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Pilosebaceous Units (pilosebaceou + unit)
Selected AbstractsMicrobiology's principle of biofilms as a major factor in the pathogenesis of acne vulgarisINTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 12 2003Craig N. Burkhart MSBS Propionibacterium acnes reside within the pilosebaceous unit in a biofilm. As such, they live in a community of bacteria that encase themselves within an extracellular polysaccharide lining, which the organisms secrete after adherence to the surface. This gylcocalyx polymer acts as a protective exoskeleton and serves as a physical barrier, limiting effective antimicrobial concentrations within the biofilm microenvironment. The gylcocalyx polymer secreted by P. acnes as a biofilm may explain the immunogenicity of the organism as well as the clinical course of the disease. The P. acnes' biofilm model explains many aspects of acne pathogenesis and therapy, including why prolonged antibiotic treatment is needed, why antibiotic resistance is not a reliable assessment of treatment outcome, why accutane offers long-lasting effectiveness, and why benzoyl peroxide radicals are beneficial. This microbiologic principle of biofilms as applied to acne leads to numerous new pathways of assessment and exploration. [source] Tea tree oil concentration in follicular casts after topical delivery: Determination by high-performance thin layer chromatography using a perfused bovine udder modelJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 2 2005S.S. Biju Abstract Tea tree oil, a popular antimicrobial agent is recommended for the treatment of acne vulgaris, a disease of the pilosebaceous unit. Tea tree oil formulations (colloidal bed, microemulsion, multiple emulsion, and liposomal dispersion containing 5% w/w tea tree oil) were applied to bovine udder skin. The follicular uptake of tea tree oil upon application was determined by a cyanoacrylate method. Tea tree oil was determined by quantifying terpinen-4-ol content using high-performance thin layer chromatography. The accumulation of tea tree oil in the follicular casts was 0.43,±,0.01, 0.41,±,0.009, 0.21,±,0.006, and 0.16,±,0.005 percentage by weight (milligram oil/gram of sebum plug) for microemulsion, liposomal dispersion, multiple emulsion, and colloidal bed, respectively. This is the first study of its kind to quantify tea tree oil concentration in the follicles. © 2004 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 94:240,245, 2005 [source] Deep Phenol Peeling and Fat Injection: Treatment Option for Perioral Wrinkles in a Scleroderma PatientDERMATOLOGIC SURGERY, Issue 7 2005Yitzhack Ramon MD Background Scleroderma is characterized by abnormal growth of connective tissue, often manifested with hard and tight skin. The viscous properties of the skin are impaired, and the main histologic changes include a thicker dermis, absence of pilosebaceous units, and a decreased space between collagen bundles. Often these patients have wound healing problems. Objective The objective was to demonstrate a case of scleroderma that had deep phenol perioral peeling and fat injection into the lips. According to our bibliographic search, this is the first report in the English literature of using these modalities in scleroderma patients. Methods A 64-year-old woman suffering from scleroderma for more than 20 years came for improvement of her perioral appearance. We decided to manage her deep perioral wrinkles by deep peeling using the Baker formula and concomitantly to use autologous fat injection to augment her thin lips. Results The healing of our patient after these two interventions was uneventful, and satisfactory results have been obtained. Conclusion Based on our experience, this intervention may be suggested for patients suffering from scleroderma after a detailed explanation of the possible wound healing difficulties is provided to the patients. [source] Immunoreactivity of corticotropin-releasing hormone, adrenocorticotropic hormone and , -melanocyte-stimulating hormone in alopecia areataEXPERIMENTAL DERMATOLOGY, Issue 7 2006Hei Sung Kim Abstract:, Psychological factors are believed to play a role in the pathogenesis of alopecia areata (AA), a frequently encountered hair disorder. In our study, statistically significant elevation of psychological stress was felt by AA patients prior hair loss compared with control, which was strongly believed contributory to hair loss (t -test, P < 0.01). The corticotropin-releasing hormone (CRH) and proopiomelanocortin (POMC) mRNA have been identified in the basal layer of the epidermis and pilosebaceous units of the normal scalp. And with the recent discovery of melanocytes and dermal fibroblasts capable of corticosterone production, the presence of a local stress response system resembling the hypothalamic,pituitary,adrenal (HPA) axis has been suggested. The local stress response system is involved in regulation of the normal hair cycle, but its precise role in AA is unknown. The influence of a local HPA axis or rather, CRH,POMC axis in AA was investigated by analysing immunohistochemically the expression levels of CRH and POMC peptides, including the adrenocorticotropic hormone (ACTH) and , -melanocyte-stimulating hormone (, -MSH), in a number of AA lesions and normal scalp (as control). The epidermis and pilosebaceous units of normal scalp stained weakly with CRH, ACTH and , -MSH, whereas those from the affected sites of the AA group showed intense expression of the peptides (chi-square test, P < 0.01). The meaning of this enhanced expression and their role in the pathogenesis of AA should be further evaluated in future. [source] Congenital panfollicular nevus: report of a new entityJOURNAL OF CUTANEOUS PATHOLOGY, Issue 1 2005Laura S. Finn The various forms of non-melanocytic nevi (hamartomas) are usually encountered in pediatric patients, and nevus sebaceous of Jadassohn is the most common to have undifferentiated pilosebaceous units. We report a unique congenital follicular nevus that fails to meet the criteria of any previously described follicular neoplasm, despite the plethora of alternatives. Clinically considered a syringocystadenoma papilliferum, the excised lesion contained multiple dermal nodules that exhibited nearly all stages of follicular differentiation. The periodicity of the follicular proliferations was akin to normal terminal hair, and a prominent perifollicular sheath surrounded each. This benign lesion of abortive hair follicles was unassociated with any established genodermatous syndrome or other adnexal neoplasm. [source] Porphyrin distribution after topical aminolevulinic acid in a novel porcine model of sebaceous skin,,LASERS IN SURGERY AND MEDICINE, Issue 2 2009Fernanda H. Sakamoto MD Abstract Background and Objective Aminolevulinic acid photodynamic therapy (ALA-PDT) depends on drug metabolism into porphyrins. Clinically, ALA-PDT has been used with a wide range of protocols for treating both epidermal and dermal targets, despite limited understanding of porphyrin biodistribution over time. We studied porphyrin accumulation after topical application of ALA in vivo, and also describe the porcine ear as a new animal model to study adnexal glands. Study Design/Materials and Methods The microanatomy of anterior ear skin of swine was measured. Topical 20% ALA in water/ethanol was applied under occlusion. Biopsies taken after 5, 10, 15, and then every 15 minutes for a total of 3 hours were examined by fluorescence microscopy of frozen sections to assess accumulation and distribution of porphyrins. Results Porphyrin fluorescence of digital photomicrograph images was not visually apparent until 30,45 minutes after application, although quantitative pixel analysis showed a statistically significant increase in epidermal fluorescence only 15 minutes after ALA application. From 30 to 120 minutes, epidermis, hair follicles (HF), and sebaceous glands (SG) became progressively more fluorescent. Eccrine gland fluorescence began to be detected after 30 minutes; SG showed fluorescence starting at 45,75 minutes. Fluorescence in all sites reached maximum intensity from 75 to 180 minutes of incubation. There was a trend for HF and SG to express stronger fluorescence compared with epidermis and eccrine glands. Conclusion Anterior pig ear skin is microanatomically similar to human sebaceous skin. The time-dependent accumulation of porphyrins in pilosebaceous units and eccrine glands in this model suggests other routes of uptake of topical ALA in addition to the trans-epidermal route. Apparently, time interval between ALA application and light exposure could be optimized for different uses of ALA-PDT. Lasers Surg. Med. 41:154,160, 2009. © 2009 Wiley-Liss, Inc. [source] Current knowledge of host response in human tineaMYCOSES, Issue 4 2009J. Brasch Summary Skin infection caused by dermatophytes is called tinea. In this short review, the known mechanisms and factors involved in human tinea and important for the host response are briefly delineated. To establish tinea, fungal propagules must attach to the skin, germinate and overcome the epidermal barrier. Keratinases and other enzymes are released in this process and host keratinocytes are activated. This is followed by an inflammatory response mediated by a plentitude of cytokines and receptors, comprising innate as well as acquired immunity, including neutrophilic granulocytes, macrophages, antibodies and T cells. Cellular defence mechanisms appear to be decisive for clearing of infection. Nails and hair follicles are the particular sites often invaded by dermatophytes that show distinctive patterns of infection. Nails are largely excluded from defence mechanisms and steroid hormones of the pilosebaceous units may have a particular effect on follicular infection. Fungal invasion of the dermis can cause granulomatous reactions. Immune reactions to dermatophytes may lead to sterile eruptions distant from the infected skin areas. [source] | ||||||||||