Levels of fluconazole in serum, stratum corneum, epidermis-dermis (without stratum corneum) and eccrine sweat

The distribution in the skin of orally active antifungals and other drugs claimed to be active in the treatment of skin diseases is of major importance, but to date has been studied only rarely. In the present study the distribution of fluconazole in stratum corneum, epidermis dermis (without stratum corneum), eccrine sweat and serum was studied in human male volunteers after dosages of 50 mg daily for 12 days and 150 mg once weekly for 2 weeks. In the present study high levels of fluconazole were found especially in the stratum corneum. At a dose of 50 mg once daily the concentration of fluconazole after 12 days was 73·0 μg/g and 7 days after cessation of treatment the concentration was still 5·8 μg/g. At the 150 mg once a week dose the concentration 7 days after the second dose was still 7·1 μg/g in stratum corneum indicating that medication once a week may be effective in the treatment of dermatomycoses. High concentrations, all above the serum concentrations, were also seen in sweat and epidermis/dermis. These results indicate that fluconazole is delivered to the stratum corneum, where it is accumulated, through sweat and by direct diffusion through the dermis-epidermis. These pharmacokinetic results indicate that the drug should be very effective in the treatment of dermatomycoses. An extremely high concentration of the drug in the stratum corneum combined with concentrations from 2·93 to 4·62 μg/g in the rest of the epidermis and dermis is important in the treatment of these diseases.     

Levels of terbinafine in plasma, stratum corneum, dermis–epidermis (without stratum corneum), sebum, hair and nails during and after 250 mg terbinafine orally once daily for 7 and 14 days

In earlier skin pharmacokinetic studies we have shown that terbinafine is rapidly delivered to the stratum corneum, nails and hair both through sebum and by direct diffusion through dermis epidermis. In the present study the skin pharmacokinetic profile of terbinafine was studied in two groups of eight human male volunteers during and after 250 mg orally once daily for 7 and 14 days. In the 7-day study high terbinafine levels were found in sebum (19.0 μg/g) and stratum corneum (2.5 μg/g), and a concentration in stratum corneum above the minimal inhibitory concentration for most dermatophytes was still found 48 days after the last day of medication. Terbinafine was found in peripheral nail clippings after 7 days of medication and the concentration was, in the 7-day study, 0.5 μg/g 1 day after stopping medication; it was still 0.2 μg/g 90 days after stopping treatment. The results in the 14–day study were in parallel with, but higher than, in the 7-day study. The elimination of terbinafine from several compartments is biphasic, with a faster initial elimination followed by a slower secondary elimination. For nails, the elimination is slower compared with the other compartments. The results indicate that terbinafine may be effective in short-term treatment of several dermatophytoses. The concentration of 0.2 μg/g of terbinafine found in nails 90 days after stopping medication, following 7 days of treatment, indicates that the duration of therapy, even in tinea ungium, may be shorter than is currently the case.     

我国正常人皮肤表面皮脂和水分含量的研究

目的：了解我国不同年龄、不同性别正常人皮肤角质层含水量、皮肤表面皮脂含量及皮肤皮脂的分泌速度。方法：利用皮肤表面皮脂测量仪和皮肤水分含量测量仪对我国北方325名正常人的前额及前臂屈侧皮肤皮脂量和皮肤含水量进行测量。结果：12岁以前,男女前额皮脂量无差异;13岁以后,男性前额的皮脂量明显高于女性。除36～50岁年龄组外,女性前额的皮脂分泌快于男性。男女前臂的皮脂量无差异。除男性13～35岁组的前额皮肤含水量高于女性外,其他各年龄组各部位男、女皮肤含水量无显著差别。13～35岁组男、女性前额的含水量均高于前臂。其他各年龄组前额和前臂皮肤含水量无明显部位差异。13-35岁组男性前额皮肤含水量最高。结论：正常人皮肤表面含水量和皮脂含量因性别、年龄和部位的不同而有差异。     

Effect of lactic acid isomers on keratinocyte ceramide synthesis,stratum corneum lipid levels and stratum corneum barrier function

Alpha-hydroxy acids are effective agents for the treatment of skin xerosis and it is known that, following treatment with lotions containingd,l-lactic acid, the stratum corneum prevents xerosis more effectively. To date, the relative efficacy of the different isomers of lactic acid has not been evaluated and the mode of action of lactic acid in improving stratum corneum resilience is not known. The objective of the present studies was to determine the effects of lactic acid isomers on keratinocyte ceramide biosynthesis, stratum corneum barrier function and the resistance of the straum corneum to the appearance of skin xerosis. In vitro, lactic acid enhanced the production of ceramides by keratinocytes.l-Lactic acid was more effective than thed isomer (300% increase vs 100% increase). Carbon label from lactic acid was incorporated into all keratinocyte lipid species and a greater incorporation of label into ceramides was achieved withl-lactate than withd-lactate. In vivo, lactic acid increased the levels of stratum corneum ceramides. Whereas, lotions containingl-lactic acid resulted in the greatest increase (48% increase) followed byd,l-lactic acid (25% increase),d-lactic acid had no effect on stratum corneum ceramide levels. The increases in stratum corneum ceramide levels following lactic acid treatment also led to improvements in stratum corneum barrier function, measured by transepidermal water loss following a challenge to the skin with SLS and in the regression phase of a moisturization efficacy study. Significant improvements in barrier function and resistance to the appearance of skin xerosis were observed followingl-lactic acid andd,l-lactic acid, but not followingd-lactic acid treatment. From these results we believe that lactic acid, particularly thel isomer, stimulates ceramide biosynthesis leading to increased stratum corneum ceramide levels which results in superior lipid barrier and a more effective resistance against xerosis.     

Skin aging. Effect on transepidermal water loss, stratum corneum hydration, skin surface pH, and casual sebum content.

This study investigates the effect of cutaneous aging on transepidermal water loss, stratum corneum hydration (capacitance), skin surface pH, and causal sebum content. Because the physiologic condition of skin varies considerably with anatomic region and skin aging might demonstrate regional variability, all factors were studied on 11 anatomic locations in 14 young adult (seven female and seven male subjects; 26.7 +/- 2.8 years [mean +/- SD]) and 15 aged human volunteers (seven female and seven male subjects; 70.5 +/- 13.8 years). Significant anatomic variability was noted for all factors in both age groups. However, no significant differences between the two groups were noted for sebum, capacitance, and pH on most anatomic regions. Transepidermal water loss, however, was significantly lower in the aged population on all anatomic regions tested, except for the postauricular region and the palm. Comparing male and female volunteers, none of the four factors showed significant differences. Of all measured factors, only transepidermal water loss showed significant age-related differences on most anatomic regions studied. The additionally observed differences between the age groups on the ankle for pH and sebum might be related to the stasis frequently observed on the lower limbs in aged individuals.     

Pathologic S-phase in the cells of eccrine sweat glands and of hair follicles in psoriasis

Summary The prolongation of the S-phase, characteristic of psoriatic keratinocytes, can be observed in cells of the eccrine sweat glands as well as in those of the infundibular part of hair follicles. In healthy individuals the average duration of DNA-synthesis time (ts) in the cells of the hair follicle is 6.8 h, in unaffected psoriatic skin 11.6 h, and in affected psoriatic skin 8.4 h. Ts in the proliferating cells of the eccrine sweat glands reveals no difference between normal skin and unaffected psoriatic skin, but is markedly prolonged in affected psoriatic skin.This work was supported by the Deutsche Forschungsgemeinschaft     

Glycosylated proteins of stratum corneum, nail and hair in diabetes mellitus: correlation with cutaneous manifestations

Nonenzymatic glycosylation of protein may play some role in the development of diabetic complications. To study the association of nonenzymatically glycosylated protein in keratinized tissues with the prevalence of cutaneous manifestations frequently observed in diabetics, we measured furosine values of stratum corneum, nail and hair from 61 diabetics and assessed their cutaneous manifestations. The manifestation most frequently found in this study was 10 cases of pigmented pretibial patches. We did not detect significant correlations between the prevalence of any cutaneous manifestations and furosine values of any keratinized tissues. However, 11 of the 17 patients with yellow nail showed high nail furosine values. Our data suggest that nonenzymatically glycosylated protein levels in the keratinized tissues do not correlate with the prevalence of cutaneous manifestations in diabetics, but do not exclude a role in the formation of yellow nail.     

Amputee skin condition: occlusion,stratum corneum hydration and free amino acid levels

Patients with a prosthetic limb report negative skin effects, including irritation, rash and chaffing, which can lead to infection, discomfort and reduced wear time to significantly impact normal activities. The aims were to examine the epidermal integrity (transepidermal water loss, TEWL), stratum corneum (SC) hydration [moisture accumulation rate (MAT)], friction and biomechanical properties in active below the knee amputees and to determine the effects of an inert sock liner on skin condition. The liner reduced hydration, TEWL and friction and increased elasticity versus the amputee’s conventional skin care methods. Residual limb TEWL was increased and MAT was reduced versus the contralateral normal skin. In a second study, we hypothesized that complete occlusion would decrease free amino acids (FAA) and quantified them by high performance liquid chromatography in an adult volar forearm model. Occlusion with a water vapor impermeable wet dressing led to increased TEWL, erythema and dryness and reduced MAT versus normal skin, comparable to the results in the amputees. The FAA levels were significantly reduced for the occluded sites. The results suggest that residual limb occlusion in amputees may block the formation of FAA in the upper SC. Therapies based on replacement of water binding FAAs, may alleviate the consequences of long-term occlusion.     

Immunohistochemical staining characteristics of epidermal appendages (hair follicles and eccrine sweat glands) to anti-epidermal keratin antisera

The cellular characteristics of the epidermal appendages and their differentiations in relation to those of the epidermis have been chiefly studied from the morphological points in the past. We investigated them from the immunohistochemical characteristics of the constituent keratin protein to the antiserum against total keratin isolated from human plantar stratum corneum (TKA) which stains the whole epidermis, and to the antiserum against 64K keratin separated from total keratin (64KA) which stains the whole epidermis except the basal layer. In the hair follicles, medulla and cortex of the hair shaft and inner root sheath were positively stained with both types of the antisera only at the keratogenous zone. The staining pattern of the outer root sheath with 64KA were variable at different levels of the hair follicle. The secretory portion of the eccrine glands showed a heterogeneous staining pattern as compared with the ductal portions which were stained homogeneously by both antisera. In eccrine poroma, all of the tumor cells were stained positively with TKA, while negatively or positively stained cells were intermingled with 64KA, suggesting that only some tumor cells showed mature keratinization.     

Water distribution and related morphology in human stratum corneum at different hydration levels

This study focused on the water distribution in human stratum corneum and on the swelling of the corneocytes. For this purpose stratum corneum was hydrated to various levels and used either for Fourier transform infrared spectroscopy or for cryo-scanning electron microscopy. The images were analyzed with respect to water localization and cell shape. The Fourier transform infrared spectra were measured to study the water-lipid interactions. The results show that water only slightly changes the lipid transitions in the stratum corneum even at a hydration level of 300% wt/wt compared to stratum corneum and that water is inhomogeneously distributed in the stratum corneum. No gradual increase in water level was observed in depth. At 57%-87% wt/wt water content the hydration level in the central part of stratum corneum is higher than in the superficial and deeper cell layers. Water domains are mainly present within the corneocytes and not in the intercellular regions. At a very high hydration level (300% wt/wt), the corneocytes are strongly swollen except for the deepest cell layers adjacent to the viable epidermis. The corneocytes in these layers are not swollen. At 300% wt/wt hydration level water domains are also present in intercellular regions. Between 17% wt/wt and 300% wt/wt the cell thickness increases linearly with the hydration level suggesting that swelling of cells mainly occurs in the direction perpendicular to the skin surface. At an increased hydration level, the corneocyte envelope more efficiently surrounds the cell content compensating for the increased cell volume. The changes in stratum corneum morphology with increasing water level have also been observed in dermatomed skin.     

Cytokines at different stratum corneum levels in normal and sodium lauryl sulphate-irritated skin

BACKGROUND/PURPOSE: Cytokines play an important role in inflammatory and repair processes occurring in the skin. The objectives of this study were to determine the amounts of cytokines and protein isolated by tape stripping in the different layers of the stratum corneum (SC), and to compare normal skin with skin exposed in vivo to the irritant sodium lauryl sulphate (SLS). METHODS: In eight volunteers, we determined the amount of total and soluble protein and also interleukin-1alpha (IL-1alpha) in pooled tape strips obtained from the upper, intermediate and lower parts of the SC. Three different types of tape were compared (Diamond , D-squame or Sentega tape). In a separate study, 20 volunteers were repeatedly exposed to 0.1% SLS over a 3-week period. The amounts of IL-1alpha, IL-1RA and IL-8 in strips obtained from the three different SC levels of SLS-exposed skin were compared with an unexposed site. RESULTS: For normal skin, the amounts of soluble protein and IL-1alpha were similar for the three tapes. Diamond tape showed the highest yield of total protein. The total protein yield per strip decreased to lower SC levels, whereas soluble protein and IL-1alpha normalized by soluble protein did not change across the SC. After SLS induced skin irritation, IL-1alpha decreased and IL-1RA and IL-8 increased at increasing depth into the SC. CONCLUSIONS: Tape stripping is a suitable method to determine SC cytokine concentrations in human skin. With this technique, it is possible to study changes in cytokine concentrations at different SC layers after skin irritation.     

Aberrant human tissue kallikrein levels in the stratum corneum and serum of patients with psoriasis: dependence on phenotype, severity and therapy

BACKGROUND: Human tissue kallikreins (KLKs) are a family of 15 trypsin-like or chymotrypsin-like secreted serine proteases (KLK1-KLK15). Multiple KLKs have been quantitatively identified in normal stratum corneum (SC) and sweat as candidate desquamation-related proteases. OBJECTIVES: To quantify KLK5, KLK6, KLK7, KLK8, KLK10, KLK11, KLK13 and KLK14 in the SC and serum of patients with psoriasis, and their variation between lesional and nonlesional areas and with phenotype, therapy and severity. The overall SC serine protease activities were also measured. METHODS: Enzyme-linked immunosorbent assays and enzymatic assays were used. RESULTS: The lesional SC of psoriasis generally contained significantly higher levels of all KLKs. KLK6, KLK10 and KLK13 levels were significantly elevated even in the nonlesional SC. The overall trypsin-like, plasmin-like and furin-like activities were significantly elevated in the lesional SC. Plasmin-like activity was significantly elevated also in the nonlesional SC. The SC chymotrypsin-like activity was only slightly elevated in psoriasis. KLK7 serum levels did not differ between normal volunteers and patients with psoriasis. Serum KLK6, KLK8, KLK10 and KLK13 levels in patients with untreated psoriasis significantly correlated with Psoriasis Area and Severity Index score. Serum KLK5 and KLK11 levels decreased in patients with psoriasis after therapy, especially with etretinate. Patients with erythrodermic psoriasis exhibited significantly higher serum KLK levels than normal subjects or patients with psoriasis vulgaris or arthropathic psoriasis. CONCLUSIONS: We found aberrant KLK levels in the SC and serum of patients with psoriasis and suggest that KLKs might be involved in the pathogenesis of this disease.     

Beneficial effects of synthetic phospholipid polymer,poly(2-methacryloyloxyethyl phosphorylcholine-co-n-butyl methacrylate), on stratum corneum function

The effects of a newly synthesized phospholipid polymer, poly(2-methacryloyloxyethyl phosphorylcholine-co-n-butyl methacrylate) [poly(MPC-co-BMA)], on the water barrier function and water-holding capacity of the stratum corneum were examined by measuring transepidermal water loss (TEWL) and electrical conductance of the skin surface. On the backs of four NC mice, the epidermal permeability barrier was abrogated by cellophane tape stripping 30 times. The skin was then treated with 0.1% poly(MPC-co-BMA) or distilled water twice daily for the following 3 days. Poly(MPC-co-BMA) reduced TEWL significantly compared with the control after the first treatment (P = 0.044) and this effect was observed for 3 days. In human skin, water-holding capacity was measured at 5, 10, 15, 30 min and 1, 2, and 4 h after the application of poly(MPC-co-BMA) or distilled water to both volar forearms of 21 healthy volunteers. Skin treated with poly(MPC-co-BMA) showed significantly greater ability to retain water at all time points. Poly(MPC-co-BMA) is the first synthetic material that can enhance both the water barrier function and water-holding capacity of the stratum corneum. Our results indicate that this substance may be useful clinically in the treatment of dry skin.