Dietary fibre supplementation enhances radiotherapy tumour control and alleviates intestinal radiation toxicity.

BACKGROUND: Non-toxic approaches to enhance radiotherapy outcomes are beneficial, particularly in ageing populations. Based on preclinical findings showing that high-fibre diets sensitised bladder tumours to irradiation by modifying the gut microbiota, along with clinical evidence of prebiotics enhancing anti-cancer immunity, we hypothesised that dietary fibre and its gut microbiota modification can radiosensitise tumours via secretion of metabolites and/or immunomodulation. We investigated the efficacy of high-fibre diets combined with irradiation in immunoproficient C57BL/6 mice bearing bladder cancer flank allografts. RESULT: Psyllium plus inulin significantly decreased tumour size and delayed tumour growth following irradiation compared to 0.2% cellulose and raised intratumoural CD8+ cells. Post-irradiation, tumour control positively correlated with Lachnospiraceae family abundance. Psyllium plus resistant starch radiosensitised the tumours, positively correlating with Bacteroides genus abundance and increased caecal isoferulic acid levels, associated with a favourable response in terms of tumour control. Psyllium plus inulin mitigated the acute radiation injury caused by 14 Gy. Psyllium plus inulin increased caecal acetate, butyrate and propionate levels, and psyllium alone and psyllium plus resistant starch increased acetate levels. Human gut microbiota profiles at the phylum level were generally more like mouse 0.2% cellulose profiles than high fibre profiles. CONCLUSION: These supplements may be useful in combination with radiotherapy in patients with pelvic malignancy. Video Abstract.

Feeling known and informed: Serial qualitative interviews evaluating a consultation support intervention for patients with high-grade glioma.

OBJECTIVE: Interventions to support patients' engagement in shared decision making (SDM) are lacking within high-grade glioma (HGG) healthcare. Consultation Planning, Recording and Summarising (CPRS) has shown evidence of increasing patient decision self-efficacy, reducing uncertainty, and regret of decisions. This is the first study of CPRS within a HGG population and delivered over serial medical consultations. METHOD: A one-arm prospective qualitative longitudinal design was used to evaluate the CPRS intervention and evaluated with participants at sequential clinic appointments depending on their care, in Edinburgh, Scotland. We report on serial semi structured interviews of 16 patients and their partners. RESULTS: Consultation planning before the consultation supported patients to feel known by strengthening the patient voice within the consultation. It prepared patients to actively participate in the consultation, despite the distressing nature of the content. Recording and summarising supported patients to understand their situation. The provision of a consultation record enabled accurate recall, a paced uptake of information and supported the family to feel fully informed. Ultimately, patients understood why decisions were being made rather than being part of making decisions. CONCLUSIONS: The CPRS intervention helped patients to understand and to feel known by increasing patient capacity for communication in the consultation, with support before, during, and after the consultation. The intervention focused on preparing patients for SDM but patients did not perceive that they had meaningful choices to make. Further research could look at the inclusion of patient decision aids to support this process.

An interpretative phenomenological analysis of the meaning of work to women living with breast cancer.

OBJECTIVE: Work is an important aspect of everyday life. This remains true for those living with and beyond cancer. Less is known about how the meaning of work may change over the cancer journey, the needs of the individual in response to changes and how healthcare professionals and employing organisations can meet these needs. The aim of this study was to explore the lived experience of work after treatment for breast cancer in a group of professional working women within the UK. METHODS: This article presents an Interpretative Phenomenological Analysis (IPA) of the experiences of 15 professional women diagnosed with breast cancer. RESULTS: We discuss these women's journey from (1) rethinking the meaning of work to (2) making decisions about work ability and advice on work to (3) transitioning back in to the workplace and the value of continued engagement with employer. DISCUSSION: The findings from this study demonstrate the complex interplay between living with cancer, treatment decisions and work. This study highlights two key areas for inclusion in practice: (1) support from Healthcare Professionals and judgements of functional ability and work ability and (2) the role of line managers in managing cancer and work.

A membrane-depolarizing toxin substrate of the Staphylococcus aureus type VII secretion system mediates intraspecies competition.

The type VII protein secretion system (T7SS) is conserved across Staphylococcus aureus strains and plays important roles in virulence and interbacterial competition. To date, only one T7SS substrate protein, encoded in a subset of S. aureus genomes, has been functionally characterized. Here, using an unbiased proteomic approach, we identify TspA as a further T7SS substrate. TspA is encoded distantly from the T7SS gene cluster and is found across all S. aureus strains as well as in Listeria and Enterococci. Heterologous expression of TspA from S. aureus strain RN6390 indicates its C-terminal domain is toxic when targeted to the Escherichia coli periplasm and that it depolarizes the cytoplasmic membrane. The membrane-depolarizing activity is alleviated by coproduction of the membrane-bound TsaI immunity protein, which is encoded adjacent to tspA on the S. aureus chromosome. Using a zebrafish hindbrain ventricle infection model, we demonstrate that the T7SS of strain RN6390 promotes bacterial replication in vivo, and deletion of tspA leads to increased bacterial clearance. The toxin domain of TspA is highly polymorphic and S. aureus strains encode multiple tsaI homologs at the tspA locus, suggestive of additional roles in intraspecies competition. In agreement, we demonstrate TspA-dependent growth inhibition of RN6390 by strain COL in the zebrafish infection model that is alleviated by the presence of TsaI homologs.

Differences in long-term physical activity trajectories among individuals with chronic widespread pain: A secondary analysis of a randomized controlled trial.

BACKGROUND: Little is known about long-term physical activity (PA) maintenance in those with chronic widespread pain (CWP) following an exercise intervention. This study examined PA over time to identify the existence and characteristics of subgroups following distinct PA trajectories. METHODS: Data come from individuals with CWP who took part in a 2 × 2 factorial randomized controlled trial, receiving either exercise or both exercise and cognitive behavioural therapy treatment. Information, including self-report PA, was collected at baseline recruitment, immediately post-intervention, 3, 24 and 60+ month post-treatment. Analyses were conducted on 196 men and women with ≥ 3 PA data points. Group-based trajectory modelling was used to identify latent PA trajectory groups and baseline characteristics (e.g., demographics, pain, self-rated health, fatigue, coping-strategy use and kinesiophobia) of these groups. RESULTS: The best fitting model identified was one with three trajectories: "non-engagers" (n = 32), "maintainers" (n = 144) and "super-maintainers" (n = 20). Overall, mean baseline PA levels were significantly different between groups (non-engagers: 1.1; maintainers: 4.6; super-maintainers: 8.6, p < 0.001) and all other follow-up points. Non-engagers reported, on average, greater BMI, higher disabling chronic pain, poorer self-rated health, physical functioning, as well as greater use of passive coping strategies and lower use of active coping strategies. CONCLUSIONS: The majority of individuals with CWP receiving exercise as part of a trial were identified as long-term PA maintainers. Participants with poorer physical health and coping response to symptoms were identified as non-engagers. For optimal symptom management, a stratified approach may enhance initiation and long-term PA maintenance in individuals with CWP. SIGNIFICANCE: Chronic pain can be a major barrier to engaging in exercise, a popular self-management strategy. Our findings identify three distinct long-term physical activity trajectories for individuals receiving the same exercise intervention. This suggests an approach by health care providers which identifies individuals who would benefit from additional support to enhance initiation and long-term physical activity maintenance could deliver better outcomes for such patients.

Randomised controlled trial of a repeated consultation support intervention for patients with colorectal cancer.

OBJECTIVE: UK healthcare policy for improving cancer outcomes supports participation of patients in care decisions with clinicians. Consultation Planning, Recording and Summarising (CPRS) has shown evidence of increasing patient decision self-efficacy, reducing uncertainty, and regret of decisions. This is the first trial of CPRS within the colorectal cancer population and delivered over serial medical consultations. METHODS: This randomised controlled trial compared usual care to the addition of CPRS over consecutive oncology consultations with newly diagnosed colorectal cancer (CRC) patients in Edinburgh, Scotland. The study primarily evaluated patients' perception of their decision self-efficacy, preparation for decision-making, decisional conflict, and decisional regret, with secondary measures of anxiety and depression. RESULTS: Compared with usual care, overall, the intervention group reported significantly higher decision self-efficacy (P = 0.001) and preparation for decision-making (P < 0.001) and significantly lower decisional conflict (P = 0.018) and regret (P = 0.039). The repeated intervention patients felt significantly better prepared for each consultation (P < 0.05); reported higher DSE before (P = 0.05) and after (P = 0.031) consultation one, and after consultation three (P = 0.004); and reported lower decisional conflict after consultation two (P = 0.007). Analyses comparing groups over time on decisional variables and anxiety and depression were underpowered because of attrition. CONCLUSIONS: Among colorectal cancer patients, CPRS was associated with decisional benefits before and after each consultation and 3 months after the last consultation. It appears that CPRS patients began their first medical consultation on a better trajectory but did not widen the gap over time. More research is needed on the benefits of CPRS being administered once or consecutively.

Haemophilus influenzae responds to glucocorticoids used in asthma therapy by modulation of biofilm formation and antibiotic resistance.

Glucocorticosteroids are used as a main treatment to reduce airway inflammation in people with asthma who suffer from neutrophilic airway inflammation, a condition frequently associated with Haemophilus influenzae colonization. Here we show that glucocorticosteroids have a direct influence on the behavior of H. influenzae that may account for associated difficulties with therapy. Using a mouse model of infection, we show that corticosteroid treatment promotes H. influenzae persistence. Transcriptomic analysis of bacteria either isolated from infected mouse airway or grown in laboratory medium identified a number of genes encoding regulatory factors whose expression responded to the presence of glucocorticosteroids. Importantly, a number of these corticosteroid-responsive genes also showed elevated expression in H. influenzae within sputum from asthma patients undergoing steroid treatment. Addition of corticosteroid to H. influenzae led to alteration in biofilm formation and enhanced resistance to azithromycin, and promoted azithromycin resistance in an animal model of respiratory infection. Taken together, these data strongly suggest that H. influenzae can respond directly to corticosteroid treatment in the airway potentially influencing biofilm formation, persistence and the efficacy of antibiotic treatment.

Novel cyclic di-GMP effectors of the YajQ protein family control bacterial virulence.

Bis-(3',5') cyclic di-guanylate (cyclic di-GMP) is a key bacterial second messenger that is implicated in the regulation of many critical processes that include motility, biofilm formation and virulence. Cyclic di-GMP influences diverse functions through interaction with a range of effectors. Our knowledge of these effectors and their different regulatory actions is far from complete, however. Here we have used an affinity pull-down assay using cyclic di-GMP-coupled magnetic beads to identify cyclic di-GMP binding proteins in the plant pathogen Xanthomonas campestris pv. campestris (Xcc). This analysis identified XC_3703, a protein of the YajQ family, as a potential cyclic di-GMP receptor. Isothermal titration calorimetry showed that the purified XC_3703 protein bound cyclic di-GMP with a high affinity (K(d)∼2 µM). Mutation of XC_3703 led to reduced virulence of Xcc to plants and alteration in biofilm formation. Yeast two-hybrid and far-western analyses showed that XC_3703 was able to interact with XC_2801, a transcription factor of the LysR family. Mutation of XC_2801 and XC_3703 had partially overlapping effects on the transcriptome of Xcc, and both affected virulence. Electromobility shift assays showed that XC_3703 positively affected the binding of XC_2801 to the promoters of target virulence genes, an effect that was reversed by cyclic di-GMP. Genetic and functional analysis of YajQ family members from the human pathogens Pseudomonas aeruginosa and Stenotrophomonas maltophilia showed that they also specifically bound cyclic di-GMP and contributed to virulence in model systems. The findings thus identify a new class of cyclic di-GMP effector that regulates bacterial virulence.

Polybacterial human disease: the ills of social networking.

Polybacterial diseases involve multiple organisms that act collectively to facilitate disease progression. Although this phenomenon was highlighted early in the 20th century, recent technological advances in diagnostics have led to the appreciation that many infections are far more complex than originally believed. Furthermore, it is apparent that although most treatments focus on the dominant bacterial species in an infection, other microbes, including commensals, can have a profound impact on both the response to therapy and virulence. Very little is known about the molecular mechanisms that underpin interactions between bacteria during such infections. Here, we discuss recent studies identifying and characterizing mechanisms of bacterial interaction and the biological processes they govern during certain diseases. We also highlight how possible strategies for targeting these interbacterial interactions may afford a route towards development of new therapies, with consequences for disease control.

The opportunistic pathogen Serratia marcescens utilizes type VI secretion to target bacterial competitors.

The type VI secretion system (T6SS) is the most recently described and least understood of the protein secretion systems of Gram-negative bacteria. It is widely distributed and has been implicated in the virulence of various pathogens, but its mechanism and exact mode of action remain to be defined. Additionally there have been several very recent reports that some T6SSs can target bacteria rather than eukaryotic cells. Serratia marcescens is an opportunistic enteric pathogen, a class of bacteria responsible for a significant proportion of hospital-acquired infections. We describe the identification of a functional T6SS in S. marcescens strain Db10, the first report of type VI secretion by an opportunist enteric bacterium. The T6SS of S. marcescens Db10 is active, with secretion of Hcp to the culture medium readily detected, and is expressed constitutively under normal growth conditions from a large transcriptional unit. Expression of the T6SS genes did not appear to be dependent on the integrity of the T6SS. The S. marcescens Db10 T6SS is not required for virulence in three nonmammalian virulence models. It does, however, exhibit dramatic antibacterial killing activity against several other bacterial species and is required for S. marcescens to persist in a mixed culture with another opportunist pathogen, Enterobacter cloacae. Importantly, this antibacterial killing activity is highly strain specific, with the S. marcescens Db10 T6SS being highly effective against another strain of S. marcescens with a very similar and active T6SS. We conclude that type VI secretion plays a crucial role in the competitiveness, and thus indirectly the virulence, of S. marcescens and other opportunistic bacterial pathogens.

Commenting on hepatitis.

The interesting article by Marie Kedzierski on 'Management of viral hepatitis' (Nursing Standard July 10) referred to several practices in relation to hepatitis A infection which are not always required in modern hospitals.