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Changes in long-term sebum production from isotretinoin therapy.

Sebum production has been measured in twenty patients in whom 13-cis-retinoic acid therapy had been discontinued for at least 20 weeks. While sebum production had returned to pretreatment levels by 30 weeks in seven subjects, 30% to 80% reduction in sebaceous gland activity was still present for as long as 80 weeks in eight subjects. Four of these eight patients, who were followed for more than a year, still had marked sebaceous inhibition when last tested. The prolonged remission seen in patients with nodulocystic acne may be related in part to continued sebaceous gland inhibition in some patients, but it obviously is not the only actor responsible for the long-term improvement that is seen.

Acne Vulgaris↗

Sebum, cosmetics, and skin care.

Recent contributions to the understanding of the physiology and biochemistry of sebum production and of the lipids on the skin surface are leading to the development of effective strategies to regulate excessive sebum production and its consequences through the use of cosmetics and skin care products.

Acne Vulgaris↗

Disposition of cocaine in skin, interstitial fluid, sebum, and stratum corneum.

The aim of this study was to determine whether or not the skin acts as a reservoir for cocaine. Cocaine-d5 (1 mg/kg) was administered to five nondependent, cocaine-experienced volunteers. Skin tissue, interstitial fluid, sebum, stratum corneum, and plasma were collected for 72 h after drug administration. Cocaine and benzoylecgonine (BE) levels were determined using GC-MS. Cocaine concentrations peaked in plasma at 1 h after administration, with pharmacokinetic parameters (t(1/2), CL, Vd) also in the expected ranges. In skin, cocaine levels peaked around 1.5 h after administration and became undetectable by 6 h. A correlation was found between the plasma and skin AUC for cocaine (R = 0.99, p = 0.006, N = 4). BE was not detected in skin. In interstitial fluid (N = 4), cocaine concentrations peaked around 5 h after drug administration and were undetectable by 24 h. BE peaks varied between 2 and 24 h and were not detectable at 48 h. In sebum, cocaine levels peaked between 3 and 24 h. BE was found in three samples between 12 and 24 h. In stratum corneum, cocaine was measurable in only one sample from one subject. These findings suggest that skin does not act as a reservoir for cocaine. Rather, cocaine appears to be distributed rapidly to the skin and eliminated, following a time course similar to that of plasma.

Adult↗

Variation in sebum fatty acid composition among adult humans.

Quartz capillary gas chromatography was used to analyze the wax ester fatty acids of 4 sebum samples collected at 2-week intervals from each of 10 adult human subjects. Marked differences in wax ester fatty acid composition between subjects were apparent. The greatest variation was present in the even-carbon-numbered iso-branched acids, which ranged from 1-22% of the monounsaturated acids and from 1-13% of the saturated acids. The anteiso chain structures formed 3-7.5% of the unsaturated acids and 3-13.5% of the saturated acids. Fatty acids bearing one or more methyl branches at other positions in the chain made up 12-22% of the saturated acids, but were not present in the unsaturated fatty acid fraction. This and other features of the composition of the unsaturated fatty acids indicate that the delta 6-desaturase that produces the monounsaturated fatty acids of human sebum requires a substrate having a straight chain of at least 12 carbon atoms extending from the carboxyl group. The differences in fatty acid composition between subjects and the constancy of composition for each of the subjects over the 2-month period indicate that the synthesis of each of the types of chain structure is under genetic control.

Adult↗

Measurement of sebum secretion rates in young children.

Sustainable rates of lipid secretion were measured on the foreheads of 24 children, ages 6-8. The method of measurement involved absorption of skin surface lipid into bentonite clay and subsequent separation and measurement of the various lipid classes by quantitative thin-layer chromatography. In 9 of the children, sebum secretion appeared to be virtually nonexistent, judging by the low amounts of lipid recovered and the low percentages of wax esters and squalene, which are purely sebaceous lipid classes. An effect of age on sebum secretion rates was observed with median rates of wax ester secretion, being 7, 28, and 48 micrograms/10 cm2/3 h for 6-, 7-, and 8-year-olds, respectively. These values are well below those of most young adults. The relation between wax ester secretion rate and skin surface lipid composition on the forehead was investigated and found to conform to the formula: microgram wax esters/10 cm2/3 h = 28 X wax esters/(cholesterol + cholesterol esters), with a correlation coefficient (r) of 0.94.

Aging↗

Sebum composition: a comparison of thin-layer chromatography and infrared reflectance spectroscopy.

Thin-layer chromatography and infrared reflectance spectroscopy were compared as methods for measuring sebum composition. Solutions of varying known concentrations of free fatty acids and triglycerides were analyzed by both methods. Skin surface lipid samples were similarly analyzed. Infrared spectroscopy produced more variable data than thin-layer chromatography with photodensitometry. This was particularly true at low concentrations of free fatty acids. It is concluded that thin-layer chromatography with photodensitometry is a more accurate method for the measurement of sebum composition.

Chromatography, Thin Layer↗

The effect of topically applied progesterone on sebum excretion rate.

There is evidence that anti-androgens may help in the treatment of acne vulgaris. We therefore performed a double-blind trial to assess the effect of topically applied progesterone on sebum excretion rate. Thirty-eight patients took part in the trial which was for 3 months. The preparation had no effect in males. However, a significant reduction in sebum excretion rate was found in females, the effect being maximal at the end of the second month. There was a significant loss of effect at the end of the third month and this was not related to deterioration of the progesterone preparation.

Acne Vulgaris↗

Determination of density of follicles on various regions of the face by cyanoacrylate biopsy: correlation with sebum output.

The density of follicles on various regions of the human face has received scant attention. We used cyanoacrylate follicular biopsies to determine the number of follicles on the forehead, cheek, chin and nose of 12 healthy adult white women. Sebum output was assessed on the same regions by means of Sebutape. The density of follicles and sebum output followed a centrolateral decreasing gradient. There was no correlation between these two parameters. These regional patterns are important for studies of the pathogenesis of common disorders of the face and their response to treatment.

Adult↗

Levels of terbinafine in plasma, stratum corneum, dermis-epidermis (without stratum corneum), sebum, hair and nails during and after 250 mg terbinafine orally once daily for 7 and 14 days.

In earlier skin pharmacokinetic studies we have shown that terbinafine is rapidly delivered to the stratum corneum, nails and hair both through sebum and by direct diffusion through dermis-epidermis. In the present study the skin pharmacokinetic profile of terbinafine was studied in two groups of eight human male volunteers during and after 250 mg orally once daily for 7 and 14 days. In the 7-day study high terbinafine levels were found in sebum (19.0 micrograms/g) and stratum corneum (2.5 micrograms/g), and a concentration in stratum corneum above the minimal inhibitory concentration for most dermatophytes was still found 48 days after the last day of medication. Terbinafine was found in peripheral nail clippings after 7 days of medication and the concentration was, in the 7-day study, 0.5 microgram/g 1 day after stopping medication; it was still 0.2 microgram/g 90 days after stopping treatment. The results in the 14-day study were in parallel with, but higher than, in the 7-day study. The elimination of terbinafine from several compartments is biphasic, with a faster initial elimination followed by a slower secondary elimination. For nails, the elimination is slower compared with the other compartments. The results indicate that terbinafine may be effective in short-term treatment of several dermatophytoses. The concentration of 0.2 microgram/g of terbinafine found in nails 90 days after stopping medication, following 7 days of treatment, indicates that the duration of therapy, even in tinea ungium, may be shorter than is currently the case.

Administration, Oral↗

Sebum measurements for rapid identification of hyperandrogenism due to an ovarian Leydig cell tumor.

Direct measurements of sebum with the Sebumeter were used in a patient with a benign androgen-producing tumor of the ovary. Androgen levels fell immediately after surgery, whereas the markedly elevated sebum levels found preoperatively dropped to normal after a delay of more than 2 weeks. Therefore, the Subumeter, due to its simplicity, may be useful for the preliminary screening and follow-up of patients with hyperandrogenic states.

Aged↗

Sebum excretion in hidradenitis suppurativa.

BACKGROUND: Clinical and histological similarities between hidradenitis suppurativa and acne have been pointed out. The possible role of sebaceous glands in hidradenitis has not previously been investigated. Acne treatment, in particular is however not effective in hidradenitis. No previous information was found on regional sebum excretion in hidradenitis. OBJECTIVE: Investigate the sebum excretion (SE) and markers of cutaneous virilization in hidradenitis patients. METHODS: Sebutapes and scores of acne, hirsutes and alopecia in 16 women with hidradenitis suppurativa were compared with 16 healthy controls. RESULTS: The SE and the number of active glands followed a similar pattern in both groups (face > axillae/genitofemoral fold, p < 0.0001) but no significant differences were seen between the two groups. No differences were seen in the median Body Mass Index, number of obese persons in either group or any of the clinical markers of virilization studied. CONCLUSION: No significant axillary, genitofemoral or facial seborrhea was found in hidradenitis. It is suggested that SE is not an important factor in the development of hidradenitis, and this may help explain the generally unsatisfactory therapeutic effect of retinoids in this disease. The results further suggest that general cutaneous virilization is not a feature of hidradenitis.

Acne Vulgaris↗

Seasonal modulation of sebum excretion.

It is currently agreed that ambient temperature influences the sebum excretion rate. By using the Sebutape technique we have confirmed this concept, which is related to an increased delivery of sebum to the surface of the skin without an increment in the number of active sebaceous follicles.

Adult↗

[Effects of gasoline on syntheses of DNA, protein and sebum in keratinocyte and fibroblast].

OBJECTIVE: To study the cellular and molecular mechanism of gasoline-induced adverse effects on skin, particularly on keratinocyte and fibroblast in vitro. METHODS: The primary cell culture of keratinocyte and fibroblast were treated with 0, 0.001%, 0.01%, 0.1% and 1.0% gasoline, respectively. (3)H-thymidine ((3)H-TdR), (3)H-leucine ((3)H-Leu), (3)H-proline ((3)H-Pro) and (14)C-linoleic acid incorporation tests were applied to elucidate their capacity of synthesizing DNA, protein and sebum. RESULTS: The incorporation of (3)H-TdR in keratinocyte and (3)H-TdR and (3)H-Pro in fibroblast inhibited significantly after exposure to 0.01% gasoline (P < 0.05), with inhibition rates 68.5%, 45.1% and 40.6% for (3)H-TdR in keratinocyte, and (3)H-TdR and (3)H-Pro in fibroblast, respectively. Significant depression in incorporation of (3)H-Leu and (14)C-linoleic acid in keratinocyte were found even in the group treated with 0.001% gasoline (P < 0.05), with inhibition rates of 20.2% and 41.2%, respectively. CONCLUSIONS: Solvent gasoline has certain toxic effect on keratinocyte and fibroblast, intervening their normal metabolic and physiological process and affecting their ability of synthesizing DNA, protein and sebum, and their physiological functions, which could be one of the mechanisms causing skin damage by gasoline. The results also indicated that keratinocyte was more susceptible to gasoline than fibroblast.

Animals↗

Keloids: a study of the immune reaction to sebum.

A controlled study of the "immune reaction to sebum" pathogenesis of keloids was carried out at the University College Hospital, Ibadan, Nigeria; on 22 humans using a homogenate solution of liquid paraffin and vernix caseosa from neonates. The 22 human volunteers comprised two groups, 11 of which were keloid formers and 11 non keloid formers. 0.1cc of sterile liquid paraffin was injected intradermally into the anterior aspect of the left forearm. The mean reaction in keloid formers was 11.55mm while in non keloid formers, it was 8.18mm. Although a higher reaction was demonstrated in this study, in keloid formers, this was found not to be significant (p less than 0.05), thus suggesting that sebum may not be an important factor in the pathogenesis of keloid.

Adolescent↗

The effect of ketoconazole on sebum secretion in patients suffering from acne and seborrhoea.

Ketoconazole, an imidazolic antimycotic derivative, has proved to have an antiandrogenous effect, which may be observed to inhibit the adrenal and gonadal steroid synthesis. The authors wished to verify this effect of the drug in men and women suffering from acne and seborrhoea, conditions believed to indicate a heightened androgenous effect in the sebaceous gland. They aimed to do this by studying the cutaneous sebum, which is considered a reliable indirect indicator of androgenous activity. They found a statistically significant decrease in the rate of sebum production in all patients administered with a single daily oral dose of ketoconazole (200 mg). Moreover no untoward side-effects were reported. The anti-androgenous property of ketoconazole would therefore suggest that the drug could be proposed as a useful alternative in the treatment of acne and seborrhoea.

Acne Vulgaris↗

The structure of triglyceride in human sebum.

1) A relatively large quantity of branched chain and odd-carbon-number fatty acids were found in human sebum. 2) These acids were present in each lipid fraction (cholesterol ester, triglyceride and free fatty acid) of sebum. 3) In the triglyceride molecule, these acids were found mainly on the 2-position.

Chemical Phenomena↗

[Decrease of the sebum excretion rate and improvement of acne in acneic women treated with the association: cyproterone acetate-ethinyl estradiol (author's transl)].

37 women have received during a total of 429 cycles (mean 12 cycles/patients) an association containing cyproterone acetate 2 mg and ethinyl estradiol 0.05 mg. A marked improvement in the clinical symptoms (acne 35 cases) has been observed. The sequential determination of the sebum excretion rate has been made in the same time (150 measurements) and revealed an important, early and durable decrease in the sebum excretion rate. The respective role of the CA and EE has been analysed in a second trial. It seems that the antiandrogen might play a role in the clinical improvement and in the reduction of the sebaceous flow.

Acne Vulgaris↗

[Increased sebum secretion due to oral administration of zinc sulfate].

In 87 patients hospitalized for chronic leg ulcers the effect of oral zinc on sebum secretion was determined. The patients were divided into three groups according to serum zinc concentrations. Patients with zinc levels in the upper normal range (Zn greater than or equal to 1.0 mg/l) were not treated. Patients with zinc levels in the lower normal range (Zn < 1.0 mg/l) received either three daily doses of 220 mg zinc sulphate or a placebo. The zinc-treated group displayed significantly increased sebum secretion. This effect was more marked in males, and may be due to a zinc-induced rise in plasma testosterone. Indications for oral zinc in dermatological conditions are discussed.

Administration, Oral↗