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51.
The association of antiphospholipid antibodies with unexplained thrombo-occlusive vascular disease is well known but often remains unrecognized. The most well-studied clinical manifestation is venous thrombosis, but arterial occlusive disease involving multiple sites is also well documented. Twenty-six cases of thrombo-occlusive disease were observed in 22 patients over a 3-year period. Magnetic resonance imaging and angiography were used to make the diagnoses. None of the patients who underwent angiography or venography developed thrombolytic disease related to the puncture site. This group of patients with antiphospholipid antibody syndrome had a wide distribution of arterial and venous thrombotic disease. Radiologists should consider antiphospholipid antibody syndrome in the differential diagnosis when evaluating thrombo-occlusive vascular disease that is unexpected or occurs without risk factors. Knowledge of antiphospholipid antibody status has important implications for prognosis and therapy. 相似文献
52.
Barks available in commercial quantities in Australia and overseas have been examined for their efficacy as raw materials for conversion to high quality adhesives for reconstituted wood products. Previously bark from maturePinus radiata was found to be suitable. This paper examines the suitability of barks from four mature pine species (Pinus caribaea, Pinus elliottii, Pinus pinaster andPinus sylvestris), one young pine species (Pinus radiata) and one spruce species (Picea abies). Only the bark extracts ofPinus caribaea andPinus pinaster gave high quality (Type A bond, WBP) wood adhesives. The gluing properties of the adhesives derived from the extracts appeared to be dependent on their contents of formaldehyde-reactive polyflavanoids as indicated by their Stiasny values, with a value of 65% being the minimum for producing a high quality adhesive by the methods used. 相似文献
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Describes the development and validation of the UCLA Multidimensional Condom Attitudes Scale (MCAS). The relationships between the MCAS and gender, sexual experience, intentions to use a condom, and past condom use were assessed. The MCAS has 5 distinct factors: (1) Reliability and Effectiveness of condoms, (2) the sexual Pleasure associated with condom use, (3) the stigma attached to persons who use condoms (Identity Stigma), (4) the Embarrassment About Negotiation and Use of condoms, and (5) the Embarrassment About the Purchase of condoms. Results strongly suggest that condom attitudes are multidimensional and thus cannot meaningfully be summed to a single global score. Results further indicate that men and women hold very different attitudes toward condoms. Implications of scale multidimensionality and directions for future research are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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JT Schmidt 《Canadian Metallurgical Quarterly》1995,12(6):1093-1103
The cholinergic circuit within the tectum and the cholinergic input from the nucleus isthmi mediate a presynaptic augmentation of retinotectal transmitter release via nicotinic receptors. In this study, the cholinergic systems were either eliminated using the cholinergic neurotoxin AF64A or blocked using nicotinic antagonists to test for effects on the activity-driven sharpening of the regenerating retinotectal projection. The effectiveness of the AF64A was verified by recording field potentials elicited by optic tract stimulation and by immunohistochemical staining for choline acetyltransferase (ChAT). At 1 week after intracranial (IC) injection of AF64A (12 to 144 nmoles) into the fluid above the tectum, field potentials showed a selective dose-dependent decrement of the cholinergic polysynaptic component with no effect on the amplitude of the glutamatergic monosynaptic component. The decrement was only partially recovered in recordings at 2 and 6 weeks. In normal fish, the ChAT antibody stains a population of periventricular neurons, their apical dendrites, and a dense plexus within the optic terminal lamina that consists of their local axons and fine dendrites and of input fibers from the nucleus isthmi. One week after IC AF64A injection (48-72 nmoles), most immunostaining in superficial tectum was lost but most neuronal somas in the deep tectum could still be seen, and staining in the tegmentum below the tectum was completely intact. At 2 weeks and later, the staining of neuronal somata largely recovered, but staining of the superficial plexus did not. AF64A treatment at 18 days after nerve crush, when regenerating retinal fibers are beginning to form synapses, prevented retinotopic sharpening of the projection. Recordings showed a rough retinotopic map on the tectum but the multiunit receptive fields (MURFs) at each tectal point averaged 34 deg vs. 11 deg in vehicle-injected control regenerates. AF64A treatment before nerve crush also blocked sharpening, ruling out a direct effect on retinal growth cones or retinal fibers, as AF64A rapidly decomposes, whereas its effect on the cholinergic fibers is long-lasting. IC injection or minipump infusion of the nicotine antagonists alpha-bungarotoxin (alpha BTX), neuronal bungarotoxin (nBTX), and pancuronium during regeneration also prevented sharpening (MURFs averaging 29.4 deg, 33.0 deg, and 31.4 deg, respectively). Control Ringer's solution infusions or injections over the same period (19-37 days postcrush) had no effect on regenerated MURF size (11.7 deg). The results show that the cholinergic innervation, which modulates transmitter release, is required for activity-driven retinotopic sharpening, thought to be triggered by NMDA receptor activation. 相似文献
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The extracellular environment controls many cellular activities thereby linking external material cues to internal cell function. By better understanding these processes, synthetic extracellular material niches can be tailored to present cells with highly regulated physical and/or chemical cues that promote or suppress selected cell functions. Here, poly(ethylene glycol) (PEG) hydrogels were functionalized with fluvastatin-releasing grafts and growth factor binding heparin domains to enable the dynamic exchange of information between the material and cells from the outside-in and inside-out (i.e., bidirectional signaling). By incorporating a fluvastatin-releasing graft and carefully controlling the dose and temporal release, materials were designed to promote bone morphogenic protein (BMP2) and alkaline phosphatase (ALP) production by human mesenchymal stem cells (hMSCs). When the release of fluvastatin was controlled to occur over 2 weeks, BMP2 and ALP production was increased 2.2-fold and 1.7-fold, respectively, at day 28 compared to hMSCs cultured in the absence of fluvastatin. By introducing a heparin functionality into the gel to sequester and localize the hMSC-produced BMP2, the osteogenic differentiation of hMSCs was further augmented over fluvastatin delivery alone. Osteopontin and core binding factor α1 gene expression was 6-fold and 4-fold greater for hMSCs exposed to fluvastatin in the presence of the heparin functionalities, respectively. These results demonstrate how multifunctional gels that interact with cells in a bidirectional manner can efficiently promote selected cell functions, such as the osteogenic differentiation of hMSCs. 相似文献
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KW Mahaffey CB Granger R Collins CM O'Connor EM Ohman SD Bleich JJ Col RM Califf 《Canadian Metallurgical Quarterly》1996,77(8):551-556
Intravenous heparin is routinely given after thrombolytic therapy for patients with acute myocardial infarction in the United States and in some, but by no means all, other countries. Several trials have documented improved infarct-artery patency in patients treated with heparin; however, none was large enough individually to assess the effect of heparin on clinical outcomes. We performed a systematic overview of the 6 randomized controlled trials (1,735 patients) to summarize the available data concerning the risks and benefits of intravenous heparin versus no heparin after thrombolytic therapy. Mortality before hospital discharge was 5.1% for patients allocated to intravenous heparin compared with 5.6% for controls (relative risk reduction of 9%, odds ratio 0.91, 95% confidence interval 0.59 to 1.39). Similar rates of recurrent ischemia and reinfarction were observed among those allocated to heparin therapy or control. The rates of total stroke, intracranial hemorrhage, and severe bleeding were similar in patients allocated to heparin; however, the risk of any severity of bleeding was significantly higher (22.7% vs 16.2%; odds ratio 1.55, 95% confidence interval 1.21 to 1.98). There was no significant difference in the observed effects of heparin between patients receiving tissue-type plasminogen activator and those receiving streptokinase or anisoylated plasminogen streptokinase activator complex, or between patients who did and did not receive aspirin. The findings of this overview demonstrate that insufficient clinical outcome data are available to support or to refute the routine use of intravenous heparin therapy after thrombolysis. It is not known if these findings are due to lack of statistical power, inappropriate levels of anticoagulation, or lack of benefit of intravenous heparin. Large randomized studies of heparin (and of new antithrombotic regimens) are needed to establish the role of such therapy. 相似文献