the use of high-frequency ultrasound is an established method that has been studied previously, it allows measurements of the slow-reacting dermal thickness only. Objectives, To investigate the decreasing epidermal thickness, which occurs earlier, we used optical coherence tomography (OCT), a high-resolution noninvasive imaging technique, and compared it with 20-MHz ultrasound and profilometry. Patients/methods, In this double-blind placebo-controlled trial 20 healthy volunteers applied four different corticosteroids and the cream base formulation as placebo to the volar part of both arms once a day over a 4-week period. The epidermal thickness, the dermal thickness and the skin surface roughness were assessed using OCT, high-frequency ultrasound and profilometry. Results, Each of the three methods allowed the detection and monitoring of significant corticosteroid-induced skin atrophy and its reversibility. The changes correlated with the potency of the steroids. The epidermal thickness decreased significantly in all test areas, even in the placebo and the untreated fields. As expected, the reduction in epidermal thickness was more pronounced and could be detected earlier by OCT than the reduction of dermal thickness using ultrasound. The epidermal surface roughness investigated using profilometry showed a slight smoothing. Conclusions, OCT allows a simple, fast and noninvasive in vivo measurement of the epidermal thickness. To evaluate the atrophogenic potential of corticosteroids it is more suitable than high-frequency ultrasound as epidermal thickness decreases earlier. In addition, epidermal thickness is a more sensitive indicator of steroid atrophy as the degree of thinning is much higher compared with the dermal atrophy. Profilometry might give further information; however, it would not be suitable for clinical use as the results were generally less pronounced. In the future, OCT might be useful to detect corticosteroid-induced side-effects at the beginning for monitoring the therapy. [source] Histological effects of tazarotene 0·1% cream vs. vehicle on photodamaged skin: a 6-month, multicentre, double-blind, randomized, vehicle-controlled study in patients with photodamaged facial skinBRITISH JOURNAL OF DERMATOLOGY, Issue 6 2004L.A. Machtinger Summary Background, Topical tazarotene has been shown to offer efficacy in ameliorating multiple effects of photodamage. Objectives, To evaluate the histological effects of tazarotene cream on photodamaged skin. Methods, In this multicentre, double-blind, randomized, vehicle-controlled study, 50 patients with photodamaged facial skin (at least mild fine wrinkling and mottled hyperpigmentation, with at least one of these being moderate) were randomized to apply tazarotene 0·1% cream or vehicle cream to their face, once daily for 24 weeks. Results, Blinded assessments showed that tazarotene was less likely than vehicle to be associated with an increase in keratinocytic and melanocytic atypia, and more likely than vehicle to be associated with a reduction in atypia. Between-group comparisons in distribution of change from baseline categories of severity were in favour of tazarotene (P = 0·055 for keratinocytic atypia, P = 0·034 for melanocytic atypia, and P < 0·001 for the number of granular cell layers). Compared with vehicle, tazarotene was associated with an increase in epidermal polarity (P = 0·008) and epidermal thickness (P = 0·012), and a tendency for stratum corneum compaction. Tazarotene was also associated with widened intercellular spaces (reported as epidermal oedema) relative to vehicle (P < 0·001). Conclusions, Treatment of photodamaged skin with tazarotene is associated with an amelioration of keratinocytic and melanocytic atypia, an improvement in epidermal polarity, and an increase in epidermal thickness. [source] UVA1 and UVB irradiated skin investigated by optical coherence tomography in vivo: a preliminary studyCLINICAL & EXPERIMENTAL DERMATOLOGY, Issue 1 2005T. Gambichler Summary In histological studies, it has frequently been demonstrated that ultraviolet (UV) exposure, in particular UVB, can induce significant thickening of the viable epidermis and/or stratum corneum. Since skin biopsy alters the original skin morphology and always requires an iatrogenic trauma, we aimed to introduce optical coherence tomography (OCT) in vivo for the investigation of changes of epidermal thickness (ET) following UVA1 and UVB irradiation. Twelve healthy subjects received daily 60 J/cm2 of UVA1 and 1.5 minimal erythema doses UVB on their upper back over 3 consecutive days. Twenty-four hours after the last irradiation, OCT assessments were performed on UV exposed and adjacent nonirradiated control sites. Data of ET as expressed by comparison of the averaged A-scans differed significantly between nonirradiated (94.2 ± 15.7 µm), UVA1 (105.4 ± 12.8 µm) and UVB (125.7 ± 22.1 µm) exposed sites. In comparison to the nonirradiated sites, UVA1 exposed skin showed significant (P = 0.022) increase of ET of 11% and UVB exposed sites a significant (P < 0.001) increase of 25%. ET of UVA1 and UVB exposed skin sites differed significantly (P =0.005). Our results obtained from OCT in vivo measurements confirm data of previous histological studies indicating that not only erythemogenic doses of UVB, but also suberythemogenic doses of UVA1 may have a significant impact on ET. OCT appears to be a promising bioengineering technique for photobiological studies. However, further studies are needed to establish its measurement precision and validity, and to investigate in vivo spectral dependence on UV induced skin changes such as skin thickening. [source] | ||||||||||