首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 0 毫秒
1.
BACKGROUND: Cancer patients treated with the anticancer drug, paclitaxel (Taxol) often experience mild to severe hypersensitivity reactions. It is not known how these reactions are induced and whether the inducer is paclitaxel or its vehicle (i.e., Cremophor EL in 50% ethanol). Molecules present in Cremophor EL are similar in structure to certain nonionic block copolymers that activate complement proteins (i.e., proteins involved in various immune processes). To explore the role of complement in the observed hypersensitivity reactions, we studied the effects of paclitaxel and Cremophor EL plus ethanol on human complement in vitro. METHODS: Serum specimens from healthy individuals and cancer patients were incubated with paclitaxel or with relevant control compounds (Cremophor EL with ethanol, ethanol only, docetaxel, and cyclosporine), and markers of complement activation (SC5b-9 and Bb) were measured by enzyme-linked immunosorbent assay. Similar incubations were performed in the presence of inhibitors of complement activation (i.e., EGTA/Mg2+ and soluble complement receptor type 1 [sCR1]). RESULTS: Paclitaxel in Cremophor EL plus ethanol caused increased formation of SC5b-9 in serum specimens from 10 of 10 healthy control subjects and from five of 10 cancer patients. Experiments with one or more individual sera indicated the above effect was due to Cremophor EL plus ethanol, that increased formation of Bb also occurred, that the drug-induced rise in SC5b-9 was inhibited by sCR1, and that EGTA/Mg2+ partially inhibited SC5b-9 formation and stimulated Bb formation. IMPLICATION: The role of complement activation in hypersensitivity reactions associated with administration of paclitaxel in Cremophor EL plus ethanol should be studied in vivo.  相似文献   

2.
3.
OBJECTIVE: To determine the limits of agreement between the cardiac output and volumetric data estimated by impedance cardiography with the cardiac output determined by thermodilution and the left ventricular ejection fraction and end-diastolic volume estimated from left ventriculography. DESIGN: A prospective study. SETTING: The cardiac catheterization laboratory of a university-affiliated teaching hospital. PATIENTS: Twenty-four patients with coronary artery disease undergoing elective left- and right heart catheterization. INTERVENTIONS: Cardiac output was measured by the thermodilution method and the ejection fraction and left ventricular volumetric data were determined by ventriculography. These same measurements were obtained by simultaneously performed impedance cardiography using a commercially available bioimpedance device. MEASUREMENTS AND MAIN RESULTS: The patients' mean cardiac output was 4.6 +/- 1.7 L/min by bioimpedance and 5.0 +/- 1.1 L/min by thermodilution. The limits of agreement between the two methods was -4.1 to 3.5 L/min. The 95% confidence intervals for the lower and upper limits of agreement were -2.7 to -5.5 L/min and 2.1 to 4.9 L/min, respectively. The mean ejection fraction was 63 +/- 8% by bioimpedance and 53 +/- 15% by ventriculography. The limits of agreement between the ejection fraction estimated by bioimpedance and ventriculography was -35% to 37%. The 95% confidence intervals for the lower and upper limits of agreement were -22% to -48% and 24% to 50%, respectively. The mean left ventricular end-diastolic volume was 108 +/- 47 mL, as estimated by bioimpedance, and 121 +/- 35 mL, as estimated by ventriculography. The limits of agreement between the left ventricular end-diastolic volume as estimated by bioimpedance and ventriculography was -139 to 113 mL. The 95% confidence intervals for the lower and upper limits of agreement were -184 to -94 mL and 68 to 158 mL, respectively. CONCLUSIONS: The 95% confidence range defining the limits of agreement between cardiac output and volumetric data estimated by bioimpedance, with the cardiac output measurement by thermodilution and the volumetric data estimated from left ventriculography, were wide, making the degree of agreement clinically unacceptable. In the opinion of the authors, impedance cardiography should not replace invasive hemodynamic monitoring at this time.  相似文献   

4.
This paper compares an extended conventional filter technique for automated detection and analysis of rapid eye movements (REM) in neonates, using amplitude, synchrony, velocity, and coherence threshold criteria, with a matched filtering technique using the morphology of the REM waveform. Analyses of both simulated and real data were carried out. Automated REM tabulations are compared with visual scoring by a trained observer. Both preterm and fullterm neonates were used to test these methods. Both the advantages and disadvantages of these two techniques are discussed as compared with conventional methods which use only amplitude and synchrony threshold criteria. The major advantage of the extended conventional over the conventional method, as well as the matched filtering over the extended conventional technique, is the increased REM detection rate for ten minute intervals of artifact-free sleep. More accurate methods of automated REM detection that can be applied over extended monitoring periods are still needed.  相似文献   

5.
Learning style is the method an individual uses to concentrate and to process and retain new information. This developmental set of characteristics can make identical instruction effective for some learners and ineffective for others. Even though learners are capable of mastering the identical information or skills, if they are taught through methods that complement their preferred learning style, analytical and global learners have different environmental and physiological needs. An important relationship between learning style and instruction is that individuals are likely to teach the way they prefer to learn. The objectives of this study were to identify learning styles of students enrolled in selected animal science courses. The majority (58%) of students enrolled in selected courses preferred a field-independent learning style (analytical). With respect to gender and learning style, there was no difference between males and females. Classification of high school demographics showed students from rural areas preferred a field-dependent learning style (global) and students from suburban or urban areas were more likely to prefer a field-independent style. There was a difference in the preferred learning style of animal science faculty (field-dependent) and those students who declared their majors as animal science and preveterinary medicine (field-independent). The inverse relationship was found between dairy/poultry science faculty and students. Faculty should be aware of their own learning style and the learning styles of their students so they may facilitate learning for all students.  相似文献   

6.
BACKGROUND AND METHODS: The role of noninvasive positive-pressure ventilation delivered through a face mask in patients with acute respiratory failure is uncertain. We conducted a prospective, randomized trial of noninvasive positive-pressure ventilation as compared with endotracheal intubation with conventional mechanical ventilation in 64 patients with hypoxemic acute respiratory failure who required mechanical ventilation. RESULTS: Within the first hour of ventilation, 20 of 32 patients (62 percent) in the noninvasive-ventilation group and 15 of 32 (47 percent) in the conventional-ventilation group had an improved ratio of the partial pressure of arterial oxygen to the fraction of inspired oxygen (PaO2:FiO2) (P=0.21). Ten patients in the noninvasive-ventilation group subsequently required endotracheal intubation. Seventeen patients in the conventional-ventilation group (53 percent) and 23 in the noninvasive-ventilation group (72 percent) survived their stay in the intensive care unit (odds ratio, 0.4; 95 percent confidence interval, 0.1 to 1.4; P=0.19); 16 patients in the conventional-ventilation group and 22 patients in the noninvasive-ventilation group were discharged from the hospital. More patients in the conventional-ventilation group had serious complications (66 percent vs. 38 percent, P=0.02) and had pneumonia or sinusitis related to the endotracheal tube (31 percent vs. 3 percent, P=0.003). Among the survivors, patients in the noninvasive-ventilation group had shorter periods of ventilation (P=0.006) and shorter stays in the intensive care unit (P=0.002). CONCLUSIONS: In patients with acute respiratory failure, noninvasive ventilation was as effective as conventional ventilation in improving gas exchange and was associated with fewer serious complications and shorter stays in the intensive care unit.  相似文献   

7.
Double change channel angular extrusion(DCCAE) was performed in dual-phase Mg-9.5Li-3Al-1.6Y(wt.%) alloy to develop fine-grained microstructures. The microstructure evolution during DCCAE and conventional extrusion(CE) was investigated. The microstructure of the extruded dual-phase Mg-Li alloy consisted of recrystallized β-Li grains, banded α-Mg phases, and Al_2Y phases distributed in β-Li phases and phase-interface uniformly. Compared with CE, the specimens after DCCAE had smaller β-Li grain size(3–5 μm by the DCCAE and 6–10 μm by the CE) and the α-Mg phases were refined during the DCCAE. The distribution of the Al2 Y phases was improved a lot by DCCAE. Furthermore, the specimens after DCCAE had better tensile strength than conventional extrusion ones.  相似文献   

8.
9.
The high cost of mental health surveys of the general population has sparked interest in less costly research methods. Two low-cost mental health survey strategies (mail and telephone) were compared in terms of cost, response rate and quality of data obtained. A total of 1,074 persons agreed to participate in the study as a sample, one-half by telephone and the other half by mail. They completed the Diagnostic Interview Schedule Self-Administered, a questionnaire designed to be self-administered, which was used to assess specific mental disorders and to evaluate risk factors. In addition, 239 respondents who were selected according to the presence or absence of specific diagnoses were reinterviewed face-to-face using the Diagnostic Interview Schedule as an external criterion. The telephone method yielded a better response rate (15% higher) and better control over answers (for example, less missing data). The mail strategy was less expensive and appeared to yield data of slightly better quality, particularly for respondents suffering from anxiety disorders.  相似文献   

10.
This study compares hospital- (n = 67) and community-based (n = 55) mental health nurses in relation to their perceptions of the work environment and also their psychological health. Measures include: the General Health Questionnaire, the Maslach Burnout Inventory and the Work Environment Scale. The data, obtained from self-returned questionnaires, show that community nurses rated their work environments higher for the dimensions of Involvement, Supervisor Support, Autonomy, Innovation and Work Pressure. Hospital nurses saw their environments as being higher in (managerial) Control. There were no differences between the groups for the dimensions of Peer Cohesion, Task Orientation, Clarity or (physical) Comfort. Furthermore, there were no overall differences between the two groups in relation to psychological health, although the pattern of factors associated with emotional well-being differed. Finally, analyses of the community data revealed that those nurses with 'flexitime' arrangements evaluated their work environments less positively and showed higher levels of psychological strain than did those working 'fixed-time' schedules. The findings suggest that the hospital and community environments make different demands on nursing staff, and that this should be considered when organizing nursing services if stress is to be avoided.  相似文献   

11.
PURPOSE: To compare the accuracy of digital luminescence radiography (DLR) and conventional film-screen radiography (FSR) in diagnosing fractures. MATERIAL AND METHOD: Both conventional and digital radiographs were acquired from a consecutive series of 57 patients with suspected wrist or hand fractures. The digital images were obtained with a 30% dose reduction. A ROC-analysis (receiver-operating characteristics) was performed. RESULTS: The area under the curve was 0.89 for conventional FSR, 0.93 for DLR, "gray scale" and 0.94 for DLR, "edge enhanced". CONCLUSIONS: Although its spatial resolution is lower, DLR provided better results than conventional FSR, when contrast processing algorithms were optimised for the specific clinical question. The edge-enhanced version was superior to the non-edge enhanced version. The reason for this seems to be the higher contrast resolution of DLR compared to FSR.  相似文献   

12.
13.
14.
The heritability of total plasma testosterone levels, determined from blood samples, was examined in 160 adolescent twin pairs and their parents. Subjects were tested as part of a larger study of cardiovascular risk factors, conducted in Amsterdam. Each subject provided a sample of blood which was assayed to measure testosterone concentrations. Correlations of testosterone in monozygotic twins were higher than in dizygotic twins. No resemblance was found between testosterone values in fathers and those in their children and a moderate correlation was seen between mothers and their daughters. The lack of resemblance between family members of opposite sex suggests that different genetic factors influence plasma testosterone concentrations in men and women. In adolescent men, approximately 60% of the variance in testosterone levels is heritable. The lack of father-son resemblance suggests that different genetic factors may be expressed in adolescence and adulthood. In women, 40% of the variance in testosterone levels is heritable, both in adolescence and in adulthood.  相似文献   

15.
16.
We investigate the hypothesis that the utility (subjective value) of survival duration and health quality is determined by a multiplicative model. According to this model, there are separate subjective scales for the utility of survival duration and health quality. A critical prediction of the multiplicative model is the hypothesis that preferences between gambles for health outcomes satisfy a property called utility independence. After defining this property and explaining how it can be tested in behavioral data, we report an experimental test of whether the health preferences of medical patients satisfy utility independence. Individual analyses revealed that most subjects satisfy utility independence. Some subjects appear to violate a fundamental assumption of utility theory, that a single utility scale represents both the ordinal preference relations between certain outcomes and the subjective averaging that underlies the utility of gambles. The violation is inferred from an inconsistency between preferences for multiattribute outcomes when they are viewed as certain outcomes and when they are viewed as the outcomes of gambles. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

17.
The U.S. Nuclear Regulatory Commission recently amended its regulation governing the calibration of dose calibrators. The changes include (1) the radioactivity of radiopharmaceutical dosages that contain photon-emitting radionuclides has to be measured by a dose calibrator prior to administration to patients and human research subjects; (2) the lower end of the radioactivity limits for linearity testing has been raised to 1.1 MBq (30 microCi) to be consistent with the Nuclear Regulatory Commission Quality Management Program Requirements; and (3) the requirement for signature of the Radiation Safety Officer on the records for accuracy, linearity, and geometry dependence tests has been removed. Although these are practical amendments, further clarification of the new Nuclear Regulatory Commission regulation is required for the following issues: (1) inconsistency in individual's identification requirement for the record keeping (i.e., initials of the individual who performed the constancy check and identity of the operator for the accuracy, linearity, and geometry dependence tests); (2) whether the use of 99mTc is adequate for linearity testing when other radionuclides are being measured in the dose calibrator; and (3) lack of provision for dose calibrator adjustment when conducting the accuracy test. In addition, Nuclear Regulatory Commission Regulatory Guide 10.8 should be revised to become consistent with the Nuclear Regulatory Commission's regulation in order to assist licensees with full compliance of the requirements or recommendations.  相似文献   

18.
Describes and evaluates an adaptation of a school-based preventive mental health program. Teachers at one school and college student volunteers at another used behavioral reinforcement techniques to work with groups of maladapting 2nd graders. Evaluation of the 8-wk intervention program included a 7-mo follow-up. Experimental Ss improved significantly more than controls in classroom adjustment. Results support a school-based model of preventive intervention and the effectiveness of behavioral treatment strategies in such a program. (17 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

19.
Our aim was to test the effect of hypotonicity and extracellular Ca2+ (Cao) on cell volume and membrane potential (VM) in barnacle muscle cells. Under isotonic conditions the resting VM of isolated cells mounted in the experimental chamber exposed to either Ca(2+)-free or Ca(2+)-containing (11 mM) solutions was -46.3 +/- 1.0 mV (n = 24) and -56.2 +/- 0.9 mV (n = 38), respectively. In the absence of Cao, the cells depolarized at a rate of 2.3 +/- 0.47 mV/hr; the presence of Cao reduced this rate of depolarization by 2.9-fold. Both in the absence or presence of Cao, the cells swelled in response to hypotonicity but underwent regulatory volume decrease (RVD) when Cao was present. Addition of the Ca2+ channel blocker, verapamil (0.1 mM), inhibited the Cao-dependent RVD. The percentage of cells responding with RVD increased with larger hypotonic challenges. There was a Cao-independent direct relationship between cell swelling and membrane depolarization which can be explained by dilution of the concentration of intracellular K+ ([K+]i). RVD was accompanied by a small hyperpolarization (3.0 +/- 0.38 mV/2 hr) which may represent increases in [K+]i during cell shrinking and activation of a conductive pathway. The results indicate the following: (1) the presence of Cao stabilizes VM; (2) cell swelling produces a depolarization which can be explained by dilution of [K+]i; (3) cell swelling activates a verapamil-sensitive Ca2+ influx responsible for promoting RVD; and (4) RVD is accompanied by a hyperpolarization which may result from activation of a conductive pathway.  相似文献   

20.
OBJECTIVE: To compare 2.5 mg bendrofluazide daily (the standard antihypertensive dose), 1.25 mg bendrofluazide daily and 2.5 mg bendrofluazide on alternate days, in terms of reduction of blood pressure, patient compliance and adverse effect profile. DESIGN: A single-blind parallel group trial of patients who were randomly assigned to 16 weeks' treatment with bendrofluazide at doses of 2.5 mg daily, 1.25 mg daily and 2.5 mg every other day after a 4-week placebo run-in period. SETTING: General practices in the greater Belfast and Lisburn area in Northern Ireland. PATIENTS: Ninety-three patients with newly diagnosed or previously diagnosed hypertension, who had a mean diastolic blood pressure of 90-110 mmHg after receiving placebo for 4 weeks. MAIN OUTCOME MEASURES: Reduction in blood pressure, patient compliance and changes in biochemical variables. RESULTS: Sitting systolic and diastolic blood pressures in members of all three groups were significantly lowered with respect to baseline (P < 0.01) with no differences among groups. Overall mean compliance was 97%. No clear relation between dose and biochemical changes was apparent. CONCLUSIONS: Bendrofluazide at doses of 1.25 mg daily or 2.5 mg every other day reduces blood pressure as effectively as does the conventional 2.5 mg daily regimen.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号