Sequence-specific cleavage of RNA by a hybrid ribonuclease H

AbstractSite-specific cleavage of the 22-, 132- and 534-base RNAs by the DNA/protein hybrid R Nase H were examined. The 22-base RNA was chemically synthesized, and 132- and 534-base RNAs were prepared by run-off transcription. The hybrid enzyme cleaves these RNAs, which contain a single target sequence, primarily at the unique phosphodiester bond within the target sequence. The hybrid enzyme performs multiple turnovers, and at a substrate/enzyme ratio of 10:1 the RNAs are almost completely cleaved by the hybrid enzyme at 37°C within 1 h. We propose that hybrid RNase H molecules with various oligodeoxyribonucleotides function as RNA restriction enzymes and are useful for structural and functional studies of RNA

Electrical storm after cardiac resynchronization therapy in a patient with nonischemic cardiomyopathy: Signal-averaged vector-projected 187-channel electrocardiogram-based risk stratification for lethal arrhythmia

AbstractWe describe treatment of atrial flutter and electrical storm presenting as incessant ventricular tachycardia (VT) after implantation of a cardiac resynchronization therapy defibrillator (CRT-D) in a patient with dilated cardiomyopathy. No prior arrhythmic event had occurred. Our treatment strategy, including amiodarone administration, was guided in part by signal-averaged vector-projected 187-channel electrocardiogram (SAVP-ECG)-based risk stratification for ventricular arrhythmia. Corrected recovery time (RTc) dispersion and Tpeak-end dispersion were used to evaluate transmural dispersion of repolarization. RTc and Tpeak-end dispersion increased during the period of electrical storm. Values were improved 2 years after CRT-D implantation, and the amiodarone was discontinued. The VT has not recurred despite discontinuation of the antiarrhythmic agent. SAVP-ECG-based risk stratification for ventricular arrhythmia proved useful for the management of antiarrhythmic therapy

Phaseâ amplitude coupling between interictal highâ frequency activity and slow waves in epilepsy surgery

ObjectiveWe hypothesized that the modulation index (MI), a summary measure of the strength of phaseâ amplitude coupling between highâ frequency activity (>150 Hz) and the phase of slow waves (3â 4 Hz), would serve as a useful interictal biomarker for epilepsy presurgical evaluation.MethodsWe investigated 123 patients who underwent focal cortical resection following extraoperative electrocorticography recording and had at least 1 year of postoperative followâ up. We examined whether consideration of MI would improve the prediction of postoperative seizure outcome. MI was measured at each intracranial electrode site during interictal slowâ wave sleep. We compared the accuracy of prediction of patients achieving International League Against Epilepsy class 1 outcome between the full multivariate logistic regression model incorporating MI in addition to conventional clinical, seizure onset zone (SOZ), and neuroimaging variables, and the reduced logistic regression model incorporating all variables other than MI.ResultsNinety patients had class 1 outcome at the time of most recent followâ up (mean followâ up = 5.7 years). The full model had a noteworthy outcome predictive ability, as reflected by regression model fit R2 of 0.409 and area under the curve (AUC) of receiver operating characteristic plot of 0.838. Incomplete resection of SOZ (P < 0.001), larger number of antiepileptic drugs at the time of surgery (P = 0.007), and larger MI in nonresected tissues relative to that in resected tissue (P = 0.020) were independently associated with a reduced probability of class 1 outcome. The reduced model had a lower predictive ability as reflected by R2 of 0.266 and AUC of 0.767. Anatomical variability in MI existed among nonepileptic electrode sites, defined as those unaffected by magnetic resonance imaging lesion, SOZ, or interictal spike discharges. With MI adjusted for anatomical variability, the full model yielded the outcome predictive ability of R2 of 0.422, AUC of 0.844, and sensitivity/specificity of 0.86/0.76.SignificanceMI during interictal recording may provide useful information for the prediction of postoperative seizure outcome.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146440/1/epi14544_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146440/2/epi14544.pd

Effects of a high-fat diet on the electrical properties of porcine atria

AbstractBackgroundBecause obesity is an important risk factor for atrial fibrillation (AF), we conducted an animal study to examine the effect of a high-fat diet (HFD) on atrial properties and AF inducibility.MethodsTen 8-week-old pigs (weight, 18–23kg) were divided into two groups. For 18 weeks, five pigs were fed a HFD (HFD group) and five were fed a normal diet (control group). Maps of atrial activation and voltages during sinus rhythm were created for all pigs using the EnSite NavX system. Effective refractory period (ERP) and AF inducibility were also determined. When AF was induced, complex fractionated atrial electrogram (CFAE) mapping was performed. At 18 weeks, hearts were removed for comparing the results of histological analysis between the two groups. Body weight, lipid levels, hemodynamics, cardiac structures, and electrophysiological properties were also compared.ResultsTotal cholesterol levels were significantly higher (347 [191–434] vs. 81 [67–88]mg/dL, P=0.0088), and left atrium pressure was higher (34.5 [25.6–39.5] vs. 24.5 [21.3–27.8]mmHg, P=0.0833) in the HFD group than in the control group, although body weight only increased marginally (89 [78–101] vs. 70 [66–91]kg, P=0.3472). ERPs of the pulmonary vein (PV) were shorter (P<0.05) and AF lasted longer in the HFD group than in the control group (80 [45–1350] vs. 22 [3–30]s, P=0.0212). Neither CFAE site distribution nor histopathological characteristics differed between the two groups.ConclusionsThe shorter ERPs for the PV observed in response to the HFD increased vulnerability to AF, and these electrophysiological characteristics may underlie obesity-related AF

Efficacy of salvage therapies for advanced acral melanoma after anti-PD-1 monotherapy failure: a multicenter retrospective study of 108 Japanese patients

BackgroundAnti-programmed cell death protein 1 (PD-1) monotherapy is one of the standard systemic therapies for advanced melanoma; however, the efficacy of salvage systemic therapies after PD-1 monotherapy failure (PD-1 MF), particularly in acral melanoma (AM), the main clinical melanoma type in Japanese patients, is unclear. This study aimed to investigate the efficacy of salvage systemic therapies in Japanese patients with AM after PD-1 MF.Patients and methodsThe study included 108 patients with advanced AM (palm and sole, 72; nail apparatus, 36) who underwent salvage systemic therapy at 24 Japanese institutions. We mainly assessed the objective response rate (ORR), progression-free survival (PFS), and overall survival (OS).ResultsThirty-six (33%) patients received ipilimumab, 23 (21%) received nivolumab and ipilimumab (nivo/ipi), 10 (9%) received cytotoxic chemotherapy, 4 (4%) received BRAF and MEK inhibitors (BRAFi/MEKi), and the remaining 35 (32%) continued with PD-1 monotherapy after disease progression. The ORRs in the ipilimumab, nivo/ipi, cytotoxic chemotherapy, and BRAFi/MEKi groups were 8, 17, 0, and 100%, respectively. The nivo/ipi group showed the longest OS (median, 18.9 months); however, differences in ORR, PFS, and OS between the groups were insignificant. The OS in the nivo/ipi group was higher in the palm and sole groups than in the nail apparatus group (median: not reached vs. 8.7 months, p &lt; 0.001). Cox multivariate analysis demonstrated that nail apparatus melanoma independently predicted unfavorable PFS and OS (p = 0.006 and 0.001). The total OS (from PD-1 monotherapy initiation to death/last follow-up) was insignificant between the groups.ConclusionNivo/ipi was not more effective than cytotoxic chemotherapy and ipilimumab after PD-1 MF in patients with advanced AM. The prognosis after PD-1 MF would be poorer for nail apparatus melanoma than for palm and sole melanoma

Autophagy–physiology and pathophysiology

“Autophagy” is a highly conserved pathway for degradation, by which wasted intracellular macromolecules are delivered to lysosomes, where they are degraded into biologically active monomers such as amino acids that are subsequently re-used to maintain cellular metabolic turnover and homeostasis. Recent genetic studies have shown that mice lacking an autophagy-related gene (Atg5 or Atg7) cannot survive longer than 12 h after birth because of nutrient shortage. Moreover, tissue-specific impairment of autophagy in central nervous system tissue causes massive loss of neurons, resulting in neurodegeneration, while impaired autophagy in liver tissue causes accumulation of wasted organelles, leading to hepatomegaly. Although autophagy generally prevents cell death, our recent study using conditional Atg7-deficient mice in CNS tissue has demonstrated the presence of autophagic neuron death in the hippocampus after neonatal hypoxic/ischemic brain injury. Thus, recent genetic studies have shown that autophagy is involved in various cellular functions. In this review, we introduce physiological and pathophysiological roles of autophagy

エギロプストコムギニオケルエステラーゼアイソザイムノヘンイニカンスルイデンガクテキケンキュウ

京都大学0048新制・論文博士農学博士乙第3856号論農博第789号新制||農||273(附属図書館)学位論文||S54||N1073(農学部図書室)5945UT51-54-H156(主査)教授 常脇 恒一郎, 教授 田中 正武, 教授 山縣 弘忠学位規則第5条第2項該当Kyoto UniversityDA