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排序方式: 共有1419条查询结果,搜索用时 609 毫秒
1.
Intracranial circulation: pulse-sequence considerations in three- dimensional (volume) MR angiography 总被引:2,自引:0,他引:2
The technique and feasibility of magnetic resonance (MR) angiography of intracranial vessels were studied in 35 healthy volunteers. Variations in image orientation, repetition time (TR), and flip angle were evaluated to determine their effects on flow-related enhancement. Gradient modifications--including echo time (TE), motion compensation, bandwidth, and field of view--were also studied in an effort to reduce motion-induced phase shifts. Results indicated that a FISP (fast imaging with steady precession) sequence with a TR of 50 msec, TE of 15 msec, velocity compensation in the read and section-select directions, acceleration compensation in the read direction, anisotropic volume, and a 1.25-mm partition thickness produced three-dimensional angiographic MR images that were accurate and reproducible in the depiction of the major intracranial vessels. Difficulties with field of view, persistent signal void secondary to higher-order motion, and spatial resolution remain major problems requiring additional study. 相似文献
2.
Shigeru Ichioka MD ; Naomi Sekiya MT ; Masahiro Shibata PhD ; Takashi Nakatsuka MD 《Wound repair and regeneration》2007,15(4):572-576
The leukocyte-endothelium interaction is known to contribute to reperfusion injury, which is considered to participate in the pathophysiology of pressure ulcers, and integrin alphaV beta3 (alphavbeta3) has been shown to mediate the processes of cellular adhesion in various types of cells. This study aims to clarify leukocyte behavior in our original microcirculatory pressure-induced reperfusion model, which can visualize the microcirculation in vivo. We also estimated the effect of alphavbeta3 integrin inhibition on the reduction of the leukocyte-endothelium interaction. Mice with dorsal skinfold chambers were divided into three groups: the baseline group (n=6), in which animals received no compression; the compression-reperfusion group (n=6), in which animals underwent 2-hour compression of the dorsal skin, followed by release, and the inhibitor-treated group (n=7), in which an alphavbeta3 inhibitor, CP4715, was administered in addition to the compression-release procedure. Staining with rhodamine 6G quantitatively visualized leukocyte behavior under the intravital fluorescent microscope. Compression-reperfusion induced a significant increase in rolling, sticking, and extravasation of the leukocytes. Treatment with the inhibitor strikingly reduced leukocyte sticking and extravasation. The present experiment has provided evidence that alphavbeta3 inhibition reduces leukocyte-endothelium interaction in our original pressure-induced reperfusion model. 相似文献
3.
Dr. S. Eggstein MD G. Manthey MT T. Hirsch PhD F. Baas MA B. U. V. Specht MD E. H. Farthmann MD 《Digestive diseases and sciences》1996,41(6):1069-1075
Epidermal growth factor receptors (EGFR) andras mutations are known to play a significant role in controlling cell growth and tumor promotion. Both of them transmit mitogenic signals to the nucleus by activation of Raf-1 kinase. In this study, the expression of EGFR and mutant Ras proteins, and, for the first time, the expression, phosphorylation and kinase activity of Raf-1 kinase have been determined in paired samples of colorectal cancer and mucosa. The tumor and mucosa samples did not differ significantly with regard to Raf-1 kinase content and activity. A major difference between tumors and mucosa was found, however, in the phosphorylation of Raf-1. Most of the mucosa samples (13/20), but only 1/20 of the cancer samples, contained hyperphosphorylated Raf-1. EGFR were significantly (p=0.0025) decreased in the tumors. The decreased phosphorylation of Raf-1 in colonic carcinomas could be the result of activation of Raf-1 phosphatases or inactivation of kinases phosphorylating Raf-1. New forms of treatment based on EGFR overexpression do not seem to be suitable for the majority of colonic cancers.This work was supported by the state of Baden-Württemberg (Verbundforschungsprojekt: Aufklärung von Mechanismen der Tumorentstehung und Tumorabwehr). 相似文献
4.
Analysis of ischemia-reperfusion injury in a microcirculatory model of pressure ulcers 总被引:2,自引:0,他引:2
Shinsaku Tsuji MD ; Shigeru Ichioka MD ; Naomi Sekiya MT ; Takashi Nakatsuka MD 《Wound repair and regeneration》2005,13(2):209-215
The aim of this study was to establish a pressure ulcer model that visualizes the microcirculation, and to examine the participation of ischemia-reperfusion injury in the pathophysiology of pressure ulcers. An original system composed of a new skin fold chamber and compression device allowed loading quantitative vertical stress to the skin. An intravital microscopic technique enabled direct visualization of the microcirculation in the physiological condition and in response to pressure application. To estimate the effect of ischemia-reperfusion injury, animals were divided into two groups: the compression-release group (n = 8), in which the animals received four cycles of compression-release which consisted of 2 hours of compression followed by 1 hour of pressure release; and the compression alone group (n = 8) in which the animals underwent continuous compression for 8 hours. Functional capillary density was quantified before the compression procedure and on day 1 (35 hours) after the first evaluation. The cyclic compression-release procedure significantly decreased functional capillary density as compared to continuous compression, indicating that in our experimental setting repetition of ischemia-reperfusion cycle more severely damaged the microcirculation than single prolonged ischemic insult. This finding supports the significant contribution of ischemia-reperfusion injury to the pathophysiology of pressure ulcers at the level of dynamic in vivo microcirculation. 相似文献
5.
Lack of interaction between diazepam and nimodipine during chronic oral administration to healthy elderly subjects. 总被引:1,自引:1,他引:0
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P R Heine G Weyer H P Breuel W Mück N Schmage J Kuhlmann 《British journal of clinical pharmacology》1994,38(1):39-43
1. Nimodipine (30 mg three times daily) and diazepam (10 mg once daily), were given orally to 24 elderly healthy subjects in a randomized, non-blinded, threefold-crossover study. Each of the three treatment periods lasted 5 days separated by 2 week washout phases. 2. Plasma concentrations of nimodipine and diazepam were not affected by the combined treatment. 3. No clinically relevant changes in haemodynamics, ECG recordings, clinical chemistry or haematology were observed after all of the three treatments. The overall frequency of side effects was lowest during monotherapy with nimodipine and highest during diazepam monotherapy. 4. In the test of subjective rating of tiredness (VAS) and the Pauli calculation test, diazepam, alone and with nimodipine co-medication, produced an increase in tiredness and a clear reduction in performance and endurance. After nimodipine monotherapy an improvement was observed only in the Pauli test. Using the critical flicker fusion frequency test (CFF) significant decrements in performance were found after diazepam monotherapy only. 5. In summary, there was no evidence that either nimodipine or diazepam affected the pharmacokinetics, safety and tolerance of each other. However, the CNS-effects of diazepam were compensated partially by nimodipine. 相似文献
6.
Vascularized bone graft pedicled on the volar carpal artery for non-union of the scaphoid 总被引:2,自引:0,他引:2
J N Kuhlmann M Mimoun A Boabighi S Baux 《The Journal of hand surgery, European volume》1987,12(2):203-210
A bone graft, taken from the medial part of the radial epiphysis can be pedicled on the radial branch of the volar carpal arch, freed back to its origin. The graft can be transferred into the proximal row of the carpus to fill up a loss of bony substance or to provide vascularised bone. This permits the treatment of chronic pseud-arthrosis of the scaphoid where a Matti-Russe operation has failed. In the first three cases operated upon, favourable results have been obtained. 相似文献
7.
Improved cytosolic free calcium mobilization and superoxide production in bicarbonate-based peritoneal dialysis solution 总被引:1,自引:0,他引:1
Dobos G; Burger M; Kuhlmann J; Passlick-Deetjen J; Schollmeyer P; Bohler J 《Nephrology, dialysis, transplantation》1997,12(5):973-977
Background. Intraperitoneal phagocytes play an
important role in local host defence to prevent CAPD peritonitis. The
intracellular calcium [Ca2+]i is thought to be
involved in the regulation of various cell functions. This study therefore
investigates the effect of lactate-based dialysis solution (LBDS) and
bicarbonate-based dialysis solution (BBDS) on cytosolic free calcium
mobilization and superoxide production (SP) as important steps in signal
transduction and bacterial killing. Methods. We
studied changes in [Ca2+]i and SP following
stimulation with N-formyl-methionyl-leucyl-phenylalanine (fMLP) in
polymorphonuclear neutrophils (PMNs) incubated in either LBDS-pH 5.2, LBDS
adjusted to pH 7.4, 1:10 diluted spent and fresh LBDS or BBDS-pH 7.4 with
different glucose concentrations, comparing the data with cells treated
with Hanks buffer (HBSS) pH 7.4 as control. To elucidate the effect of
glucose and lactate PMNs were additionally incubated in HBSS-pH 7.4,
containing glucose (HBSS-Glu-pH 7.4) or lactate (HBSS-Lact-pH 7.4) in the
same concentrations as contained in CAPD solutions and tested as above.
PMNs were isolated from healthy blood donors and incubated with dialysis
solution 10 min prior to stimulation with fMLP.
Results. [Ca2+]i mobilization
and SP were completely inhibited in PMNs incubated in LBDS pH 5.2. pH
adjustment of LBDS to 7.4 and 1:10 dilution of spent and fresh LBDS
corrected some of the suppression of the calcium influx and superoxide
production. BBDS pH 7.4, however, preserved physiological cell function
significantly better at low (1.5 and 2.3%) glucose concentrations.
Conclusion. In comparison to conventional
lactate-based dialysis solution, pH adjusted and 1:10 diluted LBDS,
bicarbonate-based dialysis solution is more biocompatible since it
preserves significantly better neutrophil cell functions. 相似文献
8.
9.
10.
Immunotopographic assessment of lymphoid and plasma cell malignancies in the bone marrow 总被引:4,自引:0,他引:4
Rene Kronland MD Thomas Grogan MD Catherine Spier MD Daniel Wirt HTL Catherine Rangel MT Lynne Richter MD Brian Durie MD Bernard Greenberg MD Thomas Miller MD Stephen Jones 《Human pathology》1985,16(12):1247-1254
To determine the utility of tissue section immunochemistry in the evaluation of bone marrow involved by lymphoid and plasma cell malignancies, snap-frozen, undecalcified bone marrow core and aspirate samples from 23 patients with these disorders were studied with a battery of monoclonal antibodies. With techniques that preserve architecture, difficult diagnostic cases characterized by core but not aspirate involvement, or the reverse, were resolved. By means of an extensive battery of monoclonal antibodies applied to serial sections, complex tumor cell phenotypes were established in all 23 cases. In addition to the identification of straightforward monoclonal surface immunoglobulin expression in small cleaved cell lymphomas (four cases), the battery approach added immunologic certainty in malignancies with unusual or difficult phenotypes: peripheral T-cell lymphomas with idiosyncratic antigen expression, and chronic lymphocytic leukemias and small cell lymphomas with faint surface immunoglobulin expression (four cases). For the chronic lymphocytic leukemias and the small cell lymphomas, the combined IgD+, B2+, B1+, Ia+, Leu-1+ phenotype taken as a whole had greater utility than any isolated marker. The acute lymphocytic leukemias and the myelomas studied demonstrate the wide range of B-cell antigens that must be detected to account for the variety of B-cell neoplasms encountered. Additionally, the previously undescribed phenotypic subset of CALLA+ myelomas, which is of prognostic relevance, was identified. Marrow frozen section immunotyping is a major asset in the evaluation of patients with lymphoma, leukemia, and myeloma when special care is accorded to tissue handling and to treatment of endogenous peroxidase/pseudoperoxidase and interstitial immunoglobulin. 相似文献