AtMYB41 acts as a dual-function transcription factor that regulates the formation of lipids in an organ- and development-dependent manner.

The plant cuticle controls non-stomatal water loss and can serve as a barrier against biotic agents, whereas the heteropolymer suberin and its associated waxes are deposited constitutively at specific cell wall locations. While several transcription factors controlling cuticle formation have been identified, those involved in the transcriptional regulation of suberin biosynthesis remain poorly characterized. The major goal of this study was to further analyse the function of the R2R3-Myeloblastosis (MYB) transcription factor AtMYB41 in formation of the cuticle, suberin, and suberin-associated waxes throughout plant development. For functional analysis, the organ-specific expression pattern of AtMYB41 was analysed and Atmyb41ge alleles were generated using the CRISPR/Cas9 system. These were investigated for root growth and water permeability upon stress. In addition, the fatty acid, wax, cutin, and suberin monomer composition of different organs was evaluated by gas chromatography. The characterization of Atmyb41ge mutants revealed that AtMYB41 negatively regulates the production of cuticular lipids and fatty acid biosynthesis in leaves and seeds, respectively. Remarkably, biochemical analyses indicate that AtMYB41 also positively regulates the formation of cuticular waxes in stems of Arabidopsis thaliana. Overall, these results suggest that the AtMYB41 acts as a negative regulator of cuticle and fatty acid biosynthesis in leaves and seeds, respectively, but also as a positive regulator of wax production in A. thaliana stems.

Wound-induced triacylglycerol biosynthesis is jasmonoy-l-isoleucin and abscisic acid independent.

Triacylglycerol (TAG) plays a significant role during plant stress - it maintains lipid homeostasis. Upon wounding plants accumulate TAG, likely as a storage form of fatty acids (FAs) that originate from damaged membranes. This study asked if this process depends on the two phytohormones jasmonoyl-isoleucine (JA-Ile) and abscisic acid (ABA), which are involved in wound signalling. To analyse regulation of wound-induced TAG accumulation, we used mutants deficient in JA-Ile, with reduced ABA and the myb96 mutant, which is deficient in an ABA-dependent transcription factor. The expression of genes involved in TAG biosynthesis, and TAG content after wounding were analysed via LC-MS and GC-FID, plastidial lipid content in all mentioned mutant lines was also determined. The localization of newly synthesized TAG was investigated using lipid droplet staining. TAG accumulation upon wounding was confirmed as well as the fact that the newly synthesized TAG are mostly composed of polyunsaturated fatty acids. Nevertheless, all tested mutant lines were able to accumulate TAG similar to the WT. We observed differences in reduction of plastidial lipids - in WT plants this was higher than in mutant lines. Newly synthesized TAGs were stored in lipid droplets at and around the wounded area. Our results show that TAG accumulation upon wounding is not dependent on JA-Ile or ABA. The newly synthesized TAG species are composed of unsaturated fatty acids of membrane origin, and most likely serves as a transient energy store.

Morphology of TiO2 nanotubes revealed through electron tomography.

In this work, scanning-transmission electron microscopy (STEM) tomography was successfully applied to characterize the three-dimensional structure of titanium oxide nanotubes prepared by the electrochemical anodization of the Ti substrate. The results provided detailed information about the morphology of nanotubes as well as insight into their growth. The segmentation of reconstructed images made it possible to estimate the surface area and volume of the nanotubes. The highest specific surface area was obtained for the lowest anodization voltage of 10V, and corresponds closely to that obtained using the porosimetry technique.

Concordance of KRAS mutation status between luminal and peripheral regions of primary colorectal cancer. A laser-capture microdissection-based study.

The presence of KRAS mutation in colorectal cancer (CRC) is a marker of resistance to anti-EGFR therapy. However, there are conflicting reports concerning intratumoral heterogeneity of KRAS mutations. The aim of this study was to determine whether within primary CRCs with KRAS mutations intratumoral KRAS mutation heterogeneity can be detected between two strictly defined areas, i.e. the luminal (mucosa/submucosa) and peripheral invasive front of the tumor. Using laser-capture microdissection, from every tumor about 400-500 nests of cancer cells were excised from each of the examined areas (luminal and peripheral) and PNAClamp, a high-sensitivity real-time PCR-based diagnostic assay for KRAS mutation testing, was used for molecular analysis. KRAS mutations were detected in codon 12 in both luminal and peripheral regions in all tumors examined. We conclude that from the point of view of practical KRAS mutation testing for predictive purposes in patients with CRC (i.e. testing mutations in codons 12 and 13) sampling errors are unlikely to occur if in CRCs with KRAS mutations only the luminal (as in biopsy tissue) or peripheral region is examined, provided a sensitive system of detection is applied and an appropriate number of tumor cells with minimal contamination by benign cells is analyzed.

Gastric hyperplastic polyps coexisting with early gastric cancers, adenoma and neuroendocrine cell hyperplasia.

Gastric hyperplastic polyps (GHP) constitute up to 93% of all benign epithelial polyps of the stomach. The average probability of malignant transformation in GHP is 0.6-22% in large series. The aim of the study was to present the coexistence of GHP with early gastric cancer (EGC), gastric adenoma (GA), neuroendocrine cell hyperplasia (NH) and well-differentiated neuroendocrine tumour (NET G1). Three cases were studied to reveal clinical data and morphological changes and to assess the relationship between GHP and accompanying gastric neoplastic lesions.

STEM study of Li4 Ti5 O12 anode material modified with Ag nanoparticles.

Comprehensive scanning transmission electron microscopy (STEM) analysis of Li4 Ti5 O12 (LTO) powder modified by deposited Ag nanoparticles was performed. Nanocomposite powders with Ag content of 1 wt.%, 4 wt.%, 10 wt.% were fabricated in a chemical process from suspensions of Ag and LTO. Apart from the STEM results, the presence of pure silver on the surface of the ceramic powder was confirmed by XRD and XPS analyses. The silver particles deposited on the LTO particles were characterized using the EDS mapping technique. The quantified results of the EDS mapping showed a relatively homogenous distribution of silver nanoparticles on the powder surface for every metal content. The mean diameter of the nanoparticles deposited on the LTO powder was about 4 nm in all cases. An increase in the Ag content during chemical surface modification did not cause changes in the microstructure. Focusing on an analysis of the metallic nanoparticles on the ceramic powder, electron tomography was used as an investigative technique. A very precise analysis of three-dimensional nanostructures is desirable for a comprehensive analysis of complex materials. The quantified analysis of the Ag nanoparticles visualized using electron tomography confirmed the results of the size measurements taken from the two-dimensional EDS maps.

A novel hybrid nanofibrous strategy to target progenitor cells for cost-effective in situ angiogenesis.

Although the impact of composites based on Ti-doped calcium phosphate glasses is low compared with that of bioglass, they have been already shown to possess great potential for bone tissue engineering. Composites made of polylactic acid (PLA) and a microparticle glass of 5TiO2-44.5CaO-44.5P2O5-6Na2O (G5) molar ratio have already demonstrated in situ osteo- and angiogenesis-triggering abilities. As many of the hybrid materials currently developed usually promote osteogenesis but still lack the ability to induce vascularization, a G5/PLA combination is a cost-effective option for obtaining new instructive scaffolds. In this study, nanostructured PLA-ORMOGLASS (organically modified glass) fibers were produced by electrospinning, in order to fabricate extra-cellular matrix (ECM)-like substrates that simultaneously promote bone formation and vascularization. Physical-chemical and surface characterization and tensile tests demonstrated that the obtained scaffolds exhibited homogeneous morphology, higher hydrophilicity and enhanced mechanical properties than pure PLA. In vitro assays with rat mesenchymal stem cells (rMSCs) and rat endothelial progenitor cells (rEPCs) also showed that rMSCs attached and proliferated on the materials influenced by the calcium content in the environment. In vivo assays showed that hybrid composite PLA-ORMOGLASS fibers were able to promote the formation of blood vessels. Thus, these novel fibers are a valid option for the design of functional materials for tissue engineering applications.

Towards 4th generation biomaterials: a covalent hybrid polymer-ormoglass architecture.

Hybrid materials are being extensively investigated with the aim of mimicking the ECM microenvironment to develop effective solutions for bone tissue engineering. However, the common drawbacks of a hybrid material are the lack of interactions between the scaffold's constituents and the masking of its bioactive phase. Conventional hybrids often degrade in a non-homogeneous manner and the biological response is far from optimal. We have developed a novel material with strong interactions between constituents. The bioactive phase is directly exposed on its surface mimicking the structure of the ECM of bone. Here, polylactic acid electrospun fibers have been successfully and reproducibly coated with a bioactive organically modified glass (ormoglass, Si-Ca-P2 system) covalently. In comparison with the pure polymeric mats, the fibers obtained showed improved hydrophilicity and mechanical properties, bioactive ion release, exhibited a nanoroughness and enabled good cell adhesion and spreading after just one day of culture (rMSCs and rEPCs). The fibers were coated with different ormoglass compositions to tailor their surface properties (roughness, stiffness, and morphology) by modifying the experimental parameters. Knowing that cells modulate their behavior according to the exposed physical and chemical signals, the development of this instructive material is a valuable advance in the design of functional regenerative biomaterials.

Molecular studies on ancient M. tuberculosis and M. leprae: methods of pathogen and host DNA analysis.

Humans have evolved alongside infectious diseases for millennia. Despite the efforts to reduce their incidence, infectious diseases still pose a tremendous threat to the world population. Fast development of molecular techniques and increasing risk of new epidemics have resulted in several studies that look to the past in order to investigate the origin and evolution of infectious diseases. Tuberculosis and leprosy have become frequent targets of such studies, owing to the persistence of their molecular biomarkers in ancient material and the characteristic skeletal lesions each disease may cause. This review examines the molecular methods used to screen for the presence of M. tuberculosis and M. leprae ancient DNA (aDNA) and their differentiation in ancient human remains. Examples of recent studies, mainly from Europe, that employ the newest techniques of molecular analysis are also described. Moreover, we present a specific approach based on assessing the likely immunological profile of historic populations, in order to further elucidate the influence of M. tuberculosis and M. leprae on historical human populations.

Mitochondrial DNA genetic diversity and LCT-13910 and deltaF508 CFTR alleles typing in the medieval sample from Poland.

We attempted to confirm the resemblance of a local medieval population and to reconstruct their contribution to the formation of the modern Polish population at the DNA level. The HVR I mtDNA sequence and two nuclear alleles, LCT-13910C/T SNP and deltaF508 CFTR, were chosen as markers since the distribution of selected nuclear alleles varies among ethnic groups. A total of 47 specimens were selected from a medieval cemetery in Cedynia (located in the western Polish lowland). Regarding the HVR I profile, the analyzed population differed from the present-day population (P = 0.045, F(st) = 0.0103), in contrast to lactase persistence (LP) based on the LCT-13910T allele, thus indicating the lack of notable frequency changes of this allele during the last millennium (P = 0.141). The sequence of the HVR I mtDNA fragment allowed to identify six major haplogroups including H, U5, T, K, and HV0 within the medieval population of Cedynia which are common in today's central Europe. An analysis of haplogroup frequency and its comparison with modern European populations shows that the studied medieval population is more closely related to Finno-Ugric populations than to the present Polish population. Identification of less common haplogroups, i.e., Z and U2, both atypical of the modern Polish population and of Asian origin, provides evidence for some kind of connections between the studied and foreign populations. Furthermore, a comparison of the available aDNA sequences from medieval Europe suggests that populations differed from one another and a number of data from other locations are required to find out more about the features of the medieval gene pool profile.

TiO2 nanotube composite layers as delivery system for ZnO and Ag nanoparticles - an unexpected overdose effect decreasing their antibacterial efficacy.

Enhancement of biocompatibility and antibacterial properties of implant materials is potentially beneficial for their practical value. Therefore, the use of metallic and metallic oxide nanoparticles as antimicrobial coatings components which induce minimized antibacterial resistance receives currently particular attention. In this work, TiO2 nanotubes layers loaded with ZnO and Ag nanoparticles were designed for biomedical coatings and delivery systems and evaluated for antimicrobial activity. TiO2 nanotubes themselves exhibited considerable and diameter-dependent antibacterial activity against planktonic Staphylococcus epidermidis cells but favored bacterial adhesion. Loading of nanotubes with moderate amount of ZnO nanoparticles significantly diminished S. epidermidis cell adhesion and viability just after 1.5h contact with modified surfaces. However, an increase of loaded ZnO amount unexpectedly altered the structure of nanoparticle-nanolayer, caused partial closure of nanotube interior and significantly reduced ZnO solubility and antibacterial efficacy. Co-deposition of Ag nanoparticles enhanced the antibacterial properties of synthesized coatings. However, the increase of ZnO quantity on Ag nanoparticles co-deposited surfaces favored the adhesion of bacterial cells. Thus, ZnO/Ag/TiO2 nanotube composite layers may be promising delivery systems for combating post-operative infections in hard tissue replacement procedures. However, the amount of loaded antibacterial agents must be carefully balanced to avoid the overdose and reduced efficacy.

Frequency of P2RX7 A1513C and TLR2 -196 to -174 ins/del in healthy Polish individuals.

Polymorphisms within genes coding innate immune response proteins are involved in genetic susceptibility to various conditions. We investigated the frequency of P2RX7 A1513C and TLR2 -196 to -174 ins/del polymorphisms in healthy Polish population. Frequency of minor alleles was relatively similar to the pattern presented by Caucasian populations while it differed significantly when compared to non-European populations, which could be a result of variable selection pressure put upon studied alleles or hindered gene flow between populations.

Changes in fMRI BOLD response to increasing and decreasing task difficulty during auditory perception of temporal order.

We have discovered changes in brain activation during difficult and easy milliseconds timing. Structures engaged in difficult and easier auditory temporal-order judgment were identified in 17 young healthy listeners presented with paired-white-noises of different durations. Within each pair, a short (10 ms) and a long (50 ms) noise was separated by a silent gap of 10, 60 or 160 ms, corresponding to three levels of task difficulty, i.e. difficult, moderate and easy conditions, respectively. A block design paradigm was applied. In temporal-order judgment task subjects were required to define the order of noises within each pair, i.e. short-long or long-short. In the control task they only detected the presentation of the stimulus pair. A multiple regression with 'task difficulty' as a regressor ('difficult', 'moderate', 'easy') showed dynamic changes in neural activity. Increasing activations accompanying increased task difficulty were found in both bilateral inferior parietal lobuli and inferior frontal gyri, thus, in classic regions related to attentional and working memory processes. Conversely, decreased task difficulty was accompanied by increasing involvement of more specific timing areas, namely bilateral medial frontal gyri and left cerebellum. These findings strongly suggest engagement of different neural networks in difficult or easier timing and indicate a framework for understanding timing representation in the brain.

Microstructure investigations of dental composite samples prepared by focused ion beam technique.

In this study, microstructures of dental composites were observed using high resolution scanning transmission electron microscopy (HR STEM). Samples for these observations were prepared by focused ion beam system. Two kinds of dental composites were investigated: (1) polymer-ceramic composite containing nano-sized ceramic fillers and (2) ceramic-polymer composite based on the nano-structured yttrium stabilized zirconia. The first composite is a popular material for dental fillings whereas the second is used for the fabrication of fixed partial dentures. The results are discussed in terms of the evaluation of fabrication process of the composites.

Structure and function of the perinucleolar compartment in cancer cells.

The perinucleolar compartment (PNC) is a subnuclear body that forms in cancer cells. In vivo analyses using human tumor tissues demonstrate a close correlation between PNC prevalence and disease progress in colorectal carcinoma, and a high PNC prevalence is associated with poor patient outcome. These findings are consistent with previous observations in breast cancer and cancer cell lines in vitro. The PNC is composed of thick strands that form a filamental meshwork often extending into the nucleolus. Although it appears to be electron dense as observed by transmission electron microscopy (TEM), the actual density of the structure imaged by electron spectroscopy is much lower, similar to that of the interchromatin space, and is lined with ribonucleoproteins (RNPs). In situ detections show that the PNC is highly enriched with a subset of small RNAs of polymerase III (Pol III) origins and RNA-binding proteins primarily implicated in pre-mRNA processing. A novel gel-shifting approach demonstrates that the addition of PNC-associated RNAs into HeLa cell lysates increases the mobility of polypyrimidine tract-binding (PTB) protein in a native gel electrophoresis, suggesting an interaction between these RNAs and PTB proteins. On the basis of these and other findings, we propose a working model in which novel RNPs have a key role in regulating gene expression at the PNC in cancer cells.

Towards electrophysiological correlates of auditory perception of temporal order.

Recent studies have postulated that the temporal order (TO) of two successive events can be correctly identified if they are separated by an inter-stimulus interval (ISI) of at least 30 ms duration. Using Auditory Evoked Potentials, we tested 21 students for the cortical activation associated with TO detection of two successively presented tones in either 'easy' (ISI=60 ms) or 'difficult' (ISI=10 ms) conditions. The amplitude of P2 component was related to difficulty of TO perception and was significantly higher in 'difficult' than 'easy' condition. Moreover, in 'difficult' condition the correlation analyses revealed a negative association at both Fz and Cz electrodes between P2 amplitudes and the correctness level. Correct responses in this condition were accompanied by lower P2 amplitudes than the incorrect ones.

Need for rehabilitation in renal replacement therapy involving allogeneic kidney transplantation.

Physical rehabilitation is a form of therapy that complements medical treatment for allogenic kidney transplantation recipients. The aim of this research was to assess the effectiveness of motor therapy among a population of allogenic kidney recipients. Physical rehabilitation was conducted both in the clinic after renal transplantation and over 1 year after the procedure. The 67 patients included 26 women and 41 men of overall average age 44.45 years. The cohort was divided into two subgroups: those undertaking regular exercise (n = 35) and a control subgroup (n = 32). The rehabilitation program covered recuperation, isometric, coordination, relaxation, and breathing exercises. Moreover, the following elements were assessed several times: respiratory system (peak expiratory floor [PEF] test), circulatory system, namely, arterial blood pressure and in some cases electrocardiograph, along with the motor system examining upper extremity strength and movement range in distal joints in the upper and the lower extremities. Biochemical blood analysis examined hemoglobin, total protein and albumin, transaminase activity, lactate dehydrogenase, isoenzymes (LD1-5), and creatine kinase (CK), along with CK-MB and CK-MM. A significant improvement was observed in the range of movement in the radiocarpal joint (P < .05) and an increased PEF value (P < .05). Among the total kidney transplantation recipients, 81.3% of patients subjected to rehabilitation and 77.8% the control subgroup accepted the need for long-term motor exercise. The analysis of the implemented rehabilitation program, and biochemical analyses confirmed the need to establish rehabilitation centers, for example, in dialysis centers and/or transplant institutes, for patients subjected to renal replacement therapy, and particularly after successful kidney transplantation.

Interferon alpha induces a good molecular response in a patient with chronic eosinophilic leukemia (CEL) carrying the JAK2V617F point mutation.

The JAK2 V617F point mutation is very rare in hypereosinophilic syndrome and/or chronic eosinophilic leukemia. Here we report on a patient with chronic eosinophilic leukemia and detectable JAK2 mutant clone, who achieved a good molecular response to interferon alpha-2a after 4 months of treatment. The molecular response correlated with only moderate haematological improvement.

Morphology and chemical characterization of Ti surfaces modified for biomedical applications.

The aim of the present work is to characterize in detail the chemical composition and morphology of titanium surfaces subjected to various environments. Modifications consisted of exposure of Ti to acidic, alkaline or polymer solutions. Such modifications result in chemical and/or morphological changes in the Ti surface. Special attention has been given to identifying the factors influencing cell adhesion and growth. SEM examinations provided morphological characterization of the Ti samples. Surface analytical techniques such as AES or XPS combined with Ar(+) ion sputtering allowed examination of the chemical properties of the Ti surface after chemical pretreatments and investigating the chemical composition of the Ti oxide layer. Raman spectroscopy investigations allowed determination of the crystalline phases of the Ti-oxide layers and characterization of the dextran-modified surface. The results show large differences in the morphology of Ti pretreated with different procedures whereas only minor differences in the chemistry of the surfaces were found. High-resolution Auger investigations have revealed that all the chemical modifications of Ti surfaces resulted in the formation of a titanium oxide layer. XPS confirmed that TiO(2) is the main component of the chemically modified Ti surface. The Raman spectroscopy investigations showed that the titanium surface with a dextran coating is rich in hydroxyl groups. All the surfaces investigated exhibit a hydrophilic character. The possible influence of various surface features on surface biocompatibility is discussed.

Microstructure evolution in age-hardenable aluminium alloy during processing by hydrostatic extrusion.

In the present work, scanning and transmission electron microscopy were used to investigate the microstructural evolution occurring during the hydrostatic extrusion of an age-hardenable aluminium alloy. It was shown that processing by hydrostatic extrusion leads to grain refinement to 95 nm in equivalent diameter. Hydrostatic extrusion also influences the geometrical parameters of two different types of particle: intermetallic inclusions and precipitates. The intermetallic inclusions slightly decrease in mean equivalent diameter, but their size remains at the micrometre level. The precipitates are fragmented to nanoscale spherical particles, and their evolution delays the process of grain refinement.