RESUMO
BACKGROUND: Excitotoxicity is an important mechanism in secondary neuronal injury after traumatic brain injury (TBI). Excitatory amino acids (EAAs) are increased in cerebrospinal fluid (CSF) in adults after TBI; however, studies in pediatric head trauma are lacking. We hypothesized that CSF glutamate, aspartate, and glycine would be increased after TBI in children and that these increases would be associated with age, child abuse, poor outcome, and cerebral ischemia. METHODS: EAAs were measured in 66 CSF samples from 18 children after severe TBI. Control samples were obtained from 19 children who received lumbar punctures to rule out meningitis. RESULTS: Peak and mean CSF glycine and peak CSF glutamate levels were increased versus control values. Subgroups of patients with TBI were compared by using univariate regression analysis. Massive increases in CSF glutamate were found in children <4 years old and in child abuse victims. Increased CSF glutamate and glycine were associated with poor outcome. A trend toward an association between high glutamate concentration and ischemic blood flow was observed. CONCLUSIONS: CSF EAAs are increased in infants and children with severe TBI. Young age and child abuse were associated with extremely high CSF glutamate concentrations after TBI. A possible role for excitotoxicity after pediatric TBI is supported.
Assuntos
Ácido Aspártico/líquido cefalorraquidiano , Lesões Encefálicas/líquido cefalorraquidiano , Lesões Encefálicas/etiologia , Ventrículos Cerebrais , Maus-Tratos Infantis , Aminoácidos Excitatórios/líquido cefalorraquidiano , Ácido Glutâmico/líquido cefalorraquidiano , Glicina/líquido cefalorraquidiano , Adolescente , Fatores Etários , Lesões Encefálicas/diagnóstico por imagem , Lesões Encefálicas/mortalidade , Isquemia Encefálica/etiologia , Estudos de Casos e Controles , Criança , Maus-Tratos Infantis/estatística & dados numéricos , Pré-Escolar , Pessoas com Deficiência/estatística & dados numéricos , Escala de Coma de Glasgow , Escala de Resultado de Glasgow , Humanos , Lactente , Prognóstico , Análise de Sobrevida , Fatores de Tempo , Tomografia Computadorizada por Raios XRESUMO
Oxidation of both of the methionine residues (positions 8 and 18) in parathyroid hormone (PTH) eliminates many of its biological effects. The present studies were performed to examine the actions of 1,34 bovine PTH and 1-34 bovine PTH oxidized selectively at Met 8, at Met 18, and at both sites on renal electrolyte handling and on adenylate cyclase (AC) stimulation. In clearance studies in anesthetized rabbits, PTH caused a phosphaturia and an anticalciuria. PTH also stimulated renal proximal tubular AC in vitro and increased renal cortical cAMP content in vivo. PTH oxidized at Met 18 was anticalciuric, but not phosphaturic, stimulated renal AC and increased cortical cAMP content. PTH oxidized at Met 8 also produced an anticalciuria without a phosphaturia, but only weakly stimulated AC and did not alter cortical cAMP content. PTH oxidized at both Met 8 and Met 18 was phosphaturic but not anticalciuric, was a weak agonist for AC and decreased cortical cAMP content. In the isolated perfused rabbit proximal straight tubule, PTH inhibited fluid and phosphate transport, whereas the doubly oxidized peptide was inactive. The data are consistent with the possibility that the effects of PTH on renal tubular phosphorus transport are mediated by more than one mechanism and are, in part, independent of the cAMP messenger system.
Assuntos
Adenilil Ciclases/metabolismo , Rim/fisiologia , Hormônio Paratireóideo/metabolismo , Animais , Bicarbonatos/sangue , Transporte Biológico , Pressão Sanguínea , Cálcio/sangue , Cálcio/urina , AMP Cíclico/metabolismo , Inulina/farmacocinética , Túbulos Renais Proximais/efeitos dos fármacos , Oxirredução , Fósforo/sangue , Fósforo/urina , CoelhosRESUMO
A previous report showed that infection with the nematode Nippostrongylus brasiliensis stimulates a basophilia as well as an eosinophilia in the blood of August rats. The present study shows that blood levels of basophils and eosinophils were increased in two other rat strains, one inbred and one outbred, after infection with N. brasiliensis, and infection of two inbred rat strains with Trichinella spiralis also stimulated a basophilia as well as an eosinophilia. No increase occurred in basophils or eosinophils in athymic (nude) rats infected with N. brasiliensis, although both these cell types were found in the blood of control, specific pathogen free, nude rats in numbers comparable to those in specific pathogen free, heterozygote controls of the same strain. Rat basophils usually have few granules and in blood smears often appear as if they were partly degranulated. Basophils from uninfected nude rats contained more negative than positive staining granules compared with basophils from parasitized heterozygotes. The possession of small numbers of granules which vary in their reaction to stains of the Romanowski type is a normal feature of rat basophils in blood smears. Consequently rat basophils differ in these respects from those of other species.
Assuntos
Basófilos , Eosinófilos , Infecções por Nematoides/sangue , Ratos Endogâmicos/genética , Triquinelose/sangue , Animais , Basófilos/imunologia , Eosinófilos/imunologia , Heterozigoto , Contagem de Leucócitos , Infecções por Nematoides/imunologia , Nippostrongylus , Ratos , Organismos Livres de Patógenos Específicos , Timo/fisiologia , Triquinelose/imunologiaRESUMO
The course of each of three successive infections with Eimeria nieschulzi in nude (athymic) rats was the same as the primary infection in nu/+ animals, with the production of more oocysts. This indicates that resistance to reinfection with this parasite is mediated by T lymphocytes but that these cells do not control the duration of the life cycle, since oocyst production was not prolonged in the nu/nu rats. After the three infections with E. nieschulzi, the rats were exposed twice to the intestinal nematode Nippostrongylus brasiliensis, and the nu/nu were completely susceptible even to the second infection. Egg production by both infections in the nu/nu animals was similar and continued at a high plateau level for 28 days before falling to a low level. It appears that the strain of N. brasiliensis used in this study is unable to sustain high egg production for more than 4 weeks in T cell deficient rats.