Characterisation of the role of two two-component signal transduction systems and a putative zinc metalloprotease in the virulence of Streptococcus pneumoniae

This thesis aimed to evaluate the contribution of several pneumococcal two-component systems to virulence by analysis of null mutants in a murine model of infection. In addition, a putative zinc metalloprotease, ZmpB, located immediately downstream of one of the TCS, was analysed for its role in virulence. Data indicated that one of the systems studied, TCS08, does not contribute significantly to virulence in serotype 2 pneumococcus, but may have a slightly more important role in a serotype 3 background. A second two-component system, TCS09, was found to be essential for virulence in a serotype 2. Despite the completely avirulent phenotype of the mutant, no difference in expression of many of the previously identified pneumococcal virulence-associated genes was detected in the mutant compared to its isogenic parental strain. Microarray analysis indicated that in serotype 2, TCS09 may be involved in nutrient perception in nutrient perception. TCS09 was found to be required for full virulence in a serotype 3 strain. In this strain, mutants appeared to be impaired in their ability to disseminate from the lungs to the blood in a pneumonia model of infection, but were not attenuated in virulence following direct inoculation into the systemic circulation. These data provide evidence that virulence determinants can behave differently based on the genetic background of the parental strain. ZmpB was found to contribute significantly to pneumococcal virulence in a serotype 3 strain. Further analysis of the contribution of this protein to infection found that ZmpB appears to have a role in promoting inflammation. Thus this work has identified ZmpB as being a novel pneumococcal virulence factor. The role of this protein in inflammation is being investigated further. This thesis has thus identified several genes important in the virulence of S. pneumoniae and work is currently ongoing to assess the potential of these genes as future vaccine or drug candidates. Data presented within this work also provides evidence that virulence determinants can behave differently based on the genetic background of the parent bacterial strain. This important observation could have significant implication for the future characterisation of pneumococcal virulence factors and may apply to other bacterial pathogens

Invisible & Voiceless: Latinos in Council Bluffs Iowa

While Latino immigrant workers in Council Bluffs, Iowa have contributed significantly to the Iowa and Nebraska economies, they remain virtually invisible and lack a voice in the city’s key venues and institutions – this according to a new report being released by the University of Nebraska at Omaha (UNO) Office of Latino/Latin American Studies (OLLAS) and funded in part by the Iowa West Foundation. The report, titled “Invisible & Voiceless” combines data from the 2010 Census with 26 interviews with members of Council Bluffs’ civic, government, education, religious, non-profit and business communities as well as Latino voices gathered at interviews and a small number of Spanish-language workshops and focus groups

The cytosolic entry of diphtheria toxin catalytic domain requires a host cell cytosolic translocation factor complex

In vitro delivery of the diphtheria toxin catalytic (C) domain from the lumen of purified early endosomes to the external milieu requires the addition of both ATP and a cytosolic translocation factor (CTF) complex. Using the translocation of C-domain ADP-ribosyltransferase activity across the endosomal membrane as an assay, the CTF complex activity was 650–800-fold purified from human T cell and yeast extracts, respectively. The chaperonin heat shock protein (Hsp) 90 and thioredoxin reductase were identified by mass spectrometry sequencing in CTF complexes purified from both human T cell and yeast. Further analysis of the role played by these two proteins with specific inhibitors, both in the in vitro translocation assay and in intact cell toxicity assays, has demonstrated their essential role in the productive delivery of the C-domain from the lumen of early endosomes to the external milieu. These results confirm and extend earlier observations of diphtheria toxin C-domain unfolding and refolding that must occur before and after vesicle membrane translocation. In addition, results presented here demonstrate that thioredoxin reductase activity plays an essential role in the cytosolic release of the C-domain. Because analogous CTF complexes have been partially purified from mammalian and yeast cell extracts, results presented here suggest a common and fundamental mechanism for C-domain translocation across early endosomal membranes

Evidence-based Kernels: Fundamental Units of Behavioral Influence

This paper describes evidence-based kernels, fundamental units of behavioral influence that appear to underlie effective prevention and treatment for children, adults, and families. A kernel is a behavior–influence procedure shown through experimental analysis to affect a specific behavior and that is indivisible in the sense that removing any of its components would render it inert. Existing evidence shows that a variety of kernels can influence behavior in context, and some evidence suggests that frequent use or sufficient use of some kernels may produce longer lasting behavioral shifts. The analysis of kernels could contribute to an empirically based theory of behavioral influence, augment existing prevention or treatment efforts, facilitate the dissemination of effective prevention and treatment practices, clarify the active ingredients in existing interventions, and contribute to efficiently developing interventions that are more effective. Kernels involve one or more of the following mechanisms of behavior influence: reinforcement, altering antecedents, changing verbal relational responding, or changing physiological states directly. The paper describes 52 of these kernels, and details practical, theoretical, and research implications, including calling for a national database of kernels that influence human behavior

Contribution of a Response Regulator to the Virulence of Streptococcus pneumoniae Is Strain Dependent

Bacterial two-component signal transduction systems (TCS) enable bacteria to respond to environmental changes and regulate a range of genes accordingly. They have a crucial role in regulating many cellular responses and have excellent potential as antibacterial-drug targets. We have constructed mutations in a TCS response regulator gene for two different strains of the human pathogen Streptococcus pneumoniae. These mutants have been analyzed in our murine model of infection. Data suggest that in a D39 background the response regulator gene is essential for virulence; an isogenic mutant is avirulent via intraperitoneal, intranasal, and intravenous routes of infection. This mutant, which does not show impaired growth in vitro, is unable to grow in the lung tissue or in blood. Mutation of the response regulator in a 0100993 background results in a strain that is fully virulent intraperitoneally and intravenously but shows decreased levels of bacteremia and increased murine survival following intranasal infection. The ability to grow in the lung tissue is not impaired in this mutant, suggesting that it has an impaired ability to disseminate from the lungs to the systemic circulation. Our data highlight the importance of assessing the contribution of putative virulence factors to the infection process at different sites of infection and provide evidence that virulence determinants can behave very differently based on the genetic background of the bacterial strain. These important findings may be relevant to other bacterial pathogens

Regulation of gene expression in Streptococcus pneumoniae by response regulator 09 is strain dependent

Recent murine studies have demonstrated that the role of response regulator 09 (RR09) of Streptococcus pneumoniae in virulence is different in different strains. In the present study, we used a murine pneumonia model of infection to assess the virulence of a TIGR4 rr09 mutant, and we found that TIGR4 Delta rr09 was attenuated after intranasal infection. Furthermore, we investigated the in vitro transcriptional changes in pneumococcal rr09 mutants of two strains, D39 and TIGR4, by microarray analysis. The transcriptional profiles of the rr09 mutants of both strains had clear differences compared to the profiles of the parental wild-type strains. In D39 Delta rr09, but not in TIGR4 Delta rr09, genes involved in competence (e.g., comAB) were upregulated. In TIGR4, genes located on the rlrA pathogenicity islet, which are not present in the D39 genome, appeared to be regulated by RR09. Furthermore, several phosphotransferase systems (PTSs) believed to be involved in sugar uptake (e.g., the PTS encoded by sp0060 to sp0066) were strongly downregulated in D39 Delta rr09, while they were not regulated by RR09 in TIGR4. To examine the role of one of these PTSs in virulence, D39 Delta sp0063 was constructed and tested in a murine infection model. No difference between the virulence of this strain and the virulence of the wild type was found, indicating that downregulation of the sp0063 gene alone is not the cause of the avirulent phenotype of D39 Delta rr09. Finally, expression of rr09 and expression of three of our identified RR09 targets during infection in mice were assessed. This in vivo experiment confirmed that there were differences between expression in wild-type strain TIGR4 and expression in the rr09 mutant, as well as differences between expression in wild-type strain D39 and expression in wild-type strain TIGR4. In conclusion, our results indicate that there is strain-specific regulation of pneumococcal gene expression by RR09

Telemedicine in the Era of Coronavirus Disease 2019 (COVID-19): A Neurosurgical Perspective

Despite the substantial growth of telemedicine and the evidence of its advantages, the use of telemedicine in neurosurgery has been limited. Barriers have included medicolegal issues surrounding provider reimbursement, interstate licensure, and malpractice liability as well as technological challenges. Recently, the coronavirus disease 2019 (COVID-19) pandemic has limited typical evaluation of patients with neurologic issues and resulted in a surge in demand for virtual medical visits. Meanwhile, federal and state governments took action to facilitate the rapid implementation of telehealth programs, placing a temporary lift on medicolegal barriers that had previously limited its expansion. This created a unique opportunity for widespread telehealth use to meet the surge in demand for remote medical care. After initial hurdles and challenges, our experience with telemedicine in neurosurgery at Penn Medicine has been overall positive from both the provider and the patients\u27 perspective. One of the unique challenges we face is guiding patients to appropriately set up devices in a way that enables an effective neuroexamination. However, we argue that an accurate and comprehensive neurologic examination can be conducted through a telemedicine platform, despite minor weaknesses inherent to absence of physical presence. In addition, certain neurosurgical visits such as postoperative checks, vascular pathology, and brain tumors inherently lend themselves to easier evaluation through telehealth visits. In the era of COVID-19 and beyond, telemedicine remains a promising and effective approach to continue neurologic patient care

An Interdisciplinary Approach to the Urban Streetscape of Budapest's Andrassy Ut

As Budapest's most prominent boulevard, Andrassy Ut (Andrassy Way) exhibits a variety of urban land uses designed to showcase Hungarian history and culture and provide modern housing and leisure amenities for the city's elite. Designed and constructed in the 1870s, it is anchored in by Erzsebet tor (Erzsebet Square) in the city center and extends 2.42 km (1.5 mi) northeast to Varosliget (City Park). This study, conducted in summer 2014 by students in UW-Eau Claire's interdisciplinary Central European Travel Seminar (CETS), examined the cultural streetscape of the boulevard through the lens of geography, history, and music. Teams of researchers were dispatched to designated stretches of Andrassy Ut to document the ways in which historically and musically significant buildings and institutions coincide with high-end residential and commercial land uses. Landscape analysis was then utilized to document concentrations of specific types of land uses. As the city embarks on a massive redevelopment project that will convert Andrassy Ut from mixed use corridor into the tourism-focused Andrassy Quarter, this study marks an important transition period in the boulevard's history