Graphene: One Material, Many Possibilities—Application Difficulties in Biological Systems

Energetic technologies, nanoelectronics, biomedicine including gene therapy, cell imaging or tissue engineering are only few from all possible applications for graphene, the thinnest known carbon configuration and a basic element for other more complicated, better discovered and widely used nanostructures such as graphite, fullerenes and carbon nanotubes. The number of researches concerning graphene applications is rising every day which proves the great interest in its unique structure and properties. Ideal pristine graphene sheet presents a flat membrane of unlimited size with no imperfections while in practice we get different flakes with irregular edges and structural defects which influence the reactivity. Nanomaterials from graphene family differ in size, shape, layer number, lateral dimension, surface chemistry and defect density causing the existence of graphene samples with various influence on biological systems. Whether graphene induces cellular stress and activates apoptosis, or on the contrary facilitates growth and differentiation of the cells depends on its structure, chemical modifications and the growth process. A certain number of in vitro studies has indicated cytotoxic effects of graphene while the other show that it is safe. The diversity of the samples and methods of the production make it impossible to establish clearly the biological impact of graphene

Znaczenie dermoskopii w chorobie Grovera. Korelacja dermoskopowo-histologiczna

Abstact: Grover’s disease (transient acantholytic dermatosis) is characterized by the eruption of pruritic papules and papulovesicular lesions, mainly on the trunk and proximal extremities. The etiology of the disease remains unknown, however some drug-induced cases were reported. The diagnosis of Grover’s disease is based on histopathological examination which usually shows the presence of focal suprabasal acantholysis with dyskeratosis within the epidermis. There are four main histopathological patterns of this disease, including the Darier-like pattern, the Hailey-Hailey-like pattern, pemphigus-like pattern and eczema-like pattern. The main purpose of the study was to describe clinical, dermoscopic and histopathological features of skin lesions in three patients with three different patterns of Grover’s disease. The study was carried out on three patients with observable characteristic dermoscopic features of skin lesions who had been diagnosed with Grover’s disease based on the histopathological examination. In dermoscopy of the first one, yellow-brown polygonal structures with a white “halo” corresponding to focal acantholysis with dyskeratosis and hyperkeratosis were observed. Some areas with enlarged and dilated blood vessels were also seen, as well as regular oval white structures with yellow centres, which might correspond to empty hair follicles with abnormal keratosis in their ostia. In dermoscopy of the second patient, polygonal brown structures with scales corresponding to focal acantholysis with desquamation and dilated irregular blood vessels were observed. In dermoscopy of the third one, yellow-brown polygonal structures covered with scale and haemorrhagic crusts were observed. Dermoscopy is a useful diagnostic tool in patients suspected for Grover’s disease and gives characteristic dermoscopic features of yellow-brown polygonal structures corresponding to irregular acantholysis and disturb keratinization in histopathology. Streszczenie: Choroba Grovera (przemijająca dermatoza z akantolizą) charakteryzuje się obecnością rozsianych swędzących grudek lub zmian pęcherzykowo-grudkowych głównie na tułowiu i proksymalnych częściach kończyn. Etiologia choroby pozostaje nieznana, ale opisywano przypadki indukowane różnymi lekami. Rozpoznanie choroby Grovera opiera się na badaniu histopatologicznym, które wykazuje obecność ogniskowej nieregularnej akantolizy ponad warstwą podstawną naskórka z towarzysząca dyskeratozą lub zaburzonym rogowaceniem keratynocytów powyżej. Wyróżnia się cztery główne wzory histopatologiczne tej choroby: obraz podobny do choroby Dariera, do choroby Hailey-Hailey, do pęcherzycy i obraz wypryskopodobny. Celem badania było opisanie klinicznych, dermoskopowych i histopatologicznych cech zmian skórnych u trzech pacjentów z trzema różnymi odmianami choroby Grovera. Badanie dermoskopowe zmian skórnych przeprowadzono u trzech pacjentów z rozpoznaniem histologicznym choroby Grovera, w celu określenia najbardziej charakterystycznych cech dermoskopowych tej choroby. W badaniu dermoskopowym pierwszego pacjenta stwierdzono obecność żółto-brązowych wielokątnych struktur z białawą obwódką odpowiadających ogniskowej akantolizie z dyskeratozą i hiperkeratozą. Widoczne były również obszary z powiększonymi i poszerzonymi naczyniami krwionośnymi, a także regularne owalne białe struktury z żółtymi środkami, które mogły odpowiadać pustym mieszkom włosowym z nieprawidłowym rogowaceniem w ich lejkach. U drugiego pacjenta dermoskopowo stwierdzono obecność wielokątnych brązowych struktur pokrytych łuską odpowiadających ogniskowej akantolizie z nieprawidłowym rogowaceniem na powierzchni, oraz poszerzone nieregularnie naczynia krwionośne. U trzeciego pacjenta w dermoskopii stwierdzono żółto-brązowe wielokątne struktury pokryte łuską i krwotocznymi strupami. Dermoskopia jest użytecznym narzędziem diagnostycznym u pacjentów podejrzanych o chorobę Grovera i obrazuje charakterystyczne żółto-brązowe, wielokątne struktury odpowiadające nieregularnej akantolizie z nieprawidłowym rogowaceniem w badaniu histopatologicznym.Abstact: Grover’s disease (transient acantholytic dermatosis) is characterized by the eruption of pruritic papules and papulovesicular lesions, mainly on the trunk and proximal extremities. The etiology of the disease remains unknown, however some drug-induced cases were reported. The diagnosis of Grover’s disease is based on histopathological examination which usually shows the presence of focal suprabasal acantholysis with dyskeratosis within the epidermis. There are four main histopathological patterns of this disease, including the Darier-like pattern, the Hailey-Hailey-like pattern, pemphigus-like pattern and eczema-like pattern. The main purpose of the study was to describe clinical, dermoscopic and histopathological features of skin lesions in three patients with three different patterns of Grover’s disease. The study was carried out on three patients with observable characteristic dermoscopic features of skin lesions who had been diagnosed with Grover’s disease based on the histopathological examination. In dermoscopy of the first one, yellow-brown polygonal structures with a white “halo” corresponding to focal acantholysis with dyskeratosis and hyperkeratosis were observed. Some areas with enlarged and dilated blood vessels were also seen, as well as regular oval white structures with yellow centres, which might correspond to empty hair follicles with abnormal keratosis in their ostia. In dermoscopy of the second patient, polygonal brown structures with scales corresponding to focal acantholysis with desquamation and dilated irregular blood vessels were observed. In dermoscopy of the third one, yellow-brown polygonal structures covered with scale and haemorrhagic crusts were observed. Dermoscopy is a useful diagnostic tool in patients suspected for Grover’s disease and gives characteristic dermoscopic features of yellow-brown polygonal structures corresponding to irregular acantholysis and disturb keratinization in histopathology. Streszczenie: Choroba Grovera (przemijająca dermatoza z akantolizą) charakteryzuje się obecnością rozsianych swędzących grudek lub zmian pęcherzykowo-grudkowych głównie na tułowiu i proksymalnych częściach kończyn. Etiologia choroby pozostaje nieznana, ale opisywano przypadki indukowane różnymi lekami. Rozpoznanie choroby Grovera opiera się na badaniu histopatologicznym, które wykazuje obecność ogniskowej nieregularnej akantolizy ponad warstwą podstawną naskórka z towarzysząca dyskeratozą lub zaburzonym rogowaceniem keratynocytów powyżej. Wyróżnia się cztery główne wzory histopatologiczne tej choroby: obraz podobny do choroby Dariera, do choroby Hailey-Hailey, do pęcherzycy i obraz wypryskopodobny. Celem badania było opisanie klinicznych, dermoskopowych i histopatologicznych cech zmian skórnych u trzech pacjentów z trzema różnymi odmianami choroby Grovera. Badanie dermoskopowe zmian skórnych przeprowadzono u trzech pacjentów z rozpoznaniem histologicznym choroby Grovera, w celu określenia najbardziej charakterystycznych cech dermoskopowych tej choroby. W badaniu dermoskopowym pierwszego pacjenta stwierdzono obecność żółto-brązowych wielokątnych struktur z białawą obwódką odpowiadających ogniskowej akantolizie z dyskeratozą i hiperkeratozą. Widoczne były również obszary z powiększonymi i poszerzonymi naczyniami krwionośnymi, a także regularne owalne białe struktury z żółtymi środkami, które mogły odpowiadać pustym mieszkom włosowym z nieprawidłowym rogowaceniem w ich lejkach. U drugiego pacjenta dermoskopowo stwierdzono obecność wielokątnych brązowych struktur pokrytych łuską odpowiadających ogniskowej akantolizie z nieprawidłowym rogowaceniem na powierzchni, oraz poszerzone nieregularnie naczynia krwionośne. U trzeciego pacjenta w dermoskopii stwierdzono żółto-brązowe wielokątne struktury pokryte łuską i krwotocznymi strupami. Dermoskopia jest użytecznym narzędziem diagnostycznym u pacjentów podejrzanych o chorobę Grovera i obrazuje charakterystyczne żółto-brązowe, wielokątne struktury odpowiadające nieregularnej akantolizie z nieprawidłowym rogowaceniem w badaniu histopatologicznym

Molecular Inversion Probes for targeted resequencing in non-model organisms

Applications that require resequencing of hundreds or thousands of predefined genomic regions in numerous samples are common in studies of non-model organisms. However few approaches at the scale intermediate between multiplex PCR and sequence capture methods are available. Here we explored the utility of Molecular Inversion Probes (MIPs) for the medium-scale targeted resequencing in a non-model system. Markers targeting 112 bp of exonic sequence were designed from transcriptome of Lissotriton newts. We assessed performance of 248 MIP markers in a sample of 85 individuals. Among the 234 (94.4%) successfully amplified markers 80% had median coverage within one order of magnitude, indicating relatively uniform performance; coverage uniformity across individuals was also high. In the analysis of polymorphism and segregation within family, 77% of 248 tested MIPs were confirmed as single copy Mendelian markers. Genotyping concordance assessed using replicate samples exceeded 99%. MIP markers for targeted resequencing have a number of advantages: high specificity, high multiplexing level, low sample requirement, straightforward laboratory protocol, no need for preparation of genomic libraries and no ascertainment bias. We conclude that MIP markers provide an effective solution for resequencing targets of tens or hundreds of kb in any organism and in a large number of samples

Linkage map of Lissotriton newts provides insight into the genetic basis of reproductive isolation

Linkage maps are widely used to investigate structure, function, and evolution of genomes. In speciation research, maps facilitate the study of the genetic architecture of reproductive isolation by allowing identification of genomic regions underlying reduced fitness of hybrids. Here we present a linkage map for European newts of the Lissotriton vulgaris species complex, constructed using two families of F2 L. montandoni × L. vulgaris hybrids. The map consists of 1146 protein-coding genes on 12 linkage groups, equal to the haploid chromosome number, with a total length of 1484 cM (1.29 cM per marker). It is notably shorter than two other maps available for salamanders, but the differences in map length are consistent with cytogenetic estimates of the number of chiasmata per chromosomal arm. Thus, large salamander genomes do not necessarily translate into long linkage maps, as previously suggested. Consequently, salamanders are an excellent model to study evolutionary consequences of recombination rate variation in taxa with large genomes and a similar number of chromosomes. A complex pattern of transmission ratio distortion (TRD) was detected: TRD occurred mostly in one family, in one breeding season, and was clustered in two genomic segments. This is consistent with environment-dependent mortality of individuals carrying L. montandoni alleles in these two segments and suggests a role of TRD blocks in reproductive isolation. The reported linkage map will empower studies on the genomic architecture of divergence and interactions between the genomes of hybridizing newts

The influence of passivation type on corrosion resistance of Ti15Mo alloy in simulated body fluids

This work reports on determination of the influence of passivation type of Ti15wt.%Mo implant alloy surface on its corrosion resistance in simulated body fluids. The alloy under investigation was subjected to natural self-passivation in air, and forced passivation by autoclaving in steam, boiling in 30 % solution of H2O2, and electrochemical passivation in 0.9 % NaCl solution. Resistance of the passivated Ti15Mo alloy to pitting corrosion was studied at 37°C in 0.9 % NaCl solution using open circuit potential method, anodic polarization curves, and electrochemical impedance spectroscopy (EIS). Comparative estimation of the determined parameters of corrosion resistance revealed that the obtained passive layers improve anticorrosive properties of the tested alloy. Surface of the alloy subjected to passivation in steam autoclave reveals the highest protection against pitting corrosion. Anodic potentiodynamic curves showed that the Ti15Mo alloy after different passivation types of the surface is characterized by a lack of susceptibility to pitting corrosion up to potential of 9 V. Based on the EIS investigations, the thickness of the formed oxide layers (TiO2, anatase) was determined to be in the range from 2.0 to 7.8 nm in dependence on the applied type of passivation. It was ascertained that electrochemical properties of the Ti15Mo alloy and possibility of its surface passivation using simple methods, make it an attractive material for use in biomedicine for long-term implants