Responsiveness of bovine cumulus-oocyte-complexes (COC) to porcine and recombinant human FSH, and the effect of COC quality on gonadotropin receptor and Cx43 marker gene mRNAs during maturation in vitro

Substantially less development to the blastocyst stage occurs in vitro than in vivo and this may be due to deficiencies in oocyte competence. Although a large proportion of bovine oocytes undergo spontaneous nuclear maturation, less is known about requirements for proper cytoplasmic maturation. Commonly, supraphysiological concentrations of FSH and LH are added to maturation media to improve cumulus expansion, fertilization and embryonic development. Therefore, various concentrations of porcine FSH (pFSH) and recombinant human FSH (rhFSH) were investigated for their effect on bovine cumulus expansion in vitro. Expression of FSHr, LHr and Cx43 mRNAs was determined in cumulus-oocyte complexes to determine whether they would be useful markers of oocyte competence. In serum-free media, only 1000 ng/ml pFSH induced marked cumulus expansion, but the effect of 100 ng/ml pFSH was amplified in the presence of 10% serum. In contrast, cumulus expansion occurred with 1 ng/ml rhFSH in the absence of serum. FSHr mRNA was highest at 0–6 h of maturation, then abundance decreased. Similarly, Cx43 mRNA expression was highest from 0–6 h but decreased by 24 h of maturation. However, the relative abundance of LHr mRNA did not change from 6–24 h of maturation. Decreased levels of FSHr, LHr and Cx43 mRNAs were detected in COCs of poorer quality. In conclusion, expansion of bovine cumulus occurred at low doses of rhFSH in serum-free media. In summary, FSHr, LHr and Cx43 mRNA abundance reflects COC quality and FSHr and Cx43 mRNA expression changes during in vitro maturation; these genes may be useful markers of oocyte developmental competence

Casitas B-lineage lymphoma linker helix mutations found in myeloproliferative neoplasms affect conformation

Background: Casitas B-lineage lymphoma (Cbl or c-Cbl) is a RING ubiquitin ligase that negatively regulates protein tyrosine kinase (PTK) signalling. Phosphorylation of a conserved residue (Tyr371) on the linker helix region (LHR) between the substrate-binding and RING domains is required to ubiquitinate PTKs, thereby flagging them for degradation. This conserved Tyr is a mutational hotspot in myeloproliferative neoplasms. Previous studies have revealed that select point mutations in Tyr371 can potentiate transformation in cells and mice but not all possible mutations do so. To trigger oncogenic potential, Cbl Tyr371 mutants must perturb the LHR-substrate-binding domain interaction and eliminate PTK ubiquitination. Although structures of native and pTyr371-Cbl are available, they do not reveal how Tyr371 mutations affect Cbl’s conformation. Here, we investigate how Tyr371 mutations affect Cbl’s conformation in solution and how this relates to Cbl’s ability to potentiate transformation in cells. Results: To explore how Tyr371 mutations affect Cbl’s properties, we used surface plasmon resonance to measure Cbl mutant binding affinities for E2 conjugated with ubiquitin (E2–Ub), small angle X-ray scattering studies to investigate Cbl mutant conformation in solution and focus formation assays to assay Cbl mutant transformation potential in cells. Cbl Tyr371 mutants enhance E2–Ub binding and cause Cbl to adopt extended conformations in solution. LHR flexibility, RING domain accessibility and transformation potential are associated with the extent of LHR-substrate-binding domain perturbation affected by the chemical nature of the mutation. More disruptive mutants like Cbl Y371D or Y371S are more extended and the RING domain is more accessible, whereas Cbl Y371F mimics native Cbl in solution. Correspondingly, the only Tyr371 mutants that potentiate transformation in cells are those that perturb the LHR-substrate-binding domain interaction. Conclusions: c-Cbl’s LHR mutations are only oncogenic when they disrupt the native state and fail to ubiquitinate PTKs. These findings provide new insights into how LHR mutations deregulate c-Cbl

EXOS-A衛星で観測されたLHRホイスラ(c.磁気圏内の波動粒子相互作用)(第2回極域における電離圏磁気圏総合観測シンポジウム : Part I)

EXOS-A衛星で観測されたLHRホイスラの諸特性を解析し,その解釈のために1つの伝搬機構モテルを提出する.LHRホイスラのスペクトルの特徴は,周波数が下がるとともに分散値が増大し,局所LHR周波数の近くで共鳴状態となることにある.その共鳴現象を説明するためには,地球磁界にほぼ垂直な方向にプラスマ密度勾配が存在する必要があり.LHRホイスラは,そのような勾配を持つプラスマ圏の中を,共鳴角に近い大きなwave normal angleで非タクト伝搬しているホイスラモート波であると思われるLHR (lower hybrid resonance) whistlers have been found in the mid-latitude records from a bioadband VLF receiver aboard the EXOS-A satellite. Characteristics of the LHR whistlers are the successive enhancement of dispersion and the frequency resonance, in the vicinity of the local LHR frequency. The resonance phenomenon of the LHR whistlers has been interpreted as a nonducted propagation of whistler-mode waves with a large wave normal angle in the magnetospheric plasma, whose density gradient is pearly perpendicular to the earth\u27s magnetic fiel

Collusion in Board of Directors

There is a large literature on the composition of the boards as well as the monitoring role and the advisory role of the boards. Nevertheless, the problem of collusion between the CEO and the board has receive little attention. The aim of this paper is to study collusive aspects of the board of directors. Our paper sheds light on the problem of composition of the board of directors. We study what is the optimal composition of the board of directors in particular if it is preferable to have a insider-oriented board or a outsider-oriented board with a majority of independent directors. We consider that a board of independent directors that are all chosen directly by the CEO is a friendly board if the independent directors follow the decision of the CEO. We study the case of collusion considering a CEO facing a choice of projects.We propose a model where we have di¤erent projects each with a certain level of risk. The choice of the best project for the company is function of remuneration of the CEO as well as the private benefits of the CEO

Chest CT scoring for evaluation of lung sequelae in congenital diaphragmatic hernia survivors

Objectives Data on long-term structural lung abnormalities in survivors of congenital diaphragmatic hernia (CDH) is scarce. The purpose of this study was to develop a chest computed tomography (CT) score to assess the structural lung sequelae in CDH survivors and to study the correlation between the CT scoring and clinical parameters in the neonatal period and at 1 year of follow-up. Methods A prospective, clinical follow-up program is organised for CDH survivors at the University Hospital of Leuven including a chest CT at the age of 1 year. The CT scoring used and evaluated, named CDH-CT score, was adapted from the revised Aukland score for chronic lung disease of prematurity. Results Thirty-five patients were included. All CT scans showed some pulmonary abnormalities, ranging from very mild to severe. The mean total CT score was 16 (IQR: 9-23), with the greatest contribution from the subscores for decreased attenuation (5; IQR: 2-8), subpleural linear and triangular opacities (4; IQR: 3-5), and atelectasis/consolidation (2; IQR: 1-3). Interobserver and intraobserver agreement was very good for the total score (ICC coefficient > 0.9). Total CT score correlated with number of neonatal days ventilated/on oxygen as well as with respiratory symptoms and feeding problems at 1 year of age. Conclusion The CDH-CT scoring tool has a good intraobserver and interobserver repeatability and correlates with relevant clinical parameters. This holds promise for its use in clinical follow-up and as outcome parameter in clinical interventional studies