Lipomembranous changes and calcification associated with systemic lupus erythematosus

Lipomembranous changes are histological findings without specific clinical correlations, and are thought to be related to vascular impairment in fatty tissue. We describe a case of systemic lupus erythematosus (SLE) in which subcutaneous induration of the lower leg showed lipomembranous changes and calcification. This patient showed thrombophilia with thrombosis of the femoral and iliac veins, and cerebellar and myocardial infarction. A biopsy specimen from the subcutaneous tissue surrounding the multiple leg ulcers revealed degeneration of fat cells, lipomembranous changes in the fatty tissues, and calcification. Another biopsy specimen from the outer edges of the ulcers showed microthrombi and fibrinoid changes in the vessel walls, and mononuclear cell infiltrates in the dermis. Lipomembranous changes have been seen in connective tissue disorders such as lupus profundus, morphoea, systemic sclerosis, and panniculitis associated with dermatomyositis, but rarely associated with SLE. We speculate that ischaemic changes due to the vascular disturbance of the lower legs may have induced lipomembranous changes and calcification in the subcutaneous tissues in the present case.

Gene transfer in human skin with different pseudotyped HIV-based vectors

Pseudotyping lentiviral vector with other viral surface proteins could be applied for treating genetic anomalies in human skin. In this study, the modification of HIV vector tropism by pseudotyping with the envelope glycoprotein from vesicular stomatitis virus (VSV), the Zaire Ebola (EboZ) virus, murine leukemia virus (MuLV), lymphocytic choriomeningitis virus (LCMV), Rabies or the rabies-related Mokola virus encoding LacZ as a reporter gene was evaluated qualitatively and quantitatively in human skin xenografts. High transgene expression was detected in dermal fibroblasts transduced with VSV-G-, EboZ- or MuLV-pseudotyped HIV vector with tissue irregularities in the dermal compartments following repeated injections of EboZ- or LCMV-pseudotyped vectors. Four weeks after transduction, double-labeling immunofluorescence of beta-galactosidase and involucrin or integrin beta1 demonstrated that VSV-G-, EboZ- or MuLV-pseudotyped HIV vector effectively targeted quiescent epidermal stem cells which underwent terminal differentiation resulting in transgene expression in their progenies. Among the six different pseudotyped HIV-based vectors evaluated, VSV-G-pseudotyped vector was found to be the most efficient viral glycoprotein for cutaneous transduction as demonstrated by the highest level of beta-galactosidase expression and genome copy number evaluated by TaqMan PCR.

Moderate magnesium-restricted diet affects bone formation and bone resorption in rats

This study investigated the effects of moderate magnesium (Mg)-restricted diet on bone formation and bone resorption in rats. Weanling Wistar strain rats were randomly divided into three dietary groups of 6 rats each and fed their respective diets; a control diet containing 0.05% Mg (C), a half Mg diet containing 0.025% Mg (1/2Mg), or a one-fifth Mg diet containing 0.01% Mg (1/5Mg), for 21 days. Serum osteocalcin level was significantly reduced with decreasing dietary Mg level. Urinary excretion of C-terminal telopeptide of type 1 collagen was significantly higher in the 1/5Mg group than in the C group. Serum insulin-like growth factor-1 (IGF-1) level was significantly lower in the 1/2Mg and 1/5Mg groups than in the C group. Serum soluble receptor activator of nuclear factor-kappaB ligand (sRANKL) level was significantly higher in the 1/2Mg and 1/5Mg groups than in the C group. These results showed that a moderate Mg-restricted diet induced a decrease in bone formation and an increase in bone resorption. Furthermore, these changes of bone formation and bone resorption might be caused by serum IGF-1 and sRANKL levels, respectively.

CDK5 regulates cell-cell and cell-matrix adhesion in human keratinocytes

BACKGROUND

CDK5 is a member of proline-directed serine/threonine kinases. Although its cDNA was originally cloned as a homologue to those for the other members of the cyclin-dependent kinase (CDK) family, CDK5 has been shown to function differently from other CDKs. CDK5 is activated by non-cyclin partners, p35 and p39, and important during brain development by influencing adhesion, migration and differentiation of neurones.

OBJECTIVES

We sought to investigate the expression and functions of CDK5 in human keratinocytes.

METHODS

Expression of CDK5/p35, interaction of CDK5/p35 with adhesion molecules, and its roles in cell-cell and cell-matrix adhesion were studied by reverse transcriptase-polymerase chain reaction, immunoblotting and aggregation/adhesion assays in primary cultured normal human keratinocytes from infant foreskins and a human keratinocyte HaCaT cell line. Localization of CDK5 and p35 in normal human epidermis and psoriatic epidermis was studied by immunohistochemistry.

RESULTS

Both CDK5 and p35 were expressed in primary cultured keratinocytes, HaCaT cells and normal human epidermis. Roscovitine, an inhibitor of CDK5, enhanced Ca2+-dependent (cadherin-dependent) aggregation of HaCaT cells whereas it inhibited adhesion of HaCaT cells to fibronectin associated with reduced active states of beta1 integrin. Interestingly, psoriatic skin showed reduced CDK5 and p35 expression in the lower half of the epidermis, which might be associated with decreased amount of activated beta1 integrin in the epidermis of psoriatic skin.

CONCLUSIONS

CDK5/p35 may be involved in cell-cell and cell-matrix adhesion in human keratinocytes by differently regulating cadherins and integrins. Furthermore, reduced expression of CDK5/p35 in the epidermis might be involved in the pathogenesis of psoriasis.

Smads regulate collagen gel contraction by human dermal fibroblasts

BACKGROUND

Transforming growth factor (TGF)-beta induces fibroblast contraction that is implicated in efficient wound healing. The Smad family of proteins mediates signal transduction of the TGF-beta superfamily. However, its role in fibroblast contraction remains unclear.

OBJECTIVES

To determine whether Smad proteins regulate fibroblast contraction.

METHODS

We used an in vitro type I collagen gel contraction assay with human dermal fibroblasts infected with adenoviruses carrying Smads.

RESULTS

Overexpression of Smad3, a major signal transducer in the Smad family, enhanced collagen gel contraction by fibroblasts when compared with fibroblasts overexpressing a control lacZ. Addition of a very low concentration of TGF-beta1 that did not affect the collagen gel contraction by itself enhanced the contraction by fibroblasts overexpressing Smad3. In contrast, TGF-beta1-mediated collagen gel contraction was suppressed by overexpression of Smad7, a major inhibitory regulator in the Smad family, in fibroblasts. In addition, inhibitors of the Erk and p38 pathways, PD98059 and SB203580, did not affect TGF-beta1-mediated collagen gel contraction by dermal fibroblasts.

CONCLUSIONS

Modulation of Smad3 or Smad7 expression in dermal fibroblasts affected their contraction of collagen gels possibly by regulating TGF-beta signalling in fibroblasts.

[Molecular analysis of malassezia microflora on the skin of atopic dermatitis patients and healthy subjects]

We compared cutaneous colonization levels of Malassezia species in patients with AD and healthy subjects using nested PCR. Malassezia-specific DNA was detected in all 32 of the patients with AD. M. globosa and M. restricta were detected in approximately 90% of these patients, with M. furfur and M. sympodialis being detected in approximately 40% of the cases. In healthy subjects, Malassezia DNA was detected in 78% of the samples, M. globosa, M. restricta and M. sympodialis were detected at frequencies ranging from 44 to 61%, and M. furfur was found in 11% of healthy subjects. Our results suggest that M. furfur, M. globosa, M. restricta and M. sympodialis are common inhabitants of the skin of both AD patients and healthy subjects, while the skin microflora of patients with AD shows more diversity than that of healthy subjects.

Transforming growth factor-beta1 suppresses atopic dermatitis-like skin lesions in NC/Nga mice

BACKGROUND

Atopic dermatitis is a chronic, relapsing inflammatory disorder characterized by pruritic and eczematous skin lesions. Transforming growth factor (TGF)-beta1 has been implicated in the suppression of inflammatory responses.

OBJECTIVE

The purpose of this study is to determine whether TGF-beta1 suppresses skin lesions in a mouse model of atopic dermatitis.

METHODS

We used the NC/Nga strain of mice as an in vivo model of atopic dermatitis. The effects of exogenous TGF-beta1 on atopic dermatitis-like skin lesions in NC/Nga mice were evaluated clinically, histologically and immunologically.

RESULTS

Subcutaneous injection of recombinant TGF-beta1 macroscopically suppressed eczematous skin lesions in NC/Nga mice associated with reduced serum immunoglobulin E (IgE) levels. Histological analysis showed that TGF-beta1 significantly inhibited the infiltration of inflammatory cells such as mast cells and eosinophils into the skin of NC/Nga mice. Spontaneous interferon (IFN)-gamma production from splenocytes of NC/Nga mice was down-regulated by the treatment with TGF-beta1 and neutralizing antibody against IFN-gamma inhibited skin lesions in NC/Nga mice. The inhibitory effect of TGF-beta1 on the skin lesions lasted at least 1 week after cessation of the treatment.

CONCLUSION

These findings indicate that TGF-beta1 suppressed atopic dermatitis-like skin lesions in NC/Nga mice at least in part through down-regulation of IFN-gamma. These results suggest that TGF-beta1 may have a therapeutic potential for atopic dermatitis.

Quantification of Candida albicans actin mRNA by the LightCycler system as a means of assessing viability in a model of cutaneous candidiasis

The LightCycler system (two-step reverse transcription-PCR-fluorescent hybridization [LC RT-PCR-FH]) was used to quantify Candida albicans actin mRNA as a means of assessing its viability in a reconstituted skin model of cutaneous candidiasis following the application of an antimycotic. A 192-bp ACT exon fragment was ligated into the pCR2.1 plasmid vector, and dilutions of the cloned insert (pACT; 4.092 kb) were used as the standard reference template. The LC RT-PCR-FH system could detect 1 fg of pACT, equivalent to 2.2 copies of the plasmid. The ACT exon-based PCR primers and FH probes were C. albicans specific, and electrophoretic analysis of the LC RT-PCR-FH assay product showed a 174-bp band in agarose gel. The number of copies of C. albicans ACT mRNA per milligram of tissue decreased with increasing amounts of amorolfine applied to a C. albicans-infected skin model, showing a reduction in viability. Detection and quantification of ACT mRNA in tissue by the LC RT-PCR-FH assay corresponded with cultural isolation of C. albicans from samples. The ACT mRNA-targeted LC RT-PCR-FH assay represents a sensitive, specific, rapid, and quantitative means of assessing the viability of C. albicans in infected tissue. This method may also be useful in evaluating the therapeutic efficacies of antifungal drugs in the treatment of various forms of candidiasis and other fungal diseases.

Molecular analysis of Malassezia microflora on the skin of atopic dermatitis patients and healthy subjects

Members of the genus Malassezia, lipophilic yeasts, are considered to be one of the exacerbating factors in atopic dermatitis (AD). We examined variation in cutaneous colonization by Malassezia species in AD patients and compared it with variation in healthy subjects. Samples were collected by applying transparent dressings to the skin lesions of AD patients. DNA was extracted directly from the dressings and amplified in a specific nested PCR assay. Malassezia-specific DNA was detected in all samples obtained from 32 AD patients. In particular, Malassezia globosa and M. restricta were detected in approximately 90% of the AD patients and M. furfur and M. sympodialis were detected in approximately 40% of the cases. The detection rate was not dependent on the type of skin lesion. In healthy subjects, Malassezia DNA was detected in 78% of the samples, among which M. globosa, M. restricta, and M. sympodialis were detected at frequencies ranging from 44 to 61%, with M. furfur at 11%. The diversity of Malassezia species found in AD patients was greater (2.7 species detected in each individual) than that found in healthy subjects (1.8 species per individual). Our results suggest that M. furfur, M. globosa, M. restricta, and M. sympodialis are common inhabitants of the skin of both AD patients and healthy subjects, while the skin microflora of AD patients shows more diversity than that of healthy subjects. To our knowledge, this is the first report of the use of a nested PCR as an alternative to fungal culture for analysis of the distribution of cutaneous Malassezia spp.

Comparative study of Staphylococcus aureus isolated from lesional and non-lesional skin of atopic dermatitis patients

The skin of patients with atopic dermatitis (AD) is often colonized by Staphylococcus aureus, and superantigenic exotoxins produced by the organism are thought to be an important precipitating factor of AD. However, there are few reports comparing the characteristics of S. aureus isolated from the lesional and non-lesional skin of identical AD patients. In this study, therefore, we examined whether the presence of superantigen-producing S. aureus correlates with the formation of eczematous lesion of AD patients. The detection rate of S. aureus on the lesional skin of AD patients was higher than on the non-lesional skin of AD patients. Furthermore, the bacterial cell count of S. aureus on the lesional skin of AD patients was also significantly higher than that of the non-lesional skin of AD patients. However, there was no significant difference between the detection rate of superantigenic exotoxin-producing S. aureus on the lesional and nonlesional skin of AD patients. These results suggest that the number of S. aureus present is more important in the formation of eczematous lesion of AD patients than the presence of superantigenic exotoxin-producing S. aureus strains per se.

Hepatocyte growth factor (HGF) activator expressed in hair follicles is involved in in vitro HGF-dependent hair follicle elongation

Hepatocyte growth factor (HGF), a paracrine factor secreted by follicular papilla cells, acts on neighboring follicular epithelial cells to promote follicular growth, while HGF activator is a serine proteinase, which converts inactive single-chain HGF to the active heterodimeric form. In this study, using 3' rapid amplification of cDNA end/nested polymerase chain reaction (3' RACE/nested PCR) and immunoblotting, we confirmed the expression of HGF activator in both cultured human follicular papilla cells and outer root sheath cells. HGF activator mRNA was expressed in all of the isolated 15 anagen hair follicles taken from the scalps of seven individuals. In an organ culture system, single-chain HGF stimulated hair follicle elongation, which was partially inhibited by aprotinin, a serine proteinase inhibitor (P<0.01). These results suggest that single-chain HGF secreted from follicular papilla cells is converted to an active heterodimeric form by intrinsic HGF activator and that the resultant active form of HGF stimulates hair growth.

Cyclin-dependent kinase inhibitors, p21(waf1/cip1) and p27(kip1), are expressed site- and hair cycle-dependently in rat hair follicles

In order to investigate the role of cyclin-dependent kinase (CDK) inhibitors in hair growth, we analyzed the expressions of p21(waf1/cip1) and p27(kip1) during the synchronized hair cycle of rat coat. The mRNAs of both p21(waf1/cip1) and p27(kip1) were detected in anagen hair follicles by reverse transcription and polymerase chain reaction and their localization was clearly demonstrated in the upper half portion of the hair bulb and the cortex by in situ hybridization. The dermal tissue containing hair follicles was then excised from the anterior dorsal skin of the 5-12-week-old rats at 0.5 week intervals and the expressions of p21(waf1/cip1) and p27(kip1) were analyzed by northern blot hybridization. The mRNA of both CDK inhibitors was expressed at relatively high levels during anagen than during telogen, a fact which correlated with the mRNA expression levels of hair differentiation markers, type I hair keratin (Ha3) and high sulfur protein B2. These results imply that CDK inhibitors, p21(waf1/cip1) and p27(kip1), are involved in the differentiation of follicular epithelial cells.

Isolation of an intron-containing partial sequence of the gene encoding dermatophyte actin (ACT) and detection of a fragment of the transcript by reverse transcription-nested PCR as a means of assessing the viability of dermatophytes in skin scales

An internal partial sequence of the gene encoding actin (ACT), 725 to 762 bp in length, was amplified by PCR from the genomic DNA extract of 12 species of dermatophytes and sequenced. An intron that is 56 to 93 bp in length was located along the ACT fragment of all of the dermatophytes at codon position 301 (-3) (a codon number followed by "-3" indicates that the intron directly follows the codon) with reference to the amino acid sequence of human alpha-smooth muscle actin. A primer pair that annealed to exon sequences flanking the ACT-associated intron produced a dermatophyte-specific 171-bp amplicon by reverse transcription-nested PCR (RT-PCR) of dermatophyte ACT mRNA. PCR primer pairs with antisense sequence based on the ACT intron sequence were species specific for dermatophytes, suggesting a potential for use in the identification of dermatophytes. The viability of dermatophytes in skin scales was subsequently assessed by the presence of ACT mRNA in total RNA extracted from a 48-h culture of scale samples in 250 microl of yeast carbon base broth. RT-nested PCR of dermatophyte-infected samples amplified an ACT fragment of the predicted size of 171 bp. The results of viability testing based on ACT mRNA detection by RT-nested PCR correlated with cultural isolation from skin scales. This method is a potential tool for rapidly assessing fungal viability in the therapeutic efficacy testing of antimycotics.

Competitive Incorporation of Arachidonic Acid Analogs by Cultured Rat Keratinocytes

Arachidonic acid (20:4 n-6) and its metabolic products, such as prostaglandins and leukotrienes, have been known to be associated with skin inflammatory reactions. However, the mechanism of the competitive incorporation of 20:4 n-6 into keratinocytes among polyunsaturated fatty acids (PUFAs) remains uncertain. To investigate the relationship between the molecular structure of PUFAs and the rate of incorporation of PUFAs into cells, a fetal rat skin keratinocyte (FRSK) cell line was used. The cells were incubated for 24 h with any two of the following arachidonic acid analogs: mead acid (20:3 n-9), dihomo-gamma-linolenic acid (20:3 n-6), 11,14,17-cis-eicosatrienoic acid (20:3 n-3), arachidonic acid (20:4 n-6), eicosapentaenoic acid (20:5 n-3) and 5,8,11,14-cis-nonadecatetraenoic acid (19:4 n-5), at the ratio of 1:0, 0.5:0.5, or 0:1; and their incorporation into lipid was measured by capillary gas-liquid chromatography. The experiments indicated that 20:3 n-6 was preferentially incorporated into phospholipids of FRSK rather than 20:3 n-9 or 20:3 n-3, and 19:4 n-5 as well as 20:4 n-6 was preferentially incorporated into total cellular lipid and phospholipids rather than 20:3 n-9 or 20:5 n-3. When two PUFAs were added simultaneously to the medium, 19:4 n-5 most effectively reduced the competitive incorporation of 20:4 n-6 into phospholipids. These results suggest that keratinocytes discriminate 20:4 n-6 from other arachidonic acid analogs by its double bond positions from the carboxyl group.

Sphingosylphosphorylcholine stimulates contraction of fibroblast-embedded collagen gel

Sphingosylphosphorylcholine (SPC), a sphingolipid metabolite, has recently been reported to stimulate wound healing in an animal model. To clarify the mechanism of SPC on the healing process, we examined the effect of SPC on wound contraction using an in vitro model. A mixture of human dermal fibroblasts and porcine type I collagen in a serum-free medium was gelled, and then separated from the well after a 12-h incubation. Various reagents were applied to the medium, and its contractile activity was analysed by measuring the amount of contracted surface area. Among the sphingolipid metabolites, SPC and sphingosine-1-phosphate, but not sphingosine, C2-ceramide and C6-ceramide, stimulated collagen gel contraction. Maximal gel contraction, observed at 10 micromol L-1 of SPC, occurred as early as 1 h after the treatment and persisted for more than 48 h. The effect of SPC was not inhibited by pretreatment with antitransforming growth factor-beta or antiplatelet-derived growth factor-BB antibodies. Among the various signal transduction inhibitors, pertussis toxin, staurosporine and H7 were found to inhibit the action of SPC, whereas genistein and tyrphostin A47 were not, suggesting that fibroblast contraction induced by SPC is mediated by a trimeric guanosine triphosphate-binding protein (G protein)-coupled receptor and protein kinase. Our findings imply that the effect of SPC as a healing stimulant might be due in part to stimulation of fibroblast contraction in granulation tissue.

A Japanese case of Kindler syndrome

A 25-year-old Japanese woman presented with contracture of the fingers and toes, and difficulty in opening her mouth. Her grandparents are first cousins, but none of the other members of the family are affected. Bulla formation started at birth on areas of the skin that received pressure, and in infancy and early childhood the lesions were limited only to the acral areas. She also had bilateral, incomplete syndactylies involving all web spaces (Fig. 1a). The formation of blisters ceased after the age of 15 years, but a generalized progressive poikiloderma then appeared with accompanying cutaneous atrophy of the skin of the neck, trunk, and extremities (Fig. 1b). The patient experienced mild photosensitivity of the face and neck. At age 18 years, surgical removal of the webbing of all her fingers was performed. Oral examination showed atrophy of the buccal mucosa, and an inability to fully open the mouth. The patient also suffered from poor dentition and easily bleeding gums, but had no symptoms of esophageal dysfunction. Histology of separate biopsy specimens, taken from the poikilodermatous pretibial and trunk skin, showed classical features of poikiloderma, namely epidermal atrophy with flattening of the rete ridges, vacuolization of basal keratinocytes, pigmentary incontinence, and mild dermal perivascularization (Fig. 2a). Interestingly, dyskeratotic cells (Fig. 2b) and eosinophilic rounded bodies (colloid bodies) (Fig. 2c) were frequently found at the basal keratinocyte layer and in the upper dermis, respectively. Pigment was also present in the upper epidermis. To rule out the possibility of a congenital epidermolysis bullosa, ultrastructural and immunofluorescence studies were performed. Ultrastructural studies demonstrated the reduplication of the basal lamina with branching structures within the upper dermis and cleavage between the lamina densa and the cell membrane of the keratinocytes (Fig. 3a). The numbers of associated anchoring fibrils did not seem to be reduced, and colloid bodies and dyskeratotic cells were detected. Immunofluorescence studies with the antibody against type VII collagen (LH 7 : 2) were subsequently carried out. The results showed extensive broad bands with intermittently discontinuous and reticular staining at the dermo-epidermal junction (DEJ) (Fig. 3b), whereas a linear distribution is typically seen in healthy tissue (data not shown). Interestingly, direct immunofluorescence studies revealed intracellular accumulation of immunoglobulin G (IgG), IgM, IgA, and C3 in colloid bodies under the basement membrane (Fig. 3c).

A case of ichthyosis linearis circumflexa successfully treated with topical tacrolimus

We report a case of ichthyosis linearis circumflexa (ILC) without the typical atopic manifestations and deformities of the hair shaft. The patient responded positively to treatment with topical tacrolimus, suggesting that abnormalities in the immunoregulatory mechanism may be involved in the pathogenesis of ILC.

Fluorometric assessment of In vitro antidermatophytic activities of antimycotics based on their keratin-penetrating power

Keratin particles impregnated with amorolfine or clotrimazole in serial doubling dilutions (64 to 0.125 microg/ml) were used to evaluate the activities of these agents against 20 isolates each of Trichophyton mentagrophytes and Trichophyton rubrum in a yeast carbon broth medium incorporating Alamar Blue dye. The proposed MIC with keratin impregnation (MIC(K)) is defined as the lowest concentration of an agent used to impregnate keratin particles that effects a fluorescence-based fungal growth quotient of 0.05 or less. The conventional colorimetric and visual MICs of amorolfine for the dermatophytes, </=0.03 microg/ml for T. mentagrophytes and </=0.063 microg/ml for T. rubrum, were approximately half of those of clotrimazole for the same isolates. The superiority of the MIC(K)s of amorolfine for isolates of T. mentagrophytes (2.0 microg/ml; range, 0.5 to 8.0 microg/ml) and T. rubrum (4.0 microg/ml; range, 2. 0 to 8.0 microg/ml) over those of clotrimazole (32 microg/ml [range, 8.0 to >64 microg/ml] and 64 microg/ml [range, 16 to >64 microg], respectively) may indicate the strong in vivo antidermatophytic activity of amorolfine as a topical agent. The new antidermatophytic susceptibility testing procedure has potential clinical utility for the in vitro screening of agents for use in the topical treatment of superficial mycoses.

Histological increase in inflammatory infiltrate in sun-exposed skin of female subjects: the possible involvement of matrix metalloproteinase-1 produced by inflammatory infiltrate on collagen degradation

To investigate morphological changes occurring during cutaneous photoageing, a correlation between the number of infiltrating cells in the dermis and the degree of collagen damage was examined using sections from clinically normal chronically sun-exposed and sun-protected skin of Japanese female subjects. Haematoxylin and eosin-stained sections from 134 sun-exposed (subjects aged 3-82 years) and 73 sun-protected (subjects aged 1-86 years) areas demonstrated a predominant lymphoid cell and to a lesser extent histiocyte infiltration. The mean +/- SD number of lymphoid cells and histiocytes in the sun-exposed skin sections (427.0+/-192.2 and 147.8+/-83.3 cells/mm2, respectively) was significantly higher than in the sun-protected skin sections (292.6+/-98.3 and 125.9+/-59.0 cells/mm2, respectively) (P < 0.001 and P < 0.05, respectively), and the number of lymphoid cells in the sun-exposed skin sections increased significantly with age up to 50 years (r = 0.400, P < 0.001). Sun-exposed skin sections with severe collagen degeneration had a significantly higher number of lymphoid cells than those with slightly degenerated collagen (mean 626.3 vs. 482.4 cells/mm2, P < 0.01). The mean count of mast cells in sun-exposed skin was 202.0 cells/mm2; this did not vary with the age of the subjects or the level of collagen damage. Immunohistochemical studies using 24 frozen sections identified most of the lymphoid cells infiltrating sun-exposed skin as memory T lymphocytes (CD3+, CD4+ and CD45RO+). The number of cells which displayed immunoreactivity to matrix metalloproteinase (MMP)-1 in the sun-exposed skin sections was significantly higher than in the sun-protected skin sections (mean 170.2 vs. 113.6 cells/mm2, P < 0.05). Among these cells were observed CD3 and MMP-1 double-stained T lymphocytes, and T lymphocytes contacting MMP-1-positive cells. These morphological observations suggest that T lymphocytes infiltrating photodamaged skin may play a part in the degeneration and reduction of collagen through MMP-1 activity.

Reverse transcription - 3' rapid amplification of cDNA ends-nested PCR of ACT1 and SAP2 mRNA as a means of detecting viable Candida albicans in an in vitro cutaneous candidiasis model

The presence of viable cells of Candida albicans, in broth or in a reconstructed living skin equivalent, was determined by the detection of amplicons of partial mRNA sequences of the genes encoding fungal actin (ACT1) and secreted aspartyl proteinase 2 (SAP2). The mRNA of both genes were amplified by reverse transcription-3' rapid amplification of cDNA ends-nested polymerase chain reaction. Single bands of ACT1 (315 bp) and SAP2 (162 bp) mRNA were amplified from total RNA extracts of C. albicans grown in yeast carbon base-albumin broth or in living skin equivalent tissue; only the former was amplified from Sabouraud broth-grown organisms. Primer pairs targeted for ACT1 and SAP2 were Candida genus-specific and C. albicans-specific, respectively. The sensitivity limits of the assay were 100 fg of total RNA or 10 cells of C. albicans, by ethidium bromide staining. When C. albicans-infected living skin equivalent was exposed to amorolfine, amplicons of ACT1 and SAP2 mRNA were not detected in total RNA extracts. Non-amplification of the mRNA correlated with the absence of C. albicans growth in Sabouraud agar cultures of living skin equivalent samples. Reverse transcription-3' rapid amplification of cDNA ends-nested polymerase chain reaction of the mRNA encoding specific proteins of an organism has potential application in determining the viability of the organism in tissue, thus monitoring the efficacy of an antimicrobial therapy, and in detecting mRNA expressed in very little amounts in tissue.

Hair cycle-dependent expression of hepatocyte growth factor (HGF) activator, other proteinases, and proteinase inhibitors correlates with the expression of HGF in rat hair follicles

We previously reported that hepatocyte growth factor (HGF) had a stimulatory effect on hair growth in vivo and in vitro. The secreted inactive form of HGF is processed into an active form by serine proteinases such as HGF activator and urokinase. The mRNA expressions of various proteinases and their inhibitors in relation to HGF activation in hair growth were examined using animals with a synchronous hair cycle. Total RNA were extracted from the anterior dorsal skin of rats in different hair cycle stages, and mRNA expressions of the specific genes were compared using semiquantitative reverse transcription polymerase chain reaction. The mRNA of HGF, HGF activator, urokinase, plasminogen activator inhibitor (PAI)-1, nexin-1, matrix metalloproteinase (MMP)-2, and tissue inhibitor of metalloproteinase (TIMP)-1 were expressed strongly in anagen tissue and slightly in telogen tissue. Moreover, topical application of 1% minoxidil sulfate to the anterior dorsal skin of rats in telogen stimulated hair growth and increased the mRNA expressions of HGF and MMP-2. These findings suggest that some proteinases and their inhibitors, strongly expressed in anagen, may act as hair growth regulatory molecules, and may also be involved in processing the latent form of HGF.

Dermatophytes and host defence in cutaneous mycoses

Dermatophytosis is the infection of keratinized tissues such as hair, nails and the stratum corneum of the skin by dermatophyte fungi. These fungi are onygenalean anamorphs and anamorphic species belonging to the genera Trichophyton, Microsporum and Epidermophyton. An important characteristic of the dermatophytes as parasites is their restriction to the dead keratinized tissues, except in rare cases where the patient is immunosuppressed. In contrast to many fungi, including normally non-pathogenic species, which can invade systemically in severely immunocompromised (e.g. neutropenic) patients, dermatophytes appear to be unable to cause systemic infection in this population. Thus, these fungi appear to have an unique interaction with the immune system. A better understanding of this interaction will contribute significantly to our knowledge of mammalian host defences.

[Topical treatment of onychomycosis by occlusive dressing using bifonazole cream containing 40% urea]

Topical treatment with an antifungal agent was performed in 70 cases of onychomycosis (69 cases of tinea unguium and 1 case of Candida onychomycosis). The patients were treated every night by occlusive dressing using bifonazole cream containing 40% urea, and then by simple application of 1% bifonazole solution in the morning. During the treatment period, the softened affected nails were removed as completely as possible with nail clippers and files. The nails were observed every two weeks, and the efficacy was evaluated after 12 weeks. Two cases were excluded and 28 cases dropped out leaving 40 cases for efficacy evaluation. Among the 40 patients, 20 appeared to be mycologically negative (mycological cure rate: 50.0%). Clinical response was judged by the changes in opacity and thickness of the nails. Nine patients were evaluated as showing "marked improvement" and 16 as showing "improvement" (improvement rate: 62.5%). Erosion was noted as an adverse reaction in 2 patients. In one patient, treatment was stopped and the lesion was improved by antibiotic ointment, and in another, treatment was resumed when erosion was cured by discontinuation of the treatment. These results suggest that the topical treatment of onychomycosis by occlusive dressing is a useful method for those patients who have difficulties in or do not wish to be treated with oral antifungal agents.

Local injection of hepatocyte growth factor/scatter factor (HGF/SF) alters cyclic growth of murine hair follicles

Hepatocyte growth factor/scatter factor (HGF/SF) has recently been shown to stimulate the hair follicle growth of mouse vibrissae in vitro. In this study, we analyzed the effect of cutaneous injections of recombinant human HGF/SF on hair follicle growth using mice in different hair cycle stages. Five male newborn mice, five male mice in second anagen, and five male mice in second telogen were administered a dorsal intradermal injection of 1 microg HGF/SF dissolved in 0.1% albumin-phosphate-buffered saline once daily for five or seven consecutive days, and then sacrificed on days 7 or 10. Hair follicle growth was evaluated photometrically and histologically using three parameters: the skin color of the reverse side of the resected skin, the skin thickness, and the area occupied by hair follicle tissue. The HGF/SF injected skin of newborn mice had hair follicles that were histologically longer and larger than those of the 0.1% albumin-phosphate-buffered saline injected skin. Mice that had received HGF/SF injection in second anagen, retained anagen hair follicles after 10 d only at the injection site, suggesting that HGF/SF delayed the transition from anagen to telogen. The HGF/SF injected skin of telogen mice had a significant increase in hair follicle tissue in the dermis, suggesting a mild anagen inducible activity by HGF/SF. Furthermore, precise measurements of the 20 hairs plucked from the HGF/SF injection sites revealed mild hair elongation in all the aforementioned experiments. These results imply that HGF/SF acts as a paracrine factor that alters cyclic hair growth of mice.