Prognostic impact of right ventricular overload in patients with acute coronary syndrome

Background

Right ventricular (RV) overload is associated with adverse outcome in patients with chronic heart failure. However, its prognostic value in acute coronary syndrome (ACS) patients remains unknown.

Purpose

The purpose of this study was to investigate the prevalence and prognostic impact of right ventricular overload in ACS patients.

Methods

We studied 2797 ACS patients from Mie ACS registry, a prospective and multicenter registry in Japan. They were divided into 4 subgroups according to the severity of RV overload and the extent of Left Ventricle Ejection Fraction (LVEF) assessed by echocardiography before hospital discharge. High RV overload was defined as trans-tricuspid pressure gradient (TRPG) ≥40mmHg and preserved LVEF was defined as ≥50%. The primary outcome was defined as 2-year all-cause mortality. Median follow up duration was 730 days (1–2215 days).

Results

High RV overload was detected in 76 patients (2.7%). In basic patients characteristics, high RV overload patients were significantly older and higher killip classification than low RV overload patients (P<0.01, respectively). Laboratory data in high RV overload patients showed lower hemoglobin level and higher serum creatinine level than those in low RV overload patients (P<0.01, respectively).

Echocardiographic findings in high RV overload represented lower LVEF, higher rate of moderate or severe mitral regurgitation and left atrial enlargement than those in low RV overload patients (P<0.01, respectively).

During the follow-up periods (median 730 days), 260 (9.3%) patients experienced all-cause death. Multivariate cox hazard regression analysis for all-cause mortality demonstrated that high RV overload was an independent poor prognostic factor in the entire study population. Among patients with preserved LVEF, high RV overload resulted in an increased risk of all-cause mortality compared to low RV overload (P<0.0001).

Conclusion

In ACS patients, high RV overload strongly contributes to worsening of prognosis regardless of the extent of LVEF.

Kaplan-Meier survival curve

Funding Acknowledgement

Type of funding source: None

P3632Prognostic impact of aortic valve stenosis in patients with acute myocardial infarction

Background

Aortic valve stenosis (AS) is associated with the presence and severity of coronary artery disease independently of clinical risk factors, which leads to increased cardiovascular mortality. However, the prevalence of AS and its prognostic value among patients with acute myocardial infarction (AMI) remain unknown.

Purpose

The purpose of this study was to investigate the prevalence and prognostic impact of AS in AMI patients.

Methods

We studied 2,803 AMI patients using data from Mie ACS registry, a prospective and multicenter registry. Patients were divided into subgroups according to the presence and severity of AS based on maximal aortic flow rate by Doppler echocardiography before hospital discharge: non-AS <2.0 m/s, 2.0 m/s≤mild AS <3.0 m/s, 3.0 m/s≤moderate AS <4.0m/s and severe AS≥4.0 m/s. The primary outcome was defined as 2-year all-cause mortality.

Results

AS was detected in 79 patients (2.8%) including 49 mild AS, 23 moderate AS and 6 severe AS. AS patients were significantly older (79.9±9.8 versus 68.3±12.6 years), and higher killip classification than non-AS patients (P<0.01, respectively). However, left ventricular ejection fraction, and prevalence of primary PCI was similar between the 2 groups. During the follow-up periods (median 725 days), 333 (11.9%) patients experienced all-cause death. AS patients demonstrated the higher all-cause mortality rate compared to that of non-AS patients during follow up (47.3% versus 11.3%, P<0.0001, chi square). Kaplan-Meier curves showed that the probability of all-cause mortality was significantly higher among AS patients than non-AS patients, and was highest among moderate and severe AS (See figure A and B). Cox regression analyses for all-cause mortality demonstrated that the severity of AS was the strongest and independent poor prognostic factor (HR 1.71, 95% CI 1.30–2.24, P<0.001, See table).

Cox hazard regression analysis Hazard ratio 95% Confidential interval P-value Severity of aortic valve stenosis 1.71 1.30–2.24 <0.001 Killip classification 1.63 1.46–1.82 <0.001 Age 1.07 1.06–1.09 <0.001 Serum creatinine level 1.05 1.03–1.08 <0.001 Max CPK level 1.00 1.00–1.01 <0.001 Left ventricular ejection fraction 0.96 0.95–0.97 <0.001 Primary percutaneous coronary intervention 0.67 0.47–0.96 0.03 CPK suggests creatinine phosphokinase.

All cause mortality

Conclusions

The presence of AS of any severity contributes to worsening of patients' prognosis following AMI independently of other known risk factors.

Acknowledgement/Funding

None

Successful Peritoneal Dialysis for the Treatment of Inotrope-Dependent End-Stage Heart Failure

Extra- and/or intracorporeal renal replacement therapy can improve the cardiorenal hemodynamics in patients with advanced heart failure (HF) refractory to medical therapy and renal failure. Here, we report the case of a 51-year-old woman with inotrope-dependent end-stage HF and chronic renal failure due to anthracycline-induced cardiomyopathy, in whom the induction of hemodiafiltration and subsequent chronic peritoneal dialysis (PD) provided a dramatic improvement of her cardiac hemodynamics from restrictive to almost normal physiology assessed by echocardiography and cardiac catheterization. The patient returned to office work with New York Heart Association functional class I-II symptoms for at least 3 years with continuous ambulatory PD after hospital discharge.

A novel method for the quantitative evaluation of diurnal respiratory instability in patients with heart failure: A pilot study

BACKGROUND

There is no established method to quantitatively measure the presence and the severity of respiratory instability (RI). The purpose of this pilot study was to propose a novel index of diurnal RI as a surrogate measure of clinical severity of heart failure (HF).

METHODS AND RESULTS

We prospectively enrolled 60 patients with symptomatic HF [70±14 years, 75% male, and New York Heart Association (NYHA) functional classes II-IV] who underwent right heart catheterization (RHC), and recorded diurnal respiration using a nasal pressure sensor during bed rest while awake within 2 days before or after RHC. Non-uniformity of the breath-by-breath respiratory slopes during 15min calculated as the ratio of peak expiratory amplitude to corresponding peak-to-peak interval was assessed by histogram-based frequency distribution measurement, and was defined as the "RI-index". The RI-index was significantly different among NYHA functional classes and was highest in NYHA class IV. The presence of atrial fibrillation (β coefficient: 0.300, p=0.01) and stroke volume index (β coefficient: -0.462, p<0.01) were independently associated with RI index among hemodynamic parameters. Furthermore, the high RI index above the median value was the independent predictor of the composite outcome of death from any cause, a life-threatening arrhythmia, and an unplanned hospitalization for worsening HF.

CONCLUSIONS

The RI index stratified functional severity of HF well, and was a significant independent predictor of poor outcomes.

Tocilizumab for uncontrollable systemic inflammatory response syndrome complicating adult-onset Still disease: Case report and review of literature

RATIONALE

Adult-onset Still disease (AOSD) is a rare systemic inflammatory disease of unknown etiology characterized by evanescent salmon-pink rash, fever spikes, arthralgia, and lymphadenopathy. AOSD usually has a good prognosis, but it can sometimes be fatal, especially when it is complicated by systemic inflammatory response syndrome (SIRS) and multiple organ failure.

PATIENT CONCERNS

A previously healthy 26-year-old woman was referred to our hospital for persistent high fever and mild systemic edema. Five days later, the patient presented with dyspnea, hypotension, and anuria. Anasarca developed with massive pleural effusion, ascites, and systemic edema, resulting in an increase of 47 kg in body weight.

DIAGNOSES

The patient was diagnosed as AOSD after infection, malignancy, hematologic disorders, and other autoimmune diseases were excluded.

INTERVENTIONS

We administered tocilizumab, an IL-6 receptor inhibitor, intravenously in addition to cyclosporine, prednisolone, plasma exchange, and continuous hemodiafiltration.

OUTCOMES

The patient's systemic condition improved. After stabilization by all medications, the patient was managed and responded to tocilizumab alone. To the best of our knowledge, this was the first case of severe SIRS complicating AOSD that was successfully treated with an anti- IL-6 receptor antibody.

LESSONS

SIRS should not be overlooked in a patient with steroid-resistant AOSD and edema. Inhibitors of the IL-6 receptor can be used safely and effectively to control AOSD complicated with severe SIRS.

Effect of Anemia on Cardiovascular Hemodynamics, Therapeutic Strategy and Clinical Outcomes in Patients With Heart Failure and Hemodynamic Congestion

BACKGROUND

We investigated the effect of anemia on cardiovascular hemodynamics, therapeutic strategies and clinical outcomes in heart failure (HF) patients.Methods and Results:We divided 198 consecutive HF patients who underwent right heart catheterization before in-hospital HF treatment into 2 groups according to the presence or absence of hemodynamic congestion (HC: mean pulmonary capillary wedge pressure ≥15 mmHg and/or mean right atrial pressure ≥10 mmHg). The hemoglobin level correlated with the cardiac index (CI) and systemic vascular resistance index (SVRI) (r=-0.34 and 0.42, P<0.05, respectively), and was the strongest contributor of SVRI only in the HC group. Anemic patients more frequently required intravenous inotropic support despite having higher CI and lower SVRI than non-anemic patients in the HC group. The novel hemodynamic subsets based on mean right atrial pressure and estimated left ventricular stroke work index but not Forrester subsets appropriately predicted the need for intravenous inotropic support. The probability of hospitalization for worsening HF during 2-year follow-up period was significantly higher in anemic patients than in non-anemic patients in the HC group.

CONCLUSIONS

Anemia had a direct effect on cardiovascular hemodynamics and thus can confound therapeutic planning in HF patients with HC. The novel hemodynamic subsets can be applied in daily clinical practice regardless of the presence or absence of anemia.

Fulminant Myocarditis With Prolonged Active Lymphocytic Infiltration After Hemodynamic Recovery

Fulminant myocarditis is a highly mortal syndrome. Meanwhile, the clinical course in surviving patients is generally self-limiting. This is a rare case of fulminant myocarditis with prolonged lymphocytic infiltration after hemodynamic recovery. A 64-year-old man was diagnosed with fulminant myocarditis and required intensive care with veno-arterial extracorporeal membrane oxygenation. Left ventricular function gradually improved but complete atrioventricular block (CAVB) persisted. Follow-up endomyocardial biopsies (EMBs) showed prolonged active infiltration of lymphocytes along with ¹⁸F-FDG uptake in ¹⁸F-FDG PET/CT until about 70 days after the onset. Therefore, he underwent immunosuppressive therapy for 3 months. Follow-up EMB revealed no evidence of infiltration of lymphocytes and no abnormal ¹⁸F-FDG uptake despite irreversible CAVB. Although repeated EMB and ¹⁸F-FDG PET/CT was not a standard strategy, it played an important role in the treatment decision in the present case.

Combination of Urinary Sodium/Creatinine Ratio and Plasma Brain Natriuretic Peptide Level Predicts Successful Tolvaptan Therapy in Patients With Heart Failure and Volume Overload

To evaluate the short-term clinical and hemodynamic effects of tolvaptan therapy and to identify predictors of the therapeutic outcomes, we retrospectively recruited 60 consecutive hospitalized heart failure (HF) patients (70 ± 11 years) with volume overload. The subjects were divided into two groups on the basis of the changes in HF symptom scores and hemodynamic status assessed by right heart catheterization after tolvaptan therapy (median: 7 days). The majority of patients were successfully treated (group 1). However, 22% of patients (group 2) were unsuccessfully treated, in whom 1) the HF symptom score worsened or 2) there was a stationary HF symptom score ≥ 6 points, and mean PCWP > 18 mmHg and mean RAP > 10 mmHg, after tolvaptan therapy. HF symptom scores, hemodynamic parameters, and plasma brain natriuretic peptide (BNP) level improved in group 1, but all of these parameters remained unchanged in group 2. Lower urine sodium/creatinine ratio (UNa/UCr) and higher BNP level at baseline were independently associated with unsuccessful tolvaptan therapy, and UNa/UCr best predicts unsuccessful tolvaptan therapy with a cut-off value of 46.5 mEq/g·Cr (AUC 0.847, 95% CI: 0.718-0.976, sensitivity 77%, specificity 81%, P < 0.01). Double-positive results of UNa/UCr < 46.5 mEq/g·Cr and plasma BNP level > 778 pg/mL predicted unsuccessful tolvaptan therapy with high diagnostic accuracy (sensitivity 54%, specificity 100%, positive predictive value 100%, negative predictive value 89%, and accuracy 90%). In summary, short-term tolvaptan therapy ameliorated HF symptoms and provided hemodynamic improvement in the majority of patients, and UNa/UCr and BNP level strongly predicted the therapeutic outcomes.

Renal resistive index as an indicator of the presence and severity of anemia and its future development in patients with hypertension

BACKGROUND

We examined whether renal resistive index (RI), a simple index of renal vascular resistance, is associated with the presence and severity of anemia, and can predict the future development of anemia in patients with hypertension.

METHODS

We retrospectively examined 175 patients with hypertension (mean age 67 ± 11 years, 32-85 years, 134 males) who underwent renal ultrasonography. Anemia was defined as a reduction in the concentration of hemoglobin <13.0 g/dL for men and <12.0 g/dL for women. Renal RI was measured in the interlobar arteries.

RESULTS

Anemia was present in 37% of men and 34% of women. The mean estimated glomerular filtration rate (eGFR) was 58 ± 23 ml/min/1.73 m(2) (median: 56 ml/min/1.73 m(2), range: 16-168 ml/min/1.73 m(2)) and the mean renal RI was 0.70 ± 0.09 (median: 0.70, range: 0.45-0.92). Proteinuria was present in 29% of patients. Both eGFR and renal RI correlated significantly with hemoglobin levels. In the stepwise multivariate linear regression analysis, renal RI was associated with hemoglobin levels independently of potential confounders including eGFR. During the follow-up period (median: 959 days, range: 7-3595 days), Kaplan-Meier curves demonstrated that patients with renal RI above the median value had a higher incidence of the future development of anemia than other patients. Cox regression analysis showed that renal RI (hazard ratio 1.18, 95% CI 1.02-1.37 per 0.05 rises in renal RI, p =0.03) and the presence of proteinuria were (hazard ratio 1.80, 95% CI 1.08-3.01, p =0.03) were independently associated with the future development of anemia after correcting for confounding factors.

CONCLUSIONS

Measurement of renal RI can be useful for elucidating the pathogenesis of anemia and for inferring its potential risk in patients with hypertension.

Quantifying longitudinal right ventricular dysfunction in patients with old myocardial infarction by using speckle-tracking strain echocardiography

BACKGROUND

We investigated longitudinal right ventricular (RV) function assessed using speckle-tracking strain echocardiography in patient with myocardial infarction (MI), and identified the contributing factors for RV dysfunction.

METHODS

We retrospectively studied 71 patients with old MI (the OMI group) and 45 normal subjects (the Control group) who underwent a transthoracic echocardiography. Global and free wall RV peak systolic strains (PSSs) in the longitudinal direction were measured by using speckle-tracking strain echocardiography. Left ventricular (LV) PSSs were measured in the longitudinal, radial and circumferential directions. Cardiac hemodynamics including peak systolic pulmonary artery pressure was also assessed non-invasively. Plasma brain natriuretic peptide (BNP) levels were measured in all patients.

RESULTS

In the OMI group, 73% of the patients had a normal estimated peak systolic pulmonary artery pressure of less than 35 mmHg. Global and free wall RV PSS were impaired in the OMI group compared with the Control group, and these RV systolic indices were significantly associated with heart rate, logarithmic transformed plasma BNP, greater than 1 year after onset of MI, Doppler-derived estimated pulmonary vascular resistance, LV systolic indices, LV mass index, infarcted segments within a territory of the left circumflex artery and residual total occlusion in the culprit right coronary artery. Multivariable linear regression analysis indicated that reduced longitudinal LV PSS in the 4-chamber view and BNP levels ≥500 pg/ml were independently associated with reduced global and free wall RV PSS. Moreover, when patients were divided into 3 groups according to plasma BNP levels (BNP <100 pg/ml; n = 31, 100 ≤BNP <500 pg/ml; n = 24, and BNP ≥500 pg/ml; n = 16), only patients with BNP ≥500 pg/ml had a strong correlation between RV PSS and longitudinal LV PSS in the 4-chamber view (r = 0.78 for global RV PSS and r = 0.71 for free wall RV PSS, p <0.05).

CONCLUSION

Longitudinal RV systolic strain depends significantly on longitudinal LV systolic strain especially in patients with high plasma BNP levels, but not on estimated peak systolic pulmonary artery pressure. These results indicate that process of RV myocardial dysfunction following MI may be governed by neurohormonal activation which causing ventricular remodeling rather than increased RV afterload.

Evolution of the domain topology in a ferroelectric

Topological materials, including topological insulators, magnets with Skyrmions and ferroelectrics with topological vortices, have recently attracted phenomenal attention in the materials science community. Complex patterns of ferroelectric domains in hexagonal REMnO(3) (RE: rare earths) turn out to be associated with the macroscopic emergence of Z(2)×Z(3) symmetry. The results of our depth profiling of crystals with a self-poling tendency near surfaces reveal that the partial dislocation (i.e., wall-wall) interaction, not the interaction between vortices and antivortices, is primarily responsible for topological condensation through the macroscopic breaking of the Z(2) symmetry.

Heart failure exacerbation associated with newly developed atrioventricular dyssynchrony after chemical conversion to a sinus rhythm in a patient receiving cardiac resynchronization therapy

A 58-year-old woman with chronic heart failure (CHF) received cardiac resynchronization-defibrillator (CRT-D) therapy without atrial lead implantation due to longstanding atrial fibrillation (AF). Three months after oral amiodarone therapy was initiated for the treatment of non-sustained ventricular tachycardia detected by the CRT-D device, the patient's heart failure symptoms worsened and 12-lead electrocardiography showed newly emerged p-waves with atrioventricular (AV) dissociation. Immediately after the device was upgraded to the DDD-biventricular pacemaker, the patient's heart failure symptoms and cardiac function dramatically improved, which suggests that AV dissociation has a much more negative impact on the cardiac function than AF in patients with CHF.

Direct observation of the proliferation of ferroelectric loop domains and vortex-antivortex pairs

We discovered stripe patterns of trimerization-ferroelectric domains in hexagonal REMnO(3) (RE=Ho,···,Lu) crystals (grown below ferroelectric transition temperatures (T(c)), reaching up to 1435 °C), in contrast with the vortex patterns in YMnO(3). These stripe patterns roughen with the appearance of numerous loop domains through thermal annealing just below T(c), but the stripe domain patterns turn to vortex-antivortex domain patterns through a freezing process when crystals cross T(c) even though the phase transition appears to not be Kosterlitz-Thouless-type. The experimental systematics are compared with the results of our six-state clock model simulation and also the Kibble-Zurek mechanism for trapped topological defects.

Interobserver agreement in endoscopic evaluation of reflux esophagitis using a modified Los Angeles classification incorporating grades N and M: a validation study in a cohort of Japanese endoscopists

The Los Angeles classification system is the most widely employed criteria associated with the greatest interobserver agreement among endoscopists. In Japan, the Los Angeles classification system has been modified (modified LA system) to include minimal changes as a distinct grade of reflux esophagitis, rather than as auxiliary findings. This adds a further grading M defined as minimal changes to the mucosa, such as erythema and/or whitish turbidity. The modified LA system has come to be used widely in Japan. However, there have been few reports to date that have evaluated the interobserver agreement in diagnosis when using the modified LA classification system incorporating these minimal changes as an additional grade. A total of 100 endoscopists from university hospitals and community hospitals, as well as private practices in the Osaka-Kobe area participated in the study. A total of 30 video clips of 30-40 seconds duration, mostly showing the esophagocardiac junction, were created and shown to 100 endoscopists using a video projector. The participating endoscopists completed a questionnaire regarding their clinical experience and rated the reflux esophagitis as shown in the video clips using the modified LA classification system. Agreement was assessed employing kappa (kappa) statistics for multiple raters. The kappa-value for all 91 endoscopists was 0.094, with a standard error of 0.002, indicating poor interobserver agreement. The endoscopists showed the best agreement on diagnosing grade A esophagitis (0.167), and the poorest agreement when diagnosing grade M esophagitis (0.033). The kappa-values for the diagnoses of grades N, M, and A esophagitis on identical video pairs were 0.275-0.315, with a standard error of 0.083-0.091, indicating fair intraobserver reproducibility among the endoscopists. The study results consistently indicate poor agreement regarding diagnoses as well as fair reproducibility of these diagnoses by endoscopists using the modified LA classification system, regardless of age, type of practice, past endoscopic experience, or current workload. However, grade M reflux esophagitis may not necessarily be irrelevant, as it may suggest an early form of reflux disease or an entirely new form of reflux esophagitis. Further research is required to elucidate the pathophysiological basis of minimal change esophagitis.

Highly aligned epitaxial nanorods with a checkerboard pattern in oxide films

One of the central challenges of nanoscience is fabrication of nanoscale structures with well-controlled architectures using planar thin-film technology. Herein, we report that ordered nanocheckerboards in ZnMnGaO4 films were grown epitaxially on single-crystal MgO substrates by utilizing a solid-state method of the phase separation-induced self-assembly. The films consist of two types of chemically distinct and regularly spaced nanorods with mutually coherent interfaces, approximately 4 x 4 x 750 nm3 in size and perfectly aligned along the film growth direction. Surprisingly, a significant in-plane strain, more than 2%, from the substrate is globally maintained over the entire film thickness of about 820 nm. The strain energy from Jahn-Teller distortions and the film-substrate lattice mismatch induce the coherent three-dimensional (3D) self-assembled nanostructure, relieving the volume strain energy while suppressing the formation of dislocations.

A novel autosomal dominant spinocerebellar ataxia (SCA16) linked to chromosome 8q22.1-24.1

OBJECTIVE

To characterize a distinct form of autosomal dominant cerebellar ataxia (ADCA) clinically and genetically.

BACKGROUND

ADCAs are a clinically, pathologically, and genetically heterogeneous group of neurodegenerative disorders. Nine responsible genes have been identified for SCA-1, -2, -3, -6, -7, -8, -10, and -12 and dentatorubral-pallidoluysian atrophy (DRPLA). Loci for SCA-4, -5, -11, -13, and -14 have been mapped.

METHODS

The authors studied a four-generation Japanese family with ADCA. The 19 members were enrolled in this study. The authors performed the mutation analysis by PCR and a genome-wide linkage analysis.

RESULTS

Nine members (five men and four women) were affected. The ages at onset ranged from 20 to 66 years. All affected members showed pure cerebellar ataxia, and three patients also had head tremor. Head MRI demonstrated cerebellar atrophy without brain stem involvement. The mutation analysis by PCR excluded diagnoses of SCA-1, -2, -3, -6, -7, -8, and -12 and DRPLA. The linkage analysis suggested linkage to a locus on chromosome 8q22.1-24.1, with the highest two-point lod score at D8S1804 (Z = 3.06 at theta = 0.0). The flanking markers D8S270 and D8S1720 defined a candidate region of an approximately 37.6-cM interval. This candidate region was different from the loci for SCA-4, -5, -10, -11, -13, and -14.

CONCLUSION

The family studied had a genetically novel type of SCA (SCA-16).

Identification of susceptibility loci for autoimmune thyroid disease to 5q31-q33 and Hashimoto's thyroiditis to 8q23-q24 by multipoint affected sib-pair linkage analysis in Japanese

Autoimmune thyroid disease (AITD), including Graves' disease (GD) and Hashimoto's thyroiditis (HT), is caused by multiple genetic and environmental factors. The clinical and immunological features of GD and HT are distinct; however, there are multiplex families with both GD and HT, and cases in which GD evolves into HT. Thus, there may be specific susceptibility loci for GD or HT, and common loci controlling the susceptibility to both GD and HT may exist. A genome-wide analysis of data on 123 Japanese sib-pairs affected with AITD was made in which GD- or HT-affected sib-pairs (ASPs) were studied to detect GD- or HT-specific susceptibility loci, and all AITD-ASPs were used to detect AITD-common susceptibility loci. Our study revealed 19 regions on 14 chromosomes (1, 2, 3, 5, 6, 8, 9, 10, 11, 12, 13, 15, 18 and 22) where the multipoint maximum LOD score (MLS) was >1. Especially, chromosome 5q31-q33 yielded suggestive evidence for linkage to AITD as a whole, with an MLS of 3.14 at D5S436, and chromosome 8q23-q24 yielded suggestive evidence for linkage to HT, with an MLS of 3.77 at D8S272. These observations suggest the presence of an AITD susceptibility locus at 5q31-q33 and a HT susceptibility locus at 8q23-q24.

Effects of dopamine beta-hydroxylase inhibition with nepicastat on the progression of left ventricular dysfunction and remodeling in dogs with chronic heart failure

BACKGROUND

Inhibition of dopamine beta-hydroxylase (DBH) results in a decrease in norepinephrine synthesis. The present study was a randomized, blinded, placebo-controlled investigation of the long-term effects of therapy with the DBH inhibitor nepicastat (NCT) on the progression of left ventricular (LV) dysfunction and remodeling in dogs with chronic heart failure (HF).

METHODS AND RESULTS

Moderate HF (LV ejection fraction [LVEF] 30% to 40%) was produced in 30 dogs by intracoronary microembolization. Dogs were randomized to low-dose NCT (0.5 mg/kg twice daily, n=7) (L-NCT), high-dose NCT (2 mg/kg twice daily, n=7) (H-NCT), L-NCT plus enalapril (10 mg twice daily, n=8) (L-NCT+ENA), or placebo (PL, n=8). Transmyocardial (coronary sinus-arterial) plasma norepinephrine (tNEPI), LVEF, end-systolic volume, and end-diastolic volume were measured before and 3 months after initiating therapy. tNEPI levels were higher in PL compared with NL (86+/-20 versus 13+/-14 pg/mL, P:<0.01). L-NCT alone and L-NCT+ENA reduced tNEPI toward normal (28+/-4 and 39+/-17 pg/mL respectively), whereas HD-NCT reduced tNEPI to below normal levels (3+/-10 pg/mL). In PL dogs, LVEF decreased but was unchanged with L-NCT and increased with L-NCT+ENA. L-NCT and L-NCT+ENA prevented progressive LV remodeling, as evidenced by lack of ongoing increase in end-diastolic volume and end-systolic volume, whereas H-NCT did not

CONCLUSIONS

In dogs with HF, therapy with L-NCT prevented progressive LV dysfunction and remodeling. The addition of ENA to L-NCT afforded a greater increase in LV systolic function. NCT at doses that normalize tNEPI may be useful in the treatment of chronic HF.

Case-control study of perinatal factors and hepatoblastoma in children with an extremely low birthweight

BACKGROUND

There is a significant association between hepatoblastoma and low birthweight. A case-control study was conducted to reveal risk factors for hepatoblastoma in children of extremely low birthweight (< 1,000 g).

METHODS

Prenatal and postnatal histories, including parental histories, of 12 hepatoblastoma cases and 75 birthweight-matched controls were compared.

RESULTS

The gestational age of the hepatoblastoma cases (23-32 weeks: median 25 weeks), tended to be lower than that of the controls (23-36 weeks; median, 27 weeks; P = 0.072). The time for an infant's bodyweight to return to the same level as the birthweight also tended to be longer in hepatoblastoma cases than in controls (P = 0.055). All hepatoblastoma cases received oxygen therapy for a period of 4-508 days (median 114 days), which was significantly longer than the 0-366 days (median 62 days) in the controls (P = 0.022). Furosemide was given to all hepatoblastoma cases and was used for a significantly longer period in these infants (6460 days; median 89 days) than in the controls (0-241 days; median 44 days P = 0.027). A univariate Cox regression demonstrated that the time taken to regain bodyweight at birth and the duration of both oxygen therapy and furosemide treatment were significantly associated with the development of hepatoblastoma (hazard ratio (HR)= 1.044, P= 0.013; HR = 1.006, P= 0.001; and HR = 1.007, P= 0.001, respectively). Although there were significant correlations between the factors, a multivariate Cox regression analysis identified the duration of oxygen therapy as a significant independent risk factor (HR = 1.006, P = 0.001).

CONCLUSIONS

Oxygen therapy and furosemide treatment, along with the rate of growth, are risk factors for the development of hepatoblastoma in children of extremely low birthweight, and the duration of oxygen therapy is the most important factor in predicting the development of hepatoblastoma. Further studies are necessary to determine the real reasons for the development of hepatoblastoma and to protect children of low birthweight from the development of cancer.

Detection of circulating cancer cells with von hippel-lindau gene mutation in peripheral blood of patients with renal cell carcinoma

Mutations of the von Hippel-Lindau (VHL) tumor suppressor gene have been detected in up to 60% of sporadic clear cell renal carcinomas (RCCs). Even patients with RCCs believed to be curable with radical nephrectomy sometimes develop distant metastasis 5-10 years after surgery, suggesting hematogenous circulation of cancer cells. Useful tumor markers have not yet been established for RCC. To detect patients at high risk of metastasis after surgery, we developed a highly sensitive and specific nested reverse transcription-PCR method using VHL gene mutation to detect circulating cancer cells. We screened 29 sporadic clear cell RCCs from patients for mutations of the VHL gene by direct sequencing. We next examined blood samples from patients with the VHL gene mutation using mutation-specific nested reverse transcription-PCR. Somatic mutations were detected in 20 of 29 (69.0%) sporadic clear cell RCCs. The VHL gene mutations were detected in peripheral and/or renal venous blood from 15 of 20 (75%) patients. The mutations were detected in the peripheral blood in 2 of 17 (11.8%) patients before surgery, 6 of 16 (37.5%) patients within 24 h after surgery, 3 of 16 (18.8%) patients on day 7 after surgery, and 2 of 11 (18.2%) patients on day 30 after surgery. In seven of nine (77.8%) patients, mutations were detected in renal venous blood during surgery. These findings indicate the presence of circulating cancer cells with VHL gene mutation. Although much larger studies are needed to determine the clinical significance, our study shows that this technique is feasible for detecting circulating RCC cells.

Intraductal papillary tumors of the pancreas. Histopathologic correlation of MR cholangiopancreatography findings

PURPOSE

To evaluate MR cholangiopancreatography (MRCP) findings of intraductal papillary tumors of the pancreas and correlate them with histopathology.

MATERIAL AND METHODS

Seventeen patients with intraductal papillary tumor of the pancreas underwent MRCP before surgery. MRCP findings were correlated to histopathology with regard to the presence of septa and excrescent nodules in the cystic lesion, communication between the cystic lesion and the main pancreatic duct (MPD), degree of dilatation of MPD, and dilatation of the common bile duct (CBD).

RESULTS

MRCP demonstrated septa in 17 cases (100%), excrescent nodules in 8 cases (47.1%), communication between the intraductal papillary tumor and the MPD in 14 cases (82.3%), dilatation of MPD over 50% in 6 cases (35.3%), and dilatation of CBD in 3 cases (17.6%). These findings showed excellent correlation with histopathology. The septum on MRCP corresponded with a layer of connective tissue with pancreatic duct epithelium. Excrescent nodules in the carcinomas consisted not only of malignant cells, but also of dysplasia and adenoma. Excrescent nodules in adenomas were consistent not only with minimal papillary growth of adenoma, but also with proliferation of fibrosis, and hematoma and organized fibrin with minimal fibrosis. Pancreatic tissue was affected by chronic pancreatitis in all cases. Cases with dilatation of CBD on MRCP were due to microscopic invasion by the carcinoma.

CONCLUSION

MRCP appearances of intraductal papillary tumors are well correlated with the findings at histopathology.

Hemodynamic effects of a novel sodium channel activator in dogs with chronic heart failure

The use of positive inotropic agents, such as sympathomimetics and phosphodiesterase inhibitors, in heart failure (HF) is limited by proarrhythmic and positive chronotropic effects. In the present study, we compared the hemodynamic effects of intravenous LY366634 (LY), a Na+ channel enhancer, with dobutamine (DOB), in eight dogs with HF produced by intracoronary microembolizations. We also determined whether intravenous LY has synergistic effects when combined with digoxin. After baseline measurements, infusion of DOB was initiated at a dose of 2 micrograms/kg/min and increased until an increase of heart rate (HR) 30% of baseline or ventricular arrhythmias developed. Once hemodynamics returned to baseline, LY was infused at a dose of 2 micrograms/kg/min and increased until the LV fractional area of shortening (FAS), determined echocardiographically, reached a similar level as with DOB. Both drugs increased FAS equivalently compared to baseline (DOB, 24 +/- 3 to 47 +/- 2; LY, 27 +/- 2 to 46 +/- 2%). DOB increased HR from 78 +/- 4 min-1 at baseline to 107 +/- 7 min-1 at maximal dose (p < 0.05) and provoked serious arrhythmias in one dog. In contrast, LY infusion did not increase HR (82 +/- 7 vs. 80 +/- 8 min-1) or elicit arrhythmias. After 1 week of oral digoxin, dogs were infused again with LY. A lower dose of LY was needed to achieve the same increase in FAS compared to LY alone, but this was not statistically significant. The combination of LY with digoxin did not increase HR or evoke arrhythmias. We conclude that in dogs with HF, intravenous LY improves LV function to the same extent as DOB without increasing HR or evoking ventricular arrhythmias. The combination of LY with digoxin elicits a safe positive inotropic response.

Effects of long-term therapy with bosentan on the progression of left ventricular dysfunction and remodeling in dogs with heart failure

OBJECTIVES

In this study, we examined the effects of long-term therapy with bosentan on the progression of LV dysfunction and remodeling in dogs with moderate HF.

BACKGROUND

Acute intravenous administration of bosentan, a mixed endothelin-1 type A and type B receptor antagonist, was shown to improve left ventricular (LV) function in patients and dogs with heart failure (HF).

METHODS

Left ventricular dysfunction was induced by multiple, sequential intracoronary microembolizations in 14 dogs. Embolizations were discontinued when LV ejection fraction (EF) was between 30% and 40%. Dogs were randomized to three months of therapy with bosentan (30 mg/kg twice daily, n = 7) or no therapy at all (control, n = 7).

RESULTS

In untreated dogs, EF decreased from 35 +/- 1% before initiating therapy to 29 +/- 1% at the end of three months of therapy (p = 0.001), and LV end-diastolic volume (EDV) and end-systolic volume (ESV) increased (EDV: 71 +/- 3 vs. 84 +/- 8 ml, p = 0.08; ESV: 46 +/- 2 vs. 60 +/- 6 ml, p = 0.03). By contrast, in dogs treated with bosentan, EF tended to increase from 34 +/- 2% before initiating therapy to 39 +/- 1% at the end of three months of therapy (p = 0.06), and EDV and ESV decreased (EDV: 75 +/- 3 vs. 71 +/- 4 ml, p = 0.05; ESV: 48 +/- 2 vs. 43 +/- 3 ml, p = 0.01). Furthermore, compared with untreated dogs, dogs treated with bosentan showed significantly less LV cardiomyocyte hypertrophy and LV volume fraction of interstitial fibrosis.

CONCLUSIONS

In dogs with moderate HF, long-term therapy with bosentan prevents the progression of LV dysfunction and attenuates LV chamber remodeling. The findings support the use of mixed endothelin-1 receptor antagonists as adjuncts to the long-term treatment of HF.

Effects of AT1-receptor blockade on progression of left ventricular dysfunction in dogs with heart failure

The objective of the present study was to determine the effects of early long-term monotherapy with the angiotensin II AT1-receptor antagonist valsartan on the progression of left ventricular (LV) dysfunction and remodeling in dogs with moderate heart failure (HF). Studies were performed in 30 dogs with moderate HF produced by multiple sequential intracoronary microembolizations. Embolizations were discontinued when LV ejection fraction was 30-40%. Two weeks after the last embolization, dogs were randomized to 3 mo of oral therapy with low-dose valsartan (400 mg twice daily, n = 10), to high-dose valsartan (800 mg twice daily, n = 10), or to no treatment at all (control, n = 10). Treatment with valsartan significantly reduced mean aortic pressure and LV end-diastolic pressure compared with control. In untreated dogs, LV ejection fraction decreased (37 +/- 1 vs. 29 +/- 1%, P = 0.001) and end-systolic volume (ESV) and end-diastolic volume (EDV) increased (81 +/- 5 vs. 92 +/- 5 ml, P < 0.001; 51 +/- 3 vs. 65 +/- 3 ml, P = 0.001, respectively) after 3 mo of follow-up compared with those levels before follow-up. In dogs treated for 3 mo with low-dose valsartan, ejection fraction was preserved (37 +/- 1 vs. 38 +/- 2%, pretreatment vs. posttreatment) as was ESV but not EDV. In dogs treated for 3 mo with high-dose valsartan, ejection fraction decreased (35 +/- 1 vs. 31 +/- 2%, P = 0.02) and ESV and EDV increased in a manner comparable to those levels in controls. Valsartan had no significant effects on cardiomyocyte hypertrophy or on the extent of interstitial fibrosis. We conclude that, for dogs with moderate HF, early long-term therapy with the AT1-receptor blocker valsartan decreases preload and afterload but has only limited benefits in attenuating the progression of LV dysfunction and chamber remodeling.

Effects of ACE inhibition on cardiomyocyte apoptosis in dogs with heart failure

Cardiomyocyte apoptosis or programmed cell death has been shown to occur in end-stage explanted failed human hearts and in dogs with chronic heart failure (HF). We tested the hypothesis that early long-term monotherapy with an angiotensin-converting enzyme (ACE) inhibitor attenuates cardiomyocyte apoptosis in dogs with moderate HF. Left ventricular (LV) dysfunction (ejection fraction 30-40%) was produced in dogs by multiple sequential intracoronary microembolizations. Dogs were randomized to 3 mo of therapy with enalapril (Ena, 10 mg twice daily, n = 7) or to no therapy at all (control, n = 7). After 3 mo of therapy, dogs were euthanized and the hearts removed. Presence of nuclear DNA fragmentation (nDNAf), a marker of apoptosis, was assessed in frozen LV sections using the immunohistochemical deoxynucleotidal transferase-mediated dUTP-digoxigenin nick-end labeling (TUNEL) method. Sections were also stained with ventricular anti-myosin antibody to identify cells of cardiocyte origin. From each dog, 80 fields (x40) were selected at random, 40 from LV regions bordering old infarcts and 40 from LV regions remote from any infarcts, for quantifying the number of cardiomyocyte nDNAf events per 1,000 cardiomyocytes. The average number of cardiomyocyte nDNAf events per 1,000 cardiomyocytes was significantly lower in Ena-treated dogs compared with controls (0.81 +/- 0.13 vs. 2.65 +/- 0.81, P < 0.029). This difference was due to a significantly lower incidence of cardiomyocyte nDNAf events in LV regions bordering scarred tissue (infarcts) in Ena-treated dogs compared with controls. We conclude that early long-term Ena therapy attenuates cardiomyocyte apoptosis in dogs with moderate HF. Attenuation of cardiomyocyte apoptosis may be one mechanism by which ACE inhibitors preserve global LV function in HF.

Increased risk of hepatoblastoma among immature children with a lower birth weight

Hepatoblastomas among children with very low birth weights have significantly increased recently, according to the data from the Japan Children's Cancer Registry for the years 1985-1993. We then analyzed more Registry data for 1969-1994 to clarify the possible relationship between low birth weight and hepatoblastoma. The percentage of low birth weights was compared between 543 hepatoblastoma children in the Registry and all live births in Japan in four successive periods during the 26 years from 1969 to 1994, in relation to the given birth year. The percentage of children with birth weights of 1500-1999 g among hepatoblastomas was higher, at 2.94-1.60%, than that among all live births in each of the four periods (0.79-0.92%), and the percentage of children with birth weights of 2000-2499 g was slightly higher. The percentage of children with birth weights of <1500 g and, especially, <1000 g, has increased rapidly among children born after 1988 (1.60 and 6.40%, respectively), when most very low birth weight infants began to survive. Compared with children with a birth weight of 2500 g or more, the relative risks of hepatoblastoma among children with birth weights of <1000, 1000-1499, 1500-1999, and 2000-2499 g were 15.64 (P < 0.001), 2.53 (P = 0.129), 2.71 (P = 0.001), and 1.21 (P = 0.381), respectively, suggesting the lower the birth weight, the higher the risk of hepatoblastoma. There was no association between hepatoblastomas with a low birth weight and either age at diagnosis or congenital malformations or light-for-date weight. The risk of hepatoblastoma for low birth weight children may be inherently high, especially for lower birth weights, and the recent rapid increase may be a result of an increase in the number of more immature infants with a more sensitive liver and also more frequent exposure to risk factors related to perinatal treatment.

Relationship between action potential, contraction-relaxation pattern, and intracellular Ca2+ transient in cardiomyocytes of dogs with chronic heart failure

Abnormalities of contractile function have been identified in cardiomyocytes isolated from failed human hearts and from hearts of animals with experimentally induced heart failure (HF). The mechanism(s) responsible for these functional abnormalities are not fully understood. In the present study, we examined the relationship between action potential duration, pattern of contraction and relaxation, and associated intracellular Ca2+ transients in single cardiomyocytes isolated from the left ventricle (LV) of dogs (n = 7) with HF produced by multiple sequential intracoronary microembolizations. Comparisons were made with LV cardiomyocytes isolated from normal dogs. Action potentials were measured in isolated LV cardiomyocytes by perforated patch clamp, Ca2+ transients by fluo 3 probe fluorescence, and cardiomyocyte contraction and relaxation by edge movement detector. HF cardiomyocytes exhibited an abnormal pattern of contraction and relaxation characterized by an attenuated initial twitch (spike) followed by a sustained contracture ('dome') of 1 to 8 s in duration and subsequent delayed relaxation. This pattern was more prominent at low stimulation rates (58% at 0.2 Hz, n = 211, 21% at 0.5 Hz, n = 185). Measurements of Ca2+ transients in HF cardiomyocytes at 0.2 Hz manifested a similar spike and dome configuration. The dome phase of both the contraction/relaxation pattern and Ca2+ transients seen in HF cardiomyocytes coincided with a sustained plateau of the action potential. Shortening of the action potential duration by administration of saxitoxin (100 nM) or lidocaine (30 microM) reduced the duration of the dome phase of both the contraction/relaxation profile as well as that of the Ca2+ transient profile. An increase of stimulation rate up to 1 Hz caused shortening of the action potential and disappearance of the spike-dome profile in the majority of HF cardiomyocytes. In HF cardiomyocytes, the action potential and Ca2+ transient duration were not significantly different from those measured in normal cells. However, the contraction-relaxation cycle was significantly longer in HF cells (314 +/- 67 ms, n = 21, vs. 221 +/- 38 ms, n = 46, mean +/- SD), indicating impaired excitation-contraction uncoupling in HF cardiomyocytes. The results show that, in cardiomyocytes isolated from dogs with HF, contractile abnormalities and abnormalities of intracellular Ca2+ transients at low stimulation rates are characterized by a spike-dome configuration. This abnormal pattern appears to result from prolongation of the action potential.

Clinical and epidemiologic studies of familial hemophagocytic lymphohistiocytosis in Japan. Japan LCH Study Group

BACKGROUND AND PROCEDURE

The etiology of familial hemophagocytic lymphohistiocytosis (FHL), which is characterized by fever, hepatosplenomegaly, pancytopenia, and coagulopathy, remains unknown. We analyzed 43 FHL patients, all with affected siblings, in 18 families who were identified during the period 1986-1995 in Japan.

RESULTS

The presence of consanguinity was evident in two families (11%). The majority of families lived in western Japan, where the frequency of consanguineous marriage is high. The incidence of FHL was significantly higher in the western island, Kyushu, than in other areas. The segregation ratio calculated for these families was 0.35 by the Weinberg proband method, showing the autosomal-recessive inheritance of the disease. Since the diagnosis of an FHL patient without affected siblings (sporadic case) is quite difficult, we calculated the possible number of sporadic cases; approximately 122 patients could be identified as sporadic FHL cases during the same period in Japan. Most of the clinical and laboratory findings were not distinguishable from those of other types of lymphohistiocytosis. However, atypical lymphoid cells with azurophilic granules in peripheral blood were observed in half of the patients at diagnosis, suggesting the clinical importance of this parameter for early diagnosis. Despite intensive therapy, the prognosis of FHL was extremely poor; but 4 of the 8 patients who have survived had received bone marrow transplantation (BMT), indicating the effectiveness of BMT for this disorder.

CONCLUSIONS

The distribution of FHL in areas of highly frequent consanguineous marriage and the segregation analysis indicated a genetic factor in FHL. The identification of the genes for FHL is expected to contribute to a cure for this disorder, and might also enable FHL carrier detection and donor selection for BMT.

Development of unfavorable hepatoblastoma in children of very low birth weight: results of a surgical and pathologic review

BACKGROUND

The incidence of hepatoblastoma in children of very low birth weight (< 1500 g) is increasing in Japan. The authors reviewed surgical and pathologic aspects of the tumor to clarify the characteristics of the patients.

METHODS

Fifteen patients (9 boys and 6 girls) who were diagnosed between the ages of 6-77 months (median, 16 months) were identified from the data in the Japan Children's Cancer Registry and the data base of medical journals. The patients' birth weights ranged from 560-1380 g (median, 826 g) and the gestational age ranged from 23-33 weeks (median, 25 weeks). The medical records of all patients were reviewed and the patient's stage of disease according to the classification of the Japanese Society of Pediatric Surgeons, treatment, and outcome were analyzed.

RESULTS

Ten tumors (67%) were classified as Stage II or IIIA and 5 (33%) were classified as Stage IIIB or IV. There was a significant correlation between the gestational age and tumor stage (correlation coefficient - 0.6851; P = 0.0048). The gestational age of the 5 patients with Stage IIIB or IV tumors was 23-25 weeks (median, 24 weeks), whereas it was 25-33 weeks (median, 27.5 weeks) for the 10 patients with Stage II or IIIA tumors (P = 0.0036). Birth weight ranged from 560-826 g (median, 734 g) in Stage IIIB and IV patients, which was significantly lower than that in Stage II and IIIA patients (range, 607-1380 g, median, 909 g; P = 0.0500). Complete tumor resection was achieved in 7 patients (47%). The actuarial 2-year survival of all patients was 0.42, and the 2-year survival of patients who underwent complete tumor resection was 0.69, which was significantly better than the 2-year survival of those who underwent incomplete resection (0.17; P = 0.0211). The 2-year survival of the patients with tumors of well differentiated histology was 0.60, which also was significantly better than the 2-year survival of those with tumors of poorly differentiated histology (0.19; P = 0.0453).

CONCLUSIONS

These results indicate that children of very low birth weight (< 1500 g) are at high risk of developing advanced hepatoblastomas and that hepatoblastoma with unfavorable biologic behavior develops in children who are extremely premature at birth. These new findings suggest the presence of etiologic factors relevant to the patient's immaturity and the development of unfavorable hepatoblastoma.

Short-term hemodynamic effects of mibefradil in dogs with chronic heart failure: comparison with diltiazem

Despite the marked vasodilator and antiischemic actions of existing calcium channel blockers, their use in the treatment of patients with chronic heart failure (HF) remains highly controversial. We compared the short-term hemodynamic effects of i.v. mibefradil, a predominant T-type calcium channel blocker with only partial L-type calcium channel antagonism, and diltiazem, a selective L-type calcium channel antagonist in dogs with chronic HF. Each of three drugs namely, mibefradil, diltiazem and normal saline (as placebo control), were studied in random order (6 days between each drug intervention), in each of 8 dogs with chronic HF produced by multiple intracoronary microembolizations. Intravenous mibefradil and diltiazem were administered as a 100 micrograms/kg bolus followed by a continuous infusion of 6 and 4 micrograms/kg/min, respectively, for 15 min. Equal volumes of normal saline were administered in an identical fashion. In all instances, hemodynamics were obtained at base line and at 5, 10, 15, 30 and 60 min after bolus drug administration. Left ventriculograms were obtained at baseline, and at 15 and 60 min after bolus drug administration. Saline infusion had no effects on hemodynamic or angiographic indexes of left ventricular (LV) function. At 15 min, mibefradil caused significant increases of LV stroke volume and LV ejection fraction compared to baseline (40 +/- 5 vs. 31 +/- 3 ml, P < .05 and 41 +/- 1 vs. 28 +/- 1%, P < .05, respectively). In contrast, at 15 min, diltiazem produced no significant changes of LV stroke volume or ejection fraction compared to baseline despite reducing mean aortic pressure to the same extent as mibefradil. Short-term i.v. mibefradil improves LV function in dogs with chronic HF. The beneficial effects of mibefradil compared to diltiazem may be a consequence of T-type calcium channel selectivity resulting in a vasodilatory response that is free of negative inotropy.

Spontaneous regression of localized neuroblastoma detected by mass screening

PURPOSE

To clarify whether and when neuroblastomas identified through screening do regress, and to ascertain how to treat them appropriately, we observed screened patients who had localized tumors, without any therapeutic intervention.

PATIENTS AND METHODS

The criteria for the observation program were as follows: disease stage I or II; tumor less than 5 cm in diameter; no invasion to the intraspinal canal or growth to the great vessels; urinary vanillylmandelic acid (VMA) and homovanillic acid (HVA) less than 50 microg/mg creatinine; and informed consent. Of 25 patients identified through screening for 6-month-old infants in Saitama Prefecture, Japan between April 1994 and March 1996, 11 patients who met the criteria and one other patient with stage III tumor were enrolled onto the program. They were examined by abdominal ultrasonography (US) and their urinary VMA and HVA levels were assessed approximately once per month. The observation periods ranged from 4 to 27 months.

RESULTS

The 11 tumors decreased in size, although one of these 11 tumors initially enlarged until the patient was 12 months of age and decreased in size thereafter. One other tumor slightly increased in size. Urinary VMA levels decreased in all patients. None of the tumors had completely disappeared by the last observation day.

CONCLUSION

Our results suggest that regression of screened neuroblastoma is not a rare phenomenon. At present, it seems reasonable to adopt a wait-and-see strategy, with careful observation, for selected stage I or II tumors identified in infants screened at 6 months of age.

SR Ca(2+)-ATPase activity and expression in ventricular myocardium of dogs with heart failure

The purpose of this study was to examine the activity and expression of sarcoplasmic reticulum (SR) Ca(2+)-ATPase in left ventricular (LV) myocardium of dogs with chronic heart failure (HF). LV and right ventricular (RV) tissue specimens were obtained from six normal (NL) control dogs and six dogs with chronic HF (LV ejection fraction, 23 +/- 2%) produced by multiple sequential intracoronary microembolizations. Thapsigargin-sensitive Ca(2+)-ATPase activity was measured in isolated SR membrane fractions prepared from LV and RV myocardium. Ca(2+)-ATPase expression, using a specific dog myocardium monoclonal antibody, was measured in sodium dodecyl sulfate (SDS) extract prepared from LV and RV myocardium. Ca(2+)-ATPase activity in both ventricles of NL or HF dogs increased with increasing Ca2+ concentration and reached a plateau at 3 microM Ca2+. The maximal velocity (Vmax, mumol Pi released.min-1.mg-1) of Ca(2+)-ATPase activity was significantly lower in LV of HF dogs compared with NL (0.15 +/- 0.01 vs. 0.23 +/- 0.01, P < 0.05), whereas the affinity of the Ca2+ pump for Ca2+ was unchanged. LV tissue levels of Ca(2+)-ATPase (densitometric units/5 micrograms noncollagen protein) were also significantly lower in LV myocardium of HF dogs compared with NL (3.52 +/- 0.43 vs. 5.53 +/- 0.47, P < 0.05). No significant differences in Ca(2+)-ATPase activity or expression were observed in RV myocardium of HF dogs compared with NL. We conclude that SR Ca(2+)-ATPase activity and protein levels are reduced in LV myocardium of dogs with chronic HF. This abnormality of the SR Ca2+ pump of the failed LV can result in impaired Ca2+ uptake and ultimately to Ca2+ overload and global LV dysfunction.