The impact of chronic obstructive pulmonary disease on right ventricular dysfunction and remodeling after aortic valve replacement

Background

Chronic obstructive pulmonary disease (COPD) is one of the most common comorbidities in patients with aortic stenosis (AS) and has been associated with a poor prognosis after both transcatheter and surgical aortic valve replacement (AVR). Since COPD is associated with an increase in right ventricular (RV) afterload, some studies already suggested that COPD causes RV dysfunction (RVD) and dilatation. On the other hand, RVD and remodeling can also occur due to chronic pressure overload secondary to the AS itself. However, there is no data that studied RVD and remodeling in AVR recipients in terms of COPD severity.

Purpose

We aimed to evaluate the impact of COPD on RVD and remodeling in patients with severe AS undergoing AVR before AVR and at 1-year follow-up, as well as the association between COPD severity and all-cause mortality.

Methods

Patients with severe AS who received either transcatheter or surgical AVR were included. Patients' demographic data, medical history and documented spirometry data were carefully collected, while two-dimensional and speckle tracking echocardiography measurements were performed according to recommended guidelines to evaluate RV systolic function and RV size. RVD was defined as tricuspid annular plane systolic excursion (TAPSE) ≤17mm. RV dilatation was defined by RV mid cavity >35 mm, RV basal diameter >42mm, and RV longitudinal diameter >83mm. RV wall thickness above 5mm was considered as RV hypertrophy. Diagnosis of COPD was determined by the Society of Thoracic Surgeons' definition based on forced expiratory volume in first second (FEV 1<75%, cut-off for COPD). The primary outcome was all-cause death at 1-year.

Results

A total of 293 patients (78.0 years, 58.4% male) were included. RVD was detected in 54 (18.4%) patients, while 55 (18.8%) patients had mild COPD and 43 (14.7%) patients had moderate or severe COPD. At 1-year follow-up, the prevalence of RVD significantly increased (18.4% versus 23.6%, p=0.004). Compared to baseline, RV free wall strain of lateral basal segment (p=0.046), TAPSE (p<0.0001) and tricuspid regurgitation gradient (p=0.018) impaired whereas RV wall thickness (p=0.014), RV diameter index of lateral basal segment (p<0.0001), and RV diameter index of lateral mid segment (p<0.0001) increased, respectively. At 1-year follow-up, 33 patients died (Figure 1). On multivariate cox regression analysis, RVD (hazard ratio (HR) 2.781, 95% confidence interval (CI) 1.172–6.598; p=0.020) as well as mild (HR 4.695, 95% CI 1.787–12.336; p=0.002) and moderate-severe COPD (HR 4.725, 95% CI 1.717–13.006; p=0.003) were significantly associated with the endpoint (Table 1).

Conclusions

The prevalence of RVD significantly increased and it deteriorated at 1-year after AVR. RV remodeling observed more at lateral basal and mid segments of RV as well as wall thickness. RV dysfunction and COPD were the strongest predictors of mortality in this population.

Funding Acknowledgement

Type of funding sources: None.

Pathophysiological mechanisms and prognostic implications of right atrial reservoir strain in patients with heart failure

Background

Renal and hepatic dysfunction complicate the treatment course of patients with heart failure and negatively affect outcomes. Because the right atrium functions as a reservoir between the right ventricle and the venous circulation, a reduced right atrial compliance may enhance venous congestion, thereby promoting worsening renal function and hepatic congestion.

Purpose

To evaluate the association between RA reservoir strain (RS) and end-organ dysfunction (renal dysfunction and hepatic congestion), as well as survival in patients with advanced HF.

Methods

RARS was evaluated with speckle-tracking echocardiography in patients with advanced HF (i.e. left ventricular ejection fraction <35% and persistent symptoms of HF despite optimal medical therapy). Linear regression analysis was used to investigate the association between RARS and renal function (i.e. estimated glomerular filtration rate [eGFR]) and hepatic congestion (i.e. gamma-glutamyl transferase [GGT]). Patients were followed-up for all-cause mortality.

Results

A total of 917 patients (mean age 65±11 years, 76% male) were included. Age, male sex, atrial fibrillation, larger left atrial and right ventricular dimensions and right ventricular systolic dysfunction were all associated with lower RARS values. On multivariable analysis (adjusting for age, sex, hypertension, diabetes mellitus, dyslipidemia, body mass index, ischemic etiology, atrial fibrillation, QRS duration, left ventricular end-diastolic volume, left ventricular ejection fraction, left atrial volume index, RV basal diameter and tricuspid annular plane systolic excursion), RARS was independently associated with eGFR (β 0.076; 95% CI 0.012 to 0.367; p=0.037) and GGT (β −0.122; 95% CI −1.800 to −0.034; p=0.038). On multivariable Cox regression analysis, adjusting for baseline clinical and echocardiographic variables, RARS was independently associated with all-cause mortality (HR 0.984; 95% CI 0.972 to 0.996; p=0.008) (Figure 1 and Table).

Conclusion

Reduced RARS is independently associated with renal dysfunction and hepatic congestion. In addition, RARS is independently associated with mortality. Consequently, RARS may be useful for the risk-stratification of patients with HF.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): ESC Training Grant App000064741

Association between chronic obstructive pulmonary disease and all-cause mortality after aortic valve replacement for aortic stenosis

Introduction

Chronic obstructive pulmonary disease (COPD) and aortic stenosis (AS) are the most common diseases in aging population that their prevalence and percental change in mortality increase over the years. In severe AS, aortic valve replacement (AVR) is the only treatment that has demonstrated to improve survival, however the presence of comorbidities increases the operative risk and influences negatively on the outcomes after AVR. Therefore, the definition of COPD varies across the studies and is not always based on the use of pulmonary functional tests. Accordingly, the aim of the present study is to evaluate the association between pulmonary functional parameters and all-cause mortality after AVR in a large cohort of patients with severe AS.

Methods

Total of 400 patients (78.0 year-old, 56.7% men) with severe AS and documented preoperative pulmonary functional test (PFT) were retrospectively analyzed. Demographic and clinical characteristics were collected from electronic medical records while echocardiography was performed and measured according to the recommendations. PFTs were performed prior to AVR and categories defined in the Society of Thoracic Surgeons (STS) Adult Cardiac Surgery Database: normal pulmonary function was defined by an FEV1 >75% of predicted; mild COPD if FEV1 was 60–75% of predicted; moderate COPD if FEV1 was 50–59% of predicted and severe COPD when FEV1 <50% of predicted.

Results

Mild, moderate and severe COPD were documented in 75 (19%), 31 (8%) and 22 (5%) while the remaining 68% had normal PFTs. Patients with moderate and severe COPD had significantly larger LV mass and LV end-systolic volume whereas LV ejection fraction was significantly lower. The FVC, FEV1, Tiffeneau index, VC, PEF, and IC were the worst among patients with moderate and severe COPD (per definition) (p<0.0001). Over a median follow-up of 32 months, 92 (23%) patients died. The survival rates were significantly lower in patients with moderate and severe COPD (Log rank p=0.003, Figure 1). In multivariable Cox regression analysis, some clinical factors and COPD were independently associated with all-cause mortality (table 1). Remarkably, any grade of COPD was associated with 2-fold increased risk of all cause-mortality (HR 1.933; 95% CI 1.166–3.204; p=0.011 for mild COPD and HR 2.028; 95% CI 1.154–3.564; p=0.014 for moderate/ severe COPD, separately).

Conclusion

Patients with moderate and severe COPD had higher LV hypertrophy and reduced LV ejection fraction while PFT parameters were the worst among these patients. The survival rates were significantly lower in patients with moderate and severe COPD compared with patients without COPD. In addition to other clinical factors, any grade of COPD was associated with 2-fold increased risk of all cause-mortality.

Funding Acknowledgement

Type of funding sources: None.

Evolution of functional mitral regurgitation and left atrial function in patients receiving cardiac resynchronization therapy

Background

Left atrial (LA) function is a strong prognostic marker in patients with heart failure and patients with functional mitral regurgitation (MR). Although cardiac resynchronization therapy (CRT) has shown to improve MR severity, the interaction between a reduction in MR severity and an improvement in LA function, as well as their association with outcomes, has not been investigated.

Purpose

To investigate the association between a reduction in MR severity and an improvement in LA function, as well as their association with outcomes.

Methods

LA reservoir strain (RS) was evaluated with speckle tracking echocardiography in patients with moderate and severe functional MR. MR improvement was defined as at least 1 grade improvement in MR severity at 6 months after CRT implantation. The association between MR improvement and change in LARS was evaluated using multivariable logistic regression analysis. Patients were dividing into 3 groups: MR non-improvers; MR improvers with no LARS improvement; and MR improvers with LARS improvement. The primary endpoint was all-cause mortality.

Results

A total of 340 patients (mean age 66±10 years, 73% male) were included, of whom 200 (59%) showed MR improvement after CRT implantation. On multivariable analysis, an improvement in MR was independently associated with an improvement in LARS (OR 1.008; 95% CI 1.003–1.013; p=0.002) (Table 1). MR improvers showing LARS improvement had the lowest mortality rate, whereas outcomes were not significantly different between MR non-improvers and MR improvers showing no LARS improvement (p=0.236) (Figure 1).

Conclusion

In patients with HF and significant functional MR, an improvement in MR after CRT implantation is independently associated with an improvement in LARS, which in turn, is associated with better survival.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): ESC Training Grant App000064741

The impact of atrial fibrillation on prognosis in aortic stenosis

Background

Atrial fibrillation (AF) and aortic stenosis (AS) are both highly prevalent and increasing with age. Various studies have focused on the complex relationship between these entities that frequently coexist. AS might induce adverse cardiac remodelling, which is associated with poor prognosis in severe AS. Left atrial remodelling, especially left atrial enlargement, is also an important risk factor for AF.

Purpose

To evaluate the additive prognostic value of AF besides markers of left atrial and left ventricular remodelling in patients with AS, irrespective of severity of AS and left ventricular ejection fraction (LVEF).

Methods

Patients with moderate and severe AS were selected and history of AF was assessed. Subgroups were defined according to LVEF (reduced (<50%) vs. preserved (≥50%)) and severity of AS (moderate vs. severe). The endpoint was all-cause mortality. Unadjusted Kaplan-Meier survival curves were plotted. Four multivariable Cox regression models were constructed.

Results

In total, 2849 patients with moderate and severe AS (mean age 72±12 years, 54.7% men) were evaluated of whom 686 (24.1%) had a history of AF. Regarding the defined subgroups, 1091 (38.3%) patients had severe AS and 2207 (77.5%) patients had preserved LVEF. During a median follow-up time of 60 months (interquartile range 30 to 97), 1182 (41.5%) patients died. Ten-year mortality rate in patients with AF was 46.8% compared with 36.8% in patients with sinus rhythm (SR) (Figure 1) (p<0.001). In subgroup analysis, patients with AF and severe AS, moderate AS or preserved LVEF had worse survival than those who maintained SR (p=0.015, p<0.001 and p<0.001 respectively). On univariable (HR: 1.42; 95% CI: 1.25 to 1.62; p<0.001) and multivariable Cox regression analysis (HR: 1.19; 95% CI: 1.02 to 1.38; p=0.026) adjusting for age, body mass index, hypertension, diabetes mellitus, coronary artery disease, chronic obstructive pulmonary disease, kidney function, New York Heart Association class, aortic valve replacement as a time-dependent covariate, left ventricular mass index, left ventricular end-diastolic volume index, LVEF, mean aortic valve gradient, tricuspid annular plane systolic excursion, AF is independently associated with mortality (Table 1; model 1). However, when correcting for LAVI, E/e' or both, AF is no longer independently associated with all-cause mortality (Table 1; model 2–4).

Conclusion

Patients with moderate or severe AS and AF have a significantly higher 10-year mortality rate than patients with SR. This finding is irrespective of AS severity and also apparent in the subgroup with preserved LVEF. Nonetheless, when correcting for markers of diastolic dysfunction, AF is not independently associated with outcome in patients with moderate or severe AS.

Funding Acknowledgement

Type of funding sources: None.

Prevalence and prognostic implications of discordant grading and flow-gradient patterns in moderate aortic stenosis

Background

The prognostic implications of discordant grading in severe aortic stenosis (AS) are well known. However, the prevalence of different flow-gradient patterns and their prognostic implications in moderate AS are unknown.

Purpose

To investigate the occurrence and prognostic implications of different flow-gradient patterns in patients with moderate AS.

Methods

Patients with moderate AS (aortic valve area 1.0–1.5 cm2) were divided in 4 groups, based on transvalvular mean gradient (MG), stroke volume index (SVi) and left ventricular ejection fraction (LVEF): concordant moderate AS (MG ≥20 mmHg); normal-flow, low-gradient discordant moderate AS (MG <20 mmHg, SVi ≥35 ml/m2); “classical” low-flow, low-gradient discordant moderate AS (MG <20 mmHg, SVi <35 ml/m2 and LVEF <50%) and “paradoxical” low-flow, low-gradient discordant moderate AS (MG <20 mmHg, SVi <35 ml/m2 and LVEF ≥50%). The primary endpoint was all-cause mortality.

Results

Of 1974 patients (age 73±10 years, 51% men) with moderate AS, 788 (40%) had discordant grading. Patients with discordant grading showed significantly higher mortality rates than patients with concordant grading (p<0.001), even in the subgroup of patients having preserved LVEF (p=0.028) or preserved SVi (p=0.002). Of the patients with discordant grading, 71% had normal-flow, low-gradient moderate AS, 14% had “classical” low-flow, low-gradient moderate AS, and 14% had “paradoxical” low-flow, low-gradient moderate AS (Figure 1). Patients with normal-flow, low-gradient moderate AS, “classical” low-flow, low-gradient moderate AS, and “paradoxical” low-flow, low-gradient moderate AS had worse survival rates than patients with concordant grading (p<0.001) (Figure 2). On multivariable analysis “paradoxical” low-flow, low-gradient (HR: 1.533; 95% CI: 1.133–2.075; p=0.006) and “classical” low-flow, low-gradient (HR: 1.926; 95% CI: 1.442–2.572; p<0.001) but not normal-flow, low-gradient moderate AS were independently associated with all-cause mortality.

Conclusion

Discordant grading is frequently (40%) observed in patients with moderate AS. Low-flow, low-gradient patterns account for an important proportion of the discordant cases and are associated with increased mortality. These findings underline the need for better phenotyping patients with discordant moderate AS.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): ESC Training Grant App000064741

Prognostic implications of left ventricular diastolic dysfunction in moderate aortic stenosis

Funding Acknowledgements

Type of funding sources: Other. Main funding source(s): ESC Training Grant App000064741

Background

Moderate aortic stenosis (MAS) is associated with an increased risk of adverse events. Although left ventricular (LV) diastolic dysfunction (DDF) has shown to carry an unfavorable prognosis in severe AS, the prognostic value of LV DDF in MAS has not been investigated.

Purpose

To investigate the prognostic impact of LV DDF in patients with MAS and preserved LV ejection fraction (EF).

Methods

LV diastolic function was evaluated in patients with MAS (aortic valve area >1.0 and ≤1.5cm2)  and preserved LVEF (≥50%) using echocardiography according to the 2016 American Society of Echocardiography/European Association of Cardiovascular Imaging guidelines. Clinical outcomes were defined as all-cause mortality and a composite endpoint of all-cause mortality and aortic valve replacement (AVR).

Results

Of 1247 patients (age 74 ± 10 years, 47% men) with MAS and preserved LVEF, 396 (32%) had normal diastolic function, 316 (25%) had indeterminate diastolic function and 535 (43%) had DDF. Patients with DDF were more likely to be female, had more comorbidities (hypertension, atrial fibrillation, chronic kidney disease) and were more symptomatic (NYHA ≥2) than patients with normal diastolic function. Patients with DDF also had smaller aortic valve area and higher peak aortic velocities than patients with normal/indeterminate diastolic function. During a median follow-up of 53 (26 – 81) months, 484 (39%) patients died. For the composite endpoint, 770 patients (62%) underwent AVR (n = 376) or died (n = 394) during a median follow-up of 37 (IQR 15 – 62) months. Patients with DDF had significantly lower survival rates (p <0.001) and event-free survival rates (p = 0.015) compared to patients with normal/indeterminate diastolic function (Figure 1). On multivariable analysis, DDF was independently associated with all-cause mortality (HR: 1.368; 95% CI: 1.085 – 1.725; p = 0.008) and the composite endpoint of all-cause mortality and AVR (HR: 1.241; 95% CI: 1.035 – 1.488; p = 0.020) (Figure 2).

Conclusion

LV DDF is associated with worse outcomes in patients with MAS. Assessment of LV diastolic function may contribute significantly to risk stratification of patients with MAS. Abstract Figure.  Abstract Figure.

Prognostic value of left ventricular global longitudinal strain in patients with moderate aortic stenosis

Funding Acknowledgements

Type of funding sources: Other. Main funding source(s): ESC Training Grant App000064741

Background

Impaired left ventricular (LV) global longitudinal strain (GLS) is associated with worse outcomes in patients with severe aortic stenosis, but its prognostic value in patients with moderate aortic stenosis (MAS) is largely unknown.

Purpose

To investigate the prognostic implications of LV GLS in patients with MAS and preserved LV ejection fraction (EF).

Methods

LV GLS was evaluated by speckle tracking echocardiography in 621 patients (age 71 ± 12 years, 59% men) with MAS (aortic valve area 1.0 – 1.5cm2) and preserved LVEF (≥50%). Impaired LV GLS was defined as an LV GLS value <16%, based on spline curve analysis (i.e. where the hazard ratio for all-cause mortality was ≥1). Clinical outcomes were defined as all-cause mortality and a composite endpoint of all-cause mortality and aortic valve replacement.

Results

Patients with LV GLS <16% (n = 282) were significantly older, more likely to be male and had more comorbidities (diabetes mellitus, atrial fibrillation, more impaired renal function) compared to patients with LV GLS ≥16% (n = 339). In terms of echocardiographic data, patients with LV GLS <16% had larger LV volumes, lower LVEF and higher E/e’. During a median follow-up of 53 (27 – 102) months, 199 (32%) patients died. For the composite endpoint, 409 patients (66%) underwent AVR (n = 290) or died (n = 119) during a median follow-up of 29 (IQR 14 – 54) months. Patients with LV GLS <16% experienced significantly lower survival rates (p < 0.001) and event-free survival rates (p = 0.001) compared to patients with LV GLS ≥16% (Figure 1). On multivariable analysis, LV GLS was independently associated with all-cause mortality (HR 2.442; 95% CI: 1.762 – 3.384; p < 0.001) and the composite endpoint of all-cause mortality and aortic valve replacement  (HR 1.862; 95% CI: 1.498 – 2.315; p = 0.040) (Figure 2).

Conclusions

In patients with MAS and preserved LVEF, reduced LV GLS is associated with an increased risk of all-cause mortality and the composite endpoint of all-cause mortality and AVR. Assessment of LV GLS may be useful in the risk stratification of these patients. Abstract Figure. Kaplan-Meier curves  Abstract Figure. Cox regression analysis

Left ventricular remodeling patterns in patients with moderate aortic stenosis

Funding Acknowledgements

Type of funding sources: Other. Main funding source(s): ESC Training Grant App000064741

Background

Moderate aortic stenosis (MAS) is associated with an increased risk of adverse events. Although left ventricular (LV) adverse remodeling is associated with worse outcomes in patients with severe AS, the prognostic significance of different patterns of LV remodeling in MAS has not been investigated.

Purpose

To investigate the association between different patterns of LV remodeling on outcomes in patients with MAS.

Methods

Patients with MAS (aortic valve area >1.0 and ≤1.5cm2) were stratified into 4 groups according to the pattern of LV remodeling: normal geometry (NG), concentric remodeling (CR), concentric hypertrophy (CH) or eccentric hypertrophy (EH). Clinical outcomes were defined as all-cause mortality and a composite of all-cause mortality and aortic valve replacement (AVR).

Results

Of 1931 patients (age 73 ± 10 years, 52% men) with MAS, 344 (18%) had NG, 469 (24%) CR, 698 (36%) CH and 420 (22%) EH. Patients with CH were more likely to be female, had more hypertension, were more symptomatic (NYHA ≥III) and had more pronounced LV diastolic dysfunction, whereas patients with EH had more coronary artery disease, were more symptomatic (NYHA ≥III) and had lower LV ejection fraction than patients with NG. Patients with CH had higher aortic mean pressure gradients and peak aortic jet velocities than patients with NG. During a median follow-up of 51 (IQR 25 - 83) months, 833 (43%) patients died. For the composite endpoint, 1286 (67%) patients underwent AVR (n = 613) or died (n = 673) during a median follow-up of 35 (IQR 14 - 60) months. Patients with CH and EH had significantly lower survival rates (p < 0.001; Figure 1) and event-free survival rates (p = 0.004) compared to patients with NG/CR. On multivariable analysis, CH was independently associated with all-cause mortality (HR:1.267; 95% CI:1.024 – 1.568; p = 0.029), whereas both CH (HR:1.293; 95% CI:1.090 – 1.533; p = 0.003) and EH (HR:1.222; 95% CI:1.013 – 1.474; p = 0.036) were associated with the composite endpoint of AVR and all-cause mortality (Figure 2).

Conclusions

In patients with MAS, different patterns of LV remodeling are observed with CH being independently associated with an increased risk of all-cause mortality. Risk stratification according to the different patterns of LV remodeling may help to identify patients with MAS who are at increased risk of adverse events and may benefit from closer follow-up. Abstract Figure. Kaplan-Meier curves  Abstract Figure. Cox regression analysis

Sex differences in left ventricular remodeling in patients with severe aortic valve stenosis

Background

Women with severe aortic valve stenosis (AS) have better long-term outcomes after transcatheter aortic valve implantation (TAVI) but worse survival after surgical aortic valve replacement compared to men. Whether this is related to sex differences in left ventricular (LV) remodeling is unknown.

Purpose

To examine sex differences in LV remodeling and outcomes in patients with severe AS undergoing TAVI.

Methods

Patients with severe AS who underwent TAVI between 2007 and 2018 with a pre-procedural multidetector row computed tomography (MDCT) scan were included. LV volumes, mass and function were analyzed with MDCT. Patients were classified into 4 LV remodeling patterns based on LV mass index and LV mass-to-volume ratio: 1) normal geometry, 2) concentric remodeling, 3) concentric hypertrophy and 4) eccentric hypertrophy. The primary endpoint was all-cause mortality after TAVI.

Results

A total of 289 patients (age 80±6 years, 54% male) were included. Women showed smaller LV volumes and mass compared to men. Concentric hypertrophy (50%) was the most frequent pattern of LV remodeling followed by eccentric hypertrophy (33%), normal geometry (13%) and concentric remodeling (4%). Concentric remodeling was more frequently observed in men compared to women (91% vs. 9% respectively, p=0.011). However, no sex differences were observed in the remaining LV remodeling patterns (Figure 1). During a median follow-up of 3.8 (IQR 2.2–5.1) years after TAVI, 87 patients died. Women demonstrated better outcome after TAVI compared to men (log-rank χ2=4.29, p=0.038). The survival benefit of women over men was mainly present among patients with concentric hypertrophy (log-rank χ2=4.91, p=0.027, Figure 2).

Conclusion

LV concentric and eccentric hypertrophy are similarly observed in men and women with severe AS. Women demonstrated better outcome after TAVI as compared to men, particularly among those with LV concentric hypertrophy. However, the outcome benefit of females after TAVI seems not to be related to sex-differences in LV remodeling.

Funding Acknowledgement

Type of funding sources: None. Distribution of sex in LV remodelingAll-cause mortality after TAVI

Right ventricular remodeling and prognostic relevance after ST-segment elevation myocardial infarction in patients treated with primary percutaneous coronary intervention

Background

ST-segment elevation myocardial infarction (STEMI) often involves changes in right ventricular (RV) function and size over time. However, the prognostic implications of RV remodeling after STEMI are unknown. The aim of current study was to characterize RV remodeling in post-STEMI patients and to investigate it's prognostic relevance.

Methods

RV remodeling in post-STEMI patients who underwent primary percutaneous coronary intervention (PCI) was defined by RV end-systolic area (RV ESA) change at 6 months after STEMI, compared to baseline. The optimal threshold of RV ESA change (≥40%) to define RV remodeling was derived from spline curve analysis (Figure 1A). The primary endpoint was the composite of all-cause mortality and heart failure (HF) hospitalization. Long term outcomes were compared between patients with and without RV remodeling by means of a log rank test.

Results

A total of 2280 patients were analyzed (mean age 60±11 years, 76% male) and RV remodeling was present in 320 patients (14%). After a median follow-up of 75 months (interquartile range 50–106 months), the composite endpoint of all-cause mortality and HF hospitalization occurred in 292 patients (13%). After adjustment for various risk factors, including tricuspid annular plane systolic excursion (TAPSE), post-STEMI RV remodeling was independently associated with a higher risk of all-cause mortality and HF hospitalization (HR=1.37, 95% CI 1.00–1.87, p=0.049. Finally, patients with RV remodeling were had a significantly lower event-free survival rate compared with patients without RV remodeling during follow-up (log-rank test p=0.009) (Figure 1B).

Conclusion

RV post-infarct remodeling is associated with mortality and HF hospitalization, independent of RV systolic function.

Funding Acknowledgement

Type of funding sources: None. Figure 1. A) Spline and B) Kaplan-Meier curve

Impact of left atrial strain assessed with feature-tracking computed tomography on long-term mortality after transcatheter aortic valve implantation

Background

Aortic stenosis (AS) induces left atrial (LA) remodeling through the increase of left ventricular (LV) filling pressure. Peak left atrial longitudinal strain (PALS) has been proposed as a prognostic marker in patients with AS. Novel feature-tracking (FT) software allows to assess LA strain from multidetector computed tomography (MDCT) dataset.

Purpose

To investigate the association between PALS using FT MDCT and moratlity in patients who underwent transcatheter aortic valve implantation (TAVI).

Methods

A total of 369 Patients (mean 80±7 years, 51% male) who underwent preprocedual MDCT before TAVI and had suitable data for measureing PALS using dedicated FT software were included. Patients were classified into 4 groups according to PALS quartiles; PALS more than 19.3% (Q1), 19.3% or less to more than 15.0% (Q2), 15.0% or less to more than 9.1% (Q3), and 9.1% or less (Q4). The primary outcome was all-caurse mortality.

Results

During median follow-up of 45 [22 - 68] months, 124 patients (34%) were died. On multivariable Cox regression analysis, PALS is an independently associated with all-cause mortality (HR: 0.958 [95% CI: 0.925–0.993], P=0.006). Kaplan-Meier analysis showed the worse outcome of the quatile with more impaired PALS (Logrank P<0.001). Compared to Q1, Q3 and Q4 had higher risk of mortality after TAVI (HR: 2.475 [95% CI: 1.411–4.340] for Q3, HR: 3.253 [95% CI: 1.878–5.633] for Q4).

Conclusion

In this retrospective study, PALS measured with FT MDCT was strongly associated with all-cause mortality after TAVI. LA functial assessment using MDCT may have a importan role for risk stratification in patients referred to TAVI.

Funding Acknowledgement

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): ESC research grant 2018 K-M curve according to PALS quartiles

Impact of tricuspid annular shape on late worsening tricuspid regurgitation after transcatheter aortic implantation: insight from multidetector row computed tomography assessment

Background

Worsening of tricuspid regurgitation (TR) in patients undergoing transcatheter aortic valve implantation (TAVI) is associated with adverse clinical outcomes. The geometrical factors that determine the occurrence of significant TR after TAVI are uncertain. Multi-detector row computed tomography (MDCT) may provide additional geometrical insights in the pathophysiology of worsening TR after TAVI.

Purpose

To investigate the impact of right atrial and tricuspid annular (TA) geometryassessed by MDCT on the occurrence of significant TR (≥ moderate) at 1-year after TAVI.

Methods

Patients without significant TR who had undergone a full-beat MDCT prior to TAVI were included. Right and left atrial and ventricular volumes and TA parameters including the anterior-posterior (AP) and septal-lateral (SL) diameters, area and circularity (AP/SL ratio) were measured and correlated to the occurrence of significant TR at 1-year after TAVI.

Results

A total of 205 patients (80±7 years, 51% male) who underwent TAVI for severe aortic stenosiswere included. Moderate or severe TR at 1-year follow-up occurred in 59 patients (29%). Patients who developed significant TR were more likely to have atrial fibrillation and lower left ventricular (LV) volumes, but larger right and left atrial volumes and TA dimensions at baseline. After adjusting for atrial fibrillation and LV and right atrial volumes, larger end-diastolic TA SL diameter (odds-ratio 1.182 95% CI 1.047–1.334, P=0.007) and more circular TA shape were independently associated with the occurrence of significant TR.

Conclusion

In patients without significant TR prior to TAVI, TA dilation and loss of the elliptical shape of the TA at baseline are associated with of the occurrence of significant TR 1-year after TAVI.

Funding Acknowledgement

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): ESC research grant 2018 Representative cases

P304Prognostic significance of transvalvular flow rate during exercise in asymptomatic patients with aortic stenosis

Background

The optimal management of asymptomatic aortic stenosis (AS) remains controversial. The aim of this study is to investigate the prognostic value of exercise stress echocardiography (ESE) in asymptomatic patients with AS.

Purpose

To investigate the additive value of ESE in asymptomatic patients with AS.

Methods and results

We retrospectively enrolled 109 consecutive patients (mean age 73±13 years, 55 men) with AS (aortic valve area ≤1.5cm2) who underwent ESE. Of these, 10 patients referred for aortic valve replacement without symptoms were excluded; finally, 99 conservatively managed patients were enrolled. During the mean follow-up period of 14±11 months, 23 patients (23%) suffered from AS related events. Although no differences in mean pressure gradient at rest and during exercise were found between the patients with and without adverse events, transvalvular flow rate during exercise (Ex-FR) was lower in patients with adverse events than those without adverse events (236±55 ml/sec vs 274±64 ml/sec, P=0.01). Using multivariate Cox regression analysis, low Ex-FR (<270 ml/sec) was an independent predictor for adverse events in patients with asymptomatic AS (hazard ratio: 3.53, P<0.01). The Kaplan–Meier analysis showed that Ex-FR was clearly stratified the event-free survival (Figure, log-rank P<0.01).

K-M curve according to Ex-FR

Conclusion

These results suggested that Ex-FR measured by ESE should play crucial roles in risk stratification in asymptomatic patients with AS.

P1493Prognostic significance of right ventricular function during exercise in patients with non-obstructive hypertrophic cardiomyopathy

Background

Hypertrophic cardiomyopathy (HCM) is a heterogeneous condition that may present crucial complication including life-threatening arrhythmia and sudden cardiac death. However, the risk stratification of HCM without left ventricular outflow tract (LVOT) obstruction had not been fully elucidated. Moreover, although recent studies have revealed the right ventricle (RV) involvement of HCM, the prognostic importance of RV function during exercise is unclear.

Purpose

To investigate the prognostic significance of RV function in patients with non-obstructive HCM using exercise stress echocardiography (ESE).

Methods and results

This study conducted on 100 HCM patients (age 62.9±13.6 years, 63% men) with preserved left ventricular ejection fraction who underwent ESE using semi-supine bicycle ergometer. Ten patients with significant LVOT obstruction (≥30mmHg) were excluded and 9 were also excluded because of the inadequate imaging quality or insufficiency of data. Among remaining 81 non-obstructive HCM patients, 9 patients suffered from HCM related cardiac events including cardiac death, unexpected hospitalization, life-threatening arrhythmias, and new-onset of syncope during the mean follow up period of 2.6±1.6 years. A multivariate Cox Hazard analysis revealed that low tricuspid annular plane systolic excursion during exercise (Ex-TAPSE, cut-off: 24mm) was an independent predictor of cardiac events. (hazard ratio: 18.66, 95% confidence interval: 3.66–338.46, P<0.001) The estimated cumulative cardiac event free survival using the Kaplan-Meier method was significantly lower in patients with reduced Ex-TAPSE (<24mm) than those with preserved Ex-TAPSE (Log-rank, P<0.01).

K-M curve according to Ex-TAPSE

Conclusion

Ex-TAPSE had a strong predictive value of clinical outcomes in non-obstructive HCM patients. Right ventricular function during exercise may have crucial role in the risk stratification of non-obstructive HCM.

P5622Clinical significance of late-acquired malapposition observed by serial optical coherence tomography after second-generation drug eluting stents

Background

Previous studies have demonstrated that the presence of late-acquired stent malapposition after stent implantation may be a risk of late and very late stent thrombosis and myocardial infarction, which is however still controversial.

Purpose

We sought to investigate the incidence and prognosis of late acquired stent malapposion after second-generation drug eluting stents (2G-DES) implantation.

Methods

A total of 199 lesions in 139 patients who underwent optical coherence tomography (OCT) at both immediately after implantation (Baseline) and 6–12 months after 2G-DES implantation (follow-up) were investigated. We excluded lesions with stent failure before follow-up examination. We evaluated presence or absence of malapposed strut at 1mm interval of OCT images and stents with one or more cross-sections with >30% malapposed strut was defined as stents with malapposition (MP), otherwise well-apposed (WA). We divided the lesions into 4 groups according to the presence of malapposition at baseline and follow-up; WA and WA, persistent well-apposed; MP and WA, resoloved malapposition; WA and MP, late acquired malapposition (LAMP); and MP and MP, persistent malapposition. We compared the target lesion failure (TLF) rate after follow-up examination among 4 groups with Kaplan–Meier analysis.

Results

Median follow-up period was 469 (IQR 71–1416) days. follow-up OCT examination was performed at median 9 months (IQR 7.6–10.5). There were no significant differences in patient's and procedural characteristics among the 4 groups. TLF rate in LAMP group was 12.0% and Kaplan–Meier analysis showed no significant differences among the 4 groups in TLF rate.

TLF-free suvival curves (Kaplan-Meier)

Conclusion

LAMP was observed by OCT at 6–12 months in 12.0% of lesions after 2G-DES implantation, which was not associated with TLF at 5 years.

Hepatitis C Virus Infection of Cultured Human Hepatoma Cells Causes Apoptosis and Pyroptosis in Both Infected and Bystander Cells

Individuals infected with hepatitis C virus (HCV) are at high risk of developing progressive liver disease, including cirrhosis and hepatocellular carcinoma (HCC). How HCV infection causes liver destruction has been of significant interest for many years, and apoptosis has been proposed as one operative mechanism. In this study, we employed a tissue culture-adapted strain of HCV (JFH1_T) to test effects of HCV infection on induction of programmed cell death (PCD) in Huh-7.5 cells. We found that HCV infection reduced the proliferation rate and induced caspase-3-mediated apoptosis in the infected cell population. However, in addition to apoptosis, we also observed infected cells undergoing caspase-1-mediated pyroptosis, which was induced by NLRP3 inflammasome activation. By co-culturing HCV-infected Huh-7.5 cells with an HCV-non-permissive cell line, we also demonstrated induction of both apoptosis and pyroptosis in uninfected cells. Bystander apoptosis, but not bystander pyroptosis, required cell-cell contact between infected and bystander cells. In summary, these findings provide new information on mechanisms of cell death in response to HCV infection. The observation that both apoptosis and pyroptosis can be induced in bystander cells extends our understanding of HCV-induced pathogenesis in the liver.

Effects of Left Amygdala Lesions on Respiration, Skin Conductance, Heart Rate, Anxiety, and Activity of the Right Amygdala During Anticipation of Negative Stimulus

The present study reports the effects of lesions in the left amygdala on anxiety, respiration, skin conductance, heart rate, and electrical potentials in the right amygdala in two patients. Trait and anticipatory-state anxiety were measured before and after left amygdala resection to control medically intractable epilepsy in the patients. Lesions in the left amygdala resulted in decreases of trait and state anxiety, respiratory rate, and activity in the right amygdala in both patients; one patient also showed notable decreases in skin conductance and heart rate. The study also reports that activities in the right amygdala before the lesion were not observed after the lesion. We suggest that the activity of the right amygdala is dominantly activated in anxiety and anxiety-related physiological responses but needs excitatory inputs from the left amygdala.

Global gene analysis identifying genes commonly regulated by the Ras/Raf/MEK and type I IFN pathways

Oncolytic viruses exploit alterations in cancer cells to specifically infect cancer cells but not normal healthy cells. Previous work has shown that oncogenic Ras interferes with interferon (IFN) signaling to promote viral replication. Furthermore, inhibition of the Ras/Raf/MEK/ERK pathway at the level of Ras, MEK, or ERK was sufficient to restore IFN signaling. In order to identify genes that were commonly regulated by the inhibition of the Ras pathway and the IFN pathway, we treated NIH/3T3 cells that overexpress oncogenic Ras with the MEK inhibitor, U0126, or IFN-α for 6 h, and performed DNA microarray analysis (Gene Expression Omnibus accession number GSE49469). Here, we also provide additional information on the experimental and functional analysis of the genes responsive to U0126 and IFN.

Effect of maternal stress on fetal heart rate assessed by vibroacoustic stimulation

This study was designed to determine whether maternal stress levels, state and trait anxiety levels, and stress hormones affect fetal heart rate (FHR) patterns after vibroacoustic stimulation (VAS) at 30 weeks of gestation. A total of 24 healthy pregnant women with a single fetus pregnancy were enrolled. Corticotropin releasing hormone (CRH) and adrenocorticotropic hormone in maternal plasma and cortisol, and chromogranin A in saliva were measured. The FHR patterns after VAS were divided into three types: type I, a long period of acceleration or one acceleration lasting > 1 min or at least two accelerations lasting > 15 s; type II, a biphasic response with acceleration followed by deceleration; and type III, no response or prolonged deceleration. In the high trait anxiety group, CRH levels were significantly higher than in the low trait anxiety group, and FHR patterns after VAS showed mostly a type II response pattern. These findings suggest that stress in pregnant women with high trait anxiety may influence FHR patterns after VAS.

Learning Petri network and its application to nonlinear system control

According to recent knowledge of brain science it is suggested that there exists functions distribution, which means that specific parts exist in the brain for realizing specific functions. This paper introduces a new brain-like model called Learning Petri Network (LPN) that has the capability of functions distribution and learning. The idea is to use Petri net to realize the functions distribution and to incorporate the learning and representing ability of neural network into the Petri net. The obtained LPN can be used in the same way as a neural network to model and control dynamic systems, while it is distinctive to a neural network in that it has the capability of functions distribution. An application of the LPN to nonlinear crane control systems is discussed. It is shown via numerical simulations that the proposed LPN controller has superior performance to the commonly-used neural network one.

Universal learning network and its application to robust control

Universal learning networks (ULNs) and robust control system design are discussed, ULNs provide a generalized framework to model and control complex systems. They consist of a number of interconnected nodes where the nodes may have any continuously differentiable nonlinear functions in them and each pair of nodes can be connected by multiple branches with arbitrary time delays. Therefore, physical systems which can be described by differential or difference equations and also their controllers can be modeled in a unified way. So, ULNs constitute a superset of neural networks or fuzzy neural networks. In order to optimize the systems, a generalized learning algorithm is derived for the ULNs, in which both the first order derivatives (gradients) and the higher order derivatives are incorporated. The derivatives are calculated by using forward or backward propagation schemes. These algorithms for calculating the derivatives are extended versions of back propagation through time (BPTT) and real time recurrent learning (RTRL) by Williams in the sense that generalized nonlinear functions and higher order derivatives are dealt with. As an application of ULNs, the higher order derivative, one of the distinguished features of ULNs, is applied to realizing a robust control system in this paper. In addition, it is shown that the higher order derivatives are effective tools to realize sophisticated control of nonlinear systems. Other features of ULNs such as multiple branches with arbitrary time delays and using a priori information will be discussed in other papers.

A new control method of nonlinear systems based on impulse responses of universal learning networks

A new control method of nonlinear dynamic systems is proposed based on the impulse responses of universal learning networks (ULNs), ULNs form a superset of neural networks. They consist of a number of interconnected nodes where the nodes may have any continuously differentiable nonlinear functions in them and each pair of nodes can be connected by multiple branches with arbitrary time delays. A generalized learning algorithm is derived for the ULNs, in which both the first order derivatives (gradients) and the higher order derivatives are incorporated. One of the distinguished features of the proposed control method is that the impulse response of the systems is considered as an extended part of the criterion function and it can be calculated by using the higher order derivatives of ULNs. By using the impulse response as the criterion function, nonlinear dynamics with not only quick response but also quick damping and small steady state error can be more easily obtained than the conventional nonlinear control systems with quadratic form criterion functions of state and control variables.

Brachial-ankle pulse wave velocity measured automatically by oscillometric method is elevated in diabetic patients with incipient nephropathy

AIMS

To examine whether brachial-ankle pulse wave velocity (baPWV), a possible early marker of atherosclerotic vascular damage, is associated with albuminuria in patients with Type 2 diabetes.

METHODS

BaPWV was measured by automatic oscillometric method in 346 Type 2 diabetic patients with normoalbuminuria (a mean level of three times measurements of albumin-to-creatinine (ACR)<30 microg/mg creatinine; n=200), incipient nephropathy (a mean level of ACR> or =30 and <300 microg/mg creatinine; n=119), and clinical nephropathy (a mean level of ACR> or =300 microg/mg creatinine; n=27), and without peripheral vascular disease.

RESULTS

BaPWV (cm/s) was significantly higher in patients with incipient nephropathy (1722 +/- 382) and clinical nephropathy (1763 +/- 322) than in patients with normoalbuminuria (1559 +/- 343, P<0.0001, respectively). By univariate analysis it correlated significantly with age (r=0.44, P<0.0001), systolic blood pressure (r=0.55, P<0.0001), diastolic blood pressure (r=0.42, P<0.0001), albuminuria (r=0.24, P<0.0001) and HbA1C (r=0.11, P<0.05). Albuminuria revealed an independent significant association with baPWV (P<0.01) after adjustment for age, sex, smoking, BMI, HbA1C, hyperlipidemia, and hypertension. Multiple regression analysis showed age, diastolic blood pressure and albuminuria were independently associated with baPWV (adjusted R2=0.42, P<0.0001).

CONCLUSIONS

The results might indicate a possible link between the pathogenesis of atherosclerosis and diabetic nephropathy. Future studies are needed to clarify the usefulness and its predictable value.

Musculoskeletal disorders among hospital nurses in rural Japan

INTRODUCTION

Although musculoskeletal disorders (MSD) represent a significant occupational problem for hospital nurses, few investigations target nurses in rural facilities. This study investigated the prevalence and correlates of MSD among nurses within an affiliated hospital conglomerate of rural Japan.

METHODS

A self-reporting survey was used as diagnostic tool; the reliability, validity and cost-effectiveness of this method has been established.

RESULTS

An initial group of 329 nurses was recruited from three affiliated, rural locations in Yamanashi prefecture, central Japan; 247 usable replies were obtained (final response rate: 75.1%). The 12-month period-prevalence of self-reported MSD at any body site was 91.9% (95% CI 87.8-94.7). Low back pain (LBP) was the most commonly reported MSD with a prevalence of 82.6% (95% CI 77.4-86.8). Next most reported were shoulder (61.1%, 95% CI 54.9-67.0), neck (36.8%, 95% CI 31.1-43.0), upper back (29.1%, 95% CI 23.8-35.1), knee (23.5%, 95% CI 18.6-29.1) and upper leg MSD (19.4%, 95% CI 15.0-24.8). MSD of the wrist (14.2%, 95% CI 10.4-19.1), upper arm (13.0%, 95% CI 9.3 -17.7) and lower arm (11.7% 95% CI 8.3-16.4) were less common. Logistic regression indicated that nurses who were regularly involved in the manual handling of patients had an increased LBP risk of 16.7 (OR 16.7, 95% CI 1.3-412.7, p = 0.0340) when compared with nurses who were not involved in manual handling of patients.

CONCLUSION

Overall, our study indicated that MSD is common among rural Japanese nurses and its prevalence is consistent between related facilities. The excessive amount of LBP, however, suggests that Japanese nurses are at higher risk of this condition compared with their foreign counterparts.

Improvement of generalization ability for identifying dynamical systems by using universal learning networks

This paper studies how the generalization ability of models of dynamical systems can be improved by taking advantage of the second order derivatives of the outputs with respect to the external inputs. The proposed method can be regarded as a direct implementation of the well-known regularization technique using the higher order derivatives of the Universal Learning Networks (ULNs). ULNs consist of a number of interconnected nodes where the nodes may have any continuously differentiable nonlinear functions in them and each pair of nodes can be connected by multiple branches with arbitrary time delays. A generalized learning algorithm has been derived for the ULNs, in which both the first order derivatives (gradients) and the higher order derivatives are incorporated. First, the method for computing the second order derivatives of ULNs is discussed. Then, a new method for implementing the regularization term is presented. Finally, simulation studies on identification of a nonlinear dynamical system with noises are carried out to demonstrate the effectiveness of the proposed method. Simulation results show that the proposed method can improve the generalization ability of neural networks significantly, especially in terms that (1) the robust network can be obtained even when the branches of trained ULNs are destructed, and (2) the obtained performance does not depend on the initial parameter values.

Increased synchronization of cortical oscillatory activities between human supplementary motor and primary sensorimotor areas during voluntary movements

In human, both primary and nonprimary motor areas are involved in the control of voluntary movements. However, the dynamics of functional coupling among different motor areas has not been fully clarified yet. Because it has been proposed that the functional coupling among cortical areas might be achieved by the synchronization of oscillatory activity, we investigated the electrocorticographic coherence between the supplementary motor and primary sensorimotor areas (SMA and S1-M1) by means of event-related partial coherence analysis in 11 intractable epilepsy patients. We found premovement increase of coherence between the SMA proper and S1-M1 at the frequency of 0-33 Hz and between the pre-SMA and S1-M1 at 0-18 Hz. Coherence between the SMA proper and M1 started to increase 0.9 sec before the movement onset and peaked 0.3 sec after the movement. There was no systematic difference within the SMA (SMA proper vs pre-SMA) or within the S1-M1, in terms of the time course as well as the peak value of coherence. The phase spectra revealed near-zero phase difference in 57% (20 of 35) of region pairs analyzed, and the remaining pairs showed inconsistent results. This increase of synchronization between multiple motor areas in the preparation and execution of voluntary movements may reflect the multiregional functional interactions in human motor behavior.

Magnetic resonance imaging and clinical findings examined in adulthood-studies on three adults with Rett syndrome

PURPOSE

To clarify magnetic resonance imaging (MRI) findings in three adult patients with Rett syndrome who had been diagnosed with mental retardation and autism.

METHOD

Clinical and MRI findings in three adult cases with Rett syndrome were studied. Ages (in years) in three adult cases with Rett Syndrome were 46 in Case 1, 35 in Case 2 and 20 in Case 3. They were able to walk and their convulsions were well controlled.

RESULTS

MRI findings in all patients showed mild cerebral atrophy, especially in the frontal and temporal lobes and two of the cases also had mild cerebellar atrophy. One case also showed a narrowing of the brainstem and thinning of the corpus callosum.

CONCLUSIONS

These results indicate that abnormalities in MRI imaging, in cases where there is narrowing of the brainstem and thinning of the corpus callosum, may be due to congenital hypoplasia. It was also seen that cerebellar atrophy became more distinct in older cases.

Effects of cryopreservation of pronuclear-stage rabbit zygotes on the morphological survival, blastocyst formation, and full-term development after DNA microinjection

The objectives of this study were to examine the freezing sensitivity of pronuclear-stage rabbit zygotes and to produce transgenic rabbits using the cryopreserved zygotes. Zygotes were cryopreserved either by one of two vitrification protocols or by one of the two conventional freezing protocols. The morphological survival rates of zygotes subjected to two-step freezing in 1.5 M ethylene glycol and 0.1 M sucrose (74%) or to vitrification in 7.2 M ethylene glycol and 1.0 M sucrose (81%) were higher than those subjected to freezing in 1.5 M DMSO (46%) or to vitrification in a mixture of 2.0 M DMSO, 1.0 M acetamide, and 3.0 M propylene glycol (41%). But the in vitro development into blastocysts of zygotes cryopreserved by vitrification (17%) or to a lesser extent by freezing (52%) was impaired, when compared to that of fresh control zygotes (89%). Next, a fusion gene composed from bovine aS1-casein promoter and a human GH structural gene (2.8 kb) was microinjected into the pronucleus of rabbit zygotes frozen-thawed in ethylene glycol and sucrose. Then, the presence of exogenous DNA in the genome of newborn offspring was determined by PCR. The post-injection survival of frozen zygotes (97%) was the same as that of fresh control zygotes (96%). However, of 18 offspring derived from 414 frozen-thawed and DNA-injected zygotes, no transgenic rabbits were produced. Of 52 offspring derived from 403 DNA-injected fresh zygotes, 3 transgenic rabbits were found. Here we report the first rabbit offspring resulting from zygotes cryopreserved at the pronuclear-stage, although the cryopreservation procedure employed must be improved if zygotes are to be used for systematic production of transgenic rabbits.

Microbial desulfurization of alkylated dibenzothiophene and alkylated benzothiophene by recombinant Rhodococcus sp. strain T09

The dibenzothiophene (DBT) desulfurizing operon, dsz, was introduced into various benzothiophene (BT)-desulfurizing bacteria using a Rhodococcus-E. coli shuttle vector. Of the tested recombinant bacteria, only those from Rhodococcus sp. strain T09 grew with both DBT and BT as the sole sulfur source. These recombinant cells desulfurized not only alkylated BTs, but also various alkylated DBTs, producing alkylated hydroxybiphenyls as the desulfurized products. Recombinant strain T09 also desulfurized alkylated DBT in an oil-water, two-phase resting-cell reaction. The dsz operon had the same desulfurizing activity when inserted into the vector in either orientation, indicating that the promoter region of the operon was functional in strain T09.

Comparison of source localization of interictal epileptic spike potentials in patients estimated by the dipole tracing method with the focus directly recorded by the depth electrodes

The purpose of the study was to investigate the accuracy of location of equivalent current dipoles estimated by the dipole tracing method (DT) utilizing a realistic 3-shell (scalp-skull-brain) head model (SSB-DT). Three patients with intractable complex partial seizures, diagnosed as having typical temporal seizures were investigated. We recorded the interictal spike potentials with surface electrodes (International 10/20 system) and with intracerebral depth electrodes simultaneously. We compared the location of dipoles of the spikes estimated by the SSB-DT with the focus of the spikes determined by the recording from the depth electrodes. We found that the location of the dipoles estimated by SSB-DT corresponded to the location of the depth electrodes, which could record the epileptic spikes. This finding proved that SSB-DT is reliable and valid for estimating neural activity in deep locations such as the limbic system.

A comparative study on the integration of exogenous DNA into mouse, rat, rabbit, and pig genomes

Transgenic mammals, from small laboratory rodents to domestic animals, have been successfully produced to date, but their production efficiency within or across species has been variable. This is probably due to the differences in the type of injected DNA and/or technical procedures employed in each laboratory, as well as the reproductive characteristics of the species. Here we report the direct comparison of the efficiencies of producing transgenic mice, rats, rabbits and pigs by one technician using a fusion gene composed of the bovine alpha S1-casein promoter and human growth hormone (hGH) gene. Before the fusion gene was injected into the zygotes, high magnitude centrifugation to visualize the pronuclei was necessary for all of the pig zygotes and one-third of the rabbit zygotes, but not for mouse and rat zygotes. Post-injection survival of the mouse zygotes (67.1%) was lower than those of the rat, rabbit and pig zygotes (89.6 to 100%). The volume change of the pronucleus following DNA injection was the lowest in mice (50% increase), moderate in rabbits (148% increase), and the most prominent in rats (238% increase). The data from only 1 pig zygote indicated a 22% increase in the pronucleus volume by DNA injection. The PCR analyses of the tail DNA of new born offspring indicated that 0.8% (4/493), 4.8% (22/463), 0.8% (3/367) and 0.9% (2/221) of the injected eggs in mice, rats, rabbits and pigs, respectively, developed into transgenic offspring. Some of the founder animals in all four species expressed the transgene in the mammary gland which was confirmed in hGH mRNA by RT-PCR and/or hGH peptide in Witch's milk with ELISA. These results suggest that the maximum volume of DNA solution injectable into the pronucleus is a possible factor explaining the species differences in the production of transgenic animals.

Improvement of desulfurization activity in Rhodococcus erythropolis KA2-5-1 by genetic engineering

Rhodococcus erythropolis KA2-5-1 can desulfurize dibenzothiophene (DBT) into 2-hydroxybiphenyl. A cryptic plasmid, pRC4, which was derived from R. rhodochrous IFO3338, was combined with an Escherichia coli vector to construct an E. coli-Rhodococcus shuttle vector. The complete nucleotide sequence of 2582-bp pRC4 was analyzed. Based on the characteristics of its putative replication genes, pRC4 was assigned to the family of pAL5000-related replicons. The desulfurization gene cluster, dszABC, and the related reductase gene, dszD, cloned from KA2-5-1, were reintroduced into KA2-5-1 and efficiently expressed. The DBT desulfurization ability of the transformant carrying two dszABC clusters and one dszD on the vector was about 4-fold higher than that of the parent strain, and the transformant also showed improved desulfurization activity for light gas oil (LGO). Sulfur components in LGO before and after the reaction were analyzed with gas chromatography-atomic emission detection.

Kinetic analysis of microbial desulfurization of model and light gas oils containing multiple alkyl dibenzothiophenes

The reaction mechanism of biodesulfurization was investigated using whole cells of Rhodococcus erythropolis KA2-5-1, which have the ability to convert dibenzothiophene (DBT) into 2-hydroxybiphenyl. The desulfurization patterns of alkyl DBTs were represented by the Michaeis-Menten equation. The values of rate constants, the limiting maximal velocity (Vmax) and Michaelis constant (Km), for desulfurization of alkyl DBTs were calculated. The relative desulfurization activities of various alkyl DBTs were reduced in proportion to the total carbon numbers of alkyl substituent groups. Alkyl DBTs that had a total of six carbons of alkyl substituent groups were not desulfurized. The type or position of alkyl substituent groups had little effect on desulfurization activity. The desulfurization activity of each alkyl DBT, when mixed together, was reduced. This phenomenon was caused by apparent competitive inhibition of substrates. Using the apparent competitive inhibition model, the desulfurization pattern of a multiple components system containing alkyl DBTs was elucidated. This model was also applicable for biodesulfurization of light gas oil.

Photo-responsive retention behavior of azobenzene-modified cyclodextrin stationary phase in micro-HPLC

An azobenzene-modified gamma-cyclodextrin stationary phase (Az gamma-CDSP) was prepared and its photo- and temperature-responses for the retention of perylene and pentacene were investigated using a mixture of methanol and water as the mobile phase in micro-HPLC. The retention of perylene slightly increased, whereas that of pentacene significantly decreased by UV light irradiation to Az gamma-CDSP. These retentions recovered upon irradiation with visible light. Both retentions decreased upon an increase in the column temperature. It was presumed that the trans-azobenzene moiety acts as a preventive cap for perylene and a spacing for pentacene in filling the CD cavity. An azobenzene-modified stationary phase changed its retention behavior with the column temperature and the light irradiation. An improvement in the micro-HPLC system and the optimization of the molecular structure of the photo-responsive stationary phase would provide selective retention control by the irradiation of light in micro-separation systems.

Effects of higenamine on regulation of ion transport in guinea pig distal colon

Effects of higenamine on Na+, K+ and Cl- transport were studied on stripped guinea pig distal colonic mucosa in vitro using Ussing chambers. Addition of 10(-5) M higenamine induced a biphasic change in short circuit current (Isc): a transient increase followed by a long-lasting decrease that was accompanied by an increase in transepithelial conductance (Gt). The initial phase with an increase in Isc was partially inhibited by serosal bumetanide and abolished by mucosal diphenylamine-2-carboxylate, a chloride channel blocker, indicating transient induction of Cl- secretion. The second phase with a decrease in Isc was composed of two effects: the inhibition of the amiloride-sensitive electrogenic Na+ absorption and the stimulation of the bumetanide-sensitive K+ secretion. However, the initial transient increase was not observed at the lower concentration of higenamine (10(-8)-10(-6) M). All the changes in Isc and Gt induced by higenamine were suppressed by the non-selective beta-adrenergic receptor antagonist propranolol and by the beta2-adrenergic receptor antagonist ICI-118,551, but not by the beta1-adrenergic-receptor-selective antagonist atenolol or by the alpha-antagonists phentolamine, prazosin and yohimbine. These results suggest that higenamine inhibits electrogenic Na+ absorption and stimulates electrogenic K+ and Cl- secretion through beta2-adrenergic receptors in guinea pig distal colon.

Prognostic value of impaired myocardial fatty acid uptake in patients with acute myocardial infarction

Impaired cardiac fatty acid uptake, assessed by the radiolabelled fatty acid analogue beta-methyl-p-iodophenyl pentadecanoic acid (I-123-BMIPP), is observed in the myocardium following acute ischaemic events, but the long-term prognostic implication has not been established. This study aimed to determine the prognostic value of cardiac BMIPP uptake in patients with acute myocardial infarction. Following the assessment of thallium-201 and I-123-BMIPP uptake, 101 post-infarct patients were prospectively followed up with primary end points of cardiac death, heart failure and non-fatal infarction. During a mean follow-up of 28 months, three cardiac deaths, three non-fatal infarctions, 23 revascularizations and four recurrences of angina pectoris were observed. Multivariate analysis identified reduced uptake of BMIPP and perfusion, no beta-blocking treatment and greater thallium-BMIPP mismatch (i.e. larger BMIPP defect than thallium defect) as significant predictors for overall cardiac events. Prior myocardial infarction, reduced left ventricular ejection fraction and greater thallium-BMIPP mismatch were selected as independent predictors of harder cardiac events. Female patients, those with greater BMIPP defect or greater thallium-BMIPP mismatch showed worse clinical outcomes. The inclusion of BMIPP data improved the prognostic values of conventional significant predictors. In conclusion, impaired myocardial I-123-BMIPP uptake and perfusion-BMIPP mismatch are related to a high probability of fatal and non-fatal cardiac events, suggesting the aetiological relevance and prognostic value of impaired cardiac fatty acid metabolism in viable, but jeopardized, myocardium following acute myocardial infarction.

Change in circulating blood volume following craniotomy

OBJECT

The importance of monitoring circulating blood volume (CBV) during perioperative management is widely recognized in critically ill patients. The purpose of this study was to investigate the change in CBV following craniotomy by using indocyanine-green pulse spectrophotometry.

METHODS

Circulating blood volume and plasma hormones related to stress and fluid regulation were measured five times: preoperatively, immediately postoperatively, and 1, 2, and 7 days after craniotomy was performed in 17 patients with a brain tumor or an unruptured aneurysm. The mean value of CBV preoperatively was 82 ml/kg, which decreased to 64 ml/kg (78%) immediately postoperatively and gradually recovered to 82 ml/kg on Day 7 postsurgery (p = 0.0069). The mean values of adrenaline, noradrenaline, arginine vasopressin, renin, and aldosterone were highest immediately postoperatively. The mean intraoperative balances of water and sodium were 1,090 ml and 113 mEq, respectively. Partial correlation coefficients of CBV to noradrenaline and serum sodium during the entire study were -0.430 (p = 0.0036) and 0.418 (p = 0.0048), respectively.

CONCLUSIONS

Attention should be paid to decreased CBV following craniotomy, which is caused by the shift of fluid to interstitial spaces due to surgical stress. Hypovolemia can be suspected from a postoperative decrease in serum sodium.

Production of transgenic rabbits using centrifuged pronuclear zygotes

Superovulation of female rabbits was induced by subcutaneous injection(s) of porcine FSH. Zygotes were recovered 17 to 19 hr after hCG injection and were classified into two categories under a microscope equipped with Nomarski interference-contrast optics at x 200 magnification: (A) zygotes with clearly visible pronuclei, or (B) zygotes with visualized pronuclei after 10 min centrifugation at 12,000 x g. No significant difference between strains was found in the proportion of category-A zygotes (JW 72.6% vs NZW 79.3%). Pronuclei of category-A zygotes were located in the center of the cytoplasm, and the pronuclei of category-B zygotes were slightly moved by centrifugation toward the mass of cytoplasmic lipid droplets. Exogenous DNA solution (5 microg/ml of fusion gene composed of bovine alphaS1-casein promoter and human growth hormone structural gene) was microinjected into the pronucleus of the JW zygotes. The pronucleus of category-A zygotes with a mean volume of 7.4 pl swelled up to 16.6 pl (132% increase), while that of category-B zygotes with a mean volume of 6.1 pl swelled up to 15.9 pl (148% increase). Nevertheless, similar proportions of category-A and category-B zygotes developed into offspring after transfer to recipient females (11.1 and 11.2%, respectively). The efficiency to produce hGH-carrying transgenic rabbits was 0.9% (2/235) from category-A zygotes and 0.5% (1/215) from category-B zygotes (P>0.05). To date, transgenic rabbits have been produced without centrifugation of pronuclear zygotes. However approximately 25% of fertilized rabbit zygotes can be used for DNA microinjection after they have been centrifuged to visualize their pronuclei.

Adenine-induced selective apoptosis toward HIV chronically infected cells in vitro

A novel strategy for anti-HIV therapy is the clearance of the residual infected cells from the body. Here, we show that 6-aminopurine, adenine, induced selective apoptosis toward HIV-1 producing chronically infected MOLT4 cells (MOLT4/HIV) without augmentation of virus production, whereas the growth of uninfected MOLT4 was stimulated. This selective apoptosis did not occur with other adenine nucleotides or with other bases. The purine ring and the amino residue of adenine were responsible for the apoptosis induction and selectivity, respectively. In addition, adenine slightly but consistently reduced viable cell numbers and the production of virus in a fraction of HIV-1 chronically infected human peripheral blood mononuclear cells (PBMCs/HIV) at day 7. On the other hand, blastogenic response of normal PBMCs to PHA, PWM and Candida albicans were potentiated in the presence of adenine. These results indicated that the effect of adenine may be attributable to activation-induced selective apoptosis toward virus-infected cells.

[Left Sylvian fissure meningioma in a one-year-eight-month old child]

We report a case of a Sylvian fissure meningioma in a one-year-eight-month old child who experienced the onset of a convulsive seizure. He had no neurological deficit and no developmental disorders. Computed tomography (CT) and magnetic resonance imaging (MRI) showed a large left temporal tumor which was well enhanced and without dural attachment. Angiography revealed a slight tumor stain in the left Sylvian fissure supplied by branches of the internal carotid artery. Total removal of the tumor was performed, and we found that the tumor had no dural attachment, but was strongly attached to the M2 segment of the left middle cerebral artery. Pathological examinations revealed it to be a fibrous meningioma without malignancy. This is the youngest case among the reported five pediatric deep Sylvian meningiomas. Introducing this case, we discuss the clinical features of pediatric meningiomas.

Ovarian mucinous cystadenocarcinoma as a cause of Zollinger-Ellison syndrome: report of a case and review of the literature

Gastrin producing ovarian tumor is a rare cause of the Zollinger-Ellison syndrome. We report the case of an ovarian carcinoma showing increased plasma gastrin concentration. A 60-yr-old woman presented with epigastric pain and diarrhea. Physical examination showed a large mass in the lower abdomen. Computed tomography revealed a large multilocular ovarian cyst. Upper gastrointestinal endoscopy examination showed multiple ulcerations of the stomach and duodenum. The plasma gastrin level was 1500 pg/ml. No tumors were found in the pancreas and duodenum, and salpingo-oophorectomy was performed. Histologic examination revealed a mucinous tumor of borderline malignant potential. Immunoperoxidase studies for gastrin showed many gastrin-producing cells within the epithelium of the tumor. There have been 11 cases (including our patient) of gastrin-producing ovarian tumor reported in the literature. We review here the relevant literature. Although ovarian gastrinoma is extremely rare, it should be considered as a possible cause of the Zollinger-Ellison syndrome in women.

Operon structure and functional analysis of the genes encoding thermophilic desulfurizing enzymes of Paenibacillus sp. A11-2

Paenibacillus A11-2 can efficiently cleave two carbon&bond;sulfur bonds in dibenzothiophene (DBT) and alkyl DBTs, which are refractory by conventional petroleum hydrodesulfurization, to remove sulfur atom at high temperatures. An 8.7-kb DNA fragment containing the genes for the DBT desulfurizing enzymes of A11-2 was cloned in Escherichia coli and characterized. Heterologous expression analysis of the deletion mutants identified three open reading frames that were required for the desulfurization of DBT to 2-hydroxybiphenyl (2-HBP). The three genes were designated tdsA, tdsB, and tdsC (for thermophilic desulfurization). Both the nucleotide sequences and the deduced amino acid sequences show significant homology to dszABC genes of Rhodococcus sp. IGTS8, but there are several local differences between them. Subclone analysis revealed that the product of tdsC oxidizes DBT to DBT-5,5'-dioxide via DBT-5-oxide, the product of tdsA converts DBT-5,5'-dioxide to 2-(2-hydroxyphenyl) benzene sulfinate, and the product of tdsB converts 2-(2-hydroxyphenyl)benzene sulfinate to 2-HBP. Cell-free extracts of a recombinant E. coli harboring all the three desulfurization genes converted DBT to 2-HBP at both 37 and 50 degrees C. In vivo and in vitro exhibition of desulfurization activity of the recombinant genes derived from a Paenibacillus indicates that an E. coli oxidoreductase can be functionally coupled with the monooxygenases of a gram-positive thermophile.