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PubMed1990

Fatty acid composition of sebum wax esters and urinary androgen level in normal human individuals.

To investigate the effects of androgens on the fatty acid compositions of sebum wax esters, we examined sebum and urinary samples from 36 healthy individuals, aged from 3 to 59 years. The percentages of C16:1 straight chain components in wax esters were correlated positively with the urinary testosterone levels in both sexes, and with the urinary levels of etiocholanolone and total 17-ketosteroids (17-KS) in females. These data suggest that more active sebaceous glands in lipid production excrete sebum with a higher proportion of C16:1 straight chain fatty acid, which is considered to be purely endogenous. It appears, therefore, that the proportion of C16:1 straight chain fatty acid in sebum wax esters may indicate the sebaceous gland activity in both sexes. In comparison of the amounts of various straight and terminally branched fatty acids in sebum with urinary androgen levels, the straight even fatty acids tended to change in a positive correlation with testosterone levels, in contrast to the changes of the iso even fatty acids in both sexes and to those of the iso odd fatty acids in males. The straight odd fatty acids showed a similar change to that of the straight even fatty acids in males, while in females, there was no significant correlation between the amounts of the fatty acids and testosterone levels. Anteiso fatty acids showed no notable change correlated with testosterone levels. This result suggests that the synthesis of iso or anteiso fatty acids may be controlled by complex factors and that there may be a unique source of anteiso fatty acids in human sebaceous glands.

17-Ketosteroids↗
PubMed1986

Hair follicles and associated glands as androgen targets.

The growth of hair, except that on the scalp, and the secretion of sebum are, in general, under the major influence of androgens. However, the responses of the hair follicles and their associated glands vary greatly between sites and between individuals. On the face, trunk and extremities the most important role of testosterone is to increase the period of activity, the anagen phase, of the hair follicle, though it also increases the rate of growth, thickness, extent of medullation and pigmentation of the hair. These effects involve high levels of hormone and its conversion to 5 alpha-dihydrotestosterone in the target organ. In contrast, the lower pubic triangle develops luxuriantly even in absence of 5 alpha-reductase. In the sebaceous glands, cell replication and lipid synthesis do not seem to be identically controlled, since they respond differently to inhibitors. The response of the sebaceous glands to androgens involves the interaction at the target site of pituitary factors, for which growth hormone, prolactin, and melanocyte stimulating hormone are all putative candidates. The most important scientific and clinical question is whether, in any particular circumstances, the degree of response of the hair follicles or sebaceous glands is determined by the level of available androgen or by the sensitivity of the target organ. While it is true that some patients with hirsutism or acne have above normal levels of plasma androgens or below normal levels of SHBG, a substantial proportion are normal in all respects. Moreover, the rates of hair growth on the extremities or of sebum excretion on the forehead do not seem to be correlated either positively with plasma androgens or negatively with SHBG, though they each have been shown to be correlated with circulating 5 alpha-dihydrotestosterone. The conclusion must be that, although male-type hair growth and high sebaceous secretion may be caused by, or at least accompanied by, high levels of free testosterone, the critical factor is more likely to be the peripheral response.

Adult↗
PubMed1989

Glands of the eyelids of rhesus monkeys (Macaca mulatta).

The various glands of rhesus monkey eyelids and human eyelids are similar. Numerous modified sebaceous glands are located along the tarsus. These conform with the meibomian glands, while typical sebaceous glands associated with the hair follicles of the lashes are consistent with the glands of Zeis. Lobules of accessory lacrimal tissue, corresponding to the glands of Krause and Wolfring, are located in the conjunctiva of the fornix and along the orbital border of the tarsal plate. Goblet cells are plentiful in the mucosa of the palpebral and bulbar conjunctiva, and along the lid margin are the sweat glands of Moll.

Animals↗
PubMed1995

Local and systemic reduction by topical finasteride or flutamide of hamster flank organ size and enzyme activity.

The hamster flank organ is a widely used model of the control of sebaceous gland activity by androgens and anti-androgens. Finasteride, a 5 alpha-reductase inhibitor, was administered locally on the surface of the right flank organ and right ear twice daily for 4 weeks. The treatment caused similar 12% to 30% reductions in the size of the sebaceous glands in both flank organs. Moreover, relative mRNA levels of the androgen-regulated FAR-17a gene measured by in situ hybridization as well as [3H]-thymidine incorporation and 5 alpha-reductase activity were similarly decreased in the two flank organs after topical application. The pure anti-androgen flutamide, at the same doses, exerted a more potent effect on all the same parameters, and the effect was also comparable on both the treated and untreated sides of flank organs. Finasteride and flutamide significantly decreased ventral and dorsal prostatic weights after topical application. The present data show that the topical administration of finasteride, in analogy with flutamide, causes local inhibition of sebaceous gland growth in both the costovertebral organs and ears. However, as demonstrated by the similar inhibitory effect in the contralateral untreated side and the reduced weight of the dorsal and ventral lobes of the prostate and seminal vesicles, finasteride and flutamide both exert significant systemic effects.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗
PubMed1979

The effect of the bis-(2-pyridil-1-oxide)-disulfide adduct with Mg SO4 on the scalp and hair lipids.

Animal experiments demonstrate that the topical application of the bis-(2-pyridyl-l-oxide)- disulfide adduct with MgSO4(Omadine MDS) increases the mitosis rate and also the size of the sebaceous glands in the Syrian hamster ear. Corresponding results have been obtained in human subjects in whom the secretion of the sebaceous glands was shown to increase after application of the compound. The studies also demonstrate that it decreases the fatty acid content of the scalp lipids. In this way a seborrhoea oleosa is transformed into a seborrhoea sicca. The undesired side effect of a stimulation of the sebaceous gland secretion is thus in part compensated for the patient's subjective feeling.

Adolescent↗
PubMed2006

Smad7-induced beta-catenin degradation alters epidermal appendage development.

To assess whether Smad signaling affects skin development, we generated transgenic mice in which a Smad antagonist, Smad7, was induced in keratinocytes, including epidermal stem cells. Smad7 transgene induction perturbed hair follicle morphogenesis and differentiation, but accelerated sebaceous gland morphogenesis. Further analysis revealed that independent of its role in anti-Smad signaling, Smad7 bound beta-catenin and induced beta-catenin degradation by recruiting an E3 ligase, Smurf2, to the Smad7/beta-catenin complex. Consequently, Wnt/beta-catenin signaling was suppressed in Smad7 transgenic hair follicles. Coexpression of the Smurf2 and Smad7 transgenes exacerbated Smad7-induced abnormalities in hair follicles and sebaceous glands. Conversely, when endogenous Smad7 was knocked down, keratinocytes exhibited increased beta-catenin protein and enhanced Wnt signaling. Our data reveal a mechanism for Smad7 in antagonizing Wnt/beta-catenin signaling, thereby shifting the skin differentiation program from forming hair follicles to sebaceous glands.

Animals↗
PubMed1989

Vulvar intraepithelial neoplasia and skin appendage involvement.

Vulvar intraepithelial neoplasia may extend into the pilosebaceous units of the hairy and non-hairy skin of the vulva, and inadequate removal may cause treatment failure. We measured with a calibrated microscope the thickness of vulvar intraepithelial neoplasia and the depth to which it extended into the underlying pilosebaceous units of the vulvar skin. The mean thickness of vulvar intraepithelial neoplasia in 329 histologic sections from 62 cases was 0.38 mm; 99.5% of all vulvar intraepithelial neoplasia measured less than 0.77 and 0.69 mm in the hairy and non-hairy skin, respectively. Sebaceous-gland and hair-follicle involvement by vulvar intraepithelial neoplasia was 21 and 32%, respectively. The mean depth of sebaceous-gland involvement was 0.77 mm in the hairy skin and 0.50 mm in its non-hairy counterpart; 99.5% of all vulvar intraepithelial neoplasias extended less than 2.03 and 1.07 mm in the hairy and non-hairy skin, respectively. The mean depth of hair-follicle involvement was 1.04 mm; 99.5% of all hair follicles were involved less than 2.55 mm. Our findings suggest that removal of vulvar intraepithelial neoplasia to a depth of 1.0 and 2.0 mm in the non-hairy and hairy skin, respectively, is appropriate for successful treatment.

Adult↗
PubMed1998

Activity of 17beta-(N-alkyl/arylformamido) and 17beta-[(N-alkyl/aryl) alkyl/arylamido]-4-methyl-4-aza-5alpha-androstan-3-ones as 5alpha-reductase inhibitors in the hamster flank organ and ear.

Skin disorders such as acne, seborrhea, hirsutism, and androgenic alopecia are secondary to excess local androgenic activity. Because the most potent androgen, dihydrotestosterone, is formed from testosterone by the action of 5alpha-reductase, the inhibition of 5alpha-reductase is a logical approach to interfere with androgenic action in the skin. In this study, we have investigated the inhibitory effect of a series of 17beta-(N-alkyl/arylformamido)-and 17beta-[(N-alkyl/aryl)alkyl/arylamido]-4-methyl-4-aza-5alpha -androstan-3-one derivatives as 5alpha-reductase inhibitors following their topical application on the flank organs and ears of Golden Syrian hamsters. The parameters measured were mainly the size of the underlying sebaceous glands and 5alpha-reductase activity in the flank organs and ears. We found that 17beta-(N-amylformamido)-4-methyl-4-aza-5alpha-androstan+ ++-3-one (EM-401), 17beta-(N-hexylformamido)-4-methyl-4-aza-5alpha-androstan -3-one (EM-402), and 17beta-(N-heptylformamido)-4-methyl-4-aza-5alpha-andro -stan-3-one (EM-540) are potent inhibitors of 5alpha-reductase activity. EM-402 decreases the size of treated flank organs by 22%, 31%, and 32% (p < 0.01 for all) after topical application at the doses of 30, 100, and 300 microg, respectively, twice daily for 4 wk. EM-402 also reduced the size of underlying sebaceous glands by 38%, 42%, and 59% of intact control values at the same doses. Comparable results were observed on the size of the sebaceous glands of the ears. In addition, we have observed a concentration-dependent 47%-80% (p < 0.01) and 46%-80% (p < 0.01) inhibition of 5alpha-reductase activity in the right flank organs and ears, respectively, using topical EM-402. EM-402 had no significant effect on the same parameters in the left contralateral flank organs or ears. In addition, EM-402 had no effect on prostatic and seminal vesicle weights whereas EM-401 and EM-540 showed some systemic effects. These data illustrate that EM-402 applied topically, at the concentrations used, exerts a potent local anti-androgenic effect without any systemic action in the hamster.

Androgen Antagonists↗
PubMed2002

Sebaceous carcinoma in children.

Sebaceous carcinoma is a rare malignant tumor derived from the epithelium of sebaceous glands. It potentially may develop from any sebaceous gland, but most commonly occurs in the periorbital area. We report a case of sebaceous carcinoma in a 14-year-old girl who was first seen with an asymptomatic 2.5 x 2.3-cm firm, multilobulated cutaneous nodule on the anterior thorax, which had been present for 1 year. She was adopted, and no family history is available. A skin biopsy specimen revealed a poorly differentiated infiltrative carcinoma involving the dermis and subcutaneous fat and focally involving the epidermis. Tumor cells had sebaceous and squamous differentiation. A diagnosis of sebaceous carcinoma was made. She was treated by surgical excision with a 2-cm margin. Further work-up showed no evidence of Muir-Torre syndrome.

Adenocarcinoma, Sebaceous↗
PubMed2001

Treatment options and future prospects for the management of eyelid malignancies: an evidence-based update.

PURPOSE: To provide evidence-based clinical recommendations for treatment options and future prospects for the management of common malignant eyelid tumors, including global ratings for the strength of published evidence supporting them. CLINICAL RELEVANCE: Approximately 5% to 10% of all skin cancers occur in the eyelid. Incidence studies indicate that basal cell carcinoma is the most frequent malignant eyelid tumor, followed by squamous cell carcinoma, sebaceous gland carcinoma, and malignant melanoma. Many therapeutic methods have been suggested to combat the morbidity and mortality associated with these lesions. LITERATURE REVIEWED: A MEDLINE and PubMed literature search (1966-1999) was conducted for English language abstracts and appropriate (selected) full-text references retrieved regarding treatment of malignant eyelid tumors. These sources then were used to prepare recommendations for patient care. Each recommendation was rated according to: (1) its importance in the care process and (2) the strength of evidence supporting the given recommendation. RESULTS: All recommendations were rated as level A (very important to patient-care outcome). For basal cell carcinoma, squamous cell carcinoma, and sebaceous gland carcinoma, the published evidence supporting two recommendations (Mohs' micrographic surgery or excision with frozen-section control) were graded as I (providing strong evidence in support of a recommendation). For sebaceous gland carcinoma, the recommendations also included conjunctival map biopsies. The published evidence supporting all other recommendations for these three eyelid tumors were graded II (substantial evidence in support of a recommendation), primarily because of the small numbers of patients in each clinical study. For malignant melanoma, the recommendation for therapy (i.e., excision with variable margins depending on tumor thickness) was based on published papers individually variably rated as I, II, and III, reflecting ongoing debate as to the best method of therapy. CONCLUSIONS: Published reports regarding the treatment of malignant eyelid tumors include a myriad of treatment options. The strongest evidence favors complete surgical removal using histologic controls for verifying tumor-free margins of excision.

Adenocarcinoma, Sebaceous↗
PubMed2001

Muir-Torre syndrome.

Muir-Torre syndrome is a rare autosomal dominant condition in which multiple primary malignancies occur together with a sebaceous gland tumour. Early recognition of the syndrome in patients with sebaceous gland tumours should facilitate early detection of subsequent malignancies if the patient with entered into appropriate screening programmes. A case occurring in Scotland is described and implications for management, screening for members of the family are discussed.

Adenocarcinoma↗
PubMed2007

Temporal changes in sebum excretion and propionibacterial colonization in preadolescent children with and without acne.

BACKGROUND: It is generally accepted that the onset of sebum secretion occurs before puberty in boys and girls as a result of increasing androgen output during the adrenarche. Propionibacteria are part of the commensal skin flora and, in adults, are found in highest numbers in sebum-rich areas of skin such as the face and upper trunk. Previous studies investigating the association between sebum output and propionibacterial population densities have been cross-sectional and have been carried out mainly in adults. OBJECTIVES: The purpose of this study was to examine the association between the onset of sebum secretion and expansion of the propionibacterial flora in a population of early adolescent children aged between 5.5 and 12 years, and to evaluate the temporal relation between the two factors longitudinally. In addition, the study aimed to evaluate the change with age in sebaceous gland activity and propionibacterial colonization on the skin and in the nares between children who developed acne and those who did not. METHODS: Biannual examinations of volunteers included age, pubertal (Tanner) stage, weight and height, lesion counting on the face, propionibacterial colonization on the skin surface and in the nares and sebum secretion. A longitudinal analysis based on all observations of each subject throughout the study was applied to examine the change of sebaceous gland activity and propionibacterial colonization with age and pubertal stage. A generalized estimating equation was used with a 0.05 level of significance. RESULTS: The commencement of sebum production was asynchronous, with only a small number of follicles initially starting to secrete sebum onto the skin surface. The number of secreting follicles and the area of sebum increased with age and pubertal stage (P < 0.0001, P < 0.05, respectively). Numbers of propionibacteria on the skin tended to increase after the age of 9 years, but not significantly so. In contrast, numbers of propionibacteria in the nares increased significantly with age (P < 0.0001) but not with pubertal maturation. Children who developed acne had higher sebum output and propionibacterial densities with increasing age than children who did not develop acne. This effect was significant for the increase of total sebum area with age in pubertal children (P = 0.0023), the increase in number of secreting follicles with age (P = 0.020) in prepubertal children, and the increase in propionibacteria densities in the nares with age (P = 0.0005) in pubertal children. Sebaceous gland activity and propionibacterial numbers on the skin surface remained unchanged with increasing age in children who did not develop acne. Propionibacterial population densities in the nares increased with age regardless of the development of acne. CONCLUSIONS: Onset of sebum secretion and consequently expansion of the propionibacterial skin flora occur earlier in children who develop acne than in children of the same age and pubertal status who do not develop acne. These observations suggest that postponing the onset of sebum production or the expansion of the propionibacterial skin flora until after puberty may represent ways of preventing the disease or minimizing its severity. Determinants of propionibacterial colonization on the skin and in the nares may be different.

Acne Vulgaris↗
PubMed1993

Immunelectron microscopic localization of cathepsin B in human exocrine glands.

The distribution of the lysosomal enzymes cathepsin B, lysozyme, chymotrypsin, and neutrophil elastase was examined in eccrine, apocrine, and sebaceous glands using a postembedding immunogold labeling procedure. Various amounts of cathepsin B were detected in all glands. Lysozyme, however, was detected in apocrine glands only. The other two lysosomal enzymes were not detectable immunologically. In apocrine and eccrine glands, anti-cathepsin B antibody labeled all secretory granules. In sebaceous glands, only the peripheral layer of cells showed immunological activity for cathepsin B. In apocrine glands, granules containing remnants of cristae were more intensively labeled than those lacking cristae which supports the assumption that both granules are derived from mitochondria by acquiring lysosomal enzymes. The enzymes convert mitochondria to granules with cristae and finally to granules without cristae. Thus the difference in morphology is part of a spectrum of the degradation of mitochondria to granules.

Apocrine Glands↗
PubMed1994

Percutaneous absorption of estradiol and progesterone in normal and appendage-free skin of the hairless rat: lack of importance of nutritional blood flow.

Percutaneous absorption occurs after passive diffusion through the different layers of the skin and its appendages. Thereafter, a resorption process into the cutaneous microcirculation brings the compounds into the systemic circulation. The objective of this in vivo study in the hairless rat was to compare the percutaneous absorption of two steroids on normal and appendage-free (scar) skin and to show if differences in absorption result only from the lack of hair follicles and sebaceous glands and/or from a modification of local blood flow. Percutaneous absorption was evaluated with estradiol and progesterone after 30 min, 2 and 6 h. Except after 30 min, the reservoir function of the stratum corneum of scar skin was approximately twice as high as in normal skin. Eighty to ninety percent of the estradiol and progesterone found in the stratum corneum were located in its superficial layers. Inversely, whatever the application time was, the concentrations of both steroids in the epidermis and dermis were significantly higher in normal skin than in scar skin with maximal difference between about 40 and 400 microns, the area of sebaceous gland localization. Cutaneous blood flow in full-thickness skin, assessed by the thallium-201 method, was globally identical in normal and in scar skin. In scar skin, at the level of papillary dermis, a decrease in blood flow due to the thicker viable epidermis and the flat dermoepidermal junction has been shown without implying an accumulation of drug in the epidermis and superficial dermis. Under these conditions, our results clearly demonstrate that the nutritional blood flow does not interfere with the percutaneous absorption of estradiol and progesterone in normal and scar skin. Thus, they confirm the significant contribution of hair follicles and sebaceous glands to drug penetration into the skin and subsequently the systemic circulation.

Animals↗
PubMedDate not supplied

MUC1 and sialoglycan expression associated with cytotoxic T lymphocyte infiltration in eyelid malignant tumors.

PURPOSE: To elucidate the relation between infiltrating cytotoxic T lymphocytes and the expression of MUC1 and sialoglycans in malignant eyelid tumors. METHODS: The distribution of MUC1, Maackia amurensis lectin-II (MAL-II)-recognized sialoglycan, and CD8-positive T lymphocytes was examined histochemically in 14 patients with malignant eyelid tumors: three squamous cell carcinomas, six sebaceous gland carcinomas, and five basal cell carcinomas. The density of CD8-positive cells was examined and correlated with MUC1 and sialoglycan expression. RESULTS: MUC1 was identified in squamous cell carcinoma and sebaceous gland carcinoma, but not in basal cell carcinoma. CD8-positive cells were more densely distributed in those squamous cell and sebaceous gland carcinoma cases that were more intense in MUC1 expression and weaker in MAL-II binding. Tumors with a strong expression of both MUC1 and MAL-II-bound sialoglycans showed few CD8-positive cells. CONCLUSIONS: MUC1 with few sialoglycans is likely to induce an intense infiltration of CD8-positive cytotoxic T lymphocytes in eyelid cancers.

Adenocarcinoma, Sebaceous↗
PubMed1993

Mantleoma. A benign neoplasm with mantle differentiation.

Four cases of neoplasms with mantle differentiation are presented. The mantle (sebaceous mantle) is a well-described but little known part of the sebaceous gland cycle. In the resting phase of that cycle, the mantle is seen as cords of undifferentiated cells that emanate from the infundibulum of a hair follicle and droop down aside the follicle in the form of a mantle or skirt. Cyclically, vacuolated sebocytes appear at the terminus of these cords, singly, then in groups, and finally as fully developed sebaceous lobules and glands. Presumably, sebaceous glands involute to become undifferentiated mantles. Clinically, neoplasms with mantle distribution occur on the face. Three of our cases were found fortuitously in sections of tissue removed because of basal-cell carcinoma. One was thought by the clinician to be a basal-cell carcinoma. Histopathologically, mantleomas vary in complexity. Presumably early neoplasms consist only of cords and columns of undifferentiated epithelial cells that radiate from an infundibulum. Later on, these cords interweave in a retiform pattern that contains sebocytes of varying degrees of vacuolization and sebaceous ductal structures. Mantleomas are benign because none in our series recurred after surgical removal and no atypical neoplastic cells were seen histopathologically.

Epithelium↗
PubMed1992

Fel d I allergen: skin and or saliva?

To determine the relative importance of saliva and sebaceous glands as sources of Fel d I allergen, we compared Fel d I levels at the base and tip of the hair in areas presenting more or less sebaceous glands and areas licked more or less frequently. The amount of Fel d I was significantly higher at the base than the tip of the hair. Further, it was strongly correlated with the density of sebaceous glands. This study demonstrated that the most abundant source of Fel d I allergen is cat skin.

Allergens↗