Short-term reactivation of retinopathy of prematurity following primary ranibizumab treatment.

PURPOSE: Investigate risk factors for short term reactivation of retinopathy of prematurity (ROP) after intravitreal ranibizumab (IVR) therapy and determine safety and efficacy of repeat injections. METHODS: Retrospective chart review study of patients screened for ROP as inpatients between 2013-2023 who received IVR within the UCLA healthcare system. Primary outcomes were rates and timing of short term ROP reactivation, defined as repeat worsening of ROP to stage 2 or 3 before 52 weeks postmenstrual age (PMA), as well as risk factors for reactivation. Other outcomes included adverse events and rates of reactivation after a second intravitreal injection. RESULTS: 82 eyes of 43 patients received primary IVR 0.25mg/0.025cc for type 1 ROP. 13 patients (22 eyes) (30.2% of patients, 26.8% of eyes) developed short term reactivation an average of 7.2±1.7 weeks after treatment. Increased reactivation risk was associated with zone I disease (OR 6.23, 95% CI 1.35-28.7, p=0.019), lower PMA at 1st injection (OR 1.64, 95% CI 1.19-2.26; p=0.003), and lower gestational age at birth (OR 1.80, 95% CI 1.04-3.13, p=0.037). Of the 13 patients that received repeat injections, 5 required laser treatment for a second reactivation (11.6% of patients receiving IVR). No eyes developed retinal vascular occlusion, endophthalmitis or cataract. CONCLUSION: Repeat injections may be required after primary IVR for aggressive ROP. Repeat IVR treatment for ROP is effective and poses few ophthalmic adverse events, though additional reactivation remains a risk.

APMPPE and Placoid Variant Diseases Masquerading as Age-Related Macular Degeneration in the Elderly: A Case Series.

PURPOSE: To report eight cases of acute posterior multifocal placoid pigment epitheliopathy (APMPPE) or persistent placoid maculopathy (PPM) initially masquerading as age-related macular degeneration (AMD) in elderly individuals. METHODS: APMPPE or PPM eyes in patients above age 55 years with macular RPE disruption including drusenoid lesions on macular examination and/or with multimodal imaging were included. At least one method of multimodal imaging including fluorescein angiography (FA), indocyanine green angiography (ICGA), optical coherence tomography (OCT) and OCT angiography (OCTA) was performed in all eyes for diagnosis and to monitor for macular neovascularization (MNV). RESULTS: Eight elderly male patients presented with vision loss and were all initially diagnosed with non-neovascular or neovascular AMD. With the aid of multimodal retinal imaging, a final diagnosis of either APMPPE or PPM was rendered. With FA and ICGA, choroidal hypoperfusion was detected in all but one eye. With OCT, the angular sign of Henle fiber layer hyperreflectivity (ASHH) was identified in >50% of eyes. With OCTA, inner choroidal flow deficits were detected in all eyes. MNV requiring anti-VEGF injection therapy complicated 3 of 8 cases. CONCLUSIONS: Both APMPPE and PPM may develop in elderly individuals and may masquerade as AMD on presentation. Multimodal imaging including FA, ICGA, and OCTA are important diagnostic modalities to assess for inner choroidal hypoperfusion to arrive at an accurate diagnosis, and to detect MNV which frequently complicates APMPPE and PPM. In these patients, serial anti-VEGF intravitreal injections are essential in treating MNV and in preventing significant vision loss.

A novel online genomic counseling and variant interpretation certificate: Learning design, learning analytics, and evaluation.

In this paper we describe the analysis, planning, design, development, implementation and evaluation of a new online Graduate Certificate in Genomic Counselling and Variant Interpretation (GCGCVI) at The University of British Columbia (UBC). Genetic counselling is now a prerequisite for diagnostic genomic testing in many countries, demanding that genetic counselling practitioners have up-to-the-moment genomic counselling skills and knowledge. Current practitioners reported a desire for more training in this rapidly developing field: our international survey revealed substantial interest in online continuing education addressing themes such as testing and clinical bioinformatics, applied variant interpretation, evidence-based genomic counselling, and other emerging genomic topics. However, our market analysis found no post-graduate program globally that offered such training. To fill this gap, our oversight team of genetic counsellors and geneticists therefore guided development of curriculum and materials, and online learning specialists developed rigorous interactive asynchronous online graduate courses through collaboration with subject matter experts, following best practices in online learning design. Since launch in September 2020, we have gathered learner feedback using surveys and focus groups, and we have used learning analytics to understand how learners engaged with each other and with course materials. Together, these have helped us understand learner behaviour and guide the continuous process of design improvement to support the learning goals of this audience of professional learners. Our courses have been reviewed and approved by the UBC Faculty of Medicine, UBC Senate, and the Province of British Columbia Ministries of Advanced Education and Health, and assessed by the National Society of Genetic Counselors (NSGC, USA) and the Canadian Association of Genetic Counsellors (CAGC) to enable learners to receive North American continuing education credits. To date, 151 individuals from 18 countries have succeeded in one or more course and 43 have completed the entire certificate.

Feasibility and acceptability of electronic EQ-5D-5L for routine measurement of HRQOL in patients with chronic musculoskeletal problems in Hong Kong primary care.

BACKGROUND: Information on HRQOL can enhance patient diagnosis and management but it is rarely available in routine clinical practice. This mixed-method study evaluated the feasibility and acceptability of the electronic EQ-5D-5L measurement of HRQOL in patients with chronic musculoskeletal problems in primary care. METHODS: In three primary care clinics, 665 patients with musculoskeletal problems completed the electronic EQ-5D-5L and Visual Analogue Scale (e-EQ-5D-5L/VAS), and a questionnaire on socio-demographics, perceived ease of use (PEOU), and perceived usefulness (PU) at baseline and two follow-ups. Patient completion and response rates, and time to complete the e-EQ-5D-5L/VAS were measured. During the same consultations, 49 doctors reviewed the e-EQ-5D-5L/VAS reports and completed a clinician questionnaire on PEOU, PU, and time spent to address each report. Individual interviews along with focus group discussions were conducted on patients, doctors, and research assistants for further exploration. RESULTS: Mean completion time reduced from baseline to first and second follow-up (120.66, 83.99, and 105.22 s, respectively). Completion and response rates were high at each follow-up visit (> 99.8% and > 91.11%, respectively). Doctors needed less than 2 min to read the report but felt the time required to address the report was a significant barrier. Some patients had difficulties using e-platforms, in understanding or answering questions; but, PEOU improved with time (p < 0.001). Most patients found the e-platforms useful (> 85.3%). Clinicians agreed a great majority of the reports were easy to use (76.0-85.1%) and useful (69.2-72.0%), particularly aiding with a holistic view of the patient's musculoskeletal problem. CONCLUSION: The e-EQ-5D-5L/VAS is a feasible and acceptable measurement of HRQOL of patients with chronic musculoskeletal problems in routine primary care in Hong Kong which can assist real-time management decisions. TRIAL REGISTRATION: NCT03609762.

Effects of Health Literacy in the Fight Against the COVID-19 Infodemic: The Case of Japan.

This study quantitatively examines whether health literacy can reduce belief in COVID-19 misinformation and conspiracy theories. Conducting path and cluster analyses on survey data collected from 1,488 adults in Japan in 2021, we found that while health literacy reduces people's belief about COVID-19 and vaccination misinformation, it has no direct effect on their belief in COVID-19 conspiracy theories. That said, the results also highlighted the importance of health literacy. It is found that even though high health literacy does not guarantee a low degree of conspiracy beliefs, low health literacy is associated with high susceptibility to both misinformation and conspiracy theories. Moreover, people who relied more on social media than mass media for COVID-19 news and reported on having been more severely affected by the pandemic were found to be more likely to have lower health literacy and higher belief in misinformation and conspiracy theories. Based on the findings, we discussed ways to enhance health literacy research and promotion in Japan.

Phase II evaluation of anti-MAdCAM antibody PF-00547659 in the treatment of Crohn's disease: report of the OPERA study.

OBJECTIVE: This phase II, randomised, double-blind, placebo-controlled clinical trial was designed to evaluate the efficacy and safety of PF-00547659, a fully human monoclonal antibody that binds to human mucosal addressin cell adhesion molecule (MAdCAM) to selectively reduce lymphocyte homing to the intestinal tract, in patients with moderate-to-severe Crohn's disease (CD). DESIGN: Eligible adults were aged 18-75 years, with active moderate-to-severe CD (Crohn's Disease Activity Index (CDAI) 220-450), a history of failure or intolerance to antitumour necrosis factor and/or immunosuppressive agents, high-sensitivity C reactive protein >3.0 mg/L and ulcers on colonoscopy. Patients were randomised to PF-00547659 22.5 mg, 75 mg or 225 mg or placebo. The primary endpoint was CDAI 70-point decrease from baseline (CDAI-70) at week 8 or 12. RESULTS: In all, 265 patients were eligible for study entry. Although CDAI-70 response was not significantly different with placebo versus PF-00547659 treatment at weeks 8 or 12, remission rate was greater in patients with higher baseline C reactive protein (>5 mg/L vs >18.8 mg/L, respectively). Soluble MAdCAM decreased significantly from baseline to week 2 in a dose-related manner and remained low during the study in PF-00547659-treated patients. Circulating ß7+ CD4+ central memory T-lymphocytes increased at weeks 8 and 12 with PF-00547659 treatment. No safety signal was seen. CONCLUSIONS: Clinical endpoint differences between PF-00547659 and placebo did not reach statistical significance in patients with moderate-to-severe CD. PF-00547659 was pharmacologically active, as shown by a sustained dose-related decrease in soluble MAdCAM and a dose-related increase in circulating ß7+ central memory T cells. TRIAL REGISTRATION NUMBER: NCT01276509; Results.

Reversibility of peripheral blood leukocyte phenotypic and functional changes after exposure to and withdrawal from tofacitinib, a Janus kinase inhibitor, in healthy volunteers.

This study evaluated the short-term effects of tofacitinib treatment on peripheral blood leukocyte phenotype and function, and the reversibility of any such effects following treatment withdrawal in healthy volunteers. Cytomegalovirus (CMV)-seropositive subjects received oral tofacitinib 10 mg twice daily for 4 weeks and were followed for 4 weeks after drug withdrawal. There were slight increases in total lymphocyte and total T-cell counts during tofacitinib treatment, and B-cell counts increased by up to 26%. There were no significant changes in granulocyte or monocyte counts, or granulocyte function. Naïve and central memory T-cell counts increased during treatment, while all subsets of activated T cells were decreased by up to 69%. T-cell subsets other than effector memory cluster of differentiation (CD)4+, activated naïve CD4+ and effector CD8+ T-cell counts and B-cell counts, normalized 4 weeks after withdrawal. Following ex vivo activation, measures of CMV-specific T-cell responses, and antigen non-specific T-cell-mediated cytotoxicity and interferon (IFN)-γ production, decreased slightly. These T-cell functional changes were most pronounced at Day 15, partially normalized while still on tofacitinib and returned to baseline after drug withdrawal. Total natural killer (NK)-cell counts decreased by 33%, returning towards baseline after drug withdrawal. NK-cell function decreased during tofacitinib treatment, but without a consistent time course across measured parameters. However, markers of NK-cell-mediated cytotoxicity, antibody-dependent cellular cytotoxicity and IFN-γ production were decreased up to 42% 1 month after drug withdrawal. CMV DNA was not detectable in whole blood, and there were no cases of herpes zoster reactivation. No new safety concerns arose. In conclusion, the effect of short-term tofacitinib treatment on leukocyte composition and function in healthy CMV+ volunteers is modest and largely reversible 4 weeks after withdrawal.

Improving Discharge Instructions in a Pediatric Emergency Department: Impact of a Quality Initiative.

BACKGROUND: Effective communication between physician and patient is essential to optimize care after discharge from the emergency department (ED). Written discharge care instructions (DCI) complement verbal instructions and have been shown to improve communication and patient management. In 2012, Centers for Medicare and Medicaid Services proposed a quality measure (OP-19) that assesses compliance with key elements considered essential for high-quality written DCI. OBJECTIVE: To evaluate the impact of a QI intervention on improving quality of written DCI in a pediatric emergency department (PED). METHODS: A QI initiative was conducted at a tertiary PED with greater than 60,000 annual visits. Based on Centers for Medicare and Medicaid Services OP-19 measure and group consensus, 8 elements were defined a priori as requisites for good quality DCI. These elements are:Providers reviewed a random sample of DCI of patients. Proportion of DCI that had each element documented was compared between preintervention phase (PRE) and postintervention phase (POST). RESULTS: Three hundred twenty-nine DCI (PRE) and 1434 DCI (POST) were reviewed. The POST DCI showed statistically significant improvement for each of the 8 elements. The bundle measure (proportion containing all 8 elements) increased from 23% (PRE) to 79% (POST) (P < 0.001). CONCLUSIONS: The ED DCI improved in all 8 elements after a QI intervention. A detailed DCI at ED discharge enhances the patient's ability to comply with postdischarge treatment plan. Further studies are needed to evaluate the impact of improving DCI on ED return rates and other outcomes.

Use of Cough and Cold Medications in Severe Bronchiolitis before and after a Health Advisory Warning against Their Use.

We compared the use of cough and cold medications in 2 multicenter studies of young children hospitalized with bronchiolitis before and after the 2008 Food and Drug Administration cough and cold medications advisory. Although cough and cold medication use decreased after the advisory, nearly 20% of children age 12-23.9 months with severe bronchiolitis received cough and cold medications.

pSTAT3: a target biomarker to study the pharmacology of the anti-IL-21R antibody ATR-107 in human whole blood.

BACKGROUND: IL-21 has been shown to play an important role in autoimmune diseases. ATR-107 is an antibody which directly targets the IL-21 receptor (IL-21R). To aid the clinical development of ATR-107, there is a need for understanding the mechanism of action (MOA) of this antibody when assessing target engagement in human subjects. METHODS: To determine ATR-107 biological activity and potency in human blood, its inhibitory function against IL-21 induced STAT3 phosphorylation in human peripheral T and B cells was measured. RESULTS: The data show that IL-21 induces STAT3 phosphorylation in a concentration-dependent manner, consistent with its migration to the nuclear. Using a flow cytometry based functional whole blood assay, ATR-107 is demonstrated to be a potent IL-21 pathway inhibitor. It competes with IL-21 for receptor binding in a competitive manner, but once it binds to the receptor it behaves like a non-competitive inhibitor, most probably due to the long observed k(off). The concentration-dependent inhibition observed with ATR-107 correlates inversely with the levels of receptor occupancy, both in ex vivo whole blood assays and directly in human blood when ATR-107 was given to healthy volunteers. CONCLUSIONS: IL-21 induced phosphorylation of STAT3 in T and B cells can be used as a biomarker to evaluate the target engagement of ATR-107 in human whole blood. The antibody behaves like a potent non-competitive inhibitor blocking IL-21 induced STAT3 phosphorylation for a long period of time. These results may help with the translation of preclinical information and dose selection towards ATR-107 clinical efficacy.

Effect of Resident Involvement in Ophthalmic Surgery on Patient Outcomes: A Systematic Review and Meta-analysis.

PURPOSE: To determine the effect of resident- vs attending-led surgeries on patient outcomes in ophthalmic surgery. DESIGN: Systematic review and meta-analysis. METHODS: Two independent authors searched PubMed, EMBASE, and Cochrane Library from inception to March 2022. Categorical data from studies were pooled to report odds ratio (OR) and 95% CIs. Continuous data were analyzed to yield standardized mean difference (SMD) and 95% CIs. Propensity-matched studies were analyzed separately. Study quality was assessed using the Newcastle-Ottawa Scale. RESULTS: Twenty-four studies were included in this meta-analysis. Seventeen of the 20 outcomes had no significant differences between the 2 cohorts. Notably, many critical cataract surgery-related outcomes showed no significant differences, including posterior capsular tear, lens fragment retainment, and retinal detachment. Among propensity-scored studies, the resident-led surgeries had longer operative duration (SMD 0.81, 95% CI 0.29, 1.33; 3 studies [260 patients], I2 = 74%) and had an increased risk of an unplanned return to the operating room (OR 2.58, 95% CI 1.31, 5.06; 4 studies [342 patients], I2 = 0%). Among 2 non-propensity-scored, resident-led surgeries had increased incidence of choroidal detachment or choroidal effusion (OR 2.28, 95% 1.02, 5.09; 2 studies [401 patients], I2 = 19%). No significant difference was found for ocular hypotony. Significant heterogeneity existed among propensity-scored studies. CONCLUSIONS: Resident-led surgeries appear overall safe, effective, and comparable to attending-led surgeries with respect to commonly encountered perioperative complications. Specific differences in outcomes exhibit significant heterogeneity and small sample sizes, and may be of unclear or equivocal clinical significance.

Patient enablement and health-related quality of life for patients with chronic back and knee pain: a cross-sectional study in primary care.

BACKGROUND: Chronic back and knee pain impairs health- related quality of life (HRQoL) and patient enablement can improve HRQoL. AIM: To determine whether enablement was a moderator of the effect of chronic back and knee pain on HRQoL. DESIGN AND SETTING: A cross-sectional study of Chinese patients with chronic back and knee problems in public primary care clinics in Hong Kong. METHOD: Each participant completed the Chinese Patient Enablement Instrument-2 (PEI-2), the Chinese Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and the Pain Rating Scale (PRS). Multivariable regression examined the effects of PRS score and PEI-2 score on WOMAC total score. A moderation regression model and simple slope analysis were used to evaluate whether the interaction between enablement (PEI-2) and pain (PRS) had a significant effect on HRQoL (WOMAC). RESULTS: Valid patient-reported outcome data from 1306 participants were analysed. PRS score was associated with WOMAC total score (ß = 0.326, P<0.001), whereas PEI-2 score was associated inversely with WOMAC total score (ß = -0.260, P<0.001) and PRS score. The effect of the interaction between PRS and PEI-2 (PRS × PEI-2) scores on WOMAC total score was significant (ß = -0.191, P<0.001) suggesting PEI-2 was a moderator. Simple slope analyses showed that the relationship between PRS and WOMAC was stronger for participants with a low level of PEI-2 (gradient 3.056) than for those with a high level of PEI-2 (gradient 1.746). CONCLUSION: Patient enablement moderated the impact of pain on HRQoL. A higher level of enablement can lessen impairment in HRQoL associated with chronic back and knee pain.

The importance of bacterial membrane composition in the structure and function of aurein 2.2 and selected variants.

For cationic antimicrobial peptides to become useful therapeutic agents, it is important to understand their mechanism of action. To obtain high resolution data, this involves studying the structure and membrane interaction of these peptides in tractable model bacterial membranes rather than directly utilizing more complex bacterial surfaces. A number of lipid mixtures have been used as bacterial mimetics, including a range of lipid headgroups, and different ratios of neutral to negatively charged headgroups. Here we examine how the structure and membrane interaction of aurein 2.2 and some of its variants depend on the choice of lipids, and how these models correlate with activity data in intact bacteria (MICs, membrane depolarization). Specifically, we investigated the structure and membrane interaction of aurein 2.2 and aurein 2.3 in 1:1 cardiolipin/1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-(1'-rac-glycerol) (CL/POPG) (mol/mol), as an alternative to 1:1 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine(POPC)/POPG and a potential model for Gram positive bacteria such as S. aureus. The structure and membrane interaction of aurein 2.2, aurein 2.3, and five variants of aurein 2.2 were also investigated in 1:1 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine (POPE)/POPG (mol/mol) lipids as a possible model for other Gram positive bacteria, such as Bacillus cereus. Solution circular dichroism (CD) results demonstrated that the aurein peptides adopted α-helical structure in all lipid membranes examined, but demonstrated a greater helical content in the presence of POPE/POPG membranes. Oriented CD and ³¹P NMR results showed that the aurein peptides had similar membrane insertion profiles and headgroup disordering effects on POPC/POPG and CL/POPG bilayers, but demonstrated reduced membrane insertion and decreased headgroup disordering on mixing with POPE/POPG bilayers at low peptide concentrations. Since the aurein peptides behaved very differently in POPE/POPG membrane, minimal inhibitory concentrations (MICs) of the aurein peptides in B. cereus strain C737 were determined. The MIC results indicated that all aurein peptides are significantly less active against B. cereus than against S. aureus and S. epidermidis. Overall, the data suggest that it is important to use a relevant model for bacterial membranes to gain insight into the mode of action of a given antimicrobial peptide in specific bacteria.

Ocular adverse events following vaccination: overview and update.

The Food and Drug Administration has licensed, approved, and expanded guidelines for dozens of vaccines since 2010. Although advancements in biotechnology have made vaccines more effective and safer, none are completely free from adverse effects. Many vaccines have been implicated in causing ocular adverse events based on the temporal association of exposure and putative complication. Determination of causality is difficult. We provide an overview of vaccine side effects and also examine the English literature and the Vaccine Adverse Events Reporting System (VAERS) from 2010 through 2020 for vaccine-implicated ocular adverse events. While reactions of eyelids and conjunctiva are commonly reported, the most frequently implicated serious adverse events are optic neuritis and various patterns of intraocular inflammation. Live attenuated vaccines have the potential to cause ocular infection from vaccine-strain organisms, particularly in those immunosuppressed. While postmarketing registries for suspect vaccination adverse events, such as VAERS, are unable to determine causal associations, they are a mainstay in signaling suspected trends that require investigation. The majority of probable and possible serious ocular adverse effects are distinctly uncommon.

Improving Isotonic Maintenance Intravenous Fluid Use in the Emergency Department.

BACKGROUND: Maintenance intravenous fluids (IVFs) are commonly used in the hospital setting. Hypotonic IVFs are commonly used in pediatrics despite concerns about high incidence of hyponatremia. We aimed to increase isotonic maintenance IVF use in children admitted from the emergency department (ED) from a baseline of 20% in 2018 to >80% by December 2019. METHODS: We included patients aged 28 days to 18 years receiving maintenance IVFs (rate >10 mL/hour) at the time of admission. Patients with active chronic medical problems were excluded. Interventions included institutional discussions on isotonic IVF based on literature review, education on isotonic IVF use per the American Academy of Pediatrics guideline (isotonic IVF use with appropriate potassium chloride and dextrose), electronic medical record changes to encourage isotonic IVF use, and group practice review with individual physician audit and feedback. Balancing measures were the frequency of serum electrolyte checks within 24 hours of ED admission and occurrence of hypernatremia. Data were analyzed by using statistical process control charts. RESULTS: Isotonic maintenance IVF use improved, with special cause observed twice; the 80% goal was met and sustained. No difference was noted in serum electrolyte checks within 24 hours of admission (P > .05). There was no increase in occurrence of hypernatremia among patients who received isotonic IVF compared with those who received hypotonic IVF (P > .05). CONCLUSIONS: The application of improvement methods resulted in improved isotonic IVF use in ED patients admitted to the inpatient setting. Institutional readiness for change at the time of the American Academy of Pediatrics guideline release and hardwiring of preferred fluids via electronic medical record changes were critical to success.

Interprofessional Informatics Education: A Digital Health Game.

The purpose of this project was to develop and implement an interprofessional informatics curriculum. We developed a digital health serious game at the centre of this curriculum where the focus was a team-based approach to learning technologies used in the healthcare setting. The overall satisfaction scores were moderately high after the game. Serious games can be engaging for health sciences students.

Rapid Assembly of Infection-Resistant Coatings: Screening and Identification of Antimicrobial Peptides Works in Cooperation with an Antifouling Background.

Bacterial adhesion and the succeeding biofilm formation onto surfaces are responsible for implant- and device-associated infections. Bifunctional coatings integrating both nonfouling components and antimicrobial peptides (AMPs) are a promising approach to develop potent antibiofilm coatings. However, the current approaches and chemistry for such coatings are time-consuming and dependent on substrates and involve a multistep process. Also, the information is limited on the influence of the coating structure or its components on the antibiofilm activity of such AMP-based coatings. Here, we report a new strategy to rapidly assemble a stable, potent, and substrate-independent AMP-based antibiofilm coating in a nonfouling background. The coating structure allowed for the screening of AMPs in a relevant nonfouling background to identify optimal peptide combinations that work in cooperation to generate potent antibiofilm activity. The structure of the coating was changed by altering the organization of the hydrophilic polymer chains within the coatings. The coatings were thoroughly characterized using various surface analytical techniques and correlated with the efficiency to prevent biofilm formation against diverse bacteria. The coating method that allowed the conjugation of AMPs without altering the steric protection ability of hydrophilic polymer structure results in a bifunctional surface coating with excellent antibiofilm activity. In contrast, the conjugation of AMPs directly to the hydrophilic polymer chains resulted in a surface with poor antibiofilm activity and increased adhesion of bacteria. Using this coating approach, we further established a new screening method and identified a set of potent surface-tethered AMPs with high activity. The success of this new peptide screening and coating method is demonstrated using a clinically relevant mouse infection model to prevent catheter-associated urinary tract infection (CAUTI).

Self-Limiting Mussel Inspired Thin Antifouling Coating with Broad-Spectrum Resistance to Biofilm Formation to Prevent Catheter-Associated Infection in Mouse and Porcine Models.

Catheter-associated urinary tract infections (CAUTIs) are one of the most commonly occurring hospital-acquired infections. Current coating strategies to prevent catheter-associated biofilm formation are limited by their poor long-term efficiency and limited applicability to diverse materials. Here, the authors report a highly effective non-fouling coating with long-term biofilm prevention activity and is applicable to diverse catheters. The thin coating is lubricous, stable, highly uniform, and shows broad spectrum prevention of biofilm formation of nine different bacterial strains and prevents the migration of bacteria on catheter surface. The coating method is adapted to human-sized catheters (both intraluminal and extraluminal) and demonstrates long-term biofilm prevention activity over 30 days in challenging conditions. The coated catheters are tested in a mouse CAUTI model and demonstrate high efficiency in preventing bacterial colonization of both Gram-positive and Gram-negative bacteria. Furthermore, the coated human-sized Foley catheters are evaluated in a porcine CAUTI model and show consistent efficiency in reducing biofilm formation by Escherichia coli (E. coli) over 95%. The simplicity of the coating method, the ability to apply this coating on diverse materials, and the high efficiency in preventing bacterial adhesion increase the potential of this method for the development of next generation infection resistant medical devices.

Importance of residue 13 and the C-terminus for the structure and activity of the antimicrobial peptide aurein 2.2.

Previous studies on aurein 2.2 and 2.3 in DMPC/DMPG and POPC/POPG membranes have shown that bilayer thickness and phosphatidylglycerol content have a significant impact on the interaction of these peptides with membrane bilayers. Further examination with the DiSC(3)5 assay has indicated that aurein 2.2 induces greater membrane leakage than aurein 2.3 in Staphylococcus aureus C622. The only difference between these peptides is a Leu to Ile mutation at residue 13. To better understand the importance of this residue, the structure and activity of the L13A, L13F, and L13V mutants were investigated. In addition, we investigated a number of peptides with truncations at the C-terminus to determine whether the C-terminus, which contains residue 13, is crucial for antimicrobial activity. Solution circular dichroism results demonstrated that the L13F mutation and the truncation of the C-terminus by six residues resulted in decreased helical content, whereas the L13A or L13V mutation and the truncation of the C-terminus by three residues showed little to no effect on the structure. Oriented circular dichroism results demonstrated that only an extensive C-terminal truncation reduced the ability of the peptide to insert into lipid bilayers. (31)P NMR spectroscopy showed that all peptides disorder the headgroups. The implications of these results in terms of antimicrobial activity and the ability of these peptides to induce leakage in S. aureus are discussed. The results suggest that the presence of the 13th residue in aurein 2.2 is important for structure and activity, but the exact nature of residue 13 is less important as long as it is a hydrophobic residue.

Validation of a standardized method for enumerating circulating endothelial cells and progenitors: flow cytometry and molecular and ultrastructural analyses.

PURPOSE: Antigenic overlap among circulating endothelial cells (CEC) and progenitors (CEP), platelets, and other blood cells led to the need to develop a reliable standardized method for CEC and CEP quantification. These cells are emerging as promising preclinical/clinical tools to define optimal biological doses of antiangiogenic therapies and to help stratify patients in clinical trials. EXPERIMENTAL DESIGN: We report the experimental validation of a novel flow cytometry method that precisely dissects CEC/CEP from platelets and other cell populations and provides information about CEC/CEP viability. RESULTS: Sorted DNA/Syto16(+)CD45(-)CD31(+)CD146(+) CECs, investigated by electron microscopy, were found to be bona fide endothelial cells by the presence of Weibel-Palade bodies. More than 75% of the circulating mRNAs of the endothelial-specific gene, VE-cadherin, found in the blood were present in the sorted population. CECs were 140 +/- 171/mL in healthy subjects (n = 37) and 951 +/- 1,876/mL in cancer patients (n = 78; P < 0.0001). The fraction of apoptotic/necrotic CECs was 77 +/- 14% in healthy subjects and 43 +/- 23% in cancer patients (P < 0.0001). CEPs were 181 +/- 167/mL in healthy donors and 429 +/- 507/mL in patients (P = 0.00019). Coefficients of variation were 4 +/- 4% (intrareader), 17 +/- 4% (interreader), and 17 +/- 7% (variability over 0-72 h), respectively. Parallel samples were frozen by a standardized protocol. After thawing, coefficients of variation were 12 +/- 8% (intrareader), 16 +/- 10% (interreader), and 26 +/- 16% (variability over 0-14 days of frozen storage), respectively. CONCLUSIONS: This procedure enumerates a truly endothelial cell population with limited intrareader and interreader variability. It appears possible to freeze samples for large-scale CEC enumeration during clinical trials. This approach could be enlarged to investigate other angiogenic cell populations as well.