Impact of Hemoglobin Level, White Blood Cell Count, Renal Dysfunction, and Staphylococcus as the Causative Organism on Prediction of In-Hospital Mortality from Infective Endocarditis.

Infective endocarditis (IE) is a highly fatal disease in cases of delayed diagnosis and treatment, although its incidence is low. However, there have been few single-center studies in which the risk of in-hospital death from IE was stratified according to laboratory findings on admission and the organism responsible for IE. In this study, a total of 162 patients who were admitted to our hospital during the period from 2009 to 2021, who were suspected of having IE according to the modified Duke classification, and for whom IE was confirmed by transesophageal echocardiography were retrospectively analyzed. Patients were observed for a mean-period of 43.7 days with the primary endpoint being in-hospital death. The in-hospital death group had a lower level of hemoglobin (Hb), higher white blood cell (WBC) count, lower level of estimated glomerular filtration rate (eGFR), and higher frequency of Staphylococcus being the causative agent than those in the non-in-hospital death group. In overall multivariate analysis, Hb, WBC count, eGFR, and Staphylococcus as the causative agent were identified to be significant prognostic determinants. IE patients with Hb < 10.6 g/dL, WBC count > 1.4 × 104/µL, eGFR < 28.1 mL/minute/1.7 m2, and Staphylococcus as the causative agent had significantly and synergistically increased in-hospital death rates compared to those in other IE patients. Low level of Hb, high WBC count, low eGFR, and Staphylococcus as the causative agent of IE were independent predictors of in-hospital mortality, suggesting that these 4 parameters may be combined to additively stratify the risk of in-hospital mortality.

The biological effects and thermal degradation of NPB-22, a synthetic cannabinoid.

PURPOSE: NPB-22 (quinolin-8-yl 1-pentyl-1H-indazole-3-carboxylate), Adamantyl-THPINACA (N-(1-adamantantyl)-1-[(tetrahydro-2H-pyran-4-yl)methyl]-1H-indazole-3-carboxamide), and CUMYL-4CN-B7AICA (1-(4-cyanobutyl)-N-(2-phenylpropan-2-yl)-1H- pyrrolo[2,3-b]pyridine-3-carboxamide), synthetic cannabinoids were evaluated in terms of CB1 (cannabinoid receptor type 1) and CB2 (cannabinoid receptor type 2) activities, and their biological effects when inhaled similar to cigarettes were examined. METHODS: The half maximal effective concentration values of the aforementioned synthetic cannabinoids at the CB1 and CB2 were investigated using [35S]guanosine-5'-O-(3-thio)-triphosphate binding assays. In addition, their biological effects were evaluated using the inhalation exposure test with mice. The smoke generated was recovered by organic solvents in the midget impingers, and the thermal degradation compounds of the smoke components were identified and quantified using a liquid chromatography-photo diode array detector. RESULTS: NPB-22 and Adamantyl-THPINACA had equivalent CB1 activity in in vitro assays. Meanwhile, NPB-22 had a weaker biological effect on some items on the inhalation exposure test than Adamantyl-THPINACA. When analyzing organic solvents in the midget impingers, it was revealed that NPB-22 was degraded to 8-quinolinol and pentyl indazole 3-carboxylic acid by combustion. In addition, these degradation compounds did not have CB1 activity. CONCLUSION: It was estimated that the biological effects of NPB-22 on the inhalation exposure test weakened because it underwent thermal degradation by combustion, and the resultant degradation compounds did not have any CB1 activity in vitro.

Neural Representations of Post-Decision Accuracy and Reward Expectation in the Caudate Nucleus and Frontal Eye Field.

Performance monitoring that supports ongoing behavioral adjustments is often examined in the context of either choice confidence for perceptual decisions (i.e., "did I get it right?") or reward expectation for reward-based decisions (i.e., "what reward will I receive?"). However, our understanding of how the brain encodes these distinct evaluative signals remains limited because they are easily conflated, particularly in commonly used two-alternative tasks with symmetric rewards for correct choices. Previously we used a motion-discrimination task with asymmetric rewards to identify neural substrates of forming reward-biased perceptual decisions in the caudate nucleus (part of the striatum in the basal ganglia) and the frontal eye field (FEF, in prefrontal cortex). Here we leveraged this task design to partially decouple estimates of accuracy and reward expectation and examine their impacts on subsequent decisions and their representations in those two brain areas. We identified distinguishable representations of these two evaluative signals in individual caudate and FEF neurons, with regional differences in their distribution patterns and time courses. We observed that well-trained monkeys (both sexes) used both evaluative signals, infrequently but consistently, to adjust their subsequent decisions. We found further that these behavioral adjustments had reliable relationships with the neural representations of both evaluative signals in caudate, but not FEF. These results suggest that the cortico-striatal decision network may use diverse evaluative signals to monitor and adjust decision-making behaviors, adding to our understanding of the different roles that the FEF and caudate nucleus play in a diversity of decision-related computations.

Synthesis and structure determination of a synthetic cannabinoid CUMYL-THPINACA metabolite with differentiation between the ortho-, meta-, and para-hydroxyl positions of the cumyl moiety.

Synthetic cannabinoids, a type of new psychoactive substances, are likely to be rapidly metabolized; thus, the detection of their metabolites, rather than the parent compound, is a common method used to prove drug consumption. Although the analysis of metabolites is generally performed by mass spectrometry, it is limited to structural estimation because of few commercially available standards. In particular, distinguishing between positional isomers is difficult. Synthetic cannabinoids with a cumyl moiety can be hydroxylated at the cumyl moiety during metabolism, but it remains unclear whether the hydroxylation occurs at the ortho, meta, or para position. This study determined the structures of a metabolite formed by mono-hydroxylation at the cumyl moiety of the synthetic cannabinoid CUMYL-THPINACA, used as a model compound. Chemical synthesis was performed to create possible metabolites with one hydroxyl group at the ortho, meta, or para positions of the cumyl moiety. Using the synthesized metabolites and liquid chromatography-quadrupole time-of-flight mass spectrometry, the metabolite detected in the microsomal reaction of CUMYL-THPINACA was identified as a compound mono-hydroxylated at the para position based on retention time and product ion spectra. Moreover, the rapid metabolism of CUMYL-THPINACA was demonstrated with an in vitro half-life of 4.9 min and the identified metabolite could be detected for a relatively long time in vitro. The synthesized metabolite may be utilized as a good reference standard for proof of CUMYL-THPINACA consumption. These findings have potential applications in the synthesis of metabolites of other synthetic cannabinoids bearing a cumyl moiety.

Decreased cholinesterase level combined with renal dysfunction and sympathetic denervation associated with increased cardiac mortality in systolic heart failure.

Aims: Cardiac mortality in patients with heart failure (HF) is likely to be aggravated by malnutrition, assessed by serum cholinesterase (ChE) level, as well as by kidney dysfunction or impairment of cardiac sympathetic denervation. Their prognostic interactions, however, have not been determined. Methods: A total of 991 systolic HF patients were enrolled in our HF database following clinical evaluation including evaluation of the nutrition state and assessment of standardized heart-to-mediastinum ratio (sHMR) of iodine-123-labeled meta-iodobenzylguanidine activity. Patients were followed up for an average of 43 months with the primary endpoint of fatal cardiac events (CEs). Results: The CE patient group had a lower level of ChE, lower estimated glomerular filtration rate (eGFR) and lower late sHMR than those in the non-CE patient group. A five-parameter model with the addition of serum ChE selected in the multivariate logistic analysis (model 2) significantly increased the AUC predicting risk of cardiac events compared with a four-parameter model without serum ChE (model 1), and net reclassification analysis also suggested that the model with the addition of serum cholinesterase significantly improved cardiac event prediction. Moreover, in overall multivariate Cox hazard analysis, serum ChE, eGFR and late sHMR were identified to be significant prognostic determinants. HF patients with two or all of the prognostic variables of serum ChE < 230 U/L, eGFR < 48.8 ml/min/1.73 m2 and late sHMR < 1.90 had significantly and incrementally increased CE rates compared to those in HF patients with none or only one of the prognostic variables. Conclusion: Decreases in cholinesterase level and kidney function further increase cardiac mortality risk in HF patients with impairment of cardiac sympathetic innervation.

Mitral valve infective endocarditis in a dialysis patient with a tunneled dialysis catheter and prior MitraClip® implantation: an autopsy case.

BACKGROUND: The number of patients with heart disease who can benefit from treatment is continuing to increase due to the widespread use of cardiac implantable devices. Accordingly, the number of cardiac device-related infective endocarditis (CDRIE) cases has been increasing year by year. We report a very rare experience of performing an autopsy on a patient who died of CDRIE at the site of MitraClip ® implantation, which has recently been developed as a treatment option for severe mitral regurgitation. In addition to hematoxylin-eosin (H-E) staining, Elastica-Masson staining in the present case revealed destruction of all of the atrial, trabecular, fiber and myocardial layers. CASE PRESENTATION: The patient was hemodialyzed with a dialysis catheter. Hemodialysis treatment was difficult due to functional mitral regurgitation caused by cardiac dysfunction, and the MitraClip® procedure was performed. However, he subsequently developed a fever and dialyzation became difficult again, and he was admitted to the cardiology department. Echocardiography revealed a large vegetation at the site of MitraClip® implantation and a diagnosis of CDRIE was made. Guidelines recommend removal of the device and surgical intervention. However, considering the patient's general condition, a decision was made at a heart team conference to give priority to antibiotic therapy. However, the patient did not respond to antibiotic therapy and died of septic shock. CONCLUSION: To our knowledge, this is the first reported case of CDRIE and death after MitraClip® implantation that resulted in an autopsy. Furthermore, not only H-E staining but also Elastica-Masson staining was performed, and it was confirmed that there was significant valve tissue destruction. In the future, the MitraClip® procedure, even though it is minimally invasive, should be carefully considered in immunocompromised patients.

Rapid Determination of Preservatives in Cosmetics Using a Core-Shell Column.

Preservatives are frequently added to cosmetics to maintain product quality. Our laboratory quantifies 11 preservatives in cosmetics each year for regulatory purposes. In laboratories, many manufactures also analyze the preservatives in their products for quality control. To analyze many cosmetic samples, a rapid analysis method is required for efficiency. In this study, we developed a rapid method for the simultaneous determination of 11 regulated preservatives in cosmetics using a core-shell column by high-performance liquid chromatography. In this method, the 11 preservatives were separated within 17 min, which was approximately half the time reported in the previous study. The peak resolution for each preservative was >2.6, the correlation coefficients of the calibration curves were >0.9988, the percent recoveries were 92.0-111.9% and the relative standard deviations were <3.5% (n = 3). The relative standard deviations among 6 researchers were <4.7%. Thus, it is an effective rapid determination method for the analysis of preservatives in cosmetics.

Methyl 1-(4-fluoro-benz-yl)-1H-indazole-3-carboxyl-ate.

The title compound, C16H13FN2O2, was synthesized by nucleophilic substitution of the indazole N-H hydrogen atom of methyl 1H-indazole-3-carboxyl-ate with 1-(bromo-meth-yl)-4-fluoro-benzene. In the crystal, some hydrogen-bond-like inter-actions are observed.

Human and rat microsomal metabolites of N-tert-butoxycarbonylmethamphetamine and its urinary metabolites in rat.

PURPOSE: N-tert-Butoxycarbonylmethamphetamine (BocMA), a masked derivative of methamphetamine (MA), converts into MA under acidic condition and potentially acts as a precursor to MA following ingestion. To investigate the metabolism and excretion of BocMA, metabolism tests were conducted using human liver microsomes (HLM), rat liver microsomes (RLM) and rat. METHODS: BocMA metabolites were analyzed after 1000-ng/mL BocMA incubation with microsomes for 3, 8, 13, 20, 30, and 60 min. Rats were administered intraperitoneal injections (20 mg/kg) of BocMA and their urine was collected in intervals for 72 h. Metabolites were detected by liquid chromatography-tandem mass spectrometry with five authentic standards. RESULTS: Several metabolites including 4-hydroxy-BocMA, N-tert-butoxycarbonylephedrine and N-tert-butoxycarbonyl-cathinone were detected for HLM and RLM. In the administration test, three glucuronides of hydroxylated metabolites were detected. The total recovery values of BocMA and the metabolites during the first 72 h accounted for only 0.3% of the administered dose. Throughout the microsomal and administration experiments, MAs were not detected. CONCLUSION: Hydroxylation, carbonylation and N-demethylation were proposed as metabolic pathways. However, BocMA and phase I metabolites were hardly detected in urine. This study provides useful information to interpret the possibility of BocMA intake as the cause of MA detection in biological sample.

Infective endocarditis of transcatheter atrial septal occluder devices: A case report.

Infective endocarditis (IE) is caused by bacterial vegetation in valves, but it can also occur in implanted mechanical devices. We report a rare case of IE occurring at the site of percutaneous atrial septal closure devices in a patient in her 50s that had been placed for residual defects on a closure patch in her childhood for an atrial septal defect (ASD). She also had a medical history of distal pancreatectomy for insulinoma in her 40s and had insulin-dependent diabetes mellitus, which means she had been immunocompromised.She visited our hospital with complaints of fever and lumbar pain. A computed tomography scan revealed liver abscess. In blood, urine, and drainage specimens submitted for culture testing, extended spectrum beta-lactamase-producing Escherichia coli was cultured in all specimens. Echocardiography showed vegetation at the atrial septal closure devices. In accordance with IE therapy, removal of the atrial septal patch and closure device was performed after antibiotic treatment for 6 weeks.Because the atrial septal patch was calcified and the two devices implanted on the patch were not well covered by neointima, bacteria could easily form vegetation. Percutaneous residual ASD closure on an atrial patch, especially for immunocompromised hosts, should be carefully considered. Learning objective: In general, neointima forms and coats a closure device several years after its insertion. However, as in the present case, the closed atrial septal patch may be severely calcified and the neointima may not be sufficiently formed on the closure device, and infective endocarditis may occur at the site of implantation. In some cases, the indication for closure device implantation after atrial septal patch closure should be carefully considered.

Human inference reflects a normative balance of complexity and accuracy.

We must often infer latent properties of the world from noisy and changing observations. Complex, probabilistic approaches to this challenge such as Bayesian inference are accurate but cognitively demanding, relying on extensive working memory and adaptive processing. Simple heuristics are easy to implement but may be less accurate. What is the appropriate balance between complexity and accuracy? Here we model a hierarchy of strategies of variable complexity and find a power law of diminishing returns: increasing complexity gives progressively smaller gains in accuracy. The rate of diminishing returns depends systematically on the statistical uncertainty in the world, such that complex strategies do not provide substantial benefits over simple ones when uncertainty is either too high or too low. In between, there is a complexity dividend. In two psychophysical experiments, we confirm specific model predictions about how working memory and adaptivity should be modulated by uncertainty.

Prognostic value of nutritional parameters in systolic heart failure with renal dysfunction.

Although it is known that assessment and management of the nutritional status of patients are important for treatment of patients with heart failure (HF), there are currently no established indicators. Therefore, we investigated the effects of nutritional parameters as well as conventional parameters on the prognosis of HF patients. A total of 1954 consecutive HF patients with left ventricular ejection fraction (LVEF) less than 50% were enrolled in this study. Transthoracic echocardiography was performed and conventional parameters for HF patients and parameters to assess nutritional status were measured in all patients. Patients were followed up with a primary endpoint of lethal cardiac events (CEs) for 30.2 months. During the follow-up period, cardiac events were documented in 619 HF patients. The CEs group had a lower level of cholinesterase (201.5U/L vs 265.2U/L, P <0.0001), lower estimated GFR (35.2 ml/min/1.73m2 vs 50.3ml/min/1.73m2, P< 0.0001), and lower Geriatric Nutritional Risk Index (GNRI) (91.9 vs 100.0, P< 0.0001) than those in the non-CEs group. Serum cholinesterase, estimated GFR, and GNRI were identified as significant prognostic determinants in multivariate analysis. ROC analyses revealed cut-off values of serum cholinesterase, estimated GFR, and GNRI of 229U/L, 34.2 ml/min/1.73m2, and 95.6, respectively, for identifying high-risk HF patients. HF patients with serum cholinesterase< 229U/L, estimated GFR<34.3 ml/min/1.73m2, and GNRI< 95.6 had a significantly greater rate of CEs than that in the other patients (P<0.0001). Low serum cholinesterase and low GNRI can predict cardiac mortality risk in systolic HF patients with renal dysfunction.

The development of dual-function solid-phase method as extraction and a decomposition reaction media for the determination of a formaldehyde releaser, imidazolidinyl urea, in cosmetics.

In this study, we present a simple method to determine imidazolidinyl urea (IU) in cosmetics using a solid phase as both a decomposition field and an extraction phase. IU is difficult to quantify because it is a mixture of allantoin-formaldehyde condensation products that are easily decomposed to release formaldehyde. In our method, IU is decomposed to allantoin and 1-[4-(hydroxymethyl)-2,5-dioxoimidazolidin-4-yl]urea (4-HU) on an aminopropyl-bonded silica solid phase. Subsequent high-performance liquid chromatography enables quantification of the resulting allantoin and 4-HU. The quantified value was converted to the total allantoin amount on the basis of molecular weight, and the calculated value was compared with that of an IU reference standard to determine the contents. The calibration curves of the decomposed IU as allantoin and 4-HU were both linear over an IU solution concentration range from 0.05 to 0.65% (w/v). The recoveries from lotion, body soap, and conditioners, which contained 0.1%, 0.3%, and 0.6% (w/w) of IU, respectively, ranged from 88.2 to 107.5%. The relative standard deviation values for the recovery tests of six replicates ranged from 1.03 to 6.97%. The intra-laboratory precisions for the lotion and conditioner A containing 0.3% IU were 3.02 and 4.94%, respectively. This method was well validated and would be helpful in determining IU in cosmetic samples.

Impact of catheter contact angle on lesion formation and durability of pulmonary vein isolation.

PURPOSE: This study is aimed to evaluate the impact of catheter contact angle on lesion formation and durability of pulmonary vein isolation (PVI). METHODS: Both in vitro experiment and retrospective observational study were conducted. For in vitro experiment, radiofrequency lesions were created on explanted swine hearts in three different catheter contact angles (0°, 45°, and 90°). In the retrospective observational study, we assessed patients who had undergone repeat catheter ablation due to atrial fibrillation recurrence after initial PVI. When pulmonary vein (PV) reconnection was observed, we analyzed the previous ablation points within and without the gap area. The gap areas were where ablation had changed the PV activation sequence or eliminated the PV potential in the repeat session. RESULTS: In the in vitro experiment, lesion width was the smallest (5.3 ± 0.4 mm) in perpendicular contact compared to 0° (vs 5.8 ± 0.5 mm, p = 0.040) and 45° (vs 6.4 ± 0.4 mm, p < 0.001). In the retrospective observational study, we assessed 666 tags of 16 patients with PV reconnections, and 60 tags were in the gap area. Tags in the gap area had longer interlesion distance (odds ratio [OR] 1.49, p < 0.001), greater contact force variability (OR 1.03, p = 0.008), and higher rate of perpendicular contact (OR 3.26, p < 0.001) on multivariate analysis. CONCLUSIONS: Perpendicular contact was associated with a smaller lesion and higher rate of PV reconnection.

Machine learning-based risk model using 123I-metaiodobenzylguanidine to differentially predict modes of cardiac death in heart failure.

BACKGROUND: Cardiac sympathetic dysfunction is closely associated with cardiac mortality in patients with chronic heart failure (CHF). We analyzed the ability of machine learning incorporating 123I-metaiodobenzylguanidine (MIBG) to differentially predict risk of life-threatening arrhythmic events (ArE) and heart failure death (HFD). METHODS AND RESULTS: A model was created based on patients with documented 2-year outcomes of CHF (n = 526; age, 66 ± 14 years). Classifiers were trained using 13 variables including age, gender, NYHA functional class, left ventricular ejection fraction and planar 123I-MIBG heart-to-mediastinum ratio (HMR). ArE comprised arrhythmic death and appropriate therapy with an implantable cardioverter defibrillator. The probability of ArE and HFD at 2 years was separately calculated based on appropriate classifiers. The probability of HFD significantly increased as HMR decreased when any variables were combined. However, the probability of arrhythmic events was maximal when HMR was intermediate (1.5-2.0 for patients with NYHA class III). Actual rates of ArE were 3% (10/379) and 18% (27/147) in patients at low- (≤ 11%) and high- (> 11%) risk of developing ArE (P < .0001), respectively, whereas those of HFD were 2% (6/328) and 49% (98/198) in patients at low-(≤ 15%) and high-(> 15%) risk of HFD (P < .0001). CONCLUSION: A risk model based on machine learning using clinical variables and 123I-MIBG differentially predicted ArE and HFD as causes of cardiac death.

Improved risk-stratification in heart failure patients with mid-range to severe abnormalities of QRS duration and systolic function using mechanical dyssynchrony assessed by myocardial perfusion-gated SPECT.

BACKGROUND: The use of left ventricular mechanical dyssynchrony (LVMD), which has been reported to be responsible for unfavorable outcomes, might improve conventional risk-stratification by clinical indices including QRS duration (QRSd) and systolic dysfunction in patients with heart failure (HF). METHODS AND RESULTS: Following measurements of 12-lead QRSd and left ventricular ejection fraction (LVEF), three-dimensional (3-D) LVMD was evaluated as a standard deviation (phase SD) of regional mechanical systolic phase angles by gated myocardial perfusion imaging in 829 HF patients. Patients were followed up for a mean period of 37 months with a primary endpoint of lethal cardiac events (CEs). In an overall multivariate Cox proportional hazards model, phase SDs were identified as significant prognostic determinants independently. The patients were divided into 4 groups by combining with the cut-off values of LVEF (35% and 50%) and QRSd (130 ms and 150 ms). The groups with lower LVEF and prolonged QRSd more frequently had CEs than did the other groups. Patient groups with LVEF < 35% and with 35% ≦ LVEF < 50% were differentiated into low-risk and high-risk categories by using an optimal phase SD cut-off value of both QRSd thresholds. CONCLUSIONS: 3-D LVMD can risk-stratify HF patients with mid-range as well as severe abnormalities of QRSd and systolic dysfunction.

Impaired Cardiac Sympathetic Innervation Increases the Risk of Cardiac Events in Heart Failure Patients with Left Ventricular Hypertrophy and Mechanical Dyssynchrony.

BACKGROUND: Left ventricular mechanical dyssynchrony (LVMD), left ventricular hypertrophy, and impaired cardiac sympathetic innervation are closely related to the development of heart failure (HF) and unfavorable outcomes. METHODS AND RESULTS: A total of 705 consecutive HF patients with reduced left ventricular ejection fraction (EF) < 50% were registered in our hospital HF database. LVMD and left ventricular mass index (LVMI) were evaluated three-dimensionally by gated myocardial perfusion SPECT. LVMD was measured as a heterogeneity index (phase SD) of the regional contraction phase angles calculated by Fourier analysis. Cardiac sympathetic innervation was quantified as a normalized heart-to-mediastinum ratio (HMR) of the 123I-metaiodobenzylguanidine (MIBG) activity. The patients were followed up with a primary end point of lethal cardiac events (CEs) for 42 months. CEs were documented in 246 of the HF patients who had a greater phase SD, greater LVMI, and lower MIBG HMR than those in HF patients without CEs. In the overall multivariate analysis, phase SD, LVMI, and MIBG HMR were identified as significant CE determinants. The three biomarkers were incrementally related to increases in CE risks. CONCLUSIONS: Assessment of cardiac sympathetic innervation can further stratify patients with systolic heart failure at increased cardiac risk identified by left ventricular hypertrophy and mechanical dyssynchrony.

Edwardsiella tarda Native Valve Infective Endocarditis in a Young and Non-Immunocompromised Host: A Case Report.

BACKGROUND Infective endocarditis (IE) is an infectious disease that occurs in valves, centered on the endocardium and ventricular septal defects. It is a serious disease that is easily misdiagnosed and has a high mortality rate if left untreated. Edwardsiella tarda is an extremely rare cause of IE, especially in young and non-immunocompromised hosts. CASE REPORT A woman in her 20s presented to our hospital with fever of unknown cause and liver dysfunction. She was admitted to the Department of Gastroenterological Medicine owing to suspicion of gastrointestinal infection. Gastrointestinal examination, including contrast-enhanced computer tomography and endoscopic ultrasonography, was performed; however, there were no significant findings. Liver dysfunction improved spontaneously, but her fever did not improve with antibiotic treatment. Transthoracic echocardiography was performed on day 9 of hospitalization because E. tarda was detected in a blood culture test, revealing vegetation at the mitral valve. Asymptomatic cerebral infarction was shown by brain magnetic resonance imaging, and mitral valvuloplasty was performed on day 14. After surgery, transthoracic echocardiography was performed on day 22, showing no vegetation or mitral regurgitation. However, postoperative transesophageal ultrasonography performed on day 29 revealed severe mitral regurgitation. Redo mitral valvuloplasty was performed on day 38. She clinically improved and was discharged on day 67. CONCLUSIONS This is the first case in which E. tarda was diagnosed as the causative agent of IE on a native valve in a young and non-immunocompromised host. Aggressive source control resulted in a good clinical outcome.

Stress-Strain and Stress-Relaxation Behaviors of Solution-Coated Layers Composed of Block Copolymers Mixed with Tackifiers.

The relationship between the mechanical properties and the structure of block copolymers mixed with tackifiers whose relative solubility to the respective components of block copolymers differs was examined. Coated layers were prepared by solution coating using a block copolymer composed of polystyrene (PS) and polyisoprene (PI), which forms spherical microdomains of PS in the PI matrix, mixed with three types of tackifiers: aliphatic (C5) resin, aliphatic-aromatic (C5-C9) resin, and rosin ester (RE) resin. Furthermore, the correlation between the changes in the nanostructure and mechanical properties including the stress-relaxation behaviors was clarified by two-dimensional small-angle X-ray scattering measurement. The amount of the PI-bridge conformation in the case of C5 resin is the lowest, resulting in the lowest stress. On the contrary, the largest amount of RE resin was solubilized in the PS phase so that it can be considered that pulling out of the PS chains took place easily. We were able to explain the stress-relaxation behavior by fitting with the three-component exponent functions. The triple exponential decay functions indicate the hierarchy of the structures that are the origins of the ″fast mode″ relating to the local relaxation due to the rotation of the repeating unit of polymer chains; the ″intermediate mode″ of the disentanglement of the mid-PI chains; and the ″slow mode″ relating to, in this particular case, pulling out of the PS chains from the PS sphere.