bluuebunny/crossref_metadata_2025 huggingface dataset:
The expected variation of random bounded integer sequences of finite length
Authors: Angeles Rudolfo , Rawlings Don , Sze Lawrence , Tiefenbruck Mark
Published: September 2005

From the enumerative generating function of an abstract adjacency
statistic, we deduce the mean and variance of the variation on
random permutations, rearrangements, compositions, and bounded
integer sequences of finite length.
On weak convergence of iterates in quantum Lp‐spaces(p ≥ 1)
Authors: Grabarnik Genady Ya. , Katz Alexander A. , Shwartz Laura
Published: September 2005

Equivalent conditions are obtained for weak convergence of
iterates of positive contractions in the L1‐spaces for
general von Neumann algebra and general JBW algebras, as well as
for Segal‐Dixmier Lp‐spaces (1 ≤ p < ∞) affiliated
to semifinite von Neumann algebras and semifinite JBW algebras
without direct summands of type I2.
Some interesting series arising from the power seriesexpansion of (sin-1x) q
Authors: Muzaffar Habib
Published: September 2005

Starting from the power series expansions of ,
for 1 ≤ p ≤ 4, formulae are obtained for the sum of several
infinite series. Some of these evaluations involve ζ(3).
Predictors of an Appropriate Admission to an ICU after a Major Pulmonary Resection
Authors: Pieretti Paola , Alifano Marco , Roche Nicolas , Vincenzi Matteo , Forti Parri Sergio N. , Zackova Monica , Boaron Maurizio , Zanello Marco
Published: September 2005

Background: There are no recommendations about admission to an ICU after a major lung resection and there are considerable differences among institutions in this respect. Objectives: To audit the practice of admission to an ICU after a major lung resection and evaluate factors predicting the need for intensive care. Methods: Clinicalrecords of all patients who underwent major pulmonary resections in a 14-month period were reviewed retrospectively. The criteria for postoperative admission to the ICU were: (1) standard pneumonectomy if comorbidity index (CI) >0 and/or ASA score >1, and/or abnormal spirometry or arterial gas analysis; (2) extended pneumonectomy; (3) lobectomy if CI ≧4 and/or ASA ≧3; (4) lobectomy if FEV1 <60% of predicted; (5) lobectomy if FEV1 is between 60 and 80% and hypercapnia. Results: Among the 49 patients postoperatively admitted to the surgical ward, only 1 needed late intensive care. Among the 55 patients admitted to the ICU, 25 did not require specific intensive care and were discharged 24 h postoperatively, whereas the remaining 30 patients required specific intensive care. Multivariate analysis identified ASA score, predictive postoperative DLCO, and predictive postoperative product (PPP) as independent predictors of a need for admission to an ICU. Conclusion: This empirical protocol was useful in identifying patients not likely to need admission to the ICU. ASA score, predictive postoperative DLCO, and PPP are independent predictors of a need for admission to an ICU.
Prevention of fatal pulmonary embolism and mortality in surgical patients
Authors: Wolf Helmut , Kakkar Ajay K. , Fareed Jawed , Encke Albrecht , Haas Sylvia
Published: September 2005

The incidences of fatal pulmonary embolism and death in surgical patients receiving low-molecular-weight heparin thromboprophylaxis have not been previously determined in large, adequately designed clinical trials and information on the relative efficacy and safety of unfractionated and low-molecular-weight heparin in preventing these clinical endpoints is not available. In a double-blind study, 23078 surgical patients randomly received the low-molecular-weight heparin, certoparin (3000 anti Xa IU) subcutaneously once-daily, or unfractionated heparin (5000 IU) subcutaneously three-times daily, for a minimum of 5 days. The primary outcome measure, autopsy-proven fatal pulmonary embolism recorded up to 14 days after the end of prophylaxis, occurred in 0.152% (95% confidence interval (CI) 0.10, 0.20%; 35of 23078 patients) of cases, with no significant difference between the certoparin-treated patients (0.147% (95% CI 0.077, 0.217%; 17 of 11542 patients) and patients treated with unfractionated heparin (0.156% (95% CI 0.084, 0.228%; 18 of 11,536 patients, P=0.868). The autopsy rate was 70.2%. Comparing mortality, there was no significant difference between the groups (1.44% [166 of 11542 certoparin patients] versus 1.27% [146 of 11536 unfractionated heparin patients]; P=0.279). The safety profiles of both treatment groups were similar. Once-daily certoparin and three-times daily unfractionated heparin are equally effective and safe in reducing fatal pulmonary embolism and death to low levels in surgical patients and mirror the findings of comparative efficacy studies using surrogate endpoints.
Evaluation of perioperative fatal pulmonary embolism and death in cancer surgical patients
Authors: Haas Sylvia , Wolf Helmut , Encke Albrecht , Kakkar Ajay K.
Published: September 2005

Cancer patients undergoing surgery are at a high risk of venous thromboembolism, but few studies have described the rate of autopsy-confirmed fatal pulmonary embolism after heparin thromboprophylaxis. In a post hoc analysis of a randomized study (MC-4), which compared the efficacy and safety of certoparin (3000 anti-Xa IU, subcutaneously, once-daily) with unfractionated heparin (5000 IU, subcutaneously, three-times daily) in 23078 patients undergoing surgery lasting more than 30 min, the incidence of autopsy-confirmed fatal pulmonary embolism, death and bleeding in the cancer patients (n=6124) was compared with non-cancer patients (n=16954). Fatal pulmonary embolism was significantly more frequent in cancer patients (0.33% [20/6124]) than in non-cancer patients (0.09% [15/16954], relative risk (RR), 3.7 [95% confidence intervals (CI), 1.80, 7.77], p=0.0001) at 14 days post-prophylaxis. Perioperative mortality was also significantly higher in cancer patients than in noncancer patients (3.14% [192/6124] vs. 0.71% [120/16954], RR, 4.54 [95% CI, 3.59, 5.76], p=0.0001), as were blood loss (p<0.0001), and transfusion requirements (p<0.0001). Prevention of venous thromboembolism in cancer surgical patients remains a clinical challenge.
High dose dexamethasone increases circulating P-selectin and von Willebrand factor levels in healthy men
Authors: Cvitko Tuende , Winter-Fabry Astrid , Petroczi Karin , Quehenberger Peter , Blann Andrew D. , Jilma Bernd
Published: September 2005

Although glucocorticoids are widely used in a number of inflammatory disorders associated with endothelial and platelet activation, their effect on the endothelium and platelets in humans remain poorly defined. Hence, we measured changes of a specific endothelial cell marker (von Willebrand factor [vWF]) and of a platelet marker (soluble P-selectin) by infusing therapeutic doses of dexamethasone (0.04 mg/kg and 1.0 mg/kg b.i.d on two days) or placebo into nine healthy men. Venous citrated plasma was obtained before infusion, and at 24 and 48 h. Compared to baseline levels, we found increased levels of vWF at both time points at the higher dose (p=0.011). Plasma levels of sP-selectin rose at 48 h after the high dose (p=0.017). Human umbilical endothelial cells were cultured in the presence or absence of de-xamethasone (0, 0.01, 1 μM), to determine the possible mechanism for the increase in vWF. The vWF-mRNA levels as quantified by RT-PCR increased 2-fold (p<0.05), and the vWF-concentrations in cell lysates increased by 38% (p<0.05), whereas the vWF-concentrations in the supernatants were unaffected. In summary, high dose DEXA increases sP-selectin and vWF. The probable underlying mechanism for the latter was a DEXA induced up-regulation of vWF-mRNA transcription. Together, this indicates that high dose glucocorticoids may enhance haemostasis, which could be beneficial under certain conditions, but which may also contribute to adverse vascular events by increasing platelet activation and vWF dependent thrombosis.
Microparticles from apoptotic vascular smooth muscle cells induce endothelial dysfunction, a phenomenon prevented by β3-integrin antagonists
Authors: Essayagh Sanah , Brisset Anne-Cecile , Terrisse Anne-Dominique , Dupouy Dominique , Tellier Lise , Navarro Chantal , Arnal Jean-François , Siè Piérre
Published: September 2005

Fragile atherosclerotic plaques are rich in apoptotic smooth muscle cells (SMCs) and macrophages, generating microparticules (MPs) which accumulate locally and may be released in blood in case of mechanical or spontaneous plaque disruption. Besides being highly procoagulant, this material may interact with downstream endothelium. Using a model of mouse aorta vaso-reactivity, we have investigated the effects of apoptotic MPs preparedin vitro from Fas-ligand sensitive SMCs. Short-term preincubation of aorta rings with the MPs dose-dependently reduced the vasodilatory response to acetylcholine dependent on the endothelium. This effect was prevented by the addition of abxicimab or eptifibatide, indicating a role for a β3 integrin in thisprocess. We further investigated its mechanism using cultured endothelial cells. The MPs were found to bind to the cells and to inhibit the production and the release of nitric oxide (NO) in response to bradykinin. This phenomenom was redox sensitive, independent of the generation of activated coagulation proteases, and was abrogated when the MPs were pretreated by trypsin. The metabolic effects of MPs were prevented by the addition of eptifibatide. Taken together, these results suggest a potential, platelet-independent, mechanism for the improvement of microvascular perfusion observed with β3-integrin antagonists.
Circulating endothelial cells in acute ischaemic stroke
Authors: Nadar Sunil K. , Lip Gregory Y. H. , Lee Kaeng W. , Blann Andrew D.
Published: September 2005

Increased numbers of CD146-bearing circulating endothelial cells (CECs) in the peripheral blood probably represent the most direct evidence of endothelial cell damage. As acute ischaemic strokes are associated with endothelial abnormalities, we hypothesised that these CECs are raised in acute stroke, and that they would correlate with the other indices of endothelial perturbation, i.e. plasma von Willebrand factor (vWf) and soluble E-selectin. We studied 29 hypertensive patients (19 male; mean age 63 years) who presented with an acute stroke and compared them with 30 high risk hypertensive patients (21 male; mean age 62 years) and 30 normotensive controls (16 male; mean age 58 years). CECs were estimated by CD146 immunobead capture, vWf and soluble E-selectin by ELISA. Patients with an acute ischaemic stroke had significantly higher numbers of CECs/ml of blood (p<0.001) plasma vWf (p=0.008) soluble E-selectin (p=0.002) and higher systolic blood pressure (SBP) as compared to the other groups. The number of CECs significantly correlated with soluble E-selectin (r=0.432, p<0.001) and vWf (r=0.349, p=0.001) but not with SBP (r=0.198, p=0.069). However, in multivariate analysis, only disease group (i.e. health, hypertension or stroke) was associated with increased CECs. Acute ischaemic stroke is associated with increased numbers of CECs. The latter correlate well with established plasma markers of endothelial dysfunction or damage, thus unequivocally confirming severe vasculopathy in this condition. However, the greatest influence on CECs numbers was clinical group.
Agonists of toll-like receptor (TLR)2 and TLR4 are unable to modulate platelet activation by adenosine diphosphate and platelet activating factor
Authors: Ward Jon R. , Bingle Lynne , Judge Heather M. , Brown Simon B. , Storey Robert F. , Whyte Moira K. B. , Dower Steven K. , Buttle David J. , Sabroe Ian
Published: September 2005

Inappropriate platelet activation is a feature of acute and chronic diseases such as disseminated intravascular coagulation (DIC) and atherosclerosis. Since proinflammatory microbial-derived agonists can be involved in the pathogenesis of these diseases, we examined the potential role ofTLR4 (mediating responses to LPS) andTLR2 (which responds to bacterial lipopeptides) in platelet activation. Our data suggested low-level expression of TLR2 andTLR4 on platelets, determined by flow cytometry, and we also observed expression of TLR4 on a megakaryocytic cell line by both flow cytometry and immunohistochemistry. Stimulation of the platelets with the TLR4 agonist LPS, and the synthetic TLR2 agonist Pam3CSK4, resulted in no platelet aggregation, no increase in CD62P surface expression and no increase in the cytosolic concentration of Ca2+. The TLR agonists were also unable to directly activate platelets primed with epinephrine, or pretreated with a low concentration ofADP or PAF. Pretreatment of platelets with LPS or Pam3CSK4 also failed to modulate the platelet response to submaximal concentrations of the classical platelet agonists ADP and PAF. We conclude that theTLR agonists LPS and Pam3CSK4 have no direct effect on platelet activation and that platelet TLRs may be a remnant from megakaryocytes. TLR2 and TLR4 agonists are thought to have a significant role in diseases such as atherosclerosis and DIC, but our research suggests that this is through a mechanism other than direct platelet activation or by modification of platelet responses to other agonists.
Indication of a role of plasminogen activator inhibitor type 1 in protecting murine fibrosarcoma cells against apoptosis
Authors: Rømer Maria Unni , Due Anne Kirkebjerg , Larsen Jørgen Knud , Hofland Kenneth Francis , Christensen Ib Jarle , Buhl-Jensen Peter , Almholt Kasper , Nielsen Ole Lerberg , Lademann Ulrik , Brünner Nils
Published: September 2005

In a number of cancer types high tumor tissue levels of plasminogen activator inhibitor type 1 (PAI-1) protein are strongly associated with shorter cancer patient survival. This association has been intriguing since PAI-1 is known to inhibit urokinase plasminogen activator (uPA) that converts plasminogen to plasmin, which is actively involved in tumor progression and invasion. In order to further explore the biological role of PAI-1 in cancer, we have prepared fibroblasts from PAI-1 gene deficient mice and from their wild type littermates. From these fibroblasts fibrosarcoma cell lines were established and characterized. Both types of fibroblasts underwent spontaneous transformation as indicated by aneuploidy, immortalization, clonogenicity in soft agar and tumor formationin vivo. While both PAI-1 deficient and PAI-1 expressing cell lines showed similar proliferation ratesin vitro, cells devoid of PAI-1 were significantly more sensitive to apoptotic stimuli. When inoculated subcutaneously into nude mice PAI-1 expressing cells rapidly established tumors, while PAI-1 deficient cells had a significantly longer lag-phase before they started to grow (p<0.0001). The present study suggests that PAI-1,besides its uPA inhibiting function, has a role in cancer progression by protecting tumor cells from undergoing apoptosis.
Nitric oxide differentially regulates proliferation and mobilization of endothelial progenitor cells but not of hematopoietic stem cells
Authors: Özüyaman Burcin , Ebner Petra , Niesler Ulrike , Ziemann Jutta , Kleinbongard Petra , Jax Thomas , Gödecke Axel , Kelm Malte , Kalka Christoph
Published: September 2005

To investigate the role of nitric oxide in controlling endothelial progenitor (EPC) and hematopoietic stem cell (HSC) mobilization, wild-type mice, L-NAME treated WT and eNOS-/- mice received either PBS or G-CSF for 5 days. Under unstimulated conditions bone marrow of either L-NAME treated WT and eNOS-/- mice, representing acute and chronic NO-deficiency, showed higher CD34+Flk-1+ EPC numbers compared to their WT littermates. Furthermore, CD34+Flk-1+ progenitors under NO-deficient conditions showed a higher cell turn over since the proliferation and apoptosis activity underin vivo as well as in vitro conditions were enhanced. In line with this finding bone marrow derived EPC differentiation towards endothelial cells was modulated in an NO-dependent manner. Administration of G-CSF resulted in an increase of EPC within the bone marrow of WT animals with a consecutive release of these cells into the peripheral circulation. Under NO-deficient conditions G-CSF failed to increase EPC numbers. In contrast, the HSC population c-kit+Lin− was not influenced by nitric oxide. Thus, NO differentially supports the mobilization of the endothelial committed progenitor subpopulation in bone marrow but does not have an effect on HSCin vivo.
Site-directed mutagenesis of coumarin-type anticoagulant-sensitive VKORC1
Authors: Rost Simone , Fregin Andreas , Hünerberg Mirja , Bevans Carville G. , Müller Clemens R. , Oldenburg Johannes
Published: September 2005

Coumarin and homologous compounds are the most widely used anticoagulant drugs worldwide. They function as antagonists of vitamin K, an essential cofactor for the posttranslational γ-glutamyl carboxylation of the so-called vitamin K-dependent proteins. As vitamin K hydroquinone is converted to vitamin K epoxide (VKO) in every carboxylation step, the epoxide has to be recycled to the reduced form by the vitamin K epoxide reductase complex (VKOR). Recently, a single coumarin-sensitive protein of the putativeVKOR enzyme complex was identified in humans (vitamin K epoxide reductase complex subunit 1, VKORC1). Mutations inVKORC1 result in two different phenotypes: warfarin resistance (WR) and multiple coagulation factor deficiency type 2 (VKCFD2). Here, we report on the expression of site-directed VKORC1 mutants, addressing possible structural and functional roles of all seven cysteine residues (Cys16, Cys43, Cys51, Cys85, Cys96, Cys132, Cys135), the highly conserved residue Ser/Thr57, and Arg98, known to cause VKCFD2 in humans. Our results support the hypothesis that the C132-X-X-C135 motif inVKORC1 comprises part of the redox active site that catalyzes VKO reduction and also suggest a crucial role for the hydrophobicThr-Tyr-Ala motif in coumarin binding. Furthermore, our results support the concept that different structural components of VKORC1 define the binding sites for vitamin K epoxide and coumarin.
Circulating endothelial cells in atrial fibrillation with and without acute cardiovascular disease
Authors: Freestone Bethan , Chong Aun Yeong , Nadar Sunil , Lee Kaeng W. , Blann Andrew D. , Lip Gregory Y. H.
Published: September 2005

Normal adults have very few circulating endothelial cells (CECs) in their blood, but increased levels have been shown in association with conditions associated with endothelial damage such as myocardial infarction and stroke. As atrial fibrillation (AF) is associated with a hypercoagulable state and abnormalities of plasma indices of endothelial damage/dysfunction, we hypothesised that CECs would also be raised in this condition, and would correlate with these plasma markers. We measured CECs (by immunofluoresence) as an indicator of frank endothelial damage, alongside 3 plasma indices of endothelial perturbation: von Willebrand factor (vWf), soluble E-selectin and soluble thrombomodulin (sTM) (all ELISA) in 28 patients with chronic ‘stable’ AF, 63 patients with AF plus an acute cardiovascular or cerebrovascular event as positive controls, and 20 healthy subjects in sinus rhythm as negative controls. Chronic ‘stable’AF patients had significantly higher levels of plasma vWf (p<0.001),but comparable numbers of CECs (p=0.1638) in comparison to healthy controls. In patients with AF associated with an acute cardiovascular or cerebrovascular event, levels of CECs (p<0.0001) and sTM (p=0.004), but not vWf or sEsel, were significantly increased in comparison to chronic‘stable’AF patients. Patients with uncomplicated AF have abnormal systemic endothelial damage/dysfunction, as evident by increased plasma vWf levels, but normal numbers of CECs, compared to subjects in sinus rhythm. However, following clinical complications, such as stroke or significant haemodynamic compromise, further endothelial disturbance (as indicated by high levels of sTM and CECs) suggests additional endothelial damage.
D-dimer levels in combination with residual venous obstruction and the risk of recurrence after anticoagulation withdrawal for a first idiopathic deep vein thrombosis
Authors: Legnani Cristina , Cini Michela , Guazzaloca Giuliana , Palareti Gualtiero , Cosmi Benilde
Published: September 2005

We assessed the predictive value of D-dimer levels in combination with residual venous obstruction (RVO) for recurrent venous thromboembolism (VTE) in a prospective cohort of outpatients after oral anticoagulant therapy (OAT) suspension for a first episode of idiopathic proximal deep vein thrombosis of the lower limbs during a 2-year follow-up. Patients (n=400) were enrolled on the day of OAT suspension when RVO was determined by compression ultrasonography (present in 48.6% of patients). D-dimer (cut-off value: 500 ng/mL) was measured 30±10 days afterwards (abnormal in 56.4% of patients). The overall recurrence rate was 16.7% (67/400; 95% confidence intervals - CI -:13–21%). The multivariate hazard ratio (HR) for recurrence was 3.32 (95% CI:1.78–6.75; p > 0.0001) for abnormal D-dimer compared to normal D-dimer and 1.2 (95% CI:0.72–2.07; p>0.05) for RVO compared to absent RVO. The recurrence rate was 5.7% (95% CI:2–13%) and 10.4% (95% CI:6–18%), respectively, for normal D-dimer either without or with RVO, 22.9% (95% CI:14–33%) and 25.9% (95% CI: 18–35%), respectively, for abnormal D-dimer, either without or with RVO. When compared with normal D-dimer without RVO, the multivariate HR for recurrence was similar for abnormal D-dimer either with RVO (4.76 – 95% CI:1.78–12.8) or without RVO (4.3–95%:1.56–11.88). Abnormal D-dimer at one month after OAT withdrawal is an independent risk factor for recurrent VTE, while RVO at the time of OAT withdrawal, either with normal or abnormal D-dimer after one month, does not influence the risk of recurrence.
Anti-factor VIII antibodies
Authors: Lavigne-Lissalde Géraldine , Schved Jean-François , Granier Claude , Villard Sylvie
Published: September 2005

The development of anti-factorVIII (FVIII) antibodies is currently one of the most serious complications in the treatment of haemophilia A patients. Numerous studies in literature report on their epitope specificity, their mechanism of FVIII inactivation, and their relationship with FVIII genetic alterations. During the last two years, however, a particular effort has been made to better understand their generation, with particular emphasis on the interplay of T cells and B cells specific for FVIII and the generation of anti-FVIII antibodies. Moreover, novel strategies to improve the management or treatment of patients with anti- FVIII antibodies have been recently proposed: the use of less immunogenic engineered recombinant FVIII molecules, neutralization of inhibitors by blocking their deleterious activity either by low molecular weight peptide decoys or by anti-idiotypic antibodies, and attempts to suppress the T-cell response involved in the antibody formation. All of these represent promising therapeutic approaches. This review attempts to sum up current knowledge of the nature and properties of anti-FVIII antibodies, their mechanism of action, their neutralization by anti-idiotypic antibodies, and the role of T cells in FVIII inhibitor formation. In the final part, some of the new strategies susceptible to improve the management or the eradication of anti-FVIII antibodies are presented.
Detection of known haemophilia B mutations and carrier testing by microarray
Authors: Chan Kaimin , Sasanakul W. , Mellars Gillian , Chuansumrit Ampaiwan , Perry D , Lee Christine A , Wong Man-Sim , Chan Tai-Kwong , Chan Vivian
Published: September 2005

The molecular basis of haemophilia B is heterogeneous and many mutations of the Factor IX (FIX) gene have been characterised. Using the allele-specific arrayed primer extension (ASAPEX) technology, we have designed a FIX array to simultaneously analyse 69 mutations found in British, Thai and Chinese patients. This technology overcomes the problem of multiple reverse dot-blot analysis and has a 100% accuracy in the detection of both affected subjects and carriers in families with known mutations. In seven unknown mutations from Thailand, the array could detect the specific mutation in five and in the remainders the normal primer at specific spots failed to extend due to a mutation a few nucleotides upstream, thus allowing their identification. Hence this FIX array can detect 53% of the 2891 mutation entries in the FIX database. Each of the microarray slide can be used for three different test samples and would be useful for carrier testing for common mutations and prenatal diagnosis. It is simpler and more cost effective than genome sequencing and would be particularly useful in laboratories with limited technical capabilities.
Exercise paradoxically modulates oxidized low density lipoproteininduced adhesion molecules expression and trans-endothelial migration of monocyte in men
Authors: Chow Shu-Er , Ou Hsiu-Chung , Sheu Wayne Huey-Herng , Wang Jong-Shyan , Chen Yu-Wen
Published: September 2005

Physical exercise can affect the risk of cardiovascular disease. Oxidized-low density lipoprotein (ox-LDL) promotes transendothelial migration (TEM) of monocyte, thereby accelerating the pathogenesis of atherosclerosis. This study investigated how exercise intensity affects monocyte/EC interactions under ox LDL-mediated condition. Light (LIE), moderate (MIE) and high (HIE) intensity exercise (i.e., 40%, 60%, and 80%V . O2max, respectively) on a bicycle ergometer in 18 sedentary healthy men were performed on three separate occasions. Before and immediately after exercise, ox-LDL-promoted expressions of monocyte adhesion molecules and TEM of monocyte, as well as oxidation of LDL and amounts of soluble adhesion molecules in plasma were measured. Analytical results showed that (1) ox-LDL furthered monocyte L-selectin shedding and Mac-1 expression, and an attendant increase in TEM of monocyte, while treating the monocyte with Mac-1 antibody inhibited the ox-LDL-promoted TEM of monocyte; (2) under ox-LDL-treated condition, MIE increased monocyte Mac-1 and LFA-1 expressions, enhancing the TEM of monocyte, whereas HIE downregulated monocyte Mac-1 expression, suppressing theTEM of monocyte; (3) LIE decreased basal LFA-1 expression as well as basal and ox-LDL-promoted TEM of monocyte; and (4) MIE and HIE, but not LIE, elevated plasma ox-LDL level, while there were no significant changes in sL-selectin, sE-selectin, sICAM-1, and sVCAM-1 following these exercises. Therefore, we conclude that monocyte activation and subsequent TEM promoted by ox-LDL are changed by short-term exercise in an intensity-dependent manner. These findings provide a new insight into the may aid the development of suitable exercise intensity enable people to prevent early atherogenesis.
Tissue plasminogen activator extravasated through the cerebral vessels
Authors: Harada Tadashi , Katayama Yoichi , Matsuzaki Toshinori , Tejima Emiri , Koshinaga Morimichi , Kano Tsuneo
Published: September 2005

Neurotoxic effects of endogenous tissue plasminogen activator (tPA) have recently been reported. Employing a rat model of thromboembolic stroke, we evaluated the extent and degree of extravasation of exogenous tPA administered for the purpose of fibrinolysis. In a thromboembolic model using Sprague-Dawley rats, focal cerebral ischemia was induced at the territory of the middle cerebral artery (MCA). Early reperfusion was induced by administering tPA (10 mg/kg) intravenously at 30 minutes after the onset of ischemia. Extravasated tPA was evaluated by immunohistochemistry, and the concentration of tPA in the brain tissue was quantified by enzyme-linked immunosorbent assay methods. The integrity of the blood-brain barrier (BBB) was examined electronmicroscopically. In a thread model of transient ischemia, reperfusion was induced without tPA adminis-tration at 30 minutes or 2 hours after the onset of ischemia, and the tPA content of the brain was quantified. In the rats with thromboembolic stroke, extravasation of tPA was observed at the territory of the MCA. Both the endogenous and exogenous tPA contents were 3.5±1.6 ng/ml of homogenized brain in saline. Electronmicroscopically, mild ischemic changes were observed, although the integrity of the BBB was preserved. In the thread model rats, the endogenous tPA contents of the ischemic hemisphere were 0.9±0.1 and 1.0±0.2 ng/ml in the 30-minute and 2-hour ischemia groups, respectively, and were significantly lower than the tPA contents in the thromboembolic stroke rats (p < 0.01). The present findings indicate that significant extravasation of exogenous tPA occurs through the cerebral vessels even though early reperfusion is induced.
Plasma markers of endothelial damage/dysfunction, inflammation and thrombogenesis in relation to TIMI risk stratification in acute coronary syndromes
Authors: Lee Kaeng , Blann Andrew , Lip Gregory
Published: September 2005

Risk stratification at presentation with acute coronary syndromes (ACS) on the basis of theTIMI risk score for unstable angina and non-ST-elevation myocardial infarction (UAP/NSTEMI) identifies patients at high risk of recurrent cardiac events and those who benefit from more aggressive treatment strategy. We hypothesised the following: (a) that a high TIMI risk score brings a greater degree of acute changes in endothelial damage/dysfunction (circulating endothelial cells [CECs], von Willebrand factor [vWf]), inflammation (interleukin-6, IL-6) and blood thrombogenicity (plasma tissue factor, TF); and (b) that these indices are higher in those with high TIMI risk score who experienced recurrent cardiac event at day 14 and day 30. TIMI risk scores were determined at admission and 48 hours later in 88 ACS patients (60 male, age 67±12 yrs) with UAP or NSTEMI. CECs, IL-6 andTF levels were measured at both time points and the acute change (Δ) calculated. Patients were split into high (score ≥4) or low (<4) TIMI score groups. The composite end point of death, myocardial infarction, and refractory angina requiring revascularisation following 14 and 30 days’ follow-up was ascertained. Fifty-eight patients with high TIMI risk score (mean 4.7) had significantly higher baseline and 48 h CEC, vWf, IL-6, TF and ΔTF levels, compared to low TIMI risk score (mean 2.4) patients (all p<0.05). Multivariate Cox regression analysis adjusted for clinical variables and TIMI risk score expressed as either continuous or categorical variable identified baseline CECs and ΔvWf levels (both p≤0.01) as independent predictors of subsequent cardiac events at both 14 days and 30 days. TIMI risk score for UA/NSTEMI identifies those patients with more profound vascular insult, inflammation and thrombogenicity that, in the ‘high risk’ patient group, predicts short-term outcomes although vascular damage was the more sensitive predictor. These indices may further refine global risk stratification for short-term adverse cardiac events in these patients.
Effects of antithrombin and heparin cofactor II levels on anticoagulation with Intimatan
Authors: Szlam Fania , Vinten-Johansen Jakob , Cardin Alan D. , Levy Jerrold H. , Tanaka Kenichi A.
Published: September 2005

Heparin is the current mainstay drug for anticoagulation during cardiac surgery, but it requires normal levels of antithrombin (AT) for optimal anticoagulation. Heparin anticoagulation may be less effective in cardiac surgical patients because of decreased AT levels due to the prolonged heparin therapy. Therefore, other anticoagulants that would work well in AT deficient patients may be more desirable. One such agent currently being evaluated is Intimatan, which catalyzes heparin cofactor II (HCII) dependent inhibition of thrombin. In the current in vitro study we examined the effects of Intimatan (20 μg/ml), heparin (0.25 U/ml), or both drugs in combination on thrombin generation in plasma with decreasing levels of AT, HCII or both cofactors, using a novel method based on the continuous measure-ment of thrombin generation. For the study, we collected blood samples from healthy volunteers, isolated platelet poor plasma by centrifugation and mixed it withAT, HCII, orAT-HCII deficient plasma samples to achieve different levels of AT, HCII and AT-HCII. Thrombin generation was inhibited equally well with heparin or Intimatan when the level of their respective cofactors was within the normal range. With decreasing levels of AT or HCII, heparin and Intimatan became less effective in thrombin inhibition, respectively. With the absence of both cofactors, neither agent alone or in combination had any effect on thrombin generation. We conclude that Intimatan may be an effective adjunct to heparin therapy under low AT conditions.

The study was presented in part at the annual meeting of the Society of Cardiovascular Anesthesiologists, Honolulu, HI on April 26, 2004
Stem cells for clinical use in cardiovascular medicine
Authors: Menasché Philippe
Published: September 2005

Cell transplantation is currently gaining a growing interest as a potential new means of improving the prognosis of patients with cardiac failure. The basic assumption is that left ventricular dysfunction is largely due to the loss of a critical number of cardiomyocytes and that it can be partly reversed by implantation of new contractile cells into the postinfarction scars. Primarily for practical reasons, autologous skeletal myoblasts have been the first to undergo clinical trials and now that the feasibility of the procedure is well established, efficacy data are expected from the ongoing randomized studies. Bone marrow stem cells are also generating a great deal of interest, particularly in patients with acute myocardial infarction, and are currently undergoing extensive clinical testing although recent data have raised a cautionary note about the transdifferentiation potential of these cells. While experimental studies and early-phase clinical trials tend to support the concept that cell therapy may enhance cardiac repair, several key issues still need to be addressed including (1) the optimal type of donor cells in relation to the clinical profile of the patients, (2) the mechanism by which cell engraftment improves cardiac function, (3) the optimization of cell survival, (4) the development of less invasive cell delivery techniques and (5) the potential benefits of cell transplantation in nonischemic heart failure. Current evidence suggests, however, that adult stem cells (myogenic or marrow-derived) fail to electromechanically integrate within the recipient heart, thereby mandating the search for second generation cell types able to achieve this goal which is the prerequisite for an effective enhancement of contractile function. Preliminary data suggest that cells that feature a true cardiomyogenic phenotype such as cardiac stem cells and cardiac-precommitted embryonic stem cells may fall in this category and carry the potential for ensuring a true regeneration of dead myocardium.
Ximelagatran for the secondary prevention of venous thromboembolism
Authors: Schulman Sam , Lundström Torbjörn , Wåhlander Karin , Billing Clason Solveig , Eriksson Henry ,   for the THRIVE III Investigators
Published: September 2005

In the randomized, double-blind THRIVE III trial, the oral direct thrombin inhibitor ximelagatran (24 mg twice daily) significantly reduced the incidence of recurrent venous thromboembolism (VTE) versus placebo over 18 months or until premature study drug discontinuation. A complementary follow-up analysis (intention-to-treat) was conducted post-study to evaluate the cumulative risks of locally-confirmed recurrent VTE and death (Kaplan-Meier procedure) over the full 18-month study period, regardless of whether patients discontinued study drug prematurely. Hazard ratios (HRs) between treatments were estimated using Cox proportional hazard modeling. Of 612 and 611 patients receiving ximelagatran and placebo, respectively, 149 and 181 discontinued treatment prematurely. Of these discontinuations, further information could not be collected for 14 and 13patients in the ximelagatran and placebo groups, respectively; among the remaining patients, four VTE events and four deaths occurred in the ximelagatran group, and oneVTE event and five deaths occurred in the placebo group. The resulting cumulative risks of VTE (3.2% vs. 12.7%; HR 0.21; 95% confidence interval [CI], 0.12, 0.36;P < 0.0001) and pulmonary embolism (0.8% vs. 5.2%; HR 0.13; 95% CI 0.04, 0.36;P < 0.0001) were significantly lower in the ximelagatran than in the placebo group over 18 months. Death from any cause over 18 months occurred in 10 and 12 patients, respectively (HR 0.83;95% CI 0.36,1.93;P = 0.7). This complementary follow-up analysis confirms the benefit of oral ximelagatran 24 mg twice daily, administered without coagulation monitoring or dose adjustment, for the long-term secondary prevention of VTE.
In search of the best candidate for regeneration of ischemic tissues
Authors: Emanueli Costanza , Lako Majlinda , Stojkovic Miodrag , Madeddu Paolo
Published: September 2005

Human stem cells and progenitor cells from the bone marrow have been proposed for the regeneration of ischemic cardiac tissues. Early clinical trials indicate that infusion of autologous bone-marrow cells into the infarcted heart enhances ventricular function, albeit the long-term benefit remains to be ascertained. Alternatively, angiogenic growth factors could be used to stimulate the recruitment of vascular progenitor cells into tissues in need of regeneration. Unfortunately, in atherosclerotic patients, the curative potential of autologous stem cells might be impoverished by underlying disease and associated risk factors. Thus, research is focusing on the use of embryonic stem cells which are capable of unlimited self-renewal and have the potential to give rise to all tissue types in the body. Ethical problems and technical hurdles may limit the immediate application of embryonic stem cells. In the meanwhile, fetal hematopoietic stem cells, which have been routinely used to reconstitute the hematopoietic system in man, could represent an alternative, owing to their juvenile phenotype and ability to differentiate into vascular endothelial, muscular, and neuronal cell lineages. With progresses in stem cell expansion, the blood of a single cord could be sufficient to transplant an adult. These observations raise the exciting possibility of using fetal cells as a new way to speed up the healing of damaged tissues.

This study was partially supported by the Italian Health Institute (Stem Cell Program).
Effective inhibition of experimental metastasis and prolongation of survival in mice by a potent factor Xa-specific synthetic serine protease inhibitor with weak anticoagulant activity
Authors: Banke Ingo , Arlt Matthias , Mueller Markus , Sperl Stefan , Stemberger Axel , Stürzebecher Jörg , Amirkhosravi Ali , Moroder Luis , Krüger Achim
Published: September 2005

Clinical and experimental evidence suggests that the blood coagulation system is involved in the dissemination of malignant tumors. Consequently, anticoagulant agents have been tested as metastasis suppressors in experimental models. Recently, we have found a close correlation between factor Xa (FXa)-specificity of a series of synthetic serine protease inhibitors and their anti-metastatic potential in a murineT-cell lymphoma metastasis model. Interference of such inhibitors with blood-coagulation may represent a major experimental and clinical obstacle. Here, we test anti-metastatic effects of a recently developed, highly specific 3-amidinophenylalanine-type FXa inhibitor, WX-FX4, with weaker anticoagulant activity when compared to well-established FXa inhibitors, such as DX-9065a, as measured by the activated partial thromboplastin time, prothrombin time, prothrombinase complex activity, and coagulation time. Treatment of mice with WX-FX4 (1.5 mg/kg twice daily) led to significant reduction of experimental liver metastasis of a syngeneic T-cell lymphoma in DBA/2 mice (> 90%), and of experimental lung metastasis of a human fibrosarcoma in CD1 nu/nu mice (> 60%). Due to its relatively low anticoagulant activity, daily treatment over 100 days was possible, leading to significant survival benefits without inducing bleeding anomalities. FXa-inhibitors with highly efficient anti-metastatic potential without coagulationrelated side effects may represent important new tools as anticancer agents.
Molecular and phenotypic analyses of human embryonic stem cell-derived cardiomyocytes
Authors: Goh Gareth , Self Tim , Barbadillo Muñoz Maria D. , Hall Ian P. , Young Lorraine , Denning Chris
Published: September 2005

Differentiation of human embryonic stem cells (hESCs) into cardiomyocytes in culture may offer unique opportunities for modeling genetic disorders, screening potentially cardiotoxic pharmaceutical agents or replacing cells of the diseased heart. However, before clinical utility can be realized, numerous hurdles must be overcome. Comprehensive molecular and phenotypic characterization is required but has so far been restricted to cardiomyocytes derived from a limited subset of hESC lines. Thus, we have initiated analysis of cardiomyocyte differentiation and function from a further two independently derived lines, BG01 and HUES-7. The challenge of improving cardiac cell induction, enrichment and maturation must also be addressed to meet the demands of high throughput pharmaceutical screening or to provide sufficient cells to repair an infarcted heart. Transplanted cells must functionally integrate without inducing arrhythmias, while survival and evasion of immune surveillance must be accomplished without tumorigenicity. This review evaluates the opportunities presented by hESC-derived cardiomyocytes and the progress towards surmounting the challenges of clinical translation.
VKORC1 haplotypes and their impact on the inter-individual and inter-ethnical variability of oral anticoagulation
Authors: Geisen Christof , Watzka Matthias , Sittinger Katja , Steffens Michael , Daugela Laurynas , Seifried Erhard , Müller Clemens R. , Wienker Thomas F. , Oldenburg Johannes
Published: September 2005

In order to elucidate the role of VCORC1 sequence variants in warfarin sensitivity, we established a complete SNP map of the VKORC1 gene locus in 200 blood donors from Western Germany. Nearly all of the genetic variability of the VKORC1 gene in Europeans is reflected by three main haplotypes. Recently described polymorphisms associated with low warfarin dose requirement (dbSNP:rs9934438; dbSNP:rs17878363) were found in complete linkage disequilibrium with the VKORC1*2 haplotype. In two patient cohorts of European origin with either increased coumarin sensitivity (n=14) or partial coumarin resistance (n=36) the VKORC1*2 frequency varied highly significant between the two groups and also when compared to 200 blood donor controls (coumarin sensitive 96%, coumarin resistant 7%, controls 42%) thus demonstrating a strong association between these two phenotypes and the VKORC1 haplotype (p = 1.6 x 10−8 for coumarin sensitive and p = 1.9 x 10−8 for coumarin resistant). Analysis of database derived VKORC1 genotypes of African Americans and Chinese revealed that haplotype frequencies in these populations differ significantly from the European sample (for VKORC1*2: Europeans 42%, Chinese 95%, African Americans 14%). These observations suggest VKORC1 as principal genetic modulator of the ethnic differences in warfarin response. Since hereditary pharmacodynamic (VKORC1) and pharmacokinetic (CYP2C9) factors account for up to 50% of the inter-individual variability of the warfarin response, these genetic markers may serve as clinically relevant predictors of warfarin dosing in future studies.
Safety and pharmacokinetics of recombinant factor XIII in healthy volunteers
Authors: Visich Jennifer E. , Zuckerman Linda A. , Butine Michael D. , Gunewardena Kulasiri A. , Wild Richard , Morton Kirsten M. , Reynolds Thomas C.
Published: September 2005

Factor XIII (FXIII) is a plasma transglutaminase that covalently cross-links fibrin proteins to one another and to other proteins, increasing the mechanical strength of blood clots. Endogenous FXIII is the final enzyme in the clotting cascade and circulates as a heterotetramer comprising 2 FXIII-A subunits and 2 FXIII-B subunits. Recombinant human FXIII A2 (rFXIII) homodimer is produced inSaccharomyces cerevisiae. Upon injection, rFXIII combines with the free FXIIIB subunit that circulates in excess to form the rA2B2 tetramer. In this placebo-controlled, doubleblind, multi-dose study, the safety, pharmacokinetics, and pharmacodynamics of rFXIII were studied in 24 healthy volunteers, who were randomized in 2 cohorts of 12 subjects each. In each cohort, 8 subjects received 5 daily intravenous doses of rFXIII (10 or 25 U/kg), and 4 subjects received placebo. Recombinant FXIII was well tolerated. No deaths or serious adverse events occurred. The type and frequency of adverse events showed no pattern or dose response. No clinically significant changes in haematology, serum chemistry, or urinalysis laboratory values were observed. No clinical coagulopathy or thrombosis was observed. Recombinant FXIII did not produce any anti-yeast or anti-FXIII antibodies. After 5 daily doses of rFXIII, accumulation indices indicated a 3 to 4fold accumulation of rFXIII in plasma. The elimination half-life, estimated for rFXIII as the heterotetramer, ranged from 228-346 hours for the 10U/kg dose group and 167-197 hours for the 25U/kg dose group. The safety, pharmacokinetic, and immunogenic profile of rFXIII suggests it may have potential use in patients with congenital or acquired FXIII deficiency
Bone morphogenetic proteins and vascular differentiation
Authors: Patterson Cam , Moser Martin
Published: September 2005

Vasculogenesis is an important mechanism of blood vessel formation not only in embryos but also in adults. It may contribute to reparative effects of progenitor cell therapy in ischemic diseases such as myocardial infarction. Signaling pathways involved in embryonic development, including the BMP pathway, are reactivated in adult vasculogenesis. As a consequence knowledge about embryonic signaling events will help to understand blood vessel formation in the adult. The role of BMPs in embryonic development has been studied extensively in the past decades but only recently their role in vasculogenesis has been recognized. Gain and loss of function models indicate that BMPs stimulate vasculogenesis in the embryo as well as in the adult. Additionally, BMPs interact with other pathways involved in blood vessel formation, such as VEGF signaling. Studying novel molecules such as BMPER that modulate BMP activity and that are expressed in vascular cells will help to understand vasculogenetic signaling and may open up new therapeutic avenues in vascular disease.
Few predictors of massive deep vein thrombosis
Authors: Joffe Hylton , Kucher Nils , Tapson Victor , Goldhaber Samuel
Published: September 2005

Factors that predispose to thrombus propagation from the femoropopliteal veins to the pelvic veins are poorly understood. Our goal was to determine whether there are characteristics that identify patients with massive deep vein thrombosis (DVT). We compared the 122 (2.5%) patients presenting with massive DVT (pelvic plus lower-extremity DVT) to the 4,674 (97.5%) patients with isolated lower-extremity DVT from a prospective United States multicenter DVT registry. Patients with massive DVT were younger (59.4±18.9 years vs. 64.3±16.8 years; p<0.01), less likely to have hypertension (40% vs. 51%; p=0.02), and more likely to smoke (21% vs. 13%; p=0.02) and have on- going radiation therapy (7% vs. 3%; p=0.02). The massive DVT group more commonly presented with extremity edema (80% vs. 69%; p<0.01) and erythema (21% vs. 12%; p<0.01) than the isolated lower-extremity DVT group. However, after multivariable logistic regression analysis, extremity erythema (adjusted odds ratio 1.86; 95% CI 1.13–3.04) was the only independent sequela of massive DVT and younger age (adjusted odds ratio 1.17 per decreasing decade of age; 95% confidence interval: 1.02-1.34) was the only independent predictor of massive DVT. Thrombus propagation from the femoropopliteal system cannot be reliably predicted using demographic or clinical characteristics.