Living alone predicts poor prognosis among patients with acute myocardial infarction

BACKGROUND

Living alone as a proxy for social isolation has been considered to increase the risk of cardiovascular disease. We thus investigated the impact of living alone on mortality in acute myocardial infarction (AMI) patients.

METHODS

Subjects comprised 277 AMI patients who underwent percutaneous coronary intervention (PCI). Associations between all-cause and cardiac deaths after PCI and baseline characteristics including living alone and Global Registry of Acute Coronary Events (GRACE) risk score were assessed.

RESULTS

Eighty-three patients (30%) were living alone. Thirty patients died after PCI, including 20 cardiac deaths. Patients living alone showed higher incidences of both all-cause and cardiac deaths compared with patients not living alone (18% vs. 8%, P  = 0.019 and 14% vs. 4%, P  = 0.004). Multivariate Cox proportional hazards regression analysis models showed living alone [hazard ratio (HR), 2.60; 95% confidence interval (CI), 1.20-5.62; P  = 0.016 and HR, 4.17; 95% CI, 1.60-10.84; P  = 0.003] and GRACE risk score (HR, 1.02; 95% CI, 1.01-1.03; P  = 0.003 and HR, 1.03; 95% CI, 1.01-1.04; P  < 0.001) correlated significantly with all-cause and cardiac deaths. Cox proportional hazards modeling revealed that patients living alone with GRACE risk score ≥162 derived from the receiver-operating characteristic curve showed a significantly greater risk of all-cause death than patients not living alone with GRACE risk score <162 (HR 16.57; 95% CI 6.67-41.21; P  < 0.001).

CONCLUSION

Among AMI patients, living alone represents an independent risk factor for all-cause and cardiac deaths after PCI, separate from GRACE risk score. Furthermore, AMI patients living alone with high GRACE risk scores may experience an additively increased risk of mortality after PCI.

Different effects of medications for hypertension on renal function between patients with and without diabetes mellitus undergoing percutaneous coronary intervention: a retrospective single-center cohort study

BACKGROUND

Diabetes mellitus (DM) and hypertension are well-known atherosclerosis risk factors. Furthermore, renal dysfunction is a crucial risk factor for patients with coronary artery disease (CAD), and managing renal function in these patients is complicated because of comorbid conditions and potential side effects during treatment. Therefore, this study aimed to investigate the effect of medications for hypertension on renal function after percutaneous coronary intervention (PCI) between patients with and without DM with statins.

METHODS

In 297 consecutive patients undergoing PCI for stable angina pectoris, cystatin C (CysC) was evaluated at baseline and 9 months after PCI, and the percent change in CysC (%CysC) was calculated. The association of worsening renal function (WRF: %CysC ≥ 0) and baseline characteristics, including medications, was assessed.

RESULTS

Among 297 hypertensive patients with statins, 196 and 101 were with and without DM, respectively. Angiotensin-converting enzyme inhibitor (ACEI), angiotensin II receptor blocker, and β-blocker were prescribed in 56 (29%), 82 (42%), and 91 (46%) patients in the DM group, and 20 (20%), 52 (51%), and 52 (51%) in the non-DM group, respectively. The patients with WRF after PCI were 100 (51%) and 59 (58%) in the DM and non-DM groups (p = 0.261). Additionally, the %CysC had no significant differences between groups [median: 0%, interquartile range (IQR): -7.9% to 8.5% vs. median: 1.1%, IQR: -6.6% to 9.6%, p = 0.521]. Multivariate logistic analysis for WRF using relevant factors from univariate analysis showed that only β-blocker [odds ratio (OR): 2.76, 95% confidence interval (CI): 1.03-7.90, p = 0.048] was independently associated with WRF in the DM group whereas ACEI (OR: 0.07, 95% CI: 0.01-0.47, p = 0.012) was negatively correlated with WRF in the non-DM group.

CONCLUSION

The β-blocker was the independent risk factor for WRF in patients with DM in the late phase after PCI for stable angina pectoris, while the use of ACEI had a renoprotective effect in patients without DM.

Secondary rotational atherectomy is associated with reduced occurrence of prolonged ST-segment elevation following ablation

Elevation of the ST segment after percutaneous coronary intervention (PCI) using rotational atherectomy (RA) for severely calcified lesions often persists after disappearance of the slow-flow phenomenon on angiography. We investigated clinical factors relevant to prolonged ST-segment elevation following RA among 152 patients with stable angina undergoing elective PCI. PCI procedures were divided into two strategies, RA without (primary RA strategy) or with (secondary RA strategy) balloon dilatation before RA. Incidence of prolonged ST-segment elevation after disappearance of slow-flow phenomenon was higher in the 56 patients with primary RA strategy (13%) than in the 96 patients with secondary RA strategy (3%, p = 0.039). Univariate logistic regression analysis showed levels of low-density lipoprotein cholesterol (LDL-C) (odds ratio [OR] 0.95, 95% confidence interval [CI] 0.93-0.99; p = 0.013), levels of triglycerides (OR 0.97, 95%CI 0.94-0.99; p = 0.040), and secondary RA strategy (OR 0.23, 95% CI 0.05-0.85; p = 0.028) were inversely associated with occurrence of prolonged ST-segment elevation following ablation. However, hemodialysis, diabetes mellitus, left-ventricular ejection fraction, lesion length ≥ 20 mm, and burr size did not show significant associations. Multivariate logistic regression analysis modeling revealed that secondary RA strategy was significantly associated with the occurrence of prolonged ST-segment elevation (Model 1: OR 0.24, 95% CI 0.05-0.95, p = 0.042; Model 2: OR 0.17, 95% CI 0.03-0.68, p = 0.018; Model 3: OR 0.21, 95% CI 0.03-0.87, p = 0.041) even after adjusting for levels of LDL-C and triglycerides. Secondary RA strategy may be useful to reduce the occurrence of prolonged ST-segment elevation following RA.

Secondary rotational atherectomy strategy may reduce the occurrence of prolonged ST-segment elevation following ablation

Background

Rotational atherectomy (RA) has been widely used for severely calcified lesions in performing percutaneous coronary intervention (PCI). The slow flow phenomenon is the most frequently observed complication of RA and leads to prolonged ST-segment elevation. The incidence of the slow flow phenomenon was reported as approximately 5–20%. Several methods have been recommended to treat the slow flow phenomenon; however, the elevation of ST-segment may often persist after disappearance of slow flow phenomenon on angiography.

Purpose

The aim of the present study was to investigate the clinical factors on the incidence of prolonged ST-segment elevation following ablation of RA.

Methods

The subject comprised 140 consecutive stable angina patients with severe calcified lesions. All patients had undergone successfully elective PCI using RA and intravascular ultrasound, and had been prescribed strong statins more than 2 week before PCI regardless dyslipidemia. We investigated the occurrence of prolonged ST-segment elevation following ablation of RA with resistance to use of nitroprusside as intra-coronary vasodilators, and the clinical factors including of primary or secondary RA strategy for calcification lesions. Secondary RA strategy was defined as RA performed after pre-dilatation with small balloon (balloon/artery ratio = 0.6).

Results

Median of age was 71 years (66–80) and 98 cases (70%) were male. Of 140 target lesions, 82 (59%) were LAD (RCA; 24%, LCX; 16%, and LMT; 1%, respectively). The rates of hemodialysis and diabetes mellitus were 31% and 61%. The incidence of prolonged ST-segment elevation with resistance to use of nitroprusside as intra-coronary vasodilators was 8 cases (6%). Major complications of RA including coronary perforation, coronary rupture, burr entrapment and cardiogenic shock requiring the mechanical support were none. Univariate logistic regression analysis showed that age [Odds ratio (OR); 1.07, 95% confidence interval (CI) 0.99–1.17, p=0.103], hemodialysis (OR; 0.71, 95% CI: 0.10–3.25, p=0.688), diabetes mellitus (OR; 1.08, 95% CI: 0.25–5.46, p=0.915), use of β-blocker (OR; 0.70, 95% CI: 0.14–2.96, p=0.633), left ventricular ejection fraction (OR; 0.99, 95% CI: 0.94–1.05, p=0.781), lesion length ≥20mm (OR; 1.04, 95% CI: 0.23–7.33, p=0.962), and burr size (OR; 2.42, 95% CI: 0.53–16.95, p=0.289) were not associated with the incidence of prolonged ST-segment elevation. Multivariate logistic regression analysis for the incidence of prolonged ST-segment elevation revealed that secondary RA strategy and levels of low-density lipoprotein cholesterol (LDL-C) were independent factors of the incidence of prolonged ST-segment elevation following ablation of RA (OR; 0.05, 95% CI: 0.01–0.39, p=0.017 and LDL-C: OR 0.91, 95% CI 0.83–0.96, p=0.010, respectively).

Conclusion

Secondary RA strategy may be useful to reduce the occurrence of prolonged ST-segment elevation following ablation of RA.

Funding Acknowledgement

Type of funding sources: None.

Association of wound, ischemia, and foot infection clinical stage with frailty and malnutrition in chronic limb-threatening ischemia patients undergoing endovascular intervention

OBJECTIVE

The Wound, Ischemia, and foot Infection (WIfI) clinical stage has been thought to have a prognostic value in Chronic limb-threatening ischemia (CLTI) patients, and frailty and nutritional status appear to represent pivotal factor affecting prognosis among CLTI patients. The purpose of this study was to examine clinical factors (including frailty and nutritional status) relevant to WIfI clinical stage.

METHODS

This retrospective study investigated 200 consecutive CLTI patients. We individually assessed WIfI clinical stage, frailty according to the Clinical Frailty Scale (CFS) score, and malnutrition according to Geriatric Nutritional Risk Index (GNRI). We then compared mortality after endovascular intervention between a WIfI stage 1, 2 group and a stage 3, 4 group, and investigated associations between baseline characteristics (including CFS and GNRI) and WIfI clinical stage.

RESULTS

Among 200 patients, 123 patients (62%) showed WIfI stage 1 or 2, and the remaining 77 patients (38%) had WIfI stage 3 or 4. CFS score was significantly higher in the WIfI stage 3, 4 group [median 6.0, interquartile range (IQR) 5.5-7.0] compared with the WIfI stage 1, 2 group (median 5.0, IQR 4.0-6.0, p < 0.001), and GNRI was significantly lower in the WIfI stage 3, 4 group (median 88, IQR 80-97) than in the WIfI stage 1, 2 (median 103, IQR 94-111, p < 0.001). Forty patients (20%) died after endovascular intervention. Incidences of all-cause and cardiac deaths were higher in the WIfI stage 3, 4 group than in the WIfI stage 1, 2 group (27% vs. 15%, p = 0.047 and 12% vs. 3%, p = 0.040, respectively). Kaplan-Meier analysis showed a significantly lower survival rate in the WIfI stage 3, 4 group than in the WIfI stage 1, 2 group (p = 0.002 by log-rank test). Multivariate logistic regression analysis using relevant factors from univariate analysis showed CFS score [odds ratio (OR) 2.06, 95% confidence interval (CI) 1.41-3.13, p < 0.001), diabetes mellitus (OR 3.17, 95%CI 1.17-8.61, p = 0.023) and GNRI (OR 0.93, 95%CI 0.89-0.97, p = 0.002) significantly associated with WIfI stage 3 or 4. In addition, multivariate ordinal logistic regression analysis for WIfI clinical stage showed CFS score (OR 1.43, 95%CI 1.09-1.89, p = 0.011), diabetes mellitus (OR 1.77, 95%CI 1.26-2.54, p < 0.001), and high-sensitivity C-reactive protein (OR 1.14, 95%CI 1.02-1.28, p = 0.041) were positively associated with WIfI clinical stage, and GNRI correlated negatively with WIfI clinical stage (OR 0.95, 95%CI 0.91-0.97, p < 0.001).

CONCLUSIONS

These results indicate that CLTI patients with high WIfI clinical stage may be more frail and malnourished, and be associated with poor prognosis after endovascular intervention.

Impact of nutritional status on prognosis in acute myocardial infarction patients undergoing percutaneous coronary intervention

BACKGROUND

Malnutrition affects the prognosis of cardiovascular disease. Acute myocardial infarction (AMI) has been a major cause of death around the world. Thus, we investigated the impact of malnutrition as defined by Geriatric Nutritional Risk Index (GNRI) on mortality in AMI patients.

METHODS

In 268 consecutive AMI patients who underwent percutaneous coronary intervention (PCI), associations between all-cause death and baseline characteristics including malnutrition (GNRI < 92.0) and Global Registry of Acute Coronary Events (GRACE) risk score were assessed.

RESULTS

Thirty-three patients died after PCI. Mortality was higher in the 51 malnourished patients than in the 217 non-malnourished patients, both within 1 month after PCI (p < 0.001) and beyond 1 month after PCI (p = 0.017). Multivariate Cox proportional hazards regression modelling using age, left ventricular ejection fraction and GRACE risk score showed malnutrition correlated significantly with all-cause death within 1 month after PCI (hazard ratio [HR] 7.04; 95% confidence interval [CI] 2.30-21.51; p < 0.001) and beyond 1 month after PCI (HR 3.10; 95% CI 1.70-8.96; p = 0.037). There were no significant differences in area under the receiver-operating characteristic (ROC) curve between GRACE risk score and GNRI for predicting all-cause death within 1 month after PCI (0.90 vs. 0.81; p = 0.074) or beyond 1 month after PCI (0.69 vs. 0.71; p = 0.87). Calibration plots comparing actual and predicted mortality confirmed that GNRI (p = 0.006) was more predictive of outcome than GRACE risk score (p = 0.85) beyond 1 month after PCI. Furthermore, comparison of p-value for interaction of malnutrition and GRACE risk score for all-cause death within 1 month after PCI, beyond 1 month after PCI, and the full follow-up period after PCI were p = 0.62, p = 0.64 and p = 0.38, respectively.

CONCLUSIONS

GNRI may have a potential for predicting the mortality in AMI patients especially in beyond 1 month after PCI, separate from GRACE risk score. Assessment of nutritional status may help stratify the risk of AMI mortality.

The Priority of Non-HDL-C Assessment to Predict New Lesions among Stable Angina Patients with Strong Statins

Aim: In this study, we aim to examine the clinical meaning of low-density lipoprotein cholesterol (LDL-C) ＜70 mg/dL as assessed by Friedewald equation [LDL-C (F)] and Martin method [LDL-C (M)] and non-high-density lipoprotein cholesterol (HDL-C) ＜100 mg/dL on the occurrence of new lesions among Japanese patients with stable angina who underwent percutaneous coronary intervention (PCI) and were prescribed with strong statins.

Methods: Among the 537 consecutive stable angina patients who had underwent PCI and had been prescribed with strong statins, the association between the occurrence of new lesions with myocardial ischemia at the 9-month follow-up coronary angiography and ≤ 2 years after PCI and baseline characteristics were assessed.

Results: New lesions appeared 9 months and ≤ 2 years after PCI in 31 and 90 patients, respectively. Multivariate logistic regression analysis revealed diabetes mellitus (DM) was significantly associated with the occurrence of new lesions ≤ 2 years after PCI [odds ratio (OR) 1.71, 95 % confidence interval (CI) 1.06–2.83,p=0.031], and only non-HDL-C ≥ 100 mg/dL was associated with the occurrence of new lesions both at 9 months and ≤ 2 years after PCI [OR 1.80, 95 % CI 1.10–3.00,p=0.021 and OR 1.85, 95 % CI 1.13–3.07,p=0.016].

Conclusions: Non-HDL-C ≥ 100 mg/dL was determined to be the independent risk factor for the occurrence of new lesions 9 months and ≤ 2 years after PCI among stable angina patients with strong statins. Residual risk after PCI should be considered by assessing not only DM but also non-HDL-C beyond the scope of LDL-C-lowering therapy with strong statins.

Coronary artery perforation secondary to lifesaving pericardiocentesis for cardiac tamponade: a case report

BACKGROUND

Pericardiocentesis is frequently performed when fluid needs to be removed from the pericardial sac, for both therapeutic and diagnostic purposes, however, it can still be a high-risk procedure in inexperienced hands and/or an emergent setting.

CASE PRESENTATION

A 78-year-old male made an emergency call complaining of the back pain. When the ambulance crew arrived at his home, he was in a state of shock due to cardiac tamponade diagnosed by portable echocardiography. The pericardiocentesis was performed using a puncture needle on site, and the patient was immediately transferred to our hospital by helicopter. Contrast-enhanced computed tomography showed a small protrusion of contrast media on the inferior wall of the left ventricle, suggesting cardiac rupture due to acute myocardial infarction. Emergency coronary angiography was then performed, which confirmed occlusion of the posterior descending branch of the left circumflex coronary artery. In addition, extravasation of contrast medium due to coronary artery perforation was observed in the acute marginal branch of the right coronary artery. We considered that coronary artery perforation had occurred as a complication of the pericardial puncture. We therefore performed transcatheter coil embolization of the perforated branch, and angiography confirmed immediate vessel sealing and hemostasis. After the procedure, the patient made steady progress without a further increase in pericardial effusion, and was discharged on the 50th day after admission.

CONCLUSIONS

When performing pericardial drainage, it is important that the physician recognizes the correct procedure and complications of pericardiocentesis, and endeavors to minimize the occurrence of serious complications. As with the patient presented, coil embolization is an effective treatment for distal coronary artery perforation caused by pericardiocentesis.

Use of proton pump inhibitors is associated with an increase in adverse cardiovascular events in patients with hemodialysis: Insight from the kids registry

BACKGROUND

Proton pump inhibitors (PPIs) are known to increase the risk of mortality and cardiovascular events in the general population. However, in patients with maintenance hemodialysis, PPI effects are under investigated.

METHODS

We analyzed the risk of PPIs for cardiovascular events using the Kagoshima Dialysis (KIDS) registry, a prospective, multicenter, observational study in patients with maintenance hemodialysis in Japan.

RESULTS

In all, 531 patients were enrolled from June 2015 to December 2018. One-year follow-up data were available for 376 patients (Use of PPIs at baseline (PPI group): 217 patients and without PPIs (No PPI group): 159 patients). The incidence of a composite outcome (all-cause mortality, non-fatal myocardial infarction, or non-fatal stroke) was higher in patients in the PPI group than the No PPI group (15.2% vs. 4.4%; hazard ratio (HR): 3.65, 95% confidence interval (CI): 1.61-8.23, P = 0.002). In the multivariate analysis, even after adjustment for covariates, the use of PPIs was an independent risk factor for a composite outcome (HR: 2.38, 95% CI: 1.02-5.54, P = 0.045). We performed propensity score matching analysis as a sensitivity analysis, showing a consistent result. The incidence of bleeding showed no difference between the two groups (15.7% vs. 11.3%; HR: 1.46, 95% CI: 0.83-2.59, P = 0.19).

CONCLUSIONS

These results indicate that the use of PPIs in patients with maintenance hemodialysis might increase mortality and cardiovascular events without decreasing the risk of bleeding. Therefore, it should always be analyzed if a patient truly needs PPIs.

Malnutrition and Clopidogrel Non-Use Worsen Prognosis of Critical Limb Ischemia Patients After Revascularization

Background: Critical limb ischemia (CLI) patients have high risk for major adverse cerebrovascular and cardiovascular events. This study investigated the risk factors of cerebrovascular or cardiovascular death in CLI patients with concomitant coronary artery disease (CAD). Methods and Results: The association between baseline characteristics and cerebrovascular or cardiovascular death ≤2 years after revascularization for CLI was investigated in 137 CLI patients who previously underwent successful revascularization for CAD before treatment for CLI. Twenty-three patients (17%) died. Geriatric nutritional risk index (GNRI) in the deceased group (DG) was significantly lower than in the surviving group (SG). On Cox proportional hazard multivariate analysis, hemodialysis (HD) and malnutrition (defined as GNRI <92) were significantly associated with cerebrovascular or cardiovascular death. Also, on Kaplan-Meier analysis, survival rate was significantly lower in CLI patients with either malnutrition or HD compared with patients without either malnutrition or HD, respectively. Furthermore, clopidogrel was less used in the DG than in the SG. The use of clopidogrel was associated with cerebrovascular or cardiovascular death. Especially, non-use of clopidogrel in the malnutrition group further increased the correlation with cerebrovascular or cardiovascular death. Conclusions: Malnutrition is a crucial risk factor for cerebrovascular and cardiovascular death in CLI patients with CAD. Nutritional status intervention and use of clopidogrel may be an important strategy for CLI.

P3626Malnutrition is a major factor to affect prognosis of coronary artery disease patients with myocardial damage

Background

Malnutrition is the important factor to cause frailty and sarcopenia which affect the prognosis of cardiovascular diseases. However, the effect of malnutrition on prognosis of coronary artery disease (CAD) patients with myocardial damage is still uncertain.

Purpose

The aim of the present study was to investigate the effect of malnutrition on prognosis of CAD patients with myocardial damage who received percutaneous coronary intervention (PCI).

Methods

The subjects were 241 CAD patients with myocardial damage due to myocardial ischemia by coronary artery stenosis or occlusion. These patients underwent successful revascularization for CAD by PCI using second-generation drug eluting stents and discharged. Geriatric Nutritional Risk Index (GNRI) was used to assess nutritional status in this study, and patients with GNRI<92 at baseline were defined as malnutrition group. The association between MACCE (major cardiovascular and cerebrovascular events) after discharged and patient's characteristics including nutritional status at baseline were assessed.

Results

The mean follow-up period was 546±310 days, with a maximum follow-up duration of 1092 days. MACCE within 3 years after PCI were 42 cases (17%) and malnutrition group had high rate of MACCE (38 vs. 11%, P<0.01) compared with non- malnutrition group. In malnutrition group, age (77±9 vs. 67±11 years, P<0.01) and high-sensitivity C-reactive protein (hs-CRP) level (5.52±6.63 vs. 0.72±1.86 mg/dl, P<0.01) were higher than those of non-malnutrition group. The serum albumin (Alb) level (3.0±0.5 vs. 4.0±0.4 mg/dL, P<0.01), hemoglobin (Hb) (10.4±1.9 vs. 12.8±2.4 g/dL, P<0.01), total cholesterol (151.8±32 vs. 174.1±41.6 mg/dL, P<0.01), triglycerides (96.9±49.1 vs. 140.6±128.3 mg/dL, P<0.01), and left ventricular ejection fraction (LVEF) (50.2±15.9 vs. 55.9±15.3%, P=0.03) were lower in malnutrition group than those in non-malnutrition group. Moreover, malnutrition group had lower rate of hemodialysis (HD) (35 vs. 65%, P<0.01), dyslipidemia (16 vs. 84%, P<0.01) and using of statins (16 vs. 83%, P=0.02) than those in non-malnutrition group. As a result of Cox proportional hazards analysis, MACCE was associated with age [hazard ratio (HR): 1.04, 95% confidence interval (CI): 1.01–1.07, p p<0.01)], hs-CRP (HR: 1.08, 95% CI: 1.03–1.11, p<0.01), HD (HR: 2.63, 95% CI: 1.51–4.58, p<0.01) and malnutrition (HR: 3.69, 95% CI: 2.11–6.42, p<0.01) in the univariate analysis. The multivariate Cox proportional hazards analysis revealed that HD (HR: 2.24, 95% CI: 1.24–4.08, p<0.01) and malnutrition (HR: 2.10, 95% CI: 1.04–4.23, p=0.03) were significantly associated with MACCE. Furthermore, malnutrition additively facilitated incidence of MACCE among patients underwent HD (GNRI <92+HD: HR 4.19, 95% CI: 2.22–7.88, p<0.001, GNRI >92+HD: HR 1.26, 95% CI: 0.65–2.47, p=0.493).

Conclusions

In CAD patients with myocardial damage, malnutrition (GNRI<92) is a major risk factor for MACCE after PCI.

Validity of a Novel Method for Estimating Low-Density Lipoprotein Cholesterol Levels in Cardiovascular Disease Patients Treated with Statins

AIM

The Friedewald equation is the standard method for estimating low-density lipoprotein cholesterol (LDL-C) levels [LDL-C(F)] and fixes the ratio of triglyceride (TG) to very LDL-C at 5. However, this has been reported to underestimate LDL-C, particularly in patients with LDL-C ＜70 mg/dL. A novel method for LDL-C estimation [LDL-C(M)] using an adjustable factor instead of a fixed value of 5 has recently been proposed. The purpose of this study was to validate LDL-C(M) in Japanese patients with cardiovascular disease (CVD) treated with statins.

METHODS

In 385 consecutive CVD patients treated with statins, LDL-C(M) and LDL-C(F) levels were compared with directly measured LDL-C [LDL-C(D)].

RESULTS

Mean LDL-C(D), LDL-C(F), and LDL-C(M) were 81.7±25.5, 76.4±24.6, and 79.9±24.5 mg/dL, respectively. In all patients, both LDL-C(F) and LDL-C(M) were significantly correlated with LDL-C(D) [LDL-C(F) vs. LDL-C(D): R=0.974, p＜0.001; LDL-C(M) vs. LDL-C(D): R=0.987, p＜0.001]. In patients with LDL-C(D) ＜70 mg/dL, LDL-C(M) showed a better correlation with LDLC(D) compared with LDL-C(F) [LDL-C(M) vs. LDL-C(D): R=0.935, p＜0.001; LDL-C(F) vs. LDLC(D): R=0.868, p＜0.001]. In contrast, the correlation of LDL-C(D) with LDL-C(M) or LDL-C(F) was similar in patients with LDL-C(D) ≥70 mg/dL.

CONCLUSIONS

In Japanese patients with CVD treated with statins, LDL-C level estimated by this novel method might be more accurate than those estimated using the Friedewald equation for LDL-C levels ＜70 mg/dL.

Prospective Study on the Incidence of Cerebrovascular Disease After Coronary Angiography

AIM

Previous studies have reported a 10.2%-22% rate of silent cerebral infarction and a 0.1%-1% rate of symptomatic cerebral infarction after coronary angiography (CAG). However, the risk factors of cerebral infarction after CAG have not been fully elucidated. For this reason, we investigated the incidence and risk factors of CVD complications within 48 h after CAG using magnetic resonance imaging (MRI) (Diffusion-weighted MRI) at Kagoshima University Hospital.

METHODS

From September 2013 to April 2015, we examined the incidence and risk factors, including procedural data and patients characteristics, of cerebrovascular disease after CAG in consecutive 61 patients who underwent CAG and MRI in our hospital.

RESULTS

Silent cerebral infarction after CAG was observed in 6 cases (9.8%), and they should not show any neurological symptoms of cerebral infarction. Only prior coronary artery bypass grafting (CABG) was more frequently found in the stroke group (n=6) than that in the non-stroke group (n=55); however, no significant difference was observed (P=0.07). After adjusting for confounders, prior CABG was a significant independent risk factor for the incidence of stroke after CAG (odds ratio: 11.7, 95% confidence interval: 1.14-129.8, P=0.04).

CONCLUSIONS

We suggested that the incidence of cerebral infarction after CAG was not related to the catheterization procedure per se but may be caused by atherosclerosis with CABG.

Angiotensin-Converting Enzyme Inhibitor Prevents the Worsening of Renal Function in the Late Phase after Percutaneous Coronary Intervention

AIM

The amount of contrast media and renal atheroemboli are risk factors for acute kidney injury after percutaneous coronary intervention (PCI). However, the chronic kidney injury after PCI has not been fully characterized. The purpose of this study was to investigate factors affecting renal function in the late phase after PCI by measuring serum Cystatin C (CysC).

METHODS

In 143 consecutive patients who underwent elective PCI, CysC was evaluated at baseline and at 9 months after PCI, and the percent change in CysC (%CysC) was calculated. The association between %CysC and baseline characteristics, including medication use, was assessed.

RESULTS

Of 143 patients, 86 had worsening renal function (WRF; %CysC ≥0), and 57 did not (non-WRF; %CysC <0). Only the use of angiotensin-converting enzyme inhibitor (ACEI) and baseline CysC were significantly different between WRF and non-WRF patients (15 vs. 40%, p=0.001 and 1.02±0.26 vs. 1.13±0.26 mg/L, p=0.015). In univariate analysis, the use of ACEI and CysC were negatively associated with WRF [Odds ratio (OR)=0.26, 95% confidence interval (CI)=0.12-0.57, p<0.001 and OR=0.20, 95% CI=0.05-0.73, p=0.015]. Furthermore, multivariate analysis revealed that the use of ACEI and CysC significantly correlated with WRF (OR=0.26, 95% CI=0.11-0.57, p<0.001 and OR=0.20, 95% CI=0.05-0.74, p=0.016). The %CysC in 36 patients with ACEI was significantly lower than that in 107 patients without ACEI [median: -3.8%; interquartile range (IQR), -11.0 to 4.2%; vs. median: 3.3%; IQR -2.9 to 11.0%, p=0.001].

CONCLUSION

The use of ACEI was associated with lower CysC after PCI, suggesting that ACEI prevents worsening of renal function in late phase after PCI.

Plaque characteristics and arterial remodeling in coronary and peripheral arterial systems

BACKGROUND

Few studies have examined plaque characteristics among multiple arterial beds in vivo. The purpose of this study was to compare the plaque morphology and arterial remodeling between coronary and peripheral arteries using gray-scale and radiofrequency intravascular ultrasound (IVUS) at clinical presentation.

METHODS AND RESULTS

IVUS imaging was performed in 68 patients with coronary and 93 with peripheral artery lesions (29 carotid, 50 renal, and 14 iliac arteries). Plaques were classified as fibroatheroma (VH-FA) (further subclassified as thin-capped [VH-TCFA] and thick-capped [VH-ThCFA]), fibrocalcific plaque (VH-FC) and pathological intimal thickening (VH-PIT). Plaque rupture (13% of coronary, 7% of carotid, 6% of renal, and 7% of iliac arteries; P = NS) and VH-TCFA (37% of coronary, 24% of carotid, 16% of renal, and 7% of iliac arteries; P = 0.02) were observed in all arteries. Compared with coronary arteries, VH-FA was less frequently observed in renal (P < 0.001) and iliac arteries (P < 0.006). Lesions with positive remodeling demonstrated more characteristics of VH-FA in coronary (84% vs. 25%, P < 0.001), carotid (72% vs. 20%, P = 0.001), and renal arteries (42% vs. 4%, P = 0.001) compared with those with intermediate/negative remodeling. There was positive relationship between remodeling index and percent necrotic area in all four arteries.

CONCLUSIONS

Atherosclerotic plaque phenotypes were heterogeneous among four different arteries; renal and iliac arteries had more stable phenotypes compared with coronary artery. In contrast, the associations of remodeling pattern with plaque phenotype and composition were similar among the various arterial beds.

REV-ERBα and the clock gene machinery in mouse peripheral tissues: a possible role as a synchronizing hinge

Rhythmic oscillations of cellular biological processes are driven by translational-transcriptional feedback loops that realize molecular clocks ticking in every single cell, driven by neural and humoral outputs from the suprachiasmatic nuclei of the hypothalamus that are entrained by environmental photon inputs. The nuclear receptor REV-ERBα has the capability to reset the molecular oscillators of peripheral tissues. The aim of our study was to evaluate the clock gene machinery function in light/dark cycles (LD) and in constant darkness (DD) exploiting in particular the REV-ERBα pattern of expression by using data from two independent experimental settings to reduce procedure related influences. In the LD study C57BL/6 male mice housed on a 12L:12D cycle were sacrificed at 4 h intervals. Liver, kidney, spleen, thymus and testis were harvested and blood was collected. Expression levels of PER1, PER2, CRY1, CRY2, BMAL1, REV-ERBα, CLOCK were evaluated by qRT-PCR. In the DD study Balb/c male mice in the third DD cycle as a continuation of the dark phase of the last LD cycle were sacrificed at 4 h intervals. Lung, heart, liver, stomach, kidney, spleen, and testis were harvested and mRNA expression of PER1, PER2, CRY1, CRY2, BMAL1, REV-ERBα, CLOCK, was evaluated by qRT-PCR. A statistically significant difference was found for the size of the semi-interquartile range of acrophases of clock gene expression in different organs evaluated in LD and DD conditions (4:38∓1:12h versus 1:16∓0:10h, p=0.026). A statistically significant difference was found for the acrophases of clock gene expression in different organs evaluated in LD (p=0.01) and in DD (p<0.0001). In LD study only REV-ERBα showed concomitant expression in the different peripheral tissues with the phase peaking around 07:03∓0.8h. In the DD study all the core clock genes showed concomitant phases in different peripheral mouse tissues and REV-ERB alpha expression peaked around 07:09∓0.9h. In conclusion, REV-ERBα is the only clock gene that maintains its timing of oscillation in the LD study and in the DD study and its phase of expression remains concomitant in the different mouse peripheral tissues in the presence of LD alternance, or in constant darkness. Oscillation in REV-ERBα ligands (heme, carbon monoxide) may affect not only the phase and amplitude of circadian rhythms, but also physiological outputs of the circadian system and REV-ERBalpha may participate in the entrainment of central and peripheral clocks, functioning as a synchronizing hinge of the clock gene machinery.

Characterization of the effect of serum bilirubin concentrations on coronary endothelial function via measurement of high-sensitivity C-reactive protein and high-density lipoprotein cholesterol

Bilirubin can prevent oxidation of low-density lipoprotein (LDL) and may protect against atherosclerosis and coronary heart disease (CHD). The goal of this study was to characterize the relationship between bilirubin and CHD through measurements of bilirubin concentration, coronary endothelial function, and markers of oxidative stress, inflammation, and lipid/glucose metabolism. The study population consisted of 141 patients without CHD who underwent Doppler flow study. Vascular reactivity was examined by intracoronary administration of papaverine, acetylcholine (ACh) and nitroglycerin using a Doppler guide wire. Serum bilirubin, high-sensitivity C-reactive protein (hsCRP), malondialdehyde-modified LDL, LDL cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), fasting plasma glucose (FPG), and immunoreactive insulin were also measured. Homeostasis model assessment insulin resistance index and estimated glomerular filtration rate (eGFR) were calculated. Univariate analysis revealed that both percent change in coronary blood flow (CBF) and coronary artery diameter induced by ACh correlated positively with log-transformed bilirubin (r = 0.22, P < 0.05; r = 0.20, P < 0.05, respectively). Percent change in CBF in response to ACh correlated positively with eGFR (r = 0.24, P < 0.05) and correlated inversely with age, LDL-C, and log-transformed FPG (r = -0.24, P < 0.05; r = -0.17, P < 0.05, r = -0.22, P < 0.05, respectively). Multivariate analysis revealed that log-transformed bilirubin was the only independent predictor of percent change in CBF in response to ACh. Multivariate analysis revealed that log-transformed hsCRP and HDL-C were independent predictors of log-transformed bilirubin. These results suggest that a high level of bilirubin is associated with favorable coronary endothelial function, which may be mediated via the effect of bilirubin on inflammation and HDL-C.

The association between renal atherosclerotic plaque characteristics and renal function before and after renal artery intervention

OBJECTIVE

To evaluate the effect of plaque composition on renal function after renal artery intervention (RAI).

PATIENTS AND METHODS

In 33 consecutive patients with atherosclerotic renal artery stenosis (enrolled between January 1, 2007, and April 30, 2009), renal angiography, pressure gradients across the lesion, and intravascular ultrasonography (IVUS) with virtual histology (VH)-derived plaque characteristics were assessed. In 25 patients who underwent RAI, estimated glomerular filtration rate (eGFR) was evaluated at baseline and at 3 months.

RESULTS

Mean pressure gradients across the lesion were poorly associated with baseline eGFR (r=-0.37; P=.07). In gray scale IVUS data, only remodeling index was significantly correlated with baseline eGFR (r=-0.38; P=.03). Plaque components classified by VH-IVUS had no correlation with baseline eGFR. During follow-up of 25 patients, the improvement in eGFR after RAI was observed in 9 patients, unchanged in 3, and deteriorated in 13. Overall, follow-up eGFR (median, 49.0 mL/min/1.73 m(2); interquartile range [IQR], 40.6-63.9 mL/min/1.73 m(2)) was unchanged compared with baseline eGFR (median, 53.8 mL/min/1.73 m(2); IQR, 41.4-63.4 mL/min/1.73 m(2); P=.38). The percent change in eGFR (median, -0.2%; IQR, -16.0% to 16.0%) after RAI had a significant negative correlation with the mean percentage of necrotic core classified by VH-IVUS (r=-0.47; P=.02), and the mean percentage of necrotic core was significantly larger in patients with deterioration of eGFR than in patients without deterioration of eGFR (median, 12.7%; IQR, 9.5%-19.5%; vs median, 8.3%; IQR, 5.5%-11.6%; P=.04).

CONCLUSION

In patients with atherosclerotic renal artery stenosis, the change in eGFR after RAI was related to plaque composition classified by VH-IVUS. The evaluation of plaque composition may provide more insights into the change in renal function after RAI.

Coronary endothelial dysfunction is associated with a reduction in coronary artery compliance and an increase in wall shear stress

OBJECTIVE

Endothelial dysfunction is associated with arterial stiffness in large arteries. The purpose of this study was to investigate the association between coronary endothelial dysfunction, coronary artery compliance and wall shear stress in patients with early atherosclerosis.

METHODS

Coronary endothelial function was assessed according to responses to intracoronary acetylcholine in 120 patients without significant coronary stenosis. Acceleration of peak velocity (ACC), which is inversely related to coronary artery compliance, was derived from coronary flow velocity spectra, and wall shear rate (WSR) was calculated. Measurements were performed at baseline and after intracoronary nitroglycerin in order to eliminate the contribution of vascular smooth muscle tone to coronary artery compliance.

RESULTS

In all patients, heart rate significantly increased (72+/-1 to 77+/-1 bpm, p<0.01) and mean arterial pressure decreased (97+/-2 to 93+/-1 mm Hg, p<0.01) after nitroglycerin. Coronary blood flow (CBF) and resistance were not significantly changed, but the diastolic to systolic velocity ratio increased significantly (2.15+/-0.08 to 5.36+/-0.61, p<0.01). Patients with abnormal endothelial function (n=70) had a higher WSR at baseline (559+/-41 vs 440+/-26 s(-1), p<0.05) and after nitroglycerin (457+/-41 vs 339+/-29 s(-1), p<0.05), and a higher ACC after nitroglycerin (3.9+/-0.4 vs 2.8+/-0.4 m/s(2), p<0.05) than patients with normal function (n=50).

CONCLUSIONS

The current study demonstrates that intracoronary nitroglycerin does not contribute to an increase of CBF but alters the phasic coronary flow pattern. Furthermore, early coronary atherosclerosis characterised by endothelial dysfunction is associated with a decrease in coronary artery compliance and an increase in wall shear stress. Therefore, coronary wall properties are affected early in the atherosclerosis process.

Relationship between hyperglycemia and coronary vascular resistance in non-diabetic patients

BACKGROUND

Hyperglycemia upon hospital admission in patients with acute myocardial infarction is associated with the no-reflow phenomenon after successful reperfusion, and increased mortality. However, the mechanism underlying this phenomenon remains unclear. Therefore, the aim of this study was to characterize coronary hemodynamics in a homogenous group of non-diabetic patients without coronary artery disease.

METHODS AND RESULTS

A total of 104 consecutive non-diabetic patients (mean age, 62+/-14 years) without coronary artery disease underwent Doppler flow study of the left anterior descending coronary artery. Vascular reactivity was examined by intra-coronary administration of papaverine, acetylcholine (Ach), and nitroglycerin using a Doppler guidewire. Coronary vascular resistance (CVR) was calculated as the mean arterial pressure divided by coronary blood flow (CBF). Baseline CVR was shown as CVR at control and minimal CVR was shown as CVR with papaverine administration. Fasting plasma glucose (FPG) level had a significant, positive correlation with baseline CVR and minimal CVR (r=0.24, p<0.02 and r=0.21, p<0.05, respectively). Hemoglobin A1c (HbA1c) also had a significant, positive correlation with baseline CVR and minimal CVR (r=0.31, p<0.01 and r=0.32, p<0.01, respectively). The percent change in CBF induced by Ach was inversely correlated with HbA1c but not with FPG (r=0.22, p<0.05 and r=0.06, p=0.57, respectively). By contrast, neither FPG nor HbA1c had significant correlation with coronary flow reserve to papaverine.

CONCLUSION

These data demonstrate that elevated glucose levels are associated with increases in baseline and minimal coronary vascular resistance. These changes may contribute to unfavorable coronary hemodynamics in non-diabetic patients without coronary heart disease.

Time microscopy of circadian expression of cardiac clock gene mRNA transcription: chronodiagnostic and chrono-therapeutic implications

BACKGROUND AND PURPOSE

Molecular clocks present in organs and individual cells throughout the body are central for the temporal coordination of internal biological processes among themselves and with external environmental cycles. Relationships between circadian clocks and normal vs. abnormal organ physiology can have significant impact relevant to not only cardiovascular health, but also to the general treatment and prognosis of human disease. Chronobiological statistical procedures were applied to previously published circadian clock gene (CG) mRNA expression data which were described macroscopically, in order to establish rhythm probability and point and interval estimates for amplitudes and acrophases for 14 clock and clock-controlled genes in mouse heart. CGs in general and their importance to cardiovascular health, as well as to diagnosis and treatment of human disease, are reviewed.

MATERIALS AND METHODS

Organs from male Balb/c mice were harvested every 4 h for 24-h on the 3rd day in constant darkness and analyzed by quantitative real-time reverse transcription-polymerase chain reaction for 14 CGs: mPer1, mPer2, mPer3, mCry1, mCry2, mBmal1, mCK1delta, mCK1epsilon, mClock, mDbp, mNpas2, mRev-erbalpha, mRev-erbbeta, and mTim. Relative mRNA levels normalized to corresponding G3-PDH RNA levels were re-expressed as percent of the highest value for each CG and analyzed for circadian time effect by one-way ANOVA and for circadian rhythm characteristics by single cosinor.

RESULTS

12 CGs showed a significant time-effect at p < or = 0.031 by ANOVA and 13 CGs displayed a significant 24-h rhythm at p < or = 0.011 by cosinor analysis. Five CGs (mRev-erbalpha, mDbp, mPer1, mRev-erbbeta, mPer3) reached their maxima late in the presumed resting span, 5 CGs (mPer2, mCry2, mCK1delta, mCK1epsilon, mCry1) reached their peak early in the presumed activity span, while 3 genes (mBmal1, mClock, mNpas2) reached their peak late in the presumed activity span.

CONCLUSIONS

Macroscopic inspection concluded a robust circadian rhythm in 8 CGs, while cosinor analysis detected significance in 13 of 14 CGs (the developmental gene mTim is usually not circadian rhythmic) and computed point and interval estimates for amplitudes and acrophases, useful in making future objective comparisons among organisms and conditions. Information on statistically-determined rhythm characteristics of the molecular clock presents new avenues for diagnosis and therapeutic intervention in conditions where disturbance of circadian CG expression is an important cause of morbidity in chronic illnesses and diseases with a strong circadian component, including coronary vascular disease.

Limitation of angiography to identify the culprit plaque in acute myocardial infarction with coronary total occlusion utility of coronary plaque temperature measurement to identify the culprit plaque

OBJECTIVES

The purpose of this study was to test the hypothesis that the maximal temperature (Tmax) site, as measured by thermal wire, coincides with the culprit plaque by intravascular ultrasound (IVUS) in patients with acute myocardial infarction (AMI).

BACKGROUND

Subsequent thrombosis developing to the proximal region from the site of plaque rupture or erosion can potentially complicate the ability of coronary angiography to identify the accurate culprit plaque in patients with coronary total occlusion.

METHODS

In 45 consecutive patients with a first anterior AMI, the Tmax site by thermal wire and the culprit plaque by IVUS were evaluated in the left anterior descending coronary artery (LAD).

RESULTS

Twenty-five patients had LAD total occlusion, and the remaining 20 had LAD reperfusion. In both groups of patients, the Tmax site was significantly more distal to the angiographically most stenotic site or occlusive site (reperfusion: mean distance [MD] = 1.1 mm distal, 95% confidence interval [CI] 0.3 to 1.9 mm, p = 0.01; total occlusion: MD = 8.8 mm distal, 95% CI 8.0 to 9.6 mm, p < 0.0001). The culprit plaques by IVUS approximately coincided with those by angiography or thermal wire in patients with reperfusion. However, the angiographic occlusive site was significantly more proximal to the culprit plaque by IVUS (MD = 9.2 mm, 95% CI 7.9 to 10.6 mm, p < 0.0001), but the Tmax site coincided with the culprit plaque by IVUS (MD = 0.3 mm distal, 95% CI 0.3 mm proximal to 1.0 mm distal, p = 0.293) in patients with total occlusion.

CONCLUSIONS

Temperature measurement of coronary plaque enables accurate localization of the culprit plaque in AMI with coronary total occlusion.

Correlation Between Distal Left Anterior Descending Artery Flow Velocity by Transthoracic Doppler Echocardiography and Corrected TIMI Frame Count Before Mechanical Reperfusion in Patients With Anterior Acute Myocardial Infarction

BACKGROUND

This study was designed to determine the utility of transthoracic Doppler echocardiography (TTDE) in evaluating angiographic Thrombolysis in Myocardial Infarction (TIMI) frame count as a quantitative index of coronary reperfusion in patients with anterior acute myocardial infarction (AMI) before mechanical reperfusion.

METHODS AND RESULTS

Color and pulsed TTDE was performed to evaluate distal left anterior descending coronary artery (LAD) reperfusion in 56 consecutive patients with a first anterior AMI before coronary intervention, and these findings were compared with the corrected TIMI frame count (cTFC) by subsequent angiography. Twenty-four of the 56 patients had LAD reperfusion (TIMI 2 or 3) by angiography. Visual antegrade distal LAD flow by color TTDE was detected in 21 of these 24 patients. In the 21 patients, diastolic peak velocity of the distal LAD flow by pulsed TTDE showed a significant correlation with cTFC by angiography (r = -0.74, p < 0.001). The diagnosis of high risk with angiographic cTFC >40 by distal LAD peak velocity <21 cm/s using TTDE had a sensitivity, specificity, and accuracy of 82%, 93%, and 91%, respectively.

CONCLUSION

TTDE enables noninvasive and quantitative evaluation of distal LAD reperfusion in patients with anterior AMI in the acute phase before mechanical reperfusion.

Evidence that TGF beta may directly modulate POMC mRNA expression in the female rat arcuate nucleus

The purpose of the present study was to determine whether TGF beta, a cytokine secreted by hypothalamic astrocytes, was able to regulate POMC neurons in the arcuate nucleus. In a first set of experiments, mediobasal hypothalamic fragments were exposed to TGF beta(1), and the relative POMC mRNA expression was assessed by in situ hybridization using a radiolabeled POMC riboprobe. The results showed that 4 x 10(-10) M TGF beta(1) was efficient in decreasing significantly the amounts of POMC mRNA (P < 0.01). Interestingly, the decrease of relative POMC mRNA levels was higher in the rostral than in the caudal parts of the arcuate nucleus. In a second set of experiments, we examined the occurrence of TGF beta receptors expression in arcuate POMC neurons. Dual labeling in situ hybridization and in situ hybridization, coupled to immunohistochemical labeling, were performed to examine mRNA expression of the type I serine-threonine kinase receptor for TGF beta and the presence of type II receptor for TGF beta, respectively, in POMC neurons. The results indicated that TGF beta receptor I mRNA and TGF beta receptor II protein were expressed in numerous POMC neurons. Regional analysis revealed that the highest proportion of POMC neurons expressing TGF beta receptors was located in the rostral part of the arcuate nucleus. Using dual labeling immunohistochemistry, we also found that Smad2/3 immunoreactivity, a TGF beta(1) downstream signaling molecule, was present in the cytoplasm and nucleus of some POMC (beta-endorphin) neurons. We next examined whether the number of POMC neurons expressing TGF beta-RI mRNA was affected by sex steroids. Quantification of the number of POMC neurons expressing TGF beta receptor I mRNA in ovariectomized, ovariectomized E2-treated, and ovariectomized E2 plus progesterone-treated animals revealed that estrogen treatment decreased the expression of TGF beta receptor I mRNA in POMC neurons located in the rostral half of the arcuate nucleus, an effect reversed by progesterone in a subset of the most rostral cells. Taken together, these data reveal that TGF beta(1) may directly modulate the activity of POMC neurons through the activation of TGF beta receptors. Therefore, the present study provides additional evidence for the involvement of TGF beta(1) in the regulation of neuroendocrine functions and supports the existence of a glial-to-neurons communication within the arcuate nucleus.

Inhibition of cardiac delayed rectifier K+ currents by an antisense oligodeoxynucleotide against IsK (minK) and over-expression of IsK mutant D77N in neonatal mouse hearts

The IsK (minK or KCNE1) protein is known to co-assemble with the KvLQT1 (KCNQ1) protein to form a channel underlying the slowly activating delayed rectifier K+ current (IKs). Controversy remains as to whether the IsK protein assembles with ERG (the ether-a-go-go-related gene) products to form or modulate the channel-underlying the rapidly activating delayed rectifier K+ current (IKr). We investigated the effects of antisense oligodeoxynucleotides (AS-ODN) against IsK and its mutant D77N [which underlies a form of long QT syndrome (LQT5) in humans] on the delayed rectifier K+ current (IK) of neonatal mouse ventricular myocytes in primary culture. Patch-clamp experiments on these cells showed that IK consists of IKs and IKr. IK was not recorded from ventricular cells transfected with AS-ODN, while it was recorded from cells transfected with the corresponding sense oligodeoxynucleotides (S-ODN). IK was not recorded from cells transfected with the D77N mutant, and the action potential duration was much longer than in cells transfected with wild-type IsK. Furthermore, HERG could not induce currents in COS-1 cells co-expressed with the D77N mutant and HERG (the human form of ERG). These results indicate that the IsK protein associates with both KvLQT1 and ERG products to modulate IKr and IKs in cardiac myocytes.

Psychological and physical reactions on children after the Hanshin-Awaji earthquake disaster

Children who experienced the Hanshin-Awaji Earthquake Disaster were followed to ascertain how the psychological and physical reactions after this disaster changed. Changes observed in the symptoms of children at one and two years after the earthquake were compared between those who had lived in severely damaged area (level 7 on the Japan Meteorological Agency intensity scale) and those who had lived in mildly damaged area (less than 5 on the same scale). The survey was conducted using a questionnaire filled out by the children's parents. Two years after the earthquake, the children had returned to normal in terms of their physical conditions, even in the severely damaged area. However, symptoms of PTSD (Post-Traumatic Stress Disorder) such as persistent reexperiencing, persistent avoidance, and increased arousal were significantly more frequently found among children from the severely damaged area than among those from the mildly damaged area. To evaluate the psychological and physical reactions after the disaster is very important in order to support the children when large-scale disasters occur.

Evidence that members of the TGFbeta superfamily play a role in regulation of the GnRH neuroendocrine axis: expression of a type I serine-threonine kinase receptor for TGRbeta and activin in GnRH neurones and hypothalamic areas of the female rat

The present study was designed to determine whether transforming growth factor (TGF)beta and/or activin participate in the regulation of the gonadotropin releasing hormone (GnRH) neuroendocrine axis in vivo. Single-label in situ hybridization histochemistry was used to determine the anatomical distribution of a TGFbeta and activin type I receptor (B1) mRNA, in the adult female rat hypothalamic areas that are known to be important sites for the regulation of reproduction. Dual-label in situ hybridization histochemistry was performed to determine whether B1 mRNA was expressed in GnRH neurones. The results of these studies revealed an extensive distribution of B1 mRNA in the hypothalamic regions, including diagonal bands of Broca, preoptic area, arcuate nucleus and median eminence. In the median eminence, B1 mRNA was detected in tanycytes and in the endothelial cells of the pituitary portal blood capillaries. Dual-label in situ hybridization histochemistry showed that 31+/-5% of GnRH neurones expressed B1 mRNA, thus providing evidence that TGFbeta and/or activin can act directly on GnRH neurones to modulate their activity. Taken together, these data provide morphological arguments in favour of a participation of TGFbeta and/or activin in the regulation of reproduction at the hypothalamic level.

A putative transcription factor with seven zinc-finger motifs identified in the developing suprachiasmatic nucleus by the differential display PCR method

The suprachiasmatic nucleus (SCN) is a mammalian central circadian pacemaker. This nucleus develops in the last stage of fetal life and matures to make strong synaptic connections within 2 weeks of postnatal life to establish strong oscillation characteristics. To identify factors that initiate the circadian oscillation, we applied a differential display PCR method to developing SCN, and isolated a gene with seven zinc-finger motifs, Lot1, which encodes a gene that appeared at a very high level in the SCN during the early postnatal days. Lot1 mRNA first appeared at postnatal day 1 (P1) at a very high level, and the signal in the SCN continued to be very high until P10 and thereafter rapidly decreased until P20 and was expressed at a very faint level during adulthood. Lot1 mRNA expression was observed only in neurons of the dorsomedial SCN throughout the course of development. During the developmental stage, Lot1 mRNA expression shows a circadian rhythm with a peak in the day time and a trough at night time in both light-dark and constant dark conditions. These observations imply that Lot1 is the first identified putative transcription factor expressed only in the period of active synaptogenesis in the SCN, where Lot1 might play a role in establishing autonomous oscillation.

A mammalian ortholog of Drosophila timeless, highly expressed in SCN and retina, forms a complex with mPER1

BACKGROUND

It is now becoming clear that the circadian rhythm of behaviours and hormones arises from a rhythm at the level of gene expression, and that mammals and Drosophila essentially use homologous genes as molecular gears in the control of circadian oscillation. In Drosophila, the period and timeless genes form a functional unit of the clock and its autoregulatory feedback loop for circadian rhythm. However, in mammals, the counterpart of timeless has not been found.

RESULTS

We have isolated a mammalian homologue of timeless, mTim, from the mouse brain. mTim is highly expressed, with a weak or absent rhythm in the suprachiasmatic nucleus, the mammalian circadian centre. In the retina, mTim mRNA was found to be expressed with a circadian rhythm, and a particularly robust cycle was observed in the presence of light/dark cycles. We demonstrated that mTIM physically associates with mPER1 in vitro and in the nuclei of cultured COS7 cells.

CONCLUSIONS

We have reported the isolation of the mouse timeless cDNA, the expression of the mTim mRNA and an interaction of mTIM with mPER1. These results indicate that the autoregulatory feedback mechanism of circadian oscillation of the period gene may also be conserved in mammals.

A light-independent oscillatory gene mPer3 in mouse SCN and OVLT

A new member of the mammalian period gene family, mPer3, was isolated and its expression pattern characterized in the mouse brain. Like mPer1, mPer2 and Drosophila period, mPer3 has a dimerization PAS domain and a cytoplasmic localization domain. mPer3 transcripts showed a clear circadian rhythm in the suprachiasmatic nucleus (SCN). Expression of mPer3 was not induced by exposure to light at any phase of the clock, distinguishing this gene from mPer1 and mPer2. Cycling expression of mPer3 was also found outside the SCN in the organum vasculosum lamina terminalis (OVLT), a potentially key region regulating rhythmic gonadotropin production and pyrogen-induced febrile phenomena. Thus, mPer3 may contribute to pacemaker functions both inside and outside the SCN.

Mosaic variegated aneuploidy with multiple congenital abnormalities: homozygosity for total premature chromatid separation trait

Separation of chromatids of all mitotic chromosomes, here called total premature chromatid separation (total PCS), was observed in 67 to 87.5% of repeated cultures of peripheral blood lymphocytes from two unrelated infants. Also noted was a variety of mosaic aneuploidies, especially trisomies, double trisomies, and monosomies, to be called mosaic variegated aneuploidy. The infants both showed severe pre- and postnatal growth retardation, profound developmental retardation, uncontrollable seizures, severe microcephaly, hypoplasia of the brain, Dandy-Walker anomaly, abnormal facial appearance, and bilateral cataract. Patient 1, a girl, in addition had a cleft palate, multiple renal cysts, and Wilms tumor of the left kidney. Whereas patient 2, a boy, had ambiguous external genitalia. They both died within 2 years of age. In the two families of the infants, their parents and three other members showed 2.5 to 47% lymphocytes with total PCS but without mosaic variegated aneuploidy or phenotypic abnormalities. Another 10 relatives studied showed 0 to 1% cells with total PCS and so were judged negative for the total PCS trait. It was deduced that the total PCS trait in the two families was transmitted in an autosomal-dominant fashion, and the two affected infants were homozygous for the trait.

A new mammalian period gene predominantly expressed in the suprachiasmatic nucleus

BACKGROUND

In mammals, two possible clock genes (Clock, Per1) have very recently been reported. mPer1 (the first identified mouse period gene), in particular, shows a circadian expression in suprachiasmatic nuclei (SCN), the mammalian circadian centre. However, only mPer1 and Clock as clock components may not be sufficient to understand all the events in circadian oscillation and entrainment.

RESULTS

A mammalian period complementary DNA, mPer2, has been isolated from the mouse brain. The amino acid sequence of mPer2 is similar to mPer1 and Drosophila Period (dPer), indicating that mPer2 is a member of the family which contains mPer1, itself a homologue of dPer. mPer2 mRNA is predominantly expressed in SCN. A robust circadian rhythmic expression in the SCN supports the view that mPer2 is a clock gene. mPer2 is strongly expressed at the subjective afternoon in constant darkness, distinct from a morning-phase clock mPer1. Our precise quantitative in situ hybridizations have revealed that the peak expression of mPer2 transcripts is delayed by 8 h in LD (light-dark) or 4 h in DD (dark-dark) conditions when compared to mPer1. A short brief light exposure at the early subjective night, prompting a phase-shift in locomotor rhythms, induces a transient increase of mPer2 transcripts with delayed onset, as compared to mPer1 mRNA induction. Furthermore, mPer2 is co-expressed with mPer1 in single SCN cells.

CONCLUSIONS

Mammalian period genes show molecular heterogeneity, each of which is composed of a different oscillator, and may serve to establish stable circadian rhythms in mammalian oscillating cells.

Identification of novel homologues of mouse importin alpha, the alpha subunit of the nuclear pore-targeting complex, and their tissue-specific expression

Transport of karyophilic proteins into the nucleus is mediated by nuclear localization signals (NLSs) via a multistep process. The karyophiles are recognized by the importin alpha subunit in the cytoplasm to form a stable complex, termed the nuclear pore-targeting complex (PTAC). To date, three different mammalian alpha subunits (mSRP1/NPI-1, PTAC58/mPendulin/Rch1 and Qip1) have been identified. In this study, we report the identification of three additional mouse genes homologous to the known alpha subunits using RT-PCR methodology and show that the mouse alpha subunits can be classified into at least three subfamilies, alpha-P, alpha-Q and alpha-S families, each composed of closely related members (more than 80% amino acid sequence identity). These three subfamilies, however, have approximately 50% amino acid identity to one another. Northern blot analysis showed that all were differentially expressed in various mouse tissues. These results suggest that the function of these proteins may be controlled in a tissue-specific manner and that their combinatorial expression may play a role in differentiation and organogenesis.

Distinct localization of two serine-threonine kinase receptors for activin and TGF-beta in the rat brain and down-regulation of type I activin receptor during peripheral nerve regeneration

The localizations of serine-threonine kinase receptor mRNA for the novel type I TGF-beta and/or activin receptor named B1 (rat), ALK-4 (mouse) or ActR-IB (human) were demonstrated by in situ hybridization. As the putative ligand for this receptor in the brain has not yet been clearly determined, we compared its localization to type II activin receptor (ActR-II) which is the counterpart of the type I activin receptor. B1 mRNA was widely observed in neuronal cells throughout the brain, and especially strong positive signals were found in the cerebral cortex, olfactory tubercle, and hippocampus. The localization of B1 mRNA coincided well with that of ActR-II. This strongly suggests that B1 (ALK-4/ActR-IB) could be the type I activin receptor, as type I and type II activin receptor were supposed to form a receptor complex. In addition, we examined the localization of type II TGF-beta receptor (TbetaRII) mRNA which is an essential counterpart of the type I TGF-beta receptors for TGF-beta signaling. TbetaRII mRNA was expressed mainly in non-neuronal cells such as choroid plexus. In addition, TbetaRII mRNA expression was also found in a minor population of neuronal cells. TbetaRII mRNA-positive neurons were observed in the reticular thalamus, laterodorsal tegmental nucleus, pedunculopontine tegmental nucleus and the ventral tegmental nucleus. The localization of TbetaRII was markedly different from that of activin receptors in the rat brain. Since TGF-betas and activins are known as growth factors and/or survival factors, we examined changes in levels of B1 and TbetaRII mRNA expression during peripheral nerve regeneration. Expression of B1 mRNA in the axotomized hypoglossal motoneurons was substantially decreased from day 3 after axotomy and this decrease was significant until postoperative day 28, whereas no TbetaRII signal was observed in hypoglossal nucleus prior or after axotomy. This transient down-regulation of B1 mRNA expression suggests that activin signaling is somehow suppressed during peripheral nerve regeneration.

A novel ubiquitously distributed isoform of GIRK2 (GIRK2B) enhances GIRK1 expression of the G-protein-gated K+ current in Xenopus oocytes

We have isolated a novel variant form of GIRK2, designated GIRK2B, from mouse brain cDNA library. GIRK2B was much shorter than the first type of GIRK2 (GIRK2A), but its amino acid sequence was identical to the corresponding part of GIRK2A except the C-terminal eight amino acid residues. When GIRK2B cRNA was co-injected with GIRK1 and m2-receptor cRNAs to Xenopus oocytes, acetylcholine-induction of the inwardly rectifying K+ current was enhanced dramatically. This suggests that GIRK2B can form a heteromultimeric G-protein-gated K+ channel with GIRK1. The reverse transcription polymerase chain reaction analysis showed that GIRK2B mRNA distributed much more broadly than GIRK1 mRNA. Therefore, GIRK2B might also play other unrecognized roles in various tissues than to form a K+ channel with GIRK1.

G beta gamma directly binds to the carboxyl terminus of the G protein-gated muscarinic K+ channel, GIRK1

beta gamma Subunits of heterotrimeric GTP-binding proteins (G beta gamma) activate the inwardly rectifying muscarinic K+ channel, GIRK1. The significant role for the carboxyl (C) terminus of GIRK1 in this interaction has been suggested. However, it is still unknown whether G beta gamma directly interacts with GIRK1. To elucidate the molecular basis of G beta gamma-activation of GIRK1, we examined the binding properties of G beta gamma to the C terminus of GIRK1 cloned from mouse brain cDNA library (MB-GIRK1). The C terminus of MB-GIRK1 fused with glutathione S-transferase directly bound to purified G beta gamma. Incubation of the C terminus with Gi pretreated with GTP gamma S, but not with GDP, resulted in the binding of Gi beta gamma to the protein. Purified G alpha-GDP, but not G alpha-GTP gamma S, inhibited the binding of G beta gamma to the fusion protein. These results indicate that G beta gamma dissociated from G alpha may directly bind to the C terminus of GIRK1.

A novel ATP-dependent inward rectifier potassium channel expressed predominantly in glial cells

We have isolated a novel inward rectifier K+ channel predominantly expressed in glial cells of the central nervous system. Its amino acid sequence exhibited 53% identity with ROMK1 and approximately 40% identity with other inward rectifier K+ channels. Xenopus oocytes injected with cRNA derived from this clone expressed a K+ current, which showed classical inward rectifier K+ channel characteristics. Intracellular Mg.ATP was required to sustain channel activity in excised membrane patches, which is consistent with a Walker type-A ATP-binding domain on this clone. We designate this new clone as KAB-2 (the second type of inward rectifying K+ channel with an ATP-binding domain). In situ hybridization showed KAB-2 mRNA to be expressed predominantly in glial cells of the cerebellum and forebrain. This is the first description of the cloning of a glial cell inward rectifier potassium channel, which may be responsible for K+ buffering action of glial cells in the brain.