Continuous infusion of chemotherapy: focus on 5-fluorouracil and fluorodeoxyuridine

Continuous infusion of chemotherapy is one of the developments to try to improve the treatment of metastatic cancer. There is a sound theoretical rationale to deliver cytotoxic drugs as a continuous infusion. Furthermore, the development of reliable venous access devices and portable infusion pumps enables patients to be treated in an ambulatory setting. This review focuses on the continuous infusion of the most frequently used drugs: 5-fluorouracil (5-FU) and fluorodeoxyuridine (FUDR). An overview is given of both preclinical studies and studies in humans. Continuous infusion of 5-FU and FUDR has proven to be feasible in all studies. However, the results (response rate and especially survival) are rather disappointing. So far, continuous infusion of cytostatic drugs can still be considered as an experimental procedure. Whether protracted, intermittent of circadian modulated continuous infusion is the optimal treatment schedule has still to be proven in future studies. Furthermore, studies are needed to demonstrate whether dose intensity for most tumours is important for treatment outcome. Also, studies are needed to investigate quality of life and economic issues.     

The new causal principle of cognitive learning theory: Perspectives on Bandura's "reciprocal determinism."

In conceptualizing person–environment interaction, A. Bandura (see record 1979-08427-001) contended that the traditional view of unidirectional causation had to be abandoned in favor of what he called "reciprocal determinism." It is argued that the unidirectional account can be made to work in the cases that Bandura cited and that the criticisms of the neo-Hegelian view of causation can also be applied to Bandura's arguments. In addition, in his Social Learning Theory (1977), Bandura stressed the history of the interaction between a person and the environment, and here "reciprocal determinism" is a misleading expression. (16 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Development of a proxy for past surface UV-B irradiation: a thermally assisted hydrolysis and methylation py-GC/MS method for the analysis of pollen and spores

A method was developed for the analysis of the UV-absorbing sporopollenin monomers p-coumaric acid and ferulic acid in very low numbers of pollen. This enables the analysis of pollen or spores from cultured plants, from herbarium collections, and from sediment, soil, and peat cores. The method involves thermally assisted hydrolysis and methylation using tetramethylammonium hydroxide combined with gas chromatography and mass spectrometry. Pyrolysis, gas chromatographic, and mass spectrometric conditions were optimized for the analysis of minimal amounts of pollen. The method has a detection limit of approximately 60 fresh pollen of Alnus glutinosa and a relative standard deviation of approximately 10% between 100 and 600 pollen.     

Reliability of human serum protein profiles generated with C8 magnetic beads assisted MALDI-TOF mass spectrometry

Protein profiling with mass spectrometry is a promising approach for classification and identification of biomarkers; however, there is debate about measurement quality and reliability. Here, we present a pipeline for preprocessing, statistical data analysis and presentation. Serum samples of 16 healthy individuals are used to generate protein profiles with high-resolution MALDI-TOF after isolation of peptides with C8 magnetic beads. Analysis of variance was performed after binning, baseline correction and normalization of the mean spectra. Relative variations in the spectra are expressed as coefficient of variation, which depending on the respective preanalytical variation parameter investigated, was found to range between 0.15 and 0.67 in this study. With this novel method, the reproducibility of our protein profiling procedure could be quantified. We showed that circadian rhythm and the number of freeze-thaw cycles had relatively limited influence on serum protein profiles, whereas the period between collection and serum centrifugation had a more pronounced effect.     

Effect of weightlifting upon left ventricular function and markers of cardiomyocyte damage

The purpose of this study was to assess left ventricular (LV) function and biochemical markers of myocyte after prolonged weightlifting activity. Seventeen male subjects (age range 20-34 years) performed a 90-min bout of weightlifting exercise consisting of three sets of 8-10 repetitions at 70% one-repetition maximum. Body mass, heart rate, systolic blood pressure (SBP) and echocardiographically determined indices of LV loading (LV internal diameter during diastole, LV meridonial wall stress), systolic function (stroke volume (SV), ejection fraction (EF), end-systolic pressure volume relationship; SBP/ESV) and diastolic filling (ratio of early to late; E:A) were obtained pre-exercise, immediately after and 24 h post-exercise. A 5-ml venous blood sample was obtained for the assessment of cardiac troponin T (cTnT) via third generation electrochemiluminescence assay. Data were assessed via one-way ANOVA and Pearson's correlation. Although SV declined (80.9 +/- 18.3 vs. 66.9 +/- 17.2, p < 0.05) there was no alteration in LV contractility (EF 62 +/- 6 vs. 59 +/- 7; SBP/ESV 3.51 +/- 1.4 vs. 3.51 +/- 1.4, p > 0.05). The E:A ratio was significantly decreased following exercise (1.78 +/- 0.41 vs. 1.33 +/- 0.37, p < 0.05). This decrease was not fully explained by loading conditions (r2 = 0.05 to 0.24). All values returned to baseline 24 h post-exercise. No cTnT was reported in any of the blood samples. In conclusion, there was no significant evidence of any LV contractile depression and no cTnT was observed post exercise. The small reduction in diastolic filling could not be explained by changes in haemodynamic loading or the post-exercise elevation in heart rate.     

Perceptual processes used by drivers during overtaking in a driving simulator

This study investigated the control strategies and decision making of drivers who were executing overtaking maneuvers in a fixed-base driving simulator. It was found that drivers were frequently inaccurate in deciding whether it was safe to overtake in front of an oncoming vehicle. One source of error in this situation was the control strategy adopted by the driver; in several instances our drivers initiated an overtaking maneuver when the oncoming car's distance was above a critical value, even though there was not sufficient time to complete a safe maneuver. Adaptation to closing speed (produced by driving on a straight open road) also had large effects on overtaking behavior. For all participants, closing speed adaptation resulted in decisions that were delayed, of higher risk, and more variable. Actual or potential applications of this research include improved training for younger drivers and the development of in-car interfaces that reduce closing speed adaptation.     

Intermodal tuning behavior of an etalon-tuned three-mirror TEA CO2 laser

The detailed tuning behavior within a single ro-vibrational line of a TEA CO₂ laser was studied by using a wedged etalon and a pyroelectric array. The fine tuning of the laser was performed by using a temperature controlled etalon inside a three-mirror resonator. As the laser wavelength was scanned at a constant rate, single-longitudinal-mode pulses were observed ~82% of the time. Two-mode operation occurred over a narrow tuning range near the midpoint between successive cavity modes. The detailed structure of the staircase-like mode-to-mode tuning curve and the corresponding output intensity variations are explained using a simple theoretical model     

值得信赖的渠道

Future Electronics很荣幸能够成为全球各大领先技术制造商的电子元器件授权分销商。无论您是在寻找陶瓷电容器还是32位微控制器,     

Synthesis and Evaluation of New Thiodigalactoside‐Based Chemical Probes to Label Galectin‐3

Light up galectin: Photoprobes based on thiodigalactoside were prepared for galectin‐3, a lectin linked to cancer. The probes contained either benzophenone or acetophenone moieties as the photolabel for covalent attachment to the protein. One particular probe labeled galectin‐3 selectively, even in the presence of cell lysate.