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排序方式: 共有1909条查询结果,搜索用时 15 毫秒
1.
C W Scott D P Blowers P T Barth M M Lo A I Salama C B Caputo 《Journal of neuroscience research》1991,30(1):154-162
Three isoforms of human tau protein were compared for their abilities to induce microtubule assembly. The three isoforms, tau 3 (tau containing three microtubule-binding domains), tau 4 (tau containing four microtubule-binding domains) and tau 4L (tau containing four microtubule binding domains plus a 58-amino-acid insert near the N-terminus) were expressed in E. coli and purified using ammonium sulfate precipitation, ion exchange, and size exclusion chromatography. All three isoforms induced microtubule assembly at micromolar concentrations and showed similar critical concentrations for assembly of 0.4-0.45 microM. However, tau 4 induced microtubule formation at a rate five- to tenfold faster than either tau 3 or tau 4L. The rate of microtubule elongation seen with tau 4 was twofold greater than with tau 3 or tau 4L, suggesting that the faster rate of microtubule assembly seen with tau 4 was due, at least in part, to faster elongation. Tau 4 induced a greater number of microtubules to form at steady state than did tau 3 or tau 4L. The microtubules generated with each tau isoform had similar steady-state length distributions and were equally susceptible to cold-induced disassembly. These results indicate that the additional microtubule-binding domain in tau 4 enhances microtubule assembly, while the 58-amino-acid insert negates the stimulatory effect of the fourth microtubule-binding domain. 相似文献
2.
Using fura-2 loaded neural tumour cells, SK-N-SH, we demonstrate that receptor-mediated activation of phosphoinositide hydrolysis not only causes the release of Ca2+ from intracellular stores but also causes a concomitant influx of extracellular Ca2+. Thapsigargin (TG), a sesquiterpene lactone, causes a sustained elevation of intracellular Ca2+ and depletion of the inositol 1, 4, 5-trisphosphate-sensitive intracellular Ca2+ stores. In the absence of extracellular Ca2+, the increase in intracellular Ca2+ concentration ([Ca2+]i) was transient, suggesting that thapsigargin activates both intracellular mobilization and the influx of Ca2+ from extracellular space. These results are consistent with the proposal that the depletion of the inositol 1, 4, 5-trisphosphate-sensitive intracellular Ca2+ pool serves as a signal for Ca2+ influx. 相似文献
3.
Domenick P Coletti Andrew Salama John F Caccamese 《Journal of oral and maxillofacial surgery》2007,65(9):1746-1750
PURPOSE: The use of intermaxillary fixation (IMF) in the treatment of maxillofacial trauma represents the cornerstone of fracture reduction and immobilization. Many modalities of IMF have been described; recently IMF screws have been introduced into clinical practice, however, hardware failure can occur. We performed a retrospective study evaluating hardware-associated complications for self-drilling/tapping IMF screws. MATERIALS AND METHODS: A retrospective study on 49 patients requiring IMF was performed. The diagnosis, duration of IMF, screw site, use of elastic or wire fixation, and associated complications were recorded. IMF screws were used to adjunct open reduction techniques, for definitive closed reduction, or fracture prevention following dentoalveolar surgery. Follow-up examinations were performed until fracture healing was complete (6 to 8 weeks). RESULTS: A single adverse event occurred in 19 patients (39%) while 4 patients (8%) had more than 1 complication. The most common event was screw loosening; 29% of patients had at least 1 screw dislodged in the treatment period. Of the total number of screws placed (229), 15 (6.5%) became loose, and were equally distributed among the mandible and maxilla. The remaining complications noted were root fracture, 4% (2 of 49); loosened wires, 6% (3 of 49); screw shear, 2% (1 of 49); malocclusion, 2% (1 of 49); and ingested hardware, 2% (1 of 49). CONCLUSIONS: Overall the IMF self-drilling/tapping screws have been shown to be a useful modality to establish maxillomandibular fixation. It is a safe, and time-sparing technique; however, it is not without limitations or potential consequences which the surgeon must be aware of in order to provide safe and effective treatment. 相似文献
4.
Two patients with acute immune haemolytic anaemia caused by diclofenac are described. Both patients had developed IgG drug-independent autoantibodies and drug-dependent antibodies. The drug-dependent antibodies in one patient reacted with red blood cells (RBC) only in the presence of urine from patients receiving diclofenac (ex vivo antigen) but not in the presence of the drug itself or its known metabolites. This antibody appeared to recognize a trace metabolite which has not yet been identified. The drug-dependent antibodies in the second patient reacted with RBC in the presence of urine as ex vivo antigen as well as in the presence of the drug itself and its main metabolites. Incorrect diagnosis of such cases often is due to the occurrence of autoantibodies and/or unusual drug metabolism and excretion. 相似文献
5.
Yasser EMAD Yasser RAGAB Ahmed EL‐MARAKBI Salama MOHAMED HANFI 《International journal of rheumatic diseases》2007,10(4):326-329
A 48‐year‐old male patient with long‐standing ulcerative colitis since February 2001 which was diagnosed by endoscopy, developed acute digital ischemia affecting both hands with fixed colour changes in the left index finger which was followed shortly by digital ulceration. Magnetic resonance angiography (MRA) of both upper limbs showed evidence of vasculitis affecting digital arterioles on both sided and right subclavian occlusion. The patient received pulse methylprednisolone followed by cyclophosphamide pulse therapy, the latter continuing on a monthly basis for 6 months with appreciable improvement and remission of the vasculitic process; follow‐up MRA showed reperfusion of the previously occluded subcalvian artery. To the authors’ knowledge vasculitis complicating the course of ulcerative colitis is a rare association and is only sporadically reported in the literature. This rare entity should be diagnosed early and aggressively treated; MRA is a very promising diagnostic tool that is suitable for both diagnosis and follow‐up of patients with this rare entity. 相似文献
6.
7.
Novel 5-flucytosine-resistant clade of Candida dubliniensis from Saudi Arabia and Egypt identified by Cd25 fingerprinting
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Al Mosaid A Sullivan DJ Polacheck I Shaheen FA Soliman O Al Hedaithy S Al Thawad S Kabadaya M Coleman DC 《Journal of clinical microbiology》2005,43(8):4026-4036
DNA fingerprinting of Candida dubliniensis isolates using the species-specific probe Cd25 previously showed that this species consists of two distinct groups, termed Cd25 group I and Cd25 group II. The present study investigated the population structure of 30 C. dubliniensis oral isolates from Saudi Arabia and Egypt using Cd25 fingerprinting and rRNA gene internal transcribed spacer region-based genotyping. Cd25 fingerprinting analysis of these isolates revealed two distinct populations, the first of which consisted of 10 closely related genotype 1 isolates (average similarity coefficient [S(AB)] value, 0.86). The second population of 20 isolates was much more heterogeneous (average S(AB) value, 0.35) and consisted of two distinct subpopulations, one of which consisted of genotype 3 isolates (n = 13) and the other of genotype 4 isolates (n = 7). A mixed dendrogram generated from the fingerprint data from the 30 Saudi Arabian and Egyptian isolates, 5 Israeli isolates, and 51 previously characterized international isolates (32 of Cd25 group I and 19 of Cd25 group II) revealed the presence of three distinct main clades. The first corresponded to the previously described Cd25 group I and contained all the Saudi Arabian, Egyptian, and Israeli genotype 1 isolates mixed with international isolates. The second clade corresponded to the previously described Cd25 group II and contained three Israeli isolates, one genotype 2 isolate, one genotype 3 isolate, and a genotype 4 variant isolate, which were mixed with international isolates. The third clade has not been described before and consisted solely of the 20 Saudi Arabian and Egyptian genotype 3 and 4 isolates identified in this study and a previously described genotype 4 Israeli isolate. All 20 Cd25 group III isolates exhibited high-level resistance to 5-flucytosine (MIC > or = 128 microg/ml), whereas all Cd25 group I and Cd25 group II isolates tested (10 Saudi Arabian and Egyptian, 16 Israeli, and 24 international) were susceptible to 5-flucytosine (MIC < or = 0.125 microg/ml). The results of this study show for the first time the presence of a novel 5-flucytosine-resistant clade of C. dubliniensis (Cd25 group III) that is predominant among isolates from Saudi Arabia and Egypt and absent from a previously characterized international collection of 98 isolates from 15 countries. 相似文献
8.
9.
Chorneyko K Giesler R Sabatino D Ross C Lobo F Shuhaibar H Chen V Elavathil L Denardi F Ansari S Salama S LeBlanc V Norman G Sheridan B Riddell R 《American journal of clinical pathology》2002,117(5):783-790
Telepathology (TP) uses telecommunication linkages to electronically capture, store, retrieve, and transmit images to distant sites. We assessed the feasibility of a dynamic real-time TP system for light microscopic (LM) diagnosis of anatomic pathology specimens, including frozen sections. Six pathologists, in 2 separate periods, read a set of 160 retrospectively retrieved slides (80 of which were frozen sections) by TP and LM. Reading times were recorded. Diagnoses were compared with the reference diagnosis (established by a group of 5 independent pathologists) and graded on a scale of 0 to 2 (2, correct; 1, incorrect but no clinical impact; 0, incorrect with clinical impact). Overall, LM was more accurate than TP compared with the reference diagnosis (score, 1.68 vs 1.54). There was no difference in accuracy between frozen section and paraffin-embedded tissue. Intraobserver agreement ranged from 82.5% to 88.2%. The average reading time was 6.0 minutes for TP and 1.4 minutes for LM. During the study, reading time decreased for TP but not for LM. These results show that despite marginally lower accuracy and longer reading times, TP isfeasible for routine light microscopic diagnosis, including frozen sections. 相似文献
10.
Value of whole-cell antigen extracts for serologic detection of Helicobacter pylori. 总被引:1,自引:0,他引:1
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S M Salama J N Wefuan S Shiro-Koulla A Mbakop M Tagni-Sartre E C Ndam J L Ngu D E Taylor 《Journal of clinical microbiology》1993,31(12):3331-3332
Whole-cell protein extracts of Helicobacter pylori strains were evaluated by enzyme-linked immunosorbent assay to detect immunoglobulin G antibody against H. pylori in 113 patients with upper gastrointestinal complaints. These antigen preparations were of value for detecting infection by H. pylori in patients with high antibody titers (> or = 12,800), whereas for patients with lower titers, the results were inconclusive. 相似文献