PubMed Health⌕ Search

Biomedical subjects

B Rotoli

Publications and source records attributed to B Rotoli.

At least 19 recordsLinked to original sources
PubMed1992

Molecular basis of chronic non-spherocytic haemolytic anaemia: a new G6PD variant (393 Arg----His) with abnormal KmG6P and marked in vivo instability.

More than 80 genetic variants of glucose-6-phosphate dehydrogenase (G6PD) are associated with chronic non-spherocytic haemolytic anaemia (CNSHA). In order to help clarify the molecular basis of this association, we have carried out a detailed biochemical and genetic characterization of two G6PD deficient brothers affected by CNSHA. The G6PD from the two patients has altered electrophoretic mobility, abnormally elevated Michaelis constant (Km) for G6P, and extreme instability in vivo and in vitro. By comparison with published information we found that this is a new G6PD variant which we have designated G6PD Portici. The entire coding region of the gene has been sequenced, and a single point mutation, a G----A transition, was found at position 1178 in exon X, causing a substitution of histidine for arginine at residue 393 in the polypeptide chain. By polymerase chain reaction (PCR) amplification followed by diagnostic restriction enzyme analysis and allele-specific oligonucleotide hybridization we have demonstrated the inheritance of this mutation in the patient's family. Our results support the notion of a causative link between this mutation in the G6PD gene and CNSHA. Our data, in combination with previous data in the literature, suggest that the three-dimensional structure of G6PD is such as to cause interaction in the binding of its two substrates, G6P and NADP.

Adolescent↗
PubMed1992

Effect of psoralen and ultraviolet A on platelet functioning: an in vitro and in vivo study.

We investigated possible alterations induced by psoralen and ultraviolet A radiation (PUVA) on platelet function both in vitro and in vivo. In vitro, using conventional aggregometry and adenosine diphosphate (ADP), collagen, ristocetin and arachidonic acid as aggregating agents, platelet aggregation was determined on platelet-rich plasma (PRP) from normal subjects at basal conditions and following the addition of increasing concentrations of 8-methoxypsoralen (8-MOP) with and without exposure to ultraviolet A (UVA) light (5 J/cm2) and compared with UVA light exposure alone. At basal conditions and following exposure to UVA light alone, no changes in the normal platelet aggregation patterns were observed. Exposure to UVA light of PRP containing 8-MOP also demonstrated no abnormality in the platelet aggregation patterns at 8-MOP concentrations of 200 ng/ml. However, abnormal platelet aggregation as a response to ADP and collagen was observed at higher concentrations of 8-MOP, which was augmented upon exposure to UVA light. In vivo, platelet aggregometry was performed on PRP from 4 patients submitted to PUVA treatment at basal conditions, 2.5 h after oral ingestion of 8-MOP (0.6-0.8 mg/kg) and after 4 PUVA sessions. No patient showed modification of the platelet aggregation profile after either 8-MOP ingestion or PUVA treatment. Our study shows that 8-MOP at high concentrations in vitro impairs platelet aggregation by ADP and collagen augmented by UVA light exposure, but PUVA therapy causes no detectable abnormality in platelet function in vivo.

Adenosine Diphosphate↗
PubMed1991

Danazol: in vitro effects on human hemopoiesis and in vivo activity in hypoplastic and myelodysplastic disorders.

We examined the effects of danazol on in vitro growth of human bone marrow and peripheral blood progenitor cells from 15 normal donors and 5 myelodysplastic patients, and on in vivo hemopoiesis in 30 patients with hypoplastic or myelodysplastic disorders. At concentrations similar to that reported as the plasma level after oral administration, danazol significantly increased CFU-GM colony growth in all normal donors, while the influence on CFU-E, BFU-E, CFU-MK and CFU-GEMM colony growth was less evident. The stimulatory effect on CFU-GM was observed even after accessory cell depletion. Np stimulatory effect either in vitro on the growth of all hemopoietic progenitors or in vivo was observed in 15 myelodysplastic patients, while 7 complete and 3 partial hematological responses occurred in 15 patients with hypoplastic disorders. In conclusion, our results suggest that danazol exerts a direct stimulatory activity in vitro at least on CFU-GM, and a hemopoietic stimulatory effect in vivo in hypoplastic but not in myelodysplastic disorders.

Adult↗
PubMed1990

Induction of alkaline phosphatase activity in chronic myeloid leukemia cells: in vitro studies and speculative hypotheses.

Three patients with Ph chromosome + chronic myeloid leukemia (CML) in chronic phase suffered from intercurrent pleuritis of undefined origin. At that time, leucocyte alkaline phosphatase activity (LAPA) score was low for circulating neutrophils, but high for those from pleural effusion. LAP negative circulating CML granulocytes were incubated with the pleural liquid: after 40-70 hr, almost all were intensely LAP positive. This finding suggests that the low LAPA score in resting CML neutrophils is attributable to the absence of appropriate stimuli rather than to an incapacity to synthesize the enzyme.

Alkaline Phosphatase↗
PubMed1989

Proliferative pathways in CD1- CD3+ CD4+ CD8+ T-prolymphocytic leukemic cells: analysis with monoclonal antibodies and cytokines.

The antigenic profile and the proliferative pathways in leukemic cells from the patient TRT with T-prolymphocytic leukemia (T-PLL) were analyzed using monoclonal antibodies (MoAbs) and cytokines. T-PLL cells expressed the phenotype CD1- CD3+ CD4+ CD8+. Incubation with the differentiating agent phorbol-12-myristate-13-acetate markedly increased the percentage of cells with the CD4- CD8+ phenotype, suggesting that leukemic cells were already committed towards a differentiated element with the CD4- CD8+ phenotype. T-PLL cells were induced to proliferate by anti-CD2 MoAb 9-1 + 9.6 and by anti-CD3 MoAb OKT3. The two pathways exhibited normal functional interactions and were susceptible to modulation by anti-HLA class I MoAbs. These results indicate that regulation of cell proliferation was preserved to a significant extent in the T-PLL cells analyzed. At variance with normal resting T cells that require previous activation to proliferate when incubated with interleukin-1 (IL-1) or interleukin-2 (IL-2), T-PLL cells proliferated vigorously when incubated with either interleukin. Furthermore, T-PLL cells proliferated when incubated with immune interferon (IFN-gamma). The latter finding parallels the enhancement by IFN-gamma of the proliferative response of lectin-activated murine T lymphocytes. These results suggest that T-PLL cells, which express a high constitutive level of c-myc mRNA, may be in an activated state. The antigenic phenotype and the characteristics of the proliferative pathways of T-PLL cells from the patient TRT are compatible with the possibility that they may be derived from an intermediate thymocyte.

Antibodies, Monoclonal↗