Muscle (n = 111), liver (n = 111), and kidney cortex (n = 101) samples from brown bears (Ursus arctos) were collected in the 2009 and 2010 hunting seasons in Croatia and analysed for selenium (Se), ...cadmium (Cd), and total mercury (Hg). The aim was to assess the levels of these elements according to age, sex, and season of collection, and to investigate possible Se/Cd and Se/Hg interactions. Median Se concentrations were 0.139 μg/g in muscle, 0.409 μg/g in liver and 1.75 μg/g wet mass in kidney cortex. Median Cd and Hg were 0.0078 and 0.0018 μg/g in muscle, 1.09 and 0.031 μg/g in liver, and 16.5 and 0.206 μg/g wet mass in the renal cortex, respectively. Se/Cd molar ratios were less than 1 in the kidney cortex, and close to or above 1 in liver and muscle, respectively. Toxic Cd and Hg correlated with Se in all of the studied tissues. Sex differences were found for all three elements (except Se in liver), with females having higher tissue concentration than males. Only Cd showed age-dependence. Bear samples collected in fall had higher Se in muscles, and Hg in muscles and liver compared to samples collected in spring. Element concentrations in brown bear tissues were within the range of previously reported studies. Bear meat is considered a rich source of Se, safe for consumption with regard to its Cd and Hg content. According to the molar ratio and correlation results, we assume that Se binding is not the primary detoxification pathway for Cd and Hg in brown bears.
The study aimed to determine reproductive span by investigation of the ovarian structures in young and elderly captive brown bear females (Ursus arctos). The ovaries of two 2-year-old females were ...obtained by ovariectomy and during the necropsies of 31 and 36 year old individuals. All the obtained ovaries were examined macroscopically and histologically. Histological examination of the ovaries of young animals (2+ years) revealed the presence of primordial, primary, secondary and tertiary follicles within the ovarian cortex. One ovary showed a mature corpus luteum, indicating recent ovulation, what is, to our knowledge, the first histological proof of the earliest age of ovulation recorded for captive brown bears. Ovarian atrophy accompanied by the development of multiple cystic subsurface epithelial structures (SES) in the case of the old bears in this study indicates that the ovaries of brown bears share similar degenerative and proliferative patterns with domestic canids. The oldest female had records of successful births at the ages of 26 and 28 years. Both recorded birth events represent one of the latest confirmed occurrences of ovulation, conception and birth amongst brown bears. Key words : reproduction; puberty; ovulation; corpus luteum; post-reproductive phase
HOHSTETER, M., I.-C. SOSTARI C -ZUCKERMANN, S. RELJIC, L. MEDVEN ZAGRADISNIK, B. ARTUKOVIC, Z. GRABAREVIC, J. KUSAK, D. HUBER, A. GUDAN KURILJ: Intestinal adenocarcinoma in a European brown bear ...(Ursus arctos) - a case report. Vet. arhiv 88, 569-579, 2018. This article presents the first case of intestinal adenocarcinoma in a free living, culled 12 year old, European female brown bear (Ursus arctos), with its characteristic macropathological and histopathological manifestations. Necropsy revealed thoracic gunshot injuries (compassionate shot) and the poor physical condition of the animal, with body fat loss and musculature atrophy. An infiltrative mass protruded the jejunal wall with infiltration of the mesentery, visceral and parietal peritoneum, and distal parts of the colon and rectum. The histopathological examination presented an infiltrative, unencapsulated, moderately cellular neoplastic mass, composed of an epithelial cell population, forming irregular nests, papillary and ribbon like structures and small number of tubules, surrounded by an extensive desmoplastic reaction. Within the tumor a small number of cysts filled with mucin were noted. The epithelial neoplastic cells exhibited mild anisocytosis and anisokaryosis, and a low mitotic index. Histochemical Van Gieson staining showed strong positivity in the desmoplastic proliferation. The epithelial tumor cells were positively imunostained with cytokerain, and stromal cells with vimentin. The histological features presented are characteristic of intestinal adenocarcinomas, of the mixed tubular and mucinous type, with a prominent scirrous reaction. Key words: intestinal adenocarcinoma; European brown bear (Ursus arctos); macropathology; histopathology; immunohistochemistry
A microwave-assisted digestion method for the determination of cadmium (Cd) and lead (Pb) by inductively coupled plasma mass spectrometry (ICP-MS) was optimised on certified reference material (CRM) ...(bovine liver, BCR-185R) and wolf liver samples. Different factors influencing digestion efficiency (temperature, time, composition of the digestion mixture, sample mass) were tested. Validation included linearity (up to 200 μg L(-1) for Cd and Pb), detection (0.003 μg L(-1) for Cd and 0.035 μg L(-1) for Pb), and quantification (0.008 μg L(-1) for Cd and 0.081 μg L(-1) for Pb) limits. Good agreement between measured and certified values was achieved in all conditions, with recoveries ranging from 94 % to 111 % for Cd and from 95 % to 105 % for Pb. The precision of the method, expressed as relative standard deviation, was up to 3 % for Cd and 8 % for Pb. The best digestion parameters (260 °C, 30 min, 1 mL HNO3+4 mL H2O, 0.1 g of CRM) based on accuracy and precision were applied on two wolf liver samples to evaluate the need for the predigestion step (freeze-drying) and appropriate mass of the sample. Freeze-drying improved precision and minimising the tissue mass to 0.1 g reduced the matrix effect. Using these optimised digestion conditions, we determined Cd and Pb in 40 wolf livers collected in Croatia, and their medians (0.055 μg g(-1) and 0.107 μg g(-1), respectively) were in the range of previously reported data for the grey wolf.
Trichinellosis in wolves from Croatia Beck, Relja; Beck, Ana; Kusak, Josip ...
Veterinary parasitology,
02/2009, Letnik:
159, Številka:
3-4
Journal Article
Recenzirano
The aim of the present study was to investigate the prevalence of Trichinella infection in wolves (Canis lupus) in a 17,468km2 area in Croatia. Muscle samples were collected from 67 wolves between ...1996 and 2007 and analyzed by artificial digestion. Muscle larvae were detected in 21 wolves (31%) and genotyped by multiplex PCR. Trichinella britovi was the predominant species confirmed in 90% (19 wolves) while Trichinella spiralis was detected in 9% (2 wolves). The presence of the so called “domestic”Trichinella species was a surprise since, to date, only T. britovi had been reported in wild animals in this region. The larval burdens in infected animals ranged from 0.3 to 45.9 larvae per gram. The prevalence of infected animals varied by geographic region; infected animals were found in the region of Gorski Kotar (20%) which has very similar environment to the region of Lika, where almost all wolves were found infected. Interestingly, this is the first report of infected wolves in Dalmatia.
The aim of this study was to investigate the temporal trends and geographical differences in
Sr and stable element (Ba, Ca, Mn, Sr, Pb, Zn) levels in the bones of Croatian and Polish brown bear ...(Ursus arctos) populations. Experimental data suggest that in the decades after nuclear weapon tests and the Chernobyl accident,
Sr bone activity concentrations decreased from 352 to 11 Bq kg
in the Croatian bear population (period 1982-2015) and from 831 to 27 Bq kg
in Polish bears (period 1962-2020). Calculated effective and ecological half-lives were 9 and 13 years for Croatian bears, and 15 and 31 years for Polish bears, respectively. Different temporal trends were noted in levels of Ba, Mn, Pb and Zn between the two countries with majority of bones having lower Pb, Sr and Zn in Croatian than in Polish bears. Estimated values for the soil-to-bear transfer of
Sr were the same order of magnitude in the studied populations. Contrary to this, the estimated transfer of stable Sr was an order of magnitude lower for the Croatian bear population compared to Polish bears. The observed differences in soil-to-bear transfer between stable Sr and
Sr found for Croatian bears might suggest the need for careful consideration on the use of stable Sr data as an analogue for
Sr. To our knowledge, this is the first study that analysed
Sr activity in tissue of brown bears. As such, it provides insight into the fate and behaviour of one of the most relevant anthropogenic radionuclides at the top of the food chain.
The aim of this study was to investigate the temporal trends and geographical differences in
90
Sr and stable element (Ba, Ca, Mn, Sr, Pb, Zn) levels in the bones of Croatian and Polish brown bear (
...Ursus arctos
) populations. Experimental data suggest that in the decades after nuclear weapon tests and the Chernobyl accident,
90
Sr bone activity concentrations decreased from 352 to 11 Bq kg
−1
in the Croatian bear population (period 1982–2015) and from 831 to 27 Bq kg
−1
in Polish bears (period 1962–2020). Calculated effective and ecological half-lives were 9 and 13 years for Croatian bears, and 15 and 31 years for Polish bears, respectively. Different temporal trends were noted in levels of Ba, Mn, Pb and Zn between the two countries with majority of bones having lower Pb, Sr and Zn in Croatian than in Polish bears. Estimated values for the soil-to-bear transfer of
90
Sr were the same order of magnitude in the studied populations. Contrary to this, the estimated transfer of stable Sr was an order of magnitude lower for the Croatian bear population compared to Polish bears. The observed differences in soil-to-bear transfer between stable Sr and
90
Sr found for Croatian bears might suggest the need for careful consideration on the use of stable Sr data as an analogue for
90
Sr. To our knowledge, this is the first study that analysed
90
Sr activity in tissue of brown bears. As such, it provides insight into the fate and behaviour of one of the most relevant anthropogenic radionuclides at the top of the food chain.
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