bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nucleoside, XIV. Zur Synthese des 4‐Amino‐7‐oxo‐7,8‐dihydropteridin‐N‐8‐β‐D‐ribofuranosids — ein strukturanaloges Nucleosid des Adenosins
Authors: Ott Manfred , Pfleiderer Wolfgang 
Published: June 2007

AbstractZur Darstellung verschieden substituierter 2‐ und 4‐Amino‐7‐oxo‐7,8‐dihydropteridin‐N‐8‐β‐D‐ribofuranoside wird eine neue Variante der „Silyl‐Methode”︁ beschrieben, die in der Lewis‐Säure katalysierten Schmelzkondensation von 7‐(Trimethylsiloxy)pteridinen 11 – 18 mit 1‐O‐Acetyl‐2,3,5‐tri‐O‐benzoyl‐β‐D‐ribofuranose (20) besteht. Die Reaktion verläuft unter sterischer Kontrolle und führt zu β‐Ribosiden 21 – 38, wobei die Anwesenheit von Elektronendonatorsubstituenten in 2‐Stellung des Pteridinringes eine N‐8‐Substitution zusätzlich günstig beeinflußt. Zur Sicherstellung der Strukturen der nach chromatographischen Verfahren isolierten neuen Substanzen werden UV‐, NMR‐ und CD‐Spektren aufgenommen sowie pK‐Werte bestimmt.
The decision to anticoagulate: Assessing whether benefits outweigh the risks for patients with atrial fibrillation
Authors: Merli Geno , Weitz Howard H. 
Published: June 2007

AbstractIn a review of relevant articles from the Medline database on stroke risk in atrial fibrillation (AF) and adverse events related to anticoagulation treatment, we found that research to date shows a major potential benefit of warfarin therapy (International Normalized Ratio [INR] 2.0–3.0) for patients with AF (68% risk reduction in primary stroke prevention with warfarin vs. placebo). Despite this highly significant reduction in stroke risk, fewer than 50% of eligible patients are treated, in many cases because of fears of intracranial hemorrhage (ICH). The decision to implement anticoagulant therapy to improve outcome requires balancing the decreased risk for stroke against the increased risk for ICH. Various methods have been developed to define patient‐specific stroke risk. In contrast, risk for ICH strongly correlates with the intensity of anticoagulation, which is an unpredictable but controllable variable requiring frequent dose adjustments. Recent studies have also identified subgroups of patients with neurologic pathologies who are at increased risk for ICH. However, when the INR is properly controlled, the benefit from anticoagulation therapy for patients with AF and other risk factors for stroke exceeds the risk for ICH. Careful monitoring of anticoagulation and warfarin dose titration to maintain the INR between 2.0 and 3.0 is critical for reducing the risk for ICH, as is excluding patients with neurologic conditions that increase the likelihood of ICH. Future developments, such as the introduction of oral direct thrombin inhibitors with more predictable pharmacokinetics than warfarin, may further improve the benefit‐to‐risk ratio of anticoagulation therapy for patients with AF.
High remnant lipoprotein levels in patients with variant angina
Authors: Miwa Kunihisa , Makita Toshinori , Ishii Katsuhisa , Okuda Nobuaki , Taniguchi Ataru 
Published: June 2007

AbstractBackground: Dyslipidemia with increased oxidative stress but without elevation of low‐density lipoprotein cholesterol has been recently implicated in the pathogenesis of coronary vasospasm.Hypothesis: Disordered triglyceride‐rich lipoprotein metabolism may be linked to the genesis of coronary artery spasm.Methods: Both serum remnant lipoprotein (RLP) and α‐tocopherol levels were determined in 18 patients with the active stage of variant angina (VA), in 16 patients with the inactive stage of variant angina (IVA), and in 19 control subjects (CONTROL).Results: The RLP levels were significantly (p < 0.05) higher in VA (6.4 ± 2.7 mg/dl) than in IVA (4.4 ± 1.5 mg/dl). In contrast, α‐tocopherol levels were significantly lower in VA than that in CONTROL. Serum trigyceride levels were not significantly different among the study groups, although serum high‐density lipoprotein cholesterol levels were significantly lower in VA than in CONTROL. Smoking was significantly (p < 0.05) more prevalent in VA (72%) than in IVA (25%) and CONTROL (37%). Serum RLP levels correlated positively with triglyceride levels (R = 0.73) and correlated inversely with α‐tocopherol levels (R = ‐ 0.31) significantly in all study subjects.Conclusions: Patients with active stage of variant angina had higher RLP levels than inactive patients with variant angina and lower α‐tocopherol levels than control subjects. Disordered triglyceride‐rich lipoprotein metabolism with increased oxidative stress appears to be linked to the activity of coronary vasospasm, suggesting a possible role in its pathogenesis.
Role of endogenous adenosine in atrial fibrillation after coronary artery bypass graft
Authors: Yavuz Turhan , Bertolet Barry , Bebooul Yavuz , Tunerir Bulent , Aslan Recep , Ocal Ahmet , Ybribim Erdooan , Kutsal Ali 
Published: June 2007

AbstractBackground: Atrial fibrillation (AF) is the most common complication following coronary artery bypass graft (CABG). The mechanism of AF after CABG is not well defined; however, it is suggested that endogenous adenosine, released in response to tissue hypoxia, may play a mechanistic role in these arrhythmias.Hypothesis: The purpose of this study was to examine whether intravenous theophylline, via adenosine A1 receptor antagonism, would correct or modify new‐onset early (< 48 h post CABG) atrial fibrillation in patients post CABG, and thereby implicate endogenous adenosine as an inciting agent.Methods: A prospective double‐blind, placebo‐controlled study design was applied to 385 consecutive patients with coronary artery disease who had undergone CABG. Any patient who developed AF within 48 h of the operative procedure was randomly assigned to receive 5 mg/kg of intravenous theophylline (Group A) or matched intravenous placebo (Group B). The patients who converted to sinus rhythm within 15 min of drug administration were accepted as showing positive responses.Results: Thirty patients comprised the study group. In Group A, 8 of the 15 patients (53%) converted from AF to sinus rhythm within 15 min of theophylline administration. One patient who converted to sinus rhythm 20 min after theophylline administration was accepted as showing a negative response. In the placebo‐treated group, no patient converted to sinus rhythm within 15 min (p < 0.007 compared with Group A).Conclusions: The mechanism of AF after CABG is not well defined and is probably multifactorial. However, this study demonstrated that antagonism of the adenosine A1 receptor can promptly convert many of these patients back to sinus rhythm, and thereby implicates endogenously released adenosine in a mechanistic role for inciting early (< 48 h) post‐CABG AF.
Evaluation of myocardial performance index to predict mild rejection in cardiac transplantation
Authors: Toumanidis Savvas T. , Papadopoulou Electra S. , Saridakis Nikolaos S. , Kalantaridou Anna T. , Agapitos Emmanuel V. , Nanas John N. , Stamatelopoulos Stamatios F. 
Published: June 2007

AbstractBackground: Early diagnosis of heart transplant rejection is mandatory, since even mild rejection can rapidly progress to more severe rejection. Noninvasive diagnosis of heart transplant rejection still remains a challenge.Hypothesis: The purpose of the study was to determine a possible association between myocardial performance index (MPI) and biopsy score of the heart transplant.Methods: This is a retrospective cohort analysis of 99 complete Doppler echocardiographic studies from 24 consecutive patients (23 men) performed within 24 h of endomyocardial biopsy. Mean age of the cohort was 50 ± 9 years and mean time from transplantation was 19 ± 21 months (1‐81). All patients were in sinus rhythm. Myocardial performance index was calculated as the ratio of isovolumic contraction time plus isovolumic relaxation time divided by ejection time. Left ventricular dimensions, left ventricular mass, ejection fraction, and a number of Doppler indices (E‐point velocity, A‐point velocity, deceleration time, and deceleration slope) were also measured. The International Society for Heart and Lung Transplantation (ISHLT) grading system was used for the classification of endomyocardial biopsies.Results: Myocardial performance index was significantly prolonged (0.60 ± 0.13, 0.68 ± 0.08, 0.75 ± 0.20, in biopsy scores 0, IA, and IB, respectively; p < 0.001). Isovolumic contraction time was significantly prolonged; isovolumic relaxation time was not significantly changed. Ejection time and deceleration time were significantly shortened. Multivariate stepwise regression analysis revealed that MPI and deceleration time were the only independent predictors of biopsy score (r = 0.48, F = 10.53, p < 0.0001).Conclusion: Myocardial performance index seems to be a useful adjunct in the follow‐up of cardiac transplant patients. These preliminary data suggest that a larger study may be indicated to clarify the relevance of myocardial performance index.
Vascular age: Integrating carotid intima‐media thickness measurements with global coronary risk assessment
Authors: Stein James H. , Fraizer Michael C. , Aeschlimann Susane , Nelson‐Worel Jane , McBride Patrick E. , Douglas Pamela S. 
Published: June 2007

AbstractBackground: An imaging test that quantifies atherosclerotic burden and that can be integrated with existing risk stratification paradigms would be avery useful clinical tool.Hypothesis: Measurement of carotid intima‐media thickness (CIMT) is feasible in a clinical setting. Such measurements can be integrated into coronary risk assessment models.Methods: Carotid intima‐media thickness was measured by B‐mode ultrasound in 82 consecutive patients without manifest atherosclerotic vascular disease. The values were used to determine “vascular age” (VA) based on nomograms from the Atherosclerosis Risk in Communities study. Vascular age was substituted for chronological age and standard and vascular age‐adjusted 10‐year coronary heart disease (CHD) risk estimates were compared.Results: The mean chronological age was 55.8 ± 9.0 years. The mean VA using CIMT was 65.5 ± 18.9 years (p<0.001). The Framingham 10‐year hard CHD risk estimate was 6.5 ± 4.9%. Substituting CIMT‐derived VA for chronological age increased the 10‐year CHD risk estimate to 8.0 ± 6.8% (p< 0.001). Of 14 subjects initially at intermediate risk, 5 (35.7%) were reclassified as higher risk and 2 (14.3%) were reclassified as lower risk. Significant predictors of reclassification were tobacco use, high‐density lipoprotein cholesterol, systolic blood pressure, and low‐density lipoprotein cholesterol.Conclusions: Measurement of CIMT, a noninvasive estimate of current atherosclerotic burden, is feasible in a clinical setting and can be integrated into CHD risk assessment models. Determining VA using CIMT values may help individualize the age component of population‐based CHD risk estimates. This strategy should be tested in a large trial with hard clinical endpoints.
Association between paraoxonase‐1 activity and lipid peroxidation indicator levels in people living in the antalya region with angiographically documented coronary artery disease
Authors: Yeşim Göçmen AyşE , Gümüşü Saadet , Semiz Ender 
Published: June 2007

AbstractBackground: Paraoxonase‐1 (PON1) is a high‐density lipoprotein (HDL)‐associated enzyme capable of hydrolyzing lipid peroxides. Thus, PON1 plays a preventing role in atherosclerosis by protecting against lipid peroxidation.Hypothesis: The incidence of coronary artery disease (CAD) is high in the Turkish population, and many risk factors have been studied as determinants of CAD. In Turkish people living in the Antalya region, we aimed to determine serum PON1 activity and its relation to lipoproteins and lipid peroxidation markers.Methods: We measured the activity of serum PON1 together with concentrations of a variety of lipid constituents—total cholesterol (TC), low‐density lipoprotein cholesterol (LDL‐C), very low‐density lipoprotein cholesterol (VLDL‐C), HDL cholesterol (HDL‐C), triglycerides (TG), apolipoprotein (apo) A‐I, apoB, and lipid peroxidation indicators (conjugated diene [CD] and thiobarbituric acid‐reactive substances [TBARS])—in 108 patients with CAD and 64 healthy subjects (controls).Results: We found that the PON1 activity was significantly reduced in patients with CAD (222.37 ± 11.31 IU/l)compared with controls (331.75 ± 20.98 IU/l). These patients had significantly lower HDL‐C, PON1/HDL‐C, apoA‐I, PON1/ApoA‐I, and ApoA‐I/ApoB, and higher LDL‐C, TC/HDL‐C, LDL‐C/HDL‐C, apoB, CD and TBARS than did controls. Total cholesterol and apoA‐I concentrations were significantly higher in women than in men in both groups. After multiple logistic regression analysis, TBARS (odds ratio [OR] 568.87; p = 0.000), age (OR 1.10; p = 0.000), gender (OR 4.58; p = 0.008), apoA‐I/apoB (OR 0.046; p = 0.003), and PON1/apoA‐I (OR 0.58; p = 0.007) were independently indicative of the presence of CAD.Conclusions: This is the first report of decreased serum PON1 activity and increased lipid peroxidation indicators (CD and TBARS) of patients with CAD living in Antalya, Turkey. Our results indicate that TBARS levels, age, gender, apoA‐1/ApoB, and PON1/apoA‐I ratios are important markers of CAD.
Ischemic heart disease: Metabolic approaches to management
Authors: Pauly Daniel F. , Pepine Carl J. 
Published: June 2007

AbstractThe number of patients with coronary artery disease and its risk factors is increasing in Western nations. New treatments for these patients may soon include a class of agents known as the metabolic modulators. This group of agents consists of the partial fatty acid oxidation inhibitors trimetazidine and ranolazine, as well as dichloroacetate, which promotes carbohydrate utilization. Metabolic modulators also include the nutriceuticals L‐carnitine and D‐ribose. The available evidence regarding the benefits of each of these five agents is reviewed.
Effects of cyclooxygenase inhibition on endothelial function in hypertensive patients treated with angiotensin‐converting enzyme inhibitors
Authors: Yamanari Hiroshi , Nakamura Kazufumi , Kakishita Mikio , Ohe Tohru 
Published: June 2007

AbstractBackground: Cyclooxygenase inhibition restores en‐dothelium‐dependent vasodilatation in hypertension, but it is unknown whether it restores endothelial function in hypertensive patients treated with angiotensin‐converting enzyme (ACE) inhibitors.Hypothesis: The purpose of the present study was to evaluate the effects of cyclooxygenase inhibition on endothelial function in hypertensive patients treated with ACE inhibitors.Methods: Endothelium‐dependent flow‐mediated dilatation (FMD) and endothelium‐independent glyceryl trinitrate‐induced dilatation were investigated in 10 patients treated with enalapril (ACE group), 11 patients treated with manidipine and metoprolol (non‐ACE group), and 12 normotensive control subjects. After administration of 1000 mg of aspirin, FMD was investigated once again. Plasma cyclic guanosine monophos‐phate (cGMP) and eicosanoids were also measured during reactive hyperemia before and after aspirin administration.Results: Flow‐mediated dilatation was more impaired in the non‐ACE group than in the ACE group (8.3 ± 3.8%, 5.7 ± 1.7%, respectively, p<0.04). Glyceryl trinitrate‐induced dilatation was similar in the ACE group, the non‐ACE group, and in the control subjects. In the ACE group, FMD was reduced after administration of aspirin (5.3 ± 4.2%, p<0.05). The percent change in FMD after administration of aspirin correlated significantly with percent change in cGMP (r = 0.77, p<0.03; y‐intercept, −62.1%, p<0.01). After aspirin administration, levels of thromboxane B2 and 6‐keto‐prosta‐glandiniα were significantly decreased compared with those before aspirin administration in all groups.Conclusions: Cyclooxygenase inhibition may reduce the beneficial effect on endothelium‐dependent vasodilatation induced by ACE inhibitors. The results suggested that prostacy‐clin in addition to nitric oxide plays a significant role in the restoration of endothelial function in hypertensive patients treated with ACE inhibitors.
Left atrial systolic function in primary and familial amyloidosis: Assessment from left atrial volume change
Authors: Moyssakis Ioannis , Triposkiadis Filippos , Pantazopoulos Nickolaos John , Kyriakidis Michael , Nihoyannopoulos Petros 
Published: June 2007

AbstractThe severity of left ventricular involvement may differ between primary (PA) and familial amyloidosis (FA). This study examined whether differences in left atrial (LA) systolic function are also present. Twenty‐eight patients (18 men, 10 women, aged 59 ± 12 years) with PA, 17(11 men, 6 women, aged 40 ± 11 years) with FA, and 25 normal controls (18 men, 7 women, aged 56 ± 14 years) underwent transthoracicM‐mode, two‐dimensional, and Doppler echocardiography. Left atrial volumes were determined at mitral valve (MV) opening (maximal, Vmax), electrocardiographic P wave (onset of atrial systole, Vp), and MV closure (minimal, Vmin) from the apical two‐and four‐chamber views using the biplane area‐length method. Left atrial systolic function was assessed with the LA active emptying volume (ACTEV) = Vp‐Vmin and fraction (ACTEF) = ACTEV/Vp. The E/A ratio was increased (1.34 ± 0.93 vs. 0.89 ± 0.3), whereas deceleration time was decreased (168.1 ± 33.7 vs. 196.2 ± 34.2 ms) in PA compared with FA (p < 0.05). Vmax and Vp were similar in PA and FA and greater than in the controls (46.6 ± 14 vs. 40 ± 11.4 vs. 27.1 ±6.3 cm3/m2, p<0.01, and33.4±11.6vs.29.7± 10.8 vs. 16.8 ± 3.8 cm3/m2, p<0.01, respectively). The ACTEV was lower in PA and in the controls than in FA (6.7 ± 2 vs. 6.2 ± 2.2 vs. 8.5± 3.3, respectively, p<0.05). The ACTEF was lower in PA than in FA and both were lower than those in the controls (20 ± 5% vs. 28 ± 7% vs. 36 ± 11%, respectively, p<0.01). Despite a similar increase in LA volume, LA systolic dysfunction is more pronounced in PA than in FA. This is most likely due to the restrictive left ventricular physiology possibly associated with depressed LA contractility in the former.
Pacemaker infection due to Aspergillus: report of two cases and literature review
Authors: Izquierdo Ricardo , Llorente Clotilde , Mayo Jose , Garcia‐Porrua Carlos , Gonzalez‐Juanatey Carlos , Gonzalez‐Gay Miguel A. 
Published: June 2007

AbstractBackground: Aspergillus infections of pacing systems are extremely uncommon, and most cases reported are characterized by an aggressive behavior that may lead to death of the patient.Hypothesis: The study was undertaken to assess the incidence of pacemaker infection due to Aspergillus in a defined population.Methods: A retrospective review of the case histories of all patients who underwent pacemaker implantation in the reference center for a defined population over a 13‐year period was undertaken. A literature review of pacemaker infections due to Aspergillus was conducted.Results: Of the 1,321 patients who required pacemaker implantation at Hospital Xeral‐Calde in the Lugo region of northwestern Spain, 38 suffered a pacemaker infection. A pacemaker pocket infection due to Aspergillus fumigatus was found in two patients. Both patients had a previous history of diabetes mellitus. Cultures from pacemaker pocket inflammatory fluid yielded positive results. Following pacemaker explantation and antifungal therapy, clinical improvement was achieved. A literature review showed another five cases of pacemaker infection due to Aspergillus. However, two peculiarities were found in our patients: In both cases an etiological diagnosis was achieved prior to surgery and, to the best of our knowledge, they also constitute the first cases of pacemaker pocket infection due to Aspergillus.Conclusion: Although pacemaker infections due to Aspergillus species are uncommon, they should be considered in immunocompromised patients.
Carvedilol's antiarrhythmic properties: Therapeutic implications in patients with left ventricular dysfunction
Authors: Naccarelli Gerald V. , Lukas Mary Ann 
Published: June 2007

AbstractCarvedilol is a beta‐and alpha‐adrenergic‐blocking drug with clinically important antiarrhythmic properties. It possesses anti‐ischemic and antioxidant activity and inhibits a number of cationic channels in the cardiomyocyte, including the HERG‐associated potassium channel, the L‐type calcium channel, and the rapid‐depolarizing sodium channel. The electrophysiologic properties of carvedilol include moderate prolongation of action potential duration and effective refractory period; slowing of atrioventricular conduction; and reducing the dispersion of refractoriness. Experimentally, carvedilol reduces complex and repetitive ventricular ectopy induced by ischemia and reperfusion.In patients, carvedilol is effective in controlling the ventricular rate response in atrial fibrillation (AF), with and without digitalis, and is useful in maintaining sinus rhythm after cardioversion, with and without amiodarone. In patients with AF and heart failure (HF), carvedilol reduces mortality risk and improves left ventricular (LV) function. Large‐scale clinical trials have demonstrated that combined carvedilol and angiotensin‐converting enzyme inhibitor therapy significantly reduces sudden cardiac death, mortality, and ventricular arrhythmia in patients with LV dysfunction (LVD) due to chronic HF or following myocardial infarction (MI).Despite intensive neurohormonal blockade, mortality rates remain relatively high in patients with post‐MI and nonischemic LVD. Recent trials of implantable cardioverter‐defibrillators added to pharmacologic therapy, especially beta blockers, have shown a further reduction in arrhythmic deaths in these patients.
Hospital protocols and evidence‐based therapies: The importance of integrating aldosterone blockade into the management of patients with post—acute myocardial infarction heart failure
Authors: Fonarow Gregg C. 
Published: June 2007

AbstractLeft ventricular systolic dysfunction (LVSD) and clinical heart failure are common complications of acute myocardial infarction (AMI) and result in substantially increased mortality and morbidity. Evidence‐based cardiovascular protective therapies, including angiotensin‐converting enzyme inhibitors, betablockers, antiplatelet agents, and lipid‐lowering medications, improve outcomes for these patients. However, this population is significantly undertreated with these guideline‐recommended agents. Critical pathways have been demonstrated to improve the quality and consistency of treatment; as such, the new American College of Cardiology/American Heart Association (ACC/AHA) guidelines for the management of patients with ST‐elevation myocardial infarction (STEMI) recommend that critical pathways be implemented for the management of these patients. The recent Eplerenone Post‐acute Myocardial Infarction Heart Failure Efficacy and Survival Study (EPHESUS) demonstrates that eplerenone, a selective aldosterone blocker, has incremental benefit in decreasing mortality and morbidity when used with standard care therapies in patients post AMI with heart failure and LVSD. The clinical trial evidence coupled with the national guidelines provides a strong rationale for routine incorporation of aldosterone blockade into new or already established critical pathways for AMI complicated by LVSD and heart failure.