Biomedical subjects

B Nobili

Publications and source records attributed to B Nobili.

At least 37 records · Page 2Linked to original sources

PubMed1997

Diamond-Blackfan anemia: expansion of erythroid progenitors in vitro by IL-9, but exclusion of a significant pathogenetic role for the IL-9 gene and the hematopoietic gene cluster on chromosome 5q.

Diamond-Blackfan anemia (DBA) is a congenital pure red blood cell aplasia that often requires lifelong transfusional therapy. Autosomal dominant and recessive inheritance have both been reported, suggesting genetic heterogeneity, but most cases occur sporadically. The origin of impaired erythropoiesis is unknown. Several erythroid growth factors have been thought to have a role in the pathogenesis of DBA. However, there is neither molecular nor clinical evidence for the involvement of erythropoietin (EPO), its receptor, stem cell factor (SCF), or interleukin (IL)-3, even if the addition of SCF to IL-3 and EPO does significantly increase the growth of erythroid progenitors in in vitro cultures in most patients. In this work we evaluated the possible role of another early-acting erythroid growth factor, IL-9. We found that the addition of IL-9 to SCF, IL-3, and EPO further increases burst-forming unit-erythroid growth in in vitro cultures of those DBA patients who responded to SCF. To investigate the role of the IL-9 gene, we evaluated its segregation in 22 families with members who have DBA by using a polymorphic microsatellite located within its intron 4. Lod score analysis ruled out any statistically significant involvement of the IL-9 gene in the pathogenesis of DBA. Moreover, linkage analysis with 11 highly polymorphic markers spanning 5q31.1-q33.2 excluded this region, which is included in the major cluster of genes active in hematopoiesis of the human genome.

Adolescent↗

PubMed1994

Erythrocyte membrane protein alterations underlying clinical heterogeneity in hereditary spherocytosis.

Hereditary spherocytosis (HS) is a very heterogenous condition both at clinical and biochemical level. To establish the relationship between these aspects we performed a clinical and biochemical study in 87 Italian HS subjects. Patients were divided into three groups based on clinical severity (mild, typical and severe) and into five subgroups based on specific membrane abnormalities identified by polyacrylamide gel electrophoresis (isolated spectrin deficiency, spectrin deficiency combined with mild ankyrin reduction, spectrin deficiency combined with severe ankyrin reduction, band 3 reduction and isolated protein 4.2 reduction). We were not able to assess any alteration in six HS patients. A good correlation between clinical HS forms and membrane protein defects is shown. We conclude that erythrocyte membrane analysis should be carried out after diagnosis of HS in order to predict the clinical course of the disease.

Adolescent↗

PubMed1993

Coexistence of hereditary spherocytosis (HS) due to band 3 deficiency and beta-thalassaemia trait: partial correction of HS phenotype.

A kindred with hereditary spherocytosis and beta-thalassaemia trait was identified. Detailed studies of the red cell membrane proteins on polyacrylamide gels with sodium dodecyl sulphate (SDS-PAGE) demonstrated the presence of band 3 (anion transporter) deficiency in all HS subjects (20-25% reduction) whereas spectrin content was in the normal range. The molecular defect of beta thalassaemia in this kindred was due to a beta(0) codon 39 (C-T) mutation, as assessed by beta globin gene amplification and ASO-probe hybridization. Seven subjects of this family were studied: two were normal, two had HS alone, two co-inherited HS and beta-thalassaemia trait, and one had beta-thalassaemia trait only. The two subjects with HS alone had a typical clinical form of spherocytosis with anaemia, reticulocytosis and increased red cell osmotic fragility. The two with both HS and beta-thalassaemia trait were not anaemic and showed a small, well-compensated haemolysis. Hence the finding of red cells with abnormalities of both HS and beta-thalassaemia indicates that beta-thalassaemic trait 'silences' HS caused by band 3 deficiency.

Adult↗

PubMed1992

Spectrin/band 3 ratio as diagnostic tool in hereditary spherocytosis.

Recently it has been clearly established that partial deficiency of spectrin (SP) evaluated by radioimmunoassay is a common feature of many different forms of hereditary spherocytosis (HS). In this paper the determination of SP density (spectrin/band 3 ratio) in 46 HS patients and in 50 normal controls is presented. The comparison between the membrane SP density of HS subjects and controls showed a statistically significant difference (P less than 0.0005). Moreover no overlap between normal and HS subjects was observed. Membrane spectrin/band 3 ratio has been found related to some clinical features: indeed patients with severe HS showed a smaller SP density than those with milder HS. Our results show that the evaluation of membrane SP density permits a prompt diagnosis of HS and avoids extensive and unnecessary studies for other anaemias.

Adolescent↗

PubMed1991

Ankyrin deficiency in dominant hereditary spherocytosis: report of three cases.

We describe three Italian subjects from two unrelated families affected with isolated hereditary spherocytosis (HS) without other clinical abnormalities, associated with partial spectrin and ankyrin deficiency. In both families the propositus has normal biological parents, and thus appears to be the result of a new mutation; in one of them the disease is further transmitted in an autosomal dominant fashion. Cytogenetic analysis of the latter family excluded abnormalities of the short arm of chromosome 8. We speculate that in both kindreds ankyrin deficiency is the primary defect related to ankyrin gene mutation. Several pieces of evidence suggest that ankyrin deficiency is probably the most common molecular defect in HS. It is inherited in a, dominant manner and its clinical and biochemical expression is heterogenous.

Adolescent↗

PubMed1989