Determination of Arsenic in Vegetable Samples by Hydride Generation Atomic Absorption Spectrometry

A procedure is described for the determination of arsenic in vegetable samples by hydride generation atomic absorption spectrometry. The samples are mineralized in a microwave acid digestion bomb with nitric acid in the presence of small amounts of vanadium pentoxide. The determination of arsenic is made by the standard addition method. A certified reference sample is analyzed, and the result obtained agreed well with the certified value. The detection limit (dry weight) was about 0.020 μg/g. Reproducibility relative standard deviations ranged from 6.45% at 0.152 μg A μ/g to 8.31 % at 0.059 μg A μ/g. The concentrations of arsenic in vegetable samples ranged from 0.029 to 0.444 μg/g (fresh weight)

Determination of Selenium in Urine by Hydride Generation Atomic Absorption Spectrometry

A procedure has been developed for determination of total selenium in urine by hydride generation atomic absorption spectrometry. Mineralization was performed with a nitric acid–perchloric acid mixture on a thermostated digestion block. The method was validated by comparison with the method involving mineralization in a microwave acid digestion bomb containing nitric acid and small amounts of vanadium pentoxide. Se(VI) was reduced to Se(IV) by dissolution in 7N HCI. Sample recoveries, precision studies, and analyses of a certified reference material demonstrated the reliability and accuracy of this technique. Urine samples had selenium concentrations ranging from 4.6 to 50.3 μg/L. These values correspond to an average of 54.9 μg per person per day total ingested and bioavailable Se in the daily diet.

Selectivity and Physicochemical Optimization of Repurposed Pyrazolo[1,5-b]pyridazines for the Treatment of Human African Trypanosomiasis

From a high-throughput screen of 42 444 known human kinases inhibitors, a pyrazolo[1,5-b]pyridazine scaffold was identified to begin optimization for the treatment of human African trypanosomiasis. Previously reported data for analogous compounds against human kinases GSK-3β, CDK-2, and CDK-4 were leveraged to try to improve the selectivity of the series, resulting in 23a which showed selectivity for T. b. brucei over these three human enzymes. In parallel, properties known to influence the absorption, distribution, metabolism, and excretion (ADME) profile of the series were optimized resulting in 20g being progressed into an efficacy study in mice. Though 20g showed toxicity in mice, it also demonstrated CNS penetration in a PK study and significant reduction of parasitemia in four out of the six mice.

P729 A shocking tumor

Introduction

Primary cardiac tumors are a relatively uncommon condition, which may appear both in asymptomatic patients or in a myriad of clinical presentations. Imaging techniques are crucial for its diagnosis, and a multi-modality approach may be useful in the evaluation of this masses.

Case description

A 57 year-old man with history of hypertension presented in the emergency department with acute pulmonary edema and cardiogenic shock. He was admitted to the coronary care unit, and on bedside echocardiography a mass on the tricuspid valve was observed.

Upon clinical improvement, a cardiac CT and cardiac MRI was performed (figure 1). A solid mass with no calcium content and dependent exclusively on the anterior leaflet of the tricuspid valve was seen on CT-scan (fig 1, A and B). Thrombus on the right atrial appendage could also be appreciated.

MRI confirmed the presence of a 18x19 mm mass with isointense signal on T1-turbo spin echo black-blood (fig 1, C) and cine steady-state free precession sequences, whereas an hyperintense signal was evident on T2 weighted images (T2-STIR; fig 1 D). In first pass sequences the central core was hypointense and late gadolinium enhancement showed peripheral enhancement with a non captating central core (fig 1, E).

The patient underwent surgery and the anatomopathological results showed a tumor constituted by dense connective tissue, scarce cellular content and an avascular matrix of mucopolysaccharides, elastic fibers and fusiform cells consistent with the diagnosis of papillary fibroelastoma.

Discussion

The imaging characteristics of papillary fibroelastoma are not commonly reported on MRI. We present an unusually large right-sided fibroelastoma with a characteristic distribution of late gadolinium enhancement, which has not been consistently described on a fibroelastoma.

Cardiac tumors are rare, and a non-invasive differential diagnosis is always a challenge. A multi-modality approach (echocardiography, cardiac-CT and cardiac MRI) as well as integration of relevant morphological information, including the location of the lesion and tissue characteristics was essential to the orientate the most plausible diagnosis. The distinctive images are presented.

Abstract P729 Figure 1.

Hit-to-Lead Optimization of Benzoxazepinoindazoles As Human African Trypanosomiasis Therapeutics

Human African trypanosomiasis (HAT) is a neglected tropical disease caused by infection with either of two subspecies of the parasite Trypanosoma brucei. Due to a lack of economic incentive to develop new drugs, current treatments have severe limitations in terms of safety, efficacy, and ease of administration. In an effort to develop new HAT therapeutics, we report the structure-activity relationships around T. brucei for a series of benzoxazepinoindazoles previously identified through a high-throughput screen of human kinase inhibitors, and the subsequent in vivo experiments for HAT. We identified compound 18, which showed an improved kinase selectivity profile and acceptable pharmacokinetic parameters, as a promising lead. Although treatment with 18 cured 60% of mice in a systemic model of HAT, the compound was unable to clear parasitemia in a CNS model of the disease. We also report the results of cross-screening these compounds against T. cruzi, L. donovani, and S. mansoni.

Determination of Lithium in Human Serum by Electrothermal Atomic Absorption Spectrometry

An efficient method was developed for the determination of nanogram levels of lithium in biological samples. Serum samples from human subjects from southeastern Spain, treated or not treated with lithium carbonate, were analyzed by electrothermal atomic absorption spectrometry. The samples were previously treated with a matrix modifier consisting of 0.1%Triton X-100 and injected through a graphite tube with L'vov platform. The Li concentrations measured by the procedure described for the 3 certified reference samples used were not significantly different (p > 0.05) than certified levels. Sample recoveries and variability during several days, with coefficients of variation from 4.00 to 14.8%, demonstrated the reliability and accuracy of this technique. Mean Li concentration determined in the serum of individuals with psychiatric disorders treated with Li (n = 117, 5.077 ± 1.795 μg Li/mL) was significantly higher (p < 0.001) than that in individuals not treated with Li (n = 24, 1.902 ± 2.054 ng Li/mL).

SUMOylated SNF2PH promotes variant surface glycoprotein expression in bloodstream trypanosomes

SUMOylation is a post‐translational modification that positively regulates monoallelic expression of the trypanosome variant surface glycoprotein (VSG). The presence of a highly SUMOylated focus associated with the nuclear body, where the VSG gene is transcribed, further suggests an important role of SUMOylation in regulating VSG expression. Here, we show that SNF2PH, a SUMOylated plant homeodomain (PH)‐transcription factor, is upregulated in the bloodstream form of the parasite and enriched at the active VSG telomere. SUMOylation promotes the recruitment of SNF2PH to the VSG promoter, where it is required to maintain RNA polymerase I and thus to regulate VSG transcript levels. Further, ectopic overexpression of SNF2PH in insect forms, but not of a mutant lacking the PH domain, induces the expression of bloodstream stage‐specific surface proteins. These data suggest that SNF2PH SUMOylation positively regulates VSG monoallelic transcription, while the PH domain is required for the expression of bloodstream‐specific surface proteins. Thus, SNF2PH functions as a positive activator, linking expression of infective form surface proteins and VSG regulation, thereby acting as a major regulator of pathogenicity.

Review: Chemosensing of nutrients and non-nutrients in the human and porcine gastrointestinal tract

The gastrointestinal tract (GIT) is an interface between the external and internal milieus that requires continuous monitoring for nutrients or pathogens and toxic chemicals. The study of the physiological/molecular mechanisms, mediating the responses to the monitoring of the GIT contents, has been referred to as chemosensory science. While most of the progress in this area of research has been obtained in laboratory rodents and humans, significant steps forward have also been reported in pigs. The objective of this review was to update the current knowledge on nutrient chemosensing in pigs in light of recent advances in humans and laboratory rodents. A second objective relates to informing the existence of nutrient sensors with their functionality, particularly linked to the gut peptides relevant to the onset/offset of appetite. Several cell types of the intestinal epithelium such as Paneth, goblet, tuft and enteroendocrine cells (EECs) contain subsets of chemosensory receptors also found on the tongue as part of the taste system. In particular, EECs show specific co-expression patterns between nutrient sensors and/or transceptors (transport proteins with sensing functions) and anorexigenic hormones such as cholecystokinin (CCK), peptide tyrosine tyrosine (PYY) or glucagon-like peptide-1 (GLP-1), amongst others. In addition, the administration of bitter compounds has an inhibitory effect on GIT motility and on appetite through GLP-1-, CCK-, ghrelin- and PYY-labelled EECs in the human small intestine and colon. Furthermore, the mammalian chemosensory system is the target of some bacterial metabolites. Recent studies on the human microbiome have discovered that commensal bacteria have developed strategies to stimulate chemosensory receptors and trigger host cellular functions. Finally, the study of gene polymorphisms related to nutrient sensors explains differences in food choices, food intake and appetite between individuals.

P1551A genetic risk score predicts recurrent events after myocardial infarction in young adults

Background

To evaluate whether a genetic risk score (GRS) improves the prediction of recurrent events in young non-diabetic patients presenting with an acute myocardial infarction and identifies a more aggressive form of atherosclerosis in this population.

Methods and results

We performed a prospective study including 81 consecutive non-diabetic patients aged below 55 y.o. presenting with an acute myocardial infarction (48±6 y.o., 89% male). A comprehensive study including serum biomarkers, genetic testing and cardiac CT was performed. We studied the association of a GRS composed of 11 genetic variants with a primary composite end-point (all-cause mortality, recurrent acute coronary syndrome, and cardiac re-hospitalisation). After a median follow-up of 4.1 (3.5 - 4.4) years 24 recurrent events were documented. A significantly higher prevalence of 9 out of 11 risk alleles was noted compared with general population. The GRS was significantly associated with recurrent events, especially when baseline LDL-cholesterol levels were elevated. Compared with the low-risk GRS category, the multivariate-adjusted hazard ratio for recurrent events for the intermediate-risk GRS category was 10.2 (95% CI 1.1–100.3, p=0.04) and for the high-risk GRS was 20.7 (2.4–181.0, p=0.006) when LDL-C ≥2.8 mmol/L. Inclusion of the GRS improved the C statistic (ΔC statistic =0.086), the continuous Net Reclassification Index (30%) and the Integrated Discrimination Improvement (0.05) compared with a multivariate clinical risk model. Cardiac CT detected coronary calcified atherosclerosis and numerous plaques but it had a limited value for prediction of recurrences. No association was observed between extracellular matrix metabolism biomarkers and GRS or recurrent events in this population.

Cox regression analysis between GRS terciles and LDL-C Univariate analysis Multivariate analysis* HR (95% CI) p-value HR (95% CI) p-value* Low GRS 1 1 Intermediate GRS 2.0 (0.7–5.8) 0.21 LDL-C≤110 mg/dL (≤2.8 mmol/L) 1.0 (0.3–4.0) >110 mg/dL (>2.8 mmol/L) 10.2 (1.1–100.3) 0.04 High GRS 3.0 (1.0–9.2) 0.05 LDL-C≤110 mg/dL (≤2.8 mmol/L) 0.3 (0.1–1.9) >110 mg/dL (>2.8 mmol/L) 20.7 (2.4–181.0) 0.006 *Multivariate model adjusted for GRACE risk score and LDL-C and interaction. There was a strong interaction between GRS terciles and LDL-C (p<0.01).

Recurrent events based on genetic risk

Conclusions

A multilocus genetic risk score identified non-diabetic young patients at increased risk for recurrent events after a myocardial infarction. The significance of LDL-cholesterol in relation to genetic predisposition for recurrences merits further evaluation.

Acknowledgement/Funding

Instituto de Salud Carlos III (PI12/0564, PI14/01152 and PI15/00667), the CIBERCV and the Spanish Society of Cardiology (2015/CC)

P14.58 Extending adjuvant temozolomide longer than six cycles doesn’t add any benefit to glioblastoma patients according to the randomized GEINO-014 TRIAL

BACKGROUND

Standard treatment of glioblastoma (GBM) is focal radiation with concomitant and adjuvant temozolomide (TMZ) for 6 cycles. The GEINO-14-01 trial (NCT02209948) investigated the role of extending adjuvant TMZ to 12 cycles in a randomized multicenter study.

MATERIAL AND METHODS

Between Aug/2014 and Nov/2018, 166 patients (p) were screened and 159 randomized to extend (80p) or not (79p) TMZ treatment to 12 cycles after proving stable disease in the MRI performed before inclusion. The trial was stratified by MGMT status and presence or absence of residual disease (defined as a residual enhancement larger than 1cm on the MRI). The primary endpoint was differences in 6monthsPFS, secondary endpoints were differences in PFS, OS, toxicity, between arms and per stratification factors.

RESULTS

Median age was 60.4 (range 29–83), 97p (61%) were methylated and 83 p (52.2%) were reported with residual disease. Median (m) PFS was 7.9 months (95%CI: 6.1–9.8) and mOS: 20.9 (95%CI: 17.6–24.1). A methylated status was a factor of better PFS (HR=0.29, 95% CI 0.46–0.95; p=0.029) and better OS (HR= 0.43: 95% CI 0.28–0.66; p=0.000) as well as the absence of residual disease (PFS: HR = 0.84: 95% CI =0.71–1.01; p=0.068; OS: HR=0.77, 95%CI 0.63–0.96; p=0.019). We didn’t find any difference in PFS (HR=1.02, 95%CI 0.85–1.21; p=0.82), or OS (HR=0.90; 0.73–1.11; p=0.34) on extending treatment with temozolomide longer than 6 cycles.

CONCLUSION

There is no benefit of continuing TMZ treatment for more than 6 cycles in the adjuvant treatment of glioblastoma. Final data will be presented at the congress. Supported by a Grant of the ISCIII: PI13/01751

Involvement in surface antigen expression by a moonlighting FG-repeat nucleoporin in trypanosomes

The nuclear pore complex is an ancient component of the eukaryotic cell. We show here that an FG nucleoporin, TbNup53b, in trypanosomes has an association with the splicing machinery and roles in gene expression, indicating that moonlighting roles for nucleoporins are highly ancient and present in the earliest eukaryotes.

Components of the nuclear periphery coordinate a multitude of activities, including macromolecular transport, cell-cycle progression, and chromatin organization. Nuclear pore complexes (NPCs) mediate nucleocytoplasmic transport, mRNA processing, and transcriptional regulation, and NPC components can define regions of high transcriptional activity in some organisms at the nuclear periphery and nucleoplasm. Lineage-specific features underpin several core nuclear functions and in trypanosomatids, which branched very early from other eukaryotes, unique protein components constitute the lamina, kinetochores, and parts of the NPCs. Here we describe a phenylalanine-glycine (FG)-repeat nucleoporin, TbNup53b, that has dual localizations within the nucleoplasm and NPC. In addition to association with nucleoporins, TbNup53b interacts with a known trans-splicing component, TSR1, and has a role in controlling expression of surface proteins including the nucleolar periphery-located, procyclin genes. Significantly, while several nucleoporins are implicated in intranuclear transcriptional regulation in metazoa, TbNup53b appears orthologous to components of the yeast/human Nup49/Nup58 complex, for which no transcriptional functions are known. These data suggest that FG-Nups are frequently co-opted to transcriptional functions during evolution and extend the presence of FG-repeat nucleoporin control of gene expression to trypanosomes, suggesting that this is a widespread and ancient eukaryotic feature, as well as underscoring once more flexibility within nucleoporin function.

2 Role of histone H3 lysine 9 trimethylation during bovine pre-implantation embryonic development

Histones play an important role in DNA’s compaction and organisation into the cellular nucleus. Depending on which histone modification occurs, chromatin can take a conformation of heterochromatin or euchromatin, which are associated with gene repression or expression, respectively. Histone H3 lysine 9 (H3K9) trimethylation (H3K9me3) is associated with gene silencing. At least 3 methyltransferases are able to change the methylation status of H3K9: SUV39H1, SUV39H2, and SETDB1. In several mammalian species, modulation of H3K9 methylation status has been demonstrated to be necessary to achieve a successful pre-implantation embryonic development after IVF or somatic cell NT. The aim of this work was to study the role of H3K9me3 in IVF pre-implantation bovine embryos. For this purpose, immunostaining of H3K9me3 at different pre-implantation stages of development was performed. Further, the relative abundances of the methyltransferases SUV39H1 and SUV39H2 were measured by real-time PCR using luciferase transcript as an exogenous gene for normalization. Finally, to evaluate H3K9me3 involvement during pre-implantation embryonic development, we generated SUV39H1 or SUV39H2 knockout embryos by the CRISPR/Cas9 system. We designed guide RNA targeting SUV39H1 or SUV39H2 and co-injected the presumptive zygote’s cytoplasm 18h post-fertilization with Cas9 protein. At Day 8 post-fertilization, the number of blastocysts was assessed and embryos were immunostained to evaluate H3K9me3. Results were analysed using Student’s t-test or ANOVA with the post-hoc Tukey test depending on data set (P ≤ 0.05) and reported as means±standard errors of the mean. Oocytes at germinal vesicle stage and metaphase II as well as embryos at different stages of pre-implantation development (2, 4, and 8 cells, morula, and blastocyst; n=6) were immunoreactive for H3K9me3. Expression of SUV39H1 and SUV39H2 mRNA decreased significantly as embryonic development progressed, reaching undetectable levels at stages where genome activation had already occurred (morula and blastocyst; P&lt;0.0001, n=3). When zygotes were co-injected with the guide RNA targeting SUV39H1/Cas9, embryonic production showed a significant increase compared with the control [42.26%±5.03 (28/65) v. 23.86%±3.99 (21/88), respectively; P=0.034, n=4], and H3K9me3 immunostaining was reduced in treated embryos. Editing efficiency was estimated at 66%. In contrast, no statistical differences were found in embryonic production or H3K9me3 immunostaining in embryos co-injected with the guide RNA targeting SUV39H2/Cas9 (P=0.57, n=3). In conclusion, we were able to characterise H3K9me3 and determine transcript levels of methyltransferases SUV39H1 and SUV39H2 in oocytes and different stages of pre-implantation embryonic development. We also demonstrated that SUV39H1 deletion led to an increased embryonic production, suggesting that H3K9me3 removal would allow a greater relaxation of the heterochromatin and consequently a successful activation of embryonic genes. This highlights the essential role of H3K9me3 during bovine pre-implantation embryonic development.

Influence of the micro-oxygenation dose and supplementation with oak staves of different potential of ellagitannin release on wine color and composition

Aliquots of a wine of Merlot were micro-oxygenated at two doses of oxygen (2.5 and 5.0 mg of O2/L.month) in the presence or not of oak staves of different potential ellagitannin release (PER) for three months. In general, micro-oxygenation increased the color intensity and stability probably because favor the formation of new pigments. The presence of staves increased the total phenolic index and the ellagitannin concentration, and this effect was higher when greater was the PER of the staves. Finally, the dose of microoxygenation only affects the concentration of total furanic compounds whereas the PER of the staves seems to determine the concentration of furanic compounds, volatile phenols and β-methyl-γ-octolactones.

Correction to: Morphological MRI-based features provide pretreatment survival prediction in glioblastoma

The original version of this article, published on 15 October 2018, unfortunately contained a mistake. The following correction has therefore been made in the original: The name of Mariano Amo-Salas and the affiliation of Ismael Herruzo were presented incorrectly.

Comparison of effectiveness and discontinuation of interferon-free therapy for hepatitis C in prison inmates and noninmates

Chronic hepatitis C treatment with direct acting antiviral (DAA) therapy during incarceration is an attractive option, due to its short duration and to the possibility of directly observed treatment or supervision. The aim of this study is to compare the effectiveness and rates of discontinuation of DAA treatment in prisoners and nonprisoners. We studied all patients treated in the 10 prisons of Catalonia and at 3 public hospitals in the Barcelona area between 1 January 2015 and 30 April 2016. We analysed sustained viral response (SVR) and rates of discontinuation through intention-to-treat and modified-intention-to-treat analyses, the latter excluding discontinuations due to release from prison. One hundred and eighty-eight inmates and 862 noninmates were included. Prisoners were significantly younger than nonprisoners, with higher proportions of men, drug users, HIV infection, genotypes 1a and 3 and more treatment with psychiatric drugs. Overall, 98.4% of patients completed treatment. The discontinuation rate was low, but higher in inmates (3.7% vs 1.2% noninmates; P = .003) and in community patients >65 years old (2.8% vs 1.2% in under 65 seconds; P = .008). Among the inmates, 7 (42.8%) discontinuations were due to release. SVR was 93.1% in inmates vs 96.5% in noninmates (P = .08) by intention-to-treat and 95.1% vs 96.5% (P = .37) by modified intention-to-treat. Virologic failure rates were similar (3.8% vs 3% in noninmates; P = .60). SVR, virologic failure and discontinuation rates were similar in inmates and noninmates. Currently, prisons are considered a priority for the implementation of DAA. Improved coordination between penitentiary and community health systems would help to ensure therapeutic continuity in released prisoners.

Morphological MRI-based features provide pretreatment survival prediction in glioblastoma

OBJECTIVES

We wished to determine whether tumor morphology descriptors obtained from pretreatment magnetic resonance images and clinical variables could predict survival for glioblastoma patients.

METHODS

A cohort of 404 glioblastoma patients (311 discoveries and 93 validations) was used in the study. Pretreatment volumetric postcontrast T1-weighted magnetic resonance images were segmented to obtain the relevant morphological measures. Kaplan-Meier, Cox proportional hazards, correlations, and Harrell's concordance indexes (c-indexes) were used for the statistical analysis.

RESULTS

A linear prognostic model based on the outstanding variables (age, contrast-enhanced (CE) rim width, and surface regularity) identified a group of patients with significantly better survival (p < 0.001, HR = 2.57) with high accuracy (discovery c-index = 0.74; validation c-index = 0.77). A similar model applied to totally resected patients was also able to predict survival (p < 0.001, HR = 3.43) with high predictive value (discovery c-index = 0.81; validation c-index = 0.92). Biopsied patients with better survival were well identified (p < 0.001, HR = 7.25) by a model including age and CE volume (c-index = 0.87).

CONCLUSIONS

Simple linear models based on small sets of meaningful MRI-based pretreatment morphological features and age predicted survival of glioblastoma patients to a high degree of accuracy. The partition of the population using the extent of resection improved the prognostic value of those measures.

KEY POINTS

• A combination of two MRI-based morphological features (CE rim width and surface regularity) and patients' age outperformed previous prognosis scores for glioblastoma. • Prognosis models for homogeneous surgical procedure groups led to even more accurate survival prediction based on Kaplan-Meier analysis and concordance indexes.