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1.
D. Mitton J Rappeneau R. Bardonnet 《European journal of orthopaedic surgery & traumatology : orthopedie traumatologie》2005,15(4):264-269
Bone allografts can be treated by various techniques before implantation. Recently, treatments based on supercritical carbon dioxide (CO2) were developed. The goal of this study was to evaluate the influence of such a treatment on the biomechanical properties of bone allografts. Thirteen human femoral heads obtained from patients who had undergone hip arthroplasty were cut along the frontal plane yielding to two slices with similar mechanical properties. For each femoral head, one of the two slices (randomly chosen) was fresh-frozen, whereas the other one underwent all steps of a supercritical CO2 based treatment in order to clean and secure bone tissue. Nine specimens (7 mm×9 mm×10 mm) per slice were then cut and loaded under compression in a physiologic saline solution maintained at 37°C. For the maximal compressive strength a mean value (SD) of 9.6 (2.4) MPa for fresh bone and 10.2 (5.2) MPa for treated one was found. Regarding the Young’s modulus a mean value of 417 (85) MPa was obtained for fresh specimens and 412 (149) MPa for the treated ones. No statistical difference was found between the bone specimens treated with supercritical CO2 and the fresh-frozen paired specimens when considering maximal compressive strength, Young’s modulus and work to failure. 相似文献
2.
Diane M. Burnard Quentin J. Pittman Brian A. MacVicar 《Journal of neuroendocrinology》1991,3(4):433-439
Intracellular recordings were obtained from pituicytes in the neural lobe of the isolated rat pituitary. Like other glia, pituicytes lacked action potentials in response to depolarizing current injection, but they tended to have more positive resting membrane potentials and higher input resistances than astrocytes in other preparations. Dye-coupling typical of astrocytes was also demonstrated amongst pituicytes, and their morphologies were similar to those of pituicytes stained for glial fibrillary acidic protein. Action potentials, anode-break spikes or barium spikes were not observed in pituicytes, even under conditions that maximized the elicitation of Ca2+-dependent responses. This suggests that pituicytes either have no or a very low density of Ca2+ channels or Ca2+ currents that are too small to generate action potentials. Dynorphin A (1–13), a kappa-opioid agonist, produced long-lasting increases in pituicyte input resistance with no significant changes in resting membrane potential. Dynorphin's action was concentration-dependent and was blocked by the opioid antagonist naloxone. This is consistent with previous reports demonstrating kappa-opioid receptors on pituicytes in the neurohypophysis. The β-adrenergic agonist isoproterenol (100 μM) reversed the increases in pituicyte input resistance produced by opioid application, with no significant changes in resting membrane potential. The fact that pituicytes responded to neurotransmitters suggests a functional link between pituicytes and neurosecretory nerve fibres. 相似文献
3.
O Jardé J de Moegen L Siboulet J C Perdu Y Quentin T Woestelandt Y Grumbach P Vives 《Journal de radiologie》1987,68(5):391-394
The syndrome of Maffucci is characterized by angioma association of the enchondromatose. It is a relatively rare syndrome. The lesions are evolutived. The treatment is surgical. His pronostic is marqued by high percentage of malign degenerescence. 相似文献
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Two putative cDNAs of acetylcholinesterase (AChE), one from Dermacentor variabilis, and the other from Rhipicephalus sanguineus, were amplified and sequenced. The deduced amino acid sequences have high amino acid identities (between 70 and 94%) to known tick AChE sequences deposited in GenBank. Furthermore, these two AChEs also possess common features in their primary AChE structure such as catalytic active sites. A 2,220-bp contiguous sequence, containing a 1,791-bp open reading frame encoding an AChE precursor with 596 amino acid residues, was obtained from D. variabilis. The deduced proteins of R. sanguineus are different in size by 6 amino acids because of alternative splicing at the 5' end. A gene tree deduced from phylogenetic analysis indicates that there are at least three lineages of AChE in arthropods. 相似文献
8.
Escherichia coli strains from pregnant women and neonates: intraspecies genetic distribution and prevalence of virulence factors 总被引:1,自引:0,他引:1
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Watt S Lanotte P Mereghetti L Moulin-Schouleur M Picard B Quentin R 《Journal of clinical microbiology》2003,41(5):1929-1935
To determine the extent to which the vagina, endocervix, and amniotic fluid screen the Escherichia coli strains responsible for neonatal infections, we studied the genetic relationships among 105 E. coli strains isolated from all of the ecosystems involved in this infectious process. Twenty-four strains were isolated from the intestinal flora, and 25 strains were isolated from the vaginas of pregnant women. Twenty-seven strains were isolated from the amniotic fluid, blood, and cerebrospinal fluid (CSF) of infected neonates. The intraspecies genetic characteristics of all of the isolates were determined by random amplified polymorphic DNA (RAPD) analysis, PCR ECOR (E. coli reference) grouping, and PCR virulence genotyping. A correlation was found between the intraspecies distributions of the strains in the A, B1, B2, and D ECOR groups and in the two major RAPD groups (I and II). Nevertheless, the distribution of the E. coli strains in the RAPD groups according to their anatomical origins was more significant than their distribution in the ECOR groups. This may be explained by the existence of an E. coli subpopulation, defined by the RAPD I group, within the ECOR B2 group. This RAPD I group presents a major risk for neonates: 75% of the strains isolated from patients with meningitis and 100% of the strains isolated from patients with bacteremia were in this group. The vagina and the amniotic fluid are two barriers that favor colonization by highly infectious strains. Indeed, only 17% of fecal strains belonged to the RAPD I group, whereas 52% of vaginal strains and 67% of amniotic fluid strains belonged to this subpopulation. The ibeA and iucC genes were significantly associated with CSF strains, whereas the hly and sfa/foc genes were more frequent in blood strains. These findings could serve as a basis for developing tools to recognize vaginal strains, which present a high risk for neonates, for use in prophylaxis programs. 相似文献
9.
Louis Journeau Marc-Antoine Pistorius Ulrique Michon-Pasturel Marc Lambert Francois-Xavier Lapébie Alessandra Bura-Riviere Philippe de Faucal Patrick Jego Quentin Didier Cécile Durant Geoffrey Urbanski Baptiste Hervier Claire Toquet Christian Agard Olivier Espitia 《Autoimmunity reviews》2019,18(5):476-483
10.
Zitterkopf NL Jones QA Bradley DS Durick K Rowland RR Plagemann PG Cafruny WA 《Viral immunology》2003,16(4):511-523
Persistent infection of mice with lactate dehydrogenase-elevating virus (LDV) is associated with polyclonal B cell activation, autoimmunity, and circulating hydrophobic IgG-containing immune complexes (ICs), which bind to the surfaces of uncoated ELISA plates in the presence of 0.05% Tween 20. We demonstrate here that hydrophobic IgG-containing ICs also appear naturally in the plasma of autoimmune MRL/lpr mice. These and the similar hydrophobic ICs of LDV-infected mice as well as pigs coincide on ELISA plate surfaces with TGF-beta, apparently in the form of an IgG-TGF-beta complex. Circulating hydrophobic IgG-containing ICs are also susceptible to considerable amplification in vitro by exposure to alkaline conditions. By this latter method, the fraction of in vivo hydrophobic IgG, relative to the maximum in vitro chemically inducible IgG, was found to be about 20% in the plasma of LDV-infected mice, 5% in normal mouse plasma, and less than about 2% in pig plasma. These results indicate the potential for both chemically induced and protein-binding contributions to the generation of hydrophobic IgG-containing molecules, and have implications for immunopathological mechanisms in autoimmunity and persistent virus infections. 相似文献