Arrhythmogenesis of T wave alternans associated with surface QRS complex alternans and the role of ventricular prematurity: observations from a canine model of LQT3 syndrome

INTRODUCTION: T wave alternans (TWA) is characterized by cycle-to-cycle changes in the QT interval and/or T wave morphology. It is believed to amplify the underlying dispersion of ventricular repolarization. The aim of this study was to examine the mechanisms and arrhythmogenesis of TWA accompanied by QRS complex and/or blood pressure (BP) waveform alternans, using transmural ventricular electrogram recordings in an anthopleurin-A model of long QT syndrome. METHODS AND RESULTS: The cardiac cycle length was gradually shortened by interruption of vagal stimulation, and TWA was induced in six canine hearts. Transmural unipolar electrograms were recorded with plunge needle electrodes from endocardial (Endo), mid-myocardial (Mid), and epicardial (Epi) sites, along with the surface ECG and BP. The activation-recovery interval (ARI) was measured to estimate local refractoriness. During TWA, ARI alternans was greater at the Mid than the Epi/Endo sites, and it was associated with the development of marked spatial dispersion of ventricular repolarization. As TWA increased, ventricular activation of the cycles associated with shorter QT intervals displayed delayed conduction at the Mid sites as a result of a critically longer ARI of the preceding cycle and longer QT interval, while normal conduction was preserved at the Epi site. Delayed conduction at the Mid sites manifested as surface ECG QRS and BP waveform alternans, and spontaneous ventricular tachyarrhythmias developed in absence of ventricular prematurity. In other instances, in absence of delayed conduction during TWA, ventricular premature complexes infringed on a prominent spatial dispersion of ventricular repolarization of cycles with long QT intervals and initiated ventricular tachyarrhythmia. CONCLUSION: TWA accompanied by QRS alternans may signal a greater ventricular electrical instability, since it is associated with intramural delayed conduction, which can initiate ventricular tachyarrhythmia without ventricular premature complexes.     

Myometrial invasion and cervical invasion by endometrial carcinoma: evaluation by CO2-volumetric interpolated breathhold examination (VIBE)

PURPOSE: To assess myometrial invasion and cervical invasion by endometrial carcinoma, using CO2-volumetric interpolated breathhold examination (VIBE) enabling more precise evaluation of depth of tumor invasion. MATERIALS AND METHODS: CO2-VIBE was performed in 21 cases of endometrial carcinoma (Stage Ia-IIb) prior to treatment. The images were interpreted by performing multiplanar reconstruction (MPR), and the findings obtained from the images (degree of myometrial invasion and presence or absence of cervical invasion) were assessed in comparison with the histopathological diagnosis. RESULTS: The sites of the endometrial carcinoma lesions were clearly visualized by the CO2-VIBE method. Evaluation of the degree of myometrial invasion enabled a high correct diagnosis rate of 90.5%, and evaluation for the presence of cervical invasion also allowed a high correct diagnosis rate of 90.5%. CONCLUSION: VIBE permits evaluation of any plane desired by means of thin slices, and it is a truly revolutionary method for preoperative evaluation of depth of invasion of endometrial carcinoma that enables highly accurate determination of the extent of lesion sites and degree of invasion before treatment.     

The significance of intraoperative Doppler ultrasonography in evaluating hepatic arterial flow when assessing the indications for the Appleby procedure for pancreatic body cancer

Background/purpose The Appleby procedure has been used in the surgical treatment of advanced gastric cancer. This procedure consists of a combined resection of the whole of the stomach, the body and tail of the pancreas, and the spleen, as well as resection of the celiac artery. This procedure can also be used for operative resection of cancer of the body of the pancreas. The hepatic arterial flow is supplied from the arcade of the supramesenteric artery. In the past, the extent of hepatic arterial flow after the celiac artery had been clamped was evaluated by finger palpation. However, this is not an objective method.Methods Here, we describe two patients with pancreatic body cancer, in one of whom the Appleby procedure was followed. However, in the other, this operation could not be performed because the residual blood supply to the liver would have been inadequate. The hepatic arterial flow was assessed using intraoperative Doppler ultrasonography (US) of the intrahepatic artery (arterial flow of segment 3).Results In case 1 (a 45-year-old man), the hepatic arterial flow prior to clamping of the celiac artery was 68.4cm/s, and this flow was reduced to 22.1cm/s after the clamping. The color and consistency of the liver surface remained good. Because there was adequate hepatic arterial flow after the celiac artery was clamped, the Appleby procedure was performed. However, in case 2 (a 65-year-old man), the hepatic arterial flow after the celiac artery had been clamped was reduced from 47.9cm/s to 14.3cm/s. The liver surface became dark and the liver shrank. In addition, there were various preoperative medical conditions in this patient. We decided not to proceed with the Appleby procedure.Conclusions Intraoperative Doppler US measurement of the hepatic arterial flow is a useful technique, particularly in combination with the assessment of the color and tension of the liver, the age of the patient, and the extent of preoperative comorbidity, in determining whether an Appleby procedure is feasible.     

Renoprotective properties of angiotensin receptor blockers beyond blood pressure lowering

Clinical studies have demonstrated that some antihypertensive agents provide renoprotection independent of BP lowering. Recent in vitro and in vivo studies evaluated the mechanisms involved in this protection. First, the in vitro effects of several angiotensin II type 1 receptor blockers (ARB), calcium channel blockers (CCB), and beta blockers (BB) on various mediators were compared: Formation of pentosidine (an advanced glycation end product), hydroxyl radical-induced formation of o-tyrosine, and transition metals-induced oxidation of ascorbic acid (the Fenton reaction). All of the six tested ARB but neither the six CCB nor the nine BB inhibited pentosidine formation. ARB, as well as BB but not CCB, inhibited hydroxyl radicals-mediated o-tyrosine formation. ARB but neither BB nor CCB inhibited efficiently transition metals-catalyzed oxidation of ascorbic acid. Second, the in vivo consequences for the kidney of these various in vitro effects were evaluated. Hypertensive, type 2 diabetic rats with nephropathy, SHR/NDmcr-cp, were given for 20 wk either olmesartan (ARB) or nifedipine (CCB), or atenolol (BB). Despite similar BP reduction, only ARB significantly reduced proteinuria and prevented glomerular and tubulointerstitial damage (mesangial activation, podocyte injury, tubulointerstitial injury, and inflammatory cell infiltration). It is interesting that only ARB prevented abnormal iron deposition in the interstitium, corrected chronic hypoxia, reduced expressions of heme oxygenase and p47phox (a subunit of NADPHoxidase), and inhibited pentosidine formation (which correlates well with proteinuria). These observations confirm unique renoprotective properties of ARB, independent of BP lowering but related to decreased oxidative stress (hydroxyl radicals scavenging and inhibition of the Fenton reaction), correction of chronic hypoxia, and inhibition of advanced glycation end product formation and of abnormal iron deposition. These benefits of ARB may contribute to the renoprotection observed beyond BP lowering.     

Functional asymmetry of visual fields for Japanese words in kana (syllable-based) writing and random shape-recognition in Japanese subjects

Random shapes or Japanese two-syallable nonsense words (in kana-writing) were presented tachistoscopically and successively as stimulus materials to 18 normal, right-handed Japanese female students, would could view them on the right or the left sode of a central fixation point. When the stimulus coincided with a stimulus previously taught as a positive one, the subjects were required to press a button as soon as possible, and the reaction time was measured.Analyses of variances for reaction times of correct responses indicate that the difference between the visual fields is significant for each type of recognition, regardless of the responding hand, and that there is a left visual field (or right cerebral hemispheric) superiority for shape recognition and a right visual field (or left hemispheric) superiority for nonsense word recognition.These results also assure us that Japanese subjects have the same interhemispheric functional asymmetry for shape and word recognition, as subjects in Europe and America do.     

An open trial of outpatient group therapy for bulimic disorders: combination program of cognitive behavioral therapy with assertive training and self-esteem enhancement

The purposes of this study were to examine the therapeutic efficacy of combined group cognitive behavioral therapy (CGCBT) and to explore the characteristics of the patients who failed to complete it. Our group cognitive behavioral therapy combined with assertiveness training for alexithymia and self-esteem enhancement therapy were attended over a 10-week period. Twenty-five participants were enrolled in the study. The clinical symptoms were assessed before and after treatment, using rating scales including the Eating Disorder Inventory-2, the Bulimic Investigatory Test, Edinburgh, the Toronto Alexithymia Scale, the Rosenberg Self-Esteem Scale, and Global Assessment of Functioning. Sixteen participants (64%) completed the CGCBT program. Completion of the CGCBT resulted in significant improvements in reducing binge-eating behavior and improving social functioning. Eight patients (32%) significantly improved using the Clinical Global Impression Change (CGI-C). Stepwise logistic regression analysis of the results indicated that a lower age (P=0.04) and psychiatric comorbidity (P=0.06) were predictors of dropout from the CGCBT program. Our CGCBT program is a promising first-line treatment for bulimic outpatients. Lower age and the presence of comorbidity had effects on dropout rates.     

Reduced D-serine to total serine ratio in the cerebrospinal fluid of drug naive schizophrenic patients

Several lines of evidence suggest that D-serine, an endogenous agonist of the glycine site on the NMDA receptors, might play a role in the pathophysiology of schizophrenia. The purpose of this study was to determine whether levels of D- and L-serine or D-serine ratio (D-serine/total serine) in cerebrospinal fluid (CSF) were altered in first episode and drug-naive schizophrenic patients. The CSF levels of D- and L-serine in 25 male first episode and drug-naive schizophrenic patients and 17 age-matched male healthy subjects were measured using a column-switching high performance liquid chromatography system. The percentage of D-serine in the total serine of patients was significantly (z = -2.01, p = 0.044) lower than that of controls. This study suggests that synthetic or metabolic pathways of D-serine may be abnormal in the brain of drug-naive schizophrenic patients, supporting the NMDA receptor dysfunction hypothesis of schizophrenia.     

Stent-supported coil embolization for carotid artery pseudoaneurysm as a complication of endovascular surgery--case report

A 57-year-old male presented with right amaurosis fugax and left transient ischemic attack caused by stenosis of the intracranial segment of the right internal carotid artery (ICA). Percutaneous transluminal angioplasty with stenting was successfully performed to dilate the stenosis. However, serial angiography revealed the development of a large pseudoaneurysm in the cervical ICA, probably as a result of carotid wall injury caused by the guiding catheter during the procedures. The patient underwent a second endovascular angioplasty. A Palmaz stent was placed across the aneurysm neck to stabilize the carotid wall. Guglielmi detachable coils were then inserted into the aneurysm cavity through the stent struts to successfully obliterate the aneurysm. Both the angiographical results and the patient's outcome were favorable. Stent-supported coil embolization is an effective and safe technique for medically refractory pseudoaneurysms, and may be a useful alternative to direct surgery.