Intrauterine expression of LIF and its receptors in the cycling and early pregnant mare

Leukaemia Inhibitory Factor (LIF) plays a critical role in blastocyst development and implantation, as clearly demonstrated by the failure of wild-type mouse embryos to implant in the uterus of LIF-knockout female mice unless the latter receive LIF supplementation. Expression of LIF and its receptors (LIF-R and gp130) in the early pregnant horse have not been described. However, the horse may be an interesting animal in which to study such ‘implantation factors’ because various aspects of implantation occur both unusually late and in a temporally distinct fashion in this species. The aim of this study was to examine LIF, LIF-R and gp130 gene expression in the endometrium of cycling and early pregnant mares, and in the early conceptus. Endometrial biopsies were recovered from 4 mares at each of late oestrus, days 7 and 14 of dioestrus (cycling mares), and days 7, 14 and 21 of gestation. Conceptuses were recovered by uterine lavage (day 7) or using a video-endoscopically guided net (days 14 and 21). For day 14 and 21 conceptuses, only the bilaminar trophoblast was used in gene expression studies. Expression of mRNA for LIF, LIF-R and gp130 was analysed by rtPCR, with relative expression calculated with respect to the 3 most stable housekeeping genes using GeNorm analysis. A dramatic increase in LIF mRNA expression (p<0.01) was observed in both the endometrium and the trophoblast on day 21 of pregnancy. Expression of LIF-R and gp 130 increased significantly in the trophoblast on day 21 (p<0.01), but did not vary in the endometrium at the various stages examined. We propose that LIF plays a role in the adhesion between trophoblast and endometrium which, in the mare, cannot begin until the blastocyst capsule is dissolved somewhere between days 18 and 22 of gestation

Kinematics and Thermodynamics of Non-Stoichiometric Oxidation Phase Transitions in Spent Fuel

ABSTRACTAt low temperatures (&lt;200°C), spent fuel from power reactors oxidizes from its UO2 lattice to a U4O9 lattice but with an oxygen-to-uranium (O/U) ratio of ∼2.4. Also, the weight gain time response has a plateau as the O/U approaches 2.4. Part of this response results from a geometrical dependency as a U4O9 oxidation front propagates into grain volumes of UO2. It may also be indicative of a metastable, non-stoichiometric U4O9 phase whose existence may inhibit the transition kinetics to the next expected phase of U3O8. To gain a mechanistic understanding and to plan future oxidation tests, lattice kinematic and thermodynamic models are developed for lattice deformations and energetics of lattice phase changes (UO2 → U4O9 → U3O7 → U3O8) that include zeroth order influences on oxidation kinetics due to interstitial oxygen atoms and vacancies plus interstitial and substitutional actinides and fission decay products in spent fuel.</jats:p

Oculomotor control in asymptomatic and recently diagnosed individuals with the genetic marker for Huntington’s disease

AbstractWe compared oculomotor control among individuals in the early stages of Huntington’s disease (HD), with that of individuals who are presymptomatic HD gene carriers (PSGC) and nongene carriers (NGC). The oculomotor testing paradigm included both traditional tests and a novel experimental procedure to assess visual scanning. Traditional tests elicited saccades, pursuit and optokinetic nystagmus (OKN). HD patients demonstrated marked delay in the initiation of volitional saccades (anti-saccade and memory-guided saccades), a reduced number of correct volitional saccades, reduced velocity of saccades, and a decreased OKN gain. We also studied visual scanning while the participants completed the Digit Symbol Subscale of the Wechsler Adult Intelligence Survey-Revised (WAIS-R). The HD participants demonstrated an abnormal gaze strategy, which may be associated with attention and/or planning deficits.Differences between the PSGC and NGC groups were only observed for two measures: PSGC had a decreased number of memory-guided saccades and a subtle delay in the initiation of volitional saccades. Our results suggest that oculomotor measures are a sensitive biomarker in the early stage of HD and demonstrate that the combination of more traditional oculomotor tests with visual scanning tests is useful in the evaluation of visual performance