Antimicrobial peptides and skin: a paradigm of translational medicine.

Antimicrobial peptides (AMPs) are small, cationic, amphiphilic peptides with broad-spectrum microbicidal activity against both bacteria and fungi. In mammals, AMPs form the first line of host defense against infections and generally play an important role as effector agents of the innate immune system. The AMP era was born more than 6 decades ago when the first cationic cyclic peptide antibiotics, namely polymyxins and tyrothricin, found their way into clinical use. Due to the good clinical experience in the treatment of, for example, infections of mucus membranes as well as the subsequent understanding of mode of action, AMPs are now considered for treatment of inflammatory skin diseases and for improving healing of infected wounds. Based on the preclinical findings, including pathobiochemistry and molecular medicine, targeted therapy strategies are developed and first results indicate that AMPs influence processes of diseased skin. Importantly, in contrast to other antibiotics, AMPs do not seem to propagate the development of antibiotic-resistant micro-organisms. Therefore, AMPs should be tested in clinical trials for their efficacy and tolerability in inflammatory skin diseases and chronic wounds. Apart from possible fields of application, these peptides appear suited as an example of the paradigm of translational medicine for skin diseases which is today seen as a 'two-way road' - from bench to bedside and backwards from bedside to bench.

Bioavailability, antipsoriatic efficacy and tolerability of a new light cream with mometasone furoate 0.1%.

Mometasone furoate, a potent glucocorticoid (class III) with a favorable benefit/risk ratio, has emerged as a standard medication for the treatment of inflammatory skin disorders. The purpose of the investigation presented here was to determine the noninferiority of a topical mometasone formulation, a light cream (O/W 60/40 emulsion) with mometasone furoate 0.1% (water content of 33%) versus marketed comparators. Using the vasoconstrictor assay, a strong blanching effect of the new cream (called Mometasone cream) comparable to that of a mometasone comparator, a fatty cream with mometasone furoate 0.1%, could be demonstrated. Thus, the topical bioavailability of the active ingredient mometasone furoate (0.1%) was regarded to be similar for Mometasone cream and the mometasone comparator. Using the psoriasis plaque test, a strong antipsoriatic effect comparable to that of the mometasone comparator was found for Mometasone cream after 12 days of occlusive treatment. A nearly identical reduction in the mean infiltrate thickness and similar mean AUC values were noted with both formulations confirmed by clinical assessment data. The noninferiority of Mometasone cream to its active comparator with respect to the AUC of change to baseline in infiltrate thickness was demonstrated. Both medications were well tolerated. Overall, Mometasone cream and the mometasone comparator showed similar efficacy and tolerability. Mometasone cream, in addition to its high potency and good tolerability, provides the properties of a light cream, which might make this new medication particularly suitable for application on acutely inflamed and sensitive skin.

Topical fluticasone propionate: intervention and maintenance treatment options of atopic dermatitis based on a high therapeutic index.

Fluticasone propionate (FP), a medium potent glucocorticoid (class III) of carbothioate nature with a favourable benefit/risk ratio, has emerged as a standard medication for the topical treatment of inflammatory skin disorders, in particular atopic dermatitis (AD). FP is available as a 0.05% cream and a 0.005% ointment formulation. The glucocorticoid is characterized by high lipophilicity, high affinity binding to the glucocorticoid receptor and a rapid hepatic biotransformation. Though skin blanching following topical application of FP surpasses that given with glucocorticoids of medium strength, clinical trials show a low potential of FP for local and systemic adverse effects. Even in paediatric patients with AD as well as in difficult-to-treat areas like face, eyelids and intertriginous areas, FP proved to be both effective and safe. Thus, the therapeutic effects of FP clearly outweigh the unwanted effects. Correspondingly, a therapeutic index of 2.0 can be attributed to this glucocorticoid. In this respect, topical FP does not differ from other topical glucocorticoids with increased benefit-to-risk ratio, e.g. prednicarbate, methylprednisolone aceponate and mometasone furoate. However, randomized controlled trials do not only support conventional intervention but also innovative maintenance treatment.

Resistance of liposomal sunscreen formulations against plain water as well as salt water exposure and perspiration.

The present in vivo investigation using a total of 30 healthy adult volunteers with Fitzpatrick skin type II examines the persistent efficacy of sunscreens using liposomal suspensions as the vehicle. Based on the COLIPA guidelines, the protective effect of a single application of 4 different liposomal sunscreen formulations (sun protection factors, SPFs: 50+, 30, 25 and 15) against sunburn at the recommended amount of 2 mg/cm(2) was determined after exposure of the skin to plain water and salt water and after profuse perspiration. Under the influence of plain water, salt water and sweating, the SPF values of sunscreen 1 (labeled SPF of 50+) were reduced only marginally to 97, 96 and 99%, respectively, those of sunscreen 2 (labeled SPF of 30) to 97, 96 and 99%, respectively, those of sunscreen 3 (labeled SPF of 25) to 90, 83 and 91%, respectively, and those of sunscreen 4 (labeled SPF of 15) to 96, 96 and 95%, respectively. This set of data shows that despite plain water and salt water immersion or profuse sweating, the liposomal sunscreen formulation may deliver a long-lasting protective effect in everyday situations encountered by outdoor workers or during leisure activities.

Management of minor acute cutaneous wounds: importance of wound healing in a moist environment.

Moist wound care has been established as standard therapy for chronic wounds with impaired healing. Healing in acute wounds, in particular in minor superficial acute wounds - which indeed are much more numerous than chronic wounds - is often taken for granted because it is assumed that in those wounds normal phases of wound healing should run per se without any problems. But minor wounds such as small cuts, scraps or abrasions also need proper care to prevent complications, in particular infections. Local wound care with minor wounds consists of thorough cleansing with potable tap water or normal saline followed by the application of an appropriate dressing corresponding to the principles of moist wound treatment. In the treatment of smaller superficial wounds, it appears advisable to limit the choice of dressing to just a few products that fulfil the principles of moist wound management and are easy to use. Hydroactive colloid gels combining the attributes of hydrocolloids and hydrogels thus being appropriate for dry and exuding wounds appear especially suitable for this purpose - although there is still a lack of data from systematic studies on the effectiveness of these preparations.

Efficacy and tolerability of pale sulfonated shale oil cream 4% in the treatment of mild to moderate atopic eczema in children: a multicentre, randomized vehicle-controlled trial.

BACKGROUND: Reports on controlled trials on the efficacy and tolerability of sulfonated shale oils in atopic eczema are not available so far. The aim of this study was to investigate whether topically applied, specially prepared pale sulfonated shale oil (PSSO) cream is capable of improving symptoms/signs of mild to moderate atopic eczema in children more efficaciously than a corresponding vehicle cream. PATIENTS AND METHODS: A total of 99 children suffering from mild to moderate atopic eczema were enrolled in this multicentre, randomized, vehicle-controlled study. Verum or vehicle cream was applied to the affected skin area three times a day over 4 weeks. As the primary outcome parameter served the reduction of the total score after 4 weeks of treatment, compared with the initial examination. Secondary outcome parameters were addressed as well. Tolerability was judged by investigators and patients/parents, and adverse events were documented. RESULTS: After 4 weeks of treatment, the total score declined from 13.4 ± 3.7 to 4.5 ± 7.4 score points in the verum group and from 13.0 ± 3.1 to 11.7 ± 8.6 score points in the vehicle group (P < 0.0001). The superiority of verum regarding total score was already apparent after a treatment period of 1 week (reduction by 5.6 ± 4.3 vs. 1.3 ± 5.9 score points; P < 0.0001). Tolerability was found superior at the end of the treatment in the verum when compared with the control group--both by investigators (P < 0.0001) and patients/parents (P = 0.0051). CONCLUSION: Pale sulfonated shale oil cream 4% is capable to treat mild to moderate atopic eczema in children more efficaciously than vehicle and is well tolerated. PSSO thus represents a valuable addition to our therapeutic armamentarium. PSSO should be considered in particular when valid alternatives for topical glucocorticoids are sought for.

[Acne vulgaris. Role of cosmetics]. / Acne vulgaris. Rolle der Kosmetik.

Appropriate cosmetics for skin cleansing are capable of contributing to a reduction of especially inflammatory lesions in acne-prone patients and to support pharmacological intervention in patients with manifest acne. Cleansing of acne-prone skin should employ acidified synthetic cleansers with a pH of 5.5 rather than soap. Furthermore, the ingredients of certain skin care products, i.e. nicotinamide, lactic acid, triethyl acetate/ethyllineolate, and prebiotic plant extracts, affect different mechanisms of acne pathogenesis and therefore may contribute to a decrease in acne lesions. At least some of these ingredients underscore the concept of evidence-based cosmetics. In contrast, the problem of acne lesions caused by comedogenic ingredients in cosmetics today is negligible.

Tetracycline actions relevant to rosacea treatment.

Until today, the pathogenesis of rosacea is not known in detail. Yet in recent years evidence has been accumulating that rosacea with its common symptoms such as inflammatory lesions, erythema, telangiectasia, phymatous changes, and ocular symptoms is of inflammatory nature. Tetracycline derivatives like doxycycline successfully used in the treatment of skin diseases like acne and rosacea seem to inhibit different inflammatory pathways involved in the pathogenesis by various modes of action. Although data for skin diseases are relatively scanty, the following modes of action of tetracyclines seem to be most relevant for an effective treatment of acne and rosacea: inhibition of matrix metalloproteinases, downmodulation of cytokines, inhibition of cell movement and proliferation, inhibition of granuloma formation, inhibition of reactive oxygen species, nitric oxide, and angiogenesis, whereas inhibition of phospholipase A2 seems to be of lower importance. The role of the saprophytic mite Demodex folliculorum remains to be clarified. Additional studies are necessary to further elucidate how tetracyclines work in rosacea treatment.

Current topical and systemic approaches to treatment of rosacea.

Rosacea is a common, often overlooked, chronic facial dermatosis characterized by intermittent periods of exacerbation and remission. Clinical subtypes and grading of the disease have been defined in the literature. On the basis of a genetic predisposition, there are several intrinsic and extrinsic factors possibly correlating with the phenotypic expression of the disease. Although rosacea cannot be cured, there are several recommended treatment strategies appropriate to control the corresponding symptoms/signs. In addition to adequate skin care, these include topical and systemic medications particularly suitable for the papulopustular subtype of rosacea with moderate to severe intensity. The most commonly used and most established therapeutic regimens are topical metronidazole and topical azelaic acid as well as oral doxycycline. Conventionally, 100-200 mg per day have been used. Today also a controlled release formulation is available, delivering 40 mg per day using non-antibiotic, anti-inflammatory activities of the drug. Anti-inflammatory dose doxycycline in particular allows for a safe and effective short- and long-term therapy of rosacea. Topical metronidazole and topical azelaic acid also appear to be safe and effective for short-term use. There are indications that a combined therapy of anti-inflammatory dose doxycycline and topical metronidazole could possibly have synergy effects. Further interesting therapy options for the short- and long-term therapy of rosacea could be low-dose minocycline and isotretinoin; however, too little data are available with regard to the effectiveness, safety, optimal dosage and appropriate length of treatment for these medications to draw final conclusions.

[Management of acne vulgaris: focus on clindamycin and zinc]. / Management der Acne vulgaris: Fokus auf Clindamycin und Zink.

Topical antibiotics, especially clindamycin, are well-accepted in the treatment of mild to moderate acne. Combinations of clindamycin and other agents such as benzoyl peroxide, retinoids or zinc, are possibly superior to clindamycin monotherapy regarding efficacy and tolerability with the combination 1% clindamycin/5% benzoyl peroxide being particularly well-supported by evidence. Moreover, a recent study has shown that patients themselves prefer a complex of zinc acetate/clindamycin phosphate.

Hypercapnic ventilatory response in humans before, during, and after 23 days of low level CO2 exposure.

Alterations in ventilation and the chemoreceptor response to CO2 during 23 d of 1.2% inspired CO2 were studied in four male subjects. Resting ventilation (VE), tidal volume (VT), respiratory frequency (fR), inspired and end tidal O2 and CO2 and the hypercapnic ventilatory response (HCVR) measured by CO2 rebreathing were measured once before entering the chamber, on days 2, 5, 11, and 22 of CO2 exposure, and one day after. Resting VE slightly increased (5%) on day 2 of exposure and significantly increased (22%) by day 5 followed by a progressive decrease to pre-chamber levels by day 22 and on the first day of recovery. Tidal volume and fR were not statistically different. During the exposure PetCO2 was significantly elevated with day 2 having the largest increase (19.6%). PetCO2 returned to normal within 24 h post exposure. The HCVR was characterized by the slope (SHCVR), intercept at zero ventilation (B), and the ventilation at a PCO2 = 60 mmHg (VE60). The SHCVR decreased (14%) on day 2, but was not significant; the SHCVR on the other exposure days were also not different. The SHCVR on the first recovery day significantly increased (37%). The HCVR B was shifted to the right on day 2 by 5.2 mmHg, then progressively returned to the pre-exposure position. On recovery the B significantly shifted 6.9 mmHg to the right of pre-exposure B. The VE60 decreased by approximately 32% and 16% on day 2 and 5, respectively, then returned within pre-exposure range for the remainder of the exposure and during recovery. During the early phase and one day after the exposure the HCVR was right shifted. One day after exposure chemoreceptor sensitivity to elevated CO2 was increased but, the B was right shifted resulting in a reduced HCVR below PCO2 of 60 mmHg and a greater HCVR above 60 mmHg.

Effects of chronically increased ambient CO2 concentrations on aerobic capacity.

As part of a joint NASA-ESA-DARA study on the effects of chronically increased CO2 concentrations in ambient air, changes in parameters indicating aerobic capacity were investigated by cycle ergometry. Two potential sources for reductions of aerobic capacities were hypothesized: 1) the adaptations to CO2 such as reduction in H(+)-buffer capacities which may influence muscle metabolism; 2) the reduced physical activities which may lead to a detraining effect. Four subjects were exposed to 0.7% and 1.2% CO2 concentration in a confined compartment for 23 d each with 3 mo in between the two campaigns. A combined exercise test was applied before, during (on days 5, 11, and 22) and after CO2 exposure. Comparing steady-states at 30 W and 80 W power, elevated ventilation was found increased during CO2 exposure with significant differences between the two campaigns. Peak oxygen uptake decreased over the period of CO2 exposure, but was found not significantly different on day 5 compared to pre-exposure measurements. This decrease was not dependent on the CO2 concentration. The lactate concentration at low exercise intensities was found elevated during CO2 exposure. A shift in reverse direction was observed after the CO2 exposure. Since peak oxygen uptake did not differ on day 5 and the lactate concentration was found increased, it was concluded that the potential changes in muscle metabolism by adaptation to elevated CO2 concentrations did not influence the aerobic capacities. Therefore, it was concluded that the changes in aerobic capacities are the result of the reduced physical activities of the subjects while living in the confined compartment.

Differential expression of the two VEGF receptors flt and KDR in placenta and vascular endothelial cells.

Vascular endothelial growth factor (VEGF) is a newly identified growth and permeability factor with a unique specificity for endothelial cells. Recently the flt-encoded tyrosine kinase was characterized as a receptor for VEGF. A novel tyrosine kinase receptor encoded by the KDR gene was also found to bind VEGF with high affinity when expressed in CMT-3 cells. Screening for flt and KDR expression in a variety of species and tissue-derived endothelial cells demonstrates that flt is predominantly expressed in human placenta and human vascular endothelial cells. Placenta growth factor (PIGF), a growth factor significantly related to VEGF, is coexpressed with flt in placenta and human vascular endothelial cells. KDR is more widely distributed and expressed in all vessel-derived endothelial cells. These data demonstrate that cultured human endothelial cells isolated from different tissues express both VEGF receptors in relative high levels and, additionally, that all investigated nonhuman endothelial cells in culture are also positive for KDR gene expression.

Angiotensin II mediates intracellular signalling in vascular smooth muscle cells by activation of tyrosine-specific protein kinases and c-raf-1.

Angiotensin II induces protein tyrosine kinase activation and apparent decreased electrophoretic mobility of the c-raf-1 serine/threonine protein kinase in cultured rat vascular smooth muscle cells. Tyrosine phosphorylation of at least 9 cellular proteins with molecular weights of 151, 131, 116, 110, 90, 65, 62, 60, 52 kd was induced in a time- and concentration-dependent manner, and included a serine/threonine protein kinase. The phosphotyrosine containing proteins differed from those induced by PDGF BB or AB. Angiotensin II by itself was shown not to act as a mitogen in cultured smooth muscle cells.

Synthesis and assembly of functionally active human vascular endothelial growth factor homodimers in insect cells.

Vascular endothelial growth factor (VEGF) is an angiogenic growth factor with a target-cell specificity highly restricted to vascular endothelial cells. Recombinant baculovirus were constructed for the production of two different forms of the human VEGF protein in insect cells. VEGF165 and VEGF121 proteins produced by Sf158 cells underwent a similar processing compared with mammalian cells, including efficient glycosylation, formation of a disulfide-linked dimer and secretion into the media. Only one of these forms, VEGF165 had a high affinity for heparin and this characteristic was used to purify this form to homogenicity by a two-step heparin-affinity chromatography. The biological activity of the purified 43-kDa homodimer was demonstrated by high-affinity binding to VEGF receptors, and by the induction of DNA synthesis in vascular endothelial cells. A positive angiogenic activity in vivo was demonstrated by the day-13 chorioallantoic-membrane assay. The mitogenic potency of VEGF121 for human umbilical vein endothelial cells was very similar compared to VEGF165. These results demonstrate that an angiogenic growth factor whose normal processing requires glycosylation and disulfide-bridge formation can be efficiently expressed in high concentration (up to 5 micrograms/ml) in insects cells.

Basic fibroblast growth factor modulates the mitogenic potency of the platelet-derived growth factor (PDGF) isoforms by specific upregulation of the PDGF alpha receptor in vascular smooth muscle cells.

Platelet-derived growth factor AA (PDGF AA), in contrast to PDGF AB and BB, is a poor mitogen for smooth muscle cells (SMC). However, together with basic fibroblast growth factor (bFGF) it acts synergistically on DNA synthesis of these cells. Northern blot analysis revealed that bFGF selectively increases the PDGF-receptor alpha subtype (PDGF-R alpha) mRNA level without a significant effect on the PDGF-R beta mRNA level. The amount of PDGF-R alpha protein is also selectively increased after stimulating SMC with bFGF as shown by immunoprecipitation of lysates from SMC with anti-PDGF-R alpha antibodies. The number of binding sites for 125I-PDGF AA is more than doubled after bFGF-treatment, whereas the specific binding for PDGF AB and BB increased only by approximately 30 and 20%, respectively. The increase in the number of PDGF-R alpha renders the SMC responsive for PDGF AA as demonstrated by the induction of the proto-oncogene c-fos as well as by an increased cell proliferation. The enhanced PDGF binding after bFGF treatment may in fact explain the observed synergistic behavior. These data are discussed with regard to a possible role of growth factor-induced transmodulation of receptor expression during atherogenesis.

Proton-transport activity, sidedness, and morphometry of tonoplast and plasma-membrane vesicles purified by free-flow electrophoresis from roots of Lepidium sativum L. and hypocotyls of Cucurbita pepo L.

Large-scale preparations of highly purified tonoplast and plasma-membrane vesicles were obtained from roots (garden cress, Lepidium sativum L.) and shoots (etiolated zucchini hypocotyl, Cucurbita pepo L.) of representative dicotyledonous seedlings. When tonoplast-enriched fractions of cress roots were prepared by centrifugation and then subjected to free-flow electrophoresis a highly purified tonoplast fraction was obtained. This fraction from cress roots was characterized by morphometry of filipin-treated freeze-fractured preparations and by enzymology to be about 90% homogeneous. Using latency of nitrate-inhibited ATPase and H(+)-pumping as criteria we found that the majority of the tonoplast vesicles from both sources were oriented right(cytoplasmic)-side-out. Plasma-membrane vesicles were first purified by two-phase partitioning and then subjected to free-flow electrophoresis for further purification. From cress roots, the fraction of highest purity contained 89% plasma-membrane vesicles as judged by morphometry of filipin-treated, freeze-fractured preparations and by enzymology. From both sources, the major plasma-membrane subfraction in the upper phase after two-phase partitioning was shown to have the least electrophoretic mobility in free-flow electrophoresis and to be oriented right(extracytoplasmic)-side-out a slightly more mobile plasma-membrane subfraction was oriented inside-out and originated after freezing thawing from outside-out plasma-membrane vesicles.