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1.
Nicholls-Grzemski FA Belling GB Priestly BG Calder IC Burcham PC 《Journal of biochemical and molecular toxicology》2000,14(6):335-345
Pretreatment with peroxisome proliferators protects mice against various hepatotoxicants. Since our previous work suggested that the hepatoprotection may involve an increased ability to cope with oxidative stress, the present work directly addressed this possibility. Several observations indicated a heightened defense against oxidative stress accompanies the hepatoprotection produced by clofibrate. Firstly, the carbonyl content of hepatic proteins from clofibrate-pretreated mice was 40% lower than those from vehicle-treated controls. Secondly, liver homogenates from clofibrate-pretreated mice produced less thiobarbituric acid reactive substances upon incubation under aerobic conditions or exposure to ferrous sulfate. This effect was not due to lower levels of peroxidation-prone polyunsaturated fatty acids in clofibrate-treated livers. Thirdly, in vitro experiments indicated that the antioxidant factor in liver homogenates from clofibrate-pretreated mice was not glutathione. Rather, since it was inactivated by proteases and heat treatment, we concluded that a protein is involved. Collectively, our results suggest that a resistance to lipid peroxidation develops in mouse liver during exposure to clofibrate. The identity of the putative antioxidant protein and its contribution to the protection against liver toxicity observed in this and other laboratories awaits future investigation. 相似文献
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Ali C Akyildiz Lambert Speelman Harald van Brummelen Miguel A Gutiérrez Renu Virmani Aad van der Lugt Anton FW van der Steen Jolanda J Wentzel Frank JH Gijsen 《Biomedical engineering online》2011,10(1):25
Background
Rupture of the cap of a vulnerable plaque present in a coronary vessel may cause myocardial infarction and death. Cap rupture occurs when the peak cap stress exceeds the cap strength. The mechanical stress within a cap depends on the plaque morphology and the material characteristics of the plaque components. A parametric study was conducted to assess the effect of intima stiffness and plaque morphology on peak cap stress. 相似文献4.
L W Adams G C Priestly J A Witkowski G E Jones 《Cell biology international reports》1986,10(7):509-515
In order to clarify the possible involvement of the cell surface in the pathogenesis of Duchenne muscular dystrophy, we have examined the behaviour of fibroblasts cultured from Duchenne patients in hydrated collagen lattices. No differences could be found between Duchenne and normal skin fibroblasts, either after initial seeding or following prolonged culture within the collagen gel. 相似文献
5.
The detection of genotoxins in the mouse bone-marrow micronucleus (MN) test is sensitive to factors which may inhibit bone-marrow proliferation. We have shown that three commercially available cooking oils (olive, peanut and sunflower seed oils), commonly used as vehicles in toxicological tests, were able to induce a cytotoxic effect in mouse bone marrow. The effects observed were reversible and the magnitude of the responses varied with the oil administered. The results suggest a need to examine vehicle effects when conducting the MN test. 相似文献
6.
Frank JH Gijsen Francesco Migliavacca Silvia Schievano Laura Socci Lorenza Petrini Attila Thury Jolanda J Wentzel Anton FW van der Steen Patrick WS Serruys Gabriele Dubini 《Biomedical engineering online》2008,7(1):23
Background
The process of restenosis after a stenting procedure is related to local biomechanical environment. Arterial wall stresses caused by the interaction of the stent with the vascular wall and possibly stress induced stent strut fracture are two important parameters. The knowledge of these parameters after stent deployment in a patient derived 3D reconstruction of a diseased coronary artery might give insights in the understanding of the process of restenosis. 相似文献7.
Forbes SH; Hogg JT; Buchanan FC; Crawford AM; Allendorf FW 《Molecular biology and evolution》1995,12(6):1106-1113
We compared genotypes at eight (AC)n microsatellite loci in domestic sheep
(Ovis aries) and wild Rocky Mountain bighorn sheep (O. canadensis). The
domestic sheep had greater genetic variation, higher allele-size variances,
and larger allele sizes than the wild sheep. Accumulating evidence from
higher taxonomic comparisons shows that these parameters are biased if
microsatellite loci are selected in one taxon and used in another. Our
results demonstrate similar biases between congeneric species. We compared
standard measures of genetic variation, differentiation, and distance
within and between species (H, D, FST) to newer measures based on
allele-size variance (SW, SB, RST). The size-based distances better
detected species-level divergence, but standard measures better
distinguished allopatric populations. Empirical calibration of these
measures at the subspecies level is needed to establish their useful
ranges.
相似文献
8.
Species differences in dispositional factors such as distribution, metabolism and excretion may often account for species differences in the toxic responses to foreign chemicals. In this study we compared the genotoxic responses of cyclophosphamide (CP) and styrene (ST) between Porton rats and LACA Swiss mice in three in vivo assays (bone marrow micronucleus (MN), sperm morphology (SM) and sister-chromatid exchange (SCE) assays). The sensitivities of the three assays were compared by the doses of the compounds required to elicit a significant genotoxic response. The baseline levels for the MN, SCE and SM assays were 1.1-1.4 and 1.2-1.3 MNPCEs/1000 PCEs, 0.23-0.24 and 0.20-0.21 SCEs/chromosome, 3.5-5.7% and 1.6-1.9% abnormal sperm in mice and rats, respectively. CP was a potent genotoxin in the MN and SCE assays but weakly genotoxic in the SM assay. At comparable doses, the rat was approximately 3-, 2.5- and 1.8-fold more sensitive to CP than mice in the MN, SM and SCE assays, respectively. ST produced weak genotoxic responses in all assays in mice and only in the SM and SCE assays in rats. The mice were more sensitive to ST in the MN and SM assays, while it was difficult to compare the species in the SCE assay. For both compounds the sensitivity of the three assays, in decreasing order, were SCE greater than MN much greater than SM. For CP the relative responses in the Porton rats and LACA Swiss mice were qualitatively similar to previous reports. Although the use of different strains may explain differences between the studies in the magnitude of the responses observed. The results for ST in the rat shows that the choice of genotoxic endpoint can determine whether a response is detectable. Moreover, the discrepancies between the results for ST in this study and others, suggest that as well as using a battery of in vivo tests, it may be prudent to select more that one strain or species to fully assess a compound's ability to produce DNA damage. 相似文献
9.
Olfactory sensitivity in tsetse flies: a daily rhythm 总被引:3,自引:0,他引:3
The diurnal tsetse Glossina morsitans morsitans bites especially in early
morning and late afternoon; around midday feeding is at a low. In
laboratory apparatus that measures the amount of locomotion under constant
conditions over the photophase, the flies display a similar patterning of
activity levels. The profile of daily rhythms for G. morsitans reported in
the literature includes a number of motor and sensory motor systems that
fluctuate cophasically. Lacking is a study on the patterning of the senses'
response levels. In this paper we present the first instance of a daily
modulation in the sense of smell. We stimulated the antennae with
concentration series of host-derived odours and measured the spiking rate
of cells at different times during the photophase. The
concentration-response curves suggest that the sensitivity of antennal
olfactory cells flows in parallel with the other daily rhythms. This was
also reflected in electroantennograms (EAGs). The electroantennography was
extended to G. fuscipes fuscipes, whose level of spontaneous locomotor
activity--instead of following a U- shaped pattern--rises gradually over
the photophase. Again, the EAGs appeared to parallel the species' locomotor
activity. What we believe happens is that the organism tones down the
sensitivity of its odour receptors during periods of anticipated inactivity
for reasons of economy.
相似文献
10.
B G Priestly M G C?té G L Plaa 《Canadian journal of physiology and pharmacology》1971,49(12):1078-1091