NaNbV(PO4)3: Multielectron NASICON-Type Anode Material for Na-Ion Batteries with Excellent Rate Capability.

NASICON-type NaNbV(PO4)3 electrode material synthesized by the Pechini sol-gel technique undergoes a reversible three-electron reaction in a Na-ion cell which corresponds to the Nb5+/Nb4+, Nb4+/Nb3+, and V3+/V2+ redox processes and provides a reversible capacity of 180 mAh·g-1. The sodium insertion/extraction takes place in a narrow potential range at an average potential of 1.55 V versus Na+/Na. Structural characterization by operando and ex situ X-ray diffraction disclosed the reversible evolution of the NaNbV(PO4)3 polyhedron framework during cycling, while XANES measurements in the operando regime confirmed the multielectron transfer upon sodium intercalation/extraction into NaNbV(PO4)3. This electrode material demonstrates extended cycling stability and excellent rate capability maintaining the capacity value of 144 mAh·g-1 at 10 C current rates. It can be regarded as a superior anode material suitable for application in high-power and long-life sodium-ion batteries.

Proteasomes in Patient Rectal Cancer and Different Intestine Locations: Where Does Proteasome Pool Change?

A special problem in the surgery of rectal cancer is connected with a need for appropriate removal of intestine parts, along with the tumor, including the fragment close to the sphincter. To determine the length of fragments to remove, it is necessary to reveal areas without changes in molecule functioning, specific for tumor. The purpose of the present study was to investigate functioning the proteasomes, the main actors in protein hydrolysis, in patient rectal adenocarcinoma and different intestine locations. Chymotrypsin-like and caspase-like activities, open to complex influence of different factors, were analyzed in 43-54 samples by Suc-LLVY-AMC- and Z-LLE-AMC-hydrolysis correspondingly. Both activities may be arranged by the decrease in the location row: cancer→adjacent tissue→proximal (8-20 cm from tumor) and distal (2 and 4 cm from tumor) sides. These activities did not differ noticeably in proximal and distal locations. Similar patterns were detected for the activities and expression of immune subunits LMP2 and LMP7 and expression of 19S and PA28αß activators. The largest changes in tumor were related to proteasome subtype containing LMP2 and PA28αß that was demonstrated by native electrophoresis. Thus, the results indicate a significance of subtype LMP2-PA28αß for tumor and absence of changes in proteasome pool in distal fragments of 2-4 cm from tumor.

Fracture of a coronary guidewire during graft thrombectomy with the X-sizer device.

We present the first case reported of fracture of a coronary guidewire during thrombectomy of a massive thrombus in a recently occluded coronary bypass graft with the recently developed atherectomy catheter X-Sizer. The thrombus was successfully aspirated without distal embolisation and the guidewire fragment was trapped in the graft after covering with a coronary stent. Possible reasons for this unusual complication of X-Sizer are discussed.

Pseudoventricular fibrillation.

A case of atrial fibrillation with asystole was diagnosed as ventricular fibrillation because of the autogain feature of the electrocardiographic monitor. Direct current shock therapy was withheld only because the patient regained consciousness.

ST elevation in the anterior precordial leads during right ventricular infarction: lessons learned during primary coronary angioplasty--a case report.

ST elevation in the anterior leads may be due to isolated right ventricular infarction associated with occlusion of a nondominant or codominant right coronary artery. The authors report a case of isolated right ventricular infarction from a dominant right coronary artery's proximal occlusion in the presence of collateral circulation provided by the left coronary artery. Extensive damage occurred owing to compromise of the collateral circulation during primary coronary angioplasty. This is an unusual angiographic pattern for isolated right ventricular infarction. The potential consequences of percutaneous interventions to collateral vessels is discussed.

Significance of balloon imprint during coronary angioplasty.

Balloon imprint during angioplasty is often seen, but not at all inflations. We prospectively studied 235 consecutive patients undergoing 282 PTCAs during a 4-month period, who were divided into two groups: those with balloon imprint during inflation (159 patients, 190 lesions; 67%) and those without (76 patients, 92 lesions; 33%). Clinical and lesion characteristics and immediate outcome were compared. Patients undergoing urgent PTCA had less balloon imprint than those undergoing nonurgent PTCA (14.2% vs. 28.3%; P < 0.005). Although not reaching statistical significance, younger patients and diabetic patients tended toward less balloon imprint (P < 0.06). Patients with observed imprint had less visible thrombus at lesion site (31.1% vs. 42.4%; P < 0.05), and a tendency without statistical significance toward more dissections but less acute closure was observed (P < 0.07). In addition, more stents were implanted in the imprint group (79.5% vs. 66.3%; P < 0.02). Patients needing pressure > 6 atm to break the imprint had more eccentric lesions (68% vs. 27.1%; P < 0.000) and more dissections (13.9% vs. 5.1%; P < 0.03) than those needing lower pressure. Patient and lesion characteristics may determine the appearance of balloon imprint at PTCA, which in turn influences the procedure and its immediate outcome. Cathet Cardiovasc Intervent 2001;53:331-333.

Low-pressure deployment of stents: short- and long-term outcome.

This study investigates a strategy of low-pressure stenting with concomitant anti-platelet treatment designed to prevent short- and long-term events after stenting. Ninety consecutive patients who underwent percutaneous transluminal coronary angioplasty with stenting using low-pressure stent deployment (mean 8.1 atmospheres) with concomitant anti-platelet therapy based on ticlopidine and aspirin were followed. The 30-day outcome revealed a stent thrombosis rate of 6.4%, while the 9-month major clinical event rate was 8.6%. Low-pressure stent deployment appears to confer added risk for acute or sub-acute thrombosis even when aspirin and ticlopidine are used. Conversely, low-pressure inflation is associated with excellent long-term results.

Development and cross-cultural and clinical validation of a brief comprehensive scale for assessing hostility in medical settings.

This study presents the development and validation of a brief comprehensive hostility scale. Two items of each subscale from the Buss-Perry (1992) Aggression Questionnaire, most strongly correlated with their subscale score, were selected, yielding the eight-item New-Buss. Internal reliability was .66 to .81, and full and brief scales correlated r = .92 to .94. In Study 1 (95 Israeli students), New-Buss scores were significantly higher in self-rated deviant or speeding drivers than nondeviant or nonspeeding drivers, respectively. In Study 2 (279 American students), New-Buss scores correlated significantly with Barefoot's Ho, Anger-Out, Anger-In, and Agreeableness. In Study 3 (79 Israeli patients undergoing angiography), New-Buss scores were significantly correlated with coronary artery disease severity independent of SBP in men below age 60 alone but not in women. Our findings support the cross-cultural feasibility, reliability, and concurrent, construct, and criterion validity of the New-Buss.

Left anterior descending artery length in left and right coronary artery dominance.

BACKGROUND: Coronary stenosis of the left anterior descending artery (LAD) is respected by cardiologists because of its negative influence on morbidity and mortality. An important anatomical consideration is the length of the LAD. OBJECTIVE: To investigate the relationship between length of LAD and coronary dominance. DESIGN: Retrospective comparison of 100 consecutive angiograms with left coronary dominance with 100 consecutive angiograms with right coronary dominance. The relationship between the length of the LAD and coronary dominance was analyzed. METHODS: We retrospectively compared 100 consecutive angiograms with left coronary dominance (the posterior descending artery being supplied by the circumflex artery) with 100 consecutive angiograms with right coronary dominance (the posterior descending artery being supplied by the right coronary artery). LADs were categorized into three types: type A, LAD terminating before the cardiac apex; type B, LAD reaching the apex but not supplying the inferoapical segment of the left ventricle; and type C, LAD wrapping around the apex and supplying the inferoapical segment. LAD typing was also analyzed in relation to gender. RESULTS: It was found that the LAD wrapped around the apex in 87% of cases of left coronary dominance but only in 47% of patients with right coronary dominance, and that the long LADs were more frequently seen in women than in men, irrespective of coronary dominance. CONCLUSIONS: We found that the LAD in left coronary dominance is usually long and wraps around the apex, and believe that angiographic interventions in such cases have important clinical significance.

Incidence and clinical significance of bacteremia and sepsis among cardiac patients treated with intra-aortic balloon counterpulsation pump.

In this prospective study, a significant incidence of fever (47%), true bacteremia (15%), and sepsis (12%), were found in 60 cardiac patients treated with an intra-aortic balloon counterpulsation pump. The benefit of antibiotic prophylaxis in this setting should therefore be evaluated.

Arthropod poisons and the cardiovascular system.

Animal poisons induce myocardial damage after envenomation. The cardiac manifestations after black widow spider bite are rarely observed and their prognostic significance are not known. Hymenoptera induce anaphylactic manifestations commonly observed in adults with previous coronary artery disease although myocardial involvement is observed in a few without previous heart disease. The mechanism of cardiac involvement after scorpion envenomation has been elucidated, however after widow spider bite or hymenoptera stings the mechanism of myocardial damage of those without previous heart disease is not clear.

Cardiogenic shock: single center experience with and without on-site catheterization facilities.

BACKGROUND: The beneficial effect of on-site catheterization facilities on the survival of all patients with myocardial infarction complicated by cardiogenic shock has been questioned. Our objective was to evaluate the impact of the availability of on-site catheterization facilities on the outcome of unselected patients with cardiogenic shock. METHODS AND RESULTS: We studied the hospital records of 70 consecutive patients with cardiogenic shock admitted to our intensive coronary care unit during 1990-1996, and compared two groups of patients: those admitted before (n = 34) and after (n = 36) the opening of our catheterization laboratory. Patients admitted when the catheterization laboratory was available were of similar age, but included fewer males and fewer patients with prior myocardial infarction. Following the activation of the catheterization laboratory, utilization rates of coronary angiography, percutaneous transluminal coronary angioplasty and intra-aortic balloon pump increased, compared with the previous period. However, there was no improvement in in-hospital (88 vs. 83%; p = 0.7) and 30-day mortality (91 vs. 86%; p = 0.7) before versus after the activation of our catheterization laboratory. Twelve patients selected to cardiac catheterization (9 underwent percutaneous transluminal coronary angioplasty) experienced lower in-hospital and 30-day mortality compared with patients who were not selected (58 vs. 96, and 67 vs. 96%, respectively; p < 0.02). CONCLUSIONS: Following the activation of the catheterization laboratory, the mortality of the entire population of cardiogenic shock patients remained relatively unchanged. Still, a small subgroup of these patients selected for urgent cardiac catheterization had a lower mortality compared with patients who were not selected.

QRS prolongation: a sensitive marker of ischemia during percutaneous transluminal coronary angioplasty.

The purpose of this study is to measure QRS duration changes in the human model of ischemia during percutaneous transluminal coronary angioplasty (PTCA) and compare these results to the commonly used ischemia markers, chest pain, and classical ST-T changes. Using a computerized method, QRS duration was measured in 51 patients undergoing elective PTCA. Three milliseconds (msec) or more prolongation of the QRS at peak inflation was considered to be an ischemic response. The results were compared to chest pain and ST-T changes and were analyzed for inflation site within individual coronary arteries. Forty-two patients had a pathological prolongation of the QRS during PTCA. Thirty-two patients developed chest pain, while 19 had ischemic ST-T changes. QRS duration was more prolonged in PTCA to proximal or middle segments of major arteries or their large branches, while it was less prolonged in distal segments or smaller branches. Using our method, QRS prolongation was an ischemia marker in most patients during PTCA and was more sensitive than chest pain or ST-T changes. QRS duration was more prolonged with occlusion of proximal and middle segments of major arteries. Cathet. Cardiovasc. Intervent. 50:177-183, 2000.

Repeated balloon rupture during coronary stenting due to a calcified lesion: an intravascular ultrasound study.

We describe a patient in whom balloon rupture occurred three times during inflation in a stent with restenosis in the left anterior descending artery. The cause of rupture was detected by intravascular ultrasound: a calcified ridge that protruded between the stent struts in the distal stent body.

Contribution of stenting to the results of rescue PTCA.

Failed thrombolysis in acute myocardial infarction (AMI) is associated with increased mortality. Controversial benefit of rescue percutaneous transluminal coronary angioplasty (PTCA) in these setting has been published. The feasibility, safety, and contribution of stenting to the outcome of AMI patients treated with this strategy is unknown. We studied the angiographic result and clinical outcome of 33 patients with failed thrombolysis referred for rescue angioplasty. Twenty-three patients had stenting and 10 patients did not have stenting. Both groups had similar clinical and angiographic characteristics. Stent indications were nonoptimal result, 40%; bailout, 40%; elective, 20%. Angiographic success was 100% with stent vs. 91% with balloon alone (P < 0.8). Postprocedure residual stenosis was 1.5% (0%-10%) with stent vs. 18.05% (0%-30%) with balloon alone (P < 0.01). Thirty-day outcome with and without stent was mortality, 0% vs. 13% (P < 1.0); reinfarction, 10% vs. 0% (P < 0.30); target vessel revascularization, 0% vs. 21% (P < 0.21). The 6-month mortality was 0% with stent vs. 14% (P < 0.5). We conclude that stenting during rescue angioplasty is feasible, safe, and is associated with better immediate angiographic results. Although no obvious clinical benefit was found, a potential decrease in the revascularization rate was suggested.

Upper posterior mediastinal tumor supplied by an atrial branch of the left circumflex artery.

We report a case of a 39-year-old woman with an upper posterior mediastinal tumor. The tumor was demonstrated by echocardiography and further defined by computerized tomography and magnetic resonance imaging. The tumor was fed by a large atrial branch of the left circumflex artery. Because of its location (adjacent to large vessels), it could not be resected by surgery.

Right-sided pulsus alternans in diastolic left ventricular dysfunction.

Pulsus alternans is usually found in patients with reduced systolic ventricular function. We describe a patient with shortness of breath, hypertension, and left ventricular hypertrophy, but with normal left and right systolic function. Pulsus alternans was demonstrated in the pulmonary wedge position, pulmonary artery, and right ventricle, but not in the aorta or left ventricle. Cathet. Cardiovasc. Intervent. 47:336-339, 1999.

Exaggerated blood pressure response at exercise in normotensive subjects: demographic and stress performance characteristics.

BACKGROUND: Exercise testing is an important diagnostic and prognostic procedure in the assessment of patients with hypertension. An exaggerated blood pressure response to exercise among normotensive subjects was found to be one of the best predictors of future hypertension. The demographic characteristics of patients with an exaggerated blood pressure response during exercise have not been adequately described. METHODS AND RESULTS: The demographic and stress performance characteristics of 2 groups of normotensive patients referred for exercise testing, one composed of patients with an exaggerated blood pressure response (group I, n=146) and a group of patients with a normal blood pressure response (group II, n=439) were prospectively compared. Patients in group I were older than those in group II (54+/-12 vs 51+/-13 years, P < .05). More men than women were found in both groups, yet significantly more in group I than in group II (83% vs 69% P < .001). Significantly more among the patients in group I had a higher level of education and were of Western origin than those in group II (P < .01). The resting systolic and diastolic blood pressures were higher in group I than in group II (131+/-18 vs 119+/-14 mm Hg, P< .001, and 81+/-8 vs 76+/-7 mm Hg, P < .001, respectively). The patients in group I achieved a higher percentage of the maximal predicted heart rate (88+/-7 vs 85+/-9 beats/min, P < .01). No significant differences were found between the groups in the duration of stress test and effort ischemia. CONCLUSIONS: Patients with a hypertensive blood pressure response during stress testing have specific demographic and exercise characteristics.