Showing papers by "Maastricht University published in 1994"
TL;DR: In this article, the authors reconstruct and classify the patterns of human right atrial (RA) activation during electrically induced atrial fibrillation (AF) in humans, based on multiple reentering wavelets.
Abstract: Background. Mapping studies in animals have suggested that atrial fibrillation (AF) is based on multiple reentering wavelets. Little information is available about the patterns of activation during AF in humans. The objective of the present study was to reconstruct and classify the patterns of human right atrial (RA) activation during electrically induced AF.
1,004 citations
TL;DR: In the elderly, influenza vaccination may halve the incidence of serological and clinical influenza (in periods of antigenic drift), which is less pronounced for self-reported influenza.
Abstract: Objective. —To determine the efficacy of influenza vaccination in elderly people. Design. —Randomized double-blind placebo-controlled trial. Setting. —Fifteen family practices in the Netherlands during influenza season 1991-1992. Participants. —A total of 1838 subjects aged 60 years or older, not known as belonging to those high-risk groups in which vaccination was previously given. Intervention. —Purified split-virion vaccine containing A/Singapore/6/86(H1N1), A/Beijing/353/89(H3N2), B/Beijing/1/87, and B/Panama/45/90 (n=927) or intramuscular placebo containing physiological saline solution (n=911). Main Outcome Measures. —Patients presenting with influenzalike illness up to 5 months after vaccination; self-reported influenza in postal questionnaires 10 weeks and 5 months after vaccination; serological influenza (fourfold increase of antibody titer between 3 weeks and 5 months after vaccination). Results. —The incidence of serological influenza was 4% in the vaccine group and 9% in the placebo group (relative risk [RR], 0.50; 95% confidence interval [CI], 0.35 to 0.61). The incidences of clinical influenza were 2% and 3%, respectively (RR, 0.53; 95% CI, 0.39 to 0.73). The effect was strongest for the combination of serological and clinical influenza (RR, 0.42; 95% CI, 0.23 to 0.74). The effect was less pronounced for self-reported influenza. Conclusion. —In the elderly, influenza vaccination may halve the incidence of serological and clinical influenza (in periods of antigenic drift). (JAMA. 1994;272:1661-1665)
850 citations
TL;DR: In this paper, the effect of strategic technology partnering on companies engaged in such joint efforts is investigated, and the empirical analysis is expanded with linear structural modeling of a number of relevant explanatory variables setting strategic partnering in a more complex environment.
Abstract: Strategic technology partnering between firms has become a growing subject of interest to both companies experimenting with this mode of economic organization and researchers from a wide variety of academic disciplines. In this study an effort is made to measure the effect of strategic technology partnering on companies engaged in such joint efforts. A study of the relevant literature on interfirm cooperation generates some basic understanding of this phenomenon, after which the empirical analysis is expanded with linear structural modeling of a number of relevant explanatory variables setting strategic partnering in a more complex environment.
816 citations
Journal Article•
TL;DR: This core set includes the following measures: pain, patient global assessment, physical disability, swollen joints, tender joints, acute phase reactants, and physician global assessment.
Abstract: The WHO/ILAR core set of endpoints for rheumatoid arthritis clinical trials signifies progress in a continuing worldwide effort. This core set includes the following measures: pain, patient global assessment, physical disability, swollen joints, tender joints, acute phase reactants, and physician global assessment; in studies of one or more years' duration, radiographs of joints should be performed.
309 citations
TL;DR: Results from BIS and BIA were comparable, but it is argued that BIS has the potential of improved standardization of the method.
222 citations
TL;DR: Investigating the predictive value of vital exhaustion for the occurrence of new cardiac events after percutaneous transluminal coronary angioplasty (PTCA) while explicitly controlling for the severity of coronary artery disease revealed that vital exhaustion continued to be of predictive value when other significant risk factors for new cardiac Events were controlled for.
Abstract: Excessive tiredness is one of the most prevalent premonitory symptoms of myocardial infarction and sudden cardiac death. This state is labelled as vital exhaustion and consists of three components: fatigue, increased irritability, and demoralization. Vital exhaustion has been found to be an independent risk-indicator of myocardial infarction in one prospective study and several case-control studies. It is as yet unclear whether the association between vital exhaustion and future myocardial infarction can be explained by confounding of (subclinical) coronary artery disease. Therefore, the present study investigates the predictive value of vital exhaustion for the occurrence of new cardiac events after percutaneous transluminal coronary angioplasty (PTCA), while explicitly controlling for the severity of coronary artery disease. Patients with a successful PTCA were followed during 1.5 years. A new cardiac event was defined as present if one of the following end points occurred: cardiac death, myocardial infarction, coronary bypass surgery, repeat-PTCA, increase of coronary atherosclerosis, or new anginal complaints with documented ischemia. Vital exhaustion was assessed using the Maastricht Questionnaire two weeks after hospital discharge. Participants of the present study were 127 patients (mean age 55.6 +/- 9.1; 105 men, 22 women). Fifteen (35%) of the 43 exhausted patients experienced a new cardiac event, whereas 14 (17%) of the 84 not exhausted patients had a new cardiac event (OR = 2.7; CI = 1.1-6.3; p = .02). Multiple logistic regression analysis revealed that vital exhaustion continued to be of predictive value when other significant risk factors for new cardiac events were controlled for (i.e., severity of coronary artery disease and hypercholesterolemia).(ABSTRACT TRUNCATED AT 250 WORDS)
218 citations
TL;DR: It is concluded that the preparation and isolation of interphase nuclei from murine embryos with acid and Tween 20 offers high reproducibility, good morphology of the cells and a high hybridization efficiency.
Abstract: A new method was developed to prepare and isolate interphase nuclei from murine preimplantation embryos for analysis by fluorescence in-situ hybridization. Embryos were washed with phosphate-buffered saline and disaggregated in a small drop of bidistilled water containing HCl and Tween 20. During the disaggregation procedure embryos were watched continuously with an inverted microscope. Embryonic nuclei were digested with pepsin to make them accessible for hybridization to the probes and to remove remnants of cytoplasm. Nuclear and probe DNA were denatured simultaneously and hybridization was done overnight, followed by immunocytochemical detection of the probes. Using this method we were able to perform successful in-situ hybridization on all preimplantation stages of the mouse embryo (pronuclei, 2-cell, 4-cell, morula and blastocyst). Probes for the X and Y chromosomes were applied for sex determination. From the results described in this paper we conclude that the preparation and isolation of interphase nuclei from murine embryos with acid and Tween 20 offers high reproducibility, good morphology of the cells and a high hybridization efficiency.
181 citations
TL;DR: Comparison of the scores on the selection with information provided by the original SIP showed very promising results: the 68 item selection may serve as a valid short SIP-version.
173 citations
TL;DR: The efficacy of cyclosporin (Sandimmun®) given in a daily dose of 5 mg/kg for 6 weeks in severe atopic dermatitis was confirmed in this double‐blind, placebo‐controlled, short‐term study.
Abstract: The efficacy of cyclosporin (Sandimmun) given in a daily dose of 5 mg/kg for 6 weeks in severe atopic dermatitis was confirmed in this double-blind, placebo-controlled, short-term study. Of the 46 patients included in the study, 23 were randomized to receive cyclosporin and 23 to receive placebo. Four of the 23 patients (17%) on cyclosporin, and 14 of the 23 patients (61%) who received placebo, discontinued the trial because of inefficacy. All patients who discontinued the trial were assessed following the principle of 'intention to treat'. Compared with the baseline, the mean scores for disease severity [6-area, total body severity assessment (TBSA)] improved by 55%, and the mean scores for extent of disease [rule-of-nines area assessment (RoNAA)] improved by 40%, in patients treated with cyclosporin. Nine of the patients who received cyclosporin and completed the study (n = 14) had an individual reduction of disease severity (TBSA) of 75% or more, and in three patients this reduction was nearly 100%. In the placebo group, a mean worsening of disease severity (4%) and of extent of the disease (25%), compared with the baseline, was observed at week 6. Patients' and investigators' mean scores for the overall efficacy were similar, and showed a statistically significant difference in favour of cyclosporin. Two patients on cyclosporin developed hypertension during therapy, and one of these withdrew from the study. At the end of the trial, no statistically significant differences in the systolic or diastolic blood pressures were observed between the two groups. In the cyclosporin group, the increases in the values of serum creatinine and bilirubin at week 6, compared with the respective values at the baseline, were statistically significantly different from those in the placebo group, but all values normalized in the post-treatment period. Cyclosporin can be a safe and very effective treatment in episodes of severe atopic dermatitis, provided that the recommended guidelines for its administration are strictly observed.
172 citations
TL;DR: It seems that with respect to subjective pain responses the attentional theory on the influence of anxiety on pain can explain the results, and the attributional theory seems to hold for autonomic pain responses.
Abstract: Two psychological processes mediating the influence of anxiety on pain have been proposed: an attributional process in which the pain-relevance of anxiety is the essential factor, and an attentional process in which the focus of attention is the essential factor. The present study investigated the influences of attentional focus, pain-irrelevant anxiety and pain-relevant anxiety in a within-subject design (n = 40). Subjects received painful electrical stimulation in each of 5 experimental conditions. The results indicate that pain ratings were only influenced by attentional focus and not by anxiety, regardless of whether it was pain-relevant or pain-irrelevant. Autonomic responses (skin conductance responses) were, however, only influenced by pain-relevant anxiety. Thus, it seems that with respect to subjective pain responses the attentional theory on the influence of anxiety on pain can explain the results. The attributional theory seems to hold for autonomic pain responses. However, these responses might as well be considered as fear responses. Whereas there is clear evidence for a role of attentional focus in the influence of anxiety on pain, the role of attributional processes remains to be demonstrated.
171 citations
TL;DR: In this article, a cross-sectional study included 103 pregnant women who smoked and 40 women who had quit during the last year, and five groups were formed: precontemplators, contemplators, actors, maintainers, and relapsers.
TL;DR: The results indicate that asynchronous electrical activation causes a redistribution of mechanical work and oxygen demand and that regional total mechanical power is a better and more general estimate of regional oxygen demand than the regional pressure‐sarcomere length area.
Abstract: 1. In the present study the relation between regional left ventricular contractile work, regional myocardial blood flow and oxygen uptake was assessed during asynchronous electrical activation. 2. In analogy to the use of the pressure-volume area for the estimation of global oxygen demand, the fibre stress-fibre strain area, as assessed regionally, was used to estimate regional oxygen demand. The more often used relation between the pressure-sarcomere length area and regional oxygen demand was also assessed. 3. Experiments were performed in six anaesthetized dogs with open chests. Regional differences in mechanical work were generated by asynchronous electrical activation of the myocardial wall. The ventricles were paced from the right atrium, the left ventricular free wall, the left ventricular apex or the right ventricular outflow tract. Regional fibre strain was measured at the epicardial anterior left ventricular free wall with a two-dimensional video technique. 4. Regional fibre stress was estimated from left ventricular pressure, the ratio of left ventricular cavity volume to wall volume, and regional deformation. Total mechanical power (TMP) was calculated from the fibre stress-fibre strain area (SSA) and the duration of the cardiac cycle (tcycle) using the equation: TMP = SSA/tcycle. Regional myocardial blood flow was measured with radioactive microspheres. Regional oxygen uptake was estimated from regional myocardial blood flow values and arteriovenous differences in oxygen content. 5. During asynchronous electrical activation, total mechanical power, pressure-sarcomere length area, myocardial blood flow and oxygen uptake were significantly lower in early than in late activated regions (P < 0.05). 6. Within the experiments, the correlation between the pressure-sarcomere length area and regional oxygen uptake was not significantly lower than the one between total mechanical power (TMP) and regional oxygen uptake (VO2,reg). However, variability of this relation between the experiments was less for total mechanical power. Pooling all experimental data revealed: VO2,reg = k1 TMP+k2, with k1 = 4.94 +/- 0.31 mol J-1 k2 = 24.2 +/- 1.9 mmol m-3 s-1 (means +/- standard error of the estimate). 7. This relation is in quantitative agreement with previously reported relations between the pressure-volume area and global oxygen demand. The results indicate that asynchronous electrical activation causes a redistribution of mechanical work and oxygen demand and that regional total mechanical power is a better and more general estimate of regional oxygen demand than the regional pressure-sarcomere length area.
TL;DR: It was concluded that underestimation of one's own dietaryFat intake could be a major barrier in healthy diet promotion aimed at reducing fat consumption in The Netherlands, and improving dietary fat intake awareness should be given priority as a first step inhealthy diet promotion strategies.
TL;DR: There is selective tissue distribution of K1 and MK-4, dietary K1 is a source of menaquinone-4 and the results suggest there may be an as yet unrecognized physiological function for vitamin K (MK-4).
Abstract: The present study was undertaken to determine whether there is selective tissue distribution of vitamin K in the rat and whether this distribution mirrors the distribution of tissue vitamin K metabolism. The effects of feeding a vitamin K-free diet followed by resupplementation with phylloquinone (K1) were studied. K1 was recovered in all tissues. In K1-supplemented rats, most tissues accumulated K1 relative to plasma K1 with the highest levels in liver, heart, bone, and cartilaginous tissue (sternum). Low K1 levels were found in the brain. In the K1-free rats, relatively high K1 levels were still found in heart, pancreas, bone and sternum. Surprisingly, menaquinone-4 (MK-4) was detected in all tissues, with low levels in plasma and liver, and much higher levels in pancreas, salivary gland and sternum. MK-4 levels exceeded K1 levels in brain, pancreas, salivary gland and sternum. Supplementation with K1, orally and by intravenous infusion, caused MK-4 levels to rise. Some accumulation of K1 and MK-4 in the mitochondrial fraction was found for kidney, pancreas and salivary gland. In the liver the higher menaquinones (MK-6-9) accumulated in the mitochondria. The results indicate that: (1) there is selective tissue distribution of K1 and MK-4, (2) dietary K1 is a source of MK-4. The results also suggest there may be an as yet unrecognized physiological function for vitamin K (MK-4).
TL;DR: In this paper, a tool management problem for flexible machines is discussed, where the problem is to decide how to sequence the parts to be produced, and what tools to allocate to the machine, in order to minimize the number of tool setups.
Abstract: A central problem of tool management for flexible machines is to decide how to sequence the parts to be produced, and what tools to allocate to the machine, in order to minimize the number of tool setups. The problem becomes especially crucial when the time needed to change a tool is significant with respect to the processing times of the parts, or when many small batches of different parts must be processed in succession. These phenomena have been observed in the metal-working industry by Hirabayashi, Suzuki and Tsuchiya (1984), Finke and Kusiak (1987), Bard (1988), Tang and Denardo (1988a), Bard and Feo (1989), etc. Blazewicz, Finke, Haupt and Schmidt (1988) describe for instance an NC-forging machine equipped with two tool magazines, each of which can handle eight tools. The tools are very heavy, and exchanging them requires a sizeable fraction of the actual forging time. Another situation where minimizing the number of tool setups may be important is described by Forster and Hirt (1989, p. 109). These authors mention that, when the tool transportation system is used by several machines, there is a distinct possibility that this system becomes overloaded. Then, minimizing the number of tool setups can be viewed as a way to reduce the strain on the tool transportation system. Bard (1988) mentions yet another occurrence of the same problem in the electronics industry. Suppose several types of printed circuit boards (PCBs) are produced by an automated placement machine (or a line of such machines).
TL;DR: The vessel wall movement detector system has a good technical reproducibility and intraobserver intrasession and intersession variability are comparable, and are larger in muscular arteries.
Abstract: Objective: Arterial distensibility (DC) and compliance (CC) are vessel wall properties of large arteries that can be measured non-invasively with a custom made vessel wall movement detector system (VWMDS). This study investigated the reproducibility of this device in 10 volunteers. Methods: To investigate intraobserver intrasession and intraobserver intersession variability, arterial diameter (D) and relative change in diameter during the heart cycle (ΔD/D) were measured in the elastic common carotid artery, and in the muscular femoral and brachial arteries. Interobserver intrasession variability was examined in common carotid artery by two observers, while interobserver variability on the same image was assessed for common carotid and femoral arteries. Variability was expressed as the coefficient of variation. Results: For common carotid artery, intraobserver intrasession variability was 7.9(SEM 1.6)% (ΔD/D), 4.5(1.1)% (D), 8.3(1.3)% (DC), and 9.1(2.6)% (CC), respectively. In femoral artery it was 12.4(2.2)% (ΔD/D), 2.7(0.6)% (D), 13.4(2.2)% (DC), and 12.5(2.1)% (CC). For brachial artery it was 13.4(2.8)% (ΔD/D). 2.5(0.5)% (D), 16.1(2.5)% (DC), and 15.6(2.6)% (CC). Intraobserver intersession variability was comparable to intraobserver intrasession variability for all vessels. Interobserver intrasession variability for common carotid artery was 11.3(2.6)% (ΔD/D) and 8.6(1.9)% (D), but was larger for DC and CC. Interobserver variability on the same image was <5% for common carotid and femoral arteries. Conclusions: In conclusion, the vessel wall movement detector system has a good technical reproducibility. Intraobserver intrasession and intersession variability are comparable, and are larger in muscular arteries. This might be due to a larger variation in tone of these arteries, which are under permanent neurohumoral control. Interobserver intrasession variability was larger than intraobserver variability and might be influenced by differences in observers' skill and spontaneous variation in vessel wall properties.
Cardiovascular Research 1994; 28 :610-614
TL;DR: An inverse relationship was established between the volume of the thyroid and serum thyroid stimulating hormone (TSH) levels, and drinking of nitrate-contaminated water was dose-dependently related with 24-h urinary nitrate excretion and salivary nitrate levels.
TL;DR: FABP released from the heart after AMI is quantitatively recovered in plasma and that FABP is a useful biochemical plasma marker for the estimation of myocardial infarct size in humans.
Abstract: BACKGROUND--There are substantial amounts of cytoplasmic heart-type fatty-acid-binding protein (FABP) (15 kDa) in myocardial tissue. The rapid release of FABP into plasma during ischaemia indicates the possibility of using this protein as a biochemical marker for ischaemic myocardial injury. OBJECTIVE--To study the completeness of the release of FABP from damaged tissue in patients with acute myocardial infarction (AMI) and the suitability of serial plasma FABP concentrations for estimation of myocardial infarct size. METHODS--Immunochemically assayed FABP and enzymatically assayed creatine kinase isoenzyme MB (CK-MB) and alpha-hydroxybutyrate dehydrogenase (HBDH) were determined serially in plasma samples from 49 patients with AMI who had been treated with thrombolytic agents within six hours after the onset of AMI. Previously validated circulatory models and a value of 2.6 h-1 for the fractional clearance rate of FABP from plasma were used to calculate cumulative protein release into plasma. RESULTS--Release of FABP was completed earlier (24-36 h) after AMI than that of CK-MB (50-70 h) and that of HBDH (> 70 h). However, infarct size estimated from the cumulative release of the proteins and expressed as gram equivalents of healthy myocardium per litre of plasma yielded a comparable value of 4-6 for both FABP and the two enzymes. CONCLUSION--The data indicate that FABP released from the heart after AMI is quantitatively recovered in plasma and that FABP is a useful biochemical plasma marker for the estimation of myocardial infarct size in humans.
TL;DR: It is suggested that students in a problem‐based curriculum become more accomplished self‐directed learners over the four curriculum years, even although they are provided with many clues which may play a role in their decisions on what to study.
Abstract: In problem-based learning, the development of self-directed learning skills is encouraged through confronting students with (professional) problems. However, several other elements of a problem-based curriculum, such as general teaching objectives, lectures and tutors, may have an impact on students' actual learning activities. The present study focuses on the extent to which various elements of a problem-based curriculum influence students' decisions on what to study. First, interviews were conducted to obtain qualitative data about what actually takes place when students initiate learning activities during self-study. Based on the findings of these interviews, a questionnaire was developed, consisting of statements describing elements of the learning process and their influence on student learning. Elements included in the questionnaire were: the discussion in the tutorial group, content tested, course objectives, lectures, the tutor and reference literature. The students reported that all these elements may have an impact on decisions on what to study. Moreover, first-year students tend to rely more on the literature cited in the references list and content covered in lectures and tests than students in the other three curriculum years. In general, the influence of these elements showed a decrease over the four curriculum years. The influence of the discussion in the tutorial group, on the contrary, tended to increase over the four curriculum years. These findings suggest that students in a problem-based curriculum become more accomplished self-directed learners over the four curriculum years, even although they are provided with many clues which may play a role in their decisions on what to study.
TL;DR: The results show that vessel wall distensibility of the common carotid artery is decreased in younger hemodialysis patients as compared with age-matched healthy subjects, and the volume expanded state in hemodIALysis patients cannot account for the decreased arterial Distensibility.
TL;DR: Reliability appears to be high in both the independent SIP68 as well as the extracted SIP136, indicating that the SIP 68 may very well serve as a generic alternative to the Sip136.
TL;DR: It is concluded that studies which are different in expression of exercise intensity (%Wmax or %VO2max) can be compared and that the relation between %Wmax and %HRmax needs to be determined individually when an appropriate individualized training intensity based on heart rate is required.
Abstract: As the exercise intensity is often expressed as percentage of either maximal workload (%Wmax), percentage of maximal heart rate (%HRmax), or as percentage of maximal oxygen uptake, the relationship between %Wmax, %VO2max, and %HRmax was determined in 53 male cyclists. All subjects performed an incremental maximal cycle ergometer test. In all athletes examined, a linear relation between power output, oxygen uptake and heart rate was observed. The relationships between %Wmax and %VO2max as well as between %Wmax and %HRmax were linear (r = 0.98 and r = 0.97; p < 0.001). It is concluded that studies which are different in expression of exercise intensity (%Wmax or %VO2max) can be compared and that the relation between %Wmax and %HRmax needs to be determined individually when an appropriate individualized training intensity based on heart rate is required.
TL;DR: It was concluded that as long as exhaustive training is alternated by light exercise, overtraining is unlikely to occur and no single parameter can be used to detect early overtraining.
Abstract: To evaluate markers for overtraining, seven male race horses were subjected to 272 days of training consisting of daily exercise bouts of either endurance running (heart rate 140/min) or interval training (maximal heart rate), both increasing in duration and intensity. An incremental exercise test was held every 4 wk, and from day 187 it was held every 2 wk. Muscle glycogen, muscle lactate, energy-rich phosphates, adrenal response to adrenocorticotropic hormone, plasma and red blood cell volumes, and a number of blood chemical variables were measured. The horses showed symptoms of weight loss, irritability, and an inability to complete the training after the intensity of the endurance exercise was increased. Test performance was not decreased. The adrenal response to adrenocorticotropic hormone was not changed during overtraining. The decline in muscle ATP concentration during maximal exercise was less during the period of staleness, whereas plasma volume, red blood cell volume, and blood chemical variables were unchanged. It was concluded that as long as exhaustive training is alternated by light exercise, overtraining is unlikely to occur. Furthermore, no single parameter can be used to detect early overtraining.
TL;DR: It is concluded that influenza vaccination in elderly people provides a reasonable to good immune response and research is needed on whether a good immuneresponse decreases the incidence of influenza.
TL;DR: In this in-vitro study of pressure-perfused human coronary arteries, 104 matching intracoronary ultrasound imaging images and histologic cross-sections from 12 hearts were compared to determine the diagnostic accuracy of 30 MHz commercially available intracoregressive ultrasound imaging.
Abstract: The purpose of this study was to validate intracoronary ultrasound imaging by correlation with histologic examination. In this in-vitro study of pressure-perfused human coronary arteries, 104 matching intracoronary ultrasound imaging images and histologic cross-sections from 12 hearts were compared to determine the diagnostic accuracy of 30 MHz commercially available intracoronary ultrasound imaging. For lipid deposits, sensitivity was 46% and specificity 97%. The smallest lipid deposit that was visualized measured 0.25 mm in axial diameter on histologic study. For calcific deposits, sensitivity was 77% and specificity 100%. The smallest calcific deposit that was visualized measured 0.25 mm in axial diameter on histologic examination. Atherosclerotic intimal thickening could not be distinguished qualitatively or quantitatively from nonatherosclerotic intimal thickening unless there were localized deposits of lipids or calcium. Intracoronary ultrasound imaging is accurate in detecting lipid and calcium deposits. Intimal thickening in intracoronary ultrasound imaging images does not prove the presence of atherosclerosis.
Posted Content•
TL;DR: In this paper, the authors revisited the Foot and Frankel results on the sources of forward discount bias and found that the bias in the forward discount is due to the failure of rational expectations and the existence of time-varying risk premia.
Abstract: In this article we reconsider the Foot and Frankel results on the sources of forward discount bias. We question the economic validity of some estimation restrictions that they impose and, thus, are led to question some of their results. We employ a new exchange rate survey database that includes European Monetary System currencies and use univariate and pooling estimation techniques that impose fewer restrictions than those of Froot and Frankel to test our hypotheses. We find that the bias in the forward discount to BOTH (author emphasis) the failure of rational expectations and the existence of time-varying risk premia.
TL;DR: The expression of mucin MUC2 was investigated in normal colonic tissue, in colonic adenomas and in carcinomas of the mucinous and non‐mucinous type, indicating that the M UC2 expression pattern is different in the 3 carcinoma types investigated.
Abstract: The expression of mucin MUC2 was investigated in normal colonic tissue, in colonic adenomas and in carcinomas of the mucinous and non-mucinous type. The latter were subdivided into carcinomas originating from the adenoma-carcinoma sequence (ACS) and de novo (DN) carcinomas. The expression was assayed by immunohistochemistry with the monoclonal anti-MUC2 antibody CCP58 and by mRNA semiquantitation. MUC2 protein epitope CCP58 was strongly expressed in 21% of normal colonic tissues, in 40% of villous and in 48% of tubular adenomas. Mucinous carcinomas exhibited strong expression in 72%, ACS carcinomas in 21% and DN adenocarcinomas in none of the tumors investigated. Compared with the adjacent non-malignant tissue (transitional mucosa), CCP58 epitope expression in the tumor was higher in 74% of mucinous carcinomas, but equal or lower in 69% of ACS carcinomas and in 100% of de novo carcinomas. The alterations of MUC2 expression detected by immunohistochemistry in adenocarcinomas were confirmed on mRNA level. These data indicate that the MUC2 expression pattern is different in the 3 carcinoma types investigated. MUC2 over-expression occurs in the adenomatous tissue. It is always maintained in mucinous carcinomas, but frequently decreased in non-mucinous ACS carcinomas. DN carcinomas are most frequently associated with decreased expression of MUC2.
TL;DR: It is concluded that 10h equilibration is preferable to the shorter 4h and 6h, for the determination of TBW.
Abstract: Deuterium dilution for the measurement of total body water (TBW) has been conducted using varying protocols for equilibration. We measured TBW from deuterium dilution in urine samples in twenty-eight subjects using three protocols: (1) early morning dosage without breakfast, measuring deuterium in a second voiding at 4 h and 6 h; (2) early morning dosage with breakfast with the same measurement times; (3) dosage as last consumption before overnight sleep, measuring deuterium in a second voiding at 10 h. Results were compared with TBW estimates from underwater weighing (UWW). Because UWW is an indirect measure of TBW, it is used as an independent reference method in order to compare only relative discrepancies between the two methods. TBW values in the fasted state were not significantly different from those obtained in the fed state. The urinary deuterium enrichment was higher at 4 h than at 6 h (resulting TBW differences: 0.6 (SD 0.4) l). At 4 h and 6 h, differences in TBW measurements from deuterium and densitometry were positively related to the amount of TBW, indicating incomplete equilibration in larger water compartments. At 10 h no such relationship existed, indicating complete mixing of deuterium. It is concluded that 10 h equilibration is preferable to the shorter 4 h and 6 h, for the determination of TBW.
TL;DR: The results suggest that students need a minimum level of structure in order to profit from problem-based instruction and may explain the widely divergent results of tutor-expertise research.
Abstract: Purpose. To investigate under what conditions tutors' subject-matter expertise influences student achievement. Method. Data were analyzed from 1,800 University of Limburg Faculty of Health Sciences students who in 1989- 90 participated in tutorial groups led by content-expert staff tutors, non- expert staff tutors, or student tutors. Each student participated in an average of 4.1 tutorial groups. Overall, 4,111 data records were available for analysis. The basic analyses were of (1) students' achievement scores as a function of tutors' levels of subject-matter expertise and students' prior knowledge; (2) students' achievement scores as a function of tutors' levels of subject-matter expertise and educational units' levels of structure; and (3) differences in achievement between students guided by tutors of different levels of expertise in either high- or low-structure units. Statistical methods included analyses of variance. Results. The level of subject-matter expertise of tutors had a positive influence on student achievement. Similar results were found for the students' prior knowledge and the levels of structure of the units; the more prior knowledge students had the better were their performances on the end-of-unit test; and the higher the level of structure of the unit, the better the achievement. More important, interactions were found between tutor expertise on the one hand and prior knowledge and unit structure on the other, tutor expertise being mainly important if the unit was poorly structured or students reported lack of prior knowledge. Conclusion. The results suggest that students need a minimum level of structure in order to profit from problem-based instruction. This structure can be internally provided through prior knowledge available for understanding the new subjects, or offered by the environment in the form of cues of what is relevant and what should be the focus of the activities. If prior knowledge falls short, or if the environment lacks structure, students will turn to their tutors for help and direction. Under those conditions, students who are guided by a subject-matter expert tutor may benefit more than students guided by a non-expert staff tutor or by a student tutor. These findings may explain the widely divergent results of tutor-expertise research.
TL;DR: It is suggested that mainly vocal expressions, especially crying, influence nurses' decisions to administer analgesics and nurses' negative views on non-narcotic analgesics were striking.
Abstract: Research is lacking on factors influencing nurses' decision-making directed at the diagnosis of pain in children and its related interventions. This paper reports on two studies, namely a qualitative study and its replication, in which we explored factors influencing nurses' pain assessments and interventions in children. Those factors found to influence nurses' decisions were: medical diagnosis, child's expressions, age, and parents, and the nurses' knowledge, experience, attitude and workload. Some of these factors seem to have more influence than others. For example, the presence of a medical diagnosis seems to legitimate being in pain. Furthermore, it is suggested that mainly vocal expressions, especially crying, influence nurses' decisions to administer analgesics. Finally, nurses' negative views on non-narcotic analgesics were striking. In this paper, the results of both studies and their relationship to information reported in the literature are further elaborated and discussed, and hypotheses on strength and direction of influence of factors on pain assessment and intervention are generated.