116 research outputs found
Comprehensive analysis of type 1 fimbriae regulation in fimB -null strains from the multidrug resistant Escherichia coli ST131 clone
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Uropathogenic Escherichia coli (UPEC) of sequence type 131 (ST131) are a pandemic multidrug resistant clone associated with urinary tract and bloodstream infections. Type 1 fimbriae, a major UPEC virulence factor, are essential for ST131 bladder colonization. The globally dominant sub-lineage of ST131 strains, clade C/H30-R, possess an ISEc55 insertion in the fimB gene that controls phase-variable type 1 fimbriae expression via the invertible fimS promoter. We report that inactivation of fimB in these strains causes altered regulation of type 1 fimbriae expression. Using a novel read-mapping approach based on Illumina sequencing, we demonstrate that ‘off’ to ‘on’ fimS inversion is reduced in these strains and controlled by recombinases encoded by the fimE and fimX genes. Unlike typical UPEC strains, the nucleoid-associated H-NS protein does not strongly repress fimE transcription in clade C ST131 strains. Using a genetic screen to identify novel regulators of fimE and fimX in the clade C ST131 strain EC958, we defined a new role for the guaB gene in the regulation of type 1 fimbriae and in colonisation of the mouse bladder. Our results provide a comprehensive analysis of type 1 fimbriae regulation in ST131, and highlight important differences in its control compared to non-ST131 UPEC
Patients’ perceptions and experiences of living with a surgical wound healing by secondary intention : a qualitative study
Background: Most surgical wounds heal by primary intention, that is to say, the edges of the wound are brought together with sutures, staples, adhesive glue or clips. However, some wounds may be left open to heal (if there is a risk of infection, or if there has been significant tissue loss), and are known as ‘surgical wounds healing by secondary intention’. They are estimated to comprise approximately 28% of all surgical wounds and are frequently complex to manage. However, they are under researched and little is known of their impact on patients’ lives. Objectives: To explore patients’ views and experiences of living with a surgical wound healing by secondary intention. Design: A qualitative, descriptive approach. Settings: Participants were recruited from acute and community nursing services in two locations in the North of England characterised by high levels of deprivation and diverse populations. Participants: Participants were aged 18 years or older and had at least one surgical wound healing by secondary intention, which was slow to heal. Purposeful sampling was used to include patients of different gender, age, wound duration and type of surgery (general, vascular and orthopaedic). Twenty people were interviewed between January and July 2012. 2 Methods: Semi-structured interviews were conducted, guided by use of a topic guide developed with input from patient advisors. Data were thematically analysed using steps integral to the ‘Framework’ approach to analysis, including familiarisation with data; development of a coding scheme; coding, charting and cross comparison of data; interpretation of identified themes. Findings: Alarm, shock and disbelief were frequently expressed initial reactions, particularly to “unexpected” surgical wounds healing by secondary intention. Wound associated factors almost universally had a profound negative impact on daily life, physical and psychosocial functioning, and wellbeing. Feelings of frustration, powerlessness and guilt were common and debilitating. Patients’ hopes for healing were often unrealistic, posing challenges for the clinicians caring for them. Participants expressed dissatisfaction with a perceived lack of continuity and consistency of care in relation to wound management. Conclusions: Surgical wounds healing by secondary intention can have a devastating effect on patients, both physical and psychosocial. Repercussions for patients’ family members can also be extremely detrimental, including financial pressures. Health care professionals involved in the care of patients with these wounds face multiple, complex challenges, compounded by the limited evidence base regarding cost-effectiveness of different treatment regimens for these types of wounds
Detection of myxoma viruses encoding a defective M135R gene from clinical cases of myxomatosis; possible implications for the role of the M135R protein as a virulence factor
<p>Abstract</p> <p>Background</p> <p>Myxoma virus is a member of the <it>Poxviridae </it>and causes disease in European rabbits. Laboratory confirmation of the clinical disease, which occurs in the autumn of most years in Denmark, has been achieved previously using antigen ELISA and electron microscopy.</p> <p>Results</p> <p>An unusually large number of clinically suspected cases of myxomatosis were observed in Denmark during 2007. Myxoma virus DNA was detected, using a new real time PCR assay which targets the M029L gene, in over 70% of the clinical samples submitted for laboratory confirmation. Unexpectedly, further analysis revealed that a high proportion of these viral DNA preparations contained a frame-shift mutation within the M135R gene that has previously been identified as a virulence factor. This frame-shift mutation results in expression of a greatly truncated product. The same frame-shift mutation has also been found recently within an avirulent strain of myxoma virus (6918). However, three other frame-shift mutations found in this strain (in the genes M009L, M036L and M148R) were not shared with the Danish viruses but a single nucleotide deletion in the M138R/M139R intergenic region was a common feature.</p> <p>Conclusions</p> <p>It appears that expression of the full-length myxoma virus M135R protein is not required for virulence in rabbits. Hence, the frame-shift mutation in the M135R gene in the nonpathogenic 6918 virus strain is not sufficient to explain the attenuation of this myxoma virus but one/some of the other frame-shift mutations alone or in conjunction with one/some of the thirty two amino acid substitutions must also contribute. The real time PCR assay for myxoma virus is a useful diagnostic tool for laboratory confirmation of suspected cases of myxomatosis.</p
Identification and Specification of the Mouse Skeletal Stem Cell
SummaryHow are skeletal tissues derived from skeletal stem cells? Here, we map bone, cartilage, and stromal development from a population of highly pure, postnatal skeletal stem cells (mouse skeletal stem cells, mSSCs) to their downstream progenitors of bone, cartilage, and stromal tissue. We then investigated the transcriptome of the stem/progenitor cells for unique gene-expression patterns that would indicate potential regulators of mSSC lineage commitment. We demonstrate that mSSC niche factors can be potent inducers of osteogenesis, and several specific combinations of recombinant mSSC niche factors can activate mSSC genetic programs in situ, even in nonskeletal tissues, resulting in de novo formation of cartilage or bone and bone marrow stroma. Inducing mSSC formation with soluble factors and subsequently regulating the mSSC niche to specify its differentiation toward bone, cartilage, or stromal cells could represent a paradigm shift in the therapeutic regeneration of skeletal tissues
Third-generation cephalosporin resistance conferred by a chromosomally encoded blaCMY-23 gene in the Escherichia coli ST131 reference strain EC958
Objectives: Escherichia coli ST131 is a globally disseminated MDR clone originally identified due to its association with the bla(CTX-M-15) gene encoding an ESBL. It is thus assumed that bla(CTX-M-15) is the major determinant for resistance to beta-lactam antibiotics in this clone. The complete sequence of EC958, a reference strain for E. coli ST131, revealed that it contains a chromosomally located bla(CMY-23) gene with an upstream ISEcp1 element as well as several additional plasmid-encoded beta-lactamase genes. Here, we examined the genetic context of the bla(CMY-23) element in EC958 and other E. coli ST131 strains and investigated the contribution of bla(CMY-23) to EC958 resistance to a range of beta-lactam antibiotics
Clinical relevance of ErbB-2/HER2 nuclear expression in breast cancer
<p>Abstract</p> <p>Background</p> <p>The biological relevance of nuclear ErbB-2/HER2 (NuclErbB-2) presence in breast tumors remains unexplored. In this study we assessed the clinical significance of ErbB-2 nuclear localization in primary invasive breast cancer. The reporting recommendations for tumor marker prognostic studies (REMARK) guidelines were used as reference.</p> <p>Methods</p> <p>Tissue microarrays from a cohort of 273 primary invasive breast carcinomas from women living in Chile, a Latin American country, were examined for membrane (MembErbB-2) and NuclErbB-2 expression by an immunofluorescence (IF) protocol we developed. ErbB-2 expression was also evaluated by immunohistochemistry (IHC) with a series of antibodies. Correlation between NuclErbB-2 and MembErbB-2, and between NuclErbB-2 and clinicopathological characteristics of tumors was studied. The prognostic value of NuclErbB-2 in overall survival (OS) was evaluated using Kaplan-Meier method, and Cox model was used to explore NuclErbB-2 as independent prognostic factor for OS.</p> <p>Results</p> <p>The IF protocol we developed showed significantly higher sensitivity for detection of NuclErbB-2 than IHC procedures, while its specificity and sensitivity to detect MembErbB-2 were comparable to those of IHC procedures. We found 33.6% NuclErbB-2 positivity, 14.2% MembErbB-2 overexpression by IF, and 13.0% MembErbB-2 prevalence by IHC in our cohort. We identified NuclErbB-2 positivity as a significant independent predictor of worse OS in patients with MembErbB-2 overexpression. NuclErbB-2 was also a biomarker of lower OS in tumors that overexpress MembErbB-2 and lack steroid hormone receptors.</p> <p>Conclusions</p> <p>We revealed a novel role for NuclErbB-2 as an independent prognostic factor of poor clinical outcome in MembErbB-2-positive breast tumors. Our work indicates that patients presenting NuclErbB-2 may need new therapeutic strategies involving specific blockage of ErbB-2 nuclear migration.</p
Environmental sustainability assessment of ready-made baby foods: Meals, menus and diets
Although there is a growing body of literature on the environmental impacts of food, virtually none of the studies has addressed baby foods. Therefore, this work explored the life cycle environmental impacts of different ready-made baby foods, both at the level of individual meals and their combinations within a weekly menu. Twelve different meals were considered, based on baby food products available on the UK market, spanning breakfast, lunch and dessert. Menus following four different diets – omnivorous, vegetarian, pescatarian and dairy-free – were also evaluated. The results showed that, on average, lunch meals had the highest impacts and desserts the lowest. Breakfast has either intermediate (wet porridge) or low (dry porridge) impacts. Among the lunch meals, spaghetti Bolognese and salmon risotto had the highest impacts and among the desserts, strawberry, raspberry and banana as well as apple, pear and banana purees had the lowest. The key hotspots across the meals were raw materials and packaging. Meals with more meat and cream were found to have higher impacts. Manufacturing also played a significant role for global warming potential as well as depletion of fossil resources and the ozone layer due to the fossil fuels used in the process. When the impacts were analysed per mass of baby food consumed weekly, the dairy-free diet had higher impacts than the other three, but the difference among them was relatively small. The trends changed when nutritional value was taken into account, with the dairy-free diet exhibiting considerably higher impacts per unit of energy content. In that case, the pescatarian diet became the best option for most impacts. There was little difference between the omnivore and vegetarian diets. It is expected that these results will be of interest to baby food manufacturers and consumers, helping them to make more informed manufacturing and purchasing decisions
Guideline for Care of Patients with the Diagnoses of Craniosynostosis: Working Group on Craniosynostosis
This guideline for care of children with craniosynostosis was developed by a national working group with representatives of 11 matrix societies of specialties and the national patients' society. All medical aspects of care for nonsyndromic and syndromic craniosynostosis are included, as well as the social and psychologic impact for the patient and their parents. Managerial aspects are incorporated as well, such as organizing a timely referral to the craniofacial center, requirements for a dedicated craniofacial center, and centralization of this specialized care. The conclusions and recommendations within this document are founded on the available literature, with a grading of the level of evidence, thereby highlighting the areas of care that are in need of high-quality research. The development of this guideline was made possible by an educational grant of the Dutch Order of Medical Specialists. The development of this guideline was supported by an educational grant of the Dutch Order of Medical Specialists
Effects of fluoxetine on functional outcomes after acute stroke (FOCUS): a pragmatic, double-blind, randomised, controlled trial
Background
Results of small trials indicate that fluoxetine might improve functional outcomes after stroke. The FOCUS trial aimed to provide a precise estimate of these effects.
Methods
FOCUS was a pragmatic, multicentre, parallel group, double-blind, randomised, placebo-controlled trial done at 103 hospitals in the UK. Patients were eligible if they were aged 18 years or older, had a clinical stroke diagnosis, were enrolled and randomly assigned between 2 days and 15 days after onset, and had focal neurological deficits. Patients were randomly allocated fluoxetine 20 mg or matching placebo orally once daily for 6 months via a web-based system by use of a minimisation algorithm. The primary outcome was functional status, measured with the modified Rankin Scale (mRS), at 6 months. Patients, carers, health-care staff, and the trial team were masked to treatment allocation. Functional status was assessed at 6 months and 12 months after randomisation. Patients were analysed according to their treatment allocation. This trial is registered with the ISRCTN registry, number ISRCTN83290762.
Findings
Between Sept 10, 2012, and March 31, 2017, 3127 patients were recruited. 1564 patients were allocated fluoxetine and 1563 allocated placebo. mRS data at 6 months were available for 1553 (99·3%) patients in each treatment group. The distribution across mRS categories at 6 months was similar in the fluoxetine and placebo groups (common odds ratio adjusted for minimisation variables 0·951 [95% CI 0·839–1·079]; p=0·439). Patients allocated fluoxetine were less likely than those allocated placebo to develop new depression by 6 months (210 [13·43%] patients vs 269 [17·21%]; difference 3·78% [95% CI 1·26–6·30]; p=0·0033), but they had more bone fractures (45 [2·88%] vs 23 [1·47%]; difference 1·41% [95% CI 0·38–2·43]; p=0·0070). There were no significant differences in any other event at 6 or 12 months.
Interpretation
Fluoxetine 20 mg given daily for 6 months after acute stroke does not seem to improve functional outcomes. Although the treatment reduced the occurrence of depression, it increased the frequency of bone fractures. These results do not support the routine use of fluoxetine either for the prevention of post-stroke depression or to promote recovery of function.
Funding
UK Stroke Association and NIHR Health Technology Assessment Programme
The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance
INTRODUCTION
Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic.
RATIONALE
We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs).
RESULTS
Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants.
CONCLUSION
Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century
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