A safety assessment of branched chain saturated alcohols when used as fragrance ingredients.

The Branched Chain Saturated Alcohol (BCSA) group of fragrance ingredients was evaluated for safety. In humans, no evidence of skin irritation was found at concentrations of 2-10%. Undiluted, 11 materials evaluated caused moderate to severe eye irritation. As current end product use levels are between 0.001% and 1.7%, eye irritation is not a concern. The materials have no or low sensitizing potential. For individuals who are already sensitized, an elicitation reaction is possible. Due to lack of UVA/UVB light-absorbing structures, and review of phototoxic/photoallergy data, the BCSA are not expected to elicit phototoxicity or photoallergy. The 15 materials tested have a low order of acute toxicity. Following repeated application, seven BCSA tested were of low systemic toxicity. Studies performed on eight BCSA and three metabolites show no in vivo or in vitro genotoxicity. A valid carcinogenicity study showed that 2-ethyl-1-hexanol is a weak inducer of liver tumors in female mice, however, the relevance of this effect and mode of action to humans is still a matter of debate. The Panel is of the opinion that there are no safety concerns regarding BCSA under the present levels of use and exposure.

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.

p51/p63 Inhibits ultraviolet B-induced apoptosis via Akt activation.

The epidermis must be protected against excess apoptotic cell death in response to ultraviolet-B (UV-B) irradiation. p53 is known to be critical for this protection. Although the p53 family member DeltaNp51B/DeltaNp63alpha (an N terminal-deleted form of p51/p63) is abundantly expressed in keratinocytes, its contribution to UV-B-dependent apoptosis is largely unknown. We found that, after a transient increase, DeltaNp51B is downregulated in UV-B-irradiated keratinocytes undergoing apoptosis, whereas p53 is upregulated with delayed kinetics. Furthermore, the reduction of DeltaNp51B by small interfering RNAs augmented UV-B-dependent apoptosis in keratinocytes, indicating that DeltaNp51B blocks keratinocyte apoptosis. Although the exogenous expression of DeltaNp51B in keratinocytes did not further block the UV-B-dependent apoptosis, to our surprise the expression of TAp51B (an isoform with a full NH(2)-terminal transactivation domain that is structurally and functionally similar to p53) decreased apoptosis significantly. The blockade of keratinocyte apoptosis by the p51 was dependent on the phosphorylation of Akt, resulting in the activation of a survival pathway. Thus, in addition to its indispensable roles in epithelial development, p51 acts in adult cells to protect the epidermis against UV-B irradiation by preventing excess depletion of keratinocytes.

Gene expression profiling analysis of solar lentigo in relation to immunohistochemical characteristics.

BACKGROUND: Solar lentigo appears as dark brown spots that occur on sun-exposed areas and is considered to be a hallmark of aged skin. Although considerable knowledge about acute pigmentation has recently been accumulated, little is yet known about the mechanisms underlying chronic- and delayed-type hyperpigmentation, such as solar lentigo. OBJECTIVES: To clarify further the mechanisms underlying the development of solar lentigo, we carried out gene expression analysis in skin biopsy specimens obtained from human solar lentigines using DNA microarray analysis. METHODS: Two pairs of skin specimens were obtained from solar lentigo and adjacent sun-exposed normal skin, as well as normal skin on the buttocks of 16 volunteers aged 40-55 years. One set of specimens was frozen and RNA was extracted for microarray and the other set was prepared for histological sections and analysed by antibodies and probes. RESULTS: Sixty-five genes were upregulated more than 1.8-fold in solar lentigo compared with adjacent control skin and seven melanocyte-related genes were included. Compared with sun-protected skin, many inflammation-related genes were upregulated in solar lentigo, and compared with sun-exposed control skin, upregulation of genes related to fatty-acid metabolism was apparent in solar lentigo. Moreover, we found downregulation of cornified envelope-related genes, which suggests suppression of cornification in the epidermis in solar lentigo. Immunohistochemically, larger numbers of TRP1-positive cells were found in the basal layer of solar lentigo than in normal skin. Fatty acid-related genes were highly expressed in the epidermis as detected by in situ hybridization, and they were much more prominent in the lesional skin of solar lentigo. However, cycling epidermal cells detectable with Ki67 antibody were fewer in the lesional skin of solar lentigo. Expression of filaggrin and involucrin was decreased in the lesional skin, where the number of cell layers of the stratum corneum was significantly higher than in normal skin. CONCLUSIONS: The results of the present microarray analysis of solar lentigo, demonstrating upregulation of genes related to inflammation, fatty-acid metabolism and melanocytes and downregulation of cornified envelope-related genes, suggest that solar lentigo is induced by the mutagenic effect of repeated ultraviolet light exposures in the past, leading to the characteristic enhancement of melanin production, together with decreased proliferation and differentiation of lesional keratinocytes on the background of chronic inflammation.

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.

Basal cell carcinoma showing connections with epidermal cysts.

Basal cell carcinomas arising from epidermal cysts are rare. A 76-year-old Japanese man had had a blackish nodule on his right knee for 15 years, under which he later noticed the development of a subcutaneous nodule. On histological examination masses of tumour cells showed the feature of adenoid and solid patterns of basal cell carcinoma that were connected to the wall of epidermal cysts in many places as well as with the overlying epidermis.

Differential expression of cornified cell envelope precursors in normal skin, intraorally transplanted skin and normal oral mucosa.

BACKGROUND: Skin flaps have routinely been used as substitutes for oral mucosa after extensive resection of oral tissues. However, it remains unknown how the transplanted skin flaps perform as a host defence in the new environment of the oral cavity. OBJECTIVES: To evaluate the expression of cornified cell envelope (CCE) precursors in pretransplanted (normal) skin, intraorally transplanted skin and normal oral mucosa, because CCEs are highly responsible for a protective barrier in each type of epithelium. METHODS: We used immunohistochemistry and immunoelectron microscopy to examine the expression of CCE precursors, small proline-rich protein (SPR) 2 and 3 and loricrin, in biopsy specimens of normal skin, transplanted skin and normal oral mucosa, including buccal and lingual (non-keratinized) mucosae, and palatal (keratinized) mucosa. RESULTS: Transplanted skin flaps were classified into two groups. About two-thirds of the transplanted skin flaps displayed a reddish appearance and were devoid of the stratum corneum (SC) together with a psoriasiform inflammatory tissue reaction. Others showed a native appearance, retaining the SC. While SPR2 expression was limited to the stratum granulosum (SG) in both normal and transplanted skin retaining the SC, it extended to the stratum spinosum (SS) of the transplanted skin lacking the SC and that of the normal oral mucosa. Although SPR3 expression was not found in normal skin or in the transplanted skin retaining the SC, it was strongly expressed in the SS of the transplanted skin lacking the SC and the non-keratinized oral mucosa, and in the SS and SG of the keratinized oral mucosa. Loricrin, which was expressed in the SG of normal skin, the transplanted skin retaining the SC and the keratinized oral mucosa, was not detected in the transplanted skin lacking the SC or in the non-keratinized oral mucosa. Immunoelectron microscopy confirmed the ultrastructural localization of SPR3 directly under the cytoplasmic membrane of keratinocytes of the transplanted skin lacking the SC and that of the oral mucosa. CONCLUSIONS: The altered expression of SPR2, SPR3 and loricrin reflects the possible adaptation of epidermal keratinocytes in the new environment of the oral cavity.

A subepidermal blistering dermatosis associated with coexistent IgG and IgA anti-dermal basement membrane zone antibodies; demonstration of IgG antibodies reactive against a 200-kDa dermal antigen.

We report a 66-year-old woman presenting with an annular erythematous and bullous eruption. Her clinical and histological findings were similar to those of linear IgA bullous dermatosis or dermatitis herpetiformis. Direct immunofluorescence revealed linear deposition of IgA, IgG and C3 along the basement membrane zone (BMZ). Indirect immunofluorescence detected IgG and IgA antibodies against the BMZ. Salt-split skin technique demonstrated that IgG antibodies bound exclusively to the dermal side, while IgA antibodies bound not only to the dermal side, but also to the epidermal side with relatively weak intensity. On immunoblot analysis, the patient's IgG antibodies exclusively reacted with a band of 200-kDa, while the antigenic target of IgA antibodies was not identified. The present case is thought to be a unique bullous dermatosis mediated by both the IgG antibodies to a novel 200-kDa antigen and IgA antibodies against undetermined antigens.

Acral angiokeratoma-like pseudolymphoma: one adolescent and two adults.

In 1988, Ramsay et al proposed an entity of acral pseudolymphomatous angiokeratoma of children (with an abbreviation of APACHE) for the unilateral multiple angiomatous papules affecting the acral region of the extremities of children. We report here similar lesions that developed in the acral portions of 1 female adolescent and 2 women. Histopathologically, they showed pseudolymphomatous features rather than those of angiokeratoma. Thus, the term should be acral angiokeratoma-like pseudolymphoma would be more appropriate than APACHE originally proposed.

Topically applied tissue factor pathway inhibitor reduced intimal thickness of small arterial autografts in rabbits.

PURPOSE: The purpose of this study was to investigate whether topically applied tissue factor pathway inhibitor (TFPI) reduces intimal thickness and increases long-term patency of small arterial autografts in rabbits. METHODS: An entire 10-mm long section of the left femoral artery was harvested and immersed in saline solution (control group, n = 10), 100 IU/mL of heparin (heparin group, n = 15), or 40 microg/mL of TFPI (TFPI group, n = 15) for 15 minutes. Then the graft was interposed to the right femoral artery. Patency rates were determined by flow measurements throughout the time course of the study, and the grafts were analyzed for measurement of intimal thickness at 3 months after operation. Immunohistochemical analysis was performed to examine whether topically applied TFPI binds to endothelial cells of the grafts. RESULTS: Three-month postoperative patency rates were 10% in the control group, 47% in the heparin group, and 73% in the TFPI group. The TFPI group had a significantly higher patency rate than that of the control group (P <.005). Compared with the heparin group, the TFPI group had a significant reduction in intimal area (0.19 +/- 0.05 mm(2) vs 0.30 +/- 0.09 mm(2), P =.0051), in percentage of stenosis (35.7% +/- 7.7% vs 61.4% +/- 15.8%, P <.0001), and in intimal/media areas ratio (0.64 +/- 0.24 vs. 1.04 +/- 0.33, P =.0051). Immunohistologic analyses confirmed that topically applied TFPI bound to endothelial cells. CONCLUSION: These results indicate that topically applied TFPI reduces intimal thickness and increases long-term patency of small arterial autografts in rabbits.

Occurrence of neutrophils and activated Th1 cells in UVB-induced erythema.

We investigated the sequential changes in infiltrating inflammatory cells and several cytokine levels over a period of 48 h in human back skin exposed to 3 minimal erythematous doses of UVB. The measurement of blood flow, using a laser Doppler method, indicated that UVB-induced erythema reached a peak 12-24 h after irradiation. Immunohistochemically, an increase in the number of CD4+ T cells was observed in perivascular areas 6 h after the UVB treatment and continued for up to 48 h. CD8+ T cells were scarce until 24 h, but their numbers gradually increased thereafter. HLA-DR+ cells were detected perivascularly and interstitially in parallel with the pattern of CD4+ T-cell infiltration. In contrast, neutrophils were found 3 h after UVB exposure and reached a peak at 24 h. Using a RT-PCR method, we demonstrated that mRNAs for the Th1 cytokines (interferon-gamma and interleukin-2), together with a proinflammatory cytokine (interleukin-8), became detectable at 6 h, whereas mRNA for the Th2 cytokine (interleukin-4) was not found at all during the first 48 h. In contrast, we found an increase in mRNA levels for C3 and tumor necrosis factor-alpha even at 3 h, suggesting a relationship between complement activation and accumulating neutrophils. Our results suggest that neutrophils and CD4+ T cells in UVB-induced inflammation play different roles: neutrophils are more closely related to UVB-induced erythema, while T cells appear to be involved in subsequent dermal and epidermal inflammation accompanied by epidermal hyperproliferation.