[Acne and free fatty acids in sebum, modification by doxycycline]. / Akne und freie Fettsäuren im Hauttalg, Beeinflussung durch Doxycyclin.

The severity of acne correlates with the quotient of triglycerides to free fatty acids in sebum. This quotient increases during systemic therapy with doxycycline, while the clinical picture of the disease improves.

[Efficacy of fenticonazole in patients with pityriasis versicolor]. / Studio dell'efficacia del fenticonazolo su pazienti affetti da Pityriasis versicolor.

Thirty patients suffering from Pityriasis versicolor were treated with fenticonazole in cream or lotion form with two applications a day. At microscopy, Malassezia furfur was encountered in 25 cases and Pityrosporum orbiculare in 5. Disappearance of the yeast was obtained on average in 2 weeks of treatment. Measurement of sebum content with a Sebumeter apparatus did not reveal significant difference (p greater than 0.05) between patients suffering from Pityriasis versicolor and controls and in treated patients, in the course of topical therapy.

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.

[Substantiation of the system of sanitary-hygienic procedures]. / Obosnovanie rezhima sanitarno-gigienicheskikh prostsedur.

Various aspects of endogenous contamination of the human skin are discussed. The contamination rate and intensity were measured by analyzing wash water obtained after sanitary-hygienic procedures (SHP) in which no detergents were used. It was found that endogenous contamination of the human skin reached its maximum 3-4 days after the previous SHP and then became stabilized. The wash water composition was shown to be independent of the skin type. The endogenous contamination level did not influence the bactericidal effect of the skin of healthy people. Due to complementary processes such as epidermis desquamation and sebum cutaneum, the role of which is different for different skin types, the amount of indigenous microorganisms is maintained at an optimal level irrespective of the skin type. It is concluded that water SHPs should be performed no more than once every four days. If they are conducted oftener than that, the normal function of the human skin may become deteriorated: epidermis desquamation increases drastically, skin state changes, and the concentration of indigenous microorganisms on the skin surface decreases as compared to the individual norm.

Changes in the relative amounts of endogenous and exogenous fatty acids in sebaceous lipids during early adolescence.

Skin surface lipid samples were collected from the scalps of 40 males, aged 9-15, and the lipid class composition of each was analyzed by quantitative thin layer chromatography. The ratio of wax esters/[cholesterol + cholesterol esters] (WE/[CH + CE]) increased with age. The wax ester, cholesterol ester, triglyceride, and free fatty acid classes were isolated from each sample and the fatty acid compositions were determined by capillary gas chromatography of fatty acid methyl esters (FAME) prepared from each lipid class. The concentrations of most of the different types of fatty acids were found to be correlated with the WE/[CH + CE] ratio. Those straight chain fatty acids that are thought to be synthesized mainly within the sebaceous glands, such as 14:0, 14:1, 16:1, and 18:2 delta 5, 8 tended to increase with increasing WE/[CH + CE], while fatty acids which circulate in the blood, such as 18:0, 18:1, and 18:2 delta 9, 12, tended to decrease with increasing WE/[CH + CE]. For the majority of straight chain fatty acid types, the data could be fitted to the equation y = a + b/[x + 1], which can be derived from simple assumptions concerning the origins of the various sebum components. The FAME from the wax esters were separated into saturated and monounsaturated fractions and analyzed by capillary gas chromatography to determine the concentrations of the different types of branched chain FAME present. In the wax esters, straight chain fatty acids tended to increase with increasing WE/[CH + CE], while terminally branched (iso and anteiso) fatty acids tended to decrease. Other branched chain fatty acids increased up to a WE/[CH + CE] ratio of about 2 and then decreased at higher ratios.

[Hygienic aspects of wash water reclamation systems]. / Gigienicheskie aspekty razrabotki sistem regeneratsii sanitarno-gigienicheskoi vody.

The quality of reclaimed wash water and the composition of used wash water can be best determined by pH, oxygen chemical index, electric conductivity and chlorides that show individual variations but are sex-independent. Wash water contained mostly staphylococci and small amounts of sarcines, diplococci and micrococci. The use of washing and disinfecting agents may significantly modify the microbial characteristics of wash water, reducing noticeably its microbial content and increasing the content of organic substances and chlorides due to chemicals they include and due to more effective removal of sebaceous secretion. It is indicated that chemical components of washing and disinfecting agents that produce organic contaminants should be given special attention when developing a wash water reclamation system.

Tinea versicolor of the face in black children in a temperate region.

Tinea versicolor is a common superficial fungal infection that typically affects young adults in warm, humid climates. We describe two young black children in the temperate northeastern Ohio area with tinea versicolor limited to the face. The occurrence of tinea versicolor on the face is unusual, as is its appearance before puberty. The mycologic and pathophysiologic characteristics of tinea versicolor infection are discussed, and several hypothesis are offered to explain the presence of tinea versicolor in these patients.

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.

Effect of aging on sebaceous gland activity and on the fatty acid composition of wax esters.

Using fused-silica capillary gas chromatography, we investigated sebum samples from 55 healthy individuals to discover the effects of aging on the sebaceous gland activity and on the fatty acid composition of wax exters. The sebaceous gland activity, which was expressed by the ratio of wax esters/[cholesterol + cholesterol esters] (WE/[C + CE]), showed a distinct change from infancy through maturity to senescence; the curve of the ratio made a peak in our subjects's 20s. Using the fatty acid analyses, we found an interesting relationship between C16:1 straight and C16:1 iso-branched chains, each of which occupied a large proportion in the fatty acids of wax esters; the former increased in proportion from infancy toward the 20s, with a correlation with aging (r = 0.788, p less than 0.01), and decreased thereafter until our subject's 50s (r = -0.611, p less than 0.01). In contrast, the proportion of the latter followed an entirely reversed course with advancing age. The percentages of C16:1 straight chain components were correlated positively with the WE/[C + CE] ratio (r = 0.642, p less than 0.01), while there was found to be a negative correlation between the proportion of C16:1 iso-branched chain components and the WE/[C + CE] ratio (r = -0.556, p less than 0.01). The results suggest that more active sebaceous glands in lipid production excrete lipids with a higher proportion of C16:1 straight chain fatty acid and a lower proportion of C16:1 iso-branched chain fatty acid. As well as the sebaceous gland activity, the fatty acid composition in sebum wax esters is affected by advancing age in Japanese.

The effect of 13-cis-retinoic acid on sebaceous glands.

The drug, 13-cis-retinoic acid, which has been demonstrated to have a marked effect on nodulocystic acne, probably has several mechanisms of action. This article summarizes the effects on the sebaceous glands, and the accompanying changes in cutaneous lipids that result from 13-cis-retinoic acid therapy. These changes in lipid composition support the concept that linoleate may be of importance in the pathogenesis of acne.

Skin surface lipids of the mole Scalopus aquaticus.

Skin surface lipids of the mole Scalopus aquaticus were found to consist principally of squalene (70%), wax esters (15%), and sterol esters (5%), together with small amounts of triglycerides, free fatty acids, free fatty alcohols, and free sterols. Analysis of the fatty acids occurring free and as wax esters and sterol esters showed these to consist of approximately equal amounts of saturated and monounsaturated compounds. The saturated fatty acids consisted predominantly of odd-carbon anteiso and even-carbon straight-chain compounds, with minor amounts of even-carbon iso-branched chains. The unsaturated fatty acids had double bond positions that would have been produced by delta 9-desaturation of C14, C16 and C18 straight chain saturated precursors. Both the free and the esterified fatty alcohols had chain structures corresponding with those of the fatty acids but of somewhat greater average chain length. Discovery of a major proportion of squalene in the sebum of this animal extends the number of non-human species that have this characteristic to four, all of which inhabit a damp environment, suggesting that squalene conveys some biological advantage under these conditions.

Effect of androgenic and anabolic steroids on the sebaceous gland in power athletes.

The effect of androgenic and anabolic steroids on sebaceous gland activity and the composition of sebum was studied in power athletes. The subject self-administered large doses of androgenic and anabolic hormones during a 12-week-period of strength training. After 4 weeks of administration of hormones the sebum excretion rate increased significantly (p = 0.002) and it remained high throughout the period of exogenous steroid use. The amounts of cholesterol were significantly increased during that period. There were no differences in the amounts of the following lipid groups; free fatty acids, squalen, triglycerides, wax esters, diglycerides and paraffins. It was concluded that large doses of androgenic and anabolic steroids lead to an increase in sebum output in healthy young adult males.

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.

Possible genetic control of the proportions of branched-chain fatty acids in human sebaceous wax esters.

The composition of human sebum varies among individuals with respect to the proportions of various types of fatty acids in the ester lipid classes. Iso-branched fatty acids with even numbers of carbons (iso-even) are particularly variable. However, in 13 identical twin pairs, intrapair differences in the proportions of iso-even fatty acids in sebaceous wax esters were found to be very small, while interpair differences were as large as in the nontwin population. Intrapair differences in iso-even fatty acids were also quite small in 4 of 8 fraternal twin pairs. Heritability estimates suggested that proportions of iso-even fatty acids in human sebum are controlled, at least in part, by genotype.

Essential fatty acids and acne.

Acne is characterized by hyperkeratosis of the follicular epithelium, leading to horny impactions that may lie dormant as open or closed comedones or may cause inflammation of the follicle. Although persons with acne have consistently been observed to have elevated levels of sebum secretion, no mechanism relating sebum secretion rates to comedogenesis is known. Acne patients have also been shown to have low levels of linoleic acid in their skin surface lipids. To explain this observation, the hypothesis is advanced that the linoleate concentration in human sebum depends on the quantity of linoleic acid present in each sebaceous cell at the commencement of its differentiation and on the extent to which this initial charge is diluted by subsequent endogenous lipid synthesis in each sebaceous cell. A corollary hypothesis holds that low concentrations of linoleate in sebum impose a state of essential fatty acid deficiency on the cells of the follicular epithelium and induce the characteristic response of hyperkeratosis. Both hypotheses could hold, without there being a systemic deficiency of linoleic acid, simply as the result of elevated lipogenesis in individual sebaceous cells.