Altered embryotrophic capacities of the bovine oviduct under elevated free fatty acid conditions: an in vitro embryo--oviduct co-culture model

Maternal metabolic stress conditions are of growing importance in both human and dairy cattle settings as they can have significant repercussions on fertility. Upregulated lipolysis is a common trait associated with metabolic disorders and results in systemically elevated concentrations of non-esterified fatty acids (NEFAs). The effects of high NEFA concentrations on the follicular environment, oocyte and embryo development is well documented. However, knowledge on the effects of NEFAs within the oviduct, representing the initial embryonic growth environment, is currently lacking. Therefore, the experiments outlined here were designed to obtain fundamental insights into both the direct and indirect interactions between NEFAs, bovine oviductal cells and developing zygotes. Hence, zygotes were co-cultured with NEFA-pre-exposed bovine oviductal cells or subjected to simultaneous NEFA exposure during the co-culture period. The outcome parameters assessed were embryo development with cleavage (48h post insemination (pi)), morula (120-126h pi) and blastocyst (192h pi) rates, as well as morula intracellular lipid content and blastocyst quality using Bodipy and differential staining respectively. Our data suggest a direct embryotoxicity of NEFAs as well as impaired embryo development through a reduced oviductal ability to support and protect early embryo development.

6119Correction of transcatheter aortic valve replacement induced left bundle branch block by His bundle pacing

Background

Left bundle branch block (LBBB) occurs frequently after transcatheter aortic valve replacement (TAVR) and is associated with increased risk of permanent pacemaker implantation, heart failure hospitalization and sudden cardiac death. This pilot study explored the feasibility of TAVR-induced LBBB correction with His bundle pacing (HBP).

Methods

Patients with TAVR -induced LBBB and postoperative need for permanent pacemaker implant were planned for electrophysiology study and HBP. Patients with persistent high degree AV-block were excluded. HBP was performed using the Select Secure pacing lead, delivered through a fixed curve or a deflectable sheath. Successful HBP was defined as correction of LBBB by selective or non-selective HBP with LBBB correction thresholds less than 3.5V at 1.0ms at implant.

Results

The study enrolled 6 patients (mean age 85±2.5 years, 50% male). Mean QRS duration was 152±10ms, PR-interval 212±12ms AH-interval 166±16ms and HV-interval 62±12ms. Successful HBP was achieved in 5/6 (83%) patients. Mean QRS duration decreased from 153±11ms to 88±14ms (p=0.002). At implantation, mean threshold for LBBB correction was 1.6±1.0V (unipolar) and 2.2±1.3V (bipolar) at 1.0ms. Periprocedural, two complete AV-blocks occurred, both spontaneously resolved by the end of the procedure. Thresholds remained stable at 1 month follow up: 1.8±1.0V (unipolar) and 2.3±1.5V (bipolar) at 1.0ms.

Figure 1

Conclusion

Permanent His bundle pacing can safely correct TAVR-induced LBBB in the majority of patients. Further studies are needed to assess potential benefits of His bundle pacing over conventional right ventricular pacing in this population.

Differential effects of high and low glucose concentrations during lipolysis-like conditions on bovine in vitro oocyte quality, metabolism and subsequent embryo development

Lipolytic metabolic conditions are traditionally associated with elevated non-esterified fatty acid (NEFA) concentrations, but may also be accompanied by hyperglycaemia in obesity or by hypoglycaemia during a negative energy balance status. Elevated NEFA concentrations disrupt oocyte and embryo development and quality, but little is known about whether the effects of lipolytic conditions on oocyte developmental competence are modulated by glucose availability. To answer this, bovine cumulus-oocyte complexes (COCs) were matured under different conditions: physiological NEFA (72µM) and normal glucose (5.5mM), pathophysiologically high NEFA (420µM) and normal glucose, high NEFA and high glucose (9.9mM), high NEFA and low glucose (2.8mM). Developmental potential, cumulus expansion and metabolism of COCs exposed to high NEFA and low glucose were affected to a greater extent compared with COCs matured under high NEFA and high glucose conditions. High NEFA and high glucose conditions caused a moderate increase in oocyte reactive oxygen species compared with their high NEFA and low glucose or control counterparts. Blastocyst metabolism and the transcriptome of metabolic and oxidative stress-related genes were not affected. However, both lipolytic conditions associated with hyper- or hypoglycaemia led to surviving embryos of reduced quality with regards to apoptosis and blastomere allocation.

A clinical approach to arrhythmias revisited in 2018 : From ECG over noninvasive and invasive electrophysiology to advanced imaging

Understanding arrhythmias and their treatment is not always easy. The current straightforward approach with catheter ablation and device therapy is an amazing achievement, but does not make management of underlying or other cardiac disease and pharmacological therapy unnecessary. The goal of this paper is to describe how much of the knowledge of the 1980s and early 1990s can and should still be applied in the modern treatment of patients with arrhythmias. After an introduction, this review will focus on paroxysmal atrial fibrillation and a prototype of ‘idiopathic’ ventricular arrhythmias, two diseases with a striking similarity, and will discuss the arrhythmogenesis. The ECG continues to play an important role in diagnostics. Both diseases are associated with a structurally normal heart; the autonomic nervous system plays an important role in triggering arrhythmias at both the atrial and ventricular level.

Maternal metabolic stress may affect oviduct gatekeeper function

We hypothesized that elevated non-esterified fatty acids (NEFA) modify in vitro bovine oviduct epithelial cell (BOEC) metabolism and barrier function. Hereto, BOECs were studied in a polarized system with 24-h treatments at Day 9: (1) control (0 µM NEFA + 0% EtOH), (2) solvent control (0 µM NEFA + 0.45% EtOH), (3) basal NEFA (720 µM NEFA + 0.45% EtOH in the basal compartment) and (4) apical NEFA (720 µM NEFA + 0.45% EtOH in the apical compartment). FITC-albumin was used for monolayer permeability assessment and related to transepithelial electric resistance (TER). Fatty acid (FA), glucose, lactate and pyruvate concentrations were measured in spent medium. Intracellular lipid droplets (LD) and FA uptake were studied using Bodipy 493/503 and immunolabelling of FA transporters (FAT/CD36, FABP3 and CAV1). BOEC-mRNA was retrieved for qRT-PCR. Results revealed that apical NEFA reduced relative TER increase (46.85%) during treatment and increased FITC-albumin flux (27.59%) compared to other treatments. In basal NEFA, FAs were transferred to the apical compartment as free FAs: mostly palmitic and oleic acid increased respectively 56.0 and 33.5% of initial FA concentrations. Apical NEFA allowed no FA transfer, but induced LD accumulation and upregulated FA transporter expression (↑CD36, ↑FABP3 and ↑CAV1). Gene expression in apical NEFA indicated increased anti-apoptotic (↑BCL2) and anti-oxidative (↑SOD1) capacity, upregulated lipid metabolism (↑CPT1, ↑ACSL1 and ↓ACACA) and FA uptake (↑CAV1). All treatments had similar carbohydrate metabolism and oviduct function-specific gene expression (OVGP1, ESR1 and FOXJ1). Overall, elevated NEFAs affected BOEC metabolism and barrier function differently depending on NEFA exposure side. Data substantiate the concept of the oviduct as a gatekeeper that may actively alter early embryonic developmental conditions.

2 ELEVATED NONESTERIFIED FATTY ACID CONCENTRATIONS HAMPER IN VITRO BOVINE OVIDUCTAL EPITHELIAL CELL PHYSIOLOGY

Elevated nonesterified fatty acids (NEFA) have been recognised as an important link between lipolysis-based metabolic conditions and impaired fertility in high-yielding dairy cattle. However, NEFA effects on the oviductal micro-environment currently remain unknown. We hypothesise that elevated NEFAs may contribute to the complex pathology of subfertility and infertility by exerting a negative effect on bovine oviductal epithelial cell (BOEC) physiology. Therefore, the objectives of this study were to elucidate NEFA toxicity effects on BOEC, both qualitatively and morphologically, by assessing BOEC-sperm binding affinity, monolayer integrity, proliferation capacity and morphology. The BOEC of 4 bovine oviducts (4 replicates) at Day 3–5 of the oestrous cycle from a local slaughterhouse were mechanically isolated, pooled, and cultured in a polarized cell culture system (ThinCert, Greiner Bio-One, Frickenhausen, Germany) with DMEM/F12-based culture medium for 9 days until transepithelial electric resistance (TER) reached at least 700 Ω cm2 to prevent leakage between the 2 compartments. At Day 10, monolayers were exposed to a 720 µM NEFA mixture of OA, SA, and PA, for 24 h in 4 treatment groups according to exposure side: control, basal (B), apical (A), and A+B. The BOEC were washed and monolayer quality was assessed by means of a sperm binding assay (30 min co-culture of BOEC monolayer and 106 spermatozoa mL–1), TER measurements (pre- and post-exposure) and a wound healing assay (8-h observation of BOEC proliferation capacity after over an artificial gap). Morphology of BOEC was assessed by scanning electron microscopy on cell polarity, presence of microvilli and cilia, and monolayer integrity. Data (mean ± s.d.) were analysed by mixed model ANOVA. In A+B, monolayers (31.28 ± 6.16 sp/0.05 mm2) showed a significantly reduced sperm binding affinity compared to the control (97.90 ± 10.76 sp/0.05 mm2; P < 0.05), and treatment A tended to be more affected (39.95 ± 19.30 sp/0.05 mm2) than treatment B (68.55 ± 15.38 sp/0.05 mm2; P = 0.051). The absolute TER increase post-NEFA exposure in the control (110 ± 11 Ω cm2) was significantly higher than in all the other treatments. Also, the TER increase differed significantly depending on the exposure side: in treatment A (3 ± 6 Ω cm2), the TER increase was lower than in treatment B (29 ± 8 Ω cm2), and monolayers in treatment A+B were even associated with a significant TER reduction (–15 ± 10 Ω cm2; P < 0.05). Cell proliferation capacity showed a significant closure of the gap in all treatments, but only the control group (41.64% closure) differed significantly (P < 0.05) from the other groups (B = 28.3%, A = 31.62%, A+B = 30.9% closure) irrespective of the exposure side; BOEC morphology was not affected. Depending on the exposure side, elevated NEFA exert a negative effect on BOEC physiology but not morphology. Ultimately, these physiological alterations in its micro-environment may result in suboptimal development of the pre-implantation embryo and a reduced reproductive outcome.

186 THE EFFECT OF SHORT VERSUS LONG TERM ELEVATED NONESTERIFIED FATTY ACID CONCENTRATIONS DURING MURINE IN VITRO FOLLICLE GROWTH ON OOCYTE DEVELOPMENTAL COMPETENCE

Metabolic disorders, like obesity and type 2 diabetes are characterised by lipolysis-linked elevated nonesterified fatty acid (NEFA) concentrations. Exposure to high NEFA concentrations during the final phase of bovine in vitro oocyte maturation (24 h) impairs oocyte developmental competence and subsequent embryo quality. However, because elevated NEFA concentrations in vivo are often present for a longer period of time, our recent research focused on a more in vivo-like long-term NEFA exposure (12 d) of whole murine follicles in vitro. The model covers follicular growth from the early secondary to the antral stage in vitro, including final oocyte maturation after an ovulatory stimulus (OS). Results showed an altered follicular growth and physiology (steroid synthesis, gene expression) and a subsequent reduced oocyte developmental competence. However, it remains unclear what specific time frame in follicular development is the most sensitive to such metabolic insult. Therefore, we hypothesised that chronic elevated NEFA concentrations throughout follicle growth affect oocyte developmental competence more severely than short-term NEFA exposure limited to the final phase of oocyte maturation. The aim was to study the effect of elevated NEFA concentrations 1) during the final phase of follicular oocyte maturation (after the OS) and 2) during the whole period of in vitro murine follicle growth until the antral stage, including final oocyte maturation. Early secondary follicles, isolated from the ovaries of 13-day-old B6CBAF1 mice, were cultured in vitro until the antral stage (3 replicates). Follicles were exposed to: BASAL NEFA mix for 12 days (BASAL-BASAL, control); HIGH stearic acid (SA) for 12 days (SA-SA); HIGH NEFA mix for 12 days (NEFA-NEFA); HIGH SA after the OS (BASAL-SA); and HIGH NEFA mix after the OS (BASAL-NEFA). Oocytes were isolated out of antral follicles 20 hours after the OS, routinely fertilized and presumptive zygotes cultured. Cleavage (n cleaved zygotes/n oocytes) and blastocyst (n blastocysts/n oocytes) rates were documented and analysed by means of binary logistic regression. Cleavage rate was reduced for BASAL-BASAL (37%) compared to BASAL-NEFA embryos (52%; P = 0.045). The BASAL-NEFA treatment (43%) presented with a higher blastocyst percentage than BASAL-BASAL (23%; P = 0.004), NEFA-NEFA (26%; P = 0.037) and SA-SA (15%; P = 0.001) treatments. The BASAL-SA (30%) treatment performed better than the SA-SA treatment (P = 0.049). Even though BASAL-BASAL (control) embryo development was surprisingly low, the results indicate that long-term NEFA exposure during follicle growth in vitro affects oocyte developmental competence more severely than an exposure limited to the final phase of maturation after the OS. The results thus emphasise that the maternal micro-environment throughout follicular growth and not only during final oocyte maturation is essential for optimal oocyte quality.

ICDs at higher age and clinical risk factors

BACKGROUND

The implantable cardioverter defibrillator (ICD) is effective in preventing sudden cardiac death. However, in elderly patients (aged 75 years or older) the role of ICDs is still not well-defined and controversial.

METHODS

We retrospectively analysed all clinical and survival data of all ICD patients who were ≥75 years at the date of implantation in the Erasmus MC, Rotterdam, the Netherlands and the University Hospital, Basel, Switzerland. Kaplan-Meier survival analysis was performed, and mortality predictors were identified. Mortality of the cohort was compared with a random sample of patients aged 60-70 years originating from the same database and to an age- and sex-matched cohort of Dutch persons.

RESULTS

The study cohort consisted of 179 patients aged 75 years or older who were implanted between February 1999 and July 2008. The median follow-up time was 2.0 (IQR 2.8) years. Survival rates after 1, 2 and 3 years were 87, 82, 75 %, respectively. Survival was similar for primary and secondary prevention. Mortality in this study population could be predicted by combining four clinical risk factors: QRS duration >120 ms, NYHA class > II, renal failure and atrial fibrillation (AF). Survival was worse compared with the group of ICD patients aged 60-70 years and to the age- and sex-matched group of elderly persons. However, survival was not significantly worse when comparing elderly ICD patients without additional risk factors to the general population.

CONCLUSIONS

Elderly patients still have an acceptable survival probability independent of prevention indication, certainly if there are no additional clinical risk factors. The presence or absence of additional clinical risk factors should be taken into account when making the decision for implantation, since they strongly correlate with survival.

85 THE EFFECT OF 17α-ETHINYL ESTRADIOL EXPOSURE OF IN VITRO-CULTURED BOVINE MORULAE ON SUBSEQUENT EMBRYONIC DEVELOPMENT AND QUALITY

Research has shown that 17-α-ethinyl oestradiol (EE2), an important component of most oral birth-control pills, acts as a xeno-oestrogen after being released into the environment through urine and feces. Although this emphasizes the need for the evaluation of its toxicity, several oocyte and embryo-toxic effects have been reported (Beker-Van Woudenberg et al. 2012). Therefore, the aim of the present study was to evaluate the effect of EE2 exposure during bovine early embryonic development, specifically at the morula stage (18 h), on subsequent embryonic development and quality. Bovine cumulus–oocyte complexes (COC) from 2- to 6-mm-diameter follicles were matured in groups of 50 in 500 μL of TCM with 20 ng mL–1 epidermal growth factor (EGF) for 24 h and subsequently fertilized in groups of 100 in 500 μL of fertilization medium for 22h (5% CO2, 38.5°C). Presumptive zygotes were denuded and cultured in groups of  ±25 in 50 μL of SOF with ITS (5 μg mL–1 insulin, 5 μg mL–1 transferrin, 5 ng mL–1 selenium) and 2% BSA, covered with mineral oil (5% O2, 5% CO2, 38.5°C). Subsequently, embryonic developmental stage was determined at 135 h post-insemination (p.i.). Sole embryos at morula stage were selected and randomly allocated to treatment groups (n) divided over 5 replicates: (1) Control (67), (2) solvent control: 0.1% ethanol (49), (3) 10 ng mL–1 EE2 (49), or (4) 10 μg mL–1 EE2 (63). The morulas were cultured individually in 30 μL of standard SOF medium supplemented with the desired concentrations ethanol or EE2 (5% O2, 5% CO2, 38.5°C) in 96-well half-area culture plates, without oil coverage for 18 h. Following exposure, embryos were cultured singly in standard culture medium for 2 more days. Subsequently, developmental competence was evaluated and blastocyst rates calculated (blastocyst rate = total blastocyst/number of grade 1 selected morula). Expanded (EB) and hatched blastocysts (HB) were fixed with 4% paraformaldehyde, and total cell number and apoptotic cell ratio were determined by DAPI and TUNEL staining (13 EB and 7 HB per treatment). Comparable blastocyst rates were obtained in all treatment groups: solvent control (77.8%), 10 ng mL–1 EE2 (69.0%), and 10 μg mL–1 EE2 (84.0%) compared with the controls (88.2%; P > 0.05; binary logistic regression). In addition, no significant effect of treatment could be found on total cell number or apoptotic cell ratio: solvent control (149.70 ± 23.47 and 3.46 ± 1.73), 10 ng mL–1 EE2 (154.75 ± 23.26 and 3.22 ± 1.35), and 10 μg mL–1 EE2 (150.50 ± 26.69 and 4.23 ± 1.85) compared with the controls (145.02 ± 24.71 and 3.07 ± 2.03; P > 0.05; two-way ANOVA). Although our results show no immediate statistical significant effect of short-term EE2 exposure during the morula stage in in vitro culture on subsequent blastocyst development and quality, additional research is necessary to find out if EE2 may affect gene-expression patterns, eventually resulting in still unknown embryotoxic effects that might turn up during later embryonic development.

94 A POLARIZED CELL-CULTURE SYSTEM TO STUDY THE EFFECTS OF ELEVATED SERUM NONESTERIFIED FATTY ACID CONCENTRATIONS ON THE BOVINE OVIDUCTAL MICROENVIRONMENT IN VITRO

The detrimental consequences of elevated serum nonesterified fatty acid concentrations (NEFA) typical in negative energy balance, obesity, or type II diabetes have previously been demonstrated in ovarian follicles. However, regardless its key role in reproduction, the consequences of elevated NEFA on oviductal physiology are unclear. Therefore, the aim of this study was to 1) determine whether serum NEFAs can be found in the oviductal microenvironment using a polarized oviductal epithelial cell culture and more specifically to 2) study the effect of the BSA gradient and the direction of the NEFA gradient. Bovine oviductal epithelial cells from slaughterhouse oviducts in Day 3 to 5 of the luteal phase were mechanically isolated and cultured for 7 days in a flask. Cells were transferred in a polarized oviductal epithelial cell culture-system (Snapwell® polyester membrane, pore size 0.4 µm, 4 × 106 pores cm–2) with an apical (A) and basal (B) medium supporting cell growth until the transepithelial electric resistance reached 700 Ωcm2 (Day 6). Then, cells were exposed to a transmembranary BSA (0.75 or 3% BSA) or NEFA gradient (0 or 360 µM NEFA: 115 µM oleic acid, 140 µM stearic acid, 105 µM palmitic acid) for 48 h in 4 experimental setups: 1) A and B containing 0.75% BSA and B supplemented with NEFA, 2) same as in 1 but NEFAs were added in A, 3) A containing 0.75% BSA and B supplemented with 3% BSA and NEFA, 4) same as in 3 but with 3% BSA + NEFA in A and B contained 0.75% BSA. Samples were analyzed for total NEFA and specific fatty-acid concentrations by photometric and gas chromatographic assays. In total, 72 wells in 4 replicates were cultured and analyzed. Data were processed by paired sample t-tests and student t-tests. Exposure to NEFA did not alter the transepithelial electric resistance. In Exp. 1, the total NEFA concentration in A increased with 0.013 µM (21.11%) over 48 h of NEFA exposure in the basal compartment explained by a significant rise of stearic (8.52 µM, 20.68%) and oleic acid (12.86 µM, 45.17%) accompanied with only a 19.45% decrease of total NEFA in B (P < 0.05). When the transport direction was reversed in Exp. 2, the total NEFA concentration decreased 53.4% in A, with no obvious NEFA rise in B. Implementing a BSA gradient (Exp. 3 and 4) was associated with a slight decrease (13 and 15.7%, respectively; P < 0.05) of NEFA concentration in the supplemented compartment, but no obvious NEFA increase in the opposite compartment could be detected. Overall, these results suggest that NEFA transport in this culture system is tightly regulated and can only be influenced by the transport direction of the NEFA. Further research should focus on transport and metabolisation of the fatty acids added.

5 THE EFFECT OF ELEVATED NONESTERIFIED FATTY ACID CONCENTRATIONS ON MURINE IN VITRO FOLLICULOGENESIS AND SUBSEQUENT OOCYTE DEVELOPMENTAL COMPETENCE

Metabolic disorders, like negative energy balance and obesity, are characterized by elevated serum non-esterified fatty acid (NEFA) concentrations, due to upregulated lipolysis. We previously showed that short-term (24-h) NEFA exposure of bovine oocytes during their final maturation is detrimental to oocyte and embryo quality (Van Hoeck et al. 2011 PLoS ONE 6, e23183). However, the typical chronic exposure as present in diseased females has never been studied before. Therefore, we aimed to use a murine preantral follicle culture model to study the effect of long-term NEFA exposure on folliculogenesis, antrum formation, and the developmental competence of the enclosed oocyte. Early secondary murine follicles (n = 629) from 13-day-old B6CBAF1 mice were individually cultured for 12 days. Follicles were exposed to 4 treatments containing physiological or pathological concentrations of stearic acid (SA), palmitic acid (PA), or oleic acid (OA) for 12 days: BASAL (72 µM NEFA mix, n = 154), high SA (280 µM SA, n = 160), high OA (210 µM OA, n = 159), and NEFA (720 µM NEFA mix, n = 156). Oocytes were routinely fertilized 20 h after a final maturation stimulus [hCG, epidermal growth factor (EGF)]. Presumptive zygotes were denuded and cultured until the blastocyst stage (Day 5 pre-implantation). Data were analyzed with a mixed-model ANOVA or binary logistic regression. The SA-exposed follicles displayed a reduced Day-12 antrum formation, compared to BASAL and NEFA follicles (68 v. 78 and 83%, P = 0.03 and P < 0.01), which was similar for OA follicles compared with the NEFA follicles (72 v. 83%, P = 0.04). Follicles cultured in SA conditions were, on average, 10, 13, and 11% smaller in diameter compared with BASAL, OA, and NEFA follicles (P = 0.05, P = 0.01, and P = 0.04, respectively). Likewise, the follicular growth during the 12-day culture was significantly reduced for SA follicles compared with BASAL and NEFA follicles (P < 0.01). Neither Day-12 oocyte diameter nor oocyte growth were affected by treatment. After fertilization, the oocytes from NEFA-exposed follicles showed a decreased cleavage rate on Day 1 pre-implantation, compared with BASAL oocytes (53 v. 69%; P < 0.01). Accordingly, the percentage of Day-5 blastocysts was reduced for oocytes from NEFA follicles compared with BASAL follicles (42 v. 63%; P < 0.01). Also, oocytes from SA and OA follicles showed reduced blastocyst rates compared with BASAL oocytes (32 and 33 v. 63%; P < 0.01). Exposure of follicles to SA or OA seems to slightly impair antrum formation and follicle growth. Furthermore, oocytes originating from NEFA-, OA-, and SA-exposed follicles had a dramatically reduced developmental competence compared with oocytes from follicles cultured in physiological BASAL conditions, an effect most apparent at blastocyst formation. In conclusion, we show for the first time that elevated NEFA concentrations affect murine follicular development and that this negative effect is carried through to the oocyte and pre-implantation embryo development. Ongoing research focuses on the pathways involved.

Use of remote monitoring in the management of system-related complications in implantable defibrillator patients

Remote monitoring of implantable defibrillators (ICDs) is designed to minimise regular follow-up visits and to facilitate early detection of adverse events. With the increased rate of ICD implantations in today's clinical setting and multiple device advisories, which pose management challenges, this approach becomes very attractive. The aim of this article is to present the role of remote monitoring in the detection of system-related complications, its potential benefits and its barriers in the outpatient management of ICD patients.