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41.
Moore ST Clément G Raphan T Cohen B 《Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale》2001,137(3-4):323-335
During the 1998 Neurolab mission (STS-90), four astronauts were exposed to interaural centripetal accelerations (Gy centrifugation)
of 0.5g and 1g during rotation on a centrifuge, both on Earth and during orbital space flight. Subjects were oriented either left-ear out
or right-ear out, facing or back to motion. Binocular eye movements were measured in three dimensions using a video technique.
On Earth, tangential centrifugation that produces 1g of interaural linear acceleration combines with gravity to tilt the gravitoinertial acceleration (GIA) vector 45° in the
roll plane relative to the head vertical, generating a summed vector of 1.4g. Before flight, this elicited mean ocular counterrolling (OCR) of 5.7°. Due to the relative absence of gravity during flight,
there was no linear acceleration along the dorsoventral axis of the head. As a result, during in-flight centrifugation, gravitoinertial
acceleration was strictly aligned with the centripetal acceleration along the interaural axis. There was a small but significant
decrease (mean 10%) in the magnitude of OCR in space (5.1°). The magnitude of OCR during postflight 1g centrifugation was not significantly different from preflight OCR (5.9°). Findings were similar for 0.5g centrifugation, but the OCR magnitude was approximately 60% of that induced by centrifugation at 1g. OCR during pre- and postflight static tilt was not significantly different and was always less than OCR elicited by centrifugation
on Earth for an equivalent interaural linear acceleration. In contrast, there was no difference between the OCR generated
by in-flight centrifugation and by static tilt on Earth at equivalent interaural linear accelerations. These data support
the following conclusions: (1) OCR is generated predominantly in response to interaural linear acceleration; (2) the increased
OCR during centrifugation on Earth is a response to the head dorsoventral 1g linear acceleration component, which was absent in microgravity. The dorsoventral linear acceleration could have activated
either the otoliths or body-tilt receptors that responded to the larger GIA magnitude (1.4g), to generate the increased OCR during centrifugation on Earth. A striking finding was that magnitude of OCR was maintained
throughout and after flight. This is in contrast to most previous postflight OCR studies, which have generally registered
decreases in OCR. We postulate that intermittent exposure to artificial gravity, in the form of the centripetal acceleration
experienced during centrifugation, acted as a countermeasure to deconditioning of this otolith-ocular orienting reflex during
the 16-day mission.
Electronic Publication 相似文献
42.
Eric Hergon Jean-Yves Py Stéphanie Jullien Jean-Fran?ois Quaranta Gilles Folléa Georges Andreu Jean-Jacques Cabaud Pascal Staccini Philippe Rouger 《Transfusion Clinique et Biologique》2007,14(3):371-377
The evaluation of the professional practices (EPP) is obligatory for all the physicians since July 1, 2005 for a first five-year period. It represents one of the components of the continuous medical training (CMT). The French Society of Blood Transfusion and National Institute of Blood Transfusion are the promoters of the EPP in transfusion technology and medicine. Initially, the programs of EPP will be conceived and controlled by experts and will relate to their basic activities. During a five years cycle, the physician taking part in a program must validate a specific action and take part in a rolling programme. At the end of the programme, the physician will receive a certificate issued by National Institute of Blood Transfusion and will have to submit it to a committee placed under the responsibility of the regional physicians' committee. 相似文献
43.
Christine Gilles Myriam Polette Philippe Birembaut Nils Brünner Erik W Thompson 《Clinical & experimental metastasis》1997,15(5):519-526
We have previously observed in vitro that some stromal proteinases (MMP-2, MT1-MMP) were expressed or activated by invasive carcinoma cell lines exhibiting mesenchymal features, presumably acquired through an epithelial to mesenchymal transition (EMT). To examine the potential contribution of c-ets-1 to this phenotype, we have compared here the expression of c-ets-1 with invasiveness in vitro and expression of vimentin, E-cadherin, uPA, MMP-1 and MMP-3 in a panel of human breast cancer cell lines. Our results clearly demonstrate an association between c-ets-1 expression and the invasive, EMT-derived phenotype, which is typified by the expression of vimentin and the lack of E-cadherin. While absent from the two non-invasive, vimentin-negative cell lines, c-ets-1 was abundantly expressed in all the four vimentin-positive lines. However, we could not find a clear quantitative or qualitative relationship between the expression of c-ets-1 and the three proteinases known to be regulated by c-ets-1, except that when they were expressed, it was only in the invasive c-ets-1-positive lines. UPA mRNAs were found in three of the four vimentin-positive lines, MMP-1 in two of the four, and MMP-3 could not be detected in any of the cell lines. Intriguingly, MDA-MB-435 cells, which exhibit the highest metastatic potential of these cell lines in nude mice, expressed vimentin and c-ets-1, but lacked expression of these three proteinases, at least under the culture conditions employed. Taken together, our results show that c-ets-1 expression is associated with an invasive, EMT-derived phenotype in breast cancer cells, although it is apparently not sufficient to ensure the expression of uPA, MMP-1 or MMP-3, in the vimentin-positive cells. Such proteases regulation is undoubtedly qualified by the cellular context. This study therefore advances our understanding of the molecular regulation of invasiveness in EMT-associated carcinoma progression, and suggests that c-ets-1 may contribute to the invasive phenotype in carcinoma cells. 相似文献
44.
Identification of iduronate sulfatase gene alterations in 70 unrelated Hunter patients 总被引:4,自引:0,他引:4
Roseline Froissart Irène Maire Gilles Millat Stéphane Cudry Anne-Marie Birot Véronique Bonnet Olivier Bouton Dominique Bozon 《Clinical genetics》1998,53(5):362-368
We studied 70 unrelated Hunter patients and found a gene alteration in every patient. The molecular heterogeneity was very important. Large gene rearrangements were identified in 14 patients. Forty-three different mutations were identified in the 56 other patients and 31 were not previously described. Deletions and insertions, splice site mutations were associated with a severe phenotype as nonsense mutations except Q531X. Only a few mutations were present in several patients making difficult genotype-phenotype correlations. Mutation identification allows accurate carrier detection improving prenatal diagnosis. The mother was not found to be a carrier in five cases among the 44 sporadic cases. Haplotype analysis demonstrated a higher frequency of mutations in male meiosis. 相似文献
45.
Equine arteritis virus (EAV) is the etiological agent of equine viral arteritis, a contagious viral disease of equids. EAV is the prototype virus of the arteriviruses, a group of small enveloped viruses with positive single-stranded RNA genomes. Because apoptosis or programmed cell death is believed to play an important role in the biogenesis of several cytopathogenic viruses, we examined whether EAV was able to induce cell apoptosis in vitro. To do this, Vero cells were infected with EAV at a multiplicity of infection of 0.1 tissue culture infectious dose (TCID50) per cell, and analyzed at various time intervals for the appearance of apoptotic signs. Fragmentation of chromosomal DNA into nucleosomal oligomers and caspase activation were observed in the infected cells at the time (e.g. 24 h postinfection) where a noticeable cytopathic effect was observed. The kinetics of the DNA fragmentation correlated with that of the production of progeny virus, so that viral multiplication was not interrupted by the apoptotic cell damage. All these data provide evidence that EAV is able to induce apoptotic cell death in vitro. 相似文献
46.
Der-Sarkissian H Vergnaud G Borde YM Thomas G Londoño-Vallejo JA 《Genome research》2002,12(11):1673-1678
The subtelomeric domains of chromosomes are probably the most rapidly evolving structures of the human genome. The highly variable distribution of large duplicated subtelomeric segments has indicated that frequent exchanges between nonhomologous chromosomes may have been taking place during recent genome evolution. We have studied the extent and variability of such duplications using in situ hybridization techniques and a set of well-defined subtelomeric cosmid probes that identify discrete regions within the subtelomeric domain. In addition to reciprocal translocation and illegitimate recombination events that could explain the observed mosaic pattern of subtelomeric regions, it is likely that homology-based recombination mechanisms have also contributed to the spread of distal subtelomeric sequences among particular groups of nonhomologous chromosome arms. The frequency and distribution of large-scale subtelomeric polymorphisms may have direct implications for the design of chromosome-specific probes that are aimed at the identification of cryptic subtelomeric deletions. Furthermore, our results indicate that the relevance of some of the telomere closures proposed within the present Human Genome Sequence draft are restricted to specific allelic variants of unknown frequencies. 相似文献
47.
We examined the interaction of the albino locus with the maternal environment on the behavioral development of two coisogenic strains of mice. Subjects of the pigmented C57BL/6 strain (=B6+/+) and of the albino C57BL/6c2J strain (=B6c/c) were either fostered by a mother of their own strain or cross-fostered at birth to an F1 hybrid dam. They were compared for the amount and daily distribution of activity displayed during 48 h in a seminatural device at weaning and when 75 days old. Food hoarding in the nest and food consumption at the food-search place were also recorded in adult subjects. When animals were fostered by a mother of their own strain, albino mice were more active and less nocturnal than pigmented mice at both ages. They hoarded less food in the nest and ate more at the food-search place. Most of these differences disappeared when both strains were fostered by an F1 dam. The amount of activity displayed during 48 h increased between 21 and 75 days of age. This increase was affected by cross-fostering to an F1 dam in B6c/c mice only. The developmental pattern of daily distribution of activity was changed by F1 dams in B6+/+ mice only. Whereas these influences of F1 dams produced subjects resembling the mother's phenotypic score, maternal effects on hoarding behavior in B6c/c mice produced subjects which did not resemble their foster mother. The results are discussed in terms of different possible ways of hereditary transmission of behavior and some methodological consequences are emphasized. 相似文献
48.
Latex allergosorbent test (LAST): a new immunoassay for specific IgE with latex particles 总被引:1,自引:0,他引:1
J G Gilles J C Mareschal J M Saint-Remy 《The Journal of allergy and clinical immunology》1988,82(1):35-39
We describe a two-step latex (Lx) agglutination assay for the titration of specific anti-Dermatophagoides pteronyssinus IgE. The samples are first incubated with allergen-coated Lx of 2.3 microns diameter. Bound IgE is digested by pepsin and then titrated by its agglutinating activity on 0.8 micron Lx particles coated with antihuman Fc epsilon rabbit F(ab')2. This latex allergosorbent test detects 100 pg of specific IgE per milliliter and does not depend on the concentration of total IgE. Owing to a tenfold increase in the allergosorbent surface, no competition with the binding of specific anti-D. pteronyssinus IgG is observed. Pepsin digestion eliminates potential interferences caused by autoantibodies against IgE. A good correlation (r = 0.92) is found with Phadebas RAST on a series of 91 samples. The latex allergosorbent test does not make use of radioisotopes and can be performed in less than 6 hours. 相似文献
49.
Nicole Chabot Valérie CharbonneauMarie-Eve Laramée Robin TremblayDenis Boire Gilles Bronchti 《Neuroscience letters》2008
Anatomical and imaging studies show ample evidence for auditory activation of the visual cortex following early onset of blindness in both humans and animal models. Anatomical studies in animal models of early blindness clearly show intermodal pathways through which auditory information can reach the primary visual cortex. There is clear evidence for intermodal corticocortical pathways linking auditory and visual cortex and also novel connections between the inferior colliculus and the visual thalamus. A recent publication [L.K. Laemle, N.L. Strominger, D.O. Carpenter, Cross-modal innervation of primary visual cortex by auditory fibers in congenitally anophthalmic mice, Neurosci. Lett. 396 (2006) 108–112] suggested the presence of a direct reciprocal connection between the inferior colliculus and the primary visual cortex (V1) in congenitally anophthalmic ZRDCT/An mice. This implies that this mutant mouse would be the only known vertebrate having a direct tectal connection with a primary sensory cortex. The presence of this peculiar pathway was reinvestigated in the ZRDCT/An mouse with highly sensitive neuronal tracers. We found the connections normally described in the ZRDCT/An mouse between: (i) the inferior colliculus and the dorsal lateral geniculate nucleus, (ii) V1 and the superior colliculus, (iii) the lateral posterior nucleus and V1 and between (iv) the inferior colliculus and the medial geniculate nucleus. We also show unambiguously that the auditory subcortical structures do not connect the primary visual cortex in the anophthalmic mouse. In particular, we find no evidence of a direct projection from the auditory mesencephalon to the cortex in this animal model of blindness. 相似文献