Epidermal Thinning Research Articles

Accelerated chronic skin changes without allograft vasculopathy: A 10-year outcome report after face transplantation

BackgroundLong-term outcomes after face transplantation are rarely reported in the scientific literature. Here we present outcome data of a partial face allograft recipient 10 years after transplantation. MethodsMedical records were reviewed for functional and psychosocial outcomes as well as complications. Histopathologic analyses of autopsy tissues and characterization of skin immune cells were performed. ResultsThe patient retained long-term motor and sensory function, though with a noticeable drop in sensory function after year 5. Social reintegration of the patient was marked by reconnection with his family and participation in public social activities. Immunosuppressive therapy consisted of tacrolimus (target levels 6–8 ng/mL after the first year), mycophenolate, and prednisone, while steroids were completely weaned between years 1 and 7. One acute cellular rejection episode of grade II or higher occurred on average per year and led to chronic skin changes (papillary dermal sclerosis with superficial hyalinization, epidermal thinning with loss of rete ridges, perieccrine fibrosis), but the allograft vessels, muscles, adipose tissue, and bone were spared. Allograft skin was characterized by increased number of CD4+ TNF-α/IL17A producing T-cells as compared with native skin. Long-term kidney function was maintained at 60 mL/min estimated glomerular filtration rate. Unfortunately, the preexisting hepatitis C virus infection with liver cirrhosis was resistant to 3 treatments with new direct-acting antivirals and eventually hepatocellular carcinoma developed, causing the patient’s death 10 years after transplantation. ConclusionThis report suggests that face transplants can maintain their function for at least 10 years. Chronic skin changes can occur independently of allograft vasculopathy.

Effect of Nanostructured Chitosan/Propolis Coatings on the Quality and Antioxidant Capacity of Strawberries During Storage

Strawberries have a thin epidermis and a high respiration rate. The use of edible coatings containing chitosan nanoparticles (CSNPs) and propolis (P) has been effective in preserving the shelf life and antioxidant capacity of various fruit and vegetable products. The present research evaluated the effect of coatings with CSNPs and P on the quality, antioxidant compounds, and antioxidant capacity of strawberries. The specific coatings that were evaluated were chitosan (CS), CS+CSNPs33%, CS + CSNPs + P10%, CS + CSNPs + P20%, CS + CSNPs + P30%, and a control with no coating. The variables were weight loss, firmness, total soluble solids (TSS), color, phenols, total flavonoids, antioxidant capacity, and sensory characteristics. An ANOVA and a Tukey test (p ≤ 0.05) were used to analyze the data. Strawberries covered with CS + CSNPs + P10% showed the lowest weight loss (9.77%), while those covered with CS + CSNPs + P20% had the greatest firmness (4.96 N). CS + CSNPs + P coatings at 10%, 20%, and 30% concentrations maintained the antioxidant compounds and antioxidant capacity in the evaluated fruit (28.49 mg GAE g−1, 554.61 μg quercetin g−1, and 92.48% DPPH, respectively). The application of nanostructured coatings did not modify the sensory characteristics of the fruit. Coatings with CSNPs and/or P could therefore be a viable alternative for preserving the quality and antioxidant capacity of strawberries.

The skin structures and their role in the thermoregulation of the South American fur seal (Arctocephalus australis).

The skin of the South American fur seal (Arctocephalus australis) is important for animal thermoregulation in both terrestrial and aquatic environments. Skin tissue samples were collected from A. australis for microscopic analysis and were related to anatomical references. The aim of this study was to describe the skin morphology, as well as to suggest the major anatomical regions and skin components involved in the thermoregulation of this species. Using light microscopy, the skin of six animals was examined based on histological, morphometric, and immunohistochemical criteria. Hair follicle morphology was examined using scanning electron microscopy. The skin was classified as either thick or thin based on its epidermal thickness. The thin epidermis regions had more abundant hair follicles, as well as high pigmentation, whereas the thick epidermis regions had very pigmented epidermal layers. Pigmentation of hair and skin is fundamental for protection against ultraviolet rays; moreover, hair is important in preventing abrasion, and provides an insulating layer against the external environment, which can be much colder than body temperature. Furthermore, the dermis is well vascularized, especially the superficial dermis. All regions of the skin have adaptations for maintaining the animal's condition in both terrestrial and aquatic environments. Among the studied regions, the interdigital region from hindflipper showed important morphological characteristics related to thermoregulation, such as having an epidermis of intermediate thickness, a dermis with a small number of hairs, a large amount of blood vessels, and sweat glands with large lumens, indicating that heat exchange in this region may be faster.

Pharmacognostic and Phytochemical Investigations of Bahunia Variegata Leaves (Kovidra)

Bauhinia variegata L belonging to the Caesalpinioideae family, commonly called as kovidra in sanskrit and kachnar in hindi. Kovidra is a medium sized deciduous tree mostly observed at altitude 1300 to 1800 in Himalayas. The plant is extensively utilized by the tribals all over in India and accepted in medicinal systems like Ayurveda, Unani and Homoeopathy. Secondary metabolites like carbohydrates, tannins, alkaloids, and flavonoids are present in Bauhinia variegata plant. The aim of the current research is to develop different pharmacognostic and phytochemical analysis for the evaluation of leaf of this plant. Microscopy, Phytochemical analysis of leaf drug was performed and results were maintained. In microscopical view of Bauhinia variegata leaf, the presence of thin walled epidermis, spongy paranchymatous cells, plenty of solitary calcium oxalate crystals, unicellular and multicellular covering trichomes were observed. Phytochemical tests indicated the occurrence of flavonoids, tannins, steroids and phenols etc. Further physicochemical analysis such as extractive value was determined which includes petroleum ether soluble extractive value, chloroform, methanol, and aqueous soluble extractive values. The results obtained from standardization of leaf drug recognized the macro and microscopical parameters, physicochemical parameters. Fluorescence analysis of leaf drug distinguishes the authenticity of plant drug; therefore these techniques are helpful for rapid recognition of crude drug. The outcome of the research study possibly will be helpful in setting investigative indices for the identification and grounding of a monograph of the plant drug.

Disentangling evolutionary, environmental and morphological drivers of plant anatomical adaptations to drought and cold in Himalayan graminoids

Understanding what determine plants ability to survive drought and cold is crucial for predicting how plants may respond to ongoing climate change. Plant survival strategies are usually characterized by morphological and physiological adaptations, while their underlying anatomical settings are largely unknown. Woody angiosperms and herbaceous dicots have repeatedly evolved small water transporting conduits and large storage parenchyma tissues at colder or drier places to cope with freezing‐ and drought‐induced damages. However, whether these adaptations are also valid for graminoids remains unclear. Here we show that stem anatomical variations in grasses, sedges and rushes dominating in western Himalayan grasslands are driven by elevation and soil moisture via control over aboveground plant stature and belowground clonal growth, while phylogenetic constraints have only a weak effect. Phylogenetic comparative analyses controlling for confounding factors showed that the elevation‐related cooling controls the conductive system through reduced vessel diameter and extended assimilatory and storage tissues with more chlorenchyma and less sclerenchyma around vessels. The soil moisture deficit, on the other hand, determines stabilization structures by promoting short‐rhizomatous turf graminoids with hollow stems, thicker epidermis and deep adventitious roots in dry steppes and semi‐deserts. Saline wetlands and moist alpine pastures promote long‐rhizomatous short‐stature plants with lower need for mechanical support (absence of hollow stem) and exposure to high evaporative forcing (thinner epidermis). Observed trends of decreasing vessel sizes and lignification rate with elevation supports the existing knowledge that narrower vessels and extensive parenchyma assist plants to grow in cold environments by avoiding freezing‐induced cavitation. Our results bring novel information on ecological drivers influencing the evolution of anatomical adaptations in high mountain graminoids. Distinct grassland types, covering elevations from 2650 to 6150 m, harbor unrelated species with different evolutionary histories that have converged towards similar anatomical structures.

Reflectance confocal microscopy and histological features of depigmentation after local corticosteroid injection.

Clinically, depigmentation after local corticosteroid injection is not rare. But there are less articles about its reflectance confocal microscopy (RCM) and histological features. This study aimed to define the RCM features and histopathologic findings of hypopigmentation after local corticosteroid injection and to analyze the correlations between the above two methods. Forty cases with hypopigmentation after local corticosteroid injection were used to analyze the clinical and RCM features. Subsequently, for 20 of 40, an excision biopsy of the same imaged areas for histopathologic examination was executed. Our results showed that all 40 cases had round or ellipse hypopigmented macules with obscure boundary and 26 of 40 lesions' long diameter went along limbs. The RCM features and the histological findings revealed all patients had variable degrees of epidermal thinning, flattening rete ridges, reduced melanin, and no inflammatory cell infiltration. MART-1 analysisrevealed the number of melanocytes was normal but with no or less melanin by Fontana-Masson staining. Depigmentation after local corticosteroid injection was a kind of disease with intact melanocytes, whose function was impaired. RCM features offer a high consistency with histopathologic findings. It thus constitutes a promising adjuvant tool for its diagnosis and for therapeutic follow-up.

IGF-1R deficiency in human keratinocytes disrupts epidermal homeostasis and stem cell maintenance

BackgroundEpidermal stem cells (ESCs) are keratinocytes that reside in the basal layer of the epidermis and mediate epidermal homeostasis. Insulin-like growth factor 1 (IGF-1) signaling through its receptor (IGF-1R) has been identified as an important regulator in rodent skin development and differentiation. However, the role of IGF-1/IGF-1R signaling in human keratinocytes is not yet well understood. ObjectiveThis study aimed to clarify the role of IGF-1/IGF-1R signaling in human epidermal homeostasis. MethodsIGF-1R specific knockout (KO) HaCaT keratinocytes were generated by CRISPR-Caspase-9-mediated non-homologous end joining frame-shift mutations. Further, the behavior of these keratinocytes in epidermal homeostasis was investigated using reconstructed epidermis and human skin equivalents. ResultsIGF-1R KO HaCaT keratinocytes were successfully established and produced thin epidermis in three-dimensional culture models. Keratin10-positive cells were frequently found in the basal layer of the reconstructed epidermis. ConclusionsIGF-1/IGF-1R signaling was demonstrated to play a key role in maintaining human epidermal homeostasis. This method provides a new framework to investigate gene function in human epidermal homeostasis.

682 Characterization of a novel selective non-steroidal glucocorticoid receptor agonist with low systemic exposure and reduced potential for skin atrophy

Topical glucocorticoids (GCs) are widely used drugs in dermatology but are associated with both local and systemic adverse effects. With the aim to provide an effective but safer topical treatment, we here describe LEO 134310, a novel non-steroidal glucocorticoid receptor (GR) agonist with low systemic exposure and reduced potential for induction of skin atrophy. LEO 134310 is a full GR agonist with high affinity for GR and nanomolar potency in human PBMCs. Furthermore, selectivity for GR was demonstrated within a panel of nuclear hormone receptors, including the mineralocorticoid receptor, which has been associated with induction of skin atrophy. Topical treatment with LEO 134310 in human skin explants resulted in full agonism, measured by GR target engagement, with maximal effects comparable to BMV and CP, although at higher dosage strength. The lower potency of LEO 134310 in human skin explants could be explained by a combination of lower skin penetration, metabolism in the skin and in vitro potency. LEO 134310 was rapidly deactivated in the blood and other compartments by enzymatic hydrolysis, leading to low systemic exposure of active parent compound. Consequently, a 10-fold higher therapeutic index was achieved with LEO 134310 compared to BMV and CP in the TPA-induced skin inflammation mouse model. Induction of skin atrophy after topical treatment with LEO 134310 in minipigs was minimal in contrast to significant epidermal thinning induced by treatment with CP and BMV. In conclusion, LEO 134310 may potentially offer an improved topical treatment solution for patients with inflammatory skin diseases.

Immunohistochemical expression and localization of MMP-9, MMP-13, E-Cadherin and Ki-67 in road pavers' skin chronically exposed to bitumen products.

To investigate the matrix metalloproteinase (MMP)-9, (MMP)-13, E-Cadherin and Ki-67 expressions in road pavers' skin chronically exposed to bitumen products in order to contribute to a better understanding of the earlier tissue alteration. Skin punch biopsies from 16 daily exposed workers and a control group were studied by immunohistochemistry. Morphometric and densitometric analyses were also conducted. Morphological specimen evaluation of skin of road pavers showed epidermal thinning, flattening and loss of intercellular junction with a decreased expression of E-cadherin confined to the basal skin layer, together with MMP-9 and MMP-13 overexpressions in all epidermis layers, vascular structures and adnexa. No immunohistochemical alteration was reported for Ki-67 vs normal skin. Results from this study show that overexpression of MMP-9 and MMP-13 may represent an early response of the first human barrier to exposure to bitumen products. Regulation of MMPs could be one of the strategies to prevent primary skin disease.

Cells to Surgery Quiz: April 2019

Cells to Surgery Quiz: April 2019

Biomarker responses (serum biochemistry) in pregnant female wistar rats and histopathology of their neonates exposed prenatally to pesticides

Experiments were conducted to investigate the effects on health of pregnant female rats exposed to pesticides glyphosate and carbendazim. Glyphosate is used as herbicide and carbendazim as a fungicide; all are commercially available readily for various agricultural and domestic purposes. The hypothesis tested in this investigation is that pesticide exposure during pregnancy causes changes in biomarker responses like serum glucose level, total protein, total cholesterol, triglycerides, SGOT, SGPT, and billirubin level. Significant changes were observed in all above biomarker responses, when compared with the reference. Histopathology of skin and kidney of rat neonates showed marked damage. Degenerative changes and vacuolization with eroded capsule were observed in kidney sample and thinning of epidermis in skin sample was seen in pesticides exposed neonates of rats. The serum biochemistry and histopathological findings are valuable markers for observing the changes caused by pesticide exposure.

Triple dermoid sinus in sacro-caudal region in Rhodesian Ridgeback dog.

The aim of this report is to describe a case of a triple dermoid sinus in the sacro-caudal region in an 11-month-old Rhodesian Rhidgeback dog. A clinical examination of the patient revealed a dermoid sinus in the sacro-caudal region. Neurological examination did not show any abnormalities. A blood test and a radiological examination were performed, but the owner refused to perform an MRI. A decision about surgical treatment was made. Two smaller lesions, located 2 cm and 4 cm caudally to the first one, were discovered during skin shaving. The skin around the lesions looked smoother and less pigmented than in the other parts of the body. All three lesions were resected up to the spinous process top or the supraspinous ligament. Histopathological examination showed a typical anatomy of the sinuses and anatomical changes in the skin between them: thinner epidermis and an abnormal shape of hair follicles. In the soft tissue between the ends of the sinus lumina and the supraspinous ligament there were no adnexal structures, such as hair or hair follicles. The sinus type was classified as IIIa. The surgical wound healed without complications. The owner was contacted 14 days and 6 months after surgery, and no signs of complications, pain or gait abnormalities were reported. Dermoid sinus diagnosis is based on medical history, clinical examination and diagnostic imaging. Computed tomography and magnetic resonance imaging are regarded as the most valuable. In many cases, however, their results are inconsistent with those of intraoperative exploration, for example, when a fibrous strand cannot be seen or the depth of the sinus has been inaccurately assessed. Often the depth and type of the dermoid sinus can be exactly assessed only by surgical exploration, so in some cases advanced imaging techniques can be omitted. The most commonly described location of a dermoid sinus is the cervical segment, with multiple lesions present. Only one case of a double dermoid sinus in the sacro-caudal section has been described in the literature. To our knowledge, a triple dermoid sinus at this location and skin anatomy changes in the dorsal medial line between sinuses have not yet been reported.

Chronic rejection of human face allografts.

Face vascularized composite allografts (FVCAs) have helped patients with severe facial disfigurement, with acute rejection now largely controlled through iatrogenic immunosuppression. However, little is known regarding the incidence and mechanism(s) of more long-term pathologic alterations in FVCAs that may affect function and graft durability. Protocol surveillance biopsy specimens for up to an 8-year interval in 7 patients who received FVCAs at our institution revealed histopathologic evidence of chronic rejection. Clinical manifestations included features of premature aging, mottled leukoderma accentuating suture lines, telangiectasia, and dryness of nasal mucosa. Pathologic changes consisted of epidermal thinning accompanied by discrete foci of lymphocyte-mediated cytotoxicity, hyperkeratosis, follicular plugging, vascular ectasia, and sclerosis beneath the epidermal layer associated with collagen type I deposition. Genomic interrogation and immunohistochemistry of sclerotic zones revealed upregulation of the AP-1 pathway components, JunB and c-Fos, previously implicated in overproduction of type I dermal collagen in the setting of systemic sclerosis. We conclude that some patients develop chronic rejection in FVCAs with striking similarities to alterations seen in certain autoimmune cutaneous disorders (lupus erythematosus and scleroderma/chronic sclerodermoid graft-versus-host disease). Identification of relevant pathways and genes, such as JunB and c-Fos, may provide new targets for preventative therapies for chronic immune-mediated changes in vascularized composite allografts.

Scar free healing mediated by the release of aloe vera and manuka honey from dextran bionanocomposite wound dressings

Scar preventive dextran based bionanocomposite dressings containing aloe vera (AV) and manuka honey (MH) were developed as wound care devices. This work was a challenge to fabricate herbal dressing that promotes healing, which at the same time is biocompatible, non-toxic, biodegradable, and cost effective in terms of the simplicity of application in complex chronic wound situations. With this aim, we synthesized in-situ crosslinked dextran/nanosoy/glycerol/chitosan (DNG/Ch) nanocomposite membranes via solvent casting technique followed by subsequent addition of AV and MH to obtain DNG/Ch/AV and DNG/Ch/MH herbal dressings. The drug release kinetics of the bionanocomposite dressings indicated an initial burst release of AV and MH, followed by controlled release when examined in-vitro using non-fickian and quasi-fickian model. Antibacterial studies confirmed >99% antibacterial activity against both Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) and bacterial adherence test demonstrated its efficacy for arresting microbial invasion. Wound healing analysis conducted in-vivo showed enhanced epithelialization in the terms scar prevention and aesthetics with absolute wound contraction for the mice treated with AV loaded dressings after 14th post wounding day. Histological features displayed ordered deposition of collagen with a thin epidermis layer. Hence, the present herbal dressing could function without many cytotoxicity and biocompatibility issues.

Revisiting the Beneficial Effects of Estrogen on the Skin: A Comprehensive Review of the Literature and a Look to the Future

The process of aging is associated with anticipated cutaneous changes such as epidermal thinning, dehydration, loss of barrier function, and decreased extracellular matrix components. These physiologic changes translate to clinical findings such as atrophy, pigmentary changes, and wrinkling. Over the past century, the role of decreased circulating estrogens in the process of cutaneous aging has been elucidated. Estrogen replacement, both systemic and topical, has been shown to have positive effects on aging skin by promoting fibroblast proliferation and increasing collagen density. However, despite these positive effects on skin health and appearance, estrogens also display a wide-range of actions on various other systems. Even topical estrogen application can result in unwanted systemic effects. Research into alternative substances such as soft estrogens—synthetic, non-hormonal molecules that produce local, cutaneous estrogenic effects and are then metabolized to inactive compounds prior to being absorbed into the systemic circulation— suggests that estrogenic-like benefits on aging skin could be harnessed safely, while avoiding the potential pitfalls associated with estrogen use.

A Case of Familial Focal Dermal Hypoplasia: A Report of 3 Cases in Consecutive Generations

Focal dermal hypoplasia (FDH), or Goltz syndrome, is a rare multisystem disorder affecting mesodermal and ectodermal structures, with the skin, eyes, teeth, and musculoskeletal systems most commonly affected. FDH results from mutations in the PORCN gene. Ninety-five percent of cases arise from novo mutations, whereas 5% are hereditary with an X-linked dominant inheritance pattern. Here, we describe an uncommon presentation of FDH in three consecutive generations. Patient 1 is an 8-month-old female born of non-consanguineous marriage who presented with diffuse alopecia of the scalp, linear hypopigmented, atrophic papules, and plaques with peripheral hyperpigmentation on the left hemiabdomen and right lateral leg along Blaschko's lines as well as syndactyly of the right second and third toes. Skin biopsy from the abdomen showed a thin epidermis with flattened rete ridges and massive dermal edema within collagen fibers and reactive capillaries. Family history was significant for similar skin lesions and bone deformities in her mother and similar skin lesions in her grandmother. Patient 2 (patient 1’s mother) is a 17-year-old female with similar linear hypopigmented, atrophic plaques with peripheral hyperpigmentation on the abdomen and right axilla, syndactyly of the right hand, patchy alopecia of the scalp, microdontia, teeth fusion, enamel defects, verrucous papillomas in the axillae and onycholysis. Patient 3 (patient 1’s grandmother), presented with similar hypopigmented, atrophic plaques on the abdomen and left arm.

Clinicopathological analysis of six cases of disabling pansclerotic morphea

Objective To investigate clinical and pathological features of 6 cases of disabling pansclerotic morphea (DPM). Methods Clinical and pathological manifestations of and follow-up results in 6 patients, who were clinically and histopathologically diagnosed with DPM in the Department of Pathology, Hospital for Skin Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College from 2007 to 2017, were retrospectively analyzed. Results Among the 6 patients, 4 were male and 2 were female. The age of onset ranged from 3 to 10 years, with an average age of 6.5 years. The average duration from the occurrence to the confirmation of the diagnosis was 6.2 years (range, 2-10 years). At all the lesional sites, skin atrophy, thining and tightness occurred, and the limbs became thin. Additionally, there were muscular atrophy and visible deep thick veins on the surface of the limbs. The contracture, deformity and dysfunction of the adjacent joints occurred in 4 cases, and the lower limbs were obviously shortened in 2 cases. Peripheral blood examination showed no increase of eosinophils or hypergammaglobulinemia. Imaging examination revealed smooth cortical bone and clear trabecular bone, and no osseous abnormality was observed. Histopathological examination of contracted skin lesions of the lower limbs revealed atrophic and thinned epidermis, hyperpigmentation in the basal layer, hyperplastic, thickened, hardened and partly homogenized collagen fibers in the middle to deep dermis, subcutaneous adipose tissue region and deep tissue of the skin. Conclusions DPM usually does not affect viscera, but often involves deep tissue of the limbs. Histopathologically, DPM is mainly characterized by obviously hyperplastic and hardened collagen fibers in the dermis and subcutaneous tissue. Key words: Scleroderma, localized; Child; Skin manifestations; Pathologic processes; Therapy; Disabling pansclerotic morphea

Anti-ageing skin effects of Korean bamboo salt on SKH1 hairless mice.

Bamboo salt is generated by baking bamboo and sea salt and is used as a traditional food or medicine. The aim of this study was to investigate the anti-ageing skin effects of Korean bamboo salt and to compare the antioxidant, anti-ageing and anti-inflammatory effects of various salts, including purified salt, solar salt, bath solar salt, Masada solar salt, 1-time baked bamboo salt (1× bamboo salt), and 9-times baked bamboo salt (9× bamboo salt). Based on the content of mineral elements, pH, OH groups and redox potential amperometric analysis, the 9× bamboo salt showed the most antioxidant components and characteristics compared to the other salts. The in vitro results showed that the 9× bamboo salt could inhibit oxidative damage by hydrogen peroxide (H2O2) treatment in HaCaT keratinocytes, and its effect was better than that of the other salts. In an in vivo experiment, SHK-1 hairless mice were treated with UV (ultraviolet) radiation to induce ageing. The epidermal thickness and epidermal structures were then assessed by phenotypic and histological analyses. The 0.2% 9× bamboo salt- and 1× bamboo salt-treated mice had a thinner epidermis than the control mice, and the sebaceous glands were almost intact with a regular arrangement that was similar to those in the normal group. Compared with the UV-treated group (control group) and other salt-treated groups, the 9× bamboo salt- and 1× bamboo salt-treated groups had higher dermal collagen and elastic fibre content. Fewer mast cells were observed in the 9× bamboo salt- and 1× bamboo salt-treated groups than in the control group. The activities of the skin antioxidant-related enzymes superoxide dismutase (SOD) and catalase (CAT) in the 9× bamboo salt- and 1× bamboo salt-treated groups were higher than those in other groups and similar to those in the normal group, but lipid peroxide (LPO) activity and carbonylated protein levels showed the opposite trends. Furthermore, the 9× bamboo salt- and 1× bamboo salt-treated groups had protein contents similar to those of the normal group. In addition, the 9× bamboo salt and 1× bamboo salt effectively down-regulated the expression of matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9) and up-regulated the expression of tissue inhibitor expression of matrix metalloproteinase-1 (TIMP-1), matrix metalloproteinase-2 (TIMP-2), SOD and CAT compared to the other salts at a concentration of 0.2% (p < 0.05). These results suggest that at appropriate concentrations, bamboo salt could prevent skin ageing induced by ultraviolet radiation b (UVB) photodamage.

Non-invasive measurement of effective thermal conductivity of human skin with a guard-heated thermistor probe

This paper describes a non-invasive method for measurement of the effective thermal conductivity of human skin with a guard-heated thermistor probe. The guard-heated thermistor probe makes it possible to accurately measure the absolute surface temperature of a material at temperatures higher than the ambient temperature. In this study, the probe was used for a non-invasive measurement of the effective thermal conductivity of human skin by measuring skin surface temperature response for a short time. The effective thermal conductivity of human skin was measured at different body locations, such as cheeks, forearms, and heels, on five healthy volunteers. The measured values reflect the effects of multi-layered skin structure and biological processes, such as blood perfusion and metabolism beneath the skin. The results reveal a correlation between the effective thermal conductivity and the skin structure. A numerical simulation was performed to assess the effects of the epidermis thickness and the thermal conductivities of skin layers on the effective thermal conductivity of human skin. The results show that the thickness of the epidermis has a large impact on the effective thermal conductivity measured with a guard-heated thermistor probe. This is because the measured effective thermal conductivity is a function of the thermal conductivities of both the epidermis and dermis, depending on the thermal penetration depth during measurement. At locations on the body with a thicker epidermis, such as the heel, the epidermal thermal conductivity dominates over the effective thermal conductivity. At locations on the body with a thinner epidermis, such as the cheek and forearm, the dermal thermal conductivity dominates over the effective thermal conductivity. The influences of physiological conditions, such as blood perfusion beneath the skin and metabolism, on the effective thermal conductivity of human skin, were also analyzed numerically. Variations in the blood perfusion rate and metabolic heat generation rate of the dermis layer were found to have a slight impact on the effective thermal conductivity; however, only the blood perfusion rate and the arterial blood temperature were found to influence the skin surface temperature.

Use of homeobox gene expression patterns to determine anatomical regions of origin for body surface tissues derived from adult mice

Anatomical regions of the skin have distinct functions and anatomical characteristics, including thicker or thinner epidermis, more or fewer hair follicles, and lighter or darker skin. For a better therapeutic outcome of skin transplantation, site-specific characteristics of grafted tissues need to be taken into account in terms of their functionality and beauty. However, there is no method for evaluating positional information of epidermal cells. Homeobox genes are expressed along the anterior-posterior axis and direct the body plan in the animal development process. Although the expression of several HOX genes is known to be retained as the positional information in adult tissue, their expression patterns in the body surface tissues in adult mammals are still incompletely understood. In this study, we investigated the expression patterns of 40 homeobox genes, including 39 Hox genes and the paired box 6 (Pax6) gene, in body surface tissues of adult mice. On the basis of the results obtained, we proposed, for the first time, a method for determining anatomical regions of origin for body surface tissues derived from adult mice using Hox genes and Pax6. Evaluation of expression levels of at least 7 Hox genes and Pax6 should be sufficient to distinguish 11 anatomical body surface tissues derived from the adult mouse body. The proposed method may be useful not only for determining the origin of surface tissues from specific anatomical regions of the mammalian body but also for predicting positional information of epithelial cells generated from pluripotent stem cells.