bluuebunny/crossref_metadata_2025_split huggingface dataset:
In‐Hospital mortality of elderly patients with acute myocardial infarction: Data from the mitra (maximal individual therapy in acute myocardial infarction) registry
Authors: Haase K. K. , Schiele R. , Wagner S. , Fischer F. , Burczyk U. , Zahn R. , Schuster S. , Senges J. 
Published: February 2009

AbstractBackground: Advanced age remains one of the principal determinants of mortality in patients with acute myocardial infarction (AMI).Hypothesis: The aim of this study was to determine the in‐hospital outcome of elderly (>75 years) patients with AMI who were admitted to hospitals participating in the national MITRA (Maximal Individual Therapy in Acute Myocardial Infarction) registry.Methods: MITRA is a prospective, observational German multicenter registry investigating current treatment modalities for patients presenting with AMI. All patients with AMI admitted within 96 h of onset of symptoms were included in the MITRA registry. MITRA was started in June 1994 and ended in January 1997. This registry comprises 6,067 consecutive patients with a mean age of 65 ± 12 years, of whom 1,430 (17%) were aged > 75 years. Patients were compared with respect to patient characteristics, prehospital delays, early treatment strategies, and clinical outcome.Results: In the elderly patient population, the prehospital delay was 210 min, which was significantly longer than that for younger patients (155 min, p = 0.001). Although the incidence of potential contraindications for the initiation of thrombolysis was almost equally distributed between the two age groups (8.7 vs. 8.2%, p = NS), elderly patients (> 75 years) received reperfusion therapy less frequently (35.9 vs. 64.6%) than younger patients. Mortality increased with advanced age and was 26.4% for all patients aged > 75 years. If reperfusion therapy was initiated, in‐hospital mortality was 21.8 versus 28.9% in patients aged > 75 years (p = 0.001) and 29.4 versus 38.5% in patients aged > 85 years (p = 0.001).Conclusion: In this registry, elderly patients with AMI had a much higher in‐hospital mortality than that expected from randomized trials. In MITRA, the mortality reduction with reperfusion therapy was found to be highest in the very elderly patient population.
Isosorbide dinitrate inhibits platelet adhesion and aggregation in nonthrombolyzed patients with acute myocardial infarction
Authors: Gebalska Jadwiga , Wolk Robert , Ceremuzynski Leszek 
Published: February 2009

AbstractBackground: Apart from their vasodilatator properties, nitrates have been shown to inhibit platelet aggregation. The effects of nitrates on platelet adhesion have not been studied. Nonselected patients with acute myocardial infarction (AMI) have been suggested to gain no benefit from administration of nitrates. However, the importance of nitrates may be greater in a subgroup of nonthrombolyzed patients with AMI.Hypothesis: Isosorbide dinitrate (ISDN) decreases platelet adhesion and aggregation in nonthrombolyzed patients with AMI.Methods: Consecutive 48 men with AMI, not eligible for thrombolytic therapy because of late presentation (> 12 h), were prospectively randomized 2:1 to double‐blind ISDN (mean dose 2.4 ± 0.9 mg/h) (n = 33) or placebo (0.9% sodium chloride) (n = 15) infusion. All patients received aspirin. Blood samples were taken at baseline (no study medication) and 3 h into ISDN or placebo infusion. Platelet adhesion to collagen was measured in the ethylene diamine tetraacetic acid (EDTA)‐platelet rich plasma by recording changes in light transmission with an optical aggregometer. Platelet aggregation was measured using the Born's method.Results: Isosorbide dinitrate significantly decreased both platelet adhesion and aggregation. No effect was seen in the placebo group.Conclusions: In patients with AMI who do not receive thrombolytic therapy, ISDN effectively inhibits platelet adhesion and aggregation. These effects of nitrates may be of therapeutic and prognostic significance in this group of patients.
Detection of coronary stenoses by stress echocardiography using a previously implanted pacemaker for ventricular pacing: Preliminary report of a new method
Authors: Benchimol Daniel , Mazanof Marc , Benchimol HÉLÈNe , Bernard Virginie , Couffinhal Thierry , Roudaut Raymond , Dubroca BÉNÉDicte , Dartigues Jean François , Bonnet Jacques , Pillois Xaver 
Published: February 2009

AbstractBackground: The number of patients with pacemakers has been increasing and a large number of them will present with chest pain or symptoms suggesting angina pectoris. Myocardial ischemia and presence of coronary artery disease are difficult to detect and assess by noninvasive methods in patients with a pacemaker; the electrocardiogram (ECG) at rest and during exercise is usually very difficult to analyze in terms of ischemia or even presence of an acute myocardial infarction.Hypothesis: To detect significant coronary stenosis in patients with previously implanted pacemakers, we tested a new stress echocardiography method using incremental ventricular pacing by already implanted pacemakers.Methods: We studied prospectively 25 consecutive patients who underwent stress echocardiography with increasing ventricular pacing up to either 85% of the age‐predicted maximal heart rate or chest pain. Positive tests were defined by new hypokinesia or worsening of a preexisting alteration in wall motion in at least two adjacent territories. All patients underwent coronary angiograms to define the presence and severity of coronary stenoses.Results: Among the 25 tests, 11 (44%) were stopped for chest pain, 1 (4%) for moderate discomfort, 1 (4%) for a drop in blood pressure, and the target pacing rate was achieved in the tests of the remaining 12 patients (48%). There were no complications. Thirteen patients had significant stenoses. In 10 cases, stress echocardiography was a true positive test with respect to coronary angiography. There were 11 true negative, 1 false positive, and 3 false negative tests. The sensitivity was 77%, specificity was 90%, the positive predictive value was 91%, and the negative predictive value 79%. The accuracy was 84%.Conclusions: This new stress echocardiography method appears feasible, easy, safe, and effective for detection of significant coronary stenoses in patients with pacemakers.
Two‐Year case collection of the brugada syndrome electrocardiogram pattern at a large teaching hospital
Authors: Monroe Michael H. , Littmann Laszlo 
Published: February 2009

AbstractBackground: Recommendations have recently emerged suggesting that the presence of the Brugada electrocardiographic (ECG) pattern in an otherwise asymptomatic individual warrants electrophysiologic testing for inducible ventricular arrhythmias. However, the prevalence of this pattern in the general population and its specificity for identifying those likely to develop the true Brugada syndrome are not known.Hypothesis: The purpose of this study was to collect ECGs that displayed the Brugada pattern from unselected, noncar‐diac patients at a single institution to determine whether the implied prevalence in the literature may represent a significant underestimation of the true prevalence.Methods: We performed a prospective case collection of Brugada‐patterned ECGs over a 2‐year time period from unselected, noncardiac patients at a large urban teaching hospital.Results: Of approximately 12,000 noncardiac patients, 52 were found to have an ECG pattern fully consistent with the Brugada sign.Conclusions: The Brugada type ECG pattern is much more prevalent than previously reported when rigorously searched for in a prospective manner. More data are needed on its specificity for predicting future arrhythmic events in asymptomatic individuals before recommendations are made for extensive evaluation in this group.
Coronary artery stent infection
Authors: Dieter Robert S. 
Published: February 2009

AbstractThis paper aimed to examine the literature for cases of coronary artery stent infection in order to provide comprehensive data to clinicians regarding its prevalence, clinical presentations, and possible treatments. Coronary artery stenting was initially reported in 1987. Stenting of the coronary arteries is now used in 40–60% of all interventional coronary artery procedures. The understanding of the pathophysiology of coronary artery disease is evolving. It has been suggested that atherosclerosis may be a complication of an infectious etiology. By using a stent to treat coronary artery disease, a foreign body is directly juxtaposed with an area of inflammation. The first reported case of an infected coronary artery stent was in 1993. Although this is an exceedingly rare event, the associated mortality is alarmingly high. Analysis of the literature reveals a total of four reported cases of coronary artery stent infection. Symptoms of stent infection present days to weeks after the initial coronary intervention. All four patients developed fevers and at least two patients developed postintervention angina. In patients who have had a coronary artery stented, the presence of angina and fevers should make the clinician suspicious for a stent‐related infection. Two of the patients had infection with Pseudomonas aeruginosa, which seems to be an unusual organism for a catheter‐related infection. Surgical removal of the infected stent and artery complex was performed on nearly all cases. Despite aggressive measures, the majority of patients died. Few data are available on the long‐term risk for coronary artery stent infection. In a patient who has undergone coronary artery stent placement, the clinician must be very sensitive to fever, return of angina, and bacteremia. The complication rate at the present time does not warrant the use of prophylactic antibiotics prior to high‐risk procedures (e.g., dental procedures). Furthermore, the low infection rate of coronary artery stents may be a result of the inflammatory nature of atherosclerosis, which may provide a protective benefit against bacterial infection of the stent.
A Prospective Study of an Algorithm Using Cardiac Troponin I and Myoglobin as Adjuncts in the Diagnosis of Acute Myocardial Infarction and Intermediate Coronary Syndromes in a Veteran's Hospital
Authors: Maisel Alan S. , Templin Kathleen , Love Martha , Clopton Paul 
Published: February 2009

AbstractBackground: Accurate and cost‐effective evaluation of acute chest pain has been problematic for years. The high prevalence of missed myocardial infarctions (MI) has led to conservative triage behavior on the part of physicians, leading to expensive admissions to coronary care units. New algorithms are sorely needed for more rapid and accurate triage of patients with chest pain to appropriate treatment settings.Hypothesis: We sought to test an algorithm for rapid diagnosis of MI and acute coronary syndromes using cardiac troponin I (cTnI) and myoglobin as adjuncts to creatine kinase (CK)‐MB. We hypothesized our algorithm would be both sensitive and specific at early time points, and would allow safe stratification of patients not ruling in by conventional CK‐MB criteria.Methods: This was a 6‐month prospective study of 505 consecutive patients who presented with chest pain at a university‐affiliated veteran's hospital. The percentage of MIs at various time points was identified using combinations of markers. Safety outcomes were assessed by follow‐up of patients discharged home. Cost savings analysis was assessed by surveying the physicians as to whether the use of the algorithm affected their disposition of patients. Forty‐nine patients ruled in for MI. Using the combination of cTnI, 2‐h doubling of myoglobin, and CK‐MB, 37 (76%) ruled in at the time of presentation, 43 (88%) at 2 h, and 100% by 6 h.Results: Cardiac troponin I plus a 2‐h myoglobin was as accurate as the combination of all three markers and performed better than CK‐MB in detecting patients presenting late and as a predictor for complications when CK‐MB was normal. Of the 456 patients with normal markers after 6 h, only 140 were sent to the coronary care unit (CCU), and 176 were sent home. A 3‐month follow‐up showed minimal adverse events. One‐half of physicians completing a survey stated the use of markers changed their disposition of patients, leading to an estimated 6‐month cost savings of a half‐million dollars.Conclusions: We developed an algorithm using troponin I and myoglobin as adjuncts to usual CK‐MB levels that allowed for rapid and accurate assessment of patients with acute MI. It also afforded physicians important input into their decision making as to how best to triage patients presenting with chest pain. Their comfort in sending home certain subgroups of patients who otherwise would have been admitted to the CCU was rewarded with a good short‐term prognosis and a large cost savings to the hospital.
Zn1.2H0.6PW12O40 Nanotubes with Double Acid Sites as Heterogeneous Catalysts for the Production of Biodiesel from Waste Cooking Oil
Authors: Li Jing , Wang Xiaohong , Zhu Weimin , Cao Fenghua 
Published: February 2009

AbstractOut of the frying pan: A ZnPW nanotube catalyst containing Brønsted and Lewis double acid sites promotes the conversion of waste cooking oil into biodiesel. The catalytic activity of the ZnPW nanotubes is stable to the presence of free fatty acids or water in the feedstock. The high catalytic activity of the ZnPW nanotubes is attributed to the synergistic effect of Lewis acid sites and Brønsted acid sites.magnified imageZinc dodecatungstophosphate (Zn1.2H0.6PW12O40; ZnPW) nanotubes, which feature Lewis acid and Brønsted acid sites, were prepared using cellulose fibers as templates. The structure, acid properties, and catalytic activity of the nanotubes as heterogeneous catalysts for biodiesel production were then studied in detail. The ZnPW nanocatalyst exhibited higher catalytic activities for the simultaneous esterification and transesterification of palmitic acid than the parent acid catalyst 12‐tungstophosphoric acid (H3PW12O40). Moreover, the doubly acidic nanotubes led to markedly enhanced yields of methyl esters in the conversion of waste cooking oil (containing 26.89 wt % free fatty acids and 1 % moisture) to biodiesel. The catalyst could be recycled and reused with negligible loss in activity over five cycles. The ZnPW nanocatalyst is acid‐ and water‐tolerant and is an environmentally benign heterogeneous catalyst for the production of biodiesel from low‐quality feedstocks.
Synthesis of Dispersed Anatase Microspheres with Hierarchical Structures via Homogeneous Precipitation
Authors: Liu Shaohong , Sun Xudong , Li Ji‐Guang , Li Xiaodong , Xiu Zhimeng , Huo Di 
Published: February 2009

AbstractSpherical anatase microparticles with good crystallinity have been synthesized by homogeneous precipitation under mild conditions (83–100 °C), employing ammonium fluotitanate as the titanium source and urea as the precipitant instead of more commonly used and highly reactive titanium sources such as titanium alkoxides and tetrachloride, which are sensitive to atmospheric moisture and therefore require special precautions. The as‐prepared anatase particles were characterized by XRD, FE‐SEM, UV/Vis spectroscopy, TG‐DSC, and FTIR spectroscopy. The microspheres obtained in this work are hierarchically structured and are built up of rounded anatase nanocrystallites with a diameter of approximately 15–40 nm. The morphology of the nanoparticles within each microparticle changes from sphere to spindle as the reaction time is increased from 30 to 120 min in the experimental temperature range from 83 to 100 °C. A higher reaction temperature leads to enhanced growth of the nanocrystallites (primary particles) in solution and somewhat smaller anatase microspheres. The optical bandgaps and indirect bandgaps for all samples are approximately 3.23 and 2.95 eV, respectively, irrespective of their morphologies.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Recent Advances in Organoselenium Chemistry
Authors: Freudendahl Diana M. , Shahzad Sohail A. , Wirth Thomas 
Published: February 2009

AbstractThis microreview highlights new developments of organoselenium chemistry and new selenium compounds as versatile reagents in synthesis. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Cognitive function and common mental disorders in older people with vascular and non‐vascular disorders: a national survey
Authors: Begum Aysha , Tsopelas Christos , Lindesay James , Stewart Robert 
Published: February 2009

AbstractObjectiveVascular disorders are important potential causes of cognitive impairment and common mental disorders but their specificity as risk factors has yet to be clarified. The objectives of this analysis were to compare vascular and non‐vascular health problems with respect to their associations with cognitive function and common mental disorder.MethodAn analysis was carried out of cross‐sectional data from the 2000 UK National Survey of Psychiatric Morbidity. The two dependent variables analysed were common mental disorder (revised Clinical Interview Schedule) and cognitive function (TICSm and animal naming) in survey participants who were aged 60–74 years (n = 2007). Associations with self‐reported vascular and common non‐vascular (musculoskeletal, respiratory or gastrointestinal) disorders were compared. Disability (SF‐12 physical scale) was considered as a potential confounding/mediating factor).ResultsVascular disorders were associated with impaired global cognitive function and lower memory but not verbal fluency scores after adjustment for age, gender, education and social class. No such associations were found for non‐vascular disorders. Vascular and non‐vascular disorders were associated with common mental disorder to a similar extent, and associations were substantially explained by disability.ConclusionsLower cognitive function was specifically associated with vascular disorders. Findings for common mental disorder were more consistent with an effect of disability rather than the actual consequences of specific health complaints. Copyright © 2009 John Wiley & Sons, Ltd.
Long-term monitoring shows hepatitis B virus resistance to entecavir in nucleoside-naïve patients is rare through 5 years of therapy #
Authors: Tenney Daniel J. , Rose Ronald E. , Baldick Carl J. , Pokornowski Kevin A. , Eggers Betsy J. , Fang Jie , Wichroski Michael J. , Xu Dong , Yang Joanna , Wilber Richard B. , Colonno Richard J. 
Published: February 2009

Abstract
Patients with chronic hepatitis B virus (HBV) infection who develop antiviral resistance lose benefits of therapy and may be predisposed to further resistance. Entecavir (ETV) resistance (ETVr) results from HBV reverse transcriptase substitutions at positions T184, S202, or M250, which emerge in the presence of lamivudine (LVD) resistance substitutions M204I/V ± L180M. Here, we summarize results from comprehensive resistance monitoring of patients with HBV who were continuously treated with ETV for up to 5 years. Monitoring included genotypic analysis of isolates from all patients at baseline and when HBV DNA was detectable by polymerase chain reaction (≥300 copies/mL) from Years 1 through 5. In addition, genotyping was performed on isolates from patients experiencing virologic breakthrough (≥1 log10 rise in HBV DNA). In vitro phenotypic ETV susceptibility was determined for virologic breakthrough isolates, and for HBV containing novel substitutions emerging during treatment. The results over 5 years of therapy showed that in nucleoside-naïve patients, the cumulative probability of genotypic ETVr and genotypic ETVr associated with virologic breakthrough was 1.2% and 0.8%, respectively. In contrast, a reduced barrier to resistance was observed in LVD-refractory patients, as the LVD resistance substitutions, a partial requirement for ETVr, preexist, resulting in a 5-year cumulative probability of genotypic ETVr and genotypic ETVr associated with breakthrough of 51% and 43%, respectively. Importantly, only four patients who achieved <300 copies/mL HBV DNA subsequently developed ETVr. Conclusion: Long-term monitoring showed low rates of resistance in nucleoside-naïve patients during 5 years of ETV therapy, corresponding with potent viral suppression and a high genetic barrier to resistance. These findings support ETV as a primary therapy that enables prolonged treatment with potent viral suppression and minimal resistance. (Hepatology 2009.)
The summer hydrology of a small upland tundra thaw lake: implications to lake drainage
Authors: Pohl S. , Marsh P. , Onclin C. , Russell M. 
Published: February 2009

AbstractThe phenomenon of thaw lake disappearance through rapid drainage has been identified as a potential issue for many circumpolar Arctic regions. These drainage events and the associated flood waves pose a considerable danger to human and animal habitat especially in lake‐rich Arctic regions. The significance of this phenomenon is further heightened by the recent increase in human activity in Arctic regions, such as resource exploration, as well as the projected changes in climatic conditions for Arctic regions.This study is aimed at providing improved understanding of the hydrology of upland tundra thaw lakes, a type of lake that is prone to rapid drainage, by using a combination of observed and modelled data to calculate the complete summer lake water balance for a small thaw lake located to the east of the Mackenzie delta in northwestern Canada. The lake level calculation is subsequently extended to provide a 32‐year estimate of lake levels for the study lake. This long‐term dataset is used to detect patterns and trends in peak summer lake levels. Furthermore, it is used together with climate data for the same time period to look at lake levels and climatic conditions at the time of known rapid lake drainage events. The results of the study suggest that while high lake levels are considered to be a contributing factor for rapid lake drainage, climatic conditions such as above‐average summer air temperature and precipitation values also seem to be key factors. These findings are a first step in determining how projected future climate conditions might influence the rate of rapid lake drainages of Arctic tundra thaw lakes. Copyright © 2009 John Wiley & Sons, Ltd and Her Majesty the Queen in right of Canada. The contributions of P. Marsh, C. Onclin and M. Russell belong to the Crown in right of Canada and are reproduced with the permission of Environment Canada.
Beaver dams along an agricultural stream in southern Ontario, Canada: their impact on riparian zone hydrology and nitrogen chemistry
Authors: Hill Alan R. , Duval Tim P. 
Published: February 2009

AbstractThe hydrology and nitrogen biogeochemistry of a riparian zone were compared before and after the construction of beaver dams along an agricultural stream in southern Ontario, Canada. The beaver dams increased surface flooding and raised the riparian water table by up to 1·0 m. Increased hydraulic gradients inland from the stream limited the entry of oxic nitrate‐rich subsurface water from adjacent cropland. Permeable riparian sediments overlying dense till remained saturated during the summer and autumn months, whereas before dam construction a large area of the riparian zone was unsaturated in these seasons each year. Beaver dam construction produced significant changes in riparian groundwater chemistry. Median dissolved oxygen concentrations were lower in riparian groundwater after dam construction (0·9–2·1 mg L−1) than in the pre‐dam period (2·3–3·9 mg L−1). Median NO3‐N concentrations in autumn and spring were also lower in the post‐dam (0·03–0·07 mg L−1) versus the pre‐dam period (0·1–0·3 mg L−1). In contrast, median NH4‐N concentrations in autumn and spring months were higher after dam construction (0·3–0·4 mg L−1) than before construction (0·13–0·14 mg L−1). Results suggest that beaver dams can increase stream inflow to riparian areas that limit water table declines and increase depths of saturated riparian soils which become more anaerobic. These changes in subsurface hydrology and chemistry have the potential to affect the transport and transformation of nitrate fluxes from adjacent cropland in agricultural landscapes. Copyright © 2009 John Wiley & Sons, Ltd.