Collaborative Biosynthesis of Maleimide- and Succinimide-Containing Natural Products by Fungal Polyketide Megasynthases.

Fungal polyketide synthases (PKSs) can function collaboratively to synthesize natural products of significant structural diversity. Here we present a new mode of collaboration between a highly reducing PKS (HRPKS) and a PKS-nonribosomal peptide synthetase (PKS-NRPS) in the synthesis of oxaleimides from the Penicillium species. The HRPKS is recruited in the synthesis of an olefin-containing free amino acid, which is activated and incorporated by the adenylation domain of the PKS-NRPS. The precisely positioned olefin from the unnatural amino acid is proposed to facilitate a scaffold rearrangement of the PKS-NRPS product to forge the maleimide and succinimide cores of oxaleimides.

A potential pitfall of the modified 12 lead electrocardiogram (Mason-Likar modification) in catheter ablation of idiopathic ventricular arrhythmias originating from the outflow tract.

AIMS: The Mason-Likar modified electrocardiogram (ML-ECG) can be interchanged with standard 12 lead ECG electrode positions (standard ECG) without affecting the diagnostic interpretation during sinus rhythm, but the morphological differences during ventricular arrhythmias have not been sufficiently evaluated. This study aimed to elucidate the morphological changes in the ML-ECG precordial leads. METHODS AND RESULTS: In 53 consecutive patients with premature ventricular contractions predicted to originate from the outflow tract (OT-PVCs), the arrhythmias were analysed by those two ECG methods. The OT-PVC origin sites, which were predicted by currently published criteria with the respective ECG methods prior to catheter ablation, were compared with the successful ablation sites. Compared with the standard-ECG, S-waves in the ML-ECG became shallower in leads V1-4 (P < 0.05 in lead V1; P < 0.001 in leads V2-4), and pseudo-R-waves in lead V1 appeared in seven patients. The precordial leads transition zone shifted counter-clockwise in 18 patients in the ML-ECG. In leads I and aVL, the negative deflection amplitudes of the ML-ECG were greater than those of the standard ECG (P < 0.001), and polarity reversals in lead I appeared in 18 patients. The R-wave amplitudes in all ML-ECG inferior leads were greater than those in the standard-ECG leads (all for P < 0.001). Those changes had an effect on the diagnostic indexes for the localization, and the specificity of the criteria for the ML-ECG was poorer than that for the standard-ECG. CONCLUSION: Great differences were found between those two ECG methods. Predicting OT-PVC origins by diagnostic criteria with the ML-ECG might result in a misdiagnosis and inefficient ablation.

Induction of apoptosis by a potent caffeic acid derivative, caffeic acid undecyl ester, is mediated by mitochondrial damage in NALM-6 human B cell leukemia cells.

Caffeic acid esters have various biological activities, and we previously reported that undecyl caffeate (caffeic acid undecyl ester, CAUE), a new caffeic acid derivative, has strong pharmacological activity. The present study investigated the cytotoxicity of both CAUE and its parent compound, caffeic acid phenethyl ester (CAPE), and characterized the mechanisms by which they induce apoptosis in the human B cell leukemia cell line NALM-6. Treatment with CAUE reduced cell survival in NALM-6 cells but had no significant effect on the survival of normal lymphocytes. When assessing the 50% inhibitory concentration (IC(50)) for cytotoxicity, CAUE had 10-fold higher activity than CAPE in NALM-6 cells. CAUE treatment resulted in induction of apoptotic features in NALM-6 cells, including cleaved poly (ADP-ribose) polymerase and activated caspase-3. A caspase inhibitor completely blocked CAUE-induced apoptosis. CAUE treatment resulted in a concentration- and time-dependent decrease in both mitochondrial membrane potential and downregulation of Bcl-2 expression. Moreover, CAUE-induced apoptosis was enhanced in the Bcl-2 knockdown condition induced by small interfering RNA. These data suggest that CAUE-induced apoptosis was mediated via an apoptotic intrinsic pathway including mitochondrial damage and was caspase-dependent. These data also suggest that CAUE is a powerful anti-leukemic agent that acts via induction of apoptosis by mitochondrial damage and selective action in leukemia cells.

Transportation of de novo synthesized jasmonoyl isoleucine in tomato.

In plants, jasmonic acid (JA) and its derivatives are thought to be involved in mobile forms of defense against biotic and abiotic stresses. In this study, the distal transport of JA-isoleucine (JA-Ile) that is synthesized de novo in response to leaf wounding in tomato (Solanum lycopersicum) plants was investigated. JA-[¹³C6]Ile was recovered in distal untreated leaves after wounded leaves were treated with [¹³C6]Ile. However, as [¹³C6]Ile was also recovered in the distal untreated leaves, whether JA-Ile was synthesized in the wounded or in the untreated leaves was unclear. Hence, stem exudates were analyzed to obtain more detailed information. When [¹³C6]Ile and [²H6]JA were applied separately into the wounds on two different leaves, JA-[¹³C6]Ile and [²H6]JA-Ile were detected in the stem exudates but [²H6]JA-[¹³C6]Ile was not, indicating that JA was conjugated with Ile in the wounded leaf and that the resulting JA-Ile was then transported into systemic tissues. The [²H3]JA-Ile that was applied exogenously to the wounded tissues reached distal untreated leaves within 10 min. Additionally, applying [²H3]JA-Ile to the wounded leaves at concentrations of 10 and 60 nmol/two leaves induced the accumulation of PIN II, LAP A, and JAZ3 mRNA in the distal untreated leaves of the spr2 mutant S. lycopersicum plants. These results demonstrate the transportation of de novo synthesized JA-Ile and suggest that JA-Ile may be a mobile signal.

Olmesartan improves coronary flow reserve of hypertensive patients using coronary magnetic resonance imaging compared with amlodipine.

OBJECTIVES: Hypertension impairs coronary endothelial cell function, coronary microvascular function and the coronary flow (CF) reserve (CFR). Angiotensin II receptor blockers (ARBs) have been reported to possibly improve coronary endothelial function and coronary microvascular function. The purpose of this study was to determine whether treatment with the ARB olmesartan was more effective for improving CFR than the calcium channel blocker amlodipine. METHODS: Twenty patients with untreated essential hypertension (M/F = 13/7, aged 55.6 ± 11.6 years) were randomly assigned to treatment with either olmesartan (n = 10) or amlodipine (n = 10) for 6 months. CF was measured in the proximal left anterior descending artery by magnetic resonance imaging before and during intravenous infusion of adenosine. CFR was calculated as the ratio of the hyperemic to baseline diastolic peak flow before and after 6 months of treatment. RESULTS: The extent of systolic blood pressure reduction was similar in both groups (-40.0 ± 19.1 vs. -48.8 ± 14.7 mm Hg, p = 0.26). The olmesartan group showed significant improvement of CFR (from 1.9 ± 1.0 to 3.1 ± 1.1, p = 0.005), but this did not occur in the amlodipine group. CONCLUSION: Olmesartan, but not amlodipine, improves CFR in hypertensive patients.

Phylogenetic groups and cephalosporin resistance genes of Escherichia coli from diseased food-producing animals in Japan.

A total of 318 Escherichia coli isolates obtained from different food-producing animals affected with colibacillosis between 2001 and 2006 were subjected to phylogenetic analysis: 72 bovine isolates, 89 poultry isolates and 157 porcine isolates. Overall, the phylogenetic group A was predominant in isolates from cattle (36/72, 50%) and pigs (101/157, 64.3%) whereas groups A (44/89, 49.4%) and D (40/89, 44.9%) were predominant in isolates from poultry. In addition, group B2 was not found among diseased food-producing animals except for a poultry isolate. Thus, the phylogenetic group distribution of E. coli from diseased animals was different by animal species. Among the 318 isolates, cefazolin resistance (minimum inhibitory concentrations: ≥32 µg/ml) was found in six bovine isolates, 29 poultry isolates and three porcine isolates. Of them, 11 isolates (nine from poultry and two from cattle) produced extended spectrum ß-lactamase (ESBL). The two bovine isolates produced bla(CTX-M-2), while the nine poultry isolates produced bla(CTX-M-25) (4), bla(SHV-2) (3), bla(CTX-M-15) (1) and bla(CTX-M-2) (1). Thus, our results showed that several types of ESBL were identified and three types of ß-lactamase (SHV-2, CTX-M-25 and CTX-M-15) were observed for the first time in E. coli from diseased animals in Japan.

Cellulase applied to the leaves of sweet pepper (Capsicum annuum L. var. grossum) upregulates the production of salicylic and azelaic acids.

Treating the leaves of sweet pepper (Capsicum annuum L. var. grossum) with an aqueous solution of cellulase resulted in a four-fold increase in the salicylic acid level compared to a control plant. The level of endogenous azelaic acid was also elevated by the cellulase treatment. Azelaic acid has recently been reported to act as a mobile "priming" agent to arm plants against pathogenic attack. Our results are consistent with this and that the cellulase treatment enhanced the ability of sweet pepper to withstand viral attack.

Distal transport of exogenously applied jasmonoyl-isoleucine with wounding stress.

Determining the mobile signal used by plants to defend against biotic and abiotic stresses has proved elusive, but jasmonic acid (JA) and its derivatives appear to be involved. Using deuterium-labeled analogs, we investigated the distal transport of JA and jasmonoyl-isoleucine (JA-Ile) in response to leaf wounding in tobacco (Nicotiana tabacum) and tomato (Solanum lycopersicum) plants. We recovered [(2)H(2)-2]JA ([(2)H(2)]JA) and [(2)H(3)-12]JA-Ile ([(2)H(3)]JA-Ile) in distal leaves of N. tabacum and S. lycopersicum after treating wounded leaves with [(2)H(2)]JA or [(2)H(3)]JA-Ile. We found that JA-Ile had a greater mobility than JA, despite its lower polarity, and that application of exogenous JA-Ile to wounded leaves of N. tabacum led to a higher accumulation of JA and JA-Ile in distal leaves compared with wounded control plants. We also found that exudates from the stem of S. lycopersicum plants with damaged leaflets contained JA and JA-Ile at higher levels than in an undamaged plant, and a significant difference in the levels of JA-Ile was observed 30 min after wounding. Based on these results, it was found that JA-Ile is a transportable compound, which suggests that JA-Ile is a signaling cue involved in the resistance to biotic and abiotic stresses in plants.

Epidemiology of plasmid-mediated quinolone resistance in salmonella enterica serovar typhimurium isolates from food-producing animals in Japan.

A total of 225 isolates of Salmonella enterica serovar Typhimurium from food-producing animals collected between 2003 and 2007 were examined for the prevalence of plasmid-mediated quinolone resistance (PMQR) determinants, namely qnrA, qnrB, qnrC, qnrD, qnrS, qepA and aac(6')Ib-cr, in Japan. Two isolates (0.8%) of S. Typhimurium DT104 from different dairy cows on a single farm in 2006 and 2007 were found to have qnrS1 on a plasmid of approximately 9.6-kbp. None of the S. Typhimurium isolates had qnrA, qnrB, qnrC, qnrD, qepA and acc(6')-Ib-cr. Currently in Japan, the prevalence of the PMQR genes among S. Typhimurium isolates from food animals may remain low or restricted. The PFGE profile of two S. Typhimurium DT104 isolates without qnrS1 on the farm in 2005 had an identical PFGE profile to those of two S. Typhimurium DT104 isolates with qnrS1. The PFGE analysis suggested that the already existing S. Typhimurium DT104 on the farm fortuitously acquired the qnrS1 plasmid.

Transesophageal echocardiography for thrombus screening prior to left atrial catheter ablation.

BACKGROUND: Transesophageal echocardiography (TEE) is useful for detecting left atrial (LA) thrombus prior to percutaneous LA catheter ablation in patients with atrial fibrillation (AF). This study was designed to evaluate clinical predictors of LA thrombus and determine indications for TEE screening prior to LA ablation. METHODS AND RESULTS: The study consisted of 446 patients with drug-resistant AF who were scheduled to undergo initial LA ablation (age 59+/-11 years, 312 males, 136 persistent AF). TEE was performed in all cases within 24 h before ablation. We assessed clinical parameters including CHADS(2) score and echocardiographic parameters. LA thrombus was detected in 13 cases (2.9%) prior to LA ablation (67+/-8 years, 10 males, 12 persistent AF). In multiple logistic regression analysis, advanced age (odds ratio (OR) 1.1, 95% confidence interval (CI) 1.0-1.2; P<0.05), persistent AF (OR 38.1, 95%CI 1.4-988; P<0.05) and structural heart diseases (OR 29.8, 95%CI 2.8-383; P<0.01) were independent positive predictors of LA thrombus prior to ablation, while CHADS(2) score and LA volume were not significant predictors. None of the 136 patients with paroxysmal lone AF whose age was below 60 years had LA thrombus prior to ablation. CONCLUSIONS: It might be reasonable to omit TEE as a screening examination for LA thrombus prior to LA ablation in younger paroxysmal lone AF patients.

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.

Kinetics of the accumulation of jasmonic acid and its derivatives in systemic leaves of tobacco (Nicotiana tabacum cv. Xanthi nc) and translocation of deuterium-labeled jasmonic acid from the wounding site to the systemic site.

In plants, the mobile signal needed for wound-induced systemic acquired resistance (WSR) has been elusive. The signal compound involved in WSR is supposed to be JA or its derivatives. On the basis of kinetic study of the accumulation of JA or its derivatives, it was discovered that JA, JA-Ile, tuberonic acid (TA, 12-OH epi-JA), and tuberonic acid glucoside (TAG) accumulated in systemic tissues in response to mechanical wounding stress in the tobacco plant (Nicotiana tabacum). Attempts to recover deuterium-labeled JA in systemic leaves after feeding the wounded leaves with deuterium-labeled JA were successfully done. It was also found that the translocated deuterium-labeled JA was metabolized to TA in systemic leaves under feeding of deuterium-labeled JA to the wounding leaves.

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.

Change in blood pressure just after initiation of cardiac resynchronization therapy predicts long-term clinical outcome in patients with advanced heart failure.

BACKGROUND: The aim of this study was to retrospectively investigate the long-term effect of cardiac resynchronization therapy (CRT) and to clarify the useful predictors of clinical outcome. Methods and Results The study group comprised 43 patients with advanced heart failure who underwent CRT (10 females; 66+/-10 years): 23 were in sinus rhythm (SR group) and 20 had chronic atrial fibrillation (AF group). The clinical parameters and echocardiographic data were evaluated before and after CRT. There were no significant differences in the clinical parameters, echocardiographic data at baseline or frequency of responders between the 2 groups. In both groups, the clinical characteristics at baseline did not differ between the responders and non-responders. A prompt rise in systolic blood pressure (SBP) just after CRT was observed more often in responders than in non-responders, and SBP rise > or =5 mmHg was the only significant independent predictor of a CRT responder (P=0.0033). Furthermore, there was a significant difference in the event-free survival between patients with and without SBP rise > or =5 mmHg, demonstrated by Kaplan-Meier method, at 2 years of follow-up (P=0.045). Conclusion A prompt BP rise just after CRT may predict short- and long-term clinical improvement in CRT recipients.