Showing papers by "University of Rijeka published in 2017"

Guidelines for the use of flow cytometry and cell sorting in immunological studies

Abstract: The marriage between immunology and cytometry is one of the most stable and productive in the recent history of science. A rapid search in PubMed shows that, as of July 2017, using “flow cytometry immunology” as a search term yields more than 68 000 articles, the first of which, interestingly, is not about lymphocytes. It might be stated that, after a short engagement, the exchange of the wedding rings between immunology and cytometry officially occurred when the idea to link fluorochromes to monoclonal antibodies came about. After this, recognizing different types of cells became relatively easy and feasible not only by using a simple fluorescence microscope, but also by a complex and sometimes esoteric instrument, the flow cytometer that is able to count hundreds of cells in a single second, and can provide repetitive results in a tireless manner. Given this, the possibility to analyse immune phenotypes in a variety of clinical conditions has changed the use of the flow cytometer, which was incidentally invented in the late 1960s to measure cellular DNA by using intercalating dyes, such as ethidium bromide. The epidemics of HIV/AIDS in the 1980s then gave a dramatic impulse to the technology of counting specific cells, since it became clear that the quantification of the number of peripheral blood CD4+ T cells was crucial to follow the course of the infection, and eventually for monitoring the therapy. As a consequence, the development of flow cytometers that had to be easy-to-use in all clinical laboratories helped to widely disseminate this technology. Nowadays, it is rare to find an immunological paper or read a conference abstract in which the authors did not use flow cytometry as the main tool to dissect the immune system and identify its fine and complex functions. Of note, recent developments have created the sophisticated technology of mass cytometry, which is able to simultaneously identify dozens of molecules at the single cell level and allows us to better understand the complexity and beauty of the immune system.

Dynamic Consent: a potential solution to some of the challenges of modern biomedical research

Abstract: Background Innovations in technology have contributed to rapid changes in the way that modern biomedical research is carried out. Researchers are increasingly required to endorse adaptive and flexible approaches to accommodate these innovations and comply with ethical, legal and regulatory requirements. This paper explores how Dynamic Consent may provide solutions to address challenges encountered when researchers invite individuals to participate in research and follow them up over time in a continuously changing environment. Methods An interdisciplinary workshop jointly organised by the University of Oxford and the COST Action CHIP ME gathered clinicians, researchers, ethicists, lawyers, research participants and patient representatives to discuss experiences of using Dynamic Consent, and how such use may facilitate the conduct of specific research tasks. The data collected during the workshop were analysed using a content analysis approach. Results Dynamic Consent can provide practical, sustainable and future-proof solutions to challenges related to participant recruitment, the attainment of informed consent, participant retention and consent management, and may bring economic efficiencies. Conclusions Dynamic Consent offers opportunities for ongoing communication between researchers and research participants that can positively impact research. Dynamic Consent supports inter-sector, cross-border approaches and large scale data-sharing. Whilst it is relatively easy to set up and maintain, its implementation will require that researchers re-consider their relationship with research participants and adopt new procedures.

IL-1R8 is a checkpoint in NK cells regulating anti-tumour and anti-viral activity

Abstract: Interleukin-1 receptor 8 (IL-1R8, also known as single immunoglobulin IL-1R-related receptor, SIGIRR, or TIR8) is a member of the IL-1 receptor (ILR) family with distinct structural and functional characteristics, acting as a negative regulator of ILR and Toll-like receptor (TLR) downstream signalling pathways and inflammation. Natural killer (NK) cells are innate lymphoid cells which mediate resistance against pathogens and contribute to the activation and orientation of adaptive immune responses. NK cells mediate resistance against haematopoietic neoplasms but are generally considered to play a minor role in solid tumour carcinogenesis. Here we report that IL-1R8 serves as a checkpoint for NK cell maturation and effector function. Its genetic blockade unleashes NK-cell-mediated resistance to hepatic carcinogenesis, haematogenous liver and lung metastasis, and cytomegalovirus infection.

Innovative technologies for encapsulation of Mediterranean plants extracts

Abstract: Background High-added value biological compounds (BACs) from herbal and plant sources, such as essential oils (EO), antioxidants and volatile compounds, often exhibit remarkable features, ranging from nutritive and medicinal properties, as well as antimicrobial and antioxidant activities, which can be exploited in the production of functional foods. However, most BACs exhibit low water solubility, strong off-flavors/odors, and are generally unstable and easily degraded under common processing and storage conditions. Encapsulation is a technology that enables the delivery in food systems, the protection, as well as the controlled and targeted release of BACs. Scope and approach The aim of this review is to summarize the most important information for encapsulation of natural extracts using unconventional technologies. Key findings and conclusions Encapsulation is an excellent choice to stabilize BACs, and in particular EOs, and mask their strong flavors and odors. In particular, spray drying is one of the most economic and common encapsulation technologies. However, the challenges of reducing the operating costs, of developing high-throughput processes, of minimizing the use of organic solvents, and of increasing the level of functionality of the encapsulation systems are driving the research towards the implementation of innovative strategies and non-conventional methods, which incorporate the concepts of Green Food Processing.

Exact solutions of inflected functionally graded nano-beams in integral elasticity

Abstract: The elastostatic problem of a Bernoulli-Euler functionally graded nanobeam is formulated by adopting stress-driven nonlocal elasticity theory, recently proposed by G. Romano and R. Barretta. According to this model, elastic bending curvature is got by convoluting bending moment interaction with an attenuation function. The stress-driven integral relation is equivalent to a differential problem with higher-order homogeneous constitutive boundary conditions, when the special bi-exponential kernel introduced by Helmholtz is considered. Simple solution procedures, based on integral and differential formulations, are illustrated in detail to establish the exact expressions of nonlocal transverse displacements of inflected nano-beams of technical interest. It is also shown that all the considered nano-beams have no solution if Eringen's strain-driven integral model is adopted. The solutions of the stress-driven integral method indicate that the stiffness of nanobeams increases at smaller scales due to size effects. Local solutions are obtained as limit of the nonlocal ones when the characteristic length tends to zero.

A closed-form model for torsion of nanobeams with an enhanced nonlocal formulation

Abstract: An enhanced model of nonlocal torsion based on the Eringen theory is provided in this paper. The variational formulation is given and then the governing differential equation and boundary conditions of nonlocal nanobeams subjected to torsional loading are consistently derived. No higher-order boundary conditions are required for the enhanced model. It is assumed that the ends of nanobeams are not perfectly restrained thus focusing the attention also on the influence of elastically compliant boundary conditions on the behaviour of nonlocal models. Closed-form solutions are then provided for nanocantilevers and fully clamped nanobeams subject to distributed torsional loads. It is shown that the dimensionless small-scale parameter must fulfil a suitable inequality in order to avoid that a positive distributed torsional load provides a negative torsional rotation. The size-dependent static torsional behaviour of the proposed model in terms of torsional rotations and moments is tested. Contrary to the nonlocal Eringen model, the proposed enhanced model provides the small-scale effect also for nanobeams subjected to uniformly distributed torsional loads. Comparisons with Eringen model, gradient elasticity theory and classical (local) model are provided.

The Effect of Intra-articular Injection of Autologous Microfragmented Fat Tissue on Proteoglycan Synthesis in Patients with Knee Osteoarthritis.

Abstract: Osteoarthritis (OA) is one of the leading musculoskeletal disorders in the adult population. It is associated with cartilage damage triggered by the deterioration of the extracellular matrix tissue. The present study explores the effect of intra-articular injection of autologous microfragmented adipose tissue to host chondrocytes and cartilage proteoglycans in patients with knee OA. A prospective, non-randomized, interventional, single-center, open-label clinical trial was conducted from January 2016 to April 2017. A total of 17 patients were enrolled in the study, and 32 knees with osteoarthritis were assessed. Surgical intervention (lipoaspiration) followed by tissue processing and intra-articular injection of the final microfragmented adipose tissue product into the affected knee(s) was performed in all patients. Patients were assessed for visual analogue scale (VAS), delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) and immunoglobulin G (IgG) glycans at the baseline, three, six and 12 months after the treatment. Magnetic resonance sequence in dGEMRIC due to infiltration of the anionic, negatively charged contrast gadopentetate dimeglumine (Gd-DTPA2-) into the cartilage indicated that the contents of cartilage glycosaminoglycans significantly increased in specific areas of the treated knee joint. In addition, dGEMRIC consequently reflected subsequent changes in the mechanical axis of the lower extremities. The results of our study indicate that the use of autologous and microfragmented adipose tissue in patients with knee OA (measured by dGEMRIC MRI) increased glycosaminoglycan (GAG) content in hyaline cartilage, which is in line with observed VAS and clinical results.

Porphyrin-based cationic amphiphilic photosensitisers as potential anticancer, antimicrobial and immunosuppressive agents.

Abstract: Photodynamic therapy (PDT) combines a photosensitiser, light and molecular oxygen to induce oxidative stress that can be used to kill pathogens, cancer cells and other highly proliferative cells. There is a growing number of clinically approved photosensitisers and applications of PDT, whose main advantages include the possibility of selective targeting, localised action and stimulation of the immune responses. Further improvements and broader use of PDT could be accomplished by designing new photosensitisers with increased selectivity and bioavailability. Porphyrin-based photosensitisers with amphiphilic properties, bearing one or more positive charges, are an effective tool in PDT against cancers, microbial infections and, most recently, autoimmune skin disorders. The aim of the review is to present some of the recent examples of the applications and research that employ this specific group of photosensitisers. Furthermore, we will highlight the link between their structural characteristics and PDT efficiency, which will be helpful as guidelines for rational design and evaluation of new PSs.

Antiobesity Effects of Anthocyanins in Preclinical and Clinical Studies.

Abstract: The natural phytochemicals present in foods, including anthocyanins, might play a role in attenuating obesity by producing a decrease in weight and adipose tissue. This review focused on current knowledge about anthocyanins’ role in obesity and its related comorbidities reported in animal models and humans. We summarized their target identification and mechanism of action through several pathways and their final effects on health and well-being. Into consideration of ongoing researches, we highlighted the following key points: a healthy relationship between anthocyanin supplementation and antiobesity effects suffers of the same pros and cons evidenced when the beneficial responses to other phytochemical treatments towards different degenerative diseases have been considered; the different dosage applied in animal versus clinical studies; the complex metabolism and biotransformation to which anthocyanins and phytochemicals are subjected in the intestine and tissues; the possibility that different components present in the supplemented mixtures can interact generating antagonistic, synergistic, or additive effects difficult to predict, and the difference between prevention and therapy. The evolution of the field must seriously consider the need to establish new and adequate cellular and animal models which may, in turn, allow the design of more efficient and prevention-targeted clinical studies.

The European Renal Association - European Dialysis and Transplant Association Registry Annual Report 2014: A summary

Abstract: Background: This article summarizes the European Renal Association - European Dialysis and Transplant Association Registry's 2014 annual report. It describes the epidemiology of renal replacement therapy (RRT) for end-stage renal disease (ESRD) in 2014 within 35 countries. Methods: In 2016, the ERA-EDTA Registry received data on patients who in 2014 where undergoing RRT for ESRD, from 51 national or regional renal registries. Thirty-two registries provided individual patient level data and 19 provided aggregated patient level data. The incidence, prevalence and survival probabilities of these patients were determined. Results: In 2014, 70 953 individuals commenced RRT for ESRD, equating to an overall unadjusted incidence rate of 133 per million population (pmp). The incidence ranged by 10-fold; from 23 pmp in the Ukraine to 237 pmp in Portugal. Of the patients commencing RRT, almost two-thirds were men, over half were aged ≥65 years and a quarter had diabetes mellitus as their primary renal diagnosis. By day 91 of commencing RRT, 81% of patients were receiving haemodialysis. On 31 December 2014, 490 743 individuals were receiving RRT for ESRD, equating to an unadjusted prevalence of 924 pmp. This ranged throughout Europe by more than 10-fold, from 157 pmp in the Ukraine to 1794 pmp in Portugal. In 2014, 19 406 kidney transplantations were performed, equating to an overall unadjusted transplant rate of 36 pmp. Again this varied considerably throughout Europe. For patients commencing RRT during 2005-09, the 5-year-adjusted patient survival probabilities on all RRT modalities was 63.3% (95% confidence interval 63.0-63.6). The expected remaining lifetime of a 20- to 24-year-old patient with ESRD receiving dialysis or living with a kidney transplant was 21.9 and 44.0 years, respectively. This was substantially lower than the 61.8 years of expected remaining lifetime of a 20-year-old patient without ESRD.

Atmospheric impact of ship traffic in four Adriatic-Ionian port-cities: comparison and harmonization of different approaches

Abstract: Shipping is a growing transport sector representing a relevant share of atmospheric pollutant emissions at global scale. In the Mediterranean Sea, shipping affects air quality of coastal urban areas with potential hazardous effects on both human health and climate. The high number of different approaches for investigating this aspect limits the comparability of results. Furthermore, limited information regarding the inter-annual trends of shipping impacts is available. In this work, an approach integrating emission inventory, numerical modelling (WRF-CAMx modelling system), and experimental measurements at high and low temporal resolution is used to investigate air quality shipping impact in the Adriatic/Ionian area focusing on four port-cities: Brindisi and Venice (Italy), Patras (Greece), and Rijeka (Croatia). Results showed shipping emissions of particulate matter (PM) and NOx comparable to road traffic emissions at all port-cities, with larger contributions to local SO2 emissions. Contributions to PM2.5 ranged between 0.5% (Rijeka) and 7.4% (Brindisi), those to PM10 were between 0.3% (Rijeka) and 5.8% (Brindisi). Contributions to particle number concentration (PNC) showed an impact 2–4 times larger with respect to that on mass concentrations. Shipping impact on gaseous pollutants are larger than those to PM. The contribution to total polycyclic aromatic hydrocarbon (PAHs) concentrations was 82% in Venice and 56% in Brindisi, with a different partition gas-particle because of different meteorological conditions. The inter-annual trends analysis showed the primary contribution to PM concentrations decreasing, due to the implementation of the European legislation on the use of low-sulphur content fuels. This effect was not present on other pollutants like PAHs.

Satisfaction as a determinant of tourist expenditure

Abstract: The main aim of this study is to analyse the influence of tourist satisfaction with the tourism offering on tourist expenditure in the destination. Quantitative analysis is based on 523 self-administered questionnaires collected from tourists visiting Rijeka and the Opatija Riviera (Croatia) during the summer of 2014. Principal component analysis was conducted on 22 elements of the offering in order to reduce the dimensionality of satisfaction with the tourism offering, resulting in four dimensions of satisfaction. Regression analysis was conducted with the log of daily expenditure as a dependent variable. The results revealed that only one satisfaction dimension (related to the diversity of facilities) out of the four proved to be a significant predictor of tourist expenditure in the destination. The study also confirms that family income, type of accommodation, past behaviour and length of stay significantly influence daily expenditure.

Application of gradient elasticity to armchair carbon nanotubes: Size effects and constitutive parameters assessment

Abstract: The central focus of the paper is set on modelling of bending of armchair carbon nanotubes by means of the gradient elasticity theory. Influence of small-size effects on the Young's modulus is investigated. An attempt to determine small size (or nonlocal) parameter employed in the Bernoulli-Euler and Timoshenko gradient formulations is presented. To obtain such a goal, the paper provides an extensive set of molecular structural mechanics simulations of armchair nanotubes with different loading and kinematic boundary conditions. Dependence of the Young's modulus on small size effects is clearly noticed. Based on these results, small scale parameters for the gradient model are identified and limits of the method are pointed out. Results of the study indicate that the widely used theory should be modified to obtain a physically justified and reliable nanobeam model based on Bernoulli-Euler or Timoshenko kinematic assumptions.

NKG2D-Dependent Antitumor Effects of Chemotherapy and Radiotherapy against Glioblastoma.

Abstract: Purpose: NKG2D is a potent activating immune cell receptor, and glioma cells express the cognate ligands (NKG2DL). These ligands are inducible by cellular stress and temozolomide (TMZ) or irradiation (IR), the standard treatment of glioblastoma, could affect their expression. However, a role of NKG2DL for the efficacy of TMZ and IR has never been addressed.Experimental Design: We assessed the effect of TMZ and IR on NKG2DL in vitro and in vivo in a variety of murine and human glioblastoma models, including glioma-initiating cells, and a cohort of paired glioblastoma samples from patients before and after therapy. Functional effects were studied with immune cell assays. The relevance of the NKG2D system for the efficacy of TMZ and IR was assessed in vivo in syngeneic orthotopic glioblastoma models with blocking antibodies and NKG2D knockout mice.Results: TMZ or IR induced NKG2DL in vitro and in vivo in all glioblastoma models, and glioblastoma patient samples had increased levels of NKG2DL after therapy with TMZ and IR. This enhanced the immunogenicity of glioma cells in a NGK2D-dependent manner, was independent from cytotoxic or growth inhibitory effects, attenuated by O6-methylguanine-DNA-methyltransferase (MGMT), and required the DNA damage response. The survival benefit afforded by TMZ or IR relied on an intact NKG2D system and was decreased upon inhibition of the NKG2D pathway.Conclusions: The immune system may influence the activity of convential cancer treatments with particular importance of the NKG2D pathway in glioblastoma. Our data provide a rationale to combine NKG2D-based immunotherapies with TMZ and IR. Clin Cancer Res; 24(4); 882-95. ©2017 AACR.

Diagnostic Accuracy of Abdominal Ultrasound for Diagnosis of Acute Appendicitis: Systematic Review and Meta-analysis.

Abstract: To determine the diagnostic accuracy of abdominal ultrasound (US) for the diagnosis of acute appendicitis (AA), in terms of sensitivity, specificity and post-test probabilities for positive and negative result. A systematic search of MEDLINE, Embase, The Cochrane library and Science Citation Index Expanded from January 1994 to October 2014 was performed. Two authors independently evaluated studies for inclusion, extracted data and performed analyses. The reference standard for evaluation of final diagnosis was pathohistological report on tissue obtained at appendectomy. Summary sensitivity, specificity and post-test probability of AA after positive and negative result of US with corresponding 95% confidence intervals (CI) were calculated. Out of 3306 references identified through electronic searches, 17 reports met the inclusion criteria, with 2841 included participants. The summary sensitivity and specificity of US for diagnosis of AA were 69% (95% CI 59–78%) and 81% (95% CI 73–88%), respectively. At the median pretest probability of AA of 76.4%, the post-test probability for a positive and negative result of US was 92% (95% CI 88–95%) and 55% (95% CI 46–63%), respectively. Abdominal ultrasound does not seem to have a role in the diagnostic pathway for diagnosis of AA in suspected patients. The summary sensitivity and specificity of US do not exceed that of physical examination. Patients that require additional diagnostic workup should be referred to more sensitive and specific diagnostic procedures, such as computed tomography.

Link prediction on Twitter.

Abstract: With over 300 million active users, Twitter is among the largest online news and social networking services in existence today. Open access to information on Twitter makes it a valuable source of data for research on social interactions, sentiment analysis, content diffusion, link prediction, and the dynamics behind human collective behaviour in general. Here we use Twitter data to construct co-occurrence language networks based on hashtags and based on all the words in tweets, and we use these networks to study link prediction by means of different methods and evaluation metrics. In addition to using five known methods, we propose two effective weighted similarity measures, and we compare the obtained outcomes in dependence on the selected semantic context of topics on Twitter. We find that hashtag networks yield to a large degree equal results as all-word networks, thus supporting the claim that hashtags alone robustly capture the semantic context of tweets, and as such are useful and suitable for studying the content and categorization. We also introduce ranking diagrams as an efficient tool for the comparison of the performance of different link prediction algorithms across multiple datasets. Our research indicates that successful link prediction algorithms work well in correctly foretelling highly probable links even if the information about a network structure is incomplete, and they do so even if the semantic context is rationalized to hashtags.

Multiband variability studies and novel broadband SED modeling of Mrk 501 in 2009

Abstract: We present an extensive study of the BL Lac object Mrk 501 based on a data set collected during the multi-instrument campaign spanning from 2009 March 15 to 2009 August 1, which includes, among other instruments, MAGIC, VERITAS, Whipple 10 m, and Fermi-LAT to cover the γ-ray range from 0.1 GeV to 20 TeV; RXTE and Swift to cover wavelengths from UV tohard X-rays; and GASP-WEBT, which provides coverage of radio and optical wavelengths. Optical polarization measurements were provided for a fraction of the campaign by the Steward and St. Petersburg observatories. We evaluate the variability of the source and interband correlations, the γ-ray flaring activity occurring in May 2009, and interpret the results within two synchrotron self-Compton (SSC) scenarios. Aims. The multiband variability observed during the full campaign is addressed in terms of the fractional variability, and the possible correlations are studied by calculating the discrete correlation function for each pair of energy bands where the significance was evaluated with dedicated Monte Carlo simulations. The space of SSC model parameters is probed following a dedicated grid-scan strategy, allowing for a wide range of models to be tested and offering a study of the degeneracy of model-to-data agreement in the individual model parameters, hence providing a less biased interpretation than the “single-curve SSC model adjustment” typically reported in the literature. Methods. We find an increase in the fractional variability with energy, while no significant interband correlations of flux changes are found on the basis of the acquired data set. The SSC model grid-scan shows that the flaring activity around May 22 cannot be modeled adequately with a one-zone SSC scenario (using an electron energy distribution with two breaks), while it can be suitably described within a two (independent) zone SSC scenario. Here, one zone is responsible for the quiescent emission from the averaged 4.5-month observing period, while the other one, which is spatially separated from the first, dominates the flaring emission occurring at X-rays and very-high-energy (>100 GeV, VHE) γ rays. The flaring activity from May 1, which coincides with a rotation of the electric vector polarization angle (EVPA), cannot be satisfactorily reproduced by either a one-zone or a two-independent-zone SSC model, yet this is partially affected by the lack of strictly simultaneous observations and the presence of large flux changes on sub-hour timescales (detected at VHE γ rays). Results. The higher variability in the VHE emission and lack of correlation with the X-ray emission indicate that, at least during the 4.5-month observing campaign in 2009, the highest energy (and most variable) electrons that are responsible for the VHE γ rays do not make a dominant contribution to the ~1 keV emission. Alternatively, there could be a very variable component contributing to the VHE γ-ray emission in addition to that coming from the SSC scenario. The studies with our dedicated SSC grid-scan show that there is some degeneracy in both the one-zone and the two-zone SSC scenarios probed, with several combinations of model parameters yielding a similar model-to-data agreement, and some parameters better constrained than others. The observed γ-ray flaring activity, with the EVPA rotation coincident with the first γ-ray flare, resembles those reported previously for low frequency peaked blazars, hence suggesting that there are many similarities in the flaring mechanisms of blazars with different jet properties.

Regulatory module involving FGF13, miR-504, and p53 regulates ribosomal biogenesis and supports cancer cell survival

Abstract: The microRNA miR-504 targets TP53 mRNA encoding the p53 tumor suppressor. miR-504 resides within the fibroblast growth factor 13 (FGF13) gene, which is overexpressed in various cancers. We report that the FGF13 locus, comprising FGF13 and miR-504, is transcriptionally repressed by p53, defining an additional negative feedback loop in the p53 network. Furthermore, we show that FGF13 1A is a nucleolar protein that represses ribosomal RNA transcription and attenuates protein synthesis. Importantly, in cancer cells expressing high levels of FGF13, the depletion of FGF13 elicits increased proteostasis stress, associated with the accumulation of reactive oxygen species and apoptosis. Notably, stepwise neoplastic transformation is accompanied by a gradual increase in FGF13 expression and increased dependence on FGF13 for survival ("nononcogene addiction"). Moreover, FGF13 overexpression enables cells to cope more effectively with the stress elicited by oncogenic Ras protein. We propose that, in cells in which activated oncogenes drive excessive protein synthesis, FGF13 may favor survival by maintaining translation rates at a level compatible with the protein quality- control capacity of the cell. Thus, FGF13 may serve as an enabler, allowing cancer cells to evade proteostasis stress triggered by oncogene activation.