Hidetoshi Fujino

Bernard-Soulier syndrome associated with 22q11.2 microdeletion

We describe a Japanese girl with Bernard-Soulier syndrome and 22q11.2 microdeletion. She had viral infections and recurrent thrombocytopenia and hemorrhagic diathesis after cardiac surgery. As congenital heart defects and abnormal immunity are the most common clinical manifestations associated with 22q11.2 deletion, patients with this association may have a greater risk of developing a severe bleeding disorder.

Effects of Intracoronary Tissue-Type Plasminogen Activator Treatment in Kawasaki Disease and Acute Myocardial Infarction

We retrospectively studied 3 patients with Kawasaki disease (KD) and acute myocardial infarction (AMI) who were treated with intracoronary administration of tissue-type plasminogen activator (t-PA). Two-dimensional echocardiogram on the next day of the treatment revealed reduction of thrombus and improvement of the cardiac function in all 3 patients. However, a 12-month-old patient treated with 200,000 U/kg of t-PA at 48 h after the onset of AMI died of recurrent myocardial infarction. The other 2 patients treated with 400,000 and 800,000 U/kg, respectively, showed clear, though not prompt, improvement in clinical symptoms and laboratory data. The intracoronary thrombolytic therapy using high-dose t-PA appears effective in treating AMI associated with KD.

Serious cardiac and pulmonary calcification in a young peritoneal dialysis patient: potential role of continuous correction of acidosis.

We describe a 40-month-old male infant with renal failure, treated with peritoneal dialysis, who developed massive calcification of soft tissues including the heart and lungs with subsequent cardiopulmonary insufficiency. A diagnosis of Jeune syndrome was made. After starting peritoneal dialysis, the patient exhibited an intractable metabolic acidosis of unknown etiology necessitating treatment with intravenous or oral sodium bicarbonate. Myocardial calcification was first detected by 2-dimensional echocardiography performed 3 months after starting dialysis. The patient was not suitable for renal transplantation because of his cardiac dysfunction and died of cardiac and respiratory failure at the age of 6 years. Although the patient exhibited a variety of risk factors for ectopic calcification including hyperphosphatemia, hyperparathyroidism, high calcium-phosphate product and treatment with vitamin D, the early and massive soft tissue calcification may have been accelerated by correction of the metabolic acidosis. Therefore, the use of sodium bicarbonate may be involved in the etiology of the myocardial calcification.

Chemotherapy-induced unconjugated hyperbilirubinemia caused by a mutation of the bilirubin uridine-5'-diphosphate-glucuronosyltransferase gene.

Chemotherapy for malignant neoplasms sometimes causes unconjugated hyperbilirubinemia in the absence of liver dysfunction. We analyzed the association of chemotherapy-induced hyperbilirubinemia with mutations of the bilirubin uridine-5´-diphosphate (UDP)-glucuronosyltransferase gene (UGT1A1) from two leukemic patients in whom chemotherapy resulted in a hyperbilirubinemic response. We isolated genomic DNA from peripheral blood samples and amplified UGT1A1 by polymerase chain reaction. The amplified DNA fragments were analyzed by direct sequencing. The genes of the two patients revealed an identical heterozygous missense mutation in exon 1 (211G→A: G71R). This UGT1A1 mutation may be the basis of chemotherapy-induced unconjugated hyperbilirubinemia.

Developmental defects of coronary vasculature in rat embryos administered bis‐diamine

BACKGROUND Conotruncal anomalies are often associated with abnormal coronary arteries. Although bis-diamine is known to induce conotruncal defects, its pathological effects on coronary vascular development have not been demonstrated. This study sought to assess the teratogenic effects of bis-diamine on coronary vascular development and the pathogenesis of this anomalous association. METHODS AND RESULTS A single 200 mg dose of bis-diamine was administered to pregnant Wistar rats at 10.5 days of gestation. Fifty-two embryos from 10 mother rats underwent morphological analysis of the coronary arteries. Three embryos each were removed from four mothers on embryonic days (ED) 14.5, 15.5, 16.5, and 17.5 and used for immunohistochemical studies using the anti-vascular cell adhesion molecule (VCAM)-1 antibody. Conotruncal anomalies were detected in 48 of 52 embryos, and an aplastic or hypoplastic left coronary artery was found in all of them. In control embryos at ED 16.5, VCAM-1-positive epicardial cells were transformed into mesenchymal cells in vascular plexus, which appeared to differentiate into the endothelial cells of coronary vasculature. In the heart at ED 17.5, coronary vasculature was well developed and connected with coronary ostia near the aorta. However, poor epicardial-mesenchymal transformation and subsequent differentiation was revealed in bis-diamine-treated embryos at EDs 16.5 and 17.5, causing abnormal development of the coronary vasculature and incomplete connections with coronary ostia of the aorta. CONCLUSIONS Anomalous coronary arteries in the bis-diamine-treated embryos are induced by the disruption of epicardial-mesenchymal transformation and subsequent poor development of coronary vasculature. Incomplete hatching of the coronary ostium is associated with abnormal truncal division.

Immunohistochemical Distribution of HNK‐1 and N‐CAM in Rat Embryos Treated with Bis‐Diamine

Bis‐diamine is known to induce congenital anomalies including cardiac defects, thymic hypoplasia and snout defects in rat embryos. Cardiovascular lesions consist of persistent truncus arteriosus, tetralogy of Fallot and aortic arch anomalies, which are often found in DiGeorge syndrome. In the the present study, we investigated effects of bisdiamine on cardiac neural crest cells, which may be important to the teratogenecity. A single dose of 200 mg bis‐diamine was administered to pregnant rats at 10.5 embryonic day (ED). Immunohistochemical studies were performed on embryos at 11.5, 12.5 and 13.5 ED using anti‐HNK‐1 and anti‐N‐CAM antibodies. The embryos at 11.5 and 12.5 ED showed the similar distributional patterns of either HNK‐1 or N‐CAM positive cells in control and bis‐diamine treated embryos. N‐CAM immunoreactivities in the splanchnic mesoderm were quite weakly detectable in the bis‐diamine treated embryos at 12.5 ED. Closure of the neural tube was delayed in the treated embryos at this period. Immunohistochemistry of the control embryos at 13.5 ED demonstrated a continuous chain of N‐CAM expression between the neural plexus near the foregut and the fourth aortic arch, while no apparent continuity of N‐CAM positive tissue was observed in the bis‐diamine treated embryos. These findings suggested that bis‐diamine reduced the amount of neural crest cells which appeared to participate in the aortic arch formation or conotruncal septation. The primary effect of bis‐diamine in the induction of various congenital anomalies including cardiovascular malformations may be an inhibition of the normal development of the neural tube and neural crest.

Clinical characteristics and diagnosis of double-orifice left atrioventricular valve associated with other congenital heart disease.

Four cases of double-orifice left atrioventricular (AV) valve are reported. Three of the four patients with double-orifice left AV valve had other associated congenital heart diseases, and the fourth had double-orifice left AV valve alone. A patient with associated ventricular septal defect, who presented with pulmonary congestion and hypertension, suffered from severe heart failure. However, these symptoms improved with the spontaneous closure of the ventricular septal defect. The patient with double-orifice left AV valve alone showed no cardiac symptoms. Two-dimensional and Doppler echocardiography did not detect the double-orifice left AV valve in two of the four patients. More recently, the echocardiographic technique has allowed a noninvasive and more frequent detection of this abnormality. But both of these patients had left-to-right atrial shunt and subsequent reduced transmitral flow and left ventricular volume, which may have made it difficult to detect the morphological and hemodynamic characteristics of double-orifice left AV valve. Careful and repeated echocardiographic observation of mitral configuration is required to determine the presence of double-orifice left AV valve when heart disease is associated with a left-to-right atrial shunt.

Morphological differences in cardiovascular anomalies induced by bis-diamine between Sprague-Dawley and Wistar rats.

ABSTRACT  It is known that animals show different responses to the same teratogen between different strains. We examined cardiac malformations in Sprague–Dawley (SD) and Wistar rats induced by bis‐diamine, which produced conotruncal anomalies and aortic arch malformations in embryos when administered to the dams, to elucidate the morphological differences and pathogenesis in the two strains. Two hundred milligrams of bis‐diamine dissolved in 1% gum‐tragacanth was administered to pregnant rats on embryonic day (ED) 9.5, 10.5 and 11.5 in each strain. The embryos were removed on ED 20.5. External appearances, cardiovascular morphology and associated anomalies were examined under a dissecting microscope. An immunohistological study with an anti‐N‐CAM antibody, an excellent marker for neural crest cells, was performed on ED 12.5 embryos. Isolated aortic arch anomalies were common features of malformations induced by bis‐diamine in SD rats and intracardiac defects were found in a small number of the embryos. Wistar rats showed more serious cardiovascular anomalies, such as persistent truncus arteriosus and tetralogy of Fallot, especially when dams were treated on ED 10.5 and isolated arch anomalies were significantly less prevalent than in SD rats. Immunohistology demonstrated that there were fewer N‐CAM positive cells in the conotruncal region in Wistar rats than in SD rats. Bis‐diamine induced more critical cardiovascular malformations in Wistar rats because neural crest cells, which play an important role in conotruncal septation, were more extensively damaged. Different susceptibility to bis‐diamine and/or different time of neural crest cell emigration from the hindbrain might explain those morphological differences.

Relationship between electrocardiographic signs and shunt volume in atrial septal defect

The aim of this study was to determine whether electrocardiographic signs correlate with hemodynamics and the magnitude of the intracardiac shunt in children with ostium secundum atrial septal defects (ASD).

Teratogenic effect of bis‐diamine on embryonic rat heart

ABSTRACT  Bis‐diamine induces conotruncal anomalies including persistent truncus arteriosus, tetralogy of Fallot, interruption of the aortic arch, and ventricular septal defect in rat embryos when administered to the mother. Bis‐diamine also induces extracardiac malformations including thymic hypoplasia, facial dysmorphism, forelimb anomalies and diaphragmatic hernia. However, the teratogenic mechanisms of this chemical in early developing rat hearts have not been fully established. Chimeric studies in chick and quail embryos demonstrated that the cranial neural crest cells reached the cardiac outflow tract, contributing to aorticopulmonary and truncal septation. Since an ablation of the cranial neural crest also produced the conotruncal anomalies, bis‐diamine is proposed to disturb the normal migration of cardiac neural crest cells to the heart. Based on our data concerning cardiac anomalies induced by bis‐diamine, we reviewed how the cardiac malformations were morphologically established in early developing rat hearts. Our data showed that 1) cardiovascular anomalies induced by bis‐diamine are time‐ and species or strain‐ dependent. 2) bis‐diamine reduces the number of neural crest cells migrating to participate in the conotruncal septation, 3) bis‐diamine induces anomalous coronary arteries, thin ventricular walls and epicardial defects, and 4) some embryos cultured in the medium containing bis‐diamine had extra‐cardiac abnormalities including abnormal location of the otic placodes and delay in mid brain closure. Conclusively, bis‐diamine does not appear to merely affect the cardiac development, but rather disturbs normal development of all the organs contributed to by neural crest cells.