Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Sebum”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 847 records · Page 47Linked to original sources
PubMed1989

Lipid cell tumor of the ovary: steroid hormone secretory pattern and localization using 75Se-selenomethylcholesterol.

Ovarian lipid cell tumors are rare and can be difficult to localize by conventional means. We report a postmenopausal patient where rapid progression of symptoms and very high sebum levels suggested the presence of such a tumor which could not be visualized by computed tomography or ultrasound. Localization was accomplished noninvasively using 75Se-selenomethylcholesterol. Peripheral and ovarian vein steroid concentrations suggest that the tumor produced androgens preferentially by way of the delta 4 steroidogenesis pathway.

Adrenal Rest Tumor↗
PubMed1990

Fordyce's granules of the incisor and molar gingiva in F344 rats.

Fordyce's granules were observed in the gingiva of the upper incisor and molar teeth in F344 rats. The data were based on 734 males and 722 females that were used as control and treated animals in 26-week, 65-week, and 2-year studies by the National Toxicology Program. The incidence of Fordyce's granules was markedly different when comparing sex, age, and site of the lesion. Fordyce's granules were very common in the midsagittal gingiva of the upper incisor in males and increased in incidence with age (34.2, 50, and 56.3% in 26-week, 65-week, and 2-year studies, respectively). The granules of the incisor gingiva were rare in females (0,0, and 2.8% in 26-week, 65-week, and 2-year studies, respectively). Fordyce's granules of the molar gingiva were very rare in both sexes and were found only in 9/734 (1.2%) males and in 3/722 (0.4%) females. Only three unilateral granules of the molar were grossly recognized as focal swelling of the gingiva or a white nodule with a huge cyst in the third upper molar. Histologically, Fordyce's granules were arranged as a collection of sebaceous glands unassociated with hair follicles. In addition, the granules of the molar gingiva were associated with cystically dilated ducts filled with sebum. Ultrastructurally, the sebaceous cells were characterized by varying numbers of cytoplasmic lipid droplets and occasional desmosome and hemidesmosome formation. Fordyce's granules previously reported in rats of other strains were also reviewed and compared with those in F344 rats in regard to incidence, location, and age.

Animals↗
PubMed1990

PCB reduction and clinical improvement by detoxification: an unexploited approach?

1. A detoxification trial was administered to a female worker from a capacitor factory who had been exposed to polychlorinated biphenyls (PCBs) and other lipophilic industrial chemicals. 2. The patient presented with severe abdominal complaints, chloracne, liver abnormalities, and a spontaneous nipple discharge of approximately 50 ml d-1. 3. PCB levels were high in adipose tissue (102 mg kg-1), serum, (512 micrograms l-1), skin lipids (66.3 mg kg-1), and in the nipple discharge (712 micrograms l-1). 4. The patient's history, the medical evaluation and prior unsuccessful symptomatic treatments were indicative of consequences elicited by occupational exposure to chemicals. 5. Detoxification treatment reduced the PCB levels in adipose tissue to 37.4 mg kg-1 and in serum to 261 micrograms l-1, a 63% and 49% reduction, respectively. 6. The nipple discharge ceased and the symptoms improved. 7. Excretion of intact PCBs in sebum was appreciable before treatment and was enhanced by up to five-fold during detoxification. 8. This therapeutic approach appears promising for cases involving occupational exposure to lipophilic chemicals.

Acne Vulgaris↗
PubMed1999

Growth hormone and insulin-like growth factors have different effects on sebaceous cell growth and differentiation.

Several observations suggest that GH stimulates sebaceous gland growth and development. Therefore, we studied the effects of GH and insulin-like growth factors (IGFs), alone and with androgen, on sebaceous epithelial cell (sebocyte) growth and differentiation in vitro. The rat preputial cell culture model system was used to judge differentiation (induction of lipid-forming colonies, LFCs) and DNA synthesis. GH increased sebocyte differentiation. At a dose of 10(-8) M in the presence of micromolar insulin, GH was 3.8 times more potent than IGF-I (38.1+/-4.2%, SEM, vs. 10+/-1.5% LFCs) and 6 times more potent than IGF-II (6+/-0.5% LFCs). IGF-I 10(-8) M alone stimulated a similar amount of differentiation as insulin 10(-6) M, although it was less effective than insulin in augmenting the effect of GH on differentiation. GH had no effect on sebocyte uptake of 3H-thymidine at doses up to 10(-6) M. On the other hand, IGF-I was the most potent stimulus of DNA synthesis (168% of control; P < 0.001 vs. all others). IGF-II 10(-8) M stimulated 3H-thymidine incorporation similarly to insulin 10(-6) M. In the presence of insulin, dihydrotestosterone (DHT) 10(-6) M induced 31.4+/-1.7% LFCs, and there was a tendency of DHT and GH to interact in promoting differentiation. When insulin was omitted from the system, differentiation was decreased overall, but GH +/- DHT slightly improved differentiation. The IGFs had no effect on the response to DHT. DHT decreased DNA synthesis by 40%, an effect unaltered by GH or IGFs. These results suggest that GH and IGFs have different functions in sebaceous cell growth and differentiation: GH stimulated differentiation beyond that found with IGFs or insulin, yet had no effect on DNA synthesis, a parameter stimulated most potently by IGF-I. While GH augmented the effect of DHT on differentiation, the IGFs had no effect on the response of DHT. These data indicate that GH may in part act directly on sebocytes rather than indirectly through IGF production. These data are consistent with the concept that increases in GH and IGF production contribute in complementary ways to the increase in sebum production during puberty and in acromegaly.

Animals↗
PubMed1994

[Hand eczema. The clinical classification of the roles of exogenous and endogenous factors in each type].

Hand eczema is one of the most common dermatological disorders. Although it is a general term referring to eczematous dermatitis of the hands, it actually covers a wide range of diseases. The classification of hand eczema is controversial even now, as definitions of individual diseases have not yet been established. It is well-known that exogenous factors, such as chemicals or water, are associated with the occurrence of hand eczema. In this study, we focused on endogenous factors, especially personal or family history of atopy as a causative factor in hand eczema. According to exogenous and endogenous factors, we classified hand eczema into three types: atopic dermatitis, contact dermatitis and dysidrosis. This classification is useful because it makes the definition of each disease clear. Skin-humidity and sebum measurement are simple and rapid methods of determining personal atopy, skin condition and the effect of treatment on hand eczema patients.

Adult↗
PubMed1998

Oral ketoconazole in cutaneous fungal infections.

Few data are available on the mechanism by which oral ketoconazole reaches the stratum corneum and exhibits its antifungal activity. The rapid onset of effect and the isolation of ketoconazole from the sweat support the theory that this agent reaches its site of action through eccrine sweat secretion. However, passive diffusion from the bloodstream and sebum secretion may also account for the antimycotic effect at the level of the stratum corneum. Oral ketoconazole has been shown to be effective in a variety of cutaneous fungal infections. However, systemic antifungal therapy is best reserved for extensive infections or those resistant to topical therapy.

Administration, Oral↗
PubMed2004

In vitro contamination of hair by marijuana smoke.

BACKGROUND: The deposition of cannabinoids on/into hair from environmental smoke can be considered as a potential source of drug findings in hair. We studied external uptake of cannabinoids from marijuana smoke, investigating possible influencing factors on drug uptake and the efficiency of decontamination procedures. METHODS: Strands of a natural hair sample were moistened with water, greased with sebum or sebum/sweat, or bleached or permed. Treated and untreated samples were exposed to marijuana smoke for 60 min. Aliquots of each hair strand were either kept unwashed or were washed with methanol, dichloromethane, or 5 g/L dodecyl sulfate in water. Cannabinoid concentrations in unwashed and washed hair samples, as well as in air samples collected from the exposure chamber and in the marijuana sample being combusted, were quantified by gas chromatography-mass spectrometry or gas chromatography. RESULTS: Cannabinoids were deposited on the hair fibers from marijuana smoke. Cannabinoid concentrations were dependent on air concentration and hair pretreatment. Uptake was less in untreated than in pretreated hair. Concentrations were increased in damp hair, but were even higher in greased hair. There was no significant difference in concentration between bleached and permed strands. External contaminants were completely removed by washing with methanol and dichloromethane in untreated hair only. Washing with dodecyl sulfate in water was insufficient in all cases. CONCLUSIONS: Exposures of hair to marijuana smoke yields detectable cannabinoids depending on concentrations in the air, hair care habits, and cosmetic treatment. Environmental marijuana smoke exposure may produce false-positive or falsely increased test results in hair.

Cannabinoids↗
PubMed2004

Seborrhoeic dermatitis: current treatment practices.

Seborrhoeic dermatitis (SD) is a recurrent, chronic inflammation of the skin that occurs on sebum rich areas such as the face, scalp and chest, characterised by red scaly lesions. The are many studies indicating that Malassezia yeasts play an important role in the aetiology of this condition, most of the evidence for which comes from demonstrated responsiveness to treatment with antifungal agents. Its aetiology, however, is far from being resolved. Some believe that it is the immune response of the skin to the Malassezia that is the cause of the disease. Traditional treatments of SD have been the use of keratolytic agents or corticosteroids. Since the discovery of ketoconazole, a considerable amount of research has been focused on determining the efficacy of various antifungal agents. This article reviews clinical trial data on treatment options available for SD.

Administration, Cutaneous↗
PubMed2005

Oestrogen functions in skin and skin appendages.

Oestrogens have significant effects on different cell types important in skin physiology, including the epidermal keratinocytes, dermal fibroblasts and melanocytes. In addition, they can also modulate skin appendages such as the hair follicle, the sebaceous gland and the apocrine glands. Oestrogens may also have important modulatory roles in events such as skin ageing, pigmentation, hair growth, sebum production and skin cancer. It is now recognised that oestrogens can modulate their actions via two distinct intracellular receptors (ERalpha and ERbeta) or via cell surface receptors, which activate specific second messenger signalling pathways. This paper highlights the effects of oestrogens on different components of the skin and reviews some of the more recent developments in terms of receptor expression and cell signalling pathways.

Estrogens↗
PubMed1977

In-vitro metabolism of [3H]testosterone by scalp and back skin: conversion of testosterone into 5alpha-androstane-3beta, 17beta-diol.

The in-vitro metabolism of [3H]testosterone by human scalp and back skin was examined for possible differences in enzyme activity in skin from these two areas, both of which contain large sebaceous glands but only one of which, the back, is prone to develop acne. Punch biopsy specimens of skin, obtained from the scalp and back of adult men, were minced and incubated with [3H]testosterone. The metabolic products were diluted with carrier steroids, then separated and measured by thin-layer chromatography and by gas chromatography on an instrument equipped with a splitter. The results showed that of the 5alpha-reduced metabolites identified, a major one in both the scalp and back skin incubations was 5alpha-androstane-3beta,17beta-diol. Formation of the androstanediol was especially pronounced in scalp skin where it accounted for up to 50% of the 5alpha-reduced metabolites produced. This finding that 5alpha-androstane-3beta,17beta-diol is a major product of testosterone metabolism in vitro by human skin containing sebaceous glands, supports the possibility, previously suggested by studies in the rat, that this steroid can stimulate sebum secretion.

Androstane-3,17-diol↗
PubMed2006

Physiological and subjective responses to low relative humidity in young and elderly men.

In order to compare the physiological and the subjective responses to low relative humidity of elderly and young men, we measured saccharin clearance time (SCT), frequency of blinking, hydration state of the skin, transepidermal water loss (TEWL), sebum level recovery and skin temperatures as physiological responses. We asked subjects to evaluate thermal, dryness and comfort sensations as subjective responses using a rating scale. Eight non-smoking healthy male students (21.7+/-0.8 yr) and eight non-smoking healthy elderly men (71.1+/-4.1 yr) were selected. The pre-room conditions were maintained at an air temperature (Ta) of 25 degrees C and a relative humidity (RH) of 50%. The test-room conditions were adjusted to provide 25 degrees C Ta and RH levels of 10%, 30% and 50%. RH had no effect on the activity of the sebaceous gland or change of mean skin temperature. SCT of the elderly group under 10% RH was significantly longer than that of the young group. In particular, considering the SCT change, the nasal mucous membrane seems to be affected more in the elderly than in the young in low RH. Under 30% RH, the eyes and skin become dry, and under 10% RH the nasal mucous membrane becomes dry as well as the eyes and skin. These findings suggested that to avoid dryness of the eyes and skin, it is necessary to maintain greater than 30% RH, and to avoid dryness of the nasal mucous membrane, it is necessary to maintain greater than 10% RH. On the thermal sensation of the legs, at the lower humidity level, the elderly group felt cooler than the young group. On the dry sensation of the eyes and throat, the young group felt drier than the elderly group at the lower humidity levels. From the above results, the elderly group had difficulty in feeling dryness in the nasal mucous membrane despite being easily affected by low humidity. On the other hand, the young group felt the change of humidity sensitively despite not being severely affected by low humidity. Ocular mucosa and physiology of skin by dryness showed no difference by age. In the effect of longer exposure (180 min.) to low RH, only TEWL showed a slight decrease after 120 minutes in 30% RH, and all the measured results showed no noticeable differences compared with the result at 120 minutes.

Acclimatization↗
PubMed1984

Isotretinoin. A review of its pharmacological properties and therapeutic efficacy in acne and other skin disorders.

Isotretinoin is a new orally active retinoic acid derivative for the treatment of severe refractory nodulocystic acne. The pharmacological profile of isotretinoin suggests that it acts primarily by reducing sebaceous gland size and sebum production, and as a result alters skin surface lipid composition. Bacterial skin microflora is reduced, probably as a result of altered sebaceous factors. Isotretinoin 1 to 2 mg/kg/day for 3 to 4 months produces 60 to 95% clearance of inflammatory lesions in patients with severe, recalcitrant nodulocystic acne, with evidence of continued healing and prolonged remissions in many patients after treatment withdrawal. Doses as low as 0.1 mg/kg/day have also proven successful in the clearance of lesions; however, with such low doses the duration of remission after discontinuation of therapy is usually shorter. Encouraging results have also been seen in small numbers of patients with rosacea, Gram-negative folliculitis, Darier's disease, ichthyosis and pityriasis rubra pilaris, the response in keratinising disorders resembling that with the related drug etretinate. While long term follow-up studies in these patients have not been reported, prolonged remission after withdrawal of isotretinoin in disorders of keratinisation is unlikely, as with other drugs used in these conditions. Isotretinoin is only partially effective in psoriasis, in contrast to etretinate which is very effective in psoriasis but ineffective in severe acne. Some encouraging results have also been reported with isotretinoin in patients with squamous and basal cell carcinomas, but isotretinoin has proven unsuccessful in non-squamous cell epithelial and non-epithelial cancer. Side effects affecting the mucocutaneous system occur in nearly all patients receiving isotretinoin, but rarely lead to drug withdrawal. Raised serum triglyceride levels are also commonly reported. The possibility of long term spinal or skeletal bone toxicity may restrict the use of isotretinoin in severe disorders of keratinisation requiring prolonged administration. Isotretinoin is strictly contraindicated in women of childbearing potential due to its severe teratogenic properties, unless an effective form of contraception is used. Thus, isotretinoin offers an effective advance on the treatment options available in a difficult therapeutic area - those patients with severe, nodulocystic acne not responding to 'traditional' therapy.

Acne Vulgaris↗
PubMed1990

Current views on the aetiology, pathogenesis and treatment of acne vulgaris.

Acne may vary from a relatively trivial condition to a severe disfiguring disease and management must be tailored to suit individuals. Pathogenetic factors that may be addressed by treatment include increased sebum secretion, abnormal follicular keratinisation, bacterial colonisation and local inflammation. Mild acne can be controlled with topical preparations alone but many patients with more severe disease require oral therapy with antibiotics, antiandrogens or retinoids. Combinations of topical and systemic treatments are often appropriate. The choice of drug requires knowledge of their efficacy, ease of use and possible adverse effects.

Acne Vulgaris↗
PubMed1994

Acne. A review of optimum treatment.

Acne vulgaris is a disease of the pilosebaceous unit of the skin. It may have profound psychological sequelae. The lesions are due to abnormally adherent keratinocytes causing plugging of the follicular duct followed by accumulation of sebum and keratinous debris. This results in the formation of the primary lesion of acne, the comedo. Inflammation of comedones produces papules, pustules and nodules, which often prompt patients to seek treatment. Various effective treatments include topical anti-inflammatory, antibiotic and peeling agents, oral antibiotics, topical and oral retinoids, and hormonal agonists and antagonists. Useful combination regimens are discussed, and treatment approaches suggested. Mild cases of comedonal acne may respond to a topical retinoid or benzoyl peroxide, while inflammatory lesions benefit from topical antibiotics. More severe inflammatory acne is treated with systemic antibiotics. Recalcitrant cases often require oral isotretinoin or hormonal manipulation.

Acne Vulgaris↗
PubMed2001

Optimal management of acne to prevent scarring and psychological sequelae.

Acne vulgaris is one of the most common inflammatory dermatoses and is seen in both the hospital setting and in general practice. Multiple factors are involved in the pathophysiology of acne, including: an alteration in the pattern of keratinization within the pilosebaceous follicles resulting in comedone formation; an increase in sebum production which is influenced by androgens; the proliferation of Propionibacterium acnes; and the production of perifollicular inflammation. Genetic and hormonal factors may also contribute to acne. Better understanding of the pathophysiology of the disease has led to the development of novel therapies which are directed at one or more of the implicated etiologic factors. Systemic antibiotics for acne have been the mainstay of treatment for many years. The main cause for concern following the use of systemic antibiotics is the emergence of antibiotic-resistant strains of P. acnes. Concomitant use of non-antibiotic therapies such as benzoyl peroxide helps to decrease the occurrence of resistance and can be effective in the treatment of resistant and nonresistant propionibacterial strains. However, no one agent is able to eradicate resistant strains completely and as resistant strains correlate to poor clinical response to therapy, prescribing strategies are required to minimize the occurrence of resistance to P. acnes. When assessing acne it is important to take an all embracing approach and to examine carefully for both the clinical and psychologic effects of the disease process. There are numerous forms of acne scarring and it is important to be aware of these as patients who are developing scarring merit early effective therapy. Some patients with acne will develop psychologic problems as a consequence of their condition. Even mild to moderate disease can be associated with significant depression and suicidal ideation and psychologic change does not necessarily correlate with disease severity. Acne scars themselves have been shown to produce significant psychopathology. When initiating treatment it is important to consider the aims of therapy. Treatment should be aimed at achieving clearance of acne, prevention of scarring and, where necessary, relief from any psychologic stress resulting from the acne. Therapy should be commenced early in the disease process in order to prevent scarring and it is important to select appropriate therapies according to the clinical signs and psychologic disability. It is also important to ensure that the patient is able to comply with therapy and clear guidelines regarding treatment, possible adverse effects and realistic expectations should be provided.

Acne Vulgaris↗
PubMed2001

Estrogen and skin. An overview.

As the population of postmenopausal women increases, interest in the effects of estrogen grows. The influence of estrogen on several body systems has been well-documented; however, one area that has not been explored is the effects of estrogen on skin. Estrogen appears to aid in the prevention of skin aging in several ways. This reproductive hormone prevents a decrease in skin collagen in postmenopausal women; topical and systemic estrogen therapy can increase the skin collagen content and therefore maintain skin thickness. In addition, estrogen maintains skin moisture by increasing acid mucopolysaccharides and hyaluronic acid in the skin and possibly maintaining stratum corneum barrier function. Sebum levels are higher in postmenopausal women receiving hormone replacement therapy. Skin wrinkling also may benefit from estrogen as a result of the effects of the hormone on the elastic fibers and collagen. Outside of its influence on skin aging, it has been suggested that estrogen increases cutaneous wound healing by regulating the levels of a cytokine. In fact, topical estrogen has been found to accelerate and improve wound healing in elderly men and women. The role of estrogen in scarring is unclear but recent studies indicate that the lack of estrogen or the addition of tamoxifen may improve the quality of scarring. Unlike skin aging, the role of endogenous and exogenous estrogen in melanoma has not been well established.

Cicatrix↗
PubMed2003

Antibacterial therapy for acne: a guide to selection and use of systemic agents.

Acne vulgaris is a very common disorder, affecting virtually every adolescent at some point in time. Systemic antibacterials have been used in the treatment of acne for many years, and there are several commonly used antibacterials which have established efficacy and safety records. In recent years, the issue of antibacterials resistance has become more prominent, especially with concerns that Propionibacterium acnes can transfer antibacterials resistance to other bacteria within the resident skin flora. Commonly used antibacterials include tetracycline, doxycycline, minocycline, erythromycin (and other macrolides) and trimethoprim/sulfamethoxazole (cotrimoxazole). The choice of antibacterial should take into account efficacy, cost-effectiveness, benefit-risk ratios, patient acceptability and the potential for the development of resistance. Poor clinical response can be the result of poor compliance, inadequate duration of therapy, development of gram-negative folliculitis, resistance of P. acnes to the antibacterial(s) administered, or a high sebum excretion rate. In order to help prevent the development of resistance a number of measures should be undertaken: antibacterials are prescribed for an average of 6 months; if retreatment is required, utilize the same antibacterial; generally, antibacterials should be given for at least 2 months before considering switching due to poor therapeutic response; concomitant use of oral and topical chemically-dissimilar antibacterials should be avoided (try benzoyl peroxide and/or retinoids instead) and systemic isotretinoin should be considered if several antibacterials have been tried without success.

Acne Vulgaris↗
PubMed2006

Persistent acne in women : implications for the patient and for therapy.

Acne is traditionally regarded as a skin disorder of the teenage years. However, recent epidemiologic studies have shown that a significant number of female patients aged >25 years experience acne. One recent community-based UK study estimated the prevalence of facial acne in adult women aged between 26 and 44 years to be 14%. It is not clear whether there is a true increase in acne in this age group or whether these patients are less tolerant of their acne and/or better informed of available therapies and so seek advice. The reasons for persistent acne are not fully understood. External factors such as use of certain cosmetics, ingestion of drugs, and endocrine abnormalities should all be considered when managing these patients. Post-adolescent acne in females can be divided into 'persistent acne', which represents a continuation of acne from adolescence into adult life, and 'late-onset' acne, which describes significant acne occurring sometimes for the first time after the age of 25 years. The clinical picture of each of these forms of acne in adult females can differ slightly from conventional adolescent disease. The course of each form is more indolent. Because of these variations, the approach to investigation and management of these cases may have subtle differences when compared with that for teenage disease. Acne treatment should aim to reduce sebum, comedogenesis, propionibacteria population, and inflammation. Treatment selection will depend on the acne grade and site as well as the patient's preference and ability to comply with therapy. Maintenance therapy plays an important role in managing this group of patients. As the response to treatment is inevitably slow, patients must be encouraged to adhere to the chosen treatment regimen. This article reviews the literature on persistent acne in women in terms of clinical presentation and possible etiologic factors, and outlines principles of therapy related to managing these cases.

Acne Vulgaris↗