Showing papers by "University of Amsterdam published in 1993"

Principles of Critical Discourse Analysis

Abstract: This paper discusses some principles of critical discourse analy- sis, such as the explicit sociopolitical stance of discourse analysts, and a focus on dominance relations by elite groups and institutions as they are being enacted, legitimated or otherwise reproduced by text and talk. One of the crucial elements of this analysis of the relations between power and discourse is the patterns of access to (public) discourse for different social groups. Theoretically it is shown that in order to be able to relate power and discourse in an explicit way, we need the cognitive interface of models. knowledge, attitudes and ideologies and other social represen- tations of the social mind, which also relate the individual and the social, and the micro- and the macro-levels of social structure. Finally, the argu- ment is illustrated with an analysis of parliamentary debates about ethnic affairs.

Measurement of co-localization of objects in dual-colour confocal images

Abstract: A method to measure the degree of co-localization of objects in confocal dual-colour images has been developed. This image analysis produced two coefficients that represent the fraction of co-localizing objects in each component of a dual-channel image. The generation of test objects with a Gaussian intensity distribution, at well-defined positions in both components of dual-channel images, allowed an accurate investigation of the reliability of the procedure. To do that, the co-localization coefficients were determined before degrading the image with background, cross-talk and Poisson noise. These synthesized sources of image deterioration represent sources of deterioration that must be dealt with in practical confocal imaging, namely dark current, non-specific binding and cross-reactivity of fluorescent probes, optical cross-talk and photon noise. The degraded images were restored by filtering and cross-talk correction. The co-localization coefficients of the restored images were not significantly different from those of the original undegraded images. Finally, we tested the procedure on images of real biological specimens. The results of these tests correspond with data found in the literature. We conclude that the co-localization coefficients can provide relevant quantitative information about the positional relation between biological objects or processes.

Treatment of Colonic and Rectal Adenomas with Sulindac in Familial Adenomatous Polyposis

Abstract: Background Familial adenomatous polyposis is an autosomal dominant disorder characterized by the formation of hundreds of colorectal adenomas and eventual colorectal cancer. Administration of the nonsteroidal antiinflammatory drug sulindac has been followed by regression of polyps in patients with this disorder, but no controlled trial of this drug in patients who have not had surgery has been reported. Methods We conducted a randomized, double-blind, placebo-controlled study of 22 patients with familial adenomatous polyposis, including 18 who had not undergone colectomy. The patients received sulindac at a dose of 150 mg orally twice a day for nine months or identical-appearing placebo tablets. The number and size of the polyps were evaluated every three months for one year. Results A statistically significant decrease in the mean number of polyps and their mean diameter occurred in patients treated with sulindac, as compared with those given placebo. When treatment was stopped at nine months, the number...

Alteration in a new gene encoding a putative membrane-organizing protein causes neuro-fibromatosis type 2

Abstract: Neurofibromatosis type 2 (NF2) is a monogenic dominantly inherited disease predisposing carriers to develop nervous system tumours. To identify the genetic defect, the region between two flanking polymorphic markers on chromosome 22 was cloned and several genes identified. One is the site of germ-line mutations in NF2 patients and of somatic mutations in NF2-related tumours. Its deduced product has homology with proteins at the plasma membrane and cytoskeleton interface, a previously unknown site of action of tumour suppressor genes in humans.

Prognostic Value of HIV-1 Syncytium-Inducing Phenotype for Rate of CD4+ Cell Depletion and Progression to AIDS

Abstract: Objective: To investigate the relation between detection of syncytium-inducing (SI), human immunodeficiency virus type 1 (HIV-1) variants, rate of CD4+ cell decline, and clinical progression. Desig...

Software Engineering: Principles and Practice

Abstract: Software Engineering: Principles and Practice challenges the reader to appreciate the issues, design trade-offs and teamwork required for successful software development. This new edition has been brought fully up to date, with complete coverage of all aspects of the software lifecycle and a strong focus on all the skills needed to carry out software projects on time and within budget. Highlights of the third edition include: * Fully updated chapters on requirements engineering and software architecture. * New chapters on component-based software engineering, service orientation and global software development. * Extensive coverage of the human and social aspects of software development. * Balanced coverage of both traditional, heavyweight development and agile, lightweight development approaches such as Extreme Programming (XP). Written to support both introductory and advanced software engineering courses, this book is invaluable for everyone in software development and maintenance who wants an accessible account of the problems incurred in large-scale software development and the proposed solutions. A companion website with additional resources for students and instructors can be found at www.wileyeurope.com/college/van vliet

The Influence of Socio-structural Variables on Identity Management Strategies

Abstract: This chapter attempts to provide empirical support for some of the key predictions of social identity theory. This theory not only describes the psychological processes underlying the desire to establish positive social identity, it also identifies antecedent conditions to the use of different options to improve one's status position. On the basis of the theoretical statements provided by social identity theory, a research programme, designed to investigate conditions under which group members would be inclined to pursue status improvement individually or as a group, was set up. A theoretical analysis implies that status structures can be characterized with a limited number of variables and that such socio-structural variables are likely to be important determinants of people's preference to display individualist or collectivist behaviour when striving for higher status. The main variables in this respect seem to be: (1) the relative status position of one's group; (2) the permeability of group boundaries...

Fluorescent labeling of nascent RNA reveals transcription by RNA polymerase II in domains scattered throughout the nucleus

Abstract: Several nuclear activities and components are concentrated in discrete nuclear compartments. To understand the functional significance of nuclear compartmentalization, knowledge on the spatial distribution of transcriptionally active chromatin is essential. We have examined the distribution of sites of transcription by RNA polymerase II (RPII) by labeling nascent RNA with 5-bromouridine 5'-triphosphate, in vitro and in vivo. Nascent RPII transcripts were found in over 100 defined areas, scattered throughout the nucleoplasm. No preferential localization was observed in either the nuclear interior or the periphery. Each transcription site may represent the activity of a single gene or, considering the number of active pre-mRNA genes in a cell, of a cluster of active genes. The relation between the distribution of nascent RPII transcripts and that of the essential splicing factor SC-35 was investigated in double labeling experiments. Antibodies against SC-35 recognize a number of well-defined, intensely labeled nuclear domains, in addition to labeling of more diffuse areas between these domains (Spector, D. L., X. -D. Fu, and T. Maniatis. 1991. EMBO (Eur. Mol. Biol. Organ.) J. 10:3467-3481). We observe no correlation between intensely labeled SC-35 domains and sites of pre-mRNA synthesis. However, many sites of RPII synthesis colocalize with weakly stained areas. This implies that contranscriptional splicing takes place in these weakly stained areas. These areas may also be sites where splicing is completed posttranscriptionally. Intensely labeled SC-35 domains may function as sites for assembly, storage, or regeneration of splicing components, or as compartments for degradation of introns.

Expression of CD44 Variant Proteins in Human Colorectal Cancer Is Related to Tumor Progression

Abstract: Specific CD44 variant glycoproteins are overexpressed at particular stages of colorectal tumor progression. Some variants of the CD44 glycoprotein without exon v6 sequences appear at the earliest stage of tumorigenesis, i.e., in early adenomas. Expression of variants containing exon v6 sequences is largely restricted to the advanced stages of tumor development and in addition is more prevalent and intense in metastatic (Dukes C/D) than in nonmetastatic (Dukes A/B) carcinomas. The observation that CD44 variants containing a protein domain of CD44 that confers full metastatic potential to rat carcinoma and sarcoma cell lines is increasingly expressed during colorectal tumor progression indicates that this domain may have an important role in tumor progression and metastasis in humans. Information on v6 expression, which can be obtained by routine immunohistochemistry, may prove of important prognostic value, particularly in carcinomas (Dukes A and B) that have not yet given rise to detectable metastases.

Different Genospecies of Borrelia burgdorferi Are Associated with Distinct Clinical Manifestations of Lyme Borreliosis

Abstract: Borrelia burgdorferi sensu lato has been subdivided into three genospecies: B. burgdorferi sensu stricto, B. garinii, and B. burgdorferi group VS461. Sixty-eight isolates cultured from patients and 26 strains from ticks were characterized with use of SDS-PAGE, western blotting, and rRNA gene restriction analysis. Fifty-seven of 58 strains obtained from the skin of 70 patients who had erythema migrams or acrodermatitis chronica atrophicans were of group VS461, whereas the genotype of the remaining strain was unidentifiable. Of 10 strains cultured from CSF (n = 3) and skin (n = 7) of 20 patients with extracutaneous symptoms of Lyme borreliosis, nine were B. garinii and one was B. burgdorferi sensu stricto. Of these 20 patients, 17 had neuroborreliosis, one had arthritis and carditis, one had myalgia, and one had erythema and arthralgia. All 26 isolates from ticks were of group VS461. In conclusion, infections due to group VS461 and B. garinii are associated with cutaneous and extracutaneous symptoms, respectively. Our findings suggest that B. burgdorferi genotypes have different pathogenic potentials.

The place of appraisal in emotion

Abstract: The concept of “appraisal” has been used in the literature in a dual way: to refer to the content of emotional experience, as well as to the cognitive antecedents of emotions. I argue that appraisal in the former sense is what is contained in information in self-reports and that this information is of limited use for making inferences on emotion antecedents. This is so because emotional experience may contain appraisals that are part of the emotional response rather than belonging to its causes. They often result from elaboration of the experience after it has begun to be generated. Although in most or all emotions some cognitive appraisal processes are essential antecedents, these processes may be much simpler than self-reports (and the semantics of emotion words) may suggest. The appraisal processes that account for emotion elicitation can be assumed to be of a quite elementary kind.

Overexpression of a M(r) 110,000 vesicular protein in non-P-glycoprotein-mediated multidrug resistance.

Abstract: A M r110,000 protein (p110) is overexpressed in P-glycoprotein-negative multidrug-resistant tumor cell lines of different histogenetic origins. These cell lines show an ATP-dependent drug accumulation defect, suggesting the presence of drug transporter molecules different from P-glycoprotein. Immunohistochemical staining with a p110-specific monoclonal antibody (LRP-56) showed that, like P-glycoprotein, the molecule has a high expression in normal epithelial cells and tissues chronically exposed to xenobiotics and potentially toxic agents, such as bronchial cells, cells lining the intestines, and kidney tubules. Staining of LRP-56 is primarily cytoplasmic, in a coarsely granular fashion, indicating that it reacts with a molecule closely associated with vesicular/lysosomal structures. Involvement of p110 in the energy-dependent drug transport process present in the cell lines is unknown.

Prostaglandin E2 differentially modulates cytokine secretion profiles of human T helper lymphocytes.

Abstract: PGE2 is a well known immunomodulator that has multiple effects on the immune system We demonstrate that PGE2 selectively and dose dependently inhibits IL-2 and IFN-gamma production by mitogenically stimulated human PBL and CD4+ TLC, although at low concentrations IL-4 production is not affected and IL-5 production is even up-regulated In the tested TLC, PGE2 induced a dramatic elevation (up to 85-fold) of the intracellular cAMP levels The action of PGE2 may, therefore, be associated with elevation of intracellular cAMP levels, affecting IL-4 and IL-5 differentially from IL-2 and IFN-gamma production To test this hypothesis we investigated cytokine production by TLC in the absence or presence of agents that affect cAMP levels, either directly (2'-O-dibutyrylcAMP) or through activation of adenylate cyclase (forskolin) or by blocking of phosphodiesterase (3-isobutyl-1-methyl-xanthine) Similar to PGE2, forskolin, 2'-O-dibutyrylcAMP, and 3-isobutyl-1-methyl-xanthine induced inhibition of IL-2 production by TLC and up-regulation of IL-5 production However, in contrast to PGE2, these agents suppressed IL-4 production although IFN-gamma production was only moderately affected No significant differences were found between intracellular cAMP levels of mitogenically stimulated Th1 cell clones, which predominantly secrete IL-2 and IFN-gamma, and those of Th2 cell clones, which mainly secrete IL-4 and IL-5 Our results indicate that PGE2 selectively modulates cytokine secretion profiles of human T cells and that elevation of cAMP levels has an important, but possibly not exclusive, regulatory role in this phenomenon

Reconstructing Argumentative Discourse

Abstract: Reconstructing Argumentative Discourse analyzes argumentation in ordinary disputes. The analysis begins with an ideal model: a theoretical structure of discourse that might be used to resolve a dispute about the merits of two opposing cases. The ideal model does not describe actual argumentative practice. Argumentative discourse does not always seek genuine resolution and, when it does, the participants may not perform as ideal arguers. A central challenge for argumentation theory is to give an account of argumentation occurring under less-than-ideal conditions and conducted by less-than-ideal participants. The authors offer detailed analysis of argument in such contexts as ordinary conversation, third party dispute mediation, and religious confrontation. An adequate analytic approach to such forms of discourse, the authors argue, must offer critical insight into actual practice; must begin with a defensible normative standard against which practice can be compared; and must also offer an applicable analytic machinery for making the comparison, so its methods can be tailored to empirical circumstances. The authors position their study of argumentation within a general 'normative pragmatics' characterized by a dual commitment to usefulness and adequacy in description. A distinctive set of practical applications and a distinctive view of practicality follow from this approach, characterized not by the search for generalizable means-end relationships but by the development and testing of plans for making real argumentation look as much as possible like ideal argumentation. This book integrates for the first time the normative interest of dialectical theories of argumentation with the descriptive interests of the empirical study of everyday language use. This ambitious project is achieved by adopting a distinctively social and pragmatic view of argumentation - by seeing argumentation as a language activity structured for the function of resolving disagreements. The authors examine argumentation in a wide variety of contexts - including everyday conversation, campus evangelism, political speeches, newspaper letters to the editor, and the formal mediation of disputes. In doing so, they illustrate how to analyze the details of actual argumentation and tackle a variety of theoretical and methodological puzzles encountered in the effort to apply normative models to real life argumentation.

Smoking and risk of Graves' disease.

Abstract: Objective. —To assess if smoking is associated with Graves' disease and, if so, to ascertain whether this association persists when controlling for confounding factors. Design. —Consecutive entry case-control study with two age- and sex-matched control subjects from two different populations per case patient. Setting. —University hospital. Patients. —Five groups were studied: (1) Graves' ophthalmopathy and Graves' hyperthyroidism (n=100; divided in four subgroups according to the severity of the eye disease); (2) Graves' hyperthyroidism without clinical eye involvement (n=100); (3) sporadic nontoxic goiter (n=100); (4) autoimmune hypothyroidism (n=75); and (5) toxic nodular goiter (n=75). The study comprised 200 subjects from a hospitalbased population, and 200 from a population-based group served as control subjects. Main Outcome Measure. —Smoking status was determined from a questionnaire at the time of onset of the disease to exclude any effect of the disease itself on smoking. Results. —Smoking greatly increased the risk for Graves' ophthalmopathy (odds ratio, 7.7; 95% confidence interval, 4.3 to 13.7), but patients with Graves' hyperthyroidism alone were also more often smokers than control subjects (odds ratio, 1.9; 95% confidence interval, 1.1 to 3.2). Smoking was not associated with the other thyroid diseases studied. Essentially similar results were obtained after adjustment for differences in education between case patients and control subjects. Among the patients with Graves' ophthalmopathy, smokers had more severe eye disease than nonsmokers, but no association was found between the number of cigarettes smoked per day or the duration of smoking and the severity of the ophthalmopathy. However, there was a significant increase in the odds ratios in patients with more severe eye disease. Conclusions. —Smoking is associated with Graves' disease, and it especially increases the risk for the development of more severe ophthalmopathy. Thus, smoking appears to be one of the multiple factors inducing Graves' disease in genetically predisposed individuals. ( JAMA . 1993;269:479-482)

The eubacterium Ectothiorhodospira halophila is negatively phototactic, with a wavelength dependence that fits the absorption spectrum of the photoactive yellow protein.

Abstract: The motile, alkalophilic, and extremely halophilic purple sulfur bacterium Ectothiorhodospira halophila is positively photophobotactic. This response results in the accumulation of bacteria in light spots (E. Hustede, M. Liebergesell, and H. G. Schlegel, Photochem. Photobiol. 50:809-815, 1989; D. E. McRee, J. A. Tainer, T. E. Meyer, J. Van Beeumen, M. A. Cusanovich, and E. D. Getzoff, Proc. Natl. Acad. Sci. USA 86:6533-6537, 1989; also, this work). In this study, we demonstrated that E. halophila is also negatively phototactic. Video analysis of free-swimming bacteria and the formation of cell distribution patterns as a result of light-color boundaries in an anaerobic suspension of cells revealed the existence of a repellent response toward intense (but nondamaging) blue light. In the presence of saturating background photosynthetic light, an increase in the intensity of blue light induced directional switches, whereas a decrease in intense blue light gave rise to suppression of these reversals. To our knowledge, this is the first report of a true repellent response to light in a free-swimming eubacterium, since the blue light response in Escherichia coli and Salmonella typhimurium (B. L. Taylor and D. E. Koshland, Jr., J. Bacteriol. 123:557-569, 1975), which requires an extremely high light intensity, is unlikely to be a sensory process. The wavelength dependence of this negative photoresponse was determined with narrow band pass interference filters. It showed similarity to the absorption spectrum of the photoactive yellow protein from E. halophila. Images

A retrospective look at PD projects

Abstract: W h i l e m o d e r n m e t h o d s f o r i n f o r m a t i o n s y s t e m d e v e l o p m e n t g e n e r a l l y a c c e p t t h a t u s e r s s h o u l d b e i n v o l v e d in s o m e w a y [15], t h e f o r m o f t h e i n v o l v e m e n t d i f f e r s c o n s i d e r a b l y . M o s t l y , u s e r s a r e v i e w e d a s r e l a t i v e l y p a s s i v e s o u r c e s o f i n f o r m a t i o n , a n d t h e i n v o l v e m e n t is r e g a r d e d a s \" f u n c t i o n a l , \" in t h e s e n s e t h a t i t s h o u l d y i e l d b e t t e r s y s t e m r e q u i r e m e n t s a n d i n c r e a s e d a c c e p t a n c e b y u s e r s .

A Comparison of Real-Time Compression Ultrasonography with Impedance Plethysmography for the Diagnosis of Deep-Vein Thrombosis in Symptomatic Outpatients

Abstract: Background Impedance plethysmography performed serially over a one-week period has been shown to be an effective diagnostic strategy for patients with clinically suspected acute deep-vein thrombosis. Compression ultrasonography has a high sensitivity and specificity for the detection of proximal-vein thrombosis. The clinical value of repeated ultrasonography in the management of symptomatic deep-vein thrombosis is unknown. Methods We conducted a randomized trial in 985 consecutive outpatients with clinically suspected deep-vein thrombosis to compare the diagnostic value of serial impedance plethysmography (494 patients) and serial compression ultrasonography (491 patients). We compared the positive predictive values of both tests for the diagnosis of venous thrombosis, using contrast venography as a reference. The frequencies of venous thromboembolism during a six-month follow-up period were also compared in patients with repeatedly normal results in order to evaluate the safety of withholding anticoagula...

Pathogenesis of disseminated intravascular coagulation in sepsis

Abstract: Objective. —To review new insights in the pathogenetic mechanisms involved in the development of disseminated intravascular coagulation (DIC) in septic patients, in order to develop new directions for therapeutic intervention. Data Sources. —Articles and published peer-reviewed abstracts on the mechanism of the initiation of DIC in sepsis. Study Selection. —Studies selected for detailed review were those reporting specifics about the mechanism of activation of coagulation and fibrinolysis in experimental human and animal models of sepsis. Data extraction guidelines for assessing data quality included validity of the model, quality of the laboratory assessment of activation of coagulation and fibrinolysis, and methodological considerations, such as the presence of control experiments and statistical analysis. Data Synthesis. —After the presence of endotoxin in the circulation, significant coagulation activation can be detected. This activation is preceded by an increase in the serum levels of various cytokines, such as tumor necrosis factor and interleukins. Inhibition of the increase in tumor necrosis factor results in inhibition of coagulation activation. Measurement of molecular markers for the activation of coagulation proteins at various levels indicates that the activation of coagulation is mediated by the tissue factor—dependent pathway, which is further confirmed by experiments in which the inhibition of the tissue factor—dependent pathway resulted in complete inhibition of coagulation activation. The activation of coagulation seems to be amplified by impaired function of the protein C—protein S inhibitory pathway. An imbalance between coagulation and fibrinolysis, ultimately leading to plasminogen activator inhibitor type 1—mediated inhibition of fibrinolysis, may further promote the procoagulant state. Conclusion. —The increased knowledge of the various pathogenetic mechanisms of coagulation activation and fibrinolysis in sepsis may have therapeutic implications; however, their efficacy needs to be assessed in appropriate clinical trials. (JAMA. 1993;270:975-979)

Activated human lymphocytes and aggressive non-Hodgkin's lymphomas express a homologue of the rat metastasis-associated variant of CD44

Abstract: A recently described splice variant of CD44 expressed in metastasizing cell lines of rat tumors, has been shown to confer metastatic potential to nonmetastasizing rat pancreatic carcinoma and sarcoma cell lines. Using antibodies raised against a bacterial fusion protein encoded by variant CD44 sequences, we have explored the expression of variant CD44 glycoproteins on human lymphoid cells and tissues and on non-Hodgkin's lymphomas. Normal lymphohematopoietic cells express barely detectable low levels of variant CD44 glycoproteins, whereas T lymphocytes, upon activation by mitogen or antigen, transiently upregulate expression of specific CD44 variant glycoproteins. The reaction pattern of various antibodies indicates that these CD44 variants contain the domain encoded by exon v6, which is part of the variant that in the rat confers metastatic capability. It is interesting that overexpression of v6 was also found in several aggressive, but not low-grade, non-Hodgkin's lymphomas.

Awareness and Recall during General Anesthesia: Facts and Feelings

Abstract: Background:Experiences of awareness and recall during general anesthesia can be most distressing for patients. To obtain relevant information, the authors systematically interviewed patients in whom awareness during surgery had occurred, and questioned them about their experiences.Methods:Twenty-six

Spectrum of primary cutaneous CD30 (Ki-1)-positive lymphoproliferative disorders: A proposal for classification and guidelines for management and treatment

Abstract: Primary cutaneous CD30 (Ki-1)-positive, large cell lymphomas (LCLs) represent a recently recognized group of cutaneous T-cell lymphomas with a favorable prognosis. The characteristic features of this cutaneous lymphoma are reviewed, differences with primary noncutaneous CD30+ LCLs emphasized, and its relation with other CD30+ cutaneous lymphoproliferative disorders, in particular lymphomatoid papulosis, is discussed. These primary cutaneous CD30+ LCLs, lymphomatoid papulosis, and related conditions represent a clinical and histologic continuum. A classification with practical guidelines for the management and treatment of patients within this spectrum of lymphoproliferative disorders is presented.