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51.
Karina Barbara Andersen Mette Tingleff Skaanild Mads Frost Bertelsen Leon Brimer 《European Journal of Wildlife Research》2010,56(6):915-921
Tissues from two juvenile brown bears (Ursus arctos), suspected to have died from yew (Taxus baccata) toxicosis, were chemically examined using thin layer chromatography and high performance liquid chromatography. Extraction
and analysis were conducted on heart and liver tissue samples as well as stomach content from the two bears and also on fresh
material from an authenticated yew tree which was used as a standard for comparison. The taxine complex comprised of taxine
B, 1-deoxytaxine B, isotaxine B, 2-acetyltaxin B, 1-deoxyisotaxine B, 2-acetylisotaxine B, and cinnamates were detected in
all extracted samples. taxine B and its isomer isotaxine B are the main toxic constituents in yew. The heart, the target organ
of taxine B, is arrested when reaching the lethal tissue concentration of taxine complex. In the present cases, the concentration
in the hearts was found to be 37 and 17 μg taxine complex per gram tissue, respectively. As no further absorption into the
heart occurs following cardiac arrest, the concentration determined is the actual lethal tissue concentration. Yew ingestion
was confirmed by microscopic examination of stomach contents of both bears. Histopathological findings of contraction band
necrosis in heart specimens were also consistent with yew intoxication. 相似文献
52.
Østergaard KH Bertelsen MF Brøndum ET Aalkjaer C Hasenkam JM Smerup M Wang T Nyengaard JR Baandrup U 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》2011,181(5):691-698
Giraffes are the tallest animals on earth and the effects of gravity on their cardiovascular system have puzzled physiologists
for centuries. The authors measured arterial and venous pressure in the foreleg of anesthetized giraffes, suspended in upright
standing position, and determined the ratio between tunica media and lumen areas along the length of the femoral/tibial arteries
in the hindleg. Volume fraction of elastin, density of vasa vasorum and innervations was estimated by stereology. Immunohistological
staining with S100 was used to examine the innervation. The pressure increase in the artery and vein along the foreleg was
not significantly different from what was expected on basis of gravity. The area of the arterial lumen in the hindleg decreased
towards the hoof from 11.2 ± 4.2 to 0.6 ± 0.5 mm2 (n = 10, P = 0.001), but most of this narrowing occurred within 2–4 cm immediately below the knee. This abrupt narrowing was associated
with a marked increase in media to lumen area ratio (from 1.2 ± 0.5 to 7.8 ± 2.5; P = 0.001), and a decrease in mean volume fraction of elastin from 38 ± 6% proximal to the narrowing to 5.8 ± 1.1% distally
(P = 0.001). The narrowing had a six-fold higher innervation density than the immediate distal and proximal regions. The sudden
narrowing was also observed in the hind legs of neonates, indicating that it does not develop as an adaptation to the high
transmural pressure in the standing giraffe. More likely it represents a preadaptation to the high pressures experienced by
adult giraffes. 相似文献
53.
The ficolins recognize carbohydrates and acetylated compounds on microorganisms and dying host cells and are able to activate the lectin pathway of the complement system. In humans, three ficolin genes have been identified: FCN1, FCN2 and FCN3, which encode ficolin-1, ficolin-2 and ficolin-3, respectively. Rodents have only two ficolins designated ficolin-A and ficolin-B that are closely related to human ficolin-1, while the rodent FCN3 orthologue is a pseudogene. Ficolin-2 and ficolin-3 have so far only been observed in humans. Thus, we performed a systematic investigation of the FCN genes in non-human primates. The exons and intron-exon boundaries of the FCN1-3 genes were sequenced in the following primate species: chimpanzee, gorilla, orangutan, rhesus macaque, cynomolgus macaque, baboon and common marmoset. We found that the exon organisation of the FCN genes was very similar between all the non-human primates and the human FCN genes. Several variations in the FCN genes were found in more than one primate specie suggesting that they were carried from one species to another including humans. The amino acid diversity of the ficolins among human and non-human primate species was estimated by calculating the Shannon entropy revealing that all three proteins are generally highly conserved. Ficolin-1 and ficolin-2 showed the highest diversity, whereas ficolin-3 was more conserved. Ficolin-2 and ficolin-3 were present in non-human primate sera with the same characteristic oligomeric structures as seen in human serum. Taken together all the FCN genes show the same characteristics in lower and higher primates. The existence of trans-species polymorphisms suggests that different FCN allelic lineages may be passed from ancestral to descendant species. 相似文献
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56.
Cbl-dependent ubiquitination is required for progression of EGF receptors into clathrin-coated pits 下载免费PDF全文
Stang E Blystad FD Kazazic M Bertelsen V Brodahl T Raiborg C Stenmark H Madshus IH 《Molecular biology of the cell》2004,15(8):3591-3604
Ligand binding causes the EGF receptor (EGFR) to become ubiquitinated by Cbl upon association with the adaptor protein Grb2. We have investigated the role of ubiquitin and Grb2 in ligand-induced endocytosis of the EGFR. Incubation of cells with EGF on ice caused translocation of Grb2 and Cbl from the cytosol to the rim of coated pits. Grb2 with point mutations in both SH3 domains inhibited recruitment of the EGFR to clathrin-coated pits, in a Ras-independent manner. On overexpression of the Cbl-binding protein Sprouty, ubiquitination of the EGFR was inhibited, the EGFR was recruited only to the rim of coated pits, and endocytosis of the EGFR was inhibited. Conjugation-defective ubiquitin similarly inhibited recruitment of EGF-EGFR to clathrin-coated pits. Even though this does not prove that cargo must be ubiquitinated, this indicates the importance of interaction of ubiquitinated protein(s) with proteins harboring ubiquitin-interacting domains. We propose that Grb2 mediates transient anchoring of the EGFR to an Eps15-containing molecular complex at the rim of coated pits and that Cbl-induced ubiquitination of the EGFR allows relocation of EGFR from the rim to the center of clathrin-coated pits. 相似文献
57.
Genome‐wide association studies of alcohol dependence,DSM‐IV criterion count and individual criteria
Dongbing Lai Leah Wetherill Sarah Bertelsen Caitlin E. Carey Chella Kamarajan Manav Kapoor Jacquelyn L. Meyers Andrey P. Anokhin David A. Bennett Kathleen K. Bucholz Katharine K. Chang Philip L. De Jager Danielle M. Dick Victor Hesselbrock John Kramer Samuel Kuperman John I. Nurnberger Towfique Raj Marc Schuckit Denise M. Scott Robert E. Taylor Jay Tischfield Ahmad R. Hariri Howard J. Edenberg Arpana Agrawal Ryan Bogdan Bernice Porjesz Alison M. Goate Tatiana Foroud 《Genes, Brain & Behavior》2019,18(6)
Genome‐wide association studies (GWAS) of alcohol dependence (AD) have reliably identified variation within alcohol metabolizing genes (eg, ADH1B) but have inconsistently located other signals, which may be partially attributable to symptom heterogeneity underlying the disorder. We conducted GWAS of DSM‐IV AD (primary analysis), DSM‐IV AD criterion count (secondary analysis), and individual dependence criteria (tertiary analysis) among 7418 (1121 families) European American (EA) individuals from the Collaborative Study on the Genetics of Alcoholism (COGA). Trans‐ancestral meta‐analyses combined these results with data from 3175 (585 families) African‐American (AA) individuals from COGA. In the EA GWAS, three loci were genome‐wide significant: rs1229984 in ADH1B for AD criterion count (P = 4.16E?11) and Desire to cut drinking (P = 1.21E?11); rs188227250 (chromosome 8, Drinking more than intended, P = 6.72E?09); rs1912461 (chromosome 15, Time spent drinking, P = 1.77E?08). In the trans‐ancestral meta‐analysis, rs1229984 was associated with multiple phenotypes and two additional loci were genome‐wide significant: rs61826952 (chromosome 1, DSM‐IV AD, P = 8.42E?11); rs7597960 (chromosome 2, Time spent drinking, P = 1.22E?08). Associations with rs1229984 and rs18822750 were replicated in independent datasets. Polygenic risk scores derived from the EA GWAS of AD predicted AD in two EA datasets (P < .01; 0.61%‐1.82% of variance). Identified novel variants (ie, rs1912461, rs61826952) were associated with differential central evoked theta power (loss ? gain; P = .0037) and reward‐related ventral striatum reactivity (P = .008), respectively. This study suggests that studying individual criteria may unveil new insights into the genetic etiology of AD liability. 相似文献
58.
Mukta Chakraborty Solveig Wall?e Signe Nedergaard Emma E. Fridel Torben Dabelsteen Bente Pakkenberg Mads F. Bertelsen Gerry M. Dorrestein Steven E. Brauth Sarah E. Durand Erich D. Jarvis 《PloS one》2015,10(6)
The ability to imitate complex sounds is rare, and among birds has been found only in parrots, songbirds, and hummingbirds. Parrots exhibit the most advanced vocal mimicry among non-human animals. A few studies have noted differences in connectivity, brain position and shape in the vocal learning systems of parrots relative to songbirds and hummingbirds. However, only one parrot species, the budgerigar, has been examined and no differences in the presence of song system structures were found with other avian vocal learners. Motivated by questions of whether there are important differences in the vocal systems of parrots relative to other vocal learners, we used specialized constitutive gene expression, singing-driven gene expression, and neural connectivity tracing experiments to further characterize the song system of budgerigars and/or other parrots. We found that the parrot brain uniquely contains a song system within a song system. The parrot “core” song system is similar to the song systems of songbirds and hummingbirds, whereas the “shell” song system is unique to parrots. The core with only rudimentary shell regions were found in the New Zealand kea, representing one of the only living species at a basal divergence with all other parrots, implying that parrots evolved vocal learning systems at least 29 million years ago. Relative size differences in the core and shell regions occur among species, which we suggest could be related to species differences in vocal and cognitive abilities. 相似文献
59.
Accurately resolving population structure in a sample is important for both linkage and association studies. In this study we investigated the power of single-nucleotide polymorphisms (SNPs) in detecting population structure in a sample of 286 unrelated individuals. We varied the number of SNPs to determine how many are required to approach the degree of resolution obtained with the Collaborative Study on the Genetics of Alcoholism (COGA) short tandem repeat polymorphisms (STRPs). In addition, we selected SNPs with varying minor allele frequencies (MAFs) to determine whether low or high frequency SNPs are more efficient in resolving population structure. We conclude that a set of at least 100 evenly spaced SNPs with MAFs of 40-50% is required to resolve population structure in this dataset. If SNPs with lower MAFs are used, then more than 250 SNPs may be required to obtain reliable results. 相似文献
60.