91 research outputs found
Extensive Genomic Diversity among Bovine-Adapted Staphylococcus aureus: Evidence for a Genomic Rearrangement within CC97
peer-reviewedStaphylococcus aureus is an important pathogen associated with both human and veterinary disease and is a common cause of bovine mastitis. Genomic heterogeneity exists between S. aureus strains and has been implicated in the adaptation of specific strains to colonise particular mammalian hosts. Knowledge of the factors required for host specificity and virulence is important for understanding the pathogenesis and management of S. aureus mastitis. In this study, a panel of mastitis-associated S. aureus isolates (n = 126) was tested for resistance to antibiotics commonly used to treat mastitis. Over half of the isolates (52%) demonstrated resistance to penicillin and ampicillin but all were susceptible to the other antibiotics tested. S. aureus isolates were further examined for their clonal diversity by Multi-Locus Sequence Typing (MLST). In total, 18 different sequence types (STs) were identified and eBURST analysis demonstrated that the majority of isolates grouped into clonal complexes CC97, CC151 or sequence type (ST) 136. Analysis of the role of recombination events in determining S. aureus population structure determined that ST diversification through nucleotide substitutions were more likely to be due to recombination compared to point mutation, with regions of the genome possibly acting as recombination hotspots. DNA microarray analysis revealed a large number of differences amongst S. aureus STs in their variable genome content, including genes associated with capsule and biofilm formation and adhesion factors. Finally, evidence for a genomic arrangement was observed within isolates from CC97 with the ST71-like subgroup showing evidence of an IS431 insertion element having replaced approximately 30 kb of DNA including the ica operon and histidine biosynthesis genes, resulting in histidine auxotrophy. This genomic rearrangement may be responsible for the diversification of ST71 into an emerging bovine adapted subgroup
Prevalence of pathogens causing subclinical mastitis in 15 dairy herds in the Republic of Ireland
<p/> <p>Milk samples from 285 cows in 15 dairy herds were collected for bacteriological analysis. Cows were selected on the basis of a somatic cell count (SCC) exceeding 200,000 cells per ml at the three most recent milk recordings prior to sampling. <it>Staphylococcus aureus </it>and <it>Streptococcus uberis </it>were the predominant isolates accounting for 21% (n = 61) and 19% (n = 53) of isolates, respectively. <it>Streptococcus uberis </it>was more frequently isolated from split-calving herds than from spring-calving herds and this difference was statistically significant (P < 0.005). Herds with suboptimal housing had a significantly greater prevalence of <it>S. uberis </it>than did herds where housing was adequate (P < 0.005). The isolation rates for <it>S. aureus </it>was significantly greater in herds where parlour hygiene was suboptimal (P < 0.05).</p
Crazy Rich Asians: A tale of immigration, globalization and consumption in East Asia
We review the 2018 film Crazy Rich Asians in order to highlight its relevance for debates on immigration, globalization and consumption. In doing so, we argue that a new model of immigration for East Asians, distant and distinct from the American Dream, a âpull yourself up by the bootstrapsâ narrative infused with an Asian ethic, is being valorized in the film. We also illuminate the complexities of East Asian representation on screen, as evidenced by varying receptions to the film in America and in various regions of Asia. And, finally, we note that while the film celebrates excess in consumption on the surface, in the film, critiques of this orientation are manifest as well. Overall, we see the film to be a harbinger of new frontiers in global blockbusters, ushering in an era where the values depicted on screen are no longer solely dominated by an American orientation
Through the Looking Glass: Visualizing Leukemia Growth, Migration, and Engraftment Using Fluorescent Transgenic Zebrafish
Zebrafish have emerged as a powerful model of development and cancer. Human, mouse, and zebrafish malignancies exhibit striking histopathologic and molecular similarities, underscoring the remarkable conservation of genetic pathways required to induce cancer. Zebrafish are uniquely suited for large-scale studies in which hundreds of animals can be used to investigate cancer processes. Moreover, zebrafish are small in size, optically clear during development, and amenable to genetic manipulation. Facile transgenic approaches and new technologies in gene inactivation have provided much needed genomic resources to interrogate the function of specific oncogenic and tumor suppressor pathways in cancer. This manuscript focuses on the unique attribute of labeling leukemia cells with fluorescent proteins and directly visualizing cancer processes in vivo including tumor growth, dissemination, and intravasation into the vasculature. We will also discuss the use of fluorescent transgenic approaches and cell transplantation to assess leukemia-propagating cell frequency and response to chemotherapy. Zebrafish Models of Leukemia Zebrafish models of hematological malignancies exhibit striking similarities with human and mouse disease Although characterized by increased circulating white blood counts, chronic leukemias are often much slower growing and take months or years to progress. Leukemias can be further subdivided based on the blood lineage in which cells have become transformed Zebrafish first emerged as a powerful genetic model of leukemia with the description of transgenic approaches in which cMYC was overexpressed in developing thymocytes Advances in Hematology Moreover, GFP+ thymocytes exhibited stereotypical homing to the nasal placode, periocular space, and kidney marrow when assessed by serial fluorescent imaging over days Many exciting new models of hematopoietic malignancy have been created including B-cell acute lymphoblastic leukemia (B-ALL), acute myeloid leukemia (AML), and myeloproliferative neoplasm Fluorescent Transgenic Approaches to Label Leukemia Cells Cell Transplantation Approaches to Visualize Tumor Cell Engraftment Investigators have utilized cell transplantation of fluorescently labeled cancer cells into sublethally irradiated adult zebrafish to assess tumorigenicity Cell Transplantation Approaches to Examine Tumor Cell Homing and Intravasation into Vessels Intravasation of cancer cells into the vasculature is a critical step in cancer progression, allowing the spread of tumor cells beyond the site of origin Fluorescence Imaging to Visualize Leukemia Responses to Drug Treatment and Gamma-Irradiation Fluorescence imaging of transplanted cancer cells can also be used to visualize response to chemotherapy and radiation. For example, the Revskoy group recently showed that GFP-labeled T-ALL cells could be serially transplanted into syngeneic strain larvae Cell Transplantation Approaches to Quantify Leukemia Propagating Cell Frequency and Aggression Leukemia-propagating cells (LPCs) have the capacity to produce all the other cell types contained within the leukemia, are responsible for continued tumor growth, and ultimately drive relapse. Investigators have used fluorescence-activated cell sorting (FACS) to identify unique cell populations and limiting dilution cell transplantation to assess if molecularly defined leukemia cells retain LPC activity in human disease. For example, in AML a rare CD34+, CD38â cell enriches for leukemia-propagating potential Conclusion and Challenges for the Future Zebrafish has fast emerged as a powerful model of leukemia. When coupled with fluorescent transgenic approaches and powerful imaging techniques, these models are uniquely positioned to uncover mechanisms driving tumor dissemination, progression, and relapse. Moreover, the use of multifluorescent transgenic animals will allow for labeling of tumor cell compartments similar to those defined in RASinduced rhabdomyosarcoma model
Coping With Traumatic Experience In Stephen Chboskyâs The Perks Of Being A Wallflower Novel (1999): Individual Psychology
This study investigates the trauma experienced by the main character in Stephen Chbosky's novel The Perks of Being a Wallflower. Individual psychology theory is used by researcher to analyze the data. The research analysis aims to investigate the symptoms of traumatic experience in the work, to describe the traumatic experiences of the main characters in the work, to examine the reasons the author addressing the issue of traumatic experience in the work. This research is qualitative research. The type of data from this research consists of two parts. The main data source is the novel The Perks of Being a Wallflower by Stephen Chbosky and supporting data sources include previous research, theses, online journals, websites that support the data, books related to this research, articles and other sources that are appropriate in conducting the analysis. The results are as follows: first there are three symptoms of trauma that Charlie experienced which includes re-experiencing, avoidance, and hyperarousal. Second, there are two factors that describe Charlie's coping strategies in dealing with traumatic experiences which include internal factors and external factors. The last, the reason the author addressing the issue of traumatic experiences is because he wants millennial to not feel alone in dealing with mental health or depression. Chbosky suggests finding someone to talk to about the problem you're having, such as a friend or boyfriend and girlfriend
What is the evidence-base for atopic eczema treatments? A summary of published randomised controlled trials
Atopic eczema (AE) is a common chronic inflammatory skin condition. Whilst many AE treatment options are available, the evidence to support their efficacy varies in depth and quality. In 2000, an NIHR HTA systematic review identified and evaluated existing randomised controlled trials (RCTs) of AE treatments. To ensure continuing utility, the NIHR commissioned an update to the review. Here, we present an overview of the updated report and key findings.
Systematic reviews and RCTs of AE treatments that included participants with AE (criteria based or diagnosed) were identified using: MEDLINE, EMBASE, CENTRAL, LILACS, AMED, CINAHL and Cochrane Skin Group Specialised Register (searched to August 31st 2013 (RCTs) and 31st December 2015 (systematic reviews)). Outcome measures included: symptoms, AE severity, quality-of-life, and adverse effects. Study quality was assessed using the Cochrane Collaboration risk of bias tool.
Of the 287 new RCTs identified, only 22 (8%) were judged to be low risk of bias. When combined with RCTs from the previous review (n= 254), we found âreasonable evidence of benefitâ for corticosteroids, calcineurin inhibitors, Atopiclairâą, ciclosporin, azathioprine, ultraviolet light and education programmes.
Interventions with reasonable evidence of âno benefitâ included some dietary interventions, ion exchange water softeners, multiple daily applications of topical corticosteroids and antibiotic-containing corticosteroids for non-infected AE. Many common treatments lack evidence of efficacy and warrant further evaluation.
The evidence base for AE is still hampered by poor trial design and reporting. The trials included in this review were used to establish the Global Resource of Eczema Trials (GREAT) Database
Clinical presentation and immune characteristics in first-lactation Holstein-Friesian cows following intramammary infection with genotypically distinct Staphylococcus aureus strains
peer-reviewedStaphylococcus aureus is an important cause of bovine mastitis, and intramammary infections caused by this pathogen are often characterized as mild, chronic, or persistent. The strains of Staph. aureus associated with mastitis belong to several distinct bovine-adapted bacterial lineages. Studies of host-pathogen interactions have demonstrated that significant differences exist between Staph. aureus strains and lineages in their ability to internalize and to elicit expression of chemokines and pro-inflammatory mediators in bovine cells in vitro. To determine the effect of bacterial strain on the response to intramammary infection in vivo, 14 disease-free, first-lactation cows were randomly allocated to 2 groups and challenged with Staph. aureus strain MOK023 (belonging to CC97) or MOK124 (belonging to CC151). Clinical signs of infection, as well as somatic cell count (SCC), bacterial load, IL-8 and IL-1ÎČ in milk, anti-Staph. aureus IgG in milk and serum, anti-Staph. aureus IgA in milk, and white blood cell populations in milk and blood were monitored for 30 d after the challenge. Cows infected with MOK023 generally developed subclinical mastitis, whereas cows infected with MOK124 generally developed clinical mastitis. Milk yield was reduced to a greater extent in response to infection with MOK124 compared with MOK023 in the first week of the study. Significantly higher SCC, IL-8, and IL-1ÎČ in milk as well as higher anti-Staph. aureus IgG and IgA in milk and anti-Staph. aureus IgG in serum were also observed in response to MOK124 compared with the response to MOK023. Higher proportions of neutrophils were observed in milk of animals infected with MOK124 than in animals infected with MOK023. Higher neutrophil concentration in blood was also observed in the MOK124 group compared with the MOK023 group. Overall, the results indicate that the outcome of mastitis mediated by Staph. aureus is strain dependent
Bovine milk somatic cell transcriptomic response to Staphylococcus aureus is dependent on strain genotype
peer-reviewedBackground
Mastitis is an economically important disease of dairy cows with Staphylococcus aureus a major cause worldwide. Challenge of Holstein-Friesian cows demonstrated that S. aureus strain MOK124, which belongs to Clonal Complex (CC)151, caused clinical mastitis, while strain MOK023, belonging to CC97, caused mild or subclinical mastitis. The aim of this study was to elucidate the molecular mechanisms of the host immune response utilising a transcriptomic approach. Milk somatic cells were collected from cows infected with either S. aureus MOK023 or MOK124 at 0, 24, 48, 72 and 168âh post-infection (hpi) and analysed for differentially expressed (DE) genes in response to each strain.
Results
In response to MOK023, 1278, 2278, 1986 and 1750 DE genes were found at 24, 48, 72 and 168 hpi, respectively, while 2293, 1979, 1428 and 1544 DE genes were found in response to MOK124 at those time points. Genes involved in milk production (CSN1, CSN10, CSN1S2, CSN2, a-LACTA and PRLR) were downregulated in response to both strains, with a more pronounced decrease in the MOK124 group. Immune response pathways such as NF-ÎșB and TNF signalling were overrepresented in response to both strains at 24 hpi. These immune pathways continued to be overrepresented in the MOK023 group at 48 and 72 hpi, while the Hippo signalling, extracellular matrix interaction (ECM) and tight junction pathways were overrepresented in the MOK124 group between 48 and 168 hpi. Cellular composition analysis demonstrated that a neutrophil response was predominant in response to MOK124, while M1 macrophages were the main milk cell type post-infection in the MOK023 group.
Conclusions
A switch from immune response pathways to pathways involved in maintaining the integrity of the epithelial cell layer was observed in the MOK124 group from 48 hpi, which coincided with the occurrence of clinical signs in the infected animals. The higher proportion of M1 macrophages in the MOK023 group and lack of substantial neutrophil recruitment in response to MOK023 may indicate immune evasion by this strain. The results of this study highlight that the somatic cell transcriptomic response to S. aureus is dependent on the genotype of the infecting strain
Scoping systematic review of treatments for eczema
Background: Eczema is a very common chronic inflammatory skin condition.Objectives: To update the National Institute for Health Research (NIHR) Health Technology Assessment (HTA) systematic review of treatments for atopic eczema, published in 2000, and to inform health-care professionals, commissioners and patients about key treatment developments and research gaps.Data sources: Electronic databases including MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Cochrane Skin Group Specialised Register, Latin American and Caribbean Health Sciences Literature (LILACS), Allied and Complementary Medicine Database (AMED) and Cumulative Index to Nursing and Allied Health Literature (CINAHL) were searched from the end of 2000 to 31 August 2013. Retrieved articles were used to identify further randomised controlled trials (RCTs).Review methods: Studies were filtered according to inclusion criteria and agreed by consensus in cases of uncertainty. Abstracts were excluded and non-English language papers were screened by international colleagues and data were extracted. Only RCTs of treatments for eczema were included, as other forms of evidence are associated with higher risks of bias. Inclusion criteria for studies included availability of data relevant to the therapeutic management of eczema; mention of randomisation; comparison of two or more treatments; and prospective data collection. Participants of all ages were included. Eczema diagnosis was determined by a clinician or according to published diagnostic criteria. The risk of bias was assessed using the Cochrane Collaboration risk-of-bias tool. We used a standardised approach to summarising the data and the assessment of risk of bias and we made a clear distinction between what the studies found and our own interpretation of study findings.Results: Of 7198 references screened, 287 new trials were identified spanning 92 treatments. Trial reporting was generally poor (randomisation method: 2% high, 36% low, 62% unclear risk of bias; allocation concealment: 3% high, 15% low, 82% unclear risk of bias; blinding of the intervention: 15% high, 28% low, 57% unclear risk of bias). Only 22 (8%) trials were considered to be at low risk of bias for all three criteria. There was reasonable evidence of benefit for the topical medications tacrolimus, pimecrolimus and various corticosteroids (with tacrolimus superior to pimecrolimus and corticosteroids) for both treatment and flare prevention; oral ciclosporin; oral azathioprine; narrow band ultraviolet B (UVB) light; Atopiclairâą and education. There was reasonable evidence to suggest no clinically useful benefit for twice-daily compared with once-daily topical corticosteroids; corticosteroids containing antibiotics for non-infected eczema; probiotics; evening primrose and borage oil; ion-exchange water softeners; protease inhibitor SRD441 (Serentis Ltd); furfuryl palmitate in emollient; cipamfylline cream; and Mycobacterium vaccae vaccine. Additional research evidence is needed for emollients, bath additives, antibacterials, specialist clothing and complementary and alternative therapies. There was no RCT evidence for topical corticosteroid dilution, impregnated bandages, soap avoidance, bathing frequency or allergy testing
PHF6 expression levels impact human hematopoietic stem cell differentiation
Transcriptional control of hematopoiesis involves complex regulatory networks and functional perturbations in one of these components often results in malignancies. Loss-of-function mutations in PHF6, encoding a presumed epigenetic regulator, have been primarily described in T cell acute lymphoblastic leukemia (T-ALL) and the first insights into its function in normal hematopoiesis only recently emerged from mouse modeling experiments. Here, we investigated the role of PHF6 in human blood cell development by performing knockdown studies in cord blood and thymus-derived hematopoietic precursors to evaluate the impact on lineage differentiation in well-established in vitro models. Our findings reveal that PHF6 levels differentially impact the differentiation of human hematopoietic progenitor cells into various blood cell lineages, with prominent effects on lymphoid and erythroid differentiation. We show that loss of PHF6 results in accelerated human T cell development through reduced expression of NOTCH1 and its downstream target genes. This functional interaction in developing thymocytes was confirmed in vivo using a phf6-deficient zebrafish model that also displayed accelerated developmental kinetics upon reduced phf6 or notch1 activation. In summary, our work reveals that appropriate control of PHF6 expression is important for normal human hematopoiesis and provides clues towards the role of PHF6 in T-ALL development
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