Impact of high frequency stimulation to confirm a complete box isolation in catheter ablation of non-paroxysmal atrial fibrillation.

INTRODUCTION: Pulmonary vein (PV) isolation (PVI) including the left atrial posterior wall (LAPW) (Box-PVI) is proposed as an additional strategy for non-paroxysmal atrial fibrillation (NPAF), however, the efficacy remains controversial. The more reliable and durable the Box-PVI we can create, the better the rhythm outcomes might be than with a conventional PVI alone. This study focused on the potential exit conduction of the box lesion and investigated whether the conventional Box-PVI would be sufficient. METHODS AND RESULTS: We enrolled 350 consecutive patients with NPAF that underwent a conventional encircling Box-PVI and examined whether latent exit conduction and dormant "exit" conduction independently remained on the LAPW and in the PVs using high frequency stimulation (HFS) and an adenosine triphosphate (ATP) injection. All electrograms inside the box lesion were eliminated in all cases, however, HFS inside the box propagated outward in 23 cases (6.6%) without any exit conduction by conventional burst stimulation, and 24 cases (6.9%) exhibited only dormant "exit" conduction of the LAPW. Additional ablation where positive HFSs were observed created a complete bidirectional Box-PVI in 43 (41.3%) of the cases without a first pass Box-PVI. The recurrence rates depended on the groups classified according to the HFS response. CONCLUSION: HFS delivered with an ATP injection on the LAPW and in the PVs following a Box-PVI could not only elucidate true exit block but also identified possible incomplete lesions or connections outside the ablation line, whose elimination could achieve a complete Box-PVI leading to a better rhythm outcome.

Micro-computed tomography analysis of the relationship between root canal number and root concavity in maxillary first and second molars in a Japanese population.

PURPOSE: The aim of this study was to investigate root canal configurations in maxillary first and second molars from a Japanese population, as well as the relationship between the root canal number and root concavity depth, using micro-computed tomography. METHODS: Maxillary first (N = 74) and second (N = 70) molars from a Japanese population were used. Virtual horizontal sections were created, and the number of root canals and the degree of root concavity were measured. Mesiobuccal (MB) roots were categorized into Group 1 (with a single root canal) or Group 2 (with two or more root canals). The relationship between the root canal number and root concavity depth was evaluated using the Mann-Whitney U test. RESULTS: Approximately 51% and 35% of the MB roots in the three-rooted maxillary first and second molars, respectively, had two or more root canals. The depths of the root concavities in maxillary first molars differed significantly between Groups 1 and 2 at the mesial and distal sides of the MB root, in the section 2 mm apical to the furcation area (p < 0.05). CONCLUSIONS: A significant relationship between the number of root canals and the depth of root concavity in the MB root of the maxillary first molars was observed. Close clinical monitoring is needed during the removal of calculus and cleaning of the root surfaces of maxillary first molars: specifically, excessive removal of cementum and dentin should be avoided, particularly when the molar has already undergone root canal treatment.

Low-temperature NO oxidation using lattice oxygen in Fe-site substituted SrFeO3-δ.

Improvement of the low-temperature activity for NO oxidation catalysts is a crucial issue to improve the NOx storage performance in automotive catalysts. We have recently reported that the lattice oxygen species in SrFeO3-δ (SFO) are reactive in the oxidation of NO to NO2 at low temperatures. The oxidation of NO using lattice oxygen species is a powerful means to oxidize NO in such kinetically restricted temperature regions. This paper shows that Fe-site substitution of SFO with Mn or Co improves the properties of lattice oxygen such as the temperature and amount of oxygen release/storage, resulting in the enhancement of the activity for NO oxidation in a low-temperature range. In particular, NO oxidation on SrFe0.8Mn0.2O3-δ is found to proceed even at extremely low temperatures <423 K. From oxygen release/storage profiles obtained by temperature-programmed reactions, Co doping into SFO increases the amount of released oxygen owing to the reducibility of the Co species and promotes the phase transformation to the brownmillerite phase. On the other hand, Mn doping does not increase the oxygen release amount and suppresses the phase transformation. However, it significantly decreases the oxygen migration barrier of SFO. Substitution with Mn renders the structure of SFO more robust and maintains the perovskite structure after the release of oxygen. Thus, the oxygen release properties are strongly dependent on the crystal structure change before and after oxygen release from the perovskite structure, which has a significant effect on NO oxidation and the NOx storage performance.

Structural characterization of molybdenum-dinitrogen complex as key species toward ammonia formation by dispersive XAFS spectroscopy.

The structural characterization of a hardly-isolatable molybdenum-dinitrogen complex bearing a PNP-type pincer ligand, which is assumed to be a key reactive complex in the stoichiometric transformation of a molybdenum triiodide complex [MoI3(PNP)] into the corresponding molybdenum nitride complex under an atmospheric pressure of dinitrogen, was carried out by using dispersive XAFS.

[SUMMER-TYPE HYPERSENSITIVITY PNEUMONITIS CAUSED BY A HUMIDIFIER INDUCED IN SPRING, IN A 5-YEAR-OLD GIRL LIVING IN FUKUSHIMA-A CASE REPORT].

A 5-year-old girl living in Koriyama, Fukushima Prefecture was admitted in April with cough persisting for 1 month and fever. Chest X-ray showed diffuse ground-glass shadows in both lungs. After treatment with antibiotics, her fever went down on the 2nd day, and her cough subsided gradually. She was discharged on the 7th day, but her symptoms relapsed on the 8th day. Due to her worsening symptoms, she was readmitted on the 16th day. Chest CT scans showed enhancement of interstitial density. Serum anti-Trichosporon asahii antibody was positive. Her symptoms rapidly improved on a steroid regimen, and she was discharged on the 23th day. She was diagnosed as having summer-type hypersensitivity pneumonitis (SHP). She was instructed not to use a moldy humidifier and not to go to her grandmother's 57 years old wooden house. She has had no symptom after discharge. However, suspected mold was not found at her grandmother's house, and a provocation test there was negative. The HLA typing of the patient showed HLA-DQ8, which was previously described as SHP-sensitive.

Deep heat therapy system with resonant cavity applicator for articular cartilage in knee osteoarthritis.

[Purpose] Heat can prevent cartilage degeneration when applied to articular cartilage, but the size of the human knee joint makes it difficult to target cartilage during heat treatment. In this study, we aimed to establish a heat therapy method capable of safely applying heat to deep intra-articular tissues utilizing a resonant cavity applicator and to confirm the extent of cartilage heating in the human knee when using this system. [Participants and Methods] Heating experiments were carried out on the knees of healthy three volunteers using a resonant cavity applicator and a microwave diathermy system. After heat application, temperature distributions inside the knee were measured noninvasively using our measurement method based on ultrasound imaging techniques. [Results] We observed an increase in the temperature around the cartilage tissue in the knees of the volunteers using an ultrasonic thermometer; there was no increase in temperature in the overlying layers. During heating with up to 20 W of power, none of the volunteers experienced adverse reactions. [Conclusion] This study indicates the potential safety and effectiveness of the resonant cavity heat therapy system for knee osteoarthritis in a clinical setting.

Potential complications in patients undergoing an ethanol injection into the vein of Marshall.

BACKGROUND: Ethanol injections into the vein of Marshall (VOM) (EIM) are considered to be a good therapeutic option for atrial tachyarrhythmias, however, the safety remains to be determined. To elucidate what would affect the safety and potential complications of an EIM, we investigated the anatomical features of the VOM and patient background. METHODS: We performed the EIM before the conventional pulmonary vein isolation for drug-resistant atrial fibrillation in 88 patients and evaluated the anatomical features of the VOM and their background. RESULTS: All procedures were completed, however, other than myocardial staining, trivial contrast medium leaked out of the VOM into the pericardial space, that is, extravasation of contrast medium with capillary rupture, during the EIM in 20 patients (22.7%) regardless of the features of the VOM. No pericardial effusions requiring further intervention developed after the extravasation, which resolved by the next day on echocardiography in 18 of those patients. However, two patients who had extravasation other than during the initial contrast injection required additional therapeutic intervention for nonnegligible pericardial effusions. Their body weights were significantly lower and the latter two patients were also small lean women with heart failure and a preserved ejection fraction. CONCLUSIONS: The physical constitution, regardless of the characteristics of the VOM, could be strongly associated with adverse events during the EIM. We must take extreme care in smaller patients with poor compliant hearts during the EIM.

Dynamic Behavior of Rh Species in Rh/Al2O3 Model Catalyst during Three-Way Catalytic Reaction: An Operando X-ray Absorption Spectroscopy Study.

The dynamic behavior of Rh species in 1 wt% Rh/Al2O3 catalyst during the three-way catalytic reaction was examined using a micro gas chromatograph, a NOx meter, a quadrupole mass spectrometer, and time-resolved quick X-ray absorption spectroscopy (XAS) measurements at a public beamline for XAS, BL01B1 at SPring-8, operando. The combined data suggest different surface rearrangement behavior, random reduction processes, and autocatalytic oxidation processes of Rh species when the gas is switched from a reductive to an oxidative atmosphere and vice versa. This study demonstrates an implementation of a powerful operando XAS system for heterogeneous catalytic reactions and its importance for understanding the dynamic behavior of active metal species of catalysts.

Enhanced oxygen-release/storage properties of Pd-loaded Sr3Fe2O7-δ.

This study proves that a small amount of Pd loading (1 wt%) on Sr3Fe2O7-δ can dramatically enhance the oxygen-storage properties of Sr3Fe2O7-δ. The topotactic oxygen intake and release between Sr3Fe2O6.75 and Sr3Fe2O6 takes place in response to gas switching between an O2 flow and H2 flow, regardless of the presence or absence of Pd loading. The effect of Pd loading is significant for the oxygen-release process under H2 atmosphere; that is, highly dispersed Pd metal nanoparticles sized less than 1 nm formed on Pd/Sr3Fe2O7-δ to promote H2 dissociation, resulting in the improvement of the oxygen-release temperature and rate. Pd/Sr3Fe2O7-δ with a layered perovskite structure has a higher oxygen-release property at lower temperature than Pd/SrFeO3-δ with a perovskite phase without the layered structure. These facts indicate that the surface reaction as well as the crystal structure are responsible for the oxide ion mobility in perovskite structure, and also provide guidelines for designing novel oxygen-storage materials.

A pilot study comparing the efficacy of radiofrequency and microwave diathermy in combination with intra-articular injection of hyaluronic acid in knee osteoarthritis.

[Purpose] This study aimed to compare the efficacy of radiofrequency diathermy with that of microwave diathermy in combination with intra-articular injection of hyaluronic acid into the knee of patients with osteoarthritis (OA). [Subjects] A total of 17 patients with knee OA were enrolled. The participants were randomly divided into two groups: a radiofrequency diathermy group (RF group, 9 subjects), and a microwave diathermy group (MW group, 8 subjects). [Methods] Subjects received radiofrequency or microwave thermal therapy 3 times at 1-week intervals. Intra-articular injection of hyaluronic acid was administered 10 min before every thermal therapy session. The outcome was evaluated using the Japan Orthopaedic Association (JOA) and the Lequesne Index (LI) at baseline, at weeks 1 (1 week after the first thermal therapy) and 3 (1 week after the last thermal therapy). [Results] The JOA scale increased significantly after three sessions of thermal therapy in the RF group, while no significant increase was observed in the MW group. LI decreased significantly after 3 weeks in the RF group. In the MW group, there was no significant difference in LI between the two time points. [Conclusion] This study revealed that symptom relief in patients with knee OA was greater with radiofrequency diathermy than with microwave diathermy with concurrent use of hyaluronic acid injection, presumably due to the different heating characteristics of the two methods.

Patterns of pulmonary vein potential disappearance during encircling ipsilateral pulmonary vein isolation can predict recurrence of atrial fibrillation.

BACKGROUND: The relationship between pulmonary vein (PV) potential (PVP) disappearance patterns during encircling ipsilateral pulmonary vein isolation (EIPVI) of atrial fibrillation (AF), and outcome was examined. METHODS AND RESULTS: A total of 352 consecutive AF patients (age, 61±12 years; 269 men, 76.4%; paroxysmal AF, n=239; persistent AF, n=73; and long-standing persistent AF, n=40) who underwent initial AF ablation were studied. After EIPVI with a double Lasso technique, pacing was performed from the PV carina to confirm isolation of the carina. PVP disappearance patterns were classified into 3 types: A, both superior and inferior PVP disappeared simultaneously; B, superior and inferior PVP disappeared separately; and C, additional RF applications were required inside the encircling lesions to eliminate the PVP after creating anatomical encircling lesions. The relationship between these patterns and outcome was examined. Six groups were defined according to the combination of right and left ipsilateral PVP disappearance patterns. The incidence of A-A, A-B, B-B, A-C, B-C, and C-C was 7.1%, 14.2%, 16.2%, 15.3%, 27.3%, and 19.9%, respectively. AF recurrence-free rate at 2 years for these 6 groups was 96%, 81%, 78%, 64%, 64%, and 59%, respectively (P<0.02). The incidence of a carina isolation was 153/154 (99.4%) for type A, 221/259 (85.3%) for type B, and 145/290 (50.0%) for type C. CONCLUSIONS: PVP disappearance pattern during EIPVI was significantly associated with the incidence of residual PV carina conduction and AF recurrence.

Febuxostat (Feburic tablet) in the management of hyperuricemia in a general practice cohort of Japanese patients with a high prevalence of cardiovascular problems.

Hyperuricemia is increasing in prevalence and this is paralleled by an increased incidence of acute gout. In addition, there is growing evidence of an association between high serum levels of uric acid (sUA) and cardiovascular disease (CVD). In this preliminary report, we present 12-16 week results from a multicenter, general practice study in which we evaluated the usefulness of febuxostat in a cohort of untreated patients with hyperuricemia with a high prevalence of CVD. Febuxostat titrated from 10 mg/day up to 40 mg/day resulted in statistically significant and clinically relevant reductions in sUA after 12-16 weeks. A "responder" level of 6.0 mg/dL or lower was achieved in 95 of 100 (95%) patients. Significant reductions in sUA were achieved regardless of the presence/absence of coexisting diseases (e.g. CVD, renal insufficiency, diabetes and obesity) or the class of antihypertensive agent being used by the patient. No serious adverse reactions were noted with febuxostat. Although allopurinol has been used generally for hyperuricemia/gout, it is excreted fully via the kidneys, restricting its use in patients with reduced renal function, and its three-times-daily administration leads to poor adherence. Based on the results of this study, febuxostat may provide an easier option than allopurinol for clinicians specializing in CVDs.

What are the active species in the photoinduced H2 production with terpyridyl Pt(II) complexes? An investigation by in situ XAFS.

Origin of the species: In situ X-ray absorption measurements show that monomeric Pt(II) species are the active components for photocatalytic H2 evolution under visible-light illumination for both [PtCl(tpy)]Cl on its own and a three-component system comprising Ru(bpy)3Cl2, MV(2+) and [PtCl(tpy)]Cl in the presence of a sacrificial electron donor (EDTA).

The incidence and clinical significance of non-isolation of the pulmonary vein carina after encircling ipsilateral pulmonary veins isolation for paroxysmal atrial fibrillation: a pitfall of the double-Lasso technique.

AIMS: Encircling ipsilateral pulmonary veins (PVs) isolation (EIPVsI) with the double-Lasso technique has proven to be effective to cure atrial fibrillation (AF). However, in this technique, PV mapping with circular catheters may miss a non-isolation of the PV carina. The purpose of this study was to reveal the incidence and clinical significance of a non-isolation of the PV carina after EIPVsI. METHODS AND RESULTS: We studied 81 consecutive paroxysmal AF patients (age 61 ± 12 years, 56 men), in whom EIPVsI was successfully performed in one encircling line with the endpoint of the demonstration of bidirectional conduction block between the PVs and left atrium (LA) with the double-Lasso technique. After a successful EIPVsI, pacing from the PV carina was performed and it captured the LA in 17 (21.0%) patients. During a mean follow-up period of 19 ± 13 months, AF recurred in 13 (16.0%) patients. A multivariate Cox proportional analysis revealed that a non-isolation of the PV carina after the EIPVsI was a significant predictor (hazard ratio = 3.91, 95% confidence interval = 1.13-14.16, P = 0.03) of AF recurrence. CONCLUSIONS: Pulmonary vein mapping with the double-Lasso technique did miss the non-isolation of the PV carina after a successful EIPVsI, which was an independent predictor of AF recurrence after the EIPVsI. Pacing from the PV carina may be required to confirm the electrical isolation of the PV carina after EIPVsI with the double-Lasso technique.

High blood pressure enhances brain stem neuronal nitric oxide synthase activity in Dahl salt-sensitive rats.

The aims of the present study were to determine the mechanism underlying enhanced neuronal nitric oxide synthase (nNOS) activity in the brain of hypertensive Dahl salt-sensitive (DSS) rats and the consequences of enhanced nNOS activity. Male DSS rats were fed either a regular (0.4% NaCl) or high-salt (8% NaCl) diet, with or without 0.25% nifedipine, for 4 weeks. The effects of nifedipine, which lowers blood pressure peripherally, on central nNOS were determined by measuring nNOS activity, as well as the number of nNOS-positive neurons in the brain stem and diencephalon. The effects of chronic (12 days) infusion of 7 µg (0.5 µL/h, i.c.v.) S-methyl-L-thiocitrulline (SMTC; a stereoselective competitive nNOS inhibitor) on mean arterial pressure were assessed in conscious DSS rats using a radiotelemetry system. In addition, the number of central nNOS-positive neurons was compared between DSS and salt-insensitive Sprague-Dawley rats. Normalization of blood pressure by nifedipine attenuated the increase in nNOS activity in the brain stem of DSS rats. Chronic i.c.v. infusion of SMTC further enhanced hypertension in DSS rats. Feeding of a high-salt diet increased nNOS-positive neurons in the lateral parabrachial nucleus, rostral ventrolateral medulla and nucleus tractus solitarius of DSS compared with Sprague-Dawley rats, whereas nNOS-positive neurons in the paraventricular nucleus remained downregulated in DSS rats. The results of the present study suggest that hypertension, rather than a high-salt diet, increases central nNOS activity in hypertensive DSS rats to buffer high blood pressure. However, this compensatory response may be insufficient to relieve salt-induced hypertension.

Congenic strain differences of renal malformations in ACI/Mna rats by introgression of the chromosomal region of BUF/Mna rats containing Pur1.

The ACI rats developed hereditary renal malformations including agenesis and hydronephrosis at moderate penetrance. During construction of a variety of congenic strains based on ACI/Mna (ACI), BUF/Mna (BUF), and WKY/NCrj (WKY) rats, we found that the renal malformations were significantly suppressed by introgression of a segment of chromosome 13 of BUF rats containing Pur1 locus. It is plausible that this region contain a modifier locus influencing development of renal malformations.

Electromyographic study of neck muscle activity according to head position in rugby tackles.

[Purpose] This study examined differences in neck muscle activity in two different head positions during tackles with the aim of contributing to the prevention of sports injuries. [Subjects] The subjects were 28 male high-school rugby players. [Methods] Two tackle positions were considered: a head-up position and a head-down position. Muscle activities of the sternocleidomastoid muscles and the upper, middle, and lower parts of the trapezius muscles were measured. [Results] Muscle activities of the sternocleidomastoid muscles and the right upper trapezius muscle were significantly increased in the head-up position, and the activity of the lower trapezius was significantly increased in the head-down position. [Conclusion] Tackling with the head-up position increases neck muscle activity and stability of the head and the neck.

Emergence of Dynamically-Disordered Phases During Fast Oxygen Deintercalation Reaction of Layered Perovskite.

Determination of a reaction pathway is an important issue for the optimization of reactions. However, reactions in solid-state compounds have remained poorly understood because of their complexity and technical limitations. Here, using state-of-the-art high-speed time-resolved synchrotron X-ray techniques, the topochemical solid-gas reduction mechanisms in layered perovskite Sr3 Fe2 O7- δ (from δ ∼ 0.4 to δ = 1.0), which is promising for an environmental catalyst material is revealed. Pristine Sr3 Fe2 O7- δ shows a gradual single-phase structural evolution during reduction, indicating that the reaction continuously proceeds through thermodynamically stable phases. In contrast, a nonequilibrium dynamically-disordered phase emerges a few seconds before a first-order transition during the reduction of a Pd-loaded sample. This drastic change in the reaction pathway can be explained by a change in the rate-determining step. The synchrotron X-ray technique can be applied to various solid-gas reactions and provides an opportunity for gaining a better understanding and optimizing reactions in solid-state compounds.

Seroepidemiological survey of sheep flocks from Northern Japan for Mycoplasma ovipneumoniae and Mycoplasma agalactiae.

Sheep flocks from Hokkaido, Iwate and Aomori, three northern prefectures of Japan, were screened for antibodies to Mycoplasma ovipneumoniae and Mycoplasma agalactiae by ELISA. Sixty four animals out of 246 (26%) were seropositive to M. ovipneumoniae, with positive results obtained from all three prefectures. None of the sera tested were serologically positive to M. agalactiae.