bluuebunny/crossref_metadata_2025_split huggingface dataset:
On the origin of (CD105+) circulating endothelial cells
Authors: Verhoef Cornelis , Gratama Jan , Sleijfer Stefan , Strijbos Michiel 
Published: July 2009

SummaryCells designated by the CellSearch™ assay as circulating endothelial cells (CEC) (CD146+/CD105+/CD45− nuclear cells) are thought to derive from damaged vasculature.As CD105 has been suggested to be expressed by endothelial cells from malignant vasculature particularly, it is currently unknown whether this assay is suitable to determine CECs in non-malignant diseases.Also,more insight is needed whether CECs as detected by this assay predominantly measures CECs or also endothelial progenitor cells (EPCs), which originate from the bone marrow and reflect angiogenesis rather than vascular damage. CEC counts were determined in nine patients treated with isolated limb perfusion with tumour necrosis factor (TNF) a and melphalan, and in 10 healthy donors. Given the severe vascular damage caused by venesection and cannulation of the main vessels, we expected a significant increase in CEC counts in case CEC were of vascular rather than of bone marrow origin.Additionally, this finding, as well as the presence of CD105+ CEC in the blood of healthy controls, would confirm that healthy endothelial cells express CD105. Numbers of CD146+/CD105+/CD45− nuclear CEC increased significantly after venesection and cannulation. After administration of TNF, a large fraction of non-intact, possibly apoptotic CEC appeared. This study shows that the Cell-Search™ assay detects CECs originating from damaged vasculature. Furthermore, CD105 expression is found on CEC from damaged normal vasculature rendering further exploration of the value of CEC determined by this assay worthwhile not only in malignant diseases but also in non malignant disorders characterised by vascular damage.
Two cases of congenital dysfibrinogenemia associated with thrombosis – Fibrinogen Praha III and Fibrinogen Plzeň
Authors: Reicheltová Zuzana , Malý Martin , Suttnar Jiří , Sobotková Alžbòta , Salaj Peter , Hirmerová Jana , Riedel Tomáš , Dyr Jan E. , Kotlín Roman 
Published: July 2009

SummaryCongenital dysfibrinogenemia is a rare disease characterised by inherited abnormality in the fibrinogen molecule, resulting in functional defects. Two patients, a 26-year-old woman and a 61-year-old man, both with history of thrombotic events, had abnormal coagulation test results. DNA sequencing showed the heterozygous γY363N mutation (Fibrinogen Praha III) and the heterozygous Aα N106D mutation (Fibrinogen Plzeň), respectively. Fibrin polymerisation, after addition of either thrombin or reptilase, showed remarkably delayed polymerisation in both cases. Fibrinolysis experiments showed slower tPA initiated lysis of clots. SDS-PAGE did not show any difference between normal and Praha III and Plzeň fibrinogens. Both mutations had a significant effect on platelet aggregation. In the presence of either ADP or TRAP, both mutations caused the decrease of platelet aggregation. SEM revealed abnormal clot morphology, with a large number of free ends and narrower fibres of both fibrin Praha III and Plzeň. Praha III mutation was situated in the polymerisation pocket “a”. The replacement of the bulky aromatic side chain of tyrosine by the polar uncharged small side chain of asparagine may lead to a conformational change, possibly altering the conformation of the polymerisation pocket. The Plzeň mutation is situated in the coiled-coil connector and this replacement of polar uncharged asparagine residue by polar acidic aspartate changes the alpha-helical conformation of the coiled-coil connector;and may destabilise hydrogen bonds in its neighborhood. Although both mutations are situated in different regions of the molecule, both mutations have a very similar effect on fibrinogen functions and both are connected with thromboses.
The VEGF-induced transcriptional response comprises gene clusters at the crossroad of angiogenesis and inflammation
Authors: Schweighofer Bernhard , Testori Julia , Sturtzel Caterina , Sattler Susanne , Mayer Herbert , Wagner Oswald , Bilban Martin , Hofer Erhard 
Published: July 2009

SummaryVEGF-A is the major trigger of vasculogenesis and physiologic angiogenesis. We have investigated to which extent the gene repertoire induced by VEGF-A in endothelial cells is distinct from that of other growth factors and inflammatory cytokines. Genes upregulated in human umbilical vein endothelial cells treated with VEGF, EGF or IL-1 were compared by microarray analysis and clusters characteristic for individual or combinations of inducers were defined. VEGF-A upregulated in comparison to EGF a five-fold larger gene repertoire, which surprisingly overlapped to 60% with the inflammatory repertoire of IL-1. As shown by real-time RT-PCR for selected genes, VEGFinduction was mostly mediated by VEGF receptor-2 and the capacity of VEGF-A to induce genes in common with IL-1 largely depended on activation of the calcineurin/NFAT pathway, since cyclosporin A inhibited this induction. Another angiogenic growth factor, bFGF, did not share a comparable induction of inflammatory genes, but partially induced a small group of genes in common with VEGF-A, which were not regulated by EGF. Thus, the data display that VEGF-A induces a distinct gene repertoire, which, contrasting with other growth factors such as EGF or bFGF, includes an inherent inflammatory component possibly contributing to the cross-regulation of angiogenesis and inflammation as further indicated by the VEGF-mediated induction of leukocyte adhesion. Furthermore, a small group of genes selectively induced by VEGF-A with potential importance for angiogenesis is defined.
Natural history of mesenteric venous thrombosis in patients treated with vitamin K antagonists
Authors: Ageno Walter , Witt Dan , Malato Alessandra , Clark Nathan , Garcia David , McCool Kathleen , Siragusa Sergio , Dyke Shannon , Crowther Mark , Dentali Francesco ,   for the WARPED consortium
Published: July 2009

summaryKnowledge on the natural history of mesenteric vein thrombosis (MVT) and of the efficacy and safety of long-term oral anticoagulant therapy (OAT) in this setting is based on small uncontrolled series of patients with a limited follow-up. It was the aim of the study to assess the natural history of MVT in a cohort of patients treated with OAT. The charts of all MVT patients currently attending or who have attended four anticoagulation clinics were reviewed. Information on risk factors, treatment, recurrence, major bleeding and mortality was collected. Seventyseven patients (mean age 49.2 years; 45 males) were included with a median follow-up of 36 months (range 2–204 months). Forty-six patients were treated with long-term OAT. Seven patients had venous thromboembolism (VTE) recurrence (5 splanchnic vein thromboses and two pulmonary emboli) for an incidence rate of 23.4 events /1,000 year patients. In two patients recurrentVTE occurred during OAT, for an incidence rate of 10.5 events /1,000 year patient. Five patients had VTE recurrence when OAT was suspened for an incidence rate of 45.9 events /1,000 year patient. Two patients (2.6%) had a major bleeding event. 97.3% of patients were alive at one year, and seven patients (9.1%) died during follow up. In conclusion, patients with MTV seem to have a low risk of recurrentVTE while receiving OAT. This risk appears increased after treatment is stopped.
Haplotype M2 in the annexin A5 (ANXA5) gene and the occurrence of obstetric complications
Authors: Tiscia Giovanni , Colaizzo Donatella , Chinni Elena , Pisanelli Daniela , Sciannamè Natale , Favuzzi Giovanni , Margaglione Maurizio , Grandone Elvira 
Published: July 2009

SummaryInherited or acquired thrombophilias have been largely explored as a cause of pregnancy complications. However, pathogenesis of obstetric complications, as fetal loss and pregnancyrelated hypertensive disorders is still partly unexplained. Recently, a common haplotype (M2) within the annexin A5 (ANXA5) gene has been described as a risk factor in recurrent fetal losses (RFL). It has been demonstrated to reduce the promoter activity of the ANXA5 promoter in luciferase reporter assays. Aim of this study was to investigate the prevalence of M2 haplotype in three different settings of women with previous obstetric complications: RFL, intra-uterine fetal death (IUFD) and pregnancy-related hypertension (gestational hypertension [GH] and pre-eclampsia [PE]). One hundred three patients with previous RFL, 54 with IUFD, 158 with hypertensive disease (67 GH, 91 PE) were investigated. As controls,195 women from the same ethnic background with uneventful pregnancies were enrolled. Logistic regression, correcting for age, gravidity and parity showed that the ANXA5 haplotype is significantly and independently associated with the occurrence of RFL (3.1; 95%CI: 1.1–9.5; p=0.047) and pregnancy-related hypertensive disorders (2.1; 95%CI: 1.2–3.5; p=0.008).The M2 haplotype might be a new and relevant risk factor for obstetric complications.
Integrin-dependent translocation of LASP-1 to the cytoskeleton of activated platelets correlates with LASP-1 phosphorylation at tyrosine 171 by Src-kinase
Authors: Traenka Julia , Hauck Christof R , Lewandrowski Urs , Sickmann Albert , Gambaryan Stepan , Thalheimer Petra , Butt Elke 
Published: July 2009

SummaryDuring platelet adhesion, the complex cytoskeletal structure is rearranged resulting in the formation of F-actin-based filopodia and lamellipodia. Stimulatory platelet signalling pathways include binding of integrin αIIbβ3 to fibrinogen followed by activation of protein tyrosine kinases (PTK) and phosphorylation of downstream signalling proteins. In this study, we demonstrate that the scaffolding and F-actin binding protein LASP-1 undergoes tyrosine phosphorylation in thrombin-stimulated human platelets. By means of specific inhibitors we identified Src-kinase as the primary enzyme phosphorylating LASP-1 in intact cells. These data were confirmed in platelet model cells (A5-CHO cells), constitutively expressing integrin αIIbβ3. Fibrinogen-mediated cell stimulation resulted in a similar tyrosine phosphorylation of transiently transfected LASP-1. Site directed mutagenesis identified tyrosine 171 as the Src-kinase phosphorylation site. Immunofluorescence microscopic analysis of these cells revealed a relocation of LASP-1 to focal contacts and the leading edge of the membrane upon fibrinogen activation and tyrosine 171 phosphorylation. This translocation was also seen in adherent platelets. Concomitant with adhesion, LASP-1 translocated from the cytosol along the arms of the pseudopodia into the leading lamellae of the spreading platelets, indicating a crucial role of the protein in platelet cytoskeleton rearrangement.
α1-acid glycoprotein (AGP)-induced platelet shape change involves the Rho/Rho kinase signalling pathway
Authors: Levander Louise , Påhlsson Peter , Grenegård Magnus , Gunnarsson Peter 
Published: July 2009

Summaryα1-acid glycoprotein (AGP) is an acute-phase protein that contributes to inflammation processes.The role of AGP in platelet activation and thrombosis is, however, largely unknown.Therefore, we thoroughly investigated the effects of AGP on human platelets. Platelets were isolated from healthy volunteers and subsequently exposed to AGP. Platelet responses were monitored as change in light transmission, intracellular calcium concentration, light microscopy and protein phosphorylation by Western blot.We found that AGP induced platelet shape change independently of a second release of adenine nucleotides or thromboxane A2, and that effect was abolished by endotheliumderived platelet inhibitors such as nitric oxide (NO) and adenosine. Furthermore,AGP triggered a minor calcium response and a pronounced Rho/Rho-kinase-dependent increase in Thr696 phosphorylation of myosin phosphatase target subunit 1 (MYPT1). Moreover, the Rho/Rho-kinase inhibitor Y-27632 significantly decreased the AGP-induced shape change.The results also showed that the AGP-elicited shape change was antagonised by pretreatment with low doses of collagen and thrombospondin-1.Our results describe a novel mechanism by whichAGP stimulates platelet shape change via activation of the Rho/Rhokinase signalling pathway. Physiological important platelet inhibitors, such as NO, completely counterbalance the effect of AGP. Hence, the present study indicates that AGP directly contributes to platelet activation,which in turn might have an impact in physiological haemostasis and/or pathological thrombosis.
The recruitment of blood coagulation factor X into snake venom gland as a toxin
Authors: Kwong Shiyang , Woods Anthony E. , Mirtschin Peter J. , Ge Ruowen , Kini R. 
Published: July 2009

SummaryTrocarin D is a prothrombin activator from the Tropidechis carinatus venom. It is a functional and structural homologue to mammalian blood coagulation factor Xa.Trocarin D is hypothesised to have evolved from its factor X counterpart (TrFX) through gene duplication and recruitment.The genes of trocarin D and TrFX have significant sequence identities, except for insertions/deletions in their intron 1 and promoter regions. In trocarin D intron 1 region, there are three insertions and two deletions. In trocarin D promoter region, there is a novel 264 bp insertion which has potential cis-elements.This insertion is termed as Venom Recruitment/Switch Element (VERSE) and is hypothesised to account for switching the low-level constitutive expression of factor X in the liver to the high-level inducible expression of trocarin D in the venom gland. To understand the role of VERSE in the trocarin D expression,its cis-elements were characterised by luciferase assays in mammalian cell lines as well as snake venom gland cells. The ability of VERSE to drive luciferase expression is comparable to that of the trocarin D promoter. The predicted cis-elements are important in promoting expression as their mutagenesis resulted in lower luciferase expression.VERSE minimal core promoter and three novel cis-elements (two up-regulatory and one suppressor elements) were identified using deletion/site-directed mutagenesis studies. VERSE is primarily responsible for the increase of trocarin D expression. The insertions/deletions within trocarin D intron 1 need to be characterised for their role in tissue-specific and inducible expression of trocarin D.
Mechanisms of platelet activation: Need for new strategies to protect against platelet-mediated atherothrombosis
Authors: Jennings Lisa 
Published: July 2009

SummaryPlatelets are central mediators of haemostasis at sites of vascular injury, but they also mediate pathologic thrombosis. Activated platelets stimulate thrombus formation in response to rupture of an atherosclerotic plaque or endothelial cell erosion, promoting atherothrombotic disease. They also interact with endothelial cells and leukocytes to promote inflammation, which contributes to atherosclerosis. Multiple pathways contribute to platelet activation, and current oral antiplatelet therapy with aspirin and a P2Y12 adenosine diphosphate (ADP) receptor antagonist target the thromboxane A2 and ADP pathways, respectively. Both can diminish activation by other factors, but the extent of their effects depends upon the agonist, agonist strength, and platelet reactivity status. Although these agents have demonstrated significant clinical benefit, residual morbidity and mortality remain high. Neither agent is effective in inhibiting thrombin, the most potent platelet activator. This lack of comprehensive inhibition of platelet function allows continued thrombus formation and exposes patients to risk for recurrent thrombotic events. Moreover, bleeding risk is a substantial limitation of antiplatelet therapy, because these agents target platelet activation pathways critical for both protective haemostasis and pathologic thrombosis. Novel antiplatelet therapies that provide more complete inhibition of platelet activation without increasing bleeding risk could considerably decrease residual risk for ischemic events. Inhibition of the protease-activated receptor (PAR)-1 platelet activation pathway stimulated by thrombin is a novel, emerging approach to achieve more comprehensive inhibition of platelet activation when used in combination with current oral antiplatelet agents. PAR-1 inhibition is not expected to increase bleeding risk, as this pathway does not interfere with haemostasis.
Risk stratification of patients with pulmonary embolism based on pulse rate and D-dimer concentration
Authors: van Bladel Esther R. , Schutgens Roger E. G. , Snijder Repke J. , Tromp Ellen A. M. , Prins Martin H. , Biesma Douwe H. , Agterof Mariette J. 
Published: July 2009

SummaryTo enable outpatient treatment of a selected group of patients with pulmonary embolism (PE), insight in the determinants of adverse clinical outcome is warranted. We have identified risk factors for serious adverse events (SAE) within the first 10 days of acute PE. We have retrospectively analysed data of 440 consecutive patients with acute PE. Collected data included age, gender, medical history, blood pressure, pulse rate and D-dimer concentration. The variables associated with SAE in the first 10 days in univariate analysis (p<0.15) have been included in a multivariate logistic regression model (backward conditional, p out>0.10). In 440 patients with acute PE, 20 SAEs occurred in a 10-day follow-up period. Pulse rate ≥100 beats per minute (bpm) (OR, 6.85; 95%CI 1.43–32.81) and D-dimer concentration ≥3,000 µg/ml (OR, 5.51; 95%CI 0.68–44.64) were significantly related to the SAEs. All SAEs were predicted by a pulse rate ≥100 bpm and/or a D-dimer concentration ≥3,000 µg/ml. Older age, gender, history of venous thromboembolism (VTE), heart failure, chronic obstructive pulmonary disease, cancer or a systolic blood pressure < 90 mm Hg had no significant influence on short term SAEs. Pulse rate and D-dimer concentration can be used to identify patients with acute PE, who are at risk for adverse clinical outcome during the first 10 days of hospitalisation. Outpatient treatment of PE-patients with a pulse rate ≥100 bpm and/or a D-dimer concentration ≥3,000 µg/ml has to be discouraged.
How much is too much? Interleukin-6 and its signalling in atherosclerosis
Authors: Schuett Harald , Luchtefeld Maren , Grothusen Christina , Grote Karsten , Schieffer Bernhard 
Published: July 2009

SummaryThe importance of inflammation as a driver of pathology is no longer confined to autoimmune and infectious diseases. In line with convincing experimental data as well as abundant clinical findings the current view of atherosclerosis points to inflammation as a critical regulator of atherosclerotic plaque formation and progression leading to the fatal clinical endpoints myocardial infarction, stroke or sudden cardiac death. The underlying mechanisms have been a matter of intense research during the last decades. In this regard, the interleukin-6 (IL-6) cytokines and their signalling events have been shown to contribute to both, atherosclerotic plaque development and plaque destabilisation via a variety of mechanisms. These involve the release of other pro-inflammatory cytokines, oxidation of lipoproteins by phospholipases, stimulation of acute phase protein secretion, the release of prothrombotic mediators, and the activation of matrix metalloproteinases. Moreover, the formation of reactive oxygen species generated by vascular enzyme systems may play a critical role in the regulation of IL-6 indicating a cross talk between vasoactive substances i.e. angiotensin II or adrenalin and pro-inflammatory cytokines such as IL-6. In this review we will summarise and discuss the underlying molecular and cellular mechanisms how IL-6 as an early and central regulator of inflammation contributes to atherosclerosis and how this knowledge can be integrated into the clinical context.
Homing and invasiveness of MLL/ENL leukemic cells is regulated by MEF2C
Authors: Schwieger Maike , Schüler Andrea , Forster Martin , Engelmann Afra , Arnold Michael A. , Delwel Ruud , Valk Peter J. , Löhler Jürgen , Slany Robert K. , Olson Eric N. , Stocking Carol 
Published: July 2009

Abstract
Acute myelogenous leukemia is driven by leukemic stem cells (LSCs) generated by mutations that confer (or maintain) self-renewal potential coupled to an aberrant differentiation program. Using retroviral mutagenesis, we identified genes that generate LSCs in collaboration with genetic disruption of the gene encoding interferon response factor 8 (Irf8), which induces a myeloproliferation in vivo. Among the targeted genes, we identified Mef2c, encoding a MCM1-agamous-deficiens-serum response factor transcription factor, and confirmed that overexpression induced a myelomonocytic leukemia in cooperation with Irf8 deficiency. Strikingly, several of the genes identified in our screen have been reported to be up-regulated in the mixed-lineage leukemia (MLL) subtype. High MEF2C expression levels were confirmed in acute myelogenous leukemia patient samples with MLL gene disruptions, prompting an investigation of the causal interplay. Using a conditional mouse strain, we demonstrated that Mef2c deficiency does not impair the establishment or maintenance of LSCs generated in vitro by MLL/ENL fusion proteins; however, its loss led to compromised homing and invasiveness of the tumor cells. Mef2c-dependent targets included several genes encoding matrix metalloproteinases and chemokine ligands and receptors, providing a mechanistic link to increased homing and motility. Thus, MEF2C up-regulation may be responsible for the aggressive nature of this leukemia subtype.
Coordinated patterns of gene expressions for adult muscle build-up in transgenic mice expressing myostatin propeptide
Authors: Zhao Baoping , Li Eileena J , Wall Robert J , Yang Jinzeng 
Published: July 2009

Abstract

Background
Skeletal muscle growth and maintenance are essential for human health. One of the muscle regulatory genes, namely myostatin, a member of transforming growth factor-β, plays a dominant role in the genetic control of muscle mass. Myostatin is synthesized as a precursor protein, which generates the N-terminal propeptide and the C-terminal mature myostatin peptide by a post-translational cleavage event. Previously, transgenic over-expression of myostatin propeptide in skeletal muscle results in significant muscle growth in early stages of development. The objectives of present study were to further characterize muscle growth in later stages of life and to identify genes and their expression patterns that are responsible for adult muscle build-up by myostatin propeptide.

Results
Immunohistochemical staining with an antibody to the N-terminus indicates a high level of myostatin propeptide present in the muscles of transgenic mice while there were no apparent differences in myostatin protein distribution in the muscle fibers between the transgenic and wild-type mice. Main individual muscles increased by 76–152% in the transgenic mice over their wild-type littermate mice at 12 months of age. A large number of nuclei were localized in the central and basal lamina of the myofibers in the transgenic mice as the number of nuclei per fiber and 100 μm2 area was significantly higher in transgenic mice than wild-type mice. By systemic comparisons of global mRNA expression patterns between transgenic mice and wild-type littermates using microarray and qRT-PCR techniques, we have identified distinct gene expression patterns to support adult muscle build-up by myostatin propeptide, which are comprised of enhanced expressions of myogenic regulatory factors and extracelullar matrix components, and differentially down-regulated expressions of genes related to protein degradation and mitochondrial ATP synthesis.

Conclusion
The results present a coordinated pattern of gene expressions for reduced energy utilization during muscle build-up in adult stage. Enhanced muscle buildup by myostatin propeptide is sustained by reduced ATP synthesis as a result of a decreased activity of protein degradation. Myostatin propeptide may have a therapeutic application to the treatment of clinical muscle wasting problems by depressing myostatin activity.