The requirement for water-soluble vitamins in patients with chronic kidney disease in the period of conservative treatment

Niedobór witamin jest jedną z form niedożywienia. Przewlekła choroba nerek (PChN) predysponuje dotego powikłania ze względu na specyfikę diety, upośledzone wchłanianie, nieprawidłowy metabolizm oraz straty z moczem. Ocena zasobów witamin jest trudna w PChN ze względu na niepewną wielkość strat związanych ze stopniowo pogarszającą się funkcją nerek. Dodatkowo, oznaczenie stężeń poszczególnych witamin rozpuszczalnych w wodzie (z wyjątkiem witaminy B12, kwasu foliowego) nie jest możliwe w ramach rutynowych badań laboratoryjnych. Wiedza o funkcji i zasobach witaminu pacjentów z niskimi wartościami współczynnika przesączania kłębuszkowego (GFR) jest fragmentaryczna i nieusystematyzowana. Zagadnienie niedoborów witamin rozpuszczalnych w wodzie oraz ich suplementacji w poszczególnych stadiach PChN wymaga dalszych zakrojonych na dużą skalę badań. Jednak dostępne zalecania dotyczące rekomendowanego spożycia i suplementacji witamin rozpuszczalnych w wodzie powinny być uwzględniane w codziennej praktyce.Vitamin deficiency is one of the forms of malnutrition. Chronic kidney disease (CKD) predisposes to this complication due to the specific diet, malabsorption, abnormal metabolism and loss of urine. Resource assessment of vitamins is difficult in chronic kidney disease due to the uncertain amount of losses associated with progressively worsening renal function. In addition, the determination of concentrations of individual water-soluble vitamins (except for vitamin B12, folic acid) is not possible under routine laboratory practice. Knowledge of the functions and resources of vitamins in patients with low GFR is fragmented and unstructured. The problem of water soluble vitamins deficiency and their supplementation in different stages of CKD require further extensive research. However, the available recommendations on intake and supplementation of water soluble vitamins should be taken into account in daily practice

First experience in operation of cold model of fb-clc-sf (fluidized-bed chemical-looping-combustion solid-fuels) facility

The first experiences with the cold model of dual fluidized bed unit designed for chemical looping combustion of solid fuels (FB-CLC-SF) will be presented. The constructed facility combines two different type reactors. The first one, which is the Air Reactor (AR) is operated in a regime of fast fluidized bed, whereas, the second one, which is the Fuel Reactor (FR) works under bubbling fluidized bed conditions. However, the integrated reactors make the whole construction being a CFB-type (Circulating Fluidized Bed) unit. The facility is made entirely of transparent material (Plexiglas). This feature supports effectively the measurements, which enables to conduct the comprehensive studies in the field of investigations. During this research, the air was used for bed fluidization in both reactors. As an inventory, the round glass beads were employed, since they size and density relate closely to the properties of the oxygen carriers developed concurrently in the project, whereas they are significantly less expensive and friendlier in use. Over a dozen ports for pressure measurements are provided along the main circulation path of the solids. These experimental data enable to determine the pressure balance around the whole CFB loop, which becomes the starting point for further studies. The cold simulations of solids flow demonstrate the conditions that are expected in the case of the hot 5 kW test rig operation, which remains under construction. Therefore, the main goal of this work and the challenge as well are to establish the operating conditions that consider both: a smooth fluidization throughout the FB-CLC-SF unit and an efficient oxidation/reduction of oxygen carriers in AR and FR, respectively. Moreover, these studies support directly the modelling work (Submitted paper: A 1.5D model of a laboratory scale fluidized bed CLC equipment), which makes the whole investigations being complementary

Functional protein composition in femoral glands of sand lizards (Lacerta agilis)

Proteins are ubiquitous macromolecules that display a vast repertoire of chemical and enzymatic functions, making them suitable candidates for chemosignals, used in intraspecific communication. Proteins are present in the skin gland secretions of vertebrates but their identity, and especially, their functions, remain largely unknown. Many lizard species possess femoral glands, i.e., epidermal organs primarily involved in the production and secretion of chemosignals, playing a pivotal role in mate choice and intrasexual communication. The lipophilic fraction of femoral glands has been well studied in lizards. In contrast, proteins have been the focus of only a handful of investigations. Here, we identify and describe inter-individual expression patterns and the functionality of proteins present in femoral glands of male sand lizards (Lacerta agilis) by applying mass spectrometry-based proteomics. Our results show that the total number of proteins varied substantially among individuals. None of the identified femoral gland proteins could be directly linked to chemical communication in lizards, although this result hinges on protein annotation in databases in which squamate semiochemicals are poorly represented. In contrast to our expectations, the proteins consistently expressed across individuals were related to the immune system, antioxidant activity and lipid metabolism as their main functions, showing that proteins in reptilian epidermal glands may have other functions besides chemical communication. Interestingly, we found expression of the Major Histocompatibility Complex (MHC) among the multiple and diverse biological processes enriched in FGs, tentatively supporting a previous hypothesis that MHC was coopted for semiochemical function in sand lizards, specifically in mate recognition. Our study shows that mass spectrometry-based proteomics are a powerful tool for characterizing and deciphering the role of proteins secreted by skin glands in non-model vertebrates

Practical aspects of a low-protein diet

The updated 2020 Kidney Disease Outcome Quality Initiative (KDOQI) guidelines resulted in an increased interest in the use of a low-protein diet in patients with chronic kidney disease. In Poland, from March 2021, patients can be enrolled, provided that they meet certain criteria, into the therapeutic program including the use of a low-protein diet and ketonanalogues of aminoacids. However, it is very important to properly educate medical personnel and patients so that the KDOQI recommendations are implemented in clinical practice and bring benefits by slowing the progression of the chronic kidney disease

Fibronectin-, vitronectin- and laminin-binding proteins at the cell walls of Candida parapsilosis and Candida tropicalis pathogenic yeasts

Background : Candida parapsilosis and C. tropicalis increasingly compete with C. albicans—the most common fungal pathogen in humans—as causative agents of severe candidiasis in immunocompromised patients. In contrast to C. albicans, the pathogenic mechanisms of these two non-albicans Candida species are poorly understood. Adhesion of Candida yeast to host cells and the extracellular matrix is critical for fungal invasion of hosts. Methods : The fungal proteins involved in interactions with extracellular matrix proteins were isolated from mixtures of β-1,3-glucanase– or β-1,6-glucanase–extractable cell wall-associated proteins by use of affinity chromatography and chemical cross-linking methods, and were further identified by liquid chromatography-coupled tandem mass spectrometry. Results : In the present study, we characterized the binding of three major extracellular matrix proteins—fibronectin, vitronectin and laminin—to C. parapsilosis and C. tropicalis pseudohyphae. The major individual compounds of the fungal cell wall that bound fibronectin, vitronectin and laminin were found to comprise two groups: (1) true cell wall components similar to C. albicans adhesins from the Als, Hwp and Iff/Hyr families; and (2) atypical (cytoplasm-derived) surface-exposed proteins, including malate synthase, glucose-6-phosphate isomerase, 6-phosphogluconate dehydrogenase, enolase, fructose-1,6-bisphosphatase, transketolase, transaldolase and elongation factor 2. Discussion : The adhesive abilities of two investigated non-albicans Candida species toward extracellular matrix proteins were comparable to those of C. albicans suggesting an important role of this particular virulence attribute in the pathogenesis of infections caused by C. tropicalis and C. parapsilosis. Conclusions : Our results reveal new insight into host–pathogen interactions during infections by two important, recently emerging, fungal pathogens

Joint genomic and proteomic analysis identifies meta-trait characteristics of virulent and non-virulent Staphylococcus aureus strains

Staphylococcus aureus is an opportunistic pathogen of humans and warm-blooded animals and presents a growing threat in terms of multi-drug resistance. Despite numerous studies, the basis of staphylococcal virulence and switching between commensal and pathogenic phenotypes is not fully understood. Using genomics, we show here that S. aureus strains exhibiting virulent (VIR) and non-virulent (NVIR) phenotypes in a chicken embryo infection model genetically fall into two separate groups, with the VIR group being much more cohesive than the NVIR group. Significantly, the genes encoding known staphylococcal virulence factors, such as clumping factors, are either found in different allelic variants in the genomes of NVIR strains (compared to VIR strains) or are inactive pseudogenes. Moreover, the pyruvate carboxylase and gamma-aminobutyrate permease genes, which were previously linked with virulence, are pseudogenized in NVIR strain ch22. Further, we use comprehensive proteomics tools to characterize strains that show opposing phenotypes in a chicken embryo virulence model. VIR strain CH21 had an elevated level of diapolycopene oxygenase involved in staphyloxanthin production (protection against free radicals) and expressed a higher level of immunoglobulin-binding protein Sbi on its surface compared to NVIR strain ch22. Furthermore, joint genomic and proteomic approaches linked the elevated production of superoxide dismutase and DNA-binding protein by NVIR strain ch22 with gene duplications

The wettability and surface free energy of sawn, sliced and sanded european oak wood

The main objective of this work was to evaluate the effects of two machining processes on European oak wood surface characteristics. The relationships between wettability, free surface energy and machining methods were studied. Sawing and slicing, with or without sanding, were used to prepare surfaces prior to testing whether they produce surfaces with different characteristics. For the wood surfaces machined by slicing and sawing, there was a significant difference in contact angle measurements. This indicates that the influence of machining processes such as slicing and sawing on contact angle value is remarkable. Sanded surfaces showed good wettability and high process roughness

SNAIL promotes metastatic behavior of rhabdomyosarcoma by increasing EZRIN and AKT expression and regulating microRNA networks

Rhabdomyosarcoma (RMS) is a predominant soft tissue tumor in children and adolescents. For high-grade RMS with metastatic involvement, the 3-year overall survival rate is only 25 to 30%. Thus, understanding the regulatory mechanisms involved in promoting the metastasis of RMS is important. Here, we demonstrate for the first time that the SNAIL transcription factor regulates the metastatic behavior of RMS both in vitro and in vivo. SNAIL upregulates the protein expression of EZRIN and AKT, known to promote metastatic behavior, by direct interaction with their promoters. Our data suggest that SNAIL promotes RMS cell motility, invasion and chemotaxis towards the prometastatic factors: HGF and SDF-1 by regulating RHO, AKT and GSK3β activity. In addition, miRNA transcriptome analysis revealed that SNAIL-miRNA axis regulates processes associated with actin cytoskeleton reorganization. Our data show a novel role of SNAIL in regulating RMS cell metastasis that may also be important in other mesenchymal tumor types and clearly suggests SNAIL as a promising new target for future RMS therapies

Expression of alternatively spliced variants of the Dclk1 gene is regulated by psychotropic drugs

Abstract Background The long-term effects of psychotropic drugs are associated with the reversal of disease-related alterations through the reorganization and normalization of neuronal connections. Molecular factors that trigger drug-induced brain plasticity remain only partly understood. Doublecortin-like kinase 1 (Dclk1) possesses microtubule-polymerizing activity during synaptic plasticity and neurogenesis. However, the Dclk1 gene shows a complex profile of transcriptional regulation, with two alternative promoters and exon splicing patterns that suggest the expression of multiple isoforms with different kinase activities. Results Here, we applied next-generation sequencing to analyze changes in the expression of Dclk1 gene isoforms in the brain in response to several psychoactive drugs with diverse pharmacological mechanisms of action. We used bioinformatics tools to define the range and levels of Dclk1 transcriptional regulation in the mouse nucleus accumbens and prefrontal cortex. We also sought to investigate the presence of DCLK1-derived peptides using mass spectrometry. We detected 15 transcripts expressed from the Dclk1 locus (FPKM > 1), including 2 drug-regulated variants (fold change > 2). Drugs that act on serotonin receptors (5-HT2A/C) regulate a subset of Dclk1 isoforms in a brain-region-specific manner. The strongest influence was observed for the mianserin-induced expression of an isoform with intron retention. The drug-activated expression of novel alternative Dclk1 isoforms was validated using qPCR. The drug-regulated isoform contains genetic variants of DCLK1 that have been previously associated with schizophrenia and hyperactivity disorder in humans. We identified a short peptide that might originate from the novel DCLK1 protein product. Moreover, protein domains encoded by the regulated variant indicate their potential involvement in the negative regulation of the canonical DCLK1 protein. Conclusions In summary, we identified novel isoforms of the neuroplasticity-related gene Dclk1 that are expressed in the brain in response to psychotropic drug treatments