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PubMed1995

Multiple-dose pharmacokinetics and distribution in tissue of terbinafine and metabolites.

The pharmacokinetics of terbinafine and its inactive metabolites SDZ 86-621 (the N-demethyl form), SDZ 280-027 (the carboxybutyl form), and SDZ 280-047 (N-demethyl- carboxybutyl form) in plasma were characterized for 10 healthy male subjects receiving 250 mg of terbinafine orally once a day for 4 weeks and in the subsequent 8-week washout phase. Terbinafine concentrations were also measured in sebum, hair, nail, and stratum corneum samples. Concentrations of the parent compound and metabolites were determined by validated high-performance liquid chromatography methods. Terbinafine was rapidly absorbed, with peak concentrations in plasma of 1.70 +/- 0.77 micrograms/ml occurring 1.2 +/- 0.3 h postdose. Concentrations subsequently exhibited a triphasic decline, with a terminal deposition half-life of 16.5 +/- 2.8 days. Terbinafine accumulated approximately twofold over the 4-week dosing phase. The predominant metabolite in plasma samples was SDZ 280-027; specifically, the ratios of metabolite area under the curve to terbinafine area under the curve following the last dose were 1.25, 1.38, and 1.08 for metabolites SDZ 86-621, SDZ 280-027, and SDZ 280-047. Measurable concentrations of terbinafine were achieved in sebum and hair samples within the first week of administration and by week 3 in stratum corneum and nail samples. Fungicidal concentrations persisted in plasma and peripheral tissue samples for prolonged periods (weeks to months) after administration of the last dose. These pharmacokinetic properties are likely an underlying factor in the shorter treatment times and good clinical cure rates which have been reported for terbinafine in the therapy of onychomycoses and dermatomycoses.

Adult↗
PubMed1983

Acne and anticonvulsants.

The severity of acne and rate of excretion of sebum were assessed in 243 patients with epilepsy taking various anticonvulsants who were in hospital long term and in matched controls derived from a normal population of 2176 people. Neither the prevalence of acne nor the sebum excretion rate significantly increased in the patients compared with the controls or in patients taking phenytoin compared with those not. It is concluded that anticonvulsant treatment does not cause acne.

Acne Vulgaris↗
PubMed1989

Control and function of sebaceous glands.

This review describes the various types of sebaceous glands, their locations, and where possible their different functions. All sebaceous glands are similar in structure and secrete sebum by a holocrine process. However, the nature of this secretion and the regulation of the secretory process seem to differ among the various types of glands. Methods for measuring sebum secretion and assessing sebaceous gland activity are also described. The area of major interest during the last 20 years has undoubtedly been the mechanisms that control sebaceous gland function. Most studies have focused on the endocrine control and in particular on the role of androgens and pituitary hormones, although evidence suggests that nonendocrine factors may also be important. However, many questions remain and during the next few years attention will certainly be given to the role of retinoids and their mode of action in the treatment of acne.

Animals↗
PubMed2001

Investigation of follicular penetration of topically applied substances.

The influence of specific follicle properties, sebum production and hair growth on the follicular penetration of topically applied substances was investigated. The behavior of follicles identified in selected skin areas of volunteers was analyzed by various tape stripping and staining methods in combination with laser scanning microscopy. Furthermore hair growth in the selected skin areas was determined. A correlation between sebum production, hair growth activity and follicular penetration was observed.

Administration, Topical↗
PubMed1994

2-in-1 shampoo technology: state-of-the-art shampoo and conditioner in one.

Consumers have expressed a need for cleaning and conditioning in one step. Conventional shampoo technology using anionic surfactants and cationic conditioners results in charge interaction and complexing of the ingredients. Neither shampoo nor conditioners achieves the desired result. The successful solution was to incorporate charge neutral dimethicone conditioning ingredients, suspended as microfine droplets within complex crystal lattices, into anionic surfactant shampoo technology. The same solution has also been applied to amphoteric surfactant systems. This provides complete cleaning, and hair conditioning fully equal to separate conditioners without the problems of sebum interactions and conditioner build-up. This was achieved by keeping the dimethicone in suspension throughout the shampoo process. During rinsing, excess water breaks the crystalline lattice and allows deposition of the dimethicone droplets onto the hair. Full cleaning and conditioning are, therefore, achieved in one application. Dimethicone build-up is not encountered as subsequent washes first remove soil and previously deposited dimethicone. Neither do neutral dimethicones show any reactions with sebum. The development of effective 2-in-1 technology has had a major impact on shampoo technology and consumer habits and practices. This has significantly changed the way consumers care for their hair.

Hair↗
PubMed1995

The biochemical and phenotypic characterization of females homozygous for 5 alpha-reductase-2 deficiency.

The biochemical and physiologic manifestations of decreased 5 alpha-dihydrotestosterone (DHT) in females are characterized. Three females from the large Dominican kindred with 5 alpha-reductase-2 deficiency were identified as homozygous for a point mutation (R246W, C-->T) on exon 5 of the 5 alpha-reductase-2 gene by single strand DNA conformational polymorphism analysis and DNA sequence analysis. Body hair was decreased; there was no history of acne. Despite delayed menarche, all were fertile, and two had twins. Urinary 5 beta/5 alpha C19 and C21 steroid metabolite ratios were elevated. Plasma testosterone was normal to elevated, with low DHT, resulting in an increased testosterone/DHT ratio. 3 alpha,5 alpha-Androstanediol glucuronide was low. Menstrual cycle profiling performed in two subjects showed ovulatory gonadotropin peaks. Sebum production was normal. 5 alpha-Reductase-2-deficient homozygotic females demonstrate the importance of DHT in the physiology and pathophysiology of body hair growth. Normal sebum implies regulation by the 5 alpha-reductase-1 isoenzyme. Delayed puberty suggests involvement of 5 alpha-reductase-2 in menarche at the hypothalamic/pituitary and/or ovarian level. As two had nonidentical twins, DHT and/or the DHT/estradiol ratio may regulate follicular development, with lower levels permitting more than one dominant follicle per cycle and higher levels impairing follicular development and ovulation. Thus, females with 5 alpha-reductase-2 deficiency highlight a role for DHT in hirsutism and/or menstrual disorders.

Adult↗
PubMed1996

Spontaneous comedones on the skin of hairless descendants of Mexican hairless dogs.

In the first experiment, the skin sebum and humidity, perspiration ability of sweat glands, and histology of spontaneous comedones were examined in hairless descendants of Mexican hairless dogs. The skin of females showed lower humidity than that of males. Some animals with a large number of comedones exhibited remarkably high skin sebum scores. The comedones were distributed throughout the dorsal skin, and a cluster of lesions was found mainly in the limbs and prepuces. The sweat glands showed no perspiration in the sudorific test. Histologically, both infant and adult animals had lesions of micro- and/or "blackhead" comedones. Plugged follicles containing abundant keratic substances associated well-developed sebaceous glands. Spontaneous comedones in the skin of hairless dogs were grossly and histologically similar to the acne vulgaris observed in human beings. The skin of some adult animals showed a large number of protrusive comedones which were solid cystic structures containing organized substances. In the second experiment, three kinds of antiacne agents (sulfur and camphor, sulfur and resorcinol, and ibuprofen piconol) were applied daily to the test sites for one month. These antiacne agents caused prominent extrusion of keratin plugs from follicular sites. The results suggest that the hairless dogs are a predictive model for evaluating the efficacy of antiacne agents proposed for acne treatment.

Acne Vulgaris↗
PubMed1980

Role of the gonads in the regulation of sebaceous glands in rats: comparison of the effects of castration at and after birth.

Sprague-Dawley rats were castrated either within 24 h of birth or at 4 weeks of age. Control animals were sham operated. Intact female rats were also included for comparison. Sebum production was assessed at 80 days of age by measuring the amount of skin-surface lipids that could be extracted with acetone and which had been produced during 2 days. The removal of the testes at birth reduced the activity of the sebaceous glands to level more nearly approaching that seen in the female rats whereas castration at 4 weeks of age only partially decreased the rate of sebum secretion so that it was intermediate between the male and female rats. The weights of the pituitary gland, thyroid and adrenal glands increased after castration but there were no differences between rats castrated at birth and those castrated at 4 weeks of age except in the weight of the thyroid gland. It would appear that the role of the testes in the control of the activity of the sebaceous glands is a sequential event which has already started at birth.

Animals↗
PubMed1980

Effect of ovariectomy at birth on the regulation of sebaceous glands in rats.

Inbred Sprague-Dawley rats were ovariectomized within 24 h of birth. Sham-operated and untreated male and female rats were also included for comparison. At the age of 80 days, the secretion rate of sebum was assessed from the amount of skin-surface lipids that could be extracted by acetone and which had been produced during 2 days. There were no differences in sebum secretion, when expressed both in relationship to body weight and to surface area of the body, when rats ovariectomized at birth, sham-operated and intact female rats were compared. The removal of the ovaries within 24 h of birth increased the body weight, however. Although the weights of the pituitary, thyroid and adrenal glands, when corrected for body weight, were significantly smaller in rats ovariectomized at birth than in the sham-operated or intact female rats, there were no statistically significant differences in the absolute weights of these endocrine organs between neonatally spayed rats and sham-operated animals. The uterus became atrophic in the absence of ovaries. It has been concluded that the presence or absence of ovaries in the early stage of life had no effect on the activity of the sebaceous glands.

Animals↗
PubMed1992

The Sebutape technique for monitoring androgen dependent disorders.

Sebaceous gland function is androgen dependent in man and animals. Many studies have suggested a relationship between the rate of sebum excretion and the severity of androgen-dependent disorders. We present a review of a recently developed non-invasive method to accurately measure sebum excretion. The Sebutape technique provides information that may be used in monitoring androgen-dependent disorders and in screening the efficacy of antiandrogens.

Adolescent↗
PubMed1992

Sebaceous gland activity and serum dehydroepiandrosterone sulfate levels in boys and girls.

BACKGROUND AND DESIGN: Increases in sebaceous gland activity are often the earliest sign of the approach of puberty in children. These increases have been attributed to increases in the secretion of adrenal androgens, but the supporting data are sparse and are based on measurements of urinary, rather than serum, androgen concentrations. In this study, we examined sebum composition, serum levels of dehydroepiandrosterone sulfate, and pubertal stage in 111 boys and girls, aged 2 to 15 years. Sebum composition was evaluated by measuring the ratio of wax esters/(cholesterol + cholesterol esters), a ratio known to increase with increasing sebaceous gland activity. RESULTS: Both wax esters/(cholesterol + cholesterol esters) ratios and serum dehydroepiandrosterone sulfate levels began to increase in children 7 to 10 years old. These changes occurred in many children before the appearance of any physical signs of puberty. Wax esters/(cholesterol + cholesterol esters) ratios were correlated with dehydroepiandrosterone sulfate levels in both boys and girls. In prepubertal children, the regression lines passed through the origin. In subjects who were in early or late puberty, the y intercepts of the regression lines had positive values. CONCLUSION: Adrenal androgens appear to be the major determinants of sebaceous gland activity during the prepubertal period and to be additive to another hormone or hormones during puberty.

Adolescent↗
PubMed2004

Evaluation of inherent differences between African American and white skin surface properties using subjective and objective measures.

Conflicting data have been published on the inherent differences in skin surface properties among various ethnic groups, though there is a widespread perception that differences exist. This study included subjective and objective assessments of skin surface properties in African American and white subjects. A dermatologist conducted visual assessments of photodamage and irritation. Instrumentation was employed to perform objective measurements of skin surface sebum level, pH, moisture content, and barrier function. In addition, resistance of skin to chemical challenge as a measure of barrier integrity was assessed in a subset of the populations. Results showed differences in photodamage and hyperpigmentation between the 2 ethnic groups tested, but no significant differences between the 2 groups were seen in the results of instrumental measurements for sebum, pH, corneometry (skin moisture), or transepidermal water loss (barrier function). These data help fill the gap in knowledge about photoaging-related differences in the skin of various ethnic groups, especially in textural and pigmentation parameters, as well as increase the knowledge base of differences in objective measures.

Adult↗
PubMedDate not supplied

A pilot study on efficacy treatment of acne vulgaris using a new method: results of a randomized double-blind trial with Acne Dressing.

For many years the positive effect of hydrocolloid dressings on skin-related conditions attracted the attention of the medical scientific community. The use of Acne Dressing, a tape of hydrocolloid dressing, for the treatment of acne has not been reported previously. The aim of this study was to evaluate the clinical efficacy and beneficial effect of Acne Dressing on the marker for sebum output evaluations. We also determined the cosmetic outcome of this application during the treatment of acne and whether the material could prevent hand touching and UVB light from reaching the skin surface. The objective of this study was to assess improvement in acne vulgaris and tolerability during one week of short contact treatment with Acne Dressing compared to skin tapes. Efficacy data specific to treatment of acne vulgaris with Acne Dressing (3M Health Care) from a double-blind, randomized, skin types-controlled study is reported. A total of 20 patients with mild-to-moderate acne vulgaris applied the skin tapes or Acne Dressing every two days for up to one week. Twenty patients were enrolled in this study: ten patients received Acne Dressing and ten patients received skin tapes. Both groups showed decreases from baseline to the end of treatment in the mean of the overall severity scale (decrease of 1.37 from 1.8 to 0.43 with Acne Dressing and 0.28 from 1.08 to 0.8 with skin tapes). A statistically significant greater reduction was observed over a period of three to seven days in the overall severity of acne and inflammation in the Acne Dressing group compared with the mono-therapy (skin tapes) group. Similarly, Acne Dressing resulted in a significantly greater improvement in the redness, oiliness, dark pigmentation, and sebum casual level at days 3, 5, and 7. The ratio of transmission of UVB light with Acne Dressing was 7.4%, and 38% with skin tapes, which shows less UVB light reaching the skin surface with the Acne Dressing. No significant adverse events were identified in either group. The pilot study shows the benefit of treatment with Acne Dressing in improving mild-to-moderate inflammatory acne vulgaris. A future study will investigate a large set of patients in longer followup periods.

Acne Vulgaris↗
PubMed1985

Incorporation in vitro of 14C fatty acids into bovine sebaceous gland and dermal lipids.

A study has been made of the incorporation in vitro of 14C palmitic, oleic and linoleic acids into the skin lipids of cattle. Linoleic acid was incorporated into the triglyceride (triacylglycerol) fraction of the sebaceous gland lipid at a greater rate than palmitic and oleic acids. Its incorporation was much greater when presented as a free acid than when presented either as cholesteryl linoleate or linoleoyl lecithin. However, the ability of cholesteryl ester and phospholipid to make a substantial indirect contribution of linoleic acid to sebum triglyceride synthesis by hydrolytic release of fatty acid was indicated. The association between the observed preferential incorporation of linoleic acid into the sebum triglycerides and the uniquely unsaturated triglycerides found on the skin surface of cattle is discussed.

Animals↗
PubMed1982

Cimetidine-induced xerosis and asteatotic dermatitis.

Cimetidine, a histamine H2-receptor antagonist, has previously been shown to have antiandrogenic activity in animals and to decrease the sebum excretion rate in humans. Two patients had generalized xerosis and asteatotic dermatitis that developed while they were receiving cimetidine therapy and resolved when cimetidine therapy was discontinued. We postulate that this skin change is related to the antiandrogenic properties of the drug and its effect on the sebum secretion rate.

Aged↗
PubMedDate not supplied

Environmental factors affecting mechanical properties of facial prosthetic elastomers.

This study evaluated the degradation of elastomers for facial prostheses exposed to environmental factors normally present in a service environment. Two silicone elastomers and a polyurethane were evaluated. Samples were exposed to ultraviolet radiation, simulated sebum, ozone, chlorine, and nitrogen dioxide, and tested for tear propagation and resistance. Test results revealed significant differences in the tear characteristics between silicones and polyurethane. Differences in tear patterns were observed between the control and the specimens exposed to environmental factors. The environmental factors affected the polyurethane Epithane-3 the most and silicone MDX 4-4210 the least. When exposed to chlorine and nitrogen dioxide, Cosmesil and Epithane-3 were degraded to a point where sample testing was not possible. When exposed to ultraviolet radiation, Epithane-3 was degraded and could not be tested. Simulated sebum and ozone affected Cosmesil and Epithane-3, but no clear trends were observed.

Analysis of Variance↗
PubMedDate not supplied

Comparison between testosterone enanthate-induced azoospermia and oligozoospermia in a male contraceptive study. V. Localization of higher 5 alpha-reductase activity to the reproductive tract in oligozoospermic men administered supraphysiological doses of testosterone.

Sex steroid contraceptive regimes result in incomplete suppression of spermatogenesis in 30-45% of Caucasian men. The basis for this is unclear, but differences in the activity of 5 alpha-reductase (5 alpha R) have been demonstrated. Two isoforms of 5 alpha R have been described: 5 alpha R1 is found in skin, whereas the predominant from in reproductive tissues is 5 alpha R2. To investigate possible contributions of these isoenzymes, we have investigated androgen-dependent changes in seminal plasma androgens (5 alpha R2) and sebum production (5 alpha 1) during administration of a supraphysiological dose (200 mg IM weekly) of testosterone enanthate (TE) to 33 normal men. Eighteen men rapidly (< 20 weeks treatment) became azoospermic, the remainder having a mean sperm density of 2.0 +/- 0.6 x 10(6) at that time. The concentrations of testosterone and 3 alpha, 17 beta-androstanediol glucuronide (AdiolG) were lower in seminal plasma than in blood but rose by a similar degree (100%) after 16 weeks TE treatment in both groups. There were no differences in seminal-plasma concentration of testosterone or AdiolG between azoospermic and oligozoospermic responders, either pretreatment or after 16 weeks TE treatment. Although the concentrations of dihydrotestosterone (DHT) were similar in seminal plasma and blood pre- and posttreatment, there was a selective increase in seminal plasma DHT concentration in the oligozoospermic responders from 2.12 +/- 0.29 to 2.94 +/- 0.33 nmol/L (P < 0.05), while there was no significant change in the azoospermic responders (2.18 +/- 0.31-2.54 +/- 0.27 nmol/L) after 16 weeks of TE treatment. Dihydrotestosterone in seminal plasma is primarily derived from 5 alpha R activity in the epididymis. The concentration of prostaglandin E2 (PGE2) in seminal plasma was unchanged during TE treatment. Sebum excretion was increased during TE treatment, but there were no difference between azoospermic and oligozoospermic responders pretreatment or after 16 weeks TE treatment. These results are consistent with the hypothesis that incomplete suppression of spermatogenesis during TE treatment is associated with a relatively higher 5 alpha R activity in the reproductive tract (epididymis and/or testis) during TE treatment. As the predominant form of 5 alpha R in the reproductive tract is 5 alpha R2 (type 2), we conclude that the increase in activity derives from this form of the enzyme, rather than the type 1 form (5 alpha R1) predominantly found in nongenital skin.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗
PubMed1996

Immunocytochemical localization of androgen receptor in the comb, uropygial gland, testis, and epididymis in the domestic chicken.

Nuclear, but not cytoplasmic androgen receptors (AR), were localized immunocytochemically in the comb, uropygial (preen) gland, testis, and epididymis of juvenile and adult cockerels. Androgen receptor immunoreactivity (AR-ir) was seen in the comb, in the stratum germinativum of the epidermis and in fibromucoid cells in the dermis in juvenile and adult cockerels. AR-ir was observed in the glandular epithelial (sebum-producing) cells lining the peripheral and middle sections of the tubules in the uropygial gland. AR-ir was not detected in innermost part of the tubules which conduct the sebum to the surface of the skin. AR-ir labeling was not observed in the uropygial gland of juveniles. In the testis, AR-ir was seen in the Leydig cells, in adults but not juveniles. The epithelial cells lining the tubules in the epididymis contained AR-ir in both juveniles and adults.

Aging↗