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51.
Rats maintained on a high fat diet reduce their food intake less in response to exogenous cholecystokinin (CCK) than rats maintained on a low fat diet. In addition, inhibition of gastric emptying by CCK is markedly attenuated in rats maintained on a high fat diet. Both inhibition of food intake and gastric emptying by CCK are mediated by sensory fibers in the vagus nerve. These fibers terminate on dorsal hindbrain neurons of the nucleus of the solitary tract and area postrema. To determine whether diet-induced changes in the control of feeding and gastric emptying are accompanied by altered vagal sensory responsiveness, we examined dorsal hindbrain expression of Fos-like immunoreactivity (Fos-li) following intraperitoneal CCK injection of rats maintained on high fat or low fat diets. Following CCK, there were numerous Fos-li nuclei in the area postrema and in the commissural and medial subnuclei of the nucleus of the solitary tract of rats maintained on a low fat diet. However, Fos-li was absent or rare in the brains of rats maintained on a high fat diet. These data suggest that the vagal sensory response to exogenous CCK is reduced in rats maintained on a high fat diet. Our results also are consistent with our previous findings that CCK-induced reduction of food intake and gastric emptying are both attenuated in rats maintained on a high fat diet. In addition our results support the hypothesis that attenuation of CCK-induced inhibition of food intake and gastric emptying may be due to diet-induced diminution of vagal CCK responsiveness. 相似文献
52.
Monstein HJ Olsson C Nilsson I Grahn N Benoni C Ahrné S 《Journal of microbiological methods》2005,63(3):239-247
Amplifying bacterial DNA by PCR from human biopsy specimens has sometimes proved to be difficult, mainly due to the low amount of bacterial DNA present. Therefore, nested or semi-nested 16S rDNA PCR amplification has been the method of choice. In this study, we evaluate the potential use of whole genome amplification of total DNA isolated from human colon and rectum biopsy specimens, followed by 16S rDNA PCR amplification of multiple displacement amplified (MDA)-DNA. Subsequently, a H. pylori-specific 16S rDNA variable V3 region PCR assay was applied directly on MDA-DNA and, combined with pyrosequencing analysis; the presence of H. pylori in some biopsies from colon in patients with microscopic colitis was confirmed. Furthermore, temporal temperature gradient gel electrophoresis (TTGE) of 16S rDNA amplicons using primers flanking variable regions V3, V4, and V9, was used to establish bacterial profiles from individual biopsies. A variation of the bacterial profiles in the colonic mucosa in microscopic colitis and in normal rectal mucosa was observed. In conclusion we find the MDA technique to be a useful method to overcome the problem of insufficient bacterial DNA in human biopsy specimens. 相似文献
53.
The Siamese cat has a highly recognized coat colour phenotype that expresses pigment at the extremities of the body, such as the ears, tail and paws. This temperature-sensitive colouration causes a 'mask' on the face and the phenotype is commonly referred to as 'pointed'. Burmese is an allelic variant that is less temperature-sensitive, producing more pigment throughout the torso than Siamese. Tyrosinase (TYR) mutations have been suspected to cause these phenotypes because mutations in TYR are associated with similar phenotypes in other species. Linkage and synteny mapping in the cat has indirectly supported TYR as the causative gene for these feline phenotypes. TYR mutations associated with Siamese and Burmese phenotypes are described herein. Over 200 cats were analysed, representing 12 breeds as well as randomly bred cats. The SNP associated with the Siamese phenotype is an exon 2 G > A transition changing glycine to arginine (G302R). The SNP associated with the Burmese phenotype is an exon 1 G > T transversion changing glycine to tryptophan (G227W). The G302R mutation segregated concordantly within a pedigree of Himalayan (pointed) Persians. All cats that had 'pointed' or the Burmese coat colour phenotype were homozygous for the corresponding mutations, respectively, suggesting that these phenotypes are a result of the identified mutations or unidentified mutations that are in linkage disequilibrium. Because the same mutations were identified in different breeds with similar phenotypes, the mutations are likely to be identical by descent rather than multiple mutation events occurring at the same site. 相似文献
54.
Per-Erik?OlssonEmail author A?H?kan?Berg Jonas?von Hofsten Birgitta?Grahn Anna?Hellqvist Anders?Larsson Johnny?Karlsson Carina?Modig Bertil?Borg Peter?Thomas 《Reproductive biology and endocrinology : RB&E》2005,3(1):37
Although 11-ketotestosterone is a potent androgen and induces male secondary sex characteristics in many teleosts, androgen
receptors with high binding affinity for 11-ketotestosterone or preferential activation by 11-ketotestosterone have not been
identified. So, the mechanism by which 11-ketotestosterone exhibits such high potency remains unclear. Recently we cloned
the cDNA of an 11-ketotestosterone regulated protein, spiggin, from three-spined stickleback renal tissue. As spiggin is the
only identified gene product regulated by 11-ketotestosterone, the stickleback kidney is ideal for determination of the mechanism
of 11-ketotestosterone gene regulation. A single androgen receptor gene with two splicing variants, belonging to the androgen
receptor-β subfamily was cloned from stickleback kidney. A high affinity, saturable, single class of androgen specific binding
sites, with the characteristics of an androgen receptor, was identified in renal cytosolic and nuclear fractions. Measurement
of ligand binding moieties in the cytosolic and nuclear fractions as well as to the recombinant receptor revealed lower affinity
for 11-ketotestosterone than for dihydrotestosterone. Treatment with different androgens did not up-regulate androgen receptor
mRNA level or increase receptor abundance, suggesting that auto-regulation is not involved in differential ligand activation.
However, comparison of the trans-activation potential of the stickleback androgen receptor with the human androgen receptor,
in both human HepG2 cells and zebrafish ZFL cells, revealed preferential activation by 11-ketotestosterone of the stickleback
receptor, but not of the human receptor. These findings demonstrate the presence of a receptor preferentially activated by
11-ketotestosterone in the three-spined stickleback, so far the only one known in any animal. 相似文献
55.
Design and evaluation of a new linear thermistor velocity probe 总被引:2,自引:0,他引:2
56.
A 22‐year‐old captive Brazilian rainbow boa (Epicrates cenchria cenchria) gave birth to four offspring after being housed with a vasectomized male. Sexual reproduction as a result of failed prior vasectomy, recanalization of the vas deferens, or prolonged sperm storage was ruled out using the clinical history, histopathology, and gross necropsy. Short tandem repeat (STR) DNA markers were genotyped in the male, female, and four offspring. None of the offspring possessed a diagnostic STR allele present in the potential sire. In addition, all offspring were homozygous at each STR locus evaluated, supporting parthenogenetic reproduction. This is the first report of parthenogenesis in a Brazilian rainbow boa and has implications for the conservation of reptiles maintained in captive breeding programs. Zoo Biol. 32:172–176, 2013. © 2012 Wiley Periodicals, Inc. 相似文献
57.
Hans Grahn Ulf Edlund Yvon Th van den Hoogen Cornelis Altona Frank Delaglio Mark W. Roggenbuck 《Journal of biomolecular structure & dynamics》2013,31(6):1135-1150
Abstract A multivariate data-representation of a portion of the 1H-NOESY spectrum of an RNA octamer duplex was used to explore the possibility of using Principal Component Analysis and Partial Least Squares Discrimination for pattern recognition. In this case, it is found that the methods can: (i) distinguish slices containing signal from those containing only noise, (ii) locate slices containing overlapping signals, and (iii) in some cases to segregate slices with unique aspects such as those from terminal nucleotides, overlapping signals, purine-H8, pyrimidine-H6 and adenine-H2 containing slices. These properties can easily be included in a scheme to automate spectral analysis. The formulation described here does not distinguish patterns needed to automate sequential assignment of resonances in NOESY spectra of RNA. 相似文献
58.
59.
Grahn E Askarieh G Holmner A Tateno H Winter HC Goldstein IJ Krengel U 《Journal of molecular biology》2007,369(3):710-721
MOA, a lectin from the mushroom Marasmius oreades, is one of the few reagents that specifically agglutinate blood group B erythrocytes. Further, it is the only lectin known to have exclusive specificity for Galalpha(1,3)Gal-containing sugar epitopes, which are antigens that pose a severe barrier to animal-to-human organ transplantation. We describe here the structure of MOA at 2.4 A resolution, in complex with the linear trisaccharide Galalpha(1,3)Galbeta(1,4)GlcNAc. The structure is dimeric, with two distinct domains per protomer: the N-terminal lectin module adopts a ricinB/beta-trefoil fold and contains three putative carbohydrate-binding sites, while the C-terminal domain serves as a dimerization interface. This latter domain, which has an unknown function, reveals a novel fold with intriguing conservation of an active site cleft. A number of indications suggest that MOA may have an enzymatic function in addition to the sugar-binding properties. 相似文献
60.
We examined the reproductive success of 48 adult brown trout (Salmo trutta L.) which were allowed to reproduce in a stream that was controlled for the absence of other trout. Parentage analyses based on 11 microsatellites permitted us to infer reproductive success and mate choice preferences in situ. We found that pairs with intermediate major histocompatibility complex (MHC) dissimilarity mated more often than expected by chance. It appears that female choice was the driving force behind this observation because, compared with other individuals, males with intermediate MHC dissimilarity produced a larger proportion of offspring, whereas female reproductive output did not show this pattern. Hence, rather than seeking mates with maximal MHC dissimilarity, as found in several species, brown trout seemed to prefer mates of intermediate MHC difference, thus supporting an optimality-based model for MHC-dependent mate choice. 相似文献