University of Zagreb

About: University of Zagreb is a education organization based out in Zagreb, Grad Zagreb, Croatia. It is known for research contribution in the topics: Population & European union. The organization has 21769 authors who have published 50267 publications receiving 783239 citations. The organization is also known as: Zagreb University & Sveučilište u Zagrebu.

Teaching in the Age of Covid-19

Abstract: A collection of 84 author's testimonies and workspace photographs between 18 March and 5 May 2020

Mucoadhesive liposomal delivery systems: the choice of coating material

Abstract: Objective: Development of liposomal mucoadhesive drug delivery system, which is able to improve the bioavailability of poorly absorbed oral drugs by prolonging their gastric and intestinal residence time, through facilitating the intimate contact of the delivery system with the absorption membrane. Materials and methods: Liposomes containing model drug atenolol were prepared by the modified ethanol injection method. Liposomes containing atenolol were coated by different mucoadhesive polymers, for example, chitosan, Carbopol 974P, Eudragit L100, and Eudragit S100, to optimize the choice of coating material. The delivery systems were tested for their in vitro mucoadhesiveness. Results: Liposomes prepared by the ethanol injection method were of satisfactory size (around 100 nm, before coating). Through the coating of liposomes in the presence of unentrapped material, the entrapment efficiency for drug was increased. In vitro mucoadhesive test confirmed the mucoadhesive properties of the coated layer for all tested polymers; however, Eudragit S100-coated liposomes were superior to other coating materials. Discussion: Eudragit coating appeared to be an optimal polymer choice. These preliminary data indicate that polymer-coated mucoadhesive liposomes are able to carry sufficient amount of drug and to remain attached to the intestinal mucosa for a sufficient period of time to enable prolonged absorption of entrapped drug. Conclusion: While keeping in mind that the in vivo conditions may vary with the in vitro ones, we may recommend the system described in our work for possible oral delivery of peptides and phytochemicals.

Antimicrobials: a global alliance for optimizing their rational use in intra-abdominal infections (AGORA)

Abstract: Intra-abdominal infections (IAI) are an important cause of morbidity and are frequently associated with poor prognosis, particularly in high-risk patients. The cornerstones in the management of complicated IAIs are timely effective source control with appropriate antimicrobial therapy. Empiric antimicrobial therapy is important in the management of intra-abdominal infections and must be broad enough to cover all likely organisms because inappropriate initial antimicrobial therapy is associated with poor patient outcomes and the development of bacterial resistance. The overuse of antimicrobials is widely accepted as a major driver of some emerging infections (such as C. difficile), the selection of resistant pathogens in individual patients, and for the continued development of antimicrobial resistance globally. The growing emergence of multi-drug resistant organisms and the limited development of new agents available to counteract them have caused an impending crisis with alarming implications, especially with regards to Gram-negative bacteria. An international task force from 79 different countries has joined this project by sharing a document on the rational use of antimicrobials for patients with IAIs. The project has been termed AGORA (Antimicrobials: A Global Alliance for Optimizing their Rational Use in Intra-Abdominal Infections). The authors hope that AGORA, involving many of the world's leading experts, can actively raise awareness in health workers and can improve prescribing behavior in treating IAIs.

Thyroid‐Stimulating Hormone Restores Bone Volume, Microarchitecture, and Strength in Aged Ovariectomized Rats*

Abstract: We show the systemic administration of low levels of TSH increases bone volume and improves bone microarchitecture and strength in aged OVX rats. TSH's actions are mediated by its inhibitory effects on RANKL-induced osteoclast formation and bone resorption coupled with stimulatory effects on osteoblast differentiation and bone formation, suggesting TSH directly affects bone remodeling in vivo. Introduction Thyroid-stimulating hormone (TSH) receptor haploinsufficient mice with normal circulating thyroid hormone levels have reduced bone mass, suggesting that TSH directly affects bone remodeling. We examined whether systemic TSH administration restored bone volume in aged ovariectomized (OVX) rats and influenced osteoclast formation and osteoblast differentiation in vitro. Materials and methods Sprague-Dawley rats were OVX at 6 months, and TSH therapy was started immediately after surgery (prevention mode; n = 80) or 7 mo later (restoration mode; n = 152). Hind limbs and lumbar spine BMD was measured at 2- or 4-wk intervals in vivo and ex vivo on termination at 8-16 wk. Long bones were subjected to microCT, histomorphometric, and biomechanical analyses. The direct effect of TSH was examined in osteoclast and osteoblast progenitor cultures and established rat osteosarcoma-derived osteoblastic cells. Data were analyzed by ANOVA Dunnett test. Results In the prevention mode, low doses (0.1 and 0.3 microg) of native rat TSH prevented the progressive bone loss, and importantly, did not increase serum triiodothyroxine (T3) and thyroxine (T4) levels in aged OVX rats. In restoration mode, animals receiving 0.1 and 0.3 microg TSH had increased BMD (10-11%), trabecular bone volume (100-130%), trabecular number (25-40%), trabecular thickness (45-60%), cortical thickness (5-16%), mineral apposition and bone formation rate (200-300%), and enhanced mechanical strength of the femur (51-60%) compared with control OVX rats. In vitro studies suggest that TSH's action is mediated by its inhibitory effects on RANKL-induced osteoclast formation, as shown in hematopoietic stem cells cultivated from TSH-treated OVX rats. TSH also stimulates osteoblast differentiation, as shown by effects on alkaline phosphatase activity, osteocalcin expression, and mineralization rate. Conclusions These results show for the first time that systemically administered TSH prevents bone loss and restores bone mass in aged OVX rats through both antiresorptive and anabolic effects on bone remodeling.

Centrality dependence of low-momentum direct-photon production in Au plus Au collisions at root s(NN)=200 GeV

Abstract: The PHENIX experiment at RHIC has measured the centrality dependence of the direct photon yield from Au+Au collisions at sNN−−−√=200 GeV down to pT=0.4 GeV/c. Photons are detected via photon conversions to e+e− pairs and an improved technique is applied that minimizes the systematic uncertainties that usually limit direct photon measurements, in particular at low pT. We find an excess of direct photons above the Ncoll-scaled yield measured in p+p collisions. This excess yield is well described by an exponential distribution with an inverse slope of about 240MeV/c in the pT range 0.6–2.0 GeV/c. While the shape of the pT distribution is independent of centrality within the experimental uncertainties, the yield increases rapidly with increasing centrality, scaling approximately with Nαpart, where α=1.38±0.03(stat)±0.07(syst).