Ca2Lib: Simple and Accurate LiDAR-RGB Calibration Using Small Common Markers

Modern visual perception techniques often rely on multiple heterogeneous sensors to achieve accurate and robust estimates. Knowledge of their relative positions is a mandatory prerequisite to accomplish sensor fusion. Typically, this result is obtained through a calibration procedure that correlates the sensors' measurements. In this context, we focus on LiDAR and RGB sensors that exhibit complementary capabilities. Given the sparsity of LiDAR measurements, current state-of-the-art calibration techniques often rely on complex or large calibration targets to resolve the relative pose estimation. As such, the geometric properties of the targets may hinder the calibration procedure in those cases where an ad hoc environment cannot be guaranteed. This paper addresses the problem of LiDAR-RGB calibration using common calibration patterns (i.e., A3 chessboard) with minimal human intervention. Our approach exploits the flatness of the target to find associations between the sensors' measurements, leading to robust features and retrieval of the solution through nonlinear optimization. The results of quantitative and comparative experiments with other state-of-the-art approaches show that our simple schema performs on par or better than existing methods that rely on complex calibration targets.

P-300 Evaluation of CYP19A1 gene expression in luteinized granulosa cells of women affected by endometriosis undergoing assisted reproductive technology (ART) treatments

Study question

Does endometriosis affect the expression of the aromatase gene CYP19A1 in the cumulus oophorous (COCs) and mural lutein-granulosa cells (GCs) influencing ART procedures?

Summary answer

Endometriosis does not impair CYP19A1 gene expression. However, the correlation between the aromatase expression and the number of oocytes retrieved is lost in endometriosis patients.

What is known already

Endometriosis-related infertility could be associated with a dysregulation of oocytes development. Indeed, endometriosis seems to have a negative effect on the intrafollicular environment, hindering oocyte maturation. A dysregulated synthesis of steroid hormones by GCs in the ovaries of affected women may be at the basis of an inadequate folliculogenesis. In line, some studies have investigated the expression levels of aromatase p450 ( CYP19A1 ) -the key enzyme involved in 17β-estradiol (E2) synthesis - in GCs and COCs collected from endometriosis women, reporting controversial results.

Study design, size, duration

In order to identify novel prognostic factors of ART outcomes in affected women, we set the evaluation of CYP19A1 expression in GCs samples isolated from endometriosis patients undergoing ART in comparison to control women. In a subgroup of patients, COCs were also collected. CYP19A1, StAR and 3βHSD gene expression was evaluated in both cell types. Finally, we evaluated the association between the expression of the analyzed genes and E2 levels with the clinical ART outcomes

Participants/materials, setting, methods

GCs were isolated from follicular fluids(FF) of n = 68 women with stage III-IV endometriosis and of n = 69 control patients. CYP19A1 gene expression was quantified by qPCR. 17β-estradiol levels in FF were assessed using an ELISA kit. In addition to CYP19A1 gene expression, mRNA levels of StAR and 3βHSD both in GCs and COCs (n = 20 endometriosis;n=21 controls) were evaluated in both cell types using qPCR. Differences between the two patients’ groups were estimated using linear regression models.

Main results and the role of chance

qPCR results showed no differences in mRNA expression of CYP19A1, StAR and 3βHSD in both GCs and COCs between the two groups of ART patients. These results were supported by the presence of the same concentration of E2 in the FF of controls (median: 877.7 ng/mL) and endometriosis patients (median: 878.3 ng/mL) (p-value=0.87). Linear regression model including as input variables gene expression values and ART outcomes showed that the blastulation rate was the only ART outcome associated with the expression levels of CYP19A1  (p-value=0.043, 95% CI: 0.001-0.061). In particular, a decrease of aromatase levels was associated with an increase in blastulation rate. After stratification of the population based on the presence of the disease, it emerged that, in the control group, the CYP19A1 expression correlated with the number of oocytes retrieved [β:-1.214;95%CI: -2.085 - (-0.343); p-value=0.007], while in the group of patients with endometriosis this association was no more present [β:-0.003;95%CI:-0.468 - 0.461; p-value=0.988)]. These results do not support data from the literature indicating that aromatase expression is reduced in GCs of affected women, but they highlight a potential disease-related mechanism affecting the ovulation process in these women

Limitations, reasons for caution

These findings need to be validated in a different cohort of samples. An RNA-seq approach is needed in order to validate our results and to obtain the overall transcriptome profiles of GCs and COCs in endometriosis patients.

Wider implications of the findings

Our data do not confirm previous evidence supporting a reduced expression/activity of aromatase in GCs in endometriosis. However, they suggest that aromatase may have a complex and sophisticated regulation of its expression in this cell type, which is not maintained in presence of endometriosis.

Trial registration number

not applicable

P-408 IL-10 and IL-17 pathway enrichment in uterine fluid-derived extracellular vesicles (UF-EVs) is associated with failed implantation in women with recurrent implantation failure undergoing PGT-A

Study question

Can the UF-EVs transcriptome provide markers of implantation in women diagnosed with recurrent implantation failure (RIF)?

Summary answer

Enrichment in IL-10 and IL-17 pathway transcripts in UF-EVs of women with RIF might identify those at risk for negative outcome after euploid blastocyst transfer.

What is known already

Our group has recently found that transcriptomic changes occur in UF-EVs during the window of implantation and closely resemble those occurring in the endometrial tissue. Patients affected by RIF represent a debated and heterogeneous population of patients who currently undergo several investigations, empirical therapies and embryo transfer attempts, with inconclusive results. We investigated whether UF-EVs can provide markers to define subgroups of patients within the RIF population, to predict outcomes and tailor interventions.

Study design, size, duration

We herein present the first sub-analysis of our previous larger observational study on the human UF-EVs transcriptome (Giacomini et al., 2021). RIF was defined by > 3 failed embryo transfers (ETs) with high quality embryos and patients affected by RIF and undergoing their first PGT-A cycle were enrolled (n = 19). Fertile women undergoing PGT-A+PGT-M for monogenic diseases and achieving successful implantation were used as controls (n = 29). PGT-A was performed by Next Generation Sequencing.

Participants/materials, setting, methods

RNA-Seq was performed on UF-EVs collected on day LH + 7 of the cycle preceding that of the blastocyst transfer. Differential Gene Expression (DGE) analysis was performed between RIF patients failing implantation (Group A) versus RIF patients achieving implantation (Group B) and between Group A and fertile controls achieving implantation (Group C). Pre-ranked gene set enrichment (GSEA) with WebGestalt was used for pathway enrichment analysis, with Normalized Enrichment Score (NES) indicating the strength of the enrichment.

Main results and the role of chance

RIF patients had a mean (± SD) age of 36.6 (± 3.4) and 5.1 ± 2.1 (mean ± SD) previous failed ETs. DGE comparisons between UF-EVs of RIF women who failed implantation (n = 10) showed 135 up- and 32 down-regulated genes compared to Group B, and 258 up- and 44 down-regulated genes compared to Group C, with 63 genes showing consistent significantly different ‘expression’ values in both comparisons. UF-EVs of Group A were enriched in transcripts belonging to the IL-17 pathway compared to both groups (Group A vs B, NES=2.2044, FDR <0.0001; Group A vs C, NES=2.3584, FDR <0.0001).Also transcripts belonging to the IL-10 pathway were enriched compared to both groups (Group A vs B NES=2.2741, FDR = 0.002; Group A vs C NES=2.2047, FDR < 0.0001). Among genes enriched in both DGE comparisons, C-X-C motif chemokine ligand (CXCL)1, CXCL2, CXCL8, and prostaglandin-endoperoxide synthase 2 (PTGS2) belonged to both the IL-10 and IL-17 pathway. On multivariate analysis controlling for relevant confounders (i.e. number of previous failed ETs), expression levels of CXCL8 emerged as a significant negative predictor of implantation (OR 0.675, 95%CI 0.493-0.925, p = 0.01).

Limitations, reasons for caution

As the main limitation of our study, we collected UFs in the cycle immediately preceding (and not corresponding to) the euploid ET. This approach was considered the most appropriate in relation to the current paucity of data regarding the safety of UF aspiration in the same cycle of an ET.

Wider implications of the findings

UF-EVs represent a source of transcriptomic markers related to the endometrial immune profile in RIF patients. Enrichment in the IL-17 and IL-10 pathways in this population could define the subgroup who is at risk for implantation failure even after euploid ET and who could potentially benefit from tailored immunotherapies.

Trial registration number

not applicable

P342 REAL–WORLD ANALYSIS ON THE ECONOMIC VALUE OF REACHING LIPID TARGET IN ITALY

The study aimed to evaluate the healthcare direct costs for Italian National Health System of patients treated with lipid–lowering drugs that do not achieve the low–density lipoprotein (LDL)–cholesterol target compared to those reaching their targets, and to analyze costs according to the distance from LDL target by using real–world data.

An observational analysis was performed on administrative and laboratory data from selected Italian Healthcare Departments. Patients were included if they presented at least one laboratory LDL test between 2012 and 2019 and if they were prescribed lipid–lowering drugs during 6 months prior the last LDL detection (index date). Mean annual direct costs were evaluated in the 12 months before index date in terms of all drugs prescribed, all–cause hospitalizations and all outpatient services. Distance to LDL target was calculated as difference between the index LDL level and LDL target. Total mean annual healthcare direct cost for patients that did not reach LDL target was higher compared to total cost of patients achieving LDL target (€3,678 vs €2,906). Costs were mainly driven by hospitalization (€1,330) followed by drugs expenditure (€1,012) and outpatient services (€563). Mean total annual healthcare costs increased with the distance from LDL target, specifically from €3,004 for patients with 10% distance from LDL target up to €4,823 for those 50% or more distance from LDL target. This trend was particularly evident for the cost item related to hospitalization, that went from €1,486 to €2,819 moving from 10% to ≥ 50 distance from LDL target. Results from this real–world study highlighted the higher economic burden for patients that do not reach the therapeutic LDL target, that tend to rise along with increasing distance from the LDL target. Overall, our findings could suggest that reducing the distance from LDL target could have a positive impact also on the economic outcomes for these patients.

P358 THE ROLE OF ADHERENCE TO LIPID–LOWERING THERAPIES IN ACHIEVING LIPID TARGET: FINDINGS FROM REAL–WORLD ANALYSIS IN ITALY

The objective of the present real–world analysis was to evaluate the impact of adherence to lipid–lowering drugs in reaching the lipid target in settings of clinical practice in Italy.

The analysis was based on administrative and laboratory database of selected Healthcare Units in Italy covering approximately 10% of Italian population. Adult patients prescribed with statin and with at least a low–density lipoprotein (LDL) determination were included between 2012 and 2019. The index date was defined as the first prescription for statin within the inclusion period. Patients fell into 4 clusters collectively exhaustive and mutually exclusive based on their characteristics assessed during the year prior index date. Patients were considered as adherent if they had a proportion of days covered (PDC)≥80%. Among overall patients prescribed statin and with a LDL determination, 1% was with familial hypercholesterolemia, 28% with previous cardiovascular events, 21% with diabetes and 50% in primary prevention. Regardless their risk profile, the increasing of adherence was related to a higher achievement of LDL–target, with an increment of + 53.2% among familial hypercholesterolemia, +43.1% in diabetes and +30% in previous cardiovascular events and primary prevention clusters while progressing from low (PDC<40%) to high (PDC≥80%) levels of adherence. However, while in diabetes and primary prevention clusters 80% and 86% of adherent patients, respectively, had their cholesterol level under control, in the familial hypercholesterolemia and previous cardiovascular events clusters only 46% of adherent patients achieve the lipid target.

The analysis showed adherence to be a key factor for cholesterol control. However, our findings underline a therapeutic need for patients that, although adherent, fail to achieve the lipid target, especially among patients with previous cardiovascular events (that have low level of LDL to achieve) and with familial hypercholesterolemia (that have high LDL basal level), suggesting therapeutic intensification should be applied.

P357 THE MANAGEMENT OF CHOLESTEROL LEVEL CONTROL WITH LIPID–LOWERING DRUGS IN ITALIAN CLINICAL PRACTICE: FINDINGS FROM THE STREAM (SUPPORTING WITH THE REAL–WORLD EVIDENCE THE ASSESSMENT OF MEDICINES AND HEALTH TECHNOLOGIES) STUDY

The study aimed to evaluate the proportion of patients not reaching their low–density lipoprotein (LDL)–cholesterol target according to their risk profile in real–world settings of Italian clinical practice.

This observational analysis was based on administrative and laboratory databases from a pool of Italian Entities covering around 10% of Italian population. All patients included had at least one laboratory LDL test between 2012 and 2019. Presence of lipid–lowering drugs was analyzed in the 6 months before index date (last LDL test detected), during which time adherence to these therapies was measured as proportion of days covered (PDC). Risk profile was assessed based on ESC guidelines.1 Among patients with LDL tests that received lipid–lowering drugs, 49.7% were deemed as very high–risk (VHR), 38.3% at high risk (HR), 12% with other risks (OR). Overall, 80% of patients did not reach their LDL–cholesterol target: 87.2% in the HR–cohort, 82.9% in the VHR–cohort (LDL level target 70 mg/dl and 55 mg/dl, respectively) and 49.6% in OR–cohort (LDL level target 116 mg/dl). Statin and ezetimibe combination was observed only in 6.5% of HR and OR and 10.3% of VHR patients, while patients were mainly in monotherapy with statins (87.5 VHR, 91.2% HR, 90.6% OR). Furthermore, patients adherent to treatment (PDC≥80%) accounted for the 52% of VHR–cohort, 47.2% of HR–cohort and 39.1% of OR–cohort. Our findings highlight the need to optimize the management of cholesterol control, especially among patients at risk. Despite the high proportion of patients not reaching LDL target, sub–optimal levels of adherence and a low use of combination regimens were observed, thus suggesting LDL–control could be supported by increasing adherence and/or the use of combination therapies and, if the target is not yet achieved, by the utilization of more recent therapies.

European Heart Journal (2020) 41, 111–188

P-240 Human extracellular vesicles (EVs) secreted by aneuploid embryos potentiate development of non-invasive PGT-A RNA biomarkers and stimulate MUC1 up-regulation in primary endometrial stromal cells (ESCs)

Study question

Could EVs secreted by aneuploid embryos a) serve for development of RNA biomarkers for PGT-A and b) elicit a relevant transcriptomic response in decidualised ESCs?

Summary answer

Aneuploid embryo EVs a) contain PPM1J, LINC00561, ANKRD34C and TMED10 in differential abundance from euploid EVs and b) induce up-regulation of MUC1 in decidualised ESCs.

What is known already

Embryo aneuploidy accounts for approximately 50% of all recurrent implantation failures in women >35 years old. PGT-A identifies euploid embryos to increase implantation probability but the technology is controversial as it requires an invasive embryo biopsy with an elusive long-term biosafety. The development of non-invasive methods to screen out aneuploid embryos is paramount. It is also critical to decode the embryo-endometrial dialog underlying implantation failure. We have previously reported that IVF embryos secrete EVs that can be internalised by ESCs, conceptualising that successful implantation to the endometrium is facilitated by EVs, which may additionally serve as biomarkers of ploidy status.

Study design, size, duration

Embryos destined for biopsy on days 5-7 for PGT-A were grown under standard conditions. Spent media (30μl) were collected from euploid (n = 175) and aneuploid embryos (n = 145) at both cleavage (days 1-3) and blastocyst (days 3-5) stage. Media samples from n = 35 cleavage embryos were pooled in order to obtain five euploid and four aneuploidy pools. Blastocyst media were pooled to create one euploid and one aneuploid pool. ESCs were obtained from five women undergoing diagnostic laparoscopy.

Participants/materials, setting, methods

The study was realised at a research hospital. EVs were isolated from euploid and aneuploid Day3 pools with differential ultracentrifugation and EV-RNA sequencing was performed following the SMARTer Stranded Total RNA-Seq approach. ESCs were decidualised (E2:10nM, P4:1uM, cAMP:0.5 mM twice every 48 hours) and treated for 24 hours with 50 ng/ml euploid or aneuploid EVs extracted from blastocyst media. RNA sequencing was performed on ESCs following the Truseq RNAseq protocol.

Main results and the role of chance

Aneuploid cleavage stage embryos (n = 4) secreted EVs that were less abundant in RNA fragments originating from the genes PPM1J (log2fc=-5.13, p = 0.011), LINC00561 (log2fc=-7.87, p = 0.010) and ANKRD34C (log2fc=-7.30, p = 0.017) and more abundant in TMED10 (log2fc=1.63 p = 0.025) compared to EVs (n = 5) from euploid embryos. Decidualisation per se induced downregulation of MUC1 (log2FC=-0.54, p = 0.0028) in ESCs as prerequisite for the establishment of receptive endometrium. The expression of MUC1 transcript in decidualised ESCs was significantly increased following treatment with aneuploid compared to euploid embryo-secreted EVs (log2FC=0.85, p = 0.0201).

Limitations, reasons for caution

The findings of the study may require validation utilising a second cohort of EVs samples.

Wider implications of the findings

This discovery that the RNA cargo of EVs secreted from aneuploid cleavage stage embryos is diverse from that of euploid embryos potentiates the development of non-invasive methodology for PGT-A. The upregulation of MUC1 in decidualised ESCs following aneuploid embryo EV treatment proposes a new mechanism underlying implantation failure.

Trial registration number

NA

P–240 Human extracellular vesicles (EVs) secreted by aneuploid embryos potentiate development of non-invasive PGT-A RNA biomarkers and stimulate MUC1 up-regulation in primary endometrial stromal cells (ESCs)

Study question

Could EVs secreted by aneuploid embryos a) serve for development of RNA biomarkers for PGT-A and b) elicit a relevant transcriptomic response in decidualised ESCs?

Summary answer

Aneuploid embryo EVs a) contain PPM1J, LINC00561, ANKRD34C and TMED10 in differential abundance from euploid EVs and b) induce up-regulation of MUC1 in decidualised ESCs.

What is known already

Embryo aneuploidy accounts for approximately 50% of all recurrent implantation failures in women >35 years old. PGT-A identifies euploid embryos to increase implantation probability but the technology is controversial as it requires an invasive embryo biopsy with an elusive long-term biosafety. The development of non-invasive methods to screen out aneuploid embryos is paramount. It is also critical to decode the embryo-endometrial dialog underlying implantation failure. We have previously reported that IVF embryos secrete EVs that can be internalised by ESCs, conceptualising that successful implantation to the endometrium is facilitated by EVs, which may additionally serve as biomarkers of ploidy status.

Study design, size, duration

Embryos destined for biopsy on days 5–7 for PGT-A were grown under standard conditions. Spent media (30μl) were collected from euploid (n = 175) and aneuploid embryos (n = 145) at both cleavage (days 1–3) and blastocyst (days 3–5) stage. Media samples from n = 35 cleavage embryos were pooled in order to obtain five euploid and four aneuploidy pools. Blastocyst media were pooled to create one euploid and one aneuploid pool. ESCs were obtained from five women undergoing diagnostic laparoscopy.

Participants/materials, setting, methods

The study was realised at a research hospital. EVs were isolated from euploid and aneuploid Day3 pools with differential ultracentrifugation and EV-RNA sequencing was performed following the SMARTer Stranded Total RNA-Seq approach. ESCs were decidualised (E2:10nM, P4:1uM, cAMP:0.5 mM twice every 48 hours) and treated for 24 hours with 50 ng/ml euploid or aneuploid EVs extracted from blastocyst media. RNA sequencing was performed on ESCs following the Truseq RNAseq protocol.

Main results and the role of chance

Aneuploid cleavage stage embryos (n = 4) secreted EVs that were less abundant in RNA fragments originating from the genes PPM1J (log2fc=–5.13, p = 0.011), LINC00561 (log2fc=–7.87, p = 0.010) and ANKRD34C (log2fc=–7.30, p = 0.017) and more abundant in TMED10 (log2fc=1.63 p = 0.025) compared to EVs (n = 5) from euploid embryos. Decidualisation per se induced downregulation of MUC1 (log2FC=–0.54, p = 0.0028) in ESCs as prerequisite for the establishment of receptive endometrium. The expression of MUC1 transcript in decidualised ESCs was significantly increased following treatment with aneuploid compared to euploid embryo-secreted EVs (log2FC=0.85, p = 0.0201).

Limitations, reasons for caution

The findings of the study may require validation utilising a second cohort of EVs samples.

Wider implications of the findings: This discovery that the RNA cargo of EVs secreted from aneuploid cleavage stage embryos is diverse from that of euploid embryos potentiates the development of non-invasive methodology for PGT-A. The upregulation of MUC1 in decidualised ESCs following aneuploid embryo EV treatment proposes a new mechanism underlying implantation failure.

Trial registration number

NA

Global transcriptomic changes occur in uterine fluid-derived extracellular vesicles during the endometrial window for embryo implantation

STUDY QUESTION

Are uterine fluid-derived extracellular vesicles (UF-EVs) a 'liquid biopsy' reservoir of biomarkers for real-time monitoring of endometrial status?

SUMMARY ANSWER

The transcriptomic cargo of UF-EVs reflects the RNA profile of the endometrial tissue as well as changes between the non-receptive and the receptive phase, possibly supporting its use for a novel endometrial receptivity test.

WHAT IS KNOWN ALREADY

EVs have been previously isolated from uterine fluid, where they likely contribute to the embryo-endometrium crosstalk during implantation. Based on a meta-analysis of studies on endometrial tissue implantation-associated genes and the human exosomes database, 28 of the 57 transcripts considered as receptivity markers refer to proteins present in human exosomes. However, the specific transcriptomic content of receptive phase UF-EVs has yet to be defined.

STUDY DESIGN, SIZE, DURATION

Two experimental series were set up. First, we simultaneously sequenced RNA species derived from paired UF-EVs and endometrial tissue samples collected from physiologically cycling women. Second, we analyzed RNA species of UF-EVs collected during the non-receptive (LH + 2) and receptive (LH + 7) phase of proven fertile women and from the receptive (LH + 7) phase of a population of women undergoing ART and transfer of euploid blastocysts.

PARTICIPANTS/MATERIALS, SETTING, METHODS

For paired UF-endometrial tissue sampling, endometrial tissue biopsies were obtained with the use of a Pipelle immediately after UF collection performed by lavage of the endometrial cavity. Overall, n = 87 UF samples were collected and fresh-processed for EV isolation and total RNA extraction, while western blotting was used to confirm the expression of EV protein markers of the isolated vesicles. Physical characterization of UF-EVs was performed by Nanoparticle Tracking Analysis. To define the transcriptomic cargo of UF-EV samples, RNA-seq libraries were successfully prepared from n = 83 UF-EVs samples and analyzed by RNA-seq analysis. Differential gene expression (DGE) analysis was used to compare RNA-seq results between different groups of samples. Functional enrichment analysis was performed by gene set enrichment analysis with g:Profiler. Pre-ranked gene set enrichment analysis (GSEA) with WebGestalt was used to compare RNA-seq results with the gene-set evaluated in a commercially available endometrial receptivity array.

MAIN RESULTS AND THE ROLE OF CHANCE

A highly significant correlation was found between transcriptional profiles of endometrial biopsies and pairwise UF-EV samples (Pearson's r = 0.70 P < 0.0001; Spearman's ρ = 0.65 P < 0.0001). In UF-EVs from fertile controls, 942 gene transcripts were more abundant and 1305 transcripts less abundant in the LH + 7 receptive versus the LH + 2 non-receptive phase. GSEA performed to evaluate concordance in transcriptional profile between the n = 238 genes included in the commercially available endometrial receptivity array and the LH + 7 versus LH + 2 UF-EV comparison demonstrated an extremely significant and consistent enrichment, with a normalized enrichment score (NES)=9.38 (P < 0.001) for transcripts up-regulated in LH + 7 in the commercial array and enriched in LH + 7 UF-EVs, and a NES = -5.40 (P < 0.001) for transcripts down-regulated in LH + 7 in the commercial array and depleted in LH + 7 UF-EVs. When analyzing LH + 7 UF-EVs of patients with successful versus failed implantation after transfer of one euploid blastocyst in the following cycle, we found 97 genes whose transcript levels were increased and 64 genes whose transcript levels were decreased in the group of women who achieved a pregnancy. GSEA performed to evaluate concordance in transcriptional profile between the commercially available endometrial receptivity array genes and the comparison of LH + 7 UF-EVs of women with successful versus failed implantation, demonstrated a significant enrichment with a NES = 2.14 (P = 0.001) for transcripts up-regulated in the commercial array in the receptive phase and enriched in UF-EVs of women who conceived, and a not significant NES = -1.18 (P = 0.3) for transcripts down-regulated in the commercial array and depleted in UF-EVs. In terms of physical features, UF-EVs showed a homogeneity among the different groups analyzed except for a slight but significant difference in EV size, being smaller in women with a successful implantation compared to patients who failed to conceive after euploid blastocyst transfer (mean diameter ± SD 205.5± 22.97 nm vs 221.5 ± 20.57 nm, respectively, P = 0.014).

LARGE SCALE DATA

Transcriptomic data were deposited in NCBI Gene Expression Omnibus (GEO) and can be retrieved using GEO series accession number: GSE158958.

LIMITATIONS, REASONS FOR CAUTION

Separation of RNA species associated with EV membranes might have been incomplete, and membrane-bound RNA species-rather than the internal RNA content of EVs-might have contributed to our RNA-seq results. Also, we cannot definitely distinguish the relative contribution of exosomes, microvesicles and apoptotic bodies to our findings. When considering patients undergoing ART, we did not collect UFs in the same cycle of the euploid embryo transfer but in the one immediately preceding. We considered this approach as the most appropriate in relation to the novel, explorative nature of our study. Based on our results, a validation of UF-EV RNA-seq analyses in the same cycle in which embryo transfer is performed could be hypothesized.

WIDER IMPLICATIONS OF THE FINDINGS

On the largest sample size of human EVs ever analyzed with RNA-seq, this study establishes a gene signature to use for less-invasive endometrial receptivity tests. This report is indeed the first to show that the transcriptome of UF-EVs correlates with the endometrial tissue transcriptome, that RNA signatures in UF-EVs change with endometrial status, and that UF-EVs could serve as a reservoir for potential less-invasive collection of receptivity markers. This article thus represents a step forward in the design of less-invasive approaches for real-time monitoring of endometrial status, necessary for advancing the field of reproductive medicine.

STUDY FUNDING/COMPETING INTEREST(S)

The study was funded by a competitive grant from European Society of Human Reproduction and Embryology (ESHRE Research Grant 2016-1). The authors have no financial or non-financial competing interests to disclose.

TRIAL REGISTRATION NUMBER

NA.

FRI0288 TREATMENT PATTERNS AND PHARMACOUTILIZATION AMONG PATIENTS AFFECTED BY ANKYLOSING SPONDYLITIS: AN ITALIAN REAL-WORLD STUDY

Background:

Ankylosing spondylitis (AS) is a chronic rheumatologic condition requiring lifelong treatments. To date, few real-world studies on AS patients in Italy are reported.

Objectives:

Aims of the study were to evaluate treatment patterns and to analyse pharmacoutilization on patients affected by AS in a real-world setting of Italian clinical practice.

Methods:

This observational study was based on administrative databases of a pool of Italian settings. A retrospective cross-sectional analysis was performed for years 2015-2017 to evaluate AS-diagnosed patients and, among them, to estimate percentage of treated and untreated ones. Patients were included if having a hospitalization discharge diagnosis at any level of AS (ICD-9-CM: 720.0) or exemption code for AS (054.720.0). Index date (ID) was date in which patients met one of the inclusion criteria. Patients with a prescription for drugs indicated for AS [non-steroidal anti-inflammatory drugs, disease-modifying antirheumatic drugs (DMARDs) - targeted synthetic (tsDMARDs) and biological (bDMARDs)] at ID were defined “treated”. Patients without such drug prescriptions at ID were considered “untreated”. To analyse treatment patterns of b/tsDMARDs-treated patients a longitudinal cohort study was conducted considering as inclusion periods the year 2014 and a period from 01/07/2016 to 30/06/2017. ID was date of first b/tsDMARDs prescription during inclusion period. Follow-up (F-up) lasted one year after ID. The interruption of treatment was defined as the absence of prescriptions in the last 3 months of F-up.

Results:

For cross-sectional-cohort: AS-diagnosed patients were 4,824 in 2015, 5,357 in 2016, 5,894 in 2017. In all years analysed, about 50% of patients were male. Mean age±SD ranged from 51.5±13.7 (2015) to 52.4±14.0 (2017). Untreated patients were 33.6% (2015), 35.1% (2016) and 37.9% (2017), while patients in therapy with b/tsDMARDs were 22.7% (2015), 22.3% (2016) and22.2% (2017). The remaining percentage of patients were treated with csDMARDs/NSAIDS: 43.7% (2015), 42.6% (2016), 39.9% (2017)). In 2015 and 2016 all b/tsDMARDs-treated patients were in therapy with anti-TFN agents, while the advent of IL-inhibitors was observed starting from 2017 (8.2% b/tsDMARDs-treated patients with IL-inhibitors). For longitudinal-cohort: in 2014, 310 patients had a b/tsDMARDs prescription and during 1-year F-up 11.9% of them interrupted the treatment after a mean time ±SD of 83.3±66.9 days. Of the 183 patients who had a prescription of b/tsDMARDs at ID during 2016-2017, 22.4% had a treatment interruption after a mean time±SD of 134.4±86.1 days during F-up.

Conclusion:

This real-world study provided insights on AS treatment patterns. Preliminary results showed that approximately one third of AS patients are untreated and about one in five are treated with b/tsDMARDs. Despite the improvement in treatment duration observed from 2014 to 2016/17, still 22.4% of b/tsDMARDs-treated patients interrupted therapy in the most recent cohort. A larger sample size is needed to confirm results.

Disclosure of Interests:

Valentina Perrone: None declared, Serena Losi Shareholder of: minor stockholder at Eli Lilly, Employee of: Employed by Eli Lilly, Erica Filippi Shareholder of: minor stockholder at Eli Lilly, Employee of: Employed by Eli Lilly, Silvia Antonelli Shareholder of: minor stockholder at Eli Lilly, Employee of: Employed by Eli Lilly, Massimo Giovannitti Shareholder of: minor stockholder at Eli Lilly, Employee of: Employed by Eli Lilly, Elisa Giacomini: None declared, Diego Sangiorgi: None declared, Luca Degli Esposti: None declared

Embryonic extracellular vesicles as informers to the immune cells at the maternal-fetal interface

Extracellular vesicle (EV) exchange is emerging as a novel method of communication at the maternal-fetal interface. The presence of the EVs has been demonstrated in the preimplantation embryo culture medium from different species, such as bovines, porcines and humans. Preimplantation embryo-derived EVs have been shown to carry molecules potentially able to modulate the local endometrial immune system. The non-classical major histocompatibility complex (MHC) class I molecule human leucocyte antigen (HLA)-G, the immunomodulatory molecule progesterone-induced blocking factor and some regulatory miRNAs species are contained in embryo-derived EV cargo. The implanted syncytiotrophoblasts are also well known to secrete EVs, with microvesicles exerting a mainly proinflammatory effect while exosomes in general mediate local immunotolerance. This review focuses on the current knowledge on the potential role of EVs released by the embryo in the first weeks of pregnancy on the maternal immune cells. Collectively, the data warrant further exploration of the dialogue between the mother and the embryo via EVs.

Characterization of Brachyspira hyodysenteriae isolates from Italy by multilocus sequence typing and multiple locus variable number tandem repeat analysis

AIMS

To evaluate and compare the capabilities of multilocus sequence typing (MLST) and multiple locus variable number tandem repeat analysis (MLVA) techniques to characterize Brachyspira hyodysenteriae isolates and to investigate the relationship between pleuromutilin resistance and genetic variability.

METHODS AND RESULTS

MLST genotyping was performed on 180 B. hyodysenteriae isolates, and the results were evaluated considering profiles from 108 other strains previously reported in the database. In total, 37 sequence types were obtained. The MLVA approach completely characterized 172 strains and grouped the isolates into 22 different profiles. The combination of MLST and MLVA showed a slight increase in the discriminatory power, identifying 33 joint profiles. An antibiotic resistance analysis showed a reduction in the susceptibility to pleuromutilins over time, and a weak association between susceptibility to valnemulin and inclusion in clonal complex 4.

CONCLUSION

MLST and MLVA are reliable methods for characterizing B. hyodysenteriae strains and they have comparable discriminatory power.

SIGNIFICANCE AND IMPACT OF THE STUDY

The genotyping of B. hyodysenteriae isolates and a database of all the genetic profiles collected during the diagnostic activities could support traditional epidemiological investigations in identifying infection sources and routes of transmission among herds, and in developing more effective control measures.

Inactivated Salmonella enterica serovar Typhimurium monophasic variant (S. Typhimurium 1,4,[5],12:i-) in sows is effective to control infection in piglets under field condition

The monophasic variant of Salmonella enterica serovar Typhimurium, namely Salmonella 1,4,[5],12:i-, has been increasingly responsible for foodborne human cases of disease and is most frequently detected in pork, since the variant is widely spread in pig farms. The aim of this study was to assess the efficacy of an autologous vaccine in decreasing the prevalence of Salmonella 1,4,[5],12:i-, in pigs. The trial was performed in a multisite pig production system of Northern Italy. The autogenous vaccine was prepared from the Salmonella 1,4,[5],12:i- strain isolated from the clinical case occurring in the Farm. Different immunization protocols were applied, ranging from interventions only in sows or piglets, or both. Microbiological analysis was performed to assess faecal shedding in sows and their offspring from birth till end of the production cycle and organ colonization of slaughtered pigs. Body weight of pigs was recorded at different time-points. Humoral immune response was evaluated in serum samples of sows and piglets. S. Typhimurium 1,4,[5],12:i- determines reduction of animal growth and farm production, furthermore, contamination of carcasses at the slaughterhouse. The load of bacteria entering into the food processing chain is differently influenced by the regimen of administration of inactivated vaccine. In particular, a combined vaccination of sows and their offspring was able to improve the weight gain of growing pigs, to limit Salmonella colonization of organs and to reduce the number of carrier pigs, and hence lowering the risk of introducing Salmonella organisms in the slaughter process.

Parallel-transmission-enabled magnetization-prepared rapid gradient-echo T1-weighted imaging of the human brain at 7 T

One of the promises of Ultra High Field (UHF) MRI scanners is to bring finer spatial resolution in the human brain images due to an increased signal to noise ratio. However, at such field strengths, the spatial non-uniformity of the Radio Frequency (RF) transmit profiles challenges the applicability of most MRI sequences, where the signal and contrast levels strongly depend on the flip angle (FA) homogeneity. In particular, the MP-RAGE sequence, one of the most commonly employed 3D sequences to obtain T1-weighted anatomical images of the brain, is highly sensitive to these spatial variations. These cause deterioration in image quality and complicate subsequent image post-processing such as automated tissue segmentation at UHF. In this work, we evaluate the potential of parallel-transmission (pTx) to obtain high-quality MP-RAGE images of the human brain at 7 T. To this end, non-selective transmit-SENSE pulses were individually tailored for each of 8 subjects under study, and applied to an 8-channel transmit-array. Such RF pulses were designed both for the low-FA excitation train and the 180° inversion preparation involved in the sequence, both utilizing the recently introduced k(T)-point trajectory. The resulting images were compared with those obtained from the conventional method and from subject-specific RF-shimmed excitations. In addition, four of the volunteers were scanned at 3 T for benchmarking purposes (clinical setup without pTx). Subsequently, automated tissue classification was performed to provide a more quantitative measure of the final image quality. Results indicated that pTx could already significantly improve image quality at 7 T by adopting a suitable RF-Shim. Exploiting the full potential of the pTx-setup, the proposed k(T)-point method provided excellent inversion fidelity, comparable to what is commonly only achievable at 3 T with energy intensive adiabatic pulses. Furthermore, the cumulative energy deposition was simultaneously reduced by over 40% compared to the conventional adiabatic inversions. Regarding the low-FA k(T)-point based excitations, the FA uniformity achieved at 7 T surpassed what is typically obtained at 3 T. Subsequently, automated white and gray matter segmentation not only confirmed the expected improvements in image quality, but also suggests that care should be taken to properly account for the strong local susceptibility effects near cranial cavities. Overall, these findings indicate that the k(T)-point-based pTx solution is an excellent candidate for UHF 3D imaging, where patient safety is a major concern due to the increase of specific absorption rates.

kT -points: short three-dimensional tailored RF pulses for flip-angle homogenization over an extended volume

With Transmit SENSE, we demonstrate the feasibility of uniformly exciting a volume such as the human brain at 7T through the use of an original minimalist transmit k-space coverage, referred to as "k(T) -points." Radio-frequency energy is deposited only at a limited number of k-space locations in the vicinity of the center to counteract transmit sensitivity inhomogeneities. The resulting nonselective pulses are short and need little energy compared to adiabatic or other B 1+-robust pulses available in the literature, making them good candidates for short-repetition time 3D sequences at high field. Experimental verification was performed on three human volunteers at 7T by means of an 8-channel transmit array system. On average, whereas the standard circularly polarized excitation resulted in a 33%-flip angle spread (standard deviation over mean) throughout the brain, and a static radio-frequency shim showed flip angle variations of 17% and up, application of k(T) -point-based excitations demonstrated excellent flip angle uniformity (8%) for a small target flip angle and with sub-millisecond durations.

Measuring perfusion and bioenergetics simultaneously in mouse skeletal muscle: a multiparametric functional-NMR approach

A totally noninvasive set-up was developed for comprehensive NMR evaluation of mouse skeletal muscle function in vivo. Dynamic pulsed arterial spin labeling-NMRI perfusion and blood oxygenation level-dependent (BOLD) signal measurements were interleaved with (31)P NMRS to measure both vascular response and oxidative capacities during stimulated exercise and subsequent recovery. Force output was recorded with a dedicated ergometer. Twelve exercise bouts were performed. The perfusion, BOLD signal, pH and force-time integral were obtained from mouse legs for each exercise. All reached a steady state after the second exercise, justifying the pointwise summation of the last 10 exercises to compensate for the limited (31)P signal. In this way, a high temporal resolution of 2.5  s was achieved to provide a time constant for phosphocreatine (PCr) recovery (τ(PCr)). The higher signal-to-noise ratio improved the precision of τ(PCr) measurement [coefficient of variation (CV) = 16.5% vs CV = 49.2% for a single exercise at a resolution of 30  s]. Inter-animal summation confirmed that τ(PCr) was stable at steady state, but shorter (89.3 ± 8.6  s) than after the first exercise (148  s, p < 0.05). This novel experimental approach provides an assessment of muscle vascular response simultaneously to energetic function in vivo. Its pertinence was illustrated by observing the establishment of a metabolic steady state. This comprehensive tool offers new perspectives for the study of muscle pathology in mice models.

Brain activation by short-term nicotine exposure in anesthetized wild-type and beta2-nicotinic receptors knockout mice: a BOLD fMRI study

RATIONALE

The behavioral effects of nicotine and the role of the beta2-containing nicotinic receptors in these behaviors are well documented. However, the behaviors altered by nicotine rely on the functioning on multiple brain circuits where the high-affinity beta2-containing nicotinic receptors (beta2*nAChRs) are located.

OBJECTIVES

We intend to see which brain circuits are activated when nicotine is given in animals naïve for nicotine and whether the beta2*nAChRs are needed for its activation of the blood oxygen level dependent (BOLD) signal in all brain areas.

MATERIALS AND METHODS

We used functional magnetic resonance imaging (fMRI) to measure the brain activation evoked by nicotine (1 mg/kg delivered at a slow rate for 45 min) in anesthetized C57BL/6J mice and beta2 knockout (KO) mice.

RESULTS

Acute nicotine injection results in a significant increased activation in anterior frontal, motor, and somatosensory cortices and in the ventral tegmental area and the substantia nigra. Anesthetized mice receiving no nicotine injection exhibited a major decreased activation in all cortical and subcortical structures, likely due to prolonged anesthesia. At a global level, beta2 KO mice were not rescued from the globally declining BOLD signal. However, nicotine still activated regions of a meso-cortico-limbic circuit likely via alpha7 nicotinic receptors.

CONCLUSIONS

Acute nicotine exposure compensates for the drop in brain activation due to anesthesia through the meso-cortico-limbic network via the action of nicotine on beta2*nAChRs. The developed fMRI method is suitable for comparing responses in wild-type and mutant mice.

Cholera toxin subunit B inhibits IL-12 and IFN-{gamma} production and signaling in experimental colitis and Crohn's disease

BACKGROUND AND AIMS

Cholera toxin B subunit (CT-B) is a powerful modulator of immune responses. The authors have previously demonstrated that oral administration of recombinant CT-B (rCT-B) is able to prevent and cure the Crohn's disease (CD)-like trinitrobenzene sulfonic acid (TNBS) mediated colitis. In this study they extended their observations and examined if rCT-B interferes with the molecular signaling underlying the Th1 type response both in TNBS colitis and in ex vivo human CD explants.

METHODS

TNBS treated mice were fed with rCT-B, and IFN-gamma and IL-12 production by colonic lamina propria mononuclear cells (LPMC) was examined by ELISA. In vitro culture of mucosal explants from CD patients and non-inflammatory bowel disease controls, pre-incubated with rCT-B, were examined for IFN-gamma and IL-12 production by ELISA and semiquantitative reverse transcription polymerase chain reactions. STAT-1, -4, -6 activation and T-bet expression were examined following rCT-B treatment by western blotting both in TNBS treated mice and in human mucosal explants.

RESULTS

rCT-B significantly reduced IL-12 and IFN-gamma secretion by LPMC from TNBS treated mice. Consistent with this, rCT-B inhibited both STAT-4 and STAT-1 activation and downregulated T-bet expression. Inhibition of Th1 signaling by CT-B associated with no change in IL-4 synthesis and expression of active STAT-6 indicating that rCT-B does not enhance Th2 cell responses. Moreover, in vitro treatment of CD mucosal explants with rCT-B resulted in reduced secretion of IL-12/IFN-gamma and inhibition of STAT-4/STAT-1 activation and T-bet expression.

CONCLUSIONS

These studies indicate that CT-B inhibits mucosal Th1 cell signaling and suggest that rCT-B may be a promising candidate for CD therapy.

N-acetylcysteine inhibits the induction of an antigen-specific antibody response down-regulating CD40 and CD27 co-stimulatory molecules

We investigated the effect of N-acetylcysteine (NAC) on normal human B cell functions. We found that NAC significantly inhibited both the induction of the specific antibody response to the T-dependent antigen Candida albicans and T-dependent pokeweed mitogen (PWM)-induced polyclonal Ig production. NAC did not induce either cell death due to a non-specific toxicity or apoptosis. The NAC-induced inhibitory effect might be a functional consequence of: (i) a down-regulation of the expression on the B cell surface of CD40 and CD27 co-stimulatory molecules and (ii) a down-regulation of interleukin (IL-4) production. In contrast, NAC up-regulated interferon-gamma (IFN-gamma) production. NAC did not induce any effect on the T cell-independent B cell polyclonal activation system. These results indicate that NAC down-regulates T dependent B cell activation and leads to T helper cell type 1 (Th1) polarization.

Infection of human macrophages and dendritic cells with Mycobacterium tuberculosis induces a differential cytokine gene expression that modulates T cell response

Macrophages and dendritic cells (DC) play an essential role in the initiation and maintenance of immune response to pathogens. To analyze early interactions between Mycobacterium tuberculosis (Mtb) and immune cells, human peripheral blood monocyte-derived macrophages (MDM) and monocyte-derived dendritic cells (MDDC) were infected with Mtb. Both cells were found to internalize the mycobacteria, resulting in the activation of MDM and maturation of MDDC as reflected by enhanced expression of several surface Ags. After Mtb infection, the proinflammatory cytokines TNF-alpha, IL-1, and IL-6 were secreted mainly by MDM. As regards the production of IFN-gamma-inducing cytokines, IL-12 and IFN-alpha, was seen almost exclusively from infected MDDC, while IL-18 was secreted preferentially by macrophages. Moreover, Mtb-infected MDM also produce the immunosuppressive cytokine IL-10. Because IL-10 is a potent inhibitor of IL-12 synthesis from activated human mononuclear cells, we assessed the inhibitory potential of this cytokine using soluble IL-10R. Neutralization of IL-10 restored IL-12 secretion from Mtb-infected MDM. In line with these findings, supernatants from Mtb-infected MDDC induced IFN-gamma production by T cells and enhanced IL-18R expression, whereas supernatants from MDM failed to do that. Neutralization of IFN-alpha, IL-12, and IL-18 activity in Mtb-infected MDDC supernatants by specific Abs suggested that IL-12 and, to a lesser extent, IFN-alpha and IL-18 play a significant role in enhancing IFN-gamma synthesis by T cells. During Mtb infection, macrophages and DC may have different roles: macrophages secrete proinflammatory cytokines and induce granulomatous inflammatory response, whereas DC are primarily involved in inducing antimycobacterial T cell immune response.

HIV-1 Nef protein inhibits the in vitro induction of a specific antibody response to Candida albicans by an early up-regulation of IL-15 production

We have previously demonstrated that exogenous Nef protein induced activation of normal human T cells up-regulating IL-15 production by monocytes. Since HIV-1 infection results in the early impairment of immune functions we decided to evaluate if Nef is able to modulate the induction of a specific antibody response. Human peripheral blood mononuclear cells from healthy donors were induced in vitro to mount a specific antibody response to the Candida albicans antigen. We show that Nef inhibited, in a dose-dependent manner, the induction of the anti-C. albicans antibody response. The ability of an anti-Nef antibody to prevent such inhibition indicates that the effect was indeed Nef-specific. In the Nef-treated cultures an early increase of IL-15 production was observed and the addition of anti-IL-15 antibody abrogated the Nef-induced inhibitory effect. Moreover the addition of IL-15 to the cultures inhibited, as well as Nef, the induction of the specific antibody response. Thus, our results suggest that Nef may inhibit the induction of a specific antibody response by an early up-regulation of IL-15 production. A better comprehension of this phenomenon may be important for unravelling some aspects of the B cell defects in HIV infection.

Functional MR evaluation of temporal and frontal language dominance compared with the Wada test

OBJECTIVE

To evaluate the reliability of temporal and frontal functional MRI (fMRI) activation for the assessment of language dominance, as compared with the Wada test.

PATIENTS AND METHODS

Ten patients with temporal lobe epilepsy were studied using blood oxygen level dependent fMRI and echoplanar imaging (1.5-T). Three tasks were used: semantic verbal fluency, covert sentence repetition, and story listening. Data were analyzed using pixel by pixel autocorrelation and cross-correlation. fMRI laterality indices were defined for several regions of interest as the ratio (L - R)/(L + R), L being the number of activated voxels in the left hemisphere and R in the right hemisphere. Wada laterality indices were defined as the difference in the percentages of errors in language tests between left and right carotid injections.

RESULTS

Semantic verbal fluency: The asymmetry of frontal activation was correlated with Wada laterality indices. The strongest correlation was observed in the precentral/middle frontal gyrus/inferior frontal sulcus area. Story listening: The asymmetry of frontal, but not temporal, activation was correlated with Wada laterality indices. Covert sentence repetition: No correlation was observed.

CONCLUSIONS

There was a good congruence between hemispheric dominance for language as assessed with the Wada test and fMRI laterality indices in the frontal but not in the temporal lobes. The story listening and the covert sentence repetition tasks increased the sensitivity of detection of posterior language sites that may be useful for brain lesion surgery.

Possible role of the plasminogen receptor as a site of interaction of the human immunodeficiency virus p24 immunosuppressive heptapeptide Ch7 with the host immune system

Previous work from our laboratory demonstrated that a synthetic heptapeptide (Ch7: RGSDIAG), corresponding to a conserved sequence of human immunodeficiency virus (HIV) core protein p24 (amino acids 232- 238), was able to specifically abrogate antigen-induced responses in cultures of normal human peripheral blood mononuclear cells (PBMC), probably acting at the level of monocytes. The Ch7 peptide displays sequence homology to human plasminogen. In the present report we show that a compound (6-aminoexanoic acid), known to prevent plasminogen binding to monocyte-like cells, greatly reduced the immunosuppressive capacity of Ch7. We suggest that the plasminogen receptor may represent a target structure on human monocytes for the immunosuppressive p24 sequence.

Induction of a specific antibody response to Bordetella pertussis antigens in cultures of human peripheral blood mononuclear cells

The role of specific antibodies in protective immunity to Bordetella pertussis has not yet been clearly defined. In the present work, the induction of a specific antibody response to B. pertussis in cultures of human peripheral blood mononuclear cells (PBMC) was investigated, on the assumption that the capacity of circulating lymphocytes to mount a specific response in vitro may provide a useful parameter for the evaluation of protective immunity. When PBMC from normal adult donors were cultured with a heat-inactivated B. pertussis whole-cell suspension, cells secreting antibodies to pertussis toxin, pertactin and filamentous haemagglutinin were generated consistently. The antibody response peaked between days 7 and 11 of culture and the antibodies produced were exclusively of the IgM class.

Field-frequency locked in vivo proton MRS on a whole-body spectrometer

The stability of the main magnetic field is critical for prolonged in vivo magnetic resonance spectroscopy (MRS) acquisitions, especially for difference spectroscopy. This study was focused on the implementation and optimization of a field-frequency lock (FFL) on a whole body spectrometer, to correct the main field drift during localized proton MRS of the human brain. The FFL was achieved through a negative feed-back applied in real time on the Z0 shim coil current, after calculation of the frequency shift from a reference signal. This signal was obtained from the whole head with a small flip angle acquisition interleaved with the PRESS acquisition of interest. To avoid propagation of the important short-term time-correlated fluctuations of the head water frequency (mainly due to respiratory motion) onto Z0 correction, the sampling rate of the reference frequency and the smoothing window for the Z0 correction were carefully optimized. Thus, an effective FFL was demonstrated in vivo with no significant increase of the short-term variance of the water frequency. Magn Reson Med 1999 42:636-642, 1999.

Increased PGE2 production mediates the in vitro inhibitory effect of the human immunodeficiency virus P24 immunosuppressive heptapeptide Ch7

Previous work from our laboratory demonstrated that a synthetic heptapeptide (Ch7), corresponding to a conserved sequence of human immunodeficiency virus (HIV) core protein p24 (amino acids 232-238), was able to specifically abrogate antigen-induced responses in cultures of normal human peripheral blood lymphocytes (PBL). Addition of recombinant human interferon-gamma (IFN-gamma) to Ch7-suppressed cultures restored the capacity to mount an antigen-specific antibody response, suggesting that a cytokine imbalance may be at the basis of the Ch7 immunosuppressive activity. In the present paper we show that the Ch7-dependent in vitro immunosuppression was accompanied by a significant up-regulation of prostaglandin E2 (PGE2) production and induction of interleukin-10 (IL-10)-secreting cells. In the presence of the PGE2 inhibitor indomethacin, IL-10 up-regulation was prevented and the induction of a specific antibody response was partially restored. PGE2 is indeed an important regulator of immune responses with the ability to differentially affect cytokine production. Thus, our results demonstrate that the Ch7 immunosuppressive epitope may primarily act by up-regulating PGE2 production and, through this mediator, by causing a cytokine dysregulation, finally responsible for immune response suppression.

Diltiazem modulates monokine production in human mixed lymphocyte culture

BACKGROUND

Calcium channel blockers are widely used in transplantation. Their immunosuppressive activity is well known and has been demonstrated both in vitro and in vivo. Nevertheless, their effect on cytokine production has never been reported.

METHODS

One-way mixed lymphocyte cultures (MLCs) have been obtained from healthy human subjects. Cytokine production has been assessed by three different methods: by enzyme-linked immunosorbent assay on supernatants of MLC, by enzyme-linked immunospot method on MLC cells for measuring cytokine-producing cells, and by the reverse transcription polymerase chain reaction technique on MLC cells for measuring cytokine mRNAs.

RESULTS

An interesting effect on proinflammatory monokines was observed: in this study, we demonstrate that the calcium antagonist diltiazem enhances interleukin-1beta and slightly reduces interleukin-6 production in MLC, but it has no effect on tumor necrosis factor-alpha levels.

CONCLUSION

For the first time, a modulation of monokine production by diltiazem can be demonstrated. This evidence suggests that calcium antagonist drugs may exert effects on monocytes and possibly on other antigen-presenting cells.

Interleukin-12 up-regulates the induction of an antigen-specific antibody response in cultures of human lymphocytes

The influence of interleukin-12 (IL-12) on the induction of a specific antibody response to the T-dependent antigen sheep erythrocytes (SRBC) in cultures of human blood lymphocytes was investigated. The response, evaluated as number of antigen-induced antibody-producing cells, was greatly increased in the presence of IL-12. When a two-stage limiting dilution culture system was used, the plot of the number of seeded cells versus the logarithm of the fraction of negative cultures deviated from linearity in antigen- and IL-12-stimulated cultures. However, linearity was reached when IL-2 was added in the second stage. Under these latter conditions, since single-hit criteria were fulfilled, it was possible to estimate the frequency of SRBC-specific B cell precursors able to respond to the antigen and to show that such frequency was increased upon addition of IL-12. Thus, the enhancing effect of IL-12 may be based on an increased frequency of responding precursor cells. The results here presented demonstrate, to our knowledge for the first time, a definite role of IL-12 in the induction of a specific antibody response in human cells. Further, they stress the importance for such studies of appropriate in vitro systems. Finally, they show that the induction of primary immune responses in cultures of human peripheral blood lymphocytes mostly depends on the proper cytokine balance at different time points.

Simultaneous determination of muscle perfusion and oxygenation by interleaved NMR plethysmography and deoxymyoglobin spectroscopy

A novel approach is presented that combines NMR-plethysmography and NMRS of deoxymyoglobin in real-time, using line-by-line interleaved acquisitions of both gradient echo images during venous occlusion and of the N-delta proton signal of myoglobin's proximal F8 histidine. This method allowed simultaneous measurement of peripheral regional perfusion and skeletal muscle oxygen content. During reactive hyperaemia, using our combined NMRI-NMRS protocol, we explored the relationship between muscle reoxygenation (myoglobin resaturation half-time, y in s) and reperfusion (x in ml/100 g tissue/min) and found it to be highly significant (y = 70.83x-0.94; r2 = 0.70; F = 64.40; p = 9.73 x 10(-9). We also demonstrated that at low flow, muscle perfusion was a rate-limiting factor to reoxygenation. Making certain hypotheses, muscle oxygen extraction was derived from perfusion and myoglobin resaturation rate. Muscle oxygen extraction during early post-ischemic recovery (0.78 +/- 0.11, 0.79 +/- 0.09 and 0.72 +/- 0.05 at 0, 60 and 100 Torr counter-pressure, respectively) was shown to be independent of perfusion and maximum at each step of the protocol in most volunteers but also to display significant variability among subjects in this supposedly normal population sample.

An interleaved heteronuclear NMRI-NMRS approach to non-invasive investigation of exercising human skeletal muscle

Novel tools are presented that aim at more comprehensive NMR investigations of human skeletal muscle metabolism, in particular during exercise protocols. They integrate imaging (NMRI) and spectroscopy (NMRS) experiments in a single dynamic examination. The first sequence that we propose combine NMR-plethysmography, 1H-NMRS of deoxymyoglobin and 31P-NMRS. This allows simultaneous determination of skeletal muscle perfusion, oxygenation and high-energy phosphates status. It is very well suited to the study of interplay between blood supply and energy metabolism during the recovery period from aerobic or anaerobic exercise. In a second sequence, the same spectroscopic measurements are associated to a 1H double quantum coherence (DQC) edition of lactate. It is, this time, possible to estimate muscle lactate production concurrently with oxygen content, high-energy phosphates distribution and intracellular pH. This sequence is intended mainly for metabolic investigations of ischemic bouts. Examples are given of the use of these sequences in normal adult volunteers. They demonstrate the technical feasibility of these new approaches and illustrate their potential for future applications, particularly non-invasive of regulatory mechanisms of muscle metabolism in situ.

Interferon-gamma (IFN-gamma) can counteract the in vitro inhibitory effect of an HIV p24 immunosuppressive heptapeptide

Previous work from our laboratory demonstrated that a synthetic heptapeptide (Ch7), corresponding to a conserved sequence of HIV core protein p24 (aa 232-238), was able to specifically abrogate antigen-induced responses in cultures of normal human peripheral blood lymphocytes (PBL). In the present study we show that Ch7 did not inhibit the induction of IFN-gamma-secreting cells nor the accumulation of IFN-gamma mRNA in antigen-stimulated cultures. However, delayed addition of recombinant human IFN-gamma to Ch7-suppressed cultures was able to restore fully the capacity to mount an antigen-specific antibody response. Thus, although the Ch7 immunosuppressive effect may not be directly related to a decreased production of IFN-gamma, an increased level of this cytokine is certainly able to counteract the negative effect of the peptide.

An HIV p24 heptapeptide down-regulates antigen-specific responses in vitro interfering at the level of the T3-Ti complex

Ch7 (RGSDIAG), a synthetic heptapeptide derived from a conserved region of HIV p24 (aa 232-238), was previously shown to suppress antigen-induced responses in cultures of normal human peripheral blood lymphocytes (PBL). We show in this paper that Ch7 is the shortest peptide retaining full inhibitory capacity. Further, the peptide inhibited efficiently and in a dose-dependent manner the induction of a specific antibody response to the antigens SRC (sheep red cells) and Candida albicans but did not exert any effect on the induction of immunoglobulin-secreting cells in PWM-stimulated cultures. Finally, Ch7 inhibited anti-CD3-induced lymphoproliferation but did not affect anti-CD2 activation. These results suggest that a conserved epitope of HIV p24 may be able to prevent the induction of antigen-specific antibody responses by interfering with lymphocyte activation via the T3-Ti complex, resulting in the abrogation of immune functions that are defective in HIV-infected individuals.