Effects of processing steps on the phenolic content and antioxidant activity of beer.

A new analytical method (liquid chromatography-antioxidant, LC-AOx) was used that is intended to separate beer polyphenols and to determine the potential antioxidant activity of these constituents after they were allowed to react online with a buffered solution of the radical cation 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS(•+)). Using the LC-AOx method, it was possible to demonstrate that the extent of the antioxidant activity was very much dependent on the phenolic compound considered. The method was also applied to the analysis of beer extracts and allowed the evaluation of their antioxidant activity at different steps of beer processing: brewing, boiling, and fermentation.

Synergistic effect of hyaluronate fragments in retinaldehyde-induced skin hyperplasia which is a Cd44-dependent phenomenon.

Background: CD44 is a polymorphic proteoglycan and functions as the principal cell-surface receptor for hyaluronate (HA). Heparin-binding epidermal growth factor (HB-EGF) activation of keratinocyte erbB receptors has been proposed to mediate retinoid-induced epidermal hyperplasia. We have recently shown that intermediate size HA fragments (HAFi) reverse skin atrophy by a CD44-dependent mechanism.

Hyaluronate fragments reverse skin atrophy by a CD44-dependent mechanism.

Background: Skin atrophy is a common manifestation of aging and is frequently accompanied by ulceration and delayed wound healing. With an increasingly aging patient population, management of skin atrophy is becoming a major challenge in the clinic, particularly in light of the fact that there are no effective therapeutic options at present.

Methods And Findings: Atrophic skin displays a decreased hyaluronate (HA) content and expression of the major cell-surface hyaluronate receptor, CD44.

Spectral properties of topical retinoids prevent DNA damage and apoptosis after acute UV-B exposure in hairless mice.

We showed in a recent study that topical retinyl palmitate prevented UV-B-induced DNA damage and erythema in humans. Given that retinyl palmitate is a precursor of retinoic acid, the biological form of vitamin A that acts through nuclear receptors, we wondered whether these protective effects toward UV-B exposure were either receptor dependent or linked to other properties of the retinoid molecule such as its spectral properties. We determined the epidermal retinoid profile induced by topical retinoic acid in hairless mice and analyzed its effect on markers of DNA photodamage (thymine dimers) and apoptosis following acute UV-B exposure; we compared these effects to those induced by other natural topical retinoids (retinaldehyde, retinol and retinyl palmitate) which do not directly activate the retinoid receptors.

Pharmacology of RALGA, a mixture of retinaldehyde and glycolic acid.

Background: Retinoids and alpha-hydroxy acids (AHAs) are major compounds in topical therapy. They exert distinct but potentially complementary activities. However, their association is limited by their respective irritating potential.

Vitamin A exerts a photoprotective action in skin by absorbing ultraviolet B radiation.

Retinyl esters, a storage form of vitamin A, concentrate in the epidermis, and absorb ultraviolet radiation with a maximum at 325 nm. We wondered whether these absorbing properties of retinyl esters might have a biologically relevant filter activity. We first used an in vitro model to assess the photoprotective properties of retinyl palmitate.

Engineering herbicide metabolism in tobacco and Arabidopsis with CYP76B1, a cytochrome P450 enzyme from Jerusalem artichoke.

The Jerusalem artichoke (Helianthus tuberosus) xenobiotic inducible cytochrome P450, CYP76B1, catalyzes rapid oxidative dealkylation of various phenylurea herbicides to yield nonphytotoxic metabolites. We have found that increased herbicide metabolism and tolerance can be achieved by ectopic constitutive expression of CYP76B1 in tobacco (Nicotiana tabacum) and Arabidopsis. Transformation with CYP76B1 conferred on tobacco and Arabidopsis a 20-fold increase in tolerance to linuron, a compound detoxified by a single dealkylation, and a 10-fold increase in tolerance to isoproturon or chlortoluron, which need successive catalytic steps for detoxification.

Oxidative stress-independent depletion of epidermal vitamin A by UVA.

In hairless mice, epidermal vitamin A (retinol and retinyl esters) is strongly decreased following a single exposure to UVB. Here, using the same mouse model, we studied the effects of UVA on epidermal vitamin A content, lipid peroxidation, and CRBP-I expression, as well as the putative prevention of vitamin A depletion or lipid peroxidation by topical alpha-tocopherol. An acute exposure to UVA completely depleted epidermal vitamin A with EC50 of 0.

A new model using liposomes that allow to distinguish between absorption and oxidative properties of sunscreens.

We have developed a new model using liposome-encapsulated fluorescent probes, aiming at assessing both the physical and the biological protection provided by filter molecules such as those incorporated in sunscreens. The fluorescent indicator Indo-1 or 2',7'-dichlorofluorescin (DCFH) was inside the liposomes, in the aqueous inner compartment, whereas the filter molecules octyl methoxycinnamate (OMC), benzophenone-3 (BP3) or avobenzone, widely used in sunscreens, were incorporated into liposome membranes. When liposome suspensions were placed in a fluorometer cuvette exposed to an incident UV beam, the decrease of Indo-1 fluorescence as a function of filter concentration was related to the extinction coefficient of the filters.

Topical delivery of retinoids counteracts the UVB-induced epidermal vitamin A depletion in hairless mouse.

UVB irradiation depletes all-trans-retinol (ROL) and all-trans-retinyl esters (RE) from the hairless mouse epidermis. Prevention of this may be of relevance in counter-acting the long-term side effects of UVB exposure. We studied the effects of a topical treatment with natural retinoids before and after UVB exposure on three parameters involved in vitamin A metabolism: the amount of epidermal ROL and RE, the level of functional cellular retinol-binding protein I (CRBP-I), which is likely to protect ROL from UVB, as well as the cytosolic and microsomal enzyme activities which generate ROL and RE, i.

Flavonoid 6-hydroxylase from soybean (Glycine max L.), a novel plant P-450 monooxygenase.

Cytochrome P-450-dependent hydroxylases are typical enzymes for the modification of basic flavonoid skeletons. We show in this study that CYP71D9 cDNA, previously isolated from elicitor-induced soybean (Glycine max L.) cells, codes for a protein with a novel hydroxylase activity.

Cytochromes P450 for engineering herbicide tolerance.

In recent years, genome sequencing has revealed that cytochromes P450 (P450s) constitute the largest family of enzymatic proteins in higher plants. P450s are mono-oxygenases that insert one atom of oxygen into inert hydrophobic molecules to make them more reactive and hydrosoluble. Besides their physiological functions in the biosynthesis of hormones, lipids and secondary metabolites, P450s help plants to cope with harmful exogenous chemicals including pesticides and industrial pollutants, making them less phytotoxic.

Retinol and retinyl ester epidermal pools are not identically sensitive to UVB irradiation and anti-oxidant protective effect.

Background: UV irradiation can deplete epidermal vitamin A, thus the hypothesis that UV-induced depletion of vitamin A in sun-exposed skin is involved in the pathogenesis of skin cancers and skin ageing.

Objectives: In this study we addressed two questions: (1) Are retinol (ROL) and retinyl esters (RE) - the two predominant forms of vitamin A - equally sensitive to the action of UVB, and (2) could the depletion be prevented by anti-oxidants?

Methods: Hairless mice were irradiated with a single UVB dose, corresponding to the maximum of ROL and RE absorption. Retinoid content, enzyme activities catalysing the esterification of ROL (ARAT and LRAT) and the hydrolysis of RE (REH), as well as retinol-binding protein (CRBP-1) expression were determined in the epidermis.

Biological activities of topical retinaldehyde.

Background: We had hypothesised that retinaldehyde (RAL) should be an interesting precursor for topical use.

Aim: We review our observations about its biological activities.

Methods: We performed pilot studies to explore its biological effects and tolerability in human skin and compared the effects of topical RAL to that of all-trans-retinoic acid (RA) in the mouse tail test.

Metabolism of topical retinaldehyde.

Objective: In order to circumvent the tolerance problems encountered with topical application of retinoic acid - a biologically active metabolite of vitamin A - we performed in various models a series of experiments aimed at assessing the bio-availability of topical retinaldehyde and its conversion into either retinoid stores or biologically active metabolites.

Methods: (i) (3)H-retinaldehyde was used as a precursor of either (3)H-retinol or (3)H-retinoic acid in human skin extracts and human cultured keratinocytes; (ii) the concentration of various retinoids resulting from the metabolism of topical retinaldehyde was determined in mouse skin and in human plasma. Retinoids were quantified by reverse-phase HPLC with UV detection.

Topical 9-cis-retinaldehyde for delivery of 9-cis-retinoic acid in mouse skin.

The 9-cis-retinoic acid (9cRA) is an endogenous ligand of retinoid X nuclear receptors (RXRs). Although the epidermis contains five times more RXRs than RARs, little is known on the activity of topical 9cRA. In order to circumvent surface isomerization of topically applied 9cRA into all-trans-retinoic acid (atRA), we used topical 9-cis-retinaldehyde (9cRAL) as a precursor of 9cRA, hypothesizing that keratinocytes would metabolize 9cRAL into 9-cis-retinoic acid (9cRA).

Childhood bullous pemphigoid associated with IgA antibodies against BP180 or BP230 antigens.

Linear IgA bullous dermatosis (LABD) comprises a heterogeneous group of subepidermal blistering disorders characterized by in situ bound IgA antibodies in epidermal basement membrane. We report three children presenting clinical and immunopathological features characteristic of LABD. By immunoblotting, the three patients' sera contained IgA antibodies that reacted against the bullous pemphigoid (BP) antigen 180 and or BP230, molecular markers for BP.

Childhood bullous pemphigoid: report of a case with characterization of the targeted antigens.

The clinical and immunopathologic features of children with acquired subepidermal blistering disorders show considerable overlap, and their classification frequently requires characterization of the targeted antigens. A 8-month-old boy developed a generalized subepidermal blistering disorder with striking palmoplantar involvement. The patient's serum contained antibodies reacting against the epidermal side of 1 M sodium chloride separated normal human skin.

The chemically inducible plant cytochrome P450 CYP76B1 actively metabolizes phenylureas and other xenobiotics.

Cytochrome P450s (P450s) constitute one of the major classes of enzymes that are responsible for detoxification of exogenous molecules both in animals and plants. On the basis of its inducibility by exogenous chemicals, we recently isolated a new plant P450, CYP76B1, from Jerusalem artichoke (Helianthus tuberosus) and showed that it was capable of dealkylating a model xenobiotic compound, 7-ethoxycoumarin. In the present paper we show that CYP76B1 is more strongly induced by foreign compounds than other P450s isolated from the same plant, and metabolizes with high efficiency a wide range of xenobiotics, including alkoxycoumarins, alkoxyresorufins, and several herbicides of the class of phenylureas.

[Epidermolysis bullosa acquisita and metastatic cancer of the uterine cervix].

Introduction: Epidermolysis bullosa acquisita may be associated to a systemic or malignant disease. Here, we report a case of epidermolysis bullosa acquisita associated with a carcinoma of the cervix.

Case Report: A 44-year-old woman presented inflammatory, bullous and erosive mucocutaneous lesions.

Topical retinaldehyde increases skin content of retinoic acid and exerts biologic activity in mouse skin.

Retinaldehyde, a natural metabolite of beta-carotene and retinol, has been proposed recently for topical use in humans. Because retinaldehyde does not bind to retinoid nuclear receptors, its biologic activity should result from enzymatic transformation by epidermal keratinocytes into ligands for these receptors, such as all-trans retinoic acid and 9-cis-retinoic acid. In this study, we analyzed by high performance liquid chromatography the type and amounts of tissue retinoids as well as several biologic activities resulting from topical application of either retinaldehyde or all-trans retinoic acid on mouse tail skin.

Metabolism of topical retinaldehyde and retinol by mouse skin in vivo: predominant formation of retinyl esters and identification of 14-hydroxy-4, 14-retro-retinol.

We have previously shown that retinaldehyde (RAL), a natural metabolite of beta-carotene and retinol (ROL), can be used topically in human skin and exerts biological activity; it may be a convenient way to deliver multipotential vitamin A activity in epidermis. RAL can be converted enzymatically into 2 pathways: one leads to ROL (and then retinyl esters), the other to retinoic acid (RA). The aim of the present study was 2-fold: (i) to see if RAL is metabolised in vivo when topically applied on mouse skin, and (ii) if so, to analyse the occurrence and relative importance of the 2 metabolic pathways as compared to ROL.

Heavy-metal-responsive genes in maize: identification and comparison of their expression upon various forms of abiotic stress.

To identify genes involved in defense against heavy-metal stresses, a cDNA library originating from mercuric chloride-treated maize (Zea mays L. cv. INRA 258) leaves was constructed and analysed by differential screening using cDNAs derived from treated and untreated plants.

[Intra-epidermal pustulosis in a child. Demonstration of a target antigen similar to foliaceus pemphigus antigen].

Introduction: Intraepidermal IgA pustulosis is a vesiculopustular dermatosis defined by pemphigus type intercellular deposit exclusively of IgA. It is a member of the pemphigus group and may be related to neurtrophilic dermatoses.

Case Report: A child had vesiculopustular lesions of the limbs since the age of 11 years.