Effect of Mono and Di-rhamnolipids on Biofilms Pre-formed by Bacillus subtilis BBK006.

Different microbial inhibition strategies based on the planktonic bacterial physiology have been known to have limited efficacy on the growth of biofilms communities. This problem can be exacerbated by the emergence of increasingly resistant clinical strains. Biosurfactants have merited renewed interest in both clinical and hygienic sectors due to their potential to disperse microbial biofilms. In this work, we explore the aspects of Bacillus subtilis BBK006 biofilms and examine the contribution of biologically derived surface-active agents (rhamnolipids) to the disruption or inhibition of microbial biofilms produced by Bacillus subtilis BBK006. The ability of mono-rhamnolipids (Rha-C10-C10) produced by Pseudomonas aeruginosa ATCC 9027 and the di-rhamnolipids (Rha-Rha-C14-C14) produced by Burkholderia thailandensis E264, and phosphate-buffered saline to disrupt biofilm of Bacillus subtilis BBK006 was evaluated. The biofilm produced by Bacillus subtilis BBK006 was more sensitive to the di-rhamnolipids (0.4 g/L) produced by Burkholderia thailandensis than the mono-rhamnolipids (0.4 g/L) produced by Pseudomonas aeruginosa ATCC 9027. Rhamnolipids are biologically produced compounds safe for human use. This makes them ideal candidates for use in new generations of bacterial dispersal agents and useful for use as adjuvants for existing microbial suppression or eradication strategies.

Characterisation of HFBII biosurfactant production and foam fractionation with and without antifoaming agents.

The effects of foaming on the production of the hydrophobin protein HFBII by fermentation have been investigated at two different scales. The foaming behaviour was characterised in standard terms of the product enrichment and recovery achieved. Additional specific attention was given to the rate at which foam, product and biomass overflowed from the fermentation system in order to assess the utility of foam fractionation for HFBII recovery. HFBII was expressed as an extracellular product during fed-batch fermentations with a genetically modified strain of Saccharomyces cerevisiae, which were carried out with and without the antifoam Struktol J647. In the presence of antifoam, HFBII production is shown to be largely unaffected by process scale, with similar yields of HFBII on dry matter obtained. More variation in HFBII yield was observed between fermentations without antifoam. In fermentations without antifoam, a maximum HFBII enrichment in the foam phase of 94.7 was measured with an overall enrichment, averaged over all overflowed material throughout the whole fermentation, of 54.6 at a recovery of 98.1%, leaving a residual HFBII concentration of 5.3 mg L(-1) in the fermenter. It is also shown that uncontrolled foaming resulted in reduced concentration of biomass in the fermenter vessel, affecting total production. This study illustrates the potential of foam fractionation for efficient recovery of HFBII through simultaneous high enrichment and recovery which are greater than those reported for similar systems.

Seizing the opportunity of the moment; nurse education in Cameroon: a grounded theory research study.

BACKGROUND: Cameroon became a republic in 1960 but tensions have continued over the last half century; such tensions, and some of the opportunities afforded, have shaped policy decisions around issues including nursing education. AIMS: The aim of this paper is to present a constructivist grounded theory of the evolution of nurse education in Cameroon based on interviews and available historical records. METHODS: Two data sources were used to develop the theory. Semi-structured interviews were carried out by the researcher with a purposive sample of 10 informants. Informants involved in the historical and current development of nurse education policy and practice were interviewed. Historical records were also located and examined, to understand the differing philosophical and pragmatic basis for decision-making in relation to nurse education in Cameroon. RESULTS: The emergent grounded theory is entitled 'Seizing the opportunity of the moment'. This theory outlines the evolution of nurse education in Cameroon since the country gained independence. It explores the centrality of timeliness and context on the evolution of nurse education policy. CONCLUSIONS: Conclusions are drawn that identify the current context in Cameroon as a critical moment for harmonisation of policy and practice for nurse education.

A ten-year audit of perforated sigmoid diverticulitis: highlighting the outcomes of laparoscopic lavage.

PURPOSE: This study was designed to review the results of laparoscopic lavage for the management of perforated sigmoid diverticulitis. METHODS: A 10-year retrospective review was conducted of 78 consecutive cases of sigmoid diverticulitis warranting emergency surgical intervention (1999-2008). RESULTS: Hinchey grades were I (12 patients), II (31 patients), III (29 patients), and IV (6 patients). The patients' mean age was 72 years. Procedures performed were laparoscopic washout (35), Hartmann procedure (31), percutaneous drainage of abscess (4), and resection and primary anastomosis (8). Overall mortality was 5 of 78 (7%); all of these patients were in the Hartmann group. Washout was successful in 27 of 35 cases, meaning recovery from the initial episode of peritonitis without resection. The short-term failures of washout in 8 patients were because of perforated cancer (1), fecal fistula formation (2), and inadequate washout and ongoing sepsis (5). In long-term follow-up, 8 patients in the washout group developed symptoms of recurrent complicated diverticulitis, including painful phlegmon (3), stricture (1), fistulas (3), and repeat perforation (1); all 8 patients underwent delayed resection. Eight patients underwent early planned resection without experiencing further symptoms. Eleven patients were observed without further symptoms with a mean follow-up of 20 months (range, 6-60 mo). CONCLUSIONS: Laparoscopic washout is an emerging technique that is particularly applicable to the management of Hinchey III perforated peritonitis. Short- and long-term problems exist with the technique that may be overcome with further improvement in technique and case selection. Resection and radiological drainage remain widely used in managing perforated sigmoid diverticulitis.

Who am I and what am I doing? Becoming a qualitative research interviewer.

Qualitative research can be influenced by the researcher's role in the study. Here, the authors propose reflexive methodologies as a means by which the processes undertaken by the researcher can be made transparent and used as part of the data. Using this approach, this paper explores the experience of becoming a qualitative research interviewer. It provides an account of dilemmas faced while undertaking a series of semi-structured interviews as part of a discourse analytic study into the practice of clinical supervision in a number of mental health professions.

Modelling the Temperature Dependent Biaxial Response of Poly(ether-ether-ketone) Above and Below the Glass Transition for Thermoforming Applications.

Desire to accurately predict the deformation behaviour throughout industrial forming processes, such as thermoforming and stretch blow moulding, has led to the development of mathematical models of material behaviour, with the ultimate aim of embedding into forming simulations enabling process and product optimization. Through the use of modern material characterisation techniques, biaxial data obtained at conditions comparable to the thermoforming process was used to calibrate the Buckley material model to the observed non-linear viscoelastic stress/strain behaviour. The material model was modified to account for the inherent anisotropy observed between the principal directions through the inclusion of a Holazapfel-Gasser-Ogden hyperelastic element. Variations in the post-yield drop in stress values associated with deformation rate and specimen temperature below the glass transition were observable, and facilitated in the modified model through time-temperature superposition creating a linear relationship capable of accurately modelling this change in yield stress behaviour. The modelling of the region of observed flow stress noted when above the glass transition temperature was also facilitated through adoption of the same principal. Comparison of the material model prediction was in excellent agreement with experiments at strain rates and temperatures of 1-16 s-1 and 130-155 °C respectively, for equal-biaxial mode of deformation. Temperature dependency of the material model was well replicated with across the broad temperature range in principal directions, at the reference strain rate of 1 s-1. When concerning larger rates of deformation, minimum and maximum average error levels of 6.20% and 10.77% were noted. The formulation, and appropriate characterization, of the modified Buckley material model allows for a stable basis in which future implementation into representative forming simulations of poly-aryl-ether-ketones, poly(ether-ether-ketone) (PEEK) and many other post-yield anisotropic polymers.

Willow water uptake and shoot extension growth in response to nutrient and moisture on a clay landfill cap soil.

Extension growth of willow (Salix viminalis L.) and changes in soil water were measured in lysimeters containing clay and sandy loam soils with different amendment and watering treatments. No water uptake was found below 0.3m in the nutritionally poor unamended clay; amendment with organic matter to 0.4m depth resulted in water extraction down to 0.5m depth whereas in the sandy loam, there was greater extraction from all depths down to 0.6m. With water stress, wilting of plants occurred when the volumetric soil water content at 0.1m was about 31% in the clay and 22% in the sandy loam. Compared with shoots on plants in the amended clay, those in the unamended treatment showed reduced extension growth, little increase in stem basal area (SBA) and a small shoot leaf area, resulting from a reduced number of leaves shoot(-1) and a small average area leaf(-1). Water stress also reduced shoot extension growth, SBA gain and the leaf area on extension growth. Shoot growth rates were significantly correlated with air temperature and base temperatures between 2.0 and 7.6 degrees C were indicated for the different treatments. These studies have helped to explain some of the large treatment effects described previously on biomass production and plant leaf area.

Routine histologic examination is unnecessary for tonsillectomy or adenoidectomy.

OBJECTIVE: To determine whether the current practice and incurred cost of histologic examination of tonsillectomy and adenoidectomy specimens is warranted. STUDY DESIGN: Review article based on medical literature. SUBJECTS AND METHODS: A retrospective PubMed review of all pertinent literature regarding tonsillectomy, adenoidectomy, and related surgical pathology was conducted. References of the articles obtained were reviewed for additional sources. RESULTS: Twenty studies report 54,901 patients and found 54 malignancies (0.087% prevalence). Of these, 48 (88% of the patients) had suspicious features such as tonsillar asymmetry, cervical lymphadenopathy, or abnormal tonsil appearance, preoperatively. The remaining six patients without any suspicious features (better representing true occult malignancy) were 0.011% of the total cases. CONCLUSION: Submission of tonsillectomy, adenoidectomy, or both specimens is warranted only when patients demonstrate findings associated with malignancy: tonsillar asymmetry, history of cancer, neck mass, tonsil firmness or lesion, weight loss, and constitutional symptoms.

Phase I Trial of Intravenous Oncolytic Vaccinia Virus (GL-ONC1) with Cisplatin and Radiotherapy in Patients with Locoregionally Advanced Head and Neck Carcinoma.

Purpose: Preclinical models have shown that the effectiveness of GL-ONC1, a modified oncolytic vaccinia virus, is enhanced by radiation and chemotherapy. The purpose of this study was to determine the safety of GL-ONC1 when delivered intravenously with chemoradiotherapy to patients with primary, nonmetastatic head and neck cancer.Experimental Design: Patients with locoregionally advanced unresected, nonmetastatic carcinoma of the head/neck, excluding stage III-IVA p16-positive oropharyngeal cancers, were treated with escalating doses and cycles of intravenous GL-ONC1, along with radiotherapy and chemotherapy. The primary aims were to define the MTD and dose-limiting toxicities, and to recommend a dose for phase II trials.Results: Between May 2012 and December 2014, 19 patients were enrolled. The most frequent adverse reactions included grade 1-2 rigors, fever, fatigue, and rash. Grade 3 adverse reactions included hypotension, mucositis, nausea, and vomiting. In 2 patients, the rash was confirmed as viral in origin by fluorescence imaging and viral plaque assay. In 4 patients, viral presence in tumor was confirmed on midtreatment biopsy by quantitative PCR. In 1 patient, live virus was confirmed in a tongue tumor 7 days after receiving the first dose of virus. The MTD was not reached. With median follow-up of 30 months, 1-year (2-year) progression-free survival and overall survival were 74.4% (64.1%) and 84.6% (69.2%), respectively.Conclusions: Delivery of GL-ONC1 is safe and feasible in patients with locoregionally advanced head/neck cancer undergoing standard chemoradiotherapy. A phase II study is warranted to further investigate this novel treatment strategy. Clin Cancer Res; 23(19); 5696-702. ©2017 AACR.

Willow growth in response to nutrients and moisture on a clay landfill cap soil. I. Growth and biomass production.

The growth and biomass production by willow (Salix viminalis L.) was studied in lysimeters containing Oxford clay landfill cap soil with different amendments, bulk densities and watering regimes. Three years from planting, stem biomass in well-watered plants was least (0.28 kg plant(-1)) with high bulk density soil (1480 kg m(-3)) and no nutritional amendment but was increased 10-fold (2.53 kg plant(-1)) by reducing soil bulk density (1200 kg m3) and adding amendments. In comparison, on a sandy loam soil it was 6.23 kg plant(-1). There were similar differences in number of stems plant(-1), stem basal area plant(-1) and plant leaf area which can be attributed to low nitrogen and phosphorus levels in Oxford clay. Water stress reduced stem biomass production by 26-37% and caused higher root:stem ratios. These were also higher on Oxford clay than on the sandy loam. Successful biomass production from willow on Oxford clay landfill caps will therefore require nutritional amendment.

Willow growth in response to nutrients and moisture on a clay landfill cap soil. II: Water use.

Water use by willow (Salix viminalis L.) was studied in lysimeters containing clay landfill cap and sandy loam soils under different watering and amendment regimes. With plentiful water and amendments, seasonal ET increased annually and was highest in the sandy loam, increasing from 360 l plant(-1) in the establishment year to almost 1200 l plant(-1) in the third year. Seasonal ET was highly correlated with leaf area duration. Amendment of Oxford clay resulted in increases in plant leaf area, dry matter production and seasonal ET. Water stress reduced seasonal ET by 10-14% in the second year and 25-41% in the third. Water use efficiency was low for the un-amended clay treatment (1.4 g kg(-1)) but was similar in the amended clay (5.0 g kg(-1)) and sandy loam (4.9 g kg(-1)). This highlights the interdependence of water use and biomass production in willow.

Sophorolipid biosurfactants: Possible uses as antibacterial and antibiofilm agent.

Biosurfactants are amphipathic, surface-active molecules of microbial origin which accumulate at interfaces reducing interfacial tension and leading to the formation of aggregated micellular structures in solution. Some biosurfactants have been reported to have antimicrobial properties, the ability to prevent adhesion and to disrupt biofilm formation. We investigated antimicrobial properties and biofilm disruption using sophorolipids at different concentrations. Growth of Gram negative Cupriavidus necator ATCC 17699 and Gram positive Bacillus subtilis BBK006 were inhibited by sophorolipids at concentrations of 5% v/v with a bactericidal effect. Sophorolipids (5% v/v) were also able to disrupt biofilms formed by single and mixed cultures of B. subtilis BBK006 and Staphylococcus aureus ATCC 9144 under static and flow conditions, as was observed by scanning electron microscopy. The results indicated that sophorolipids may be promising compounds for use in biomedical application as adjuvants to other antimicrobial against some pathogens through inhibition of growth and/or biofilm disruption.

Clinical and cosmetic outcomes in patients treated with high-dose-rate electronic brachytherapy for nonmelanoma skin cancer.

PURPOSE: To retrospectively analyze clinical and cosmetic outcomes in patients treated for nonmelanoma skin cancer (NMSC) with high-dose-rate (HDR) electronic brachytherapy (EBT) using surface applicators. METHODS AND MATERIALS: We identified 127 patients who had 154 NMSC lesions, 149 of which were basal cell carcinoma, treated with HDR EBT at our institution between July 2012 and March 2014. Lesions were treated to 40 Gy in 8 fractions. Local control, acute toxicity, late toxicity, and cosmetic outcomes were analyzed retrospectively. Acute and late toxicities were graded using the Common Terminology Criteria for Adverse Events, version 4.0. Cosmetic outcomes were graded using a standard scale based on the Radiation Therapy Oncology Group and European Organization for Research and Treatment of Cancer Late Radiation Morbidity Scoring Schema. RESULTS: Median (range) follow-up from completion of treatment was 16.1 (3.4-34.8 months). The overall crude recurrence rate was 1.3% (n = 2). Grade 0 to 1 acute radiation dermatitis was observed in 52.6% of treated lesions (n = 81), grade 2 in 34.4% (n = 53), and grade 3 in 13.0% (n = 20). No acute toxicity greater than grade 3 was observed and all acute toxic events resolved after treatment. Grade 0 to 1 late toxicity was observed in 94.2% of cases (n = 145), and grade 2 in 5.8% (n = 9). No late toxicity greater than grade 2 was observed. Across the 152 controlled lesions, cosmetic results were excellent in 94.2% of treated lesions (n = 145), good in 3.3% (n = 5), fair in 0.7% (n = 1), and poor in 0.7% (n = 1). CONCLUSIONS: HDR EBT confers promising local control, minimal toxicity, and excellent cosmesis in our institutional experience. It should be considered ideal for NMSC of the head and neck, particularly for basal cell carcinoma involving central facial locations where surgical cosmesis may be inferior.

Dissolution testing of a poorly soluble compound using the flow-through cell dissolution apparatus.

Dissolution of Pfizer Compound PD198306, a poorly soluble compound, was studied in 25 mM pH 9 sodium phosphate solution with 0.5% SLS using the flow-through cell dissolution apparatus. Unmicronized and micronized drug powders were tested. Several methods of loading the drug powder into the flow-through dissolution cells and their impact on dissolution were investigated. The influence of flow rate of the dissolution medium on the rate and extent of dissolution were studied. PD198306 has poor wettability even in the presence of 0.5% SLS. It was found that loading the drug powder into the dissolution cell in the form of a suspension provided the best dissolution profile in terms of the rate and extent of dissolution. The flow rate of 4 ml/min resulted in good particle size discrimination.

A comparison of the occurrence and nature of vocal symptoms in two groups of Icelandic teachers.

Research suggests that teaching activities involve a high risk of developing voice disorders. The aim of this study is to examine the possible difference in the occurrence and nature of vocal symptoms in two groups of teachers-head teachers (N = 43), including both principals and assistant head teachers, and teachers of physical education (N = 43)--and to investigate the possible role of gender. The questionnaire results indicate that demands on the voice for P.E. teachers and head teachers are different. The findings suggest that (i) demands influence the occurrence and nature of reported vocal symptoms, (ii) that teachers of physical education are at a greater risk of developing voice problems, and (iii) that female P.E. teachers are at particular risk.

Long-term remission with rituximab in refractory leucine-rich glioma inactivated 1 antibody encephalitis.

Autoimmune encephalitis associated with antibodies to leucine-rich glioma inactivated 1 (LGI1) is recently described and there is a lack of detailed reports on the treatment of relapsing or refractory cases and long-term outcomes. Two case reports are presented. Both cases had faciobrachial dystonic seizures (FBDS) and received rituximab after relapsing or refractory disease. Both cases achieved sustained clinical remission of up to 15 and 56 months respectively. Rituximab use allowed withdrawal of corticosteroids and was well tolerated. Randomized clinical trials are needed in LGI1 encephalitis and other autoimmune encephalitides.

Incidence of atrial fibrillation detected by implantable loop recorders in unexplained stroke.

OBJECTIVES: The usefulness of the implantable loop recorder (ILR) with improved atrial fibrillation (AF) detection capability (Reveal XT) and the factors associated with AF in the setting of unexplained stroke were investigated. METHODS: A cohort study is reported of 51 patients in whom ILRs were implanted for the investigation of ischemic stroke for which no cause had been found (cryptogenic) following appropriate vascular and cardiac imaging and at least 24 hours of cardiac rhythm monitoring. RESULTS: The patients were aged from 17 to 73 (median 52) years. Of the 30 patients with a shunt investigation, 22 had a patent foramen ovale (73.3%; 95% confidence interval [CI] 56.5%-90.1%). AF was identified in 13 (25.5%; 95% CI 13.1%-37.9%) cases. AF was associated with increasing age (p = 0.018), interatrial conduction block (p = 0.02), left atrial volume (p = 0.025), and the occurrence of atrial premature contractions on preceding external monitoring (p = 0.004). The median (range) of monitoring prior to AF detection was 48 (0-154) days. CONCLUSION: In patients with unexplained stroke, AF was detected by ILR in 25.5%. Predictors of AF were identified, which may help to target investigations. ILRs may have a central role in the future in the investigation of patients with unexplained stroke.

Toward understanding the atrial septum in cryptogenic stroke.

Ischemic stroke in younger people is common, and often remains unexplained. There is a well-documented association between unexplained stroke in younger people, and the presence of a patent foramen ovale. Therefore, in the absence of a clear cause of stroke, the heart is often assessed in detail for such lower risk causes of stroke. This usually involves imaging with a transesophageal echo, and investigation for a right-to-left shunt. An understanding of the anatomy of the atrial septum, and its associated abnormalities, is important for the stroke neurologist charged with decision making regarding appropriate secondary prevention. In this paper, we review the development and anatomy of the right heart with a focus on patent foramen ovale, and other associated abnormalities. We discuss how the heart can be imaged in the case of unexplained stroke, and provide examples. Finally, we suggest a method of investigation, in light of the recent European Association of Echocardiography guidance. Our aim is to provide the neurologist with an understanding on how the heart can be investigated in unexplained stroke, and the significance of abnormalities detected.

Effect of a nurse back injury prevention intervention on the rate of injury compensation claims.

PROBLEM: This study evaluated the effect of introducing a No Lifting policy on back injuries to nurses, across an entire health care system. METHODS: Methods included: analysis of the data for all public health agencies in the Australian state of Victoria; compensation data from the Victorian Workcover Authority; data about workforce and program implementation from a retrospective survey of agencies; longitudinal analysis of standardized workers compensation claim rates for back injuries before, during and after the intervention. RESULTS: A statistically significant decline in back injury claim rates during implementation contrasted with no statistically significant trends within the periods before and after the intervention. A statistically significant reduction occurred in mean quarterly standard back injury claim incidence rates per 1,000 equivalent fulltime nursing staff (EFTNS), representing a 24% reduction in standard back injury claims/1000 EFTNS. DISCUSSION: Ergonomics principles encourage changing the work environment to suit the worker. This approach delivered a significant improvement in the immediate term. IMPACT OF INDUSTRY: The substantial decline in back injury rates signifies a major improvement in the safety of a critical aspect of the work environment for nurses.