Triploidy—Observations in 154 Diandric Cases

Hydatidiform moles (HMs) are abnormal human pregnancies with vesicular chorionic villi, imposing two clinical challenges; miscarriage and a risk of gestational trophoblastic neoplasia (GTN). The parental type of most HMs are either diandric diploid (PP) or diandric triploid (PPM). We consecutively collected 154 triploid or near-triploid samples from conceptuses with vesicular chorionic villi. We used analysis of DNA markers and/or methylation sensitive-MLPA and collected data from registries and patients records. We performed whole genome SNP analysis of one case of twinning (PP+PM).In all 154 triploids or near-triploids we found two different paternal contributions to the genome (P1P2M). The ratios between the sex chromosomal constitutions XXX, XXY, and XYY were 5.7: 6.9: 1.0. No cases of GTN were observed. Our results corroborate that all triploid human conceptuses with vesicular chorionic villi have the parental type P1P2M. The sex chromosomal ratios suggest approximately equal frequencies of meiosis I and meiosis II errors with selection against the XYY conceptuses or a combination of dispermy, non-disjunction in meiosis I and meiosis II and selection against XYY conceptuses. Although single cases of GTN after a triploid HM have been reported, the results of this study combined with data from previous prospective studies estimate the risk of GTN after a triploid mole to 0% (95% CI: 0–1,4%).     

Functional Modulation of the Glutamate Transporter Variant GLT1b by the PDZ Domain Protein PICK1

The dominant glutamate transporter isoform in the mammalian brain, GLT1, exists as at least three splice variants, GLT1a, GLT1b, and GLT1c. GLT1b interacts with the scaffold protein PICK1 (protein interacting with kinase C1), which is implicated in glutamatergic neurotransmission via its regulatory effect on trafficking of AMPA-type glutamate receptors. The 11 extreme C-terminal residues specific for the GLT1b variant are essential for its specific interaction with the PICK1 PDZ domain, but a functional consequence of this interaction has remained unresolved. To identify a functional effect of PICK1 on GLT1a or GLT1b separately, we employed the Xenopus laevis expression system. GLT1a and GLT1b displayed similar electrophysiological properties and EC₅₀ for glutamate. Co-expressed PICK1 localized efficiently to the plasma membrane and resulted in a 5-fold enhancement of the leak current in GLT1b-expressing oocytes with only a minor effect on [³H]glutamate uptake. Three different GLT1 substrates all caused a slow TBOA-sensitive decay in the membrane current upon prolonged application, which provides support for the leak current being mediated by GLT1b itself. Leak and glutamate-evoked currents in GLT1a-expressing oocytes were unaffected by PICK1 co-expression. PKC activation down-regulated GLT1a and GLT1b activity to a similar extent, which was not affected by co-expression of PICK1. In conclusion, PICK1 may not only affect glutamatergic neurotransmission by its regulatory effect on glutamate receptors but may also affect neuronal excitability via an increased GLT1b-mediated leak current. This may be particularly relevant in pathological conditions such as amyotrophic lateral sclerosis and cerebral hypoxia, which are associated with neuronal GLT1b up-regulation.     

Aerobic Training in Patients with Congenital Myopathy

Introduction

Congenital myopathies (CM) often affect contractile proteins of the sarcomere, which could render patients susceptible to exercise-induced muscle damage. We investigated if exercise is safe and beneficial in patients with CM.

Methods

Patients exercised on a stationary bike for 30 minutes, three times weekly, for 10 weeks at 70% of their maximal oxygen uptake (VO_2max). Creatine kinase (CK) was monitored as a marker of muscle damage. VO_2max, functional tests, and questionnaires evaluated efficacy.

Results

Sixteen patients with CM were included in a controlled study. VO_2max increased by 14% (range, 6–25%; 95% CI 7–20; p < 0.001) in the seven patients who completed training, and tended to decrease in a non-intervention group (n = 7; change -3.5%; range, -11–3%, p = 0.083). CK levels were normal and remained stable during training. Baseline Fatigue Severity Scale scores were high, 4.9 (SE 1.9), and tended to decrease (to 4.4 (SE 1.7); p = 0.08) with training. Nine patients dropped out of the training program. Fatigue was the major single reason.

Conclusions

Ten weeks of endurance training is safe and improves fitness in patients with congenital myopathies. The training did not cause sarcomeric injury, even though sarcomeric function is affected by the genetic abnormalities in most patients with CM. Severe fatigue, which characterizes patients with CM, is a limiting factor for initiating training in CM, but tends to improve in those who train.

Trial Registration

The Regional Committee on Health Research Ethics of the Capital Region of Denmark H-2-2013-066 and ClinicalTrials.gov H2-2013-066     

P2X1 receptor blockers reduce the number of circulating thrombocytes and the overall survival of urosepsis with haemolysin-producing Escherichia coli

Purinergic Signalling - Urosepsis is a severe condition often caused by Escherichia coli that spontaneously have ascended the urinary tract to the kidneys causing pyelonephritis and potentially...     

A Protein Disulfide Isomerase Controls Neuronal Migration through Regulation of Wnt Secretion

1. Download high-res image (153KB)
2. Download full-size image

     

Backbone NMR assignment of the internal interaction site of ALP

Earlier reports have shown that ALP has an internal interaction site. We were able to stablize the structure of this unfolded part to a great extent by aspartic acid, which allowed the backbone assignment. No secondary structure of the polypeptide was observed.     

A critical review on natural compounds interacting with the plant plasma membrane H+-ATPase and their potential as biologicals in agriculture

The plant plasma membrane (PM) H⁺-ATPase is an essential enzyme controlling plant growth and development. It is an important factor in response to abiotic and biotic stresses and is subject to tight regulation. We are in demand for new sustainable natural growth regulators and as a key enzyme for regulation of transport into the plant cell the PM H⁺-ATPase is a potential target for these. In this review, we have evaluated the known non-protein natural compounds with regulatory effects on the PM H⁺-ATPase, focusing on their mechanism of action and their potential as biologicals/growth regulators in plant production of future sustainable agriculture.     

RhoA exerts a permissive effect on volume-regulated anion channels in vascular endothelial cells

Cell swelling triggers in most cell typesan outwardly rectifying anion current,I_Cl,swell, via volume-regulated anion channels (VRACs). We have previously demonstrated in calf pulmonary artery endothelial (CPAE) cells that inhibition of the Rho/Rho kinase/myosin light chain phosphorylation pathway reduces the swelling-dependent activation of I_Cl,swell. However, theseexperiments did not allow us to discriminate between a direct activatorrole or a permissive effect. We now show that the Rho pathway did notaffect VRAC activity if this pathway was activated by transfecting CPAEcells with constitutively active isoforms of G (a Rho activatingheterotrimeric G protein subunit), Rho, or Rho kinase. Furthermore,biochemical and morphological analysis failed to demonstrate activationof the Rho pathway during hypotonic cell swelling. Finally,manipulating the Rho pathway with either guanosine5'-O-(3-thiotriphosphate) or C3 exoenzyme had no effect onVRACs in caveolin-1-expressing Caco-2 cells. We conclude that the Rhopathway exerts a permissive effect on VRACs in CPAE cells, i.e.,swelling-induced opening of VRACs requires a functional Rho pathway,but not an activation of the Rho pathway.

     

Alpha-LNA (alpha-D-configured locked nucleic acid)

Two pyrimidine alpha-LNA nucleoside monomers have been synthesised and incorporated into alpha-configured oligonucleotides. A fully modified mixed alpha-LNA sequence displays unprecedented parallel stranded hybridisation with complementary RNA and a remarkable selectivity for RNA over DNA. Modelling shows alpha-LNA:RNA to form an extended duplex with a very broad major groove.     

Bi- and tricyclic nucleoside derivatives restricted in S-type conformations and obtained by RCM-reactions

Ring-closing metathesis (RCM) is applied as a new and powerful technology in the construction of nucleoside analogues that are conformationally restricted in S-type conformations due to additional 3',4'- and/or 3',5'-linkages.