Monthly Archives: October 2014

[Chromium 6 in the news: striking example of occupational care recommendations from the SER].

Posted on October 22, 2014 by Jungbauer F

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[Chromium 6 in the news: striking example of occupational care recommendations from the SER].
Ned Tijdschr Geneeskd. 2014;158(0):A8270
Authors: Jungbauer F
Abstract
Over the summer occ… Continue reading →






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Smaller desmosomes are seen in the skin of pemphigus patients with anti-desmoglein 1 antibodies but not in patients with anti-desmoglein 3 antibodies.

Posted on October 2, 2014 by van der Wier G, Pas HH, Kramer D, Diercks GF, Jonkman MF

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Smaller desmosomes are seen in the skin of pemphigus patients with anti-desmoglein 1 antibodies but not in patients with anti-desmoglein 3 antibodies.
J Invest Dermatol. 2014 Aug;134(8):2287-90
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Mechanisms of natural gene therapy in dystrophic epidermolysis bullosa.

Posted on October 2, 2014 by Kiritsi D, Garcia M, Brander R, Has C, Meijer R, Jose Escámez M, Kohlhase J, van den Akker PC, Scheffer H, Jonkman MF, Del Rio M, Bruckner-Tuderman L, Pasmooij AM


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Mechanisms of natural gene therapy in dystrophic epidermolysis bullosa.

J Invest Dermatol. 2014 Aug;134(8):2097-104

Authors: Kiritsi D, Garcia M, Brander R, Has C, Meijer R, Jose Escámez M, Kohlhase J, van den Akker PC, Scheffer H, Jonkman MF, del Rio M, Bruckner-Tuderman L, Pasmooij AM

Abstract
Revertant mosaicism has been reported in several inherited diseases, including the genetic skin fragility disorder epidermolysis bullosa (EB). Here, we describe the largest cohort of seven patients with revertant mosaicism and dystrophic EB (DEB), associated with mutations in the COL7A1 gene, and determine the underlying molecular mechanisms. We show that revertant mosaicism occurs both in autosomal dominantly and recessively inherited DEB. We found that null mutations resulting in complete loss of collagen VII and severe disease, as well as missense or splice-site mutations associated with some preserved collagen VII function and a milder phenotype, were corrected by revertant mosaicism. The mutation, subtype, and severity of the disease are thus not decisive for the presence of revertant mosaicism. Although collagen VII is synthesized and secreted by both keratinocytes and fibroblasts, evidence for reversion was only found in keratinocytes. The reversion mechanisms included back mutations/mitotic recombinations in 70% of the cases and second-site mutations affecting splicing in 30%. We conclude that revertant mosaicism is more common than previously assumed in patients with DEB, and our findings will have implications for future therapeutic strategies using the patient’s naturally corrected cells as a source for cell-based therapies.

PMID: 24577406 [PubMed – indexed for MEDLINE]

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Host-pathogen interactions in epidermolysis bullosa patients colonized with Staphylococcus aureus.

Posted on October 2, 2014 by van der Kooi-Pol MM, Duipmans JC, Jonkman MF, van Dijl JM


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Host-pathogen interactions in epidermolysis bullosa patients colonized with Staphylococcus aureus.

Int J Med Microbiol. 2014 Mar;304(2):195-203

Authors: van der Kooi-Pol MM, Duipmans JC, Jonkman MF, van Dijl JM

Abstract
Patients with the genetic blistering disease epidermolysis bullosa (EB) often have chronic wounds that can become colonized by different bacteria, especially the opportunistic pathogen Staphylococcus aureus. We therefore determined the S. aureus colonization rates in EB patients from the Netherlands by collecting swabs from their anterior nares, throats and wounds. Within a period of ∼2 years, more than 90% of the sampled chronic wounds of EB patients were found to be colonized by S. aureus. Molecular typing revealed that EB patients were not colonized by a single S. aureus type. Rather the S. aureus population structure in the sampled EB patients mirrored the local S. aureus population structure within the Netherlands. Furthermore, multiple types of S. aureus were found in close proximity to each other within individual chronic wounds, indicating that these S. aureus types are not mutually exclusive. Over time, strong fluctuations in the S. aureus types sampled from individual EB patients were observed. This high exposure to different S. aureus types is apparently reflected by high plasma levels of antistaphylococcal IgG’s, especially in patients carrying multiple S. aureus types. It remains to be determined to what extent this strong immune response protects EB patients against serious staphylococcal infections. Lastly, further research is needed to define the impact of staphylococcal colonization of chronic wounds on the development, exacerbation and healing of such wounds in patients with EB.

PMID: 24444717 [PubMed – indexed for MEDLINE]

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Pigmentation and melanocyte supply to the epidermis depend on type XVII collagen.

Posted on October 2, 2014 by Gosty?ski A, Pasmooij AM, Del Rio M, Diercks GF, Pas HH, Jonkman MF


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Pigmentation and melanocyte supply to the epidermis depend on type XVII collagen.

Exp Dermatol. 2014 Feb;23(2):130-2

Authors: Gostyński A, Pasmooij AM, Del Rio M, Diercks GF, Pas HH, Jonkman MF

Abstract
Genetic deficiency of type XVII collagen (C17), laminin-332 or type VII collagen causes epidermolysis bullosa (EB). Spontaneous correction of the deficiency, also known as revertant mosaicism, is caused by a second somatic mutation that restores protein expression resulting in clinically healthy (revertant) patches surrounded by fragile (mutant) skin. Interestingly, in some patients, patches of revertant skin show hyperpigmentation. To study the possible role of affected proteins in pigmentation and melanocyte distribution, we investigated clinical documentation and skin biopsy specimens of 13 revertant EB patients having correcting mutations in the COL17A1, LAMB3 or COL7A1 genes. Analysis revealed that lack of C17 led to decreased melanin intensity and melanocyte density in the epidermis when compared with the revertant patches. Reversions of LAMB3 and COL7A1 in keratinocytes did not influence clinical pigmentation or density of melanocytes. We conclude that in human skin, melanocyte supply to the epidermis depends on C17 expression in keratinocytes.

PMID: 24330315 [PubMed – indexed for MEDLINE]

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