Comparison of the measuring efficacy of transepidermal water loss of a reasonably priced, portable closed-chamber system device H4500 with that of rather expensive, conventional devices such as Tewameter® and Vapometer®.

BACKGROUND/PURPOSE: Although measuring transepidermal water loss (TEWL) is important to assess the barrier function of the stratum corneum (SC), the commercially available instruments are rather expensive. Recently launched Model H4500 employs a closed-chamber system to measure TEWL and is more reasonably priced compared to devices currently in general use. METHODS: To check the reproducibility of the obtained data with H4500, we conducted measurements on the volar forearms of healthy volunteers and compared these data with those measured with Vapometer® and Tewameter® . Then, we checked the correlations between the TEWL data obtained with these different devices on the same volar forearms of 15 healthy volunteers before and after the artificial production of barrier damage of the SC by tape stripping or by 0.5% aqueous solution of sodium lauryl sulfate. RESULTS: The obtained intra-class correlation coefficient (ICC, [1, 1]) with 95% CI of H4500 was 0.927 (0.835-0.978). Namely, an excellent correlation could be found in the values of TEWL measured with these three different instruments not only on healthy skin but also on the artificially barrier-damaged skin. CONCLUSIONS: H4500 is considered to be practical for daily use because of its performance as well as its reasonable price as compared with conventional devices.

Electrical measurement of the hydration state of the skin surface in vivo.

Healthy skin surface is smooth and soft, because it is covered by the properly hydrated stratum corneum (SC), an extremely thin and soft barrier membrane produced by the underlying normal epidermis. By contrast, the skin surfaces covering pathological lesions exhibit dry and scaly changes and the SC shows poor barrier function. The SC barrier function has been assessed in vivo by instrumentally measuring transepidermal water loss (TEWL). However, there was a lack of any appropriate method for evaluating the hydration state of the skin surface in vivo until 1980 when we reported the feasibility of employing high-frequency conductance or capacitance to evaluate it quickly and accurately. With such measurements, we can assess easily the moisturizing efficacy of various topical agents in vivo as well as the distribution pattern of water in the SC by combining it with a serial tape-stripping procedure of the skin surface.

Characterization of facial skin of various Asian populations through visual and non-invasive instrumental evaluations: influence of seasons.

BACKGROUND/PURPOSE: This multicenter study assessed the impact of two types of extreme seasons (i.e. summer and winter) on the facial skin of female subjects living in different regions of Asia. METHODS: Facial skin of female subjects of various Asian ethnicities was characterized during summer and winter using dermatological assessments of the cheek and instrumental evaluations of the forehead and cheek. Approximately, 100 female subjects each from five cities in Asia (Harbin and Shanghai in China; New Delhi, India; Seoul, South Korea; and Sendai, Japan) ranging in age from 14 to 75 years were included in this study. RESULTS: Dermatologist assessments revealed a general decrease in severity of roughness, wrinkles, pigmentation, and lentigines during winter compared with summer. Instrumental assessments revealed significant differences in various parameters in winter vs. summer such as reductions in melanin index and skin surface hydration, and increases in transepidermal water loss, skin pH, redness, and sebum production. CONCLUSION: Facial skin in female subjects living in different Asian cities exhibited a wide range of changes and worsening of various biophysical parameters in response to the low temperature and humidity during the winter season as compared with summer.

Zinc l-pyrrolidone carboxylate inhibits the UVA-induced production of matrix metalloproteinase-1 by in vitro cultured skin fibroblasts, whereas it enhances their collagen synthesis.

Reduced collagen matrix in the dermis constitutes one of the characteristic features of chronologically aged skin, which is further enhanced on the sun-exposed portions of the body by chronic ultraviolet light (UV) irradiation, inducing the unique changes associated with skin photoageing. The zinc salt of l-pyrrolidone carboxylate (Zinc PCA) has long been used as a cosmetic ingredient, because of its astringent and anti-microbial properties. In the present study, by employing cultured normal human dermal fibroblasts, we found that Zinc PCA suppressed UVA-induced activation of activator protein-1 (AP-1) and reduced matrix metalloproteinase-1 production in these cells, which is thought to be involved in collagen degradation in photoaged skin. Moreover, Zinc PCA treatment of the cells increased the expression of an ascorbic acid transporter mRNA, SVCT2, but not SVCT1, resulting in the enhanced production of type I collagen. Based on these in vitro findings, we consider Zinc PCA to be a promising candidate for an anti-skin ageing agent.

Functional analyses of the skin surface of the areola mammae: comparison between healthy adult male and female subjects and between healthy individuals and patients with atopic dermatitis.

BACKGROUND: Although the nipple and areola of the breast constitute a unique and prominent area on the chest, so far no study has been done on the functional properties of their skin surfaces. OBJECTIVE: To study the stratum corneum (SC) covering the areola using noninvasive methods. METHODS: Eighteen adult healthy subjects comprising nine men and nine women and 18 age- and sex-matched patients with atopic dermatitis (AD), none of whom had visible skin lesions, participated in the study. Transepidermal water loss (TEWL), skin surface hydration and skin surface lipid levels were measured on the areola and adjacent breast skin. The size of the skin surface corneocytes of these skin regions was assessed. RESULTS: All the healthy subjects showed significantly higher TEWL accompanied by smaller sized corneocytes on the areola than on the adjacent breast skin. Only female subjects revealed a significantly higher skin surface hydration state together with significantly increased skin surface lipid levels on the areola than on the adjacent breast skin. These sex differences were observed even in patients with AD. Comparison between healthy individuals and the patients with AD demonstrated higher TEWL, decreased skin surface hydration state and lower skin surface lipid levels associated with smaller sized corneocytes in the areola in the patients with AD, especially in male patients. CONCLUSIONS: In adults, the SC barrier function and SC water-binding capacity of the areola were functionally poorer than in the adjacent skin, being covered by smaller sized corneocytes and lower amounts of skin surface lipids, especially in men and in patients with AD.

Pseudolymphomatous angiokeratoma: report of three cases and an immunohistological study.

BACKGROUND: Pseudolymphomatous angiokeratoma (PA), originally termed 'acral pseudolymphomatous angiokeratoma of children', is a disorder characterized clinically by development of red nodules on the extremities and histologically by a subepidermal dense lymphocyte infiltrate. METHODS: We report three cases of PA, with characteristically dense, nodular infiltrate composed predominantly of small lymphocytes, and thick-walled vessels. RESULTS: Immunohistochemical investigation revealed a dense accumulation of CD20+ cells with CD3+ cells in one case. Infiltrate in the other two cases was mainly composed of CD3+ cells and a mixture of CD4+ and CD8+ cells, with a few cells expressing CD20. CONCLUSION: Our immunohistological results reveal a wide spectrum of cellular infiltrate compositions ranging from T-cell to B-cell predominance.

p53 homologue, p51/p63, maintains the immaturity of keratinocyte stem cells by inhibiting Notch1 activity.

p53 homologue, p51/p63, predominantly expressed in keratinocyte stem cells, is indispensable for the formation of epidermis. Notch1, another such gene indispensable for the process, induces growth arrest and differentiation in keratinocytes. We found that exogenous expression of DeltaNp51B (DeltaNp63alpha), one of the isoforms of p51 specifically expressed in basal keratinocytes, blocked Notch 1-dependent growth arrest and differentiation in mouse keratinocytes by inhibiting p21 expression and maintaining integrins expression. Furthermore, DeltaNp51B by itself was found to have ability to induce expression of integrin alpha6beta4, which promotes attachment of basal cells to basal membrane thereby keeping the cells in immature state. Therefore, we conclude that DeltaNp51B expression warrants integrin expression even under the influence of Notch1 and that DeltaNp51B is a long-sought factor required to maintain basal cell keratinocytes immaturity by inhibiting Notch1 activity. We will postulate a plausible model explaining the maintenance of the squamous epithelium architectures as well as offering mechanistic explanations for pathological features of skin diseases, including cancers, psoriasis along with physiological wound healings.

A toxicologic and dermatologic assessment of cyclic acetates when used as fragrance ingredients.

An evaluation and review of a structurally related group of fragrance materials.

Location-related differences in structure and function of the stratum corneum with special emphasis on those of the facial skin.

Between the two different kinds of the skin covering the body, the glabrous skin is found only on the palmo-plantar surface because of its rather simple function to protect the underlying living tissue with its remarkably thick stratum corneum (SC) from strong external force and friction. Thus, its barrier function is extremely poor. In contrast, the hair-bearing skin covers almost all over the body surface regardless of the presence of long hair or vellus hair. In regard to its SC, many dermatologists and skin scientists think that it is too thin to show any site-specific differences, because the SC is just present as an efficient barrier membrane to protect our body from desiccation as well as against the invasion by external injurious agents. However, there are remarkable regional differences not only in the living skin tissue but also even in such thin SC reflecting the function of each anatomical location. These differences in the SC have been mostly disclosed with the advent of non-invasive biophysical instruments, particularly the one that enables us to measure transepidermal water loss (TEWL), the parameter of the SC barrier function, and the one that evaluates the hydration state of the skin surface, the parameter of the water-holding capacity of the SC that brings about softness and smoothness to the skin surface. These in vivo instrumental measurements of the SC have disclosed the presence of remarkable differences in the functional properties of the SC particularly between the face and other portions of the body. The SC of the facial skin is thinner, being composed of smaller layers of corneocytes than that of the trunk and limbs. It shows unique functional characteristics to provide hydrated skin surface but relatively poor barrier function, which is similar to that observed in retinoid-treated skin or to that of fresh scar or keloidal scars. Moreover, there even exist unexpected, site-dependent differences in the SC of the facial skin such as the forehead, eyelid, cheek, nose and perioral regions, although each location occupies only a small area. Between these locations, the cheek shows the lowest TEWL in contrast to the perioral region that reveals the highest one. Moreover, these features are not static but change with age particularly between children and adults and maybe also between genders. Among various facial locations, the eyelid skin is distinct from others because its SC is associated with poor skin surface lipids and a thin SC cell layer composed of large corneocytes that brings about high surface hydration state but poor barrier function, whereas the vermillion borders of the lips that are covered by an exposed part of the oral mucosa exhibit remarkably poor barrier function and low hydration state. Future studies aiming at the establishment of the functional mapping in each facial region and in other body regions will shed light on more delicate site-dependent differences, which will provide us important information in planning the strategy to start so called tailor-made skin care for each location of the body.

A toxicologic and dermatologic assessment of ionones when used as fragrance ingredients.

An evaluation and review of a structurally related group of fragrance materials.

A toxicologic and dermatologic assessment of salicylates when used as fragrance ingredients.

An evaluation and review of a structurally related group of fragrance materials.

A toxicologic and dermatologic assessment of related esters and alcohols of cinnamic acid and cinnamyl alcohol when used as fragrance ingredients.

An evaluation and review of a structurally related group of fragrance materials.

How is epigenetic information on chromatin inherited after DNA replication?

Although most somatic cells have identical genetic information, gene expression profiles are quite distinct in each cell type. The gene expression profiles are considered to be determined mainly by chromatin-encoded epigenetic information that includes histone modifications, histone variants, and factors such as HP1 and polycomb group proteins that organize higher-ordered chromatin structures. To gain insights into how such epigenetic information on chromatin is inherited on daughter DNA strands after DNA replication, we have purified the preassembled form of histone H3 by immunoaffinity purification. The histone H3 complex contains the two histone H3-H4 chaperones CAF1 and ASF1. Surprisingly, the H3 complex also contains a pair of H3-H4 dimers. This observation is striking because histones H3-H4 are known to exist as tetramers in solution. Since histones H3-H4 in the predeposition complex exist as a dimer, this raises the possibility that the H3-H4 dimer in the complex pairs with a parental H3-H4 dimer, assembling the de novo-synthesized and parental H3-H4 dimers in the same nucleosome. Based on these results, we propose a semi-conservative model of nucleosome duplication, which allows for segregation of parental H3-H4 dimers with encoded epigenetic information evenly to daughter DNA strands.

An evaluation of semen processing methods for eliminating HIV-1.

OBJECTIVE: Whether artificial insemination can provide adequate protection for discordant couples where the man is HIV-1 positive and the woman is HIV-1 negative is uncertain because of the paucity of HIV-1 elimination data assessing current sperm-washing techniques. We evaluated how effectively these techniques eliminate HIV-1 RNA and proviral DNA from semen. METHODS: Spermatozoa were separated from semen samples from HIV-1-positive patients with haemophilia by discontinuous Percoll gradient centrifugation and the 'swim-up' method. The HIV-1 RNA and proviral DNA were measured by a highly sensitive PCR. In another test 5 x 10(6) copies of HIV-1 RNA (LAI strain) were added to semen from healthy donors and then assessed after single and combined procedures. RESULTS: Swim-up processing after Percoll gradient centrifugation reduced HIV-1 RNA and HIV-1 proviral DNA in semen to undetectable levels in the original specimen. Although discontinuous and continuous Percoll gradient centrifugation respectively reduced HIV-1 RNA added to seminal plasma specimens from healthy donors to less than < 1 copy from 10(5) and about 1 copy per 10(3) pre-separation copies, the discontinuous method left detectable HIV-1 RNA and proviral DNA in one out of 12 samples from patients with HIV-1 infection (8%). HIV-1 RNA and proviral DNA were decreased to undetectable levels after adding the swim-up procedure. CONCLUSIONS: Swim-up separation following Percoll gradient centrifugation should offer adequate protection for HIV-1-discordant couples.

Epidermal cell proliferation in guinea pigs with experimental dermatophytosis.

To elucidate the mechanisms underlying the self-healing process of experimental dermatophytosis produced in guinea pigs by an occlusive method with Trichophyton mentagrophytes, epidermal proliferative activity was evaluated by the in vivo tritiated thymidine-labeling technique performed at various intervals after the first and second infections. Determination of labeling indices disclosed that an increased epidermal proliferation correlated well with the severity of inflammatory changes, i.e., a peak activity was noted after 10 days in primary infection and at 2 days in reinfection, respectively, and was followed by subsequent spontaneous lesion clearance after 10 days. Application of a heat-killed spore suspension produced inflammatory changes with enhanced epidermopoiesis, similar to those induced by reinoculation of living spores, only in immune animals. The present results indicate that the dermatitic changes occurring in experimental dermatophytosis increase epidermopoiesis which facilitates elimination of the fungus from the stratum corneum and that host immune activity, particularly contact sensitivity to fungal antigen, exerts a crucial role to induce these changes.

Alteration in murine epidermal Langerhans cell population by various UV irradiations: quantitative and morphologic studies on the effects of various wavelengths of monochromatic radiation on Ia-bearing cells.

The present study was undertaken in order to clarify the exact mode of the Langerhans cell (LC) depleting process caused by UV irradiation. Following irradiation with a single dose of various wavelengths of monochromatic UV radiation (UVR), we studied the number of Ia-positive cells in mouse epidermal sheets quantitatively, particularly with regard to dose-response relationship, action spectrum, and time course change. In addition, we studied morphologic alterations of these cells using electron- and immunoelectron microscopy (EM and IEM). We obtained the following results after a single dose of UVB radiation (200 mJ/cm2 of 300 nm) or PUVA (1% of 8-methoxypsoralen (8-MOP) 20 microliter and 1 J/cm2 of 360 nm): (1) EM and IEM showed that while some LCs simply lost their Ia marker without any structural alterations, the majority of the LCs disappeared due to actual cell damage. (2) During an "injury phase," the initial 48 h, and a "recovery phase," lasting from 4-14 days after irradiation, enlargement of the size of remaining Ia-positive LCs occurred. The degree of enlargement was closely related to the degree of reduction in number, suggesting a process compensating for the loss of the LC population. (3) It was found that the recovery rate of LCs after irradiation damage was slower than that of keratinocytes, indicating different cell kinetics between these distinct cell populations in the epidermis, i.e., restoration of LCs after irradiation seems to be achieved at least partially through a repopulation process originating in the bone marrow. Studies with irradiation of various monochromatic wavebands, with or without topical 8-MOP, showed that the action spectrum for Ia-positive cell depletion activity lay within the spectrum shorter than 300 nm for UVR alone, and between 320-380 nm for 8-MOP plus UVR. Since the action spectra were similar to those for keratinocyte damage, i.e., sunburn cell formation, induction of unscheduled DNA synthesis, and to those for UVR-induced erythema, we conclude that common mechanisms underlie these types of tissue damage.

Electrical determination of water content and concentration profile in a simulation model of in vivo stratum corneum.

Because of its efficient water-holding capacity, healthy stratum corneum (SC) can stay soft and flexible under any environmental conditions. There may be, however, a great difference in water content within the SC between the lowermost layer that faces the wet underlying living tissue and the superficial portion of the SC that is exposed to the relatively dry ambient atmosphere. To better understand the water profile of the SC and also to verify the accuracy of measurements of high frequency conductance used to evaluate the hydration state of the skin surface, we devised a simple and convenient in vitro model of the SC that stimulates the in vivo setting of the SC. It consists of an isolated sheet of SC whose lower surface covers a pad of water-saturated filter paper, and its upper surface is exposed to the ambient atmosphere. By placing this model in environments with different relative humidities (RH), we confirmed that the recorded conductance values correlated well with the actual water content of the SC (r = 0.94). Using a model having five layers of SC sheets, the water content of the innermost portion of the SC was estimated to be equivalent to about 90% of its dry weight; this level of water content remaining relatively constant over a wide range of ambient RH except in extraordinarily humid environments above 90% RH when water began to accumulate excessively in the whole SC. Using this five SC-sheet model, it was clearly demonstrated that there was an almost straight water concentration gradient from the lowermost layer to the uppermost layer of the SC. We also confirmed that the skin conductance of the high frequency current correlated well with the water content of the superficial portion of the SC as well as with that of the whole SC, therefore, it is a good parameter of the hydration state of the superficial layer of the SC.

Changes in expression of Ia, Thy-1, and Ly-5 antigens in epidermal cells during delayed contact sensitivity reactions in mice: flow cytometric analysis.

Ia antigen-bearing (Ia+) Langerhans cells have attained an important position as immunocompetent cells in the epidermis. Recently there have been successive reports on other new possible candidates for immunocompetent cells in the epidermis, i.e., Ia+ keratinocytes and dendritic Thy-1 antigen-bearing (Thy-1+) epidermal cells which also express Ly-5 antigen and asialo-GM1. Based on our previous findings that in allergic contact sensitivity reactions, keratinocytes express Ia antigen 3-9 days postchallenge, in this report, we have attempted to define more clearly the dynamic changes of Ia+ keratinocytes and dendritic Thy-1+ epidermal cells by enumeration of the precise percentages of Ia+, Thy-1+, and Ly-5 antigen-bearing (Ly-5+) cells in epidermal cells at various times of the challenge phase in allergic contact sensitivity reactions by use of a fluorescence-activated cell sorter. By 24 h postchallenge, the percentages of Ia+, Thy-1+, and Ly-5+ cells showed hardly any change. There were approximately 2% Ia+ cells, 50% Thy-1+ cells which consist of 2 populations (i.e., 45% weakly Thy-1 antigen-positive cells and 4% strongly Thy-1 antigen-positive cells), and 3.5% Ly-5+ cells. From 48 h postchallenge, however, the percentage of Ia+ cells and that of Thy-1+ cells began to increase and reached a plateau, with approximately 20% Ia+ cells and 70% Thy-1+ cells, respectively, at 120 h postchallenge. The change of the percentages of Ly-5+ cells appears to correspond to that of strongly Thy-1 antigen-positive cells. Only at 48 h postchallenge, Ly-5+ cells and strongly Thy-1 antigen-positive cells showed a small increase in number, comprising approximately 10% of the epidermal cells. These data suggest that among Thy-1+ epidermal cells, strongly Thy-1 antigen-positive cells correspond to dendritic Thy-1+ epidermal cells, and in contact sensitivity reactions in mice, dendritic Thy-1+ epidermal cells show only a minor dynamic change in contrast to Ia+ cells, in which more than 15% of keratinocytes express Ia antigen from 48 h postchallenge.

Role of complement in chlorpromazine-induced phototoxicity.

To evaluate the role of the complement system in inflammation induced by chlorpromazine (CPZ) and ultraviolet-A (UVA) irradiation, the phototoxic response in guinea pigs decomplemented by cobra venom factor was compared with that in saline-treated animals. Phototoxic lesions were induced in animals by intradermal injections of CPZ solution, followed by UVA irradiation. Clinically, the normal animals developed erythema and induration which showed a maximal response at 10 h with a mean value of 1.6 on a scale of 0 to 3+. The complement-depleted animals showed a weaker clinical response than the normal animals 6-24 h postirradiation (p less than 0.05). These clinical changes were associated with increased vascular permeability, as demonstrated by extravasation of i.v. injected Evans blue in saline-treated animals. In vitro UVA irradiation of serum containing CPZ resulted in a dose-dependent diminution of total complement activity. Such irradiated serum showed immunoelectrophoretic C3 conversion. These results suggest that the complement system is involved in the development of CPZ-induced phototoxic lesions.

Functional analysis of Ia antigen-bearing keratinocytes: mixed skin lymphocyte culture between Ia antigen-bearing Pam 212 cells and allogeneic and syngeneic splenic T cells.

Keratinocytes express Ia antigens in various skin disorders, although the biological role of these Ia antigen-bearing (Ia+) keratinocytes remains unclear. We induced Ia antigens on Pam 212 murine keratinocyte cell line by interferon-gamma(IFN-gamma) and using these cells, we performed the mixed skin lymphocyte culture with syngeneic BALB/c or allogeneic C3H/He splenic T cells. Unexpectedly, Pam 212 cells were found to stimulate both syngeneic and allogeneic T cells irrespective of IFN-gamma treatment. However, both syngeneic and allogeneic T cells cultured with IFN-gamma-treated Pam 212 cells incorporated [3H]thymidine much more actively than those cultured with IFN-gamma-untreated Pam 212 cells. This stimulation was not inhibited by monoclonal anti-I-Ad antibody. Analysis of the responding T cells demonstrated that the syngeneic T-cell stimulation by IFN-gamma-treated Pam 212 cells occurred in both purified Lyt 1-T cells and Lyt 2- T cells. Furthermore, we found that the T cells cultured with the IFN-gamma-treated cells were composed of two morphologically different types of cells. Determination of their surface phenotype showed that the small cell population consisted of 57% Thy-1+, 23% Lyt-1+, 6% Lyt-2+, and 9% asialo-GM1+ cells, while the large cells consisted of 53% Thy-1+, 15% Lyt-1+, 9% Lyt-2+, and 24% asialo-GM1+ cells. These findings suggest that IFN-gamma-treated Pam 212 cells could stimulate more than one kind of splenic T cell populations.