bluuebunny/crossref_metadata_2025 huggingface dataset:
Therapeutic effect of diagnostic ultrasound on enzymatic thrombolysis
Authors: Lupi Cristiana , Lazzerini Guido , Chiarelli Piero , L’Abbate Antonio , Rovai Daniele , Basta Giuseppina
Published: May 2004

If delivered at elevated intensity, ultrasound potentiates enzymatic clot dissolution; however, an elevated acoustic intensity damages vascular wall and favors reocclusion. This study’s aim was to investigate whether exposure to high-frequency, lowintensity ultrasound generated by a diagnostic scanner enhances enzymatic thrombolysis, and if this effect differs in clots from blood of normal subjects and of patients with coronary artery disease (CAD). Venous blood samples were drawn from 10 healthy volunteers and from 10 CAD patients on chronic medical treatment, which also included aspirin. Each sample generated 2 radiolabelled clots, which were positioned in 2 in vitro models filled with human plasma recirculating at 37°. One clot was exposed to acetyl salicylic acid (60 μg/ml), tissue plasminogen activator (3 μg/ml) and heparin (1 IU/ml), while the other was exposed to the same medications plus ultrasound (2.5 MHz, mechanical index = 1.0) for 3 hours. Enzymatic thrombolysis was measured as solubilization of radiolabel. Normal subjects and patients did not significantly differ as to coagulation parameters, weight, volume and density of the clots, and fibrinolytic activity (p = 0.794). Ultrasound exposure did not influence thrombolysis in clots of normal subjects (p = 0.367), while it enhanced the dissolution of clots of CAD patients (p = 0.013). The enhancement was equal to 51% at 5 minutes, 32% at 15 minutes, 27% at 30 minutes, 20% at 1 hour and 19% at 3 hours (p < 0.05). Diagnostic ultrasound enhances enzymatic dissolution of clots generated from the blood of CAD patients, likely due to chronic treatment and in particular to aspirin.
Proteasome inhibitor prevents experimental arterial thrombosis in renovascular hypertensive rats
Authors: Ostrowska Justyna , Z.Wojtukiewicz Marek , Chabielska Ewa , Buczko Wlodzimierz , Ostrowska Halina
Published: May 2004

Recent studies indicate that highly selective proteasome inhibitors can be useful in prevention of some cardiovascular events. Here we demonstrate that proteasome inhibitor, Z-IleGlu (Ot-Bu) Ala-Leucinal (PSI), is active in the prevention of platelet-dependent arterial thrombosis induced in renovascular hypertensive rats (two-kidney, one clip Goldblatt model, and 2K1C, n=5).The administration of PSI intravenously at a single dose of 0.3 mg/kg before induction of arterial thrombosis markedly increased carotid final flow rate, as compared to control (vehicle) group (10.36 ± 1.8 ml/min and 1.2 ± 1.2 ml/min, respectively), significantly decreased the wet (1.23 ± 0.23 mg and 4.1 ± 0.94 mg, respectively), and dry (0.46 ± 0.145 mg and 1.46 ± 0.39, respectively) thrombus weight, and completely prevented arterial occlusion. Moreover, platelets from PSI treated thrombotic 2K1C rats, showed in response to collagen a significant inhibition of aggregation in the whole blood (10.26 ± 0.6 ohms vs. 15.51 ± 0.91ohms in the control group). In contrast, collagen-induced platelet aggregation was not inhibited in vitro, after pre-treatment of the blood with PSI at the concentration of 10μM that effectively inhibited the 20S proteasome activity in platelets, indicating that ex vivo anti-aggregatory effect of PSI proceeds through an indirect mechanism not associated with suppression of 20S proteasome activity in platelets. In conclusion, our in vivo findings demonstrate that proteasome inhibitor, Z-Ile-Glu(Ot-Bu)Ala-Leucinal, prevents the development of arterial thrombosis in renovascular hypertensive rats and effectively suppresses platelet aggregation by an indirect mechanism. Thus the data provide a new insight into the potential role for the proteasome-dependent pathway in cardiovascular events.
Heparin binding protein is increased in chronic leg ulcer fluid and released from granulocytes by secreted products of Pseudomonas aeruginosa
Authors: Lundqvist Katarina , Herwald Heiko , Sonesson Andreas , Schmidtchen Artur
Published: May 2004

Recently it was demonstrated by Gautam, et al. that release of neutrophil-borne heparin-binding protein (HBP), also known as CAP37/azurocidin, induced endothelial hyperpermeability and neutrophil efflux. Here, we show that chronic leg ulcer fluid, in contrast to wound fluid from acute wounds, contains highly increased levels of HBP. Immunohistochemistry demonstrated the presence of HBP in chronic ulcer tissues. Furthermore, secreted products of Pseudomonas aeruginosa were found to induce release of HBP from human neutrophils. Our data suggest a possible link between bacterial presence and HBPrelease in chronic ulcers.Thus, targeting HBP offers an interesting option for reduction of endothelial barrier dysfunction in chronic ulcers.
Comparison between ticlopidine and clopidogrel in patients with ST-segment elevation myocardial infarction treated with coronary stenting
Authors: De Luca Giuseppe , van’t Hof Arnoud , Ottervanger Jan , Hoorntje Jan , Gosselink A.T. , Dambrink Jan-Henk , Zijlstra Felix , de Boer Menko-Jan , Suryapranata Harry
Published: May 2004

Controversy still surrounds the question, which antiplatelet drug should be added to aspirin in patients undergoing coronary stent implantation. The aim of the current study was to compare ticlopidine and clopidogrel in a consecutive series of patients with ST-segment elevation myocardial infarction (STEMI) treated with primary stenting. Our population is represented by 883 consecutive patients with STEMI undergoing primary stenting from April 1997 to October 2001. All clinical, angiographic, and follow-up data were prospectively collected. A total of 523 patients on clopidogrel were compared with 360 patients on ticlopidine after primary stenting. Except for age and statin therapy, no difference in demographic and clinical characteristics was observed between the two groups. Patients on clopidogrel had a higher rate of successful reperfusion (80.7% vs 73.1%, p = 0.008). No difference was observed between the two groups at both 30-day and 1-year follow-up. These data were confirmed after correction for age, successful reperfusion and statin therapy. This study shows no difference in long-term clinical outcome between clopidogrel and ticlopidine as adjunctive antiplatelet therapy in patients with STEMI undergoing stent implantation.
The effects of long-term diet and omega-3 fatty acid supplementation on coagulation factor VII and serum phospholipids with special emphasis on the R353Q polymorphism of the FVII gene
Authors: Pedersen Jan , Hjerkinn Elsa , Arnesen Harald , Veierød Marit , Ellingsen Ingrid , Seljeflot Ingebjørg , Lindman Anja
Published: May 2004

The aim of the present study was to investigate the effect of long-term diet and very long chain n-3 fatty acids (VLC n-3) intervention on plasma coagulation factor VII (FVII), cholinecontaining phospholipids (PC) and triglycerides (TG), especially related to the R353Q polymorphism of the FVII gene. The present investigation included 219 subjects from the Diet and Omega-3 Intervention Trial on atherosclerosis (DOIT), a 2x2 factorial designed study in elderly men with long-standing hypercholesterolemia. The subjects were randomly allocated to receive placebo capsules (corn oil) (control), placebo capsules and dietary advice (“Mediterranean type” diet), VLC n-3 capsules, or VLC n-3 capsules and dietary advice combined. The R353Q genotype and the levels of FVIIc, FVIIag, FVIIa, PC, and TG at baseline and after 6 months were determined. Diet interention was followed by a significant reduction of 5.1% in the levels of FVIIag and 2.4 mU/ml in FVIIa (95% CI −7.4, −2.9, and −3.8, −1.1, respectively) (both p<0.001) compared to the no diet group, independent of genotype. No effects of diet intervention on FVIIc, PC or TG were observed. After VLC n-3 supplementation the TG levels were significantly reduced compared to placebo (p=0.01), whereas all FVII levels and PC remained unchanged. Dietary advice towards a “Mediterranean type” diet, but not VLC n-3 supplementation, was shown to reduce the levels of FVIIag and FVIIa after 6 months, independent of genotype. The results indicate the dietary advice to be more favourable in reducing this risk factor for CVD as compared to specific VLC n-3 supplementation.
Transition from argatroban to oral anticoagulation with phenprocoumon or acenocoumarol: effects on prothrombin time, activated partial thromboplastin time, and Ecarin Clotting Time
Authors: Graff Jochen , Klinkhardt Ute , von Hentig Nils , Walenga Jeanine , Watanabe Hikari , Osakabe Masanori , Breddin Hans-Klaus , Harder Sebastian
Published: May 2004

Treatment with the direct thrombin inhibitor argatroban (ARG) is often followed by vitamin K-antagonist treatment (VKA). Phenprocoumon (PC) and acenocoumarol (AC) are frequently used in Europe. The standard monitoring test for VKA, prothrombin time (PT), is prolonged by direct thrombin inhibitors. Therefore the International Normalized Ratio (INR) obtained during combined treatment does not reflect the true effect of the VKA. A similar interference of the VKA on the activated partial thromboplastin time (aPTT), a monitoring assay for direct thrombin inhibitors, can occur. In 39 healthy volunteers the effect of ARG alone or combined with PC or AC on PT, INR, aPTT, and Ecarin Clotting Time (ECT) was investigated. 6 groups each of 6-8 volunteers received a 5-hour infusion of either 1.0, 2.0 or 3.0 µg/kg/min ARG (days 1, 3, 4 and 5) before initiation of either PC or AC (day 1) and during continued VKA dosing (target INR 2-3). A linear relationship (INR ARG+VKA = intercept + slope * INR VKA alone) was observed between the INR measured “on” and “off” ARG.The slope depended on the argatroban dose and on the International Sensitivity Index (ISI) of the PT reagent, the steepest slope (i.e., the largest difference between INR ARG+VKA and INR VKA alone) was seen with the highest ARG dose and the PT reagent with an ISI of 2.13.There was a close correlation between plasma levels of ARG and aPTT or ECT. Under VKA the ARG-aPTT relationship indicated an increased sensitivity of the aPTT to ARG, VKA treatment had no effect on the prolongation of the ECT induced by argatroban. In conclusion, ARG at doses up to 2 µg/kg/min can be discontinued at an INR of 4.0 on combined therapy with VKA, as this would correspond to an INR between 2.2 and 3.7 for the VKA. If it is necessary to monitor ARG in the critical transition period, the ECT which is not influenced by VKA can be used as an alternative to the aPTT.
Plasma homocysteine concentration is not associated with activated protein C resistance in patients investigated for hypercoagulability
Authors: Houston Donald , Zarychanski Ryan
Published: May 2004

Homocysteine and activated protein C (aPC) resistance are known risk factors for thromboembolism, but how elevated homocysteine influences thrombogenicity is not fully understood. The possibility that homocysteine may exert a prothrombotic effect by inducing aPC resistance has been addressed, with conflicting conclusions. The aim of this study is to evaluate the possible relationship of serum homocysteine concentration to aPC resistance in a cohort of patients investigated for hypercoagulability. Laboratory records from 1011 consecutive patients referred to the Haemostasis Laboratory at the Health Sciences Centre (Winnipeg, Canada) were reviewed from February 1997 to November 2002. Homocysteine levels, normalized aPC sensitivity ratio (aPCSR), and Factor V Leiden genotype were recorded for all 1011 patients. 394 patients had aPC-SR determined by mixing the patient plasma in 4 parts FV deficient plasma (FV-deficient-mix assay), and 617 patients had aPC-SR calculated without mixing (neat assay). Homocysteine did not significantly influence the aPC-SR when using the FV deficient assay. When aPC-SR was measured using the neat assay, homocysteine was found to correlate inversely with the degree of aPC resistance. The mean aPC-SR of FV Leiden-negative subjects measured using the neat assay was substantially lower than the expected normalized value of 1.0 that was obtained when aPC-SR was measured with the FV-deficient-mix assay. aPC resistance is common in patients being evaluated for possible hypercoagulability. In these patients, elevated plasma homocysteine levels is not associated with aPC resistance regardless of FV Leiden genotype suggesting that this is not the mechanism by which homocysteine exerts a prothrombotic effect.
New nonlipid effects of statins and their clinical relevance in cardiovascular disease
Authors: Celińska-Löwenhoff Magdalena , Kaczor Marcin , Musial Jacek , Undas Anetta
Published: May 2004

Inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A (HMGCoA) reductase, statins, have been demonstrated to reduce cardiovascular morbidity and mortality in patients with a wide range of cholesterol levels. Numerous cholesterol-independent effects of statins that may limit atherosclerosis are probably related to inhibition of the geranylgeranylation of GTP-binding intracellular signaling proteins and involve: improved vasoreactivity, mostly through increased NO bioavailability; decreased expression of proinflammatory cytokines (interleukin-6, interleukin-1β, tumor necrosis factor α), C-reactive protein, chemokines, matrix metalloproteinases, and tissue factor with the subsequent inhibition of thrombin generation; reduced platelet activity; increased thrombomodulin expression; enhanced fibrinolysis, regulation of angiogenesis and immunomodulation. However, the clinical relevance of multiple protective effects induced by statins has not been clarified yet.
The Ser460Pro mutation in recombinant protein S Heerlen does not affect its APC-cofactor and APC-independent anticoagulant activities
Authors: Koenen Rory , Gomes Lucio , Tans Guido , Rosing Jan , Hackeng Tilman
Published: May 2004

Protein S is a vitamin K-dependent plasma protein that functions as an APC-cofactor, but also exhibits anticoagulant activity in the absence of APC. The Heerlen polymorphism of protein S is characterized by a Ser460Pro substitution and lacks glycosylation at Asn458. It is associated with decreased protein S levels due to selective deficiency of free protein S Heerlen.To understand the lack of thrombotic complications associated with the protein S Heerlen mutation, we compared recombinant protein S Heerlen, wild type (wt) protein S and plasmaderived protein S. wt-Protein S and protein S Heerlen each bound 1:1 to C4BP with dissociation constants of 0.27 and 0.33 nM, respectively. Both wt-protein S and protein S Heerlen, either free or in complex with C4BP, were equally active as prothrombinase inhibitors in the absence of APC. All three protein S preparations stimulated APC-catalyzed inactivation of normal FVa, FVa Leiden and FVIIIa to the same extent. If extrapolated to plasma, it is not likely that the decreased free protein S levels in carriers of the protein S Heerlen mutation are compensated by an increased anticoagulant activity of protein S Heerlen-C4BP complexes. It is possible that an unrecognized plasma factor selectively enhances the anticoagulant activity of protein S Heerlen. If not, the reduction of free protein S levels in heterozygous protein S Heerlen-carriers combined with (low) normal total protein S levels apparently minimally affects the total anticoagulant activity of protein S (APC-cofactor and APC-independent activity) and hence is not associated with increased risk of venous thrombosis.
Warfarin dosing and cytochrome P450 2C9 polymorphisms
Authors: Johnson F. , Longtine Janina , Kucher Nils , Joffe Hylton , Xu Ruliang , Goldhaber Samuel
Published: May 2004

Two cytochrome P450 2C9 (CYP2C9) polymorphisms, CYP2C9*2 and *3, metabolize warfarin inefficiently. We assessed the extent to which these polymorphisms explain very low warfarin dose requirements and hemorrhagic complications after excluding non-genetic determinants of warfarin dosing. In this retrospective observational study, 73 patients with stable warfarin doses for ≥1 month and International Normalized Ratios (INR) of 2.0–3.0 were enrolled from our Anticoagulation Clinic. Seventeen patients required ≤2 mg (low-dose), 41 required 4–6 mg (moderate-dose), and 15 required ≥10 mg (high-dose) of daily warfarin. CYP2C9 genotyping was assessed by PCR amplification and restriction enzyme digestion analysis of DNA isolated from circulating leukocytes. The CYP2C9 polymorphisms independently predicted low warfarin requirements after adjusting for Body Mass Index, age, acetaminophen use, and race (OR 24.80; 95% CI 3.83–160.78). At least one polymorphism was present in every patient requiring ≤1.5 mg of daily warfarin, and 88%, 37%, and 7% of the low-, moderate-, and high-dose groups, respectively. All homozygotes and compound-heterozygotes for the variant alleles were in the low-dose group. Rates of excessive (INR>6.0) anticoagulation (and bleeding) were 4.5 (6.0), 7.9 (7.9), and 14.7 (0) per 100 patient-years in the wild-types, heterozygotes, and compound heterozygotes/homozygotes, respectively. In conclusion, CYP2C9*2 or *3 compound heterozygotes and homozygotes have low warfarin requirements even after excluding liver disease, excessive alcohol or acetaminophen consumption, low body weight, advancing age, and drug interactions. These polymorphisms increase the rate of excessive anticoagulation, but this risk does not appear to be associated with higher bleeding rates when anticoagulation status is closely monitored.
Admission fibrinolytic profile predicts clot lysis resistance in stroke patients treated with tissue plasminogen activator
Authors: Montaner Joan , Molina Carlos , Arenillas Juan , Santamarina Esteban , Alvarez-Sabín José , Ribo Marc
Published: May 2004

Endogenous fibrinolysis inhibitors may be involved in t-PA resistance, decreasing stroke thrombolysis beneficts. We aim to determine the impact of pretreatment levels of plasminogen activator inhibitor (PAI-1), lipoprotein(a), thrombin-activatable fibrinolysis inhibitor (TAFI) and homocysteine on arterial recanalization and outcome. Forty-four consecutive patients with acute proximal middle cerebral artery occlusion were studied, including assessment of transcraneal Doppler artery patency. The neurological status was determined by NIH Stroke Scale (NIHSS) and long-term outcome with modified Rankin Scale (mRS). Patients who recanalized after t-PA infusion had lower PAI-1 levels than those who remained occluded. Similarly, patients who achieved dramatic clinical recovery at 12 hours exhibited significantly lower PAI-1 levels as those independent (mRS≤2) at third month. We observed a trend towards lower lipoprotein p(a) in patients who achieved recanalization at 1 hour, whereas no relation was found between TAFI or homocysteine levels and recanalization. After a regression model was applied the only independent predictor of thrombolysis resistance was baseline PAI-1≤34 ng/ml, such that high PAI-1 levels interfere with tPA-induced recanalization in stroke, predicting a higher susceptibility towards clot-lysis resistance and poor outcome.
Human Smooth Muscle Cell Subpopulations Differentially Accumulate Cholesteryl Ester When Exposed to Native and Oxidized Lipoproteins
Authors: Argmann Carmen A. , Sawyez Cynthia G. , Li Shaohua , Nong Zengxuan , Hegele Robert A. , Pickering J. Geoffrey , Huff Murray W.
Published: May 2004

Background—

Vascular smooth muscle cells (SMCs) manifest diverse phenotypes and emerging evidence suggests this is caused by inherently distinct SMC subtypes. Recently, Li et al (
Circ Res
2001;89:517–525) successfully cloned 2 uniquely responsive SMC subpopulations from a single human artery and we used this unique resource to test the hypothesis that distinct SMC subtypes are differential precursors of foam cell formation.

Methods and Results—

When challenged with human atherogenic native or oxidized hypertriglyceridemic very-low-density lipoprotein (HTG-VLDL), the larger, slower-growing, spindle-shaped HITB5 SMC clone accumulated significantly more cholesteryl ester (CE) and triglyceride (TG) than the smaller, faster-growing epithelioid-shaped HITA2 SMC clone (10 versus 2 μg CE/mg cell protein [PN] and 60 versus 7 μg TG/mg PN,
P
<0.05). Lipoprotein lipase (LPL), a key enzyme involved in lipoprotein uptake, was identified as one differentially expressed protein that altered the predisposition of HITA2 SMCs for lipid accumulation. Although HITB5 SMCs secreted significantly more LPL than did HITA2 SMCs (0.7 versus 0.2 U/mL media,
P
<0.05), the addition of bovine milk LPL to HITA2 SMCs, significantly increased native and oxidized HTG-VLDL–induced lipid accumulation.

Conclusions—

Inherently distinct SMC subsets are differentially predisposed to lipoprotein-induced lipid accumulation. Moreover, the environment can influence the response of SMC subsets to atherogenic lipoproteins.
Infrarenal Aortic Diameter Predicts All-Cause Mortality
Authors: Norman Paul , Le Max , Pearce Carole , Jamrozik Konrad
Published: May 2004

Objective—

To assess the relationship between infrarenal aortic diameter and subsequent all-cause mortality in men aged 65 years or older.

Methods and Results—

Aortic diameter was measured using ultrasound in 12 203 men aged 65 to 83 years as part of a trial of screening for abdominal aortic aneurysms. A range of cardiovascular risk factors was also documented. Mortality over the next 3 to 7 years was assessed using record linkage. Initial aortic diameter was categorized into 10 intervals, and the relationship between increasing diameter and subsequent mortality was explored using Cox proportional hazard models. Median diameter increased from 21.4 mm in the youngest men to 22.1 mm in the oldest men. The cumulative all-cause mortality increased in a graded fashion with increasing aortic diameter. Using the diameter interval 19 to 22 mm as the reference, the adjusted hazard ratio for all-cause mortality increased from 1.26 (95% CI: 1.09, 1.44;
P
=0.001) for aortic diameters of 23 to 26 mm to 2.38 (95% CI: 1.22, 4.61;
P
=0.011) for aortic diameters of 47 to 50 mm. Analysis of causes of death indicated that cardiovascular disease was an important contributor to this increase.

Conclusion—

Infrarenal aortic diameter is an independent marker of subsequent all-cause mortality.
Clinical Recovery From End-Stage Heart Failure Using Left-Ventricular Assist Device and Pharmacological Therapy Correlates With Increased Sarcoplasmic Reticulum Calcium Content but Not With Regression of Cellular Hypertrophy
Authors: Terracciano C.M.N. , Hardy J. , Birks E.J. , Khaghani A. , Banner N.R. , Yacoub M.H.
Published: May 2004

Background—

Left ventricular assist device (LVAD) treatment is known to lead to structural and functional cellular modifications in the heart. The relevance of these changes for clinical recovery is unknown.

Methods and Results—

We compared properties of cardiomyocytes obtained from tissue taken at explantation of the LVAD in patients with clinical recovery with those obtained from hearts of patients who did not show clinical recovery, thus requiring transplantation. Compared with myocytes taken at implantation, both the recovery and nonrecovery groups showed ≈50% reduction in cell capacitance, an index of cell size. However, action potential duration shortened, L-type Ca
2+
current fast inactivation was more rapid, and sarcoplasmic reticulum Ca
2+
content was increased in the recovery compared with the nonrecovery group.

Conclusions—

These results show that specific changes in excitation-contraction coupling, and not regression of cellular hypertrophy, are specifically associated with clinical recovery after LVAD and further identify sarcoplasmic reticulum Ca
2+
handling as a key functional determinant in patients with heart failure.
Impaired Microvascular Function in Obesity
Authors: de Jongh Renate T. , Serné Erik H. , IJzerman Richard G. , de Vries Greetje , Stehouwer Coen D.A.
Published: May 2004

Background—

Obesity is associated with an increased risk of developing microangiopathy, hypertension, and insulin resistance. We hypothesized that obesity is a primary cause of microvascular dysfunction, which may contribute to the development of these obesity-related disorders.

Methods and Results—

We examined microvascular function in 16 lean (body mass index <24 kg/m
2
) and 12 obese (body mass index >30 kg/m
2
) healthy women (mean age, 38.9±6.7 years) in the basal state and during physiological systemic hyperinsulinemia. We determined skin capillary recruitment after arterial occlusion with capillaroscopy and skin endothelium–(in)dependent vasodilation by iontophoresis of acetylcholine and sodium nitroprusside. Obese women, compared with lean women, had higher systolic blood pressure (
P
<0.05), impaired insulin sensitivity (
P
<0.01), impaired capillary recruitment in the basal state (
P
<0.05) and during hyperinsulinemia (
P
<0.05), and impaired acetylcholine-mediated vasodilation in the basal state (
P
<0.05) and during hyperinsulinemia (
P
<0.01). Sodium nitroprusside–mediated vasodilation was similar in lean and obese women. Capillary recruitment and acetylcholine-mediated vasodilation were positively correlated with insulin sensitivity (
r
=0.58,
P
<0.01 and
r
=0.55,
P
<0.01, respectively) and negatively with blood pressure (
r
=−0.64,
P
<0.001 and
r
=−0.42,
P
<0.05, respectively) in both lean and obese women.

Conclusions—

Obesity is characterized by impaired microvascular function in the basal state and during hyperinsulinemia and, in both lean and obese women, microvascular dysfunction is associated with increased blood pressure and decreased insulin sensitivity. These findings are consistent with a contribution of impaired microvascular function to the development of obesity-related microangiopathy, hypertension, and insulin resistance.
Cardiac Angiotensin II Participates in Coronary Microvessel Inflammation of Unstable Angina and Strengthens the Immunomediated Component
Authors: Neri Serneri Gian Gastone , Boddi Maria , Modesti Pietro Amedeo , Coppo Mirella , Cecioni Ilaria , Toscano Thomas , Papa Maria Letizia , Bandinelli Manuela , Lisi Gian Franco , Chiavarelli Mario
Published: May 2004

Angiotensin (Ang) II is now recognized to be a mediator of a wide variety of inflammatory processes. This study investigated renin-angiotensin system (RAS) components and a number of inflammatory mediators in left ventricular biopsies from 2-vessel disease unstable angina (UA) (n=43) and stable angina (SA) (n=15) patients undergoing coronary bypass surgery. Biopsy samples from 6 patients undergoing valve replacement for mitral stenosis served as controls. UA patients were randomly assigned to angiotensin-converting enzyme (ACE)-inhibitor (ramipril), AT1 antagonist (valsartan), or placebo and treated during the 5 days preceding coronary bypass surgery, performed from 6 to 9 days after coronary angiography. During coronary angiography coronary blood flow was measured and samples were obtained from aorta and coronary sinus for determination of Ang I and Ang II gradients. The hearts of UA patients produced Ang II in a greater amount than in SA patients (
P
<0.01). UA biopsy samples showed numerous DR
+
cells, identified as lymphocytes, macrophages, and endothelial cells. Reverse-transcriptase polymerase chain reaction showed overexpression of AGTN, ACE, and AT1-R genes, as well as upregulation of TNF-α, IL-6, IFN-γ, and iNOS genes (
P
<0.01), with no differences between nonischemic and potentially ischemic areas. AGTN, ACE, and cytokine genes were mainly localized on endothelial cells. Ramipril and valsartan markedly decreased the expression levels of TNF-α, IL-6, and iNOS, and, to a lesser extent, of IFN-γ genes, but did not affect the number of DR
+
cells, with no significant difference between the 2 treatments. These results show that locally generated Ang II amplifies the immunomediated inflammatory process of coronary microvessels occurring in unstable angina.
High Blood Pressure Upregulates Arterial L-Type Ca
2+
Channels
Authors: Pesic Aleksandra , Madden Jane A. , Pesic Miodrag , Rusch Nancy J.
Published: May 2004

Long-lasting Ca
2+
(Ca
L
) channels of the Ca
v
1.2 gene family contribute to the pathogenesis of abnormal arterial tone in hypertension. The physiological stimulus that enhances Ca
L
channel current in the vascular smooth muscle cells (VSMCs) remains unknown. The present study investigated if high blood pressure triggers an upregulation of vascular Ca
L
channel protein. Rat aortae were banded between the origins of the left renal (LR) and right renal (RR) arteries to selectively elevate blood pressure in the proximal RR arteries. After 2 days, the immunoreactivity on Western blots corresponding to the pore-forming α
1C
subunit of the Ca
L
channel was increased 3.25-fold in RR compared with LR arteries. This finding persisted at 28 days and was associated with abnormal Ca
2+
-dependent tone and higher Ca
L
currents in the VSMCs exposed to high pressure. Based on microelectrode studies indicating that RR arteries were depolarized compared with LR arteries, further studies examined if membrane depolarization, an inherent response of VSMCs to high blood pressure, increased α
1C
expression. Isolated rat renal arteries were cultured for 2 days in low K
+
(4 mmol/L) or depolarizing high K
+
(30 mmol/L) media. Arteries preconditioned in high K
+
showed a 5.47-fold increase in α
1C
expression, enhanced Ca
L
channel current, and elevated Ca
2+
-dependent tone. These findings provide the first direct evidence that high blood pressure upregulates the Ca
L
channel α
1C
subunit in VSMCs in vivo and suggest that membrane depolarization is a potential signal involved in this interaction that may contribute to the development of abnormal vascular tone.
Vascular Endothelial Growth Factor Receptor-2–Induced Initial Endothelial Cell Migration Depends on the Presence of the Urokinase Receptor
Authors: Prager Gerald W. , Breuss Johannes M. , Steurer Stefan , Olcaydu Damla , Mihaly Judit , Brunner Patrick M. , Stockinger Hannes , Binder Bernd R.
Published: May 2004

The angiogenic response of endothelial cells initiated by different growth factors is accompanied by assembly of cell surface–bound proteolytic machinery as a prerequisite for focal invasion. We have shown previously how the vascular endothelial growth factor (VEGF) initiates proteolysis by activation of pro-urokinase (pro-PA) via the VEGF receptor-2 (VEGFR-2). We now show that the cell surface receptor of the uPA-system, the urokinase receptor (uPAR), is redistributed to focal adhesions at the leading edge of endothelial cells in response to VEGF. VEGF
165
and VEGF-E, both interacting with VEGFR-2, but not PlGF exclusively stimulating VEGFR-1, induce within minutes internalization of uPAR via an LDL receptor–like molecule, dependent on generation of active uPA and the presence of plasminogen activator inhibitor-1 (PAI-1). uPAR seems to play a pivotal role in VEGFR-2–induced endothelial cell migration because cleavage of surface uPAR impaired the migratory response of endothelial cells toward VEGF-E, but not toward PlGF.
The impact of low-dose busulfan on clonal dynamics in nonhuman primates
Authors: Kuramoto Ken , Follman Dean , Hematti Peiman , Sellers Stephanie , Laukkanen Mikko O. , Seggewiss Ruth , Metzger Mark E. , Krouse Allen , Donahue Robert E. , von Kalle Christof , Dunbar Cynthia E.
Published: May 2004

An understanding of the number and contribution of individual pluripotent hematopoietic stem cells (HSCs) to the formation of blood lineages has important clinical implications for gene therapy and stem cell transplantation. We have been able to efficiently mark rhesus macaque long-term repopulating stem and progenitor cells with retroviral vectors, and track their in vivo contributions to hematopoiesis using the linear amplification mediated–polymerase chain reaction (LAM-PCR) technique of insertion site analysis. We assessed the impact of busulfan on contributions of individual retrovirally marked clones to hematopoiesis. There were 2 macaques that received transplants of retrovirally transduced CD34+ cells 2 years previously that were then treated with 4 mg/kg busulfan. Despite only transient and mild suppression of peripheral blood counts, the numbers of individual stem/progenitor clones contributing to granulocyte production decreased dramatically, by 80% in the first monkey and by 60% in the second monkey. A similar impact was seen on clones contributing to T cells. The clone numbers recovered gradually back toward baseline by 5 months following busulfan in the first monkey and by 3 months in the second monkey, and have remained stable for more than one year in both animals. Tracking of individual clones with insertion-site–specific primers suggested that clones contributing to hematopoiesis prior to busulfan accounted for the majority of this recovery, but that some previously undetected clones began to contribute during this recovery phase. These results indicate that even low-dose busulfan significantly affects stem and progenitor cell dynamics. The clonal diversity of hematopoiesis was significantly decreased after even a single, clinically well-tolerated dose of busulfan, with slow but almost complete recovery over the next several months, suggesting that true long-term repopulating stem cells were not permanently deleted. However, the prolonged period of suppression of many clones suggests that transplanted HSCs may have a marked competitive advantage if they can engraft and proliferate during this time period, and supports the use of this agent in nonmyeloablative regimens
Tachykinins regulate the function of platelets
Authors: Graham Gwenda J. , Stevens Joanne M. , Page Nigel M. , Grant Andrew D. , Brain Susan D. , Lowry Philip J. , Gibbins Jonathan M.
Published: May 2004

Evidence has been mounting for peripheral functions for tachykinins, a family of neuropeptides including substance P (SP), neurokinin A, and neurokinin B, which are recognized for their roles in the central and peripheral nervous system. The recent discovery of 4 new members of this family, the endokinins (EKA, B, C, and D), which are distributed peripherally, adds support to the notion that tachykinins have physiologic/endocrine roles in the periphery. In the present study we report a fundamental new function for tachykinins in the regulation of platelet function. We show that SP stimulates platelet aggregation, and underlying this is the intracellular mobilization of calcium and degranulation. We demonstrate the presence of the tachykinin receptors NK1 and NK3 in platelets and present evidence for the involvement of NK1 in SP-mediated platelet aggregation. Platelets were found to contain SP-like immunoreactivity that is secreted upon activation implicating SP-like substances in the autocrine/paracrine regulation of these cells. Indeed, NK1-blocking antibodies inhibited aggregation in response to other agonists. Of particular note is the observation that EKA/B cross-react in the SP immunoassay and are also able to stimulate platelet activation. Together our data implicate tachykinins, specifically SP and EKA/B, in the regulation of platelet function.
In vitro studies of a FLT3 inhibitor combined with chemotherapy: sequence of administration is important to achieve synergistic cytotoxic effects
Authors: Levis Mark , Pham Rosalyn , Smith B. Douglas , Small Donald
Published: May 2004

Patients with acute myeloid leukemia (AML) harboring internal tandem duplication mutations of the FLT3 receptor (FLT3/ITD mutations) have a poor prognosis compared to patients lacking such mutations. Incorporation of FLT3 inhibitors into existing chemotherapeutic regimens has the potential to improve clinical outcomes in this high-risk group of patients. CEP-701, an indolocarbazole-derived selective FLT3 inhibitor, potently induces apoptosis in FLT3/ITD-expressing cell lines and primary leukemic blasts. We conducted a series of in vitro cytotoxicity experiments combining CEP-701 with chemotherapy using the FLT3/ITD-expressing cell lines MV4-11 and BaF3/ITD as well as a primary blast sample from a patient with AML harboring a FLT3/ITD mutation. CEP-701 induced cytotoxicity in a synergistic fashion with cytarabine, daunorubicin, mitoxantrone, or etoposide if used simultaneously or immediately following exposure to the chemotherapeutic agent. In contrast, the combination of pretreatment with CEP-701 followed by chemotherapy was generally antagonistic, particularly with the more cell cycle-dependent agents such as cytarabine. This effect appears to be due to CEP-701 causing cell cycle arrest. We conclude that in FLT3/ITD-expressing leukemia cells, CEP-701 is synergistic with standard AML chemotherapeutic agents, but only if used simultaneously with or immediately following the chemotherapy. These results should be considered when designing trials combining chemotherapy with each of the FLT3 inhibitors currently in clinical development. (Blood. 2004; 104:1145-1150)
Lymphocyte microvilli are dynamic, actin-dependent structures that do not require Wiskott-Aldrich syndrome protein (WASp) for their morphology
Authors: Majstoravich Sonja , Zhang Jinyi , Nicholson-Dykstra Susan , Linder Stefan , Friedrich Wilhelm , Siminovitch Katherine A. , Higgs Henry N.
Published: May 2004

Short microvilli cover the surfaces of circulating mammalian lymphocytes. The surfaces of monocytes and neutrophils are very different, containing ruffles as their predominant structure. In this study, we present the first quantitative characterization of lymphocyte microvilli. From analysis of scanning electron micrographs, we find that median microvillar length and surface density range from 0.3 to 0.4 μm and 2 to 4 microvilli/μm2, respectively, on lymphocytes from a variety of sources. As with similar structures from other cells, lymphocyte microvilli contain parallel bundles of actin filaments. Lymphocyte microvilli rapidly disassemble when exposed to the actin-sequestering molecule, Latrunculin A. This disassembly parallels cellular actin filament depolymerization and is complete within 2 minutes, suggesting that lymphocyte microvilli undergo continuous assembly and disassembly. In contrast to previous reports suggesting lymphocyte microvillar density to be reduced on lymphocytes from Wiskott-Aldrich syndrome (WAS) patient, we find no such deficiency in either mouse or human WAS protein (WASp)–deficient lymphocytes. These results suggest that WASp is either not involved in or is redundant in the rapid dynamics of lymphocyte microvilli.
Combined administration of taurine and meso 2,3–dimercaptosuccinic acid in the treatment of chronic lead intoxication in rats
Authors: Flora S JS , Pande Manisha , Bhadauria Smrati , Kannan G M
Published: May 2004

The present study describes the dose–dependent effect of taurine, an amino acid and a known antioxidant, either alone or in combination with meso 2,3–dimercaptosucci–nic acid (DMSA) in the treatment of subchronic lead intoxication in male rats. The effects of these treatments in influencing the lead–induced alterations in haem synthesis, hepatic, renal or brain oxidative stress and lead concentration from soft tissues were investigated. Exposure to lead produced a significant inhibition of blood–aminolevulinic acid dehydratase (ALAD) activity, reduction in glutathione (GSH) and an increase in zinc protoporphyrin (ZPP) suggesting an altered haem synthesis pathway. Only DMSA was able to increase the activity of ALAD, while both taurine and DMSA were able to significantly increase GSH level towards normal. Animals treated with taurine significantly reduced the alterations in some of the biochemical parameters indicative of oxidative stress. Thiobarbituric acid reactive substance (TBARS) levels reduced significantly in liver, kidney and red blood cells, while GSH level increased. Activity of superoxide dismutase (SOD) also showed an increase in blood and brain in animals treated with taurine. The data also provided a promising role of taurine during chelation of lead by potentiating the depletion of blood, liver and brain lead compared to DMSA alone. It can thus be concluded from the study that concomitant administration of an antioxidant could play a significant and important role in abating a number of toxic effects of lead when administered along with the thiol chelators.
Systemic absorption of lithium following ingestion of a lithium button battery
Authors: Mallon P T , White J S , Thompson R L E
Published: May 2004

Accidental ingestion of electrical batteries occurs commonly in children. This rarely is associated with severe morbidity and mortality.1,2 Significant symptoms can arise due to leakage of alkali or heavy metals from the battery after degradation in the gastrointestinal tract. The main heavy metal of concern in electrical batteries is mercury;3-6 this is the first report of ingestion of a lithium battery in a child associated with systemic absorption of lithium.
Oximes-induced reactivation of rat brain acetylcholinesterase inhibited by VX agent
Authors: Kuča Kamil , Kassa Jiří
Published: May 2004

A comparison of one mono- and seven bisquaternary acetylcholinesterase (AChE) reactivators of acetylcholinesterase inhibited by VX agent was performed. As a source of the acetylcholinesterase, a rat brain homogenate was taken. There were significant differences in reactivation potency of all tested oximes. The oxime TO205 seems to be the most efficacious followed by TO046, HI-6, HS-6, K027, obidoxime, MMC and 2-PAM. In addition, the results of this study showed that the reactivation potency of the tested reactivators depends on many factors-such as the number of pyridinium rings, the number of oxime groups and their position, as well as the length and the shape of linkage bridge between two pyridinium rings.
Reliability of the Glasgow Coma Scale for the emergency department evaluation of poisoned patients
Authors: Heard Kennon , Bebarta Vikhyat S
Published: May 2004

The Glasgow Coma Scale (GCS) was developed for monitoring the mental status of head-injured patients in the intensive care unit. The purpose of this study is to determine the inter-rater reliability of the GCS for poisoning patients in the emergency department. Methods: This was a prospective, observational study. Two observers used a standard assessment checklist to determine the GCS of suspected poisoning patients. Inter-rater reliability was assessed with a weighted Kappa score. Results: A total of 39 patients were enrolled. Weighted kappa for the total GCS demonstrated excellent agreement. Agreement was also good for each component of the score. Conclusion: The GCS is a reliable tool for the evaluation of mental status of poisoning patients in the emergency department.
Ex vivo zidovudine (AZT) treatment of CD34+ bone marrow progenitors causes decreased steady state mitochondrial DNA (mtDNA) and increased lactate production
Authors: Lewis L D , Amin S , Civin C I , Lietman P S
Published: May 2004

Haematopoietic suppression is one of the dose-limiting side effects of chronic zidovudine (AZT) therapy. We tested the hypothesis that AZT would reduce mitochondrial DNA (mtDNA) content in haematopoietic progenitors causing impaired haematopoiesis and mitochondrial dysfunction. We studied the effects of AZT 0 / 50 M in vitro, on normal human CD34 / haematopoietic progenitor cells cultured ex vivo for up to 12 days. The mean AZT IC50 for granulocyte (phenotype CD15 / /CD14 /) and erythroid (phenotype glycophorin / /CD45 /) cell proliferation was 2.5 M (SD9 / 0.7) and 0.023 M (SD9 / 0.005), respectively. In myeloid-rich cell cultures, the mean lactate content of the media, compared to untreated controls, increased by 86% (SD9 / 23) at 10 M AZT and in erythroid-rich cultures it increased by 134% (SD9 / 24) in the presence of 0.5 M AZT. In myeloid-rich cultures the AZT IC50 for the reduction in the mitochondrial/nuclear DNA content ratio was 5.6 M, whereas in erythroid rich cultures this AZT IC50 was B / 0.0005 M. AZT produced concentration-dependent inhibition of CD34 / progenitor proliferation into both myeloid and erythroid lineages; erythropoiesis was more sensitive than myelopoiesis. Concurrently, AZT reduced steady state mtDNA content, while increasing lactate production. These findings support the hypothesis that mtDNA is one of the intracellular targets involved in the pathogenesis of AZT-associated bone marrow progenitor cell toxicity.
Sodium nitroprusside impairs sexual competence of male rats
Authors: Ratnasooriya W D , Jayakody JRAC , Dharmasiri M G
Published: May 2004

Recently, sodium nitroprusside (SNP), a potent nitric oxide (NO) donor and a clinically used antihypertensive, has been introduced as a penile self-injection medical therapy for erectile dysfunction. However, it is known that many antihypertensives impairs sexual competence; NO regulates sexual competence and NO is cytostatic and cytotoxic for human sperm. Thus, a possibility exists that SNP may impair male reproductive competence. Testing this aspect is the aim of this study. This was assessed in male rats (using three I.P. doses: 60, 30 or 20 g/kg) using noncompetitive copulation tests. The results show that the highest dose of SNP was toxic and caused rapid mortality of treated rats (within 30 min). The mid and low doses of SNP reversibly impaired several parameters of sexual competence in a dose-related fashion: sexual arousability, libido and sexual vigour. Some parameters of sexual behaviour remained unaltered: sexual motivation and intromission ratio, whilst one parameter was improved: sexual performance. In complete contrast, the ejaculatory competence and fertility remained unchanged. The SNP-induced impairments in sexual competence may be attributable to lowered testosterone levels and sedation mediated via its specific action and/or side effect. Further, this impairment of sexual function was not due to general toxicity, inhibition of penile sensitivity, penile erection or analgesic activity. It is concluded that SNP impairs male sexual competence, at least, in rats although it promotes penile erection.
Cross-national differences in diet, the outcome of schizophrenia and the prevalence of depression: You are (associated with) what you eat
Authors: McIntosh Andrew , Lawrie Stephen
Published: May 2004

Malcolm Peet (2004, this issue) presents some evidence that the international variations in the outcome of schizophrenia are associated with higher amounts of refined sugar and dairy products in the average national diet data published by the Food and Agriculture Organization of the United Nations. An association is also found between the prevalence of depression and a low dietary intake of fish and seafood. It is a simple correlational study with a multivariate statistical analysis that finds very strong associations. The regression coefficients reported suggest that these foodstuff consumption levels account for almost all the variance in the outcome of schizophrenia and the prevalence of depression. Is Peet correct in stating that previous epidemiological studies of these issues are missing crucial information, or is the reported association between diet and psychiatric disorder at a population level just a particularly dramatic example of the ecological fallacy?
International variations in the outcome of schizophrenia and the prevalence of depression in relation to national dietary practices: An ecological analysis
Authors: Peet Malcolm
Published: May 2004

Background

Dietary variations are known to predict the prevalence of physical illnesses such as diabetes and heart disease but the possible influence of diet on mental health has been neglected.

Aims

To explore dietary predictors of the outcome of schizophrenia and the prevalence of depression.

Method

Ecological analysis of national dietary patterns in relation to international variations in outcome of schizophrenia and prevalence of depression.

Results

A higher national dietary intake of refined sugar and dairy products predicted a worse 2-year outcome of schizophrenia. A high national prevalence of depression was predicted by a low dietary intake of fish and seafood.

Conclusions

The dietary predictors of outcome of schizophrenia and prevalence of depression are similar to those that predict illnesses such as coronary heart disease and diabetes, which are more common in people with mental health problems and in which nutritional approaches are widely recommended. Dietary intervention studies are indicated in schizophrenia and depression.