ATP-induced dormant pulmonary veins originating from the carina region after circumferential pulmonary vein isolation of atrial fibrillation

INTRODUCTION

Elimination of transient pulmonary vein recurrences (dormant PVs) induced by an ATP injection and ablation at the PV carina region is an effective strategy for atrial fibrillation (AF) ablation. The relationship between dormant PVs and the PV carina region has not been evaluated.

METHODS

A total of 212 consecutive symptomatic AF patients underwent circumferential PV electrical isolation (CPVEI) with a double lasso technique. They were divided into 2 groups in a retrospective review; Group 1: those given an ATP injection during an intravenous isoproterenol infusion after the CPVEI (n = 106), and Group 2: those in which it was not given after the CPVEI (n = 106). Radiofrequency energy was applied at the earliest dormant PV activation site identified using a Lasso catheter on the CPVEI line and then PV carina region if it was ineffective.

RESULTS

After a successful PVEI, 54 patients (51%) in Group 1 had PV reconnections during an ATP injection. Acute PVEI sites were observed on the carina region within the CPVEI line in the right PVs (16%) and left PVs (10%). Dormant PVs were reisolated at the carina region in the right PVs (23%) and left PVs (26%). The distribution of the dormant PV sites, except for the RIPV, significantly differed from that of the acute PVEI sites (P < 0.05). Further, AF recurred significantly in the Group 2 patients as compared to those in Group 1 during 16 +/- 6.1 months of follow-up (P < 0.05).

CONCLUSION

PV carina region origins may partly be responsible for an acute PVEI and potential recurrences.

Preparation of a reference material containing sterigmatocystin

To assure the homogeneity of a reference material for the mycotoxin sterigmatocystin (STE), a study was first conducted to prepare a reference material of rice containing the colouring Food Red 106. The protocol developed was then used to prepare a reference material of rice containing STE. Initially, a V-shaped mixer was used to mix Food Red 106 and ground brown rice, but the resulting mixture was non-homogeneous. However, when a ShakeMaster was used for the simultaneous grinding and mixing of brown rice with Food Red 106, good homogeneity was obtained. Accordingly, a dried culture of Aspergillus versicolor NRRL5219 and brown rice was ground and mixed with the ShakeMaster. To assess the distribution of the STE an Autoprep MF-A 1000 mini-column was used to isolate the STE, and a 115-120% recovery rate was obtained. Repeatability (variability within a day) and intermediate precision (variability between days) were good. According to the IUPAC/ISO/AOAC International Harmonized Protocol for the Proficiency Testing of Analytical Chemistry Laboratories, a homogeneous candidate reference material was obtained. The particle sizes of ground brown rice, ground brown rice containing Food Red 106, and ground brown rice containing a non-STE producing culture of A. oryzae were analysed and they ranged from 10 to 700 microm.

Hybrid therapy of radiofrequency catheter ablation and percutaneous transvenous mitral commissurotomy in patients with atrial fibrillation and mitral stenosis

BACKGROUND

The rhythm control of atrial fibrillation (AF) associated with mitral stenosis (MS) is often difficult using antiarrhythmic drugs (AADs), even after a percutaneous transvenous mitral commissurotomy (PTMC). Few studies have examined the efficacy and safety of simultaneously performing radiofrequency catheter ablation (RFCA) and a PTMC in patients with MS and AF.

METHODS

Twenty consecutive patients with drug-resistant AF and rheumatic MS underwent RFCA combined with a PTMC (n = 10; persistent AF-8, long-lasting [>1 year] persistent AF-2; RFCA group) or transthoracic direct cardioversion (DC) following a PTMC (n = 10; persistent AF-7, long-lasting persistent AF-3; DC group). In all patients, the mitral valve morphology was amenable to a PTMC, and more than 2 AADs had been ineffective in maintaining sinus rhythm (SR). In the RFCA group, a segmental pulmonary vein isolation (PVI) was performed in the initial 5 patients, and an extensive PVI was performed in the remaining 5.

RESULTS

During a mean follow-up period of 4.0 +/- 2.7 years, 8 patients (80%) in the RFCA group were maintained in SR, as compared to 1 (10%) in the DC group (hazard ratio, 0.16; 95% confidence interval, 0.03 to 0.75; P = 0.008 by the log-rank test). The prevalence of the concomitant use of class I and/or class III AADs was comparable between the 2 groups (P = 0.70). No complications occurred during the procedure or follow-up period in either group.

CONCLUSIONS

The hybrid therapy using RFCA and a PTMC was safe and feasible, and significantly improved the AF free survival rate compared to DC following a PTMC.

A phase II study of S-1 for the treatment of cytokine-refractory metastatic renal cell carcinoma

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Background: S-1 is a novel oral anticancer agent, contains tegafur (FT), a prodrug of 5-fluorouracil (5-FU), with 5-chloro-2,4-dihydroxypyridine (CDHP) and potassium oxonate (Oxo) at a molar ratio of FT: CDHP: Oxo = 1:0.4:1. The purpose of this study was to evaluate the efficacy and safety of S-1 in cytokine-refractory metastatic renal cell carcinoma (mRCC), and to examine the relation between response and mRNA expression levels of 5-FU-related enzymes. Methods: Eligible patients had a histologically confirmed diagnosis of clear cell or papillary type of RCC, measurable lesions, treatment histories with cytokines, an ECOG performance status of 0 or 1 (2 was allowed in patients with bone metastasis), an age of at least 20 years, prior nephrectomy, and adequate organ functions. Any prior treatment for mRCC was discontinued more than 4 weeks before registration. S-1 was administered orally at a dose of 40 mg/m2 twice daily for 28 days, followed by 14 days of rest. The primary endpoint was the objective response rate (ORR) as confirmed by an independent reviewer. The planned sample size was 44 patients. The threshold response rate was defined as 5%, and the expected rate was set at 17.5%. If the lower limit of the 95% CI exceeded the threshold rate (6 of the 44), S-1 was evaluated to be effective. Formalin fixed paraffin embedded specimens, which had been obtained by radical nephrectomy, were used for mRNA expression assay, performed by RT-PCR method. Results: Between April 2006 and May 2007, 45 patients were enrolled, and 31 assay samples were obtained. ORR was 24.4% (11/45, 95% CI: 12.9 - 39.5%). The median PFS was 9.2 months. The median OS could not be calculated, but the survival rate at 1 year was 87.5%. The most common grade 3–4 adverse events assessed according to the CTCAE v.3.0 included anemia (6.7%), neutropenia (8.9%), anorexia (8.9%), hyperglycemia (6.7%), stomatitis (4.4%), diarrhea (4.4%), and fatigue (4.4%). On mRNA expression analysis, the expression level of 5-FU-related enzyme correlated with ORR and PFS. Conclusions: S-1 is effective and well tolerated in patients with cytokine-refractory mRCC. Measurement of the mRNA level of 5-FU-related enzyme in tumors before treatment may facilitate prediction of the response to S-1.

No significant financial relationships to disclose.

Quantitative analysis and characteristics of the electrograms recorded within the non-coronary aortic sinus of Valsalva

BACKGROUND

Some supraventricular tachycardias could be ablated from the non-coronary sinus of Valsalva (NSV). However, the characteristics of the NSV electrograms have not been clarified.

METHODS AND RESULTS

A quantitative analysis of the NSV electrograms was performed in 5 patients with tachycardias arising from near the atrioventricular node (AVN) and the His-bundle region, and in 20 control subjects. In another 7 control subjects, the NSV electrograms were compared with those recorded at the left and right sinus of Valsalva (LSV and RSV). The NSV electrograms during sinus rhythm had a larger atrial amplitude than ventricular amplitude, and the ratio of the atrial amplitude to the ventricular amplitude was usually >1, which was apparently different from the LSV and RSV electrograms. A tiny but distinct His-bundle deflection was sometimes recorded at the NSV during sinus rhythm while it was not during the tachycardia. The distance to the His-bundle region in the anteroseptal right atrium was shorter from the NSV than from the RSV or LSV.

CONCLUSIONS

The precise identification of the catheter position at the NSV is possible using the characteristics of the electrograms. Much attention should be paid during ablation to the NSV because of its vicinity to the AVN and His-bundle region.

Species differences in hydrolase activities toward OT-7100 responsible for different bioavailability in rats, dogs, monkeys and humans

OT-7100 (5-n-butyl-7-(3,4,5-trimethoxybenzoylamino)pyrazolo[1,5-a] pyrimidine) is an amide moiety-bearing pyrazolopyrimidine derivative with a potential analgesic effect. To determine the factors responsible for observed species differences in the bioavailability of this drug, human and experimental animal samples were used to investigate in vitro microsomal and cytosolic hydrolase activities in the liver and small intestine vis-à-vis the pharmacokinetics of OT-7100. The AUC(0-t) values of OT-7100 after oral administration in rats, dogs and monkeys were 0.163, 0.0383 and 0.00147 microg h ml(-1) divided by mg kg(-1), respectively. The bioavailabilities of OT-7100 after oral administration in rats, dogs and monkeys were 36, 17 and 0.3%, respectively. The plasma concentration-time profiles of intravenously administrated OT-7100 in rats, dogs and monkeys were similar. The hydrolase activities toward OT-7100 in liver microsomes or cytosol were approximately similar in rats, dogs, monkeys and humans. In contrast, hydrolase activities of small intestinal microsomes from monkeys were higher (36.1 ng mg protein(-1) min(-1)) than those of rats, dogs and humans (5.4, 1.4 and 4.3 ng mg protein(-1) min(-1), respectively). These results suggest that the primary factor influencing first-pass metabolism for the OT-7100 is enzymatic hydrolysis in the small intestine. This information provides an important index for extrapolating the pharmacokinetics of drugs in humans using studies on monkeys.

In vivoinduction of human cytochrome P450 3A4 by rifabutin in chimeric mice with humanized liver

The induction of human cytochrome P450 enzymes (CYPs) often poses a serious problem in clinical practice. The induction of CYP3A leads to a decrease in the pharmacological potency of drugs, since many drugs are substrates of CYP3A. The present study examined the in vivo induction potency of human CYP3A in chimeric mice with humanized liver, recently established in Japan, by a specific inducer of human CYP3A enzyme activity in this experimental condition, rifabutin, which is an analogue of rifampicin. The chimeric mice were treated intraperitoneally daily for 4 days with rifabutin (50 mg kg(-1) day(-1)). The mRNA, protein and enzyme activity in liver of the chimeric mice were measured by reverse-transcriptase polymerase chain reaction, Western blot analysis and high-performance liquid chromatography, respectively. In the chimeric mice, the human CYP3A4 mRNA expression, CYP3A4 protein content, testosterone 6ss-hydroxylase activity and dexamethasone 6-hydroxylase activity were increased 7.4-, 3.0-, 2.4- and 1.9-fold, respectively, by treatment with rifabutin. The mRNA expression of other human CYPs, transporters and nuclear receptors was not significantly changed by rifabutin. On the other hand, rifabutin was demonstrated not to increase the murine Cyp3a enzyme activities in the control mice. It was demonstrated that human CYP3A4 expressed in the chimeric mice with humanized liver was induced by rifabutin, suggesting that human CYP3A4 in the chimeric mice had induction potency. This chimeric mouse model may be a useful animal model to estimate and predict the in vivo induction of CYPs in human.

Docetaxel plus prednisolone for the treatment of metastatic hormone-refractory prostate cancer: a multicenter Phase II trial in Japan

BACKGROUND

Docetaxel-based chemotherapy has been shown to be effective and well tolerated by Western patients with metastatic hormone-refractory prostate cancer (HRPC). This study was undertaken to assess the feasibility of docetaxel in combination with prednisolone in Japanese patients with HRPC.

METHODS

Patients aged 50-74 years with measurable metastatic HRPC were included in this non-comparative Phase II study. Treatment consisted of docetaxel 70 mg/m(2) once every 3 weeks plus prednisolone 5 mg twice daily, for a maximum of 10 cycles. The primary endpoint was overall tumor response rate, assessed by Response Evaluation Criteria in Solid Tumors; secondary endpoints included prostate-specific antigen (PSA) response and toxicity.

RESULTS

A total of 43 patients were evaluable for efficacy and toxicity. The response rate was 44.2% (90% CI, 31.2-57.8%), with partial responses in 19/43 patients. The median duration of response was 19.3 weeks. PSA responses were recorded in 44.4% of patients (95% CI, 27.9-61.9%). The most common non-hematological adverse events (of any grade) possibly related to treatment were alopecia (88.4%), anorexia (65.1%) and fatigue (53.5%). Grade 3/4 leukopenia and neutropenia occurred in 81.4 and 93.0% of patients, respectively; however, the grade 3/4 rates of febrile neutropenia (16.3%) and infection without fever (14.0%) were lower.

CONCLUSION

The combination of docetaxel and prednisolone was feasible and active in Japanese patients with HRPC, with a manageable adverse-event profile similar to that observed in Western patients.

Plasma connective tissue growth factor is a novel potential biomarker of cardiac dysfunction in patients with chronic heart failure

BACKGROUND

Connective tissue growth factor (CTGF) has been recently reported as a mediator of myocardial fibrosis; however, the significance of plasma CTGF concentration has not been evaluated in patients with heart failure. The aim of this study was to investigate the clinical utility of plasma CTGF concentration for the diagnosis of heart failure.

METHODS AND RESULTS

We evaluated fifty-two patients with chronic heart failure. The plasma concentration of CTGF and other markers of fibrosis were assessed and compared with clinical and echocardiographic data. Plasma CTGF was significantly elevated in symptomatic patients in proportion to their NYHA classes and was significantly correlated with plasma brain natriuretic peptide (BNP) concentration (r=0.395, P<0.01). Plasma CTGF was also correlated with plasma transforming growth factor beta (TGF-beta) (r=0.512, P<0.01), matrix metalloproteinase (MMP)-2 (r=0.391, P<0.05) and tissue inhibitor of MMP (TIMP)-2 (r=0.354, P<0.05) concentrations. Interestingly, plasma CTGF was correlated with E/E' value evaluated by tissue Doppler echocardiography (r=0.593, P=0.012), but not with systolic function and left ventricular mass.

CONCLUSION

Our study suggests that plasma CTGF concentration is a novel diagnostic marker for cardiac dysfunction and may provide additional specific information about myocardial fibrosis in chronic heart failure patients.

Changes in the isolated delayed component as an endpoint of catheter ablation in arrhythmogenic right ventricular cardiomyopathy: predictor for long-term success

INTRODUCTION

Although successful ablation of ventricular tachycardia (VT) is feasible in arrhythmogenic right ventricular cardiomyopathy (ARVC), long-term recurrence is common. The aim of this study was to assess the usefulness of a change in the isolated delayed component (IDC) as an endpoint of the catheter ablation in ARVC.

METHODS AND RESULTS

Eighteen patients (48 +/- 11 years) with ARVC were studied. Detailed endocardial mapping of the right ventricle (RV) was performed during sinus rhythm. IDCs were recorded in 16 patients and the latest IDCs were related to the VT circuit. Catheter ablation was carried out in the areas with the IDCs. At the end of the session, the IDC was electrically dissociated in one, disappeared in five, exhibited second-degree block in one, was significantly delayed (>or=50 ms) in three, and remained unchanged in six. The change in the IDC was correlated with the change in the type II/III late potentials in the signal-averaged electrocardiography (ECG) and the inducibility of the clinical VT after the ablation. During a follow-up of 61 +/- 38 months, VT recurred in six. The patients with a changed IDC had a significantly lower VT recurrence than those with no IDC or an unchanged IDC (P < 0.02).

CONCLUSION

In patients with ARVC, (1) the IDCs during sinus rhythm are related to the clinical VT and can be a target for the ablation, (2) a change in the IDC can be used as an endpoint, and (3) qualitative analyses of the serial signal-averaged ECGs may be useful for the long-term follow-up.

Non-Contact Three-Dimensional Mapping and Ablation of Swallowing-Induced Atrial Tachyarrhythmias: Two Case Reports

We describe two cases of swallowing-induced tachyarrhythmias that were cured by radiofrequency ablation (RFCA) using a non-contact mapping system (NCMS). In both patients, tachyarrhythmias occurred during swallowing solids and liquids, and mapping and ablation of the arrhythmia using the NCMS was attempted during swallowing a rice ball. During a premature atrial contraction shortly after the swallow, the earliest endocardial breakthrough occurred at the right superior pulmonary vein (PV) ostium in Case 1 and at the left superior PV ostium and postero-inferior right atrium in Case 2. Guided by the NCMS catheter navigation system, the ablation catheter was easily and precisely positioned at a site where the earliest endocardial breakthrough occurred. RFCA at that site resulted in success and no recurrence or complications occurred during the follow-up in either patient.

Microbial flora alterations in jejunum and colon after chemical bowel preparation before Kasai hepatoportojejunostomy

AIM

There is little reported evidence on the effect of preoperative chemical bowel preparation by the administration of oral antibiotics in patients with biliary atresia (BA). This study was designed to examine and compare the alterations of microbial flora in feces cultures before and after the administration of oral antibiotics, and to examine fluid cultures from the tip of the jejunal limb at bile duct reconstruction by Kasai hepatoportoenterostomy (HPJ), and to evaluate the effects of preoperative oral antibiotics on postoperative cholangitis.

MATERIAL AND METHODS

Between January 2003 and July 2005, 6 infants with BA underwent surgical correction, and were treated preoperatively with polymyxin B (80 000 U/kg/day in 3 divided doses for 2 days) and metronidazole (10 mg/kg/day in 2 divided doses for 2 days). Quantitative feces cultures, both before administration of oral antibiotics and at Kasai HPJ, were obtained in patients with BA. Furthermore, fluid cultures from the tip of the jejunal limb at bile duct reconstruction by Kasai HPJ were obtained to examine alterations of bacteria and fungi.

RESULTS

Bacterial colonization of the tip of the jejunal limb did not occur at the Kasai HPJ. The most commonly encountered organisms were ENTEROCOCCUS and intestinal bacterial flora. Fungus was not detected in the feces before or after the administration of oral antibiotics. CANDIDA was detected in the tip of the jejunal limb after Kasai HPJ in only one patient.

CONCLUSIONS

The authors propose that colonic-type flora are generally found in the feces before and after the administration of oral antibiotics, and no bacteria are detected in the bilioenteric conduits.

Cystic thymoma in a child: a rare case and review of the literature

Thymomas are rare mediastinal tumors in pediatrics and cystic thymoma, is characterized by a predominantly cystic formation, is extremely rare. This report describes a 13-year-old girl with cystic thymoma, who was treated by video-assisted thoracoscopic surgery. The microscopic findings were characteristic of cystic thymoma. The literature on cystic thymoma is reviewed here and the clinical characteristics of cystic thymoma are discussed.

Swallowing-Induced Atrial Tachyarrhythmias: Prevalence, Characteristics, and the Results of the Radiofrequency Catheter Ablation

BACKGROUND

Detailed information on swallowing-induced tachyarrhythmias has been lacking.

METHODS

The prevalence, characteristics, and results of the radiofrequency catheter ablation (RFCA) of swallowing-induced tachyarrhythmias were examined in 544 patients with symptomatic premature atrial contractions (PACs), paroxysmal atrial tachycardia (AT), and/or paroxysmal atrial fibrillation (AF). We also conducted a search of the medical literature on swallowing-induced tachyarrhythmias. Further, we presented an in-depth review of the literature and investigated the published data on swallowing-induced tachyarrhythmias.

RESULTS

The prevalence of swallowing-induced tachyarrhythmias was 0.6% (three patients). An analysis of the published literature and our three cases demonstrated that (1) males predominated 9:1 over females, (2) most cases occurred over 35 years of age, (3) tachyarrhythmias occurred consistently and reproducibly shortly after each swallow, (4) 90% of the patients had PACs and/or AT as the manifesting arrhythmia, (5) the PACs provoked by swallowing usually had the same P-wave morphology as the first beat of the AT and AF, and (6) RFCA procedures performed in five cases resulted in success with no recurrence or complications.

CONCLUSIONS

Swallowing-induced tachyarrhythmias are rare, but have several distinct characteristics. RFCA should be considered in appropriately selected patients with reliable inducibility because such an ablation may offer a permanent cure.

Efficacy of CAB therapy in stage C prostate cancer: Exploratory analyses based on results of a double-blind, randomized, placebo-controlled phase III study of bicalutamide

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Background: Although the efficacy of CAB in advanced prostate cancer (PC) has been demonstrated by the PCTCG and others, more evidence is required in locally advanced (Stage C) PC. The results of a Japanese P III study of bicalutamide in Stage C/D PC suggested the efficacy of CAB was better than monotherapy. When time to progression (TTP) was evaluated in Stage C and D separately, CAB had significant benefits in both stages and results in stage D were consistent with PCTCG data. Thus, this exploratory analysis was conducted to evaluate more thoroughly the efficacy of CAB in Stage C. Methods: 205 untreated PC patients with Stage C/D were randomized to CAB (goserelin 3.6 mg/4 weeks or leuprorelin 3.75 mg/4 weeks + bicalutamide 80 mg/day) or LHRHa monotherapy (same LHRHa + placebo). Among these patients, 99 had Stage C (52/47 on CAB/monotherapy). The median of the following parameters were calculated, and log-rank tests performed: TTP in all Stage C patients; TTP in Stage C patients by age, PSA value at diagnosis, and histopathological class; time to PSA normalization when normal level was defined as =4, =1 and =0.2 ng/mL. Results: The median observation period in Stage C patients was 144 weeks. The median TTPs by each parameter in Stage C are shown below. The median times to PSA normalization on CAB and monotherapy were 7 and 16 weeks (p<0.01), 8 and 93 weeks (p<0.01) and 20 weeks and NR (p<0.01) with normal values defined as =4, =1 and =0.2 ng/mL, respectively. Conclusions: These results suggest that CAB with bicalutamide possesses superior efficacy to LHRHa monotherapy in Stage C regardless of age, PSA value at diagnosis, or degree of tumor differentiation. It is suggested that CAB in Stage C could decrease PSA to lower levels in a shorter period than with LHRHa monotherapy. The study is ongoing to assess long term survival outcome.

[Table: see text]

No significant financial relationships to disclose.

Maximum ventricular dyssynchrony predicts clinical improvement and reverse remodeling during cardiac resynchronization therapy

BACKGROUND

Tissue synchronization imaging (TSI) and tissue tracking imaging (TTI) might facilitate the evaluation of ventricular dyssynchrony.

METHODS

In 22 patients, TSI and TTI were performed before and < 1 month after onset of cardiac resynchronization therapy (CRT). With TSI guidance, maximum left ventricular (LV) intraventricular conduction delay (IVCDmax) was the greatest difference in time-to-peak velocity between septum and lateral wall. IVCD between the basal septum and lateral wall (IVCDbase) was also measured. Using TTI, the mean peak myocardial displacement of the basal septal and lateral walls (PMDbase), and the temporal coefficient of variation of the PMD in six LV regions (CV-PMDLV) were measured. The patients were divided into responders (whose LV end-systolic volume decreased by >/= 15% during a 27 +/- 9 months follow-up) and nonresponders.

RESULTS

Before CRT, IVCDbase was similar in both groups, and remained unchanged within the 1st month of CRT in both groups. However, before CRT, IVCDmax was greater in responders than in nonresponders (P < 0.05), and decreased only in the responders during CRT (P < 0.05). No significant difference was observed in PMDbase or CV-PMDLV between the two groups, before or during CRT.

CONCLUSIONS

TSI was useful to measure IVCDmax. A greater IVCDmax before CRT that decreased shortly after onset of CRT may predict long-term clinical improvement in CRT recipients.

Dimethyl sulphoxide relaxes rabbit detrusor muscle by decreasing the Ca2+ sensitivity of the contractile apparatus

BACKGROUND AND PURPOSE

The intravesical administration of dimethyl sulphoxide (DMSO) is used to alleviate the symptoms of interstitial cystitis. We investigated the relaxant effect of DMSO and its underlying mechanism in the detrusor muscle.

EXPERIMENTAL APPROACH

The effects of DMSO on contraction, on Ca2+ sensitivity of myofilaments, and on myosin light chain (MLC) phosphorylation were investigated in both intact and alpha-toxin-permeabilized strips of rabbit detrusor muscle.

KEY RESULTS

In fura-PE3-loaded strips, DMSO (>1%) induced a significant relaxation during sustained contractions induced by 60 mM K+-depolarization or 10 microM carbachol, while having no effect on the [Ca2+](i) level. DMSO decreased the level of MLC phosphorylation during the contractions induced by 60 mM K+ and 10 microM carbachol. DMSO also inhibited both the contraction and MLC phosphorylation induced by calyculin-A in intact strips. In the alpha-toxin-permeabilized preparations, DMSO relaxed the Ca2+-induced contraction and also inhibited the tension development induced by a stepwise increment of Ca2+ concentrations. Such a relaxant effect of DMSO was enhanced in the presence of phosphate.

CONCLUSIONS AND IMPLICATIONS

DMSO relaxes rabbit detrusor muscle by decreasing the Ca2+ sensitivity of myofilaments. Inhibition of the kinase activities involved in myosin phosphorylation may play a major role in DMSO-induced Ca2+ desensitization. Inhibition of the cross-bridge cycling at the step of phosphate release may also contribute to the relaxant effect of DMSO. Such relaxant effects of DMSO could be linked to the therapeutic effect of DMSO in interstitial cystitis.

Radiofrequency catheter ablation within the coronary sinus eliminates a macro-reentrant atrial tachycardia: importance of mapping in the coronary sinus

We describe a patient who underwent radiofrequency (RF) catheter ablation of symptomatic atrial fibrillation. After left atrial (LA) catheter ablation and pulmonary vein isolation, a macro-reentrant atrial tachycardia (AT) with a critical isthmus at the mitral isthmus was induced by incremental atrial pacing from the coronary sinus. Extensive RF energy applications from endocardial sites using ablation catheters with 4 mm- and 8 mm- tips resulted in no discrete potentials being recorded from the endocardial sites of the isthmus, but the tachycardia could not be terminated. However, discrete potentials were recorded within the CS, and epicardial RF energy applications from the CS eliminated the tachycardia. Thus, mapping in the CS is useful for detecting residual conduction at epicardial sites along the mitral isthmus. RF catheter ablation within the CS should be considered when no distinct electrograms are recorded after extensive ablation from the endocardial sites and when distinct electrograms are recorded within the CS.

Rare survival in a patient with severe complications of acute myocardial infarction: a case report

A 50-year-old man presented with acute myocardial infarction. Coronary angiography showed the left anterior descending artery (segment 6) was totally occluded. Direct percutaneous transluminal coronary angioplasty was performed, but a distal embolism occurred by the procedure. Consequently, he suffered cardiogenic shock and sustained ventricular tachycardia/fibrillation which exacerbated his condition. Finally, the patient was successfully treated with catheter ablation and cryosurgery to control the incessant ventricular arrhythmias, and partial left ventricular volume reduction and coronary artery bypass grafting to improve contractile performance. His left ventricular contractility did not improve, but the incessant ventricular arrhythmias could be controlled. His condition remarkably improved and he was discharged on foot. This patient with severe complications of acute myocardial infarction showed unusually good response and recovery.

Oxidative stress and DNA hypermethylation status in renal cell carcinoma arising in patients on dialysis

Renal cell carcinoma (RCC) is more frequently observed in patients on dialysis than in patients with normal renal function. However, the mechanism underlying carcinogenesis in RCC patients on dialysis is still unclear. We hypothesized that oxidative stress affects patients on dialysis and generates new neoplasms, and therefore analysed the correlation between the influences of various markers of oxidative stress and carcinogenesis in those patients. We evaluated the immunohistochemical expression of oxidative stress markers, such as iNOS, 8-OHdG, and COX-2 in 42 cases on dialysis and 51 cases with normal renal function as a control. The methylation status of p16INK4a, p14ARF, VHL, and RASSF1A was analysed together with clinicopathological factors. Histologically, the papillary type was observed more frequently in dialysis RCC than in sporadic RCC. Immunohistochemically, overexpression of iNOS (p < 0.0001) and COX-2 (p = 0.0002) was more frequently observed in dialysis RCC. Furthermore, the 8-OHdG labelling index was significantly higher in dialysis RCC than in sporadic RCC. Hypermethylation of p16INK4a was more frequently found in dialysis RCC (p < 0.05). However, no significant correlations between oxidative stress markers and DNA hypermethylation status were observed. The overexpression of iNOS, COX-2, and 8-OHdG in dialysis RCC suggests that patients on dialysis are affected by oxidative stress and that this effect plays an important role in the genesis of dialysis RCC.

Left atrial catheter ablation promotes vasoconstriction of the right coronary artery

BACKGROUND

Multiple cardiac ganglia are present in the left atrial (LA) region, and marked changes in autonomic nervous activity can occur after left atrial catheter ablation (CA) for atrial fibrillation (AF). Vasospastic angina involving the inferior wall of the left ventricle has been reported as a complication shortly after LACA.

METHODS

We studied 20 patients with drug-refractory AF who underwent LACA, performed to encircle the left- and right-sided pulmonary veins, 1 to 2 cm from their ostia under fluoroscopic guidance. Quantitative coronary angiography was performed before and after LACA, and we analyzed the minimal lesion diameter (MLD) of the proximal segment of the coronary arteries, and the basal tone, the baseline percent constriction versus maximal dilation after nitroglycerin administration.

RESULTS

No significant difference was observed in MLD or basal tone of the left coronary arteries after LACA. However, in the right coronary artery (RCA), the basal MLD was smaller (P < 0.01) and the basal tone was greater (P < 0.05) after than before LACA. No correlation was found between the baseline MLD or tone of the RCA and total amount of radiofrequency energy delivered or procedure duration. In 75% of RCA, the baseline MLD was smaller after than before LACA, which was significantly higher (P < 0.01) than observed in the left coronary arteries (38%).

CONCLUSION

Vasoconstriction was promoted in the RCA shortly after LACA, which may explain the variant angina reported after LACA.

Bicalutamide 80 mg combined with a luteinizing hormone-releasing hormone agonist (LHRH-A) versus LHRH-A monotherapy in advanced prostate cancer: findings from a phase III randomized, double-blind, multicenter trial in Japanese patients

To compare combination therapy with bicalutamide 80 mg and a luteinizing hormone-releasing hormone agonist (LHRH-A) versus LHRH-A alone in Japanese men with untreated advanced prostate cancer. A total of 205 patients with stage C/D prostate cancer were randomized to either LHRH-A+once-daily oral bicalutamide 80 mg or placebo. Primary study variables have been reported previously. Secondary variables included: time to achieve prostate-specific antigen < or = 4 ng/ml, time-to-treatment failure (TTTF), time-to-disease progression (TTP), overall survival (OS), adverse events and adverse drug reactions. Following combination therapy with bicalutamide 80 mg, there were significant (P<0.001) advantages over LHRH-A alone in terms of TTTF and TTP, but the difference in the interim OS was not statistically significant. First-line combination therapy with bicalutamide 80 mg in Japanese patients with advanced prostate cancer offers significant benefits over LHRH-A alone, with respect to TTTF and TTP. Follow-up for OS continues.

Efficacy and Safety of the Additional Bepridil Treatment in Patients With Atrial Fibrillation Refractory to Class I Antiarrhythmic Drugs

BACKGROUND

Bepridil has multiple ion-channel blocking effects and is expected to be useful for managing atrial fibrillation (AF). The purpose of this study was to clarify the efficacy and safety of additional treatment with bepridil in patients with AF who had been treated with class I antiarrhythmic drugs (AADs).

METHODS AND RESULTS

Bepridil (50-200 mg/day) was given to 76 patients with either paroxysmal (n=49) or persistent AF (n=27). All patients had been treated with class I AADs (1.9+/-0.9 drugs/patient) that failed to control the AF. With the addition of bepridil, the frequency of symptomatic AF episodes decreased to less than 10% in 38 (78%) patients with paroxysmal AF, and sinus rhythm was restored within 3 months and maintained during the follow-up in 20 (74%) patients with persistent AF. Efficacy was usually obtained with a small to moderate dose (50-150 mg/day) of bepridil. During a mean follow-up period of 27+/-22 months, no potential complications occurred in any of the patients.

CONCLUSIONS

The addition of bepridil to class I AADs is effective and safe for AF, but careful observation using periodic ECG recordings is essential for avoiding torsades de pointes caused by QT prolongation.

Prevalence and Characteristics of Left Atrial Tachycardia Following Left Atrial Catheter Ablation

BACKGROUND

Left atrial tachycardia (AT) is a complication of left atrial catheter ablation (LACA) of atrial fibrillation (AF). However, its prevalence and characteristics have not been sufficiently clarified.

METHODS

We divided 121 patients who underwent LACA into 2 groups based on the results of AT occurrence after LACA (follow-up period; 12 +/- 7 months): an AT+ group and AT- group.

RESULTS

New-onset left AT occurred in 30 patients (25%) 31 +/- 51 days after LACA. Among the 26 patients with an early onset of AT, 4 underwent a second ablation for AT, and 21 became free of AT within 6 months without a repeat ablation procedure. Among the 4 patients with a late onset of AT (> 2 months after the LACA), the tachycardia remitted without a repeat ablation procedure in a single patient within 6 months. Among 71 patients who underwent LACA with additional ablation lines, 22 (31%) developed new-onset left AT. Among 50 patients who underwent LACA alone, 8 (16%) developed new-onset left AT (P = 0.02).

CONCLUSIONS

New-onset left AT is a frequent complication of LACA for AF, especially in men and in patients with a low left ventricular ejection fraction. Early (< 2 months) onset AT does not require a repeat ablation because it often represents a transient phenomenon and disappears spontaneously.