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Biomedical subjects

M Lodén

Publications and source records attributed to M Lodén.

At least 19 recordsLinked to original sources
PubMed2005

The clinical benefit of moisturizers.

UNLABELLED: Moisturizing creams marketed to consumers often contain trendy ingredients and are accompanied by exciting names and attractive claims. Moisturizers are also an important part of the dermatologist's armamentarium to treat dry skin conditions and maintain healthy skin. The products can be regarded as cosmetics, but may also be regulated as medicinal products if they are marketed against dry skin diseases, such as atopic dermatitis and ichthyosis. When moisturizers are used on the so-called dry skin, many distinct disorders that manifest themselves with the generally recognized symptoms of dryness are treated. Dryness is not a single entity, but is characterized by differences in chemistry and morphology in the epidermis depending on the internal and external stressors of the skin. Patients and the society expect dermatologists and pharmacists to be able to recommend treatment for various dry skin conditions upon evidence-based medicine. LEARNING OBJECTIVE: Upon completing this paper, the reader should be aware of different types of moisturizers and their major constituents. Furthermore, s/he will know more about the relief of dryness symptoms and the functional changes of the skin induced by moisturizers.

Administration, Topical↗
PubMed2004

Irritation potential of bath and shower oils before and after use: a double-blind randomized study.

BACKGROUND: Difficulties in avoiding weak irritants may contribute to chronic contact dermatitis. A large variety of shower and bath oils are claimed to be suitable for use on dry skin because of their mildness and because they deposit a protective oil film on the skin. OBJECTIVES: The aim of the present study was to investigate possible differences in the irritation potential of eight shower or bath oils and to investigate whether surfactant residues may form a reservoir of irritant substance on the skin. PATIENTS AND METHODS: The study was double-blind and randomized using healthy human volunteers. The inherent capacity of the products to induce irritation was determined using conventional patch test techniques. Detection of potentially irritant residues was done by occlusion of the treated and rinsed skin area, followed by evaluation of the biological response. Instrumental measurements of transepidermal water loss and superficial skin blood flow served as indicators of the injurious effects of the products. RESULTS AND CONCLUSIONS: The results showed large differences between the products in irritant potential. Some did not irritate skin more than water, whereas others demonstrated considerably damaging effects. Moreover, the study proved the presence of barrier-impairing residues on the skin after rinsing with water. Thus, instead of protecting the skin, some formulations may induce subclinical injuries and delay skin barrier function recovery with prolonged risk for patients with eczema.

Adult↗
PubMed2003

Do moisturizers work?

Moisturizers are used on large body surfaces to maintain the smoothness of the skin and to break the dry-skin cycle. Many healthcare professionals and patients overlook the importance of moisturizers and do not consider them to be 'active' treatments. However, evidence from clinical and experimental studies shows that moisturizers enhance both the smoothness and hydration of skin. Different moisturizers have different ingredients, and each may have a different mode of action. Some smooth the skin, others affect barrier function. Some enhance barrier function in both diseased and normal skin. Others impair barrier function in both diseased and normal skin. Defective barrier function may trigger the development of eczema. The composition of a particular moisturizer should reflect its desired therapeutic effect, i.e. a moisturizer to diminish dryness may need different ingredients from those required to improve barrier function. The content of excipients, such as emulsifiers, chelating agents and antioxidants, may have greater impact than is commonly believed. Greater tailoring of moisturizers will improve their efficacy. Confidence in the therapeutic effects of moisturizers will be enhanced by well-designed randomized controlled trials.

Journal Article↗
PubMed2001

Strategy to decrease the risk of adverse effects of fragrance ingredients in cosmetic products.

In spite of extensive self-regulation of the fragrance industry, fragrance ingredients are still major causes of allergic contact dermatitis. There are indications that the problem is increasing in some countries, and that many nonregulated compounds are involved in the development of allergies. The use of essential oils in fragrance compounds might add both allergenic and carcinogenic compounds to a product and the exact composition of such ingredients is difficult to control. Herein, we propose a simple strategy to decrease the risk of adverse effects of fragrance ingredients in cosmetic products. This strategy consists of four major steps: (1) limit the concentration of fragrance compound in the products, (2) follow legislation and guidelines, (3) limit the concentration of a number of well-known sensitizing fragrance chemicals, and (4) limit the concentration of essential oils and materials with unknown composition. The strategy is discussed as an alternative to animal testing and in relation to other more resource-demanding approaches to the same problem.

Animal Testing Alternatives↗
PubMed2001

Instrumental and dermatologist evaluation of the effect of glycerine and urea on dry skin in atopic dermatitis.

BACKGROUND/AIMS: Moisturising creams are useful treatment adjuncts in inflammatory dermatoses and have beneficial effects in the treatment of dry, scaly skin. The effects on dryness and skin permeability of a new moisturising cream with 20% glycerine was compared with its placebo and with a medicinally authorised cream with 4% urea (combined with 4% sodium chloride) in the treatment of dry skin. METHODS: Patients (n=109) with atopic dermatitis were treated for 30 days with a moisturiser in a randomised, parallel and double-blind fashion. Transepidermal water loss (TEWL) and skin capacitance were assessed instrumentally, and changes in the dryness of the skin were assessed by the dermatologist. RESULTS: No difference in TEWL was found between glycerine treatment and its placebo, whereas a lower value was found in the urea-treated area compared to the glycerine-treated area. No difference in skin capacitance was found. The clinical assessment of dryness showed urea to be superior to glycerine in treating the condition. CONCLUSIONS: Moisturising creams are different, not only with respect to composition but also with respect to their influence on skin as a barrier to water in patients with atopic dermatitis.

Adult↗
PubMed2000

Unexpected skin barrier influence from nonionic emulsifiers.

Skin disorders are often treated with creams containing various active substances. The creams also contain emulsifiers, which are surface-active ingredients used to stabilize the emulsion. Emulsifiers are potential irritants and in the present study the influence of stearic acid, glyceryl stearate, PEG-2, -9, -40, and -100 stearate, steareth-2, -10 and -21 on normal as well as on irritated skin have been evaluated with non-invasive measurements. Test emulsions were created by incorporating 5% emulsifiers in a water/mineral oil mixture (50:50). The emulsions and their vehicle were then applied to normal skin for 48 h and to sodium lauryl sulfate (SLS) damaged skin for 17 h in aluminum chambers. Twenty-four hours after removal of the chambers the test sites were evaluated for degree of irritation. In normal skin, the emulsifiers induced significant differences in TEWL but not in skin blood flow. Five of the emulsifiers increased TEWL. In SLS-damaged skin an aggravation of the irritation was expected. However, no differences regarding skin blood flow was noted from the emulsifiers. Furthermore, three emulsifiers unexpectedly decreased TEWL. These results highlight the possibility of absorption of these emulsifiers into the lipid bilayer, which increase TEWL in normal skin and decrease TEWL in damaged skin.

Administration, Topical↗
PubMed2000

Long-term cultured IL-2-dependent T cell lines demonstrate p16(INK4a) overexpression, normal pRb/p53, and upregulation of cyclins E or D2.

Acquisition of an immortal phenotype by circumvention of the normal senescence program can be an important step in tumor development and progression. The regulation of life-span checkpoints is complex and abrogation of these processes can occur at different levels. To better understand these mechanisms in long-term cultured lymphocytes we have characterized two human long-term cultured IL-2-dependent T cell lines regarding telomere length, telomerase activity, and the expression of selected cell cycle regulators (pRb, p53, cyclin E, cyclin D1, cyclin D2, cyclin D3, cdk4, p16(INK4a), p21(WAF1), p27(KIP1), c-myc, bcl-2, and NPAT). We compared these cell lines with a primary T lymphoblast population with a limited life span from the same donor. Both T cell lines with extraordinary growth capacity showed telomere length stabilization, high telomerase activity and demonstrated wild-type pattern of pRb and p53 but strong p16(INK4a) protein expression. The growth inhibitory activity of p16(INK4a) seemed to be abrogated by enhanced expression of cyclin D2, cdk4, and c-myc in one T cell line and overexpression of cyclin E in the second T cell line.

Cell Culture Techniques↗
PubMed2000

Content of fragrance mix ingredients and customer complaints of cosmetic products.

BACKGROUND: In relation to the wide use of cosmetics, serious adverse effects are rare. Occasionally, unwanted effects such as contact dermatitis are reported. Allergic reactions to cosmetics are often caused by fragrances. OBJECTIVE: The aim was to investigate the content of fragrance mix (FM) ingredients in cosmetic products of the brand ACO HUD (Stockholm, Sweden) and the frequency of customer skin complaints about fragranced and unfragranced products over 4.5 years. METHOD: Content of FM ingredients in the fragrances used was both analyzed and requested from the suppliers. Customer complaints were those reported to the company. RESULTS: Between 1 and 7 of FM ingredients were present in levels of less than 0.1 to 770 ppm. The ingredients, in order of frequency, were geraniol, eugenol, hydroxycitronellal, alpha-amyl cinnamic aldehyde, isoeugenol, cinnamic alcohol, and oak moss. Cinnamic aldehyde was not found. No significant difference was found either between the frequency of complaints about products with and without fragrance (P = .21) or in a paired comparison of 17 formulas marketed with and without fragrance (P = .24). CONCLUSION: The study suggests that the investigated fragranced products had a low content of FM ingredients, which might explain the absence of a higher frequency of adversities. Furthermore, it appears that under such circumstances fragrances may be used without introducing an increased rate of spontaneous complaints of skin reactions.

Allergens↗
PubMed1999

Cyclin E dependent kinase activity in human breast cancer in relation to cyclin E, p27 and p21 expression and retinoblastoma protein phosphorylation.

The cell cycle machinery is regulated by cyclin dependent kinases and sets of activating and inhibitory proteins. The G1-S control mechanism is often deregulated in tumours supposedly leading to increased kinase activity, phosphorylation of substrates and subsequent S phase entrance. Increased kinase activity has been proposed to be essential in cell cycle aberrations, but few studies have actually shown enhanced kinase activity related to specific cell cycle defects in primary tumours. In the present study we have determined the cyclin E dependent kinase activity (cyclin E(kinase)) in 59 primary breast cancers, using an H1-kinase assay, and related the activity to the expression of cyclin E, p27 and p21. In a subgroup of 48 tumours, we further characterized the association between cyclin E(kinase), in vivo phosphorylation of the retinoblastoma protein (pRb) and proliferation. The cyclin E(kinase) correlated significantly with cyclin E content and inversely with p27 and p21 expression. P27, but not p21, was associated with low cyclin E(kinase) in specimens with normal/low levels of cyclin E. At elevated cyclin E levels, suppression of cyclin E(kinase) seemed to require high levels of both p21 and p27. The cyclin E(kinase) correlated with the phosphorylation status of pRb as well as with proliferation. Surprisingly, pRb phosphorylation did not correlate with proliferation. Our results support that pRb is a substrate for cyclin E(kinase) in primary breast cancer and that deregulation of cyclin E and p27 act through increased CDK-kinase activity, but cyclin E associated events beside pRb phosphorylation might be rate-limiting for entrance into S phase.

Breast Neoplasms↗
PubMed1999

G1-S transition defects occur in most breast cancers and predict outcome.

Cell cycle deregulation is frequently observed in tumors and has moreover been proposed to be a requirement for tumor development. By analyzing the expression of p27 by immunohistochemistry in 100 primary breast tumors and combining the analyses with our earlier characterization of cyclin E, D1, p16, and the retinoblastoma protein (pRB), we have been able to cover the majority of potential G1-S transition defects and observed that 90% of the tumors had alterations in one or several cell cycle regulatory proteins. Considerable variations in protein levels were found among tumors, with low p16 expression as the most common alteration followed by cyclin E or cyclin D1 overexpression, low p27 expression or pRB inactivation in decreasing prevalence. Tumors were grouped according to observed combinations of defects and the proliferative capacity was determined for each group by analyzing Ki-67 labeling index. Low proliferation was observed in tumors with: low p16; high cyclin D1 with normal or high p16 expression; and in tumors without cell cycle defects. Tumors with high cyclin E/low p27 or pRB defects showed higher proliferation. The survival differed noticeably for patients with various combinations of cell cycle defects, and four distinctive clusters were identified showing significantly different breast cancer specific survival (p<0.0001) for both node-positive (p = 0.0006) and node-negative patients (p<0.0001). In summary, we have shown that G1-S transition defects are nearly obligatory in breast tumors and that the specific type of cell cycle defect influences the clinical behavior of the tumor.

Breast Neoplasms↗
PubMed1999

Improvement in skin barrier function in patients with atopic dermatitis after treatment with a moisturizing cream (Canoderm).

Patients with atopic skin show a defective barrier function both in rough and in clinically normal skin, with an increasing risk of developing contact dermatitis. Moisturizing creams are often used in the treatment of dry skin. The purpose of this study was to investigate the influence of treatment with a urea-containing moisturizer on the barrier properties of atopic skin. Fifteen patients with atopic dermatitis treated one of their forearms twice daily for 20 days with a moisturizing cream. Skin capacitance and transepidermal water loss (TEWL) were measured at the start of the study and after 10 and 20 days. On day 21 the skin was exposed to sodium lauryl sulphate (SLS) and on day 22 the irritant reaction was measured non-invasively. Skin capacitance was significantly increased by the treatment, indicating increased skin hydration. The water barrier function, as reflected by TEWL values, tended to improve (P = 0.07), and the skin susceptibility to SLS was significantly reduced, as measured by TEWL and superficial skin blood flow (P < 0.05). Thus, it seems that certain moisturizers could improve skin barrier function in atopics and reduce skin susceptibility to irritants. The mechanism and the clinical relevance need further investigation.

Adult↗
PubMed1999

Biophysical characterization of skin damage and recovery after exposure to different surfactants.

The majority of adverse skin reactions to personal-care products are presumed to be caused by irritant substances, like surfactants. In this study, different aspects of the irritant reaction after a single exposure to 8 surfactants were characterized during 2 weeks. Solutions of 2% sodium lauryl sulfate, 5% sodium C12-15 pareth sulfate, 5% sodium cocoyl isethionate, 10% disodium laureth sulfosuccinate, 10% sodium cocoamphoacetate, 10% cocamide DEA, 10% cocamidopropyl betaine and 10% lauryl glucoside, respectively, were applied to the forearm of 12 volunteers. Clinical assessment, an evaporimeter, a laser Doppler flowmeter and a corneometer were used for evaluation. The surfactants induced different degrees of irritation. Erythema, transepidermal water loss and skin blood flow exhibited a similar time course, which seemed to be inversely related to the delayed scaling and reduced skin capacitance. The mechanism of the damaging effect of the surfactants seems to be similar, although some minor differences were noted.

Adult↗
PubMed1997

Barrier recovery and influence of irritant stimuli in skin treated with a moisturizing cream.

Moisturizers are used daily by many people to alleviate symptoms of clinically and subjectively dry skin. Recent studies suggest that certain ingredients in creams may accelerate the recovery of a disrupted barrier and decrease the skin susceptibility to irritant stimuli. In the present single-blind study, a moisturizing cream was tested for its influence both on barrier recovery in surfactant-damaged skin and on the susceptibility of normal skin to exposure to the irritant sodium lauryl sulphate (SLS). Parameters measured were transepidermal water loss (TEWL) and skin corneometer values, indicating degree of hydration. Treatment of surfactant-damaged skin with the test cream for 14 days promoted barrier recovery, as observed as a decrease in TEWL. Skin corneometer values also normalized more rapidly during the treatment. In normal skin, use of the test cream significantly reduced TEWL after 14 days of treatment, and irritant reactions to SLS were significantly decreased. Skin corneometer values increased after only 1 application and remained elevated after 14 days. In conclusion, the accelerated rate of recovery of surfactant-damaged skin and the lower degree of SLS-induced irritation in normal skin treated with the test cream may be of clinical relevance in attempts to reduce contact dermatitis due to irritant stimuli.

Adult↗
PubMed1996

Effect of topically applied lipids on surfactant-irritated skin.

Moisturizers are used daily by many people to alleviate symptoms of dry skin. All of them contain lipids. It has been suggested that topically applied lipids may interfere with the structure and function of the permeability barrier. The influence of a single application of nine different lipids on normal skin and skin irritated by sodium lauryl sulphate (SLS) was studied in 21 healthy subjects. Parameters assessed were visible signs of irritation, and objectively measured cutaneous blood flow and transepidermal water loss (TEWL). The substances tested were hydrocortisone, petrolatum, fish oil, borage oil, sunflower seed oil, canola oil, shea butter, and fractions of unsaponifiable lipids from canola oil and shea butter. Water was included as a control. On normal skin, no significant differences in the effects of the test substances were found, whereas significant differences were observed when they were applied to SLS-irritated skin. The visible signs of SLS-induced irritation were significantly less pronounced after treatment with the sterol-enriched fraction from canola oil than after treatment with water. This fraction, and hydrocortisone, reduced cutaneous blood flow. Furthermore, application of hydrocortisone, canola oil, and its sterol-enriched fraction, resulted in significantly lower TEWL than with water. The other lipids had no effect on the degree of irritation. In conclusion, lipids commonly used in moisturizers may reduce skin reactions to irritants. Previous studies have shown that, in barrier perturbed skin, the synthesis of sterols is increased. The observed effects of canola oil and its fraction of unsaponifiable lipids on SLS-induced irritation suggest the possibility that they assisted the skin in supplying the damaged barrier with adequate lipids.

Adult↗
PubMed1995

Distribution and keratolytic effect of salicylic acid and urea in human skin.

Salicylic acid (SA) and urea are widely used in topical preparations. Using a simple tape stripping technique the effect on the binding forces within the stratum corneum and the skin absorption of SA and urea were studied. The degree of stratum corneum removal was recorded by measuring the transmission through the tape with a digital light-measuring instrument. With successive stripping of the skin the amount of tissue adhering to the tape decreased. Exposure of the upper arm to 2% SA for 6 h increased the skin material on the tape strips significantly. No significant increase was recorded after 3-hour exposure, or after exposure to 0.5% SA. Neither did the exposure to 10% urea for 3 or 6 h influence the amount of skin adhering to the tape significantly. Radiochemical analyses showed that the amount of SA and urea in each of the first 6 tape strips was about 5-15 micrograms/cm2. This technique provides a useful tool to evaluate the binding forces within the stratum corneum in relation to absorption of topically applied substances.

Administration, Topical↗
PubMed1995

Biophysical properties of dry atopic and normal skin with special reference to effects of skin care products.

During recent years several highly developed non-invasive methods for evaluation of skin physiology and pathology have been introduced. Against this background, the present studies were undertaken with the primary aim of assessing the effects of various skin care products on some properties of the skin. Skin topography was measured by profilometry on skin replicas, friction with a newly developed friction instrument, capacitance with a Corneometer, and barrier function both with an Evaporimeter to assess transepidermal water loss (TEWL) and by application of an irritant followed by measurement of the resulting irritative reaction. Initially some of the techniques were used to further characterize the differences between dry atopic skin and normal skin. Dry skin exhibits increased values of roughness parameters and a reduced number of topographical peaks. TEWL is increased, indicating impaired barrier function. The friction and capacitance are lower and correlate significantly to each other, whereas TEWL does not appear to relate to either of these parameters. The use of a scrub cream removes the outermost part of the stratum corneum, resulting in a smoother skin. Application of moisturizers modifies the frictional response of the skin. The friction instrument gave results comparable to those of panelists trained in sensory evaluation. The study suggests that measurement of skin friction can be used to predict the degree of liking of moisturizers. Furthermore, moisturizers increase the skin hydration. They provide water directly to the skin from their water phase. Skin hydration also increases with increased degree of occlusion, as measured as a decrease in TEWL. Moisturizers may also alter the diffusional resistance of the stratum corneum and reduce the skin susceptibility to the surfactant sodium lauryl sulphate (SLS). Lipids in moisturizers may influence already developed SLS-induced irritation. A significantly lower degree of irritation was found in areas treated with canola oil and its sterol-enriched fraction than in an area treated with water. These findings emphasize that skin care products do not only form an inert, epicutaneous layer, but that they may penetrate and influence the structure and function of the skin.

Adolescent↗
PubMed1995

The presence of body hair influences the measurement of skin hydration with the Corneometer.

Techniques for the assessment of skin hydration are often based on the electrical properties of the stratum corneum. A commonly used instrument for measurements of skin moisture is the corneometer, which detects changes in the dielectric constant of the material in contact with the probe. It has been suggested that different materials, for example cream residues and desquamating scales, may interfere with the Corneometer readings, but this question has not been settled conclusively in previous studies. In the present study the influence of body hair was examined. Significantly lower Corneometer values were obtained on the dorsal aspect of the forearm than on the volar aspect (p < 0.05), indicating that the former region was less hydrated than the latter. After shaving of the skin, however, there was no difference in the Corneometer readings between the two regions. Thus, the presence of hair needs to be considered when the hydration status of the skin is examined with the use of a Corneometer.

Adult↗