Potassium Ions Decrease Mitochondrial Matrix pH: Implications for ATP Production and Reactive Oxygen Species Generation

Potassium (K+) is the most abundant cation in the cytosol and is maintained at high concentrations within the mitochondrial matrix through potassium channels. However, many effects of K+ at such high concentrations on mitochondria and the underlying mechanisms remain unclear. This study aims to elucidate these effects and mechanisms by employing fluorescence imaging techniques to distinguish and precisely measure signals inside and outside the mitochondria. We stained the mitochondrial matrix with fluorescent dyes sensitive to K+, pH, reactive oxygen species (ROS), and membrane potential in plasma membrane-permeabilized C6 cells and isolated mitochondria from C6 cells. Fluorescence microscopy facilitated the accurate measurement of fluorescence intensity inside and outside the matrix. Increasing extramitochondrial K+ concentration from 2 mM to 127 mM led to a reduction in matrix pH and a decrease in the generation of highly reactive ROS. In addition, elevated K+ levels electrically polarized the inner membrane of the mitochondria and promoted efficient ATP synthesis via FoF1-ATPase. Introducing protons (H+) into the matrix through phosphate addition led to further mitochondrial polarization, and this effect was more pronounced in the presence of K+. K+ at high concentrations, reaching sub-hundred millimolar levels, increased H+ concentration within the matrix, suppressing ROS generation and boosting ATP synthesis. Although this study does not elucidate the role of specific types of potassium channels in mitochondria, it does suggest that mitochondrial K+ plays a beneficial role in maintaining cellular health.

Tandem Kumada-Tamao catalyst-transfer condensation polymerization and Suzuki-Miyaura coupling for the synthesis of end-functionalized poly(3-hexylthiophene)

Successive Kumada-Tamao catalyst-transfer condensation polymerization of 2-bromo-5-chloromagnesio-3-hexylthiophene and Suzuki-Miyaura end-functionalization with pinacol arylboronate in one pot afforded poly(3-hexylthiophene) (P3HT) with a base-sensitive functional group at both ends. The use of poly(methyl methacrylate) (PMMA) bearing a boronic acid ester moiety at one end enabled one-pot synthesis of PMMA-b-P3HT-b-PMMA triblock copolymer.

Intramolecular Palladium Catalyst Transfer on Benzoheterodiazoles as Acceptor Monomers and Discovery of Catalyst Transfer Inhibitors

Intramolecular catalyst transfer on benzoheterodiazoles was investigated in Suzuki-Miyaura coupling reactions and polymerization reactions with t Bu3 PPd precatalyst. In the coupling reactions of dibromobenzotriazole, dibromobenzoxazole, and dibromobenzothiadiazole with pinacol phenylboronate, the product ratios of monosubstituted product to disubstituted product were 0/100, 27/73, and 89/11, respectively, indicating that the Pd catalyst undergoes intramolecular catalyst transfer on dibromobenzotriazole, whereas intermolecular transfer occurs in part in the case of dibromobenzoxazole and is predominant for dibromobenzothiadiazole. The polycondensation of 1.3 equivalents of dibromobenzotriazole with 1.0 equivalent of para- and meta-phenylenediboronates afforded high-molecular-weight polymer and cyclic polymer, respectively. In the case of dibromobenzoxazole, however, para- and meta-phenylenediboronates afforded moderate-molecular-weight polymer with bromine at both ends and cyclic polymer, respectively. In the case of dibromobenzothiadiazole, they afforded low-molecular-weight polymers with bromine at both ends. Addition of benzothiadiazole derivatives interfered with catalyst transfer in the coupling reactions.

The differences between conventional lead, thin lead, and leadless pacemakers regarding effects on tricuspid regurgitation in the early phase

PURPOSE

Trans-venous pacemaker leads are associated with worsening of tricuspid regurgitation (TR) after pacemaker implantation (PMI) in some cases. Recently, leadless pacemakers and thin ventricular pacemaker leads without a stylet lumen have become popular. However, the differences in the effects of these leads on TR are unclear. We investigated differences in the changes in TR in the early phase after PMI in patients with conventional leads, thin leads, and leadless pacemakers.

METHODS

We enrolled 65 patients who underwent PMI (32 males, 79 ± 8 years), including 48 with trans-venous PMI (29 with conventional 6.0-Fr leads and 19 with 4.1-Fr thin leads) and 17 with leadless pacemakers. Transthoracic echocardiography was performed before and 1 month after PMI for assessment of conventional echocardiographic parameters and severity of TR by quantitative assessment.

RESULTS

Atrial fibrillation was the most frequent indication for PMI in patients with leadless pacemakers (p = 0.015). In the before and 1 month after PMI comparison, left ventricular ejection fraction decreased after PMI only in the conventional lead group (p = 0.022). The TR effective regurgitant orifice area (EROA) decreased post PMI in the leadless (p = 0.002) and thin lead groups (p = 0.001), but not in the conventional lead group (p = 0.596). The change in TR EROA was greater in the leadless and thin lead groups as compared with the conventional lead group (p < 0.05).

CONCLUSION

The decrease in TR EROA in the early phase after PMI differed according to the type of pacemaker lead. The thin lead might be beneficial for reduction of TR after PMI.

Direct Analysis of Mitochondrial Damage Caused by Misfolded/Destabilized Proteins

Protein quality control is essential for cellular homeostasis. In this study, we examined the effect of improperly folded proteins that do not form amyloid fibrils on mitochondria, which play important roles in ATP production and cell death. First, we prepared domain 3 of the dengue envelope protein in wild type and four mutants with widely different biophysical properties in misfolded/aggregated or destabilized states. The effects of the different proteins were detected using fluorescence microscopy and Western blotting, which revealed that three of the five proteins disrupted both inner and outer membrane integrity, while the other two proteins, including the wild type, did not. Next, we examined the common characteristics of the proteins that displayed toxicity against mitochondria by measuring oligomer size, molten globule-like properties, and thermal stability. The common feature of all three toxic proteins was thermal instability. Therefore, our data strongly suggest that thermally unstable proteins generated in the cytosol can cause cellular damage by coming into direct contact with mitochondria. More importantly, we revealed that this damage is not amyloid-specific.

Effects of proton pumping on the structural rigidity of cristae in mitochondria

Mitochondria change their morphology and inner membrane structure depending on their activity. Since mitochondrial activity also depends on their structure, it is important to elucidate the interrelationship between the activity and structure of mitochondria. However, the mechanism by which mitochondrial activity affects the structure of cristae, the folded structure of the inner membrane, is not well understood. In this study, the effect of the mitochondrial activity on the cristae structure was investigated by examining the structural rigidity of cristae. Taking advantage of the fact that unfolding of cristae induces mitochondrial swelling, we investigated the relationship between mitochondrial activity and the susceptibility to swelling. The swelling of individual isolated mitochondria exposed to a hypotonic solution was observed with an optical microscope. The presence of respiratory substrates (malate and glutamate) increased the percentage of mitochondria that underwent swelling, and the further addition of rotenone or KCN (inhibitors of proton pumps) reversed the increase. In the absence of respiratory substrates, acidification of the buffer surrounding the mitochondria also increased the percentage of swollen mitochondria. These observations suggest that acidification of the outer surface of inner membranes, especially intracristal space, by proton translocation from the matrix to the intracristal space, decreases the structural rigidity of the cristae. This interpretation was verified by the observation that ADP or CCCP, which induces proton re-entry to the matrix, suppressed the mitochondrial swelling in the presence of respiratory substrates. The addition of CCCP to the cells induced a morphological change in mitochondria from an initial elongated structure to a largely curved structure at pH 7.4, but there were no morphological changes when the pH of the cytosol dropped to 6.2. These results suggest that a low pH in the intracristal space may be helpful in maintaining the elongated structure of mitochondria. The present study shows that proton pumping by the electron transfer chain is the mechanism underlying mitochondrial morphology and the flexibility of cristae structure.

Importance of a reversible reaction for the synthesis of telechelic polymers by means of polycondensation using an excess of one monomer

Reversible unstoichiometric polycondensation of a diol formate and dicarboxylic acid ester through an ester–ester exchange reaction is an effective strategy for the synthesis of telechelic polymers free from contamination with cyclic polymers.

Effects of Matrix pH on Spontaneous Transient Depolarization and Reactive Oxygen Species Production in Mitochondria

Reactive oxygen species (ROS) oxidize surrounding molecules and thus impair their functions. Since mitochondria are a major source of ROS, suppression of ROS overproduction in the mitochondria is important for cells. Spontaneous transient depolarization of individual mitochondria is a physiological phenomenon widely observed from plants to mammals. Mitochondrial uncoupling can reduce ROS production; therefore, it is conceivable that transient depolarization could reduce ROS production. However, transient depolarization has been observed with increased ROS production. Therefore, the exact contribution of transient depolarization to ROS production has not been elucidated. In this study, we examined how the spontaneous transient depolarization occurring in individual mitochondria affected ROS production. When the matrix pH increased after the addition of malate or exposure of the isolated mitochondria to a high-pH buffer, transient depolarization was stimulated. Similar stimulation by an increased matrix pH was also observed in the mitochondria in intact H9c2 cells. Modifying the mitochondrial membrane potential and matrix pH by adding K⁺ in the presence of valinomycin, a K⁺ ionophore, clarified that an increase in the matrix pH is a major cause of ROS generation. When we added ADP in the presence of oligomycin to suppress the transient depolarization without decreasing the matrix pH, we observed the suppression of mitochondrial respiration, increased matrix pH, and enhanced ROS production. Based on these results, we propose a model where spontaneous transient depolarization occurs during increased proton influx through proton channels opened by increased matrix pH, leading to the suppression of ROS production. This study improves our understanding of mitochondrial behavior.

Development of retake support system for lateral knee radiographs by using deep convolutional neural network

INTRODUCTION

Lateral radiography of the knee joint is frequently performed; however, the retake rate is high owing to positioning errors. Therefore, in this study, to reduce the required number and time of image retakes, we developed a system that can classify the tilting directions of lateral knee radiographs and evaluated the accuracy of the proposed method.

METHODS

Using our system, the tilting directions of a lateral knee radiographs were classified into four direction categories. The system was developed by training the DCNN based on 50 cases of Raysum images and tested on three types test dataset; ten more cases of Raysum images, one case of flexed knee joint phantom images and 14 rejected knee joint radiographs. To train a deep convolutional neural network (DCNN), we employed Raysum images created via three-dimensional (3D) X-ray computed tomography (CT); 11 520 Raysum images were created from 60 cases of 3D CT data by changing the projection angles. Thereby, we obtained pseudo images attached with correct labels that are essential for training.

RESULTS

The overall accuracy on each test dataset was 88.5 ± 7.0% (mean ± standard deviation), 81.4 ± 11.2%, and 73.3 ± 9.2%. The larger the tilting degree of the knee joint, the higher the classification accuracy.

CONCLUSION

DCNN could classify the tilting directions of a knee joint from lateral knee radiographs. Using Raysum images made it possible to facilitate creating dataset for training DCNN. The possibility was indicated for using support system of lateral knee radiographs.

IMPLICATIONS FOR PRACTICE

The system may also reduce the burden on patients and increase the work efficiency of radiological technologists.

Precision synthesis of a fluorene-thiophene alternating copolymer by means of the Suzuki–Miyaura catalyst-transfer condensation polymerization: the importance of the position of an alkyl substituent on thiophene of the biaryl monomer to suppress disproportionation

The Suzuki–Miyaura coupling polymerization of PinB-F8T(3)-Br was accompanied by disproportionation, whereas that of PinB-F8T(4)-Br proceeded in a chain-growth polymerization manner to afford a well-defined fluorene-thiophene alternating copolymer.

Recurrences of disease activity in patients with cardiac sarcoidosis under corticosteroid therapy: prevalence, clinical background and prognosis

Background

Corticosteroid therapy (CTx) has been widely accepted as first-line therapy for cardiac sarcoidosis (CS), but there are very limited data regarding recurrence of disease activity of CS. We retrospectively investigated the prevalence, patient characteristics and prognostic significance in patients with recurrences of CS.

Methods

We identified 102 consecutive patients who were clinically diagnosed CS (admission: 2012 and 2019) and whose disease activity was diminished clinically at least once. Recurrence of CS was defined as detection of increased uptake of 18F-fluoro-2-deoxyglucose or gallium-67 in the follow-up examination. Composite adverse events (events) were defined as all-cause of death or hospitalization for heart failure. Echocardiographic and laboratory data before initiation of CTx were obtained.

Results

During the follow-up term (median: 4.9 years), the recurrences of CS occurred in 28 patients at 30 months (median) after the initiation of CTx. In patients with recurrence, left ventricular (LV) ejection fraction before initiation of CTx was lower than in those without recurrences (median: 31% vs. 39%, p&lt;0.05). After the detection of CS recurrences, 17 patients were treated with only increases of PSL and remaining 11 patients were treated with adding other immunosuppressive therapies to CTx. The univariate analysis demonstrated that there were no parameters in echocardiographic and laboratory examinations to predict the recurrences of CS. The results of univariate analysis for event occurrences (n=12) are shown in the Table. Additionally, the Kaplan-Meier analysis showed that there were no differences in event free survival rate in the patients with and without CS recurrences (Figure).

Conclusion

This study showed that the recurrences of disease activity were observed in a substantial number of patients with CS even under the CTx. All patients received intensification of CTx or additional immunosuppressive therapy, and LV systolic function, rather than the recurrence itself, was associated with clinical outcomes in this study.

Kaplan-Meier analysis for events

Funding Acknowledgement

Type of funding source: None

SAT0113 DISCORDANCE OF CLINICAL REMISSION AND IMAGING REMISSION BY ULTRASONOGRAPHY IN PATIENTS WITH RHEUMATOID ARTHRITIS WITH BIOLOGIC AGENTS

Background:

Residual synovitis can be detected by sensitive modalities such as ultrasonography in patients with rheumatoid arthritis in clinical remission. On the other hand, a previous study has shown that ultrasound-guided treatment provides modest benefit compared to a conventional strategy aiming clinical remission in early patients. It is still unclear how discordant clinical remission is from imaging remission by ultrasonography in patients treated with biologic agents

Objectives:

To clarify the discordance between clinical remission and imaging remission in patients with rheumatoid arthritis treated with biologic agents.

Methods:

Patients with rheumatoid arthritis who were treated with biologic agents and in clinical remission defined as disease activity score for 28 joints (DAS28)<2.6 were enrolled. All patients were performed comprehensive ultrasound examination of 44 joints as well as physical examinations. Ultrasound images of gray scale (GS) and power doppler (PD) were evaluated with a semi-quantitative score of 0-3. Imaging remission with ultrasound was defined as no PD signal detected in any joints. Clinical information was collected from their medical charts.

Results:

A total of 41 patients were enrolled with 22 patients treated with tumor necrosis factor (TNF)-α inhibitors and 19 with interleukin (IL)-6 inhibitors. The mean age, female ratio, the mean disease duration, and the mean duration of clinical remission were 60 years old, 87%, 5.1 years and 11.5 years. The imaging remission by ultrasonography was observed only in 51.2 %. When patients were divided according to biologic agents, baseline characteristics including median age, disease duration and clinically remission duration were comparable between both groups, while the rates of seropositivity and the stage of radiological progression was higher in IL-6 group (seropositivity, p=0.04; radiological progression, p=0.02). The mean DAS28 was 1.93 in the TNFα group and 1.02 in the IL-6 group. The discordance of clinical remission and imaging remission was observed in 28.6% of the TNFα group and 71.4% of the IL-6 group (p=0.03). The residual synovitis scores of GS and PD in 44 joints were significantly lower in the TNFα than the IL-6 group (GS, 1.1±1.8 vs 4.7 ± 4.6, p<0.01; PD, 0.6 ± 1.3 vs 3.3 ± 3.5, p<0.01, respectively). A receiver operating characteristic curve demonstrated an optimal score of DAS28 that discriminated imaging remission as 1.89 in the TNFα group and 1.25 in the IL-6 group.

Conclusion:

Our results showed that there was substantial discordance between clinical remission and imaging remission, especially in the patients treated with IL-6 inhibitors. In patients treated with biologic agents, clinical remission should be assessed more stringently than the usual 2.6, and ulltrasound-guided management may be useful.

References:

[1]Smolen JS, et al. Ann Rheum Dis 2020;0:1–15.

[2]Iwamoto T, et al. Arthritis Care Res (Hoboken). 2014;66(10):1576-81

[3]Tanaka Y. Ann Rheum Dis 2010;69:1286 –91

[4]Kaneko Y, et al. Ann Rheum Dis 2018;77:1268–1275

[5]Brown AK, et al. Arthritis Rheum 2008;58: 2958 – 67.

Acknowledgments:

We would like to thank Harumi Kondo for their assistance.

Disclosure of Interests:

Yasushi Kondo: None declared, Yuko Kaneko Speakers bureau: Dr. Kaneko reports personal fees from AbbVie, personal fees from Astellas, personal fees from Ayumi, personal fees from Bristol-Myers Squibb, personal fees from Chugai, personal fees from Eisai, personal fees from Eli Lilly, personal fees from Hisamitsu, personal fees from Jansen, personal fees from Kissei, personal fees from Pfizer, personal fees from Sanofi, personal fees from Takeda, personal fees from Tanabe-Mitsubishi, personal fees from UCB, Shuntaro Saito: None declared, Yuichiro Ohta: None declared, Komei Sakata: None declared, Yumiko Inoue: None declared, Chihiro Takahashi: None declared, Kazuoto Hiramoto: None declared, Jun Inamo: None declared, Tsutomu Takeuchi Grant/research support from: Eisai Co., Ltd, Astellas Pharma Inc., AbbVie GK, Asahi Kasei Pharma Corporation, Nippon Kayaku Co., Ltd, Takeda Pharmaceutical Company Ltd, UCB Pharma, Shionogi & Co., Ltd., Mitsubishi-Tanabe Pharma Corp., Daiichi Sankyo Co., Ltd., Chugai Pharmaceutical Co. Ltd., Consultant of: Chugai Pharmaceutical Co Ltd, Astellas Pharma Inc., Eli Lilly Japan KK, Speakers bureau: AbbVie GK, Eisai Co., Ltd, Mitsubishi-Tanabe Pharma Corporation, Chugai Pharmaceutical Co Ltd, Bristol-Myers Squibb Company, AYUMI Pharmaceutical Corp., Eisai Co., Ltd, Daiichi Sankyo Co., Ltd., Gilead Sciences, Inc., Novartis Pharma K.K., Pfizer Japan Inc., Sanofi K.K., Dainippon Sumitomo Co., Ltd.

P1354 Prognostic value of the left ventricular longitudinal and circumferential function in patients with takotsubo syndrome during the acute phase

Background

Takotsubo syndrome is generally considered a benign disease with a reversible condition; however, hemodynamic and electrical instability during the acute phase exposes patients to the risk of serious adverse in-hospital events. The purpose of this study was to investigate the prognostic value of the left ventricular longitudinal and circumferential function in patients with TTS during the acute phase.

Methods

We divided the 27 patients with TTS (77.4 ± 10.2 years old, 21 females) into two groups; the severe group (SG) of 9 patients (in-hospital death, mechanical assist devices such as IABP or ECMO, oozing rupture) and non-severe group (NSG) of 18 patients. The echocardiographic examination on admission, catheter hemodynamic assessment, and laboratory data, and ST-T change in electrocardiogram were compared between two groups.

Results

There were no differences in age, laboratory data, electrocardiogram findings between the two groups. The LVEF was lower in SG (35.3 ± 6.1% vs. 45.9 ± 13.5%, p = 0.03). The index of Ballooning, the ratio of the systolic left ventricular diameter of ballooning segments to that of basal segments, was higher in SG (2.07 ± 0.61% vs.1.60 ± 0.32%, p = 0.016). The circumferential fractional shortening (CFS) of ballooning segments was lower in SG (4.6 ± 3.2% vs. 18.2 ± 8.2%, p = 0.00007), CFS of basal segments was not different between the two groups, and the ratio of CFS of ballooning segments to CFS of basal segments (CFS imbalance index) was lower in SG (5.60 ± 3.84 vs. 10.83 ± 3.92, p = 0.00003). The left ventricular longitudinal fractional shortening was lower in SG (0.12 ± 0.09 vs. 0.46 ± 0.19, p = 0.00003). The absolute value of GLS was lower in SG (7.6 ± 4.3% vs. 13.0 ± 3.6%, p = 0.002). In all three cases of in-hospital death, the CFS imbalance index was lower than 0.14.

Conclusion

In patients with TTS, left ventricular longitudinal and circumferential function could be related to serious adverse in-hospital events.

Impact of Tongue Pressure and Peak Expiratory Flow Rate on Nutritional Status of Older Residents of Nursing Homes in Japan: A Cross-Sectional Study

OBJECTIVES

Swallowing function is critical for continuing oral feeding to prevent frailty in older adults. In this study, we investigated the impact of tongue pressure and pulmonary function on the nutritional status of older adults.

DESIGN, SETTING, PARTICIPANTS

This cross-sectional study was conducted in Kitakyushu, Japan from August 2017 to November 2018. Fifty-two residents aged >65 years of age from three nursing care insurance facilities in Kitakyushu City, Japan were recruited.

MEASUREMENTS

Oral health status, swallowing function, nutritional status using a mini nutritional assessment short form (MNA-SF), cognitive function, activities of daily living, peak expiratory flow rate (PEFR) for pulmonary function, and tongue pressure were assessed. The associations between nutritional status and the above factors were analysed using a logistic regression model.

RESULTS

Participants were divided into two groups: well-nourished group (MNA-SF ≤12) and undernutrition group (MNA-SF <12). Multivariate logistic regression analysis revealed that the correlations of PEFR [odds ratio (OR) = 0.23, 95% confidence interval (CI) = 0.23-0.89 p=0.033) and tongue pressure (OR = 0.88, 95% CI = 0.88-0.99, p=0.029) remained significant even after adjustment with possible confounders.

CONCLUSION

Maximum tongue pressure and PEFR in older adults were significantly associated with their nutritional status. These findings suggest that maintaining oral and pulmonary function may be a preventive factor against a decrease in the nutritional status of older frail adults.

Serial changes of L wave according to heart rates in a heart failure patient with persistent atrial fibrillation

Mid-diastolic forward flow velocity of transmitral flow (L wave) is known as a marker of diastolic dysfunction and is occasionally observed in patients with fluid retention, low heart rate, and atrial fibrillation (AF). However, how hemodynamic condition affects L wave is still unknown. An 81-year-old woman who underwent implantation of a DDD pacemaker due to complete atrioventricular block 38 years previously suffered from congestive heart failure and was admitted to our hospital. At the time of admission, electrocardiogram showed new-onset AF resulting in mode switch to VVI, and echocardiography showed a giant L wave. At the mid-term of the treatment, AF was converted to sinus rhythm resulting in mode switch to DDD, and pacemaker check-up was performed at pre- and post-cardioversion. During the pacemaker check-ups, L wave was assessed in various pacing rates. As pacing rate was increased, L wave altered according to heart rates and disappeared at 85 bpm in VVI with AF, whereas at 75 bpm in DDD. Through the treatment, L wave got smaller as fluid retention was improved and finally disappeared at the time of discharge. This case suggests that L wave is highly variable and affected by fluid volume, heart rate, and heart rhythm.

<Learning objective: Although L wave is known as a marker of diastolic dysfunction and occasionally observed in patients with high left ventricular filling pressure, low heart rate, and atrial fibrillation, how hemodynamics affects L wave is still unknown. In this case, it was observed that L wave is highly variable in the therapeutic process of heart failure and affected by fluid volume, heart rate, and heart rhythm. L wave potentially can be a useful indicator to evaluate treatment efficacy for heart failure.>

P2461The presence of L wave was associated with non-invasively estimated left atrial stiffness in heart failure patients

Background

The mid-diastolic L wave is recorded as mid-diastolic mitral forward flow with conventional Doppler echocardiography. L wave is occasionally detected in heart failure (HF) patients but its mechanism of occurrence is still unknown. It is hypothesized that L wave was induced by a positive atrioventricular gradient caused by left atrial filling via pulmonary veins, and the magnitude of the L wave is augmented by increasing ventricular stiffness. We speculate that also Left atrium (LA) function will relate with the presence of L wave because the L wave flow occurs passing LA. LA function has been known to have reservoir, booster pump and conduit function. It is reported that LA conduit function related to LA stiffness. The aim of this study is to clarify the association between LA functions and presence of L wave in HF patients.

Methods and results

Eighty two patients who admitted to our hospital for HF were enrolled in this study. We performed echocardiography before discharge. LA speckle-tracking strain was analyzed by an external software program using apical 4 chamber view. Reservoir function was measured as peak strain value at end systole, and booster pump function was measured as the value of atrial contraction. Conduit function was calculated as the difference of the peak value at end systole and atrial contraction. There were 23 patients who had L wave before discharge and 59 patients without L wave. Transmitral E wave (E) and left atrial volume index (LAVI) were higher in patients with L wave than in those without L wave. LA reservoir strain was not different in two groups, but poster pump strain was lower and conduit strain was higher in patients with L wave than those without. LA reservoir strain and booster pump strain weakly correlated with A wave velocity (r=0.39 p=0.004, r=46 p=0.001) and LAVI (r=−0.23 p=0.0383, r=−0.31 p=0.005), but conduit strain had no correlation with A wave (r=0.12 p=0.26) and LAVI (r=−0.04 p=0.67). In multivariate regression analysis for the presence of L wave with A wave velocity, LAVI and LA conduit strain, LA conduit strain remained independent predictors of the presence of L wave (HR 1.12 95% CI 1.04–1.23; p=0.004).

Conclusion

LA conduit function was not correlated with conventional echo parameters of LA function (A wave velocity and LAVI). The presence of L wave was associated with LA conduit strain.

Coupled afterslip and transient mantle flow after the 2011 Tohoku earthquake

Modeling of postseismic deformation following great earthquakes has revealed the viscous structure of the mantle and the frictional properties of the fault interface. However, for giant megathrust events, viscoelastic flow and afterslip mechanically interplay with each other during the postseismic period. We explore the role of afterslip and viscoelastic relaxation and their interaction in the aftermath of the 2011 M _w (moment magnitude) 9.0 Tohoku earthquake based on a detailed model analysis of the postseismic deformation with laterally varying, experimentally constrained, rock rheology. Mechanical coupling between viscoelastic relaxation and afterslip notably modifies both the afterslip distribution and surface deformation. Thus, we highlight the importance of addressing mechanical coupling for long-term studies of postseismic relaxation, especially in the context of the geodynamics of the Japan trench across the seismic cycle.

Intramolecular Catalyst Transfer on a Variety of Functional Groups between Benzene Rings in a Suzuki-Miyaura Coupling Reaction

Suzuki-Miyaura coupling reaction of BrC₆ H₄ -X-C₆ H₄ Br 1 (X=CH₂ , CO, N-Bu, O, S, SO, and SO₂ ) with arylboronic acid 2 was investigated in the presence of tBu₃ PPd precatalyst and CsF/[18]crown-6 as a base to establish whether or not the Pd catalyst can undergo catalyst transfer on these functional groups. In the reaction of 1 (X=CH₂ , CO, N-Bu, O, and SO₂ ) with 2, aryl-disubstituted product 3 (Ar-C₆ H₄ -X-C₆ H₄ -Ar) was exclusively obtained, indicating that the Pd catalyst undergoes catalyst transfer on these functional groups. On the other hand, the reaction of 1 e (X=S) and 1 f (X=SO) with 2 afforded only aryl-monosubstituted product 4 (Ar-C₆ H₄ -X-C₆ H₄ -Br) and a mixture of 3 and 4, respectively, indicating that S and SO interfere with intramolecular catalyst transfer. Furthermore, we found that Suzuki-Miyaura polycondensation of 1 (X=CH₂ , CO, N-Bu, O, and SO₂ ) and phenylenediboronic acid 5 in the presence of tBu₃ PPd precatalyst afforded high-molecular-weight polymer even when excess 1 was used. The polymers obtained from 1 (X=CH₂ , N-Bu, and O) and 5 turned out to be cyclic.

Comparison of a vitamin E-infused highly crosslinked polyethylene insert and a conventional polyethylene insert for primary total knee arthroplasty at two years postoperatively

AIMS

The use of vitamin E-infused highly crosslinked polyethylene (HXLPE) in total knee prostheses is controversial. In this paper we have compared the clinical and radiological results between conventional polyethylene and vitamin E-infused HXLPE inserts in total knee arthroplasty (TKA).

PATIENTS AND METHODS

The study included 200 knees (175 patients) that underwent TKA using the same total knee prostheses. In all, 100 knees (77 patients) had a vitamin E-infused HXLPE insert (study group) and 100 knees (98 patients) had a conventional polyethylene insert (control group). There were no significant differences in age, sex, diagnosis, preoperative knee range of movement (ROM), and preoperative Knee Society Score (KSS) between the two groups. Clinical and radiological results were evaluated at two years postoperatively.

RESULTS

Differences in postoperative ROM and KSS were not statistically significant between the study and control groups. No knee exhibited osteolysis, aseptic loosening, or polyethylene failure. Additionally, there was no significant difference in the incidence of a radiolucent line between the two groups. One patient from the study group required irrigation and debridement, due to deep infection, at six months postoperatively.

CONCLUSION

Clinical results were comparable between vitamin E-infused HXLPE inserts and conventional polyethylene inserts at two years after TKA, without any significant clinical failure. Cite this article: Bone Joint J 2019;101-B:559-564.

Time-lapse imaging of Ca2+-induced swelling and permeability transition: Single mitochondrion study

Mitochondrial functions are closely related to the membrane structure. Mitochondrial swelling, which is accompanied with dissipation of the crista structure and rupture of the outer membrane, have been observed as mitochondrial damage when mitochondria are under Ca²⁺-overload or oxidative stress. Although these phenomena have been well studied, the detailed behaviors of individual mitochondria upon swelling remain unknown. The aim of this study was to investigate the detailed behavior of mitochondrial volume upon addition of Ca²⁺. Here, we report for the first time, time-lapse measurements of single mitochondrion swelling and permeability transition induced by Ca²⁺ by optical microscopy. We added 220 μM Ca²⁺ to mitochondria, and found that 1) the swelling rate depended on the mitochondrion, 2) a small number of mitochondria showed step-like swelling, 3) cyclosporin A decreased the percentage of mitochondria that underwent swelling induced by Ca²⁺, but did not affect the amplitude of swelling, 4) permeability transition is necessary but not sufficient for Ca²⁺-induced swelling, 5) permeability transition is more sensitive to Ca²⁺ than swelling, 6) Ca²⁺ stimulated mitochondrial swelling after permeability transition. These results suggest that single mitochondrion measurement of swelling is a powerful tool for examining the regulation of mitochondrial structure.

Synthesis of telechelic polyesters by means of transesterification of an A2 + B2 polycondensation-derived cyclic polyester with a functionalized diester

End-functionalized linear polyesters were synthesized by means of base-catalyzed transesterification of a cyclic polyester, obtained by A₂ + B₂ polycondensation, with a symmetric functional diester as an exchange reagent.

Synthesis of amphiphilic, Janus diblock hyperbranched copolyamides and their self-assembly in water

An amphiphilic, Janus diblock hyperbranched copolyamide was synthesized by the condensation reaction, and the morphologies of aggregates in water were changed from spherical to dendritic-like structures via cylindrical-like structures in response to increasing temperature.

Unstoichiometric Suzuki–Miyaura cyclic polymerization of extensively conjugated monomers

Suzuki–Miyaura polycondensation of an excess of extensively conjugated aromatic dibromide with 1.0 equivalent of phenylenediboronate in the presence of ^tBu₃PPd(0) precatalyst afforded cyclic polymers.

Dissecting the structural basis for the intracellular delivery of OSW-1 by fluorescent probes

The structural basis for the intracellular delivery of OSW-1 is investigated using fluorescent derivatives of OSW-1 and its closely related congeners. Despite the large differences in activity, all the fluorescent probes are found to translocate across the plasma membrane to the ER and Golgi apparatus. This observation suggests that the glycosylated cholestane moiety plays an important role in the cell internalization and intracellular localization property of OSW-1.

Diagnostic Value of Plasma Vascular Endothelial Growth Factor as a Tumor Marker in Patients with Non-Small Cell Lung Cancer

We assessed the diagnostic value of circulating VEGF as a tumor marker in patients with lung cancer and compared its clinical utility with that of other markers such as carcinoembryonic antigen (CEA) and cytokeratin 19 (CYFRA). One hundred and sixty non-small cell lung cancer patients and 70 healthy volunteers were included in the study. Circulating VEGF was assessed by enzyme-linked immunosorbent assay (ELISA). The serum concentrations of both CEA and CYFRA were measured by means of immunoradiometric assays. The diagnostic value of plasma VEGF (VEGFp) was better than that of CYFRA and similar to that of CEA. When the diagnostic value of VEGFp and CEA for the diagnosis of adenocarcinoma was compared, the two markers proved to have nearly equal discriminatory power. In diagnosing squamous cell carcinoma, VEGFp showed less discrimination than CYFRA. When the diagnostic value of VEGFp was analyzed for stage I adenocarcinoma patients, VEGFp was slightly more discriminatory than CEA. The combination assay of VEGFp and CEA had a sensitivity of 75% and a specificity of 60% at a cutoff of 104.4 pg/mL for VEGFp and 5.2 ng/mL for CEA. The combination of VEGF and CEA was superior to CEA alone in the early diagnosis of adenocarcinoma of the lung.

Exclusive Synthesis of Poly(3-hexylthiophene) with an Ethynyl Group at Only One End for Effective Block Copolymerization

Well-controlled synthesis of ethynyl-functionalized poly(3-hexylthiophene) (P3HT) is crucial for preparation of block copolymers containing the P3HT segment by means of click coupling reaction. A well-known chain end modification method, in which Kumada-Tamao catalyst-transfer polymerization is quenched with ethynylmagnesium chloride, under various conditions is re-examined, but in all cases not only P3HT with an ethynyl group at one end but also P3HT di-ethynylated at both ends is obtained. Accordingly, Sonogashira coupling reaction of P3HT having H/Br ends with trimethylsilylacetylene is tried, followed by removal of the trimethylsilyl group, and it is found that this protocol affords exclusively P3HT with an ethynyl group at one end. This post end-modification method is applied to the synthesis of an amphiphilic diblock copolymer of P3HT and poly(2-ethyl-2-oxazoline) (PEtOx) by means of click reaction between ethynylated P3HT and PEtOx with an azide group at one end, and the product is confirmed to be free from contamination with triblock copolymer. Micellization of this block copolymer is confirmed in tetrahydrofuran (THF)/water and THF/methanol mixtures.

Treatment with the MAPK kinase inhibitor U0126 during the first two hours of in vitro maturation improves bovine oocyte developmental competence

This study examined the effects of treatment with U0126, which inhibits MAPK by inhibiting MAPK kinase, during the first 2 hr of in vitro maturation on bovine developmental competence and on gap junction (GAPJ) communication between the oocyte and cumulus cells. The percentage of oocytes developing to the blastocyst stage in the group treated with 5 μM U0126 (28%) was significantly higher than that in controls (15%, p < .05), while that in the group treated with 10 μM U0126 (18%) was not. Breakdown of the GAPJs was delayed in the group treated with 5 μM U0126 when compared to controls, as estimated by immunohistochemical examination of connexin 43, which is a primary constituent of the GAPJs. These results indicate that treatment with 5 μM U0126 during in vitro maturation delays GAPJ breakdown and improves bovine oocyte developmental competence.