Quantum oscillation of the tunneling conductance in fully epitaxial double barrier magnetic tunnel junctions.

We investigated spin-dependent tunneling conductance properties in fully epitaxial double MgO barrier magnetic tunnel junctions with layered nanoscale Fe islands as a middle layer. Clear oscillations of the tunneling conductance were observed as a function of the bias voltage. The oscillation, which depends on the middle layer thickness and the magnetization configuration, is interpreted by the modulation of tunneling conductance due to the spin-polarized quantum well states created in the middle Fe layer. This first observation of the quantum size effect in the fully epitaxial double barrier magnetic tunnel junction indicates great potential for the development of the spin-dependent resonant tunneling effect in coherent tunneling regime.

Significant magnetoresistance enhancement due to a cotunneling process in a double tunnel junction with single discontinuous ferromagnetic layer insertion.

We fabricate CoFe/AlOx/CoFe/AlOx/CoFe ferromagnetic double tunnel junctions and observe spin-dependent tunneling phenomena. A middle CoFe layer becomes discontinuous by forming CoFe particles two dimensionally, of which the average diameter is evaluated to be 2.0-4.5 nm from cross-sectional transmission electron microscopy images. Below 50 K, a Coulomb gap is observed in current-voltage curves, and both magnetoresistance ratios and resistances are found to increase significantly with decreasing temperature. This indicates that a cotunneling process is dominant within the gap, which agrees very well with theoretical prediction [Phys. Rev. Lett. 80, 1758 (1998)].

Effective reduction of critical current for current-induced magnetization switching by a Ru layer insertion in an exchange-biased spin valve.

Recently, it has been predicted that a spin-polarized electrical current perpendicular to plane directly flowing through a magnetic element can induce magnetization switching through spin-momentum transfer. In this Letter, the first observation of current-induced magnetization switching (CIMS) in exchange-biased spin valves (ESPVs) at room temperature is reported. The ESPVs show the CIMS behavior under a sweeping dc current with a very high critical current density. It is demonstrated that a thin ruthenium (Ru) layer inserted between a free layer and a top electrode effectively reduces the critical current densities for the CIMS. An "inverse" CIMS behavior is also observed when the thickness of the free layer increases.

Substantial reduction of critical current for magnetization switching in an exchange-biased spin valve.

Great interest in current-induced magnetic excitation and switching in a magnetic nanopillar has been caused by the theoretical predictions of these phenomena. The concept of using a spin-polarized current to switch the magnetization orientation of a magnetic layer provides a possible way to realize future 'current-driven' devices: in such devices, direct switching of the magnetic memory bits would be produced by a local current application, instead of by a magnetic field generated by attached wires. Until now, all the reported work on current-induced magnetization switching has been concentrated on a simple ferromagnet/Cu/ferromagnet trilayer. Here we report the observation of current-induced magnetization switching in exchange-biased spin valves (ESPVs) at room temperature. The ESPVs clearly show current-induced magnetization switching behaviour under a sweeping direct current with a very high density. We show that insertion of a ruthenium layer between an ESPV nanopillar and the top electrode effectively decreases the critical current density from about 10(8) to 10(7) A cm(-2). In a well-designed 'antisymmetric' ESPV structure, this critical current density can be further reduced to 2 x 10(6) A cm(-2). We believe that the substantial reduction of critical current could make it possible for current-induced magnetization switching to be directly applied in spintronic devices, such as magnetic random-access memory.

Comparison of T-wave alternans and QT interval dispersion to predict ventricular tachyarrhythmia in patients with dilated cardiomyopathy and without antiarrhythmic drugs: a prospective study.

Microvolt T-wave alternans (TWA) and QT interval dispersion (QTD), which reflect temporal and spatial repolarization abnormalities, respectively, have been proposed as useful indices to identify patients at risk for ventricular tachyarrhythmias (VTs). The purpose of this study was to clarify which repolarization abnormality marker is more useful in predicting arrhythmic events in patients with dilated cardiomyopathy (DCM). Forty-two consecutive nonischemic DCM patients underwent the assessment of TWA and QTD. Patients undergoing antiarrhythmic pharmacotherapy, except beta-blockers and those with irregular basic rhythms, were excluded from entry. Eight patients were also excluded because of indeterminate test results. Therefore, 34 DCM patients were prospectively assessed. The end point of the study was the documentation of VT defined as > or = 5 consecutive ectopic beats during the follow-up period. TWA and QTD (> or = 65 msec) were positive in 24 (80%) and 11 (37%) of 30 patients with available follow-up data, respectively. There was no relationship between TWA and QTD. During a follow-up of 13+/-11 months, VTs occurred in 13 patients (43%). In Cox regression analysis, TWA was a significant risk stratifier (p=0.02), whereas QTD was not. The sensitivity, specificity, and positive and negative predictive values of TWA in predicting VTs were 100%, 35%, 54%, and 100%, respectively. TWA could be a useful noninvasive index to identify patients at risk for VTs in the setting of DCM. This study may suggest that temporal repolarization abnormality is associated more with arrhythmogenesis than with spatial repolarization abnormality in DCM patients.

Lack of noninvasive markers of ventricular repolarization inhomogeneity in patients with idiopathic ventricular tachyarrhythmia.

Noninvasive markers reflecting repolarization inhomogeneity have been proposed to be useful indices for identifying patients at risk of ventricular arrhythmias based on organic heart disease. In this study, we clarify whether or not repolarization inhomogeneity markers are useful in patients with idiopathic ventricular tachycardia (VT). We investigated T-wave alternans (TWA) and corrected QT-interval dispersion (QTD) in 84 consecutive patients with idiopathic VT, 90 patients with VT associated with organic heart disease (organic VT), and 87 normal individuals. VT was defined as tachycardia lasting > or =5 consecutive ventricular ectopic beats at a rate of > or =120 beats/min. TWA was positive in 20 of 84 patients (24%) with idiopathic VT, 59 of 90 patients (66%) with organic VT, and 16 of 87 normal individuals (18%). The alternans voltage was 2.6 +/- 3.1 micro V in idiopathic VT patients, 5.6 +/- 6.4 micro V in organic VT patients, and 2.9 +/- 5.7 micro V in normal individuals. QTD were 53 +/- 20 ms in idiopathic VT patients, 92 +/- 20 ms in organic VT patients, 46 +/- 18 ms in normal individuals, respectively. A positive TWA test result was seen more (P <.01) frequently, and QTD was longer (P <.01) in organic VT patients compared to normal individuals, whereas there was no difference between idiopathic VT patients and normal individuals. In addition, in patients with idiopathic VT, neither did any of these measurements differ between patients with sustained VT (lasting for > or =30 s) and those with nonsustained VT. Noninvasive markers of repolarization inhomogeneity, such as TWA and QTD, are not useful for identifying patients with idiopathic VT. Repolarization inhomogeneity may not affect to the pathogenesis of idiopathic VT.

Analysis of MUC4 mucin expression in lung carcinoma cells and its immunogenicity.

BACKGROUND: MUC4 has been cloned from tracheobronchial mucosa cDNA and reportedly is highly expressed in some human malignancies, including lung carcinoma. However, little is known about molecular and biologic characteristics. The authors analyzed expression levels of MUC4 mRNA and protein in lung carcinoma cells and analyzed the immunogenicity of this mucin. METHODS: Nine cultured lung carcinoma cell lines and 29 tumor samples from patients with lung carcinoma were examined by Northern hybridization for MUC4 mRNA expression and by flow cytometry or an immunohistochemical staining for its protein expression. Sera from the patients were examined for their reactivity with MUC4 by enzyme-linked immunosorbent assay. RESULTS: Forty-four percent of the cell lines and 72% of the tumor samples showed high levels of MUC4 mRNA expression. Although MUC4 protein was not detected in any live carcinoma cell lines by flow cytometry using rabbit antisera reactive with the MUC4 core, pretreatment with paraformaldehyde and sialidase resulted in successful detection of the protein in 50% of the cell lines. An immunohistochemical study revealed that 67% of the tumors exhibited MUC4 protein expression without any digestion. In 29% of the patients, high levels of anti-MUC4 immunoglobulin M or immunoglobulin G were detected. CONCLUSIONS: MUC4 protein expression was elevated in lung carcinoma tissues because of the increase in its mRNA expression and deglycosylation on its core. This mucin is sufficiently immunogenic to elicit humoral and cellular immunity specific for MUC4 in patients with malignant disease. MUC4 is expected to be useful as a target antigen in immunotherapy for patients with carcinoma of the lung.

Angiomatoid fibrous histiocytoma in mediastinum.

Angiomatoid fibrous histiocytoma (AFH) is a rare tumor of soft tissue with low-grade malignancy that occurs most commonly in the soft tissues of the extremities or trunk. We present a case of AFH of the mediastinum, which is a very unusual site for this tumor. The patient has survived with no recurrence of the disease for 60 months after surgery and adjuvant radiotherapy.

Clinical usefulness of the combination of T-wave alternans and late potentials for identifying high-risk patients with moderately or severely impaired left ventricular function.

Ventricular tachyarrhythmia (VT) is an independent risk factor for an increased overall mortality in patients with impaired left ventricular (LV) function, but there is not an established noninvasive tool to detect such patients. The present study aimed to clarify the most useful noninvasive approach for identification of patients with moderately or severely impaired LV function complicated by VT. Sixty-seven patients in New York Heart Association (NYHA) classes I-III with an LV ejection fraction (LVEF) less than 40% and an LV end-diastolic dimension (LVDD) of at least 55 mm on echocardiography were enrolled. Impaired LV function was caused by either ischemic (n=30) or nonischemic dilated cardiomyopathy (n=37). T-wave alternans (TWA), QT dispersion (QTD), and late potentials (LP) on signal-averaged electrocardiography were sequentially determined without using antiarrhythmic drugs. VT was defined as more than 6 consecutive ventricular ectopic beats. The mean NYHA class was 1.9+/-0.7, mean LVEF was 31+/-8%, and mean LVDD was 65+/-10mm. A history of VT was present in 26 of the patients (39%). Univariate and multivariate logistic analysis showed that TWA and LP were closely related to VT, whereas NYHA> or =III, LVEF<30%, LVDD> or =70mm, and QTD> or =90ms were not. The combination of TWA and LP had the most significant value (p=0.0004, odds ratio=8.44) by univariate analysis, and only this combination had significant value in multivariate analysis (p=0.04). Therefore, the combination of TWA and LP could be a useful index for identifying those patients with impaired LV function who are at risk for VT.

Predicting the recurrence of ventricular tachyarrhythmias from T-wave alternans assessed on antiarrhythmic pharmacotherapy: a prospective study in patients with dilated cardiomyopathy.

BACKGROUND: Microvolt T-wave alternans (TWA) has been proposed as a useful index to identify patients at risk of ventricular tachyarrhythmias. Recent studies have demonstrated that antiarrhythmic drugs, such as amiodarone and procainamide, decrease the prevalence of TWA. In this study, we tested whether TWA in patients on antiarrhythmic pharmacotherapy significantly predicts the recurrence of ventricular tachyarrhythmias in patients with dilated cardiomyopathy. METHODS: To evaluate the ability to predict the recurrence of ventricular tachyarrhythmias, determinate TWA and left ventricular ejection fraction (LVEF) were prospectively assessed in 49 patients with ischemic or nonischemic dilated cardiomyopathy on antiarrhythmic pharmacotherapy for sustained ventricular tachycardia (VT) or ventricular fibrillation (VF). The pharmacotherapy consisted of class I (17 patients), III (29 patients), and IV (3 patients) antiarrhythmic drugs. The study endpoint was the first recurrence of sustained VT or VF on treatment during the follow-up period. RESULTS: TWA was positive on antiarrhythmic pharmacotherapy in 30 patients (61%). During a follow-up of 13 +/- 11 months, the sustained VT or VF recurred in 21 of the 41 patients (51%) with available follow-up data. The sensitivity of TWA and LVEF for predicting recurrence of ventricular tachyarrhythmias was 76 and 38%, specificity was 60 and 70%, positive predictive value was 67 and 57%, and negative predictive value was 71 and 52%. Kaplan-Meier event-free analysis revealed that TWA was a significant risk stratifier (P = 0.02), whereas LVEF was not. CONCLUSIONS: This prospective study suggests that TWA significantly predicts the recurrence of ventricular tachyarrhythmias, even on antiarrhythmic pharmacotherapy, in patients with dilated cardiomyopathy. TWA may also be a useful marker for evaluating the efficacy of antiarrhythmic drugs for ventricular tachyarrhythmias.

Phylogenetic analyses of Synechococcus strains (cyanobacteria) using sequences of 16S rDNA and part of the phycocyanin operon reveal multiple evolutionary lines and reflect phycobilin content.

The genus Synechococcus (cyanobacteria), while containing morphologically similar isolates, is polyphyletic and organisms presently classified as such require reclassification into several independent genera. Studies based on analysis of 16S rRNA gene sequences have shown that members of the genus Synechococcus are affiliated to three of seven deeply branching cyanobacterial lineages. In addition, some strains do not appear to be associated with any of these lineages and may represent novel clades. In this report, a cyanobacterial phylogeny based on 16S rDNA sequences, including 14 newly sequenced Synechococcus isolates, is presented. One newly sequenced Synechococcus strain (PCC 7902) did not have any close relatives amongst cyanobacterial isolates currently contained in 16S rDNA sequence databases and was only loosely affiliated to a cyanobacterial lineage in which no other Synechococcus strains were found. Three hot-spring Synechococcus isolates, including two that were newly sequenced in this study (PCC 6716 and PCC 6717), formed an additional cyanobacterial lineage. These results indicated that Synechococcus species are affiliated to five of eight deeply branching cyanobacterial lineages. Part of the phycocyanin (PC) gene sequence (cpc), including the intergenic spacer (IGS) between cpcB and cpcA and the corresponding flanking regions (cpcBA-IGS), was used to investigate relationships between closely related Synechococcus isolates. Previously described PCR primers did not amplify this region from the majority of strains under investigation, so a new set of primers was designed that allowed amplification and sequencing of the cpcBA-IGS and flanking regions from 38 Synechococcus species. Phylogenetic analysis of this region was largely consistent with that obtained from 16S rDNA sequence analysis and revealed a relationship between the primary PC DNA sequence and the phycobilin content of cells.

[Pressure wire guide provisional coronary stent implantation].

OBJECTIVES: Whether coronary artery lesion successfully dilated by balloon angioplasty should be stented or not is unclear. The purpose of this study is to evaluate the provisional stent implantation method assessing residual ischemia by pressure wire. METHODS: Thirty-one patients with de-novo lesions suitable for stenting were enrolled in a pressure wire guided provisional stent study. The pressure wire was used to assess the fractional flow reserve(FFR) before and after balloon angioplasty. When the FFR after angioplasty was less than 0.75, stent implantation was planned. Patients with lesions consisting of an intermediate stenosis proximal to the target lesion, chronic total occlusion, bypass graft and left main lesion were excluded from the study. Stent implantation was permitted even if the FFR was more than 0.75 when the operator thought stenting was necessary. Medical treatment was given with aspirin 162 mg/day, cilostazol 200 mg/day for 6 months and additional ticlopidine 200 mg/day for a month after stenting the lesion. RESULTS: Target vessel was the left anterior descending coronary artery in 19 lesions, the right coronary artery in 3, and the circumflex coronary artery in 9. Stent implantation was performed in seven (23%) of 31 lesions and the other 24(77%) lesions were treated with only balloon angioplasty. The FFR before intervention was 0.58 +/- 0.16, and improved to 0.87 +/- 0.07 (p < 0.0001). Percentage diameter stenosis before intervention was 70.7 +/- 12.6% and improved to 20.1 +/- 13.3% (p < 0.0001) after intervention. There was no major cardiac event (death, coronary artery bypass grafting, myocardial infarction, stent thrombosis). Six months follow-up angiography was performed in 27 patients (87%). Angiographic restenosis (percentage diameter stenosis > or = 50%) was found in four patients (15%). A new lesion was found in two patients. Target vessel revascularization was performed in six patients (21%). CONCLUSIONS: Lesions successfully dilated by balloon angioplasty with FFR > or = 0.75 do not require stenting.

Assessment of noninvasive markers in identifying patients at risk in the Brugada syndrome: insight into risk stratification.

OBJECTIVES: The aim of this study was to compare the use of various noninvasive markers for detecting risk of life-threatening arrhythmic events in patients with Brugada syndrome. BACKGROUND: The role of conduction disturbance in arrhythmogenesis of the syndrome is controversial, whereas it is well established that repolarization abnormalities are responsible for arrhythmias. The value of noninvasive markers reflecting conduction or repolarization abnormalities in identifying patients at risk for significant arrhythmias has not been shown. METHODS: We assessed late potentials (LP) using signal-averaged electrocardiography (ECG), microvolt T-wave alternans (TWA), and corrected QT-interval dispersion (QTD) in 44 consecutive patients who had ECGs showing a pattern of right bundle branch block and ST-segment elevation in leads V1 to V3 but structurally normal hearts. The patients were compared with 30 normal individuals. RESULTS: Eleven patients were excluded from data analysis because of an absence of ECG manifestations of Brugada syndrome at the time of the tests. A history of life-threatening events defined as syncope and aborted sudden death was present in 19 of 33 patients (58%); in 15 of the 19 patients, stimulation induced ventricular fibrillation or polymorphic ventricular tachycardia. The LP were present in 24 of 33 patients (73%); TWA were present in 5 of 31 patients (16%); and a QTD >50 ms was present in 9 of 33 patients (27%). The incidence of LP in Brugada patients was significantly (p < 0.0001) higher than in the controls, whereas incidences of TWA and QTD were not significantly different. Multivariate logistic regression analysis revealed that the presence of LP had the most significant correlation to the occurrence of life-threatening events (p = 0.006). CONCLUSIONS: Late potentials are a noninvasive risk stratifier in patients with Brugada syndrome. These results may support the idea that conduction disturbance per se is arrhythmogenic.

Involvement of granzyme B and perforin in suppressing nodal metastasis of cancer cells in breast and lung cancers.

AIMS: Granzyme B and perforin, which are contained in cytotoxic granules produced by tumour-infiltrating immune cells, have been reported to be involved in suppression of cancer progression. In this study, the relationship between expression of these molecules and clinical factors in cancer patients was studied. METHODS: Tumour tissue obtained from 23 breast cancer patients and 13 lung cancer patients were examined for expression of granzyme B, perforin and B7-1, using an immunohistochemical technique. The percentage of cells positive for expression of these molecules and the clinical status of each case were compared. RESULTS: Both granzyme B and perforin were distributed in the cytoplasm of cancer cells in many cases rather than in tumour-infiltrating lymphocytes. This was observed even in cases of early-stage tumours. In both breast and lung cancer patients, the percentage of cells positive for granzyme B and perforin expression was inversely correlated with the status of regional node metastasis. A competitive RT-PCR analysis confirmed that the expression of mRNA from these molecules extracted from the tumours was consistent with the immunohistochemical results. CONCLUSION: Granzyme B and perforin may play a role in the suppression of nodal metastasis of cancer cells in breast and lung cancers.

Periosteal chondroma of the rib: report of two cases.

We report two cases of periosteal chondroma of the rib, an extremely rare entity. The first case involved a 5-year-old boy who was admitted with pain and swelling around his left fifth rib. Surgery was performed in May 1999, and an 8 x 6 x 5 mm tumor was resected with the fifth rib. The second case involved a 39-year-old man with a 2-month history of cough who was referred to our department after a coin lesion had been detected on a chest roentgenogram. Physical examination on admission did not reveal any pain or tenderness. The rib tumor was resected along with the fourth rib by video-assisted thoracoscopic surgery and minithoracotomy in February 2000. The tumor was well encapsulated and consisted of an elastic hard mass measuring 22 x 15 x 13 mm. Both patients had an uneventful postoperative course and have remained well with no evidence of recurrence. Our review of the literature revealed only six previously documented cases of periosteal chondroma of the rib.

[Two cases of Chlamydia psittaci infection occurring in employees of the same pet shop].

We report here 2 cases of psittacosis in a pet shop. In the first case, a 44-year-old male was admitted with fever, and a chest radiograph showed an infiltration shadow in the right lower lung. One day later, a colleague of the first patient, a 42-year-old man, developed fever and was admitted. In this patient, chest radiography revealed an infiltration shadow in the left lower lung. Both patients had mild liver dysfunction. The serum titer of a complement fixation (CF) test against Chlamydia psittaci was elevated fourfold in the first case and sixteen-fold in the second on the analysis of paired acute- and convalescent-phase serum specimens. Clinical symptoms and abnormal laboratory data were attenuated by the administration of minocycline for 2 weeks. Since both patients worked in same pet shop and since some parakeets at the shop had died, we speculated that the psittacosis had originated from these birds.

Atrial double potentials associated with the elimination of the electrical connection between the coronary sinus (CS) and the left atrium in two cases of Wolff-Parkinson-White syndrome with a CS-connected accessory pathway.

A curious retrograde conduction in connection with the coronary sinus (CS) musculature was observed in 2 patients. After the failed ablation procedure, the atrial electrogram during ventricular pacing presented double potentials, the first component of which was sharp and with an activation sequence that was the same before ablation (CS distal to proximal). The second component of the double potentials was dull and had a decremental property; its activation sequence was in reverse (proximal to distal). In both cases, the first component disappeared after successful ablation. These findings suggest that the first component was the CS electrogram conducted over the accessory pathway and the second component was the left atrial electrogram conducted through the inter-atrial septum. The separation of each electrogram is probably the result of a block between the accessory pathway connected to the CS musculature and the left atrium. These are unusual cases of an accessory pathway connected to the CS musculature, which separates the left atrial myocardium at the distal portion from the ostium.

[Evaluation of coronary flow reserve in patients with vasospastic angina].

OBJECTIVES: The presence of microvascluar impairment was evaluated in 154 patients with vasospastic angina identified by the acetylcholine provocation test. METHODS: Coronary flow reserve was evaluated with a Doppler flow guidewire in 128 vessels of 72 patients with chest pain, but no significant coronary stenosis(less than 50% stenosis) and no clinical factors that affect coronary flow reserve. Coronary flow reserve was obtained from the ratio of adenosine triphosphate-induced maximum/baseline averaged peak velocity. These vessels were classified into 2 categories according to whether acetylcholine-induced vasospasm was positive or negative. Vasospasm positive was defined as more than 90% stenosis provoked with chest pain and/or ischemic ST change. Positive vessels were subdivided according to focal or diffuse vasospasm. These vessels were also classified into 2 other categories according to whether vasospasm in the distal artery was positive or negative. RESULTS: Coronary flow reserve was significantly lower in vessels with vasospasm than in vessels without vasospasm in patients without vasospasm(2.9 +/- 0.8 vs 3.6 +/- 1.0, p = 0.0005). Coronary flow reserve was significantly lower in vessels without vasospasm in patients with vasospasm than in vessels without vasospasm in patients without vasospasm(3.0 +/- 0.8 vs 3.6 +/- 1.0, p = 0.03). There was no significant difference in coronary flow reserve between vessels with vasospasm and vessels without vasospasm in patients with vasospasm(2.9 +/- 0.8 vs 3.0 +/- 0.8, p = 0.8). There was no significant difference in coronary flow reserve between focal and diffuse vasospasm(3.2 +/- 0.8 vs 2.9 +/- 0.8, p = 0.3). Coronary flow reserve was significantly lower in vessels with vasospasm in the distal artery than in vessels without vasospasm in the distal artery (2.8 +/- 0.8 vs 3.4 +/- 1.0, p = 0.004). CONCLUSIONS: Patients with vasospastic angina have microvascular impairment in both vessels with vasospasm, and vessels without vasospasm. Microvascular impairment is prominent in vessels with vasospasm in the distal artery.

Autologous dendritic cells or cells expressing both B7-1 and MUC1 can rescue tumor-specific cytotoxic T lymphocytes from MUC1-mediated apoptotic cell death.

We attempted to induce MUC1-specific cytotoxic T lymphocytes (CTLs) by mixed-lymphocyte tumor cell culture (MLTC) using two allogeneic MUC1-positive cancer cell lines, T-47D and MCF7. The induced CTLs exhibited MUC1-specific cytotoxicity 16 days after the initial stimulation. However, these CTLs underwent apoptotic death within 16 days. To examine whether the B7-1 molecule is required for the expansion of the responder cells, a B7-1(+)/MUC1(-) cell line was transfected with MUC1 cDNA, and the resulting transfectant was employed as a stimulator in an autologous MLTC. The CTLs exhibited MUC1 specificity but also continued to propagate. In parallel, autologous dendritic cells (DCs) were added to an MLTC containing peripheral blood lymphocytes (PBLs) and the allogeneic MUC1-positive stimulators. The CTLs demonstrated MUC1 specificity and their number increased. This suggests that the B7-1 molecule is required for rescuing CTLs from MUC1-mediated apoptotic death, but not for the induction of MUC1-specific responsiveness. This strategy to obtain the CTLs efficiently may be useful for adoptive immunotherapy against cancer.

Lack of an association between T-wave alternans and ST-segment depression during exercise-induced ambulatory ischemia.

It is known that T-wave alternans (TWA), which identify patients at risk for arrhythmic events, often occur during acute coronary occlusion in association with ST-segment elevation. To test the hypothesis that TWA is associated with a certain state/severity of myocardial infarction/ischemia, we assessed the association between TWA and ST-segment depression during exercise-induced ambulatory ischemia. Of 351 consecutive patients with coronary artery disease who underwent assessment of microvolt TWA by exercise, 23 patients with effort angina without a history of infarction with ST depression (> or =0.11 mV) during TWA test were selected. These patients were compared with 222 postinfarction patients consisting of 38 patients with, and 184 patients, without the ST depression, and 18 normal individuals. The incidence (9%) of determinate TWA in the patients with angina was significantly (P < .0001) lower than that (52%) in the postinfarction patients. There was no significant difference between the angina patients and the controls (6%). There was also no difference between the patients with (58%) and without the ST depression (51%) in the postinfarction patients. Moreover, no correlation existed between the TWA voltage and the ST-depression magnitude in both angina and postinfarction patients. We concluded that there is no association between TWA and ambulatory ischemia with ST depression.