Expression of connexins in human preimplantation embryos in vitro

Intercellular communication via gap junctions is required to coordinate developmental processes in the mammalian embryo. We have investigated if the connexin (Cx) isoforms known to form gap junctions in rodent preimplantation embryos are also expressed in human embryos, with the aim of identifying species differences in communication patterns in early development. Using a combination of polyA PCR and immunocytochemistry we have assessed the expression of Cx26, Cx31, Cx32, Cx40, Cx43 and Cx45 which are thought to be important in early rodent embryos. The results demonstrate that Cx31 and Cx43 are the main connexin isoforms expressed in human preimplantation embryos and that these isoforms are co-expressed in the blastocyst. Cx45 protein is expressed in the blastocyst but the protein may be translated from a generally low level of transcripts: which could only be detected in the PN to 4-cell embryos. Interestingly, Cx40, which is expressed by the extravillous trophoblast in the early human placenta, was not found to be expressed in the blastocyst trophectoderm from which this tissue develops. All of the connexin isoforms in human preimplantation embryos are also found in rodents pointing to a common regulation of these connexins in development of rodent and human early embryos and perhaps other species

Teacher change in post-16 mathematics: a multiple case analysis of teachers in the Zone of Enactment.

This research focuses on the use of teaching resources that support an ambitious student-centred approach to learning mathematics. A multiple case study involving three teachers of post-16 mathematics is presented to develop new insights into the process of teacher change. Data sources include classroom observations in addition to teacher and student interviews. Using the concept of Zone of Enactment (ZoE) and teacher self-efficacy as a theoretical framework this research reveals the importance of teachers being aware of, and able to reflect on, the ZoE and their self-efficacy

Production values as program quality signals in Spanish linear TV: A comparison of two periods

Technology disruption, digitalization and media convergence have triggered a profound crisis in the television industry. In this context, quality is an essential strategic element for success, especially when consumers have learned through their experience with VOD, becoming more demanding and less loyal customers. Then, has the importance of quality signals changed with the emergence of new online alternatives? And the quality perception among viewers? Our research explores four production values (the host, content, the set, and technical quality) as TV program quality signals and their effect on the quality perception of entertainment programs of Spanish broadcasters. We compare two years: 2012 and 2016, a period during which the Spanish television market changed due to appearance of OTT services. Using t-tests and regression models, we establish that the importance of quality signals varied over this period, with content proving more important and the set less so in 2016 as compared with 2012. Additionally, in 2016, the results show that the quality perception of linear TV entertainment programs depended more on subjective elements such as liking and satisfaction than on objective elements, as it was in 2012. Finally, our findings are discussed, and some managerial implications and future research are suggested

The regioselective outcome of ring rearrangement metathesis transformations performed on bicyclo[2.2.2]oct-2-ene derivatives

Treatment of bicyclo[2.2.2]oct-2-en-7-one with organometallic reagents gives the addition products in good yield and moderate diastereoselectivities in favour of the syn-products. Subsequent exposure of these addition products to ruthenium catalysed ring rearrangement metathesis (RRM) conditions reveals significant product divergence as a consequence of the newly acquired stereocentre

Cycloaddition chemistry of allenamides

Allenamides are electron deficient allenamine equivalents that can participate in a range of cycloaddition events giving rise to novel heterocycles and diverse molecular architectures contained within natural products. This review summarizes some of the recent research in this area, with particular reference to predicting the stereochemical outcomes of such transformations and highlighting recent applications of allenamides in cycloaddition transformations which showcase the utility of this under-utilized synthon

Clinical Laboratory Assessment of \u3cem\u3eMycoplasma genitalium\u3c/em\u3e Transcription-Mediated Amplification Using Primary Female Urogenital Specimens

Following analysis of primary cervix, vagina, and first-void female urine specimens for Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis via commercial transcription-mediated amplification (TMA), residual material was subjected to Mycoplasma genitalium research-use-only TMA. Representation within a 2,478-specimen retrospective study set was established by comparison to a 6-month audit of clinical C. trachomatis TMA (12,999 specimens) on the basis of the C. trachomatis detection rate, specimen source distribution, clinic location, and age. M. genitalium was detected in 282 (11.4%) patients. This rate was higher than those seen with T. vaginalis (9.0%; P _ 0.005), C. trachomatis (6.2%), and N. gonorrhoeae (1.4%). Positive M. genitalium results were confirmed by repeat testing or alternative-target TMA at a rate of 98.7%. The mean age of the M. genitalium-infected females (24.7 years) was lower than that of the T. vaginalis-infected females (mean, 30.1 years; P\u3c0.0001) and higher than that of the C. trachomatis-infected females (mean, 23.8 years; P_0.003). Of 566 patient encounters positive for at least one sexually transmitted infection (STI), 35.9% exhibited sole detection of M. genitalium (P \u3c 0.0004 versus sole detection of other STI agents) and 26.1% were solely positive for T. vaginalis (P \u3c 0.0002 versus C. trachomatis). The M. genitalium and T. vaginalis detection rates among 755 patients at urban emergency departments were 14.6% and 13.0%, respectively (P _ 0.37). A 10.0% M. genitalium detection rate from other facilities exceeded that of T. vaginalis (7.2%; P _ 0.004). Incorporation of M. genitalium TMA into comprehensive testing programs would detect M. genitalium in a significant proportion of females, particularly those in outpatient obstetrics and gynecology (OB/GYN) settings

Skeletal muscle fat metabolism during post-exercise recovery in humans

Recovery after prolonged or high-intensity exercise is characterised by a substantial increase in adipose tissue lipolysis, resulting in elevated rates of plasma-derived fat oxidation. Despite the large increase in circulating fatty acids (FAs) after exercise, only a small fraction of this is taken up by exercised muscle in the lower extremities. Indeed, the predominant fate of non-oxidised FAs derived from post-exercise lipolysis is reesteriflcation hi the liver. During recovery from endurance exercise, a number of changes also occur hi skeletal muscle that allow for a high metabolic priority towards glycogen resynthesis. Reducing muscle glycogen during exercise potentiates these effects, however the cellular and molecular mechanisms regulating substrate oxidation following exercise remain poorly defined. The broad arm of this thesis was to examine the regulation of fat metabolism during recovery from glycogen-lowering exercise hi the presence of altered fat and glucose availability. In study I, eight endurance-trained males completed a bout of exhaustive exercise followed by ingestion of carbohydrate (CHO)-rich meals (64-70% of energy from CHO) at 1, 4, and 7 h of recovery. Duplicate muscle biopsies were obtained at exhaustion and 3, 6 and 18 h of recovery. Despite the large intake of CHO during recovery (491 ± 28 g or 6.8 + 0.3 g • kg-1), respiratory exchange ratio values of 0.77 to 0.84 indicated a greater reliance on fat as an oxidative fuel. Intramuscular triacylglycerol (IMTG) content remained unchanged in the presence of elevated glucose and insulin levels during recovery , suggesting IMTG has a negligible role in contributing to the enhanced fat oxidation after exhaustive exercise. It appears that the partitioning of exogenous glucose towards glycogen resynthesis is of high metabolic priority during immediate post-exercise recovery, supported by the trend towards reduced pyruvate dehydrogenase (PDH) activity and increased fat oxidation. The effect of altering plasma FA availability during post-exercise recovery was examined in study II. Eight endurance-trained males performed three trials consisting of glycogen-lowering exercise, followed by infusion of either saline (CON), saline + nicotinic acid (NA) (LFA) or Intralipid and heparin (HFA). Muscle biopsies were obtained at the end of exercise (0 h) and at 3 and 6 h in recovery. Altering the availability of plasma FAs during recovery induced changes in whole-body fat oxidation that were unrelated to differences in skeletal muscle malonyl-CoA. Furthermore, fat oxidation and acetyl-CoA carboxylase (ACC) phosphorylation appear to be dissociated after exercise, suggesting mechanisms other than phosphorylation-mediated changes in ACC activity have an important role in regulating malonyl-CoA and fat metabolism in human skeletal muscle after exercise. Alternative mechanisms include citrate and long-chain fatty acyl-CoA mediated changes in ACC activity, or differences in malonyl-CoA decarboxylase (MCD) activity. Reducing plasma FA concentrations with NA attenuated the post-exercise increase in MCD and pyruvate dehydrogenase kinase 4 (PDK4) gene expression, suggesting that FAs and/or other factors induced by NA are involved hi the regulation of these genes. Despite marked changes hi plasma FA availability, no significant changes in IMTG concentration were detected, providing further evidence that plasma-derived FAs are the preferential fuel source contributing to the enhanced fat oxidation post-exercise during recovery. To further examine the effect of substrate availability after exercise, Study III investigated the regulation of fat metabolism during a 6 h recovery period with or without glucose infusion. Enhanced glucose availability significantly increased CHO oxidation compared with the fasted state, although no differences in whole-body fat oxidation were apparent. Consistent with the similar rates of fat metabolism, no difference hi AMPK or ACCβ phosphorylation were observed between trials. In addition, no significant treatment or time effects for IMTG concentration were detected during recovery. The large exercise-induced PDK4 gene expression was attenuated when plasma FAs were reduced during glucose infusion, supporting the hypothesis that PDK4 is responsive to sustained changes in lipid availability and/or changes in plasma insulin. Furthermore, the possibility exists that the suppression of PDK4 mRNA also reduced PDK activity and thus maintained PDH activity to account for the higher rates of CHO oxidation observed during glucose infusion compared with the control trial

Induced antiferromagnetism and large magnetoresistances in RuSr2(Nd,Y,Ce)2Cu2O10-d ruthenocuprates

RuSr2(Nd,Y,Ce)2Cu2O10-d ruthenocuprates have been studied by neutron diffraction, magnetotransport and magnetisation measurements and the electronic phase diagram is reported. Separate Ru and Cu spin ordering transitions are observed, with spontaneous Cu antiferromagnetic order for low hole doping levels p, and a distinct, induced-antiferromagnetic Cu spin phase in the 0.02 < p < 0.06 pseudogap region. This ordering gives rise to large negative magnetoresistances which vary systematically with p in the RuSr2Nd1.8-xY0.2CexCu2O10-d series. A collapse of the magnetoresistance (MR) and magnetisation in the pre-superconducting region may signify the onset of superconducting fluctuations.Comment: 22 pages, 11 figure

Effects of Hawthorn on the Progression of Heart Failure in a Rat Model of Aortic Constriction

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90301/1/phco.29.6.639.pd