RESUMO
Cnidarians are a disparate and ancient phylum, encompassing corals and jellyfish, and occupy both the pelagic and benthic realms. They have a rich fossil record from the Phanerozoic eon lending insight into the early history of the group but, although cnidarians diverged from other animals in the Precambrian period, their record from the Ediacaran period (635-542 million years ago) is controversial. Here, we describe a new fossil cnidarian-Auroralumina attenboroughii gen. et sp. nov.-from the Ediacaran of Charnwood Forest (557-562 million years ago) that shows two bifurcating polyps enclosed in a rigid, polyhedral, organic skeleton with evidence of simple, densely packed tentacles. Auroralumina displays a suite of characters allying it to early medusozoans but shows others more typical of Anthozoa. Phylogenetic analyses recover Auroralumina as a stem-group medusozoan and, therefore, the oldest crown-group cnidarian. Auroralumina demonstrates both the establishment of the crown group of an animal phylum and the fixation of its body plan tens of millions of years before the Cambrian diversification of animal life.
Assuntos
Cnidários , Animais , Evolução Biológica , Florestas , Filogenia , Reino UnidoRESUMO
BACKGROUND: Liver transplantation for type IV glycogen storage disease (branching-enzyme deficiency) results in the resorption of extrahepatic deposits of amylopectin, but the mechanism of resorption is not known. METHODS: We studied two patients with type IV glycogen storage disease 37 and 91 months after liver transplantation and a third patient with lysosomal glucocerebrosidase deficiency (type 1 Gaucher's disease), in whom tissue glucocerebroside deposition had decreased 26 months after liver replacement, to determine whether the migration of cells from the allograft (microchimerism) could explain the improved metabolism of enzyme-deficient tissues in the recipient. Samples of blood and biopsy specimens of the skin, lymph nodes, heart, bone marrow, or intestine were examined immunocytochemically with the use of donor-specific monoclonal anti-HLA antibodies and the polymerase chain reaction, with preliminary amplification specific to donor alleles of the gene for the beta chain of HLA-DR molecules, followed by hybridization with allele-specific oligonucleotide probes. RESULTS: Histopathological examination revealed that the cardiac deposits of amylopectin in the patients with glycogen storage disease and the lymph-node deposits of glucocerebroside in the patient with Gaucher's disease were dramatically reduced after transplantation. Immunocytochemical analysis showed cells containing the HLA phenotypes of the donor in the heart and skin of the patients with glycogen storage disease and in the lymph nodes, but not the skin, of the patient with Gaucher's disease. Polymerase-chain-reaction analysis demonstrated donor HLA-DR DNA in the heart of both patients with glycogen storage disease, in the skin of one of them, and in the skin, intestine, blood, and bone marrow of the patient with Gaucher's disease. CONCLUSIONS: Systemic microchimerism occurs after liver allotransplantation and can ameliorate pancellular enzyme deficiencies.
Assuntos
Amilopectina/metabolismo , Quimera , Doença de Gaucher/cirurgia , Doença de Depósito de Glicogênio Tipo IV/cirurgia , Transplante de Fígado , Adulto , Movimento Celular , DNA/análise , Doença de Gaucher/metabolismo , Doença de Gaucher/patologia , Glucosilceramidas/metabolismo , Doença de Depósito de Glicogênio Tipo IV/metabolismo , Doença de Depósito de Glicogênio Tipo IV/patologia , Antígenos HLA/análise , Humanos , Imuno-Histoquímica , Lactente , Fígado/patologia , Linfonodos/patologia , Masculino , Miocárdio/patologia , Pele/patologia , Transplante HomólogoRESUMO
Progressive liver failure or hepatic complications of the primary disease led to orthotopic liver transplantation in eight children with glycogen storage disease over a 9-year period. One patient had glycogen storage disease (GSD) type I (von Gierke disease) and seven patients had type IV GSD (Andersen disease). As previously reported [19], a 16.5-year-old-girl with GSD type I was successfully treated in 1982 by orthotopic liver transplantation under cyclosporine and steroid immunosuppression. The metabolic consequences of the disease have been eliminated, the renal function and size have remained normal, and the patient has lived a normal young adult life. A late portal venous thrombosis was treated successfully with a distal splenorenal shunt. Orthotopic liver transplantation was performed in seven children with type N GSD who had progressive hepatic failure. Two patients died early from technical complications. The other five have no evidence of recurrent hepatic amylopectinosis after 1.1-5.8 postoperative years. They have had good physical and intellectual maturation. Amylopectin was found in many extrahepatic tissues prior to surgery, but cardiopathy and skeletal myopathy have not developed after transplantation. Postoperative heart biopsies from patients showed either minimal amylopectin deposits as long as 4.5 years following transplantation or a dramatic reduction in sequential biopsies from one patient who initially had dense myocardial deposits. Serious hepatic derangement is seen most commonly in types I and IV GSD. Liver transplantation cures the hepatic manifestations of both types. The extrahepatic deposition of abnormal glycogen appears not to be problematic in type I disease, and while potentially more threatening in type IV disease, may actually exhibit signs of regression after hepatic allografting.
Assuntos
Doença de Depósito de Glicogênio Tipo IV/cirurgia , Doença de Depósito de Glicogênio Tipo I/cirurgia , Transplante de Fígado , Amilopectina/análise , Biópsia , Pré-Escolar , Feminino , Seguimentos , Doença de Depósito de Glicogênio Tipo I/mortalidade , Doença de Depósito de Glicogênio Tipo I/patologia , Doença de Depósito de Glicogênio Tipo IV/mortalidade , Doença de Depósito de Glicogênio Tipo IV/patologia , Humanos , Lactente , Recém-Nascido , Fígado/patologia , Masculino , Músculos/química , Músculos/patologia , Miocárdio/química , Miocárdio/patologia , Desempenho Psicomotor , Taxa de SobrevidaRESUMO
A 3-yr 8-mo-old female was diagnosed as having a congenital stricture of the common hepatic duct. She demonstrated hepatomegaly with marked elevations of serum transaminases, alkaline phosphatase, and bile acids without clinical jaundice or hyperbilirubinemia. Liver biopsy suggested extrahepatic obstruction. Ultrasonography was nondiagnostic, but percutaneous cholangiography demonstrated blockage at the bifurcation of the hepatic ducts. A Roux-en-Y anastomosis of the jejunum to the common hepatic ducts relieved the obstruction and ameliorated clinical evidence of liver disease.
Assuntos
Colestase Extra-Hepática/diagnóstico , Ducto Hepático Comum/anormalidades , Pré-Escolar , Colestase Extra-Hepática/etiologia , Colestase Extra-Hepática/cirurgia , Constrição Patológica , Feminino , HumanosRESUMO
A 13-year-old boy had obstructive jaundice following several episodes of blunt abdominal trauma. At surgery, a stricture of the common bile duct, for which no other cause could be found, was identified and corrected. We describe our approach to the problem of obstructive jaundice in childhood. In most cases, the application of ultrasonography or computerized tomography and appropriate transhepatic cholangiography can yield a presumptive diagnosis before surgical exploration.