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The $1{T}$ polytype of TaS2 exhibits voltage-triggered threshold switching as a result of a phase transition from nearly commensurate to incommensurate charge density wave states. Threshold switching, persistent above room temperature, can be utilized in a variety of electronic devices, e.g., voltage controlled oscillators. We evaluated the total-ionizing-dose response of thin film $1{T}$ -TaS2 at doses up to 1 Mrad (SiO2). The threshold voltage changed by less than 2% after irradiation, with persistent self-sustained oscillations observed through the full irradiation sequence. The radiation hardness is attributed to the high intrinsic carrier concentration of $1{T}$ -TaS2 in both of the phases that lead to threshold switching. These results suggest that charge density wave devices, implemented with thin films of $1{T}$ -TaS2, are promising for applications in high radiation environments.

Aneurysm of the sinus of Valsalva (ASV) is a rare anomaly. It may be congenital or acquired basis. In pediatric patients, most are congenital in origin. It is frequently associated with other congenital disease, most frequently ventricular septal defect (VSD). Pathologically, this is due to the total absence of normal elastic fibers. Patients with ASV are generally asymptomatic unless aneurysm rupture occurs. Unruptured ASV with right ventricular outflow tract (RVOT) obstruction is very rare. Herein we describe an unusual ASV with RVOT obstruction associated with VSD in a 14-year-old boy. He had experienced heart failure and exertional dyspnea for 2 months. The diagnosis was made by echocardiography, angiography and surgery. After surgical repair of the VSD and resection of the ASV, dyspnea and heart failure were relieved. The patient remained well during the 3 years of follow-up.

Pulmonary valvular stenosis (PS) with intact ventricular septum is a common congenital heart disease. In general, mild PS has a benign clinical course. However, in severe PS and some cases of moderate stenosis, increasing severity of the lesion may occur. The manifestations of either cerebrovascular accident (CVA) or congestive heart failure (CHF) are rarely reported in pediatric patients with PS. In this report, we describe a girl with severe PS complicated by seizures and sudden onset of hemiparesis at 13 months of age who developed CHF when 16 months old. CHF was cured after successful balloon valvuloplasty. She remained well without residual hemiparesis or recurrent seizures during the 1-year follow-up. Early balloon valvuloplasty should be emphasized in patients with severe PS, even if there are no significant clinical symptoms. With prompt balloon valvuloplasty, these complications can be effectively prevented.

We report an infant with intractable congestive heart failure caused by coarctation of the aorta, patent ductus arteriosus, atrial septal defect, and multiple muscular ventricular septal defects. He had received balloon angioplasty for dilating the aortic coarctation and a Gianturco coil for closing the ductus at a single therapeutic catheterization session at 4 months old. After balloon angioplasty, his heart failure had dramatically resolved. A false aneurysm and mediastinal hematoma were noted on the following day. The hematoma revealed total resolution 10 weeks later. He was asymptomatic throughout 12 months of follow-up.

Hepatopulmonary syndrome (HPS) is characterized by hypoxemia in patients with severe chronic liver disease and pulmonary vasodilatation in the absence of primary cardiac or pulmonary disease. Severe hypoxemia resulting from HPS is generally considered a contraindication to liver transplantation. We describe the case of a 6-year-old girl with biliary atresia complicated with HPS who was successfully treated with liver transplantation. Cyanosis and dyspnea had initially developed at the age of 5 years. Arterial blood gas showed a PaO2 of 46.6 mm Hg on room air. The diagnosis of HPS was confirmed by contrast echocardiography, lung perfusion scan with 99mTc macroaggregate albumin, and pulmonary angiography. The lung scan revealed an intrapulmonary shunt of 24%. She underwent living donor liver transplantation and received a left lateral segment graft from her mother. One year after successful liver transplantation, she had normal arterial oxygen saturation and a normal lung scan without intrapulmonary shunting. This case demonstrates that HPS associated with end-stage liver disease is potentially curable by liver transplantation.

Pancreatic pseudocysts in children are uncommon. The purpose of this study was to investigate the clinical course, image findings (with emphasis on sonograms), and outcome of 12 patients with pancreatic pseudocysts.From January 1986 to May 2000, 12 patients with a diagnosis of pancreatic pseudocysts were encountered in our hospital. There were 8 males and 4 females with ages ranging from 3 to 18 years.The etiology was blunt abdominal trauma in all 12 cases. The cysts were detected from 3 to 57 days after injury, and the sizes ranged from 0.6 to 16 cm. Six patients received surgical treatment. External drainage was performed in 3 cases, subtotal pancreatectomy in 1, cystogastrostomy in 2. Initial serum amylase level correlated with neither the time to normalization (r = 0.354, p = 0.268), cystic appearance after trauma (r = 0.029, p = 0.933), nor resolution (r = 0.322, p = 0.309). Sonographic follow-up revealed that the disappearance of cysts was noted from 11 days to 10 months following injury. The size of the pseudocysts correlated with neither the time of detection (r = 0.284, p = 0.371) nor disappearance (r = -0.175, p = 0.586).Serial sonogram examinations play an important role in monitoring the progress of pancreatic pseudocysts, which may develop even 57 days after injury. The size of pseudocysts correlated with neither the times of detection nor disappearance, and the initial serum amylase level correlated with neither the time to normalization nor cystic appearance after trauma.

Larsen syndrome is a genetically heterogeneous group of disorders characterized by multiple joint dislocations and a characteristic face. We describe a girl with the typical features of Larsen syndrome. She also had associated multiple cardiovascular anomalies. The anomalies included elongation of the aorta, bicuspid aortic valve, subaortic stenosis, mitral valve prolapse with mitral regurgitation, atrial septal defect of the secundum type, and a patent ductus arteriosus.

A 10-year-old girl was admitted for abdominal pain for 1 week. Morning vomiting with 5 Ascaris and diarrhea with Ascaris were found. Radiograph of the abdomen disclosed no significant abnormality. Abdominal sonogram revealed a normal biliary tree; but mildly enlarged pancreatic thickness, and thickened gallbladder wall. Within the thickened gallbladder wall a linear echogenic structure with worm-like movement suspected of being Ascaris was found. We report this case because pediatric pancreatitis and a gallbladder wall thickened with worm-movement have rarely been reported. Urgent treatment and surgery are required for the very ill child with a tensely distended abdomen or signs of peritoneal irritation. Early diagnosis is very important to prevent further complications. We emphasize the role of sonography in the diagnosis of this case and the prevention of progressive deterioration.

Pheochromocytoma is very rare in children. We report a case of bilateral pheochromocytoma in a 12-year-old boy who had blurred vision due to hypertensive retinopathy. Abdominal ultrasound and computed tomography revealed bilateral suprarenal tumors. Resection of the bilateral tumors along with right total and left subtotal adrenalectomy were performed. Blood pressure and visual acuity returned to normal after surgery.

The aim of this study was to report the initial experience of using the Gianturco coil (Cook Cardiology, Bloomington, Indiana) without heparinization to close patent ductus arteriosus (PDA).Forty consecutive patients (30 females, 10 males) underwent transcatheter closure of a PDA via the right femoral artery approach without heparinization. Patients ages ranged from 7 months to 55 years (median, 6.8 years); weights ranged from 7.8 65 kg (median, 18.3 kg). Twenty-one patients had cardiomegaly (n = 21), congestive heart failure (n = 10), or both (n = 10). The PDAs measured 0.8 4.5 mm (median, 2.6 mm) at the narrowest diameter; the mean Qp/Qs ranged from 1.0 2.6 (1.4 +/- 0.4). The helical diameter of the coil that we chose was 1.7 times the narrowest PDA diameter. The length of the coil was sufficient to produce 4 or 5 loops.Successful coil placement was accomplished in all 40 patients. Thirty-five patients (87.5%) underwent single coil implantation, 2 patients (5%) had 2 coils, and 3 patients (7.5%) had 3 coils. Complete ductus occlusion was achieved in 80% of cases at the end of the procedure, while 8 patients had minimal shunt detected by aortography or echocardiography. The occlusion rate increased to 87.5% by the next day, 90% by 1 month, 92.5% by 3 months, 95% by 6 months, and 97.5% by 9 and 12 months. Only one asymptomatic patient had minimal residual shunt detected by color Doppler at 12 months follow-up. At a median follow-up of 17 months (range, 5 25 months), no patient had thromboembolism, endocarditis, coil migration, diminished femoral pulse or hemolysis.Our preliminary results suggest that retrograde transcatheter closure of PDA with the Gianturco coil without heparinization is feasible, safe and efficacious. A single coil allowed complete occlusion of PDA 3 mm in diameter.

Hypertrophic pyloric stenosis is commonly seen in infants 2 to 4 weeks old. We report a case of pyloric stenosis diagnosed in a boy 5 months and 11 days old suffering from the sudden onset of vomiting. Gastric volvulus was initially diagnosed at another hospital. Abdominal ultrasonography at first using an Acuson 5-MHz transducer revealed a negative diagnosis. However, a tubular pyloric mass measuring 5.5 mm in thickness, 15 mm in the transverse diameter, and 2.0 cm in length was detected by a 7-MHz transducer immediately after the infant vomited. On physical examination, no abdominal mass was palpable. This suggested that this might have been a case of hypertrophic pyloric stenosis which was missed until the infant was older than 5 months. We believe this is the oldest reported case of infantile hypertrophic pyloric stenosis in Taiwan.

The purpose of this study is to determine the prevalence of congenital heart disease in patients with cleft lip and/or palate. We undertook a retrospective study of 1148 cases, age15 years old, with cleft lip and/or palate from January 1991 to December 1998, of which congenital heart disease was associated in 62 patients. The overall prevalence of congenital heart disease in patients with clefts was 5.4%. Of the 62 patients, there were 38 boys and 24 girls. We classified clefts into one of three categories; group 1: cleft lip alone; group 2: cleft lip and palate; group 3: cleft palate alone. The cleft lip and palate (group 2) was present in the majority (27 of 62; 44%) of patients with congenital heart disease. Twenty-five patients (40%) had cleft palate, and ten patients (16%) had cleft lip. Isolated atrial septal defect and ventricular septal defect are the two common congenital defects, which presented 23% and 21% of patients, respectively. Apart from congenital heart disease and cleft lip or palate, 56% (35 of 62 patients) and additional abnormalities. Central nervous system and skeletal malformations were the most common associated abnormalities. In our study, congenital heart disease was more common in patients of group 2 and group 3 than of group 1. In addition, there was a significantly greater proportion of patients associated with other systemic anomalies in groups 2 and 3 than in group 1 (chi-square chi 2 = 7.535, p = 0.023), but no significant difference was noted between group 2 and group 3. We recommend that it would be appropriate for all cleft patients to receive a routine examination for associated anomalies by a pediatrician. With the widespread use of echocardiography and/or brain sonography, the early diagnosis and treatment of these anomalies are possible.

Vascular rings are a diagnostic and therapeutic challenge for pediatricians. Many diagnostic modalities contribute to the detection of these rare congenital vascular anomalies. The role of flexible bronchoscopy is still being debated. We present 3 cases to emphasize the usefulness of pediatric flexible bronchoscopy (PFB) in the early diagnosis and postoperative evaluation of vascular rings. In patient 1, PFB was performed before conventional techniques were available. A right aortic arch with a retroesophageal aortic diverticulum and mirror-image branching was later confirmed. In patients 2 and 3, pulmonary artery slings could not be detected clearly by imaging studies before PFB was performed. PFB was arranged again postoperatively for these 2 patients, because of difficulty weaning patient 2 from ventilator support and persistent respiratory distress in patient 3. In conclusion, we expect that more vascular rings will be diagnosed using PFB. This instrument is also useful in making a decision for surgery, and for detecting associated tracheobronchial anomalies preoperatively, assuring appropriate correction intraoperatively, and monitoring the condition of vascular rings postoperatively.

A 1.5-year-old girl developed congestive heart failure 9 months after she presented with hypertension. The hypertension was caused by a renal artery stenosis. A short-segment stenosis at the ostium of the left renal artery was confirmed by arteriogram. After balloon angioplasty, the blood pressure and heart function returned to normal. Angioplasty had an excellent result of relieving hypertension and heart failure in this patient. Cathet. Cardiovasc. Intervent. 48:374-377, 1999.

Background and Objective The course of atrial septal defects (ASD) in children undergoing liver transplantation is poorly described. Our objective was to present our experience in living donor liver transplantation (LDLT) in children with type II ASD. Patients and Methods Between June 1994 and December 2006, 18/140 (12.8%) pediatric LDLT were diagnosed to have both type II ASD and end-stage liver disease. We reviewed the records of these patients. The median follow-up was 48.7 months. Data were analyzed using descriptive statistics. Results There were 8 male and 10 female patients whose overall mean age was 12 months. There were 15 biliary atresia and 3 neonatal hepatitis patients. The median Child score was 9. The mean Pediatric Model End-stage Liver Disease score was 14. There were 13 with small (≤4 mm), 4 with medium (5 to 9 mm), and 1 large (>10 mm) ASD. Six small ASD closed spontaneously pretransplant. Seven small ASD closed posttransplant. The medium and large ASD persisted or increased in size posttransplant. Only one patient showed hemodynamically significant ASD based on cardiac echocardiography and catheterization. This patient underwent Amplatzer closure of the ASD at 10 months posttransplant. All patients are surviving with their original grafts to date. There were no perioperative cardiac or neurologic complications. Conclusion This series demonstrated that LDLT can be safely performed in hemodynamically stable patients with small- to large-sized ASD. Small ASD may close pre- or posttransplant.

Administration of donor-derived immature dendritic cells (DC) treated with transforming growth factor-beta (TGF-beta) to prevent allograft rejection is not applicable for clinical use. We therefore attempted to explore the use of recipient-derived DC pulsed with donor antigens via the indirect pathway (cross-priming). DC were propagated from C3H (H2(k)) bone marrow (BM) using granulocyte-macrophage colony stimulating factor (GM-CSF) and interleukin-4 (IL-4). TGF-beta (0.2 ng/mL) was added at the initiation of culture. The resultant TGF-beta DC were pulsed with B10 (H2(b)) splenocyte lysate. Expression of major histocompatibility complex (MHC) class I and II was not affected, while CD40, CD80, and CD86 costimulatory molecules on DC were significantly inhibited by treatment with TGF-beta. C3H DC pulsed with B10 antigens stimulated a proliferative response in C3H T cells which was inhibited when DC were treated with TGF-beta, and the cytotoxic T-lymphocyte (CTL) activity was also inhibited. This observation correlated with reduced interferon-gamma (IFN-gamma) and increased IL-10 production. A single injection of TGF-beta DC prolonged allograft survival (median survival time [MST] 18 days vs 10 days in no-DC treatment control; P.05). These data indicated that an approach utilizing recipient DC as a "vaccine" strategy is possible.

We report a very rare case of systemic sclerosis in a 6-year-old girl. She presented with diffuse scleroderma, Raynaud's phenomenon, pulmonary interstitial fibrosis, pulmonary hypertension, and right ventricular failure. The diagnosis was confirmed by skin manifestations, high resolution computed tomography, cardiac catheterization, and anti-nuclear antibodies. Nifedipine, prednisolone, digoxin, and furosemide were given. There was remission of the right ventricular failure and dyspnea, and the skin showed partial improvement. The patient remained asymptomatic for a year. The symptoms of respiratory and right heart failure developed again after an episode of lower respiratory tract infection and she eventually died. We discuss the clinical manifestations, treatment, and outcome.

Because of variability in the size of the thymus, imaging in children is a challenge. Difficulties in differentiating an abnormal mediastinal mass from a normal thymus may lead to unnecessary investigations. We performed a prospective sonographic study of the normal thymus in 140 infants and children aged newborn to 8 years to determine the size of the normal thymic gland. Patients were classified into five groups by age: 1) less than 6 months, 2) 6-12 months, 3) 13-24 months, 4) 25-48 months, 5) more than 48 months. The thymus was scanned through the suprasternal, transsternal, and parasternal windows with a Sonos 1000 scanner and a 5.5-MHz sector probe. The thymus was visualized in at least one of the three windows and the width and thickness were measured in 133 of the 140 cases. The mean +/- standard deviation width and thickness were 3.67 +/- 0.64 cm and 1.30 +/- 0.25 cm in boys, and 3.45 +/- 0.59 cm and 1.20 +/- 0.26 cm in girls (p = 0.047 and p = 0.033 in width and thickness, respectively). Regression analysis demonstrated an increase, mainly in the width, with increasing age (width = 3.48 + (0.05 x age) cm, p = 0.009), indicating an increase of 0.05 cm per year. In conclusion, the thymus was clearly and easily visualized on sonograms in the majority of children we studied. This study established the normal size range of the thymus in children less than 8 years old.

We report a case of right aortic arch with mirror-image branching and coarctation of the aorta and left ductus arteriosus in a 6-year-old boy. He was referred to Chang Gung Children's Hospital with suspected left ventricular failure. Physical examination revealed hypertension and a pulse discrepancy between the upper and lower extremities. Echocardiography and magnetic resonance imaging revealed a right aortic arch, a long segmental aortic coarctation, and a patent ductus arteriosus. In addition, mirror-image branching of the brachiocephalic vessels was found. The coarctation was resected and the ductus arteriosus was ligated. The postoperative recovery was uneventful and the blood pressure returned to normal. He remained normotensive and had no symptoms of heart failure within the 2 years of follow-up.

Tetralogy of Fallot (TOF) and patent ductus arteriosus complicated by pulmonary vascular obstructive disease (PVOD) and hemoptysis in a 5-year-old girl are described. The echocardiogram was typical of TOF, as well as ductus arteriosus and right aortic arch. Cardiac catheterization revealed a pulmonary vascular resistance of 44 hybrid resistance units, and the pulmonary-to-systemic resistance ratio was 1.4. Diagnosis of PVOD was made by cardiac catheterization. Angiography revealed a bronchial artery arising from the left subclavian artery. PVOD itself, rupture of a bronchial artery or both, were considered the contributory causes of hemoptysis in this patient.

Partial anomalous pulmonary venous drainage (PAPVD) with an intact atrial septum is a very rare cardiovascular anomaly. Most PAPVD cases can be detected by echocardiographic scanning of the anomalous pulmonary venous connection. This paper describes an asymptomatic 6-year-old boy who was referred because of a heart murmur. An electrocardiogram and two-dimensional echocardiography revealed right heart volume overload. Mild pulmonary valve stenosis and an intact atrial septum were noted. In addition, color flow mapping demonstrated the right upper pulmonary vein connecting to the superior vena cava. This paper emphasizes that two-dimensional echocardiography in conjunction with color flow mapping is a valuable modality in the detection of anomalous pulmonary venous drainage.

We report on a case of thymic hypoplasia (DiGeorge syndrome) associated with tetralogy of Fallot in a newborn. The diagnosis was established on the basis of echocardiography, magnetic resonance imaging (MRI) and surgical observations. In this paper, we emphasize that MRI may be used not only to characterize cardiovascular anomalies, but to diagnose thymic hypoplasia.

A female infant presented with cyanosis, respiratory distress and unique to-and-fro murmur which she had since the age of 1-month-old. Absent pulmonary valve syndrome was diagnosed by echocardiography. She developed seizure disorders with hypocalcemia and pneumonia at the age of 2-month-old. The patient died from sepsis, intractable respiratory and heart failure. The postmortem study confirmed the diagnosis of congenital absent pulmonary valve associated with DiGeorge syndrome.

We describe an aneurysm originating from the right sinus of Valsalva, with right ventricular outflow tract obstruction associated with ventricular septal defect, in a 9-year-old boy. Diagnosis was made by echocardiography and cardiac catheterization. Successful surgical repair of ventricular septal defect and aortic valvuloplasty resulted in symptomatic improvement.

Transposition of the great arteries (TGA) is characterized by severe and life-threatening hypoxemia during a newborn period. Without treatment, most of the patients die during early infancy. We reported a 20-day-old male newborn who was referred to our hospital due to severe cyanosis and respiratory distress. Echocardiograms revealed D-TGA with an intact ventricular septum. There was no pulmonary stenosis or other major cardiac anomalies. The cardiac catheterization and angiographic findings which were performed 4 days later were consistent with the diagnosis of echocardiography. The systolic left and right ventricular pressures were 65 and 69 mmHg respectively. Arterial switch operation was performed at the age of 28 days. Postoperative course was uneventful. The cardiac recatheterization and angiographic study performed 6 months after operation, and the latest non-invasive examination including chest X-ray, electrocardiogram and echocardiographic assessment revealed good ventricular performance and normal semilunar valve function. There was no obstruction at the anastomotic site. The patient has been doing well with regular follow-up at our clinic for 2 years and 6 months without medication.

Takayasu's arteritis is a rare inflammatory disease of the aorta and its major branches which occurs predominantly in young women. The clinical course has been described as two stages: 1) initial phase, with inflammatory process and systemic manifestations; and later 2) pulseless phase, with multiple arterial occlusions. A 20-year-old female came to visit this hospital for the first time at 10 years of age with occlusion of the left subclavian artery and of the thoracoabdominal aorta. Aortoaortic bypass surgery was performed using a 14 mm woven graft from the ascending aorta to the descending aorta on the infrarenal portion. The postoperative course was uneventful. Exertional dyspnea and hypertension progressively developed. However, in the past year, angiograms have shown a marked stenosis on the proximal portion of the left renal artery. Autotransplantation for the left-sided kidney was performed. The patient did well, and remained free of symptoms until this time of writing, 12 months after the operation.

We report our results with 10 infants and children who underwent atrial repair using the Senning operation between 1985 and 1990. All cases had abdominal situs solitus, levocardia and atrio-ventricular concordance (D-bulboventricular loop). Nine patients had simple D-transposition of the great arteries without ventricular septal defects (VSD) or left ventricular outflow tract obstruction. The other patient had a double outlet right ventricle with subpulmonic VSD and pulmonary hypertension (PHT) and underwent a palliative Senning procedure. All patients had a balloon atrial septostomy (BAS) before surgery, except for one with Taussig-Bing syndrome. One patient had a Blalock-Hanlon operation after BAS. The age at the time of surgery ranged from two months to four years seven months (mean: 22 months) and weight ranged from 4.3-12 kg. There were two hospital mortalities including the patient with VSD and PHT. All of the patients had echocardiographic examinations and six of the eight survivors received cardiac recatheterization four to 19 months (mean: 7.4 months) postoperatively. No baffle leaks were noted in the survivors. Two patients had both mild tricuspid regurgitation and slightly decreased right ventricular contractility, and one patient had a pressure gradient of 6 mmHg between the superior vena cava and neo-right atrium. The clinical follow-up interval was eight to 64 months (mean: 31.4 months). All survivors showed a sinus rhythm on their latest electrocardiogram and were participating in normal daily activities without medication.

There were 15 patients under 15 years of age with cases of acute rheumatic fever diagnosed by revised Jones criteria admitted to pediatric department, Chang Gung Memorial Hospital of Kaohsiung from Jan. 1986 through Dec. 1989. There were 11 boys and 4 girls. The age of onset was more commonly between 13 and 15 years old. Carditis was the most common clinical presentation, noted in 13 cases. Eleven cases had valvular involvement: mitral regurgitation (MR) and mitral valve prolapse (MVP), 5 cases; MR and aortic regurgitation (AR), 4 cases; MR, 1 case; and MVP, 1 case. One case with MR + AR also suffered transient acute glomerulonephritis, which presented with gross hematuria but improved one week later. And one case with severe MR expired due to severe congestive heart failure. Eleven of the 14 survivors had regular follow-up at our clinic with an interval of 3 months to 38 months, and received parenteral benzathine penicillin for prophylaxis. During follow-up, the murmur in 4 cases with MR + MVP and 2 cases with MR + AR disappeared within 2 months. One of the three cases who had not received secondary prophylaxis had recurrence of rheumatic fever 3 years later after the initial diagnosis.

Vallecular cyst is one of the unusual causes of respiratory distress in newborns. Recently we encountered a case of 22-day-old male infant admitted due to respiratory distress, stridor and poor feeding. A lateral view of neck X-ray examinations demonstrated a soft tissue mass in the hypopharyngeal area. On direct laryngoscopic examination, a cystic mass was noted on the left side surface of the epiglottis. The cyst appeared to be involving the vallecula compressing the tongue base and epiglottis. The cyst was partially excised and marsupialized. It was proved to be a vallecular cyst by pathological examination.

The compound previously assigned the 3β-bromo-3α-methylcholestane structure is shown to be a 3α-bromo-3β-methylcholestane, and the thermodynamically favored conformation of 1-bromo-1-methylcyclohexane is inferred to be that with the bromine axial and the methyl equatorial, contrary to earlier conclusions.

In the male retired breeder rat, arachidonic acid 1a and 2,2-dimethylarachidonic acid 3a exhibited plasma platelet disaggregation as measured after 3 hr after the compounds were administered intragastrically at 15 and 13 mg/kg/rat mean effective dose (MED), respectively. The corresponding p-t-butylphenol ester of the acids showed a remarkable potentiation of platelet disaggregation. The MED for p-t-butylphenol ester of AA was 1.1 mg/kg/rat.