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Dorsal Skin (dorsal + skin)
Selected AbstractsIn Vitro Antioxidant and In Vivo Photoprotective Effects of an Association of Bioflavonoids with Liposoluble VitaminsPHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 3 2006Patrícia M. B. G. Maia Campos ABSTRACT A new tendency in cosmetic formulations is the association of botanical extracts and vitamins to improve skin conditions by synergic effects. The objective of this study was to determine the antioxidant activity of associated bioflavonoids, retinyl palmitate (RP), tocopheryl acetate (TA) and ascorbyl tetra-isopalmitate (ATIP), as well as their photoprotective effects in preventing increased erythema, transepidermal water loss (TEWL) and sunburn cell formation in hairless mouse skin. The antioxidant activity of solutions containing the association or each substance separately was evaluated in vitro by a chemiluminescence assay. The photoprotective effect was evaluated by means of in vivo tests. Dorsal skin of hairless mice was treated daily by topical applications for 5 days with formulations containing or not containing (vehicle) the flavonoid-vitamins association (5%). The skin was irradiated (UVA/B) 15 minutes after the last application. The results showed that bioflavonoids had in vitro antioxidant properties and also that when they were associated with vitamins their antioxidant activity was more pronounced. On the other hand, erythema and UV damage to the permeability barrier function (TEWL) was not significantly reduced by previous treatment with the flavonoid-vitamin-association formulations, when compared to the irradiated vehicle-treated area. However, the treatment protected the skin from UV damage because it reduced the number of sunburn cells, when compared to the vehicle-treated area. Finally, the association of vitamins and bioflavonoids added to a dermocosmetic formulation showed a relevant biological activity in terms of photoprotection, because the association of bioflavonoids and vitamins acted by different mechanisms, such as antioxidation and absorption of UV radiation, which suggests its use in antiaging and photoprotective products. [source] Effect of Cog Threads under Rat SkinDERMATOLOGIC SURGERY, Issue 12 2005Hyo Jook Jang MD Background. The aging face loses the tensile strength of structural integrity. Cog threads have been used recently to tighten lax skin and soft tissue. Objective. A comparative study of the effects of cog, monofilament, and multifilament threads under rat skin. Methods. Each cog, monofilament, and multifilament thread was inserted under the facial skin of a cadaver and the panniculus carnosus of rat dorsal skin. The maximum holding strength (MHS) of the thread and the tearing strength of the skin around the thread were measured with a tensiometer. The thickness of the capsule around the thread and the myofibroblasts was observed histologically. Results. In the cadaver, the MHS of the cog thread was 190.7 ± 65.6 g. It was greater than that of the monofilament (22.4 ± 7.7 g) or multifilament (40.4 ± 19.7 g) thread. In the rat, the MHS of the cog thread was 95.1 ± 18.8 g. It was greater than that of the monofilament (4.3 ± 1.3 g) or multifilament (10.9 ± 2.1 g) thread in the second week. The thickness of the capsule around the cog thread was 93.0 ± 3.2 ,m. It was thicker than the monofilament thread's capsule, 39.2 ± 12.1 ,m, in the fourth week. The number of myofibroblasts presented significantly more in the cog (96.0 ± 72.4) than in the monofilament thread (4.3 ± 4.4). The rumpled in-between skin suspended by each of the three different threads returned to its original state in 2 weeks. Conclusion. The cog thread placed under the rat skin immediately pulled the skin and subcutaneous tissue. The myofibroblasts around the thread played a role in fibrous tissue contracture 4 weeks postinsertion of the thread. These findings could be the basis for clinical application. THIS STUDY WAS SUPPORTED BY A GRANT FROM THE KOREA HEALTH 21 R&D PROJECT, MINISTRY OF HEALTH AND WELFARE, REPUBLIC OF KOREA. [source] AMPA/kainate and NMDA-like glutamate receptors at the chromatophore neuromuscular junction of the squid: role in synaptic transmission and skin patterningEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 3 2003Pedro A. Lima Abstract Glutamate receptor types were examined at the chromatophore synapses of the squids Alloteuthis subulata and Loligo vulgaris, where nerve-induced muscle contraction causes chromatophore expansion. Immunoblotting with antibody raised against a squid AMPA receptor (sGluR) demonstrated that AMPA/kainate receptors are present in squid skin. Application of l -glutamate evoked chromatophore muscle contractions in both ventral and dorsal skins, while NMDA was only active on a subpopulation of dorsal chromatophores. In dorsal skin, neurotransmission was partly blocked by either AMPA/kainate receptor antagonists (CNQX and DNQX) or NMDA receptor antagonists (AP-5 and MK-801) or completely blocked by simultaneous application of both classes of antagonists. In isolated muscle fibres, ionophoretic application of l -glutamate evoked fast inward CNQX- and DNQX-sensitive currents with reversal potentials around +14 mV and a high conductance to Na+. In fibres from dorsal skin only, a slower outward glutamate-sensitive current appeared at positive holding potentials. At negative potentials, currents were potentiated by glycine or by removing external Mg2+ and were blocked by AP-5 and MK-801. Glutamate caused a fast, followed by a slow, transient increase in cytoplasmic Ca2+. The slow component was increased in amplitude and duration by glycine or by lowering external Mg2+ and decreased by AP-5 and MK-801. In cells from ventral skin, no ,NMDA-like responses' were detected. Thus, while AMPA/kainate receptors mediated fast excitatory synaptic transmission and rapid colour change over the whole skin, activation of both AMPA/kainate and NMDA-like receptors in a subpopulation of dorsal chromatophores prolonged the postsynaptically evoked Ca2+ elevation causing temporally extended colour displays with behavioural significance. [source] Photocarcinogenesis of topical tazarotene and isotretinoin alone and in combination with valproic acid in hairless miceEXPERIMENTAL DERMATOLOGY, Issue 11 2008Catharina M. Lerche Abstract:, Retinoids and the histone deacetylase inhibitor valproic acid have shown anticancer properties, but the photocarcinogenic or photoprotective effect is unclear. Therefore, we investigated whether a topical formulation of valproic acid is photocarcinogenic or photoprotective in hairless female C3.Cg/TifBomTac immunocompetent mice exposed to simulated solar radiation (SSR) and whether valproic acid changes the effect of the retinoids: tazarotene and isotretinoin. The products were applied on the dorsal skin of 400 mice (five times weekly) followed by SSR (three times weekly) 3,4 h after the application. This was performed during 12 months or until death. Tumors appeared sooner in groups treated with tazarotene and isotretinoin compared with that of the group treated with valproic acid and the control group. The present study shows that valproic acid alone is not photocarcinogenic or photoprotective in hairless mice. When valproic acid is combined with tazarotene or isotretinoin, it does not change their photocarcinogenicity significantly. [source] Influence of prostaglandin F2, and its analogues on hair regrowth and follicular melanogenesis in a murine modelEXPERIMENTAL DERMATOLOGY, Issue 5 2005S. Sasaki Abstract:, Latanoprost and isopropyl unoprostone, which are analogues of prostaglandin F2, (PGF2,), are promising drugs for the reduction of intra-ocular pressure. However, they have been reported to have side effects, including hypertrichosis and hyperpigmentation of the eyelashes and periocular skin, and occasionally poliosis. In order to investigate these effects further, PGF2,, latanoprost and isopropyl unoprostone were applied to the dorsal skin of 7-week-old C57BL/6 mice, and hair length was measured during the treatment. The three molecules all showed stimulatory effects on the murine hair follicles and the follicular melanocytes in both the telogen and anagen stages, and stimulated conversion from the telogen to the anagen phase. PGE2 is known to act synergistically with PGF2,, and hence the influence of PGE2 was also examined. PGE2 did not induce distinct telogen-to-anagen conversion, but showed moderate growth stimulatory effects on early anagen hair follicles. In addition, we observed a case of hypertrichosis and trichomegaly with an excess of melanogenesis, leading to the emergence of white hair, suggesting that poliosis can occur as a side effect of eye treatment with solutions of PGF2, analogues. The stimulatory effects of PGF2,and PGE2 on hair growth have been discussed with regard to the role of protein kinase C and mast cells. [source] Morphology of skin incubation in Pipa carvalhoi (Anura: Pipidae)JOURNAL OF MORPHOLOGY, Issue 11 2009Hartmut Greven Abstract South American Pipidae show a unique reproductive mode, in which the fertilized eggs develop in temporarily formed brood chambers of the dorsal skin after eggs have been deposited on the back of the female. We studied the skin incubation of Pipa carvalhoi using light microscopy and scanning electron microscopy. The skin consists of a stratified epithelium with a one-layered stratum corneum, and the dermis. The dermis of the dorsal skin of nonreproductive and reproductive females lacks a distinct stratum compactum, which is typical for most anuran skins. The entire dermis shows irregularly arranged collagen bundles like a stratum spongiosum. Before egg laying, the skin swells, primarily by thickening and further by loosening of the middle zone of the dermis. In the epidermis, large furrows develop that are the prospective sites of egg nidation. The epidermis, which forms a brood chamber around the developing egg becomes bi-layered and very thin and lacks a stratum corneum. Further, the dermis loosens and becomes heavily vascularized. Egg carrying females do not have mature oocytes in their ovaries indicating a slow down or interruption of egg maturation during this period. Similarities with the brood pouch of marsupial frogs are discussed. J. Morphol., 2009. © 2009 Wiley-Liss, Inc. [source] Transdermal Delivery of the Potent Analgesic Dihydroetorphine: Kinetic Analysis of Skin Permeation and Analgesic Effect in the Hairless RatJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 12 2000SATOSHI OHMORI Dihydroetorphine is an extraordinarily strong opioid analgesic. To assess its effectiveness after topical application in hairless rats we have examined the kinetic analysis of skin permeation through excised skin and the in-vitro reservoir effect of skin, and have investigated the predictability of plasma concentration and analgesic effect following in-vivo transdermal application. Dihydroetorphine was moderately permeable from an aqueous suspension through excised hairless rat skin. Dihydroetorphine flux from drug-dispersed pressure-sensitive adhesive tape was threefold that from the applied aqueous suspension. The fluxes through the abdominal and the dorsal skin during tape application fitted the Fickian diffusion equation well after the tape was removed peeling off the outer layer of the stratum corneum. The relationship between the plasma concentration and the analgesic effect was examined for four different rates of infusion of dihydroetorphine. A non-linear pharmacokinetic disposition was observed. Following abdominal (0.28 cm2, 20,g) and dorsal (0.50 cm2, 35,g) applications of the dihydroetorphine tape, plasma concentration (0.2-0.8 ng mL,1) and analgesic effect were maintained at a suitable level, for more than 8h, until removal of the tape. These profiles were predictable using the combined equation for percutaneous absorption, disposition and the analgesic effect, but the analgesic effect was slightly lower than the predicted value. The results show that it was possible to control the plasma concentration and the analgesic effect of dihydroetorphine by topical application of the analgesic using pressure-sensitive adhesive tape in the hairless rat. It was possible to predict the result using mathematical modelling. [source] Acute Ethanol Exposure Combined With Burn Injury Enhances IL-6 Levels in the Murine IleumALCOHOLISM, Issue 10 2007Michael T. Scalfani Background:, Recent studies suggest that ethanol use imposes a greater risk of trauma-associated intestinal injury than trauma alone. The initiating and regulatory factors for multiple organ dysfunction syndromes are not well defined, yet evidence points to the gut as a possible trigger of the systemic inflammatory cascade as well as a potential source of cytokines. In the current study, we hypothesized that ethanol administration would alter cytokine levels and intestinal infiltration by neutrophils within the ileum of mice exposed to burn injury (15% total body surface of dorsal skin). Methods:, Ileal samples were collected for histological assessment, myeloperoxidase quantitation and the protein presence of tumor necrosis factor alpha (TNF,), interleukin (IL-) 6, macrophage inflammatory protein-2 (MIP-2; CXCL2) and the anti-inflammatory cytokine, IL-10. Additional ileal tissue samples were examined for localization of the IL-6 immunoreactivity. Results:, We did not detect statistically significant cytokine/chemokine differences (MIP-2 and IL-10) between sham control and treatment conditions at either 2 or 24 hours. However, there was a significant decrease in TNF, at 24 hours in both burn injury alone and in combination with ethanol treatment conditions (p < 0.05). In addition, there was an increase in IL-6 levels at 24 hours in intestinal tissue obtained from mice subjected to a combination of acute ethanol and burn injury, compared to the mice receiving burn or sham injury (p < 0.001). Ileal homogenate increases in IL-6 at 24 hours were concurrent with decreased villus height in the ileum, but no discernable changes in neutrophil infiltration (myeloperoxidase activity levels) at either 2 or 24 hours. Additional immunocytochemical localization studies of ileal tissue revealed that there was a substantial increase of IL-6 in intestinal enterocytes subjected to both burn injury alone, or in combination with acute ethanol exposure. Conclusions:, The present study suggests that acute ethanol exposure combined with burn injury enhances levels of IL-6 protein in the ileum. The enhanced levels of ileal IL-6 are likely due to enterocyte production of the cytokine. [source] One-stage reconstruction of the complex midfoot defect with a multiple osteotomized free fibular osteocutaneous flap: Case report and literature reviewMICROSURGERY, Issue 1 2010Efstathios G. Lykoudis M.D., Ph.D. Complex midfoot defects represent a reconstructive challenge since midfoot plays a key role in standing and gait. We report the case of a 27-year-old patient with a complex midfoot defect due to a high-energy gun shot injury. The defect included the tarsometatarsal complex, all three arches of the foot, and the overlying dorsal skin of the foot. Reconstruction was achieved in a single stage with a free fibular osteocutaneous flap. The fibula was osteotomized into three segments, which were used to reconstruct the bone defects, while the skin paddle of the flap was used for stable soft tissue coverage of the reconstructed bony skeleton. Early and late postoperative periods were uneventful. Bone incorporation was radiographically evident at 12 weeks, and full weight bearing was possible at 6 months postop. Final follow up, at 2 years postop, showed a very good functional and esthetic outcome. © 2009 Wiley-Liss, Inc. Microsurgery, 2010. [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] Ergocalciferol promotes in vivo differentiation of keratinocytes and reduces photodamage caused by ultraviolet irradiation in hairless micePHOTODERMATOLOGY, PHOTOIMMUNOLOGY & PHOTOMEDICINE, Issue 5 2004Hiroaki Mitani Background: Ergocalciferol (VD2) is usually administered orally and it is metabolized to produce its biologically active metabolites in the liver and kidney. Active vitamin D is a well-known potent regulator of cell growth and differentiation. Purpose: Active vitamin D such as 1,25-dihydroxyvitamin D3 (1,,25(OH)2D3) prevents photodamage, including wrinkles and morphologic alterations. However, its clinical and cosmetic use is limited because of its potent, associated effect on calcium metabolism. We examined the efficacy of vitamin D analogues with few adverse effects for preventing skin photodamage. Method: Topical application of VD2 to hairless mouse dorsal skin, and exposure to solar-simulating ultraviolet (UV) radiation at a dose of 10.8 J/cm2 (UVA) were performed for 15 weeks, five times a week on weekdays. At the end of the final irradiation, histological and analytical studies were performed. Results: Topical application of VD2 significantly prevented wrinkle formation and abnormal accumulation of extracellular matrix components. In addition, VD2 suppressed excessive secretion of IL-6 induced by UV irradiation in cultured human normal keratinocytes, in a dose-dependent manner. Conclusion: VD2 promoted keratinocytes differentiation in the epidermis and showed diverse physiological effects, the same as the active form of VD3. The results suggested that the suppression of skin photodamage involved the promotion of keratinocytes differentiation and suppression of IL-6 secretion induced by exposure to UV. Topical application of VD2 may become an effective means to suppress solar UV-induced human skin damage. [source] The Melanocortin Receptor-1 Gene but not the Proopiomelanocortin Gene is Expressed in Melanoblasts and Contributes their Differentiation in the Mouse SkinPIGMENT CELL & MELANOMA RESEARCH, Issue 6 2004Tomohisa Hirobe Alpha-melanocyte stimulating hormone (, -MSH) added to serum-free primary culture of melanoblasts derived from epidermal cell suspensions of 0.5 d old C57BL/10JHir mice induced their differentiation. Analysis using the reverse transcription-polymerase chain reaction showed that the expression of the melanocyte-specific , -MSH receptor gene, melanocortin receptor-1 (MC1-R), had already been initiated before addition of , -MSH, and, in addition, no up-regulation of the MC1-R gene was observed after addition of , -MSH. However, no expression of the proopiomelanocortin (POMC) gene was observed before or after the addition of , -MSH. The expression of the MC1-R and POMC genes in the epidermis and dermis of the dorsal skin was surveyed from 13 d old embryos to 5.5 d old neonates. The expression of the MC1-R gene was first observed in the epidermis of 13 d old embryos, and gradually increased up to 0.5 d after birth, and thereafter remained constant. By contrast, the expression of the MC1-R gene in the dermis was first observed in 16 d old embryos, and gradually increased up to 3.5 d after birth, and thereafter remained constant. However, no expression of the POMC gene was observed in the epidermis or dermis of the dorsal skin at any age of mice tested. These results suggest that the expression of the MC1-R gene, but not of the POMC gene, plays an important role in the regulation of melanocyte differentiation in mouse skin. [source] Topical dorsal skin immersion in seawater induces apoptosis and proliferation in hairless miceTHE JOURNAL OF DERMATOLOGY, Issue 10 2007Min Hong PAN ABSTRACT Recreational and occupational exposure to seawater (SW), have increased but the effect of SW on skin has not been elucidated. The purpose of present study was to assess the effects of SW immersion on the dorsal skin in hairless mice. Adult hairless mice were individually immersed in SW for 3 h, 6 h and 12 h; then, full-thickness dorsal skin of 2 cm diameter was excised for pathological examination (light microscope), apoptosis detection (terminal deoxynucleotidyl transferase-mediated 2,-deoxyuridine 5,-triphosphate nick end labeling [TUNEL]) and proliferation index evaluation (immunohistochemistry). Normal and normal saline (NS)-immersed skin were used as controls. Histological examination revealed that there were randomly distributed cell deaths, presenting cell shrinkage, condensation of nuclear chromatin and eosinophilic cytoplasm in the epidermis, and neutrophil infiltration in the dermis, after SW immersion. Moreover, TUNEL showed low levels of apoptosis in normal (9.07 ± 0.70%) and NS-immersed skin (9.99 ± 1.22%). There was an apparent increase in the 6-h and 12-h SW immersed groups (29.90 ± 6.85%, P < 0.01; 45.46 ± 6.12%, P < 0.01, respectively). Ki-67 antigen was located in the basal layer of the epidermis and hair follicles, the rates of Ki-67-positive cells were 7.90 ± 1.45% and 7.76 ± 1.52% in normal and NS-immersed skin, respectively, and in the 12-h SW immersed group, the rate of Ki-67-positive cells reached 23.85 ± 4.21% (threefold, P < 0.01). In each group, the rate of apoptosis was higher than that of proliferation. We conclude that SW immersion can cause time-dependent apoptosis and proliferation in the epidermis, and the overall effect of SW immersion is injury to the epidermis. [source] Metoidioplasty: a variant of phalloplasty in female transsexualsBJU INTERNATIONAL, Issue 9 2003S.V. Perovic OBJECTIVE To describe metoidioplasty, a technique for creating a neophallus from an enlarged clitoris in female transsexuals, without needing the complex, multi-staged surgical construction of a large phallus, as this reconstruction is one of the most difficult in female transsexuals. PATIENTS AND METHODS From September 1995 to April 2002 metoidioplasty was used in 22 patients (aged 18,33 years). The technique is based on the repair of the most severe form of hypospadias and intersex. The ,urethral plate' and urethra are completely dissected from the clitoral corporeal bodies, then divided at the level of the glanular corona, and the clitoris straightened and lengthened. A longitudinal vascularized island flap is designed and harvested from the dorsal skin of the clitoris, transposed to the ventral side, tubularized and anastomosed with the native urethra. The new urethral meatus is brought to the top of the neophallus, and the skin of the neophallus and scrotum reconstructed using labia minora and majora flaps. RESULTS The mean (range) follow-up was 3.9 (0.5,6) years; the neophallus was 5.7 (4,10) cm, considered satisfactory in 17 patients but the remaining five required additional phalloplasty. The complications were urethral stenosis in two and fistula in three patients. CONCLUSIONS Metoidioplasty is an alternative to phalloplasty, allowing voiding while standing. In patients who desire a larger phallus, various techniques of phalloplasty can also be used. [source] Modulation of ultraviolet-induced hyperalgesia and cytokine upregulation by interleukins 10 and 13BRITISH JOURNAL OF PHARMACOLOGY, Issue 7 2000Nayef E Saadé Exposure to midrange ultraviolet radiation (UVB) is known to produce skin inflammation similar to sunburn. The aim of this study was to characterize the hyperalgesia and cytokine upregulation induced by UVB and their modulation by antiinflammatory cytokines. Acute exposure of the dorsal skin of mice to UVB (200, 250 and 300 mJ cm2) resulted in a dose-dependent decrease in the latencies of the hot plate and tail flick tests, without evident signs of skin lesions. The observed hyperalgesia displayed a biphasic temporal evolution with an acute phase (3,6 h) and a late (48,96 h) phase. Exposure to UVB (300 mJ cm2) elicited significant upregulation of interleukin (IL)-1,, tumour necrosis factor (TNF)-, and nerve growth factor (NGF), determined by ELISA in the exposed skin. This upregulation was more important during the acute phase of hyperalgesia. Daily treatment of mice, with i.p. injections of either IL-10 or IL-13 (1.5, 7.5 and 15 ng in 100 ,l saline) produced a dose-dependent attenuation of the UVB-induced hyperalgesia. Treatment with the highest doses of either IL-10 or IL-13, produced significant attenuation of the levels of the cytokines and NGF by UVB, with relatively more pronounced effects by IL-13. Acute exposure to moderate amounts of UVB results in a systemic hyperalgesia related to the upregulation of cytokine and NGF levels, since both were prevented by treatment with antiinflammatory cytokines. British Journal of Pharmacology (2000) 131, 1317,1324; doi:10.1038/sj.bjp.0703699 [source] | |||||||||||||