18 research outputs found
Izbor staniÅ”ta i sliÄnosti zajednica ptica pjevica u Å”umama parkova prirode Medvednica i Žumberak ā Samoborsko gorje
The effect of floristic and structural characteristics of vegetation on the forest songbird communities in two Nature Parks: Medvednica andŽumberak ā 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 (Kruskalā 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 āSamoborsko gorje respectively. Diversity was higher on Žumberak ā 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 Ā± 0.120), songbird communities showed high similarity (0.872 Ā± 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 Å”umskih staniÅ”ta ukazuju da na njihovu strukturu i gustoÄu populacija mogu utjecati floristiÄka i strukturalna svojstva vegetacije. U ovom istraživanju željeli smo, usporedbom zajednica ptica Å”umskih staniÅ”ta dvaju parkova prirode, utvrditi utjecaj floristiÄkih i strukturalnih svojstava vegetacije na zajednicu ptica gnjezdarica. Istraživanje je provedeno tijekom 2006. i 2007. u Parkovima prirode Medvednica i Žumberak ā Samoborsko gorje. Å ume pokrivaju oko 60 % povrÅ”ineu oba parka, ali su kontinuirane na Medvednici i neÅ”to rascjepkanije na Žumberku. Istraživanje ptica provedeno je metodom prebrojavanja u toÄki, a uzorkovanje staniÅ”ta metodom kružnih ploha. Istraživanje je provedeno na ukupno101 toÄki: 49 na Medvednici i 52 na Žumberku. Pri statistiÄkoj obradi koriÅ”teni su neparametrijski testovi (KruskalāWallis i Kendal Tau). Udio temeljnice stabala koriÅ”ten je za odreÄivanje pripadnosti pojedinom Å”umskim tipu: bukovoj, hrastovoj, mjeÅ”ovitoj listopadnoj i mjeÅ”ovitoj crnogoriÄnoj Å”umi. ProsjeÄna temeljnica stabla koriÅ”tena je kao indikator starosti Å”ume. Istraživanjem je zabilježeno ukupno 27 vrsta ptica pjevica u Å”umama Medvednice i32 na Žumberku (Tablica 1). Å est vrsta ptica bilo je vezano uz odreÄeni tip Å”ume, s viÅ”e od 40 % parova zabilježenih u tom Å”umskom tipu. Diverzitet vrstabio je viÅ”i na Žumberku, dok je gustoÄa populacija ptica pjevica bila veÄa na Medvednici (Slika 2). Sorensenov indeks pokazao je da zajednice ptica istog tipa Å”ume izmeÄu dva podruÄja pokazuju znatno veÄu sliÄnost nego floristiÄki sastav (Slika 3). NajveÄa sliÄnost u zajednicama ptica izmeÄu dva Parka zabilježena je u bukovim i hrastovim sastojinama. Hrastove sastojine pokazuju najmanju floristiÄku sliÄnost, ali nemaju znaÄajnih razlika u strukturalnim svojstvima niti u ekoloÅ”kim skupinama ptica. Bukove sastojine naprotiv pokazuju znaÄajne strukturalne razlike i u njima je, kao i u mjeÅ”ovitim crnogoriÄnim sastojinama, zabilježena najveÄa razlika meÄu ekoloÅ”kim skupinama ptica izmeÄu dva Parka. Strukturalne razlike tih Å”uma izmeÄu dva Parka su rezultat razliÄite starosti sastojina, a ptice su imale veÄe gustoÄe u starijim Å”u-mama. MeÄu strukturalnim svojstvima vegetacije, ona vezana uz starost Å”ume (prosjeÄna temeljnica i broj mladih stabala) bile su znaÄajno korelirane s ukupnom gustoÄom populacija pjevica i s gustoÄom razliÄitih ekoloÅ”kih skupina. ZakljuÄak je ovog istraživanja da floristiÄki sastav Å”uma ima utjecaj na odabir tipa Å”ume u kojoj Äe se neke vrste ptica pjevica gnijezditi, dok na odabir samog podruÄja gniježÄenja veÄi utjecaj imaju strukturalna svojstva Å”ume
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 āSestre milosrdniceā 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 ā proizvodnja i kliniÄko 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 nosaÄ stanica. Procijenili smo uÄinak nadomjestka kože na cijeljenje opeklina drugog i treÄeg stupnja. Fibrinski gel naÄinjen je od komercijalnog kirurÅ”kog fibrinskog ljepila. Ljudski fibroblasti kultivirani su u samom fibrinskom nosaÄu. Ljudski keratinociti zasijani su na gornju povrÅ”inu nosaÄa. Vijabilnost uzgojenih stanica odreÄena je fluorimetrijski. Nadomjestak kože analiziran je elektronskim skenirajuÄim mikroskopom. Napravljena je imunocitokemijska analiza kultiviranih stanica. SkenirajuÄi mikroskop pokazao je dobro prianjanje i proliferaciju stanica kože na nosaÄu. Imunocitokemijska analiza pokazala je prisutnost vimentina, biljega fibroblastnih stanica; citokeratina 19, biljega epitelnih matiÄnih stanica; te involukrina, biljega diferenciranih keratinocita. KliniÄka primjena ovih nadomjestaka kože pokazala je sliÄne rezulatate cijeljenja kao i dijelovi rana koji su prekriveni autolognim presatcima kože djelomiÄne debljine. ZakljuÄujemo da nadomjestci kože bazirani na fibrinskom nosaÄu imaju potencijala u lijeÄenju teÅ”kih 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 izvanstaniÄne matrice za primjenu u tkivnom inženjerstvu
Tkivno inženjerstvo je interdisciplinarno podruÄje koje isprepliÄe biomedicinske znanosti te inženjerstvo. Razvojem navedenih grana i sve strožim zahtjevima kliniÄke medicine, nametnula se potreba za razvojem biokompatibilnih te bioaktivnih implantata koji bi mogli zamjenjivati i poticati regeneraciju oboljelog tkiva. U cilju razvoja biomimetiÄkih materijala i implantata, decelularizacija se istaknula kao pogodna metoda jer izolira prirodno prisutnu izvanstaniÄnu matricu sa svim komponentama iz odabranog tkiva te uklanja stanice i genski sadržaj koji bi mogao izazvati reakciju imuniteta pacijenta. Razvijeno je viÅ”e metoda decelularizacije koje se mogu podijeliti na kemijske, fizikalne, biokemijske te kombinirane. Svaka metoda specifiÄna je i razvija se za pojedino tkivo te se najÄeÅ”Äe koriste kombinirane metode jer kombiniraju dobra svojstva pojedinih metoda pa postižu dobro uklanjanje stanica uz minimalna oÅ”teÄenja komponenti izvanstaniÄne matrice. Na tržiÅ”tu su veÄ dostupni proizvodi pripravljeni od decelularizirane izvanstaniÄne matrice te se daljnjim razvojem podruÄja oÄekuje njihov sve veÄi 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 7ādays 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, 1āday after the LFPI, and second, widespread, starting on post-injury day 3. Purkinje cell loss was detected in posterior lobule IX 1āday 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
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 patientās 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
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
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