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Biomedical subjects

P Leoni

Publications and source records attributed to P Leoni.

At least 127 records · Page 7Linked to original sources
PubMedDate not supplied

Bone marrow histopathological and molecular changes of small B-cell lymphomas after rituximab therapy: comparison with clinical response and patients outcome.

This study correlates bone marrow changes after Rituximab (RTX) treatment with the clinical characteristics and outcome of 26 patients with small B-cell lymphomas. The percentage, phenotypic profile and clonality pattern of bone marrow lymphoid infiltrate were analysed before and after RTX treatment. Clinical, histological and molecular responses to RTX were correlated to the clinical outcome of the patients. Sixteen out of twenty-six patients obtained a complete clinical remission (CR). A favourable histology--follicular lymphoma (FL), hairy cell leukaemia (HCL) and marginal zone lymphoma (MZL)--was associated with a higher frequency of clinical CR and histological remission (HR), in comparison with mantle cell lymphoma (MCL), chronic lymphocytic leukaemia (CLL) and lymphoplasmacytic lymphoma (LPL). Two patterns of bone marrow HR were observed: 1) complete lymphoid cell disappearance (9 patients); or 2) nodular/interstitial T-cell infiltration (10 patients). Three histological persistence (HP) patterns were observed: 1) persistence of CD20+ small lymphoid cells in 1 patient with MCL; 2) loss of CD20 antigen expression in 4 patients with CLL; or 3) persistence only of clusters of monotypic plasma cells in 2 patients with LPL. CR and HR were strongly correlated. The percentage of lymphomatous infiltrate after RTX was higher in patients who subsequently died of the disease. Molecular response showed no correlations with the further clinical course in 12 patients achieving a complete clinical remission. In conclusion, bone marrow morphological and immunohistochemical analysis with a restricted panel of antibodies is useful to avoid 42% false positive and 85% false negative interpretations. Persistence of monoclonality after RTX might have a role in evaluating the molecular pattern of CD20-negative clones that can emerge after RTX as a tumoral escape to therapy.

Adult↗
PubMedDate not supplied

Ultrasonographic detection of portal branches and hepatic vein gas associated with mesenteric artery occlusion: a new finding correlated with patient prognosis?

The diagnosis of bowel infarction is still a challenge. In some cases, portal venous gas is an associated feature and in these patients, the prognosis is very poor. We report on our experience with two consecutive cases in which ultrasonography showed gas in the portal venous branches, and also in the hepatic veins in one of them. At laparotomy, advanced bowel necrosis was found, and both patients died within 24 hours. Other cases of portal venous gas associated with bowel infarction have been reported, but this is the first report of gas also being found in the hepatic veins. There may be a relationship between the amount of gas in the intrahepatic veins and the stage of bowel ischemia. Confirmation of this might improve the selection of patients and eliminate unnecessary procedures.

Aged↗
PubMedDate not supplied

Platelet abnormalities in idiopathic myelofibrosis: functional, biochemical and immunomorphological correlations.

BACKGROUND: An extensive study of platelet function was performed on 18 consecutive patients affected by idiopathic myelofibrosis (IM). MATERIALS AND METHODS: Clinical hematological and morphofunctional parameters were studied in IM patients and control subjects. Platelet tests, ultrastructural data, immunocytochemical von Willebrand factor detection, freeze fracturing results and free cytosolic calcium level were evaluated. RESULTS: Bleeding time was frequently found to be prolonged, but it never reached levels which could give any cause for concern. Aggregation by ADP, collagen and epinephrine was always altered, sometimes profoundly; on the contrary, agglutination by ristocetin was almost always normal, albeit occasionally increased. Plasma beta-TG and PF4 levels were found to be elevated in 11 and 12 patients, respectively. This indicated an abnormal release from platelet alpha-granules. Depletion of alpha-granules was also confirmed by the intraplatelet von Willebrand factor (vWF) labelling with colloidal gold particles bound to polyclonal antibodies against human vWF. In fact: 1) the number of positive alpha-granules/microm2 and per single platelet was reduced; 2) the intensity of the immunocytochemical reaction for single positive alpha-granules and for each platelet was significantly reduced. Freeze-fracturing studies showed an increase in the number of intra-membrane particles (IMP) on the P face of the platelet membrane with respect to normal platelets preincubated with ADP. However, no differences in their distribution or diameter were observed. High concentrations of free cytosolic calcium were always found and Ca++ ATPase activity was increased. Conversely, Na+/K+ ATPase activity was always reduced. CONCLUSIONS: We can hypothesize that the platelet membrane is altered in IM, resulting in facilitated activation, even by subliminal stimuli, and that this continuous platelet activation ultimately leads to alpha-granule depletion.

Adenosine Diphosphate↗
PubMedDate not supplied

Fluconazole resistance of Candida krusei.

We present a case of young male treated for a recurrence of Acute Non Lymphoid Leukemia who presented a colonization by C. krusei during prophylaxis with Fluconazole. The fever episode, which he developed while neutropenic, was resolved with the addition of Amphotericin B after the failure of empiric antibiotic therapy. No isolation was performed in blood cultures. A second cycle of antiblastic chemotherapy was needed because of the resistance shown to the first. Despite the prophylaxis with Fluconazole a stream of C. krusei grew in all the blood cultures collected while febrile. Amphotericin B administered did not control the fungemia. We discuss the resistance of C. krusei to Fluconazole.

Adult↗
PubMedDate not supplied

Treatment of autoimmune thrombocytopenic purpura.

One hundred and two patients with newly diagnosed autoimmune thrombocytopenic purpura (ATP) were treated with prednisone (1.5-2 mg/kg/day for 4 weeks). A favourable response, lasting more then 12 months, was obtained in 22,5% of the cases. Different therapeutic strategies, such as immunosuppressive drugs, high dose immunoglobulins, splenectomy and others, were applied in unresponsive or relapsed patients. In our case study, splenectomy has proved the most satisfactory (87% of positive results) thus representing, in our opinion, the only effective therapy for resistant or relapsed case.

Azathioprine↗
PubMedDate not supplied

Intensive polychemotherapy experience in chronic myeloid leukaemia.

A pilot study, testing two different chemotherapeutic schedules in CML patients, was carried out in order to verify the possibility of Ph1 clone disappearance. Both therapeutic regimens, though able to induce severe marrow aplasia, determined only a reduction of Ph1 positive metaphases in two patients, while in one case no response could be detected. Therefore we believe that chemotherapy alone is probably not sufficient to eradicate the Ph1 malignant clone.

Adult↗
PubMedDate not supplied

[Idiopathic myelofibrosis. Main pathogenetic, prognostic and therapeutic aspects].

Primary myelofibrosis is a complex disorder characterized by bone marrow fibrosis with no apparent cause. It is known in literature under a wide number of terms, reflecting the variety of clinical features and the different pathogenetic hypotheses. In most cases it is plain that marrow fibrosis is secondary to a clonal myeloproliferative disorder and, in particular, to the presence of abnormal megakaryocytes secreting (MKDGF/PDGF); but probably some other growth factors synthesized by megakaryocytes and contained in platelet alpha-granules are involved. The molecular event that determines the advantage of the clonal growth is, at present, unknown, and the pathogenetic importance of some chromosome anomalies is still under discussion. Over the last years, besides megakaryocyte dysplasia, several fibrogenetic mechanisms such as a bone marrow immune damage have been taken into consideration. Studies on prognostic factors regarding the main clinical, hematological and histological parameters have given conflicting results, because of low incidence of the disease, different criteria used for the diagnosis, and different terms of the clinic presentation of the pathology. Although a great deal of progress has been made in terms of pathogenetic mechanisms, a lot of questions must be still definitively settled, further in depth studies still have to go into many matters.

Age Factors↗