47 research outputs found

    The widespread use of topical antimicrobials enriches for resistance in Staphylococcus aureus isolated from patients with atopic dermatitis.

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    BACKGROUND: Carriage rates of Staphylococcus aureus on affected skin in atopic dermatitis (AD) are approximately 70%. Increasing disease severity during flares and overall disease severity correlate with increased burden of S. aureus. Treatment in AD therefore often targets S. aureus with topical and systemic antimicrobials. OBJECTIVES: To determine whether antimicrobial sensitivities and genetic determinants of resistance differed in S. aureus isolates from the skin of children with AD and healthy child nasal carriers. METHODS: In this case-control study, we compared S. aureus isolates from children with AD (n = 50) attending a hospital dermatology department against nasal carriage isolates from children without skin disease (n = 49) attending a hospital emergency department for noninfective conditions. Using whole genome sequencing we generated a phylogenetic framework for the isolates based on variation in the core genome, then compared antimicrobial resistance phenotypes and genotypes between disease groups. RESULTS: Staphylococcus aureus from cases and controls had on average similar numbers of phenotypic resistances per isolate. Case isolates differed in their resistance patterns, with fusidic acid resistance (FusR ) being significantly more frequent in AD (P = 0·009). The genetic basis of FusR also differentiated the populations, with chromosomal mutations in fusA predominating in AD (P = 0·049). Analysis revealed that FusR evolved multiple times and via multiple mechanism in the population. Carriage of plasmid-derived qac genes, which have been associated with reduced susceptibility to antiseptics, was eight times more frequent in AD (P = 0·016). CONCLUSIONS: The results suggest that strong selective pressure drives the emergence and maintenance of specific resistances in AD

    Overexpression of the Axl tyrosine kinase receptor in cutaneous SCC-derived cell lines and tumours

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    The molecular mechanisms that underlie the development of squamous cell skin cancers (SSC) are poorly understood. We have used oligonucleotide microarrays to compare the differences in cellular gene expression between a series of keratinocyte cell that mimic disease progression with the aim of identifying genes that may potentially contribute towards squamous cell carcinoma (SCC) progression in vivo, and in particular to identify markers that may serve as potential therapeutic targets for SCC treatment. Gene expression differences were corroborated by polymerase chain reaction and Western blotting. We identified Axl, a receptor tyrosine kinase with transforming potential that has also been shown to have a role in cell survival, adhesion and chemotaxis, was upregulated in vitro in SCC-derived cells compared to premalignant cells. Extending the investigation to tumour biopsies showed that the Axl protein was overexpressed in vivo in a series of SCCs

    MicroRNA-135b Regulates Leucine Zipper Tumor Suppressor 1 in Cutaneous Squamous Cell Carcinoma

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    Cutaneous squamous cell carcinoma (cSCC) is the second most common skin malignancy and it presents a therapeutic challenge in organ transplant recipient patients. Despite the need, there are only a few targeted drug treatment options. Recent studies have revealed a pivotal role played by microRNAs (miRNAs) in multiple cancers, but only a few studies tested their function in cSCC. Here, we analyzed differential expression of 88 cancer related miRNAs in 43 study participants with cSCC; 32 immunocompetent, 11 OTR patients, and 15 non-lesional skin samples by microarray analysis. Of the examined miRNAs, miR-135b was the most upregulated (13.3-fold, 21.5-fold; p=0.0001) in both patient groups. Similarly, the miR-135b expression was also upregulated in three cSCC cell lines when evaluated by quantitative real-time PCR. In functional studies, inhibition of miR-135b by specific anti-miR oligonucleotides resulted in upregulation of its target gene LZTS1 mRNA and protein levels and led to decreased cell motility and invasion of both primary and metastatic cSCC cell lines. In contrast, miR-135b overexpression by synthetic miR-135b mimic induced further down-regulation of LZTS1 mRNA in vitro and increased cancer cell motility and invasiveness. Immunohistochemical evaluation of 67 cSCC tumor tissues demonstrated that miR-135b expression inversely correlated with LZTS1 staining intensity and the tumor grade. These results indicate that miR-135b functions as an oncogene in cSCC and provide new understanding into its pathological role in cSCC progression and invasiveness

    Topical vitamin A treatment of recalcitrant common warts

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    <p>Abstract</p> <p>Background</p> <p>Common warts (<it>verruca vulgaris</it>) are benign epithelial proliferations associated with human papillomavirus (HPV) infection. Salicylic acid and cryotherapy are the most frequent treatments for common warts, but can be painful and cause scarring, and have high failure and recrudescence rates. Topical vitamin A has been shown to be a successful treatment of common warts in prior informal studies.</p> <p>Case</p> <p>The subject is a healthy, physically-active 30 old female with a 9 year history of common warts on the back of the right hand. The warts resisted treatment with salicylic acid, apple cider vinegar and an over-the-counter blend of essential oils marketed for the treatment of warts. Daily topical application of natural vitamin A derived from fish liver oil (25,000 IU) led to replacement of all the warts with normal skin. Most of the smaller warts had been replaced by 70 days. A large wart on the middle knuckle required 6 months of vitamin A treatment to resolve completely.</p> <p>Conclusion</p> <p>Retinoids should be further investigated in controlled studies to determine their effectiveness in treating common warts and the broad range of other benign and cancerous lesions induced by HPVs.</p

    Comparing Pandemic to Seasonal Influenza Mortality: Moderate Impact Overall but High Mortality in Young Children

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    Background: We assessed the severity of the 2009 influenza pandemic by comparing pandemic mortality to seasonal influenza mortality. However, reported pandemic deaths were laboratory-confirmed - and thus an underestimation - whereas seasonal influenza mortality is often more inclusively estimated. For a valid comparison, our study used the same statistical methodology and data types to estimate pandemic and seasonal influenza mortality. Methods and Findings: We used data on all-cause mortality (1999-2010, 100% coverage, 16.5 million Dutch population) and influenza-like-illness (ILI) incidence (0.8% coverage). Data was aggregated by week and age category. Using generalized estimating equation regression models, we attributed mortality to influenza by associating mortality with ILI-incidence, while adjusting for annual shifts in association. We also adjusted for respiratory syncytial virus, hot/cold weather, other seasonal factors and autocorrelation. For the 2009 pandemic season, we estimated 612 (range 266-958) influenza-attributed deaths; for seasonal influen

    Human papillomavirus and post-transplant cutaneous squamous-cell carcinoma: a multicenter, prospective cohort study

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    Organ transplant recipients (OTRs) have a 100‐fold increased risk of cutaneous squamous cell carcinoma (cSCC). We prospectively evaluated the association between β genus human papillomaviruses (βPV) and keratinocyte carcinoma in OTRs. Two OTR cohorts without cSCC were assembled: cohort 1 was transplanted in 2003‐2006 (n = 274) and cohort 2 was transplanted in 1986‐2002 (n = 352). Participants were followed until death or cessation of follow‐up in 2016. βPV infection was assessed in eyebrow hair by using polymerase chain reaction–based methods. βPV IgG seroresponses were determined with multiplex serology. A competing risk model with delayed entry was used to estimate cumulative incidence of histologically proven cSCC and the effect of βPV by using a multivariable Cox regression model. Results are reported as adjusted hazard ratios (HRs). OTRs with 5 or more different βPV types in eyebrow hair had 1.7 times the risk of cSCC vs OTRs with 0 to 4 different types (HR 1.7, 95% confidence interval 1.1‐2.6). A similar risk was seen with high βPV loads (HR 1.8, 95% confidence interval 1.2‐2.8). No significant associations were seen between serum antibodies and cSCC or between βPV and basal cell carcinoma. The diversity and load of βPV types in eyebrow hair are associated with cSCC risk in OTRs, providing evidence that βPV is associated with cSCC carcinogenesis and may present a target for future preventive strategies
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