The dark side of p-Phenylenediamine:Biological aspects and prevalence of contact allergy to an extraordinary molecule

In hoofdstuk 2,3 en 4 wordt de prevalentie van p-phenylenediamine (PPD) contact allergieen beschreven. De prevalentie van PPD sensibilisaties in the algemene populatie is 1.3%, terwijl de prevalentie in de plakproefpopulatie van zowel Noord-Nederlands als Europa ongeveer 4% zijn. Een beroep als kapper, blootstelling aan zwarte henna tattoeages en haarverven met donkerdere tinten geven een hoger risico op sensibilisatie. Naast de verhoogde kans op sensibiliseerde te worden voor kruisreagerende stoffen, hebben PPD-gesensibiliseerde individuen een hogere kans om voor carbamix, cobalt chloride, colofonium, p-tertbutylformaldehyderesin en methylisithiazolinone te zijn. 2,5-toluenediamine (TDA) gesensibiliseerde individuen zijn vaker eveneens voor carbamix gesensibiliseerd. In hoofdstuk 5 onderzochten we het gedrag van mensen die, ondanks een haarverfallergie, hun haar blijven verven. Deze mensen schrijven hun gedrag toe aan een vermoedelijke lager cijfer voor hun leven als ze stoppen en factoren die buiten hun eigen invloedssfeer liggen (‘mooiere kleur’ p: 0.02, η2= 0.10 en ‘nodig voor het werk’ p= 0.02, η2= 0.10), maar niet aan een lager zelfvertrouwen of een negatief beeld ten opzichte van grijs haar.N-acetyltansferase 1 (NAT1) wordt aangekleurd in een granulair patroon in het stratum corneum en perinucelair in de levende epidermis (Hoofdstuk 6). Er werd geen colocalisatie met endosomen, lysosomen, het Golgi-apparaat of de mitichondrieën gevonden. In het stratum corneum is NAT1 gelegen tussen de corneocyten. In hoofdstuk 7 voorbehandeling van de huid met het antioxidant ascorbinezuur (vitamine C) zorgde voor een minder heftige elicitatiereactio op PPD in allergische personen op dag 3 na blootstelling (p=0,046).Het potentiele risico van zwarte henna tatoeages, die vaak hoge concentraties PPD bevatten, maar ook het risico van PPD-bevattende verf voor wimpers waren benadrukt in hoofdstuk 8.The Chapters 2, 3 and 4 deal with to the prevalence of p-phenylenediamine (PPD) contact allergy. The prevalence of PPD sensitizations in the general population is 1.3%, while the prevalence in the patch tested population in both northern Netherlands and Europe are persistent for many years around 4%. The occupation as a hairdresser, the exposure to a black henna tattoo and hair dyeing with darker shades are risk factors for sensitization. Apart from the higher chance of being sensitized to the cross-reacting chemicals, PPD sensitized individuals are also more often sensitized to carba-mix, cobalt chloride, colophony, p-tertbutylfenolformaldehyderesin, parabens mix and methylisothiazolinone as well. 2,5-toluenediamine (TDA) sensitized individuals were more often sensitized to carba-mix. The exploratory study performed in Chapter 5, revealed that allergic individuals continuing dyeing their hair, assign this behaviour to a decrease in the grade of their life and to factors that lie outside their own power to influence (‘nicer color’= p: 0.02, η2= 0.10 and ‘required for work’: p= 0.02, η2= 0.10), not to a decreased self-esteem or a negative image regarding grey hair. The enzyme N-acetyltransferase 1 (NAT1) stained in a granular pattern in the stratum corneum and perinuclear in the viable epidermis (Chapter 6). No co-localisation was found with either endosomes, lysosomes, Golgi apparatus or mitochondria. Whitin the stratum corneum, NAT1 was located in between the corneocytes.In Chapter 7 we showed that pretreatment of the skin with the antioxidant ascorbic acid had an attenuating effect on the elicitation reaction to PPD in sensitized individuals at D3 after exposure (p=0.046). The potential risk of black henna tattoos, often containing high concentrations of PPD, but also the risk of PPD-containing dye for eyelashes were emphasized in Chapter 8

Spanische Bezüge bei E. T. A. Hoffmann

Es soll der Versuch unternommen werden, die Nachricht von den neuesten Schicksalen des Hundes Berganza und das Coloquio de los perros, das 1613 als vorletzte der insgesamt zwölf Novelas ejemplares Cervantes’ erschien und Hoffmann in der deutschen Ausgabe von Dietrich Wilhelm Soltau vorlag, auf ihre Gemeinsamkeiten und Unterschiede zu vergleichen. Der direkte Vergleich mit dem Coloquio trägt einerseits dazu bei, die Anspielungen und Verweise zu verstehen, die Hoffmann fortlaufend in seine Erzählung einstreut, und andererseits zu einem besseren Verständnis der literarischen Schaffensweise des Autors. Darüber hinaus sollte aber nicht vergessen werden, daß es sich bei Hoffmanns Text um ein eigenständiges Werk handelt, das auch ohne die Lektüre Cervantes’ als das zu verstehen ist, was es ist: eine ironisch-satirische, witzig-humorvolle Erzählung mit einem Hund als Helden, der sein Umfeld parodiert und kritisch betrachtet und sich überdies äußerst verständig in Sachen der Kunst erweist. Schwerpunkt der Untersuchung bildet Hoffmanns Bearbeitung des "Kolloquiums", die neben ihrem inhaltlichen und sprachlichen Bezug auf die spanische Vorlage auch auf ihre literarischen Mittel hin untersucht werden soll

A novel mutation in the sterol 27-hydroxylase gene of a woman with autosomal recessive cerebrotendinous xanthomatosis

<p>Article abstract</p> <p>Mutations of the gene encoding the mitochondrial enzyme sterol 27-hydroxylase (<it>CYP27A1 </it>gene) cause defects in the cholesterol pathway to bile acids that lead to the storage of cholestanol and cholesterol in tendons, lenses and the central nervous system. This disorder is the cause of a clinical syndrome known as cerebrotendinous xanthomatosis (CTX). Since 1991 several mutations of the <it>CYP27A1 </it>gene have been reported. We diagnosed the clinical features of CTX in a caucasian woman. Serum levels of cholestanol and 7α-hydroxycholesterol were elevated and the concentration of 27-hydroxycholesterol was reduced. Bile alcohols in the urine and faeces were increased. The analysis of the <it>CYP27A1 </it>gene showed that the patient was a compound heterozygote carrying two mutations both located in exon 8. One mutation is a novel four nucleotide deletion (c.1330-1333delTTCC) that results in a frameshift and the occurrence of a premature stop codon leading to the formation of a truncated protein of 448 amino acids. The other mutation, previously reported, is a C - > T transition (c. c.1381C > T) that converts the glutamine codon at position 461 into a termination codon (p.Q461X). These truncated proteins are expected to have no biological function being devoid of the cysteine residue at position 476 of the normal enzyme that is crucial for heme binding and enzyme activity.</p

Determination of the noise parameters in a one-dimensional open quantum system

We consider an electron magnetically interacting with a spin-1/2 impurity, embedded in an external environment whose noisy term acts only on the impurity's spin, and we find expressions for the electron transmission and reflection probabilities in terms of the phenomenological noise parameters. Moreover, we give a simple example of the necessity of complete positivity for physical consistency, showing that a positive but not completely positive dissipative map can lead to negative transmission probabilities

Horizontal Gene Transfer Regulation in Bacteria as a “Spandrel” of DNA Repair Mechanisms

Horizontal gene transfer (HGT) is recognized as the major force for bacterial genome evolution. Yet, numerous questions remain about the transferred genes, their function, quantity and frequency. The extent to which genetic transformation by exogenous DNA has occurred over evolutionary time was initially addressed by an in silico approach using the complete genome sequence of the Ralstonia solanacearum GMI1000 strain. Methods based on phylogenetic reconstruction of prokaryote homologous genes families detected 151 genes (13.3%) of foreign origin in the R. solanacearum genome and tentatively identified their bacterial origin. These putative transfers were analyzed in comparison to experimental transformation tests involving 18 different genomic DNA positions in the genome as sites for homologous or homeologous recombination. Significant transformation frequency differences were observed among these positions tested regardless of the overall genomic divergence of the R. solanacearum strains tested as recipients. The genomic positions containing the putative exogenous DNA were not systematically transformed at the highest frequencies. The two genomic “hot spots”, which contain recA and mutS genes, exhibited transformation frequencies from 2 to more than 4 orders of magnitude higher than positions associated with other genes depending on the recipient strain. These results support the notion that the bacterial cell is equipped with active mechanisms to modulate acquisition of new DNA in different genomic positions. Bio-informatics study correlated recombination “hot-spots” to the presence of Chi-like signature sequences with which recombination might be preferentially initiated. The fundamental role of HGT is certainly not limited to the critical impact that the very rare foreign genes acquired mainly by chance can have on the bacterial adaptation potential. The frequency to which HGT with homologous and homeologous DNA happens in the environment might have led the bacteria to hijack DNA repair mechanisms in order to generate genetic diversity without losing too much genomic stability

Deep Sequencing Analysis of Small Noncoding RNA and mRNA Targets of the Global Post-Transcriptional Regulator, Hfq

Recent advances in high-throughput pyrosequencing (HTPS) technology now allow a thorough analysis of RNA bound to cellular proteins, and, therefore, of post-transcriptional regulons. We used HTPS to discover the Salmonella RNAs that are targeted by the common bacterial Sm-like protein, Hfq. Initial transcriptomic analysis revealed that Hfq controls the expression of almost a fifth of all Salmonella genes, including several horizontally acquired pathogenicity islands (SPI-1, -2, -4, -5), two sigma factor regulons, and the flagellar gene cascade. Subsequent HTPS analysis of 350,000 cDNAs, derived from RNA co-immunoprecipitation (coIP) with epitope-tagged Hfq or control coIP, identified 727 mRNAs that are Hfq-bound in vivo. The cDNA analysis discovered new, small noncoding RNAs (sRNAs) and more than doubled the number of sRNAs known to be expressed in Salmonella to 64; about half of these are associated with Hfq. Our analysis explained aspects of the pleiotropic effects of Hfq loss-of-function. Specifically, we found that the mRNAs of hilD (master regulator of the SPI-1 invasion genes) and flhDC (flagellar master regulator) were bound by Hfq. We predicted that defective SPI-1 secretion and flagellar phenotypes of the hfq mutant would be rescued by overexpression of HilD and FlhDC, and we proved this to be correct. The combination of epitope-tagging and HTPS of immunoprecipitated RNA detected the expression of many intergenic chromosomal regions of Salmonella. Our approach overcomes the limited availability of high-density microarrays that have impeded expression-based sRNA discovery in microorganisms. We present a generic strategy that is ideal for the systems-level analysis of the post-transcriptional regulons of RNA-binding proteins and for sRNA discovery in a wide range of bacteria

Selection and phenotypic characterization of a core collection of <i>Brachypodium distachyon</i> inbred lines

BACKGROUND: The model grass Brachypodium distachyon is increasingly used to study various aspects of grass biology. A large and genotypically diverse collection of B. distachyon germplasm has been assembled by the research community. The natural variation in this collection can serve as a powerful experimental tool for many areas of inquiry, including investigating biomass traits. RESULTS: We surveyed the phenotypic diversity in a large collection of inbred lines and then selected a core collection of lines for more detailed analysis with an emphasis on traits relevant to the use of grasses as biofuel and grain crops. Phenotypic characters examined included plant height, growth habit, stem density, flowering time, and seed weight. We also surveyed differences in cell wall composition using near infrared spectroscopy (NIR) and comprehensive microarray polymer profiling (CoMPP). In all cases, we observed extensive natural variation including a two-fold variation in stem density, four-fold variation in ferulic acid bound to hemicellulose, and 1.7-fold variation in seed mass. CONCLUSION: These characterizations can provide the criteria for selecting diverse lines for future investigations of the genetic basis of the observed phenotypic variation