A case of autosomal dominant osteopetrosis type II with a novel TCIRG1 gene mutation.

Osteopetrosis is a rare genetic disorder characterized by increased bone mineral density (BMD) due to osteoclast failure. T-cell immune regulator 1 (TCIRG1) plays crucial roles on osteoclast function, and its mutation causes autosomal recessive osteopetorosis. However, mutations in TCIRG1 have never been identified in autosomal dominant osteopetrosis (ADO). A 3-year-old boy was first presented to the clinic because of spontaneous radius and femur fractures. He has optic atrophy. The areal BMD at the lumbar spine was 1274 g/cm2 (233% of normal). Laboratory tests revealed no remarkable abnormal findings, including anemia, except for extremely elevated serum tartrate-resistant acid phosphatase-5b (14,600 mU/dL). Radiographically, the skull base, pelvis, and vertebrae showed a focal sclerosis. Genetic analysis revealed a novel de novo heterozygous missense mutation (His242Arg). Taken together with the mutation, his mild clinical features were diagnosed as ADO. This case implies that TCIRG1 could become a genetic candidate for ADO in addition to malignant forms such as ARO.

[Influenza myocarditis and pericarditis].

The true incidence of influenza myocarditis in the general population is unknown, because of the variable clinical presentation and the absence of a established noninvasive diagnostic test that can confirm the diagnosis. Influenza is, however, one of the frequently implicated viruses caused myocarditis as well as Coxsackie B, adenovirus, echovirus and cytomegalovirus. The clinical manifestations of viral myocarditis vary greatly from asymptomatic electrocardiographic changes to fulminant heart failure with fatal arrhythmias. We should recognize that subtle cardiac symptoms and signs in many subclinical cases may be overshadowed by systemic manifestations of the underlying influenza infection. Although specific therapy consisted of anti-viral agents, intravenous gamma-globulin treatment or mechanical ventricular supports may be available for influenza myocarditis, it has not been established that the myocarditic process itself will be favorably affected.

Application of signal-averaged electrocardiogram to myocardial damage in the late stage of Kawasaki disease.

BACKGROUND: Myocardial damage occurs in the late stage of Kawasaki disease (KD) regardless of whether coronary artery lesions (CALs) are present. METHODS AND RESULTS: A signal-averaged electrocardiogram (ECG) was performed in 23 patients who were in the late stage of KD (CAL was found in 12 and no CAL (non-CAL) was found in 11) and 10 healthy controls. Filtered QRS duration and the root-mean-square voltage in the last 40 ms of the QRS complex were measured using time-domain analysis. Additionally, the area ratio (AR), (area of 20-50 Hz)/(area of 0-20 Hz) x100, was calculated by frequency domain analysis. These findings were compared with the clinical data and histopathological findings. In time-domain analysis, there were no significant differences among the 3 groups. In frequency domain analysis, the AR in CAL was significantly higher than that in the other 2 groups. Furthermore, all 4 patients who underwent an endomyocardial biopsy showed a high AR and abnormal histopathological features. CONCLUSIONS: The findings of the present study suggest that patients in the late stage of KD have abnormal findings on signal-averaged ECG even without stenotic lesions, arrhythmia or ischemia, a condition that might reflect histopathological changes in the myocardium in the late stage of KD.

Determination of timing for reoperation in patients after right ventricular outflow reconstruction.

After right ventricular (RV) outflow reconstruction, patients often develop postoperative outflow tract stenosis or pulmonary regurgitation, or both. The aim of this study was to assess the relation between RV hypertrophy, volume, pressure, and function and to provide indications for repeat surgery. We performed magnetic resonance imaging to measure RV volume, wall mass, and the ratio of mass to volume in 31 patients after RV outflow reconstruction and in 12 controls. Patients were divided into 2 groups, New York Heart Association class I and the repeat surgery group. The RV stress index was defined as RV peak systolic pressure/(mass to volume); RV ejection fraction (EF) was calculated by ventriculography. The RV stress index for the repeat surgery group was significantly higher than for the remaining groups (p <0.01). In the New York Heart Association class I and control groups, a significant inverse correlation was observed between RVEF and the RV stress index (r = -0.59, p <0.01). All patients in reoperation group whose RVEF decreased to <95% confidence limit of regression had symptoms of RV failure. The RV stress index decreased substantially after reoperation, but RVEF remained at <95% limits. These findings suggest that excess RV wall stress contributes to impaired RV performance. The RV stress-RVEF relation may be useful in assessing RV function and in establishing a surgical indication.