bluuebunny/crossref_metadata_2025 huggingface dataset:
Hemodynamic effects and long‐term outcome of percutaneous balloon valvuloplasty in patients with mitral stenosis and atrial fibrillation
Authors: Tarka Elizabeth A. , Blitz Lawrence R. , Herrmann Howard C.
Published: February 2009

Background: The presence of atrial fibrillation (AF) has been identified as a predictor of a suboptimal result in some patients undergoing percutaneous balloon valvuloplasty in the treatment of symptomatic rheumatic mitral stenosis.

Hypothesis: Atrial fibrillation adversely affects the short‐and long‐term outcome of patients with mitral stenosis undergoing percutaneous balloon valvuloplasty.

Methods: A retrospective chart review of 104 consecutive patients with rheumatic mitral stenosis undergoing percutaneous balloon valvuloplasty was performed. A successful procedure was defined as a final mitral valve area ≤ 1.5 cm2 and the absence of a complication. Endpoints included freedom from mitral valve replacement, death, and repeat balloon valvuloplasty at 5 years.

Results: A successful procedure was obtained in 89% of patients with sinus rhythm and in 78% of patients with AF (p = NS). Patients in sinus rhythm had a greater cardiac output resulting in a larger final valve area than patients in AF (1.8 vs. 1.6 cm2, p<0.05). Freedom from valve replacement, death, and repeat balloon valvuloplasty at 5 years was 75% for patients in AF and 76% for patients in sinus rhythm (p = NS). Lower postprocedure mitral regurgitation grade and absence of prior commissurotomy were the only independent predictors of event‐free survival.

Conclusions: Patients with mitral stenosis and AF have lower cardiac outputs and gradients than patients with sinus rhythm, despite similar valve areas. The long‐term outcome of balloon valvuloplasty is independent of the initial cardiac rhythm.
Comparison of the efficacy and tolerability of simvastatin and atorvastatin in the treatment of hypercholesterolemia
Authors: Recto Cesar S. , Acosta Stella , Dobs Adrian
Published: February 2009

Background: Simvastatin and atorvastatin are effective statins for treating hypercholesterolemia.

Hypothesis: The study was undertaken to compare the efficacy and tolerability of simvastatin 20 and 40 mg/day and atorvastatin 10 and 20 mg/day.

Methods: In this multinational, open‐label, crossover study, 258 patients with primary hypercholesterolemia were randomized after 4 weeks of diet plus placebo to once‐daily administration of a starting dose sequence of simvastatin (20 mg) or atorvastatin (10 mg), or a higher dose sequence of simvastatin (40 mg) or atorvastatin (20 mg) for 6 weeks. Patients were then switched after a 1‐week washout to the corresponding starting or higher dose of the alternate drug for a second 6‐week period. The primary endpoint was the mean percent change from baseline to Week 6 in low‐density lipoprotein (LDL) cholesterol; percent changes from baseline in total cholesterol, high‐density lipoprotein cholesterol, triglycerides, and apolipoprotein B were also compared. Safety was assessed through adverse experiences and laboratory measurements.

Results: Both statins produced statistically significant improvements in all measured plasma lipids and lipoproteins. The main treatment comparison showed no statistically significant difference in changes in LDL cholesterol and triglycerides, whereby the overall effects were comparable when doses of 20 mg and 40 mg of simvastatin were compared with atorvastatin 10 mg and 20 mg. The mean percent reductions for LDL cholesterol from baseline to Week 6 ranged from 35–42% for the entire study cohort. An LDL cholesterol level ≤ 130 mg/dl (3.4 mmol/l) was achieved in approximately 70% of patients treated with both drugs in this study. Simvastatin and atorvastatin were well tolerated at the doses studied.

Conclusion: In patients with hypercholesterolemia, the most commonly used doses of simvastatin and atorvastatin produced similar changes in LDL cholesterol and achieved an LDL cholesterol level ≤ 130 mg/dl (3.4 mmol/l) in a similar number of patients. Both statins were well tolerated.
Intracardiac masses detected by echocardiography: Case presentations and review of the literature
Authors: Lobo Arlene , Lewis Jannet F. , Conti C. Richard
Published: February 2009

Intracardiac masses are often diagnosed by transthoracic echocardiography (TTE). Transesophageal echocardiography (TEE) improves overall visualization of masses, especially those located in the posterior cardiac structures. Masses in the heart are most commonly due to thrombi or valvular vegetations; however, a variety of tumors may also present as cardiac masses on echocardiography. Tumors of the heart most commonly occur in the setting of metastatic disease, usually from malignancies of the breast, lung, or from malignant melanoma. Primary cardiac tumors occur much less frequently and are usually benign. Atrial myxomas constitute nearly one‐half of reported primary cardiac tumors. The following discussion details the findings of five cases that illustrate the spectrum of intracardiac rumors detected by echocardiography and reviews the relevant literature.
Postoperative troponin I values: Insult or injury?
Authors: Horvath Keith A. , Parker Michelle A. , Frederiksen James W. , Palmer Arthur S. , Fullerton David A.
Published: February 2009

Background: Troponin I (TnI) is increasingly employed as a highly specific marker of acute myocardial ischemia. The value of this marker after cardiac surgery is unclear.

Hypothesis: The purpose of this study was to measure serum TnI levels prospectively at 1, 6, and 72 h after elective cardiac operations. In addition, TnI levels were measured from the shed mediastinal blood at 1 and 6 h postoperatively. Serum values were correlated with cross clamp time, type of operation, incidence of perioperative myocardial infarction, as assessed by postoperative electrocardiograms (ECG) and regional wall motion, as documented by intraoperative transesophageal echocardiography (TEE).

Methods: Sixty patients underwent the following types of surgery: coronary artery bypass graft (CABG) (n = 45), valve repair/replacement (n = 10), and combination valve and coronary surgery (n = 5). Myocardial protection consisted of moderate systemic hypothermia (30–32°C), cold blood cardioplegia, and topical cooling for all patients.

Results: Of 60 patients, 57 (95%) had elevated TnI levels, consistent with myocardial injury, 1 h postoperatively. This incidence increased to 98% (59/60) at 6 h postoperatively. There was a positive correlation between the length of cross clamp time and initial postoperative serum TnI (r = 0.70). There was no difference in the serum TnI values whether or not surgery was for ischemic heart disease (CABG or CABG + valve versus valve). There were no postoperative myocardial infarctions as assessed by serial ECGs. There was no evidence of diminished regional wall motion by TEE.

Levels of TnI in the mediastinal shed blood were greater than assay in 58% (35/60) of the patients at 1 h and in 88% (53/60) at 6 h postoperatively. Patients who received an auto‐transfusion of mediastinal shed blood (n = 22) had on average a 10‐fold postoperative increase in serum TnI levels between 1 and 6 h. Patients who did not receive autotransfusion average less than doubled their TnI levels over the same interval. At 72 h, TnI levels were below the initial postoperative levels but still indicative of myocardial injury.

Conclusion: Postoperative TnI levels are elevated after all types of cardiac surgery. There is a strong correlation between intraoperative ischemic time and postoperative TnI level. Further elevation of TnI is significantly enhanced by reinfusion of mediastinal shed blood. Despite these postoperative increases in TnI, there was no evidence of myocardial infarction by ECG or TEE. The postoperative TnI value is even less meaningful after autotransfusion of shed mediastinal blood.
Emergent angioplasty prevents left ventricular dilation in patients with acute anterior wall myocardial infarction and cardiogenic shock
Authors: Iwamori Kiyotake , Sakata Konomi , Kurihara Hiroaki , Yoshino Hideaki , Ishikawa Kyozo
Published: February 2009

Background: Percutaneous transluminal coronary angioplasty (PTCA) reduces in‐hospital mortality and improves long‐term outcome in patients with acute myocardial infarction (MI) complicated by cardiogenic shock. However, no study has evaluated the effects of different reperfusion therapies on left ventricular (LV) dimension and cardiac function in long‐term survivors of MI with cardiogenic shock.

Hypothesis: We investigated the effects of PTCA on the development of LV dilation in patients who survived MI complicated by cardiogenic shock.

Methods: We studied 34 patients with a first MI and cardiogenic shock in whom two‐dimensional echocardiography was performed immediately after admission and 1 month after infarction. Group A consisted of 17 patients who underwent emergent PTCA during the acute phase of MI, and Group B consisted of 17 patients who did not undergo PTCA. We also studied 119 patients with a first uncomplicated acute anterior MI, including 53 who underwent PTCA (Group C) and 66 who did not (Group D). The length and wall thickness of the infarcted and noninfarcted endocardial segments were determined immediately after MI and 1 month later, and LV ejection fraction (LVEF) was measured during the chronic phase.

Results: The lengths of the infarcted and noninfarcted endocardial segments were significantly greater in Group B than in the other three groups (p < 0.05). The LVEF was significantly lower in Group B than in the other three groups (p < 0.05).

Conclusions: We conclude that PTCA performed in patients during the acute phase of MI complicated by cardiogenic shock lowers in‐hospital mortality and prevents both LV dilation and a decrease in LVEF.
Assessment of left ventricular systolic function in patients with idiopathic mitral valve prolapse using dobutamine stress echocardiography
Authors: Tikiz Hakan , Balbay YÜCel , Kural Tevfik , Göksel Siber
Published: February 2009

Background: Some previous studies performed with radionuclide ventriculography and thallium scintigraphy reported that patients with idiopathic mitral valve prolapse (MVP) had some degree of left ventricular (LV) systolic dysfunction and that this dysfunction was more commonly found in symptomatic patients.

Hypothesis: The aim of the present prospective study was to investigate LV systolic function and its relationship with symptoms in patients with MVP with dobutamine stress test without associated certain mitral regurgitation and coronary artery disease.

Methods: Thirty‐three patients with echocardiographically diagnosed idiopathic MVP were enrolled into the study and were divided into two groups as symptomatic (MVP‐s) and asymptomatic (MVP‐a). Patients underwent dobutamine stress echocardiography (DSE) to determine wall motion abnormalities and ejection fraction (EF) changes during rest state and increased heart rates. Results were compared with the DSE findings of 25 healthy individuals.

Results: Symptomatic patients (MVP‐s) had lower EFs during the pretest period than the control group (59.0 ± 4.8% and 68.3 ± 5.7%, respectively, p < 0.05). Basal wall motion abnormalities were found in one patient in the MVP‐a group (6%) and in two patients in the MVP‐s group (12%). During DSE, new wall motion abnormalities (inferoapical dyskinesia) occurred in two patients in the MVP‐s group at submaximal heart rates. For EF values calculated when patients reached submaximal heart rate, the MVP‐s group showed only a 2.7 ± 3.1% increase from baseline values. This increase was 5.1 ± 3.8% in the MVP‐a group and 9.3 ± 4.3% in the control group (p < 0.05 between MVP‐s and control groups).

Conclusion: There is a close relationship between symptoms and ventricular function in patients with idiopathic MVP, and although many asymptomatic patients had nearly normal LV function, a subgroup of symptomatic patients showed diminished LV function and wall motion abnormalities.
Effects of theophylline on exercise indices in a patient with chronotropic incompetence
Authors: Dixoniv William C. , Bauch Terry D.
Published: February 2009

Several investigators have documented the successful use of oral sustained‐release theophylline in treating symptomatic bradycardia and sick sinus syndrome. This paper reports a case of chronotropic incompetence in which specific exercise indices, including the chronotropic response index, were used to measure the therapeutic efficacy of theophylline.
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

Background: 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

Background: 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

Background: 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

Background: 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.
An unusual atrial mass
Authors: Strike Philip C. , Jones Richard A. , Simpson Iain A.
Published: February 2009

Giant coronary artery aneurysm is a rare manifestation of coronary artery disease. This patient presented at echocardiography and was successfully managed by surgical resection.
Coronary artery stent infection
Authors: Dieter Robert S.
Published: February 2009

This 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

Background: 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

Out 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.

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Zinc 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

Spherical 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

This 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

Objective

Vascular 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.

Method

An 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).

Results

Vascular 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.

Conclusions

Lower 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

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

The 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

The 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.
Coupling the Xinanjiang model to a kinematic flow model based on digital drainage networks for flood forecasting
Authors: Liu Jintao , Chen Xi , Zhang Jiabao , Flury Markus
Published: February 2009

The Xinanjiang model, which is a conceptual rainfall‐runoff model and has been successfully and widely applied in humid and semi‐humid regions in China, is coupled by the physically based kinematic wave method based on a digital drainage network. The kinematic wave Xinanjiang model (KWXAJ) uses topography and land use data to simulate runoff and overland flow routing. For the modelling, the catchment is subdivided into numerous hillslopes and consists of a raster grid of flow vectors that define the water flow directions. The Xinanjiang model simulates the runoff yield in each grid cell, and the kinematic wave approach is then applied to a ranked raster network. The grid‐based rainfall‐runoff model was applied to simulate basin‐scale water discharge from an 805‐km2 catchment of the Huaihe River, China. Rainfall and discharge records were available for the years 1984, 1985, 1987, 1998 and 1999. Eight flood events were used to calibrate the model's parameters and three other flood events were used to validate the grid‐based rainfall‐runoff model. A Manning's roughness via a linear flood depth relationship was suggested in this paper for improving flood forecasting. The calibration and validation results show that this model works well. A sensitivity analysis was further performed to evaluate the variation of topography (hillslopes) and land use parameters on catchment discharge. Copyright © 2009 John Wiley & Sons, Ltd.
Novel human breast cancer cell lines IBH‐4, IBH‐6, and IBH‐7 growing in nude mice
Authors: Bruzzone Ariana , Vanzulli Silvia Inés , Soldati Rocío , Giulianelli Sebastián , Lanari Claudia , Lüthy Isabel Alicia
Published: February 2009

Breast cancer is the most frequent cancer in women. However, in vivo hormone receptor positive and metastatic models are scarce. The aim of the present manuscript was to assess if the novel steroid receptor positive human cell lines IBH‐4, IBH‐6, and IBH‐7 developed in our laboratory from primary infiltrant ductal carcinomas are good models to study in vivo human breast cancer. Cell lines or tumors were inoculated to nude mice in the presence or absence of hormone supplementation. Growth was analyzed by ANOVA followed by Tukey–Kramer's test. Steroid hormone expression was assessed by immunohistochemistry and Western blotting. The histology of the tumors was analyzed. IBH‐4 and IBH‐6 cells were inoculated to nude mice and 100% of the injected mice developed tumors in the presence or absence of hormone treatment, although tamoxifen inhibited growth. IBH‐4 and IBH‐6 cell lines in vivo gave rise to poorly differentiated carcinomas with areas of solid growth and sarcomatoid areas showing no morphological signs of epithelial differentiation. Distinct features of malignancy were observed. IBH‐7 tumors in animals receiving estradiol were semi‐differentiated adenocarcinomas. IBH‐7 cells grew only in the presence of estradiol, but even with hormone addition, the tumor take was 20%. These tumors metastasized to the uterus and lung and vascular tumor emboli were evident. IBH‐7 tumors were invasive and able to break through the peritoneum. As a conclusion, IBH‐4 and IBH‐6 are good models for studying tumor progression, whereas IBH‐7 is a good model for tumor take, being metastatic and strictly estrogen‐dependent. J. Cell. Physiol. 219: 477–484, 2009. © 2009 Wiley‐Liss, Inc.
5′‐N‐ethylcarboxamide induces IL‐6 expression via MAPKs and NF‐κB activation through Akt, Ca2+/PKC, cAMP signaling pathways in mouse embryonic stem cells
Authors: Kim Mi Ok , Kim Min Hee , Lee Sang Hun , Suh Han Na , Lee Yu Jin , Lee Min Yong , Han Ho Jae
Published: February 2009

Many studies suggest that adenosine modulates cell responses in a wide array of tissues through potent and selective regulation of cytokine production. This study examined the effects of adenosine on interleukin (IL)‐6 expression and its related signal pathways in mouse embryonic stem (ES) cells. In this study, the adenosine analogue 5′‐N‐ethylcarboxamide (NECA) increased IL‐6 protein expression level. Mouse ES cells expressed the A1, A2A, A2B, and A3adenosine receptors (ARs), whose expression levels were increased by NECA and NECA‐induced increase of IL‐6 mRNA expression or secretion level was inhibited by the non‐specific AR inhibitor, caffeine. NECA increased Akt and protein kinase C (PKC) phosphorylation, intracellular Ca2+and cyclic adenosine monophosphate (cAMP) levels, which were blocked by caffeine. On the other hand, NECA‐induced IL‐6 secretion was partially inhibited by Akt inhibitor, bisindolylmaleimide I (PKC inhibitor), SQ 22536 (adenylate cyclate inhibitor) and completely blocked by the 3 inhibitor combination treatment. In addition, NECA increased mitogen activated protein kinase' (MAPK) phosphorylation, which were partially inhibited by the Akt inhibitor, bisindolylmaleimide I, and SQ 22536 and completely blocked by the 3 inhibitor combination treatment. NECA‐induced increases of IL‐6 protein expression and secretion levels were inhibited by MAPK inhibition. NECA‐induced increase of nuclear factor (NF)‐κB phosphorylation was inhibited by MAPK inhibitors. NECA also increased cAMP response element‐binding protein (CREB) phosphorylation, which was blocked by MAPK or NF‐κB inhibitors. Indeed, NECA‐induced increase of IL‐6 protein expression and secretion was blocked by NF‐κB inhibitors. In conclusion, NECA stimulated IL‐6 expression via MAPK and NF‐κB activation through Akt, Ca2+/PKC, and cAMP signaling pathways in mouse ES cells. J. Cell. Physiol. 219: 752–759, 2009. © 2009 Wiley‐Liss, Inc.
Protective immunity against porcine circovirus 2 in mice induced by a gene‐based combination vaccination
Authors: Aravindaram Kandan , Kuo Tsun‐Yung , Lan Chun‐Wen , Yu Hsiu‐Hui , Wang Pei‐Hsueh , Chen Yu‐San , Chen Gabriel Hsu‐Chung , Yang Ning‐Sun
Published: February 2009

Background

Porcine circovirus type 2 (PCV2) is the primary cause of an emerging swine disease, postweaning multisystemic wasting syndrome, that is responsible for economic losses. To develop an effective vaccine for PCV2, we evaluated a heterologous prime‐boost vaccine approach, using a gene gun‐mediated naked DNA vector as a priming and modified vaccinia virus ankara (MVA) as a booster, in Balb/c mice.

Methods

Three open reading frames (ORF) of PCV2 viral samples from infected pigs were amplified, and gene gun‐mediated DNA priming vaccination was performed followed by boosts with MVA vectors expressing the same ORFs of PCV2. After vaccination, mice were challenged with PCV2 virus, and virus titers in the lungs and lymph nodes were measured.

Results

The combination of ORF‐2 and ‐3 in this gene‐based vaccine strategy resulted in high antibody titers and virus neutralization activity in serum, reduced PCV2 virus load, and reduced levels of apoptosis in the lungs. No cross‐reaction was observed between ORF‐1 and ‐2, but weak cross‐reaction was observed between ORF‐1 and ‐3, and between ORF‐2 and ‐3. Following vaccination, expression of chemokines, macrophage inflammatory protein‐1β and regulated upon activation, normal T cell expressed and secreted, increased significantly. The expression of T helper 1‐type cytokine (interferon‐γ) and specific lysis of PCV2‐infected cells increased; concomitantly, the level of T helper 2‐type cytokine (interleukin‐10) decreased in test mice. The expression of tumor necrosis factor‐α and granulocyte‐macrophage colony‐stimulating factor increased significantly in mice vaccinated with ORF‐2/‐3, and with ORF‐1/‐2/‐3.

Conclusions

This prime‐boost vaccination strategy, using a gene gun for DNA priming and recombinant MVA for boosts, may be an attractive vaccine strategy against PCV2 infection in swine. Copyright © 2009 John Wiley & Sons, Ltd.
Barriers to managing chronic illness among urban households in coastal Kenya
Authors: Porter Thomas , Chuma Jane , Molyneux Catherine
Published: February 2009

The burden of chronic illnesses is rising throughout the world but information on barriers to managing such diseases in developing countries is scarce. Qualitative data from focus group discussions and interview transcripts from a longitudinal study involving 22 households in urban, coastal Kenya were analysed. Themes around barriers to chronic illness care were identified and a conceptual framework developed which described relationships between these themes. The main barrier to chronic illness management was the cost of care. Other barriers identified were patient knowledge and beliefs, stigma, quality and trust in providers and long care pathways. Household resilience was adversely affected by chronic illness, further reducing households' ability to cope with illness. Policy options to address the barriers identified are discussed. Copyright © 2009 John Wiley & Sons, Ltd.
Engineered 5S ribosomal RNAs displaying aptamers recognizing vascular endothelial growth factor and malachite green
Authors: Zhang Xing , Potty Ajish S. R. , Jackson George W. , Stepanov Victor , Tang Andrew , Liu Yamei , Kourentzi Katerina , Strych Ulrich , Fox George E. , Willson Richard C.
Published: February 2009

In previous work, Vibrio proteolyticus 5S rRNA was shown to stabilize 13–50 nucleotide “guest” RNA sequences for expression in Escherichia coli. The expressed chimeric RNAs accumulated to high levels in E. coli without being incorporated into ribosomes and without obvious effects on the host cells. In this work, we inserted sequences encoding known aptamers recognizing a protein and an organic dye into the 5S rRNA carrier and showed that aptamer function is preserved in the chimeras. A surface plasmon resonance competitive binding assay demonstrated that a vascular endothelial growth factor (VEGF) aptamer/5S rRNA chimera produced in vitro by transcriptional runoff could compete with a DNA aptamer for VEGF, implying binding of the growth factor by the VEGF “ribosomal RNA aptamer.” Separately, a 5S rRNA chimera displaying an aptamer known to increase the fluorescence of malachite green (MG) also enhanced MG fluorescence. Closely related control rRNA molecules showed neither activity. The MG aptamer/5S rRNA chimera, like the original MG aptamer, also increased the fluorescence of other triphenyl methane (TPM) dyes such as crystal violet, methyl violet, and brilliant green, although less effectively than with MG. These results indicate that the molecular recognition properties of aptamers are not lost when they are expressed in the context of a stable 5S rRNA carrier. Inclusion of the aptamer in a carrier may facilitate production of large quantities of RNA aptamers, and may open an approach to screening aptamer libraries in vivo. Copyright © 2009 John Wiley & Sons, Ltd.