677 research outputs found
Endothelial cell processing and alternatively spliced transcripts of factor VIII: potential implications for coagulation cascades and pulmonary hypertension.
BACKGROUND: Coagulation factor VIII (FVIII) deficiency leads to haemophilia A. Conversely, elevated plasma levels are a strong predictor of recurrent venous thromboemboli and pulmonary hypertension phenotypes in which in situ thromboses are implicated. Extrahepatic sources of plasma FVIII are implicated, but have remained elusive. METHODOLOGY/PRINCIPAL FINDINGS: Immunohistochemistry of normal human lung tissue, and confocal microscopy, flow cytometry, and ELISA quantification of conditioned media from normal primary endothelial cells were used to examine endothelial expression of FVIII and coexpression with von Willebrand Factor (vWF), which protects secreted FVIII heavy chain from rapid proteloysis. FVIII transcripts predicted from database mining were identified by RT-PCR and sequencing. FVIII mAb-reactive material was demonstrated in CD31+ endothelial cells in normal human lung tissue, and in primary pulmonary artery, pulmonary microvascular, and dermal microvascular endothelial cells. In pulmonary endothelial cells, this protein occasionally colocalized with vWF, centered on Weibel Palade bodies. Pulmonary artery and pulmonary microvascular endothelial cells secreted low levels of FVIII and vWF to conditioned media, and demonstrated cell surface expression of FVIII and vWF Ab-reacting proteins compared to an isotype control. Four endothelial splice isoforms were identified. Two utilize transcription start sites in alternate 5 exons within the int22h-1 repeat responsible for intron 22 inversions in 40% of severe haemophiliacs. A reciprocal relationship between the presence of short isoforms and full-length FVIII transcript suggested potential splice-switching mechanisms. CONCLUSIONS/SIGNIFICANCE: The pulmonary endothelium is confirmed as a site of FVIII secretion, with evidence of synthesis, cell surface expression, and coexpression with vWF. There is complex alternate transcription initiation from the FVIII gene. These findings provide a framework for future research on the regulation and perturbation of FVIII synthesis, and of potential relevance to haemophilia, thromboses, and pulmonary hypertensive states
Deconstructed cat communities: quantifying the threat to felids from prey defaunation
Aim: Defaunation, the emptying of ecosystems of fauna, has been highlighted as a likely threat to the conservation of carnivores, but the magnitude of this threat has yet to be quantified. We quantify the potential threat defaunation presents to wild felids.
Location: Global
Methods: For the 32 wild felids that feed primarily on mammals, we used 5,330 prey records from 237 published sources to compile a new diet dataset, FelidDIET. This dataset was used to determine the relative importance of mammalian species as prey for each felid. These data were used to quantify the relationship between felid and prey species-richness, and to estimate the potential threat to wild felids from the loss of their prey.
Results: Our analyses reveal that models that include adjusted prey species-richness as a predictor of felid-richness outperform those with less precise measures of prey-richness (potential prey-richness and total mammal-richness). This is true both when examined collectively and when split into those felids that prey upon large-bodied prey and those that prey upon small-bodied prey. For seven felid species, including six large felids (over 15 kg), 33% or more of their primary prey-species are threatened. Of most concern is the Sunda clouded leopard Neofelis diardi, for which 66.0% of its primary prey-species are threatened. In total, 57.6% of large felids’ primary prey-species are threatened or declining, compared with 26.5% for small felids. Large felids are particularly vulnerable to primary prey decline in Indo-Malaya and East and Central Africa.
Main conclusions: Our findings indicate that imminent prey loss is likely to have substantial negative effects on large felids, many of which are already highly threatened. Considering the trophic cascades associated with large predators, the threat to large felids through the loss of prey diversity presents an ecosystem-scale threat
Nomograms of Iranian fetal middle cerebral artery Doppler waveforms and uniformity of their pattern with other populations' nomograms
<p>Abstract</p> <p>Background</p> <p>Doppler flow velocity waveform analysis of fetal vessels is one of the main methods for evaluating fetus health before labor. Doppler waves of middle cerebral artery (MCA) can predict most of the at risk fetuses in high risk pregnancies. In this study, we tried to obtain normal values and their nomograms during pregnancy for Doppler flow velocity indices of MCA in 20 – 40 weeks of normal pregnancies in Iranian population and compare their pattern with other countries' nomograms.</p> <p>Methods</p> <p>During present descriptive cross-sectional study, 1037 normal pregnant women with 20<sup>th</sup>–40<sup>th </sup>week gestational age were underwent MCA Doppler study. All cases were studied by gray scale ultrasonography initially and Doppler of MCA afterward. Resistive Index (RI), Pulsative Index (PI), Systolic/Diastolic ratio (S/D ratio), and Peak Systolic Velocity (PSV) values of MCA were determined for all of the subjects.</p> <p>Results</p> <p>Results of present study showed that RI, PI, S/D ratio values of MCA decreased with parabolic pattern and PSV value increased with simple pattern, as gestational age progressed. These changes were statistically significant (P = 0.000 for all of indices) and more characteristic during late weeks of pregnancy.</p> <p>Conclusion</p> <p>Values of RI, PI and S/D ratio indices reduced toward the end of pregnancy, but PSV increased. Despite the trivial difference, nomograms of various Doppler indices in present study have similar pattern with other studies.</p
A systematic approach to performing a comprehensive transesophageal echocardiogram. A call to order
<p>Abstract</p> <p>Background</p> <p>While the order for a clinical transthoracic examination is fairly standardized, there is considerable variability between laboratories and even among physicians in the same laboratory with regard to the order for transesophageal echocardiograms (TEE). A systematic approach is desirable for more efficient use of physician and patient time, avoidance of inadvertent omission of important views, and to facilitate study review.</p> <p>Methods</p> <p>We propose a standardized approach to TEE data acquisition in which cardiac structures are systematically identified and characterized at sequential positions and imaging planes to facilitate organized, efficient and comprehensive assessment.</p> <p>Results</p> <p>Our approach to TEE study begins in the mid-esophagus with the imaging plane at 0°. Based on the specific indication for the TEE, a cardiac structure (e.g., mitral valve, left atrial appendage, or interatrial septum) is chosen as the primary focal point for a comprehensive, multiplane analysis. This structure is assessed in 20° – 30° increments as the imaging plane is advanced from 0° to 165°. Using the aortic valve as a reference point, pertinent cardiac structures are then assessed as the imaging plane is reduced to 135°, to 90°, to 40 – 60° and then back to 0°. The probe is then advanced into the stomach to obtain transgastric images at 0°, 90°, and 120°. Finally, the thoracic aorta and pulmonary artery are assessed as the probe is withdrawn from the body. Using this method, an organized and comprehensive TEE can be performed in 10 – 15 minutes.</p> <p>Conclusion</p> <p>A standardized and systematic TEE approach is described for efficient and comprehensive TEE study.</p
Are mice good models for human neuromuscular disease? Comparing muscle excursions in walking between mice and humans
The mouse is one of the most widely used animal models to study neuromuscular diseases and test new therapeutic strategies. However, findings from successful pre-clinical studies using mouse models frequently fail to translate to humans due to various factors. Differences in muscle function between the two species could be crucial but often have been overlooked. The purpose of this study was to evaluate and compare muscle excursions in walking between mice and humans
[Epilogue] “Publica si domini regerent moderamina cunni”: deciphering queenship and counsel
This conclusion picks up on a theme running through the volume—that of the secretive or encoded nature of counsel in the context of queenship—and explores how this plays out in the visual and illustrative counsel of Early Modern Europe. Examining emblems, woodcuts and especially the frontispiece of John Dee’s Generall and Rare Memorials pertayning to the Perfect Arte of Navigation (1577), Joanne Paul demonstrates how symbols and visual references were used to encode counsel about and for queens. She argues that investigating the relationship between queenship and counsel in this period challenges existing understandings of what constitutes “the political”, by expanding the focus to symbol, performance, rhetoric, wardrobe, architecture and other media for counsel about politics
Optimum positioning for AP pelvis radiography : a literature review
Aim
Pelvic radiography is used for the identification of hip joint changes, including pathologies such as osteoarthritis. Several studies have recommended that the position for this radiological procedure should be standing, not supine, to reflect the functional appearances of the hip joint. The aim of this review was to evaluate pelvis radiography positioning with respect to the image appearances and information provided for clinical decision-making. Aside from this, potential recommendations to the radiographic technique for an erect pelvis projection will be considered.
Method
A literature search was performed using databases/abstract systems (ScienceDirect, Web of Science, PubMed, and MEDLINE). Only articles written in English were included.
Results
Twenty-five articles were identified. Findings from the review describe the effect of repositioning from supine to erect on a series of specific hip measurements. These include pelvic tilt, joint space width, and the acetabular component.
Conclusion
Evidence within the literature illustrates that in several studies, there were differences when repositioning from supine to standing for a number of pelvic metrics. Standing positioning is promoted by some authors since this may facilitate the early diagnosis of hip joint pathology and assist in the planning of surgical interventions. Literature is very limited on how to optimally perform erect pelvis radiography, and this should be an area for future research
The kinome of Phytophthora infestans reveals oomycete-specific innovations and links to other taxonomic groups
<p>Abstract</p> <p>Background</p> <p>Oomycetes are a large group of economically and ecologically important species. Its most notorious member is <it>Phytophthora infestans</it>, the cause of the devastating potato late blight disease. The life cycle of <it>P. infestans </it>involves hyphae which differentiate into spores used for dispersal and host infection. Protein phosphorylation likely plays crucial roles in these stages, and to help understand this we present here a genome-wide analysis of the protein kinases of <it>P. infestans </it>and several relatives. The study also provides new insight into kinase evolution since oomycetes are taxonomically distant from organisms with well-characterized kinomes.</p> <p>Results</p> <p>Bioinformatic searches of the genomes of <it>P. infestans</it>, <it>P. ramorum</it>, and <it>P. sojae </it>reveal they have similar kinomes, which for <it>P. infestans </it>contains 354 eukaryotic protein kinases (ePKs) and 18 atypical kinases (aPKs), equaling 2% of total genes. After refining gene models, most were classifiable into families seen in other eukaryotes. Some ePK families are nevertheless unusual, especially the tyrosine kinase-like (TKL) group which includes large oomycete-specific subfamilies. Also identified were two tyrosine kinases, which are rare in non-metazoans. Several ePKs bear accessory domains not identified previously on kinases, such as cyclin-dependent kinases with integral cyclin domains. Most ePKs lack accessory domains, implying that many are regulated transcriptionally. This was confirmed by mRNA expression-profiling studies that showed that two-thirds vary significantly between hyphae, sporangia, and zoospores. Comparisons to neighboring taxa (apicomplexans, ciliates, diatoms) revealed both clade-specific and conserved features, and multiple connections to plant kinases were observed. The kinome of <it>Hyaloperonospora arabidopsidis</it>, an oomycete with a simpler life cycle than <it>P. infestans</it>, was found to be one-third smaller. Some differences may be attributable to gene clustering, which facilitates subfamily expansion (or loss) through unequal crossing-over.</p> <p>Conclusion</p> <p>The large sizes of the <it>Phytophthora </it>kinomes imply that phosphorylation plays major roles in their life cycles. Their kinomes also include many novel ePKs, some specific to oomycetes or shared with neighboring groups. Little experimentation to date has addressed the biological functions of oomycete kinases, but this should be stimulated by the structural, evolutionary, and expression data presented here. This may lead to targets for disease control.</p
Towards Heat-stable Oxytocin Formulations: Analysis of Degradation Kinetics and Identification of Degradation Products
Purpose. To investigate degradation kinetics of oxytocin as a function of temperature and pH, and identify the degradation products. Materials and Methods. Accelerated degradation of oxytocin formulated at pH 2.0, 4.5, 7.0 and 9.0 was performed at 40, 55, 70 and 80°C. Degradation rate constants were determined from RP-HPLC data. Formulations were characterized by HP-SEC, UV absorption and fluorescence spectroscopy. Degradation products were identified by ESI-MS/MS. Results. The loss of intact oxytocin in RP-HPLC was pH- and temperature-dependent and followed (pseudo) first order kinetics. Degradation was fastest at pH 9.0, followed by pH 7.0, pH 2.0 and pH 4.5. The Arrhenius equation proved suitable to describe the kinetics, with the highest activation energy (116.3 kJ/mol) being found for pH 4.5 formulations. At pH 2.0 deamidation of Gln 4, Asn 5, and Gly 9-NH2, as well as combinations thereof were found. At pH 4.5, 7.0 and 9.0, the formation of tri- and tetrasulfidecontaining oxytocin as well as different types of disulfide and dityrosine-linked dimers were found to occur. Beta-elimination and larger aggregates were also observed. At pH 9.0, mono-deamidation of Gln 4, Asn 5, and Gly 9-NH2 additionally occurred. Conclusions. Multiple degradation products of oxytocin have been identified unequivocally, including various deamidated species, intramolecular oligosulfides and covalent aggregates. The strongly pH dependent degradation can be described by the Arrhenius equation. KEY WORDS: aggregation; Arrhenius kinetics; degradation; mass spectrometry; oxytocin
- …