Liver transplantation in children. Blood transfusion and metabolic disorders

Metabolic disorders during hepatic transplantation can be partly induced by blood transfusion. A retrospective survey of perioperative biological data recorded in patients under 18 years of age having liver transplantation was performed. Blood transfusion was also studied. For this evaluation, patients were divided in a paediatric group I (n = 20; mean age: 3.7 years) and an adolescent group II (n = 11; mean age: 14.3 years). Blood transfusion was significantly (p less than 0.05) more important in group I (302 +/- 286 ml X kg-1) than in group II (148.5 +/- 156 ml X kg-1). Autotransfusion of washed red cells was performed in six patients, allowing a mean 17 +/- 7% saving in blood transfusion. Severe hypernatraemia over 152 mmol X l-1 due to blood transfusion was observed only in five patients in group I. Hyperglycaemia increasing till the revascularization of the new liver was constant in both groups, but significantly more pronounced in group II. Cardiac arrest occurred twice in group I at initial revascularization. In group I, children with biliary atresia were not significantly different from the others for the duration of operation and the volume of blood transfusion; however the latter was more abundant. Conversely, in group II, the duration of operation was longer (p less than 0.05) in patients with previous abdominal surgery than in others. Finally the paediatric group differs from the adolescent group by obvious differences in anaesthesia and intensive care and specifically in hepatic transplantation by larger volume of blood transfusion leading to severe hypernatraemia. In further studies, adolescents should be distinct from the paediatric group and included in the adult group.     

Comparative dose-response studies of organophosphorus ester-induced delayed neuropathy in rats and hens administered mipafox.

A single injection of mipafox was administered to both Long-Evans hooded rats and White Leghorn hens in dosages which inhibited the activity of brain neurotoxic esterase 30-50%, 60-80%, or greater than 80% four hr after intoxication. All animals were monitored for clinical evidence of organophosphorus induced delayed neuropathy for 21 days, euthanatized, and regions of the nervous system were histologically evaluated. Only hens manifested clinical signs of neuropathy; however, light and electron microscopic lesions were present in the nervous systems of both species. In rats, these lesions were well developed in only the highest dosage group and confined to the rostral level of the fasciculus gracilis in the medulla oblongata. Swollen axons containing a single vacuole filled with flocculent material were the most prominent lesion in rats. Hens manifested more extensive and varied fiber breakdown in multiple spinal cord tracts, with the intensity of degeneration increasing with increasing dosages of mipafox. Both marked Wallerian-like degeneration and swollen axons filled with aggregates of cellular debris were observed in the nervous systems of hens. This study indicates that both rats and hens are susceptible to OPIDN. However, there are qualitative and quantitative differences in both clinical manifestations and histologic appearances between the two species.     

Substrate inhibition of adenosine phosphorylation in adenosine deaminase deficiency and adenosine-mediated inhibition of PP-ribose-P dependent nucleotide synthesis in hypoxanthine phosphoribosyltransferase deficient erythrocytes

Summary The metabolism of adenosine and its effects on phosphoribosylpyrophosphate, PP-ribose-P, dependent nucleotide synthesis were studied using erythrocytes from patients with adenosine deaminase and hypoxanthine phosphoribosyltransferase deficiency as models. The phosphorylation of adenosine was progressively inhibited by concentrations of adenosine greater than 1 µmol L^–1 for control and ADA deficient erythrocytes. There was essentially no initial rate of phosphorylation at 30 µmol L^–1 adenosine. Adenosine, 1 µmol L^–1, also caused a 60% reduction in PP-ribose-P concentration in ADA deficient erythrocytes. For HPRT deficient erythrocytes in which ADA activity was blocked by coformycin, 10 µmol L^–1 inosine stimulated PP-ribose-P dependent nucleotide synthesis from adenine, whereas, 10 µmol L^–1 adenosine inhibited nucleotide synthesis. These observations suggest that adenosine phosphorylation and PP-ribose-P dependent nucleotide synthesis are inhibited under conditions in which adenosine accumulates, such as in hereditary or pharmacologically induced ADA deficiency.