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WR Volger RS Weiner JO Moore GA Omura AA Bartolucci M Stagg 《Canadian Metallurgical Quarterly》1995,9(9):1456-1460
A phase III clinical trial was designed to determine if more intensive induction and consolidation therapy for acute myeloblastic leukemia increases the remission rate and prolongs survival. A minor objective was to determine if the use of non-cross resistant drugs was more effective than the same drugs used for induction. Patients with untreated leukemia between the ages of 15 and 50 were given daunorubicin 45 mg/m2 for the first 3 days of a 10-day continuous infusion of cytosine arabinoside, initially at a dose of 2000 mg/m2 but reduced to 100 mg/m2 because of toxicity. Those under 36 achieving a complete remission and with an histocompatible donor were assigned to a transplant arm. The rest were randomized to receive one of three consolidation arms: A, cytosine arabinoside, 200 mg/m2 daily for 7 days and daunorubicin 45 mg/m2 daily for 3 days for three courses; B, one course as in Arm A followed by amsacrine, 120 mg/m2 daily for 5 days followed by a 5-day continuous infusion of azacytidine, 150 mg/m2/day; C, thioguanine and cytosine arabinoside, 100 mg/m2 every 12 h and daunorubicin 10 mg/m2 daily for 5 days for three courses followed by four maintenance courses of cytosine arabinoside, 100 mg/m2 daily for 5 days and daunorubicin, 45 mg/m2 for 2 days every 13 weeks. From 1981 to 1986, 398 eligible patients were enrolled and 219 achieved a complete remission. The initial induction dose of cytosine arabinoside was reduced after five of 29 patients exhibited fatal gastrointestinal toxicity. Only 11 patients were assigned to the transplant arm. There were no significant differences in the consolidation arms. The 5 year disease-free survivals were 38, 31 and 27% in arms A, B, and C respectively. Intensive consolidation therapy with the same or different drugs used in induction was as effective as lower dose consolidation followed by maintenance therapy. 相似文献
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Fuzzy logic was first suggested as the mechanism by which humans drive cars. This paper addresses the use of fuzzy logic and algorithms towards the intelligent autonomous motion control of land vehicles. To cope with vehicle complexities, internal parametric changes, and with unpredictable environmental effects, the controllers that are presented, whilst heuristic in nature, are self-organizing or self-learning in that they generate automatically by observation an experiential rule base that models the vehicle, and via an appropriate performance index an optimal control rule base that is robust to large parametric changes. The methodology presented is applicable to any complex process which is too difficult to model or control using conventional methods, or which has relied on the experience of a human operator. An overview of fuzzy logic and static fuzzy logic control (akin to expert systems) is provided, together with illustrative examples. 相似文献
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Knowledge elicitation is accepted as being one of the most problematic areas in the creation of a knowledge-based system.A large amount of research has already concentrated on finding more efficient and effective techniques for eliciting knowledge from an individual expert. However, little attention has been given to the involvement of more than one source of expertise in knowledge-based system development.This paper is based on the authors' practical experience gained when developing a knowledge-based system for the conceptual design of bridges. It shows that the use of more than one expert throughout the knowledge elicitation process can improve both the efficiency of the approach and the quality of the knowledge acquired. 相似文献
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PURPOSE: To determine the improvement in pancreatic enhancement at helical computed tomography (CT) performed with an early delay after administration of contrast material compared with that performed with a standard delay. MATERIALS AND METHODS: Dual-phase helical CT of the abdomen was performed in 120 patients with a 150-mL bolus of contrast material infused at 5 mL/sec. Early and standard delayed scanning was performed beginning at 20 seconds and 49-71 seconds, respectively. Regions of interest were measured in the head, body, and tail of the pancreas in 92 patients. The difference in enhancement between early and standard delayed scanning was calculated. RESULTS: Mean pancreatic enhancement was 82 HU +/- 3 (standard error) with an early delay, whereas enhancement on standard delay scans was 62 HU +/- 2 (P < .001). An improvement in enhancement greater than 10 HU was attained in 66 of 92 cases (72%). CONCLUSION: Pancreatic enhancement at helical CT with an early delay after contrast material administration is often significantly greater than the enhancement seen with a standard delay when a monophasic, rapidly infused bolus of contrast material is used. 相似文献
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PURPOSE: We investigated the association, treatment options and outcomes of patients with ureteropelvic junction obstruction and concomitant vesicoureteral reflux. MATERIALS AND METHODS: We analyzed 6,790 consecutive pediatric urology records at our university. Treatment options included observation, and primary pyeloplasty, ureteroneocystostomy and nephroureterectomy. Hydronephrosis, reflux and obstruction were judged as resolved, improved, unchanged or worse. RESULTS: A total of 1,140 patients had vesicoureteral reflux, 224 had ureteropelvic junction obstruction and 41 had both conditions (39 ipsilateral and 6 contralateral kidneys). There was no increased risk of obstruction in patients with reflux when all grades of reflux were grouped (odds ratio 1.26, confidence interval 0.91 to 1.71). In contrast, subgroup analysis of patients with high grade reflux demonstrated a 5-fold increased risk of obstruction (odds ratio 5.0, confidence interval 2.4 to 10.8). One patient was lost to followup. Observation of 6 kidneys led to resolution of reflux in 3 (50%), resolution of obstruction in 3 (50%) and resolution or improvement of hydronephrosis in 4 (67%). Primary pyeloplasty was done on 29 kidneys with 10 (35%) requiring subsequent ureteroneocystostomy. At latest followup hydronephrosis resolved or improved in 24 patients (83%), vesicoureteral reflux resolved or improved in 19 (66%) and ureteropelvic junction obstruction resolved in all. Primary ureteroneocystostomy was performed on 5 kidneys, all of which required subsequent pyeloplasty. Hydronephrosis resolved in 3 patients (60%), and reflux and obstruction resolved in all. Two patients treated with primary nephroureterectomy, and 1 who underwent concomitant pyeloplasty and ureteroneocystostomy have had no subsequent urological problems. One patient awaits primary pyeloplasty. CONCLUSIONS: High grade vesicoureteral reflux is associated with ureteropelvic junction obstruction. No association with low or intermediate grade reflux was demonstrated. While some patients may be monitored expectantly, in our series pyeloplasty or nephrectomy was required in 81% and ureteroneocystostomy was required in 36%. In no case did primary ureteroneocystostomy protect against the subsequent need for pyeloplasty. 相似文献
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BACKGROUND: In response to the increasing rate of skin cancer, particularly melanoma in the United States, the Environmental Protection Agency, the National Weather Service, the Centers for Disease Control and Prevention, National Association of Physicians for the Environment, and the American Academy of Dermatology, developed the Ultraviolet Index (UVI) to inform the public of the strength of the sun's rays and advise on methods for sun protection. OBJECTIVE: Our purpose was to evaluate the extent to which television stations and newspapers reported the UVI and assess the public's response to it. METHODS: To evaluate the effect of this effort, we surveyed television weather forecasters at 185 stations and examined weather pages in 54 newspapers in 58 cities that received the UVI reports. We also conducted a population probability telephone survey of 700 white adults (18 years of age and older) in these 58 cities. RESULTS: Seventy-one percent of the 169 stations that provided survey data for both 1994 and 1995 broadcast the UVI; 61% of newspapers reported the UVI. Nearly 64% of the 700 respondents (n = 445) had heard of the UVI. Of these respondents, 38% (n = 170) stated that they or their family changed their sun protection practices as a result of the UVI. CONCLUSION: The majority of television weather forecasters and newspapers reported the UVI. Most of the public was aware of the UVI, causing some to change sun protection practices. Further evaluation is required to maximize the effect of the UVI on sun protection practices. 相似文献
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Tramadol hydrochloride is a centrally acting synthetic analgesic in widespread clinical use. Despite different degrees of opioid-like characteristics in preclinical tests, it is characterized by lack of full naloxone reversibility or naloxone-precipitated withdrawal in humans. To investigate this apparent discrepancy, the present study measured the affinity of tramadol (and its enantiomers) and an active O-desmethyl metabolite (M1) (and its enantiomers) to cloned human opioid receptors of the mu, delta and kappa type stably expressed in HN9.10 neuroblastoma cells. At mu sites, the Ki values for tramadol, its (+) and (-) enantiomers, M1, and its (+) and (-) enantiomers were 17000, 15700, 28800, 3190, 153 and 9680 nM, respectively, compared to 7.1 nM for morphine. These results are consistent with the suggestion of a non-opioid contribution to the clinical profile of tramadol. 相似文献
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Prostaglandin (PG) production by human amnion has been postulated to have a role in the onset of labor. Previous work by ourselves and others has demonstrated that oxytocin, phorbol esters and epidermal growth factor (EGF) increase PGE2 production in human amnion cells by activation of the Phospholipase C/Protein Kinase C (PKC) cascade system. The present study was undertaken to determine the effect of prior activation of the Adenylate Cyclase cascade system upon subsequent stimulation of PGE2 production by oxytocin, phorbol 12-myristate-13-acetate (PMA) or EGF in amnion cells and membrane discs. Isoproterenol, forskolin and dibutyryl cyclic adenosine monophosphate (dbcAMP) were utilized to activate the Adenylate Cyclase system at the receptor, enzyme and second messenger level. In control amnion cells, oxytocin, PMA and EGF each provoked dose dependent increases in PGE2 production. In cells preincubated with dbcAMP, forskolin or isoproterenol, agonist stimulated PGE2 production was markedly (50-90%) inhibited (p < 0.01). Inhibition was dose dependent upon preincubator concentrations. Maximal inhibition by adenylate cyclase activators occurred with 2-4 h of preincubation. In membrane discs, forskolin preincubation also inhibited oxytocin, PMA and EGF stimulation of PGE2 production. Activation of the Adenylate Cyclase system in human amnion cells or membrane discs inhibits the subsequent action of potent stimulators of PGE2 production in human amnion. 相似文献