Chick Embryo Chorioallantoic Membrane as a Platform for Assessing the In Vivo Efficacy of Chimeric Antigen Receptor T-cell Therapy in Solid Tumors.

The fertilized chicken egg chorioallantoic membrane (CAM), a highly vascularized membrane nourishing the developing embryo, also supports rapid growth of three-dimensional vascularized tumors from engrafted cells and tumor explants. Because murine xenograft models suffer limitations of time, cost, and scalability, we propose CAM tumors as a rapid, efficient screening tool for assessing anti-tumor efficacy of chimeric Ag receptor (CAR) T cells against solid tumors. We tested the efficacy of human epidermal growth factor receptor 2 (HER2)-specific CAR T cells against luminescent, HER2-expressing (FaDu, SCC-47) or HER2-negative (MDA-MB-468) CAM-engrafted tumors. Three days after tumor engraftment, HER2-specific CAR T cells were applied to tumors grown on the CAM. Four days post-CAR T cell treatment, HER2-expressing FaDu and SCC-47 tumors treated with CAR T showed reduced viable cancer cells as assessed by luciferase activity. This reduction in viable tumor cells was confirmed by histology, with lower Ki-67 staining observed in CAR T cell-treated tumors relative to T cell-treated controls. Persistence of CAR T in CAM and tumor tissue 4 days post-treatment was confirmed by CD3 staining. Altogether, our findings support further development of the chick CAM as an in vivo system for rapid, scalable screening of CAR T cell efficacy against human solid tumors.

Nanoscale surface modification favors benign biofilm formation and impedes adherence by pathogens.

We have found in vitro that a biofilm of benign Escherichia coli 83972 interferes with urinary catheter colonization by pathogens, and in human studies E. coli 83972-coated urinary catheters are associated with lower rates of catheter-associated urinary tract infections. We hypothesized that modifying surfaces to present mannose ligands for the type 1 fimbriae of E. coli would promote formation of dense E. coli 83972 biofilms, thereby interfering with surface colonization by Enterococcus faecalis, a common uropathogen. We covalently immobilized mannose on silicon substrates by attaching amino-terminated mannose derivative to carboxylic acid-terminated monolayers via amidation. Fluorescence microscopy showed that E. coli 83972 adherence to mannose-modified surfaces increased 4.4-fold compared to unmodified silicon surfaces. Pre-exposing mannose-modified surfaces to E. coli 83972 established a protective biofilm that reduced E. faecalis adherence by 83-fold. Mannose-fimbrial interactions were essential for the improved E. coli 83927 adherence and interference effects. From the Clinical Editor: Recurrent urinary tract infections remain major adverse events associated with catheter use. The authors report that modifying catheter surface to present mannose ligands for the type 1 fimbriae of benign Escherichia coli 83972 promotes formation of dense E. coli biofilms, which 100-fold reduces urinary catheter colonization of uropathogens. Future application of this technology is expected to result in substantial UTI risk reduction in catheter users.

Silver or nitrofurazone impregnation of urinary catheters has a minimal effect on uropathogen adherence.

PURPOSE: Bacterial adherence to the urinary catheter is an early step in biofilm formation and the pathogenesis of catheter associated urinary tract infection. We studied in vitro the effect of silver or nitrofurazone impregnation of urinary catheters on uropathogen ability to adhere to urinary catheters. MATERIALS AND METHODS: We studied commercially available nitrofurazone-silicone, silicone only, silver-silicone-hydrogel, silicone-hydrogel, silver-latex-hydrogel and latex-hydrogel catheters. Catheters were incubated in sterile broth for 0, 3, 5, 7 and 10 days, respectively, before inoculation and overnight incubation with Escherichia coli or Enterococcus faecalis. RESULTS: Adherence of E. coli and E. faecalis to nitrofurazone catheters was significantly decreased compared to that of silicone-only catheters when catheters were fresh. The anti-adherence effect of nitrofurazone on E. coli decreased with time but was still significant at 5 days. For E. faecalis the effect of nitrofurazone was lost by 3 days of pre-incubation. E. coli adherence was not significantly decreased on silver impregnated catheters compared to that on control catheters of the same base material. Silver was associated with a significant decrease in E. faecalis adherence to latex-hydrogel catheters but not to silicone-hydrogel catheters. The adherence of each species to silicone catheters with hydrogel was significantly lower than that to silicone-only control catheters. CONCLUSIONS: Silver impregnation had little effect on bacterial adherence in our model and nitrofurazone impregnation had a significant effect only for the first 5 days. Our results do not support a role for silver urinary catheters to prevent catheter associated urinary tract infection by decreasing bacterial adherence.

Measuring Quality of Life in Pediatric Paradoxical Vocal Fold Motion Using the SF-36v2.

OBJECTIVES: Paradoxical vocal fold motion (PVFM) consists of intermittent adduction of the vocal folds during inspiration, resulting in stridor and worsened by anxiety and stress. The purpose of this study was to assess the impact of PVFM on quality of life in our pediatric patient population. STUDY DESIGN: This is a prospective, descriptive survey study. METHODS: Thirty-nine consecutive patients (ages 12-17 years) presenting with a PVFM diagnosis for respiratory retraining sessions with speech-language pathology were recruited. Patients completed a brief demographic questionnaire and the Short Form 36, version 2, a validated tool for measuring health-related quality of life. RESULTS: There were 31 (79%) girls and 8 (21%) boys with a mean age of 15.5 years. Subjects reported regular participation in competitive extracurricular activities, including track or cross country (30.8%), swimming (17.9%), and cheerleading or dancing (15.4%). Of the patients in the study, 46.2% were straight-A students. On the SF-36 (population averages normalized to a score of 50), the general health of patients with PVFM was better than that of the general population (53.27); however, their physical health limited their role activities more severely (42.82). In addition, a greater proportion of the group with PVFM was at risk for first-stage depression screening when compared with the general population (28% versus 18%). CONCLUSIONS: We demonstrate a measurable detrimental impact of PVFM on health-related quality of life. This is consistent with previously published literature showing a preponderance of females with PVFM, most of whom are high achievers academically and athletically.

Development of expanded host range phage active on biofilms of multi-drug resistant Pseudomonas aeruginosa.

Phage therapy is a promising treatment of multi-drug resistant (MDR) bacterial infections but is limited by the narrow host range of phage. To overcome this limitation, we developed a host range expansion (HRE) protocol that expands the host range of Pseudomonas aeruginosa-specific phage by cycles of co-incubation of phage with multiple P. aeruginosa strains. Application of the HRE protocol to a mixture of 4 phages, using 16 P. aeruginosa strains for development, resulted in undefined phage mixtures with greatly expanded host range. Individual phage clones derived from the undefined mixture had expanded host ranges but no individual clone could lyse all of the strains covered by the undefined mixture from which it was isolated. Reconstituting host range-characterized clones into cocktails produced defined cocktails with predictable and broad host ranges. The undefined mixture from the 30th cycle of the mixed-phage HRE (4ϕC30) showed a dose-dependent ability to prevent biofilm formation by, and to reduce a pre-existing biofilm of, 3 P. aeruginosa clinical isolates that produced high amounts of biofilm. A defined cocktail reconstituted from 3 host range-characterized clones had activity on high biofilm-formers susceptible to the phage. Phage therapy was superior to antibiotic therapy (levofloxacin) in a strain of P. aeruginosa that was resistant to levofloxacin. The HRE protocol establishes a rapid approach to create libraries of phage clones and phage cocktails with broad host range, defined composition and anti-biofilm activity.

A hospital-site controlled intervention using audit and feedback to implement guidelines concerning inappropriate treatment of catheter-associated asymptomatic bacteriuria.

BACKGROUND: Catheter-associated urinary tract infection (CAUTI) is one of the most common hospital-acquired infections. However, many cases treated as hospital-acquired CAUTI are actually asymptomatic bacteriuria (ABU). Evidence-based guidelines recommend that providers neither screen for nor treat ABU in most catheterized patients, but there is a significant gap between these guidelines and clinical practice. Our objectives are (1) to evaluate the effectiveness of an audit and feedback intervention for increasing guideline-concordant care concerning catheter-associated ABU and (2) to measure improvements in healthcare providers' knowledge of and attitudes toward the practice guidelines associated with the intervention. METHODS/DESIGN: The study uses a controlled pre/post design to test an intervention using audit and feedback of healthcare providers to improve their compliance with ABU guidelines. The intervention and the control sites are two VA hospitals. For objective 1 we will review medical records to measure the clinical outcomes of inappropriate screening for and treatment of catheter-associated ABU. For objective 2 we will survey providers' knowledge and attitudes. Three phases of our protocol are proposed: the first 12-month phase will involve observation of the baseline incidence of inappropriate screening for and treatment of ABU at both sites. This surveillance for clinical outcomes will continue at both sites throughout the study. Phase 2 consists of 12 months of individualized audit and feedback at the intervention site and guidelines distribution at both sites. The third phase, also over 12 months, will provide unit-level feedback at the intervention site to assess sustainability. Healthcare providers at the intervention site during phase 2 and at both sites during phase 3 will complete pre/post surveys of awareness and familiarity (knowledge), as well as of acceptance and outcome expectancy (attitudes) regarding the relevant practice guidelines. DISCUSSION: Our proposal to bring clinical practice in line with published guidelines has significant potential to decrease overdiagnosis of CAUTI and associated inappropriate antibiotic use. Our study will also provide information about how to maximize effectiveness of audit and feedback to achieve guideline adherence in the inpatient setting. TRIAL REGISTRATION: NCT01052545.