排序方式: 共有33条查询结果,搜索用时 15 毫秒
1.
AB Chang NC Cox J Purcell JM Marchant PJ Lewindon GJ Cleghorn LC Ee GD Withers MK Patrick J Faoagali 《Respiratory research》2005,6(1):1-5
Background and methods
Human metapneumovirus (hMPV) is a recently discovered respiratory virus associated with bronchiolitis, pneumonia, croup and exacerbations of asthma. Since respiratory viruses are frequently detected in patients with acute exacerbations of COPD (AE-COPD) it was our aim to investigate the frequency of hMPV detection in a prospective cohort of hospitalized patients with AE-COPD compared to patients with stable COPD and to smokers without by means of quantitative real-time RT-PCR.Results
We analysed nasal lavage and induced sputum of 130 patients with AE-COPD, 65 patients with stable COPD and 34 smokers without COPD. HMPV was detected in 3/130 (2.3%) AE-COPD patients with a mean of 6.5 × 105 viral copies/ml in nasal lavage and 1.88 × 105 viral copies/ml in induced sputum. It was not found in patients with stable COPD or smokers without COPD.Conclusion
HMPV is only found in a very small number of patients with AE-COPD. However it should be considered as a further possible viral trigger of AE-COPD because asymptomatic carriage is unlikely. 相似文献2.
Summary The use of reticulated polyurethane foam as a support material for the immobilization of methanogenic associations and its application to the anaerobic treatment of fine particulate solid wastes was investigated. The colonization of polyurethane support particles in a continuous upflow reactor fed on a mixture of acetate, propionate and butyrate, was both rapid and dense. The combination of rumen microorganisms and colonized support particles in a two-phase digester resulted in an efficient anaerobic decomposition of papermill sludge. 相似文献
3.
4.
Olfactory contribution to Fos expression during mating in inexperienced male hamsters 总被引:1,自引:0,他引:1
Male hamsters are very dependent on chemosensory cues for normal mating
behavior. We have previously reported that central, vomeronasal pathways
are intensely and selectively activated during mating or pheromonal
stimulation. The contribution of main olfactory sensory input to the
patterns of c-fos activation was investigated in this study. Sexually
inexperienced male hamsters were either made anosmic by intranasal infusion
of zinc sulfate or remained intact. Fos protein immunoreactivity was
analyzed in main olfactory and vomeronasal pathways of the zinc
sulfate-treated, anosmic animals after mating with receptive females for 45
min, and compared with Fos patterns seen in intact mating animals, some of
which have been described in a previous publication. The zinc
sulfate-treated anosmic males described here all mated when given access to
receptive females. Whether mated or unstimulated, anosmic males had little
or no Fos expression in main olfactory pathways; significantly less even
than in unstimulated intact animals. Mating did not increase Fos expression
in main olfactory pathways of intact animals over that of unstimulated
intact controls. However, Fos expression in central vomeronasal pathways
was significantly higher in mating anosmic males, as in intact males,
compared with appropriate non-mating controls. Fos expression was
significantly different between intact and zinc sulfate-treated anosmic
mating males in only one area studied. The rostral anterior medial
amygdala, known to receive a small olfactory terminal field, had
significantly lower Fos expression in zinc sulfate-treated anosmic males
that mated when compared with intact-mating animals. Thus, functional main
olfactory input to the rostral vomeronasal amygdala can be demonstrated but
does not appear to be critical for mating behavior in previously
inexperienced male hamsters with intact vomeronasal organs. Other main
olfactory input appears to have a negligible contribution to Fos-patterns
in such animals.
相似文献
5.
Intermediate filaments in nervous tissues 总被引:59,自引:30,他引:29
Intermediate filaments have been isolated from rabbit intradural spinal nerve roots by the axonal flotation method. This method was modified to avoid exposure of axons to low ionic strength medium. The purified filaments are morphologically 75-80 percent pure. The gel electrophoretogram shows four major bands migrating at 200,000, 145,000, 68,000, and 60,000 daltons, respectively. A similar preparation from rabbit brain shows four major polypeptides with mol wt of 200,000 145,000, 68,000, and 51,000 daltons. These results indicate that the neurofilament is composed of a triplet of polypepetides with mol wt of 200,000, 145,000, and 68,000 daltons. The 51,000-dalton band that appears in brain filament preparations as the major polypeptide seems to be of glial origin. The significance of the 60,000- dalton band in the nerve root filament preparation is unclear at this time. Antibodies raised against two of the triplet proteins isolated from calf brain localize by immunofluorescence to neurons in central and peripheral nerve. On the other hand, an antibody to the 51,000-dalton polypeptide gives only glial staining in the brain, and very weak peripheral nerve staining. Prolonged exposure of axons to low ionic strength medium solubilizes almost all of the triplet polypeptides, leaving behind only the 51,000- dalton component. This would indicate that the neurofilament is soluble at low ionic strength, whereas the glial filament is not. These results indicate that neurofilaments and glial filaments are composed of different polypeptides and have different solubility characteristics. 相似文献
6.
Nuydens R Dispersyn G Van Den Keiboom G de Jong M Connors R Ramaekers F Borgers M Geerts H 《Apoptosis : an international journal on programmed cell death》2000,5(1):43-51
Bcl-2 is a gene with clear anti-apoptotic properties in neurodegenerative conditions. One of the earliest hallmarks of degeneration in neuronal cell cultures is the loss of neurite morphology. Therefore the effect of Bcl-2 on neuronal morphology and microtubule stability was studied in nerve growth factor differentiated PC12 cells. Microtubule dynamics were modulated using the microtubule stabilizer taxol and the microtubule destabilizer, okadaic acid, a protein phosphatase inhibitor. It was shown that Bcl-2 protects against both taxol- and okadaic acid induced neurite retraction. Bcl-2 overexpression also significantly reduced the increased ratio of acetylated tubulin over total tubulin induced by taxol treatment. Interestingly, Bcl-2 attenuates the decrease of the same ratio after exposure to okadaic acid, suggesting that Bcl-2 is able to normalize the level of acetylated tubulin. In addition, cell death and nuclear fragmentation, induced by okadaic acid, were reduced in Bcl-2 overexpressing cells. This protection is either downstream or independent of tau phosphorylation as quantitative immunocytochemistry with AT8 showed that Bcl-2 did not modify the level of tau phosphorylation. The data suggest that the protective effect of Bcl-2 on the neuronal cytoskeleton is probably linked to changes in the post-translational modification of tubulin. 相似文献
7.
Nawfel Ben-Hamouda Vincent-Joseph Poirel Garance Dispersyn Paul Pévet Etienne Challet Laure Pain 《Chronobiology international》2013,30(12):1735-1741
ABSTRACTBackground: Propofol anesthesia triggers phase-advances of circadian rhythms controlled by the suprachiasmatic nuclei (SCN), the master clock. Besides, inhalational anesthesia has been associated with a subsequent reduction of Per2 mRNA levels in the whole brain of rodents. The acute effects of propofol anesthesia per se on the SCN molecular clockwork remain unclear. Here we aim to study the expression of Per1 and Per2 clock genes in the SCN of rats exposed to constant darkness after a single dose of propofol. Methods: Thirty 2-months old rats were randomly divided into 2 groups receiving a single dose of either 120 mg/kg propofol 1% (n=15), or intralipid® 10% (n=15) in late day (projected circadian time (CT) 10, i.e., 10h after the expected time of lights on). Thereafter, rat brains were sampled in darkness 1h, 2h or 3h after the treatment (projected CT11, CT12 or CT13). Expression of Per1 and Per2 mRNA was analyzed by in situ hybridization in SCN coronal sections. Results: Per1 expression was affected by time and treatment. Per1 expression in the SCN after propofol treatment decreased at CT11 and CT12 when compared to the vehicle group. For Per2 expression, we observed only a treatment effect. Observed in dark conditions without hypothermia or/and concomitant surgery, such down-regulation of clock genes Per is only correlated to propofol treatment. This may explain “jet-lag-like” symptoms described by patients after anesthesia. Conclusion: We show here for the first time that short-term propofol anesthesia leads to a transient down-regulation of Per1 and Per2 expression in the SCN. 相似文献
8.
Garance Dispersyn Dominique Sage Etienne Challet Laure Pain 《Chronobiology international》2013,30(4):697-708
General anesthesia combined with surgery is commonly associated with post-operative stress-response in humans. Effects on the hypothalamic-pituitary-adrenal axis (HPA) during and after anesthesia are correlated with the magnitude of surgery and choice of anesthetics. The aim of our study in rats was to characterize the effects of general anesthesia without any surgery on HPA regulation of corticosterone and adrenocorticotropic hormone (ACTH) secretions. First, to assess whether the acute effects of general anesthesia on corticosterone concentration depend on time of day, rats were anesthetized with propofol at three different Zeitgeber times (ZT6, ZT10, and ZT16; with lights-on and -off at ZT0 and ZT12, respectively). Second, to determine the prolonged effects of general propofol anesthesia on daily corticosterone and ACTH concentrations, rats were anesthetized at ZT16 (4 h after lights-off) and euthanized either 1, 4, 12, 16, 20, or 24 h later. Third, the effects of propofol anesthesia on corticosterone and ACTH secretion were studied in rats instrumented with intracarotid cannulation. This permitted us to examine the individual patterns of corticosterone responses to propofol anesthesia as compared to their respective baseline corticosterone secretion. All of the results obtained showed that general propofol anesthesia, independent of the time-of-day of its administration, induces a significant increase of corticosterone secretion during the early recovery period without effect on ACTH secretion (i.e., no pituitary mediated stress-response). (Author correspondence: yvan.touitou@upmc.fr) 相似文献
9.
The African freshwater oyster Etheria elliptica, which is of great economic importance throughout the continent, is facing overharvesting in many fisheries in West Africa. Its reproductive traits (sex ratio, size at sexual maturity, oocyte diameter and fecundity) were studied at four stations located along the Pendjari River, northern Benin, in April 2013. Histological techniques were implemented to identify sex and gonad development stages. Oocyte sizes were measured based on the histological images and mean oocyte diameter was 38 µm. Fecundity, estimated by counting the developing eggs, averaged 106 724 eggs and increased significantly with shell size. The average sex ratio was approximately 1:1. Hermaphrodites were rare. Males reached sexual maturity at 57.6 mm dorsoventral height, earlier than females at 64.7 mm. The majority of the oyster specimens were in ripe-spawning stages, indicating that reproductive activities partly took place towards the end of the dry season. Both mature and immature individuals were subjected to harvesting at all the investigated fishing sites. The mean size of exploited oysters was 60.6 mm, lower than the size of females at maturity. Management strategies must enforce the minimum size of 65 mm required for harvesting, particularly in open access sites where juveniles are mostly harvested. 相似文献
10.
Intraspecific DNA divergence in Drosophila: a study on parthenogenetic D. mercatorum 总被引:1,自引:0,他引:1
Drosophila mercatorum is a species that can give rise to totally homozygous
parthenogenetic strains. Using the technique of DNA-DNA hybridization, we
have assessed the overall single-copy DNA differences among three
independently derived strains that represent three independent genomes.
Among strains, the average difference between homoduplex and heteroduplex
median melting temperatures is 1.3 degrees C. This represents greater than
or equal to 1.3% base-pair mismatch. Normalized percent of reassociation
indicates further genetic differences, probably reflecting
insertion/deletion differences and/or regions of the genome that are highly
variable. This overall intraspecific genetic variation is higher than
generally is thought to exist but is consistent with growing evidence of
extensive DNA diversity within species of invertebrates. High intraspecific
DNA variation may be correlated with rapid phyletic rates of evolution.
Because of this high level of variation, the technique of DNA-DNA
hybridization may be used to study intraspecific variation in invertebrates
but is limited in its usefulness for higher systematic studies.
相似文献