H. Tagami

Number of cell layers of the stratum corneum in normal skin – relationship to the anatomical location on the body, age, sex and physical parameters

Abstract We counted the number of cell layers in the stratum corneum (SC) of normal skin taken from different anatomical locations of the body of 301 individuals of various ages. Frozen 6 μm thick sections were stained with a 1% aqueous solution of safranin and observed under a microscope after application of 2% KOH solution. There were great variations in the number of SC cell layers (mean ± SD) according to location and among different individuals. The smallest number was found in genital skin (6 ± 2), followed in order by skin of the face (9 ± 2), neck (10 ± 2), scalp (12 ± 2), trunk (13 ± 4), extremities (15 ± 4) and the palms and soles (47 ± 24). The heel showed the largest number (86 ± 36). No definite correlation was found between the number of corneocyte layers and sex of the individual, whereas there was a slight increase in the number of SC layers with age in the skin of the cheek and back, particularly in male individuals. Comparison of these data with those from functional assessments of the SC of the skin from various locations of healthy adults showed that transepidermal water loss, an indicator of SC barrier function, reflected the number of corneocyte cell layers. In contrast, high-frequency conductance, an indicator of the hydration state of the outer SC, did not seem to be under the influence simply of the number of SC cell layers.

Stratum corneum hydration and amino acid content in xerotic skin

The relationship between clinical severity, the hydration state of the skin surface as assessed by a conductance with a 3.5 MHz high frequency impedance meter, and the amino acid content of the stratum corneum (SC) of six patients with ichthyosis vulgaris and 30 elderly persons with varying degrees of xerosis was investigated. With an increase in the severity of xerosis the SC showed a decrease in hydration and in its extractable amino acid content. There was a significant correlation between the hydration state and amino acid content of the SC. Although there was a significant correlation between the amino acid content of the lower leg SC and that of the forearm SC in the same subject, the former was generally lower, corresponding to the greater incidence of xerosis on the lower leg. These results suggest that a decreased amount of amino acids may be the result of low profilaggrin biosynthesis in the epidermis and that this is involved in the pathogenesis of these xerotic skin conditions. Clinical improvement of the xerosis following treatment with a urea‐containing cream was not accompanied by any significant change in the amino acid content of the SC.

Comparison of the depth profiles of water and water‐binding substances in the stratum corneum determined in vivo by Raman spectroscopy between the cheek and volar forearm skin: effects of age, seasonal changes and artificial forced hydration

Background  Dermatologists and cosmetic scientists are becoming increasingly interested in stratum corneum (SC) hydration because the SC plays an important role in keeping the skin surface soft and smooth. However, conventional in vivo noninvasive methods do not provide direct information about the depth profiles of water content or SC components that hold water.

Successful treatment of psoriasis with topical application of active vitamin D3 analogue, 1α, 24‐dihydroxycholecalciferol

We treated 11 psoriatic patients with topical 1α, 24‐dihydroxycholecalciferol, a new synthetic analogue of active vitamin D3. In 10 of 15 tests the lesions cleared completely within 1–4 weeks, although some relapses occurred shortly after cessation of treatment. There were no side‐effects. We suggest that 1α, 24(OH)2D3 merits further investigation as a potentially useful topical therapy for psoriasis.

Role of neutrophils in induction of acute inflammation in T-cell-mediated immune dermatosis, psoriasis: a neutrophil-associated inflammation-boosting loop.

Abstract: A growing body of evidence has indicated that T‐cell‐mediated immunity plays an important role in triggering and maintenance of psoriatic lesions. In this review we present our own experimental results as well as those from the literature related to the pathomechanism of the development of inflammatory changes in psoriatic lesions. First of all it is important to acknowledge the fact that psoriatic lesions are not uniform as assumed by many authors but that they are actually rather heterogeneous both clinically and histologically even within the same plaques. Lymphokines produced by activated T cells in psoriatic lesions have a strong influence on the proliferation of the epidermis, whose stimulated kertinocytes released several cytokines, which in turn enhance the activation state of T cells. Thus, they form a vicious cycle, a T‐cell‐mediated inflammation‐sustaining loop. Although the interaction between T‐cell‐mediated immunity and epidermal keratinocytes may well explain the maintenance of background “chronic” inflammatory changes diffusely observed throughout psoriatic lesions, it is not enough to explain the island‐like, “acute” inflammatory changes observed within and at the border of the plaque lesions. Characteristic neutrophil accumulation under the stratum corneum can be observed in the highly inflamed and therapeutically recalcitrant areas of psoriatic lesions. They are chemotactically attracted and activated there by synergistic action of chemokines, IL‐8 and Gro‐α released by the stimulated keratinocytes, and particularly C5a/C5a des arg produced via the alternative complement pathway activation possibly on the surface of corneocytes. In this review, we emphasize that the accumulation of neurophils is not simply a passive event. We think that those stimulated neutrophils are able to influence not only the growth and differentiation of epidermal keratinocytes but also the activation‐state of T cells by aberrant expression of HLA‐DR on their surfaces as well as by their effects. These T cells in turn influence the transepidermal neutrophil migration through the effect of their lymphokines on the keratinocyte production of pro‐inflammatory mediators including C3. Therefore, we propose a neutrophil‐associated inflammation‐boosting loop that may well explain the localized “acute” inflammatory changes scattered over the ‘’chronic” psoriatic plaques as well as in the acutely inflamed lesions of pustular psoriasis.

Age- and sex-dependent change in stratum corneum sphingolipids

We measured six stratum corneum sphingolipid species (ceramides 1–6) in 26 males and 27 females, and found a significant change in their percentage composition only among female subjects of different age groups. There was a significant increase in ceramide 1 and 2 with a corresponding decrease in ceramide 3 and 6 from prepubertal age to adulthood. Thereafter the ratio of ceramide 2 to total sphingolipids decreased with age in contrast to ceramide 3 which showed an increase. Such a pattern of change in the aging population is different from that observed in scaly skin experimentally induced by tape stripping. The present results suggest a significant influence of female hormones on the composition of stratum corneum sphingolipids. Moreover, the different patterns of change in sphingolipid composition of stratum corneum lipids between scales from inflammatory skin and those from aged skin also suggest that epidermal biosynthesis of sphingolipids is influenced by epidermal proliferative activity.

Epidemiology and prognosis of subungual melanoma in 34 Japanese patients

The incidence of malignant melanoma is much lower in the Japanese than in Caucasians. However, amongst the various types of malignant melanoma, the subungual and periungual sites are commonly found in the Japanese. One hundred and fifty‐one cases of cutaneous malignant melanoma were seen over a 25‐year period at our hospital. We found that. In 34 patients (23%). the subungual region was involved, a high frequency for one institution. We have analysed these patients and looked at their treatment. The finger nails were affected in 21 cases (62%) and the toe nails in 1 3 cases (38%). The thumb nails or great toe nails were at tecled in 25 of the 34 patients (73%). In 25 patients, histopathological features of acral lentiginous melanoma were found, with four cases of superficial spreading melanoma and five of nodular amelanotic melanoma. Of the latter group, four mimicked tibrous histiocytic tumour, and one was a desmoplastic malignant melanoma. I he proportion of patients presenting with stage III disease decreased after 1982. with a corresponding increase in patients whose tumour thickness was less than 4 mm (stage II). Concurrently, the prognosis for subungual malignant melanoma improved. The 5‐year survival rate in each of the periods 1969–82 and 1981—93 was 5 3 and 87%. respectively. This is similar to that found in plantar malignant melanoma and is fell to be due to a greater public awareness of the condition and to the introduction of effective chemotherapy (the DTIC‐AC nitro surear vincristine (OAV) regimen). Although the frequency of malignant melanoma is rather low in the Japanese, our data indicate that there is a high incidence of subungual malignant melanoma. Public awareness of the early stage of malignant melanoma seems to have improved prognosis.

An evaluation of semen processing methods for eliminating HIV-1

ObjectiveWhether 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. MethodsSpermatozoa 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 × 106 copies of HIV-1 RNA (LAI strain) were added to semen from healthy donors and then assessed after single and combined procedures. ResultsSwim-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 105 and about 1 copy per 103 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. ConclusionsSwim-up separation following Percoll gradient centrifugation should offer adequate protection for HIV-1-discordant couples.

Functional properties of the stratum corneum in patients with diabetes mellitus: similarities to senile xerosis

Background  Although diabetes mellitus is known to induce many pathophysiological changes in the skin, none of the earlier studies has focused on the state of the stratum corneum (SC) in patients with diabetes. In our previous report on a diabetic mouse model, we described a decreased SC hydration state and abnormalities in the function of the sebaceous gland together with a normally retained barrier function of the SC.

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 ΔNp51B (ΔNp63α), 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, ΔNp51B by itself was found to have ability to induce expression of integrin α6β4, which promotes attachment of basal cells to basal membrane thereby keeping the cells in immature state. Therefore, we conclude that ΔNp51B expression warrants integrin expression even under the influence of Notch1 and that ΔNp51B 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.