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Biomedical subjects

D Pedretti

Publications and source records attributed to D Pedretti.

16 recordsLinked to original sources
PubMed1994

Effects of recombinant human stem cell factor (rh-SCF) on colony formation and long-term bone marrow cultures (LTBMC) in patients with myelodysplastic syndromes.

Stem cell factor (SCF), the ligand of the c-kit receptor, is a potent enhancing cytokine for haematopoietic cells in the presence of IL-3, GM-CSF and erythropoietin (Epo). In the clonogenic assays of 63 MDS patients, the addition of rh-SCF + GM-CSF and/or IL-3 induced a significant increase (p < 0.001) in the number and size of CFU-GM. Never reaching the levels of controls, this increase was seen in all FAB subtypes, but particularly in RA. There was no significant increase in cluster formation, even in RAEB or RAEBt. Rh-SCF (10 ng/ml) led to mean increases of up to 26 times in the number of Epo-dependent BFU-E colonies, particularly in RA (p < 0.001) and RAEB (p < 0.05). Individual responses varied widely (especially in RA) from no response to supranormal levels. Added to the weekly refeed of 37 MDS LTBMC, SCF (10 ng/ml) induced only a 7% mean increase in both cell output and the number of clonogenic cells recovered in the supernatant. Immunohistochemical examination of the supernatant showed significant increases in differentiating myeloid cells in all examined cases, and in erythroid cells in 3 cases; blast cells increased in only 3 cases. These data suggest that rh-SCF is capable of at least partially reversing defective MDS myeloid haematopoiesis, and leads no overt risk of leukaemic transformation. Its potent effect on erythroid cells is encouraging for future clinical applications in patients, particularly if they are selected by means of in vitro tests.

Bone Marrow Cells↗
PubMed1990

[EDTA-induced pseudothrombocytopenia].

EDTA-induced pseudothrombocytopenia is a laboratory artifact caused in vitro by platelet aggregation, due to IgG or IgM class antibodies reacting with antigenic binding site of the GP IIb glycoprotein. Pseudothrombocytopenia is rarely found (about 1% of platelets counts), but must be considered in the differential diagnosis of thrombocytopenia, since it could lead to useless investigations and therapies. We report three patients with pseudothrombocytopenia, one of whom underwent bone marrow biopsy and danazol treatment, before establishing the correct diagnosis. The absence of hemorrhagic manifestations with persisting low platelets counts led to a re-examination of peripheral blood smear and to the diagnosis of pseudothrombocytopenia. Therefore a morphological platelets evaluation and their count on citrate-anticoagulated blood must be performed in every patient under assessment for thrombocytopenia.

Aged↗
PubMed1989

[A case of intestinal schistosomiasis with hepatic involvement: interdisciplinary diagnostic approach and peculiarity of the echographic and histologic findings].

We report a case of intestinal schistosomiasis; secondary hepatic involvement is particularly described, with a very distinctive ecographic feature of portal hypertension and a bioptic picture stressing a granulomatous periportal inflammation. In the work we emphasize the importance of a multidisciplinary approach (physicians working in the fields of internal medicine, infectious disease, gastrointestinal diseases, radiologist, pathologist) in the course of diagnostic investigation. Finally, we confirm the effectiveness of praziquantel against Schistosoma mansoni.

Adult↗
PubMed1986

[Changes in several immunological parameters and the presence of anti-HTLV III antibodies in drug addicts].

The immunological picture in a group of heroin addicts and in a methadone treated group was evaluated. Ninety-six per cent shows modifications of the lymphocyte pattern, independently of the type of opium derivative administered. The OKT4/OKT8 ratio considered one of the hallmarks of acquired immunodeficiency, turns out to be reduced in 64.6% of the cases. In these latter the most outstanding defect is made up by the T-helper drop (83.8% of cases), limited to 23.5% in the group with normal OKT4/OKT8 ratio. The most significant variant between the two groups is represented by the positivity of anti-HTLV III test, which switches from 47 to 74.1% in the patients with reduced ratio. Immunoglobulins turn out to be increased in 81.2% of the cases, independently of the opium derivative administered and without significant differences in relation to the OKT4/OKT8 ratio. Therefore two immunological patterns seem to coexist in the population studied, which very likely represents two evolutive moments of the same disorder with an earlier phase of hyperimmune condition from a persistent antigenic stimulation which characterizes the situation at risk. In a later phase, the impact of HTLV III infection causes the deletion of the lymphocyte helper subpopulation which elicits the immunodepressive situation.

Adolescent↗
PubMed1983

[Difference in the behavior of T-lymphocyte populations in heroin and methadone addicts].

An assessment of T-lymphocyte populations was performed in two groups of drug addicts by the technique of monoclonal antibodies. Group I was composed of 11 asymptomatic heroin addicts, group II being in heroin withdrawal program from at least six months. Homosexual subjects, partners of patients with AIDS and patients with liver abnormalities or with recent infectious diseases were excluded from the present study. In all the examined subjects the antibody pattern to Toxoplasma gondii, Epstein-Barr virus, Cytomegalovirus was either negative or slightly positive as after old infections. All subjects were HBsAg negative and HBsAb positive. Group I patients showed a significant inversion of OKT4/OKT8 ratio (p less than 0.01), due to a reduction in T helper lymphocytes (p less than 0.05) and an increase in T suppressors (p less than 0.05). Both groups showed a not significantly different proliferative response to Phytohemagglutinin (PHA) and Concanavalin A (Con A), although 8 out of 11 patients of group I exhibited a reduced proliferative response to PHA. Group I patients also showed a reduced proliferative response to Pokeweed mitogen (PWM). These results might suggest an involvement of B-lymphocytes in immunological changes of heroin addicts. In group II patient all the examined variables, OKT4/OKT8 ratio, absolute number as well as percentage of T-lymphocytes subpopulations and proliferative responses to the employed mitogens, resulted in the normal range. These data seem to exclude that methadone, in contrast with heroin, may induce a cell-mediated immunodepression.(ABSTRACT TRUNCATED AT 250 WORDS)

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

HIV-related thrombotic thrombocytopenic purpura (TTP) as first clinical manifestation of infection.

A case of thrombotic thrombocytopenic purpura (TTP) in a 40-year-old bisexual man unaware of being HIV positive is reported. The hematologic syndrome represented the first clinical manifestation of this viral infection. The clinical picture, characterized by severe hemolytic microangiopathic anemia, thrombocytopenia, fluctuating neurologic abnormalities and fever, quickly improved after plasma exchange and corticosteroid therapy. Two blood tests showed severe depletion of the CD4+ lymphocyte count and HIV antigenemia was positive. This case represents a clinical epiphenomenon of HIV infection in an advanced phase. According to recent CDC criteria the patient should be considered in AIDS. Antiretroviral treatment was started and after nine months of follow-up there has been no relapse.

Adult↗