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Biomedical subjects

L Didierjean

Publications and source records attributed to L Didierjean.

At least 37 records · Page 2Linked to original sources
PubMed1994

Topical retinaldehyde on human skin: biologic effects and tolerance.

The present study was designed to explore if *etinaldehyde, a natural metabolite of vitamin A, has any biologic activity and is tolerated by human skin. Biologic activity was shown by the induction of cellular retinoic acid-binding protein type 2 (CRABP 2) mRNA and protein; the rank order for CRABP-2 increase was retinoic acid > retinaldehyde > 9 cis retinoic acid > retinol > beta carotene. In volunteers treated 1-3 months with 0.5, 0.1, and 0.05% retinaldehyde, there was a dose-dependent and significant increase in epidermal thickness, keratin 14 immunoreactivity, and Ki67-positive cells. The area of distribution of involucrin, transglutaminase, and filaggrin immunoreactivity was also increased in a dose-dependent manner, and keratin 4 immunoreactivity was induced in the upper epidermis. In pilot clinical tolerance studies, 229 patients received topical retinaldehyde at different concentrations; the 1% preparation was tolerated by up to 70% of the treated subjects; tolerance of the 0.5% preparation was slightly better, whereas both 0.1 and 0.05% preparations applied on facial skin were well tolerated and allowed prolonged use (up to 3 years) in patients with inflammatory dermatoses. These findings indicate that topical retinaldehyde has biologic activity and is well tolerated on human skin.

Administration, Topical↗
PubMed1994

Topical glucocorticosteroids modulate the expression of CRABP I and II in human skin differently.

Epidermal cells express two retinotic acid-binding proteins (CRABP I and II). Because CRABP II protein is strongly induced by topical retinoic acid, the respective roles of the two proteins in the pharmacological activity and toxicity of topical retinoids deserve particular attention. Since topical steroids diminish the irritation induced by retinoic acid (RA), whereas retinoic acid may counteract the atrophogenic effects of steroids, the possible interplay of both compounds in the expression of CRABP I and II appeared worth studying. We have analyzed the effects of topical application of triamcinolone acetonide (TA) on the retinoic acid-induced altered expression of CRABP I and II in normal human skin, at the protein and mRNA levels. We found that CRABP II protein and mRNA were strongly increased upon retinoic acid application: this induction was significantly inhibited by concomitant application of triamcinolone acetonide; a more potent steroid, difluocortolone valerate, was also found to diminish normal endogenous expression of CRABP II. In contrast, CRABP I protein was decreased by topical retinoic acid, and the down modulating effect of retinoic acid was counteracted by triamcinolone acetonide.

Administration, Topical↗
PubMed1994

A thymoma as a cause of true ectopic hyperparathyroidism.

Ectopic tumoral secretion of authentic PTH is rare, as only four cases have been convincingly documented by demonstrating the presence of PTH messenger ribonucleic acid in tumor tissue. We report the case of a 25-yr-old male with biochemical alterations typical of primary hyperparathyroidism (elevated calcemia and renal tubular reabsorption of calcium, decreased phosphatemia and maximal tubular reabsorption of phosphate, and increased intact PTH serum levels). Extensive cervical exploration did not reveal any abnormally enlarged parathyroid tissue, but excision of a palpable superior retrosternal mass led to the correction of all abnormal biochemical values. Histological analysis showed a predominantly epithelial thymoma, without any detectable parathyroid gland on serial slices. Tumor extracts contained immunoreactive PTH material, with serial dilutions paralleling PTH standards in an immunoradiometric assay. By contrast, immunoreactive PTH-related protein was absent. Furthermore, on Northern blot analysis, there was a PTH messenger ribonucleic acid transcript with a size similar to that found in parathyroid adenoma or hyperplasia. The thymoma epithelial cells stained positively with antiserum against PTH-(1-34), but negatively with antichromogranin-A antiserum. These results support the ectopic production of authentic PTH by a thymoma and indicate a novel tumoral cause of primary hyperparathyroidism.

Adult↗
PubMed1993

Differential expression of bean chitinase genes by virus infection, chemical treatment and UV irradiation.

Three chitinases have been shown previously to be induced upon various stresses of bean leaves. Time course studies of mRNA accumulation of two of them (P3- and P4-chitinases) have been studied upon virus infection, mercuric chloride treatment and UV irradiation. In alfalfa mosaic virus (AlMV)-infected plants both mRNAs, absent in uninfected bean leaves, become detectable 36 h after inoculation. A maximum level of mRNAs is reached 84 h after inoculation and, whereas the amount of P3-ch mRNA decreases soon after having reached the maximum, the amount of P4-ch mRNA remains at high levels for several days. In mercuric chloride-treated leaves P4-ch mRNA becomes detectable 1-1.5 h after onset of treatment and a maximum level is observed between 6 h and 24 h after treatment; P3-ch mRNA becomes detectable later than P4-ch mRNA in treated leaves and reaches a maximum as late as 18 h after treatment has been applied. UV light also induces the synthesis of both mRNAs but, here again, important differences are observed in the accumulation rate of the two transcripts. The relative amounts of each mRNA induced by the different stresses have been compared. The most effective inducer of P3-ch mRNA is AlMV. In contrast, mercuric chloride induces P4-ch mRNA more efficiently than AlMV or UV light. We have also determined the complete nucleotide sequence of the cDNA encoding P3-chitinase that has been isolated from a cDNA library by using the cucumber lysozyme-chitinase cDNA as a probe. The 1072 bp P3-ch cDNA encodes a mature protein of 268 amino acid residues and the 25 residue NH2-terminal signal peptide of the precursor. Because of its high structural homology to the cucumber and Arabidopsis acidic chitinases as well as to the N-terminal amino acid sequence of the bifunctional lysozyme-chitinase from P. quinquifolia, bean P3-chitinase can be considered to belong to the class III chitinases. Southern blot analysis of bean genomic DNA revealed that P3-chitinase is encoded by a single gene.

Amino Acid Sequence↗
PubMed1992

The major cicatricial pemphigoid antigen is a 180-kD protein that shows immunologic cross-reactivities with the bullous pemphigoid antigen.

Recent studies have shown that sera from patients with cicatricial pemphigoid (CP) contained autoantibodies against epidermal antigens of molecular weight 230 kD and/or 180 kD by immunoblotting, similar to those recognized by bullous pemphigoid (BP) sera. Previous immunoprecipitation studies have shown that BP sera only precipitated the 230-kD antigen. To characterize the CP antigen(s) we tested 10 CP sera, 10 BP sera, and four controls by both immunoprecipitation of radiolabeled cells and immunoblotting of epidermal extracts. For immunoprecipitation, we used 0.5% NP-40 extracts of both normal human keratinocytes and Pam cells. All CP sera precipitated a 180-kD protein that co-migrated with the BP180 antigen precipitated by some individual BP sera. Two of these CP sera also faintly bound a 230-kD protein of similar molecular weight as the major BP230 antigen. CP and BP sera with an immunoblotting pattern of 180 kD immunoprecipitated a co-migrating 180-kD protein. CP sera reacting by immunoblotting with the 230-kD antigen precipitated the 180-kD and/or the 230-kD antigen. In contrast, BP sera reacting with the 230-kD antigen only precipitated this antigen. In further experiments, labeled 0.5% NP-40 extracts from Pam cells were first preabsorbed with a reference BP serum and then immunoprecipitated with CP sera. Under these conditions, CP sera that immunoprecipitated both 180-kD and 230-kD proteins with the standard procedure no longer precipitated these proteins. Our results suggest that a 180-kD protein is the major CP target-antigen that demonstrated immunologic cross-reactivities with the BP180 and the BP230 antigens.

Antigens↗
PubMed1992

A prospective immunofluorescence study of 111 cases of pruritic dermatoses of pregnancy: IgM anti-basement membrane zone antibodies as a novel finding.

Since 1981, all pregnant women presenting to our department with a pruritic dermatosis have been investigated by histological and immunopathological techniques. We recruited 111 patients and performed skin histology in 77, 109 direct immunofluorescence tests (DIF), 74 indirect immunofluorescence tests (IIF) and 15 Western blots (WB). We identified: (i) five typical cases of pemphigoid gestationis (PG) (4.5%), corresponding to an incidence of 1/7000 pregnancies. (ii) Five cases without PG but showing circulating anti-BMZ antibodies of IgM type. With the exception of one case, clinical features were homogeneous--occurrence of erythematous papular and/or urticarial lesions on the trunk, and less often, on the limbs between the 32nd and 38th week of pregnancy. Rapid clearance of lesions within a few days was the rule. Whenever performed, DIF was negative and IIF showed circulating anti-BMZ antibodies of IgM type. Western blot studies were negative in these five cases. (iii) One hundred and one cases with negative immunofluorescence tests, considered to be suffering from polymorphic eruption of pregnancy. Our results show the value of systematic immunopathological investigations in pregnant women presenting with a pruritic dermatosis, and raise the possibility of a new entity, as defined by circulating anti-BMZ antibodies of IgM type.

Adult↗
PubMed1992

Overexpression of cellular retinoic acid-binding protein type II (CRABP-II) and down-regulation of CRABP-I in psoriatic skin.

Cellular retinoic acid-binding proteins (CRABPs) might exert a physiological function by controlling the intracellular levels of free retinoic acid. The aim of this study was to analyze the relative expression of CRABP-I and CRABP-II in lesional (LPS) and nonlesional (NLPS) psoriatic skin. CRABP-I and -II proteins were analyzed by a PAGE-autoradioblotting technique, and their respective mRNA were studied by RNA blot and in situ hybridization. We found that CRABP-II levels were 6-fold higher in LPS and 2-fold in NLPS as compared to normal skin, whereas CRABP-I levels were decreased in NLPS and LPS. CRABP-II mRNA were grossly overexpressed in all LPS and some NLPS specimens. These results indicate a switch to the overexpression of CRABP-II mRNA in psoriasis which induces high levels of the protein mainly in LPS; these observations may be relevant to the pathophysiology and therapy of psoriasis as CRABP-I and -II have different ligand-binding affinities.

Carrier Proteins↗
PubMed1992

Frequency of bullous pemphigoid-like antibodies as detected by western immunoblot analysis in pruritic dermatoses.

BACKGROUND AND DESIGN: Ninety-seven patients suffering from a pruritic dermatosis were screened for the detection of bullous pemphigoid (BP) antibodies (ab) using the Western immunoblot (WB) analysis technique. RESULTS: Twenty-four patients (25%) reacted at least twice with the BP antigen on WB analysis at a 1/10 dilution: seven had typical BP, four had papular BP, 10 had pruritus and prurigo of unknown origin, two had eczema, and one had lichen planus. This corresponds to 13% of BP-type ab in patients who did not fulfill criteria for BP. Therefore, we did the following: (1) tested a control group of 24 subjects; (2) assessed the reproducibility of the WB method by retesting the same serum samples on different epidermal extracts; and (3) estimated the BP ab titer. None of the 24 control subjects had detectable BP ab, and reproducible results were obtained in all groups when serum samples were retested at the 1/10 dilution. Although 86% (6/7) of patients with BP had BP ab titers of 1/100 or greater, only 60% (6/10) of the group with pruritus and prurigo and 33% (1/3) of the group with eczema reached such titers. CONCLUSION: These results indicate that due to its sensitivity, the WB method can detect low titers of BP ab in patients with pruritic dermatoses who did not fulfill criteria for BP, and therefore we question the specificity of this method.

Adult↗
PubMed1991

Cellular retinoic acid-binding protein type 2 mRNA is overexpressed in human psoriatic skin as shown by in situ hybridization.

In situ hybridization with full length mouse cellular retinoic acid-binding protein type 1 and cellular retinoic acid-binding protein type 2 cDNA derived RNA probes showed overexpression of cellular retinoic acid-binding protein type 2 mRNA in lesional hyperplastic psoriatic skin whereas cellular retinoic acid-binding protein type 1 mRNA was undetectable. This suggests that the previously reported increase of cellular retinoic acid-binding protein in psoriatic epidermis corresponds to increased translation of cellular retinoic acid-binding protein type 2 gene. Cellular retinoic acid-binding protein types 1 and 2 mRNAs were not detectable in normal epidermis; however, type 2 message was detected in non-hyperplastic, non-lesional skin of psoriatic patients thus before altered epidermal differentiation and hyperplasia are morphologically detectable.

Antisense Elements (Genetics)↗
PubMed1991

Anti-interleukin-1 alpha autoantibodies in humans: characterization, isotype distribution, and receptor-binding inhibition--higher frequency in Schnitzler's syndrome (urticaria and macroglobulinemia).

Since autoantibodies (Abs) to cytokines may modify their biologic activities, high-affinity binding factors for interleukin-1 alpha (IL-1 alpha BF) were characterized in human sera. IL-1 alpha BF was identified as IgG (1) by sucrose density-gradient centrifugation followed by immunodiffusion autoradiography, (2) by ligand-blotting method, (3) by ligand binding to affinity-immobilized serum IgG, and (4) by IgG affinity purification followed by sucrose density-gradient centrifugation. IL-1 alpha binding activity resided in the F(ab)2 fragment. The apparent equilibrium constant was in the range of IgG found after immunization with conventional antigens (i.e., 10(-9) to 10(-10) mol/L). Anti-IL-1 alpha IgG auto-Abs represented only an extremely small fraction of total IgG (less than 1/10(-5)). Some sera with IL-1 alpha BF and purified IgG thereof were able to inhibit by 96% to 98% the binding of human recombinant IL-1 alpha to its receptor on murine thymoma EL4-6.1 cells, whereas other sera did not. When 125I-labeled anti-IL-1 alpha IgG complexes were injected into rats, they prolonged the plasma half-life of 125I-labeled IL-1 alpha several fold and altered its tissue distribution. The predominant class was IgG (12/19), mainly IgG4 (9/19), but in five of the sera, anti-IL-1 alpha IgA was also detected. In a screening of 271 sera, IL-1 alpha BF was detected in 17/98 normal subjects and was not more frequent in several control groups of patients, except in patients with Schnitzler's syndrome (fever, chronic urticaria, bone pain, and monoclonal IgM paraprotein) (6/9; p less than 0.005). The pathologic significance of these auto-Abs remains to be determined.

Aged↗
PubMed1991

Bullous pemphigoid autoantibodies, HIV-1 infection and pruritic papular eruption.

Bullous pemphigoid (BP)-type autoantibodies were found by Western blot (WB) analysis of epidermal extracts in the serum of 38% of HIV-seropositive patients compared with 21% of HIV-seronegative patients with chronic pruritus and 76% of patients with BP. They were further identified as BP autoantibodies (BPab) by immunoprecipitation and immunoelectron microscopy. Their incidence increased from 21% in HIV infection stage II to 37% and 43% in stages III and IV, respectively. Of the patients suffering from HIV-related chronic pruritic papulovesicular eruption. 75% showed circulating BPab as compared with 29% in those without skin problems (P = 0.0066) and, among them, 30% met the diagnostic criteria for BP when histology, WB, immunofluorescence and immunoelectron microscopy techniques were used. In conclusion, this study identifies an autoimmune skin reaction that may account for, or be related to, the distressing pruritic eruptions occurring in HIV-infected patients.

Adult↗
PubMed1990

Biologically active interleukin 1 in human eccrine sweat: site-dependent variations in alpha/beta ratios and stress-induced increased excretion.

Human eccrine sweat devoid of epidermal protein contamination was collected from palms, soles, and different sites on the trunk. Interleukin 1 alpha (IL 1 alpha) and interleukin 1 beta (IL 1 beta) content were analyzed for immunoreactivity by enzymo-immunoassay and immunoblotting and for bioactivity by the stimulation of prostaglandin E2 (PGE2) production in human dermal fibroblasts. The bioassay was validated by using blocking antibodies against IL 1 alpha and beta. All sweat samples were found to contain significant amounts of immunoreactive and biologically active IL 1. The immunoreactive forms were at 17 kDa as shown by immunoblotting analysis, indicating that they were mature (secreted), undegraded IL 1 peptides. Whereas IL 1 alpha was detectable in sweat samples obtained from both truncal and palmo-plantar regions, IL 1 beta was only detectable in the sweat of palms and soles (IL 1 alpha/beta ratio greater than 700 in trunk and 5.4 in palms and soles) indicating a site-dependent difference in the excretion of the two IL 1 molecules. IL 1 concentration was high in spontaneous (IL 1 alpha, 3.7; IL 1 beta, 0.3 ng/mL) and pilocarpine induced sweat (IL 1 alpha, 3.9; IL 1 beta, 1.2 ng/mL), and it was much increased during jogging and sauna (IL 1 alpha, 22.6; IL 1 beta, 3.3 ng/mL). This does not appear to represent an excretory process aimed at clearing blood IL 1, but rather a stress-induced increased production of IL 1 by sweat gland cells.

Adult↗
PubMed1990

Membrane and cytosolic interleukin-1 alpha and beta in normal human epidermal cells: variability of epitope exposure in immunohistochemistry.

Previous studies have shown that interleukin-1 (IL-1) is present in normal human epidermis. However, with immunohistochemical techniques, epidermal IL-1 immunoreactivity has been found in only a limited number of epidermal cells. In the present study, we show that both IL-1 alpha and beta immunoreactivities can be detected in all epidermal cell layers, provided optimal processing of tissue samples is used. The use of isolated epidermal cells showed that keratinocytes at various stages of maturation display both membrane-associated and cytosolic IL-1 alpha and beta immunoreactivities. After protease treatment of tissue sections, the IL-1 beta immunoreactivity of the granular cell layer was enhanced by some antibodies used, whereas in the other cell layers it was clearly lower. We a) suggest a different cellular localization, processing, and/or binding to subcellular structures of IL-1 during the differentiation process of human keratinocytes and b) outline the technical difficulties in any immunohistologic approach to IL-1 status in diseased skin.

Cell Membrane↗
PubMed1990

Effect of topical retinoic acid on the interleukin 1 alpha and beta immunoreactive pool in normal human epidermis.

The topical application of 0.1% retinoic acid (RA) on human skin over a period of 4 days, whether or not under occlusion, did not increase either IL-1 alpha or beta immunoreactivity as determined by a sensitive enzymoimmunoassay. No down modulation was seen following the application of a potent topical corticosteroid. Occlusion increased the yield of IL-1 beta immunoreactivity. Immunoblot patterns of epidermal extracts revealed both the mature form of IL-1 (17 kDa) and the precursor (36 kDa) and were identical in amounts whether the specimens were from controls or from RA- or corticosteroid-treated skin. There was a slight modification in the pattern of high molecular weight proteins (52 kDa) probed by the anti-IL-1 alpha and beta sera. It appears that the IL-1 epidermal immunoreactive pools are barely amenable to modulation because they represent a storage form linked to end-stages of keratinocyte differentiation.

Administration, Topical↗
PubMed1990

Immunohistochemical identification of interleukin I alpha and beta in human eccrine sweat-gland apparatus.

Bouin-fixed paraffin sections or acetone-fixed cryostat sections were labelled with the avidin-biotin complex (ABC) or peroxidase-antiperoxidase (PAP) method using three monoclonal antibodies (MAbs) and two polyclonal antisera to human recombinant interleukin I beta (IL-I beta) and three polyclonal antisera to human recombinant interleukin I alpha (IL-I alpha). In the secretory coil both IL-alpha and beta were detected in the clear, but not in the dark cells. Both luminal and basal cells of the coiled and straight ducts expressed IL-I alpha and beta, the IL-I labelling being more intense in the luminal cells. IL-I was not usually detected in the initial portion of the intraepidermal eccrine sweat duct, whereas intense labelling was seen in the upper part including through the stratum corneum. In skin biopsies of the palm, taken after exercise, there was only faint IL-I labelling of the secretory cells, whereas the luminal cells of the dermal ducts showed intense labelling for both IL-I alpha and beta. In the acrosyringium, exercise did not alter the pattern for IL-I alpha and beta, except that in the palm, some of the antibodies to IL-I beta produced a more intense immunolabelling of the acrosyringeal cells. This study identifies a distinct and similar distribution of the two forms of IL-I throughout the eccrine sweat-gland apparatus and indicates that part of the IL-I epidermal pool originates from the sweat.

Exercise↗