Monoclonal antibodies against GFRα3 are efficacious against evoked hyperalgesic and allodynic responses in mouse join pain models but, one of these, REGN5069, was not effective against pain in a randomized, placebo-controlled clinical trial in patients with osteoarthritis pain

The artemin-GFRα3 signaling pathway has been implicated in various painful conditions including migraine, cold allodynia, hyperalgesia, inflammatory bone pain, and mouse knees contain GFRα3-immunoreactive nerve endings. We developed high affinity mouse (REGN1967) and human (REGN5069) GFRα3-blocking monoclonal antibodies and, following in vivo evaluations in mouse models of chronic joint pain (osteoarthritic-like and inflammatory), conducted a first-in-human phase 1 pharmacokinetics (PK) and safety trial of REGN5069 (NCT03645746) in healthy volunteers, and a phase 2 randomized placebo-controlled efficacy and safety trial of REGN5069 (NCT03956550) in patients with knee osteoarthritis (OA) pain. In three commonly used mouse models of chronic joint pain (destabilization of the medial meniscus, intra-articular monoiodoacetate, or Complete Freund's Adjuvant), REGN1967 and REGN5069 attenuated evoked behaviors including tactile allodynia and thermal hyperalgesia without discernably impacting joint pathology or inflammation, prompting us to further evaluate REGN5069 in humans. In the phase 1 study in healthy subjects, the safety profiles of single doses of REGN5069 up to 3000 mg (intravenous) or 600 mg (subcutaneous) were comparable to placebo; PK were consistent with a monoclonal antibody exhibiting target-mediated disposition. In the phase 2 study in patients with OA knee pain, two doses of REGN5069 (100 mg or 1000 mg intravenous every 4 weeks) for 8 weeks failed to achieve the 12-week primary and secondary efficacy endpoints relative to placebo. In addition to possible differences in GFRα3 biology between mice and humans, we highlight here differences in experimental parameters that could have contributed to a different profile of efficacy in mouse models versus human OA pain. Additional research is required to more fully evaluate any potential role of GFRα3 in human pain.

Integrating EM and Patch-seq data: Synaptic connectivity and target specificity of predicted Sst transcriptomic types

Neural circuit function is shaped both by the cell types that comprise the circuit and the connections between those cell types ¹ . Neural cell types have previously been defined by morphology ^{2, 3} , electrophysiology ^{4, 5} , transcriptomic expression ^6-8 , connectivity ^9-13 , or even a combination of such modalities ^14-16 . More recently, the Patch-seq technique has enabled the characterization of morphology (M), electrophysiology (E), and transcriptomic (T) properties from individual cells ^17-20 . Using this technique, these properties were integrated to define 28, inhibitory multimodal, MET-types in mouse primary visual cortex ²¹ . It is unknown how these MET-types connect within the broader cortical circuitry however. Here we show that we can predict the MET-type identity of inhibitory cells within a large-scale electron microscopy (EM) dataset and these MET-types have distinct ultrastructural features and synapse connectivity patterns. We found that EM Martinotti cells, a well defined morphological cell type ^{22, 23} known to be Somatostatin positive (Sst+) ^{24, 25} , were successfully predicted to belong to Sst+ MET-types. Each identified MET-type had distinct axon myelination patterns and synapsed onto specific excitatory targets. Our results demonstrate that morphological features can be used to link cell type identities across imaging modalities, which enables further comparison of connectivity in relation to transcriptomic or electrophysiological properties. Furthermore, our results show that MET-types have distinct connectivity patterns, supporting the use of MET-types and connectivity to meaningfully define cell types.

Applying Deep Learning Cancer Subtyping Algorithms Trained on Physical Slides to Multiphoton Imaging of Unembedded Samples

Introduction/Objective

Deep learning algorithms on digital images of physical tissue slides have shown potential improvements in accuracy and precision of diagnostic interpretation of neoplastic histology. Clustering-constrained- attention multiple-instance learning (CLAM) is one such method that identifies diagnostic sub-regions to accurately classify whole slides. Often, algorithm performance degrades when deployed on datasets that differ from the original set and it is subject to physical slide preparation variability. New multiphoton imaging modalities have potential workflow and quality advantages over physical slides, producing images analogous to whole slide imaging (WSI) without cutting artifacts, but performance of existing algorithms trained on digitized physical slides and applied to multiphoton images remains completely unknown. Given this, we aimed to test the performance of CLAM algorithms for subtyping renal cell carcinoma (RCC) and lung cancer (LC) applied to pseudo-colored multiphoton WSI.

Methods/Case Report

Clinical RCC and LC surgical resection samples were processed and imaged by Clearing Histology with MulitPhoton microscopy (CHiMP, Applikate Technologies, Fairfield, CT), producing digital images of un- cut, un-embeded tissue to generate H&E-like optical slices. Multiphoton images were downscaled to 0.5 um/px to match algorithm target resolution. CLAM models for subtyping RCC (chromophobe, clear cell, papillary) and LC (squamous & adenocarcinoma) previously trained using TCGA and CPTAC whole slide images of physical slides were applied directly to CHiMP multiphoton images without adjustment. Reference cancer subtype classifications were provided from physical and digital slides.

Results (if a Case Study enter NA)

For the subtypes included during training, multiphoton WSIs of RCC and LC were accurately subtyped by the CLAM models without stain normalization nor network fine tuning producing high prediction levels. Subtypes not included during the training (namely oncocytoma for RCC) resulted in low scoring model predictions (below 0.85), indicating specificity of identification. Multiple slide levels improved interpretation of several difficult cases for CLAM predictions.

Conclusion

This preliminary data suggests that CLAM models trained on standard H&E WSIs for RCC and LC subtyping are applicable to pseudo-H&E multiphoton WSIs without domain adaptations. This implies that diagnostic histologic features have been learned by these CLAM models and are efficiently recognized in digital histology images produced via CHiMP.

Automated Gating and Interpretation of Clinical Flow Cytometry Data: A Computational Approach using Artificial Intelligence and Deep Learning

Flow cytometry (FCM) allows pathologists to accurately immunophenotype hematopoietic cells by detecting the expression of surface proteins with fluorochrome-conjugated antibodies. Accordingly, FCM plays a pivotal role in the diagnostic workup of many hematologic malignancies. However, post-analytic processing and the interpretation of FCM data are primarily manual processes that impact the consistency and limit the throughput of the method. The post-analytic processing workflow is colloquially referred to as ‘gating’ and involves the identification and characterization of immune cell populations by hand through successions of biaxial plots. The gated FCM data is then used by the pathologist to make a clinical interpretation and to then determine potential diagnoses from the patterns and cell frequencies seen in bivariate plots of the data. Since gating and interpretation are manually performed, post-analytic analyses of FCM data are not only laborious from a workflow perspective but remain subjective and prone to variability based on the experience and skill of both the medical laboratory scientist and pathologist.

The objective of this study was to develop a computational pipeline that leverages machine learning-based (ML) solutions to automate gating and clinical interpretation of FCM data to increase the throughput and improve the repeatability of FCM analysis.

Raw FCS files from clinical samples being evaluated for the presence of T-cell lymphoproliferative disease were exported from the on-instrument database. Automated gating was performed using open-source, supervised-ML packages for flow cytometry data (flowCore and flowDensity; R). These packages implement all processing steps that would typically be done manually (e.g. applying compensation, quality control (QC), and gating). Plots of interest were then generated from the gated data and classified as normal or abnormal using the clinical interpretations that were applied during the normal clinical workflow. These binary labels were used to train an ML-based classifier (VGG-19; Python). To evaluate pipeline performance, we collected FCS files from 1,188 samples that were analyzed by our flow cytometry lab. The automated gating pipeline was used to gate for CD4+CD3+ cells and to create bivariate plots for CD7/CD26 expression. 1150 (96.8%) passed QC and were all gated correctly by visual inspection. Of the 38 (3.2%) samples that failed QC, 13 (1.1%) were lymphopenic and were gated correctly by visual inspection, and the remaining 25 (2.1%) were gated manually. Using the CD7/CD26 plots, the classifier demonstrated promising predictive performance and achieved a precision of 0.85 and recall of 0.83 (weighted average across classes). Our findings represent a novel effort to automate both the gating and interpretation of FCM data using artificial intelligence. These results suggest that ML-based tools have potential utility in aiding the processing and interpretation of FCM data and can augment the efficiency and consistency of workflows in the clinical flow cytometry laboratory.

Peripheral Blood Involvement at Staging in Patients With Aggressive Peripheral T-Cell Lymphoma

INTRODUCTION

Peripheral T-Cell Lymphomas (PTCL) are a rare subgroup of lymphomas with a poor outcome.Traditional prognostic measures rely heavily on disease stage, and with the advent of targeted treatment, further stratificationcriteria are needed to guide treatment. To date, the impact of blood involvement at diagnosis on outcomes has not been assessed.

MATERIALS AND METHODS

We retrospectively reviewed blood involvement by flow cytometry at diagnosis in 102 consecutivelytreated patients who had flow cytometry data available at diagnosis. Of these, 78 patients with nodal subtypes were identified andstudied in this analysis.

RESULTS

Of 78 patients with nodal subtypes of PTCL who had flow data available at the time ofdiagnosis, circulating populations of malignant T cells matching those in the biopsied lymph nodes were found in 21 patients bymultiparameter flow cytometry. A positive flow cytometry was highly correlated with bone marrow involvement. The patientswith a negative flow cytometry had a trend toward a longer median PFS compared to those with a positive flow but there was noimpact on overall survival.

CONCLUSIONS

Circulating malignant tumor cells can be found in the peripheral blood in a subset ofpatients with aggressive nodal T-cell lymphomas, including peripheral t-cell lymphoma not otherwise specified andangioimmunoblastic T-cell lymphomas, and blood involvement is correlated with bone marrow involvement.

Perceived stress and physiological consistency during mental stress exercises and controlled breathing

Introduction

The measurement of the physiological coherence, the order and the quality of the connection of complex systems such as the cardiac and the respiratory system, varies in situations of stress and relaxation.

Objectives

We aim to assess changes in physiological coherence and perception of stress during mental stress and directed breathing exercises.

Methods

Repeated-measures study in healthy adults without prior training in breathing techniques, aged between 18 and 65 years of both sexes who were evaluated in three situations: baseline, mental stress (Stroop test and successive subtractions), and directed breathing, during which were captured heart rate and respiratory signals to estimate physiological coherence and the participants rated the perceived stress at each moment.

Results

34 participants were analyzed, 59% women, with a median age of 36 years (Rq = 13). During mental stress tasks, the median for physiological coherence was similar to baseline coherence but increased significantly with five minutes of directed breathing exercises (38% vs. 63% p <0.0001). The highest perception of stress was during successive subtractions (Me 7, Rq = 4) and the lowest during directed breathing exercises (Me 2 Rq = 3.0). The correlation was sought between physiological coherence and perception of stress during each of the four moments of the study. Basal (Rho Spearman -0.05, p 0.54); Stroop (Rho -0.17, p 0.03); successive subtractions (Rho 0.50, p 0.77); and directed breathing (Rho -0.28, p 0.09).

Conclusions

A correlation was found between physiological coherence and perception of stress during the Stroop test; however, no association was found.

Disclosure

No significant relationships.

Applications of Digital Microscopy and Densely Connected Convolutional Neural Networks for Automated Quantification of Babesia-Infected Erythrocytes

BACKGROUND

Clinical babesiosis is diagnosed, and parasite burden is determined, by microscopic inspection of a thick or thin Giemsa-stained peripheral blood smear. However, quantitative analysis by manual microscopy is subject to error. As such, methods for the automated measurement of percent parasitemia in digital microscopic images of peripheral blood smears could improve clinical accuracy, relative to the predicate method.

METHODS

Individual erythrocyte images were manually labeled as "parasite" or "normal" and were used to train a model for binary image classification. The best model was then used to calculate percent parasitemia from a clinical validation dataset, and values were compared to a clinical reference value. Lastly, model interpretability was examined using an integrated gradient to identify pixels most likely to influence classification decisions.

RESULTS

The precision and recall of the model during development testing were 0.92 and 1.00, respectively. In clinical validation, the model returned increasing positive signal with increasing mean reference value. However, there were 2 highly erroneous false positive values returned by the model. Further, the model incorrectly assessed 3 cases well above the clinical threshold of 10%. The integrated gradient suggested potential sources of false positives including rouleaux formations, cell boundaries, and precipitate as deterministic factors in negative erythrocyte images.

CONCLUSIONS

While the model demonstrated highly accurate single cell classification and correctly assessed most slides, several false positives were highly incorrect. This project highlights the need for integrated testing of machine learning-based models, even when models in the development phase perform well.

Asociación Mexicana de Hepatología A.C. Clinical guideline on hepatitis B

Hepatitis B virus (HBV) infection continues to be a worldwide public health problem. In Mexico, at least three million adults are estimated to have acquired hepatitis B (total hepatitis B core antibody [anti-HBc]-positive), and of those, 300,000 active carriers (hepatitis B surface antigen [HBsAg]-positive) could require treatment. Because HBV is preventable through vaccination, its universal application should be emphasized. HBV infection is a major risk factor for developing hepatocellular carcinoma. Semi-annual liver ultrasound and serum alpha-fetoprotein testing favor early detection of that cancer and should be carried out in all patients with chronic HBV infection, regardless of the presence of advanced fibrosis or cirrhosis. Currently, nucleoside/nucleotide analogues that have a high barrier to resistance are the first-line therapies.

Asociación Mexicana de Hepatología A.C. Clinical guideline on hepatitis B

Hepatitis B virus (HBV) infection continues to be a worldwide public health problem. In Mexico, at least three million adults are estimated to have acquired hepatitis B (total hepatitis B core antibody [anti-HBc]-positive), and of those, 300,000 active carriers (hepatitis B surface antigen [HBsAg]-positive) could require treatment. Because HBV is preventable through vaccination, its universal application should be emphasized. HBV infection is a major risk factor for developing hepatocellular carcinoma. Semi-annual liver ultrasound and serum alpha-fetoprotein testing favor early detection of that cancer and should be carried out in all patients with chronic HBV infection, regardless of the presence of advanced fibrosis or cirrhosis. Currently, nucleoside/nucleotide analogues that have a high barrier to resistance are the first-line therapies.

P–403 Sodium tungstate increases embryo adhesion through a direct effect on endometrial cells

Study question

Does sodium tungstate treatment induce a change in endometrial cells’ capacity to implant trophoblasts?

Summary answer

Administration of sodium tungstate to endometrial cells increases trophoblast adhesion.

What is known already

Sodium tungstate (ST) has shown its capacity to modulate the activity of cytokines, such as leptin, an activator of an obligatory signalling cascade in the embryo-implantation process. STAT3, a signal transducer molecule critical for the embryo implantation process, is also known to be activated by ST. Still, ST’s effect on implantation using biological systems has never been studied. Embryo implantation process and endometrium roles are complicated to study in vivo due to a lack of animal models and appropriate techniques. In vitro techniques using immortalised cell lines allows a first approach to study early implantation stages, such as embryo adhesion.

Study design, size, duration

An in vitro study was carried out using a human endometrial carcinoma cell line (HEC–1-A) treated with sodium tungstate for 24 and 48h, and choriocarcinoma cell spheroids (JAr). Different times of treatment and concentrations were studied. Each experiment was performed in triplicate.

Participants/materials, setting, methods

Confluent endometrial HEC–1-A cultures were treated with ST at concentrations (0–150mM) and withaferin A (1mM), negative control for embryo adhesion. After the treatment period, HEC–1-A cultures were washed with ST-free culture medium to eliminate ST. Immediately, 15 JAr trophoblast spheroids were added to cultures and coincubated with gentle agitation for 30, 60 and 90 minutes. An inverted light microscope was used to count adhered and floating spheroids, and determine the trophoblast adherence ratio.

Main results and the role of chance

HEC–1-A cells treated with ST showed normal morphology and growth at all doses except 150mM. At the highest dose tested, the cells’ culture was still viable (negative blue trypan staining) and maintained morphology, but the adhesion to the plate surface was affected. Doses from 0.15 to 15mM were used to perform adhesion assays.

HEC–1-A cells treated with ST for 24h showed an increased capacity to adhere JAr trophoblast spheroids. Adhesion rates reached significant differences at doses of 1.5 and 15mM after 60 and 90 minutes of coincubation. After 90 minutes, untreated cells reached 32.8% adhesion rate, while 1.5 and 15mM ST-treated cells reached 54.6% and 53.4% respectively (p &lt; 0.05 ST vs untreated). Thus, the increment of trophoblast adhesion rate induced by ST reached 66%. Lower adhesion rates were observed after 60 minutes of coincubation but were also significant with a relative increase of 49.1% at 1.5mM and 50.5% at 1.5mM when compared with untreated cells (p &lt; 0.05)

Longer treatments (48h) showed similar trends to 24h-treatments, but with a lower extent of ST effect on HEC–1-A receptivity. Maximum adhesion rates were also observed at 90 minutes of coincubation and 1.5 and 15mM doses. The Mean adhesion rate increase was &gt;40% with both doses. Limitations, reasons for caution: The current study is the first approach to evaluate sodium tungstate effect on endometrium using an in vitro model. Future research using in vivo models should be performed to assess sodium tungstate effect on endometrium receptivity and its potential as a fertility treatment.

Wider implications of the findings: We conclude that the direct effect of sodium tungstate on endometrial cells increases embryo adhesion rate. These results open a new research line to a potential treatment in human reproduction management with sodium tungstate to solve the unmet need of inducing embryo implantation.

Trial registration number

Not applicable

Initial Evaluation of Rapid, Direct-to-Digital Prostate Biopsy Pathology

CONTEXT.—

Pathologist interobserver discordance is significant in grading of prostate cancer, limiting reliability. Diagnostic reproducibility may be improved with digital images, but adoption faces workflow, cost, and quality challenges. A novel digital method using an alternative tissue processing approach and novel laser microscopy system potentially addresses these issues.

OBJECTIVE.—

To evaluate the capability of this new method for primary diagnostic interpretation in clinical prostate biopsy specimens.

DESIGN.—

Forty patients with a high likelihood of prostate cancer based on magnetic resonance imaging consented to investigational core biopsy. A subset of samples was used for direct comparison of physical slide preparation effects and time-tracking determination with multiphoton microscopy. Twenty samples were processed for diagnostic comparison between multilevel digital slides and subsequently produced physical slides. A reference diagnosis based on all data was established using grade groups. Level of diagnostic match and requests for immunohistochemistry were compared between physical and digital diagnoses. Immunohistochemical staining and length measurements were secondary outcomes.

RESULTS.—

Interpretations based on direct multiphoton imaging yielded diagnoses that were at least as accurate as standard histology; cancer diagnosis correlation was 89% (51 of 57) by physical slides and 95% (53 of 56) by multiphoton microscopy. Grade-level concordance was 73% (44 of 60) by either method. Immunohistochemistry for routine prostate cancer-associated markers on these alternatively processed tissues was unaffected. Alternatively processed tissues resulted in longer measured core and cancer lengths, suggestive of improved orientation and visualization.

CONCLUSIONS.—

Findings support high potential for complete interpretation of prostate core biopsies using solely multiphoton microscopy of intact specimens, with potential diagnostic benefits as well as reduced processing time and reduced processing complexity.

Unique Cholangiocyte-Targeted IgM Autoantibodies Correlate With Poor Outcome in Biliary Atresia

BACKGROUND AND AIMS

The etiology of biliary atresia (BA) is not known and is likely multifactorial, including a genetic predisposition, a viral or environmental trigger, an aberrant autoimmune response targeting cholangiocytes, and unique susceptibilities of the neonatal bile ducts to injury. Damaged cholangiocytes may express neo self-antigens and elicit autoreactive T-cell-mediated inflammation and B-cell production of autoantibodies. The aim of this study was to discover autoantibodies in BA that correlated with outcomes.

APPROACH AND RESULTS

An autoantigen microarray encompassing approximately 9,500 autoantigens was used to screen for serum immunoglobulin M (IgM) and immunoglobulin G (IgG) autoantibodies in patients with BA or other liver disease controls. Validation of candidate autoantibodies by enzyme-linked immunosorbent assay on a second cohort of subjects (6-12 months following Kasai portoenterostomy) and correlations of autoantibodies with outcomes were performed (serum bilirubin levels and need for liver transplant in first 2 years of life). Mean anti-chitinase 3-like 1 (CHI3L1), anti-delta-like ligand (DLL-4), and antisurfactant protein D (SFTPD) IgM autoantibodies in BA were significantly higher compared with controls, and IgM autoantibody levels positively correlated with worse outcomes. Immunofluorescence revealed cholangiocyte-predominant expression of CHI3L1, DLL-4, and SFTPD. The humoral autoantibody response was associated with C3d complement activation and T-cell autoimmunity, based on detection of cholangiocyte-predominant C3d co-staining and peripheral blood autoreactive T cells specific to CHI3L1, DLL-4 and SFTPD, respectively.

CONCLUSIONS

BA is associated with cholangiocyte-predominant IgM autoantibodies in the first year after Kasai portoenterostomy. Anti-CHI3L1, anti-DLL-4, and anti-SFTPD IgM autoantibody correlations with worse outcomes and the detection of C3d on cholangioctyes and antigen-specific autoreactive T cells suggest that autoimmunity plays a role in the ongoing bile duct injury and progression of disease.

Effects of sub-optimal illumination in plants. Comprehensive chlorophyll fluorescence analysis

The fluorescence signals emitted by chlorophyll molecules of plants is a promising non-destructive indicator of plant physiology due to its close link to photosynthesis. In this work, a deep photophysical study of chlorophyll fluorescence was provided, to assess the sub-optimal illumination effects on three plant species: L. sativa, A. hybridus and S. dendroideum. In all the cases, low light (LL) treatment induced an increase in pigment content. Fluorescence ratios - corrected by light reabsorption processes - remained constant, which suggested that photosystems stoichiometry was conserved. For all species and treatments, quantum yields of photophysical decay remained around 0.2, which meant that the maximum possible photosynthesis efficiency was about 0.8. L. sativa (C3) acclimated to low light illumination, displayed a strong increase in the LHC size and a net decrease in the photosynthetic efficiency. A. hybridus (C4) was not appreciably stressed by the low light availability whereas S. dendroideum (CAM), decreased its antenna and augmented the quantum yield of primary photochemistry. A novel approach to describe NPQ relaxation kinetics was also presented here and used to calculate typical deactivation times and amplitudes for NPQ components. LL acclimated L. sativa presented a much larger deactivation time for its state-transition-related quenching than the other species. Comprehensive fluorescence analysis allowed a deep study of the changes in the light-dependent reactions of photosynthesis upon low light illumination treatment.

Evolution of the liver biopsy and its future

Liver biopsies are commonly used to evaluate a wide variety of medical disorders, including neoplasms and post-transplant complications. However, its use is being impacted by improved clinical diagnosis of disorders, and non-invasive methods for evaluating liver tissue and as a result the indications of a liver biopsy have undergone major changes in the last decade. The evolution of highly effective treatments for some of the common indications for liver biopsy in the last decade (e.g., viral hepatitis B and C) has led to a decline in the number of liver biopsies in recent years. At the same time, the emergence of better technologies for histologic evaluation, tissue content analysis and genomics are among the many new and exciting developments in the field that hold great promise for the future and are going to shape the indications for a liver biopsy in the future. Recent advances in slide scanners now allow creation of "digital/virtual" slides that have image of the entire tissue section present in a slide [whole slide imaging (WSI)]. WSI can now be done very rapidly and at very high resolution, allowing its use in routine clinical practice. In addition, a variety of technologies have been developed in recent years that use different light sources and/or microscopes allowing visualization of tissues in a completely different way. One such technique that is applicable to liver specimens combines multiphoton microscopy (MPM) with advanced clearing and fluorescent stains known as Clearing Histology with MultiPhoton Microscopy (CHiMP). Although it has not yet been extensively validated, the technique has the potential to decrease inefficiency, reduce artifacts, and increase data while being readily integrable into clinical workflows. Another technology that can provide rapid and in-depth characterization of thousands of molecules in a tissue sample, including liver tissues, is matrix assisted laser desorption/ionization (MALDI) mass spectrometry. MALDI has already been applied in a clinical research setting with promising diagnostic and prognostic capabilities, as well as being able to elucidate mechanisms of liver diseases that may be targeted for the development of new therapies. The logical next step in huge data sets obtained from such advanced analysis of liver tissues is the application of machine learning (ML) algorithms and application of artificial intelligence (AI), for automated generation of diagnoses and prognoses. This review discusses the evolving role of liver biopsies in clinical practice over the decades, and describes newer technologies that are likely to have a significant impact on how they will be used in the future.

Ultrahigh-speed point scanning two-photon microscopy using high dynamic range silicon photomultipliers

Conventional two-photon microscopes use photomultiplier tubes, which enable high sensitivity but can detect relatively few photons per second, forcing longer pixel integration times and limiting maximum imaging rates. We introduce novel detection electronics using silicon photomultipliers that greatly extend dynamic range, enabling more than an order of magnitude increased photon detection rate as compared to state-of-the-art photomultiplier tubes. We demonstrate that this capability can dramatically improve both imaging rates and signal-to-noise ratio (SNR) in two-photon microscopy using human surgical specimens. Finally, to enable wider use of more advanced detection technology, we have formed the OpenSiPM project, which aims to provide open source detector designs for high-speed two-photon and confocal microscopy.

International guidelines for the flow cytometric evaluation of peripheral blood for suspected Sézary syndrome or mycosis fungoides: Assay development/optimization, validation, and ongoing quality monitors

Introducing a sensitive and specific peripheral blood flow cytometric assay for Sézary syndrome and mycosis fungoides (SS/MF) requires careful selection of assay design characteristics, and translation into a laboratory developed assay through development/optimization, validation, and continual quality monitoring. As outlined in a previous article in this series, the recommended design characteristics of this assay include at a minimum, evaluation of CD7, CD3, CD4, CD8, CD26, and CD45, analyzed simultaneously, requiring at least a 6 color flow cytometry system, with both quantitative and qualitative components. This article provides guidance from an international group of cytometry specialists in implementing an assay to those design specifications, outlining specific considerations, and best practices. Key points presented in detail are: (a) Pre-analytic components (reagents, specimen processing, and acquisition) must be optimized to: (i) identify and characterize an abnormal population of T-cells (qualitative component) and (ii) quantitate the abnormal population (semi/quasi-quantitative component). (b)Analytic components (instrument set-up/acquisition/analysis strategy and interpretation) must be optimized for the identification of SS/MF populations, which can vary widely in phenotype. Comparison with expert laboratories is strongly encouraged in order to establish competency. (c) Assay performance must be validated and documented through a validation plan and report, which covers both qualitative and semi/quasi-quantitative assay components (example template provided). (d) Ongoing assay-specific quality monitoring should be performed to ensure consistency.

AB0688 GAIT PATTERN DIFFERENCES BETWEEN PATIENTS WITH RADIOGRAPHIC AND NON-RADIOGRAPHIC AXIAL SPONDYLOARTHRITIS, THE MyoSpA STUDY

Background:

Axial spondyloarthritis (axSpA) is a chronic inflammatory disease classified as radiographic (r-axSpA) or non-radiographic (nr-axSpA). Defining the gait patterns associated with these two groups can improve its detection and promote early intervention. In normal walking, body segments move around the joints as struts of an inverted pendulum. The resultant cyclic rotations contribute to the forward translation of the body, while minimizing muscle work and maintaining stability. Recent literature describes a decline in this pendulum-like mechanism associated with aging and some neurological diseases (Parkinson and multiple sclerosis).

Objectives:

The aim was to compare the 3D gait kinematics of patients with r-axSpA and nr-axSpA.

Methods:

A cross-sectional study was conducted on 54 participants (18-50 years old), 27 patients with axSpA (according to ASAS criteria, with less than 10 years since symptoms onset) and 27 healthy controls, matched by gender, age and level of physical activity. A sub-analysis was performed involving the whole group of patients classified as r-axSpA (n=14) and nr-axSpA (n=6). Subjects movement was reconstructed using a 3D full-body kinematic model (Kinetikos, Coimbra, Portugal) fed by 15 inertial sensors placed in the head, arms, trunk, pelvis, thighs, shanks and feet. 3D gait kinematics was characterised based on variables that analyse the body movement as a whole (e.g. center of mass displacement, speed), conventional spatiotemporal parameters (e.g. stance/swing time, step length) and joints kinematics time-normalized to 101 points, comprising the gait cycle from 0 to 100%. Nonparametric statistical tests were used.

Results:

In the r-axSpA group, 71,4% were male, with a mean age of 34.43±7.84 years and a BASDAI of 2.84±2.39, whereas in the nr-axSpA, 50% were male, with a mean age of 41.83±6.27 years and a BASDAI of 2.99±0.58. A statistically significant difference was observed in the displacement of the center of mass (with respect to the pelvis local coordinate system) along the anteroposterior axis between the two studied groups (H = 4.96, p = 0.03), with a mean rank displacement of 8.6 for r-axSpA and 15.00 for nr-axSpa, corresponding to a reduction in displacement of 38% (mean 0.00986 vs 0.01579m), in the r-axSpa group.

Conclusion:

Our preliminary results in r-axSpA subjects show a reduction of the pendulum mechanism. Although no significant segmental (kinematics) changes were observed, the sum of all studied variables result in a clear different gait pattern between the two groups. The observed decline can be an early sign of the inefficiency of the r-axSpA group to minimise the cost of transport of the center of mass during walking (i.e. increased instability). This study shows the potential of gait analysis to identify subjects who may benefit from early physiotherapy intervention.

Disclosure of Interests:

Nuno Gonçalves: None declared, Lúcia Domingues: None declared, Atlas Mashayekhi Sardoo: None declared, Lucian Radu: None declared, Santiago Rodrigues-Manica Speakers bureau: Jansse, MSD, Novartis, Agna Neto: None declared, Rita Torres: None declared, José Marona: None declared, Jaime Branco Speakers bureau: Vitoria, César Mendes: None declared, Ricardo Matias: None declared, Fernando Pimentel dos Santos Speakers bureau: Novartis, Pfizer, Biogen, Vitoria,

Calving date and its variability as a potential trait in the breeding objective to account for reproductive seasonality in alpacas

The low fertility and offspring survival indicators in alpacas can be partially due to their particularity seasonal reproduction that reduces the opportunities of the females to become pregnant within a season, with the survival of the offspring concerned by the availability of food and exposure to diseases that depends on the calving date. Optimizing the date of delivery and reducing its variability are shown as eligible criteria that could be used as selection criteria within the genetic improvement programmes in alpacas, the calving date being a much more appropriate trait to measure and optimize fertility unlike of age at first calving and the calving interval, this due to the reproductive seasonality in camelids. For this study, 6,533 birth date records were taken between 2001 and 2018 of Peruvian alpacas, to estimate the genetic parameters. Models assuming heterogeneity in the residuals were fitted besides classical homogeneous models to address, not only the possibility of forwarding or delaying the calving date, but also the trend to have parturitions in similar dates. The heritability and repeatability ranged from 0.07 to 0.20 for a homogeneity model and from 0.08 to 0.23 for a heterogeneity model, and suggest the possibility of advancing or delaying the calving date. It should be taken into account that the gestation length of camelids makes it difficult to adapt many reproductive traits, and trying to centre the calving date could delay it. It was concluded the feasibility to genetically select the calving date, also in the production of camels and dromedaries, which have the same reproductive characteristics as alpacas. This selection can be combined with other traits. The heterogeneity model was shown to provide a better fit.

Flow cytometric evaluation of peripheral blood for suspected Sézary syndrome or mycosis fungoides: International guidelines for assay characteristics

A peripheral blood flow cytometric assay for Sézary syndrome (SS) or circulating mycosis fungoides (MF) cells must be able to reliably identify, characterize, and enumerate T-cells with an immunophenotype that differs from non-neoplastic T-cells. Although it is also important to distinguish SS and MF from other subtypes of T-cell neoplasm, this usually requires information in addition to the immunophenotype, such as clinical and morphologic features. This article outlines the approach recommended by an international group with experience and expertise in this area. The following key points are discussed: (a) At a minimum, a flow cytometric assay for SS and MF should include the following six antibodies: CD3, CD4, CD7, CD8, CD26, and CD45. (b) An analysis template must reliably detect abnormal T-cells, even when they lack staining for CD3 or CD45, or demonstrate a phenotype that is not characteristic of normal T-cells. (c) Gating strategies to identify abnormal T-cells should be based on the identification of subsets with distinctly homogenous immunophenotypic properties that are different from those expected for normal T-cells. (d) The blood concentration of abnormal cells, based on any immunophenotypic abnormalities indicative of MF or SS, should be calculated by either direct enumeration or a dual-platform method, and reported.

Primate model of chronic retinal neovascularization and vascular leakage

The purpose of this study was to characterize and develop a primate model of chronic retinal neovascularization and vascular leakage that can be employed to assess efficacy of experimental therapeutics targeting retinal ischemic and neovascular diseases. African green monkeys received bilateral intravitreal (IVT) injection of DL-alpha-aminoadipic acid (DLAAA; 5 mg) following ophthalmic examination, color fundus photography, fluorescein angiography (FA) and optical coherence tomography (OCT). Imaging was repeated to evaluate progression and subsequent stabilization of retinal vascular pathology elicited by DLAAA. Aflibercept (Eylea) was administered IVT (1.4 mg) to assess effects on vascular leakage. Ocular tissue was collected for histopathology and glial fibrillary acidic protein (GFAP), von Willebrand Factor (vWF), CD105/endoglin, VEGF and CD68 immunohistochemistry to study retinal degeneration and vascular remodeling. IVT DLAAA administration resulted in telangiectatic vessel formation as early as two-weeks post-injection, followed by retinal vascular leakage and inner retinal edema. Neovascular lesion progression was evident up to 8-10 weeks post-injection before stabilizing into a vascular leakage state that persisted beyond 90 weeks. Histopathology and immunostaining revealed retinal degeneration and neovascularization, increased expression of vWF, CD105/endoglin, VEGF and CD68 immunoreactivities in addition to Müller cell loss. Aflibercept significantly attenuated vascular leakage for 2-4 weeks before progressive return of leakage from weeks 4-8. Lesions remained responsive to anti-VEGF administration at 90 weeks after DLAAA injection. Findings support application of the primate DLAAA-induced retinal vascular leakage model for efficacy evaluations of candidate therapeutics and sustained release strategies targeting exudative AMD, diabetic retinopathy, macular telangiectasia and other retinal ischemic and neovascular diseases. Findings confirm relevance of the DLAAA primate phenotype to understanding shared retinal vascular disease mechanisms and macular susceptibility to vascular and metabolic insults.

Regulated necrosis and failed repair in cisplatin-induced chronic kidney disease

Cisplatin is an effective chemotherapeutic agent, but significant nephrotoxicity limits its clinical use. Despite extensive investigation of the acute cellular and molecular responses to cisplatin, the mechanisms of progression from acute to chronic kidney injury have not been explored. We used functional and morphological metrics to establish a time-point when the transition from acute and reversible kidney injury to chronic and irreparable kidney disease is clearly established. In mice administered 1 or 2 doses of intraperitoneal cisplatin separated by 2 weeks, kidney function returned toward baseline two weeks after the first dose, but failed to return to normal two weeks following a second dose. Multiphoton microscopy revealed increased glomerular epithelial and proximal tubular damage in kidneys exposed to two doses of cisplatin compared with those exposed to a single dose. In contrast, there was no evidence of fibrosis, macrophage invasion, or decrease in endothelial cell mass in chronically diseased kidneys. Pathway analysis of microarray data revealed regulated necrosis as a key determinant in the development of chronic kidney disease after cisplatin administration. Western blot analysis demonstrated activation of proteins involved in necroptosis and increased expression of kidney injury markers, cellular stress response regulators, and upstream activators of regulated necrosis, including Toll-like receptors 2 and 4. These data suggest that unresolved injury and sustained activation of regulated necrosis pathways, rather than fibrosis, promote the progression of cisplatin-induced acute kidney injury to chronic kidney disease.

Immunization Status at the Time of Liver Transplant in Children and Adolescents

This study characterizes the percentage of pediatric patients undergoing liver transplant who were up to date for their age on immunizations at the time of transplant and risk factors for underimmunization.

Graphene and its derivatives: Opportunities and challenges in dentistry

The emerging science of graphene-based engineered nanomaterials as either nanomedicines or dental materials in dentistry is growing. Apart from its exceptional mechanical characteristics, electrical conductivity and thermal stability, graphene and its derivatives can be functionalized with several bioactive molecules, allowing them to be incorporated into and improve different scaffolds used in regenerative dentistry. This review presents state of the art graphene-based engineered nanomaterial applications to cells in the dental field, with a particular focus on the control of stem cells of dental origin. The interactions between graphene-based nanomaterials and cells of the immune system, along with the antibacterial activity of graphene nanomaterials are discussed. In the last section, we offer our perspectives on the various applications of graphene and its derivatives in association with titanium dental implants, membranes for bone regeneration, resins, cements and adhesives, as well as tooth-whitening procedures.

Abstract GS2-04: Efficacy results from CIBOMA/2004-01_GEICAM/2003-11 study: A randomized phase III trial assessing adjuvant capecitabine after standard chemotherapy for patients with early triple negative breast cancer

Background: Triple negative breast cancers (TNBC) have a greater risk of relapse than non-TNBC. New therapeutic approaches are needed for these patients (pts). CIBOMA/2004-01_GEICAM/2003-11 is a multinational, randomized phase III trial exploring adjuvant capecitabine (X) after completion of standard treatment in early TNBC pts.

Materials and Methods: Patients with operable, node-positive (or node-negative with tumor size ≥ 1 cm), centrally confirmed hormone receptor-negative, HER2-negative early BC, who had received 6–8 cycles (cy) of standard anthracycline and/or taxane-containing chemotherapy or 4 cy of doxorubicin-cyclophosphamide (for node-negative disease) in the (neo)adjuvant setting, were eligible. Patients were randomized to either 8 cy of X (1,000 mg/m2 bid, days 1–14, every 3 weeks) or observation. Stratification factors included center, prior taxane-based therapy, number of involved axillary lymph nodes and phenotype (basal vs non-basal, according to cytokeratins 5/6 and/or EGFR positivity). The primary objective was to compare the disease-free survival (DFS) between both treatment arms, and secondary objectives included the comparison in terms of 5-year DFS, overall survival (OS) and safety. Assuming a 30% risk reduction in DFS rate at 5 years (from 64.7% to 73.7%, hazard ratio 0.70) with 80% power and a two-tailed log-rank test at 0.05, 834 evaluable pts were needed. 876 pts had to be finally enrolled considering a drop-out rate of 5%.

Results: Recruitment of 876 pts from 8 countries was completed in September 2011. Median age was 49 years; 68.5% of pts were postmenopausal, 55.5% were lymph node negative, 71.7% had a basal phenotype, 67.5% received chemotherapy based on anthracyclines and taxanes. Median follow-up was 7.3 years (range 0.0 to 11.1). DFS was not significantly prolonged with X vs observation (hazard ratio (HR) 0.82; 95% confidence interval (CI), 0.63 to 1.06; P=0.1353). Five-year DFS was 79.6% (95% CI, 75.8% to 83.4%) with X and 76.8% (95% CI, 72.7% to 80.9%) with observation. OS was not statistically different between treatment arms (HR 0.92; 95% CI, 0.66 to 1.28; P=0.6228). In subgroup analysis for DFS, we found no statistically significant interaction between X treatment and different subgroups, with the exception of basal vs non-basal phenotypes (basal HR 0.97, 95% CI 0.72 to 1.32, P=0.8620; non-basal HR 0.51, 95% CI, 0.31 to 0.86, P=0.0101; interaction P=0.0357). Similar results were found for OS (basal HR 1.20, 95% CI 0.81 to 1.77, P=0.3684; non-basal HR 0.48, 95% CI, 0.26 to 0.91, P=0.0205; interaction P=0.0155). 75.2% of pts completed 8 cy of X, with a median relative dose intensity of 86.3%. Grade (G) 3 or higher adverse events (AEs) were observed in 40.4% of pts in X arm. In 9.6% of pts the AEs were related with X. Hand-foot syndrome was the most common AE in X arm (G3 on 18.8% of pts).

Conclusions: In our study, the addition of adjuvant X after standard (neo) adjuvant anthracycline and/or taxane-containing chemotherapy was not associated with a statistically significant improvement of DFS or OS compared to observation in pts with early TNBC. However, in a subgroup analysis a significant DFS and OS improvement was observed with X in pts with non-basal phenotype.

Sponsor: CIBOMA.

Citation Format: Martín M, Barrios CH, Torrecillas L, Ruiz-Borrego M, Bines J, Segalla J, Ruiz A, García-Sáenz JA, Torres R, de la Haba J, García E, Gómez HL, Llombart A, Rodríguez de la Borbolla M, Baena JM, Barnadas A, Calvo L, Pérez-Michel L, Ramos M, Castellanos J, Rodríguez-Lescure A, Cárdenas J, Vinholes J, Martínez de Dueñas E, Godes MJ, Seguí MA, Antón A, López-Álvarez P, Moncayo J, Amorim G, Villar E, Reyes S, Sampaio C, Cardemil B, Escudero MJ, Bezares S, Carrasco E, Lluch A. Efficacy results from CIBOMA/2004-01_GEICAM/2003-11 study: A randomized phase III trial assessing adjuvant capecitabine after standard chemotherapy for patients with early triple negative breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr GS2-04.

A highly efficient and faithful MDS patient-derived xenotransplantation model for pre-clinical studies

Comprehensive preclinical studies of Myelodysplastic Syndromes (MDS) have been elusive due to limited ability of MDS stem cells to engraft current immunodeficient murine hosts. Here we report a MDS patient-derived xenotransplantation model in cytokine-humanized immunodeficient “MISTRG” mice that provides efficient and faithful disease representation across all MDS subtypes. MISTRG MDS patient-derived xenografts (PDX) reproduce patients’ dysplastic morphology with multi-lineage representation, including erythro- and megakaryopoiesis. MISTRG MDS-PDX replicate the original sample’s genetic complexity and can be propagated via serial transplantation. MISTRG MDS-PDX demonstrate the cytotoxic and differentiation potential of targeted therapeutics providing superior readouts of drug mechanism of action and therapeutic efficacy. Physiologic humanization of the hematopoietic stem cell niche proves critical to MDS stem cell propagation and function in vivo. The MISTRG MDS-PDX model opens novel avenues of research and long-awaited opportunities in MDS research.

Myelodyplastic hematopoietic stem cells (MDS HSC) have eluded in vivo modeling. Here the authors present a highly efficient MDS patient-derived xenotransplantation model in cytokine-humanized mice with replication of the donors’ genetic complexity and myeloid, erythroid, and megakaryocytic lineage dysplasia.

False-Positive Light Chain Clonal Restriction by Flow Cytometry in Patients Treated With Alemtuzumab: Potential Pitfalls for the Misdiagnosis of B-Cell Neoplasms

Objectives

To increase awareness of potential diagnostic test interference associated with alemtuzumab, which is a therapeutic immunoglobulin G1 κ monoclonal antibody used in hematologic malignancies, autoimmune diseases, and transplant-related disorders.

Methods

Bone marrow and blood from patients with T-cell prolymphocytic leukemia treated with alemtuzumab were evaluated by flow cytometry. Healthy donor blood was analyzed with or without in vitro treatment with alemtuzumab for comparison.

Results

Immunophenotypic analysis of bone marrow collected 4 weeks after alemtuzumab treatment demonstrated artifactual surface κ light chain restriction in CD19+ B cells and CD3+ T cells. Similar findings were observed in blood from another patient in a specimen collected 3 days after alemtuzumab treatment. These findings were recapitulated in healthy donor blood incubated with alemtuzumab.

Conclusions

Alemtuzumab can produce direct interference during flow cytometry analysis, resulting in false-positive evidence of light chain clonality. Clinicians and laboratorians should be cognizant of this risk to avoid misdiagnosis of B-cell neoplasms.

Genetic parameters for medullated fiber and its relationship with other productive traits in alpacas

The alpaca fiber diameter (FD) varies from 18 to 36 μm, being the finer fiber categories highly appreciated. However, the alpaca fiber presents some limitations in the textile industry due to the high incidence of fiber medullation and diameter variability, both reduces the comfort feeling of the garments. Decreasing or even removing medullation could be a possible selection objective in alpaca breeding programs for increasing economic value of the alpaca fiber. Therefore, the present work aimed to estimate genetic parameters regarding medullation traits, as well as the genetic correlations with other economical important traits, to be able to select the appropriate criteria to reduce or remove medullation on alpaca fiber and help to reduce the prickle factor in the garments. The data was collected from 2000 to 2017 and belonged to the Pacomarca experimental farm. There were 3698 medullation records corresponding to 1869 Huacaya and 414 Suri genetic types. The fiber samples were taken from the mid side, and were analyzed in an OFDA 100® device. The traits analyzed were percentage of medullation (PM), medullated fiber diameter (MFD), FD, standard deviation of FD, greasy fleece weight as fiber traits; density, crimp in Huacaya and lock structure in Suri, head conformation, leg coverage as morphological traits; weaning weight and age at first calving as secondary and functional traits. Genetic parameters were estimated via a multitrait restricted maximum likelihood. The heritabilities for PM and MFD were 0.225 and 0.237 in Huacaya genetic type and 0.664 and 0.237 in Suri genetic type, respectively; heritabilities for other traits were moderate for productive and morphological traits, and low to moderate for secondary and functional traits. The genetic correlations PM-FD and MFD-FD were high and favorable in both genetic types, between 0.531 and 0.975; the genetic correlation PM-MFD was 0.121 in Huacaya and 0.427 in Suri. The rest of genetic correlations with other traits were in general moderate and favorable. The repeatabilities were 0.556 and 0.668 for PM, and 0.322 and 0.293 for MFD in Huacaya and Suri genetic types, respectively. As a conclusion, PM was identified to be a good selection criterion, probably combined in an index with FD to reduce prickling factor.

Modified approach to fibrinogen replacement in the setting of dysfibrinogenaemia

Most fibrinogen replacement strategies focus on quantitative deficiencies. A thrombin time (TT) mixing study helped to assess qualitative defects caused by dysfibrinogens. Plasma samples were collected from non-anticoagulated subjects (n=6) meeting laboratory criteria for suspected dysfibrinogenaemia (TT > 22 s; fibrinogen activity <180) and from a control group. TT mixing studies were performed on subject plasma with increasing volumes of pooled normal plasma at 1:2, 1:4 and 1:5 dilutions. No subjects with dysfibrinogenaemia demonstrated a complete TT correction at 1:2, but 50% corrected at 1:4 and 100% at 1:5 dilution. Based on these data, a correction factor (CF), defined as the reciprocal dilution yielding complete correction, was incorporated into our clinical practice formula for fibrinogen dosing in patients with dysfibrinogenaemias. Our study incorporates TT mixing studies for assessment of dysfibrinogens. The addition of a mix-derived CF to classical formulae may better approximate dosing in patients with dysfibrinogenaemia.

The energetic physiology of juvenile mussels, Mytilus chilensis (Hupe): The prevalent role of salinity under current and predicted pCO2 scenarios

As a result of human activities, climate forecasts predict changes in the oceans pCO₂ and salinity levels with unknown impacts on marine organisms. As a consequence, an increasing number of studies have begun to address the individual influence of pCO₂ and salinity but much remains to be done to understand their combined effects on the physiology and ecology of marine species. Our study addressed this knowledge gap by measuring the influence of current and predicted levels of pCO₂ (380 and 1200 ppm, respectively) and salinity (20, 25 and 30 psμ) on the energetic physiology of juvenile mussels (Mytilus chilensis) from the south-eastern Pacific region. Our results indicate that a reduced salinity caused a significant reduction in clearance rate, absorption efficiency and scope for growth of this species. Meanwhile, an increase in pCO₂ levels caused a reduction in excretion rates and interacted significantly with salinity in the rate of oxygen uptake measured in the mussel. These results suggest that potential changes in salinity might have a direct role on the physiology of M. chilensis. The effect of pCO₂, although less prevalent among the variables measured here, did interact with salinity and is also likely to alter the physiology of this species. Given the ecological and economic importance of M. chilensis, we call for further studies exploring the influence of pCO₂ across a wider range of salinities.

Enhanced shelf-life of the formulated biocontrol agent Bacillus amyloliquefaciens CPA-8 combining diverse packaging strategies and storage conditions

Two effective biocontrol products (named as BA3 and BA4) based on Bacillus amyloliquefaciens CPA-8 have been reported as a potential alternative to chemical applications against brown rot caused by Monilinia spp. on stone fruit. To have practical use, this study aimed to describe the best packaging strategies (bags or flasks, atmosphere, and temperature of storage) to not only guarantee efficacy but also stability and ease of application of the products to be handled through the normal channels of distribution and storage. In terms of the viability neither the BA3 nor the BA4 product has been compromised after twelve months of storage. However, storage at 4 °C affected the stability and visual aspect of both CPA-8 formulations, mainly associated not only to the increase of RH but also a_w. Moreover, it should be pointed out that flasks did not conserve refrigerated BA3 samples in a suitable way, since RH and a_w increased noticeably making their visual properties unsightly after 10 months of cold storage. At that time, the BA4 products were better preserved at 4 °C when packaged in flasks. Finally, this study also demonstrated that the most suitable packaging conditions for long-term storability (stored at 22 °C) did not show any negative effect in the biocontrol efficacy of CPA-8 in nectarines artificially infected with M. fructicola and provide suitable product delivery and field application. In conclusion, these results contribute to the final stage of development of these two CPA-8 products, practically ready for registration, thus contributing to the environmental-friendly management of postharvest diseases in stone fruit.

The My Child Matters Programme: The Effect of the Implementation of a Childhood Cancer Care Network (ReNaCI) in the Treatment Abandonment of Acute Lymphoblastic Leukemia in Paraguay

Background: In Paraguay, a low-middle income country (GDP per capita of USD 4,728.7), pediatric cancer is the second cause of mortality in children and adolescents 5-19 years of age. There are approximately 300 new cases of pediatric cancer per year. The Pediatric Cancer Center (PCC) of the School of Medicine (SoM) receives 120 new cases per year, of which 40% correspond to acute lymphoblastic leukemia (ALL). Treatment abandonment is the interruption of patient contact with the health personnel and the treatment of more than 30 days after treatment initiation. At our cancer center, ALL treatment abandonment has been a serious problem. The rates were as high as 20% in 2006, lowering to 17.5% in 2008. To prevent abandonment at our center, we assessed the risk for abandonment, then, we concentrated in three basic interventions: review of compliance with appointment, training of parents and teachers, and access for care at satellites clinics closer to home. For missed appointment, parents are contacted via telephone, or through home visits; and in occasions assistance of child protection services was solicited. We systematically trained parents in the importance of the adherence to cancer treatment. Since 2009, we implemented a comprehensive system for referrals of new cases and follow-up by establishing the ReNaCI, (Red Nacional de Atencion al Cancer Infantil) network. Essential funds for building and sustaining the network has been provided by My Child Matters program under the auspices of Sanofi Espoir Fundation, Paris, France. Currently, as part of this network, there is 4 regional pediatric clinics for early cancer detection, referral, treatment, social assistance and follow up of pediatrics patients with cancer. Aim: Assess the effect of the network in the percentage of abandonment of treatment in patients with ALL treated at the PCC of the SoM in Asunción. Methods: We conducted a longitudinal descriptive study of children diagnosed with ALL at the PCC of the SoM between January 2009 and December 2017. We analyzed the percentage of abandonment since the implementation of the ReNACI network and compared with historical data. Results: From January 2009 to December 2017, 396 new patients with ALL diagnose at the PCC of the SoM. More than 70% of the families were evaluated as having an elevated social risk for abandonment. Abandonment rate decreased from 17.5% in 2008, in 2010%-1.96%, and since 2011 there were no abandonment. However, we still observed in the study period 12% of missed appointments to continue the treatment protocol. Conclusion: The ReNaCI network allowed a successful implementation of interventions to address abandonment by establishing a systems of satellite clinics for a medical and social support for the child and his family closer to home during the entire treatment period. But, despite the achievements, a continuous monitoring is still required to sustain the success of our intervention. Funding: Sanofi Espoir Foundation

Efficacy of environmental friendly disinfectants against the major postharvest pathogens of stone fruits on plastic and wood surfaces

Disinfection of surface facilities during postharvest handling operation is an important practice to avoid secondary fruit infections at stone fruit packinghouses. The aim of this work was to evaluate the effect of six environmental friendly disinfectants against Monilinia fructicola, Penicillium expansum, Rhizopus spp., and Alternaria spp. on plastic and wood surfaces. Hydrogen peroxide, peracetic acid, sodium hypochlorite, Mico-E-pro®, Proallium FRD-N®, and DMC Clean-CNS® were used as the disinfectants. Untreated and surfaces treated with water were used as controls. Plastic and wood surfaces were sampled with Rodac plates at 2 and 24 h after treatments and the number of colonies were counted. In general, all disinfectants reduce the number of viable conidia from all studied surfaces. Hydrogen peroxide used in a concentration of 150 mg L^-1 was the less effective disinfectant in all studied pathogens. The commercial product Mico-E-pro® composed of oregano, onion, and orange extract at a dose of 10 mg L^-1 was the most effective disinfectant. Rhizopus spp. was the pathogen more resistant to the disinfectants followed by P. expansum, M. fructicola, and Alternaria spp. Water decreased the number of conidia adhered to the surface. In addition, the untreated control showed substantial conidia reduction after 24 h of artificial inoculation.