RESUMO
A clinical, hematological and cytogenetical study has been carried out in a patient with Fanconi's anemia. The absence of phenotypical alterations at clinical and instrumental surveyor suggested a frame in a variant type Estren-Dameshek. The genetical problem between the classical and variant form is not yet established. The cytogenetical analysis in this case, and recent data show the impossibility to distinguish between the two forms, as regard to the frequency and characters of chromosomical instability. On the whole, the chromosomes data derived from recent studies give no support to the idea of cytogenetic heterogeneity between subjects affected by these two forms of childhood aplastic anemia.
Assuntos
Anemia Aplástica/genética , Aberrações Cromossômicas , Anemia de Fanconi/genética , Criança , Feminino , HumanosRESUMO
Isolated rat thymocytes incubated under proper metabolic conditions extrude Ca2+ previously taken up under metabolically unfavourable conditions. The extrusion can be supported by both respiratory and glycolytic energy but glycolysis seems to be more efficient for this purpose. La3+ (50--200 micron) and the ionophore A 23187 inhibit cell Ca2+ extrusion. Ruthenium Red (1--100 micron) does not influence cell Ca2+ extrusion while it inhibits the in situ mitochondrial cation uptake. All the results are consistent with a cell regulation model of Ca2+ content in which both plasma membrane and mitochondria co-operate, acting in opposite directions, in order to decrease cytosolic Ca2+ concentration. The possibility of Na+-Ca2+ hetero-exchange participation to cell Ca2+ homeostasis regulation is also discussed.
