University of Rijeka

About: University of Rijeka is a education organization based out in Rijeka, Croatia. It is known for research contribution in the topics: Population & Tourism. The organization has 3471 authors who have published 7993 publications receiving 110386 citations. The organization is also known as: Rijeka University & Sveučilište u Rijeci.

Multiple Sclerosis patients carry an increased burden of exceedingly rare genetic variants in the inflammasome regulatory genes.

Abstract: The role of rare genetic variation and the innate immune system in the etiology of multiple sclerosis (MS) is being increasingly recognized. Recently, we described several rare variants in the NLRP1 gene, presumably conveying an increased risk for familial MS. In the present study we aimed to assess rare genetic variation in the inflammasome regulatory network. We performed whole exome sequencing of 319 probands, comprising patients with familial MS, sporadic MS and control subjects. 62 genes involved in the NLRP1/NLRP3 inflammasome regulation were screened for potentially pathogenic rare genetic variation. Aggregate mutational burden was analyzed, considering the variants’ predicted pathogenicity and frequency in the general population. We demonstrate an increased (p = 0.00004) variant burden among MS patients which was most pronounced for the exceedingly rare variants with high predicted pathogenicity. These variants were found in inflammasome genes (NLRP1/3, CASP1), genes mediating inflammasome inactivation via auto and mitophagy (RIPK2, MEFV), and genes involved in response to infection with DNA viruses (POLR3A, DHX58, IFIH1) and to type-1 interferons (TYK2, PTPRC). In conclusion, we present new evidence supporting the importance of rare genetic variation in the inflammasome signaling pathway and its regulation via autophagy and interferon-β to the etiology of MS.

Effects of environmental factors on severity and mortality of COVID-19

Abstract: Background Most respiratory viruses show pronounced seasonality, but for SARS-CoV-2 this still needs to be documented. Methods We examined the disease progression of COVID-19 in 6,911 patients admitted to hospitals in Europe and China. In addition, we evaluated progress of disease symptoms in 37,187 individuals reporting symptoms into the COVID Symptom Study application. Findings Meta-analysis of the mortality risk in eight European hospitals estimated odds ratios per one day increase in the admission date to be 0.981 (0.973-0.988, p<0.001) and per increase in ambient temperature of one degree Celsius to be 0.854 (0.773-0.944, p=0.007). Statistically significant decreases of comparable magnitude in median hospital stay, probability of transfer to Intensive Care Unit and need for mechanical ventilation were also observed in most, but not all hospitals. The analysis of individually reported symptoms of 37,187 individuals in the UK also showed the decrease in symptom duration and disease severity with time. Interpretation Severity of COVID-19 in Europe decreased significantly between March and May and the seasonality of COVID-19 is the most likely explanation. Mucosal barrier and mucociliary clearance can significantly decrease viral load and disease progression, and their inactivation by low relative humidity of indoor air might significantly contribute to severity of the disease.

Expression of CD133 and CD117 in 64 Serous Ovarian Cancer Cases.

Abstract: The cancer stem cells (CSCs) represent a minority of tumor cells that are able to proliferate and self-renew and might be responsible for tumor initiation and maintenance. The CD133 and CD117 are the most commonly used markers for the putative CSCs, especially for the ovarian CSCs, but its clinical significance remains uncertain. The aim of this study was to compare the immunohistochemical expression of CD133 and CD117 in 64 primary ovarian high grade serous carcinoma and peritoneal metastasis, and to examine their potential clinical role. CD133 expression was mainly seen in the apical/endoluminal cell surface of tumor cells and was found in 61% of the carcinoma samples and 41% of the metastasis. The median of CD133 positive cells in tumors was 1 (0.1-7)%, and in metastases was 0.6 (0.1-6)%. CD117 expression appeared as a cytoplasmic and/or membranous stain and was found in 81% of the carcinoma samples and 77% of the metastasis. The median of CD117 positive cells in tumors was 1 (0.1-8)%, and in metastases was 0.1 (0.1-7)%. Multivariate analysis has shown that patients with high CD133 expression in tumor cells have significantly shorter disease free survival and overall survival (p=0.025 and p=0.014, respectively). Patients with high CD117 expression in tumor cells have significantly shorter disease free survival (p=0.031). Cox's proportional hazards model identified expression of CD133 protein in tumor as an independent prognostic factor. Our study indicates that the immunohistochemical assessment of CD133 and CD117 expression may have potential clinical value in predicting disease progression and prognosis in the high grade serous ovarian cancer. CD133 proved to be an independent prognostic factor in the high grade serous ovarian cancer patients.

Astroglial amino acid-based transmitter receptors.

Abstract: Amino acids appear in prebiotic period being one of the first organic molecules on Earth. For neurobiologists, it is of importance that AAs are not only representing building blocks of life, but are also the essential part of metabolism and cellular signaling. In the mammalian brain, the most common excitatory and inhibitory transmitters acting upon cellular plasmalemmal receptors are the amino acid glutamate and its derivative γ-aminobutyric acid, respectively. Other amino acids, i.e. aspartate, glycine, d-serine, and homocysteic acid, as well as the sulfonic acid taurine, are also active compounds involved in receptor-mediated brain signaling. Receptors for these amino acid-based transmitters are either ion channels, also referred to as ionotropic receptors, or metabotropic, i.e. seven transmembrane domain G-protein coupled receptors. In this mini-review, we focus our interest on amino acid-based transmitter receptors on neuroglia, astrocytes in particular.

Koopman Operator Spectrum for Random Dynamical Systems

Abstract: In this paper we consider the Koopman operator associated with the discrete and the continuous time random dynamical system (RDS). We provide results that characterize the spectrum and the eigenfunctions of the stochastic Koopman operator associated with different types of linear RDS. Then we consider the RDS for which the associated Koopman operator family is a semigroup, especially those for which the generator can be determined. We define a stochastic Hankel DMD (sHankel-DMD) algorithm for numerical approximations of the spectral objects (eigenvalues, eigenfunctions) of the stochastic Koopman operator and prove its convergence. We apply the methodology to a variety of examples, revealing objects in spectral expansions of the stochastic Koopman operator and enabling model reduction.