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11.
Stephen Mannion Xavier Capdevila 《Journal canadien d'anesthésie》2007,54(7):584; author reply 584-584; author reply 585
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13.
Hanzhang Lu Xavier Golay James J Pekar Peter C M Van Zijl 《Magnetic resonance in medicine》2003,50(2):263-274
During brain activation, local control of oxygen delivery is facilitated through microvascular dilatation and constriction. A new functional MRI (fMRI) methodology is reported that is sensitive to these microvascular adjustments. This contrast is accomplished by eliminating the blood signal in a manner that is independent of blood oxygenation and flow. As a consequence, changes in cerebral blood volume (CBV) can be assessed through changes in the remaining extravascular water signal (i.e., that of parenchymal tissue) without need for exogenous contrast agents or any other invasive procedures. The feasibility of this vascular space occupancy (VASO)-dependent functional MRI (fMRI) approach is demonstrated for visual stimulation, breath-hold (hypercapnia), and hyperventilation (hypocapnia). During visual stimulation and breath-hold, the VASO signal shows an inverse correlation with the stimulus paradigm, consistent with local vasodilatation. This effect is reversed during hyperventilation. Comparison of the hemodynamic responses of VASO-fMRI, cerebral blood flow (CBF)-based fMRI, and blood oxygenation level-dependent (BOLD) fMRI indicates both arteriolar and venular temporal characteristics in VASO. The effect of changes in water exchange rate and partial volume contamination with CSF were calculated to be negligible. At the commonly-used fMRI resolution of 3.75 x 3.75 x 5 mm(3), the contrast-to-noise-ratio (CNR) of VASO-fMRI was comparable to that of CBF-based fMRI, but a factor of 3 lower than for BOLD-fMRI. Arguments supporting a better gray matter localization for the VASO-fMRI approach compared to BOLD are provided. 相似文献
14.
Photocarcinogenesis and inhibition of intercellular adhesion molecule 1 expression in cells of DNA-repair-defective individuals 下载免费PDF全文
15.
Gérald Vanzetto Marc Janier Daniel Fagret Luc Cinotti Xavier André-Fouet Michel Comet Jacques Machecourt 《European journal of nuclear medicine and molecular imaging》1997,24(2):170-178
The best test presently available to ascertain residual viability within an infarct-related area involves the use of fluorine-18
fluorodeoxyglucose (FDG) to detect the persistence of some cellular metabolism. Rest reinjection of thallium-201 is a less
accurate alternative but is easy to perform. Iodinated fatty acids, which are used with standard gamma cameras, are proposed
as markers of cellular metabolism. This study was performed to assess the value of 16-iodo-3-methyl-hexadecanoic acid (MIHA)
as a marker of the residual cellular metabolism by comparison with FDG in patients with a recent myocardial infarction, and
to evaluate its contribution compared with the201Tl stress-redistribution-reinjection technique. Stress-redistribution-reinjection201T1 imaging, rest MIHA imaging and glucoseloaded FDG imaging were performed in 22 patients with recent myocardial infarction.
Out of the 628 myocardial segments obtained from the left ventricular analysis, 400 were hypoperfused (relative uptake <0.75
of maximum uptake on stress201T1 imaging), 177 of which were severely hypoperfused (relative uptake <0.50). Receiver operating characteristic (ROC) curves
for predicting metabolic myocardial viability with FDG were derived from the results in respect of (a)201T1 activity during exercise, redistribution and reinjection and (b) MIHA up-take, using the two FDG thresholds most commonly
considered to define metabolic viability (0.50 and 0.60). Analysis of the 400 hypoperfused segments demonstrated that201T1 reinjection was the most accurate test in predicting the presence of myocardial viability (area under the ROI curves=0.85
and 0.86 at the 0.50 and 0.60 FDG thresholds, respectively;P<0.05 vs other tests). The global predictive values of MIHA and201T1 reinjection were, respectively, 0.87 and 0.89 at the 0.50 FDG threshold (NS), and 0.82 and 0.87 at the 0.60 FDG threshold
(NS). When only the 177 severely hypoperfused segments were considered,201T1 reinjection remained the most accurate test (accuracy 0.84 at the 0.50 FDG threshold and 0.82 at the 0.60 FDG threshold),
while the accuracy of MIHA decreased significantly (0.78 at the 0.50 FDG threshold and 0.73 at the 0.60 FDG threshold,P<0.05 vs201T1 reinjection). In all circumstances, MIHA was less specific than201T1 reinjection for the detection of metabolic viability. In conclusion, in patients with recent myocardial infarction, MIHA
accurately detects the persistence of metabolic viability, but is not superior to201T1. 相似文献
16.
Georgios Amoiridis Ludwig Gutmann Dennis E. Wilkins Raja Sawaya Alain Lagueny Roger Marthan Philippe Schuermans Philippe Le Collen Xavier Ferrer Jean Julien Reha Kuruoglu Shin J. Oh Brian Thompson A. Aggarwal L. Gutmann A. Gutierrez Okifumi Nakazato Russel Johnsen Philip Morling B. A. Kakulas 《Muscle & nerve》1994,17(2):245-253
17.
R Mandeville S Sidrac-Ghali I Ajdukovic D Vidal J Ayoub 《Cancer Detection and Prevention》1987,10(1-2):129-139
The present study was aimed at comparing the effect of clinical staging and radiotherapy on natural killer (NK) and interferon-activated killer (IAK) cell activity in a group of endometrial cancer patients receiving a total dose of 5,000 to 8,000 rads. We report that when compared to age-matched women, a significantly higher number and percentage of patients show low NK and IAK cell activity. At diagnosis, diminished NK activity was seen in about 20% of the patients, while IAK activity was low in 49% of these patients. There was no correlation between these deficiencies and the grade or stage of the disease. In contrast, radiotherapy induced deleterious effects on both populations of NK and IAK cells. These deleterious effects were more pronounced in patients showing a low level of spontaneous NK activity. In an attempt to understand better the mechanism by which the presence of cancer itself and/or radiotherapy affects these activities, we studied in greater detail changes in peripheral blood T-cell numbers and subsets. Before radiotherapy, all lymphocyte counts were within the normal range. In contrast, after radiotherapy the absolute numbers of all T-cell subsets were significantly decreased in the majority of the patients tested, OKT4+ cells being the most radiosensitive and Leu 7+ cells the most radioresistant. 相似文献
18.
The authors report a spiny dogfish (Squalus cubensis/megalops group) sting of a professional fisherman. He was injured on the left hand by the spine anterior to the fish's dorsal fin and manifested local edema, erythema, and excruciating pain for 6 h. Sharks of the genus Squalus megalops/cubensis and Squalus acanthias are found throughout the world; they have two spines in front of their dorsal fins and channels with a whitish mass containing large vacuolated cells which secrete venom. The Squalus genus has a complex taxonomy; the species involved in this injury belongs to the megalops/cubensis group. A detailed taxonomic and toxinological study on the Squalus genus is important and would complement other work on these fish, especially as stings in humans are very rare and not fully understood. 相似文献
19.
20.
An epidural abscess due to resistant Staphylococcus aureus following epidural catheterisation 总被引:1,自引:0,他引:1
We report a case of abscess formation after epidural analgesia, a rare complication that developed in our patient 13 days after placement of a thoracic epidural catheter for patient controlled analgesia. Culture of the pus grew methicillin-resistant Staphylococcus aureus . Although early diagnosis and rapid management have been reported to yield a satisfactory outcome, the case we describe ended in severe sequelae. 相似文献