The effects of hypo- and hyperglycemia during lipolysis-like conditions on bovine oocyte maturation, subsequent embryo developmental and glucose metabolism

Abstract of a conference paper presented at the 31st meeting of the European Embryo Transfer Associaton, 11-12 September 2015, Ghent, Belgium

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 24h-treatments at day 9: 1) CONTROL (0µM NEFA + 0%EtOH), 2) SOLVENT CONTROL (0µM NEFA + 0.45%EtOH), 3) BASAL NEFA (720µM NEFA + 0.45%EtOH in the basal compartment), 4) APICAL NEFA (720µM 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 caveolin1). 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, ↑CAV1-protein-expression). 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, 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

Elevated Non-Esterified Fatty Acid Concentrations during Bovine Oocyte Maturation Compromise Early Embryo Physiology

Elevated concentrations of serum non-esterified fatty acids (NEFA), associated with maternal disorders such as obesity and type II diabetes, alter the ovarian follicular micro-environment and have been associated with subfertility arising from reduced oocyte developmental competence. We have asked whether elevated NEFA concentrations during oocyte maturation affect the development and physiology of zygotes formed from such oocytes, using the cow as a model. The zygotes were grown to blastocysts, which were evaluated for their quality in terms of cell number, apoptosis, expression of key genes, amino acid turnover and oxidative metabolism. Oocyte maturation under elevated NEFA concentrations resulted in blastocysts with significantly lower cell number, increased apoptotic cell ratio and altered mRNA abundance of DNMT3A, IGF2R and SLC2A1. In addition, the blastocysts displayed reduced oxygen, pyruvate and glucose consumption, up-regulated lactate consumption and higher amino acid metabolism. These data indicate that exposure of maturing oocytes to elevated NEFA concentrations has a negative impact on fertility not only through a reduction in oocyte developmental capacity but through compromised early embryo quality, viability and metabolism

Chasse et développement territorial. Vers un cadre d’analyse global ?

L’article propose une analyse de la contribution des activités cynégétiques au développement territorial en s’appuyant sur deux cadres théoriques complémentaires. D’une part, une version revisitée de la théorie de la base intégrant "une base de consommation" peut permettre de rendre compte des effets à la fois des chasseurs extérieurs et des chasseurs locaux. D’autre part, la chasse peut être à l’origine d’un processus d’innovation et de spécification des ressources territoriales.The paper proposes an analysis of the contribution of huntings to local development with two complementary theoretical frameworks. On one hand, a revisited version of the economic base models integrating "a consumption base" is able to measure both effects of the external hunters and the local hunters. On the other hand, hunting can generate an innovation process and specification of "territorial resources"

Behaviour support in dentistry: A Delphi study to agree terminology in behaviour management

Objectives: Dental behaviour support (DBS) describes all specific techniques practiced to support patients in their experience of professional oral healthcare. DBS is roughly synonymous with behaviour management, which is an outdated concept. There is no agreed terminology to specify the techniques used to support patients who receive dental care. This lack of specificity may lead to imprecision in describing, understanding, teaching, evaluating and implementing behaviour support techniques in dentistry. Therefore, this e-Delphi study aimed to develop a list of agreed labels and descriptions of DBS techniques used in dentistry and sort them according to underlying principles of behaviour. // Methods: Following a registered protocol, a modified e-Delphi study was applied over two rounds with a final consensus meeting. The threshold of consensus was set a priori at 75%. Agreed techniques were then categorized by four coders, according to behavioural learning theory, to sort techniques according to their mechanism of action. // Results: The panel (n = 35) agreed on 42 DBS techniques from a total of 63 candidate labels and descriptions. Complete agreement was achieved regarding all labels and descriptions, while agreement was not achieved regarding distinctiveness for 17 techniques. In exploring underlying principles of learning, it became clear that multiple and differing principles may apply depending on the specific context and procedure in which the technique may be applied. // Discussion: Experts agreed on what each DBS technique is, what label to use, and their description, but were less likely to agree on what distinguishes one technique from another. All techniques were describable but not comprehensively categorizable according to principles of learning. While objective consistency was not attained, greater clarity and consistency now exists. The resulting list of agreed terminology marks a significant foundation for future efforts towards understanding DBS techniques in research, education and clinical care

Behaviour support in dentistry: A Delphi study to agree terminology in behaviour management

Objectives: Dental behaviour support (DBS) describes all specific techniques practiced to support patients in their experience of professional oral healthcare. DBS is roughly synonymous with behaviour management, which is an outdated concept. There is no agreed terminology to specify the techniques used to support patients who receive dental care. This lack of specificity may lead to imprecision in describing, understanding, teaching, evaluating and implementing behaviour support techniques in dentistry. Therefore, this e‐Delphi study aimed to develop a list of agreed labels and descriptions of DBS techniques used in dentistry and sort them according to underlying principles of behaviour. Methods: Following a registered protocol, a modified e‐Delphi study was applied over two rounds with a final consensus meeting. The threshold of consensus was set a priori at 75%. Agreed techniques were then categorized by four coders, according to behavioural learning theory, to sort techniques according to their mechanism of action. Results: The panel (n = 35) agreed on 42 DBS techniques from a total of 63 candidate labels and descriptions. Complete agreement was achieved regarding all labels and descriptions, while agreement was not achieved regarding distinctiveness for 17 techniques. In exploring underlying principles of learning, it became clear that multiple and differing principles may apply depending on the specific context and procedure in which the technique may be applied. Discussion: Experts agreed on what each DBS technique is, what label to use, and their description, but were less likely to agree on what distinguishes one technique from another. All techniques were describable but not comprehensively categorizable according to principles of learning. While objective consistency was not attained, greater clarity and consistency now exists. The resulting list of agreed terminology marks a significant foundation for future efforts towards understanding DBS techniques in research, education and clinical care