Different contribution of sympathetic nerve activity to arterial velocity pulse index in hypertensive patients with and without diastolic dysfunction

Introduction

Left ventricular diastolic dysfunction (LVDD) is the main cause of heart failure with preserved ejection fraction (HFpEF). LVDD is related not only to arterial stiffness but also sympathetic nerve activity (SNA). Recent study demonstrated that increased muscle sympathetic nerve activity (MSNA) may be one of contributing factor for arterial stiffness. In clinical practice, Cardio-ankle vascular index (CAVI) provides a reproducible index of arterial stiffness, independent of blood pressure (BP). Recently, Arterial Velocity pulse Index (AVI), which is an index of arterial reflected waves, have been proposed as new index of arterial stiffness. We reported that AVI was associated with MSNA in hypertensive (HT) patients. However, it is still uncertain the effect of LVDD on the association between AVI and SNA in HT patients. Thus, we tested the hypothesis that AVI would be increased and related to MSNA in HT patients with LVDD.

Methods

Patients with essential HT subjects were included in this study. HT was diagnosed as systolic blood pressure (SBP) ≥140mmHg or diastolic blood pressure (DBP) ≥90mmHg. Patients with secondary HT was excluded. AVI was measured from left upper arm by NAS-1000 (Nihon Koden, Japan). CAVI was measured by VaSera VS-1500A (Fukuda Denshi, Japan). Transthoracic echocardiography was performed by trained sonographers. SNA was evaluated by direct recording of MSNA from peroneal nerves.

Results

25 HT patients were included (age 63±14 years, Male/Female 9/16). They were divided into two groups according to E/e' (no LVDD group, E/e' ≤9, N=12; LVDD group, E/e' >9, N=13). There were no significant differences between no LVDD and LVDD groups in age (63±9 vs 69±9 years p=0.205), body mass index (23±3 vs 24±4 p=0.355), BP (SBP 139±16 vs 144±20mmHg p=0.524, DBP 87±15 vs 78±14mmHg p=0.167). LV Ejection Fraction (EF) and Stroke Volume (SV) did not differ between two groups (EF 66±7 vs 69±6% p=0.471, SV 58±7 vs 62±14ml p=0.599). MSNA had tendency to increase in LVDD group compared to no LVDD group (MSNA 53±10 vs 44±12 bursts/100 heartbeats, p=0.052). Contrary to our hypothesis, AVI and CAVI did not differ between two groups (AVI 27±7 vs 29±7 p=0.398, CAVI 8.7±1.4 vs 8.6±1.4 p=0.894). However, a significant correlation was seen between AVI and MSNA in no LVDD group (r=0.57, p<0.05), but no correlation in LVDD group. There is no correlation between CAVI and MSNA in no LVDD and LVDD group. Significant relationship was observed between AVI and CAVI in LVDD group (r=0.61, p<0.05), but no relationship in no LVDD group.

Conclusion

AVI was significantly associated with MSNA in HT patients without LVDD, but not with LVDD. CAVI was related to AVI in HT patients with LVDD, but not without LVDD. MSNA was slightly increased in HT patients with LVDD compared to without LVDD. These results indicate that augmented SNA could contribute to the increase in arterial stiffness in HT patients without LVDD, however, this contribution might be attenuated in HT patients with LVDD.

Funding Acknowledgement

Type of funding sources: None.

Effect of pulmonary vein isolation on left atrial remodeling and muscle sympathetic nerve activity in patients with atrial fibrillation

Background

Catheter ablation (CA) for atrial fibrillation (AF) improves left ventricular function and induces left atrium reverse remodeling (LARR). CA is also associated with the modulation of ganglionated plexi in the left atrium (LA), including stretch-sensitive sympathetic and parasympathetic nerve mechanoreceptors. Increased filling pressure and enlargement of LA stimulate stretch-sensitive sympathetic nerve mechanoreceptors in heart failure, which contribute augmented sympathetic nerve activity. However, little is known about an effect of CA on the interaction between the changes of LARR and sympathetic nerve activity.

Purpose

To test the hypothesis that CA induce the reduction in sympathetic nerve activity in accordance with LARR in patients with atrial fibrillation.

Methods

This study was conducted as a retrospective, observational study. Twenty-eight AF patients (65.4±12.1 years old) were included in this study. We measured mean blood pressure (BP), heart rate (HR), brain natriuretic peptide (BNP), and direct recording of muscle sympathetic nerve activity (MSNA) using microneurography technique before and 12 weeks after CA. Echocardiogram was also performed to assess LARR and left ventricular function. To evaluate the interaction between LARR and MSNA, AF patients were divided into two groups by presence (LARR group; n=18) and absence (no LARR group; n=10) of LARR according to left atrium volume index (LAVi) following CA.

Results

No significant differences were observed at baseline in BP, MSNA and LAVi between two groups. BP did not change significantly after CA in both groups. HR significantly increased in the LARR group (63.1±5.7 vs 69.9±7.8, p<0.01) compared to no LARR group. CA significantly reduced MSNA in the LARR group (37.8±10.1 vs 24.9±8.8 bursts/min, p<0.01), but there was no significant change in the no LARR group. The septal E/e' ratio (11.3±3.8 vs 9.8±2.9, p<0.05), left ventricular end-systolic volume index (LVESVi) (24.4±11.9 vs 19.6±7.8 ml/m2, p<0.05) and Ln BNP (4.0±1.2 vs 3.3±1.0 log/pg/ml, p<0.05) were also significantly improved in the LARR group. On the other hand, in the no LARR group, there were no significancy in the changes of the septal E/e' ratio, LVESVi and Ln BNP. LVEF was not significantly changed in both two groups.

Conclusion

Our study shows CA reduced MSNA accompanied by LARR in AF patients. The reduction in MSNA, septal E/e' ratio, LVESVi and Ln BNP were all more pronounced in the LARR group compared to the no LARR group. These findings suggest that LARR is associated with the reduction in MSNA in AF patients, which was attributed to CA-induced modulation of stretch-sensitive sympathetic nerve mechanoreceptors.

Funding Acknowledgement

Type of funding sources: None.

Age differences in the association between arterial velocity pulse index and muscle sympathetic nerve activity in hypertensive patients

Background

Increased arterial stiffness characterize by aging. It is reported that age-related increases in muscle sympathetic nerve activity (MSNA) may be one of contributing factor for arterial stiffness. Arterial reflected wave was composed of SNA and aging. Increased arterial reflected wave partly plays an important role in blood pressure. Recently, we reported that arterial velocity pulse index (AVI), a novel index of arterial reflected waves, was associated with MSNA in hypertensive patients. It is still uncertain the effect of age on the association between AVI and SNA in hypertensive patients.

Method

Patients with essential HT and matched non-hypertensive control subjects were included in this study. HT was diagnosed as systolic blood pressure (SBP) ≥140 mmHg or diastolic blood pressure (DBP) ≥90 mmHg. AVI was measured from left upper arm by NAS-1000. SNA was evaluated by direct recording of muscle sympathetic nerve activity (MSNA) from peroneal nerves.

Results

45 HT patients and 46 control subjects were included. Age, SBP and DBP were significantly increased in HT group compared to control (Age 63±14 vs 42±16 years, p<0.001; SBP 144±16 vs 115±9 mmHg, p<0.001; DBP 80±14 vs 67±9 mmHg, p<0.001). MSNA and AVI were significantly increased in HT group compared to control (MSNA 34±10 vs 25±8 bursts/min, p<0.05; AVI 28±9 vs 17±5, p<0.05). AVI was significantly correlated with MSNA, age, and SBP in HT group. HT group was divided into two groups according to their age (group 1, age ≤63 N=21, group 2, age ≥64 N=26). AVI in group 1 showed correlation with MSNA (r=0.59, p<0.05), but no correlation was seen in group 2. However excluded SBP>160 mmHg subjects in group 2, significant correlation was clarified between AVI and MSNA (r=0.62, p<0.05).

Conclusion

The relationship between AVI and MSNA in HT patients is preserved regardless of aging, however, high blood pressure over 160mmHg might obscure its correlation. These results indicate that AVI is useful to estimate sympathetic nerve activity in high aging HT patient treated <160 blood pressure.

Funding Acknowledgement

Type of funding sources: None.

Roles of cytokines and T cells in the pathogenesis of myasthenia gravis

Myasthenia gravis (MG) is characterized by muscle weakness and fatigue caused by the presence of autoantibodies against the acetylcholine receptor (AChR) or the muscle-specific tyrosine kinase (MuSK). Activated T, B and plasma cells, as well as cytokines, play important roles in the production of pathogenic autoantibodies and the induction of inflammation at the neuromuscular junction in MG. Many studies have focused on the role of cytokines and lymphocytes in anti-AChR antibody-positive MG. Chronic inflammation mediated by T helper type 17 (Th17) cells, the promotion of autoantibody production from B cells and plasma cells by follicular Th (Tfh) cells and the activation of the immune response by dysfunction of regulatory T (T_reg ) cells may contribute to the exacerbation of the MG pathogenesis. In fact, an increased number of Th17 cells and Tfh cells and dysfunction of T_reg cells have been reported in patients with anti-AChR antibody-positive MG; moreover, the number of these cells was correlated with clinical parameters in patients with MG. Regarding cytokines, interleukin (IL)-17; a Th17-related cytokine, IL-21 (a Tfh-related cytokine), the B-cell-activating factor (BAFF; a B cell-related cytokine) and a proliferation-inducing ligand (APRIL; a B cell-related cytokine) have been reported to be up-regulated and associated with clinical parameters of MG. This review focuses on the current understanding of the involvement of cytokines and lymphocytes in the immunological pathogenesis of MG, which may lead to the development of novel therapies for this disease in the near future.

Novel index of arterial reflected waves, Arterial Velocity pulse Index, relates to muscle sympathetic nerve activity independent of Arterial Pressure volume Index in patients with hypertension

Background

Arterial reflected wave is determined by not only atherosclerosis but also sympathetic nerve activity. Recently, Arterial Velocity pulse Index (AVI), which is an index of arterial reflected waves, and Arterial Pressure volume Index (API), which is an index of volume of a conductive blood vessel, have been proposed as new index of arterial stiffness. However, it is unclear whether API and AVI would be associated with muscle sympathetic nerve activity (MSNA) in hypertensive subjects.

Purpose

The purpose of this study was to evaluate the correlation between AVI, API and MSNA in hypertensive subjects.

Method

41 hypertensive patients and 40 non-hypertensive subjects were included in this study. We performed a cross-sectional, observational study. Hypertension (HT) was defined as systolic blood pressure (SBP) ≥140 mmHg, diastolic blood pressure (DBP) ≥90 mmHg or medical treatment for HT. AVI and API was measured by NAS-1000 (Nihon Koden, Japan). MSNA, central sympathetic outflow to peripheral muscle, was recorded directly from peroneal nerve. MSNA was expressed by burst frequency (bursts/minute) and burst incidence (bursts/100heartbeats). Blood pressure, heart rate and MSNA were recorded simultaneously.

Results

Age, systolic and diastolic pressure were significantly higher in hypertensive patients compared to control (40±15 vs 61±13 years, p<0.001; 142±16 vs 113±9 mmHg, p<0.001; 81±14 vs 67±9 mmHg, p<0.001). MSNA and AVI were significantly augmented in hypertensive patients compared to control (34±11 vs. 23±6 bursts/min, p<0.05; 26±7 vs. 16±4, p<0.05). AVI was correlated with MSNA in each group (hypertension: r=0.59, P<0.001, non-hypertension: r=0.51, p<0.001). However, no correlation was shown between API and MSNA in each group (hypertension: r=0.22, p=0.15, non-hypertension: r=0.07, p=0.63). Multiple regression analysis also showed MSNA was significantly related with AVI but was not with API.

Conclusion

Our finding showed that AVI relates to MSNA independent of API in patients with hypertension. It suggested that Novel index of arterial reflected waves, AVI, is helpful to estimate augmented SNA in hypertensive subjects regardless of volume of a conductive blood vessel.

Funding Acknowledgement

Type of funding source: None

P2850Time to isolation guided hot balloon ablation for pulmonary vein isolation

Background

One disadvantage of hot balloon ablation (HBA) system is that real time monitoring of pulmonary vein (PV) potential is technically impossible. Therefore, the optimal radiofrequency-generated thermal energy application duration and application number are not completely established.

Purpose

The aim of this study is to evaluate the utility of 2Fr 4-electrode unidirectional catheter inserted into PV along with HB for real time monitoring of PV potential and investigate the time to isolation (TTI) guided optimal application strategy for HB based PV isolation in the acute phase.

Methods

We evaluated 23 consecutive patients who performed PV isolation using HBA system. Real time monitoring of PV potential was performed by 2Fr 4-electrode unidirectional catheter inserted into PV along with HB (Figure1A). After HBA applications, PV isolation was validated by high-resolution mapping with the 20-pole steerable mapping (PENTARAY) catheter as a standard. PV potentials during HBA application were categorized into five patterns. PV potentials disappeared during HBA applications and not emerged again (acute isolation), disappeared but verified by PENTARAY catheter (pseudo isolation), once disappeared but emerged again during the same application (acute reconnection), visible but not disappeared (ineffective application) and Invisible (Figure1B).

TTI, difference between TTI and time to reach target temperature (TTRT), balloon temperature at isolation and ablation time after isolation were examined for each applications.

Results

Out of 92 PVs, 69/92 (75.0%) PVs were isolated using HBA and 23/92 (25.0%) PVs required touch up ablation. In total, 120 applications were performed. Real time monitoring of the PV activity was obtained in 114 of 120 applications (95.0%). The distribution of PV potential patterns were 64/120 (53.3%), 2/120 (1.7%), 27/120 (22.5%), 23/120 (19.2%), for acute isolation, pseudo isolation, acute reconnection, ineffective application, respectively.

TTI and difference between TTI and TTRT were significantly shorter in the acute isolation group. Balloon temperature at isolation was significantly lower, TTRT and ablation time after isolation was significantly longer in the acute isolation group. Among them, TTI and difference between TTI and TTRT were highly predictive by receiver operation characteristics curve analysis. TTI <36.5s predicted successful application with sensitivity 83.9% and specificity 79.3%. Difference between TTI and TTRT <6.5s predicted with sensitivity 82.3% and specificity 89.7%.

Figure 1

Conclusions

In HBA system, real time monitoring of PV potentials can be obtained using 2Fr 4-electrode unidirectional catheter and accuracy to confirm an ostial PV isolation is relatively high.

TTI <36.5s and difference between TTI and TTRT <6.5s could be a suitable target for effective application.

P3559Renal sympathetic nerve activity, assessed by renal 123-iodine metaiodobenzylguanidine scintigraphy, reflects disease severity in heart failure with reduced ejection fraction

Background

Sympathetic nerve activity is related to cardio-renal syndrome, which plays a crucial role in deterioration in heart failure with reduced ejection fraction (HFrEF). Previous studies reported that renal denervation was effective in HFrEF patients. Recently, we have demonstrated that renal 123-iodine metaiodobenzylguanidine (MIBG) scintigraphy is useful for assessment of renal sympathetic function in hypertension. However, it is unclear whether renal MIBG would reflect disease severity in HFrEF patients.

Methods

Twenty-four HFrEF patients and eleven control without heart failure were included in this study. HFrEF patients were performed MIBG and MSNA and hemodynamics inspection using Swan-Ganz's catheter (SGC). HFrEF was defined as echocardiography with EF of 50% or less. MSNA was recorded from the right peroneal nerve to evaluate direct sympathetic nerve activity to the peripheral vascular bed. MSNA was expressed as the number per minute (burst frequency = BF) and the number per 100 heartbeats (burst incidence = BI). Renal MIBG scintigraphy was simultaneously performed with cardiac MIBG scintigraphy. The 20 minutes (early) and 180 minutes (delayed) kidney-to-mediastinum ratio (K/M), early and delayed heart-to-mediastinum ratio (H/M), and washout rate (WR) were measured.

Results

In the HFrEF group, the EF was significantly lower than control group (EF 34.8±9.51% vs. 63.0±7.43, p<0.01), and MSNA parameters were significantly increased (burst incidence (BI), 57.7±18.7 vs. 37.0±11.3, p<0.01; BF 42.7±14.4 vs. 24.1±8.50, p<0.01). WR of cardiac MIBG was not related to MSNA parameters but negatively related to cardiac output (r=−0.46, p<0.05) and stroke volume (r=−0.61, p<0.01) and delayed H/M negatively correlated with mean pulmonary capillary wedge pressure (r=−0.57, P<0.05). WR of both left and right renal MIBG showed a strong correlation with MSNA (BI; left, r=0.69, p<0.01, right 0.60, p<0.01, BF; left, r=0.64, p<0.01, right, r=0.58, p<0.01) and no significant correlation between renal MIBG and hemodynamics parameters. HFrEF patients were divided into stage B and stage C based on American College of Cardiology/American Heart Association (ACC/AHA) classification (stage B, n=13; stage C, n=11). There was no significant difference between the two groups in cardiac MIBG parameters. Renal WRs in stage C was increased than stage B (Lt renal WR,51.6±10.6 vs. 40.6±6.53, p<0.05; Rt renal WR, 43.9±9.97 vs. 35.1±11.3, p<0.05).

Conclusions

Cardiac WR negatively correlated with cardiac output and renal WR correlated with MSNA. Renal WRs had a significant difference in the heart failure stage of ACC/AHA classification, but cardiac MIBG parameters did not. These results indicate that renal MIBG might be useful to assess renal sympathetic nerve activity in patients with HFrEF and suggesting that renal SNA might be promising therapeutic target in HFrEF.

1417Effect of sodium glucose cotransporter 2 inhibitor on sympathetic nerve activity in type 2 diabetes mellitus patients

Background

Diabetes mellitus (DM) is a well-known risk factor for cardiovascular diseases. Augmented sympathetic nerve activity plays an important role in the progressive worsening disease severity. Most of anti-diabetic drugs were demonstrated to not only decrease blood glucose, but also increase sympathetic nerve activity. Recently, it has been reported that sodium glucose cotransporter 2 (SGLT2) inhibitor has beneficial effects on cardiovascular events in spite of the decrease in blood glucose in type 2 DM patients. The underlying mechanisms remain speculative; however, it is assumed that SGLT2 inhibitor would improve sympathetic nerve activity in type 2 DM patients.

Purpose

The purpose of this study was to evaluate the effect of SGLT2 inhibitor on sympathetic nerve activity in type 2 DM patients.

Methods

This study was designed as the prospective single-arm study. Type2 DM patients whose HbA1c >7.0% with at least one atherosclerotic risk factors (Hypertension, obesity, smoking history, aging ...) were included. Patients who had renal failure (eGFR<45ml/min/1.73m2) or high age patients (>80 years old) were excluded. We measured blood glucose, HbA1c and blood insulin concentration at baseline and 12 weeks after treatment of dapagliflozin (5mg/day). Muscle sympathetic nerve activity (MSNA) was applied to scrutinize accurate sympathetic nerve activity in type 2 DM patients. Also, baroreflex sensitivity was calculated by examining the relationship between MSNA and beat to beat diastolic blood pressure.

Results

Eleven type2 DM patients were included in this study. Body mass index, blood pressure, HbA1c and blood insulin concentration tended to decrease at 12weeks after dapagliflozin (body mass index: 27.2±6.3 vs. 24.9±3.2 kg/m2. systolic blood pressure: 121±12.3 vs. 118±13.6 mmHg. diastolic blood pressure: 74.3±6.3 vs. 72.5±7.6 mmHg. HbA1c: 7.6±0.3 vs. 7.2±0.7%. insulin: 9.7±7.2 vs. 8.8±5.1 μU/ml). Dapagliflozin significantly decrease MSNA and heart rate compared to baseline (46.7±7.5 vs. 38.6±6.9 bursts/minute, P<0.05. Heart rate: 80.6±8.5 vs. 72.8±7.4 beats per minute, P<0.05). However, there is no interaction between the reduction in MSNA and baroreflex sensitivity or insulin resistance.

12 weeks administration decreased MSNA

Conclusion

Our data demonstrated that dapagliflozin significantly decreased MSNA and HR beyond the lowering effect of blood glucose in type2 DM patients. These results indicate the favorable effect of SGLT2 inhibitor might be, in part, attributed to the improvement in sympathetic nerve activity.

P3495Long-term engraftment of human CD271-positive adipose-derived stem cells with pericytic and less-aged gene profile in a mouse model of hindlimb ischemia

Background

Therapeutic angiogenesis using adipose-derived stem cells (ADSCs) is an attractive strategy for ischemic cardiovascular diseases. We previously reported that human CD271+ population of adipose-derived stem cells (ADSCs) promoted neovascularization with enhanced engraftment in a mouse model of hindlimb ischemia. However, whether and how CD271+ ADSCs promote the long-term engraftment is still uncertain.

Purpose

We aimed to examine whether the angiogenic effect and cell engraftment capacity of CD271+ ADSCs would be sustained in long-term period. Then, comparative gene profiling between CD271+ and CD271- ADSCs were analyzed. Finally, cell proliferation and endothelial differentiation assays were conducted.

Methods

ADSCs were isolated from subcutaneous adipose tissue of 5 patients received cardiovascular surgery. CD271+ and CD271- ADSCs were sorted from CD45-CD31-CD34+ ADSCs fraction by FACS sorting (Fig. A). Cultured CD271+ and CD271- ADSCs at passage 6 were labeled by PKH26 cell linker dye and used for xenograft experiments. Briefly, athymic nude mice were subjected to hindlimb ischemia and one million of human ADSCs were injected into the ischemic muscles. In control group, PBS was solely injected. At 2 and 5 weeks, neovascularization was evaluated by immunohistochemistry (capillary density using lectin perfusion). Cell engraftment was assessed by counting PKH26-positive cells. Furthermore, we compared gene profiling between CD271+ and CD271- ADSCs by microarray. Proliferative capacity was evaluated by colony-forming unit (CFU) assay with Giemsa staining. In endothelial differentiation assay, CD271+ and CD271- ADSCs were cultured in differentiation induction medium containing vascular endothelial growth factor for 2 weeks and stained with anti-human CD31 antibody.

Results

Cell therapy using CD271+ ADSCs demonstrated approximately 3-fold more enhanced neovascularization than those using CD271- ADSCs or PBS in histological analysis of capillary density at 2 weeks from cell therapy (Fig. B and C). At 5 weeks, mice treated with CD271+ ADSCs were significantly rescued from limb ischemia and this was accompanied by sustained engraftment of ADSCs (Fig. D). In microarray analysis, the differentially expressed 2167 genes were extracted to classify CD271+ and CD271- ADSCs. Pathway analysis demonstrated CD271 expression on ADSCs was associated with the pathways related to stemness and cell differentiation. Indeed, we found that genes related to cell proliferation (PI3K, Cyclin D, and Cyclin D2) were up-regulated in CD271+ ADSCs. Additionally, we found the pericytic marker nestin which was significantly up-regulated in CD271+ ADSCs. Consistent with these findings, CD271+ ADSCs were more proliferative and capable for endothelial differentiation while CD271- ADSCs were not.

FACS and cell therapy experiments

Conclusion

These results suggest that CD271+ ADSCs possess long-term engraftment and angiogenic capacity due to their less-aged and more pericytic gene profile.

Acknowledgement/Funding

Japan Society for the Promotion of Science (JSPS) KAKENHI (Tokyo, Japan) Grant Number JP16H06828

P2590A liver-derived secretory protein, selenoprotein P causes pressure overload-induced cardiac hypertrophys

Background

Hepatokine selenoprotein P (SeP) contributes to insulin resistance and hyperglycemia in patients with type 2 diabetes. Inhibition of SeP protects the heart from ischemia reperfusion injury and serum levels of SeP are elevated in patients with heart failure with reduced ejection fraction.

Objective

We investigated the role of SeP in the regulation of cardiac remodeling in response to pressure overload.

Methods and results

To examine the role of SeP in cardiac remodeling, transverse aortic constriction (TAC) was subjected to SeP knockout (KO) and wild-type (WT) mice for 2 weeks. Hepatic expression of SeP in WT was significantly increased by TAC. LV weight/tibial length (TL) was significantly smaller in SeP KO mice than in WT mice (6.75±0.24 vs 8.33±0.32, p<0.01). Lung weight/TL was significantly smaller in SeP KO than in WT mice (10.46±0.44 vs 16.38±1.12, p<0.05). TAC-induced cardiac upregulation of the fetal type genes, including atrial and brain natriuretic factors, was significantly attenuated in SeP KO compared to WT. Furthermore, azan staining revealed that there was significantly less interstitial fibrosis in hearts after TAC in SeP KO than in WT mice. To determine whether hepatic overexpression of SeP affects TAC-induced cardiac hypertrophy, a hydrodynamic injection method was used to generate mice that overexpress SeP mRNA in the liver. Hepatic overexpression of SeP in SeP KO mice lead to a significant increase in LV weight/TL and Lung weight/TL after TAC compared to that in other SeP KO mice.

Conclusions

These results suggest that cardiac pressure overload induced hepatic expression of SeP and the absence of endogenous SeP attenuated cardiac hypertrophy, dysfunction and fibrosis in response to pressure overload in mice. SeP possibly plays a maladaptive role against progression of heart failure through the liver-heart axis.

P1580Left atrial volume index predicts improvement in renal function after catheter ablation of atrial fibrillation

Background

Atrial fibrillation (AF) increased the risk of development of kidney disease. The elimination of AF by catheter ablation is associated with improvement in renal function. However, the mechanism of cardio-renal interaction in AF has not been fully elucidated.

Purpose

We tested the hypothesis that left atrial volume index (LAVI), which is a marker of left atrial mechanical reserve, predicts improvement in renal function after restoring sinus rhythm with catheter ablation of AF.

Methods

We analyzed consecutive patients who underwent catheter ablation of AF from January 2012 to October 2018 and had completed follow-up more than 3 months after catheter ablation. Exclusion criteria were need for hemodialysis and acute hospitalization. Estimated glomerular filtration rate (eGFR) was assessed on admission and at the end of follow-up periods after catheter ablation and the difference was defined as ΔeGFR. Left atrial volume index was derived using the biplane area-length method.

Results

A total of 159 AF patients (paroxysmal 112 [70%], persistent 47 [30%]) were included in this study. The mean age was 65±11 years and 74% were male. During the mean follow-up period of 7.9±3.2 months, 105 patients (66%) were free from atrial tachyarrhythmias and 54 (34%) experienced the recurrence. Baseline eGFR and LAVI were not significantly different between the non-recurrence group and the recurrence group (71.0±17.4 and 75.1±22.8 mL/min/1.73m2; p=0.24, 35.7±12.5 and 37.9±15.0 ml/m2; p=0.34). ΔeGFR in the non-recurrence group was significantly greater compared with the recurrence group (+1.5±1.0 versus −4.3±1.4 mL/min/1.73m2; p=0.001). Baseline LAVI was negatively correlated with ΔeGFR in the non-recurrence group (r=−0.3; p=0.002; Figure), but not in the recurrence group (p=0.1). Multiple regression analysis in the non-recurrence group identified baseline LAVI (β=−0.35, p<0.001), baseline age (β=−0.31, p<0.001) and baseline eGFR (β=−0.59, p<0.001) as independent predictors for eGFR improvement after catheter ablation. In the patients with LAVI <34 ml/m2, age <70 years and eGFR <90 mL/min/1.73m2, the mean ΔeGFR was +6.3±1.9 mL/min/1.73m2.

Figure 1

Conclusions

LAVI, a marker of left atrial mechanical reserve, was an independent predictor of improvement in renal function after restoring sinus rhythm with catheter ablation of AF. This observation suggests that AF-related deterioration of renal function is due at least in part to impaired atrial mechanical function.

Skin inflammation exacerbates food allergy symptoms in epicutaneously sensitized mice

BACKGROUND

Cutaneous exposure to food antigen through impaired skin barrier has been shown to induce epicutaneous sensitization, thereby causing IgE-mediated food allergies.

OBJECTIVE

We examined whether skin barrier impairment following epicutaneous sensitization exacerbates food allergies.

METHODS

BALB/c mice were epicutaneously sensitized by repeated application of ovalbumin (OVA) to MC903-pretreated ear skin for 48 hours weekly and then intragastrically challenged with OVA. After the first oral challenge, the skin barrier was disrupted with topical application of MC903 or by tape-stripping. Mice were monitored for changes in body temperature and the occurrence of diarrhea after undergoing the second oral challenge. Serum levels of mouse mast cell protease-1 (mmcp1) and OVA-specific IgE, IgG1, IgG2a antibodies and OVA-specific IgA levels in intestinal lavage fluid were measured by ELISA. Tissue accumulation of eosinophils was determined histologically.

RESULTS

Epicutaneously sensitized mice developed anaphylaxis after intragastric challenge, as evidenced by diarrhea, decreased body temperature, and increased serum mmcp1 levels. Skin barrier disruption by MC903 treatment or tape-stripping exacerbated allergic reactions induced by oral challenge. MC903 treatment increased serum baseline and postchallenge mmcp1 levels. Topical pretreatment with dexamethasone alleviated allergic reactions that were exacerbated by MC903 treatment.

CONCLUSION

Even after eliminating exposure to the antigen, inflammation from skin barrier disruption can exacerbate the severity of food allergy symptoms. Serum baseline mmcp1 levels might be an effective marker for predicting the severity of antigen-induced allergic symptoms.

The Biomarker Salivary SP-D May Indicate Small Airway Inflammation and Asthma Exacerbation

BACKGROUND

Noninvasive and child-friendly biomarkers are important tools for understanding the various phenotypes of childhood asthma. Objective: The aim of this study was to examine the usefulness of salivary surfactant protein (SP) D in assessing the pathophysiology of childhood asthma.

METHODS

We measured salivary concentrations of SP-D and forced oscillation technique (FOT) indexes in 19 healthy controls and 21 asthmatic children. Regression equations for the predictive values of FOT indexes were generated from healthy controls. We analyzed the correlations between salivary SP-D concentration and percentages of the predictive values of FOT indexes, as well as the severity of exacerbation.

RESULTS

We found that salivary SP-D levels were higher in asthmatic children than in healthy controls. In the asthmatic children, salivary SP-D levels correlated with the percentages of predicted differences in resistance between 5 Hz and 20 Hz (%R5-R20), which represented the resistance of peripheral airways, and with the severity of asthma exacerbation.

CONCLUSIONS

Salivary SP-D may reflect asthmatic inflammation in peripheral small airways and may be a useful marker for monitoring the degree of exacerbation in childhood asthma.

Electromagnetic Fields Inhibit Endothelin-1 Production Stimulated by Thrombin in Endothelial Cells

Electromagnetic field (EMF) radiation has been found to induce arteriolar dilatation, but the mechanism of action remains largely unknown. This study investigated the effect of EMF radiation on the production of endothelin-1 (ET-1), a potent vasoconstrictor, by cultured endothelial cells. EMF radiation reduced ET-1 basal levels in human umbilical vein and microvascular endothelial cells, but failed to reduce ET-1 basal levels in bovine and human aortic endothelial cells. EMF radiation significantly inhibited thrombin-stimulated ET-1 production in all four endothelial cell types in a dose-dependent manner. EMF radiation significantly inhibited thrombin-induced endothelin-1 mRNA expression in all four cell types. The inhibitory effect of EMF radiation on ET-1 production was abolished by the nitric oxide synthase inhibitor NG-monomethyl-L-arginine (10−3 mol/l). These results demonstrate that EMF radiation modulates ET-1 production in cultured vascular endothelial cells and the inhibitory effect of EMF radiation is, at least partly, mediated through a nitric oxide-related pathway.

Distinct CSF cytokine/chemokine profiles in atopic myelitis and other causes of myelitis

BACKGROUND

We reported the emergence of a distinct myelitis in patients with atopic diathesis (atopic myelitis [AM]) by a nationwide survey throughout Japan. Similar cases have recently been reported in Caucasians. Pathologic studies of biopsied spinal cord specimens revealed chronic active inflammation with eosinophilic infiltration.

OBJECTIVE

To clarify the cytokine/chemokine alterations in CSF from patients with AM in comparison to other causes of myelitis.

METHODS

We measured 27 cytokines, chemokines, and growth factors simultaneously in CSF from 22 patients with AM, 20 with opticospinal multiple sclerosis (OSMS), 11 with HTLV-1-associated myelopathy (HAM), 9 with Sjögren syndrome-related myelitis (SM), and 20 with other noninflammatory neurologic diseases (OND), using a fluorescent bead-based immunoassay.

RESULTS

In patients with AM, CCL11 and interleukin (IL)-9 were significantly increased as compared with patients with OND and other myelitis while in patients with OSMS interferon-gamma and granulocyte-colony stimulating factor levels were significantly higher than in patients with OND and other causes of myelitis. Significant increase of IL-17 in comparison to patients with OND was found only in patients with OSMS, irrespective of presence or absence of anti-aquaporin-4 (AQP4) antibody. In patients with HAM, CXCL10 and CCL5 were higher than in patients with OND and other myelitis. In patients with SM, CCL3 and CCL4 were higher than in patients with OND. In patients with AM, CCL11, IL-9, and IL-1 receptor antagonist (IL-1ra) showed positive correlations with the final Kurtzke Expanded Disability Status Scale scores while IL-1ra and IL-12(p70) had positive correlations with disease duration.

CONCLUSION

Intrathecal upregulation of CCL11 and Th2 cytokines is characteristic of atopic myelitis, which is distinct from interleukin-17/interferon-gamma-related autoimmune condition of opticospinal multiple sclerosis.

Survey on pamphlet use explaining breast cancer operations in Japan

BACKGROUND

The burden on hospitals to provide information has been increasing. This study examined the demands of surgeons and patients using a pamphlet explaining breast cancer operation procedures.

METHODS

A questionnaire with an eight-page pamphlet was sent to 367 hospitals with surgery departments in Aichi and Gifu prefectures in Japan. The same pamphlet and a self-administered anonymous questionnaire were also sent to 173 members of a breast cancer patient association, who had undergone breast cancer operations and lived in the same prefectures.

RESULTS

Responses to the questionnaire from 196 hospitals (53%) and 122 patients (71%) were analyzed. Breast cancer operations were conducted at 8 departments of 5 university hospitals, 37 governmental hospitals, 25 non-profit hospitals, and 66 private hospitals, a total of 1 36 hospitals. Among them, 34 hospitals participated in clinical trials. Fourteen hospitals had already used pamphlets as a tool for the explanation of breast cancer operation procedures. Hospitals having experienced special discussion with patients regarding the operation procedure were few, and only two hospitals reported claims or lawsuits concerning the operation procedure. About 60% of the hospitals wished to use the pamphlet, while 86% of the patients answered that it would have been useful if handed out before the operation. These patients stated that hospitals should provide this kind of pamphlet to breast cancer patients before operations.

CONCLUSIONS

It was clearly demonstrated that the great majority of hospitals in Japan lacked the basic tools for information provision on breast cancer operation procedures, while patients want enough information for self-determination.

Osmotic shock-induced neurite extension via activation of p38 mitogen-activated protein kinase and CREB

Although it is known that sustained activation of classical mitogen-induced protein kinase (MAPK, also known as ERK) induced by nerve growth factor (NGF) plays an important role in the induction of neurite outgrowth, the role of p38 MAPK in neural cell function is still not clear. We developed two neuronal cell lines from PC12 cells, PC12m3 and PC12m32, in which NGF-induced neurite outgrowth is impaired and that show neurite outgrowth in response to hyperosmotic shock. The frequencies of neurite outgrowth of PC12m3 and PC12m32 cells induced by osmotic shock were approximately 10- and 12-fold greater, respectively, than that in PC12 parental cells. The p38 MAPK pathway inhibitor SB203580 but not the ERK pathway blocker U0126 inhibited the ability of PC12m3 and PC12m32 cells to induce neurite outgrowth in response to osmotic shock. Furthermore, expression of a nonactivable form of p38 but not that of wild-type p38 significantly blocked neurite outgrowth induced by osmotic shock. The extent of phosphorylation of p38 MAPK induced by osmotic shock in PC12m32 cells was much greater than that in PC12 parental cells. The upstream kinases MKK3 and MKK6, which phosphorylate and activate p38 MAPK, also showed higher levels in PC12m32 cells than in PC12 parental cells when treated with osmotic shock. Inhibition of p38 MAPK by SB203580 resulted in inhibition of the activity of the transcription factor CREB, which is activated by osmotic shock. These findings indicate that activation of CREB mediated by a p38 pathway distinct from the NGF signaling pathway may be required for neurite outgrowth.

[Intralobar pulmonary sequestration with high level of serum CEA; report of a case]

We reported a case of intralobar pulmonary sequestration with a high level of the serum CEA. A 53-year-old woman whose chief complaint was cough was admitted to our hospital. Enhanced chest computed tomography (CT) revealed the mass in the left lower lung, lymph-nodes swelling, and the aberrant artery. Magnetic resonance angiography (MRA) conformed the aberrant artery from the descending aorta. The level of serum CEA elevated at 9.6 ng/ml. Left lower lobectomy was performed. A diagnosis of intralobar pulmonary sequestration (Pryce type II) was established in this case. Histopathologically, the peribronchial epithelial cells in pulmonary sequestration showed weak positive for anti-CEA monoclonal antibody. Postoperative course was uneventful and the serum CEA level was 3.5 ng/ml in the normal range at the postoperative 17th day.