RESUMO
Clinical charts of 80 infants younger than 1 year who presented over a 14-year period (1986 to 2000) with acute liver failure (ALF), defined as prolonged prothrombin time greater than 17 seconds and decrease of clotting factor V plasma level below 50% of normal, were reviewed retrospectively. The main causes of ALF were inherited metabolic disorders in 42.5% of cases, including mitochondrial respiratory chain disorders in 17, type I hereditary tyrosinemia in 12, and urea cycle disorders in 2; neonatal hemochromatosis in 16% of cases; and acute viral hepatitis in 15% of cases (hepatitis B in 6, herpes virus type 6 in 4, and herpes simplex virus type 1 in 2). The cause of ALF remained undetermined in 16% of cases. A total of 19 (24%) infants survived without orthotopic liver transplantation; 38 (47%) infants died from sepsis, multiple organ failure, or because the underlying disease contraindicated orthotopic liver transplantation (12 [15%] infants), and 23 (29%) infants underwent orthotopic liver transplantation within 12 months from onset, 12 of whom are alive with a mean follow-up period of 5.2 years from orthotopic liver transplantation. We conclude that ALF during the first year of life is a severe condition with poor prognosis, despite the advent of liver transplantation.
Assuntos
Hospitais Pediátricos , Falência Hepática Aguda/mortalidade , Falência Hepática Aguda/cirurgia , Transplante de Fígado , Humanos , Lactente , Recém-Nascido , Falência Hepática Aguda/fisiopatologia , Prognóstico , Estudos Retrospectivos , Taxa de Sobrevida , Fatores de Tempo , Resultado do TratamentoRESUMO
The therapeutic potential of synthetic inhibitors to the major cysteine-proteinase from Trypanosoma cruzi (cruzain or cruzipain) was recently demonstrated in animal models of Chagas' disease. A possible limitation of this strategy would be the emergence of parasite populations developing resistance to cysteine-proteinase inhibitors. Here, we describe the properties of a phenotypically stable T. cruzi cell line (R-Dm28) that displays increased resistance to Z-(SBz)Cys-Phe-CHN2, an irreversible cysteine-proteinase inhibitor which preferentially inactivates cathepsin L-like enzymes. Isolated from axenic cultures of the parental cells (IC50 1.5 microM), R-Dm28 epimastigotes exhibited 13-fold (IC50) 20 microM) higher resistance to this inhibitor and did not display cross-resistance to unrelated trypanocidal drugs, such as benznidazol and nifurtimox. Western blotting (with mAb), affinity labeling (with biotin-LVG-CHN2) and FACS analysis of R-Dm28 log-phase epimastigotes revealed that the cruzipain target was expressed at lower levels, as compared with Dm28c. Interestingly, this deficit was paralleled by increased expression of an unrelated Mr 30 000 cysteine-proteinase whose activity was somewhat refractory to inhibition by Z-(SBz)Cys-Phe-CHN,. N-terminal sequencing of the affinity-purified biotin-LVG-proteinase complex allowed its identification as a cathepsin B-like enzyme. Increased antigenic deposits of this proteinase were found in the grossly enlarged and electron dense reservosomes from R-Dm28 epimastigotes. Our data suggest that R-Dm28 resistance to toxic effects induced by the synthetic inhibitor may result from decreased availability of the most sensitive cysteine-proteinase target, cruzipain. The deficit in metabolic functions otherwise mediated by this cathepsin L-like proteinase is likely compensated by increased expression/accumulation of a cathepsin B-like target.
Assuntos
Catepsina B/metabolismo , Cisteína Endopeptidases/metabolismo , Inibidores de Cisteína Proteinase/farmacologia , Trypanosoma cruzi/efeitos dos fármacos , Animais , Antígenos de Protozoários/farmacologia , Catepsina B/análise , Linhagem Celular , Cisteína Endopeptidases/análise , Resistência Microbiana a Medicamentos , Citometria de Fluxo , Glicoproteínas/farmacologia , Immunoblotting , Imuno-Histoquímica , Nifurtimox/farmacologia , Nitroimidazóis/farmacologia , Proteínas de Protozoários , Tripanossomicidas/farmacologia , Trypanosoma cruzi/crescimento & desenvolvimento , Trypanosoma cruzi/metabolismoRESUMO
OBJECTIVE: To estimate the risk of bleeding during adolescence and early adulthood in a group of children with portal vein obstruction who had not undergone an effective treatment beforehand. STUDY DESIGN: Children (n = 44) were followed up from age 12 years to a mean age of 20 years (range, 15-34 years). Actuarial risk of bleeding, related to previous occurrence of gastrointestinal bleeding and to pattern of varices at age 12, was calculated yearly. RESULTS: Twenty-four children presented with gastrointestinal bleeding after age 12, and 20 did not bleed. The overall actuarial probability of bleeding was 49% at age 16 and 76% at age 24. Probability of bleeding at age 23 was higher in children who had bled before age 12 than in children who had not bled (93% vs 56%; P =.007). Probabilities of bleeding at age 18 and at age 23 were 60% and 85%, respectively, in patients who had grade II or III esophageal varices at age 12. The 9 children without varices or with grade I varices only on endoscopy did not bleed between the ages of 12 and 20 years. CONCLUSIONS: Children with portal vein obstruction have a >50% risk of bleeding during adolescence; the pattern of varices on endoscopy at age 12 may have a prognostic value.
Assuntos
Varizes Esofágicas e Gástricas/complicações , Hemorragia Gastrointestinal/etiologia , Veia Porta , Análise Atuarial , Adolescente , Adulto , Fatores Etários , Criança , Seguimentos , Hemorragia Gastrointestinal/epidemiologia , Humanos , Fatores de Risco , Doenças Vasculares/complicaçõesRESUMO
Pulmonary arteriovenous shunting (PAVS) with hypoxemia is a severe complication of cirrhosis that may regress after liver transplantation. We report PAVS in 25 children with cirrhosis and in 1 with portal vein obstruction; proof of shunting was obtained by technetium Tc 99m microaggregated albumin pulmonary scanning or a high alveoloarterial O2 gradient or both. Cyanosis or dyspnea or both occurred at ages ranging from 6 months to 14 years, earlier in children with biliary atresia and polysplenia syndrome (p < 0.01). Mean arterial oxygen tension (PaO2) was 57 mm Hg (range, 42 to 81 mm Hg) during breathing of 21% O2 and 367 mm Hg (range, 179 to 535 mm Hg) in 100% O2. Cardiac index was always raised, significantly more in children with biliary atresia and polysplenia syndrome (p < 0.01). Seven untreated children died 3 months to 8 years after the diagnosis of PAVS. Eleven underwent liver transplantation: seven are alive (follow-up, 1 to 4 years) and have no signs of PAVS. The PaO2 value during breathing of 100% O2 was > 300 mm Hg in the survivors and < 200 mm Hg in the four nonsurvivors (p < 0.01). These results indicate (1) that PAVS can occur at any age in children with portal hypertension, and that the risk is highest and earliest in children with biliary atresia and polysplenia syndrome, (2) that early liver transplantation allows regression of PAVS, and (3) that the prognosis may in part be related to the level of PaO2 while the patient is breathing 100% O2. The results indicate that systematic screening for PAVS should be part of the examination of these children.
Assuntos
Fístula Arteriovenosa/diagnóstico , Fístula Arteriovenosa/etiologia , Cirrose Hepática/complicações , Pulmão/irrigação sanguínea , Adolescente , Anastomose Arteriovenosa , Fístula Arteriovenosa/fisiopatologia , Fístula Arteriovenosa/cirurgia , Encéfalo/diagnóstico por imagem , Criança , Pré-Escolar , Feminino , Transplante de Coração-Pulmão , Humanos , Hipertensão Portal/etiologia , Hipóxia/etiologia , Lactente , Cirrose Hepática/cirurgia , Hepatopatias/complicações , Transplante de Fígado , Pulmão/diagnóstico por imagem , Masculino , Artéria Pulmonar/anormalidades , Pressão Propulsora Pulmonar , Radiografia , Cintilografia , Testes de Função Respiratória , Estudos RetrospectivosRESUMO
During a 17-year period, 40 infants less than 1 year of age were investigated for cholelithiasis; 32 infants were seen within the past 10 years. Seventeen of them had no recognizable predisposing factors. In 6 infants, gallbladder lithiasis was a fortuitous finding on a plain radiograph or sonogram with no signs of common bile duct obstruction; under conservative management, no complications of lithiasis were observed on follow-up of 3 infants and spontaneous resolution occurred in 2 others. In the remaining 34 infants with lithiasis of the common duct or cystic duct or both, the initial symptoms were cholestatic jaundice in 21, acholic stools in 8, sepsis in 4, and abdominal pain in 1. Ultrasonography, performed in 33 of them, showed dilation of the biliary tract in 28, and stones in the gallbladder in 13 and in the bile ducts in 10. Percutaneous transhepatic cholangiography or operative cholangiography in 26 infants showed stones in the bile ducts in 23. In 3 infants, no lithiasis was visible, suggesting the spontaneous elimination of stones. Treatment was initially surgical in 9 infants, but starting in 1981 interventional radiologic procedures were attempted in 15 infants and were successful in 12. Spontaneous resolution of cholelithiasis occurred in 10 other infants with cholestasis. Recurrence of biliary stones was observed in 3 infants only after a follow-up of 7 months to 10 years. These results suggest that common bile duct lithiasis should be considered among the causes of cholestatic jaundice in infancy, and that some of the gallbladder calculi found in older children may have resulted from a lithogenic process that occurred during fetal life or shortly after birth. Percutaneous cholangiography with biliary drainage appears to be an effective means of treatment of infants with common bile duct obstruction; surgery can then be restricted to a limited number of cases, especially those with associated strictures of the bile ducts.