Risk Factors for Stoma Outlet Obstruction: Preventing This Complication after Construction of Diverting Ileostomy during Laparoscopic Colorectal Surgery

Introduction

Bowel obstruction at the outlet of the stoma, also referred to as "stoma outlet obstruction" (SOO), has been noted to be more common after laparoscopic colorectal surgery with diverting ileostomy than after laparotomy. Thus, the aim of this study is to identify the risk factors for SOO and to evaluate the effectiveness of a modified ileostomy procedure for reducing its incidence.

Methods

The medical records of 63 patients who underwent laparoscopic colorectal surgery with diverting ileostomy between January 2014 and July 2021 were retrospectively reviewed. We analyzed the risk factors for SOO using computed tomography findings.

Results

In total, 34 patients underwent surgery before modification of the ileostomy procedure (LSa group), and 29 patients underwent surgery after modification (LSb group). In the LSa group, 6 patients have reportedly developed SOO (SOO group), whereas 28 patients did not (non-SOO group). No patients in the LSb group developed SOO. The thickness of the abdominal rectus muscle (ThM) in the SOO group and the non-SOO group was 13.4 mm and 9.6 mm, respectively (p = 0.005). The angle between the ileostomy and the abdominal wall (AIW) was 95.8° in the non-SOO group and 82.2° in the SOO group (p = 0.033). The AIW was 93.4° in the LSa group and 99.7° in the LSb group (p = 0.043).

Conclusions

As per our findings, a thick abdominal rectus muscle is predictive of SOO. Correction of the AIW (eliminating medial inclination) by modifying the operative technique has eliminated the occurrence of SOO in our patient population.

Starting Neurohormonal Antagonists in Patients with Acute Heart Failure with Mid-Range and Preserved Ejection Fraction

Background

The clinical benefits of neurohormonal antagonist in patients with heart failure (HF) with mid-range and preserved ejection fraction (HFmrEF and HFpEF) were uncertain. This study aimed to evaluate the prognostic effect of starting angiotensin-converting enzyme inhibitors (ACE-I) / angiotensin II receptor blockers (ARB) and β-blocker during HF hospitalization in these patients.

Methods

We analyzed 858 consecutive patients with HFmrEF (EF:40–49%) or HFpEF (EF≥50%), who were hospitalized for acute decompensated HF, were discharged alive, and were not taking ACE-I/ARB or β-blockers at admission. The study population was classified into four groups according to the status of prescription of ACE-I/ARB and β-blocker at discharge: no neurohormonal antagonist (N=342, 39.9%), ACE-I/ARB only (N=128, 14.9%), β-blocker only (N=189, 22.0%), and both ACE-I/ARB and β-blocker (N=199, 23.2%) groups. The primary outcome measure was a composite of all-cause death or HF hospitalization.

Results

The cumulative 1-year incidence of the primary outcome measure was 41.2% in the no neurohormonal antagonist group, 34.0% in the ACE-I/ARB only group, 28.6% in the β-blocker only group, and 16.4% in the both ACE-I/ARB and β-blocker group (P<0.001). Compared with the no neurohormonal antagonist group, the both ACE-I/ARB and β-blocker group were associated with a significantly lower risk for a composite of all-cause death or HF hospitalization (HR: 0.59, 95% CI: 0.38–0.91, P=0.02).

Conclusions

In hospitalized patients with HFmrEF and HFpEF, starting both ACE-I/ARB and β-blocker was associated with a reduced risk of a composite of all-cause death or HF hospitalization compared with not starting ACE-I/ARB or β-blocker.

Funding Acknowledgement

Type of funding sources: None.

Cardio-renal protective effects of SGLT2 inhibitors in patients with type 2 diabetes mellitus and severely impaired renal function

Background

Prognostic impact of Sodium-Glucose Cotransporter 2 (SGLT2) inhibitors on cardiovascular and renal outcome was unknown in patients with type-2 diabetes mellitus (DM) and severely impaired renal function.

Methods

From July 2015 to December 2020, patients with type-2 DM who were taken SGLT2 inhibitors for more than six months were retrospectively screened. Patients with estimated glomerular filtration rate (eGFR) over 60ml/min/1.73m2 were excluded. We divided those patients into two groups by eGFR; less than 45ml/min/1,73m2 were group A and 46–60ml/min/m2 were group B. Randomly selected patients with DM not taking SGLT2 inhibitors and having severe renal dysfunction: eGFR less than 45ml/min/m2 (Group C) were set as controls. The primary outcome was a composite of cardiovascular/renal death, initiation of dialysis, doubling of the serum creatine level, decline in the eGFR more than 30%, nonfatal myocardial infraction, nonfatal stroke, and hospitalization for heart failure.

Results

Totally 418 patients were enrolled. Median age was 71 years (group A, n=106), 64 years (group B, n=115), and 77 years (group C, n=201) (p<0.001). After median 24 months follow-up, primary endpoints were observed 24.5% in group A, 4.3% in group B, 36.8% in group C (p<0.001). In Kaplan-Meier analysis, significantly lower incidence of primary endpoints were observed in SGLT2 groups (group A and B) than controls (p<0.001, Figure 1). In patients with severe renal dysfunction, taking SGLT2 inhibitors tended to decrease future renal event (Figure 2). The incidence of SGLT2 related adverse events was not different between 2 groups (A and B).

Conclusions

Even in patients with severe renal dysfunction, SGLT2 inhibitors would have cardio-renal protective effects without drug-related adverse effects.

Funding Acknowledgement

Type of funding sources: None.

Impact of polypharmacy on prognosis in patients with acute decompensated heart failure: from the CURE-HF registry

Background

Polypharmacy would be associated with poor prognosis in patients with heart failure (HF).

Methods

In 863 patients who discharged after treatment for HF were prospectively enrolled. Number of tablets prescribed at discharge was counted. Death, non-fatal myocardial infarction, non-fatal stroke, and hospitalization for HF were tracked.

Results

In our study cohort (median age, 78), 447 patients experienced adverse events during median 503 days follow-up. In Kaplan-Meier analysis, a greater number of prescribed tablets was associated with future adverse cardiac events in the crude population. Although patients with the greater number of non-HF medications showed worse outcome, those of HF medications were not associate with the outcome (Figure). Furthermore, the number of tablets was an independent predictor of future cardiovascular events after adjustment for age, gender, B-type natriuretic peptide, hemoglobin, albumin, estimated glomerular filtration rate, and left ventricular ejection fraction (HR 95% CI: 1.295 (1.066–1.573), p=0.009).

Conclusions

Polypharmacy was associated with poor prognosis. Although the numbers of tablets and non-HF medications were significantly associated with worse out come in HF patients, the number of HF medications was not.

Funding Acknowledgement

Type of funding sources: None.

A decrease in tricuspid regurgitation pressure gradient during follow-up in patients with heart failure

Objective

This study aimed to investigate the prognostic impact of the decrease in tricuspid regurgitation pressure gradient (TRPG) at 6-month follow-up in patients after discharge with heart failure (HF).

Background

No previous study has reported the association between TRPG decrease during follow-up and clinical outcomes in HF.

Methods

Among 748 patients with 6-months follow-up echocardiography after discharge from the acute decompensated heart failure in 19 centers in Japan, we analyzed 721 patients with available TRPG data and divided into two groups: the decrease in TRPG group (N=179) and no decrease in TRPG group (N=542). We defined the decrease in TRPG as >10mmHg decrease compared in the initial hospitalization. The primary outcome measure was a composite of all cause deaths and hospitalization due to HF.

Results

The patients in the decrease in TRPG group had a lower prevalence of hypertension, dyslipidemia, atrial fibrillation, and a reduced EF, higher levels of blood albumin and lower levels of sodium than those in no decrease in TRPG group. The median follow-up duration after the follow up echocardiography was 302 (inter quartile range: 206–490), with a 90.9% follow up rate at 6-month. The cumulative 6-month incidence of the primary outcome measure was significantly lower in the decrease in TRPG group than in no decrease in TRPG group (12.2% vs. 18.9%, P=0.0011). After adjusting confounders, the excess risk of the decrease in TRPG relative to no decrease in TRPG for the primary outcome measure remained significant (HR: 0.60, 95% CI 0.34–0.99). There were no significant interactions between the subgroup factors and the effect of the decrease in TRPG for primary outcomes.

Conclusions

HF patients with the decrease in TRPG at 6-month after discharge had a lower risk of clinical outcome than those without decrease in TRPG.

Funding Acknowledgement

Type of funding source: None

Prognostic impact of free-fat mass index on elderly patients with acute decompensated heart failure: from CURE-HF registry

Background

Free-Fat Mass Index (FFMI) is an indicator of malnutrition and sarcopenia. We hypothesized that low FFMI would be associated with worse prognosis in elderly patients with heart failure.

Methods

In 800 patients who discharged after treatment for HF were prospectively enrolled from 13 medical centers. Free-Fat Mass Index was calculated dividing the square of the patients heights in meters into lean body mass. All-cause mortality (cardiovascular, non-cardiovascular) was followed-up by telephone interview and chart review.

Results

In our study cohort (median age, 78 [range 72–87]), FFMI was 16.7 [15.2, 18.0]. All-cause mortality was observed in 211 patients during 631 [266, 983] days follow-up. In Kaplan-Meier analysis, lower FFMI was associated with all-cause mortality. Furthermore, FFMI was an independent predictor of mortality after adjustment for age, gender, albumin, hemoglobin, creatinine, brain natriuretic peptide, and left ventricular ejection fraction (HR 95% CI: 0.841 (0.745–0.944), p=0.004). In subgroup analysis, low FFMI was associated with both cardiac and non-cardiac mortality in patients with HF with reduced ejection fraction (EF) (Log-rank p=0.002, p=0.013, respectively) (Figure). Furthermore, low FFMI was significantly associated non-cardiac death in patients with preserved EF (Log-rank p=0.033) (Figure).

Conclusions

Free-Fat Mass Index was significantly associated with mortality in elderly patients with HF.

Funding Acknowledgement

Type of funding source: None

Phenotypic difference of sarcopenia in the prediction of mortality for elderly patients with heart failure: from CURE-HF registry

Background

Sarcopenia and malnutrition are associated with mortality in elderly patients with heart failure (HF). However, impact of phenotypic difference of sarcopenia on mortality is not well investigated. We hypothesized that evaluation using both body mass index (BMI) and free-fat mass index (FFMI) enabled distinction of phenotypic difference of sarcopenia and risk stratification for mortality in elderly patients with heart failure.

Methods

In 800 patients who discharged after treatment for HF were prospectively enrolled from 13 medical centers. Body mass index and FFMI was evaluated. Free-fat mass index was calculated dividing the square of the patients' heights in meters into lean body mass. All-cause mortality was followed-up. Patients were divided into 3 subgroups according to BMI and FFMI values, and compared incidence of mortality among them.

Results

In our study cohort (median age, 78 [range 72–87]), BMI was 21.1 [18.9, 23.8] and FFMI was 16.7 [15.2, 18.0]. 211 patients were experienced all-cause mortality during 631 [266, 983] days follow-up. In Kaplan-Meier analysis, lower BMI and lower FFMI was associated with all-cause mortality (Log-rank p<0.001, p<0.001, respectively). Furthermore, FFMI was an independent predictor of adverse events after adjustment for age, gender, albumin, hemoglobin, creatinine, brain natriuretic peptide, and left ventricular ejection fraction (HR 95% CI: 0.841 (0.745–0.944), p=0.004). In subgroup analysis, comparing with low-BMI and low-FFMI subgroup, better prognosis was observed in the other 2 subgroups (Log-rank p<0.001, p=0.022, Figure 1).

Conclusions

Phenotypic difference was evident in elderly patients with HF. A combination of BMI and FFMI would be useful for risk stratification of mortality in those patients.

Figure 1

Funding Acknowledgement

Type of funding source: None

The impact of hyperuricemia on all patients and low-BMI patients after endovascular treatments: from I-PAD registry

Background

Hyperuricemia (≥7.0 mg / dl) is known to be one of the risks of arteriosclerosis. For a long time, it has been said that metabolic syndrome and high-BMI has been implicated to hyperuricemia and also that it's a consequence of those patient background, not a cause of arteriosclerosis. Now, the accumulation of data about hyperurisemia is still not enough. Also the importance of secondary prevention for patients after endovascular treatment (EVT) is still unclear too.

Purpose

To investigate the impact of hyperuricemia on prognosis of all patients and low-BMI patients after EVT.

Methods

From July 2015 to July 2016, 335 consecutive PAD patients who performed EVT were enrolled in I-PAD registry. And we divided them into 2 groups; with hyperuricemia or not, and analyzed them. In addition to that, among them, we selected 245 low-BMI patients (<25) and divided them into 2 groups; with hyperuricemia or not, and analyzed them. The primary end point was all-cause-death and the secondary endpoint was MACLE (Major Adverse Cardiovascular and limbs Events) at 3-years.

Result

At 3 years in the patients group with hyperuricemia, overall survival and freedom from MACLE were significantly lower (57.7% vs 83.4% P=0.0012; 30.3% vs 68.6% P=0.0095) than the group without hyperuricemia. Even among the low-BMI patients, in the patients with hyperuricemia, overall survival and freedom from MACLE were significantly lower (55.2% vs 77.1% P=0.003; 48.2% vs 69.9% P=0.002) than the patients without hyperuricemia at 3 years.

Conclusion

In this study, the prognosis of patients after EVT with hyperuricemia was worse than the patient without. And even among the low-BMI patients, The prognosis after EVT with hyperuricemia was worse than the patient without.

Funding Acknowledgement

Type of funding source: None

NRSF-GNAO1-CaMK2 axis exacerbates cardiac remodeling and progresses heart failure by impairing Ca2+ homeostasis

Background

In the development of heart failure, pathological intracellular signaling reactivates fetal cardiac genes, which leads to maladaptive remodeling and cardiac dysfunction. We previously reported that a transcriptional repressor, neuron restrictive silencer factor (NRSF) represses fetal cardiac genes and maintains normal cardiac function under normal conditions, while hypertrophic stimuli de-repress this NRSF mediated repression via activation of CaMKII. Molecular mechanisms by which NRSF maintains cardiac systolic function remains to be determined, however.

Purpose

To elucidate how NRSF maintains normal cardiac homeostasis and identify the novel therapeutic targets for heart failure.

Methods and results

We generated cardiac-specific NRSF knockout mice (NRSF cKO), and found that these NRSF cKO showed cardiac dysfunction and premature deaths accompanied with lethal arrhythmias, as was observed in our previously reported cardiac-specific dominant-negative mutant of NRSF transgenic mice (dnNRSF-Tg).

By cDNA microarray analysis of dnNRSF-Tg and NRSF-cKO, we identified that expression of Gnao1 gene encoding Gαo, a member of inhibitory G proteins, was commonly increased in ventricles of both types of mice.

ChIP-seq analysis, reporter assay and electrophoretic mobility shift assay identified that NRSF transcriptionally regulates Gnao1 gene expression.

Genetic Knockdown of Gαo in dnNRSF-Tg and NRSF-cKO by crossing these mice with Gnao1 knockout mice ameliorated the reduced systolic function, increased arrhythmogenicity and reduced survival rates.

Transgenic mice expressing a human GNAO1 in their hearts (GNAO1-Tg) showed progressive cardiac dysfunction with cardiac dilation. Ventricles obtained from GNAO1-Tg have increased phosphorylation level of CaMKII and increased expression level of endogenous mouse Gnao1 gene. These data suggest that increased cardiac expression of Gαo is sufficient to induce pathological Ca2+-dependent signaling and cardiac dysfunction, and that Gαo forms a positive regulatory circuit with CaMKII and NRSF.

Electrophysiological analysis in ventricular myocytes of dnNRSF-Tg revealed that impaired Ca2+ handling via alterations in localized L-type calcium channel (LTCC) activities; decreased T-tubular and increased surface sarcolemmal LTCC activities, underlies Gαo-mediated cardiac dysfunction.

Furthermore, we also identified increased expression of Gαo in ventricles of two different heart failure mice models, mice with transverse aortic constriction and mice carrying a mutant cardiac troponin T, and confirmed that genetic reduction of Gαo prevented the progression of cardiac dysfunction in both types of mice.

Conclusions

Increased expression of Gαo, induced by attenuation of NRSF-mediated repression forms a pathological circuit via activation of CaMKII. This circuit exacerbates cardiac remodeling and progresses heart failure by impairing Ca2+ homeostasis. Gαo is a potential therapeutic target for heart failure.

Figure 1

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Grants-in –Aid for Scientific Research from the Japan Society for the Promotion of Science

P1496Impact of electrical reverse remodeling by cardiac resynchronization therapy on adverse cardiac events in patients of heart failure with reduced ejection fraction

Background

Recently, structural reverse remodeling (SRR) and electrical reverse remodeling (ERR) after cardiac resynchronization therapy (CRT) have been reported in patients of heart failure with reduced ejection fraction (HFrEF). However the relationship between ERR and subsequent adverse cardiac events is still unknown. We aimed to elucidate the impact of ERR after CRT on the occurrence of heart failure events and ventricular arrhythmias.

Methods

A total of 36 HFrEF patients who underwent newly CRT implantation were investigated retrospectively. The intrinsic QRS duration (iQRSd) had been recorded before and more than 6 months after CRT implantation. Biventricular pacing was temporarily turned off during measurement of iQRSd. ERR was defined as positive shortening of iQRSd and SRR was defined as reduction of left ventricular end systolic volume by more than 15% after CRT implantation. The primary endpoint was a composite of all cause death, heart failure hospitalizations and ventricular tachyarrhythmia events.

Results

ERR was observed in 17 patients (47.2%) and SRR in 22 patients (61.1%). The group with ERR included more patients with lower NYHA class prior to CRT and patients with SRR. The primary endpoint was observed in 15 patients (51.4 %) for a median of 181 [63, 367] days during follow-up. Kaplan-Meier analysis revealed that the group without ERR was poor prognosis compared with the group with ERR (p = 0.022, Log-rank test).

Conclusion

Patients of HFrEF with ERR after CRT may have fewer adverse cardiac events such as worsening heart failure or ventricular arrhythmia events from this short-term study.

Abstract Figure. Adverse cardiac events and ERR

P1353Echocardiographic predictor of sick sinus syndrome following catheter ablation of persistent atrial fibrillation

Funding Acknowledgements

Abbott Medical Japan, Medtronic Japan, Boston Scientific Japan, Biotronic Japan, Japan Life Line

Background / Introduction

Although sick sinus syndrome(SSS) can be associated with atrial fibrillation(AF), predictive factors of SSS following catheter ablation(CA) of persistent atrial fibrillation(perAF) are not well known.

Purpose

We investigated echocardiographic parameters to predict occurrence of SSS after restoration of sinus rhythm by CA for perAF patients.

Methods

Ninety-eight consecutive perAF patients from June 2014 to May 2018 treated with CA were retrospectively reviewed. Twelve patients(12%, SSS group) developed SSS after successful CA and 86 patients(88%, non-SSS group) did not. Baseline characteristics, blood exam, and echocardiographic findings(RA area size, LA area size, EF, etc) before AF CA were analyzed using Student’s t test, Mann-Whitney test, Chi-square test and Univariate analysis. Multivariate logistic analysis was then performed using those parameters. The atrial area size was calculated from 4 chamber view at the atrial end- systole.

Results

The multivariate analysis for predictive factors of SSS is shown in the table. Right atrium(RA) area could predict SSS(17.3 ± 4.8cm2 vs. 14.7 ± 3.6cm2, odds ratio 1.468; 95% confidence interval 1.088 to 1.981, p = 0.012). Gender (female) was also an independent predictor(4/12 (33%) vs. 8/86 (9%), odds ratio 39.832; 95% confidence interval 2.589 to 612.938, p = 0.008). The other echocardiographical findings(LA area size, EF, etc), baseline characteristics and blood exam results were not related to SSS after successful CA of perAF patients.

Conclusions

The large RA area size and gender (female) could predict SSS in perAF patients after restoration of sinus rhythm by successful CA. We may need to inform possible SSS after CA to female patients with a large RA before CA.

Multivariate Logistic analysis Total(N = 98) SSS group (N = 12) Non SSS group (N = 86) Odds ratio 95% CI P-value Age 64(58-69) 68(60-72) 63(57-69) 1.032 0.929-1.145 0.560 Gender/Female 12(12%) 4(33%) 8(9%) 39.832 2.589-612.938 0.008 CKD 27(28%) 6(50%) 21(24%) 1.264 0.179-8.945 0.814 BNP 91(53-180) 206(167-304) 82(48-169) 1.003 0.993-1.012 0.609 RDW 45.1 ± 3.9 46.4 ± 4.8 44.9 ± 3.8 1.242 0.971-1.588 0.085 RA area 15.1 ± 3.8 17.3 ± 4.8 14.7 ± 3.6 1.468 1.088-1.981 0.012 LA area 24.2(17.0-24.9) 24.4(17.7-26.3) 24.1(16.8-24.4) 0.967 0.803-1.165 0.726 Right atrium area and gender were the independent predictor of SSS in persistent atrial fibrillation patients after restoration of sinus rhythm

P29 Arrest of progression of cardiac amyloidosis after chemotherapy predicts favorable outcome in patients with light-chain amyloidosis

Funding Acknowledgements

none

Background

Many studies demonstrated that cardiac involvement predicts poor prognosis in patients with systemic light-chain amyloidosis (AL). There is no data about the effect of the arrest of progression of cardiac amyloidosis on prognosis after chemotherapy.

Hypothesis

Arrest of progression of cardiac amyloidosis is associated with favorable outcome in patients with light-chain amyloidosis.

Methods

Among 126 consecutive patients with AL, we prospectively examined 94 patients serially after optimal therapy. The mean follow-up period was 1405 ± 1510 days (median value 734 days, inter quartile range 176-2343 days). Wall thickness was measured from left ventricular (LV) m-mode trace. We defined the cardiac involvement as mean LV wall thickness >12mm, and the regression or progression of cardiac amyloidosis as change in LV mean wall thickness >1mm.

Results

Among 94 patients with AL, 28 patients (30%) showed regression by definition above, 35 patients (37%) showed no interval change and 31 patients (33%) showed progression of cardiac amyloidosis. Survival analysis of 3 groups demonstrated that the regression and arrest of progression groups showed better outcome compared with the progression group (Log-rank test P < 0.0001).

Conclusions

The arrest of progression of cardiac amyloidosis predicts favorable outcome in patients with AL amyloidosis.

Abstract P29 Figure. Kaplan-Meier Curve of 3 groups

Development of an abdominal wall abscess caused by fish bone ingestion: a case report

Background

A small percentage of patients with foreign body ingestion develop complications, which have a variety of clinical presentations. Less than 1% of cases require surgical intervention. We present a patient with an abdominal wall abscess resulting from a fish bone that pierced the cecum. The patient was treated laparoscopically.

Case presentation

A 55-year-old Japanese man presented to our hospital with a complaint of right lower abdominal pain. A physical examination revealed tenderness, swelling, and redness at the right iliac fossa. Computed tomography showed a low-density area with rim enhancement in his right internal oblique muscle and a hyperdense 20 mm-long pointed object in the wall of the adjacent cecum. Based on the findings we suspected an abdominal wall abscess resulting from a migrating ingested fish bone. He was administered antibiotics as conservative treatment, and the abscess was not seen on subsequent computed tomography.

Two months after the initial treatment, he presented with the same symptoms, and a computed tomography scan showed the foreign body in the same location as before with the same low-density area. We diagnosed the low-density area as recurrence of the abdominal wall abscess. He underwent laparoscopic surgery to remove the foreign body. His appendix, and part of his cecum and the parietal peritoneum that included the foreign body, were resected. He had an uneventful postoperative course, and at 1 year after the surgery, the abdominal wall abscess had not recurred.

Conclusions

An abdominal wall abscess developed in association with the migration of an ingested fish bone. We suggest that a laparoscopic surgical resection of the portion of the bowel that includes the foreign body is a useful option for selected cases.

P943The impact of diabetes on patients with frail after endovascular treatments: from I-PAD registry

Background

Diabetes mellitus (DM) is known to be one of the risks of arteriosclerosis. However, it is still unknown whether DM is a risk factor also in secondary prevention of frail patients after endovascular treatments (EVT)

Purpose

To investigate impact of diabetes on patients with frail after EVT.

Methods

From July 2015 to July 2016, 371 consecutive PAD patients who performed EVT were enrolled in I-PAD registry. We could conduct follow up survey 361 patients (446 lesions) and divided into 2 groups; with diabetes (185 patients, 226 lesions) or without diabetes (176 patients, 220 lesions) and analyzed. And among them,we selected 96 patients with frail and divided into 2 groups; with diabetes (49 patients, 70 lesions) or without diabetes (46 patients, 58 lesions) and analyzed. We defined frail patients as the patients with Clinical Frailty Scale 5 (mild frail) or higher. The primary end point was all-cause-death and major adverse limb events (MALE: TLR, TVR, major amputations) at 1 year.

Result

At 1 years in the patients group with diabetes, overall survival and freedom from MALE were significantly lower (81.7% vs 95.8% P<0.0001; 80.0% vs 94.6%, P<0.0001) than the group without diabetes.Among the patients with frail, between the patients group with diabetes and the group without, there is no significant differences in overall survival and freedom from MALE (88.2% vs 88.9% P=0.83; 80.7% vs 84.1%, P=0.55) at 5 years.

Conclusion

The prognosis of patients with diabetes after EVT was worse than the patient without. On the other hand, the prognosis of frail patients with diabetes after EVT was no difference with the frail patient without diabetes in this study.

1136Prognostic impact of mineralocorticoid receptor antagonists in patients hospitalized for acute heart failure

Background

The favourable effect of mineralocorticoid receptor antagonists (MRAs) on mortality was established in patients with stable heart failure (HF) with reduced ejection fraction (EF). However, its prognostic effect of MRAs in acute decompensated heart failure (ADHF) including HF with preserved EF (HFpEF) was unclear.

Purpose

This study sought to investigate the long-term impact of MRA on the post-discharge outcomes in patients with ADHF.

Methods

From the consecutive 3717 patients hospitalized for ADHF and discharged alive in the KCHF registry, we developed the propensity score (PS) for MRA use and constructed the PS-matched cohort. We compared the effect of MRA use on the primary outcome measure of all-cause death or HF hospitalization.

Results

A total of 1678 patients (45%) received MRA at discharge from the index hospitalization. Median follow-up was 470 days with 96% 1-year follow-up rate. In the PS-matched cohort (N=1034 in each group), the cumulative 1-year incidence of the primary outcome measure was significantly lower in the MRA group than in the no MRA group (28.4% vs. 33.9%, P=0.003) (Figure 1). The cumulative 1-year incidence of HF hospitalization was significantly lower in the MRA group than in the no MRA group (18.7% vs. 24.8%, P<0.001), while there was no difference in mortality between the 2 groups (15.6% vs. 15.8%, P=0.85). There was no interaction between the effect of MRA and the 3 subgroups stratified by EF (EF <40%, EF 40–49%, EF ≥50%) (interaction P=0.12).

Figure 1

Conclusion

The use of MRA was associated with lower risk for the primary composite outcome of all-cause death or HF hospitalization in patients hospitalized for ADHF including HFpEF, which was mainly driven by the lower risk for HF hospitalization.

P942Impact of left ventricular ejection fraction in patients with critical limb ischemia: from I-PAD registry

Introduction

In patients with critical limb ischemia (CLI) it is known that malnutrition, low BMI, inflammation and so on are prognostic factors. But, it is unclear whether left ventricular ejection fraction (LVEF) affects prognosis of CLI patients. So we investigated that LVEF affects prognosis of CLI patients.

Methods

From July 2015 to July 2016, 371 consecutive peripheral artery disease patients who performed endovascular treatment (EVT) were enrolled in I-PAD registry. 179 of them were patients with CLI. We could conduct follow up survey about 126 (age 75.5±11.1, men 63.5%) and divided two groups according to their LVEF (group with LVEF≤40%, n=13, group without LVEF≤40%, n=113). The primary end point was major adverse limb events (MALE: TLR, TVR, major amputations) and secondary end point was all-cause death.

Results

The median follow-up period was 11.5±6.7 months. The 18 months MALE rate was significant higher in the group with low LVEF than group without low LVEF (76.9% vs 37.2% p<0.05). The 18months all-cause death tended to be higher in the group with low LVEF, however there was not statistical significance in the two groups (53.8% vs 24.8% p=0.09).

Conclusion

LVEF was associated with MALE in patients with CLI.

P780Superiority of long-acting to short-acting loop diuretics in the treatment of heart failure with preserved ejection fraction: a sub-analysis of the CURE-HF Registry

Introduction

Long-acting loop diuretics have a possibility of better prognosis compared to short-acting loop diuretics in patients with heart failure with preserved ejection fraction (HFpEF).

Purpose

To investigate the effect of long- and short-acting loop diuretics in patients with HFpEF.

Methods

From the Clue of Risk Stratification in Patients With Heart Failure Registry (CURE-HF Registry), we enrolled 301 consecutive patients with HFpEF (median age, 84 years; 55% female). Long-acting loop diuretics (azosemide) were administrated in 127 patients, and short-acting loop diuretics (furosemide) in 174 patients. We constructed Cox models for MACE (defined as a composite of all-cause death, non-fatal myocardial infarction, non-fatal stroke, and heart failure [HF] hospitalization).

Results

During a median follow-up of 317 [174–734] days, the primary endpoint occurred in 129 patients (42.8%). On multivariate inverse probability of treatment weighted (IPTW) Cox modeling, patients treated with long-acting loop diuretics had a significantly lower incidence of adverse events than those treated with short-acting loop diuretics (hazard ratio [HR], 0.39; 95% confidence interval [CI] 0.23–0.67; P=0.001). Furthermore, on multivariate IPTW Cox modeling for the secondary endpoints, all-cause mortality (HR, 0.50; 95% CI, 0.20–0.80; P=0.01) and unplanned hospitalization for decompensated HF (HR, 0.50; 95% CI, 0.28–0.89; P=0.018) were also reduced in patients treated with long-acting loop diuretics.

Conclusions

Long-acting loop diuretics reduced the risk of MACE compared to short-acting diuretics in patients with HFpEF.

P1957Impact of fraility on the super elderly patients with peripheral artery disease

Background

The current consensus is that frail patients have high risks of mortality. However, it remains unclear whether frailty is associated with mortality risks in super-elderly patients with peripheral artery disease (PAD).

Methods

The I-PAD registry was a prospective multicenter observational study involving 12 institutions in Nagano prefecture in Japan. From July 2015 to July 2016, the I-PAD registry enrolled 371 consecutive PAD patients who had undergone endovascular therapy (EVT). Among them, we selected and analysed 109 PAD patients who were >80 years old when they had undergone EVT and divided them into two groups: those with frailty (Clinical Frailty Scale≥5, n=47) and those without frailty (Clinical Frailty Scale≤4, n=62). The primary endpoints were overall survival and major adverse limb events (MALE), defined as a composite of all-cause death, major amputation and revascularization.

Results

The median follow-up period was 1.58±0.3 years. Overall, 109 patients with a mean age of 84.8±4.0 years, of whom 63.3% were men, were included. Overall survival and freedom from MALE were significantly lower among patients with frailty than among those without frailty (60.5% vs. 91.6%, P<0.001; 51.4% vs. 87.5%, P<0.001; respectively).

Conclusion

The prognosis of super-elderly patients with frailty is worse than that of patients without frailty.

P936Impact of left ventricular ejection fraction in patients with peripheral artery disease: from I-PAD registry

Introduction

In patients with peripheral artery disease (PAD) it is known that CVD is one of prognostic factors. But, it is unclear whether left ventricular ejection fraction (LVEF) affects prognosis of PAD patients. So we investigated that LVEF affects prognosis of PAD patients.

Methods

From July 2015 to July 2016, 371 consecutive PAD patients who performed endovascular treatment (EVT) were enrolled in I-PAD registry. We could conduct follow up survey about 337 (age 73.8±9.6, men 72.4%) patients and divided two groups according to their LVEF (group with LVEF≤40%, n=18, group without LVEF≤40%, n=319). The primary end point was major adverse limb events (MALE: TLR, TVR, major amputations) and secondary end point was all-cause death.

Results

The median follow-up period was 13.6±5.7 months. The 18 months MALE and all-cause death rate were significantly higher in the group with low LVEF than group without low LVEF (61.1% vs 21.6% p<0.001, 44.4% vs 11.6% p<0.001).

Conclusion

LVEF was significantly associated with MALE and all-cause death in patients with PAD.

4968Increased Gao expression underlies cardiac dysfunction and lethal arrhythmias accompanied with abnormal Ca2+ handling

Background

We previously demonstrated that a transcriptional repressor, neuron restrictive silencer factor (NRSF), maintains normal cardiac function and electrical stability. Transgenic mice expressing a dominant-negative mutant of NRSF in their hearts (dnNRSF-Tg) exhibit systolic dysfunction with cardiac dilation and premature death due to lethal arrhythmias like human dilated cardiomyopathy (DCM). Underlining mechanisms remain to be elucidated, however.

Purpose

We studied underling mechanisms by which NRSF maintains normal cardiac function to identify novel therapeutic targets for heart failure.

Methods and results

We generated cardiac-specific NRSF knockout mice (NRSFcKO) and confirmed that cardiac phenotypes of NRSFcKO are similar to those of dnNRSF-Tg.

cDNA microarray analysis revealed that cardiac gene expression of GNAO1 that encodes Gαo, a member of inhibitory G protein Gαi family, is increased in both dnNRSF-Tg and NRSFcKO ventricles.

We confirmed that GNAO1 is a direct target of NRSF through ChIP-seq analysis, reporter assay and electrophoretic mobility shift assay.

In dnNRSF-Tg, pharmacological inhibition of Gαo with pertussis toxin improved systolic dysfunction and knockdown of Gαo by crossing with GNAO1 knockout mice improved not only systolic function but also frequency of ventricular arrhythmias and survival rates.

Electrophysiological and biochemical analysis in ventricular myocytes obtained from dnNRSF-Tg demonstrated that genetic reduction of Gαo ameliorated abnormalities in Ca2+ handling, which include increased current density in surface sarcolemmal L-type Ca2+ channel, reduced content of sarcoplasmic reticulum Ca2+ and lowered peak of Ca2+ transient. Furthermore, genetic reduction of Gαo attenuated increased phosphorylation levels of CAMKII in dnNRSF-Tg ventricles, which presumably underlies the improvement in Ca2+ handling. In addition, we identified increased Gαo expression in ventricles of heart failure model mice induced by transverse aortic constriction and cardiac troponin T mutant DCM model mice, in both of which, genetic reduction of Gαo ameliorated cardiac dysfunction.

Figure 1

Conclusions

We found that increased expression of Gαo, induced by attenuation of NRSF-mediated repression, plays a crucial role in the progression of cardiac dysfunction and lethal arrhythmias by evoking Ca2+ handling abnormality. These data demonstrate that Gαo is a potential therapeutic target for heart failure.

P1809Impact of mitral regurgitation on clinical outcome in patients with cardiac sarcoidosis

Background

Mitral regurgitation (MR) is sometimes observed in cardiac sarcoidosis (CS), and might be related to worsening heart failure. However, mechanism and clinical significance of MR associated with CS remains undetermined.

Methods

We retrospectively analyzed consecutive 51 CS patients, and identified 16 patients with moderate to severe MR evaluated by quantitative echocardiography. According to the assessment of coaptation point and tenting height, main mechanisms of the 16 patients with MR were classified into prolapse (P) in 5, and tethering in 11 (T). Prednisolone was started from 30 mg/day, gradually tapered over a period of 6 months to a maintenance dose of 5 to 10 mg/day and continued a lifetime.

Results

At the first visit, patients with MR showed higher incidence of NYHA class IV heart failure as compared to those without MR (56 vs. 9%, p<0.001). Abnormal uptake of fluorine-18 fluorodeoxyglucose in the papillary muscle was more frequent in patients with MR than those without MR (63% vs. 23%, p<0.05). Patients with tethering MR showed higher incidence of complete atrioventricular block (T: 74% vs. P: 40% vs. without MR: 31%, p<0.05), significantly reduced left ventricular (LV) ejection fraction (T: 33±7% vs. P: 52±9% vs. without MR: 52±16%, p<0.001) and increased LV end-diastolic volume index (T: 100±52ml/m2 vs. P: 66±23ml vs. without MR: 62±21ml, p<0.001). During the mean follow-up of 108 months, cardiac-event free survival was significantly worse in patients with tethering MR as compared to the other patients (log-rank; 11.7, p<0.001). Six of the 11 patients with tethering MR received cardiac resynchronization therapy, and then did not experience further hospitalization due to decompensated heart failure for at least 2 years. Multivariate analysis identified tethering MR as an independent predictor of cardiac event (HR: 6.7, p<0.05).

Conclusions

MR associated with CS has variety of mechanisms including prolapse, tethering and inflammation of the LV papillary muscle, and may be related to ventricular remodeling and poor clinical outcome.

P2696Clinical characteristics of late catch-up phenomenon after implantation of 2nd generation drug eluting stent

Introduction

Late catch-up phenomenon (LCU) of 1st generation drug eluting stent (DES) has been increasing yearly despite the rate of restenosis in 1 year has reduced compared with bare metal stent (BMS). 2nd generation DES was more improved than 1st generation DES and suggested more benefits about clinical outcome.

Purpose

To investigate the incidence and predictor of LCU after implantation of 2nd generation DES and to evaluate the association between LCU phenomenon and adverse events.

Methods

Between August 2012 and July 2013, a total of 1665 consecutive patients (1956 lesions with elective/urgent PCI) were enrolled in SHINANO 5 years Registry (a prospective observational multicenter cohort study) from 13 institutions in Nagano, Japan. 711 patients that were treated with 2nd generation DES and 576 patients with BMS were selected. Exclusion criterias were cases of 1st DES, only POBA, only aspiration and chronic total occulusion.

Results

There were significant difference about patients background between BMS and 2nd generation DES groups. Those groups were matched with propensity score. After matching, 822 patients (BMS group 411 patients, 2nd generation group 411 patients) were analyzed. The rates of 2nd DES and BMS restenosis 5 years after initial PCI were 9.2% and 8.5% (p=0.572), those of LCU were 2.6% and 5.6% (p=0.043) by 1 year landmark analysis. Cox proportional hazards analysis revealed that the DES in-stent restenosis (ISR) lesion and higher HbA1c were independent predictors for LCU from 1year to 5year (HR 5.304, p=0.009, HR 1.254, p=0.015), but 2nd generation DES was not. Kaplan Meier curve showed no association between LCU phenomenon and all cause death (p=0.446). Cox regression analysis showed LCU was not independent predictor for all cause death (p=0.414).

Conclusions

Implantation to DES-ISR lesion with 2nd generation DES was associated with higher LCU. Despite of more complex lesions with 2nd generation DES, there were no differences of LCU incidence between 2nd generation DES and BMS.

Acknowledgement/Funding

None

Effect of steroid hormones on the innate immune response induced by Staphylococcus aureus in the goat mammary gland

The objective of this study was to compare the dynamics of innate immune components after intramammary infusion of Staphylococcus aureus (SA) under conditions of high oestrogen and high progesterone in goats. In one group ("E-group"), controlled internal drug release (CIDR) devices were inserted intravaginally from days -11 to -4. Prostaglandin F2α was administered immediately after removal of the CIDR device at day -3, and then oestradiol benzoate (E) was injected intramuscularly once a day from days -2 to 3. Heat-inactivated SA was then administered via intramammary infusion to the left udder at day 0, whilst only saline was infused to the right udder as a control. In a second group ("P-group"), CIDR devices were inserted intravaginally from days -3 to 7 and SA was infused at day 0 in the same way as in the E-group. The milk yield and the concentration of innate immune components (somatic cell count (SCC), lactoferrin (LF), S100A7 and goat ß-defensin 1 (GBD-1)) in the milk were measured. Milk yield decreased drastically in both SA and control udders in the E-group, whereas the P-group exhibited increased milk yield in both SA and control udders. SCC increased after SA infusion in both E- and P-groups, although it was higher in the E-group than in the P-group. There was no significant change in LF concentration in the E-group, but a decrease was observed in the P-group. Concentrations of S100A and GBD-1 were significantly increased after SA infusion in the E-group but not in the P-group. These results suggest that E enhances the innate immune response induced by SA in the goat mammary gland. This effect may be due to the reduction in milk yield and upregulation of innate immune components.

Abstract P5-09-07: Impact of germinalcenter-associated nuclear protein polymorphisms on breast cancer risk and prognosis in a Japanese population

Background: Germinal center-associated nuclear protein (GANP) is a phosphoprotein which is involved in mRNA export and the regulation of DNA recombination. We have previously demonstrated that deficiency of GANP led to spontaneous development of mammary gland tumors in a mouse model. In addition, we found that decreased GANP expression in human breast cancer tissue was an independent prognostic factor. Here, we conducted a case-control study and a retrospective cohort study to investigate whether single nucleotide polymorphisms (SNPs) of GANP are associated with sporadic breast cancer risk and prognosis in a Japanese population.

Subjects and Methods: Six hundred-ninety-four breast cancer cases and 1,376 age- and menopausal status-matched controls were selected within the framework of the Hospital-based Epidemiologic Research Program at Aichi Cancer Center. Cases and controls were genotyped using an Infinium iSelect custom array (iCOGS, Illumina Inc., San Diego, CA, USA). We assessed 13 SNPs at the GANP locus, 2 SNPs (rs2839178 and rs11702450) were selected for further analysis by considering linkage disequilibrium. Conditional logistic regression methods were used to estimate odds ratios (ORs) and 95% confidence intervals. In addition, the survival impact of the two SNPs was retrospectively analyzed using the 694 breast cancer cases. To evaluate the effect of SNPs on overall survival (OS) and disease-free survival (DFS), multivariate Cox proportional hazards modeling was applied.

Results: Compared to the AA genotype of rs2839178, the GG genotype showed statistically significant associations with breast cancer risk (OR: 0.48, 95%CI:0.30–0.76, P = 0.002). In prognostic analysis, compared to those with the genotype AA at rs2839178, patients with AG or GG showed longer DFS (HR: 0.71, 95%CI: 0.49–1.04 and 0.42, 0.13–1.42, respectively, P for trend = 0.04). The GG genotype of rs2839178 also showed a positive tendency for longer OS although it was not statistically significant (HR: 0.69, 95%CI: 0.44–1.08, P = 0.11). We did not find that rs11702450 was associated with either breast cancer risk or prognosis.

Conclusion: This is the first study to investigate the association between GANP SNPs and breast cancer risk and prognosis. The direction of association with DFS was consistent with that of susceptibility. These results demonstrate that GANP SNPs presumably prevent the occurrence and malignant advancement of sporadic breast cancers.

Citation Format: Kotani H, Ito H, Kuwahara K, Kuzushima K, Iwata H, Tsunoda N, Nagino M, Tanaka H, Matsuo K. Impact of germinalcenter-associated nuclear protein polymorphisms on breast cancer risk and prognosis in a Japanese population [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-09-07.

Field-induced spin-density wave beyond hidden order in URu2Si2

URu₂Si₂ is one of the most enigmatic strongly correlated electron systems and offers a fertile testing ground for new concepts in condensed matter science. In spite of >30 years of intense research, no consensus on the order parameter of its low-temperature hidden-order phase exists. A strong magnetic field transforms the hidden order into magnetically ordered phases, whose order parameter has also been defying experimental observation. Here, thanks to neutron diffraction under pulsed magnetic fields up to 40 T, we identify the field-induced phases of URu₂Si₂ as a spin-density-wave state. The transition to the spin-density wave represents a unique touchstone for understanding the hidden-order phase. An intimate relationship between this magnetic structure, the magnetic fluctuations and the Fermi surface is emphasized, calling for dedicated band-structure calculations.

The strongly-correlated electron system URu₂Si₂ possesses a hidden-order phase whose order parameter remains unidentified. Here, the authors demonstrate the development of spin-density-wave phases in URu₂Si₂ under high magnetic fields, providing a potential in-road to understanding this system.

Abstract P3-06-14: DSS1 depletion is a promising strategy increasing chemosensitivity possibly independent of BRCA2 expression

Background

DSS1 (deleted in split-hand/split-foot malformation 1) was originally identified as a BRCA2-associated protein, and its downregulation results in the degradation of BRCA2. Some reports demonstrated that BRCA2 overexpression was correlated with histopathological grade III in sporadic breast cancers, implicating the involvement of BRCA2 overexpression in the proliferation rate of breast cancer cells. Because DSS1 is a stabilizer of BRCA2, we investigated whether altered expression of DSS1 was associated with malignant advancement of sporadic breast cancers. By comparison of DSS1 mRNA level, we reported that the high DSS1 expression groups in breast cancer patients showed worse prognosis in relapse-free survival; however, DSS1 expression per se was not correlated with other clinical parameters including cellular proliferation or tumor grade. Therefore, we hypothesized that breast cancer cells highly expressing DSS1 might be resistant to anti-cancer drugs, and compared chemosensitivity in overexpression or underexpression of DSS1 in breast cancer cells.

Methods

We established MCF7 overexpressing DSS1 (MCF7/DSS1) by retroviral transfection. DSS1 or BRCA2 knockdown in MCF7 was performed using siRNA transfection. The susceptibility to the cytotoxic chemotherapy such as doxorubicin and paclitaxel in breast cancer cells was analyzed by flow cytometry to detect apoptosis.

Results

MCF7/DSS1 showed more resistant to cytotoxic drugs compared with GFP-control MCF7 transfectants (MCF7/GFP). The percentages of apoptotic cells in MCF7/DSS1 and MCF7/GFP treated by doxorubicin were 40.2% and 12.0%, respectively. Conversely, depletion of DSS1 in breast cancer cells resulted in enhanced chemosensitivity compared to control cells. Although DSS1 knockdown induced the downregulation of BRCA2, BRCA2 depletion itself did not show such enhancement of chemosensitivity.

Conclusion

Consistent with the cohort study of sporadic breast cancers, we demonstrated that high expression of DSS1 increased resistance of breast cancer cells to cytotoxic chemotherapy in vitro. Conversely, DSS1 knockdown increased the susceptibility to these drugs in spite that BRCA2 depletion did not affect chemosensitivity. These results indicate that DSS1 could be a molecular target to increase chemosensitivity, which is independent of BRCA2 expression.

Citation Format: Gondo N, Rezano A, Kuzushima K, Iwata H, Kuwahara K. DSS1 depletion is a promising strategy increasing chemosensitivity possibly independent of BRCA2 expression. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P3-06-14.

Magnetic structure of phase II in U(Ru(0.96)Rh(0.04))2Si2 determined by neutron diffraction under pulsed high magnetic fields

We report neutron diffraction measurements on U(Ru(0.96)Rh(0.04))(2)Si(2) single crystal under pulsed high magnetic fields up to 30 T applied along the tetragonal c axis. The high-field experiments revealed that the field-induced phase II above 26 T corresponds to a commensurate up-up-down ferrimagnetic structure characterized by the wave vector q=(2/3,0,0) with the magnetic moments parallel to the c axis, which naturally explains the one-third magnetization plateau and the substantially changed Fermi surface in phase II. This a-axis modulated magnetic structure indicates that the phase II near the hidden order phase is closely related to the characteristic incommensurate magnetic fluctuations at Q(1)=(0.6,0,0) in the pure system URu(2)Si(2), in contrast to the pressure-induced antiferromagnetic order at Q(0)=(1,0,0).

Molecular mechanism of immunoglobulin V-region diversification regulated by transcription and RNA metabolism in antigen-driven B cells

The immune system produces specific antibodies (Ab) against any antigens (Ag) of exogenous and endogenous origins with a diverse repertoire of V-region specificities. The primary V-region repertoire is created by the rearrangement of immunoglobulin (Ig) V-region, D- and J-segments with the insertion of N- and P-sequences during early B cell differentiation. Recent studies revealed that secondary diversification of the IgV-region generated in the peripheral lymphoid organs plays a critical role in the generation of effective Ab production for protection from various pathogens. Naïve B cells that react with Ags initiate proliferation and differentiation in the follicular region and create the germinal centres (GCs), where activation-induced cytidine deaminase (AID)-dependent IgV-region somatic hypermutation (SHM) and class-switch recombination generate high-affinity and class-switched mature Ag-specific B cells. Our studies have discovered a 210-kDa nuclear protein, named GC-associated nuclear protein (GANP) that is up-regulated in GC B cells during the T cell-dependent (TD) immune responses. By studying mice with mutant forms of the ganp gene, we demonstrated that GANP is essential for the generation of high-affinity B cells against TD-Ag by affecting SHM at the IgV-regions. GANP is associated with AID in the cytoplasm and the GANP/AID complex is recruited to the nucleus, specifically, the chromatin, and targeted selectively to the IgV-region gene in B cells. GANP augments the access of AID towards IgV-regions in B cells. Here, we review the role of GANP in acquired immunity through the detailed analysis of the molecular mechanism generating SHM specifically at IgV-regions in B cells.

Materials Aspects of Oxide Superconductors - Effect of Ambient Water on Superconductivity-

It has been found that the chemical instability of Ba2LnCu3O7 causes some problems in the measurements of critical temperature and creates a highly resistive grain boundary contact which is the major cause of the low critical current density at the present moment. Firstly, measurements of the superconductive critical temperature could be seriously misled if based solely on resistive transition because apparent resistivity anomaly is observed due to electrochemical EMF which appears when the electrode contact is attacked by water. Secondly, the barrier nature of the grain boundary against charge carriers is significantly enhanced by the chemical attack of the boundary region with water and water/carbon dioxide in the annealing atmosphere. This leads to a further weakening of the Josephson weak link between polycrystalline grains in the high Tc oxide superconductors.

Angiotensin II type 1 receptor-independent beneficial effects of telmisartan on dietary-induced obesity, insulin resistance and fatty liver in mice

AIMS/HYPOTHESIS

Evidence suggests that telmisartan, an angiotensin II type 1 receptor (AT1) blocker and peroxisome proliferator-activated receptor-gamma partial agonist, has beneficial actions that limit development of the metabolic syndrome and diabetes. However, the role played by AT1 inhibition in metabolic effects elicited by telmisartan remains uncertain. Here we isolated the metabolic effects of telmisartan from AT1 antagonism.

METHODS

Male At1a (also known as Agtr1a)-deficient mice were fed a standard diet or 60% high-fat diet; those on high-fat diet were co-administered telmisartan (3 mg kg(-1) day(-1) by oral gavage) or vehicle for 12 weeks.

RESULTS

In At1a-null mice, telmisartan prevented high-fat-diet-induced increases in (1) body weight, epididymal and inguinal white adipose tissue weight, adipocyte size and plasma leptin concentration; (2) plasma glucose and insulin concentrations and HOMA index; and (3) liver weight and triacylglycerol content. Insulin tolerance testing also indicated that telmisartan improved the high-fat-diet-induced reduction of glucose-lowering by insulin.

CONCLUSIONS/INTERPRETATION

The present findings demonstrate beneficial, AT1-independent effects of the AT1 blocker telmisartan on dietary-induced obesity, insulin resistance and fatty liver in animals.

Vasodilator therapy with hydralazine induces angiotensin AT receptor-mediated cardiomyocyte growth in mice lacking guanylyl cyclase-A

BACKGROUND AND PURPOSE

Recent clinical guidelines advocate the use of the isosorbide dinitrate/hydralazine combination in treatment for heart failure. However, clinical and laboratory evidence suggest that some vasodilators may induce cardiac hypertrophy under uncertain conditions. This study investigated the effects and underlying mechanism of action of the vasodilator hydralazine on cardiac growth.

EXPERIMENTAL APPROACH

Wild-type mice and animals deficient in guanylyl cyclase-A (GCA) and/or angiotensin receptors (AT(1) and AT(2) subtypes) were treated with hydralazine ( approximately 24 mg.kg(-1).day(-1) in drinking water) for 5 weeks. Cardiac mass and/or cardiomyocyte cross-sectional area, fibrosis (van Giessen-staining) and cardiac gene expression (real-time RT-PCR) were measured.

KEY RESULTS

Hydralazine lowered blood pressure in mice of all genotypes. However, this treatment increased the heart and left ventricular to body weight ratios, as well as cardiomyocyte cross-sectional area, and cardiac expression of atrial natriuretic peptide mRNA in mice lacking GCA. Hydralazine did not affect cardiac hypertrophy in wild-type mice and mice lacking either AT(1) or AT(2) receptors alone. However, the pro-hypertrophic effect of hydralazine was prevented in mice lacking both GCA and AT(2), but not GCA and AT(1) receptors. However, hydralazine did decrease cardiac collagen deposition and collagen I mRNA (signs of cardiac fibrosis) in mice that were deficient in GCA, or both GCA and AT(2) receptors.

CONCLUSIONS AND IMPLICATIONS

The vasodilator hydralazine induced AT(2) receptor-mediated cardiomyocyte growth under conditions of GCA deficiency. However, attenuation of cardiac fibrosis by hydralazine could be beneficial in the management of cardiac diseases.

Excitation spectrum of PrOs(4)Sb(12) under a magnetic field

The evolution of the magnetic excitation spectrum of the heavy fermion superconductor PrOs(4)Sb(12) was studied by inelastic neutron scattering on crossing the critical field H(c2) for superconductivity at low temperature. The peak positions in energy and the peak intensities of the modes of the triplet split by magnetic field confirm the known crystal field parameters for PrOs(4)Sb(12) in T(h) symmetry. A selective broadening of the lineshape occurs on increasing the magnetic field: the linewidth of the upper mode of the triplet increases while the one of the middle mode does not.