Interchange trisomy 9 due to maternal t(6; 9) translocation

The occurrence of interchange trisomy due to a 3:1 malsegregation has been documented in only a few cases with trisomy 21. We describe the first case of interchange trisomy 9 due to a maternal t(6; 9) translocation. The patient, a boy neonate who died immediately after birth, had intra-uterine growth retardation, specific craniofacial features including microcephaly with a high forehead, low-set ears, upslanting short palpebral fissures, microphthalmia, bulbous nose and micrognathia, cryptorchidism, cystic kidney and various skeletal anomalies. His phenotype was consistent with that of the trisomy 9 syndrome. Cytogenetic analysis showed his karyotype of 47,XY,-6, + der(6), + der(9)t(6; 9)(q27;q21.1)mat. The present report indicates that a very rare interchange mode of a 3:1 segregation can give rise to a live birth with full trisomy 9 in female carriers with reciprocal translocations involving the proximal long arm of chromosome 9.     

Neurally mediated syncope complicated with paroxysmal atrial fibrillation

Recently, it has come to be accepted that the result of the tilt test is specific to neurally mediated syncope (vasovagal syncope). Only rarely is a case of paroxysmal atrial fibrillation without any organic diseases in childhood reported. A case reported here of a 14-year-old boy with neurally mediated syncope; which was complicated by paroxysmal atrial fibrillation, and which was diagnosed by performing the tilt test. Atrial fibrillation can be induced by the extraordinary stimulation of the vagal nerve during syncope. In a child, neurally mediated syncope complicated with paroxysmal atrial fibrillation has not been previously reported.     

Chronic effects of oral prostacyclin analogue on thromboxane A and prostacyclin metabolites in pulmonary hypertension

Abnormal biosynthesis of thromboxane and prostacyclin has been implicated in patients with primary pulmonary hypertension and secondary pulmonary hypertension associated with congenital heart disease, and could be involved in the pathogenesis of pulmonary vascular disease. The chronic effects of an oral prostacyclin analogue, beraprost sodium, on thromboxane and prostacyclin biosynthesis and on pulmonary circulation were investigated in 15 children with pulmonary hypertension. The plasma concentrations of thromboxane B, and 6-keto-prostaglandin F1_α were measured, as was the urinary excretion of 11-dehydro-thromboxane B, and 2.3-dinor-6-keto-prostaglandin F1_α, which are stable metabolites of thromboxane A, and prostacyclin, respectively. In patients with pulmonary hypertension, the plasma concentration of thromboxane B. and the ratio of thromboxane B, to 6-keto-prostaglandin F1_α were greater than in healthy controls: 210 ± 49 versus 28 ± 4 pg/mL (P<6.05) and 32.6 ± 8.9 versus 5.7± 1.8 (p<0.01), respectively. After 3 months of administration of beraprost. the plasma concentration of thromboxane B, and the ratio of thromboxane B, to 6-keto-prostaglandin F were reduced significantly: 210 ± 49 to 98 ± 26 pg/mL (P < 0.01) and 32.6 ± 8.9 to 18.0 ± 6.7 (P < 0.05). respectively. In contrast, the plasma concentrations of 6-keto-prostaglandin F in patients were slightly but not significantly higher than in controls, and did not change significantly after administration of beraprost. The concentrations of 11-dehydro-thromboxane B, and 2.3-dinor-6-keto-prostaglandin F, in urine correlated significantly with thromboxane B, and 6-keto-prostaglandin F . respectively, in plasma. Beraprost improved the imbalance of thromboxane and prostacyclin biosynthesis and has a potential efficacy for preventing the progressive development of pathological changes in pulmonary vasculature.     

Bronchial hyper-responsiveness to inhaled histamine in children with congenital heart disease

In order to assess bronchial responsiveness in patients with congestive heart failure secondary to congenital heart disease, we performed a histamine inhalation test while monitoring transcutaneous oxygen tension and compared the respiratory threshold to histamine with that obtained in patients with bronchial asthma. The inhalation test was performed by doubling concentrations of histamine solution for 2 min at 1 min intervals. The respiratory threshold of histamine was defined as the minimal concentration causing a drop in transcutaneous oxygen tension greater than 10% from baseline. Six of 10 patients with congenital heart disease and all of 12 patients with bronchial asthma had bronchial hyper-responsiveness to histamine. The mean of histamine concentration was 2750μg/mL and 937μg/mL, respectively. During the histamine inhalation test, respiratory resistance gradually increased in congenital heart disease patients. This was measured by the linear slope of transcutaneous oxygen pressure (-1.08 ± 0.75 mmHg/min), whereas in the bronchial asthma patients it rapidly decreased at the inflection point (-4.19 ± 1.86 mmHg/min). We conclude that children with congestive heart failure had bronchial hyper-responsiveness. We suggest bronchial hyper-responsiveness to inhaled histamine in congestive heart failure was caused by the gradual increased respiratory resistance, which was different from that of bronchial asthma.     

Torsades de Pointes Ventricular Tachycardia Induced by Clarithromycin and Disopyramide in the Presence of Hypokalemia

We report a 76-year-Old woman who developed TdP ventricular tachycardia induced by combined use of clarithromycin and disopyramide. She had a history of myocardial infarction 5 years earlier and has taken disopyramide for supraventricular arrhythmias. In addition, she had taken clarithromycin for upper respiratory tract infection. On admission, an ECG showed prolongation of QTc interval to 0.71 seconds and self-terminating TdP occurred several times. Disopyramide was metabolized by the cytochrome enzyme CYP3A4 and clarithromycin competitively inhibits this enzyme, probably resulting in an increase in plasma concentration of disopyramide. We should consider this possibility when prescribing clarithromycin in combination with antiarrhythmic agent disopyramide.     

Trans-mesosigmoid cutaneous ureterostomy

BACKGROUND: A new method was developed in order to create a single stoma cutaneous ureterostomy in which both ureters traverse the abdominal cavity and yet are buttressed by the mesosigmoid and covered by its visceral peritoneum. METHODS: The long mesenterium which is attached to the most mobile part of the sigmoid colon was used for the bilateral ureteral pathway. Tunnels for the ureteral path were made just underneath the visceral peritoneum on the bilateral side of the mesosigmoid. Through the tunnels both ureteral ends were brought from the retroperitoneal space to the mesenterocolonic junction (MCJ) and the MCJ is then approximated and sutured to the inside of the ureteral tract through the abdominal wall. The ureters brought outside the skin, are conjoined and sutured to the V skin flap. Eight patients who carried a high risk for operation and/or had a bladder tumor judged to be incurable underwent this cutaneous ureterostomy. RESULTS: All cases except one with low urinary output could be managed without catheter indwelling during the follow-up period. Three patients suffered from paralytic ileus and one required laparotomy for mechanical ileus during the short postoperative period. Postoperative excretory urography evaluated 14 kidneys during the follow-up period from 2 to 61 months and showed normal upper urinary tract in 11 and a mildly hydronephrotic tract in three. CONCLUSIONS: Transmesosigmoid cutaneous ureterostomy provides a single catheterless stoma even when the available ureters are relatively short. It appears to be a good method for supravesical urinary diversion when indicated.