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Search Results: 1 - 10 of 401286 matches for " Benita Westerlund-Wikstr?m "
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The Role of the Bacterial Flagellum in Adhesion and Virulence
Johanna Haiko,Benita Westerlund-Wikstrm
Biology , 2013, DOI: 10.3390/biology2041242
Abstract: The bacterial flagellum is a complex apparatus assembled of more than 20 different proteins. The flagellar basal body traverses the cell wall, whereas the curved hook connects the basal body to the whip-like flagellar filament that protrudes several μm from the bacterial cell. The flagellum has traditionally been regarded only as a motility organelle, but more recently it has become evident that flagella have a number of other biological functions. The major subunit, flagellin or FliC, of the flagellum plays a well-documented role in innate immunity and as a dominant antigen of the adaptive immune response. Importantly, flagella have also been reported to function as adhesins. Whole flagella have been indicated as significant in bacterial adhesion to and invasion into host cells. In various pathogens, e.g., Escherichia coli, Pseudomonas aeruginosa and Clostridium difficile, flagellin and/or the distally located flagellar cap protein have been reported to function as adhesins. Recently, FliC of Shiga-toxigenic E. coli was shown to be involved in cellular invasion via lipid rafts. Here, we examine the latest or most important findings regarding flagellar adhesive and invasive properties, especially focusing on the flagellum as a potential virulence factor.
Molecular adaptation of a plant-bacterium outer membrane protease towards plague virulence factor Pla
Johanna Haiko, Liisa Laakkonen, Benita Westerlund-Wikstrm, Timo K Korhonen
BMC Evolutionary Biology , 2011, DOI: 10.1186/1471-2148-11-43
Abstract: Pla and Epo expressed in Escherichia coli are both functional endopeptidases and cleave human serine protease inhibitors, but Epo failed to activate plasminogen and to mediate invasion into a human endothelial-like cell line. Swapping of ten amino acid residues at two surface loops of Pla and Epo introduced plasminogen activation capacity in Epo and inactivated the function in Pla. We also compared the structure of Pla and the modeled structure of Epo to analyze the structural variations that could rationalize the different proteolytic activities. Epo-expressing bacteria managed to invade human cells only after all extramembranous residues that differ between Pla and Epo and the first transmembrane β-strand had been changed.We describe molecular adaptation of a protease from an environmental setting towards a virulence factor detrimental for humans. Our results stress the evolvability of bacterial β-barrel surface structures and the environment as a source of progenitor virulence molecules of human pathogens.Analyses of genomic sequences of bacterial pathogens have given an unprecedented view into their biology and evolutionary processes [1,2]. A conclusion from these studies is that highly similar genes, many of which are associated with bacterial virulence, are found across great phylogenetic distances and in different genetic elements, which is indicative of horizontal gene transfer. These families of virulence factors - including toxins, transport systems, adhesins, and antibiotic resistance factors - have evolved by adaptive radiation of a functional progenitor molecule to and within other strains and species to support survival in differing ecological niches [2]. The adaptation, or "evolutionary fine-tuning" of virulence factors that results in increased fitness, can involve modification of catalytic efficiency or substrate specificity of an enzyme, or alteration of bacterial interactions with target cells [2]. The mechanisms of horizontal gene transfer and th
Adhesive polypeptides of Staphylococcus aureus identified using a novel secretion library technique in Escherichia coli
Riikka Kylv?j?, Matti Kankainen, Liisa Holm, Benita Westerlund-Wikstrm
BMC Microbiology , 2011, DOI: 10.1186/1471-2180-11-117
Abstract: Randomly fragmented chromosomal DNA of S. aureus was cloned into a unique restriction site of our expression vector, which facilitates secretion of foreign FLAG-tagged polypeptides into the growth medium of E. coli ΔfliCΔfliD, to generate a library of 1663 clones expressing FLAG-tagged polypeptides. Sequence and bioinformatics analyses showed that in our example, the library covered approximately 32% of the S. aureus proteome. Polypeptides from the growth medium of the library clones were screened for binding to a selection of S. aureus target molecules and adhesive fragments of known staphylococcal adhesins (e.g coagulase and fibronectin-binding protein A) as well as polypeptides of novel function (e.g. a universal stress protein and phosphoribosylamino-imidazole carboxylase ATPase subunit) were detected. The results were further validated using purified His-tagged recombinant proteins of the corresponding fragments in enzyme-linked immunoassay and surface plasmon resonance analysis.A new technique for identification of unknown bacterial adhesive polypeptides was constructed. Application of the method on S. aureus allowed us to identify three known adhesins and in addition, five new polypeptides binding to human plasma and extracellular matrix proteins. The method, here used on S. aureus, is convenient due to the use of soluble proteins from the growth medium and can in principle be applied to any bacterial species of interest.Bacterial adhesive proteins, proteinaceous adhesins, are frequently the most critical factor at the onset of a bacterial infection [1-3]. The identification and characterization of such adhesins at the molecular level is therefore crucial for the detailed understanding of bacterial pathogenesis, for the design of vaccines and for the development of novel antibacterial drugs [4,5]. Although some bacterial adhesins have successfully been produced on a large scale and described in detail (for examples the reader is referred to recent reviews and
Two distinct regions in the model protein Peb1 are critical for its heterologous transport out of Escherichia coli
Lena Anton, Katariina Majander, Harri Savilahti, Liisa Laakkonen, Benita Westerlund-Wikstrm
Microbial Cell Factories , 2010, DOI: 10.1186/1475-2859-9-97
Abstract: When mature Peb1 was expressed without its SecA-YEG -dependent signal sequence and without the putative signal peptidase II recognition sequence in E. coli MKS111ΔHBB lacking the flagellar secretion complex, the protein was found in the periplasm and growth medium which indicated a flagellum-independent translocation. We assessed the Peb1 secretion proficiency by an exhaustive search for transport-affecting regions using a transposition-based scanning mutagenesis strategy. Strikingly, insertion mutagenesis of only two segments, called TAR1 (residues 42 and 43) and TAR2 (residues 173 to 180), prevented Peb1 secretion individually. We confirmed the importance of TAR regions by subsequent site-specific mutagenesis and verified that the secretion deficiency of Peb1 mutants was not due to insolubility or aggregation of the proteins in the cytoplasm. We found by cell fractionation that the mutant proteins were present in the periplasm as well as in the cytoplasm of MKS12. Hence, mutagenesis of TAR regions did not affect export of Peb1 across the cytoplasmic membrane, whereas its export over the outer membrane was markedly impaired.We propose that the localization of the model protein Peb1 in the growth medium of E. coli is due to active secretion by a still unknown pathway of E. coli. The secretion apparently is a two-step process involving a periplasmic step and the TAR regions.Protein secretion is one of the main means by which bacteria interact with their environment. The interaction may take place in a variety of manners: bacteria secrete enzymes, toxins and other virulence factors, excrete metabolic waste products, and export binding proteins into the periplasm for import of nutrients or export of toxic compounds. Bacteria also use different secretion systems to assemble on their surface organelles for motility, adhesion and injection of effector molecules into host cells [1,2]. Bacterial protein secretion systems are of great importance from a virulence-associated v
The healthcare environment—The importance of aesthetic surroundings: Health professionals’ experiences from a surgical ward in Finland  [PDF]
Britt-Maj Wikstrm, Emma Westerlund, Jaana Erkkil?
Open Journal of Nursing (OJN) , 2012, DOI: 10.4236/ojn.2012.23029
Abstract: There is a growing acceptance of the vital role patient centered design plays in shaping the environment. Art can be of use in every area of health care. It is within the power of each person to share and interpret experience by means of the arts, by viewing the work of others, and by using feelings and imagination. Health professionals [n = 24 of a total of n = 35], answered the Wheel Questionnaire test instrument. It measures structure, motivation/engagement, and degree of emotional investment in a situation. Participants were requested to describe, in their own words, their perception of the enrichment of the ward interiordesign and the double-sided photos with a short poetic text, and the photo-book placed at each patient room. The results demonstrate that participants are motivated, structured and emotionally engaged when describing the new enrichment. The domains and themes are: Social interaction domain; rising thoughts and conversations. Comfort domain; atmosphere. Aesthetic do main; enrichment of the working environment. It could be concluded that the surgical ward environmental enrichment stimulated conversations between health professionals and between health professionals and patients and should be regarded as an important aspect in hospital planning.
A visual art museum in Sweden as pedagogical scenery: Gibbs’ reflective cycle guiding student nurses in the reflective process  [PDF]
Britt-Maj Wikstrm
Open Journal of Nursing (OJN) , 2012, DOI: 10.4236/ojn.2012.22020
Abstract: The pedagogy employed in health care education must continually be questioned and expanded. Student nurses must be prepared for nursing practice that continually changes, consequently alternative concepts in nurse education must be considered. The aims were to provide student nurses with reflection skills and to evaluate the potential of studying the reflective process using visual art at a museum as an enriched activity in education. A pedagogical program with Gibbs’ reflection model was used as a complement. The study was conducted at a University College of Health Sciences in Sweden in collaboration with a visual art museum. Data were collected during a period of three years. A random sample (n = 35 of n = 98 students’ reports) was selected for qualitative analysis. The painting by George-Pierre Seurat, Seated woman was used as a source of inspiration. Analysis was conducted of the excerpts generated from the steps in Gibbs’ reflection model and from students’ evaluations of the teaching-learning structure. The results show that students were able to build hypothetical situations around the character depicted in the painting. They observed and described a great many aspects of the reflective process. The chosen painting was regarded as suitable for its purpose, and a source of inspiration. It could be interpreted as a patient you might meet in clinical practice. The students′ evaluations show that they became aware of knowledge they had not thought of before, and a way of taking a step closer to clinical practice. It could be concluded that art museum could be regarded as a stimulating environment that nurtured the reflective process. Consequently, visual art museums have to be considered as possible teaching learning milieus to be used in nurse education. It is to be hoped that this study will contribute to further development of visual art museums as teaching learning settings.
Healthy lifestyle for people with intellectual disabilities through a health intervention program  [PDF]
Bente Lorentzen, Britt-Maj Wikstrm
Open Journal of Nursing (OJN) , 2012, DOI: 10.4236/ojn.2012.23024
Abstract: There are well known gaps related to health care service and public health interventions for people with Intellectual Disabilities (ID), but there is still lack of research information of what nurses can do to reducing health disparities of persons with ID. The present study aimed at exploring the views of people with ID about a healthy lifestyle, exercise, and to take part in a health promotion program. A qualitative method was an appropriate method for capturing the informants’ points of view. Participants were adults with intellectual disability who would be able to give their consent verbally and in written form. Women (n = 7) and men (n = 6). Data were collected from focus group interviews and analysed according to a qualitative content analysis of the tape-recorded and verbatim transcribed interviews. The participants took part in four workshops about healthy food, and ten physical activities addressing the connection to physical, social and emotional health. The results of the focus group interviews show that participants have knowledge about the importance of a healthy lifestyle for good health including physical activity and healthy food. Participants also describe social interaction and self-determination as important aspects in their life. It could then be concluded that the health promotion program result point at consciousness about a healthy lifestyle. There is still lack of research information of what public health nurses can do to reducing health disparities of persons with ID. Public health nurses work in community-based services and therefore they also might support persons with ID through health intervention programs.
Surnames and Identities
Solveig Wikstrm
Oslo Studies in Language , 2012,
Abstract: This paper, based on a survey of 314 Oslo residents, investigates the relationship between surname and identity. The aim was to find out whether the modern individual experiences his or her surname as a part of his or her identity, and what bond exists between surname and locale. Late modern society typically reveals a fragmentation of individuals from family background and place of origin. A hypothesized outcome of this separation, envisages a further breach between the individual and the area their surname denotes. If one's surname is experienced as part of one's identity, what then is the main reason for this? Are there in fact different experiences of identity based on some typology of names borne by individuals?
Voluntary Work for Public Health—Older Volunteers’ Participation in a Norwegian Society —Motivation Factors for Participating—Enrich Life and Positive for Health  [PDF]
Bente Lorentzen, Britt-Maj Wikstrm, P?l Joranger
Open Journal of Nursing (OJN) , 2014, DOI: 10.4236/ojn.2014.411077
Abstract: Today there is a decreasing interest in contributing to general organizations. The purpose of this study is to examine participation in volunteer work in a municipality in Norway. The main focus is determinants of motivation factors for participation as well as non-participation. A first step was to conduct a focus group interview. The second step was to make questions for a survey based on the results of the focus group interview in order to provide an overall direction for the survey. A questionnaire was sent to six local organisations in a municipality in Norway. Analysis: Multivariate logistic and linearly regression analysis. Result: The total model was statistical significant, indicating that the model was able to distinguish between volunteers who reported to be respectively happy or not happy. The model explained 36% to 62% of the variance in this variable. The variables made a statistical significant contribution to the model. The strongest predictor of being happy was the variable “energy”. The variable “positive for my health” was the second strongest predictor. “Income” has a reverse association, meaning that the volunteers are less likely to be reported to be happy when their income increases. Network and illness explain years in voluntary work. Conclusion and implications for public health nurses: The present study shows the effectiveness of volunteering for elderly. Thus, it is an important element in public health nurses work to include strategies that focus on program stimulating elderly citizens in the municipality to stay healthy physically and psychologically.
Gender Differences in Hope and Its Relevance to Depression Symptoms among Norwegian Adolescents  [PDF]
Britt-Maj Wikstrm, Bente Lorentzen, Sindre Lorentzen
Open Journal of Nursing (OJN) , 2018, DOI: 10.4236/ojn.2018.82014
Abstract:

Introduction: Several studies indicate that the number of individuals experiencing depression symptoms is growing. There is a prevailing consensus in the literature that while depression is represented among both genders, it is consistently reported that females are more exposed to depression compared to males both in frequency and severity. Studies suggest that as many as 15 - 20 percent of adolescents in Norway exhibit depression or depression like symptoms. Furthermore, several studies indicate that the number of individuals experiencing depression symptoms is growing. There is a prevailing consensus in the literature that while depression is represented among both genders, it is consistently reported that females are more exposed to depression compared to males both in frequency and severity. Methods: All data utilized in this study were extracted from the Norwegian Ungdata survey conducted in 2014 among adolescents in Norway. The sample consists of 46,374 observations. Conclusions: The finding of significant differences in prevalence of self-diagnosed depression symptoms among Norwegian adolescents, showed females are more exposed. Furthermore, as hypothesized, there is a strong and significant relation between hope and depression, where hope is proxied through expectations regarding the individuals’ future education, happiness and wealth. Based on these findings, we apply hope as an instrument for addressing depression symptoms. Results from this analysis indicate that males are significantly less optimistic for the future.

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