Long-term impact of angiotensin receptor-neprilysin inhibitor based on short-term treatment response in heart failure

AIMS

The long-term effect of angiotensin receptor-neprilysin inhibitor (ARNI) remains uncertain in patients who have experienced improvements in left ventricular (LV) systolic function or significant LV reverse remodelling following a certain period of treatment. It is also unclear how ARNI performs in patients who have not shown these improvements. This study aimed to assess the impact of prolonged ARNI use compared with angiotensin-converting enzyme inhibitors (ACEIs)/angiotensin receptor blockers (ARBs) in patients with and without significant treatment response after 1 year of heart failure (HF) treatment.

METHODS AND RESULTS

The present study enrolled patients with HF with reduced ejection fraction (HFrEF) who were treated with either ARNI or ACEIs/ARBs within 1 year of undergoing index echocardiography. After 1 year of treatment, patients were reclassified into the following groups: (i) patients with HF with improved ejection fraction and persistent HFrEF and (ii) patients with and without LV reverse remodelling based on the follow-up echocardiography. The effect of ARNI versus that of ACEIs/ARBs in each group was assessed from the time of categorizing into new groups using the composite event of all-cause mortality and HF hospitalization. A total of 671 patients with HFrEF (age, 66.4 ± 14.1 years; males, 66.8%) were included, and 133 (19.8%) composite events of death and rehospitalization for HF were observed during the follow-up (median follow-up, 44 [interquartile range, 34-51] months). ARNI had a significantly lower event rate than ACEIs/ARBs in patients with HF with improved ejection fraction (7.0% vs. 30.4%, P = 0.020) and those with persistent HFrEF (17.6% vs. 49.7%, P < 0.001). Irrespective of whether patients exhibited LV reverse remodelling (15.8% vs. 31.1%, P = 0.001) or not (15.0% vs. 54.9%, P < 0.001), ARNIs were associated with a significantly lower event rate than ACEIs/ARBs.

CONCLUSIONS

Regardless of significant treatment response measured by either LVEF or LV reverse remodelling after 1 year of treatment, the extended utilization of ARNI demonstrated a more favourable prognosis than that of ACEIs/ARBs in patients with HFrEF.

Impact of Positron Emission Tomography Viability Imaging: Guided Revascularizations on Clinical Outcomes in Patients With Myocardial Scar on Single-Photon Emission Computed Tomography Scans

BACKGROUND

Positron emission tomography (PET) viability scan is used to determine whether patients with a myocardial scar on single-photon emission computed tomography (SPECT) may need revascularization. However, the clinical utility of revascularization decision-making guided by PET viability imaging has not been proven yet. The purpose of this study was to investigate the impact of PET to determine revascularization on clinical outcomes.

METHODS

Between September 2012 and May 2021, 53 patients (37 males; mean age = 64 ± 11 years) with a myocardial scar on MIBI SPECT who underwent PET viability test were analyzed in this study. The primary outcome was a temporal change in echocardiographic findings. The secondary outcome was all-cause mortality.

RESULTS

Viable myocardium was presented by PET imaging in 29 (54.7%) patients. Revascularization was performed in 26 (49.1%) patients, including 18 (34.0%) with percutaneous coronary intervention (PCI) and 8 (15.1%) with coronary artery bypass grafting. There were significant improvements in echocardiographic findings in the revascularization group and the viable myocardium group. All-cause mortality was significantly lower in the revascularization group than in the medical therapy-alone group (19.2% vs. 44.4%, log-rank P = 0.002) irrespective of viable (21.4% vs. 46.7%, log-rank P = 0.025) or non-viable myocardium (16.7% vs. 41.7%, log-rank P = 0.046). All-cause mortality was significantly lower in the PCI group than in the medical therapy-alone group (11.1% vs. 44.4%, log-rank P < 0.001).

CONCLUSION

Revascularization improved left ventricular systolic function and survival of patients with a myocardial scar on SPECT scans, irrespective of myocardial viability on PET scans.

Acute decompensated heart failure after transcatheter aortic valve implantation: A case report

Transcatheter aortic valve implantation (TVAI) is a widely used treatment modality for severe aortic stenosis. The complication rates of the procedure have gradually decreased over time, owing to the improvements in procedural skills and development of TVAI devices. However, several rare but serious complications can still occur after TAVI. We recently encountered acute decompensated heart failure as a rare and fatal complication of TAVI and would like to share our experience.

Predictors of stroke or systemic embolism in patients with non-valvular atrial fibrillation with CHA2 DS2 -VASc score of 0

BACKGROUND

Anticoagulant therapy has been important for stroke prevention in patients with atrial fibrillation (AF). However, it was not recommended due to its relatively higher risk of bleeding than its lower risk of stroke in patients with a CHA₂ DS₂ -VASc score of 0.

HYPOTHESIS

This study aimed to evaluate the predictors of stroke in AF patients with very low risk of stroke.

METHODS

Between 1990 and 2020, 542 patients with non-valvular AF (NVAF) with a CHA₂ DS₂ -VASc score of 0 followed up for at least 6 months were enrolled. Patients with only being woman as a risk factor were included as a CHA₂ DS₂ -VASc score of 0 in this study. The primary outcome was stroke or systemic embolism.

RESULTS

The primary outcome rate was 0.78%/year. In Cox hazard model, age of ≥50 years at diagnosis (hazard ratio [HR] 6.710, 95% confidence interval [CI] 1.811-24.860, p = .004), LVEDD of ≥46 mm (HR 4.513, 95% CI 1.038-19.626, p = .045), and non-paroxysmal AF (HR 5.575, 95% CI 1.621-19.175, p = .006) were identified as independent predictors of stroke or systemic embolism. Patients with all three independent predictors had a higher risk of stroke or systemic embolism (4.21%/year), whereas those without did not have a stroke or systemic embolism.

CONCLUSION

The annual stroke or systemic embolism rate in NVAF patients with CHA₂ DS₂ -VASc score of 0 was 0.78%/year, and age at AF diagnosis, LVEDD, and non-paroxysmal AF were independent predictors of stroke or systemic embolism in patients considered to have a very low risk of stroke.

Preoperative cardiac troponin I as a predictor of postoperative cardiac events in patients with end stage renal disease undergoing non-cardiac surgery

We investigated if elevated cardiac troponin I (cTnI) serum levels before non-cardiac surgery were predictors of postoperative cardiac events in patients with end stage renal disease (ESRD) undergoing dialysis. In total, 703 consecutive patients with ESRD undergoing dialysis who underwent non-cardiac surgery were enrolled. Preoperative cTnI serum levels were measured at least once in all patients. The primary endpoint was defined as a composite of cardiac death, myocardial infarction (MI), and pulmonary edema during hospitalization or within 30 days after surgery in patients with a hospitalization longer than 30 days after surgery. Postoperative cardiac events occurred in 48 (6.8%) out of 703 patients (cardiac death 1, MI 18, and pulmonary edema 33). Diabetes mellitus (DM), previous ischemic heart disease, and congestive heart failure were more common in patients with postoperative cardiac events. Peak cTnI serum levels were higher in patients with postoperative cardiac event (180 ± 420 ng/L vs. 80 ± 190 ng/L, p = 0.008), and also elevated peak cTnI levels > 45 ng/L were more common in patients with postoperative cardiac events (66.8% vs. 30.5%, p < 0.001). Multivariate logistic regression analysis showed that DM (odds ratio [OR]  2.509, 95% confidence interval [CI] 1.178-5.345, p = 0.017) and serum peak cTnI levels ≥ 45 ng/L (OR 3.167, 95% CI 1.557-6.444, p = 0.001) were independent predictors for the primary outcome of cardiac death/MI/pulmonary edema. Moreover, cTnI levels ≥ 45 ng/L had an incremental prognostic value to the revised cardiac risk index (RCRI) (Chi-square = 23, p < 0.001), and to the combined RCRI and left ventricular ejection fraction (Chi-square = 12, p = 0.001). Elevated preoperative cTnI levels are predictors of postoperative cardiac events including cardiac death, MI, and pulmonary edema in patients with ESRD undergoing non-cardiac surgery.

The novel bio-SYNTAX scoring system for predicting the prognosis of patients undergoing percutaneous coronary intervention with left main coronary artery disease

Background

Simple and effective risk models incorporating biomarkers associated with left main coronary artery (LMCA) stenosis are limited. This study aimed to validate the novel Bio-Clinical SYNTAX score (Bio-CSS) incorporating N-terminal pro-B-type natriuretic peptide (NT-proBNP) in patients with LMCA stenosis.

Methods

Patients who underwent percutaneous coronary intervention (PCI) for LMCA stenosis using a drug-eluting stent (n = 275) were included in the study. We developed the Bio-CSS incorporating NT-proBNP and validated the ability of the Bio-CSS to predict major adverse cardiac events (MACEs) and compared its performance to that of the SYNTAX score (SS) and SS II. The MACEs were defined as death, non-fatal myocardial infarction (MI), and repeat revascularizations.

Results

The Bio-CSS (34.7 ± 18.3 vs. 51.9 ± 28.4, p &lt; 0.001), as well as SS (23.6 ± 7.3 vs. 26.7 ± 8.1, p = 0.003) and SS II (29.4 ± 9.9 vs. 36.1 ± 12.8, p &lt; 0.001), was significantly higher in patients with MACEs. In the Cox proportional hazards model, the log Bio-CSS (hazard ratio 8.31, 95% CI 1.84–37.55) was an independent prognostic factor for MACEs after adjusting for confounding variables. In the receiver operating characteristic curves, the area under the curve of the Bio-CSS was significantly higher compared to those of SS (0.608 vs. 0.706, p = 0.001) and SS II (0.655 vs. 0.706, p = 0.026). Patients were categorized into the three groups based on the tertiles of the Bio-CSS. Patients in the highest tertile of the Bio-CSS had significantly higher MACEs compared to those in the lower two tertiles (log-rank p &lt; 0.001).

Conclusion

In patients who underwent PCI for LMCA stenosis, the novel Bio-CSS improved the discrimination accuracy of established combined scores, such as SS and SS II. The addition of NT-proBNP to the clinical and angiographic findings in the Bio-CSS could potentially provide useful long-term prognostic information in these patients.

Impact of the COVID-19 Pandemic on Patient Delay and Clinical Outcomes for Patients With Acute Myocardial Infarction

BACKGROUND

It has been known that the fear of contagion during the coronavirus disease 2019 (COVID-19) creates time delays with subsequent impact on mortality in patients with acute myocardial infarction (AMI). However, difference of time delay and clinical outcome in patients with ST-segment elevation myocardial infarction (STEMI) or non-STEMI between the COVID-19 pandemic and pre-pandemic era has not been fully investigated yet in Korea. The aim of this study was to investigate the impact of COVID-19 pandemic on time delays and clinical outcome in patients with STEMI or non-STEMI compared to the same period years prior.

METHODS

A total of 598 patients with STEMI (n = 195) or non-STEMI (n = 403) who underwent coronary angiography during the COVID-19 pandemic (February 1 to April 30, 2020) and pre-pandemic era (February 1 to April 30, 2017, 2018, and 2019) were analyzed in this study. Main outcomes were the incidence of time delay, cardiac arrest, and in-hospital death.

RESULTS

There was 13.5% reduction in the number of patients hospitalized with AMI during the pandemic compared to pre-pandemic era. In patients with STEMI, door to balloon time tended to be longer during the pandemic compared to pre-pandemic era (55.7 ± 12.6 minutes vs. 60.8 ± 13.0 minutes, P = 0.08). There were no significant differences in cardiac arrest (15.6% vs. 10.4%, P = 0.397) and in-hospital mortality (15.6% vs. 10.4%, P = 0.397) between pre-pandemic and the pandemic era. In patients with non-STEMI, symptom to door time was significantly longer (310.0 ± 346.2 minutes vs. 511.5 ± 635.7 minutes, P = 0.038) and the incidence of cardiac arrest (0.9% vs. 3.5%, P = 0.017) and in-hospital mortality (0.3% vs. 2.3%, P = 0.045) was significantly greater during the pandemic compared to pre-pandemic era. Among medications, angiotensin converting enzyme inhibitors/angiotensin type 2 receptor blockers (ACE-I/ARBs) were underused in STEMI (64.6% vs. 45.8%, P = 0.021) and non-STEMI (67.8% vs. 57.0%, P = 0.061) during the pandemic.

CONCLUSION

During the COVID-19 pandemic, there has been a considerable reduction in hospital admissions for AMI, time delay, and underuse of ACE-I/ARBs for the management of AMI, and this might be closely associated with the excess death in Korea.

Racial and ethnic disparities in COVID-19 disease incidence independent of comorbidities, among people with HIV in the US

OBJECTIVES

To define the incidence of clinically-detected COVID-19 in people with HIV (PWH) in the US and evaluate how racial and ethnic disparities, comorbidities, and HIV-related factors contribute to risk of COVID-19.

DESIGN

Observational study within the CFAR Network of Integrated Clinical Systems cohort in 7 cities during 2020.

METHODS

We calculated cumulative incidence rates of COVID-19 diagnosis among PWH in routine care by key characteristics including race/ethnicity, current and lowest CD4 count, and geographic area. We evaluated risk factors for COVID-19 among PWH using relative risk regression models adjusted with disease risk scores.

RESULTS

Among 16,056 PWH in care, of whom 44.5% were Black, 12.5% were Hispanic, with a median age of 52 years (IQR 40-59), 18% had a current CD4 count < 350, including 7% < 200; 95.5% were on antiretroviral therapy, and 85.6% were virologically suppressed. Overall in 2020, 649 PWH were diagnosed with COVID-19 for a rate of 4.94 cases per 100 person-years. The cumulative incidence of COVID-19 was 2.4-fold and 1.7-fold higher in Hispanic and Black PWH respectively, than non-Hispanic White PWH. In adjusted analyses, factors associated with COVID-19 included female sex, Hispanic or Black identity, lowest historical CD4 count <350 (proxy for CD4 nadir), current low CD4/CD8 ratio, diabetes, and obesity.

CONCLUSIONS

Our results suggest that the presence of structural racial inequities above and beyond medical comorbidities increased the risk of COVID-19 among PWHPWH with immune exhaustion as evidenced by lowest historical CD4 or current low CD4:CD8 ratio had greater risk of COVID-19.

A case of paroxysmal complete atrioventricular block in a COVID-19 patient

Many types of cardiac arrhythmias can occur in people with COVID-19, and these arrhythmias can affect the patient's outcomes. We have experienced paroxysmal complete atrioventricular block in a patient with COVID-19 and would like to share the course of treatment.

Effectiveness of a new cardiac risk scoring model reclassified by QRS fragmentation as a predictor of postoperative cardiac event in patients with severe renal dysfunction

Background

It is difficult to evaluate the risk of patients with severe renal dysfunction before surgery due to various limitations despite high postoperative cardiac events. This study aimed to investigate the value of a newly reclassified Revised Cardiac Risk Index (RCRI) that incorporates QRS fragmentation (fQRS) as a predictor of postoperative cardiac events in patients with severe renal dysfunction.

Methods

Among the patients with severe renal dysfunction, 256 consecutive patients who underwent both a nuclear stress test and noncardiac surgery were evaluated. We reclassified RCRI as fragmented RCRI (FRCRI) by integrating fQRS on electrocardiography. We defined postoperative major adverse cardiac event (MACE) as a composite of cardiac death, nonfatal myocardial infarction, and pulmonary edema.

Results

Twenty-eight patients (10.9%) developed postoperative MACE, and this was significantly frequent in patients with myocardial perfusion defect (41.4% vs. 28.0%, p = 0.031). fQRS was observed 84 (32.8%) patients, and it was proven to be an independent predictor of postoperative MACE after adjusting for the RCRI (odds ratio 3.279, 95% confidence interval (CI) 1.419–7.580, p = 0.005). Moreover, fQRS had an incremental prognostic value for the RCRI (chi-square = 7.8, p = 0.005), and to the combination of RCRI and age (chi-square = 9.1, p = 0.003). The area under curve for predicting postoperative MACE significantly increased from 0.612 for RCRI to 0.667 for FRCRI (p = 0.027) and 23 patients (32.4%) originally classified as RCRI 2 were reclassified as FRCRI 3.

Conclusions

A newly reclassified FRCRI that incorporates fQRS, is a valuable predictor of postoperative MACE in patients with severe renal dysfunction undergoing noncardiac surgery.

Prognostic impact of chromogranin A in patients with acute heart failure

Background

Chromogranin A (CgA) levels have been reported to predict mortality in patients with heart failure. However, information on the prognostic value and clinical availability of CgA is limited. We compared the prognostic value of CgA to that of previously proven natriuretic peptide biomarkers in patients with acute heart failure.

Methods

We retrospectively evaluated 272 patients (mean age, 68.5±15.6 years; 62.9% male) who underwent CgA test in the acute stage of heart failure hospitalization between June 2017 and June 2018. The median follow-up period was 348 days. Prognosis was assessed using the composite events of 1-year death and heart failure hospitalization.

Results

In-hospital mortality rate during index admission was 7.0% (n=19). During the 1-year follow-up, a composite event rate was observed in 12.1% (n=33) of the patients. The areas under the receiver-operating characteristic curves for predicting 1-year adverse events were 0.737 and 0.697 for N-terminal pro-B-type natriuretic peptide (NT-proBNP) and CgA, respectively. During follow-up, patients with high CgA levels (>158 pmol/L) had worse outcomes than those with low CgA levels (≤158 pmol/L) (85.2% vs. 58.6%, p<0.001). When stratifying the patients into four subgroups based on CgA and NT-proBNP levels, patients with high NT-proBNP and high CgA had the worst outcome. CgA had an incremental prognostic value when added to the combination of NT-proBNP and clinically relevant risk factors.

Conclusion

The prognostic power of CgA was comparable to that of NT-proBNP in patients with acute heart failure. The combination of CgA and NT-proBNP can improve prognosis prediction in these patients.

N-terminal pro-brain natriuretic peptide and coronary collateral formation in patients undergoing primary percutaneous coronary intervention

There is insufficient information on the relationship between the N-terminal pro-brain natriuretic peptide (NT-proBNP) level and collateral circulation (CC) formation after primary percutaneous coronary intervention (PCI) in patients with ST-segment elevation myocardial infarction. We analyzed 857 patients who underwent primary PCI. The serum NT-proBNP levels were measured on the day of admission, and the CC was scored according to Rentrop’s classification. Log-transformed NT-proBNP levels were significantly higher in patients with good CC compared to those with poor CC (6.13 ± 2.01 pg/mL versus 5.48 ± 1.97 pg/mL, p < 0.001). The optimum cutoff value of log NT-proBNP for predicting CC was 6.04 pg/mL. Log NT-proBNP ≥ 6.04 pg/mL (odds ratio 2.23; 95% confidence interval 1.51–3.30; p < 0.001) was an independent predictor of good CC. CC development was higher in patients with a pre-TIMI flow of 0 or 1 than those with a pre-TIMI flow of 2 or 3 (22.6% versus 8.8%, p = 0.001). The incidence of left ventricular (LV) dysfunction (< 50%) was greater in patients with a pre-TIMI flow of 0 or 1 (49.8% versus 35.5%, p < 0.001). The release of NT-proBNP was greater in patients with LV dysfunction (34.3% versus 15.6%, p < 0.001). The incidence of good CC was greater in patients with log NT-proBNP levels ≥ 6.04 pg/ml (16.8% versus 26.2%, p = 0.003). The association between NT-proBNP and collateral formation was not influenced by pre-TIMI flow and LV function. NT-proBNP appears to reflect the degree of collateral formation in the early phase of STEMI and might have a new role as a useful surrogate biomarker for collateral formation in patients undergoing primary PCI.

Derivation and validation of a combined in-hospital mortality and bleeding risk model in acute myocardial infarction

Background

In the potent new antiplatelet era, it is important issue how to balance the ischemic risk and the bleeding risk. However, previous risk models have been developed separately for in-hospital mortality and major bleeding risk. Therefore, we aimed to develop and validate a novel combined model to predict the combined risk of in-hospital mortality and major bleeding at the same time for initial decision making in patients with acute myocardial infarction (AMI).

Methods

Variables from the Korean Acute Myocardial Infarction Registry (KAMIR) - National Institute of Health (NIH) database were used to derive (n = 8955) and validate (n = 3838) a multivariate logistic regression model. Major adverse cardiovascular events (MACEs) were defined as in-hospital death and major bleeding.

Results

Seven factors were associated with MACE in the model: age, Killip class, systolic blood pressure, heart rate, serum glucose, glomerular filtration rate, and initial diagnosis. The risk model discriminated well in the derivation (c-static = 0.80) and validation (c-static = 0.80) cohorts. The KAMIR-NIH risk score was developed from the model and corresponded well with observed MACEs: very low risk (0.9%), low risk (1.7%), moderate risk (4.2%), high risk (8.6%), and very high risk (23.3%). In patients with MACEs, a KAMIR-NIH risk score ≤ 10 was associated with high bleeding risk, whereas a KAMIR-NIH risk score > 10 was associated with high in-hospital mortality.

Conclusion

The KAMIR-NIH in-hospital MACEs model using baseline variables stratifies comprehensive risk for in-hospital mortality and major bleeding, and is useful for guiding initial decision making.

Impact of Cardiovascular Risk Factors and Cardiovascular Diseases on Outcomes in Patients Hospitalized with COVID-19 in Daegu Metropolitan City

BACKGROUND

Data regarding the association between preexisting cardiovascular risk factors (CVRFs) and cardiovascular diseases (CVDs) and the outcomes of patients requiring hospitalization for coronavirus disease 2019 (COVID-19) are limited. Therefore, the aim of this study was to investigate the impact of preexisting CVRFs or CVDs on the outcomes of patients with COVID-19 hospitalized in a Korean healthcare system.

METHODS

Patients with COVID-19 admitted to 10 hospitals in Daegu Metropolitan City, Korea, were examined. All sequentially hospitalized patients between February 15, 2020, and April 24, 2020, were enrolled in this study. All patients were confirmed to have COVID-19 based on the positive results on the polymerase chain reaction testing of nasopharyngeal samples. Clinical outcomes during hospitalization, such as requiring intensive care and invasive mechanical ventilation (MV) and death, were evaluated. Moreover, data on baseline comorbidities such as a history of diabetes, hypertension, dyslipidemia, current smoking, heart failure, coronary artery disease, cerebrovascular accidents, and other chronic cardiac diseases were obtained.

RESULTS

Of all the patients enrolled, 954 (42.0%) had preexisting CVRFs or CVDs. Among the CVRFs, the most common were hypertension (28.8%) and diabetes mellitus (17.0%). The prevalence rates of preexisting CVRFs or CVDs increased with age (P < 0.001). The number of patients requiring intensive care (P < 0.001) and invasive MV (P < 0.001) increased with age. The in-hospital death rate increased with age (P < 0.001). Patients requiring intensive care (5.3% vs. 1.6%; P < 0.001) and invasive MV (4.3% vs. 1.7%; P < 0.001) were significantly greater in patients with preexisting CVRFs or CVDs. In-hospital mortality (12.9% vs. 3.1%; P < 0.001) was significantly higher in patients with preexisting CVRFs or CVDs. Among the CVRFs, diabetes mellitus and hypertension were associated with increased requirement of intensive care and invasive MV and in-hospital death. Among the known CVDs, coronary artery disease and congestive heart failure were associated with invasive MV and in-hospital death. In multivariate analysis, preexisting CVRFs or CVDs (odds ratio [OR], 1.79; 95% confidence interval [CI], 1.07-3.01; P = 0.027) were independent predictors of in-hospital death after adjusting for confounding variables. Among individual preexisting CVRF or CVD components, diabetes mellitus (OR, 2.43; 95% CI, 1.51-3.90; P < 0.001) and congestive heart failure (OR, 2.43; 95% CI, 1.06-5.87; P = 0.049) were independent predictors of in-hospital death.

CONCLUSION

Based on the findings of this study, the patients with confirmed COVID-19 with preexisting CVRFs or CVDs had worse clinical outcomes. Caution is required in dealing with these patients at triage.

Incremental Predictive Value of Plasma Renin Activity as a Prognostic Biomarker in Patients with Heart Failure

BACKGROUND

The association of N-terminal pro-B type natriuretic peptide (NT-proBNP) and plasma renin activity (PRA) for the prognosis of the patients with acute heart failure (HF) has not been fully investigated. This study aimed to determine the association between NT-proBNP and PRA and to investigate the incremental value of PRA to NT-proBNP for predicting long term prognosis in patients with acute HF.

METHODS

Three hundred and ninety-six patients (mean age, 64.7 ± 15.9 years; 46.5% female) presenting with acute HF were enrolled between December 2004 and July 2013. Patients with newly diagnosed HF as well as patients with acute exacerbated chronic HF were included. The prognosis was assessed with the composite event of all-cause mortality and readmission for HF during a 2-year follow-up period.

RESULTS

The etiology of HF was ischemic in 116 (29.3%) patients. In a Cox proportional hazards model, log-transformed PRA (hazard ratio [HR], 1.205; P = 0.007) was an independent predictor of the composite outcome of all-cause mortality and readmission for HF in addition to age (HR, 1.032; P = 0.001), white blood cell (WBC) count (HR, 1.103; P < 0.001), and left ventricular ejection fraction (LVEF) (HR, 0.978; P = 0.013). Adding PRA to age, sex, LVEF, and NT-proBNP significantly improved the prediction for the composite outcome of all-cause mortality and readmission for HF, as shown by the net reclassification improvement (0.47; P < 0.001) and integrated discrimination improvement (0.10; P < 0.001).

CONCLUSION

PRA could provide incremental predictive value to NT-proBNP for predicting long term prognosis in patients with acute HF.

Perioperative outcomes of interrupted anticoagulation in patients with non-valvular atrial fibrillation undergoing non-cardiac surgery

Background

This study aimed to investigate the incidences of and risk factors for perioperative events following anticoagulant discontinuation in patients with non-valvular atrial fibrillation (NVAF) undergoing non-cardiac surgery.

Methods

A total of 216 consecutive patients who underwent cardiac consultation for suspending perioperative anticoagulants were enrolled. A perioperative event was defined as a composite of thromboembolism and major bleeding.

Results

The mean anticoagulant discontinuation duration was 5.7 (±4.2) days and was significantly longer in the warfarin group (p<0.001). Four perioperative thromboembolic (1.9%; three strokes and one systemic embolization) and three major bleeding events (1.4%) were observed. The high CHA₂DS₂-VASc and HAS-BLED scores and a prolonged preoperative anticoagulant discontinuation duration (4.4±2.1 vs. 2.9±1.8 days; p=0.028) were associated with perioperative events, whereas the anticoagulant type (non-vitamin K antagonist oral anticoagulants or warfarin) was not. The best cut-off levels of the HAS-BLED and CHA₂DS₂-VASc scores were 3.5 and 2.5, respectively, and the preoperative anticoagulant discontinuation duration for predicting perioperative events was 2.5 days. Significant differences in the perioperative event rates were observed among the four risk groups categorized according to the sum of these values: risk 0, 0%; risk 1, 0%; risk 2, 5.9%; and risk 3, 50.0% (p<0.001). Multivariate logistic regression analysis showed that the HAS-BLED score was an independent predictor for perioperative events.

Conclusion

Thromboembolic events and major bleeding are not uncommon during perioperative anticoagulant discontinuation in patients with NVAF, and interrupted anticoagulation strategies are needed to minimize these.

A Case of COVID-19 with Acute Myocardial Infarction and Cardiogenic Shock

A 60-year-old male patient with coronavirus disease-2019 showed new onset ST-segment elevation in V1-V2 leads on electrocardiogram and cardiac enzyme elevation in intensive care unit. He had a history of type 2 diabetes mellitus, hypertension, and dyslipidemia. He was receiving mechanical ventilation and veno-venous extracorporeal membrane oxygenation treatment for severe hypoxia. Two-D echocardiogram showed regional wall motion abnormalities. We performed primary percutaneous coronary intervention for acute myocardial infarction complicating cardiogenic shock under hemodynamic support. He expired on the 16th day of admission because of cardiogenic shock and multi-organ failure. Active surveillance and intensive treatment strategy are important for saving lives of COVID-19 patients with acute myocardial infarction.

P3617Systolic blood pressure, glycemic control and clinical outcome in diabetic patients with acute myocardial infarction

Background

Recent blood pressure guidelines recommend intensive blood pressure control in diabetic patients with cardiovascular disease.

Purpose

We sought to investigate combined impact of intensive blood glucose lowering and blood pressure control on clinical outcome in diabetic patients with acute myocardial infarction (AMI) has not been fully investigated yet.

Method

Korean Acute Myocardial Infarction Registry (KAMIR) – National Institute of Health (NIH) database included 12,179 patients (9,046 men; mean age = 63.6±12.6 year-old) who were discharged alive. Among them, 3,430 (28.2%) had a diabetes mellitus (DM). MACCEs were defined as a composition of all cause death, non-fatal MI, repeat revascularizations including repeated percutaneous coronary intervention and coronary bypass grafting, cerebrovascular accident and rehospitalizations at 1 year. This research was supported by a fund by Research of Korea Centers for Disease Control and Prevention.

Result

We determined cut-off value of discharge systolic blood pressure (SBP) to predict 1-year MACCE in DM and non-DM patients. Discharge SBP of less than 130mmHg was associated with a lower MACCE at 1 year compared to SBP level of 130mmHg or greater (10.8% versus 15.4%; log-rank p=0.001) in DM patients, whereas discharge SBP cut-off level was 140mmHg to discriminate 1-year MACCE in non-DM patients (6.4% versus 8.5%, log-rank p=0.045). In DM patients, there were no significant difference in 1-year MACCEs between patients with HbA1c less than 7% versus 7% or greater (12.0% versus 10.7%; log-rank p=0.325). DM patients were categorized into 4 groups; discharge SBP <130mmHg and HbA1c <7% (Group 1); discharge SBP <130mmHg and HbA1c ≥7% (Group 2); discharge SBP ≥130mmHg and HbA1c <7% (Group 3); discharge SBP ≥130mmHg and HbA1c ≥7% (Group 4). Intensive BP control was associated lower 1-year MACCEs in patients with good glycemic control (Group 1 & 3; 10.7% versus 16.7%; log-rank p=0.009). However, in patients with poor glycemic control, intensive BP control did not improve 1-year MACCEs (Group 2 & 4; 10.6% versus 11.1%; log-rank p=0.761).

Conclusion

Strict BP control is more important than glycemic control to improve short-term clinical outcome in DM patients with AMI. However, in patients with poor glycemic control, strict BP control did not improve clinical outcome.

P3583Optimal procedural strategy to improve clinical outcome in primary percutaneous coronary intervention

Background

Current guideline recommends potent antiplatelet agents and transradial intervention. However, it is uncertain whether routine use of IVUS, thrombus aspiration and glycoprotein IIB-IIIA inhibitor is beneficial for improving clinical outcome in patients with ST-segment elevation myocardial infarction (STEMI).

Purpose

The aim of this study was to investigate optimal procedural strategy to improve clinical outcome.

Methods

A total of 6,046 patients who underwent primary percutaneous coronary intervention (PCI) for STEMI were analyzed from the Korean Acute Myocardial Infarction Registry (KAMIR) – National Institute of Health (NIH) database. MACCEs were defined as a composition of all cause death, non-fatal MI, repeat revascularizations including repeated percutaneous coronary intervention and coronary bypass grafting, cerebrovascular accident and rehospitalizations. This research was supported by a fund by Research of Korea Centers for Disease Control and Prevention.

Results

During the primary PCI, potent antiplatelet agents such as prasugrel and ticagrelor were used in 2342 (38.4%). PCI was performed through transradial approach in 1490 (25.2%). Thrombus aspiration and intravascular ultrasound (IVUS) examination was done in 2204 (36.1%) and 1079 (18.1%), respectively. Glycoprotein IIB-IIIA inhibitor was administered in 1295 (21.7%). Among them, potent antiplatelet agents, transradial intervention, IVUS, and thrombus aspiration significantly reduced MACCEs at 1 year. Glycoprotein IIB-IIIA inhibitor was not effective to improved clinical outcome. In Cox-proportional hazards model, potent antiplatelet agents (hazard ratio 0.82, 95% confidence interval 0.67–0.99; p=0.045) and transradial intervention (hazard ratio 0.61, 95% confidence interval 0.47–0.78; p<0.001) was an independent predictor of MACCEs after adjusting for confounding variables. Combined use of potent antiplatelet agents and transradial intervention (hazard ratio 0.54; 95% confidence interval 0.37–0.80; p=0.002) substantially reduced MACCEs at 1 year.

Conclusion

Among evidence based procedures during the primary PCI, combined use of potent antiplatelet agents and transradial intervention was optimal procedural strategy to improve clinical outcome.

Tachycardia-Induced Right Heart Failure and Severe Tricuspid Regurgitation That Improved with Medication

Secondary tricuspid regurgitation (TR) primarily develops due to left heart failure or primary pulmonary diseases. Tricuspid annular dilation, which is commonly caused by right ventricular volume and pressure overload followed by right ventricle dilation, is believed to be the main mechanism underlying secondary TR. It is reported that once the tricuspid annulus is dilated, its size cannot spontaneously return to normal, and it may continue to dilate. These reports also suggest the use of an aggressive surgical approach for secondary TR. In the present report, we describe a case of tachycardia-induced severe TR that was completely resolved without the need for surgery.

Left Ventricular Strain as Predictor of Chronic Aortic Regurgitation

BACKGROUND

It is not well known about the implication of left ventricular (LV) strain as a predictor for mortality in patients with chronic aortic regurgitation (AR). The purpose of this study was to investigate whether global longitudinal strain measured by two-dimensional speckle-tracking echocardiography could predict long-term outcome in patients with chronic AR.

METHODS

This is a single center non-randomized retrospective observational study. The patients with chronic AR from January 2002 to December 2012 were retrospectively enrolled. Following patients were excluded; combined other significant valvular disease, previous heart surgery, aortic disease, congenital heart disease, acute AR and young age under 18 years old. Finally, 60 patients were analyzed and the LV global strain rate was measured on apical four chamber image (GS-4CH).

RESULTS

During 64 months follow-up duration, 16 patients (26.7%) were deceased and 38 patients (63.3%) underwent aortic valve replacement (AVR). Deceased group was older (69 years old vs. 51 years old, p < 0.001) and had lower longitudinal strain (-12.05 ± 3.72% vs. -15.66 ± 4.35%, p = 0.005). Kaplan-Meier survival curve stratified by GS-4CH showed a trend of different event rate (log rank p = 0.001). On multivariate analysis by cox proportional hazard model adjusting for age, sex, body surface area, history of atrial fibrillation, blood urea nitrogen, LV dilatation, LV ejection fraction and AVR, decreased GS-4CH proved to be an independent predictor of mortality in patients with chronic AR (hazard ratio 1.313, 95% confidence interval 1.010-1.706, p = 0.042).

CONCLUSION

GS-4CH may be a useful predictor of mortality in patient with chronic AR.

Replication of results of genome-wide association studies on esophageal squamous cell carcinoma susceptibility loci in a Korean population

Two recent genome-wide association studies have identified that the rs2274223 single-nucleotide polymorphism inphospholipase C epsilon 1 and the single-nucleotide polymorphism rs13042395 in C20orf54 are involved in esophageal squamous cell carcinoma (ESCC) in Chinese populations. We hypothesized that genetic polymorphisms of phospholipase C epsilon 1 and C20orf54 are also associated with ESCC in a Korean population. The rs2274223 and rs13042395 genotyping was performed using high-resolution melting analysis. The rs2274223 GG genotype was significantly associated with an increased risk of ESCC (odds ratio [OR]=1.86, 95% confidence interval [CI]=1.08-3.25) compared with the rs2274223 AA genotype. The rs13042395 G allele showed a significantly decreased risk of ESCC in the younger age group (OR=0.71, 95% CI=0.52-0.97) and no significant association in the older group (OR=1.19, 95% CI=0.87-1.62). We observed that the rs2274223 polymorphism was associated with an increased risk of ESCC in this Korean case-control study and that age may modify the association between the rs13042395 polymorphism and the risk of ESCC.

Biological evaluation of intervertebral disc cells in different formulations of gellan gum-based hydrogels

Gellan gum (GG)-based hydrogels are advantageous in tissue engineering not only due to their ability to retain large quantities of water and provide a similar environment to that of natural extracellular matrix (ECM), but also because they can gelify in situ in seconds. Their mechanical properties can be fine-tuned to mimic natural tissues such as the nucleus pulposus (NP). This study produced different formulations of GG hydrogels by mixing varying amounts of methacrylated (GG-MA) and high-acyl gellan gums (HA-GG) for applications as acellular and cellular NP substitutes. The hydrogels were physicochemically characterized by dynamic mechanical analysis. Degradation and swelling abilities were assessed by soaking in a phosphate buffered saline solution for up to 170 h. Results showed that as HA-GG content increased, the modulus of the hydrogels decreased. Moreover, increases in HA-GG content induced greater weight loss in the GG-MA/HA-GG formulation compared to GG-MA hydrogel. Potential cytotoxicity of the hydrogel was assessed by culturing rabbit NP cells up to 7 days. An MTS assay was performed by seeding rabbit NP cells onto the surface of 3D hydrogel disc formulations. Viability of rabbit NP cells encapsulated within the different hydrogel formulations was also evaluated by Calcein-AM and ATP assays. Results showed that tunable GG-MA/HA-GG hydrogels were non-cytotoxic and supported viability of rabbit NP cells.

Modulation of the murine microbiome with a concomitant anti-obesity effect by Lactobacillus rhamnosus GG and Lactobacillus sakei NR28

The microbiota of the gastrointestinal tract (GIT) constitutes the major part of the total human microbiome and is considered to be an important regulator of human health and host metabolism. Numerous investigations in recent years have focused on the connection between the human microbiota and metabolic diseases such as obesity, type II diabetes and atherosclerosis. Yet, little is known about the impact of probiotic consumption on the GIT microbial population and the potential effect on chronic diseases. In this study, the modulation of the microbial community in the murine small intestine resulting from probiotic feeding was investigated and was found to be associated with an anti-obesity effect. Changes in the microbiota of the mouse faeces and small intestine were monitored using quantitative real-time PCR and by following the mRNA expression levels of various obesity-related biomarkers following probiotic feeding in a mouse model. Lactobacillus rhamnosus GG and Lactobacillus sakei NR28 (a putative probiotic strain isolated from kimchi) were administered at a daily level of approximately 1×10(8) viable bacteria per mouse (C57BL/6J mice) for up to three weeks. Feeding these strains resulted in a significant reduction of epididymal fat mass, as well as obesity-related biomarkers like acetyl-CoA carboxylase, fatty acid synthase, and stearoyl-CoA desaturase-1 in the liver. The total number and ratio of the microbial groups, i.e. Firmicutes, Bacteroidetes, Clostridium cluster I and XIVab, and Lactobacillus spp. were modulated in the small intestine, and the Firmicutes:Bacteroidetes ratio was decreased. In contrast, no noticeable effect of probiotic feeding could be detected on the faecal microbiota, neither quantitatively, nor with regard to the bacterial groups (Firmicutes, Bacteroidetes, Clostridium cluster I and XIVab, and Lactobacillus spp.) studied.

p53 codon 72 polymorphism and the risk of esophageal cancer: a Korean case-control study

The aim of this study was to assess whether p53 codon 72 polymorphism is associated with an increased risk of esophageal cancer (EC) in South Korea. We conducted a case-control study including 340 patients with EC, and 1700 controls. P53 codon 72 polymorphism was determined by real-time polymerase chain reaction. The frequencies of p53 codon 72 polymorphisms (Arg/Arg, Arg/Pro, and Pro/Pro) in EC were 39.4%, 45.6%, and 15.0%, respectively; frequencies in the controls were 43.2%, 45.6%, and 11.2%, respectively. Compared with the Arg/Arg genotype, the OR of the Arg/Pro genotype was 1.09 (95% CI = 0.85-1.41) and that of the Pro/Pro genotype was 1.47 (95% CI = 1.02-2.11) for EC overall. When adjusted by age, gender, and smoking status, the OR of the Arg/Pro genotype was 1.24 (95% CI = 0.92-1.67) and that of the Pro/Pro genotype was 1.77 (95% CI = 1.15-2.74) for EC overall. In never-smokers and ever-smokers, the OR of the Arg/Pro genotype was 0.59 (95% CI = 0.37-0.95) and 1.39 (95% CI = 1.00-1.91), respectively, and there was a significant difference in the homogeneity test (P= 0.011). We observed that the p53 codon 72 polymorphism was associated with an increased risk of EC in this Korean case-control study, and smoking status modified the association between the p53 codon 72 polymorphism and the risk of EC.

Differences in femoral neck geometry associated with age and ethnicity

SUMMARY

We studied femoral geometry in relation to age and ethnicity in a cross-sectional study. Age-associated cortical thinning showed the most pronounced effect, and Koreans studied here had thicker cortices and lower buckling ratios than those reported for other races. Cortical thickness may thus be a major determinant of hip fracture risk.

INTRODUCTION

The rate of hip fracture varies by age and ethnicity. The geometric properties of the femur influence femoral strength and fragility, but differences in femoral geometry according to age and ethnicity are poorly understood. To explain the high prevalence of hip fractures in the elderly and the relatively low hip fracture rate in Asian populations, we studied age-related changes and ethnic differences in femoral geometry.

METHODS

We recruited 214 peri- or postmenopausal women aged 46 to 85 years (mean age, 60.6 years). Their proximal femoral bone mineral densities (BMD) were measured by quantitative computed tomography and further analyzed geometric properties.

RESULTS

We observed large declines in trabecular volumetric bone mineral density associated with aging (33.03% less than the reference value in the oldest group, respectively). Cortical thickness decreased remarkably with age as well, and only 53.94% of the baseline value remained in the oldest group. As a result, the cortical buckling ratio increased geometrically and reached 239.14% of the reference value in the oldest group. In comparisons with other ethnic groups, Korean subjects had thicker cortices than their American, European, and African counterparts.

CONCLUSIONS

In this cross-sectional study, cortical thickness showed a pronounced age-associated decrease, and the cortical buckling ratio showed a strong age-associated increase. This may in part explain the higher rates of hip fractures in the elderly. When compared with other races, Asians had thicker cortical bone and lower buckling ratios, which may partially explain the lower prevalence of hip fractures in Asians.

Centrality dependence of the charged-particle multiplicity density at midrapidity in Pb-Pb collisions at sqrt[s(NN)] = 2.76 TeV

The centrality dependence of the charged-particle multiplicity density at midrapidity in Pb-Pb collisions at sqrt[s_{NN}]=2.76  TeV is presented. The charged-particle density normalized per participating nucleon pair increases by about a factor of 2 from peripheral (70%-80%) to central (0%-5%) collisions. The centrality dependence is found to be similar to that observed at lower collision energies. The data are compared with models based on different mechanisms for particle production in nuclear collisions.

Elliptic flow of charged particles in Pb-Pb collisions at sqrt[S(NN)] = 2.76 TeV

We report the first measurement of charged particle elliptic flow in Pb-Pb collisions at sqrt[S(NN)] =2.76 TeV with the ALICE detector at the CERN Large Hadron Collider. The measurement is performed in the central pseudorapidity region (|η|<0.8) and transverse momentum range 0.2<p t<5.0 GeV/c. The elliptic flow signal v₂, measured using the 4-particle correlation method, averaged over transverse momentum and pseudorapidity is 0.087 ± 0.002(stat) ± 0.003(syst) in the 40%-50% centrality class. The differential elliptic flow v₂ p t reaches a maximum of 0.2 near p t =3 GeV/c. Compared to RHIC Au-Au collisions at sqrt[S(NN)] 200 GeV, the elliptic flow increases by about 30%. Some hydrodynamic model predictions which include viscous corrections are in agreement with the observed increase.

Charged-particle multiplicity density at midrapidity in central Pb-Pb collisions at sqrt[S(NN)] = 2.76 TeV

The first measurement of the charged-particle multiplicity density at midrapidity in Pb-Pb collisions at a center-of-mass energy per nucleon pair √ S NN = 2.76 TeV is presented. For an event sample corresponding to the most central 5% of the hadronic cross section, the pseudorapidity density of primary charged particles at midrapidity is 1584 ± 4(stat) ± 76(syst), which corresponds to 8.3 ± 0.4(syst) per participating nucleon pair. This represents an increase of about a factor 1.9 relative to pp collisions at similar collision energies, and about a factor 2.2 to central Au-Au collisions at √ S NN = 2.76 TeV. This measurement provides the first experimental constraint for models of nucleus-nucleus collisions at LHC energies.

Midrapidity antiproton-to-proton ratio in pp collisons at sqrt[s]=0.9 and 7 TeV measured by the ALICE experiment

The ratio of the yields of antiprotons to protons in pp collisions has been measured by the ALICE experiment at sqrt[s]=0.9 and 7 TeV during the initial running periods of the Large Hadron Collider. The measurement covers the transverse momentum interval 0.45<p_{t}<1.05  GeV/c and rapidity |y|<0.5. The ratio is measured to be R_{|y|<0.5}=0.957±0.006(stat)±0.014(syst) at 0.9 TeV and R_{|y|<0.5}=0.991±0.005(stat)±0.014(syst) at 7 TeV and it is independent of both rapidity and transverse momentum. The results are consistent with the conventional model of baryon-number transport and set stringent limits on any additional contributions to baryon-number transfer over very large rapidity intervals in pp collisions.

Hepatitis B vaccination in HIV-infected adults: current evidence, recommendations and practical considerations

Immunization with hepatitis B (HBV) vaccine is recommended for all HIV-infected individuals without immunity to HBV. This patient population, however, has relatively poor HBV vaccine responses. Factors associated with this impaired HBV vaccine response in HIV-infected individuals may include older age, uncontrolled HIV replication, and low nadir CD4 cell count. Postvaccination testing for HBV surface antibody is recommended and vaccine non-responders should undergo repeat immunization with a full series. The benefit of double dosage, the appropriate strategy for HIV-infected patients with isolated HBV core antibody and the timing and number of vaccinations in persons with advanced immunosuppression on highly active antiretroviral therapy remain controversial areas.

Relative transport behavior of Escherichia coli O157:H7 and Salmonella enterica serovar pullorum in packed bed column systems: influence of solution chemistry and cell concentration

The influence of solution chemistry and cell concentration on bacterial transport has been examined using Salmonella pullorum SA1685 and Escherichia coli O157:H7. A column was employed to determine the transport behavior and deposition kinetics with aquifer sand over a range of ionic strengths and cell concentrations. O157:H7 was found to be more adhesive than SA1685, with calculated deposition rate coefficients higher than those of SA1685. Comprehensive cell surface characterization techniques including size, surface charge density, extracellular polymeric substance content, electrophoretic mobility, and hydrophobicity analyses were conducted to explain observed transporttrends. The pathogens' size and hydrophobicity were not significantly different, whereas they varied in acidity, for which O157:H7 had 19 times higher surface charge density than SA1685. Electrophoretic mobilities, in general agreement with titration analysis and column experiments, revealed SA1685 to be more negative than O157:H7. This combination of column and characterization experiments indicates that SA1685 can be transported to a greater extent than O157:H7 in groundwater environments. This study is the first comprehensive work comparing the transport behavior of two important pathogens in aquifer systems.

Temporal bone CT findings in Cornelia de Lange syndrome

BACKGROUND AND PURPOSE

Cornelia de Lange syndrome is a rare developmental malformation syndrome with a high prevalence of hearing impairment. The purposes of this study were to describe the characteristic temporal bone CT findings in patients with Cornelia de Lange syndrome and to correlate audiometric data with radiologic findings in these patients.

MATERIALS AND METHODS

Ten children (6 girls and 4 boys; mean age, 42.0 months) who were clinically diagnosed with Cornelia de Lange syndrome (classic, n = 5; mild form, n = 5) were enrolled. Temporal bone CT was prospectively performed, and 32 aspects of each temporal bone CT were analyzed, 21 by direct measurement and 11 by visual inspection. Twenty age-matched children (n = 20 ears) with normal temporal bone CT scans served as a control group. Audiologic tests were also performed on all patients.

RESULTS

Characteristic temporal bone CT findings of Cornelia de Lange syndrome were external auditory canal stenosis, soft-tissue opacification of the hypoplastic tympanomastoid cavity, dysmorphic ossicle, hypoplastic cochlea, and dysplastic vestibule, all of which were more prevalent in patients with the classic form of the disease than in those with the mild form. Children who had more severe structural abnormalities on temporal bone CT had worse hearing levels compared with those without structural abnormalities.

CONCLUSION

Temporal bone CT scans in Cornelia de Lange syndrome could document combined structural abnormalities of the external, middle, and inner ear, which were one of the characteristic clinical manifestations; CT abnormalities were well correlated with the audiometric data.

The distribution of inhibitory and excitatory synapses on single, reconstructed jaw-opening motoneurons in the cat

In a previous study, we reported that the distribution of inhibitory input, in contrast to excitatory input, decreased somatofugally along dendrites of cat jaw-closing alpha-motoneurons [J Comp Neurol 414 (1999) 454]. The present study examined the distribution of GABA, glycine, and glutamate immunopositive boutons covering horseradish peroxidase-labeled cat jaw-opening motoneurons. The motoneurons were divided into four compartments: the soma, and primary, intermediate, and distal dendrites. Ninety-seven percent of the total number of studied boutons had immunoreactivity for at least one of the three amino acids. The proportion of boutons immunoreactive for GABA and/or glycine was lower than the proportion of boutons immunoreactive for glutamate. Boutons immunoreactive to glycine alone were more numerous than boutons double-labeled for GABA and glycine, which, in turn, occurred more frequently than boutons immunoreactive to GABA alone. The percentage synaptic covering (proportion of membrane covered by synaptic boutons) of the putatively excitatory (glutamate containing) and putatively inhibitory (GABA and/or glycine containing) boutons decreased somatofugally along the dendrites. Such systematic variations were not seen in the packing density (number of boutons per 100 microm(2)); the packing density showed a distinct drop between the soma and primary dendrites but did not differ significantly among the three dendritic compartments. Overall, the packing density was slightly higher for the putatively excitatory boutons than for the inhibitory ones. When taken together with previous analyses of jaw-closing alpha-motoneurons the present data on jaw-opening alpha-motoneurons indicate that the two types of neuron differ in regard to the nature of synaptic integration in the dendritic tree.

Increased inducible nitric oxide synthase expression and nitric oxide concentration in patients with aplastic anemia

Nitric oxide (NO) is a biological mediator that is synthesized from L-arginine by the nitric oxide synthase (NOS) family. We investigated the expression of iNOS in bone marrow (BM) mononuclear cells (MNCs) using a reverse transcriptase polymerase chain reaction (RT-PCR) assay and the concentration of NO from BM serum by measuring the metabolite NO(2)(-) in 13 patients with aplastic anemia (AA) compared with 10 normal controls who were donors for allogeneic bone marrow transplantation (BMT). All samples of BM MNCs in patients with AA expressed iNOS mRNA, but iNOS was not expressed in patients who were treated successfully with allogeneic BMT. Normal control samples and samples from leukemia patients who had bone marrow aplasia after chemotherapy did not show significant iNOS expression. When we measured the density of bands for both iNOS and beta(2)-microglobin expressed as the iNOS/beta(2)-microglobin density ratio, there was a significant difference in the ratio between AA and normal controls (0.88+/-0.15 vs 0.26+/-0.05, P<0.001). The BM serum NO(2)(-) concentration in the patients with AA was significantly higher than that of normal controls (88.1+/-32.8 microM vs 48.8+/-8.6 microM, P=0.002). In addition, there was a significant correlation between the NO(2)(-) concentration and the calculated iNOS/beta(2)-microglobin density ratio (r=0.567, P=0.01). These findings suggest that upregulation of iNOS expression for local NO production may contribute in part to the pathogenesis of AA.

Typical demethylation events in cloned pig embryos. Clues on species-specific differences in epigenetic reprogramming of a cloned donor genome

We investigated whether a genomic demethylation process occurs in pig preimplantation embryos produced by either normal fertilization or somatic cell nuclear transfer. The methylation status of the centromeric satellite and the PRE-1 short interspersed element (SINE) sequences was characterized using bisulfite-sequencing technology. Typical demethylation processes were identified in these repetitive sequences of the cloned donor genome during cleavage, the patterns of which were similar to the ones detected in fertilized counterparts. These findings are different from previous observations with cloned bovine embryos where various repeated regions of the donor genome exhibited aberrant methylation patterns. Our results indicate that species-specific differences exist in modifying the epigenetic status of cloned donor genomes.