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EC Claas JC de Jong R van Beek GF Rimmelzwaan AD Osterhaus 《Canadian Metallurgical Quarterly》1998,16(9-10):977-978
Introduction of influenza viruses with gene segments of avian origin into the human population may result in the emergence of new pathogenic human influenza viruses. The recent infection of a 3-year-old boy with an influenza A (H5N1) virus of avian origin can be considered as an example of such an event. However, this virus, influenza A/Hong Kong/156/97 (H5N1) and the 17 additional H5N1 viruses isolated from humans by the end of 1997 lack the ability to spread efficiently amongst humans and therefore have limited pandemic potential. However, the possibility of reassortment of these viruses with currently circulating human viruses illustrates the need for pandemic preparedness. 相似文献
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A Padovani V Di Piero M Bragoni M Iacoboni GF Gualdi GL Lenzi 《Canadian Metallurgical Quarterly》1995,92(6):433-442
Left ventricular wall motion abnormalities secondary to stress-induced myocardial ischemia can be detected with difficulty by mentally comparing echocardiographic images sequentially recorded on videotape. Digital stress-echocardiography, a combination of ultrasound imaging and digital archiving technologies, at least partially can overcome this problem: the technique is based on reviewing images at rest and after stress (exercise or pharmacological) side by side in dual- or quad-screen digital format, in a synchronized cine-loop, as if obtained simultaneously. This technique however is presently not widely used, due to the high cost of most commercially available systems. We have developed a digital stress-echo system, which is easy to use and relatively inexpensive, running on a Macintosh II personal computer with 8-bit graphics. The 2-D echocardiographic images recorded on videotape are digitized offline using a video digitizing board. The image can be displayed and analyzed using the public domain NIH image software developed by Wayne Rasband, without loss in image quality and resolution, particularly if using Super-VHS videotape. We have made a macro procedure for the montage in a quad-screen format of four digital recorded echocardiographic cardiac cycles of six frames that takes only a little more time than commercially available systems. In conclusion, the use of a personal computer and low-cost software may help to make digital stress-echo techniques more widely feasible in the clinical setting and increase the diagnostic power of the ultrasound technique in the evaluation of patients with known or suspected coronary artery disease. 相似文献
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JC Calamera GF Doncel SB Olmedo P Kolm AA Acosta 《Canadian Metallurgical Quarterly》1998,13(9):2484-2488
Loss of sperm motility is associated with the process of sperm senescence and occurs at different rates within a given normal or abnormal sperm population. Reactive oxygen species attack cell membrane phospholipids, generating fatty acid peroxides and other degradation products, that also have deleterious effects on sperm motility and fertilizing ability. The objective of this investigation was to study a modification of the original sperm stress test (MOST), changing the culture medium to one offering transitional metals and shortening the total test time, to ascertain whether it can predict fertilization under these laboratory conditions. A total of 41 semen samples was obtained from patients undergoing in-vitro fertilization (IVF) at our institution. Semen samples were grouped into those producing total fertilization rates (FR) within normal limits (>50%) and those showing low total FR (<50%). The normal FR group had a significantly greater MOST mean value than the low FR group (0.71 versus 0.44). Furthermore, there was a statistically significant correlation between the MOST score and ungrouped fertilization rates (r = 0.53, P = 0.0004). Diagnostic statistics for MOST ratio values predicting <50% FR showed an optimal threshold of 0.39. Collectively, sensitivity, specificity, positive predictive value and negative predictive value have their largest values at this threshold. Taking into account the above mentioned threshold figures, there is a significant association between MOST and FR categories (P = 0.0009). In conclusion, MOST is a simple assay that has significant predictive value for sperm related IVF abnormalities. 相似文献
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Inhibition of calcium currents in rat colon sensory neurons by kappa- but not mu- or delta-opioids. J. Neurophysiol. 80: 3112-3119, 1998. We previously reported that kappa-, but not mu- or delta-opioid receptor agonists (ORAs) have selective, potentially useful peripheral analgesic effects in visceral pain. To evaluate one potential site and mechanism by which these effects are produced, we studied opioid effects on high-voltage activated (HVA) Ca2+ currents in identified (Di-I) pelvic nerve sensory neurons from the S1 dorsal root ganglion (DRG). Results were compared with opioid effects on cutaneous neurons from L5 or L6 DRG. Di-I-labeled DRG cells were voltage clamped (perforated whole cell patch clamp), and HVA Ca2+ currents were evoked by depolarizing 240-ms test pulses to +10 mV from a holding potential of -60 mV. Neither mu-ORAs (morphine, 10(-6 )M, n = 16; [D-Ala2, N-Me-Phe4, Gly-ol5] enkephalin, 10(-6 )M, n = 12) nor delta-ORAs ([D-Pen2, D-Pen5] enkephalin, 10(-7 )M, n = 16; SNC-80, 10(-7 )M, n = 7) affected HVA Ca2+ currents in colon sensory neurons. In contrast, the kappa-ORAs U50, 488 (10(-6 )M), bremazocine (10(-6)M), and nalBzoH (10(-6 )M) significantly attenuated HVA Ca2+ currents in colon sensory neurons; effects on cutaneous sensory neurons were variable. A nonreceptor selective concentration of naloxone (10(-5 )M) and nor-BNI (10(-6 )M), a selective kappa-opioid receptor antagonist, reversed the inhibitory effect of kappa-ORAs. In the presence of N-, P-, or Q-, but not L-type Ca2+ channel antagonists, the effect of U50,488 on HVA Ca2+ currents was significantly reduced. Pretreatment with pertussis toxin (PTX) prevented the inhibition by U50,488. These results suggest that kappa-opioid receptors are coupled to multiple HVA Ca2+ channels in colon sensory neurons by a PTX-sensitive G protein pathway. We conclude that inhibition of Ca2+ channel function likely contributes in part to the peripheral analgesic action of kappa-ORAs in visceral nociception. 相似文献
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L Brusa M Iannilli G Bruno C Di Biasi GF Gualdi C Schiaffini GL Lenzi 《Canadian Metallurgical Quarterly》1996,17(6):433-436
The contents of nitric oxide (NO) in the blood were measured by electron spin resonance (ESR) method in Wistar rats with 35% TBSA III degrees burn. NO is endothelium derived relaxing factor (E-DRF) released by vascular endothelial cells. The results showed that: 1. Blood NO contents were not found to be significantly increased (72 hours postburn); 2. Escherichia coli lipopolysaccharide (LPS, endotoxin) could induce excessive NO formation in early burns. 相似文献
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