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PubMed1986

Passage of lanthanum through the intercellular spaces of the sebaceous gland.

Lanthanum introduced intradermally into cattle, sheep, goats, ponies and rats penetrated into the sebum through the intercellular spaces of the sebaceous gland. It is concluded that the sebaceous gland is permeable to the passage of small molecules outwards and probably in some circumstances inwards. Since the constituents of sebum are not all produced by necrosis it is likely that the sebaceous gland is not a simple holocrine gland.

Animals↗
PubMed1980

[Peroxidation of lipids in the inflammatory process].

Lipidoperoxidation in the sebum from 10 subjects suffering from inflammatory acne has been shown by use of mass spectroscopy, in contrast with 10 normal subjects where this was not observed. Peroxidation of sebum lipids is probably linked with the inflammation of the comedons.

Acne Vulgaris↗
PubMed1982

Reaction of male Mongolian gerbils to odors in a social situation.

The current study was designed to examine the possibility that odor from substances rubbed on the back of young stimulus animals will influence the social behavior of male Mongolian gerbils. Thirty adult subjects were tested for four 5-min sessions with young conspecifics that had water, perfume, urine, or ventral gland sebum rubbed on their back. The subjects showed significantly longer investigation duration and higher approach frequencies toward the subjects treated with urine or sebum. The results demonstrate that gerbils are attracted to relevant odors in a social situation.

Animals↗
PubMed1982

Effect of solid detergent washing on values of skin electrical impedance.

We have studied the electrical behaviour of the skin on 20 volunteers, before and after cleaning with solid detergent. The aim was to study one of the possible variables of the measurements. The results have shown that the cleaning has globally reduced the electrical skin parameters of the forehead, without influencing other parts examined (dorsal and palmar surfaces of the hand). The result has been attributed to the elimination of the hydrolipidic film of the surface and in particular that of the sebum of the forehead. The data give an idea as to how to obtain more homogeneous final results, as well as studying the sebum production function.

Adolescent↗
PubMed1981

Meibomian gland studies: comparison of steer and human lipids.

Simple surgery gave whole meibomian glands of steer yielding approximately 47 mg of lipid per pair of lids. This lipid gave a thin-layer chromatography pattern similar to that of steer or human excreta. Column chromatography of pooled steer gland lipids and pooled human lipid (excreta) gave 0.06% and 7.54% hydrocarbons, respectively, containing no squalene. Excluding human hydrocarbons (as exogenous material) the percentage composition of steer and human lipids were, respectively, sterol esters 31.7 and 29.5; wax esters 31.2 and 35.0; material in the diester region 11.4 and 8.4; triacyl glycerols 1.6 and 4.0; material in the post-triacyl glycerol region 2.8 and 3.2; free sterols 3.0 and 1.8; free fatty acids 5.1 and 2.1; and polar lipids 13.3 and 16.0. Glass capillary gas-liquid chromatography revealed the following: a series of normal odd- and even-chain hydrocarbons (C16 to C32) for the steer and a complex pattern for the human samples; unsubstituted fatty acids in total lipids and various lipid classes ranging from C12 to C31 with n-even, n-odd, iso-even and iso-odd, and anteiso-odd chains for both samples; and fatty alcohols in total lipids and wax esters ranging from C18 to C31. Anteiso structures predominated in the steer, and iso structures in the human samples. Steer fatty acids favored anteiso branching and saturation, whereas human acids favored iso branching and unsaturation. Fatty acids of sterol esters in both samples showed a wider range of chain lengths than did other lipid classes. Similarity of the fatty acid pattern suggests that the free fatty acids are derived from the triacyl glycerols as in human sebum. Identification of saturated fatty acids was confirmed by a gas liquid chromatography--mass spectrometry--data system (GLC-MS-DS). We define "meibum" and "meibocyte" as the meibomian gland equivalent of sebum and sebocyte.

Adult↗
PubMed1996

The efficiency of ultrasonography in the diagnosis of dermoid cysts.

The aim of the study was to assess the efficiency of sonography in differentiating dermoid cysts of the ovary (mature cystic teratoma) from other adnexal masses. It was carried out prospectively at Dr. Zekai Tahir Burak Women's Hospital of Ankara, Turkey. 943 women with 1035 adnexal masses who had undergone laparotomy and/or laparoscopy between January 1989 and March 1995 were included into the study group. All of these patients had a sonographic preoperatively examination within one week of surgery and the sonographic diagnosis was compared to histopathological findings. The visualization of: 1. echogenic mass with or without acoustic shadowing or enhancement (assumed to represent sebum with lipophilic contaminants or with hair) 2. Dermoid plug; layered lines and dots; fat-fluid level; isolated brigth echogenic foci with acoustic shadowing within the complex mass (assumed to represent Rokitansky protuberance; hair in low viscosity fluid; sebum as a supernatant of serous fluid; teeth or bone fragments respectively) 3. intraovarian echogenic mass with or without acoustic shadowing or enhancement (assumed to represent intraovarian dermoid cyst) were chosen as characteristical sonographic findings of dermoid cysts. Combining these with the subjective visual assessment of the operator, the sensitivity and the specificity were calculated for each visualized adnexal mass to assess the efficiency of sonography in differentiating dermoid cysts from other ovarian masses. All in all 1035 adnexal masses were visualized, 155 were suspected to be dermoid cysts and the diagnosis was confirmed by histopathology in only 147 cases. The sensitivity and specificity of sonography were 94% and 99% respectively. As a conclusion this study demonstrates that ultrasonography has an accuracy of 98% in differentiating dermoid cysts from other adnexal masses with a specificity of 99%.

Adolescent↗
PubMed1997

Treatment of acne with intermittent isotretinoin.

Adults with acne represent an increasingly important population of acne sufferers referred for treatment. Acne, in these patients, is generally mild or moderate in severity but tends to be resistant to conventional antibiotic therapy. A study was carried out to assess the efficacy of intermittent moderate dose isotretinoin as a treatment for acne. Eighty consecutive patients, over the age of 25 years, referred with acne unresponsive to, or relapsing rapidly after three or more courses of conventional antibiotic therapy were recruited. Acne severity was assessed on the face, chest and back using the Leeds grading scale and the number of inflamed lesions was counted at the site showing the highest acne grade. The patients were 22 men and 58 women. The treatment regimen consisted of isotretinoin, 0.5 mg/kg per day for 1 week in every 4 week for a total period of 6 months. Seventy-five patients completed the study. The therapy was very well tolerated with mild cheilitis as the only side-effect. At the end of treatment, both total acne grade and lesion counts were significantly reduced (P < 0.0001). The acne had resolved in 68 (88%) patients. Twelve months after treatment, acne grades and inflamed lesion counts remained significantly improved (P < 0.0001) in the 68 patients who responded; however, 26 (39%) patients had relapsed. There was a significantly higher incidence of relapse in patients with predominantly truncal acne (P = 0.01). Patients who relapsed also had a significantly higher total acne grade, lesion count (P < 0.0001) and sebum excretion rate (P < 0.001) compared with those whose acne resolved. This study suggests that intermittent moderate dose isotretinoin may be a cost-effective alternative to full dose isotretinoin in a carefully selected group of adult patients with-acne. Selection criteria should include predominantly facial acne, total acne grade less than 1, inflamed lesion count less than 20 and sebum excretion rate less than 1.25 micrograms/cm2 per min.

Acne Vulgaris↗
PubMed1997

Investigation of the mechanism of action of 2% fusidic acid lotion in the treatment of acne vulgaris.

We describe the results of a single-centre, double-blind, vehicle-controlled, parallel group study on the quantitative effects of 2% fusidic acid lotion (Fucidin lotion) in facial acne vulgaris. The trial was completed by 52 patients aged 15-25 years with mild to moderate acne who had been randomized to either Fucidin Lotion (n = 25) or its base (n = 27). Primary outcome measures included colony counts of Propionibacterium acnes and micrococcaceae and measurements of skin surface lipid free fatty acids and sebum excretion rate. Clinical assessment was based on the acne grade, count of inflamed and non-inflamed lesions and evidence of a primary irritant dermatitis. There was a variable but gradual reduction in lesion counts with the maximum improvement at 12 weeks for inflamed lesions, where the reduction was 19.9% for fusidic acid and 24.7% for the placebo. The non-inflamed lesions decreased by 10.8% in the fusidic acid group and increased by 15.9% in the placebo group; this difference was not statistically significant. Although the fusidic acid reduced the micrococcaceae count by 1 log cycle, inferring adequate compliance, there was no reduction in the counts of P. acnes, surface free fatty acids or sebum excretion rate. This study has failed to explain the mechanism of action of topical fusidic acid.

Acne Vulgaris↗
PubMed1998

Inhibitory effect of propranolol on lipid synthesis in gonadectomized male hamster flank organs.

BACKGROUND: This paper describes the inhibitory effect produced by propranolol pre-treatment on lipid synthesis in flank organs from intact, gonadectomized, and isoproterenol-treated male hamsters. Furthermore, the effect induced by the same treatments on gland sebum composition is reported. METHODS: Different groups of male hamsters were injected daily with propranolol, isoproterenol or propranolol plus isoproterenol. Treatment-effect was evaluated determining the in vitro incorporation of radioactive acetate into lipids in hamster flank organs from intact and castrated animals. Additionally, radiolabeled lipids were isolated and identified using TLC and autoradiography as methods. RESULTS: Results demonstrate that castration significantly decreases lipid synthesis in male hamster flank organs. In addition, propranolol treatment inhibits such synthesis in glands from intact, gonadectomized, and isoproterenol-treated animals. However, isoproterenol treatment was ineffective when compared to intact or gonadectomized control vehicle-treated animals. Lipid classes isolated and identified lipids either in castrated or in drug-treated animals were phospholipids, cholesterol, monoglycerides, fatty acids, waxes and cholesterol esters. CONCLUSIONS: Results indicate an inhibitory effect induced on lipid synthesis by beta-adrenergic receptor antagonists; however, beta-adrenergic agonists drugs do not stimulate it. Data suggest a permissive role of adrenergic hormones on lipid synthesis in intact and in gonadectomized animals. Furthermore, castration decreased the synthesis, suggesting that a tight coupling between beta-adrenergic receptors and androgen receptors may be a prerequisite for lipogenesis in this tissue. Pre-treatment does not modify sebum composition in gonadectomized animal glands. These data support the evidence that activation of beta-adrenergic receptors could be an independent factor in the lipid composition regulation process.

Animals↗
PubMed1981

The effect of sexual hormones on the lipid and proteinaceous secretion of the rat preputial sebaceous gland.

The diameters of Sudan Black B stained sebum vesicles and acid hematein stained perinuclear granules, and the numerical density of the latter, were determined in mature sebaceous preputial cells from normal male and female rats, testosterone-treated female rats and estradiol-treated male rats. Statistical analysis by Student's t-test showed that the diameter of lipid droplets was significantly higher in male than in female controls and that testosterone increased female values up to make control levels. Estradiol treatment decreased male values to levels below those of normal male and female controls and of testosterone-treated female rats. Diameters of perinuclear granules did not vary among animal groups but their numerical density was larger in testosterone treated than in normal female rats or estradiol treated male rats. Lipid droplet sizes and perinuclear granule numbers are thus increased by androgens and decreased by estrogens, which was interpreted an meaning that sexual hormones do not only act on sebaceous cell multiplication or turnover time as previously known, but also on the production of lipid and the output of beta-glucuronidase containing granules in this gland.

Animals↗
PubMed1988

A modified photometric quantification of skin surface lipids sampled using the cigarette paper method.

In severe cases of acne conglobata the use of substances which considerably reduce the sebum excretion rate, such as 13-cis-retinoic acid, is reasonable. To monitor the effect of such preparation a noninvasive and accurate method for measuring skin surface lipids (SSLs) is required. A new modified photometric quantification of SSLs sampled using the cigarette paper method based on reaction with phosphovanilic reagent was introduced. Our overall results indicate that a 3-h SSLs assessment measured photometrically is as accurate as the gravimetric technique; it is reproducible in situations with low and high levels of SSLs.

Acne Vulgaris↗
PubMed1983

Hormonal control of hamster ear sebaceous gland lipogenesis.

The sites and hormonal control of lipogenesis in hamster ear sebaceous glands are reported. Sebaceous lipogenesis was determined in ear biopsies by incubation with glucose and tracer concentrations of 14C-acetate in buffer. The 14C-labeled lipids were saponified, extracted, and determined by liquid scintillation counting. Histologically, the ears contained many sebaceous glands. The glands of male animals were much larger and more heavily lipid-stained than glands from females. Lipogenesis was almost entirely confined to the sebaceous glands in the dermal stroma. Lipogenesis was considerably higher in ear biopsies from male hamsters than from female, castrate male, or hypophysectomized male hamsters. In contrast to published data using hypophysectomized rats, where dihydrotestosterone potently and testosterone only weakly increased sebum secretion, both testosterone and dihydrotestosterone potently increased lipogenesis in the ears of hypophysectomized male hamsters. Dihydrotestosterone was somewhat more potent than testosterone in the hamster. Hypophyseal hormones do not appear to be essential for androgen stimulated lipogenesis in the hamster. In female hamsters, 5 alpha-androstane-3 alpha, 17 beta-diol, testosterone, dihydrotestosterone, 4-androstene-3,17-dione, and 5 alpha-androstane-3,17-dione produced dose-dependent increases in lipogenesis. From this and other studies, it is suggested that androgens other than dihydrotestosterone could be physiologically important in man and animals in stimulating lipogenesis in sebaceous glands.

Androgens↗
PubMed1975

Comedo formation in acne.

Comedones contain a considerable quantity of water. In some cases a water content of more than 40% can be detected. The comedo consists of two parts, an inner nucleus built up to unorganized materials and a capsule with concentrically arranged shells. The material of the nucleus contains small scales produced by normal keratinization. The materials of the capsule consists of larger scales, which result from hyperkeratosis. The nucleus of the comedo seems to be identical with the early comedo. A similar structure can be formed in vitro by adding water to sebum. Microorganisms have optimal growth conditions in the early comedo.

Acne Vulgaris↗
PubMed1976

Immunological studies on the proteins of human eccrine sweat.

Proteins present in the eccrine sweat collected from the skin surface of male volunteers were studied. The protein content ranged from 0.154--0.774 g per liter. A total 2282 ml sweat was concentrated until a final protein content of 25 mg/ml was reached. Paper electrophoresis revealed 3 fractions migrating like alpha-, beta-, and gamma-globulins. Eight different proteins were demonstrated by immunoelectrophoretic analyses using rabbit antisera directed against human sweat proteins. Three of these proteins were identified as blood serum proteins. One of the remaining 5 proteins could be of epidermal origin; another one which occurs in comedones as well as in sweat seems to be eluted from the sebum film present on the skin surface.

Animals↗
PubMed1991

Stratum corneum lipid abnormalities in atopic dermatitis.

Patients with atopic dermatitis (AD) often present with a dry skin. To clarify the relationship between dry skin and lipid abnormalities within stratum corneum, stratum corneum lipids were collected from six AD patients aged 15 to 25 years and from sex- and age-matched controls. All major stratum corneum lipid classes were separated and quantitated by high-performance thin-layer chromatography/photodensitometry. Six ceramide fractions were also isolated and quantitated by thin-layer chromatography/photodensitometry. Esterified fatty acids of both ceramide 1 (acylceramides) and wax esters were analysed by capillary gas chromatography. The relative amounts of all the stratum corneum lipid classes including squalene, cholesterol esters, wax esters, triglycerides, free fatty acids, cholesterol, ceramides, cholesterol sulphate and phospholipids did not differ statistically between AD patients and controls. However, a significant decrease in proportion of ceramide 1, which is believed to be a carrier of linoleate responsible for a water-barrier function, and increased levels of esterified C18:1 fatty acids (oleate) of ceramide 1 were observed in AD patients. On the other hand, the fatty acid compositions as well as the proportions of C16:1 straight-chain component in sebum wax esters of AD patients were very similar to those of controls. These results suggest that a significantly reduced amount and/or structural alterations of ceramide 1 deriving from epidermal keratinocytes may be responsible for the impaired water-barrier function of the skin in AD.

Adolescent↗
PubMed1995

Impaired water barrier function in acne vulgaris.

In acne vulgaris, abnormal follicular keratinization is important for comedo formation, yet the precise mechanisms of comedogenesis are not known. The present study examined the interrelationship between sebum secretion rate (SSR), lipid content and water barrier function (WBF) of the stratum corneum (SC) in 36 acne patients and 29 control subjects. All major SC lipid classes were separated and quantified by thin-layer chromatography/photodensitometry. WBF was evaluated by measuring transepidermal water loss (TEWL), and the hygroscopic properties and waterholding capacity of the SC. The SSR over a period of 3 h was significantly higher in patients with moderate acne than in control subjects, but no significant difference was noticed between patients with mild acne and control subjects. Significant differences between patients with both moderate and mild acne and control subjects were noted in the amount of sphingolipids (ceramides and free sphingosine), but not for any other lipid classes. Furthermore in acne patients, lower amounts of sphingolipids were observed corresponding with a diminished WBF. These results suggest that an impaired WBF caused by decreased amounts of ceramides may be responsible for comedo formation, since barrier dysfunction is accompanied by hyperkeratosis of the follicular epithelium.

Acne Vulgaris↗
PubMed1996

Culture of cells derived from the human sebaceous gland under serum-free conditions without a biological feeder layer or specific matrices.

We succeeded in serially culturing cells derived from human sebaceous gland (sebocytes) under serum-free conditions. Sebaceous glands were isolated from dispase-treated facial skin specimens and cultured using two different methods, explant culture and dispersed cell culture, in KGM. In both types of culture the sebocytes proliferated rapidly without a biological feeder layer or specific matrices. It was possible to cultivate the cells serially for at least three passages (explant culture) and six passages (dispersed cell culture), and to store the cells in liquid nitrogen with good recovery. Analytical thin-layer chromatography revealed that the cells synthesized a large amount of sebum-specific lipids, squalene and wax esters in vitro. Both testosterone and 5 alpha-dihydrotestosterone significantly stimulated the proliferation of the sebocytes. The methods presented here may permit a large series of studies on the function of sebaceous glands or cells derived from sebaceous glands.

Cell Culture Techniques↗
PubMed1985

Measurement of the time between biosynthesis and surface excretion of sebaceous lipids in the horse.

The time between the biosynthesis and excretion of sebum to the skin surface of the horse was examined by in vivo intradermal injection of [1-14C]acetate followed by periodic surface lipid collections. The radiolabelling of the major neutral lipid classes, equolides (giant ring omega-lactones, C32-C36) and cholesteryl esters, was evaluated by thin-layer chromatography and autoradiography. The distribution of radioactivity within the monounsaturated equolides was examined by oxidative fragmentation and evaluation of the products. A peak of radioactivity in the equolides and cholesteryl esters occurred 15-21 days and 10-16 days, respectively, after injection. The time-courses of specific radioactivity of the two types of equolide oxidation fragments were also found to be dissimilar. The results are interpreted as indicating that in the biosynthesis of a large proportion of the equolides, de novo fatty acid synthesis was not followed immediately by fatty acid chain elongation. The phospholipids of the sebaceous cells are proposed as the long-term intermediate in which fatty acids reside between these two biosynthetic processes.

Animals↗