Epidemiology of venous thromboembolism (VTE) associated with pregnancy

This review is focused on the epidemiology of venous thromboembolism (VTE), including deep vein thrombosis (DVT) and pulmonary embolism (PE), associated with pregnancy. Superficial vein thrombosis, a less hazardous and less studied type of thrombosis in pregnant women, is beyond the scope of this review. This study discusses the VTE incidence rate in women from developed countries for both antepartum and postpartum periods and for subpopulations of women affected by additional risk factors, such as thrombophilias, circulatory diseases, preeclampsia of varying degrees of severity, and Caesarean section. To minimize bias due to historical changes in medical and obstetric practices, lifestyle, diet, etc., this review is generally limited to relatively recent studies, i.e., those that cover the last 35 years. The absolute risk or incidence rate was used to ascertain risk of VTE associated with pregnancy. For the studies where the direct incidence rates of VTE were not reported, we calculated an estimate of the observed but not reported absolute incidence rates using the data presented in respective articles. Birth Defects Research (Part C) 105:167–184, 2015. © 2015 Wiley Periodicals, Inc.     

Mass distributions of a macromolecular assembly based on electrospray ionization mass spectrometric masses of the constituent subunits

Macromolecular assemblies containing multiple protein subunits and having masses in the megadalton (MDa) range are involved in most of the functions of a living cell. Because of variation in the number and masses of subunits, macromolecular assemblies do not have a unique mass, but rather a mass distribution. The giant extracelular erythrocruorins (Ers), ∼ 3.5 MDa, comprized of at least 180 polypeptide chains, are one of the best characterized assemblies. Three-dimensional reconstructions from cryoelectron microscopic images show them to be hexagonal bilayer complexes of 12 subassemblies, each comprised of 12 globin chains, anchored to a subassembly of 36 nonglobin linker chains. We have calculated the most probable mass distributions forLumbricus andRiftia assemblies and their globin and linker subassemblies, based on theLumbricus Er stoichiometry and using accurate subunit masses obtained by electrospray ionization mass spectrometry. The expected masses ofLumbricus andRiftia Ers are 3.517 MDa and 3.284 MDa, respectively, with a possible variation of ∼ 9% due to the breadth of the mass distributions. TheLumbricus Er mass is in astonishingly good agreement with the mean of 23 known masses, 3.524 ± 0.481 MDa.     

Allosteric alpha 1-adrenoreceptor antagonism by the conopeptide rho-TIA

A peptide contained in the venom of the predatory marine snail Conus tulipa, rho-TIA, has previously been shown to possess alpha1-adrenoreceptor antagonist activity. Here, we further characterize its pharmacological activity as well as its structure-activity relationships. In the isolated rat vas deferens, rho-TIA inhibited alpha1-adrenoreceptor-mediated increases in cytosolic Ca2+ concentration that were triggered by norepinephrine, but did not affect presynaptic alpha2-adrenoreceptor-mediated responses. In radioligand binding assays using [125I]HEAT, rho-TIA displayed slightly greater potency at the alpha 1B than at the alpha 1A or alpha 1D subtypes. Moreover, although it did not affect the rate of association for [3H]prazosin binding to the alpha 1B-adrenoreceptor, the dissociation rate was increased, indicating non-competitive antagonism by rho-TIA. N-terminally truncated analogs of rho-TIA were less active than the full-length peptide, with a large decline in activity observed upon removal of the fourth residue of rho-TIA (Arg4). An alanine walk of rho-TIA confirmed the importance of Arg4 for activity and revealed a number of other residues clustered around Arg4 that contribute to the potency of rho-TIA. The unique allosteric antagonism of rho-TIA resulting from its interaction with receptor residues that constitute a binding site that is distinct from that of the classical competitive alpha1-adrenoreceptor antagonists may allow the development of inhibitors that are highly subtype selective.     

The interaction of light irradiance with ethylene in regulating growth of Helianthus annuus shoot tissues

Shade light found in ecological niches where plants are growing under a canopy or in proximity of taller neighbouring vegetation consist mainly of two separate light signals: low red to far-red ratio and low photosynthetically active radiation (PAR). The effect of the latter on the growth of 7-day old sunflower shoots was examined by assessing hypocotyl, cotyledon and leaf tissue growth under three varying PAR levels: near-normal of 1,000 μmol m^?2 s^?1, low of 100 μmol m^?2 s^?1 and very low of 10 μmol m^?2 s^?1. Then, the possible interaction between PAR signaling and ethylene in regulating growth of these sunflower tissues was investigated. The results showed that gradual decrease in PAR level increases hypocotyl elongation and decreases ethylene evolution. However, gradual decrease in PAR level decreases cotyledon and leaf growth and increases ethylene evolution. Thus it seems possible that PAR regulation of shoot growth is mediated by changes in ethylene evolution in tissue specific manner. This hypothesis was supported by experiments with the ethylene releasing factor, ethephon, and the ethylene biosynthesis inhibitor, AVG, as well as by transfer experiments where sunflower seedlings were transferred from one PAR regime to another with subsequent growth and ethylene measurements.     

N-acetylcysteine amide, a novel cell-permeating thiol, restores cellular glutathione and protects human red blood cells from oxidative stress

Oxidative stress plays an important role in the progression of neurodegenerative and age-related diseases, causing damage to proteins, DNA, and lipids. A novel thiol N-acetylcysteine amide (AD4), the amide form of N-acetylcysteine (NAC) and a Cu(2+) chelator, was assessed for its antioxidant and protective effects using human red blood cells (RBCs) as a model. AD4 was shown by flow cytometry to inhibit tert.-butylhydroxyperoxide (BuOOH)-induced intracellular oxidation in RBCs stained with the oxidant-sensitive probe 2',7'-dichlorofluorescein diacetate. In addition, AD4 retarded BuOOH-induced thiol depletion and hemoglobin oxidation. Restoration of the thiol-depleted RBCs by externally applied AD4 was significantly greater compared with NAC and, unlike NAC, was accompanied by hemoglobin protection from oxidation. In a cell-free system we have demonstrated that AD4 reacted with oxidized glutathione (GSSG) to generate reduced glutathione (GSH). The formation of GSH was determined enzymatically using GSH peroxidase and by HPLC. Based on these results a thiol-disulfide exchange between AD4 and GSSG is proposed as the mechanism underlying the antioxidant effects of AD4 on BuOOH-treated RBCs. Together, these studies demonstrate that AD4 readily crosses cell membranes, replenishes intracellular GSH, and, by incorporating into the redox machinery, defends the cell from oxidation. These results provide further evidence for the efficient membrane permeation of AD4 over NAC, and support the possibility that it could be explored for treatment of neurodegeneration and other oxidation-mediated disorders.     

Disease modifying treatment of spinal cord injury with directly reprogrammed neural precursor cells in non-human primates

BACKGROUNDThe development of regenerative therapy for human spinal cord injury (SCI) is dramatically restricted by two main challenges: the need for a safe source of functionally active and reproducible neural stem cells and the need of adequate animal models for preclinical testing. Direct reprogramming of somatic cells into neuronal and glial precursors might be a promising solution to the first challenge. The use of non-human primates for preclinical studies exploring new treatment paradigms in SCI results in data with more translational relevance to human SCI.AIMTo investigate the safety and efficacy of intraspinal transplantation of directly reprogrammed neural precursor cells (drNPCs).METHODSSeven non-human primates with verified complete thoracic SCI were divided into two groups: drNPC group (n = 4) was subjected to intraspinal transplantation of 5 million drNPCs rostral and caudal to the lesion site 2 wk post injury, and lesion control (n = 3) was injected identically with the equivalent volume of vehicle.RESULTSFollow-up for 12 wk revealed that animals in the drNPC group demonstrated a significant recovery of the paralyzed hindlimb as well as recovery of somatosensory evoked potential and motor evoked potential of injured pathways. Magnetic resonance diffusion tensor imaging data confirmed the intraspinal transplantation of drNPCs did not adversely affect the morphology of the central nervous system or cerebrospinal fluid circulation. Subsequent immunohistochemical analysis showed that drNPCs maintained SOX2 expression characteristic of multipotency in the transplanted spinal cord for at least 12 wk, migrating to areas of axon growth cones.CONCLUSIONOur data demonstrated that drNPC transplantation was safe and contributed to improvement of spinal cord function after acute SCI, based on neurological status assessment and neurophysiological recovery within 12 wk after transplantation. The functional improvement described was not associated with neuronal differentiation of the allogeneic drNPCs. Instead, directed drNPCs migration to the areas of active growth cone formation may provide exosome and paracrine trophic support, thereby further supporting the regeneration processes.     

alpha(1C) (Ca(V)1.2) L-type calcium channel mediates mechanosensitive calcium regulation

Smooth muscle exhibitsmechanosensitivity independent of neural input, suggesting thatmechanosensitive pathways reside within smooth muscle cells. The nativeL-type calcium current recorded from human intestinal smooth muscle ismodulated by stretch. To define mechanosensitive mechanisms involved inthe regulation of smooth muscle calcium entry, we cloned the_1C L-type calcium channel subunit (Ca_V1.2)from human intestinal smooth muscle and expressed the channel in aheterologous system. This channel subunit retained mechanosensitivitywhen expressed alone or coexpressed with a ₂ calciumchannel subunit in HEK-293 or Chinese hamster ovary cells. Theheterologously expressed human cardiac _1C splice formalso demonstrated mechanosensitivity. Inhibition of kinase signalingdid not affect mechanosensitivity of the native channel. Truncation of the _1C COOH terminus, which containsan inhibitory domain and a proline-rich domain thought to mediatemechanosensitive signaling from integrins, did not disruptmechanosensitivity of the expressed channel. These data demonstratemechanical regulation of calcium entry through molecularly identifiedL-type calcium channels in mammalian cells and suggest that themechanosensitivity resides within the pore forming_1C-subunit.