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PubMed1997

[Levels of PCDDs, PCDFs and coplanar PCBs in sebum and blood of Yusho patients].

Polychlorinated dibenzo-p-dioxins (PCDDs) and it's related compounds such as polychlorinated dibenzofurans (PCDFs) can be detected in the body in Yusho patients, a condition caused by ingestion of contaminated rice oil with these compounds. These compounds are excreted out of the body in small amounts directly in the feces from the wall of the intestine. We found the PCDDs, PCDFs and coplanar polychlorinated biphenyls (Co-PCBs) in the sebum of Yusho patients and normal subjects, and there was significant correlation between their concentrations in sebum and blood in both patients and normal control subjects. The concentration of TEQ (toxic equivalent quantity of 2,3,7,8-tetrachlorodibenzo-p-dioxin: TCDD) in sebum of Yusho patients (106 pg/g lipid) was half that in the blood (215 pg/g lipid), while that of normal subjects (29 pg/g lipid) was similar to that in the blood (34 pg/g lipid). On the other hand, in Yusho patients the concentrations of TEQ in the sebum and in blood were 2.3 and 6.4 fold higher than those in normal subjects. We concluded that dioxins and it's related compounds in Yusho patients and normal subjects were excreted not only in the feces but also in the sebum.

Benzofurans↗
PubMedDate not supplied

Observations on the progress of chlordane contamination in humans by blood and sebum analysis.

Chlordane residues were determined in human blood and sebum samples. The residue levels in both types of samples were remarkably increased in pest control operators and in the general population living in an area heavily contaminated with chlordane. The compound with the highest level among the residues in the blood of control subjects was oxychlordane followed by trans-nonachlor and trans-chlordane, while in the sebum, the highest levels found was that of trans-chlordane followed by cis-chlordane and trans-nonachlor. The sebum residue was similar to technical chlordane in its component pattern, but it largely originated from sources other than simple exogenous contamination. Thus, sebum might be a unique and available sample source for evaluating direct exposure to technical chlordane. A progressive state of contamination was observed in residents whose homes had been treated with chlordane.

Air Pollutants↗
PubMed2006

Comparison of sebum secretion, skin type, pH in humans with and without acne.

Differences of skin type and pH between subjects with and without acne have not been investigated. In addition, the relationship between sebum secretion and pH in these populations has not been determined. This study assessed the differences in objective and subjective skin types between these two groups. Secondly, this study evaluated the difference in pH on five facial areas (forehead, nose, chin, right and left cheeks) between the two populations. Lastly, the relationship between pH and sebum secretion was analyzed in each population. Sebum casual levels (CL) of the five facial areas in 36 Koreans with acne and 47 Koreans without acne were measured by using a Sebumeter SM 815 and subjects were classified into objective skin types by CL. Subjects reported the type of skin they believed they had, which determined the subjective skin type. The pH levels of the five facial areas were measured by the Skin-pH-Meter PH 905. Data were assessed with adequate statistical tests depending on data type and distribution. Among the five areas, the nose of the subjects with acne showed a significantly higher CL, compared to the subjects without acne. This difference in CL on the nose resulted in the difference in CL on the T-zone and mean facial sebum excretions (MFSE). Although CL differed, objective skin types did not differ between the two groups (P > 0.05), but the subjective skin types differed significantly (P = 0.001). In addition, the objective skin types were significantly different than the subjective skin types in subjects with acne (P = 0.001), whereas the two skin types did not differ in subjects without acne. Subjects with acne actually overestimated their skin types and stated their skin types were "oilier" than they were. In respect to pH, none of the five areas differed significantly between the two groups. Among the five sites in subjects with acne, CL showed a significant negative correlation with pH on the left (r (2 )=0.12) and right (r ( 2 )=0.15) cheeks, which resulted in a significant negative correlation on the U-zone (r ( 2 )=0.14). In contrast, in subjects without acne, there was a significant negative correlation between CL and pH on the forehead (r ( 2 )=0.10) and chin (r ( 2 )=0.16), which led to a significant negative correlation on the T-zone (r ( 2 )=0.14).

Acne Vulgaris↗
PubMed1999

Laser hair removal affects sebaceous glands and sebum excretion: a pilot study.

BACKGROUND: During laser-assisted hair removal, sebaceous glands closely associated with hair follicles might also be affected. OBJECTIVE: We investigated the effect of the long-pulsed ruby laser on sebaceous glands. METHODS: Sebum excretion rates (SERs) of 16 subjects were measured quantitatively by means of sebum-absorbent tape and analyzed by means of image analysis techniques on laser-treated sites, compared with adjacent untreated areas. Evaluation was done at an average of 9 months (range, 4.5 to 12 months) after the last treatment. Histologic examinations were performed on 3 representative subjects before treatment, immediately after treatment, and 9 months after the last treatment. RESULTS: Significant increases in SERs were observed in 11 of 16 subjects (68.75%). Three subjects (18.75%) showed lower SERs, whereas 2 subjects (12.5%) demonstrated no difference in SERs between treated and untreated areas. Biopsy specimens showed an apparent reduction in sebaceous gland size. Specimens taken immediately after laser irradiation revealed sporadic damage to sebaceous glands. CONCLUSION: In some patients a variable but statistically significant increase in sebum excretion occurs 4 to 12 months after ruby-laser hair removal treatment at high fluences. A reduction in sebaceous gland sizes on laser-treated areas was observed. We hypothesize that decreased resistance to sebum outflow may explain this result, following miniaturization or absence of hair shaft after ruby laser treatment. Further study is needed to assess mechanisms for this interesting response.

Adult↗
PubMed1978

Liquid chromatographic analysis of sebum lipids and other lipids of medical interest.

A technique is described for the high-pressure liquid chromatographic (HPLC) analysis of sebum lipid classes. The lipid present in sebum are separated by gradient elution HPLC from a microparticulate silica column and detected using a moving-wire detector. The system described can be linked to a computer. Quantitation can be carried out by comparing peak areas obtained with those of an internal standard. Peak trapping for further investigations of the separated components, for example by gas chromatography-mass spectrometry, is very easy. Sebum lipids are separated into the following lipid classes: hydrocarbons and squalene, cholesterol esters and wax esters, fatty acids as their methyl esters, triglycerides, 1,3-diglycerides, 1,2-diglycerides, free cholesterol, monoglycerides and other polar materials. Besides to sebum, the method has been successfully applied to other lipid mixtures, such as serum lipids. Examples of other applications are shown.

Chromatography, High Pressure Liquid↗
PubMed2000

Markers of insulin resistance and sex steroid hormone activity in relation to breast cancer risk: a prospective analysis of abdominal adiposity, sebum production, and hirsutism (Italy).

OBJECTIVE: Insulin resistance and increased levels of serum steroids have been hypothesized to be relevant etiological factors for breast cancer. Measurements of markers of insulin resistance and elevated serum steroids may identify women at high risk for breast cancer. The present study analyzed the association of breast cancer with markers of insulin resistance and elevated serum sex steroids, abdominal adiposity, increase in sebum production and hirsutism in a case-control study nested in a prospective cohort study. METHODS: Between 1987 and 1992, 10,786 women (aged 35-69) were recruited in a prospective study on breast cancer in Italy, the ORDET study. Women with a history of cancer and on hormone therapy were excluded at baseline. At recruitment, abdominal adiposity was calculated from the ratio of waist-to-hip circumferences. Sebum production was measured on the forehead under standardized conditions using a sebumeter. Nine androgen-sensitive body areas were evaluated for hirsutism and a total hirsutism score was computed. After an average of 5.5 years of follow-up, 144 breast cancer cases were identified among the participants of the cohort. For each breast cancer case, four matched controls were randomly chosen from members of the cohort who did not develop breast cancer during the follow-up period. RESULTS: Waist-to-hip ratio was associated with breast cancer in premenopausal women: age and body mass index (BMI) adjusted relative risk (RR) for the highest tertile of waist-to-hip ratio was 2.2 [95% confidence interval (CI) 1.04-4.75], p for trend 0.03. In the analysis conducted within strata of BMI, the effect of waist-to-hip ratio was confined to the group of thinner women: RR for the highest tertile of waist-to-hip ratio was 3.4 (95% CI 1.2-9.5). Sebum production and hirsutism were associated with breast cancer among postmenopausal women. Age and BMI adjusted RRs for the upper tertiles were 2.2 (95% CI 1.1-4.6), p for trend 0.01, and 2.3 (95% CI 1.1-4.9), p for trend 0.03, for sebum and hirsutism, respectively. CONCLUSION: These results add evidence for a role of hormones and metabolic alterations in breast cancer etiology and for different relations of these risk factors with breast cancer in premenopausal and postmenopausal women.

Abdomen↗
PubMed2001

Influence of sebum and stratum corneum hydration on pesticide/herbicide collection efficiencies of the human hand.

The adhesion of house dust particles and chemical residues to the hands after contact with a variety of surfaces can yield significant exposures to children. Chemicals present on the surface or absorbed into house dust particles may adhere to the hands and subsequently are available for ingestion or absorption through the skin under normal physiological conditions. Contact of a hand with a surface occurs primarily through a thin layer of sebum and sweat on the skin surface. The study presented here examined the effect of the composition of the sebum and sweat layer on the adhesion of a mixture of pesticides and a herbicide to a hand after contact with a house-dust-laden surface. Collection efficiencies on the hand for atrazine and malathion were correlated with sebum levels on the palm of an individual hand. The increase in sebum values measured in this study caused a 13 percent and 8 percent reduction in collection efficiency, respectively, for atrazine and malathion applied to house-dust-laden surfaces. Diazinon and chlorpyrifos collection efficiencies were correlated with skin hydration levels measured on the palm of the individual's hand. The increased skin hydration measured in this study caused a 7 percent and 5 percent reduction in collection efficiency, respectively, for diazinon and chlorpyrifos.

Child↗
PubMed1981

Estimation of sebum production rates in man by measurement of the squalene content of skin biopsies.

Previous studies have shown that lipids are synthesized at a constant rate in sebaceous glands and secreted onto the skin surface an average of 8 days after synthesis. As a result, measurement of the sebum content of a skin specimen of known surface area should allow calculation of the sebum production rate which had been occurring in vivo. In the present study, such measurements have been made on scalp skin specimens from 14 men. The amount of sebum in 4-mm punch biopsies was calculated from the squalene content of the specimens, as measured by quantitative thin-layer chromatography of lipid extracts. The average sebum production rate for the group was found to be 1.45 mg/10 sq cm/3 hr.

Humans↗
PubMed1981

Local suppression of sebum secretion in rats by topical cyproterone acetate in ethanol.

Sebum production was measured on 2 symmetrically placed areas on the flanks of rats over alternating periods of 18 and 6 hr for 4 days, by absorbing the lipid on pads of cigarette paper held in place by a specially designed harness. Castrated rats receiving testosterone produced about twice as much sebum as untreated littermate controls. Once daily application of ethanol to one flank significantly reduced sebum production, in comparison with the other flank in testosterone-treated but not in untreated rats. Daily application of 5 mg cyproterone acetate in ethanol to one flank in a third group of rats significantly reduced sebum production in comparison with that of the other flank treated with vehicle only. The effects became significant within 24 hr. It seems likely that the sebaceous glands received the topically applied materials by way of the pilo-sebaceous orifices rather than by transepidermal absorption. The results demonstrate that one action of cyproterone acetate is at the target site and suggest that the anti-androgen may be effective when applied topically. The method could prove useful in assessing the local action on sebaceous activity of topically applied substances.

Administration, Topical↗
PubMed1980

The effect of marked inhibition of sebum production with 13cis-retinoic acid on skin surface lipid composition.

Sebum production and skin surface lipid composition have been measured during the oral treatment with 13cis-retinoic acid of a group of patients with severe cystic acne. Two hundred and thirty-eight paired samples have been analyzed and compared. A marked, drug-induced decrease in sebum production was accompanied by a decrease in the concentration of wax esters, a slight decrease in the squalene concentration and in increase in the cholesterol concentration in the skin surface lipids. These changes were consonant with changes in the relative contributions of sebum and epidermal lipid to the surface film, except that at very low levels of sebum production there might be preferential preservation of squalene synthesis.

Acne Vulgaris↗
PubMed1980

A modified photometric technique for measuring sebum excretion rate.

Accurate measurement of sebum excretion is necessary to evaluate drugs such as anti-androgen and the new retinoic acid derivatives. Existing techniques are good, but some are inaccurate at high levels of sebum and are time-consuming for technicians. We have therefore, re-examined sebum excretion methodology and have developed a modified photometric technique. This technique, which utilizes a robust, portable machine gives data which are accurate at all levels of sebum production and reduces the technician time of analysis without loss of accuracy or reproducibility.

Humans↗
PubMed1986

Measurement of sebum output using a lipid absorbent tape.

A sebum absorbent tape is introduced as a reproducible and convenient method for estimation of sebaceous gland output. We have tested the reproducibility of this method by serial measurements of sebum excretion rates (SER) of 10 individuals over a 6-week period, and in addition we have correlated this method with the conventional hexane extraction technique. The sebum absorbent tapes gave consistent values for the SERs, and within subjects variation over the 6-week period was statistically nonsignificant. A coefficient of variation for the tapes was calculated as 16.25 +/- 6.78% based on these serial measurements. Furthermore, the amount of total lipid collected using this technique (n = 16) correlated well with the hexane extraction technique, r = 0.89. Free fatty acids (r = 0.87), triglycerides (r = 0.92), wax and cholesterol esters (r = 0.83), and squalene (r = 0.88) also showed a good correlation. Cholesterol occasionally suffered from incomplete separation on thin-layer chromatograms; however, a sample cleanup procedure was developed for tape extracts that removed interfering materials and allowed complete separation of all sebum components.

Absorption↗
PubMed2005

Matrix metalloproteinases of epithelial origin in facial sebum of patients with acne and their regulation by isotretinoin.

Acne vulgaris is a skin disorder of the sebaceous follicles, involving hyperkeratinization and perifollicular inflammation. Matrix metalloproteinases (MMP) have a predominant role in inflammatory matrix remodeling and hyperproliferative skin disorders. We investigated the expression of MMP and tissue inhibitors of MMP (TIMP) in facial sebum specimens from acne patients, before and after treatment with isotretinoin. Gelatin zymography and Western-blot analysis revealed that sebum contains proMMP-9, which was decreased following per os or topical treatment with isotretinoin and in parallel to the clinical improvement of acne. Sebum also contains MMP-1, MMP-13, TIMP-1, and TIMP-2, as assessed by ELISA and western blot, but only MMP-13 was decreased following treatment with isotretinoin. The origin of MMP and TIMP in sebum is attributed to keratinocytes and sebocytes, since we found that HaCaT keratinocytes in culture secrete proMMP-2, proMMP-9, MMP-1, MMP-13, TIMP-1, and TIMP-2. SZ95 sebocytes in culture secreted proMMP-2 and proMMP-9, which was also confirmed by microarray analysis. Isotretinoin inhibited the arachidonic acid-induced secretion and mRNA expression of proMMP-2 and -9 in both cell types and of MMP-13 in HaCaT keratinocytes. These data indicate that MMP and TIMP of epithelial origin may be involved in acne pathogenesis, and that isotretinoin-induced reduction in MMP-9 and -13 may contribute to the therapeutic effects of the agent in acne.

Acne Vulgaris↗
PubMed1992

Influence of oral metronidazole on the endocrine milieu and sebum excretion rate.

As part of a study of the mechanism of metronidazole's efficacy in the treatment of acne and rosacea, its effects on the endocrine milieu and sebum excretion rate were assessed. Thirteen healthy males received oral metronidazole treatment (500 mg/day) for 4 weeks. Serum sex hormone levels were determined in all 13 subjects and the sebum excretion rate was determined in seven of them, before and after treatment. We measured serum levels of estrone (E1), estradiol (E2), total testosterone (T), free testosterone (FT), dihydrotestosterone (DHT), dehydroepiandrosterone sulfate (DHEA-S), and sex hormone-binding globulin (SHBG). There were no significant changes in E1, T, FT, DHT, or SHBG levels, but E2 and DHEA-S levels decreased significantly after treatment. In all seven subjects in whom the sebum excretion rates were determined, the amount of facial skin surface lipids decreased significantly after treatment. These results suggest that metronidazole exerts its clinical effects through suppressing the sebum excretion by a mechanism other than anti-androgenic action.

Administration, Oral↗
PubMed1986

A direct gravimetric technique for measuring sebum excretion rate.

The standard gravimetric method for measuring sebum excretion rates involves ether extraction of the collected sebum. We have evaluated a more direct method in which the collecting papers were pre- and post-weighed in glass beakers under conditions of stable temperature and humidity. Weights were adjusted allowing for control weight gain or loss, due mainly to day to day changes in weight room humidity. The direct method compared favourably with the ether extraction method in determining: (1) sebum collected from 43 subjects (r = 0.991, P less than 0.001), (2) left versus right forehead comparisons in 19 subjects (direct method: r = 0.966, P less than 0.001; ether extraction method: (r = 0.963, P less than 0.001), and (3) recovery of sebum from 32 premeasured standards (r = 0.997, P less than 0.001). The findings demonstrate the accuracy of the direct gravimetric procedure which is also simpler, safer and less expensive than methods currently in use.

Forehead↗
PubMed1988

Genetic control of sebum excretion and acne--a twin study.

Sebum excretion and acne grades were measured in 20 pairs each of identical and non-identical like-sex twins. The identical twins had virtually identical rates of sebum excretion (P greater than 0.05), but they had a significantly different degree of acne severity (P less than 0.01). The non-identical twins had significantly different sebum excretion rates (P less than 0.01) and acne grades (P less than 0.01). These findings suggest that sebum excretion is under genetic control and the development of clinical lesions is modified by environmental factors.

Acne Vulgaris↗
PubMed1991

Physiology of the vellus hair follicle: hair growth and sebum excretion.

The growth of vellus hair and the secretion of sebum from vellus hair follicles were measured on the forehead, cheek, chest, shoulder and back of healthy men and women aged 15-30 years. Hair growth was assessed by computerized image-analysis of photographs and sebum excretion by the use of Sebutape followed by image analysis. The density of vellus hairs and the percentage of growing hairs were higher on the face than on the thorax (439 hairs/cm2 with 49% growing hairs on the forehead compared with 85 hairs/cm2 with 31.5% growing hairs on the back). The rate of growth ranged from 0.03 mm/day on the forehead to 0.13 mm/day on the back. The maximum length of vellus hair significantly decreased with age; otherwise hair growth was not affected by age or sex. Some variations in hair growth and sebum secretion were observed over a period of 3 months, but no consistent rhythms were detected. There was no obvious link between vellus hair growth and sebum excretion.

Adolescent↗
PubMed1989

Sebum secretion in idiopathic Parkinson's disease: effect of anticholinergic and dopaminergic drugs.

Sebum secretion was measured on the foreheads of 47 unmedicated patients with idiopathic Parkinson's disease, aged 50-81 years and 80 healthy, matched volunteers. Sebum secretion was significantly higher in men patients aged 50-59 years than in controls; no such difference was observed in women of the same age. There was also no difference between patients and volunteers of either gender older than 60 years of age. The effects of either biperiden, L-Dopa + benserazide (a decarboxylase inhibitor) or bromocriptine treatments on sebum secretion and on 5 parkinsonian signs were evaluated over 127 days. There was a significant reduction of all measures during the treatment with the dopaminergic drugs. The only observable effect with biperiden was reduction of tremor. It is discussed whether the sebum suppressive effect of the dopaminergic drugs may be explained through their central effects.

Aged↗