Antibacterial Zirconia Surfaces from Organocatalyzed Atom-Transfer Radical Polymerization

Antibacterial coatings are becoming increasingly attractive for application in the field of biomaterials. In this framework, we developed polymer coating zirconia with antibacterial activity using the "grafting from" methodology. First, 1-(4-vinylbenzyl)-3-butylimidazolium chloride monomer was synthesized. Then, the surface modification of zirconia substrates was performed with this monomer via surface-initiated photo atom transfer radical polymerization for antibacterial activity. X-ray photoelectron spectroscopy, ellipsometry, static contact angle measurements, and an atomic force microscope were used to characterize the films for each step of the surface modification. The results revealed that cationic polymers could be successfully deposited on the zirconia surfaces, and the thickness of the grafted layer steadily increased with polymerization time. Finally, the antibacterial adhesion test was used to evaluate the antibacterial activity of the modified zirconia substrates, and we successfully showed the antibacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa strains.

BacA: a possible regulator that contributes to the biofilm formation of Pseudomonas aeruginosa

Previously, we pointed out in P. aeruginosa PAO1 biofilm cells the accumulation of a hypothetical protein named PA3731 and showed that the deletion of the corresponding gene impacted its biofilm formation capacity. PA3731 belongs to a cluster of 4 genes (pa3732 to pa3729) that we named bac for "Biofilm Associated Cluster." The present study focuses on the PA14_16140 protein, i.e., the PA3732 (BacA) homolog in the PA14 strain. The role of BacA in rhamnolipid secretion, biofilm formation and virulence, was confirmed by phenotypic experiments with a bacA mutant. Additional investigations allow to advance that the bac system involves in fact 6 genes organized in operon, i.e., bacA to bacF. At a molecular level, quantitative proteomic studies revealed an accumulation of the BAC cognate partners by the bacA sessile mutant, suggesting a negative control of BacA toward the bac operon. Finally, a first crystallographic structure of BacA was obtained revealing a structure homologous to chaperones or/and regulatory proteins.

Ataxia-Telangiectasia Mutated (ATM) loss of function displays variant and tissue-specific differences across tumor types

PURPOSE

Mutations in the ATM gene are common in multiple cancers, but clinical studies of therapies targeting ATM aberrant cancers have yielded mixed results. Refinement of ATM loss of function (LOF) as a predictive biomarker of response is urgently needed.

EXPERIMENTAL DESIGN

We present the first disclosure and preclinical development of a novel, selective ATR inhibitor, ART0380, and test its antitumor activity in multiple preclinical cancer models. To refine ATM LOF as a predictive biomarker, we performed a comprehensive pan-cancer analysis of ATM variants in patient tumors, and then assessed the ATM variant-to-protein relationship. Finally, we assessed a novel ATM LOF biomarker approach in retrospective clinical datasets of patients treated with platinum-based chemotherapy or ATR inhibition.

RESULTS

ART0380 had potent, selective anti-tumor activity in a range of preclinical cancer models with differing degrees of ATM LOF. Pan-cancer analysis identified 10609 ATM variants in 8587 patient tumors. Cancer-lineage specific differences were seen in: the prevalence of deleterious (Tier 1) versus unknown/benign (Tier 2) variants, selective pressure for loss of heterozygosity, and concordance between a deleterious variant and ATM loss of protein (LOP). A novel ATM LOF biomarker approach that accounts for variant classification, relationship to ATM LOP, and tissue-specific penetrance significantly enriched for patients who benefited from platinum-based chemotherapy or ATR inhibition.

CONCLUSIONS

These data help to better define ATM LOF across tumor types in order to optimize patient selection and improve molecularly targeted therapeutic approaches for patients with ATM LOF cancers.

Results from 228 Patients with Hemifacial Spasm Undergoing Microvascular Decompression without Intraoperative Neuroelectrophysiology Monitoring

BACKGROUND

Intraoperative neuroelectrophysiology monitoring (IONM) has been used to decrease complications and to increase the successful rate of microvascular decompression (MVD) MVD for hemifacial spasm (HFS). Still, it is not available at limited resource centers. We report the outcome of patients undergoing MVD for HFS without using IONM.

METHODS

The variables concerning the patients' demographics (age and gender), clinical characteristics, offending vessels (vertebral artery type and non-vertebral artery type), postoperative grade of HFS, and postoperative complications of HFS patients undergoing MVD were retrospectively reviewed and collected. The scoring system provided by the Japan Society for MVD was used to evaluate the postoperative outcome of HFS. Postoperative hearing ability was evaluated according to a subjective assessment of the patients.

RESULTS

A total of 228 patients were recruited. Their median age was 51.0 (44.0-57.0) years old. The total cure effect was observed in 207 (90.8%) patients within the first week after the surgery and in 200 (96.1%) patients in a 2-year follow-up. Permanent hearing disturbance happened in 2 patients (0.9%). No patient had permanent unilateral deafness (0%). No postoperative permanent facial paralysis was reported.

CONCLUSIONS

MVD without IONM may be performed safely and effectively to treat patients with HFS.

Antibiofilm and Antivirulence Properties of 6-Polyaminosteroid Derivatives against Antibiotic-Resistant Bacteria

The emergence of multi-drug resistant pathogens is a major public health problem, leading us to rethink and innovate our bacterial control strategies. Here, we explore the antibiofilm and antivirulence activities of nineteen 6-polyaminosterol derivatives (squalamine-based), presenting a modulation of their polyamine side chain on four major pathogens, i.e., carbapenem-resistant A. baumannii (CRAB) and P. aeruginosa (CRPA), methicillin-resistant S. aureus (MRSA), and vancomycin-resistant E. faecium (VRE) strains. We screened the effect of these derivatives on biofilm formation and eradication. Derivatives 4e (for CRAB, VRE, and MRSA) and 4f (for all the strains) were the most potent ones and displayed activities as good as those of conventional antibiotics. We also identified 11 compounds able to decrease by more than 40% the production of pyocyanin, a major virulence factor of P. aeruginosa. We demonstrated that 4f treatment acts against bacterial infections in Galleria mellonella and significantly prolonged larvae survival (from 50% to 80%) after 24 h of CRAB, VRE, and MRSA infections. As shown by proteomic studies, 4f triggered distinct cellular responses depending on the bacterial species but essentially linked to cell envelope. Its interesting antibiofilm and antivirulence properties make it a promising a candidate for use in therapeutics.

Definitive Stereotactic Body Radiation Therapy in Early-Stage Solitary Hepatocellular Carcinoma: An Australian Multi-Institutional Review of Outcomes

AIMS

Standard curative options for early-stage, solitary hepatocellular carcinoma (HCC) are often unsuitable due to liver dysfunction, comorbidities and/or tumour location. Stereotactic body radiation therapy (SBRT) has shown high rates of local control in HCC; however, limited data exist in the treatment-naïve, curative-intent setting. We report the outcomes of patients with solitary early-stage HCC treated with SBRT as first-line curative-intent therapy.

MATERIALS AND METHODS

A multi-institutional retrospective study of treatment-naïve patients with Barcelona Clinic Liver Cancer stage 0/A, solitary ≤5 cm HCC, Child-Pugh score (CPS) A liver function who underwent SBRT between 2010 and 2019 as definitive therapy. The primary end point was freedom from local progression. Secondary end points were progression-free survival, overall survival, rate of treatment-related clinical toxicities and change in CPS >1.

RESULTS

In total, 68 patients were evaluated, with a median follow-up of 20 months (range 3-58). The median age was 68 years (range 50-86); 54 (79%) were men, 62 (91%) had cirrhosis and 50 (74%) were Eastern Cooperative Oncology Group 0. The median HCC diameter was 2.5 cm (range 1.3-5) and the median prescription biologically effective dose with a tumour a/b ratio of 10 Gy (BED10) was 93 Gy (interquartile range 72-100 Gy). Two-year freedom from local progression, progression-free survival and overall survival were 94.3% (95% confidence interval 86.6-100%), 59.5% (95% confidence interval 46.3-76.4%) and 88% (95% confidence interval 79.2-97.6%), respectively. Nine patients (13.2%) experienced grade ≥2 treatment-related clinical toxicities. A rise >1 in CPS was observed in six cirrhotic patients (9.6%).

CONCLUSION

SBRT is an effective and well-tolerated option to consider in patients with solitary, early-stage HCC. Prospective, randomised comparative studies are warranted to further refine its role as a first-line curative-intent therapy.

Using Targeted Nano-Antibiotics to Improve Antibiotic Efficacy against Staphylococcus aureus Infections

The poor bioavailability of antibiotics at infection sites is one of the leading causes of treatment failure and increased bacterial resistance. Therefore, developing novel, non-conventional antibiotic delivery strategies to deal with bacterial pathogens is essential. Here, we investigated the encapsulation of two fluoroquinolones, ciprofloxacin and levofloxacin, into polymer-based nano-carriers (nano-antibiotics), with the goal of increasing their local bioavailability at bacterial infection sites. The formulations were optimized to achieve maximal drug loading. The surfaces of nano-antibiotics were modified with anti-staphylococcal antibodies as ligand molecules to target S. aureus pathogens. The interaction of nano-antibiotics with the bacterial cells was investigated via fluorescent confocal microscopy. Conventional tests (MIC and MBC) were used to examine the antibacterial properties of nano-antibiotic formulations. Simultaneously, a bioluminescence assay model was employed, revealing the rapid and efficient assessment of the antibacterial potency of colloidal systems. In comparison to the free-form antibiotic, the targeted nano-antibiotic exhibited enhanced antimicrobial activity against both the planktonic and biofilm forms of S. aureus. Furthermore, our data suggested that the efficacy of a targeted nano-antibiotic treatment can be influenced by its antibiotic release profile.

Abstract 3432: Ataxia-telangiectasia mutated loss of function displays variant and tissue specific differences across tumor types

Introduction: ATM loss of function (LOF) in cancer may serve as a predictive biomarker of response for antitumor therapies. However, clinical studies of targeted treatments in ATM-aberrant patients have yielded mixed results; thus, identifying the optimal strategy for selecting patients with ATM LOF tumors remains a critical area of unmet need.

Methods: In order to investigate the heterogeneity observed in ATM aberrant tumors, we conducted a pan-cancer genomic and proteomic profiling of ATM LOF, and also performed retrospective review of clinical outcomes for a subset of patients with ATM LOF treated with platinum or ATR inhibition.

Results: We identified 10,609 ATM variants in 8,587 patients with cancer. The prevalence of deleterious (Tier 1) versus variants of unknown significance (VUS)/benign (Tier 2) variants differed by cancer tissue type, as did selective pressure for loss of heterozygosity (LOH). Analysis of ATM protein staining in 471 patient tumors showed tumors with null, inactivating variants were significantly (p<0.005) more likely to display ATM loss of protein (LOP) than tumors with missense or wildtype, but 19% (N=27/140) and 9% (N=13/149) of tumors with ATM-VUS and wildtype showed loss of protein. In addition, concordance between inactivating mutations and loss of protein also differed based on tumor tissue context, with ovarian and breast cancer showing stronger concordance (greater than 80%) than melanoma and lung cancer ( less than 20%). Patients treated with platinum chemotherapy with select tumor types with deleterious variants in ATM and ATM LOP display improved progression free survival (PFS) (HR 0.50, P=0.03). Lastly, patients with tumor types that have stronger ATM variant-to-protein loss concordance display increased benefit from ATR inhibition (HR 0.40, P=0.04).

Conclusions: Our data highlight that there is heterogeneity in ATM LOF in patients due to multiple variables, including notable tissue-specific differences in the type of variants seen and the relationship between ATM variant status and ATM protein. This genomic heterogeneity and tissue-specificity has implications for predictive biomarker development and clinical trial designs.

Citation Format: Patrick G. Pilie, Daniel Mcgrail, Wei-Lien Wang, Natalie Ngoi, Keith Kyewalabye, Khalida Wani, Hung Le, Erick Campbell, Vijaykumar Holla, Kenna R. Shaw, Funda Meric-Bernstam, Alexander J. Lazar, Virginia Giuliani, Timothy Heffernan, Timothy A. Yap. Ataxia-telangiectasia mutated loss of function displays variant and tissue specific differences across tumor types [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3432.

Management of Adverse Events in Early Clinical Trials by Advanced Practice Providers in the Outpatient Setting: The University of Texas MD Anderson Cancer Center Experience

Background

Advanced practice providers (APPs) play important roles in enrolling, educating, and caring for patients in clinical trials. However, much remains unknown about the role of APPs in managing adverse events (AEs) in early (phase I to II) clinical trials. In this study, we assessed the outpatient management of grade 3 to 4 AEs by APPs in early trials and characterized the workflow of our APP Phase I to II Fast Track (FT) Clinic.

Patients and Methods

We retrospectively reviewed records of patients with advanced or metastatic solid tumors enrolled in phase I to II clinical trials who were seen by APPs from September 2017 to August 2018 in the APP phase I to II FT clinic in the Department of Investigational Cancer Therapeutics.

Results

A total of 808 patients enrolled in 159 clinical trials were seen in 2,697 visits (median 3 visits per patient; range 1-28) by 10 APPs. Treatment was interrupted in 6.9% of visits, and grade 3 to 4 AEs were seen in 5.4% of visits; however, patients from 1.4% of visits were sent to the emergency center (EC) and/or admitted. Patients referred to the EC and/or admitted were more likely to have baseline hypoalbuminemia, high lactate dehydrogenase, and poor Eastern Cooperative Oncology Group performance status (i.e., ECOG > 1; p < .001). There were no associations between EC referral and gender, APP years of experience, or type of treatment.

Conclusions

The APP Phase I to II FT Clinic has an important role in the management of AEs by APPs in early clinical trials in the outpatient setting, potentially avoiding EC visits and admissions.

Ebola virus protein VP40 stimulates IL-12- and IL-18-dependent activation of human natural killer cells

Accumulation of activated natural killer (NK) cells in tissues during Ebola virus infection contributes to Ebola virus disease (EVD) pathogenesis. Yet, immunization with Ebola virus-like particles (VLPs) comprising glycoprotein and matrix protein VP40 provides rapid, NK cell–mediated protection against Ebola challenge. We used Ebola VLPs as the viral surrogates to elucidate the molecular mechanism by which Ebola virus triggers heightened NK cell activity. Incubation of human peripheral blood mononuclear cells with Ebola VLPs or VP40 protein led to increased expression of IFN-γ, TNF-α, granzyme B, and perforin by CD3^–CD56⁺ NK cells, along with increases in degranulation and cytotoxic activity of these cells. Optimal activation required accessory cells like CD14⁺ myeloid and CD14^– cells and triggered increased secretion of numerous inflammatory cytokines. VP40-induced IFN-γ and TNF-α secretion by NK cells was dependent on IL-12 and IL-18 and suppressed by IL-10. In contrast, their increased degranulation was dependent on IL-12 with little influence of IL-18 or IL-10. These results demonstrate that Ebola VP40 stimulates NK cell functions in an IL-12– and IL-18–dependent manner that involves CD14⁺ and CD14^– accessory cells. These potentially novel findings may help in designing improved intervention strategies required to control viral transmission during Ebola outbreaks.

Impact of Carbon Source Supplementations on Pseudomonas aeruginosa Physiology

Pseudomonas aeruginosa is an opportunistic pathogen highly resistant to a wide range of antimicrobial agents, making its infections very difficult to treat. Since microorganisms need to perpetually adapt to their surrounding environment, understanding the effect of carbon sources on P. aeruginosa physiology is therefore essential to avoid increasing drug-resistance and better fight this pathogen. By a global proteomic approach and phenotypic assays, we investigated the impact of various carbon source supplementations (glucose, glutamate, succinate, and citrate) on the physiology of the P. aeruginosa PA14 strain. A total of 581 proteins were identified as differentially expressed in the 4 conditions. Most of them were more abundant in citrate supplementation and were involved in virulence, motility, biofilm development, and antibiotic resistance. Phenotypic assays were performed to check these hypotheses. By coupling all this data, we highlight the importance of the environment in which the bacterium evolves on its metabolism, and thus the necessity to better understand the metabolic pathways implied in its adaptative response according to the nutrient availability.

MacAB-TolC Contributes to the Development of Acinetobacter baumannii Biofilm at the Solid–Liquid Interface

Acinetobacter baumannii has emerged as one of the most problematic bacterial pathogens responsible for hospital-acquired and community infections worldwide. Besides its high capacity to acquire antibiotic resistance mechanisms, it also presents high adhesion abilities on inert and living surfaces leading to biofilm development. This lifestyle confers additional protection against various treatments and allows it to persist for long periods in various hospital niches. Due to their remarkable antimicrobial tolerance, A. baumannii biofilms are difficult to control and ultimately eradicate. Further insights into the mechanism of biofilm development will help to overcome this challenge and to develop novel antibiofilm strategies. To unravel critical determinants of this sessile lifestyle, the proteomic profiles of two A. baumannii strains (ATTC17978 and SDF) grown in planktonic stationary phase or in mature solid–liquid (S-L) biofilm were compared using a semiquantitative proteomic study. Of interest, among the 69 common proteins determinants accumulated in the two strains at the S-L interface, we sorted out the MacAB-TolC system. This tripartite efflux pump played a role in A. baumannii biofilm formation as demonstrated by using ΔmacAB-tolC deletion mutant. Complementary approaches allowed us to get an overview of the impact of macAB-tolC deletion in A. baumannii physiology. Indeed, this efflux pump appeared to be involved in the envelope stress response occurring in mature biofilm. It contributes to maintain wild type (WT) membrane rigidity and provides tolerance to high osmolarity conditions. In addition, this system is probably involved in the maintenance of iron and sulfur homeostasis. MacAB-TolC might help this pathogen face and adapt to deleterious conditions occurring in mature biofilms. Increasing our knowledge of A. baumannii biofilm formation will undoubtedly help us develop new therapeutic strategies to tackle this emerging threat to human health.

An Experimental and Clinically Controlled Study of the Prevention of Dental Caries Using 1.23% Fluoride Gel in Elderly Patients

AIM

To describe the enamel and dentin fluoride mineralization process in practical application and assess the fluoride gel (NaF 1.23%) effectiveness in dental caries prevention for elderly patients.

MATERIALS AND METHODS

Two different types of study were applied: (a) experimental study of fluoride mineralization of enamel and dentin in vitro; (b) clinical controlled interventional studies of the effectiveness in dental caries prevention using 1.23% fluoride gel. Experimental research was performed in laboratory conditions. Teeth of the elderly extracted due to dental diseases served as research objects. Enamel surface and dental root surface were examined under a scanning electron microscope (SEM) before and after demineralization with 37% phosphoric acid within 15 s, as well as after remineralization with toothpaste and 1.23% fluoride gel. Controlled clinical research included 218 older people divided into two groups (intervention group, n = 106; control group, n = 112). In the intervention group, the application of the gel lasts 4 min in the morning for 18 months. The control group received adult P/S toothpaste and a P/S toothbrush. The DIAGNOdent device was used to assess damage both before and after demineralization. For the clinical evaluation of dental caries, international caries detection and assessment system (ICDAS) has been used. Decay missing-filled index (DMFT), effective index (Ef-I), and intervention index (In-I) were determined. Statistical data were analyzed using Mann-Whitney U test and χ2 test. Differences were considered significant at P < 0.05.

RESULTS

An SEM image of the enamel surface and dental root surface after teeth remineralization with fluoride gel shows a hard enamel surface without cracks, even in color and structure. After brushing with toothpaste, numerous cracks remain on the surface of the enamel, and the surface layer of the enamel with a depth of 9.64 microns remains damaged without remineralization. After 18 months of intervention, the rate of dental caries in the control group increased from 42.1% to 68.8%, and in the intervention group it increased from 30.8% to 17.0%. A comparison of the 1.23% fluoride gel with toothpaste shows that the former exhibits performance in protecting teeth from decay and it is 108.2% more effective than the latter.

CONCLUSIONS

Practical experiments proved the function of remineralizing the enamel and dentin of 1.23% fluoride gel on the teeth of the elderly. Intervention research has proven the performance of preventing dental decay from 1.23% fluoride gel for the elderly in question.

O-233 Micronized progesterone plus dydrogesterone versus micronized progesterone alone for luteal phase support in frozen-thawed cycles: a prospective cohort study

Study question

Does the addition of oral dydrogesterone to vaginal progesterone as luteal phase support improve pregnancy outcomes during frozen embryo transfer (FET) cycles compared with vaginal progesterone alone?

Summary answer

Luteal phase support with oral dydrogesterone added to vaginal progesterone improves live birth rates and reduces miscarriage rates compared with vaginal progesterone alone.

What is known already

Progesterone is an important hormone that triggers secretory transformation of the endometrium to allow implantation of the embryo. During in vitro fertilization (IVF), exogenous progesterone is administered for luteal phase support. However, there is wide inter-individual variation in absorption of progesterone via the vaginal wall. Oral dydrogesterone is effective and well tolerated when used to provide luteal phase support after fresh embryo transfer. However, there are currently no data on the effectiveness of luteal phase support with the combination of dydrogesterone with vaginal micronized progesterone compared with vaginal micronized progesterone after FET.

Study design, size, duration

Prospective cohort study conducted at an academic infertility center in Vietnam from 26 June 2019 to 30 March 2020.

Participants/materials, setting, methods

We studied 1364 women undergoing IVF with FET. The luteal support regimen was either vaginal micronized progesterone 400 mg twice daily plus oral dydrogesterone 10 mg twice daily (second part of the study) or vaginal micronized progesterone 400 mg twice daily (first 4 months of the study). The primary endpoint was live birth after the first FET of the started cycle, with miscarriage &lt;12 weeks as one of the secondary endpoints.

Main results and the role of chance

The vaginal progesterone + dydrogesterone group and vaginal progesterone groups included 732 and 632 participants, respectively. Live birth rates were 46.3% versus 41.3%, respectively (rate ratio [RR] 1.12, 95% confidence interval [CI] 0.99–1.27, p = 0.06; multivariate analysis RR 1.30 (95% CI 1.01–1.68), p = 0.042), with a statistically significant lower rate of miscarriage at &lt; 12 weeks (3.4% vs 6.6%; RR 0.51, 95% CI 0.32–0.83; p = 0.009). Birth weight of both singletons (2971.0 ± 628.4 vs. 3118.8 ± 559.2 g; p = 0.004) and twins (2175.5 ± 494.8 vs. 2494.2 ± 584.7; p = 0.002) was significantly lower in the progesterone plus dydrogesterone versus progesterone group.

Limitations, reasons for caution

The study were the open-label design and the non-randomized nature of the sequential administration of study treatments. However, our systematic comparison of the two strategies was able to be performed much more rapidly than a conventional randomized controlled trial. In addition, the single ethnicity population limits external generalizability.

Wider implications of the findings

Oral dydrogesterone in addition to vaginal progesterone as luteal phase support in FET cycles can reduce the miscarriage rate and improve the live birth rate. Carefully planned prospective cohort studies with limited bias could be used as an alternative to randomized controlled clinical trials to inform clinical practice.

Trial registration number

NCT03998761

Validation of Prognostic Scores in Patients With Metastatic Urothelial Cancer Enrolling in Phase I Targeted Therapy or Next Generation Immunotherapy Trials

INTRODUCTION

Enrolling patients with metastatic urothelial carcinoma (mUC) in phase I trials provides an opportunity to identify biological drug activity. Developing prognostic scores may aid in patient selection for phase 1 trials.

PATIENTS AND METHODS

We analyzed records of patients with mUC who participated in targeted therapy and immunotherapy phase I clinical trials at MD Anderson Cancer Center (MDACC). The Bellmunt and Bajorin scores were calculated as bladder cancer-specific prognostic scores. The Royal Marsden Hospital (RMH) and MDACC scores were calculated as phase I prognostic scores. Hazard ratios (HR) were calculated using the Cox proportional hazard model. The prognostic value of the Bellmunt, Bajorin, RMH, and MDACC scores were assessed using the Likelihood ratio (LR) χ2 test and the c-index.

RESULTS

Between 2015 and 2019, 43 patients were enrolled in phase I trials and 12 were enrolled in >I trial leading to a total of 57 trial participants (TPs). Ninty-seven percent of TPs received prior platinum therapy and 60% received a prior checkpoint inhibitor. Median overall survival (OS) and progression-free survival (PFS) were significantly shorter with increasing Bajorin, RMH, or MDACC scores, but not with increasing Bellmunt score. The RMH (c-index=0.658, LR χ2=11.8, P=.008) and MDACC scores (c-index =0.66, LR χ2=12.76, P=.01) outperformed the Bajorin score (c-index=0.522, LR χ2=1.22, P=.5) and the Bellmunt score (c-index=0.537, LR χ2=0.36, P=.9) in predicting overall survivalover. The Bajorin, RMH, and MDACC scores, but not the Bellmunt score, were also predictive of progression-free survival (PFS)prog. The RMH and MDACC scores again outperformed the Bajorin scoreand the Bellmunt score for predicting PFS.

CONCLUSION

The RMH and MDACC phase I prognostic scores accurately predicted survival in patients with mUC and outperformed the bladder cancer-specific scores at time of enrollment on phase 1 clinical trials. The RMH and MDACC scores could optimize selection of patients with mUC for phase I clinical trials.

Decrease in tumor content assessed in biopsies is associated with improved treatment outcome response to pembrolizumab in patients with rare tumors

BACKGROUND

Decreased tumor content (TC) in resection specimens after neoadjuvant therapy is used to predict prognosis. We investigated whether TC assessed in biopsy specimens or the shift in TC from baseline to on-treatment can be used accordingly to predict response in patients with rare tumors who were treated with pembrolizumab.

METHODS

A total of 57 tumors (represented by 173 baseline and 179 on-treatment biopsies) from 57 patients with rare tumors participating in an ongoing phase II clinical trial of pembrolizumab were evaluated. TC was estimated on H&E-stained slides and tumors were dichotomized into low and high TC according to a cut-off of 10%. Necrosis, proliferative fibrosis (PF) and normal tissue were assessed in on-treatment biopsies. TC at baseline and on-treatment, as well as the shift in TC from baseline to on-treatment, was correlated with clinical response defined according to Response Evaluation Criteria in Solid Tumors.

RESULTS

A decrease in TC was seen in 14% (n=8); no change in TC was seen in 75% (n=43); and an increase in TC from baseline to on-treatment was seen in 11% (n=6). Objective response was significantly associated with decrease in TC from baseline to on-treatment (38%, 3/8) compared with no change/increase in TC (6%, 3/49) (p=0.031). Patients with a decrease in TC had a significantly increased time to progression (TTP) (75% probability) compared with patients with an increase (20% probability) or no change in TC (19% probability) (p=0.0042). Low TC was seen in 23% (13/57) of the tumors at baseline and in 26% (15/57) on-treatment. High TC was seen in 77% (44/57) of tumors at baseline and in 74% (42/57) on-treatment. No significant associations with response were seen for necrosis, PF or normal tissue in on-treatment biopsies.

CONCLUSION

Patients with a decrease in TC from baseline to on-treatment had a significant improvement in objective response and a longer TTP. Our data suggest that the shift in TC might be used to predict response to pembrolizumab in rare tumors. However, further investigations in larger cohorts are needed to determine the clinical value of TC, the shift in TC and the cut-off of 10% assessed in biopsies.

TRIAL REGISTRATION NUMBER

NCT02721732.

Implementation of a Novel Web-Based Lesion Selection Tool to Improve Acquisition of Tumor Biopsy Specimens

Introduction

For maximum utility of molecular characterization by next-generation sequencing (NGS) and better understanding of tumor microenvironment with immune correlates analysis, biopsy specimens must yield adequate tumor tissue, and sequential biopsy specimens should sample a consistent site. We developed a web-based lesion selection tool (LST) that enables management and tracking of the biopsy specimen collections.

Methods

Of 145 patients, the LST was used for 88 patients; the other 57 served as controls. We evaluated consistency of the lesion biopsied in longitudinal collections, number of cores obtained, and cores with adequate tumor cellularity for NGS. The Fisher exact test and Wilcoxon rank sum test were used to identify differences between the groups.

Results

The analysis included 30 of 88 (34%) patients in the LST group and 52 of 57 (91%) in the control group. The LST workflow ensured 100% consistency in the lesions biopsied compared with 75% in the control group in longitudinal collections and increased the proportion of patients in whom at least five cores were collected per biopsy.

Conclusions

The novel LST platform facilitates coordination, performance, and management of longitudinal biopsy specimens. Use of the LST enables sampling of the designated lesion consistently, which is likely to accurately inform us the effect of the treatment on tumor microenvironment and evolution of resistant pathways. Such studies are important translational component of any clinical trials and research as they guide the development of next line of therapy, which has significant effect on clinical utility. However, validation of this approach in a larger study is warranted.

Dentinogenesis Imperfecta and Caries in Osteogenesis Imperfecta among Vietnamese Children

Osteogenesis imperfecta (OI) is a genetic disorder characterized by increased bone fragility and low bone mass, caused mainly by mutations in collagen type I encoding genes. The current study aimed to evaluate dentinogenesis imperfecta (DI), oral manifestations and caries status of OI children. Sixty-eight children (41 males, 27 females) aged from 3 to 17 years old (mean 9 ± 4.13) participated in the study. Participants were classified into three OI type groups (I—2 cases, III—31 cases and IV—35 cases). Clinical examination and an orthopantomogram were used to obtain prevalences and associations of DI, caries status, malocclusion, crossbite, open bite, eruption, impaction and missing teeth with OI. The prevalence of DI among OI patients was 47.1%, more common in OI type III than type IV. The yellow-brown discoloration type was more vulnerable to attrition than the opalescent-grey one in the primary dentition. OI seemed not to have a high risk of caries; the prevalence of caries was 69.1%. A high incidence of malocclusion, crossbite and open bite was observed. In-depth oral information would provide valuable data for better dental management in OI patients. Parents and general doctors should pay more attention to dental care to prevent caries and premature tooth loss.

Antibody-Conjugated Nanocarriers for Targeted Antibiotic Delivery: Application in the Treatment of Bacterial Biofilms

Conventional antibiotic treatment is in most cases insufficient to eradicate biofilm-related infections, resulting in high risk of treatment failure and recurrent infections. Recent studies have shown that novel methods of antibiotic delivery can improve clinical outcomes and reduce the emergence of antibiotic resistance. The objectives of this work were to develop and evaluate a targeting nanocarrier system that enables effective delivery of antimicrobial drugs to Staphylococcus aureus, a commonly virulent human pathogen. For this purpose, we first prepared a formulation of polymeric nanoparticles (NPs) suitable for encapsulation and sustained release of antibiotics. A specific antibody against S. aureus was used as a targeting ligand and was covalently immobilized onto the surface of nanoparticulate materials. It was demonstrated that the targeting NPs preferentially bound S. aureus cells and presented an elevated accumulation in the S. aureus biofilm. Compared to free-form antibiotic, the antibiotic-loaded targeting NPs significantly enhanced in vitro bactericidal activity against S. aureus both in planktonic and biofilm forms. Using a mouse infection model, we observed improved therapeutic efficacy of these antibiotic-loaded NPs after a single intravenous administration. Taken together, our studies show that the targeting nanoparticulate system could be a promising strategy to enhance the biodistribution of antibiotics and thereby improve their efficacy.

Molecular Profiling of Metastatic Bladder Cancer Early-Phase Clinical Trial Participants Predicts Patient Outcomes

Prognosis for patients with metastatic bladder carcinoma (mBC) remains limited and in need of novel therapies. We retrospectively analyzed medical records of 43 patients with platinum-refractory metastatic bladder cancer (mBC) who participated in one or more phase I trials of various investigational therapies. Patients' tumors or circulating tumor DNA were analyzed by next-generation sequencing. The median progression-free survival was 4.2 months, the median overall survival was 9.6 months, and the overall response rate was 17.5%. TP53, ERBB2, PI3KCA, FGFR3, and ARID1A alterations were detected in 66%, 29%, 27%, 24%, and 22% of all patients, respectively. Alterations in FGFR3 were almost mutually exclusive of TP53. More than half (64%) of patients with an FGFR alt received an FGFR inhibitor, 67% of which achieved disease control. Among patients with urothelial carcinoma histology, those harboring a TP53 alteration had a shorter median progression-free survival (PFS) compared with those whose tumors carry wild-type TP53. The reverse relationship was observed in patients harboring an FGFR alteration. IMPLICATIONS: Patients with platinum-refractory mBC derive clinical benefit from participating in early-phase clinical trials and their survival outcomes correlate with the genetic profile of the tumor. VISUAL OVERVIEW: http://mcr.aacrjournals.org/content/molcanres/19/3/395/F1.large.jpg.

Validation of prognostic scoring systems for patients with metastatic renal cell carcinoma enrolled in phase I clinical trials

BACKGROUND

For patients with metastatic renal cell carcinoma (mRCC) who progress on standard-of-care therapies, there is an unmet need for novel treatments. Phase I clinical trials are designed to test the safety, toxicity and optimal dosing of novel agents. Herein, we analysed the outcomes of patients with mRCC enrolled in phase I trials and assess the utility of prognostic scores.

METHODS

Patients with all histologies of mRCC were included if they received treatment on a phase I clinical trial at MD Anderson Cancer Center (MDACC). Survival outcomes were calculated using Cox proportional hazard model. Prognostic value of the International Metastatic RCC Database Consortium (IMDC), Royal Marsden Hospital (RMH) and MDACC scores was assessed using the likelihood ratio (LR) χ² test and the c-index.

RESULTS

Among 82 patients with mRCC who received treatment, 21 patients participated in more than one trial, resulting in 106 trial participants (TP). Median prior therapies was two. For all TPs, median overall survival (OS) was 31.2 months, progression-free survival (PFS) was 5.9 months and objective response rate was 22%. Median OS and PFS were significantly shorter with increasing IMDC, RMH and MDACC scores. The RMH and MDACC scores outperformed the IMDC score for predicting OS (RMH LR χ²=8.64; MDACC LR χ²=7.74; IMDC LR χ²=2.36) and PFS (RMH LR χ²=17.5; MDACC LR χ²=20.3; IMDC LR χ²=4.28).

CONCLUSIONS

The RMH and MDACC prognostic scores can be used to predict OS for patients with mRCC in phase I trials and may guide patient selection. Patients with mRCC should be considered for phase I trials.

Phase I clinical trials as a therapeutic option for patients with metastatic renal cell carcinoma (mRCC)

5073

Background: Immune checkpoint inhibitors, multi-kinase VEGF agents, and mTOR inhibitors are approved for mRCC. Due to the overlapping mechanisms of action of the twelve approved therapies for mRCC, select patients are referred for phase I clinical trials after progression on multiple lines of treatment. We sought to evaluate the efficacy of phase I trials in patients with mRCC. Methods: Patients with all histologies of mRCC were included if they received treatment on a phase I clinical trial at MD Anderson Cancer Center. Baseline clinical characteristics and outcomes data were retrospectively collected. The historical control was a study of 1112 patients with mRCC who received third-line treatment in the IMDC database (PMID: 27318422). Time to event endpoints were calculated using Kaplan-Meier methods. Hazard ratios (HR) were calculated using the Cox proportional hazard model. Results: Between 2014 and 2019, there were 106 cases where 82 patients with mRCC were enrolled in a phase I clinical trials (40 unique trials). 30% (32/108) of the cases were in patients with non-clear cell RCC (nccRCC), and the most prevalent nccRCC histologies were papillary (n = 7) and renal medullary carcinoma (n = 7). The median number of prior systemic therapies was 2 (range 0-9). Across the entire cohort, median PFS was 5.9 months (m), median OS was 31.2 m, and the ORR was 23% (Table). In patients who received at least two prior lines of therapy (n = 70), the median PFS was 4.8 m and median OS was 24.9 m. In patients with metastatic nccRCC, median OS, PFS, and ORR were numerically lower, but statistically did not contradict the supposition that these outcomes did not differ from ccRCC (Table). Conclusions: In the largest pooled phase I clinical trial experience for patients with mRCC, phase I trials may have therapeutic value when compared to historical controls, where median PFS was 3.9 m, median OS was 12.4 m, and ORR was 10.5%. Patients with all histologies of mRCC may derive clinical benefit from phase I clinical trials, yet patients with ccRCC had numerically better outcomes. Patients with mRCC should be considered for phase I clinical trials. [Table: see text]

Outcomes and the impact of genomic characteristics on patients with metastatic urothelial carcinoma enrolled in early phase trials

5029

Background: With the recent approvals of checkpoint inhibitors (CPIs), a fibroblast growth factor receptor (FGFR) inhibitor, and an antibody-drug conjugate, patients with platinum-refractory metastatic urothelial carcinoma (mUC) have several treatment options available. However, many patients with platinum-refractory mUC need novel therapies after progressing on current therapies. We assessed the role of early phase trials in treatment of mUC and the impact of genomic alterations on their outcomes. Methods: We retrospectively analyzed medical records of patients with mUC who received an investigational therapy at the phase 1 clinic and had CLIA-certified clinical next generation sequencing. Clinical parameters and mutations were abstracted. Progression-free survival (PFS) and overall survival (OS) were calculated using Kaplan-Meier methods. Hazard ratios (HR) were calculated using the Cox proportional hazard model. Results: Among the 57 pts enrolled in 41 unique phase 1 trials between 2015 and 2019, 16% (9/57) had variant histology: neuroendocrine carcinoma (n = 3) and urachal carcinoma (n = 6). Median age was 64. Majority were males (72%). 97% received prior platinum therapy and 60% had received prior CPI therapy. Across the pure urothelial carcinoma cohort (n = 48), median PFS was 4.2 months (m), median OS was 9.8 m, and the overall response rate (ORR) was 19%. TP53, FGFR, TERT, and ARID1A alterations (alt) were detected in 54%, 41%, 21% and 17% of UC patients, respectively. Patients harboring a TP53 alt, compared to no alt, had a shorter median PFS of 3.2m vs 9.6 m (HR = 2.738 [1.247 - 6.011], p = 0.0121). On the contrary, median PFS was longer in FGFR alt, compared to no alt, 6.3m vs 3.2m (HR = 0.4662 [0.224 - 0.971], p = 0.0415). Of note, 64% of FGFR alt patients were treated under an early phase FGFR targeting trial. Median OS was numerically longer in FGFR alt and shorter in TP53 alt but did not reach statistical significance (table). Conclusions: Patients with mUC may derive clinical benefit from enrollment in phase I clinical trials. Patients with TP53 alterations had numerically worse outcomes. Patients with mUC should be considered for an FGFR targeting therapy in the setting of an FGFR alteration. [Table: see text]

Identifying functional loss of ATM gene in patients with advanced cancer

3629

Background: ATM is frequently mutated in cancer, and defects may serve as a putative predictive biomarker. However, the functional impact of most ATM variants is not well known. In this study, we examined the relationship between ATM variants and ATM protein expression to better discern ATM functional defects in patients (pts) with advanced cancer. Methods: We retrospectively identified pts seen at MD Anderson Cancer Center who had ATM variants detected on CLIA-certified next generation sequencing (NGS) assays. ATM immunohistochemistry (IHC) was performed on available tumors. We then prospectively assessed ATM IHC on tumors from pts who were referred for DNA damage repair inhibitor (DDRi) trials. Functional classification of the variants was performed via published in silico tools and/or precision oncology decision support (PODS). An IHC cut-off of 100% loss in tumor cell nuclei defined ATM loss of protein (LOP). Results: Of 1394 ATM-mutant tumors identified retrospectively, ATM alterations were classified as 16% (N = 216) inactivating, 12% (N = 163) potentially inactivating, 71% (N = 993) variant of unknown significance (VUS), and 2% (N = 22) benign. Coding variants were seen across the ATM exonic structure/splice sites, and 20 individual variants were shared in > 10 pts. 263/297 available retrospective tumor samples had interpretable IHC results; 27% (N = 72) had ATM LOP. LOP was most prevalent in tumors with inactivating ATM variants (39/100, 39%); but, importantly, LOP was seen in 20% (N = 33/162) of potentially inactivating/VUS, thus better clarifying their functional impact. In the prospective cohort of 217 pt tumors, 17% (N = 37) had ATM LOP. 29% (N = 62/217) of this cohort also had ATM variants. ATM LOP was seen in 48% of tumors with inactivating variants (N = 14/29), 25% of tumors with potentially/VUS(N = 9/36), and 9% (N = 14/156) of tumors without ATM variants identified. ATM LOP was detected most commonly in colorectal (24%; N = 8/34), cholangiocarcinoma (20%; N = 6/30), prostate (16%; N = 16/104) and pancreatic (9%; N = 1/11) cancers among this cohort of pts referred for DDRi trials. Conclusions: ATM coding variants occurred across the gene, with certain variants shared across tumor types. The functional impact of most ATM variants was VUS, and ATM LOP can help clarify function in up to 25% of these VUS. Also, ATM LOP can be seen even in tumors without ATM variants identified, suggesting epigenetic or post-translational loss. Future prospective studies assessing predictive capability of paired DNA and protein-level profiling of ATM are warranted.

Process measure of FAST tuberculosis infection control demonstrates delay in likely effective treatment

SETTING

The tuberculous infection control strategy, FAST (Find cases Actively, Separate safely and Treat effectively), recommends prompt initiation of likely effective anti-tuberculosis treatment informed by Xpert^® MTB/RIF results.OBJECTIVE: To describe FAST implementation at Quang Nam Provincial TB and Lung Disease Hospital (QNH), Tam Ky, Viet Nam, using time to initiation of effective TB treatment as a process measure.

DESIGN

Hospital logs were used to calculate the time to likely effective treatment in patients with pulmonary TB (PTB) hospitalised during the study period.

RESULTS

Between 1 January and 31 December 2016, of 858 patients treated for PTB, 493 (57.5%) received likely effective treatment. The median time to likely effective treatment was 3 days (interquartile range 2.0-6.0), with 213 (43.2%) patients receiving likely effective treatment within 2 days. Of 81 patients receiving likely effective treatment for drug-susceptible TB with a positive Xpert result as their initial in-patient diagnostic test, 64 (79.0%) received likely effective treatment within 2 days compared with 10 (5.7%) who were initially smear-negative then found to be Xpert-positive (P < 0.0001).

CONCLUSIONS

A 'time to' process measure of the FAST tuberculous infection control strategy indicates delays in the initiation of likely effective anti-tuberculosis treatment in a resource-limited hospital. Expanding access to Xpert may speed time to likely effective treatment.

Characteristics and outcomes of patients with recurrent ovarian cancer undergoing early phase immune checkpoint inhibitor clinical trials

OBJECTIVE

To describe the clinical outcomes associated with the use of checkpoint inhibitor therapy in recurrent ovarian malignancy.

METHODS

Women with recurrent ovarian cancer treated with an immune checkpoint inhibitor between 1/2012 and 8/2017 were included. RECIST criteria determined disease status, and immune related adverse events (irAE) were graded per trial protocols. Predictors of response, irAE, progression free survival (PFS) and overall survival (OS) were investigated.

RESULTS

Forty-four women were included with a median age of 53 years, median of 4 prior lines of chemotherapy, and most commonly high grade serous pathology (59.1%). 3 patients had partial response and 3 had pseudoprogression, for a response rate of 14.2%. In subset analysis of high grade serous (HGSOC) pathology, platinum sensitivity at time of checkpoint inhibitor therapy was correlated with response (p = 0.01). There were 28 grade 3/4 irAEs in 21 patients (47.7%). Combination therapy rather than monotherapy predicted irAE (OR 5.7, CI 1.6-20.9, p = 0.02). The most common severe irAE was elevation in hepatic or pancreatic enzymes in 12 total patients (13.6% each). Interestingly, the number of genes mutated was protective from hepatic/pancreatic AE (p = 0.02).

CONCLUSIONS

While response rate was similar to prior literature, in patients with HGSOC platinum sensitivity at time of checkpoint inhibitor initiation was correlated to response. Grade 3/4 hepatic and pancreatic enzyme elevations were more common in ovarian cancer patients than has been previously reported in other tumor types. The number of genes mutated was inversely correlated to risk of this type of irAEs but not to total irAEs.

Murine Methyl Donor Deficiency Impairs Early Growth in Association with Dysmorphic Small Intestinal Crypts and Reduced Gut Microbial Community Diversity

Background

Folate and choline are essential methyl donor nutrients throughout the life span; however, the adverse effects of combined deficiency on early growth, intestinal epithelial morphology, and the gut microbiome remain only partially understood.

Objectives

We investigated the effects of dietary folate and choline deficiency on early growth, small intestinal (SI) epithelial architecture, and the gut microbiota of mice. To explore potential mechanisms for adverse effects on gut epithelial morphology, we also evaluated gene expression and DNA methylation in mouse intestinal epithelial organoids (enteroids) maintained in methyl donor–deficient (MDD) conditions.

Methods

Pregnant dams were administered 1 of 4 diets: 1) control diet (CD−), 2) an isocaloric MDD− diet, or 3) CD+ and 4) MDD+ formulations containing 1% succinylsulfathiazole to inhibit folate-producing gut bacteria. We weaned pups to their dams’ diet at 3 wk of age and monitored body weight and tail length pre- and postweaning. We measured serum folate, SI crypt morphology, and microbiota composition at 7 wk of age.

Results

Both MDD+ and MDD− diets impaired early ponderal and linear growth, lowered serum folate concentrations, and produced patchy areas of increased crypt depth throughout the SI. Succinylsulfathiazole increased crypt depth independently of diet. MDD or succinylsulfathiazole, alone or in combination, altered the gut microbiome, with decreased Bacteroidales and Clostridiales, increased Lactobacillales and Erysipelotrichaceae taxa, and decreased α-diversity indexes. Enteroids maintained in MDD media displayed dysmorphic crypt domains, altered expression of stem cell and secretory differentiation genes, and decreased DNA methylation of the glycosylation genes Beta-1,4-N-Acetyl-Galactosaminyltransferase-1 (B4galnt1) and Phosphoethanolamine/Phosphocholine-Phosphatase (Phospho1).

Conclusion

MDD impairs ponderal and linear growth in mice in association with dysmorphic SI crypts and reduced gut microbial diversity. In vitro methyl donor deficiency similarly induced dysmorphic crypts in mouse enteroids in conjunction with altered gene expression and DNA methylation.

Abstract A44: No tumor or very small tumor burden in on-treatment biopsies is significantly associated with response to Pembrolizumab

Background: In phase I clinical trials, baseline and on-treatment biopsies are increasingly performed to investigate biomarkers correlating, e.g., with therapy response. Prior to use these biopsies for expensive analysis, quality control (QC) is performed regarding, e.g., morphology, tumor content. However, studies to correlate the results obtained from QC evaluation with clinical outcomes are lacking. The purpose of this study was to determine if data from the QC process correlate with therapy response.

Method: We investigated 64 baseline and 50 on-treatment (C1D15-21) biopsies from 67 patients participating in an ongoing phase I clinical trial receiving pembrolizumab for their rare tumors such as e.g. adrenocortical carcinoma, angiosarcoma, alveolar rhabdomyosarcoma, carcinoma of unknown primary, epithelioid hemangioendothelioma, malignant neoplasm of tunica vaginalis, paraganglioma, penile carcinoma, pituitary tumor, renal medullary carcinoma, teratoma, and others. Baseline and the on-treatment biopsies were taken in &gt;90% from the same amenable tumor lesion. Matched biopsies were available in n= 48 (71.64%) and data on response was available for 54 (80.60%) patients. From all biopsies the tumor content was estimated by a pathologist on an H&E slide. Low tumor burden was defined as 0-10% tumor in the biopsy. If more than one biopsy was available, the average tumor content was calculated and used for analysis. Response was defined as stable disease or partial response.

Results: The average tumor content in all biopsies was 39%, 38% baseline and 39% on-treatment. No tumor was detected in 15 (13%) of all biopsies, in 7 baseline (11%) and 8 on-treatment biopsies (16%). Low tumor burden was detected in 29 (25%) of all biopsies, in 17 baseline (27%) and in 12 on-treatment biopsies (24%). In 71% (5/7) of baseline biopsies and in 50% (4/8) of on-treatment biopsies with no tumor, fibrosis or necrosis was present. In 88% (15/17) of baseline biopsies and 67% (8/12) of on-treatment biopsies with low tumor burden fibrosis or necrosis was present. Thirty percent (7/23) of patients with response had no tumor in their on-treatment biopsies. All non-responders had tumor in their on-treatment biopsy. Forty three (10/23) patients with a low tumor burden in their on-treatment biopsies showed response compared to 5% (1/21) of non-responders. Hence, no tumor (0%) or low tumor burden (0-10%) in on-treatment biopsies was significantly associated with response (p=0.006 and p=0.003).

Conclusion: Results obtained from the QC of clinical trial biopsies provide valuable information on tissue suitability for further analysis. In addition, we showed that an on-treatment biopsy with no tumor or very little tumor burden may predict partial or stable disease. Further studies to validate the role of tumor content in on-treatment biopsies in predicting response are warranted.

Citation Format: Mingxuan Xu, Fengying Ouyang, Anas Alshawa, Joud Hajjar, Lilibeth Castillo, Hung Le, Ravi Murthy, Aung Naing, Coya Tapia. No tumor or very small tumor burden in on-treatment biopsies is significantly associated with response to Pembrolizumab [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2017 Oct 1-4; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2018;6(9 Suppl):Abstract nr A44.

Immunogenicity study of an expressed outer membrane protein U of Vibrio vulnificus in Japanese eel (Anguilla japonica)

AIMS

Vibrio vulnificus is a common bacterial pathogen causing haemorrhagic septicaemia in eel farming. This study investigates the immunogenicity of an outer membrane protein U (OmpU) of V. vulnificus and the feasibility of the protein as a new subunit vaccine against V. vulnificus.

METHODS AND RESULTS

Partial gene sequence of the OmpU of V. vulnificus was cloned, and then the OmpU was expressed and purified. Three groups of Japanese eels (Anguilla japonica) were intraperitoneally (i.p) injected with bovine serum albumin (BSA group), formalin-killed whole cell of V. vulnificus (FKC group) or the expressed OmpU of V. vulnificus (OMP group). On 14, 21, 28 and 42 days postimmunization (dpi), the whole blood cells were collected to evaluate the stimulation index (SI) and bactericidal activity. The serum was obtained to assess the titres of specific antibody, lysozyme activity, complement activity and bactericidal activity. The lysozyme activities in the suspension of kidney, skin mucus and liver in eels were also ascertained. The results showed that the SI and the titres of anti-V. vulnificus antibody in the OMP group was significantly increased on 28 dpi; lysozyme activity in the kidney and skin mucus of OMP group on 42 and 14 dpi were both significantly higher than BSA group; eels in OMP group showed strong bactericidal capacity on 21 and 28 days; and the relative percent survival of OMP vs BSA group after challenged by V. vulnificus on 28 dpi was 80%.

CONCLUSIONS

These results showed that the expressed OmpU of V. vulnificus could significantly improve the immune function of Japanese eel and the resistance of eels to the infection of V. vulnificus.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study offered an alternative preliminary strategy of making aquaculture vaccines against V. vulnificus for eel farming.

Nurses' willingness to care for patients infected with HIV or Hepatitis B / C in Vietnam

OBJECTIVES

This study examined the factors associated with nurses' willingness to care for patients infected with human immunodeficiency virus (HIV) or hepatitis B or C virus (HBV/HCV) in Vietnam.

METHODS

A cross-section of 400 Vietnamese nurses from two hospitals were selected using stratified random sampling, to whom a self-administered questionnaire was administered which included demographic items, previous experience with patients infected with HIV or HBV/HCV, and their attitudes toward these patients. Data was analyzed using descriptive statistics and multiple logistic regression.

RESULTS

The lifetime prevalence of needlestick or sharps injury whilst caring for a patient infected with HIV or HBV/HCV was 9 and 15.8%, respectively. The majority of participants expressed a willingness to care for patients infected with HIV (55.8%) or HBV/HCV (73.3%). Willingness to care for HIV-infected patients was positively associated with being 40-49 years of age and confidence in protecting themselves against infection. Regarding HBV/HCV infection, willingness to care was positively associated with individual confidence in protecting themselves against infection.

CONCLUSIONS

This study revealed that Vietnamese nurses were somewhat willing to care for patients infected with HIV or HBV/HCV, and this was associated with individual confidence in protecting themselves against infection and with negative attitudes towards HIV and HBV/HCV. Establishing a positive safety culture and providing appropriate professional education to help reduce the stigma towards infected patients offers an effective way forwards to improve quality of care in Vietnam, as elsewhere.

Intercellular Coupling of the Cell Cycle and Circadian Clock in Adult Stem Cell Culture

Circadian clock-gated cell division cycles are observed from cyanobacteria to mammals via intracellular molecular connections between these two oscillators. Here we demonstrate WNT-mediated intercellular coupling between the cell cycle and circadian clock in 3D murine intestinal organoids (enteroids). The circadian clock gates a population of cells with heterogeneous cell-cycle times that emerge as 12-hr synchronized cell division cycles. Remarkably, we observe reduced-amplitude oscillations of circadian rhythms in intestinal stem cells and progenitor cells, indicating an intercellular signal arising from differentiated cells governing circadian clock-dependent synchronized cell division cycles. Stochastic simulations and experimental validations reveal Paneth cell-secreted WNT as the key intercellular coupling component linking the circadian clock and cell cycle in enteroids.

Optimal Stopping for Processes with Independent Increments, and Applications

In this paper we present an explicit solution to the infinite-horizon optimal stopping problem for processes with stationary independent increments, where reward functions admit a certain representation in terms of the process at a random time. It is shown that it is optimal to stop at the first time the process crosses a level defined as the root of an equation obtained from the representation of the reward function. We obtain an explicit formula for the value function in terms of the infimum and supremum of the process, by making use of the Wiener–Hopf factorization. The main results are applied to several problems considered in the literature, to give a unified approach, and to new optimization problems from the finance industry.

On the induced distribution of the shape of the projection of a randomly rotated configuration

Using the geometry of the Kendall shape space, in this paper we study the shape, as well as the size-and-shape, of the projection of a configuration after it has been rotated and, when the given configuration lies in a Euclidean space of an arbitrary dimension, we obtain expressions for the induced distributions of such shapes when the rotation is uniformly distributed.

Physiologic Changes in the Heart Following Cessation of Mechanical Ventilation in a Porcine Model of Donation After Circulatory Death: Implications for Cardiac Transplantation

Hearts donated following circulatory death (DCD) may represent an additional source of organs for transplantation; however, the impact of donor extubation on the DCD heart has not been well characterized. We sought to describe the physiologic changes that occur following withdrawal of life-sustaining therapy (WLST) in a porcine model of DCD. Physiologic changes were monitored continuously for 20 min following WLST. Ventricular pressure, volume, and function were recorded using a conductance catheter placed into the right (N = 8) and left (N = 8) ventricles, and using magnetic resonance imaging (MRI, N = 3). Hypoxic pulmonary vasoconstriction occurred following WLST, and was associated with distension of the right ventricle (RV) and reduced cardiac output. A 120-fold increase in epinephrine was subsequently observed that produced a transient hyperdynamic phase; however, progressive RV distension developed during this time. Circulatory arrest occurred 7.6±0.3 min following WLST, at which time MRI demonstrated an 18±7% increase in RV volume and a 12±9% decrease in left ventricular volume compared to baseline. We conclude that hypoxic pulmonary vasoconstriction and a profound catecholamine surge occur following WLST that result in distension of the RV. These changes have important implications on the resuscitation, preservation, and evaluation of DCD hearts prior to transplantation.

Avoidance of Profound Hypothermia During Initial Reperfusion Improves the Functional Recovery of Hearts Donated After Circulatory Death

The resuscitation of hearts donated after circulatory death (DCD) is gaining widespread interest; however, the method of initial reperfusion (IR) that optimizes functional recovery has not been elucidated. We sought to determine the impact of IR temperature on the recovery of myocardial function during ex vivo heart perfusion (EVHP). Eighteen pigs were anesthetized, mechanical ventilation was discontinued, and cardiac arrest ensued. A 15-min standoff period was observed and then hearts were reperfused for 3 min at three different temperatures (5°C; N = 6, 25°C; N = 5, and 35°C; N = 7) with a normokalemic adenosine-lidocaine crystalloid cardioplegia. Hearts then underwent normothermic EVHP for 6 h during which time myocardial function was assessed in a working mode. We found that IR coronary blood flow differed among treatment groups (5°C = 483 ± 53, 25°C = 722 ± 60, 35°C = 906 ± 36 mL/min, p < 0.01). During subsequent EVHP, less myocardial injury (troponin I: 5°C = 91 ± 6, 25°C = 64 ± 16, 35°C = 57 ± 7 pg/mL/g, p = 0.04) and greater preservation of endothelial cell integrity (electron microscopy injury score: 5°C = 3.2 ± 0.5, 25°C = 1.8 ± 0.2, 35°C = 1.7 ± 0.3, p = 0.01) were evident in hearts initially reperfused at warmer temperatures. IR under profoundly hypothermic conditions impaired the recovery of myocardial function (cardiac index: 5°C = 3.9 ± 0.8, 25°C = 6.2 ± 0.4, 35°C = 6.5 ± 0.6 mL/minute/g, p = 0.03) during EVHP. We conclude that the avoidance of profound hypothermia during IR minimizes injury and improves the functional recovery of DCD hearts.

Utilization of a Cloud-Based Diabetes Management Program for Insulin Initiation and Titration Enables Collaborative Decision Making Between Healthcare Providers and Patients

BACKGROUND

Overseeing proper insulin initiation and titration remains a challenging task in diabetes care. Recent advances in mobile technology have enabled new models of collaborative care between patients and healthcare providers (HCPs). We hypothesized that the adoption of such technology could help individuals starting basal insulin achieve better glycemic control compared with standard clinical practice.

MATERIALS AND METHODS

This was a 12 ± 2-week randomized controlled study with 40 individuals with type 2 diabetes who were starting basal insulin due to poor glycemic control. The control group (n = 20) received standard face-to-face care and phone follow-up as needed in a tertiary center, whereas the intervention group (n = 20) received care through the cloud-based diabetes management program where regular communications about glycemic control and insulin doses were conducted via patient self-tracking tools, shared decision-making interfaces, secure text messages, and virtual visits (audio, video, and shared screen control) instead of office visits.

RESULTS

By intention-to-treat analysis, the intervention group achieved a greater hemoglobin A1c decline compared with the control group (3.2 ± 1.5% vs. 2.0% ± 2.0%; P = 0.048). The Diabetes Treatment Satisfaction Questionnaire showed a significant improvement in the intervention group compared with the control group (an increase of 10.1 ± 11.7 vs. 2.1 ± 6.5 points; P = 0.01). HCPs spent less time with patients in the intervention group compared with those in the control group (65.9 min per subject vs. 81.6 min per subject). However, the intervention group required additional training time to use the mobile device.

CONCLUSIONS

Mobile health technology could be an effective tool in sharing data, enhancing communication, and improving glycemic control while enabling collaborative decision making in diabetes care.

Stability of toroidal droplets inside yield stress materials

We study the stability of toroidal droplets inside a yield stress material. Similar to toroidal droplets in a viscous liquid, the slenderness of the torus controls whether it breaks into spherical droplets or grows thicker towards its center to coalesce onto itself and form a single spherical droplet. However, unlike tori generated in a viscous liquid, the elasticity of the outer medium can prevent either or both of these instabilities; this depends on the slenderness of the torus. Interestingly, we find that the value of the tube radius needed to prevent breakup is always larger than the value of the radius of the handle to prevent growth. This reflects the different deformations experienced by the yield stress material in either process. A simple model balancing the surface tension stress, which drives the evolution of the torus, and the yield stress, which favors its stability, accounts for all of our observations.