Misregulation of DNA damage repair pathways in HPV-positive head and neck squamous cell carcinoma contributes to cellular radiosensitivity

Patients with human papillomavirus type 16 (HPV)-associated oropharyngealsquamous cell carcinomas (OPSCC) display increased sensitivity to radiotherapy andimproved survival rates in comparison to HPV-negative forms of the disease. Howeverthe cellular mechanisms responsible for this characteristic difference are unclear.Here, we have investigated the contribution of DNA damage repair pathways to thein vitro radiosensitivity of OPSCC cell lines. We demonstrate that two HPV-positiveOPSCC cells are indeed more radiosensitive than two HPV-negative OPSCC cells, whichcorrelates with reduced efficiency for the repair of ionising radiation (IR)-inducedDNA double strand breaks (DSB). Interestingly, we show that HPV-positive OPSCCcells consequently have upregulated levels of the proteins XRCC1, DNA polymerase β,PNKP and PARP-1 which are involved in base excision repair (BER) and single strandbreak (SSB) repair. This translates to an increased capacity and efficiency for therepair of DNA base damage and SSBs in these cells. In addition, we demonstratethat HPV-positive but interestingly more so HPV-negative OPSCC display increasedradiosensitivity in combination with the PARP inhibitor olaparib. This suggests thatPARP inhibition in combination with radiotherapy may be an effective treatmentfor both forms of OPSCC, particularly for HPV-negative OPSCC which is relativelyradioresistant

Honey can inhibit and eliminate biofilms produced by Pseudomonas aeruginosa

© 2019, The Author(s). Chronic wound treatment is becoming increasingly difficult and costly, further exacerbated when wounds become infected. Bacterial biofilms cause most chronic wound infections and are notoriously resistant to antibiotic treatments. The need for new approaches to combat polymicrobial biofilms in chronic wounds combined with the growing antimicrobial resistance crisis means that honey is being revisited as a treatment option due to its broad-spectrum antimicrobial activity and low propensity for bacterial resistance. We assessed four well-characterised New Zealand honeys, quantified for their key antibacterial components, methylglyoxal, hydrogen peroxide and sugar, for their capacity to prevent and eradicate biofilms produced by the common wound pathogen Pseudomonas aeruginosa. We demonstrate that: (1) honey used at substantially lower concentrations compared to those found in honey-based wound dressings inhibited P. aeruginosa biofilm formation and significantly reduced established biofilms; (2) the anti-biofilm effect of honey was largely driven by its sugar component; (3) cells recovered from biofilms treated with sub-inhibitory honey concentrations had slightly increased tolerance to honey; and (4) honey used at clinically obtainable concentrations completely eradicated established P. aeruginosa biofilms. These results, together with their broad antimicrobial spectrum, demonstrate that manuka honey-based wound dressings are a promising treatment for infected chronic wounds, including those with P. aeruginosa biofilms

Antibiotic-specific differences in the response of Staphylococcus aureus to treatment with antimicrobiala combined with manuka honey

Skin infections caused by antibiotic resistant Staphylococcus aureus are a significant health problem worldwide; often associated with high treatment cost and mortality rate. Complex natural products like New Zealand (NZ) manuka honey have been revisited and studied extensively as an alternative to antibiotics due to their potent broad-spectrum antimicrobial activity, and the inability to isolate honey-resistant S. aureus. Previous studies showing synergistic effects between manuka-type honeys and antibiotics have been demonstrated against the growth of one methicillin-resistant S. aureus (MRSA) strain. We have previously demonstrated strong synergistic activity between NZ manuka-type honey and rifampicin against growth and biofilm formation of multiple S. arueus strains. Here, we have expanded our investigation using multiple S. aureus strains and four different antibiotics commonly used to treat S. aureus-related skin infections: rifampicin, oxacillin, gentamicin, and clindamycin. Using checkerboard microdilution and agar diffusion assays with S. aureus strains including clinical isolates and MRSA we demonstrate that manuka-type honey combined with these four antibiotics frequently produces a synergistic effect. In some cases when synergism was not observed, there was a significant enhancement in antibiotic susceptibility. Some strains that were highly resistant to an antibiotic when present alone become sensitive to clinically achievable concentrations when combined with honey. However, not all of the S. aureus strains tested responded in the same way to these combinational treatments. Our findings support the use of NZ manuka-type honeys in clinical treatment against S. aureus-related infections and extend their potential use as an antibiotic adjuvant in combinational therapy. Our data also suggest that manuka-type honeys may not work as antibiotic adjuvants for all strains of S. aureus, and this may help determine the mechanistic processes behind honey synergy

Not a nurse but more than a mother: The practices of mothering children with complex health care needs

This paper reports on the analysis of parent-recorded video diaries from a parent-driven campaign, #notanurse_but, supported by the charity WellChild. The campaign reveals the challenges that parents (predominantly mothers) face providing high level, ongoing clinical care for a son or daughter who has complex care needs. A team of four researchers analysed 30 videos from the WellChild website, WellChild Facebook page, a dedicated #notanurse_but campaign Facebook page, YouTube and Twitter. An interpretative, inductive qualitative analytical approach was utilised. This paper reflects on the portrayal of mothering (it was predominantly mothers who produced campaign videos) a child with complex health care needs. In particular, this paper considers the competing identities of mother and nurse that these mothers fulfil as part of their daily regimes in ‘being mum’. This paper also contributes to geographical discussions concerning methods and ethics of online data collection and the use of secondary online material

How do dentists understand evidence and adopt it in practice?

Although there is now a large evidence-based dentistry literature, previous investigators have shown that dentists often consider research evidence irrelevant to their practice. To understand why this is the case, we conducted a qualitative study. Objective: Our aim was to identify how dentists define evidence and how they adopt it in practice. Methods: A qualitative study using grounded theory methodology was conducted. Ten dentists working in eight dental practices were interviewed about their experience and work processes while adopting evidence-based preventive care. Analysis involved transcript coding, detailed memo writing, and data interpretation. Results: Findings revealed that dentists’ direct observations – referred to as clinical evidence – provided the most tangible and trusted evidence in practice and during discussions with colleagues. Dentists described a detailed process used to gather, compare and implement clinical evidence. This process began when they were exposed to novelty in daily practice and proceeded through self-driven testing, producing clinical or tangible evidence that clinicians could use in practice. Conclusion: Based on these findings, we propose an alternative to the linear form of knowledge transfer commonly represented in the literature.National Health and Medical Research Council Project Grant 63271

Sub-Meter Tree Height Mapping of California using Aerial Images and LiDAR-Informed U-Net Model

Tree canopy height is one of the most important indicators of forest biomass, productivity, and species diversity, but it is challenging to measure accurately from the ground and from space. Here, we used a U-Net model adapted for regression to map the canopy height of all trees in the state of California with very high-resolution aerial imagery (60 cm) from the USDA-NAIP program. The U-Net model was trained using canopy height models computed from aerial LiDAR data as a reference, along with corresponding RGB-NIR NAIP images collected in 2020. We evaluated the performance of the deep-learning model using 42 independent 1 km$^2$ sites across various forest types and landscape variations in California. Our predictions of tree heights exhibited a mean error of 2.9 m and showed relatively low systematic bias across the entire range of tree heights present in California. In 2020, trees taller than 5 m covered ~ 19.3% of California. Our model successfully estimated canopy heights up to 50 m without saturation, outperforming existing canopy height products from global models. The approach we used allowed for the reconstruction of the three-dimensional structure of individual trees as observed from nadir-looking optical airborne imagery, suggesting a relatively robust estimation and mapping capability, even in the presence of image distortion. These findings demonstrate the potential of large-scale mapping and monitoring of tree height, as well as potential biomass estimation, using NAIP imagery.Comment: 29 pages, 9 figures, submitted to Remote Sensing in Ecology and Conservation (RSEC

Alloactivation of naïve CD4⁺ CD8⁻ CD25⁺T regulatory cells: Expression of CD8α identifies potent suppressor cells that can promote transplant tolerance induction

Therapy with alloantigen-specific CD4+ CD25+ T regulatory cells (Treg) for induction of transplant tolerance is desirable, as naïve thymic Treg (tTreg) are not alloantigen-specific and are weak suppressor cells. Naïve tTreg from DA rats cultured with fully allogeneic PVG stimulator cells in the presence of rIL-2 express IFN-gamma receptor (IFNGR) and IL-12 receptor beta2 (IL-12Rβ2) and are more potent alloantigen-specific regulators that we call Ts1 cells. This study examined additional markers that could identify the activated alloantigen-specific Treg as a subpopulation within the CD4+ CD25+ Foxp3+ Treg. After culture of naïve DA CD4+ CD8− CD25+ T cells with rIL-2 and PVG alloantigen, or rIL-2 without alloantigen, CD8α was expressed on 10–20% and CD8β on <5% of these cells. These cells expressed ifngr and Il12rb2. CD8α+ cells had increased Ifngr that characterizes Ts1 cells as well was Irf4, a transcription factor induced by TCR activation. Proliferation induced by re-culture with rIL-12 and alloantigen was greater with CD4+ CD8α+ CD25+ Treg consistent with the CD8α+ cells expressing IL-12R. In MLC, the CD8α+ fraction suppressed responses against allogeneic stimulators more than the mixed Ts1 population, whereas the CD4+ CD8− CD25+ T cells were less potent. In an adoptive transfer assay, rIL-2 and alloantigen activated Treg suppress rejection at a ratio of 1:10 with naïve effector cells, whereas alloantigen and rIL-2 activated tTreg depleted of the CD8α+ cells were much less effective. This study demonstrated that expression of CD8α by rIL-2 and alloantigen activation of CD4+ CD8− CD25+ Foxp3+ T cells was a marker of activated and potent Treg that included alloantigen-specific Treg

Covering one eye in fixation-disparity measurement causes slight movement of fellow eye

In the subjective measurement of fixation disparity (FD), the subject fuses contours presented in the peripheral macular areas of both eyes (fusion lock). The position of the eyes relative to each other is monitored by means of two haploscopically seen vertical lines presented in the central macular area, one above and one below a binocularly seen horizontal line. The subject is instructed to shift one of the vertical lines horizontally until the two are aligned, while fixating their intersection with the horizontal line. It has recently been questioned whether the foveolae really are pointed towards the perceived intersection. In this study, we monitored the position of one eye while intermittently covering the fellow eye, while the subject maintained fixation of the intersection of the remaining vertical line and the horizontal line. We found slight differences in position of the measured eye, depending on whether the other eye was covered or not, i.e. depending on the presence or absence of fusion in the macular periphery. These differences were more pronounced in the non-dominant eye