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991.
MS Neto CH Carvalho R Fadul C Ambrogini LM Ferreira 《Canadian Metallurgical Quarterly》1998,44(4):344-346
We compared thoracoscopic surgery (TS) and open thoracotomy for the diagnosis of interstitial pneumonia. Intraoperative blood loss and duration of postoperative chest drainage were significantly less with TS than with thoracotomy. The length of postoperative hospital stay and social insurance costs with TS was significantly less than with thoracotomy. These results show that TS for the diagnosis of interstitial pneumonia is superior to open thoracotomy in terms of surgical stress and cost. 相似文献
992.
GE Soto KW Dodson D Ogg C Liu J Heuser S Knight J Kihlberg CH Jones SJ Hultgren 《Canadian Metallurgical Quarterly》1998,17(21):6155-6167
The class of proteins collectively known as periplasmic immunoglobulin-like chaperones play an essential role in the assembly of a diverse set of adhesive organelles used by pathogenic strains of Gram-negative bacteria. Herein, we present a combination of genetic and structural data that sheds new light on chaperone-subunit and subunit-subunit interactions in the prototypical P pilus system, and provides new insights into how PapD controls pilus biogenesis. New crystallographic data of PapD with the C-terminal fragment of a subunit suggest a mechanism for how periplasmic chaperones mediate the extraction of pilus subunits from the inner membrane, a prerequisite step for subunit folding. In addition, the conserved N- and C-terminal regions of pilus subunits are shown to participate in the quaternary interactions of the mature pilus following their uncapping by the chaperone. By coupling the folding of subunit proteins to the capping of their nascent assembly surfaces, periplasmic chaperones are thereby able to protect pilus subunits from premature oligomerization until their delivery to the outer membrane assembly site. 相似文献
993.
In many chilled, prepared food products, the effects of temperature, pH and %NaCl on microbial activity interact and this should be taken into account. A grey box model for prediction of microbial growth is developed. The time dependence is modeled by a Gompertz model-based, non-linear differential equation. The influence of temperature, pH and %NaCl reflected in the model parameters is described by using low-complexity, black box artificial neural networks (ANN's). The use of this non-linear modeling technique makes it possible to describe more accurately interacting effects of environmental factors when compared with classical predictive microbiology models. When experimental results on the influence of other environmental factors become available, the ANN models can be extended simply by adding more neurons and/or layers. 相似文献
994.
MI Polkey D Kyroussis CH Hamnegard PD Hughes GF Rafferty J Moxham M Green 《Canadian Metallurgical Quarterly》1997,10(8):1859-1864
The transdiaphragmatic pressure (Pdi) elicited by paired bilateral phrenic nerve stimulation may be viewed as the sum of the Pdi values produced by the first (t1) and second (t2) stimulus. The Pdi at t2 (P[di,t2]) is a function of the interstimulus interval. A reduction in the ratio obtained by dividing Pdi,t2 at 10 Hz (P[di,t2,10]) by Pdi at 100 Hz (P[di,t2,100]) (t2(10:100)) has been proposed as a test of low frequency diaphragm fatigue. The aim of the present study was to establish whether this change could also be detected using paired cervical magnetic nerve stimulation (pCMS), and whether t2(10:100) was influenced by lung volume. We studied healthy subjects at functional residual capacity (FRC), at 0.5 and 1.0 L below FRC, and at 0.5, 1.0 and 1.5 L above FRC. The subjects were then subjected to a fatiguing protocol (2 min of maximal isocapnic ventilation (MIV)). Studies were repeated at FRC 20 and 60 min after MIV and between these times at 1.0 L below and 1.5 L above FRC. In the unfatigued state, t2(10:100) had a negative relationship with increasing lung volume (r2=0.98, p=0.002). After MIV there was a fall in the Pdi elicited by a single stimulus (mean fall at 20 min 17.9% and at 60 min 14.6%, p<0.03 for both). t2(10:100) fell by a mean 28.1% after 20 min and mean 22.9% at 60 min (p<0.03 for both). This change was mainly mediated by a fall in the P[di,t2,10]. The t2(10:100) was not able to distinguish between fatigue and acute hyperinflation. We conclude that paired cervical magnetic nerve stimulation may be used to detect low frequency diaphragm fatigue but that it remains important to control for lung volume. 相似文献
995.
CH Toh 《Canadian Metallurgical Quarterly》1997,73(859):283-285
The anticoagulant agents heparin and warfarin were introduced before the era of randomised clinical trials. As a result, the indications, dosages and monitoring techniques of these drugs have undergone re-evaluation in multiple clinical trials in the past years. Low molecular weight heparin has been developed, which has led to new approaches in anticoagulant management. Current levels of laboratory, pharmacology and clinical knowledge in the treatment of venous thromboembolism are discussed. 相似文献
996.
AJ van Essen AL Kneppers AH van der Hout H Scheffer IB Ginjaar LP ten Kate GJ van Ommen CH Buys E Bakker 《Canadian Metallurgical Quarterly》1997,34(10):805-812
Detection of large rearrangements in the dystrophin gene in Duchenne and Becker muscular dystrophy is possible in about 65-70% of patients by Southern blotting or multiplex PCR. Subsequently, carrier detection is possible by assessing the intensity of relevant bands, but preferably by a non-quantitative test method. Detection of microlesions in Duchenne and Becker muscular dystrophy is currently under way. Single strand conformational analysis, heteroduplex analysis, and the protein truncation test are mostly used for this purpose. In this paper we review the available methods for detection of large and small mutations in patients and in carriers and propose a systematic approach for genetic analysis and genetic counselling of DMD and BMD families, including prenatal and preimplantation diagnosis. 相似文献
997.
998.
GS Hall CH Rice JE Lockey GK Lemasters PS Gartside 《Canadian Metallurgical Quarterly》1997,41(5):555-560
The effect of gamma-radiation on aqueous solutions of saturated phospholipids, 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), 1,2-dipalmitoyl-sn-glycero-3-phosphoglycerol (DPPG), 1-palmitoyl-2-lyso-sn-glycero-3-phosphocholine (lysoPC), and bovine brain sphingomyelin (SM) has been investigated. It is shown that the phospholipids with an OH group in beta-position to the P-O bond (DPPG and lysoPC), or to the amide bond (SM), undergo a free radical fragmentation. As a result of such fragmentation, stearoylamide, palmitoxyacetone and phosphatidic acid are formed from SM, lysoPC and DPPG, respectively. In parallel with the formation of hydrophobic fragments, an accumulation of hydrophilic species such as oxyacetone and phosphocholine in the irradiated DPPG and lysoPC dispersions was observed. On the basis of the data obtained for free radical transformation of phospholipids and their simplest analogs, such as glycero-1-phosphate, triacetin and 1,2-isopropylidene glycerol, it is suggested that the fragmentation of the radicals derived from the above compounds proceed by a concerted mechanism through a five-membered transition state. The accumulation of hydrophobic fragments in phospholipid membranes is shown to influence the temperature and co-operativity of the 'gel-to-liquid crystal' phase transition. An assumption is made that the fragmentation of phospholipids caused by free radical attack on the hydrophilic moiety, along with lipid peroxidation, may constitute principal mechanisms of radiation-induced damage of biological membranes. 相似文献
999.
JR Sheu YC Kan WC Hung CH Su CH Lin YM Lee MH Yen 《Canadian Metallurgical Quarterly》1998,92(2):53-64
In this study, the mechanism involved in the antiplatelet activity of rutaecarpine in human platelet suspensions was investigated. In platelet suspensions (4.5 x 10(8)/ml), rutaecarpine (100 and 200 microM) did not influence the binding of FITC-triflavin to platelet glycoprotein IIb/IIIa complex. Additionally, rutaecarpine (200 microM) did not significantly change the fluorescence of platelet membrane labeled with diphenylhexatriene (DPH). On the other hand, rutaecarpine (50 and 100 microM) dose-dependently inhibited the increase in intracellular free Ca2+ of Fura 2-AM loaded platelets stimulated by collagen. Moreover, rutaecarpine (100 and 200 microM) did not significantly affect the thromboxane synthetase activity of aspirin-treated platelet microsomes. Furthermore, retaecarpine (100 and 200 microM) significantly inhibited [3H]arachidonic acid released in collagen-activated platelets but not in unactivated-platelets. Nitric oxide (NO) production in human platelets was measured by a chemiluminesence detection method in this study. Rutaecarpine (100 and 200 microM) did not significantly affect nitrate production in collagen (10 microg/ml)-induced human platelet aggregation. On the other hand, various concentrations of rutaecarpine (50, 100, and 200 microM) dose-dependently inhibited [3H]inositol monophosphate formation stimulated by collagen (10 microg/ml) in [3H]myoinositol-loaded platelets at different incubation times (1, 2, 3, and 5 minutes). It is concluded that the antiplatelet activity of rutaecarpine may possibly be due to the inhibition of phospholipase C activity, leading to reduce phosphoinositide breakdown, followed by the inhibition of thromboxane A2 formation, and then inhibition of [Ca2+]i mobilization of platelet aggregation stimulated by agonists. 相似文献
1000.
BACKGROUND: C-reactive protein (CRP) is a sensitive marker of inflammation, and elevated levels have been associated with future risk of myocardial infarction (MI). However, whether measurement of CRP adds to the predictive value of total cholesterol (TC) and HDL cholesterol (HDL-C) in determining risk is uncertain. METHODS AND RESULTS: Among 14916 apparently healthy men participating in the Physicians' Health Study, baseline levels of CRP, TC, and HDL-C were measured among 245 study subjects who subsequently developed a first MI (cases) and among 372 subjects who remained free of cardiovascular disease during an average follow-up period of 9 years (controls). In univariate analyses, high baseline levels of CRP, TC, and TC:HDL-C ratio were each associated with significantly increased risks of future MI (all P values <0.001). In multivariate analyses, models incorporating CRP and lipid parameters provided a significantly better method to predict risk than did models using lipids alone (all likelihood ratio test P values <0.003). For example, relative risks of future MI among those with high levels of both CRP and TC (RR=5.0, P=0.0001) were greater than the product of the individual risks associated with isolated elevations of either CRP (RR=1.5) or TC (RR=2.3). In stratified analyses, baseline CRP level was predictive of risk for those with low as well as high levels of TC and the TC:HDL-C ratio. These findings were virtually identical in analyses limited to nonsmokers and after control for other cardiovascular risk factors. CONCLUSIONS: In prospective data from a large cohort of apparently healthy men, baseline CRP level added to the predictive value of lipid parameters in determining risk of first MI. 相似文献