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Based on the cognitive rheory of moral development of Kohlberg, refined by the addition of the dimension 'ethics of care ' and the educational theory of Janssen, the relationship of education and ethical behavior of nursing students was examined. Ethical behavior referred not only to the ethical reasoning of students but also to the relationship between this reasoning and their behavior. This study examined the responses of 2,624 nursing students to five ethical nursing dilemmas included in the Ethical Behavior Test by relating them to four educational variables: students' level of education, level of enrollment, school, and students' perceptions of the educational process. A significant relationship between education and ethical behavior was found. [ABSTRACT FROM AUTHOR]

In literature as well as in nursing practice a growing concern about nurses' ethical competence can be observed. Based on the cognitive theory of moral development by Kohlberg, this research examined nursing students' ethical behaviour in five nursing dilemmas. Ethical behaviour refers not only to the ethical reasoning of nursing students but also to the relationship between reasoning and behaviour. Kohlberg's definition of morality was refined by adding a care perspective. The results show that the majority of students can be located in the fourth moral stage according to Kohlberg's theory, that is, the conventional level of moral development. This finding implies that students are still guided by professional rules, norms and duties, and have not (yet) succeeded in making personal ethical decisions on the basis of their own principles and acting according to such decisions. [ABSTRACT FROM AUTHOR]

Cyanobacteria play a crucial role in global carbon and nitrogen cycles through photosynthesis, making them valuable subjects for understanding the factors influencing their light utilization efficiency. Photosynthetic microorganisms offer a promising avenue for sustainable energy conversion in the field of photovoltaics. It was demonstrated before that application of an external electric field to the microbial biofilm or cell improves electron transfer kinetics and, consequently, efficiency of power generation. We have integrated live cyanobacterial cultures into photovoltaic devices by embedding Limnospira indica PCC 8005 cyanobacteria in agar and PEDOT:PSS matrices on the surface of boron-doped diamond electrodes. We have subjected them to varying external polarizations while simultaneously measuring current response and photosynthetic performance. For the latter, we employed Pulse-Amplitude-Modulation (PAM) fluorometry as a non-invasive and real-time monitoring tool. Our study demonstrates an improved light utilization efficiency for L. indica PCC 8005 when immobilized in a conductive matrix, particularly so for low-intensity light. Simultaneously, the impact of electrical polarization as an environmental factor influencing the photosynthetic apparatus diminishes as matrix conductivity increases. This results in only a slight decrease in light utilization efficiency for the illuminated sample compared to the dark-adapted state., (© 2024. The Author(s).)

We present the change of light absorption of cyanobacteria in response to externally applied electrical polarization. Specifically, we studied the relation between electrical polarization and changes in light absorbance for a biophotoelectrode assembly comprising boron-doped diamond as semiconducting electrode and live Limnospira indica PCC 8005 trichomes embedded in either polysaccharide (agar) or conductive conjugated polymer (PEDOT-PSS) matrices. Our study involves the monitoring of cyanobacterial absorbance and the measurement of photocurrents at varying wavelengths of illumination for switched electric fields, i.e., using the bioelectrode either as an anode or as cathode. We observed changes in the absorbance characteristics, indicating a direct causal relationship between electrical polarization and absorbing properties of L. indica . Our finding opens up a potential avenue for optimization of the performance of biophotovoltaic devices through controlled polarization. Furthermore, our results provide fundamental insights into the wavelength-dependent behavior of a bio photovoltaic system using live cyanobacteria., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Published by American Chemical Society.)

Public-domain availability for bioinformatics software resources is a key requirement that ensures long-term permanence and methodological reproducibility for research and development across the life sciences. These issues are particularly critical for widely used, efficient, and well-proven methods, especially those developed in research settings that often face funding discontinuities. We re-launch a range of established software components for computational genomics, as legacy version 1.0.1, suitable for sequence matching, masking, searching, clustering and visualization for protein family discovery, annotation and functional characterization on a genome scale. These applications are made available online as open source and include MagicMatch, GeneCAST, support scripts for CoGenT-like sequence collections, GeneRAGE and DifFuse, supported by centrally administered bioinformatics infrastructure funding. The toolkit may also be conceived as a flexible genome comparison software pipeline that supports research in this domain. We illustrate basic use by examples and pictorial representations of the registered tools, which are further described with appropriate documentation files in the corresponding GitHub release., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Vasileiou et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Two morphotypes of the cyanobacterial Limnospira   indica (formerly Arthrospira sp.) strain PCC 8005, denoted as P2 (straight trichomes) and P6 (helical trichomes), were subjected to chronic gamma radiation from spent nuclear fuel (SNF) rods at a dose rate of ca. 80 Gy·h -1 for one mass doubling period (approximately 3 days) under continuous light with photoautotrophic metabolism fully active. Samples were taken for post-irradiation growth recovery and RNA-Seq transcriptional analysis at time intervals of 15, 40, and 71.5 h corresponding to cumulative doses of ca. 1450, 3200, and 5700 Gy, respectively. Both morphotypes, which were previously reported by us to display different antioxidant capacities and differ at the genomic level in 168 SNPs, 48 indels and 4 large insertions, recovered equally well from 1450 and 3200 Gy. However, while the P2 straight type recovered from 5700 Gy by regaining normal growth within 6 days, the P6 helical type took about 13 days to recover from this dose, indicating differences in their radiation tolerance and response. To investigate these differences, P2 and P6 cells exposed to the intermediate dose of gamma radiation (3200 Gy) were analyzed for differential gene expression by RNA-Seq analysis. Prior to batch normalization, a total of 1553 genes (887 and 666 of P2 and P6, respectively, with 352 genes in common) were selected based on a two-fold change in expression and a false discovery rate FDR smaller or equal to 0.05. About 85% of these 1553 genes encoded products of yet unknown function. Of the 229 remaining genes, 171 had a defined function while 58 genes were transcribed into non-coding RNA including 21 tRNAs (all downregulated). Batch normalization resulted in 660 differentially expressed genes with 98 having a function and 32 encoding RNA. From PCC 8005-P2 and PCC 8005-P6 expression patterns, it emerges that although the cellular routes used by the two substrains to cope with ionizing radiation do overlap to a large extent, both strains displayed a distinct preference of priorities.

For the past three decades, Cupriavidus metallidurans has been one of the major model organisms for bacterial tolerance to heavy metals. Its type strain CH34 contains at least 24 gene clusters distributed over four replicons, allowing for intricate and multilayered metal responses. To gain organic mercury resistance in CH34, broad-spectrum mer genes were introduced in a previous work via conjugation of the IncP-1β plasmid pTP6. However, we recently noted that this CH34-derived strain, MSR33, unexpectedly showed an increased resistance to other metals (i.e., Co 2+ , Ni 2+ , and Cd 2+ ). To thoroughly investigate this phenomenon, we resequenced the entire genome of MSR33 and compared its DNA sequence and basal gene expression profile to those of its parental strain CH34. Genome comparison identified 11 insertions or deletions (INDELs) and nine single nucleotide polymorphisms (SNPs), whereas transcriptomic analysis displayed 107 differentially expressed genes. Sequence data implicated the transposition of IS 1088 in higher Co 2+ and Ni 2+ resistances and altered gene expression, although the precise mechanisms of the augmented Cd 2+ resistance in MSR33 remains elusive. Our work indicates that conjugation procedures involving large complex genomes and extensive mobilomes may pose a considerable risk toward the introduction of unwanted, undocumented genetic changes. Special efforts are needed for the applied use and further development of small nonconjugative broad-host plasmid vectors, ideally involving CRISPR-related and advanced biosynthetic technologies.

In 2011, an artificial hook-shaped peninsula of 128ha beach area was created along the Dutch coast, containing thousands of iron ore lumps, which include arsenic from natural origin. Elemental arsenic and inorganic arsenic induce a range of toxicological effects and has been classified as proven human carcinogens. The combination of easy access to the beach and the presence of arsenic raised concern about possible human health effects by the local authorities. The objective of this study is therefore to investigate human health risks from the presence of arsenic-containing iron ore lumps in a beach setting. The exposure scenarios underlying the human health-based risk limits for contaminated land in The Netherlands, based on soil material ingestion and a residential setting, are not appropriate. Two specific exposure scenarios related to the playing with iron ore lumps on the beach ('sandcastle building') are developed on the basis of expert judgement, relating to children in the age of 2 to 12years, i.e., a worst case exposure scenario and a precautionary scenario. Subsequently, exposure is calculated by the quantification of the following factors: hand loading, soil-mouth transfer effectivity, hand-mouth contact frequency, contact surface, body weight and the relative oral bioavailability factor. By lack of consensus on a universal reference dose for arsenic for use in the stage of risk characterization, three different types of assessments have been evaluated: on the basis of the current Provisional Tolerable Daily Intake (PTWI), on the basis of the Benchmark Dose Lower limit (BMDL), and by a comparison of exposure from the iron ore lumps with background exposure. It is concluded, certainly from the perspective of the conservative exposure assessment, that unacceptable human health risks due to exposure to arsenic from the iron ore lumps are unlikely and there is no need for risk management actions., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Background: Pediatric drug development is hampered by practical, ethical, and scientific challenges. Microdosing is a promising new method to obtain pharmacokinetic data in children with minimal burden and minimal risk. The use of a labeled oral microdose offers the added benefit to study intestinal and hepatic drug disposition in children already receiving an intravenous therapeutic drug dose for clinical reasons., Objective: The objective of this study was to present pilot data of an oral [(14)C]paracetamol [acetaminophen (AAP)] microdosing study as proof of concept to study developmental pharmacokinetics in children., Methods: In an open-label microdose pharmacokinetic pilot study, infants (0-6 years of age) received a single oral [(14)C]AAP microdose (3.3 ng/kg, 60 Bq/kg) in addition to intravenous therapeutic doses of AAP (15 mg/kg intravenous every 6 h). Blood samples were taken from an indwelling catheter. AAP blood concentrations were measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and [(14)C]AAP and metabolites ([(14)C]AAP-Glu and [(14)C]AAP-4Sul) were measured by accelerator mass spectrometry., Results: Ten infants (aged 0.1-83.1 months) were included; one was excluded as he vomited shortly after administration. In nine patients, [(14)C]AAP and metabolites in blood samples were detectable at expected concentrations: median (range) maximum concentration (C max) [(14)C]AAP 1.68 (0.75-4.76) ng/L, [(14)C]AAP-Glu 0.88 (0.34-1.55) ng/L, and [(14)C]AAP-4Sul 0.81 (0.29-2.10) ng/L. Dose-normalized oral [(14)C]AAP C max approached median intravenous average concentrations (C av): 8.41 mg/L (3.75-23.78 mg/L) and 8.87 mg/L (3.45-12.9 mg/L), respectively., Conclusions: We demonstrate the feasibility of using a [(14)C]labeled microdose to study AAP pharmacokinetics, including metabolite disposition, in young children.

The development of a sustainable bio-based economy has drawn much attention in recent years, and research to find smart solutions to the many inherent challenges has intensified. In nature, perhaps the best example of an authentic sustainable system is oxygenic photosynthesis. The biochemistry of this intricate process is empowered by solar radiation influx and performed by hierarchically organized complexes composed by photoreceptors, inorganic catalysts, and enzymes which define specific niches for optimizing light-to-energy conversion. The success of this process relies on its capability to exploit the almost inexhaustible reservoirs of sunlight, water, and carbon dioxide to transform photonic energy into chemical energy such as stored in adenosine triphosphate. Oxygenic photosynthesis is responsible for most of the oxygen, fossil fuels, and biomass on our planet. So, even after a few billion years of evolution, this process unceasingly supports life on earth, and probably soon also in outer-space, and inspires the development of enabling technologies for a sustainable global economy and ecosystem. The following review covers some of the major milestones reached in photosynthesis research, each reflecting lasting routes of innovation in agriculture, environmental protection, and clean energy production.

Arsenic is a metalloid that occurs in food and the environment in different chemical forms. Inorganic arsenic is classified as a class I carcinogen. The inorganic arsenic intake from food and drinking water varies depending on the geographic arsenic background. Non-dietary exposure to arsenic is likely to be of minor importance for the general population within the European Union. In Europe, arsenic in drinking water is on average low, but food products (e.g. rice and seaweed) are imported from all over the world including from regions with naturally high arsenic levels. Therefore, specific populations living in Europe could also have a high exposure to inorganic arsenic due to their consumption pattern. Current risk assessment is based on exposure via drinking water. For a good estimation of the risks of arsenic in food, it is important to investigate if the bioavailability of inorganic arsenic from food is different from drinking water. The present study further explores the issue of European dietary exposure to inorganic arsenic via rice and seaweed and its associated health risks. The bioavailability of inorganic arsenic was measured in in vitro digestion experiments. The data indicate that the bioavailability of inorganic arsenic is similar for rice and seaweed compared with drinking water. The calculated dietary intake for specific European Union populations varied between 0.44 and 4.51 µg kg⁻¹ bw day⁻¹. The margins of exposure between the inorganic intake levels and the BMDL0.5 values as derived by JECFA are low. Decreasing the intake of inorganic arsenic via Hijiki seaweed could be achieved by setting legal limits similar to those set for rice by the Codex Alimentarius Commission in July 2014.

Purpose: The effectiveness of an opioid rotation to parenteral hydromorphone in advanced cancer patients has never been investigated. Therefore, the purpose of this study was to investigate the analgesic efficacy and side effects of parenteral hydromorphone on serious cancer-related pain., Methods: We included 104 consecutive advanced cancer patients who were extensively pretreated with opioids. They were rotated to parenteral hydromorphone because they failed to achieve adequate pain relief on other opioids. Pain intensity and side effects were daily assessed. The moment of adequate pain control was defined as the first of at least 2 consecutive days when the mean pain intensity at rest was ≤ 4 (on a 0-10 numeric rating scale) and side effects were tolerable., Results: The reasons for rotation to parenteral hydromorphone were inadequate pain control with/without expected delivery problems due to high opioid dosages (n = 61) and intolerable side effects with persistent pain (n = 43). Adequate pain control was achieved in 86 patients (83%) within a mean of 5 days. Eight of 86 patients still had side effects, but these were scored as acceptable. The mean pain intensity at rest decreased from 5.4 [standard deviation (sd) = 2.1] to 2.4 (sd = 1.5; p < 0.001). The median failure-free treatment period was 57 days and covered a substantial part of the median survival of 78 days in the responding patients., Conclusions: In advanced cancer patients with serious unstable cancer-related pain refractory to other opioids, continuous parenteral administration of hydromorphone often results in long-lasting adequate pain control and should be considered even after extensive pretreatment with opioids.

This paper presents the policy framework of contaminated site management in The Netherlands and the corresponding risk assessment tools, including innovations that have taken place since an overview was published in 1999. According to the Dutch Soil Protection Act assessment framework, soils are subdivided into three quality classes: clean, slightly contaminated and seriously contaminated. Historic cases of slightly contaminated soils are managed in a sustainable way by re-use of soil material within a region on the basis of risk-based and land use specific Maximal Values and Background Values. In case of serious soil contamination remediation is in principle necessary and the urgency of remediation has to be determined based on site-specific risks for human health, the ecosystem and groundwater. The major risk assessment tools in The Netherlands are the CSOIL exposure model (human health risks and food safety), Species Sensitivity Distributions and the Soil Quality Triad (ecological risks), along with a procedure to assess the risks due to contaminant spreading to and in the groundwater. Following the principle 'simple if possible, complex when necessary', tiered approaches are used. Contaminated site practices are supported with web-based decision support systems., (Copyright © 2012 Elsevier B.V. All rights reserved.)

The soil bacterium Cupriavidus metallidurans CH34 contains a high number of heavy metal resistance genes making it an interesting model organism to study microbial responses to heavy metals. In this study the transcriptional response of strain CH34 was measured when challenged to sub-lethal concentrations of various essential or toxic metals. Based on the global transcriptional responses for each challenge and the overlap in upregulated genes between different metal responses, the sixteen metals were clustered in three groups. In addition, the transcriptional response of already known metal resistance genes was assessed, and new metal response gene clusters were identified. The majority of the studied metal response loci showed similar expression profiles when cells were exposed to different metals, suggesting complex interplay at transcriptional level between the different metal responses. The pronounced redundancy of these metal resistant regions-as illustrated by the large number of paralogous genes-combined with the phylogenetic distribution of these metal response regions within either evolutionary related or other metal resistant bacteria, provides important insights on the recent evolutionary forces shaping this naturally soil-dwelling bacterium into a highly metal-resistant strain well adapted to harsh and anthropogenic environments.

Many microorganisms propel themselves through their fluid environment by means of multiple rotating flagella that self-organize to form bundles, a process that is complex and poorly understood. In the present work, the bundling behavior of a pair of flexible flagella, each driven by a constant torque motor, is investigated, using a mathematical model incorporating the fluid motion generated by each flagellum as well as the finite flexibility of the flagella. The initial stage of bundling is driven purely by hydrodynamics but the final state of the bundle is determined by a nontrivial balance between hydrodynamics and elasticity. As the flexibility of the flagella increases a regime is found where, depending on initial conditions, one finds bundles that are either tight, with the flagella in mechanical contact, or loose, with the flagella intertwined but not touching. That is, multiple coexisting states of bundling are found. The parameter regime (in terms of flexibility and distance between motors) at which this multiplicity occurs is comparable to the parameters for a number of bacteria.

Many bacteria in the environment have adapted to the presence of toxic heavy metals. Over the last 30 years, this heavy metal tolerance was the subject of extensive research. The bacterium Cupriavidus metallidurans strain CH34, originally isolated by us in 1976 from a metal processing factory, is considered a major model organism in this field because it withstands milli-molar range concentrations of over 20 different heavy metal ions. This tolerance is mostly achieved by rapid ion efflux but also by metal-complexation and -reduction. We present here the full genome sequence of strain CH34 and the manual annotation of all its genes. The genome of C. metallidurans CH34 is composed of two large circular chromosomes CHR1 and CHR2 of, respectively, 3,928,089 bp and 2,580,084 bp, and two megaplasmids pMOL28 and pMOL30 of, respectively, 171,459 bp and 233,720 bp in size. At least 25 loci for heavy-metal resistance (HMR) are distributed over the four replicons. Approximately 67% of the 6,717 coding sequences (CDSs) present in the CH34 genome could be assigned a putative function, and 9.1% (611 genes) appear to be unique to this strain. One out of five proteins is associated with either transport or transcription while the relay of environmental stimuli is governed by more than 600 signal transduction systems. The CH34 genome is most similar to the genomes of other Cupriavidus strains by correspondence between the respective CHR1 replicons but also displays similarity to the genomes of more distantly related species as a result of gene transfer and through the presence of large genomic islands. The presence of at least 57 IS elements and 19 transposons and the ability to take in and express foreign genes indicates a very dynamic and complex genome shaped by evolutionary forces. The genome data show that C. metallidurans CH34 is particularly well equipped to live in extreme conditions and anthropogenic environments that are rich in metals.

We determined the genome sequence of Arthrospira sp. PCC 8005, a cyanobacterial strain of great interest to the European Space Agency for its nutritive value and oxygenic properties in the Micro-Ecological Life Support System Alternative (MELiSSA) biological life support system for long-term manned missions into space.

Aim: The aim of this study was to evaluate the surgical treatment of stage III empyema., Methods: Between 2002 and 2005, 30 patients underwent surgery for treatment of diagnosed stage III empyema preoperatively. Patients were referred for spirometry to evaluate lung function postoperatively., Results: Twenty nine patients underwent primary thoracotomy because of an extended stage III empyema, 1 patient video-assisted thoracoscopic surgery (VATS). Mean age was 62 years. Mean period from onset of symptoms until hospital admission was 29 days and mean time interval between admission and surgery was 11 days. Intraoperative complication happened in one patient (3%), in whom a phrenic nerve lesion was diagnosed. Overall mortality rate was 3%. In 17 patients postoperative spirometry was performed, showing normal vital capacity in 59% of the patients., Conclusion: There was no reluctance in performing primary thoracotomy in our population with a stage III empyema. Decortication by means of thoracotomy restored the complete expansion of the lung; the authors claim that vital capacity returned to normal values, as it was shown by the spirometry results postoperatively. Early referral to the respiratory department in case of a non-responding pneumonia and early surgical consultation in case of a parapneumonic effusion, will prevent progression to an extensive organized stage III empyema requiring decortication by thoracotomy.

Neurotensin (NT) receptors are overexpressed in different human tumors, such as human ductal pancreatic adenocarcinoma. New stable neurotensin analogs with high receptor affinity have been synthesized by replacing arginine residues with lysine and arginine derivatives. The aim of this study was to explore the biodistribution, tumor uptake, kidney localization, and stability characteristics of these new analogs in order to develop new diagnostic tools for exocrine pancreatic cancer. Four (111)In-labeled DTPA-chelated NT analogs and one (111)In-labeled DOTA-chelated NT analog were evaluated in NMRI nude mice bearing NT receptor-positive HT29 tumors. Experiments with a coinjection of unlabeled NT or lysine were performed to investigate receptor-mediated uptake and kidney protection, respectively. In addition, the in vivo serum stability of the most promising analog was analyzed. In the biodistribution study in mice, at 4 hours postinjection, a low percentage of the injected dose per gram (%ID/g) of tissue for all compounds was found in NT receptor-negative organs, such as the blood, spleen, pancreas, liver, muscle, and femur. A high uptake was found in the colon, intestine, kidneys, and in implanted HT29 tumors. The coinjection of excess unlabeled neurotensin significantly reduced tumor uptake, showing tumor uptake to be receptor-mediated. To a lesser extent, this was also observed for the colon, but not for other tissues. We concluded that DTPA-(Pip)Gly-Pro-(PipAm)Gly-Arg-Pro-Tyr-tBuGly-Leu-OH and the DOTA-linked counterpart have the most favorable biodistribution properties regarding tumor uptake.

Neurotensin (NT) receptors are overexpressed in exocrine pancreatic cancer and Ewing's sarcoma. The potential utility of native NT in cancer diagnosis and therapy is, however, limited by its rapid degradation in vivo. Therefore, NT analogues were synthesised with modified lysine and arginine derivatives to enhance stability and coupled either to DTPA, to enable high specific activity labelling with indium-111 for imaging, or to DOTA, to enable high specific activity labelling with beta-emitting radionuclides, such as lutetium-177 and yttrium-90. Based on serum stability (4 h incubation at 37 degrees C in human serum) and receptor binding affinity, the five most promising analogues were selected and further evaluated in in vitro internalisation studies in human colorectal adenocarcinoma HT29 cells, which overexpress NT receptors. All five NT analogues bound with high affinity to NT receptors on human exocrine pancreatic tumour sections. The analogues could be labelled with (111)In to a high specific activity. The (111)In-labelled compounds were found to be very stable in serum. Incubation of HT29 cells with the (111)In-labelled analogues at 37 degrees C showed rapid receptor-mediated uptake and internalisation. The most promising analogue, peptide 2530 [DTPA-(Pip)Gly-Pro-(PipAm)Gly-Arg-Pro-Tyr-tBuGly-Leu-OH] was further tested in vivo in a biodistribution study using HT29 tumour-bearing nude mice. The results of this study showed low percentages of injected dose per gram tissue of this (111)In-labelled 2530 analogue in receptor-negative organs like blood, spleen, pancreas, liver, muscle and femur. Good uptake was found in the receptor-positive HT29 tumour and high uptake was present in the kidneys. Co-injection of excess unlabelled NT significantly reduced tumour uptake, showing that tumour uptake is a receptor-mediated process. With their enhanced stability, maintained high receptor affinity and rapid receptor-mediated internalisation, the (111)In-labelled DTPA- and DOTA-conjugated NT analogues are excellent candidates for imaging and therapy of exocrine pancreatic cancer, peptide 2530 being the most promising analogue.

Previously identified strain-specific genes of Helicobacter pylori were analysed for GC content and preference in codon usage. The results indicate that in H. pylori strain specificity is mainly driven by gene uptake. Incoming strains of Helicobacter or other species can occasionally donate genes but the identification of the donor species is hampered by ongoing evolutionary processes and the lack of an adequate number, or indeed a total absence, of gene homologues.

At the Faculty of Medicine of the KU Leuven a 'final' test is being developed, part of which consists of extended matching multiple-choice questions (EMQs). These are problem-oriented questions referring to a realistic case, with the correct answer to be chosen from a list of 7-26 possible answers. The same list can be used for several questions (cases). Staff members of 10 medical specialties have developed about 900 questions. In order to test the quality of these questions, they were submitted in series of 100 questions to 251 final-year students who were not specifically prepared for content, or for question format. The organization of the test ran without problems. It was possible to answer 100 EMQs within half a day (i.e. 4 hours). Fatigue had no measurable influence on the score over this period but increasing familiarity with the question format was observed. In order to obtain a reliable series of questions those questions that correlated negatively with the total score were deleted until a Cronbach alpha of 0.80 was reached. Split-half reliability coefficients were of the same order of magnitude. The score on a questionnaire concerning the perception of the test indicated poor face validity. The procedure of test construction gave arguments for content validity. The correlation between test score and total examination score of each of the 7 years of medical education was statistically significant, which indicates criterion validity. Therefore, starting from 100 EMQs per student it was possible to develop a reliable and valid test. EMQs seem to be appropriate for a final test of clinical knowledge in medical education.

Whole-genome clustering of the two available genome sequences of Helicobacter pylori strains 26695 and J99 allows the detection of 110 and 52 strain-specific genes, respectively. This set of strain-specific genes was compared with the sets obtained with other computational approaches of direct genome comparison as well as experimental data from microarray analysis. A considerable number of novel function assignments is possible using database-driven sequence annotation, although the function of the majority of the identified genes remains unknown. Using whole-genome clustering, it is also possible to detect species-specific genes by comparing the two H.pylori strains against the genome sequence of Campylobacter jejuni. It is interesting that the majority of strain-specific genes appear to be species specific. Finally, we introduce a novel approach to gene position analysis by employing measures from directional statistics. We show that although the two strains exhibit differences with respect to strain-specific gene distributions, this is due to the extensive genome rearrangements. If these are taken into account, a common pattern for the genome dynamics of the two Helicobacter strains emerges, suggestive of certain spatial constraints that may act as control mechanisms of gene flux.

Over the last two decades nonradioactive nucleic acid labeling and detection systems have overcome the safety, disposal, stability and cost problems that are associated with radioactive techniques. Besides traditional, enzyme-mediated, nonradioactive labeling methods (e.g., random priming, nick translation or labeling by PCR), several chemical labeling systems have been developed (e.g., ULS, psoralen, alkylating agents). These methods provide fluorescent (or hapten) labeled probes for fluorescence in situ hybridization (FISH), comparative genomic hybridization (CGH) and microarray-based techniques. In this review the DNA-based molecular diagnostic applications and perspectives of the Universal Linkage System (ULS) technology will be described.

Objective: To evaluate androgen receptor (AR) levels to predict endocrine therapy response and prognosis., Study Design: A sepharose microsphere model was employed to establish the relationship between level of immunohistochemical staining density and both antigen and primary antibody (F39.4.1) concentration. Subsequently, the results of the model system were compared with the results in routine prostate sections., Results: A log-linear relationship was observed between optical density (OD) and primary antibody dilution measured in immunostained, antigen-coated microspheres with moderate antigen density. Similar titration curves were observed in prostate sections at the same dilution range, indicating that the microsphere model can be extrapolated to routine tissue sections. With microspheres with high coating density, the loglinear range of dilutions shifted to higher dilutions., Conclusion: Differences in AR levels in prostate tissue sections might be more accurately detected by comparison of titration curves of primary antibody than by comparison of OD values at a fixed primary antibody dilution.

In literature as well as in nursing practice a growing concern about nurses' ethical competence can be observed. Based on the cognitive theory of moral development by Kohlberg, this research examined nursing students' ethical behaviour in five nursing dilemmas. Ethical behaviour refers not only to the ethical reasoning of nursing students but also to the relationship between reasoning and behaviour. Kohlberg's definition of morality was refined by adding a care perspective. The results show that the majority of students can be located in the fourth moral stage according to Kohlberg's theory, that is, the conventional level of moral development. This finding implies that students are still guided by professional rules, norms and duties, and have not (yet) succeeded in making personal ethical decisions on the basis of their own principles and acting according to such decisions.

Purpose: The presence of estrogen receptors (ER) in human prostatic tissue is a longstanding, controversial issue. In a few experimental animal models androgen deprivation was shown to be associated with a spontaneous increased ER expression in prostatic tissue. We intended to study whether these observations also apply to human prostatic tissue., Materials and Methods: Estrogen receptor expression by stromal and glandular cells was studied by immunohistochemistry in prostatectomy specimens of 21 patient with prostate cancer, treated for 3 months with a luteinizing hormone-releasing hormone (LHRH) agonist and flutamide. In addition 2 patients treated with estrogens were also examined. For comparison, ER expression was also studied in a series of 18 prostatectomy specimens of untreated patients., Results: The specimens of patients treated with androgen blockade showed atrophic changes of the gland as well as basal cell hyperplasia, features characteristic for this therapy. Although stromal cells of prostatectomy specimens from untreated patients were largely ER negative, those of patients exposed to androgen ablation therapy or estrogen therapy had an intense nuclear ER expression in a great number of stromal cells around prostatic glands. Sporadic epithelial cells lining the glands displayed some nuclear ER expression. Prostatic glands from treated patients with basal cell hyperplasia lacked ER expression. In all treated and untreated cases the carcinoma cells were ER negative., Conclusions: Androgen deprivation leads to an upregulation of stromal ER expression in human prostate. Estrogen-induced morphological epithelial changes could be explained by a paracrine interaction between stromal and epithelial cells.

Based on the cognitive theory of moral development of Kohlberg, refined by the addition of the dimension "ethics of care" and the educational theory of Janssen, the relationship of education and ethical behavior of nursing students was examined. Ethical behavior referred not only to the ethical reasoning of students but also to the relationship between this reasoning and their behavior. This study examined the responses of 2,624 nursing students to five ethical nursing dilemmas included in the Ethical Behavior Test by relating them to four educational variables: students' level of education, level of enrollment, school, and students' perceptions of the educational process. A significant relationship between education and ethical behavior was found.

Large gemistocytic cells are well-known elements of glial tumors. Recently, miniature gemistocytic cells and neoplastic glial fibrillary acidic protein (GFAP)-positive oligodendroglial cells, which are regularly seen in oligodendrogliomas, have been termed "transitional cells". The proliferative activity of the gemistocytic cell types and the GFAP-positive (gliofibrillary) oligodendrocytes was determined in eight astrocytomas, seven gemistocytic astrocytomas, eight glioblastomas, two monstrocellular glioblastomas, seven oligodendrogliomas and three mixed oligo-astrocytomas by immunohistochemical staining of the proliferation marker MIB-1 in combination with immunostaining for GFAP. Both large gemistocytic cells and the transitional cells showed cytoplasmic GFAP-positive staining. Neither in the classic gemistocytes nor in the minigemistocytes nuclear immunostaining for the MIB-1 antibody was observed. In contrast, MIB-1 staining was seen in the gliofibrillary oligodendrocytes. It is concluded that both large and miniature gemistocytic cell types contrast with gliofibrillary oligodendrocytes by their inability to proliferate.

Nine 'carcinoids' of the breast (argyrophilic carcinomas) were examined for the presence of estrogen receptor (ER), progesterone receptor (PR), and androgen receptor (AR), using immunohistochemistry. The tumours were selected on the basis of their histo-morphological appearance and positive Grimelius stain. All cases were immunoreactive for neuron-specific enolase (NSE). In one case the tumour cells were intensely chromogranin A positive. All cases were ER positive, while 5 cases expressed AR and 5 cases PR. Immunostaining for ER and simultaneous demonstration of argyrophilia or chromogranin A expression in chromogranin A positive argyrophilic carcinoid tumour of the breast provided further evidence that neuroendocrine cells in breast tumours express sex steroid receptors. The similarity in sex steroid receptor expression pattern in 'carcinoids' of the breast and the more common categories of breast cancer suggests an identical responsiveness to endocrine therapy.

The product of the neurofibromatosis type 2 (NF2) tumor suppressor gene is a 595-amino-acid protein bearing resemblance to a family of band-4.1-related proteins. These proteins, including ezrin, radixin, and moesin, probably function as molecular linking proteins, connecting the cytoskeleton to the cell membrane. On the grounds of the homology to the ezrin, radixin, and moesin proteins and on the basis of its predicted secondary structure, the NF2 protein is also thought to act as a cytoskeleton-cell membrane linking protein. Using monoclonal antibodies to amino- and carboxyl-terminal synthetic NF2 peptides we demonstrate the co-localization of the NF2 protein with elements of the cytoskeleton in a COS cell model system and in cultured human cells. Furthermore, the presence of the NF2 protein in tissue sections is shown. The monoclonal antibodies specifically stain smooth muscle cells and the stratum granulosum of the human epidermis. In cultured smooth muscle cells the NF2 protein co-localizes with actin stress fibers. Immunoelectron microscopy demonstrates the presence of the NF2 protein associated with keratohyalin granules and to a lesser extent with intermediate filaments in the human epidermis. We conclude that the NF2 protein is indeed associated with multiple elements of the cytoskeleton.

The Bacillus subtilis gltAB genes, coding for the two subunits of glutamate synthase, are transcribed divergently from the gltC gene, encoding a LysR-type transcriptional activator of gltAB. The predicted gltA and gltC transcription start sites are separated by 51 to 52 bp. A 15-bp, consensus binding site (Box I) for LysR-type proteins was found centered at position -64 with respect to the gltA transcription start. This site was shown by mutational analysis to be required both for GltC-mediated activation of gltA and for autorepression of gltC. Box II, which is similar to Box I, is centered 22 bp downstream of Box I and overlaps the -35 region of the gltA promoter. Box II was found to be essential for activation of gltA but not for gltC autoregulation. Introduction of approximately one additional helical turn of DNA between Box I and Box II enhanced gltA expression 7- to 40-fold under nonactivating conditions and about 2-fold under activating conditions. Expression of gltA was dramatically decreased when the distance between Box I and Box II was altered by a nonintegral number of helical turns of DNA. gltC autorepression was abolished by most of the inserts between Box I and Box II but was augmented by adding one helical turn.

Neurofibromatosis type 2 (NF2) is a disease resulting in the formation of schwannomas of the eighth cranial nerve, and other central nervous system tumours. A tumour suppressor gene has been found to be responsible for this disorder. The 595 amino acid NF2 protein shows a great deal of homology to a superfamily of membrane organizing proteins. To generate antibodies against the NF2 protein four synthetic peptides (SP) were injected in rabbits. COS cells transfected with an NF2 cDNA construct in an expression vector were used for immunocytochemical staining experiments; lysates of transfected COS cells were used for Western blotting experiments, as were lysates of E. coli cultures transformed with an NF2 cDNA construct subcloned in a prokaryotic expression vector. In western blots all sera detected a band indicating the appropriate molecular weight in lysates of transfected COS cells and E. coli. Immunocytochemical staining experiments indicate that the NF2 protein localizes in or near the cell membrane. Immunohistochemical staining of human tissue sections demonstrated the presence of the NF2 protein in muscle-, and Schwann cells. These results support the hypothesis that the NF2 protein functions as a membrane organizing element.

We describe the immunohistochemical detection of the human androgen receptor (AR) in routinely processed, paraffin-embedded tissue with the monoclonal antibody (MAb) F39.4. Deparaffinized sections were heated in a microwave oven for antigen retrieval. A panel of human male- and female-derived tissues was investigated. We observed a nuclear staining pattern consistent with previous results on frozen sections. Moreover, we studied the possibility of detecting AR in prolonged formalin-fixed tissue and in paraffin-embedded archival material. After prolonged fixation times or long-term storage of paraffin-embedded tissue, the staining intensity for the AR did not deteriorate. Blocking experiments with the specific synthetic peptides demonstrated the specificity of this technique. We conclude that this method is specific, allows retrospective AR studies, and offers optimally preserved morphology.

Heterogeneity in human androgen receptor (hAR) expression in prostate cancer is considered to be implicated in tumor progression. hAR expression was therefore studied immunohistochemically in localized and locally progressive, hormone refractory (HR) prostate cancer. Because altered functional activity of the hAR may be due to changes in the structural integrity of the hAR gene, exons 2 to 8 of the hAR gene were assessed for mutations by single-strand conformation polymorphism (SSCP) analysis and exon 1 was analyzed for the size of the CAG repeat. The hormone binding capacity, a prerequisite for ligand-regulated receptor function, was determined by a ligand binding assay. Coexpression of the hAR and prostate-specific antigen (PSA) was studied by a sequential double immunoenzymatic staining to verify whether PSA expression is a parameter of hAR function. Almost all human prostatic carcinomas revealed heterogeneous hAR expression, regardless of tumor differentiation and progression. Putative predominance of hAR-negative tumor areas in HR prostate cancer was not observed. No hAR gene mutations or major changes in the CAG repeat were found in the 18 HR carcinomas or in the 9 control samples. Moreover, all selected hAR-expressing cancers were able to bind the synthetic androgen methyltrienolone (R1881). Immunoenzymatic double staining revealed even PSA expression in hAR-negative tumor areas. PSA immunohistochemistry in human prostatic carcinomas therefore is of no use in determining hAR functional activity. Thus, most prostatic carcinomas, even when progressed to a state of hormone insensitivity, contain a structurally intact hAR gene, heterogeneously expressed with retained androgen binding capacity.

The presence of androgen receptors (AR) in neuroendocrine cells was investigated in benign tissue of 10 prostatectomy specimens, in 12 prostatic adenocarcinomas with focal neuroendocrine differentiation and in 1 case of a pure neuroendocrine small cell carcinoma of the prostate. Neuroendocrine cells were defined by their reactivity with an antibody to chromogranin A. Monoclonal antibody F39.4 directed against the amino-terminal domain of the AR molecule was used to detect AR. AR and chromogranin A were simultaneously visualized with a double immunofluorescence technique. The results indicate that chromogranin positive cells in both benign and malignant prostatic tissue lack detectable expression of AR. No effect of endocrine therapy was noted. These results are in agreement with the hypothesis that prostatic neuroendocrine tumour cells represent an androgen insensitive cell population, which incidentally may expand to replace the androgen-sensitive tumour cell population during androgen ablation therapy.

1. Long Evans rats were chronically instrumented with intravascular catheters and pulsed Doppler probes to assess changes in renal, mesenteric and hindquarters blood flows and vascular conductances in response to bombesin (2.5 micrograms kg-1, i.v.) and cholecystokinin (CCK) (0.5 and 5.0 micrograms kg-1, i.v.). 2. Bombesin caused an increase in heart rate and blood pressure, together with a transient renal vasoconstriction and prolonged mesenteric vasodilatation; there was an early hindquarters vasodilatation followed by vasoconstriction. 3. In the presence of phentolamine, bombesin caused a fall in blood pressure due to enhanced hindquarters vasodilatation; these effects were reversed by propranolol and hence were possibly due to circulating adrenaline acting on vasodilator beta 2-adrenoceptors. 4. During concurrent administration of phentolamine, propranolol and atropine, bombesin caused prolonged tachycardia and a rise in blood pressure. The renal vasoconstrictor and mesenteric vasodilator effects of bombesin were not reduced under these conditions and thus probably were direct and/or indirect non-adrenergic, non-cholinergic (NANC) effects. 5. CCK caused dose-dependent increases in blood pressure accompanied by renal, mesenteric and hindquarters vasoconstriction followed, after the higher dose, by vasodilatations. The lower dose of CCK increased heart rate but there was a bradycardia followed by a tachycardia after the higher dose. 6. Experiments with antagonists as described above indicated the pressor effect of CCK was mediated largely through alpha-adrenoceptors, as were the mesenteric and hindquarters vasoconstrictor effects; CCK exerted NANC negative chronotropic effects. 7. All the effects of CCK were markedly inhibited by L364,718. This observation, and the finding that L364,718 had no effect on the responses to bombesin, together with the dissimilarities in the regional haemodynamic effects of exogenous CCK and bombesin, indicate that the cardiovascular actions of the latter were not dependent on the release of endogenous CCK.

The Clostridium acetobutylicum glnA gene has two transcript start sites under the control of promoters p1 and p2. Initiation of transcription was regulated by nitrogen and a downstream region was implicated in the regulation of transcript initiation by nitrogen in Escherichia coli. Putative antisense RNA was produced from a single downstream transcript start site under the control of p3. An up-promoter mutation in p3 resulted in lower levels of glutamine synthetase (GS) activity. Putative antisense RNA had a role in down-regulating GS expression but was not involved in regulation by nitrogen. Deletion of downstream inverted repeat sequences resulted in very low levels of GS activity.

The propyl, octyl and dodecyl esters of gallic acid have been studied extensively in a large number of animal experiments involving oral dosing. Experimental data on general toxicity and studies on reproduction, teratogenicity and mutagenicity are also available. Most of the key toxicity studies, however, date back to the 1950s, do not meet current standards of toxicity testing and do not provide evidence for carcinogenic or mutagenic action of the gallates. Mutagenicity studies with octyl gallate and dodecyl gallate are lacking. The biokinetics of propyl gallate apparently differ from those of octyl and dodecyl gallate, the octyl and dodecyl esters being absorbed and hydrolysed to a lesser degree than the propyl ester. In toxicity studies with propyl gallate, growth retardation, anaemia, kidney and liver changes and hyperplasia of the forestomach were the most prominent effects at dose levels above 10,000 mg/kg feed. At 5000 mg/kg feed, liver enzyme induction was seen. In the available studies with octyl gallate or dodecyl gallate as the test compound, effects were found at 3000 mg/kg feed or higher levels. In studies performed with the various gallates, no effects were observed at a dose level of 1000 mg/kg feed, a level that was adopted as the no-effect level by the FAO/WHO Joint Expert Committee on Food Additives (JECFA) in 1976. This committee established an acceptable daily intake (ADI) for man of 0.2 mg/kg body weight (as a sum of propyl, octyl and dodecyl gallates). A re-evaluation of the toxicity of gallates indicates that a 'classic' long-term toxicity study of propyl gallate meeting current standards is required. As yet, the available toxicological evidence indicates that gallates may be used safely as antioxidants.

A simple method of diverting anaesthetic waste gases from the Engström ECS-2000 ventilator is described. Unless special precautions are taken the digital volume measurement may be influenced; the simple solution of this problem is given.

The effects of feeding inorganic tin on the gastrointestinal tract were examined in rats. Three groups of male weanling Wistar rats were fed a diet to which 0, 250, or 500 ppm Sn2+ had been added as SnCl2. A fourth group was subjected to feed restriction by pair feeding with the 500-ppm group. Comparison of the data from the tin-fed groups with both the control and the reduced diet groups allowed discrimination between effects of reduced feed intake and Sn2+ effects. Independent of the reduced feed intake, Sn2+ affected hemoglobin concentration in the blood and several small intestine parameters. Total length of the small intestine, as well as absolute and relative weights, was increased. An increase was also observed in the migration of epithelial cells along the villus, as revealed by [3H]thymidine incorporation and autoradiography in rats fed 900 ppm Sn2+ for 4 weeks. Stereo-light microscopy and scanning electron microscopy revealed the formation of ridge-like villi due to Sn2+ feeding and a decreased number of villi per unit surface. These data suggest that an increase in cell turnover in the small intestine, due to Sn2+, was responsible for these changes.

In this report the neurotoxicity of aspartame and its constituent amino acids aspartic acid and phenylalanine is reviewed. The adverse reactions ascribed to the consumption of aspartame-containing products, as reported in the U.S.A., are discussed and placed in perspective with the results of recent behavioural studies in humans and animals. The issue of common intake levels associated with proposed uses of aspartame is addressed. In brief, the following conclusions can be drawn: When aspartame is consumed at levels within the ADI-limit of 40 mg/kg body wt, there is no significant risk for an aspartate-induced neurotoxic effect in the brain. When aspartame is consumed at levels within the ADI-limit by normal subjects or persons heterozygous for phenylketonuria (PKU) the resultant plasma phenylalanine concentrations are practically always within the normal postprandial range; elevation to plasma concentrations commonly associated with adverse effects has not been observed. Persons suffering from phenylketonuria (PKU-homozygotes) on a phenylalanine-restricted diet should avoid consumption of aspartame. PKU-homozygotes on the (less strict) phenylalanine-liberalized diet should be made aware of the phenylalanine content of aspartame. In the available behavioural studies in humans with acute dosing, no adverse effects were observed. Long-term studies on behaviour and cognitive function in (sensitive) humans are lacking. Analyses of adverse reaction reports made by consumers in the U.S.A. have not yielded a specific constellation of symptoms clearly related to aspartame that would suggest a widespread public health hazard associated with aspartame use. Focussed clinical studies are now being carried out in the U.S.A.; the results should provide additional evidence concerning the interpretation of the reports on adverse reactions ascribed to aspartame. In the regulation of admitted uses for aspartame the possibility of intake levels exceeding the ADI-limit in some groups of consumers should be a point of attention.

The nucleotide sequence of a 2.0-kilobase DNA segment containing the Clostridium acetobutylicum glnA gene was determined. The upstream region of the glnA gene contained two putative extended promoter consensus sequences (p1 and p2), characteristic of gram-positive bacteria. A third putative extended gram-positive promoter consensus sequence (p3), oriented towards the glnA gene, was detected downstream of the structural gene. The sequences containing the proposed promoter regions p1 and p2 or p3 were shown to have promoter activity by subcloning into promoter probe vectors. The complete amino acid sequence (444 residues) of the C. acetobutylicum glutamine synthetase (GS) was deduced, and comparisons were made with the reported amino acid sequences of GS from other organisms. To determine whether the putative promoter p3 and a downstream region with an extensive stretch of inverted repeat sequences were involved in regulation of C. acetobutylicum glnA gene expression by nitrogen in Escherichia coli, deletion plasmids were constructed lacking p3 and various downstream sequences. Deletion of the putative promoter p3 and downstream inverted repeat sequences affected the regulation of GS and reduced the levels of GS approximately fivefold under nitrogen-limiting conditions but did not affect the repression of GS levels in cells grown under nitrogen-excess conditions.

Limitations in exercise tolerance are characteristic for patients with chronic obstructive pulmonary disease. The twelve-minute walking test has been proposed as a simple, reproducible test to assess exercise tolerance in these patients. We investigated factors, that predicted the twelve-minute walking distance in a group of fifty patients with COPD, who had a maximal reversibility in the FEV1 of 20% after inhaled salbutamol. There was a strong correlation between walking distance and IVC (%pred) (p less than 0.001), RV% TLC (%pred) (p less than 0.001), FEV1 (ml) (p less than 0.001), FEV1 (%pred) (p less than 0.001) and PaO2 (mm Hg) (p less than 0.01). It is concluded that pathophysiological factors are the main determinants of the twelve-minute walking distance.