Pouzdanost kratke verzije međunarodnog upitnika tjelesne aktivnosti za Hrvatsku

Dosadašnja istraživanja iz razlicitih zemalja ukazala su na zadovoljavajucu razinu pouzdanosti kratke verzije Medunarodnog upitnika tjelesne aktivnosti (IPAQ-SF). Pouzdanost ovog upitnika, pregledom literature, nije utvrdena za Hrvatsku. Cilj istraživanja bio je utvrditi pouzdanost kratke verzije IPAQ upitnika za Hrvatsku test-retest metodom. Uzorak sudionika cinila su 103 ucenika (42% ucenici, 58% ucenice) u dobi od 17 do 19 godina, završnih razreda Gimnazije Lucijan Vranjanin iz Zagreba. Uzorak varijabli cinile su spol, godine, tjelesna visina, tjelesna težina, indeks tjelesne mase (BMI), utvrdene zasebnim dijelom upitnika i tjelesna aktivnost ucenika (TA) utvrdena kratkom verzijom IPAQ upitnika. Istraživanje je provedeno u dvije vremenske tocke, prvo anketiranje je provedeno u trecem tjednu rujna, a drugo u prvom tjednu listopada kako ucenici ne bi pamtili svoje odgovore, te kako ne bi prošao znacajan dio vremena tijekom kojeg bi ispitanici mogli promijeniti svoje tjelesne navike. Na temelju rezultata izracunati su Spearman koeficijenti korelacije izmedu test i retesta za ukupnu tjelesnu aktivnost (TA) koji iznosi (0.64) i za pojedine kategorije tjelesne aktivnosti (0.91-0.54). Pouzdanost kratke verzije IPAQ upitnika za Hrvatsku je na zadovoljavajucoj razini kako za ukupnu tjelesnu aktivnost, tako i za pojedinu kategoriju tjelesne aktivnosti

Different Stationary Phase Selectivities and Morphologies for Intact Protein Separations

The central dogma of biology proposed that one gene encodes for one protein. We now know that this does not reflect reality. The human body has approximately 20,000 protein-encoding genes; each of these genes can encode more than one protein. Proteins expressed from a single gene can vary in terms of their post-translational modifications, which often regulate their function within the body. Understanding the proteins within our bodies is a key step in understanding the cause, and perhaps the solution, to disease. This is one of the application areas of proteomics, which is defined as the study of all proteins expressed within an organism at a given point in time. The human proteome is incredibly complex. The complexity of biological samples requires a combination of technologies to achieve high resolution and high sensitivity analysis. Despite the significant advances in mass spectrometry, separation techniques are still essential in this field. Liquid chromatography is an indispensable tool by which low-abundant proteins in complex samples can be enriched and separated. However, advances in chromatography are not as readily adapted in proteomics compared to advances in mass spectrometry. Biologists in this field still favour reversed-phase chromatography with fully porous particles. The purpose of this review is to highlight alternative selectivities and stationary phase morphologies that show potential for application in top-down proteomics; the study of intact proteins

Characterization of Ceramides with Phytosphingosine Backbone by Hydrogen-deuterium Exchange Mass Spectrometry

Ceramides are a lipid subclass of the sphingolipids that show large structural diversity. Structural characterization of the ceramides (CERs) can lead to better understanding of their role and function in the biological system. Here we investigated representatives of NP (CER III, CER IIIB) and AP ceramide classes (CER VI) that contain phytosphingosine (P) backbone. Ceramides were characterized in positive ionization mode by hydrogen-deuterium exchange mass spectrometry (HDX-MS). Fragmentation in positive ionization mode of the CER III and CER VI resulted in abundant ions assigned to phytosphingosine moiety at m/z 282, 300 and 318. HDX-MS of fragments showed increase in m/z of corresponding ions confirming the exchange of deuterium. In negative ionisation spectra multiple fragment ions were assigned to fatty acyl (RCOO–) moiety. Presence of RCOO– allowed unambiguous identification of CER III and CER IIIB which were distinguished by the presence of double bond on fatty acyl chain. This work is licensed under a Creative Commons Attribution 4.0 International License

Early-life regional and temporal variation in filaggrin-derived natural moisturizing factor, filaggrin-processing enzyme activity, corneocyte phenotypes and plasmin activity:Implications for atopic dermatitis

Background: Filaggrin is central to the pathogenesis of atopic dermatitis (AD). The cheeks are a common initiation site of infantile AD. Regional and temporal expression of levels of filaggrin degradation products [natural moisturizing factors (NMFs)], activities of filaggrin‐processing enzymes [bleomycin hydrolase (BH) and calpain‐1 (C‐1)] and plasmin, and corneocyte envelope (CE) maturity in early life are largely unknown. / Objectives: We conducted a cross‐sectional, observational study investigating regional and age‐dependent variations in NMF levels, activity of proteases and CE maturity in stratum corneum (SC) from infants to determine whether these factors could explain the observed predilection sites for AD in early life. / Methods: We measured NMF using a tape‐stripping method at seven sites in the SC of 129 children (aged < 12 months to 72 months) and in three sites in 56 neonates and infants (< 48 h to 3 months). In 37 of these neonates and infants, corneocyte size, maturity, BH, C‐1 and plasmin activities were determined. / Results: NMF levels are low at birth and increase with age. Cheek SC, compared with elbow flexure and nasal tip, has the lowest NMF in the first year of life and is the slowest to reach stable levels. Cheek corneocytes remain immature. Plasmin, BH and C‐1 activities are all elevated by 1 month of age in exposed cheek skin, but not in elbow skin. / Conclusions: Regional and temporal differences in NMF levels, CE maturity and protease activities may explain the predilection for AD to affect the cheeks initially and are supportive of this site as key for allergen priming in early childhood. These observations will help design early intervention and treatment strategies for AD

Quadruplex DNA: sequence, topology and structure.

G-quadruplexes are higher-order DNA and RNA structures formed from G-rich sequences that are built around tetrads of hydrogen-bonded guanine bases. Potential quadruplex sequences have been identified in G-rich eukaryotic telomeres, and more recently in non-telomeric genomic DNA, e.g. in nuclease-hypersensitive promoter regions. The natural role and biological validation of these structures is starting to be explored, and there is particular interest in them as targets for therapeutic intervention. This survey focuses on the folding and structural features on quadruplexes formed from telomeric and non-telomeric DNA sequences, and examines fundamental aspects of topology and the emerging relationships with sequence. Emphasis is placed on information from the high-resolution methods of X-ray crystallography and NMR, and their scope and current limitations are discussed. Such information, together with biological insights, will be important for the discovery of drugs targeting quadruplexes from particular genes

Trends in Sample Preparation for Proteome Analysis

Sample preparation is a key step in proteomics, however there is no consensus in the community about the standard method for preparation of proteins from clinical samples like tissues or biofluids. In this chapter, we will discuss some important steps in sample preparation used for bottom-up proteome profiling with mass spectrometry (MS). Specifically, tissues, which are an important source of biological information, are of interest because of their availability. Tissues are most often stored as fresh frozen (FF) or formalin-fixed paraffin-embedded (FFPE). While FF tissues are more readily available, paraffin embedding has historically been routinely used for tissue preservation. However, formaldehyde induced crosslinks during FFPE tissue preservation present a challenge to the protocols used for protein retrieval. Moreover, in our view, an important aspect to consider is also the amount of material available at the start of a protocol since this is directly related to the choice of protocol in order to minimize sample loss and maximize detection of peptides by MS. This “MS sensitivity” is of special importance when working with patient samples that are unique and often available in limited amounts making optimization of methods to analyze the proteins therein important given that their molecular information can be used in a patients’ diagnosis and treatment

Structural determinants of peptide-dependent TAP1-TAP2 transit passage targeted by viral proteins and altered by cancer-associated mutations

The TAP1-TAP2 complex transports antigenic peptide substrates into the endoplasmic reticulum (ER). In ER, the peptides are further processed and loaded on the major histocompatibility class (MHC) I molecules by the peptide loading complex (PLC). The TAP transporters are linked with the PLC; a target for cancers and viral immune evasion. But the mechanisms whereby the cancer-derived mutations in TAP1-TAP2 or viral factors targeting the PLC, interfere peptide transport are only emerging. This study describes that transit of peptides through TAP can take place via two different channels (4 or 8 helices) depending on peptide length and sequence. Molecular dynamics and binding affinity predictions of peptide-transporters demonstrated that smaller peptides (8–10 mers; e.g. AAGIGILTV, SIINFEKL) can transport quickly through the transport tunnel compared to longer peptides (15-mer; e.g. ENPVVHFFKNIVTPR). In line with a regulated and selective peptide transport by TAPs, the immunopeptidome upon IFN-γ treatment in melanoma cells induced the shorter length (9-mer) peptide presentation over MHC-I that exhibit a relatively weak binding affinity with TAP. A conserved distance between N and C terminus residues of the studied peptides in the transport tunnel were reported. Furthermore, by adversely interacting with the TAP transport passage or affecting TAPNBD domains tilt movement, the viral proteins and cancer-derived mutations in TAP1-TAP2 may induce allosteric effects in TAP that block conformation of the tunnel (closed towards ER lumen). Interestingly, some cancer-associated mutations (e.g. TAP1R372Q and TAP2R373H) can specifically interfere with selective transport channels (i.e. for longer-peptides). These results provide a model for how viruses and cancer-associated mutations targeting TAP interfaces can affect MHC-I antigen presentation, and how the IFN-γ pathway alters MHC-I antigen presentation via the kinetics of peptide transport