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排序方式: 共有1193条查询结果,搜索用时 31 毫秒
1.
Marion Tardieu Najat Salameh Line Souris David Rousseau Laurène Jourdain Hanadi Skeif François Prévot Ludovic de Rochefort Denis Ducreux Bruno Louis Philippe Garteiser Ralph Sinkus Luc Darrasse Marie Poirier-Quinot Xavier Maître 《NMR in biomedicine》2022,35(7):e4701
Magnetic resonance elastography aims to non-invasively and remotely characterize the mechanical properties of living tissues. To quantitatively and regionally map the shear viscoelastic moduli in vivo, the technique must achieve proper mechanical excitation throughout the targeted tissues. Although it is straightforward, ante manibus, in close organs such as the liver or the breast, which practitioners clinically palpate already, it is somewhat fortunately highly challenging to trick the natural protective barriers of remote organs such as the brain. So far, mechanical waves have been induced in the latter by shaking the surrounding cranial bones. Here, the skull was circumvented by guiding pressure waves inside the subject's buccal cavity so mechanical waves could propagate from within through the brainstem up to the brain. Repeatable, reproducible and robust displacement fields were recorded in phantoms and in vivo by magnetic resonance elastography with guided pressure waves such that quantitative mechanical outcomes were extracted in the human brain. 相似文献
2.
Thierry Patrice David Olivier Ludovic Bourre 《Journal of environmental pathology, toxicology and oncology》2006,25(1-2):467-485
Photodynamic therapy (PDT) is based on the selective light activation of an exogenously given drug to patients. PDT acts mainly on cell membranes either of neovascular endothelial cells or of cancer cells leading to cancer cell death. Six drugs are now marketed based on clinical assays in various indications, which showed a clear cost efficiency as compared to other classical procedures. PDT is easy to handle and can be performed in medical installations fitting the conditions of health care in developing countries. Its cost effectiveness could represent an appropriate solution to the increasing number of cancers of various origin. However despite all the clinical results now available, PDT development remains slow. The reasons for this situation include cost of development, intellectual property, and competition between pharmaceutical companies. 相似文献
3.
4.
Working memory after severe traumatic brain injury. 总被引:1,自引:0,他引:1
Claire Vallat-Azouvi Thomas Weber Ludovic Legrand Philippe Azouvi 《Journal of the International Neuropsychological Society》2007,13(5):770-780
The aim of the present study was to assess the functioning of the different subsystems of working memory after severe traumatic brain injury (TBI). A total of 30 patients with severe chronic TBI and 28 controls received a comprehensive assessment of working memory addressing the phonological loop (forward and backward digit span; word length and phonological similarity effects), the visuospatial sketchpad (forward and backward visual spans), and the central executive (tasks requiring simultaneous storage and processing of information, dual-task processing, working memory updating). Results showed that there were only marginal group differences regarding the functioning of the two slave systems, whereas patients with severe TBI performed significantly poorer than controls on most central executive tasks, particularly on those requiring a high level of controlled processing. These results suggest that severe TBI is associated with an impairment of executive aspects of working memory. The anatomic substrate of this impairment remains to be elucidated. It might be related to a defective activation of a distributed network, including the dorsolateral prefrontal cortex. 相似文献
5.
A G Assounga S Bascoul B Canaud P A Bouya J P Vendrell J P Sciolla G Mourad P Baldet A Serre C Mion 《American journal of kidney diseases》1990,15(6):556-561
This study reports on beta 2-microglobulin (beta 2M) deposits in the skin of 12 uremic patients and three kidney transplant recipients compared with eight healthy controls. Uremic patients were treated by hemodialysis (HD), hemofiltration (HF), hemodiafiltration (HDF), or continuous ambulatory peritoneal dialysis (CAPD) for a period lasting from 1 to 19 years. Congo red staining of the skin was negative in patients and controls. However, immunofluorescent staining with an anti-beta 2-microglobulin monoclonal antibody was positive in the skin of all patients and of six of the eight controls. Beta 2M skin deposition is more intense in patients than in controls and increases with patient age and the duration of dialysis. A stron correlation is observed between the extent of skin beta 2M deposits and clinical manifestations due to beta 2M deposits in internal organs. However, no correlation is found between beta 2M skin deposits and sex or beta 2M serum levels. 相似文献
6.
Erythropoietin and oxidative stress in haemodialysis: beneficial effects of vitamin E supplementation 总被引:10,自引:7,他引:3
Cristol J; Bosc J; Badiou S; Leblanc M; Lorrho R; Descomps B; Canaud B 《Nephrology, dialysis, transplantation》1997,12(11):2312-2317
Oxidative stress can produce profound alterations to cellular membrane
lipids, impairing cell metabolism and viability. This phenomenon,
previously observed in haemodialysis patients, had been proposed as a
significant factor in regard to haemodialysis-related shortened red blood
cells (RBC) survival. In the present study, several parameters associated
with oxidative stress were evaluated in a group of haemodialysis patients
either receiving erythropoietin therapy (n=12, mean erythropoietin dose
88±24 U/kg/week) or not receiving such therapy (n=20), and in 38
controls. Malonyldialdehyde (MDA, nmol/ml), an end-product of lipid
peroxidation, and RBC anti-oxidant systems were measured, including RBC
&agr;-tocopherol (RBC vitamin E, mg/l), RBC glutathione (GSH,
nmol/mgHb), and RBC superoxide dismutase activity (SOD, U/mgHb). Plasma
vitamin E concentrations were also evaluated. Finally, oral vitamin E
supplementation (500 mg daily), an exogenous antioxidant, was administered
for 6 months to seven patients from the dialysis group receiving
erythropoietin while oxidative parameters were repeatedly evaluated and
erythropoietin requirements monitored, in order to appreciate the
therapeutic relevance of an antioxidant supplementation. An elevation of
serum MDA was observed in all haemodialysis patients and a significant
decrease in RBC vitamin E, despite normal serum vitamin E levels.
Furthermore, the reduction in RBC vitamin E was more important in patients
treated with erythropoietin. Vitamin E supplementation resulted in a
significant increase in RBC vitamin E (from 0.3±0.1 to
1.2±0.2 mg/l of pellet) and a reduction in erythropoietin dose
(from 93±24 to 74±26 U/kg/week) while maintaining
stable haemoglobin concentrations. These results suggest that the oxidative
stress could be one of the resistance factors to erythropoietin response in
haemodialysis and that vitamin E supplementation could have a sparing
effect on erythropoietin dosage requirement. Key
words: antioxidant; erythropoietin; haemodiafiltration; lipid
peroxidation; oxidative stress; vitamin E
相似文献
7.
Guy Susini Ludovic Pommel Imad About Jean Camps 《Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics》2006,102(3):e19-e23
OBJECTIVE: The aim of this study was to determine if there is a significant correlation between the in vivo presence of periapical radiolucency and ex vivo apical dye penetration on the same human teeth. STUDY DESIGN: Eighty-four endodontically filled teeth that were scheduled for extraction were classified into 2 groups according to the presence or absence of a periapical radiolucency and further divided into 2 subgroups according to the quality of the root canal filling. After extraction, the apical filling was evaluated by a dye penetration method. RESULTS: The dye extraction evaluation showed no correlation between apical dye penetration and the presence of a periapical radiolucency (not significant), but a statistically significant correlation with the quality of the root canal filling (P = .03). CONCLUSION: The results of the dye penetration study were correlated to the quality of the root canal filling but had no predictive value for the development of periapical radiolucency. 相似文献
8.
BACKGROUND: The recent introduction of urea sensors for dialysis monitoring
has made possible new approaches to urea kinetic modelling. In this study
we show how the equilibrated postdialysis urea concentration (Ceq) and Kt/V
corrected for double-pool urea kinetics (Kt/Vdp) can be accurately
determined using an on-line sensor providing a continuous measure of blood
water urea. A modification of the Smye constant volume double-pool theory
led to the following equations for Ceq and Kt/Vdp [formula: see text] where
Cpre is the blood concentration measured at the start of dialysis, t is the
length of the dialysis session (in min) and S(ex) is the constant slope of
the blood urea logarithm concentration decline following development of the
intercompartmental urea concentration gradient in the first 30-60 min of
dialysis. METHODS: These equations were tested in 11 patients undergoing
165-240 min of paired filtration dialysis with continuous monitoring of
blood urea concentration. Cpre was determined as the plateau concentration
during a preliminary period of 15-20 min of slow isolated ultrafiltration.
S(ex) was accurately determined from linear regression applied to the urea
sensor data from the 80-min point to the end of dialysis. RESULTS: Ceq and
Kt/Vdp determined from the above equations compared closely to values
determined from 25-40 min of urea rebound monitoring with the urea sensor:
10.6 +/- 3.0 versus 10.8 +/- 2.7 mmol/l (mean +/- SD) for Ceq and 1.21 +/-
0.24 versus 1.18 +/- 0.20 for Kt/Vdp, compared to single-pool values of
Kt/V = 1.34 +/- 0.23. CONCLUSION: This technique may be readily programmed
into on-line urea monitors to provide current and extrapolated values of
Ceq and Kt/Vdp from about the first hour of dialysis.
相似文献
9.
Multiplex PCR targeting tpi (triose phosphate isomerase), tcdA (Toxin A), and tcdB (Toxin B) genes for toxigenic culture of Clostridium difficile 总被引:1,自引:0,他引:1 下载免费PDF全文
Lemee L Dhalluin A Testelin S Mattrat MA Maillard K Lemeland JF Pons JL 《Journal of clinical microbiology》2004,42(12):5710-5714
A multiplex PCR toxigenic culture approach was designed for simultaneous identification and toxigenic type characterization of Clostridium difficile isolates. Three pairs of primers were designed for the amplification of (i) a species-specific internal fragment of the tpi (triose phosphate isomerase) gene, (ii) an internal fragment of the tcdB (toxin B) gene, and (iii) an internal fragment of the tcdA (toxin A) gene allowing distinction between toxin A-positive, toxin B-positive (A+B+) strains and toxin A-negative, toxin B-positive (A−B+) variant strains. The reliability of the multiplex PCR was established by using a panel of 72 C. difficile strains including A+B+, A−B−, and A−B+ toxigenic types and 11 other Clostridium species type strains. The multiplex PCR assay was then included in a toxigenic culture approach for the detection, identification, and toxigenic type characterization of C. difficile in 1,343 consecutive human and animal stool samples. Overall, 111 (15.4%) of 721 human samples were positive for C. difficile; 67 (60.4%) of these samples contained A+B+ toxigenic isolates, and none of them contained A−B+ variant strains. Fifty (8%) of 622 animal samples contained C. difficile strains, which were toxigenic in 27 (54%) cases, including 1 A−B+ variant isolate. Eighty of the 721 human stool samples (37 positive and 43 negative for C. difficile culture) were comparatively tested by Premier Toxins A&B (Meridian Bioscience) and Triage C. difficile Panel (Biosite) immunoassays, the results of which were found concordant with toxigenic culture for 82.5 and 92.5% of the samples, respectively. The multiplex PCR toxigenic culture scheme described here allows combined diagnosis and toxigenic type characterization for human and animal C. difficile intestinal infections. 相似文献
10.