1/77. Biochemical and molecular genetic characteristics of the severe form of tyrosine hydroxylase deficiency.BACKGROUND: tyrosine hydroxylase (TH) catalyzes the rate-limiting step in the biosynthesis of the catecholamines dopamine, norepinephrine, and epinephrine. Recently, mutations were identified in cases of autosomal recessive dopa-responsive dystonia and infantile parkinsonism. We describe a patient with severe symptoms and a new missense mutation in TH. methods: Relevant metabolites in urine and cerebrospinal fluid were measured by HPLC with fluorometric and electrochemical detection. All exons of the TH gene were amplified by PCR and subjected to single-strand conformation polymorphism analysis. Amplimers displaying aberrant migration patterns were analyzed by dna sequence analysis. RESULTS: The patient presented with severe axial hypotonia, hypokinesia, reduced facial mimicry, ptosis, and oculogyric crises from infancy. The major metabolite of dopamine, homovanillic acid, was undetectable in the patient's cerebrospinal fluid. A low dose of L-dopa produced substantial biochemical but limited clinical improvement. dna sequencing revealed a homozygous 1076G-->T missense mutation in exon 10 of the TH gene. The mutation was confirmed with restriction enzyme analysis. It was not present in 100 control alleles. Secondary structure prediction based on Chou-Fasman calculations showed an abnormal secondary structure of the mutant protein. CONCLUSIONS: We describe a new missense mutation (1076G-->T, C359F) in the TH gene. The transversion is present in all known splice variants of the enzyme. It produces more severe clinical and biochemical manifestations than previously described in TH-deficient cases. Our findings extend the clinical and the biochemical phenotype of genetically demonstrated TH deficiency.- - - - - - - - - - ranking = 1keywords = single (Clic here for more details about this article) |
2/77. Anomalous pulmonary artery from the aorta via a patent ductus arteriosus: repair in a premature infant.A successful repair of anomalous left pulmonary artery from the ascending aorta via a left ductus arteriosus in a 1 kg baby is reported. Repair was performed at an early age to avoid pulmonary hypertension and left pulmonary artery occlusion. Utilizing the right ductus to perfuse the right lung, surgery was performed without cardiopulmonary bypass.- - - - - - - - - - ranking = 100.22960795924keywords = artery (Clic here for more details about this article) |
3/77. Balloon aortic valvuloplasty in a 1,600-gram infant.We present a 1,600 g infant who underwent successful balloon aortic valvuloplasty from the right carotid artery approach. A simple technique to facilitate access to the left ventricle and expedite the procedure is described. Issues unique to performing balloon aortic valvuloplasty on such a small child are discussed.- - - - - - - - - - ranking = 16.704934659874keywords = artery (Clic here for more details about this article) |
4/77. cerebral infarction in newborns: report of two cases.Neonates with cerebral infarction do not present with specific symptoms and the condition is usually insidious, so many atypical cases are not diagnosed properly during the neonatal stage. Normal neurological examination results may be found in newborns who have actually had a cerebral infarction insidiously. We present two newborns with cerebral infarction. One had clinical symptoms of seizures. brain computed tomography showed a low-attenuated area and magnetic resonance angiography showed a decreased caliber and number of cerebral artery branches. The other had normal neurological examination results. He was referred to our hospital due to cyanosis. brain sonography revealed a focal hyperechoic area and T2 weighted magnetic resonance image showed an increased signal intensity area. The incidence, etiologies, clinical and radiographic findings are also reviewed.- - - - - - - - - - ranking = 16.704934659874keywords = artery (Clic here for more details about this article) |
5/77. Late-diastolic forward flow in the aorta induced by left atrial contraction.Late-diastolic forward flow is a well-described phenomenon detectable by Doppler echocardiography in the pulmonary trunk. It is supported by a restrictive right ventricular diastolic function and by a low end-diastolic pulmonary artery pressure. A similar phenomenon for the left ventricle and the aorta has not been described. We report a case of a preterm infant with aortic stenosis and endocardial fibroelastosis, who underwent balloon valvuloplasty. Restrictive left ventricular diastolic filling led to high left atrial pressure (27 mm Hg) and a very pathologic ratio of early-to-late peak velocities (2.6) for an infant of 29 weeks' gestation. In combination with a low diastolic aortic pressure (24 mm Hg) caused by moderate aortic regurgitation after intervention, a late-diastolic forward flow was detectable in the aorta during left atrial contraction with pulsed Doppler echocardiography.- - - - - - - - - - ranking = 16.704934659874keywords = artery (Clic here for more details about this article) |
6/77. Use of enoxaparin in a preterm infant.OBJECTIVE: To describe the use of enoxaparin to treat suspected thrombosis in a preterm neonate. CASE DESCRIPTION: A 29-week-gestation white infant with a family history of protein s deficiency lost color and blood flow to the right hand several hours after removal of the umbilical artery catheter. Although normal color returned to all except the distal first, second, and third fingers after warming, Doppler flow showed a radial artery defect, indicating a lack of blood flow. enoxaparin 1 mg/kg intravenously every eight hours was then started. heparin concentrations measured via anti-Xa assay drawn four and eight hours after a dose were 0.78 and 0.39 units/mL, respectively. Pharmacokinetic parameters calculated from these concentrations using a one-compartment model were elimination half-life four hours, volume of distribution 0.13 L/kg, and clearance 0.022 L/kg/h. No adverse effects were noted. blood flow eventually returned, leaving only the third fingertip chronically injured. DISCUSSION: Differences between the neonatal and adult hemostatic systems contribute to an increased risk of thromboembolic events and an altered sensitivity to heparin anticoagulation in the neonate. Although heparin is currently the anticoagulant of choice, it may produce several adverse effects, such as hemorrhage and thrombocytopenia, which may be avoided by use of low-molecular-weight heparins (LMWHs). However, despite the efficacy and improved safety profile of LMWHs in adults, data regarding their use in children and neonates are scarce. This case demonstrates that enoxaparin can be used safely and effectively in a preterm infant through appropriate monitoring of heparin concentrations to adjust dosages. A larger volume of distribution of enoxaparin was noted in this neonate than in adults. CONCLUSIONS: enoxaparin 1 mg/kg intravenously every eight hours was used safely in this preterm infant with suspected thrombosis, suggesting that more than one dosing regimen may be appropriate in this population.- - - - - - - - - - ranking = 9346.2983836453keywords = umbilical artery, umbilical, artery (Clic here for more details about this article) |
7/77. Retroperitoneal abscess and mycotic aortic aneurysm: unusual septic complications of central vascular line placement in premature infants.OBJECTIVE: To describe the sonographic appearance of unusual septic complications after central vascular line placement in premature infants. methods: Two case reports are presented. RESULTS: The first patient had a retroperitoneal abscess after percutaneous central venous catheter placement. The second patient had a ruptured mycotic aneurysm of the abdominal aorta after umbilical arterial catheter placement. CONCLUSIONS: Retroperitoneal abscess and aortic aneurysm should be considered in patients with histories of long-standing catheters or line sepsis. Both of these complications are readily diagnosed on the basis of sonography.- - - - - - - - - - ranking = 978.03854158728keywords = umbilical (Clic here for more details about this article) |
8/77. Infantile presentation of the mtDNA A3243G tRNA(Leu (UUR)) mutation.Mitochondrial dna (mtDNA) disorders are clinically very heterogeneous, ranging from single organ involvement to severe multisystem disease. One of the most frequently observed mtDNA mutations is the A-to-G transition at position 3243 of the tRNA(Leu (UUR)) gene. This mutation is often related to melas syndrome. However, not all patients with the A3243G mutation share the same clinical disease expression and, on the contrary, patients clinically exhibiting melas syndrome may have other mtDNA mutations. Here we describe two patients with a very early infantile presentation of disease associated with the A3243G mutation. Patient 1 presented with hypotonia, feeding difficulties and failure to thrive (FTT) at the age of 3 months. Laboratory investigations showed persistent hyperlactic acidemia, elevated lactate/pyruvate ratios and elevated alanine concentrations in blood. Developmental delay was progressive and he developed cardiomyopathy and seizures. death occurred at the age of 3.5 years. Patient 2 was born prematurely and had persistent, severe lactic acidosis from birth on. Moderate biventricular hypertrophy was seen on ultrasound studies of the heart and, suffering from progressive lactic acidosis, he died at the age of 13 days. Because of the rarity of this very early presentation, we searched the literature for other infantile cases associated with the A3243G mutation and found 8 additional ones. In infants presenting with lactic acidosis/hyperlactic acidemia, failure to thrive, hypotonia, seizures and/or cardiomyopathy, mtDNA mutational analysis, also for the disease entities, usually only observed in juveniles or adults is warranted.- - - - - - - - - - ranking = 1keywords = single (Clic here for more details about this article) |
9/77. Isolated left ventricular ischemia after the Norwood procedure.Aortic atresia is the most severe variant of hypoplastic left heart syndrome (HLHS), and has been associated with significant mortality after stage I palliation. Coronary artery abnormalities are more prominent in this group of patients, especially in the presence of a patent mitral valve. Herein, we describe a case of isolated left ventricular ischemia after the Norwood procedure in a neonate with hypoplastic left heart syndrome, left ventricular hypertrophy, mitral stenosis, aortic atresia, and anomalous left coronary artery.- - - - - - - - - - ranking = 33.409869319747keywords = artery (Clic here for more details about this article) |
10/77. Serious complications after umbilical artery catheterization for neonatal monitoring.Umbilical artery catheterization in critically ill neonates caused major complications, including five deaths, in 15 of 165 infants with respiratory distress syndrome who underwent autopsy at the UCLA Hospital during the past eight years. Arterial occlusion leading to visceral infarction occurred in 12 patients, and vascular perforation caused hemoperitoneum in three patients. Repeated catheter manipulation and protracted catheter use were common factors identified in patients in whom complications developed. Restricted indications for catheter use, routine roentgenographic confirmation of catheter tip location below the kidneys, low-dosage heparin sodium infusion, use of cannulas with decreased thrombogenicity, avoidance of catheter manipulation, and vigilance to remove catheters when no longer required should reduce the incidence of this iatrogenic neonatal complication while still permitting arterial pressure and blood gas monitoring when clinically indicated.- - - - - - - - - - ranking = 37335.078730602keywords = umbilical artery, umbilical, artery (Clic here for more details about this article) |
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