Reaching adults who smoke cigarettes in rural Appalachia: Rationale, design & analysis plan for a mixed-methods study disseminating pharmacy-delivered cessation treatment

INTRODUCTION

Unlike other U.S. geographical regions, cigarette smoking prevalence remains stagnant in rural Appalachia. One avenue for reaching rural residents with evidence-based smoking cessation treatments could be utilizing community pharmacists. This paper describes the design, rationale, and analysis plan for a mixed-method study that will determine combinations of cessation treatment components that can be integrated within community pharmacies in rural Appalachia. The aim is to quantify the individual and synergistic effects of five highly disseminable and sustainable cessation components in a factorial experiment.

METHODS

This sequential, mixed-method research design, based on the RE-AIM (Reach, Effectiveness, Adoption, Implementation, and Maintenance) framework, will use a randomized controlled trial with a 25 fully crossed factorial design (32 treatment combinations) to test, alone and in combination, the most effective evidence-based cessation components: (1) QuitAid (yes vs. no) (2) tobacco quit line (yes vs. no) (3) SmokefreeTXT (yes vs. no) (4) combination NRT lozenge + NRT patch (vs. NRT patch alone), and (5) eight weeks of NRT (vs. standard four weeks).

RESULTS

Logistic regression will model abstinence at six-months, including indicators for the five treatment factors and all two-way interactions between the treatment factors. Demographic and smoking history variables will be considered to assess potential effect modification. Poisson regression will model quit attempts and percent of adherence to treatment components as secondary outcomes.

CONCLUSION

This study will provide foundational evidence on how community pharmacies in medically underserved, rural regions can be leveraged to increase utilization of existing evidence-based tobacco cessation resources for treating tobacco dependence.

CLINICAL TRIALS

NCT05660525.

Secondary Analysis of RRx-001 on the Incidence of Related Toxicities in Patients Treated with Concomitant Chemoradiation for Locally Advanced Head and Neck Cancer

PURPOSE/OBJECTIVE(S)

The results of an open-labeled Phase 2a trial (PREVLAR) suggested that infusion of RRx-001 (bromonitrozidine), a nitrogen-containing NLRP3 inhibitor and Nrf2 activator, attenuated the course and severity of severe oral mucositis (SOM) associated CRT (cisplatin/IMRT) in cancers of the mouth or OPC without impeding tumor response.1 Given its mechanism of action and the shared biology of radiation injury pathogenesis among other exposed tissues, we investigated the potential halo effect of RRx-001 on other regimen-related toxicities.

MATERIALS/METHODS

PREVLAR was a multi-center, open-label randomized trial in which patients (n = 46) having locally advanced, histologically confirmed SCC of the OC or OPC were centrally randomized to one of four arms. Arms 1-3 received 2 weekly doses of RRx-001 (4 mg/dose) beginning 2 weeks before the start of CRT. Arm 2 (n = 11) received 2 additional RRx-001 infusions during weeks 2 and 5 and patients in Arm 3 (n = 13) received weekly RRx-001 for the first 6 weeks of CRT. 10 mg of dexamethasone was administered before RRx-001 infusions. Arm 4 (n = 10), the control, received CRT only. Adverse events (AEs) were assessed using CTCAE v5. All patients received standard regimens of IMRT (daily fractions of 2-2.2 Gy/minimum cumulative dose of 55 Gy) plus either weekly or tri-weekly cisplatin.

RESULTS

Consistent with the observation that RRx-001 was most efficacious in attenuating the course of SOM when administered only prior to CRT (Arm 1) or prior to CRT with additional dosing on weeks 2 and 5 (Arm 2), compared to Arm 3 or control, the same dosing schedule appeared to be impactful on signs and symptoms of radiation-associated damage with tissues such as salivary glands and skin (Table 1). In particular, compared to control patients, patients in Arms 1 and 2 had a lower incidence of dry mouth (none vs. 60%), dysphagia (none vs. 70%), salivary duct inflammation (none vs. 30%), candida infection (9.1% vs 40%), radiation associated skin injury (Arm 1 none, Arm 2 18.2%, control 70%) and weight loss (none vs. 50%) as examples.

CONCLUSION

In this small proof of concept trial, RRx-001 infusion resulted in a reduction of multiple, biologically-related, side effects associated with a standard chemoradiation regimen used to the treatment of head and neck cancers. KEVLAR, a larger Phase 2b trial is planned to begin enrollment in Q4 of 2023 at about thirty sites in North America.

Investigating chemical and microbial functional indicators of nutrient retention capacity in greenhouse stormwater retention ponds in southwestern Ontario, Canada

The tributaries flowing through Leamington, Ontario are unique in the Canadian Lake Erie watershed due to the broad spatial extent of greenhouse operations, which more than doubled in size and density from 2011 to 2022. These greenhouse operations are considered to be potential nutrient point sources with respect to observed nutrient concentrations in tributaries adjacent to greenhouse stormwater retention ponds (GSWPs). Identifying causal factors of nutrient release, whether this be chemical or biological, within these ponds may be critical for mitigating their impact on the watershed and ultimately the receiving waters of Lake Erie. Specifically, phosphorus and nitrogen accumulation in freshwater ponds can contribute to environmental damage proximal to adjacent streams, serving as a potential catalyst for algal blooms and eutrophication. This study compared correlations between the water column N:P stoichiometry, sediment nutrient retention capacity, and drivers of microbial metabolism within GSWP sediments. Correlations between water column TN:TP ratios and sediment nutrient retention capacity were observed, suggesting an interplay between N and P in terms of nutrient limitation. Further, clear shifts were observed in the bacterial metabolic pathways analyzed through metatranscriptomics. Specifically, genes related to nitrogen fixation, nitrification and denitrification, and other metabolic processes involving sulfur and methane showed differential expression depending on the condition of the respective pond (i.e., naturalized wetland vs. dredged, eutrophic pond). Collectively, this research serves to highlight the interconnected role of chemical-biological processes particularly as they relate to significant ecosystem processes such as nutrient loading and retention dynamics in impaired freshwater systems.

248 Urethral Self-Insertion of a USB Cable as Sexual Experimentation: A Case Report

Introduction

The insertion of a foreign body in the urethra is an uncommon urological emergency. A wide variety of inserted objects have been described, presenting either asymptomatically or with lower abdominal discomfort and lower urinary tract symptoms. Sexual experimentation and gratification as well as mental disorders are considered the main underlying causes. The aim of this report is to present the case of a USB wire self-insertion and its challenging urological management.

Case Presentation

A 15-year-old male patient presented to his local Accident and Emergency department with gross haematuria following self-insertion of the knotted cable of a USB wire into his urethra in the context of sexual experimentation. Endoscopic approach via rigid cystoscopy and optical urethrotomy was not effective. A suprapubic catheter was inserted, and the patient was urgently transferred to our hospital for tertiary management.

Following radiological assessment to confirm the position of the wire, a longitudinal peno-scrotal incision over the palpable foreign body was made. Urethrotomy revealed the knotted cable in the proximal aspect of the penile urethra, which was cut and removed. Urethra was subsequently closed over a urethral catheter. Postoperative recovery was uneventful, and patient was discharged home with oral antibiotics. Urethral catheter was removed following normal fluoroscopic assessment of the urethra two weeks later.

Conclusions

The management of a foreign urethral body can be challenging and usually requires tertiary expertise to achieve optimal outcomes. Poor initial management could potentially lead to devastating long-term complications such as urethral strictures and fistulas.

Profiling and predicting help-seeking behaviour among trauma-exposed UK firefighters

Background: Firefighters often do not avail of psychological support services within fire services. Hence, investigating help-seeking behaviour is crucial to determine viable support options. Objective: This study attempted to characterize help-seeking behaviour among UK firefighters by profiling and identifying patterns of help-seeking. Methods: An online survey was administered to 1282 UK firefighters who were asked which help-seeking options they availed of within and outside professional settings. The analysis was conducted in two linked phases. First, latent class analysis was used to identify the fewest profiles that most accurately described help-seeking behaviour. Second, multinomial logistic regression analysis was employed to describe class composition using demographic and years in service variables, while ANOVA was employed to identify variation in alcohol consumption and openness to discussing emotions across help-seeking classes. Results: Five distinct help-seeking classes were identified. Class 1 (9.2%) represented firefighters who availed of all forms of support. Class 2, the smallest class (6.9%) represented firefighters who independently sought External Professional Psychological Support. Class 3 (12.2%) represented those who mainly sought Friends Support. Class 4, the largest class (48.7%) represented those who mainly sought Spousal Support. Class 5 (23%) represented firefighters who sought all avenues of Social Support. Regression analyses indicated that the External Psychological Support class was more likely to be single with fewer years in service. Firefighters longest in service were less likely to seek Social Support, and those who relied on Spousal support had the lowest alcohol consumption. Conclusion: Variations in help-seeking behaviour among UK firefighters were found. Firefighters who sought spousal support had the lowest alcohol consumption rates, indicating a protected profile. Firefighters who only sought friends and informal colleagues' support had the highest alcohol consumption rates and the most difficulty in discussing feelings, indicating a potential at-risk profile. Recognizing these differences in help-seeking patterns is important for targeting interventions.

Tracking functional bacterial biomarkers in response to a gradient of contaminant exposure within a river continuum

Within all aquatic environments, aside from the physical dispersal of dissolved and/or particulate phase contaminants, alteration from both biological and chemical processes are shown to change the chemistry of the parent compounds. Often these alterations can lead to secondary influences because of cooperative microbial processes (i.e. coupled respiratory pathways and/or energy and biodegradation cycles), complicating our understanding of the biological impact that these mobile compounds impose on ecosystem health. The McMurray Formation (MF) (the formation constituting the minable bituminous oil sands) is a natural, ongoing source of hydrocarbon-bound sediments to river ecosystems in the region (via terrestrial and aquatic erosion), providing a natural "mesocosm" to track and characterize the effects of these compounds on regional aquatic primary productivity. Here we characterize the natural, in-situ microbial response to increasing hydrocarbon exposure along a river continuum in the downstream direction. Using the Steepbank River (STB), suspended and bed sediment samples were collected at 3 sites from upstream to downstream, as the water flows into and through the MF. Samples were then analyzed for the active, in-situ gene expression of the microbial communities. Results from both suspended and bed sediments show clear and significant shifts in the microbial metabolic processes within each respective compartment, in response to the elevated polycyclic aromatic compound (PAC) concentrations. Specific genes likely responsible for hydrocarbon breakdown (Alkane Monooxygenase, Benzoyl-CoA Reductase etc.) experience elevated expression levels, while certain energy metabolism genes (nitrogen, sulfur, methane) reveal fundamental shifts in their pathway specificity, indicating an adaptation response in their basic energy metabolism. Expression from suspended sediments reveal subtle yet delayed metabolic response further downstream compared to bed sediments, indicative of the erosion and transport dynamics within a lotic system. These results provide insight into the use of novel clusters of gene biomarkers to track the active, in-situ microbial response of both emerging and legacy contaminants. Such information will be important in determining the best management strategies for the monitoring and assessment of aquatic health in both natural and contaminated ecosystems.

Validation of Three Rapid Screening Methods for Detection of Verotoxin-Producing Escherichia coli in Foods: Interlaboratory Study

An interlaboratory study was conducted for the validation of 3 methods for the detection of all verotoxin-producing Escherichia coli (VTEC) in foods. The methods were a multi-analyte 1-step lateral flow immunoassay (LFIA) for detection of E. coli O157 and verotoxin (VT); an enzyme-linked immunosorbent assay targeted against VT1, VT2, and VT2c (VT-ELISA); and a polymerase chain reaction (PCR) method for detection of VT genes (VT-PCR). Aliquots (25 g or 25 mL) of 4 food types (raw minced [ground] beef, unpasteurized milk, unpasteurized apple juice [cider], and salami) were individually inoculated with low numbers (<9 to 375 cells/25 g) of 6 test strains of E. coli (serogroups O26, O103, O111, O145, and O157) with differing VT-producing capabilities. Five replicates for each test strain and 5 uninoculated samples were prepared for each food type. Fourteen participating laboratories analyzed samples using the LFIA, 9 analyzed the samples by ELISA, and 9 by PCR. The LFIA for O157 and VT had a specificity (correct identification of negative samples) of 92 and 94%, respectively, and a sensitivity (correct identification of positive samples) of 94 and 55%, respectively. The VT-ELISA and VT-PCR

Microbial metatranscriptomic investigations across contaminant gradients of the Detroit River

Microbial community function in freshwater sediments is influenced by the presence and persistence of anthropogenic pollutants, yet simultaneously imposes significant control on their transformation. Thus, microbes provide valuable ecosystem services in terms of biodegradation and bioindicators of compromised habitats. From a remediation perspective it is valuable to leverage the suite of microbial genes at the transcriptional level that are active in either natural versus stressed environments to provide insight into the cycling and fate of contaminants. Metatranscriptomic analysis of total bacterial and archaeal messenger RNA (mRNA) is a useful tool in this facet and was applied to sediments sampled from the Detroit River; a binational Area of Concern (AOC) in the Great Lakes. Previously established sediment surveys and modelling delineated the river into contaminant gradients based on concentrations of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and metals. Differential expression analysis through DESeq2 revealed that microbial transcripts associated with nitrate reduction, methanogenesis, and beta-oxidation were significant in legacy polluted sediments and linked with energetic pathways key in the generation of cellular currencies (acetyl-CoA, succinyl-CoA). Gluconeogenesis and polyester synthesis also showed high abundance in contaminated regions, along with increased expression of stress response genes and transposons, despite decreases in community α-diversity. Aromatic cleavage genes were detected, but in low abundance across the contaminant gradient. These results suggest that microbial communities within the Detroit River exploit unique anabolic and catabolic pathways to derive and store energy from legacy organic contaminants while simultaneously recruiting stress-response and gene transfer mechanisms to cope with xenobiotic pressures. By coupling well-resolved chemical datasets with metatranscriptomics, this study adds to the spatial understanding of in-situ microbial activities in pristine and perturbed freshwater sediments.

Late life revision surgery for dilated colonic conduit in long gap oesophageal atresia

Long gap oesophageal atresia presents a surgical challenge as there is insufficient length of the oesophagus to restore continuity. Oesophageal replacement is generally achieved using a conduit, taken from the stomach, jejunum or colon. Preferences of approach vary between and within surgical centres. Specific to colonic interposition, the continued growth and dilation of the interposed segment may lead to redundancy. Revision surgery in these cases is challenging and has been sparsely described in adult patients. We present two patients who had colonic interposition for long gap oesophageal atresia in infancy and who then underwent successful revision surgery in their fifth decade.

Childhood tuberculosis in Mauritania, 2010-2015: diagnosis and outcomes in Nouakchott and the rest of the country

Setting: The National Tuberculosis Programme, Mauritania. Objective: To compare the diagnosis and treatment outcomes of childhood tuberculosis (TB) cases (aged <15 years) registered between 2010 and 2015 inside and outside Nouakchott, the capital city. Design: This was a retrospective comparative cohort study. Results: A total of 948 children with TB were registered. The registration rate was 10 times higher in Nouakchott. The proportion of children among all TB cases was higher inside than outside Nouakchott (7.5% vs. 4.6%, P < 0.01). Under-fives represented 225 (24%) of all childhood TB cases, of whom 204 (91%) were registered in Nouakchott. Extra-pulmonary TB was more common in Nouakchott, while smear-negative TB was less common. Treatment success was similar inside and outside Nouakchott (national rate 61%). The principal unsuccessful outcomes were loss to follow-up outside Nouakchott (21% vs. 11%, P < 0.01) while transfers out were more common in the city (25% vs. 14%, P = 0.01). Being aged <5 years (OR 1.2, 95%CI 1.1-1.5) was associated with an unsuccessful outcome. Conclusion: This study indicates problems in the diagnosis and treatment of childhood TB in Mauritania, especially outside the city of Nouakchott. We suggest strengthening clinical diagnosis and management, improving communications between TB treatment centres and health services and pressing the TB world to develop more accurate and easy-to-use diagnostic tools for children.

The symbiotic relationship of sediment and biofilm dynamics at the sediment water interface of oil sands industrial tailings ponds

Within the oil sands industry, tailings ponds are used as a means of retaining tailings until a reclamation technology such as end pit lakes (EPLs) can be developed and optimized to remediate such tailings with a water cap (although dry-land strategies for tailing reclamation are also being developed). EPLs have proven successful for other mining ventures (e.g. metal rock mines) in eventually mitigating contaminant loads to receiving waters once biochemical remediation has taken place (although the duration for this to occur may be decades). While the biological interactions at the sediment water interface of tailings ponds or EPLs have been shown to control biogeochemical processes (i.e. chemical fluxes and redox profiles), these have often been limited to static microcosm conditions. Results from such experiments may not tell the whole story given that the sediment water interface often represents a dynamic environment where erosion and deposition may be occurring in association with microbial growth and decay. Mobilization of sediments and associated contaminants may therefore have a profound effect on remediation rates and, as such, may decrease the effectiveness of EPLs as viable reclamation strategies for mining industries. Using a novel core erosion system (U-GEMS), this paper examines how the microbial community can influence sediment water interface stability and how the biofilm community may change with tailings age and after disturbance (biofilm reestablishment). Shear strength, eroded mass measurements, density gradients, high-resolution microscopy, and microbial community analyses were made on 2 different aged tailings (fresh and ∼38 years) under biotic and abiotic conditions. The same experiments were repeated as duplicates with both sets of experiments having consolidation/biostabilization periods of 21 days. Results suggest that the stability of the tailings varies between types and conditions with the fresh biotic tailings experiencing up to 75% more biostabilization than the same abiotic tailings. Further, greater microbial diversity in the aged pond could be a contributing factor to the overall increase in stability of this material over the fresh tailings source.

An enhanced temperature index model for debris-covered glaciers accounting for thickness effect

Debris-covered glaciers are increasingly studied because it is assumed that debris cover extent and thickness could increase in a warming climate, with more regular rockfalls from the surrounding slopes and more englacial melt-out material. Debris energy-balance models have been developed to account for the melt rate enhancement/reduction due to a thin/thick debris layer, respectively. However, such models require a large amount of input data that are not often available, especially in remote mountain areas such as the Himalaya, and can be difficult to extrapolate. Due to their lower data requirements, empirical models have been used extensively in clean glacier melt modelling. For debris-covered glaciers, however, they generally simplify the debris effect by using a single melt-reduction factor which does not account for the influence of varying debris thickness on melt and prescribe a constant reduction for the entire melt across a glacier. In this paper, we present a new temperature-index model that accounts for debris thickness in the computation of melt rates at the debris-ice interface. The model empirical parameters are optimized at the point scale for varying debris thicknesses against melt rates simulated by a physically-based debris energy balance model. The latter is validated against ablation stake readings and surface temperature measurements. Each parameter is then related to a plausible set of debris thickness values to provide a general and transferable parameterization. We develop the model on Miage Glacier, Italy, and then test its transferability on Haut Glacier d'Arolla, Switzerland. The performance of the new debris temperature-index (DETI) model in simulating the glacier melt rate at the point scale is comparable to the one of the physically based approach, and the definition of model parameters as a function of debris thickness allows the simulation of the nonlinear relationship of melt rate to debris thickness, summarised by the Østrem curve. Its large number of parameters might be a limitation, but we show that the model is transferable in time and space to a second glacier with little loss of performance. We thus suggest that the new DETI model can be included in continuous mass balance models of debris-covered glaciers, because of its limited data requirements. As such, we expect its application to lead to an improvement in simulations of the debris-covered glacier response to climate in comparison with models that simply recalibrate empirical parameters to prescribe a constant across glacier reduction in melt.

How much is too much? Outcomes in patients using high-dose insulin glargine

BACKGROUND AND OBJECTIVES

Many patients with type 2 diabetes mellitus (T2DM) do not achieve glycaemic control targets on basal insulin regimens. This analysis investigated characteristics, clinical outcomes and impact of concomitant oral antidiabetes drugs (OADs) in patients with T2DM treated with high-dose insulin glargine.

METHODS

Patient-level data were pooled from 15 randomised, treat-to-target trials in patients with T2DM treated with insulin glargine ± OADs for ≥ 24 weeks. Data were stratified according to whether patients exceeded three insulin dose cut-off levels (> 0.5, > 0.7 and > 1.0 IU/kg). End-points included glycated haemoglobin A1c (A1C), fasting plasma glucose, body weight, and overall, nocturnal and severe hypoglycaemia.

RESULTS

Data from 2837 insulin-naïve patients were analysed. Patients with insulin titrated beyond the three doses investigated had significantly higher baseline A1C levels and were younger, with shorter diabetes duration than those at/below cut-offs (p < 0.05 for all cut-offs); they also had greater weight gain (p < 0.001 for the > 0.5 and > 0.7 IU/kg cut-offs) than those who did not exceed the cut-offs, regardless of concomitant OAD. Patients on concomitant metformin alone had higher insulin doses at Week 24, but achieved greater reductions in A1C, less weight gain and lower hypoglycaemia rates than patients on a concomitant sulfonylurea or metformin plus a sulfonylurea, regardless of whether cut-offs were exceeded.

CONCLUSION

In patients with T2DM, increasing basal insulin doses above 0.5 IU/kg may not improve glycaemic control; treatment strategies targeting postprandial glucose control should be considered for such patients.

Why ethics is indispensable for good-quality operational research

This article outlines challenges encountered when ethics is taught and promoted in the Operational Research courses of the International Union Against Tuberculosis and Lung Disease, with a focus on ethical issues related to studies that involve health records reviews. Problems observed by the Ethics Advisory Group include engagement of all stakeholders, maintenance of confidentiality and authorship. The omission of ethics in the STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) statement and its explanatory commentary published in 2007 is highlighted and questioned.

Diagnostic management and outcomes of pulmonary tuberculosis suspects admitted to a central hospital in Malawi

SETTING

Zomba Central Hospital, Malawi.

OBJECTIVE

To determine diagnostic management and outcomes of pulmonary tuberculosis (PTB) suspects admitted to adult wards.

DESIGN

A retrospective, cross-sectional review of medical records of patients admitted to hospital between July and September 2010.

RESULTS

There were 141 PTB suspects. Sputum examination was requested and performed in 67 (48%) suspects, but none were smear-positive. Chest X-ray (CXR) was requested and performed in 26 (39%) suspects whose sputum smears were negative. Eleven suspects had a CXR suggestive of PTB: two were started on TB treatment and eight died before treatment started. Human immunodeficiency virus (HIV) status was known for 50 patients (35% of all suspects) on admission, all of whom were HIV-positive. HIV testing was requested for 37 patients, but was only performed in 12, five of whom were HIV-positive. Only one patient was referred for antiretroviral treatment. There were 41 (29%) deaths, eight of whom had probable TB and were not treated. In the remaining 33 patients who died, only nine (27%) had sputum smears examined and four (12%) had a CXR.

CONCLUSION

The study shows inadequacies in the diagnostic management of PTB suspects in the Zomba Central Hospital, but suggests opportunities for improvement.

Reintroduction of imatinib in GIST

PURPOSE

This review examines the clinical evidence showing that imatinib can be prescribed to treat recurrence or progression of gastrointestinal stromal tumors (GIST) in patients who interrupted first-line imatinib therapy in the adjuvant or advanced/metastatic setting.

METHODOLOGY

A literature search was performed in PubMed, Web of Knowledge, and Google using the following keywords: rechallenge/reinitiation/reintroduction + gastrointestinal + imatinib and rechallenge/reinitiation/reintroduction + imatinib.

RESULTS

The evidence indicates that the reintroduction of imatinib can benefit patients who experience GIST progression after interrupting treatment of advanced/metastatic disease, as well as patients who experience GIST recurrence after completing prescribed neoadjuvant and/or adjuvant therapy. Although reintroduction of imatinib may lead to suboptimal outcomes, as evidenced by higher rates of progressive disease compared to initial treatment, imatinib discontinuation does not appear to favor development of imatinib resistance, leaving dose escalation and third- or fourth-line imatinib treatment as viable options for patients.

CONCLUSION

Results indicate that after initial start and interruption of imatinib therapy, reintroduction of imatinib therapy is efficacious and provides continued survival benefit in patients with GIST.

Two Case Reports of Resensitization to Previous Chemotherapy with the Novel Hypoxia-Activated Hypomethylating Anticancer Agent RRx-001 in Metastatic Colorectal Cancer Patients

The development of chemoresistance is a persistent problem during the treatment of cancer. Although reversion or modification of acquired chemoresistance has been previously observed, no systematic exploration has been undertaken. Here, we report a case study of 2 male patients, 62 and 66 years old, both with histologically proven, radiologically progressing, extensively pretreated, metastatic and refractory (≥2 conventional regimens and drug therapy) colorectal adenocarcinoma that was previously treated with FOLFIRI. The patients were resensitized to FOLFIRI after exposure to RRx-001 in the context of a phase-1 study. RRx-001 is a novel, hypomethylating and free-radical-inducing anticancer agent that activates nitrite reduction to NO under hypoxia and has an impact on epigenetic pathways. The repression of DNA methyltransferase 1 by RRx-001 may lead to demethylation and reexpression of silenced tumor suppressor genes, leading to resensitization. These examples provide insight into a nascent strategy to improve the prognosis in heavily pretreated cancer patients and suggest routes for further exploration.

Profile and treatment outcomes of elderly patients with tuberculosis in Delhi, India: implications for their management

BACKGROUND

Given India's high rate of TB, rising burden of non-communicable diseases (NCDs) and growing elderly population, elderly TB patients may be at higher risk of adverse outcomes including death, loss-to-follow-up (LTFU) and treatment failure. This may call for modifications in their management. This study thus aimed to compare the profile and treatment outcomes between elderly (≥60 years) and non-elderly (15-59 years) TB patients.

METHODS

This was a retrospective cohort study using routinely-collected programme data from a chest clinic in Delhi, India. It included all elderly and selected non-elderly TB patients registered for treatment between 2005 and 2010. Data on patients' clinical and demographic characteristics and treatment outcomes were analysed.

RESULTS

There were 812 elderly and 1624 non-elderly TB patients. Elderly patients were more likely to be male (63.2% vs 51.1%) and have smear-positive TB (56.0% vs 47.4%). Adverse outcomes were more frequent among elderly patients (adjusted OR 1.9, 95% CI: 1.5-2.4), specifically deaths (adjusted OR 5.0, 95% CI: 3.1-8.1) and lost-to-follow-up (adjusted OR 1.4, 95% CI: 1.0-1.9).

CONCLUSIONS

The profile and worse outcomes of elderly Indian TB patients may be indicative of co-existing NCDs. This needs further investigation and likely calls for a more comprehensive and intensive approach to their management.

Conducting operational research within a non governmental organization: the example of Medecins Sans Frontieres

Like many other non governmental organizations (NGOs) that provide assistance to vulnerable populations living in difficult and resource-limited settings, Médecins Sans Frontières (MSF) is confronted with situations for which proven, effective interventions are often lacking and/or where there is need for strong advocacy for improving medical care. As a result, MSF has become an important contributor to health research, and has dedicated resources to guide operational research by establishing its own Ethics Review Board, an innovation fund, an online publications repository and by regularly contributing to major scientific conferences. However, this increased research activity has led to concern that priorities and resources may be diverted away from the essential mandate of care provision for NGOs. In response, this article discusses the potential role operational research can play within medical NGOs such as MSF, and highlights the relevance of operational research, the essential elements of developing it within the organisation and some of the perceived barriers and solutions.

An ambulance referral network improves access to emergency obstetric and neonatal care in a district of rural Burundi with high maternal mortality

OBJECTIVES

In 2006, Médecins sans Frontières (MSF) established an emergency obstetric and neonatal care (EmONC) referral facility linked to an ambulance referral system for the transfer of women with obstetric complications from peripheral maternity units in Kabezi district, rural Burundi. This study aimed to (i) describe the communication and ambulance service together with the cost; (ii) examine the association between referral times and maternal and early neonatal deaths; and (iii) assess the impact of the referral service on coverage of complicated obstetric cases and caesarean sections.

METHODS

Data were collected for the period January to December 2011, using ambulance log books, patient registers and logistics records.

RESULTS

In 2011, there were 1478 ambulance call-outs. The median referral time (time from maternity calling for an ambulance to the time the patient arrived at the MSF referral facility) was 78 min (interquartile range, 52-130 min). The total annual cost of the referral system (comprising 1.6 ambulances linked with nine maternity units) was € 85 586 (€ 61/obstetric case transferred or € 0.43/capita/year). Referral times exceeding 3 h were associated with a significantly higher risk of early neonatal deaths (OR, 1.9; 95% CI, 1.1-3.2). MSF coverage of complicated obstetric cases and caesarean sections was estimated to be 80% and 92%, respectively.

CONCLUSION

This study demonstrates that it is possible to implement an effective communication and transport system to ensure access to EmONC and also highlights some of the important operational factors to consider, particularly in relation to minimising referral delays.

Organo-selenium-containing dental sealant inhibits bacterial biofilm

Oral bacteria, including Streptococcus mutans and Streptococcus salivarius, contribute to tooth decay and plaque formation; therefore, it is essential to develop strategies to prevent dental caries and plaque formation. We recently showed that organo-selenium compounds covalently attached to different biomaterials inhibited bacterial biofilms. Our current study investigates the efficacy of an organo-selenium dental sealant (SeLECT-Defense(TM) sealant) in inhibiting S. mutans and S. salivarius biofilm formation in vitro. The organo-selenium was synthesized and covalently attached to dental sealant material via standard polymer chemistry. By colony-forming unit (CFU) assay and confocal microscopy, SeLECT-Defense(TM) sealant was found to completely inhibit the development of S. mutans and S. salivarius biofilms. To assess the durability of the anti-biofilm effect, we soaked the SeLECT-Defense(TM) sealant in PBS for 2 mos at 37°C and found that the biofilm-inhibitory effect was not diminished after soaking. To determine if organo-selenium inhibits bacterial growth under the sealant, we placed SeLECT-Defense sealant over a lawn of S. mutans. In contrast to a control sealant, SeLECT-Defense(TM) sealant completely inhibited the growth of S. mutans. These results suggest that the inhibitory effect of SeLECT-Defense(TM) sealant against S. mutans and S. salivarius biofilms is very effective and durable.

Coverage and use of insecticide-treated bed nets in households with children aged under five years in Liberia

SETTING

St John's District, Grand Bassa County, Liberia.

OBJECTIVES

In households with children aged <5 years, to examine the coverage and use of long-lasting insecticide-treated bed nets (LLINs), factors associated with non-use and the characteristics and conditions of bed nets.

DESIGN

Cross-sectional study involving interviews with mothers and visual inspection of LLINs.

RESULTS

Of 663 households visited, 492 (74%) had no LLIN and 135 (20%) had one LLIN. Of 171 households with LLINs, these were consistently used by 73 (43%) children. The main reasons for inconsistent use included LLINs being old or damaged, and LLINs generating too much heat for 20-30% of children. Visual inspection of LLINs in 130 households showed that 98% of LLINs were white, 20% were not hung above the child's sleeping place, 30% had holes, 84% were double-bed sized and 82% had been washed in the previous 6 months.

CONCLUSION

Despite reports of 100% LLIN coverage in St John's District, this study showed that only a quarter of households had an LLIN, over half of the children used LLINs inconsistently and the LLINs had several deficiencies. More surveys should be conducted to determine the true coverage of LLINs in Liberia, and measures must be taken to improve the use of LLINs.

Achieving the millennium development goal of reducing maternal mortality in rural Africa: an experience from Burundi

OBJECTIVES

To estimate the reduction in maternal mortality associated with the emergency obstetric care provided by Médecins Sans Frontières (MSF) and to compare this to the fifth Millennium Development Goal of reducing maternal mortality.

METHODS

The impact of MSF's intervention was approximated by estimating how many deaths were averted among women transferred to and treated at MSF's emergency obstetric care facility in Kabezi, Burundi, with a severe acute maternal morbidity. Using this estimate, the resulting theoretical maternal mortality ratio in Kabezi was calculated and compared to the Millennium Development Goal for Burundi.

RESULTS

In 2011, 1385 women from Kabezi were transferred to the MSF facility, of whom 55% had a severe acute maternal morbidity. We estimated that the MSF intervention averted 74% (range 55-99%) of maternal deaths in Kabezi district, equating to a district maternal mortality rate of 208 (range 8-360) deaths/100,000 live births. This lies very near to the 2015 MDG 5 target for Burundi (285 deaths/100,000 live births).

CONCLUSION

Provision of quality emergency obstetric care combined with a functional patient transfer system can be associated with a rapid and substantial reduction in maternal mortality, and may thus be a possible way to achieve Millennium Development Goal 5 in rural Africa.

Practicing medicine without borders: tele-consultations and tele-mentoring for improving paediatric care in a conflict setting in Somalia?

OBJECTIVES

In a district hospital in conflict-torn Somalia, we assessed (i) the impact of introducing telemedicine on the quality of paediatric care, and (ii) the added value as perceived by local clinicians.

METHODS

A 'real-time' audio-visual exchange of information on paediatric cases (Audiosoft Technologies, Quebec, Canada) took place between clinicians in Somalia and a paediatrician in Nairobi. The study involved a retrospective analysis of programme data, and a perception study among the local clinicians.

RESULTS

Of 3920 paediatric admissions, 346 (9%) were referred for telemedicine. In 222 (64%) children, a significant change was made to initial case management, while in 88 (25%), a life-threatening condition was detected that had been initially missed. There was a progressive improvement in the capacity of clinicians to manage complicated cases as demonstrated by a significant linear decrease in changes to initial case management for meningitis and convulsions (92-29%, P = 0.001), lower respiratory tract infection (75-45%, P = 0.02) and complicated malnutrition (86-40%, P = 0.002). Adverse outcomes (deaths and lost to follow-up) fell from 7.6% in 2010 (without telemedicine) to 5.4% in 2011 with telemedicine (30% reduction, odds ratio 0.70, 95% CI: 0.57-0.88, P = -0.001). The number needed to be treated through telemedicine to prevent one adverse outcome was 45. All seven clinicians involved with telemedicine rated it to be of high added value.

CONCLUSION

The introduction of telemedicine significantly improved quality of paediatric care in a remote conflict setting and was of high added value to distant clinicians.

Symptom screen: diagnostic usefulness in detecting pulmonary tuberculosis in HIV-infected pregnant women in Kenya

OBJECTIVE

To determine the diagnostic usefulness of tuberculosis (TB) symptom screening to detect active pulmonary TB among human immunodeficiency virus (HIV) infected pregnant women in two PMTCT (prevention of mother-to-child transmission) clinics in western Kenya that are supported by the United States Agency for International Development-Academic Model Providing Access to Healthcare partnership.

DESIGN

Cross-sectional study. Participants were interviewed for TB symptoms with a standardized questionnaire (cough >2 weeks, fever, night sweats, weight loss or failure to gain weight). Those with cough submitted sputum specimens for smear microscopy for acid-fast bacilli and mycobacterial culture. Women at >14 weeks gestation underwent shielded chest radiography (CXR).

RESULTS

Of 187 HIV-infected women, 38 (20%) were symptom screen-positive. Of these, 21 had a cough for >2 weeks, but all had negative sputum smears and mycobacterial cultures. CXRs were performed in 26 symptomatic women: three were suggestive of TB (1 miliary, 1 infiltrates and 1 cavitary). Of 149 women with a negative symptom screen, 100 had a CXR and seven had a CXR suggestive of TB (1 cavitary, 2 miliary and 4 infiltrates).

CONCLUSION

This study did not support the utility of isolated symptom screening in identification of TB disease in our PMTCT setting. CXR was useful in identification of TB suspects in both symptomatic and asymptomatic women.

The Union and Médecins Sans Frontières approach to operational research

Operational research (OR) has become a hot topic at national meetings, international conferences and donor fora. The International Union Against Tuberculosis and Lung Disease (The Union) and Médecins Sans Frontières (MSF) Operational Centre Brussels strongly promote and implement OR with colleagues in low- and middle-income countries. Here we describe how the two organisations define OR, and explain the guiding principles and methodology that underpin the strategy for developing and expanding OR in those countries. We articulate The Union's and MSF's approach to supporting OR, highlighting the main synergies and differences. Then, using the Malawi National Tuberculosis Control Programme as an example, we show how OR can be embedded within tuberculosis control activities, leading to changes in policy and practice at the national level. We discuss the difficult, yet vitally important, issue of capacity building, and share our vision of a new paradigm of product-related training and performance-based OR fellowships as two ways of developing the necessary skills at country level to ensure research is actually performed. Finally, we highlight the need to consider and incorporate into practice the ethical components of OR. This is a key moment to be involved in OR. We are confident that in partnership with interested stakeholders, including the World Health Organization, we can stimulate the implementation of quality, relevant OR as an integral part of health service delivery that in turn will lead to better health for people, particularly for those living in the poorer parts of the world.

Treatment of hypertension in rural Cambodia: results from a 6-year programme

This study was aimed to describe the outcomes of a hypertension treatment programme in two outpatient clinics in Cambodia. We determined proportions of patients who met the optimal targets for blood pressure (BP) control and assessed the evolution of mean systolic and diastolic BP (SBP/DBP) over time. Multivariate analyses were used to identify predictors of BP decrease and risk factors for LTFU. A total of 2858 patients were enrolled between March 2002 and June 2008 of whom 69.2% were female, 30.5% were aged ≥64 years and 32.6% were diabetic. The median follow-up time was 600 days. By the end of 2008, 1642 (57.4%) were alive-in-care, 8 (0.3%) had died and 1208 (42.3%) were lost to follow-up. On admission, mean SBP and DBP were 162 and 94 mm Hg, respectively. Among the patients treated, a significant SBP reduction of 26.8 mm Hg (95% CI: 28.4-25.3) was observed at 6 months. Overall, 36.5% of patients reached the BP targets at 24 months. The number of young adults, non-overweight patients and non-diabetics reaching the BP targets was more. Older age (>64 years), uncontrolled DBP (≥90 mm Hg) on last consultation and coming late for the last consultation were associated with LTFU, whereas non-diabetic patients were 1.5 times more likely to default than diabetics (95% CI: 1.3-1.7). Although the definite magnitude of the BP decrease due to antihypertension medication over time cannot be assessed definitely without a control group, our results suggest that BP reduction can be obtained with essential hypertension treatment in a large-scale programme in a resource-limited setting.

Phase I study of RAD001 (everolimus), cetuximab, and irinotecan as second-line therapy in metastatic colorectal cancer (mCRC)

e15115

Background: The PI3K/AKT/mTOR pathway is frequently dysregulated in colorectal cancer (Cancer Res 2005;65:11227). In a phase I study in patients with advanced solid tumors, everolimus an oral mTOR inhibitor demonstrated clinical benefit including a partial response in pts with colorectal cancer (J Clin Oncol 2008;26:1603–10; J Clin Oncol 2008; 26:1588–95). Methods: This open-label, multicenter phase I study uses a Bayesian logistic model to identify feasible doses of everolimus + irinotecan + cetuximab. Adult pts with mCRC progressing despite prior 5-FU/oxaliplatin (FOLFOX) or capecitabine/oxaliplatin (XELOX) plus bevacizumab (if standard practice) were treated using a sequential dose escalation scheme (Table). Dose decisions were driven by the probability of dose-limiting toxicity (DLT) in the first 2 cycles. Dose level decisions were based on maximizing the probability that end-of-cycle-2 DLT rate would be within the targeted toxicity interval (20% to <35%) and minimizing the risk of over-dosing (< 5% risk of unacceptable toxicity and < 25% risk of excessive/unacceptable toxicity). Results: 18 pts were treated from April ‘07 to August ‘08, 5 pts at dose level A1 and 13 pts at dose level B1. Two DLTs (G3 rash on cycle 2 day 1 lasting > 7 days and G3 mucositis on cycle 1 day 14 lasting > 7 days, 1 pt each) were reported in 4 evaluable pts at dose level A1. No DLTs were reported in 7 evaluable patients at dose level B1. Conclusions: At dose level B1 everolimus in combination with irinotecan and cetuximab was generally well tolerated. The study was stopped due to changes in clinical practice based on emerging data indicating that cetuximab has limited efficacy in mCRC patients with KRAS mutations and that efficacy data favors daily RAD001 over weekly dosing. Patients in this study were treated with cetuximab irrespective of KRAS status.

[Table: see text]

[Table: see text]

Multicenter randomized controlled phase III clinical trial using TNFerade (TNF) with chemoradiation (CRT) in patients with locally advanced pancreatic cancer (LAPC): Interim analysis (IA) of overall survival (OS)

4605

Intro: Local control of LAPC with CRT has historically demonstrated survival benefit vs. RT alone. TNF is a nonreplicating adenovirus vector delivering human tumor necrosis factor (TNF-α). Results from a phase II study with TNF in LAPC indicated a possible survival advantage. To confirm these findings, a randomized, open-label, controlled Pancreatic Cancer Trial with TNF (PACT) study was developed. Methods: The TNF arm received a 5 wk treatment of qw intratumoral inj of 4x1011 PU TNF, cont. iv 5-FU and 50.4Gy radiation. The standard of care (SOC) arm received CRT alone. Both groups received adjuvant gemcitabine(G) with the option of erlotinib(E). An IA of OS (primary efficacy endpoint) was planned after the first third (92) of the expected 276 total death events (from a total patient n=330). Nonparametric logrank of OS was planned; in addition, a lognormal model was used to account for an evident separation of the survival curves after the median. Results: 185 pts were available for OS analysis (117-TNF+SOC and 68-SOC). Survival in the TNF+SOC group demonstrated a HR of 0.753 (CI [0.494 - 1.15]) relative to SOC. Best fit parametric lognormal analysis indicated a median survival of 11.1 mo with TNF+SOC and 8.7 mo with SOC; nonparametric methods indicated a MS of 9.9 mo for both arms, with a pronounced “late effect” (75th percentile 19.4 mo with TNF+SOC and 11.8 mo with SOC). Prognostic information (G and E use, stage, etc) indicated equivalent distribution between groups. Conclusions: HR results of the OS IA indicate an encouraging trend in favor of the TNF treated group. Parametric medians may better reflect the true HR than nonparametric methods since the latter do not reflect the shape of the OS distribution. A second IA is planned after 2/3 total events.

[Table: see text]

Multi-center phase II/III randomized controlled clinical trial using TNFerade combined with chemoradiation in patients with locally advanced pancreatic cancer (LAPC)

4518

Background: TNFerade is a replication-deficient adenoviral vector carrying the transgene for human TNF-a protein, regulated by the radiation-inducible promoter Egr-1. A 50 patient (pt) phase II dose-escalation study in LAPC showed a possible dose-dependent improvement in survival. To confirm these findings, the randomized Pancreatic Cancer Clinical Trial with TNFerade (PACT) study was developed. PACT is a 330 pt study, powered to detect a 20% absolute increase in the primary efficacy endpoint (overall survival at 1 year) compared to standard of care (SOC) chemoradiation. An interim analysis of safety and efficacy was planned after the first 51 pts were randomized. Survival data to 11/15/06 has been evaluated and are reported here. Methods: The TNFerade arm pts received a five- wk treatment of weekly injections of 4 x 1011 pu TNFerade, continuous infusion 5-FU (200 mg/m2/day x 5 days/wk) and 50.4 Gy radiation. TNFerade was administered by percutaneous CT-guided transabdominal injection. The SOC arm received the same regimen, without TNFerade injections. Patients were randomized 2:1 to the TNFerade and SOC arms. The first 51 randomized pts were assessed for evidence of objective response (OR) and overall survival Results: Assessment of response data is still ongoing. TNFerade + SOC was well tolerated. One year survival, the primary endpoint of the study, was 70.5% in the TNFerade + SOC arm versus 28.0% in the SOC arm, an absolute increase of 42.5%. The median survival for TNFerade + SOC pts was 515 days compared to 335 days for the SOC pts. The logrank statistic for comparison between the two arms is X2 = 2.014 (p=0.16). Conclusions: The interim survival data is preliminary. The magnitude of the difference in survival in favor of the TNFerade + SOC arm, however, is encouraging. The data appears to corroborate previous findings from the dose-escalation study, which showed an apparent survival advantage in the 4×1011 pu dose group compared to 4 x 109 pu group. A second interim analysis is planned with larger patient numbers to determine whether this early positive trend is confirmed.

No significant financial relationships to disclose.

5,10-methylenetetrahydrofolic acid with 5-fluorouracil as first line treatment in metastatic colorectal cancer: Phase II study results

3599

Background: 5-Fluorouracil (FU) plus Leucovorin (LV) has historically been the standard first line treatment of colorectal cancer. Although LV modestly enhances FU activity, it can increase systemic toxicity and also must be intracellularly converted in multiple steps to its active metabolite, 5,10-methylenetetrahydrofolate (CoFactor [CO]). Unlike LV, CO directly modulates FU inhibition of thymidylate synthase without the need for metabolic conversion. Preclinical models show reduced hematologic toxicity of CO+FU with enhanced efficacy compared to FU+LV. We evaluated CO+FU chemotherapy in patients with previously untreated mCRC. Methods: Patients (pts) had performance status ECOG 0–2 and objectively measurable mCRC. Prior adjuvant therapy was allowed including FU+LV. Fifty pts were enrolled and treated with CO 60mg/m2 and FU 450mg/m2 (weekly IV bolus) for 6 weeks, followed by 14 day rest. Response was measured at 16 wks (WHO criteria). Results: As of January 2006, 50 pts received at least 1 dose of drug and are no longer on treatment. Patient demographics: median age = 65 (range 42–86), M/F = 60%/40%. Mean number of doses was 18.0 (range 2–41). Overall incidence of grade 3/4 AEs was 14 (28%). No grade 3/4 drug-related hematologic toxicity was observed. There was no significant effect on HCT, Bili, WBC, ALT, and AST during the course of the study. Objective response rate (CR + PR) to first line treatment with CO+FU based on independent blinded review was 35% (2 CR, 14 PR, 23 SD, 7 PD; 95% CI: 21.4–50.2) based on 46 pts evaluable for response. Median time to tumor progression was 163 days (95% CI: 105 -189). Twenty pts are deceased and median survival has not been reached. Conclusions: The results suggest thatCO+FU is safe, well tolerated, and has activity in mCRC. In the optimum treatment strategy afforded by the availability of numerous drugs, the high level of activity and low toxicity of CO+FU suggests that this combination may be a good initial treatment in a sequential strategy of mCRC management, especially among pts who would benefit by minimizing initial toxicity.

[Table: see text]

The PACT trial: Interim results of a randomized trial of TNFerade biologic plus chemoradiation (CRT) compared to CRT alone in locally advanced pancreatic cancer (LAPC)

4102

Background: TNFerade is a second-generation replication-deficient adenovector, carrying the transgene encoding human TNF-α, regulated by the stress-inducible promoter Egr-1. In a phase I trial of TNFerade + radiation in 36 patients with advanced or refractory solid tumors, a 47% objective tumor response rate was observed, including 100% complete responses in 3 stage 4 melanoma patients, with 2/3 disease-free at >3.5 years. Methods: This controlled phase II trial randomizes 74 patients with newly diagnosed unresectable LAPC to 5-wks of TNFerade (4 × 1011 pu via weekly intratumoral injection) + CRT (5-FU [200 mg/m2/day CIV × 5 days/wk] and 50.4 Gy radiation) or CRT alone. All patients receive maintenance gemcitabine. Endpoints: Progression-free survival, safety, radiographic tumor response, CA 19–9 and survival. Results: In dose escalation (n=50) dose-limiting toxicities occurred in 3 patients at 1 × 1012 pu (pancreatitis in 2 and biliary obstruction), setting the MTD at 4 × 1011 pu. Compared with the first two cohorts (n=30), the MTD (n = 11) was associated with greater locoregional control and progression-free survival, a higher rate of stable or decreasing CA 19–9, improved overall survival (median = 11.2), and a high (45%) resection rate. Accrual continues in the randomized phase of the study at 20+ centers. The most frequent adverse events in the first 16 enrolled patients have been nausea (75%), abdominal pain (63%), constipation (50%), anemia (38%), diarrhea (38%), vomiting (38%), and weight loss (38%), with no significant difference in severity or frequency between the TNFerade + CRT and CRT groups. No thromboembolic events have been reported. Serum TNF-alpha levels have remained low (peak = 45.3 pg/mL, in a CRT patient). CA 19–9 has been stable (no change > 100 U/mL) or decreased in all but one CRT patient. Conclusions: These initial data indicate that TNFerade plus CRT, given as weekly intratumoral injections to patients with LAPC, is feasible and tolerable compared to CRT alone. With continued accrual, comparative tumor response and toxicity data will be available and updated.

No significant financial relationships to disclose.

The in vitro activity of selected defensins against an isolate of Pseudomonas in the presence of human tears

BACKGROUND/AIMS

Pseudomonas aeruginosa is a major cause of severe bacterial keratitis and remains a difficult clinical entity to treat successfully with the current arsenal of antimicrobial agents. Defensins are small cationic peptides with broad in vitro antimicrobial activity and are potential ocular therapeutic agents. The authors characterised the in vitro activity of defensins NP-1 and NP-3a against P aeruginosa in the presence of human tears.

METHODS

A clinical Pseudomonas isolate was grown to mid-log phase, and 1 x 10(6 )colony forming units were exposed to the peptides (200 microg/ml) for up to 2 hours in the presence of varying concentrations (10-70%) of human tears.

RESULTS

For both peptides in the presence of 10% tears, >3 log units of killing was achieved within 30 minutes. In 70% tears, NP-1 produced >1 log unit of killing at 2 hours, indicating that, although reduced, its activity remained significant. In 20% tears, NP-3a demonstrated 2 log units of killing at 2 hours; however, the antimicrobial activity of this defensin was completely inhibited in the presence of 70% tears.

CONCLUSION

These in vitro data suggest that while the microbicidal activity of some defensins may be diminished at the ocular surface in vivo, significant activity is still possible with certain peptides.