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.

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

Diagnostic accuracy of left ventricular diastolic transverse strain imaging by speckle tracking echocardiography for diagnosing chest pain in diabetic patients

Background

Two-dimensional speckle tracking echocardiography (2D-STE) has been reported to be useful for the diagnosis of myocardial ischemia by detecting delayed relaxation (diastolic stunning) after an episode of angina. 2D-longitudinal strain is not specific besides ischemia such as diastolic dysfunction, and diabetes have been associated with abnormal longitudinal fibers. The aim is to evaluate the diagnostic accuracy of Left ventricular (LV) diastolic transverse strain imaging by STE to detect the presence of acute coronary syndrome (ACS) in diabetic patients with acute chest pain.

Methods

385 consecutive patients with acute chest pain and without wall motion abnormality, who were admitted to an emergency department (ED) at 1 of 12 clinical sites in Japan, were enrolled and underwent 2D-STE at ED. Left ventricular (LV) transverse strain values at aortic valve closure (A) and one-third of diastole duration (B) were measured. The strain imaging diastolic index (SI-DI) was value was determined as: (A − B)/A × 100% to assess the LV diastolic strain imaging and was used to identify the regional LV delayed relaxation. All patients underwent coronary CT or coronary angiography to establish the diagnosis of ACS. Clinicians were blinded to the 2D-STE results.

Results

Out of 385 patients, 2D-STE analysis was possible in 365 patients (94%). 76 patients were diabetic (DM+), and 289 patients were non-diabetic (DM-). With assessment of coronary CT or coronary angiography, ACS was diagnosed in 125 patients (34%). 2D-STE was obtained at a mean of 5.3 hours after chest pain episode. Transverse SI-DI of ischemic segments were significantly lower than those of non-ischemic segments (p value <0.001) in both diabetic and non-diabetic patients, and transverse SI-DI of both diabetic and non-diabetic patients demonstrated high area under curve (AUC) for detection of myocardial ischemia (Figure: RCA; right coronary artery, LAD; left anterior descending artery, LCX; left circumferencial artery). In diabetic patients, sensitivity, specificity, and negative predictive value for ACS of transverse SI-DI are 100%, 95%, 100% in RCA (a cut-off value of 36.2), and 86.4%, 95%, 93% in LAD (a cut-off value of 50.2), and 75%, 85%, 94% in LCX (a cut-off value of 52), respectively.

Conclusion

LV diastolic transverse strain imaging by 2D-STE at ED increase the sensitivity, specificity and accuracy to predict the presence of ACS in diabetic patients with chest pain, as well as non-diabetic patients. (UMIN000013859).

Figure 1. Transverse Strain (SI-DI): AUC (95% CI)

Funding Acknowledgement

Type of funding source: None

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.

P5593The association of recurrence and bleeding events with mortality after venous thromboembolism: from the COMMAND VTE Registry

Background/Introduction

Venous thromboembolism (VTE), including pulmonary embolism (PE) and deep vein thrombosis (DVT), has a long-term risk for recurrence, which can be prevented by anticoagulation therapy. The duration of anticoagulation therapy after VTE should be based on the balance between risks of recurrent VTE and bleeding. However, there is uncertainty about the impact of these events on subsequent mortality.

Purpose

We sought to evaluate the impact of recurrent VTE events and bleeding events on subsequent mortality in patients with VTE in a large retrospective observational database in Japan.

Methods

We evaluated the association of recurrent VTE and major bleeding with mortality among 3026 patients in the COMMAND VTE Registry. We estimated the risks of recurrent VTE events and major bleeding events for subsequent all-cause death with the multivariable Cox proportional hazard model. We incorporated the recurrent VTE events and major bleeding events during follow-up into the multivariable Cox model as time-updated covariates together with the clinically-relevant 16 risk-adjusting factors. We expressed the adjusted risks of each covariate as hazard ratios (HR) and their 95%confidence intervals (CI). Furthermore, to assess the risks of recurrent PE and recurrent DVT events for subsequent all-cause death respectively, we divided recurrent VTE events into recurrent PE (PE with or without DVT) and recurrent DVT (DVT only), and incorporated these events as well as major bleeding events into the multivariable Cox model as time-updated covariates.

Results

In the current study population, the mean age was 67 years, 61% were women, and mean body weight and body mass index were 57.9 kg and 23.2 kg/m2, respectively. During the median follow-up period of 1,218 days, 763 patients died, 225 patients developed recurrent VTE events, and 274 patients developed major bleeding events. The time-updated multivariable Cox proportional hazard model revealed that both the recurrent VTE events and the major bleeding events were strongly associated with subsequent mortality risk (recurrent VTE events: HR 3.24, 95% CI 2.57–4.08, P<0.001; major bleeding events: HR 3.53, 95% CI 2.88–4.31, P<0.001). Both the recurrent PE events and the recurrent DVT events were associated with subsequent mortality risk with the numerically greater magnitude of effect with the recurrent PE events than with the recurrent DVT events (recurrent PE events: HR 4.42, 95% CI 3.28–5.95, P<0.001; recurrent DVT events: HR 2.42, 95% CI 1.75–3.36, P<0.001).

Conclusions

In the real-world patients with VTE, both recurrent VTE events and major bleeding events were strongly associated with subsequent mortality risk with the comparable effect size. Recurrent PE and recurrent DVT events were also associated with increased risks for mortality, although the magnitude of the effect on mortality was numerically greater with the recurrent PE events than with the recurrent DVT events.

Acknowledgement/Funding

Research Institute for Production Development, Mitsubishi Tanabe Pharma Corporation

P772Angiotensin-converting enzyme inhibitors and angiotensin receptor blockers for heart failure patients with different left ventricular ejection fraction categories: from the KCHF Registry

Background

The current guidelines recommend different medical treatment strategies for heart failure (HF) patients according to category of left ventricular ejection fraction (LVEF). Angiotensin-converting enzyme inhibitors/angiotensin receptor blockers (ACE-I/ARB) is an established medical treatment for heart failure with reduced ejection fraction (HFrEF), whereas its usefulness remains to be elucidated for non-HFrEF, especially for heart failure with mid-range ejection fraction (HFmrEF).

Purpose

This study aimed to assess the difference in association between ACE-I/ARB and clinical outcomes depending on LVEF category.

Methods

The Kyoto Congestive Heart Failure (KCHF) Registry is a multicentre registry without any exclusion criteria which included consecutive patients hospitalized for congestive HF in Japan. In each LVEF group (HFrEF, HFmrEF and heart failure with preserved ejection fraction [HFpEF]), we compared those who were prescribed ACE-I/ARB as discharge medication and those not, and assessed their 1-year clinical outcomes. We defined the primary outcome measure as a composite of all-cause death and HF hospitalization. We constructed a multivariable Cox regression model incorporating 24 clinically relevant factors. We assessed adjusted hazard ratios (HRs) of those with ACE-I/ARB relative to those not, and also interaction between ACE-I/ARB prescription at discharge and LVEF category.

Results

A total of 3717 patients were included in this study, where the number of patients in each LVEF group were as follows; 1383 patients with HFrEF, 703 with HFmrEF and 1631 with HFpEF, respectively (Figure). As shown in the table, the HRs for the primary outcome measure were significant in the HFrEF and HFmrEF groups, whereas the HR in the HFpEF group was insignificant. The interaction between ACE-I/ARB prescription and LVEF category for the primary outcome measure was statistically significant.

Hazard ratios by LVEF category Outcome measures HFrEF HFmrEF HFpEF P interaction HR (95% CI) P value HR (95% CI) P value HR (95% CI) P value All-cause death + HF hospitalization 0.66 (0.54–0.79) <0.001 0.61 (0.45–0.82) 0.001 0.95 (0.80–1.14) 0.61 0.01 All-cause death 0.62 (0.48–0.81) <0.001 0.52 (0.35–0.77) 0.001 0.73 (0.58–0.93) 0.01 0.10 HF hospitalization 0.73 (0.57–0.92) 0.009 0.59 (0.40–0.87) 0.007 1.14 (0.90–1.44) 0.28 0.07 Hazard ratios of ACE-I/ARB relative to non-ACE-I/ARB for primary outcome measures in each LVEF category.

Study flowchart

Conclusions

The risk ratios of those who were prescribed ACE-I/ARB relative to those not were significantly low in HFmrEF as well as HFrEF, whereas the risk ratios were insignificant in HFpEF. ACE-I/ARB could be a potential choice of treatment for HFmrEF patients.

P3847Deep vein thrombosis in upper extremities: clinical characteristics, management strategies and long-term outcomes from the COMMAND VTE Registry

Background/Introduction

Pulmonary embolism (PE) is caused by blockage of pulmonary arteries by thrombus. The sources of thrombus are thought to be mostly veins in lower extremities, whereas deep vein thrombosis (DVT) in upper extremities rarely occurs spontaneously. Recent studies reported that DVT in upper extremities might have significant complications, and DVT in upper extremities could be increasing. However, there is a paucity of data on patients with DVT in upper extremities, leading to uncertainty in optimal treatment strategies including anticoagulation therapy.

Purpose

We sought to evaluate the clinical characteristics, management strategies, and long-term outcomes of patients with DVT in upper extremities in a large observational database in Japan.

Methods

The COMMAND VTE Registry is a multicenter registry enrolling 3027 consecutive patients with acute symptomatic venous thromboembolism (VTE) objectively confirmed by imaging examination or by autopsy among 29 centers in Japan between January 2010 and August 2014. The current study population consisted of 2498 patients with DVT in upper or lower extremities, after excluding 381 patients with PE only, 144 patients who had thrombus in locations other than upper or lower extremities, and 4 patients with DVT in both upper and lower extremities. The study patients were divided into 2 groups: patients with DVT in upper extremities and patients with DVT in lower extremities. We compared the clinical characteristics, management strategies and long-term outcomes between the 2 groups.

Results

There were 74 patients (3.0%) with upper extremities DVT and 2498 patients (97%) with lower extremities DVT. Patients with upper extremities DVT more often had active cancer at diagnosis (58%) and central venous catheter use (22%). The proportion of concomitant PE at diagnosis was lower in patients with upper extremities DVT than in those with lower extremities DVT (14% and 51%, P<0.001). Discontinuation of anticoagulation therapy was more frequent in patients with upper extremities DVT (63.8% and 29.8% at 1-year, P<0.001). The cumulative 3-year incidence of recurrent VTE was not different between the 2 groups (9.8% and 7.4%, P=0.43) (Figure). After adjusting confounders, the risks of upper extremities DVT relative to lower extremities DVT for recurrent VTE remained insignificant (HR 0.94, 95% CI 0.36–2.01, P=0.89).

Kaplan-Meier event curves for recurrence

Conclusions

The prevalence of patients with DVT in upper extremities was 3.0% in the current large-scale real-world registry. Patients with DVT in upper extremities more often had active cancer at diagnosis and central venous catheter use as a transient risk factor for VTE, and less often had concomitant PE. Patients with DVT in upper extremities had similar long-term risk for recurrent VTE as those with DVT in lower extremities despite shorter duration of anticoagulation.

Acknowledgement/Funding

Research Institute for Production Development, Mitsubishi Tanabe Pharma Corporation

P3846The association between statin prescription, recurrent venous thromboembolism and bleeding events: from the COMMAND VTE Registry

Background

Statin prevents occurrence and recurrence of atherosclerotic events. With regard to venous thromboembolism (VTE), a randomized controlled trial suggested that statin reduced occurrence of VTE, whereas its usefulness as secondary prevention of VTE remains to be elucidated.

Purpose

This study aimed to assess the association between statin prescription, recurrent VTE and bleeding events in patients with VTE.

Methods

The COMMAND VTE Registry is a multicentre registry enrolling consecutive 3027 patients with acute symptomatic VTE among 29 centres in Japan. We divided the cohort into the patients who were prescribed statin (N=437) and those not (N=2590), and compared the two groups. We assessed hazard ratios (HRs) of those with statin relative to those without for long-term clinical outcomes (recurrent symptomatic VTE and International Society of Thrombosis and Hemostasis [ISTH] major bleeding). Because the durations of anticoagulation therapy were widely different between the two groups, we constructed Cox's proportional hazard model incorporating status of anticoagulation during the follow-up period as a time-varying covariate. Also, because the incidences of death were strikingly different between the two groups due to the difference in the prevalence of active cancer, we used Fine-Gray's subdistribution hazard model in the presence of competing risks. We incorporated clinically relevant factors into these two models as covariates (10 factors for recurrent VTE and 11 for major bleeding).

Results

The statin group was significantly older than the non-statin group (statin 71.2±11.8 vs. non-statin 66.5±15.8, P<0.001). The prevalence of active cancer in the statin group was less than one-half of that in the non-statin group (12% vs. 25%, P<0.001), and the cumulative 3-year incidence of death was significantly lower in the statin group than in the non-statin group (12.8% vs. 26.1%, log-rank P<0.001). The table shows the adjusted HRs of the statin group relative to the non-statin group. The HRs of the statin group relative to non-statin group for recurrent VTE were significantly low, but those for major bleeding were insignificant.

Adjusted hazard ratios Outcome measures Model 1 P value Model 2 P value Adjusted HR [95% CI] Adjusted HR [95% CI] Recurrent VTE 0.59 [0.36–0.98] 0.042 0.53 [0.32–0.89] 0.02 Major bleeding 0.87 [0.60–1.24] 0.43 0.997 [0.69–1.43] 0.99 Model 1 derived from Cox's model with time-varying covariate of anticoagulation status. Model 2 derived from Fine-Gray's model.

Study flowchart

Conclusions

Prescription of satin was associated with significantly low risks for recurrent VTE, whereas that was not for major bleeding events. Statin could be a potential treatment option for secondary prevention of VTE.

Prevalence of Baylisascaris Roundworm in Captive Kinkajous in Japan

Baylisascaris potosis causes larva migrans in animals. The present study evaluated the prevalence of B. potosis in captive kinkajous ( Potos flavus ) and the ability of milbemycin to treat natural infections of B. potosis in 2 female wild-caught kinkajous. In 2012, fecal samples were collected from 16 kinkajous in 6 zoological gardens and 29 imported captive kinkajous from 4 pet traders in Japan. Although all samples from zoological gardens were negative, 8 kinkajous from traders were positive for Baylisascaris eggs, at least 4 of which were wild caught in the Republic of Guyana. No associated human illness was reported from any of the facilities. The 2 infected kinkajous received a single oral administration of Milbemycin® A Tablets, which delivers 0.69-0.89 mg/kg milbemycin oxime. Fecal examinations on days 14 and 30 were negative for Baylisascaris eggs. These results demonstrated that milbemycin oxime has possible anthelmintic efficacy against Baylisascaris roundworms in captive kinkajous. We conclude that Baylisascaris infections are highly prevalent in wild-caught kinkajous in Japan and that most of the infected kinkajous were imported from the Republic of Guyana.

Positioning bedridden patients to reduce interface pressures over the sacrum and great trochanter

OBJECTIVE

In this study, we evaluated the effect of hip-joint rotation on the interface pressure over the sacrum and greater trochanter with a new protocol for positioning of bedridden elderly patients.

METHOD

The interface pressure values over the sacrum and greater trochanter in bedridden patients were evaluated. These were collected in the supine position, 90° lateral position, and 30° and 40° laterally inclined positions with external rotation or neutral positioning of the hip joint. Each interface pressure was assessed with a device measuring pressure distribution, after which, the peak pressure index (PPI) was calculated.

RESULTS

In the 17 patients examined, the PPI over the sacrum in the supine position was significantly greater than that in other positions. In the 30° and 40° laterally inclined positions, the PPIs over the greater trochanter were significantly lower in the neutral position of the hip joint compared with those in the external rotation position.

CONCLUSION

Our findings revealed the effects of hip-joint rotation on the interface pressure for the greater trochanter, possibly due to the increased distance between the greater trochanter and the sacrum caused by neutral position of the hip joint. The results demonstrate that it is to best place the hip joint in a neutral position when the legs are in contact with the bed in order to distribute the pressure over the greater trochanter in the 30° and 40° laterally inclined positions. These results can be applied to the clinical setting to improve patient positioning and decrease pressure ulcers.

DECLARATION OF INTEREST

The authors declare that they have no competing financial interests.

Fer tyrosine kinase oligomer mediates and amplifies Src-induced tumor progression

c-Src is upregulated in various human cancers, suggesting its role in malignant progression. However, the molecular circuits of c-Src oncogenic signaling remain elusive. Here we show that Fer tyrosine kinase oligomer mediates and amplifies Src-induced tumor progression. Previously, we showed that transformation of fibroblasts is promoted by the relocation of c-Src to non-raft membranes. In this study, we identified Fer and ezrin as non-raft c-Src targets. c-Src directly activated Fer by initiating its autophosphorylation, which was further amplified by Fer oligomerization. Fer interacted with active c-Src at focal adhesion membranes and activated Fer-phosphorylated ezrin to induce cell transformation. Fer was also crucial for cell transformation induced by v-Src or epidermal growth-factor receptor activation. Furthermore, Fer activation was required for tumorigenesis and invasiveness in some cancer cells in which c-Src is upregulated. We propose that the Src-Fer axis represents a new therapeutic target for treatment of a subset of human cancers.

Primary Sjögren's syndrome complicated by sarcoidosis and psoriasis vulgaris

Abstract Primary Sjögren's syndrome (SS), sarcoidosis (SA), and psoriasis vulgaris (PV) are all chronic diseases of unknown etiology. Recent studies suggest that activated T cells play a central role in their pathogenesis. We describe a case of a Japanese woman with primary SS complicated by SA and PV. To our knowledge, this is the first case in which these three diseases coexist. Although these three disorders may have a common immunopathogenic mechanism, the extreme rarity of their coexistence suggests that distinct etiological mechanisms are also involved and appear to play an important role in triggering and developing each disease.

Gap-junction-mediated Communication in Human Periodontal Ligament Cells

Periodontal tissue homeostasis depends on a complex cellular network that conveys cell-cell communication. Gap junctions (GJs), one of the intercellular communication systems, are found between adjacent human periodontal ligament (hPDL) cells; however, the functional GJ coupling between hPDL cells has not yet been elucidated. In this study, we investigated functional gap-junction-mediated intercellular communication in isolated primary hPDL cells. SEM images indicated that the cells were in contact with each other via dendritic processes, and also showed high anti-connexin43 (Cx43) immunoreactivity on these processes. Gap-junctional intercellular communication (GJIC) among hPDL cells was assessed by fluorescence recovery after a photobleaching (FRAP) analysis, which exhibited dye coupling between hPDL cells, and was remarkably down-regulated when the cells were treated with a GJ blocker. Additionally, we examined GJs under hypoxic stress. The fluorescence recovery and expression levels of Cx43 decreased time-dependently under the hypoxic condition. Exposure to GJ inhibitor or hypoxia increased RANKL expression, and decreased OPG expression. This study shows that GJIC is responsible for hPDL cells and that its activity is reduced under hypoxia. This is consistent with the possible role of hPDL cells in regulating the biochemical reactions in response to changes in the hypoxic environment.

A new calpain inhibitor protects left ventricular dysfunction induced by mild ischemia-reperfusion in in situ rat hearts

We have previously indicated that a new soluble calpain inhibitor, SNJ-1945 (SNJ), attenuates cardiac dysfunction after cardioplegia arrest-reperfusion by inhibiting the proteolysis of α-fodrin in in vitro study. Nevertheless, the in vivo study design is indispensable to explore realistic therapeutic approaches for clinical use. The aim of the present in situ study was to investigate whether SNJ attenuated left ventricular (LV) dysfunction (stunning) after mild ischemic-reperfusion (mI-R) in rat hearts. SNJ (60 μmol/l, 5 ml i.p.) was injected 30 min before gradual and partial coronary occlusion at proximal left anterior descending artery. To investigate LV function, we obtained curvilinear end-systolic pressure-volume relationship by increasing afterload 60 min after reperfusion. In the mI-R group, specific LV functional indices at midrange LV volume (mLVV), end-systolic pressure (ESP(mLVV)), and pressure-volume area (PVA(mLVV): a total mechanical energy per beat, linearly related to oxygen consumption) significantly decreased, but SNJ reversed these decreases to time control level. Furthermore, SNJ prevented the α-fodrin degradation and attenuated degradation of Ca(2+) handling proteins after mI-R. Our results indicate that improvements in LV function following mI-R injury are associated with inhibition of the proteolysis of α-fodrin in in situ rat hearts. In conclusion, SNJ should be a promising tool to protect the heart from the stunning.

Optimum microcurrent stimulation intensity for galvanotaxis in human fibroblasts

OBJECTIVE

In this study, we develop methods to measure galvanotaxis of fibroblasts and determined the optimum conditions of electrical stimulation.

METHOD

An inverted 35mm dish containing cell suspensions (3×105 primary human skin fibroblasts, DMEM, and 10% FBS) was placed on the centre of a 100mm dish. The 35mm dish was removed 24 hours later, and culture medium was added to the 100mm dish. Fibroblasts were randomised (double-blind) into three groups, where electrical stimulation was given at varying intensities: 0UA (control), 50UA, and 100UA. Electrical stimulation (frequency=0.3Hz) was conducted, for a duration of 4 hours, with platinum electrodes in a CO2 incubator. We took pictures immediately before and 20 hours after stimulation. We calculated the migration ratio to the negative pole by dividing the area of attached fibroblasts after stimulation with that before stimulation.

RESULTS

The migration ratio to the negative pole was significantly higher in the 100UA group than in the control group (p<0.05). The ratios were 0.902±0.292 in the control group, 1.128±0.253 in the 50UA group, and 1.24±0.300 in the 100UA group.

CONCLUSION

This study observed the change in cell proliferation during the initial 24-hour period after plating and was thus able to quantitatively evaluate the migration. The results suggest that a low-intensity direct current promotes migration to the negative pole of human dermal fibroblasts, which is charged with positive electricity. Several clinical reports using the methods in this study showed the microcurrent efficacy for pressure ulcer healing. Electrical stimulation based on our in vitro experiment might be important for the development of physical therapy for pressure ulcers.

Structural and functional analyses of chicken liver ferritin

Characterization of ferritins from different species has provided insight into iron regulation mechanisms and evolutionary relationships. Here, we examined chicken liver ferritin, which comprises only H subunit and has 14.8 µg of Fe/100 µg of protein. The chicken H subunit apo homopolymer showed the same iron uptake rate as bovine H subunit homopolymer expressed with a baculovirus expression system (0.31 and 0.28 mmol of Fe/min per micromole of protein for chicken and bovine H subunit, respectively). Chicken H subunit apo homopolymer showed a significantly higher biotinylated hemin-binding activity than liver holoferritin. Although bovine spleen apoferritin, which has an L (liver or light):H (heart or heavy) subunit ratio of 1:1, also shows a significantly higher biotinylated hemin-binding activity than its holoferritin, these biotinylated hemin-binding activities were markedly lower than those of both chicken holo- and apoferritins. Binding of chicken holo- and apoferritin with biotinylated hemin was strongly inhibited by hemin but not iron-free hemin, protoporphyrin IX, or Zn-protoporphyrin. These findings demonstrate that chicken ferritin comprises only an H subunit, possesses ferroxidase activity as in mammalian ferritin H subunits, and binds heme more strongly than mammalian ferritins.

196 GLUTATHIONE S-TRANSFERASE THETA1 (GSTT1) IS DIFFERENTIALLY REGULATED FROM OTHER GLUTATHIONE S-TRANSFERASES IN GRANULOSA CELLS

Oxidative stress is a major source of aging that damages genomic and mitochondrial DNA, causing female reproductive disorders. Glutathione S-transferases (GST) are known to detoxify the metabolites of genotoxic molecules to more water-soluble and readily excretable forms. Therefore, most GST have been considered to be down-regulated by aging. We recently demonstrated that only GSTT1 is up-regulated in granulosa cells from aged, infertile patients and aged mice, although other kinds of GST are down-regulated in these cells (Ito et al. 2008 Fertil. Steril. 90, 1026–1035). Measurement of the GSTT1 level in granulosa cells binding to the patient’s oocytes could be used in the selection of oocytes of high quality, meaning that the GSTT1 level in granulosa cells could be a good indicator of age-related infertility. To do that, an understanding of the concrete relationship between aging and GSTT1 up-regulation is necessary. However, the regulation mechanism of GSTT1 in granulosa cells remains unclear. In the present study, we attempted to examine the difference in expression mechanisms between GSTT1 and other GST. First, the expression patterns of GSTT1 and GSTP (a major member of the GST) in aged granulosa cells from patients were observed by immunostaining. The GSTT1 was up-regulated (young: 25 to 34 years old, N = 9; aged: 38 to 43 years old, N = 12; P < 0.05) but the GSTP was down-regulated (young: 28 to 30 years, N = 5; aged: 38 to 42 years, N = 7; P < 0.05) in the aged group. Nuclear factor erythroid 2 p45-related factor 2 (Nrf2) is a transcription factor that regulates the expression of most GST, so in the next experiment, we examined the expression patterns of GSTT1 and GSTP in granulosa cells from Nrf2-disrupted (Nrf2–/–) mice by immunostaining. The GSTP was down-regulated in granulosa cells of Nrf2–/– mice compared with those of Nrf2+/– mice, although a significant difference was not observed in GSTT1. In addition, we confirmed these results by using mouse embryonic fibroblasts (MEF) from Nrf2–/– and Nrf2+/– mice, and the same results were obtained. Our previous experiment showed that GSTT1 was induced by FSH in human granulosa-like tumour cells (KGN cells). We analysed the expression level of other genes in FSH-stimulated KGN cells. The transcription levels of GSTP and Nrf2 were not induced by FSH. These results suggest that the expression of GSTT1 is not regulated by Nrf2 and is differentially regulated from other GST. The difference in regulation mechanisms between GSTT1 and other GST may result in the up-regulation of GSTT1 in the aging granulosa cells, and it may contribute to the constitution of the diagnosis of oocyte quality using the GSTT1 measurement.