Based on the assumption that dietary and faecal nitrogen correlate, the number of studies using faecal samples collected in the wild to understand diet selection by wild herbivores and other ecological patterns has been growing during the last years, especially due to the recent development of cheap tools for analysis of nutrients like Near-Infrared Reflectance Spectroscopy (NIRS). Within the annual reproductive cycle, cervids (members of the family Cervidae) face strong seasonal variations in nutritional demands, different for hinds (gestation and lactation) and stags (antler growth) and reflected in differential patterns of seasonal diet selection. In this study we aimed to quantify how pasture availability, season and individual factors like sex, age, reproductive status, body mass and body condition affect faecal nutrients in captive red deer with the goal of understanding how these factors may influence the interpretation of results from samples obtained in the wild with little or no information about the animals who dropped those faeces. We used NIRS for analysing nitrogen, neutral and acid detergent fibres in faeces. The relative influence of some individual factors like pregnancy was low (around 4%), while age and weight may induce a variability up to 18%. The presence or absence of pasture contributed to a variability around 13%, while the season contributed to an average variability around 17% (and up to 21% in certain situations). This high variability in faecal nutrients was observed in a controlled setting with captive animals and controlled diets. Thus, in natural situations we suspect that there would be even greater variation. According to the results, we recommend that preliminary research with captive animals of the species of interest should be conducted before collecting samples in the wild, which should help in the interpretation of results.
- MeSH
- feces chemie MeSH
- fyziologie výživy zvířat * MeSH
- věkové faktory MeSH
- vysoká zvěř * MeSH
- živiny analýza MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Španělsko MeSH
In this study, we have compared four 68Ga-labeled peptides (three Arg-Gly-Asp (RGD) peptides and substance-P) with two 18F-tracers clinically approved for tumor imaging. We have studied in vitro and in vivo characteristics of selected radiolabeled tracers in a glioblastoma multiforme tumor model. The in vitro part of the study was mainly focused on the evaluation of radiotracers stability under various conditions. We have also determined in vivo stability of studied 68Ga-radiotracers by analysis of murine urine collected at various time points after injection. The in vivo behavior of tested 68Ga-peptides was evaluated through ex vivo biodistribution studies and PET/CT imaging. The obtained data were compared with clinically used 18F-tracers. 68Ga-RGD peptides showed better imaging properties compared to 18F-tracers, i.e., higher tumor/background ratios and no accumulation in non-target organs except for excretory organs.
- Klíčová slova
- 18F-FDG, 18F-FLT, PET, RGD peptides, biodistribution, gallium-68, glioblastoma multiforme,
- MeSH
- glioblastom diagnostické zobrazování metabolismus MeSH
- lidé MeSH
- myši SCID MeSH
- nádorové buněčné linie MeSH
- nádory mozku diagnostické zobrazování metabolismus MeSH
- oligopeptidy chemie MeSH
- PET/CT MeSH
- počítačová rentgenová tomografie MeSH
- pozitronová emisní tomografie metody MeSH
- radiofarmaka chemie MeSH
- radioizotopy fluoru MeSH
- radioizotopy galia chemie MeSH
- tkáňová distribuce MeSH
- transplantace nádorů MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- arginyl-glycyl-aspartic acid MeSH Prohlížeč
- Fluorine-18 MeSH Prohlížeč
- oligopeptidy MeSH
- radiofarmaka MeSH
- radioizotopy fluoru MeSH
- radioizotopy galia MeSH
Stable isotope measurements are increasingly being used to gain insights into the nutritional ecology of many wildlife species and their role in ecosystem structure and function. Such studies require estimations of trophic discrimination factors (i.e. differences in the isotopic ratio between the consumer and its diet). Although trophic discrimination factors are tissue- and species-specific, researchers often rely on generalized, and fixed trophic discrimination factors that have not been experimentally derived. In this experimental study, captive wild boar (Sus scrofa) were fed a controlled diet of corn (Zea mays), a popular and increasingly dominant food source for wild boar in the Czech Republic and elsewhere in Europe, and trophic discrimination factors for stable carbon (Δ13C) and nitrogen (Δ15N) isotopes were determined from hair samples. The mean Δ13C and Δ15N in wild boar hair were -2.3‰ and +3.5‰, respectively. Also, in order to facilitate future derivations of isotopic measurements along wild boar hair, we calculated the average hair growth rate to be 1.1 mm d(-1). Our results serve as a baseline for interpreting isotopic patterns of free-ranging wild boar in current European agricultural landscapes. However, future research is needed in order to provide a broader understanding of the processes underlying the variation in trophic discrimination factors of carbon and nitrogen across of variety of diet types.
- MeSH
- dieta veterinární MeSH
- izotopy dusíku analýza MeSH
- izotopy uhlíku analýza MeSH
- kukuřice setá chemie MeSH
- nutriční stav MeSH
- potravní řetězec MeSH
- Sus scrofa růst a vývoj MeSH
- vlasy, chlupy chemie růst a vývoj MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- izotopy dusíku MeSH
- izotopy uhlíku MeSH
