The pulmonary circulation in cystic fibrosis.
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The hearts and lungs of 36 patients dying of cystic fibrosis have been studied to establish the relationship between right ventricular hypertrophy (RVH), pathological changes in the pulmonary circulation, and the clinical features. The presence and degree of RVH were measured by Fulton's technique of weighing the ventricles separately. Of the subjects who died after the age of 3 years, one in six had no RVH, although the mean age of this group was not significantly different from that of the remainder. There was no correlation between duration of cyanosis, haemoglobin levels, and RVH. Although not statistically significant, the cases without RVH tended to have had clubbing of the finger-nails for longer periods before death. The electrocardiogram was useful in the diagnosis of RVH. Right ventricular hypertrophy was common in children with lungs of large volume as judged by the radiographic centile of lung length. Cases with RVH show reduced background haze in the arteriogram and fewer arteries per unit area of lung. For the first time thickening of the medial muscle layer proportional to the degree of RVH has been demonstrated, only in the smaller arteries. Arterial subintimal fibrosis is more common in cases with RVH, as is thickening of the walls of small pulmonary veins. The implications of these findings are discussed. (+info)
Angiogenic growth factors in patients with cyanotic congenital heart disease and in normal children.
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Previous studies have demonstrated that the expression of angiogenic growth factors is induced in hypoxic models. However, little is known about these factors in patients with cyanotic heart disease. The purpose of this study was to examine the relationship between the plasma level of angiogenic growth factors and the severity of cyanosis. The study included 85 patients with cyanotic heart disease and age matched 81 controls. Median age was 4.2 years in the cyanotic group and 4.8 years in the control group. Mean systemic oxygen saturation was 80.6 +/- 7.3% in the cyanotic group and 98.1 +/- 0.5% in the control group. In the control group, vascular endothelial growth factor (VEGF) in the neonatal period was significantly elevated, then rapidly decreased within 3 months after birth. After 3 months of age, VEGF levels remained at a plateau. In contrast, this age dependency did not occur in hepatocyte growth factor (HGF) levels. Although VEGF and HGF levels were not different between the cyanotic and control groups within 3 months after birth, the VEGF level in the cyanotic group after 3 months of age was significantly elevated compared to the levels measured in the control group (149.2 +/- 105.6 vs. 66.3 +/- 22.5 pg/ml, p < 0.0001). Moreover, the VEGF level was negatively correlated with oxygen saturation (y = 440.6-3.53x, R = 0.47, p < 0.0001) in cases more than 3 months old. In contrast, no correlation was found between HGF level and oxygen saturation. Although physiologically increased VEGF in the neonatal period was rapidly decreased under normal oxygen saturation, a higher VEGF level persisted if systemic hypoxia was present. Persistently higher VEGF level may be related to the development of systemic to pulmonary collateral arteries in patients with cyanotic heart disease. (+info)
Diagnosis and therapeutics of pulmonary arteriovenous fistula in childhood. Case report and review of the literature.
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We report the case of a 3-year-old female patient, who, since birth, had cyanosis difficult to explain with usual diagnostic tests. The only findings on physical examination were cyanosis and clubbing of her fingers. Chest computerized tomography showed images of excessive attenuation in the right lung, which resembled arteriovenous fistulae that were later confirmed on cardiac catheterization. The fistulous trajectories were then embolized with 7 Gianturco coils, which resulted in an immediate increase in the arterial saturation of blood oxygen. (+info)
Hypoxaemia in acute respiratory and non-respiratory illnesses in neonates and children in a developing country.
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AIMS: To determine, in sick neonates and children requiring admission to a hospital in the highlands of Papua New Guinea: (1) the incidence and severity of hypoxaemia; (2) the proportion with hypoxaemia who do not fulfil criteria for acute lower respiratory infection (ALRI); and (3) the power of clinical signs to predict hypoxaemia, according to age and disease category. METHODS: Age dependent normal values for transcutaneous oxygen saturation (SpO(2)) were established in 218 well neonates and children in Goroka. A total of 491 sick neonates and children were then studied on presentation to the paediatric department at Goroka Hospital. RESULTS: A total of 257 sick neonates and children (52%) were hypoxaemic. Hypoxaemia was present in 179/245 (73%) with clinical criteria for ALRI; 79/246 (32%) with non-ALRI illnesses (including meningitis, septicaemia, severe malnutrition, low birth weight, birth asphyxia, and congenital syphilis) were also hypoxaemic. For children aged 1 month to 5 years with ALRI, the clinical signs best predicting hypoxaemia were cyanosis, respiratory rate >60, poor feeding, or reduced spontaneous activity; in those without ALRI the best predictors were cyanosis, respiratory rate >60 per minute, and inability to feed, but the positive predictive value was much lower than for children with ALRI. For neonates cyanosis was predictive of hypoxaemia, but tachypnoea or inability to feed were not. CONCLUSIONS: Hypoxaemia is an under recognised complication of non-ALRI illnesses in children and in sick neonates in developing countries. Use of algorithms with high sensitivity for the recognition of hypoxaemia, and protocols for administration of oxygen to neonates, and to children with non-ALRI illnesses, might substantially reduce case fatality. (+info)
Overproduction of platelet microparticles in cyanotic congenital heart disease with polycythemia.
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OBJECTIVES: We sought to clarify the role of platelets in the pathogenesis of abnormal coagulation in patients with cyanotic congenital heart disease (CCHD) with polycythemia; we evaluated the production of platelet microparticles (MPs), platelet degranulation and aggregation response, as well as the correlations of these variables with polycythemia. BACKGROUND: A shortened life span and suppressed aggregability of platelets are well known in patients with CCHD. Although platelet MPs are overproduced and play an important role in the coagulation process in various hematologic and cardiovascular disorders, the production of MPs remains to be elucidated in CCHD. We studied 19 patients who had CCHD with polycythemia and 21 age-matched subjects with acyanotic congenital heart disease (ACHD). Flow cytometry, using monoclonal antibodies, showed the presence of MPs as particles positive for the surface antigen (glycoprotein IIb/IIIa) specific to platelets, and platelet alpha-degranulation was recognized as platelets positive for the surface antigen of P-selectin. Platelet aggregation was assessed as the response to adenosine diphosphate (ADP). Relationships between these indexes and hematocrit (Hct) values were also evaluated. RESULTS: Production of MPs correlated positively with Hct and markedly increased at Hct values above 60% in patients with CCHD. Surface P-selectin and the mean platelet volume in patients with CCHD were comparable with those in patients with ACHD. The platelet aggregation response to ADP significantly and negatively correlated with Hct. In two subjects who showed hemoptysis and underwent phlebotomy, MPs were reduced 6 h after the procedure. CONCLUSIONS: Platelet MPs are overproduced in patients who have CCHD with polycythemia, probably due to a high shear stress derived from blood hyperviscosity. Circulating incompetent platelets, which have already been activated, as well as MPs, might play an important role in the coagulation abnormalities identified in such patients. (+info)
Variations in clinical presentation of Fallot's tetralogy in infancy. Angiographic and pathogenetic implications.
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Striking variability has been observed in the presenting features in infancy of patients subsequently shown to have tetralogy of Fallot. Some patients presented with severe cyanosis in the neonatal period while others had a systolic murmur and cyanosis only on crying. In these latter patients cyanosis became present at rest over the subsequent months. Yet others presented with episodic attacks of unconsciousness, and a final group presented with dyspnoea and heart failure, accompanying a left-to-right shunt. Angiography demonstrates corresponding variations in the anatomy of the ventricular outflow tracts. In the severely cyanosed patients, the conus septum was deviated so as to obstruct the pulmonary outflow tract, and was best visualized in the lateral projection. In the patients with increasing cyanosis or episodic attacks of unconsciousness, the conus septum again obstructed the pulmonary infundibulum, but was obliquely orientated, not being seen clearly on either lateral or frontal projections. The episodic attacks were considered to be related to infundibular spasm, as previously shown to occur in Fallot's tetralogy. In contrast, increasing cyanosis was believed to be related to hypertrophy of infundibular musculature. In the patients with an initial left-to-right shunt, the arteries were orientated side-by-side so that the conus septum was observed in the frontal projection. Again, subsequent cyanosis was related to ventricular hypertrophy producing outflow tract obstruction. These findings are interpreted in the setting of a recent study, indicating that Fallot's tetralogy is produced by rotation of the embryonic conus together with sinistro-anterior deviation of the conus septum. (+info)
Stereochemical aspects of the biosynthesis of the epimeric cyanogenic glucosides dhurrin and taxiphyllin.
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Dhurrin, I ((S)-p-hydroxymandelonitrile-beta-D-glucopyranoside), and taxiphyllin, II (the (R) epimer), occur in the genera Sorghum and Taxus, respectively. Both derive biosynthetically from L-tyrosine via the hydroxylation of p-hydroxyphenylacetonitrile, III. (3R)- and (3S)-L-[3-3H1]tyrosine, prepared by enzymic hydroxylation of the corresponding phenylalanines, were fed separately to shoots from sorghum seedlings (Sorghum bicolor (Linn) Moench) and cuttings from Japanese Yew (Taxus cuspidata Sieb. and Zucc.) and the appropriate cyanogenic glycoside was isolated (I or II). The fraction of the 3H conserved in I and II was calculated from both parallel feeding and 3H:14C double labeling experiments. The results for II were the reverse of I. Both hydroxylations of III, which give rise to the enantiomeric products (S)- and (R)-p-hydroxymandelonitrile, occurred with retention of configuration. The retention mode is characteristic of hydroxylations at aliphatic carbons catalyzed by mixed function oxidases. (+info)
Peripheral gangrene in hypernatraemic dehydration of infancy.
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Gangrene of the extremities complicating diarrhoea and severe hypernatraemic dehydration occurred in 6 infants. This is a rare complication of gastroenteritis, and its association with hypernatraemia does not seem to have previously been emphasized. The increased blood viscosity resulting from serum hyperosmolarity may have been responsible for the gangrene, and studies in our patients suggested that disseminated intravascular coagulation was present. In addition to fluid and electrolyte replacement, the infants were treated with heparin with some recovery of the affected extremities. (+info)