Biomedical subjects

Hiraku Doi

Publications and source records attributed to Hiraku Doi.

5 recordsLinked to original sources

PubMed2006

Development of pulmonary hypertension in 5 patients after pediatric living-donor liver transplantation: de novo or secondary?

The development of portopulmonary hypertension (PH) in a patient with end-stage liver disease is related to high cardiac output and hyperdynamic circulation. However, PH following liver transplantation is not fully understood. Of 617 pediatric patients receiving transplants between June 1990 and March 2004, 5 (median age 12 yr, median weight 24.5 kg) were revealed to have portopulmonary hypertension (PH) after living-donor liver transplantation (LDLT), as confirmed by echocardiography and/or right heart catheterization. All children underwent LDLT for post-Kasai biliary atresia. In 2 patients with refractory biliary complications, PH developed following portal thrombosis; 2 with stable graft function, who had had intrapulmonary shunting (IPS) before LDLT, were found to have PH in spite of overcoming liver dysfunction due to hepatitis. PH developed shortly after distal splenorenal shunting in 1 patient, who suffered liver cirrhosis due to an intractable outflow blockage. The onset of PH ranged from 2.8 to 11 yr after LDLT, and mean pulmonary artery pressure (mPAP) estimated by echocardiography at the time of presentation ranged from 43 to 120 mmHg. Three of the 5 patients are alive under prostaglandin I2 (PGI2) treatment. Of these, 1 is prepared for retransplantation for an intractable complications of liver allograft, while the other 2 with satisfactory grafts are being considered for lung transplantation. Even after LDLT, PH can develop with portal hypertension. Periodic echocardiography is essential for early detection and treatment of PH especially in the recipients with portal hypertension not only preoperatively but also postoperatively.

Adolescent↗

PubMed2005

Successful liver transplantation for congenital absence of the portal vein complicated by intrapulmonary shunt and brain abscess.

A 27-day-old boy had convulsion associated with brain abscesses and severe hypoxemia at the age of 3 months. Congenital absence of the portal vein (CAPV) and some associated anomalies were detected by radiological examinations. Brain abscess and hypoxemia were thought to be serious complications resulting from CAPV and were successfully corrected by living donor liver transplantation at the age of 4 months. This is the first report of a successful transplantation indicated for intrapulmonary shunt and brain abscess in an infant with CAPV.

Abnormalities, Multiple↗

PubMed2005

Identification of cardiac stem cells with FLK1, CD31, and VE-cadherin expression during embryonic stem cell differentiation.

We evaluated the expression of the FLK1, one of the lateral mesoderm early markers where cardiogenesis occurs, to characterize and isolate cardiac stem/progenitor cells from ES cells. Dissociated cells from embryoid bodies (EBs) on day 3, 4, or 5 were collected into two subpopulations with or without FLK1 expression and coculture on OP9 stromal cells was continued to examine whether contracting colonies came out or not. FLK1+ cells from EBs at days 3 and 4 formed spontaneous contracting colonies more efficiently than FLK1- cells on the same days, but not at day 5. Most contracting cardiac colonies derived from FLK1+cells mainly on day 4 were detected on endothelial cells along with hematopoietic cells. Further characterization of cells with these capabilities into three lineages revealed the FLK1+ CD31-VE-cadherin-phenotype. Our findings indicate that FLK1+cells, especially FLK1+ CD31-VE-cadherin-cells, could act as cardiohemangioblasts to form cardiac cells as well as endothelial cells and hematopoietic cells.

Antigens, CD↗

PubMed2005

[Postoperative complete atrioventricular block induced by carbamazepine in a patient with congenital heart disease].

We report here a boy with epilepsy and congenital heart defect, complicated postoperatively by complete atrioventricular (A-V) block caused by an adverse effect of carbamazepine (CBZ). He had been taking CBZ for 7 years to treat complex partial seizures. He also had endocardial cushion defect and first-degree A-V block, and underwent cardiac surgery at the age of 17 years. The postoperative course was unremarkable except transient complete left bundle branch block occuring one day after the surgery. Oral CBZ (400 mg per day) was continued. Five days after the surgery, bradycardia (20 beats per minute) suddenly developed, and electrocardiography (ECG) showed complete A-V block. Pervenous pacing was begun, and the heart rate gradually recovered. CBZ was discontinued on the suspicion that it caused the arrhythmia, although its serum level was estimated to be within the therapeutic range (4 to 5 microg/ml). He underwent pervenous pacing for 12 days. He was discharged 27 days after the surgery, when ECG returned to first-degree A-V block. In this case, the cardiac conduction system was affected by an adverse effect of CBZ, in combination with the preoperative first-degree A-V block and the effects of cardiac surgery, resulting in complete A-V block. Although reports of similar cases are scarce, caution should be made in prescribing CBZ to patients who either have cardiac conduction abnormalities or undergo cardiac surgery.

Adolescent↗

PubMed2003

[Not Available].

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Journal Article↗