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排序方式: 共有739条查询结果,搜索用时 15 毫秒
91.
92.
Selectin and alpha 4 beta 7-integrins have been shown to mediate transient leucocyte interactions with endothelial cells which is a crucial step in the initial immune response to pathogens. We have previously shown that stimulation of T lymphocytes via L-selectin results in activation of a signalling cascade from the L-selectin molecule via the tyrosine kinase p56lck and tyrosine phosphorylation of L-selectin to the stimulation of p21Ras and Rac proteins. In the present study we demonstrate that stimulation of Jurkat T lymphocytes via L-selectin results in an activation of Jun N-terminal kinase (JNK) but not of p38-K. L-selectin-initiated activation of JNK is mediated by src-like tyrosine kinases and the small G-protein Rac 1/2, since genetic or pharmacological inhibition of p56lck or Rac proteins prevent the stimulation of JNK by L-selectin. Thus, the data point to a novel signalling cascade from L-selectin via src-like tyrosine kinases and Rac proteins to JNK. 相似文献
93.
Kallahalla M. Uysal M. Swaminathan R. Lowell D.E. Wray M. Christian T. Edwards N. Dalton C.I. Gittler F. 《Computer》2004,37(11):38-46
Utility computing aims to aggregate server, network, and storage systems into a single, centrally managed pool of resources. SoftUDC, a virtual machine monitor, lets applications and administrative domains share physical resources while maintaining full functional isolation. 相似文献
94.
We have designed a general protocol to assess the rate of replicon initiation in mammalian cells in the presence of inhibitors of DNA synthesis. It is based on cross-linking DNA in vivo with trioxsalen, which effectively blocks the movement of the replication forks along DNA, while having little effect on initiation of replication. We applied this protocol to study the effect of the plant amino acid mimosine on the rate of replicon initiation in exponentially growing murine erythroleukemia F4N cells. We found out that during the first 2 h after application of 25-400 microM mimosine, the initiation step was inhibited more efficiently than the overall DNA synthesis. In this respect, the effect of mimosine was similar to that of gamma-ray irradiation and differed from that of hydroxyurea and aphidicolin. The results suggest that in addition to inhibiting the elongation step of DNA synthesis, mimosine inhibits the initiation of DNA replication as well. 相似文献
95.
BB Fredholm 《Canadian Metallurgical Quarterly》1997,94(19):1787-1788
96.
BB Fresco 《Canadian Metallurgical Quarterly》1998,105(11):2123-2126
OBJECTIVE: This study aimed to compare the results of pressure phosphene tonometry, a new tonometric technique, with Goldmann applanation tonometry. DESIGN: Comparative case series. PARTICIPANTS: A total of 100 consecutive patients (192 eyes) without diagnostic specificity, plus a separate subset of 14 eyes with intraocular pressure (IOP) above 19 mmHg, participated. INTERVENTION: Intraocular pressure was measured with Goldmann tonometry by one examiner and pressure phosphene tonometry by a different examiner. There was no communication between the examiners regarding test results. MAIN OUTCOME MEASURES: Intraocular pressure. RESULTS: In the group without diagnostic specificity, the mean difference between the two techniques was 0.3 mmHg. Fifty-one percent of the measurements were within +/-1 mmHg, 74.9% of the measurements were within +/-2 mmHg of each other, and the average deviation for 100% of the data was 1.8 mmHg. For pressure phosphene tonometry, the mean IOP was 15.2 mmHg with a standard deviation of 2.9 and a range of 18 mmHg (minimum, 10; maximum, 28). With Goldmann, the mean was 15.5 mmHg, the standard deviation was 3.1, and the range was 20 mmHg (minimum, 8; maximum, 28). The t test for paired data showed a Gaussian approximation with a P value of 0.05. A comparison between the results of the two techniques gave a correlation coefficient of 0.71. Results for the separate 14 patients with higher IOPs yielded a statistically significant mean difference of 0.1 mmHg between the two techniques (P < 0.05, t test for paired data). For pressure phosphene, the mean was 21 mmHg with a standard deviation of 5.5 and a range of 24 mmHg (minimum, 14; maximum, 38). For Goldmann, the mean was 21.1 mmHg with a standard deviation of 4.7 and a range of 19 mmHg (minimum, 15; maximum, 34). The correlation coefficient was 0.73. CONCLUSIONS: The close agreement between the two techniques suggests that pressure phosphene tonometry offers an alternative method for measuring IOP. It has the advantages that it is simple, noninvasive, and inexpensive. Potential uses of the pressure phosphene tonometer may include self-administered home testing, in outreach clinics by nonophthalmic technicians, and in patients with corneal conditions that preclude the use of Goldmann tonometry. 相似文献
97.
98.
N el-Guebaly JM Lockyer J Drought J Parboosingh BB Juschka WA Weston W Campbell S Chang 《Canadian Metallurgical Quarterly》1995,14(2):23-31
As the initial stage in developing a curriculum to assist family physicians to diagnose and manage alcohol abuse in their practices, questionnaires were mailed to a selected group of family physicians. A total of 117 physicians (34%) completed the questionnaire. The majority of physicians (70.1%) reported that fewer than 10% of their caseload experienced alcohol-related problems. Most physicians (59.3%) did not use any of the standard diagnostic instruments but reported that screening and detection was the most challenging alcohol-related problem along with patient management. The questionnaire identified a number of areas that could be used in the development of educational strategies to increase the expertise of primary care physicians in the diagnosis and management of alcohol-related problems. 相似文献
99.
RR Gaiser P Venkateswaren TG Cheek E Persiley J Buxbaum J Hedge TH Joyce BB Gutsche 《Canadian Metallurgical Quarterly》1997,9(7):564-568
STUDY OBJECTIVE: Part 1: To measure ropivacaine levels in the mother and infant at delivery after continuous lumbar epidural infusion. Part 2: To compare epidural ropivacaine to epidural bupivacaine for labor analgesia in regard to effectiveness, motor blockade, and maternal and neonatal effects. DESIGN: Part 1: Open-labelled, non-blind study. Part 2: Randomized, double-blind study. SETTING: Labor and delivery units of two academic hospitals. PATIENTS: Part 1: 20 ASA physical status I and II parturients in active labor. Part 2: 81 ASA physical status I and II parturients in active labor. INTERVENTIONS: For Part 1, 8 to 12 ml of 0.25% ropivacaine was administered through a lumbar epidural catheter to achieve a T10 dermatomal sensory level. An infusion of 0.25% ropivacaine, 8 to 10 ml/hr, maintained this sensory level. Maternal and umbilical cord blood samples obtained at delivery were analyzed for ropivacaine concentration. For Part 2, anesthetic management was similar to that previously described except patients were randomized to receive either 0.25% ropivacaine or 0.25% bupivacaine. Onset, regression, maximal spread of sensory block, and onset and degree of motor blockade were measured. Contraction pain as assessed using a visual analog scale (VAS), maternal blood pressure, and heart rate were determined every 5 minutes until a stable VAS-contraction score was achieved, and every 30 minutes thereafter. Neonatal assessment included Apgar scores and neurologic and adaptive capacity scores (NACS) at 15 minutes, 2 hours, and 24 hours. MEASUREMENTS AND MAIN RESULTS: For Part 1, the total and free maternal arterial concentrations of ropivacaine at delivery were 0.64 +/- 0.14 microgram/ml and 0.10 +/- .02 microgram/ml, respectively; the umbilical venous total and free concentrations were 0.19 +/- 0.03 microgram/ml and 0.12 +/- 0.07 microgram/ml, respectively (n = 12). The umbilical arterial and venous concentrations did not differ for both the free and total concentrations. For Part 2, there was no difference between ropivacaine and bupivacaine in the variables measured. Umbilical cord gases and Apgar scores were not different between the two groups; NACS were higher at 15 minutes and 2 hours in the ropivacaine group (p < 0.05) than the bupivacaine group. CONCLUSION: Both ropivacaine and bupivacaine produced excellent analgesia for labor with no major adverse effect on the mother or neonate. 相似文献
100.