Izbor staništa i sličnosti zajednica ptica pjevica u šumama parkova prirode Medvednica i Žumberak – Samoborsko gorje

The effect of floristic and structural characteristics of vegetation on the forest songbird communities in two Nature Parks: Medvednica andŽumberak – Samoborsko gorje was studied. The point-count method was used for analyzing songbird communities and circular plot method for habitat mapping, on 101 points at both sites. Non-parametric test were used (Kruskal– Wallis and Kendal Tau). The tree basal area was used to classify studied points into five forest types (beech, oak, mixed deciduous, coniferous and mixed coniferous forests) and as indication of the stand maturity. The total of27 and 32 songbird species were recorded on Medvednica and Žumberak –Samoborsko gorje respectively. Diversity was higher on Žumberak – Samoborsko gorje due to greater habitat fragmentation, while population density of songbirds was greater on Medvednica. Among structural characteristics, those related to forest age (average tree basal area and number of the small trees) had the most pronounced effect to the total songbird density and densities of different ecological groups of birds. Sorensen index showed that in spite of the differences in floristic composition between particular forest types in two studied areas (0.475 ± 0.120), songbird communities showed high similarity (0.872 ± 0.070). The highest similarity of songbird communities between Parks was recorded in beech and oak stands. Oak stands showed the lowest similarity in tree species composition and no significant difference in structural characteristics, while beech stands had many different structural features and several differences in densities of ecological groups of birds. The greatest difference of bird densities in the particular forest type between two Parks was found in beech and mixed coniferous stands. High structural differences between these two forests were the result of the forest age; bird populations had higher densities in older stands.Istraživanja zajednica ptica pjevica šumskih staništa ukazuju da na njihovu strukturu i gustoću populacija mogu utjecati floristička i strukturalna svojstva vegetacije. U ovom istraživanju željeli smo, usporedbom zajednica ptica šumskih staništa dvaju parkova prirode, utvrditi utjecaj florističkih i strukturalnih svojstava vegetacije na zajednicu ptica gnjezdarica. Istraživanje je provedeno tijekom 2006. i 2007. u Parkovima prirode Medvednica i Žumberak – Samoborsko gorje. Šume pokrivaju oko 60 % površineu oba parka, ali su kontinuirane na Medvednici i nešto rascjepkanije na Žumberku. Istraživanje ptica provedeno je metodom prebrojavanja u točki, a uzorkovanje staništa metodom kružnih ploha. Istraživanje je provedeno na ukupno101 točki: 49 na Medvednici i 52 na Žumberku. Pri statističkoj obradi korišteni su neparametrijski testovi (Kruskal–Wallis i Kendal Tau). Udio temeljnice stabala korišten je za određivanje pripadnosti pojedinom šumskim tipu: bukovoj, hrastovoj, mješovitoj listopadnoj i mješovitoj crnogoričnoj šumi. Prosječna temeljnica stabla korištena je kao indikator starosti šume. Istraživanjem je zabilježeno ukupno 27 vrsta ptica pjevica u šumama Medvednice i32 na Žumberku (Tablica 1). Šest vrsta ptica bilo je vezano uz određeni tip šume, s više od 40 % parova zabilježenih u tom šumskom tipu. Diverzitet vrstabio je viši na Žumberku, dok je gustoća populacija ptica pjevica bila veća na Medvednici (Slika 2). Sorensenov indeks pokazao je da zajednice ptica istog tipa šume između dva područja pokazuju znatno veću sličnost nego floristički sastav (Slika 3). Najveća sličnost u zajednicama ptica između dva Parka zabilježena je u bukovim i hrastovim sastojinama. Hrastove sastojine pokazuju najmanju florističku sličnost, ali nemaju značajnih razlika u strukturalnim svojstvima niti u ekološkim skupinama ptica. Bukove sastojine naprotiv pokazuju značajne strukturalne razlike i u njima je, kao i u mješovitim crnogoričnim sastojinama, zabilježena najveća razlika među ekološkim skupinama ptica između dva Parka. Strukturalne razlike tih šuma između dva Parka su rezultat različite starosti sastojina, a ptice su imale veće gustoće u starijim šu-mama. Među strukturalnim svojstvima vegetacije, ona vezana uz starost šume (prosječna temeljnica i broj mladih stabala) bile su značajno korelirane s ukupnom gustoćom populacija pjevica i s gustoćom različitih ekoloških skupina. Zaključak je ovog istraživanja da floristički sastav šuma ima utjecaj na odabir tipa šume u kojoj će se neke vrste ptica pjevica gnijezditi, dok na odabir samog područja gniježđenja veći utjecaj imaju strukturalna svojstva šume

ROUTINE PROCEDURES AND PREVENTIVE MEASURES IN TISSUE BANKING AND CELL THERAPY DURING COVID-19 PANDEMIC

Following the rapid spread of SARS-CoV-2 worldwide, this article describes routine procedures and preventive measures for tissue banking and cell therapy in University Hospital Centre “Sestre milosrdnice” in the Republic of Croatia. This paper describes our current practice for preventing contamination and microbiological environmental monitoring of cleanrooms, the protection of healthcare personnel as well as patients from SARS-CoV-2. These measures are based on the recommendations obtained from the Ministry of Health of the Republic of Croatia, the Croatian Institute of Public Health and the European Centre for Disease Prevention and Control. We also present data on samples collected and treated in this period in comparison to normal work conditions before COVID-19

Fibrin u tkivnom inženjerstvu kože – proizvodnja i kliničko iskustvo

The purpose of this study was to create a fibrin-based human skin substitute in vitro with epidermal and dermal component and to assess its healing potential in deep partial and full thickness burns. Fibrin scaffolds were prepared from commercial fibrin glue kits. Human fibroblasts were cultured in fibrin gel. Human keratinocytes were seeded on the top of the gel. Viability of cells was determined fluorimetrically. Scanning electron microscope and immunocytochemistry analysis of cultured cells were performed. After hydrosurgical preparation of deep burn necrotic tissue, wound bed was prepared for skin substitutes. Progress of healing was documented using visual estimation and photos. Scanning electron microscope images showed good cell attachment and colony spreading of keratinocytes and fibroblasts on fibrin scaffold. Immunofluorescent staining of cell cultures on fibrin scaffold showed expression of vimentin, a marker of fibroblast cells, cytokeratin 19, a marker of epithelial stem cells, as well as involucrin, a marker of differentiated keratinocytes. Clinical results clearly showed that appearance of the skin did not differ significantly from the areas of transplanted skin using split-thickness skin graft techniques. In conclusion, using these fibrin-cultured autografts on massive full-thickness burn resulted in good healing.Cilj ovoga istraživanja bio je kreirati in vitro nadomjestak ljudske kože s epidermalnim i dermalnim dijelom. Pritom smo koristili fibrinski gel kao nosač stanica. Procijenili smo učinak nadomjestka kože na cijeljenje opeklina drugog i trećeg stupnja. Fibrinski gel načinjen je od komercijalnog kirurškog fibrinskog ljepila. Ljudski fibroblasti kultivirani su u samom fibrinskom nosaču. Ljudski keratinociti zasijani su na gornju površinu nosača. Vijabilnost uzgojenih stanica određena je fluorimetrijski. Nadomjestak kože analiziran je elektronskim skenirajućim mikroskopom. Napravljena je imunocitokemijska analiza kultiviranih stanica. Skenirajući mikroskop pokazao je dobro prianjanje i proliferaciju stanica kože na nosaču. Imunocitokemijska analiza pokazala je prisutnost vimentina, biljega fibroblastnih stanica; citokeratina 19, biljega epitelnih matičnih stanica; te involukrina, biljega diferenciranih keratinocita. Klinička primjena ovih nadomjestaka kože pokazala je slične rezulatate cijeljenja kao i dijelovi rana koji su prekriveni autolognim presatcima kože djelomične debljine. Zaključujemo da nadomjestci kože bazirani na fibrinskom nosaču imaju potencijala u liječenju teških opeklina

Synthetic vs natural scaffolds for human limbal stem cells

Aim To investigate the impact of synthetic electrospun polyurethane (PU) and polycaprolactone (PCL) nanoscaffolds, before and after hydrolytic surface modification, on viability and differentiation of cultured human eye epithelial cells, in comparison with natural scaffolds: fibrin and human amniotic membrane. Methods Human placenta was taken at elective cesarean delivery. Fibrin scaffolds were prepared from commercial fibrin glue kits. Nanoscaffolds were fabricated by electrospinning. Limbal cells were isolated from surpluses of human cadaveric cornea and seeded on feeder 3T3 cells. The scaffolds used for viability testing and immunofluorescence analysis were amniotic membrane, fibrin, PU, and PCL nanoscaffolds, with or without prior NaOH treatment. Results Scanning electron microscope photographs of all tested scaffolds showed good colony spreading of seeded limbal cells. There was a significant difference in viability performance between cells with highest viability cultured on tissue culture plastic and cells cultured on all other scaffolds. On the other hand, electrospun PU, PCL, and electrospun PCL treated with NaOH had more than 80% of limbal cells positive for stem cell marker p63 compared to only 27%of p63 positive cells on fibrin. Conclusion Natural scaffolds, fibrin and amniotic membrane, showed better cell viability than electrospun scaffolds. On the contrary, high percentages of p63 positive cells obtained on these scaffolds still makes them good candidates for efficient delivery systems for therapeutic purpose

Postupci obrade i pripreme životinjske izvanstanične matrice za primjenu u tkivnom inženjerstvu

Tkivno inženjerstvo je interdisciplinarno područje koje isprepliće biomedicinske znanosti te inženjerstvo. Razvojem navedenih grana i sve strožim zahtjevima kliničke medicine, nametnula se potreba za razvojem biokompatibilnih te bioaktivnih implantata koji bi mogli zamjenjivati i poticati regeneraciju oboljelog tkiva. U cilju razvoja biomimetičkih materijala i implantata, decelularizacija se istaknula kao pogodna metoda jer izolira prirodno prisutnu izvanstaničnu matricu sa svim komponentama iz odabranog tkiva te uklanja stanice i genski sadržaj koji bi mogao izazvati reakciju imuniteta pacijenta. Razvijeno je više metoda decelularizacije koje se mogu podijeliti na kemijske, fizikalne, biokemijske te kombinirane. Svaka metoda specifična je i razvija se za pojedino tkivo te se najčešće koriste kombinirane metode jer kombiniraju dobra svojstva pojedinih metoda pa postižu dobro uklanjanje stanica uz minimalna oštećenja komponenti izvanstanične matrice. Na tržištu su već dostupni proizvodi pripravljeni od decelularizirane izvanstanične matrice te se daljnjim razvojem područja očekuje njihov sve veći broj

Pattern of Neuronal and Axonal Damage, Glial Response, and Synaptic Changes in Rat Cerebellum within the First Week following Traumatic Brain Injury

Abstract We examined damage and repair processes in the rat cerebellum within the first week following moderate traumatic brain injury (TBI) induced by lateral fluid percussion injury (LFPI) over the left parietal cortex. Rats were killed 1, 3, or 7 days after the injury or sham procedure. Fluoro-Jade B staining revealed 2 phases of neurodegenerative changes in the cell bodies and fibers: first, more focal, 1 day after the LFPI, and second, widespread, starting on post-injury day 3. Purkinje cell loss was detected in posterior lobule IX 1 day following LFPI. Apoptosis was observed in the cerebellar cortex, on days 1 and 7 following LFPI, and was not caspase- or apoptosis-inducing factor (AIF)-mediated. AIF immunostaining indicated axonal damage in the cerebellar white matter tracts 3- and 7-days post-injury. Significant astrocytosis and microgliosis were noticed on day 7 following LFPI at the sites of neuronal damage and loss. Immunohistochemical labeling with the presynaptic markers synaptophysin and growth-associated protein-43 revealed synaptic perturbations already on day 1 that were more pronounced at later time points following LFPI. These results provide new insights into pathophysiological alterations in the cerebellum and their mechanisms following cerebral TBI

Long-Term Effects of Repetitive Mild Traumatic Injury on the Visual System in Wild-Type and TDP-43 Transgenic Mice

Little is known about the impairments and pathological changes in the visual system in mild brain trauma, especially repetitive mild traumatic brain injury (mTBI). The goal of this study was to examine and compare the effects of repeated head impacts on the neurodegeneration, axonal integrity, and glial activity in the optic tract (OT), as well as on neuronal preservation, glial responses, and synaptic organization in the lateral geniculate nucleus (LGN) and superior colliculus (SC), in wild-type mice and transgenic animals with overexpression of human TDP-43 mutant protein (TDP-43G348C) at 6 months after repeated closed head traumas. Animals were also assessed in the Barnes maze (BM) task. Neurodegeneration, axonal injury, and gliosis were detected in the OT of the injured animals of both genotypes. In the traumatized mice, myelination of surviving axons was mostly preserved, and the expression of neurofilament light chain was unaffected. Repetitive mTBI did not induce changes in the LGN and the SC, nor did it affect the performance of the BM task in the traumatized wild-type and TDP-43 transgenic mice. Differences in neuropathological and behavioral assessments between the injured wild-type and TDP-43G348C mice were not revealed. Results of the current study suggest that repetitive mTBI was associated with chronic damage and inflammation in the OT in wild-type and TDP-43G348C mice, which were not accompanied with behavioral problems and were not affected by the TDP-43 genotype, while the LGN and the SC remained preserved in the used experimental conditions

The Reliability of PCL/Anti-VEGF Electrospun Scaffolds to Support Limbal Stem Cells for Corneal Repair

Since only few reported studies propose anti-vascular endothelial growth factor (anti-VEGF) delivery through electrospun scaffolds, this study greatly contributes to the potential prevention of patient’s vision loss, as it explores electrospun polycaprolactone (PCL) coated with anti-VEGF for the blockage of abnormal cornea vascularization. In terms of physicochemical properties, the biological component increased the PCL scaffold fiber diameter (by ~24%) and pore area (by ~82%), while ut slightly reduced its total porosity as the anti-VEGF solution filled the voids of the microfibrous structure. The addition of the anti-VEGF increased the scaffold stiffness almost three-fold at both strains of 5 and 10%, as well as its biodegradation rate (~36% after 60 days) with a sustained release profile after Day 4 of phosphate buffered saline incubation. In terms of scaffold application function, the PCL/Anti-VEGF scaffold proved to be more favorable for the adhesion of cultured limbal stem cells (LSCs); this was confirmed by the SEM images, where the cells showed flat and elongated conformations. Further support of the LSC growth and proliferation was confirmed by the identified p63 and CK3 markers after cell staining. These results demonstrate the advantageous effect of the surface-adsorbed anti-VEGF to stop vision loss and help damaged corneal tissue repair

Differential Expression Patterns of TDP-43 in Single Moderate versus Repetitive Mild Traumatic Brain Injury in Mice

Traumatic brain injury (TBI) is a disabling disorder and a major cause of death and disability in the world. Both single and repetitive traumas affect the brain acutely but can also lead to chronic neurodegenerative changes. Clinical studies have shown some dissimilarities in transactive response DNA binding protein 43 (TDP-43) expression patterns following single versus repetitive TBI. We explored the acute cortical post-traumatic changes of TDP-43 using the lateral fluid percussion injury (LFPI) model of single moderate TBI in adult male mice and investigated the association of TDP-43 with post-traumatic neuroinflammation and synaptic plasticity. In the ipsilateral cortices of animals following LFPI, we found changes in the cytoplasmic and nuclear levels of TDP-43 and the decreased expression of postsynaptic protein 95 within the first 3 d post-injury. Subacute pathological changes of TDP-43 in the hippocampi of animals following LFPI and in mice exposed to repetitive mild TBI (rmTBI) were studied. Changes in the hippocampal TDP-43 expression patterns at 14 d following different brain trauma procedures showed pathological alterations only after single moderate, but not following rmTBI. Hippocampal LFPI-induced TDP-43 pathology was not accompanied by the microglial reaction, contrary to the findings after rmTBI, suggesting that different types of brain trauma may cause diverse pathophysiological changes in the brain, specifically related to the TDP-43 protein as well as to the microglial reaction. Taken together, our findings may contribute to a better understanding of the pathophysiological events following brain trauma