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Biomedical subjects

P Leoni

Publications and source records attributed to P Leoni.

At least 91 records · Page 5Linked to original sources
PubMed1990

Intermediate filaments in smooth muscle from pregnant and non-pregnant human uterus.

The intermediate filament proteins desmin and vimentin from pregnant and non-pregnant uterine muscle and smooth-muscle cells in culture were analysed using SDS/PAGE. The desmin content in uterine muscle increases dramatically during pregnancy, whereas vimentin remains unchanged or changes very little. When muscle cells are kept in culture, a considerable increase in vimentin content is observed as compared with vimentin in freshly isolated non-pregnant uterine tissue. Our results strengthen the view that vimentin and desmin filaments have independent function and turnover, and point to a predominantly structural role for desmin filaments.

Blotting, Western↗
PubMed1990

Idarubicin and high-dose cytarabine in the treatment of refractory and relapsed acute lymphoblastic leukemia.

Between August 1985 and April 1989, 88 patients (31 children and 57 adults) with refractory of relapsed acute lymphoblastic leukemia (ALL) were treated in a cooperative Italian trial by an induction schedule of high-dose Cytarabine (HDAra-C) plus Idarubicin (IDA). Complete remission (CR) was achieved in 52 of the 88 patients (59%); 23 patients (26%) did not respond to treatment and 13 (15%) died during induction. The CR rate was significantly affected by the WBC count at the beginning of treatment and by the duration of first CR of the patients treated at first relapse. All of the patients experienced profound myelosuppression; the median time to recovery to neutrophils greater than 0.5 x 10(9)/l was 15 days (range 4-40), and 14 days (range 3-50) to platelets greater than 50 x 10(9)/l. The most common non-hematologic side effects observed were nausea and vomiting (51%), mucositis (40%) and diarrhea (23%). Twenty-one of the 52 patients who achieved CR underwent bone marrow transplantation (BMT), 16 autologous and 5 allogeneic. Eleven patients relapsed at a median of 4 months (range 1-31) after the transplantation, and three patients died while in CR. Seven patients have been in continuous CR (CCR) for a median of 36 months (range 26-42 months). Thirty-one patients were not entered in the BMT program: for two adults it was too early, three adults died in CR and 25 patients relapsed at a median of four months (range 1-25). Only one adult is still in CCR at 33 months.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

[Color Doppler in the echographic evaluation of breast nodules].

The authors report on their experience with color Doppler sonography in the diagnosis of solid breast masses. Twenty-two patients were examined; breast masses were studied with B-mode US first, and then with color Doppler US to evaluate eventual tumor vascularization. Color Doppler US demonstrated only one vascular pole in histologically confirmed benign masses. On the contrary, in 92.8% of histologically confirmed malignant masses, color Doppler easily depicted 2 or more groups of nutritional arteries. Color Doppler makes the diagnosis of malignant masses easier, thus allowing, in the author's opinion, a reduction in the number of biopsies of solid breast masses clinically/mammographically detected. The use of color Doppler US is therefore suggested: the technique is noninvasive, fast, and easy and its widespread use would translate into advantages for both the patient and the clinician.

Adenofibroma↗
PubMed1989

High-dose Ara-C (HiDAC) plus asparaginase in elderly patients with acute non-lymphocytic leukemia: a pilot multicentric study by the Italian Cooperative Group GIMEMA.

A multicentric prospective pilot study using three different schedules of high-dose Ara-C at dosage of 3 g/m2 every 12 hours during 3 h of infusion was undertaken by the Italian Cooperative Group GIMEMA in order: 1. to evaluate the safety and efficacy of such treatment in previously untreated ANLL patients more than 50 years old; 2. to investigate whether the addition of a standard maintenance treatment after consolidation with 4 courses of DAT (Daunorubicin + Ara-C + 6-Thioguanine) could improve the duration of complete remission (CR) and the proportion of long-term survival. Overall 43/125 evaluable patients (34.4%) achieved CR. 32/125 died during the induction phase, the remaining 50 patients (40%) failed to achieve CR. As for the toxicity, the most significant toxicity of all schedules was hematologic. No substantial neurological or cardiac toxicity was observed. The multivariated analysis of several pretreatment characteristics revealed that age more than 60 yr, male sex and presence of infections at diagnosis were the most significant adverse factors for achievement of CR. The median duration of DFS for all responders was 9 months, with relapse-free survival at 4 yr estimated at 29%. The addition of maintenance treatment to consolidated patients had no advantages in respect to the control group, even though the statistical analysis revealed a p = 0.058. However, because of the small number of randomized patients, no conclusions can be drawn concerning the importance of maintenance treatment.

Aged↗
PubMed1987

Prognosis in chronic lymphocytic leukemia: a retrospective multicentric study from the GIMEMA group.

Clinical and biological data were evaluated using Desu univariate analyses or Cox multivariate analyses in a series of 1,777 chronic lymphocytic leukemia (CLL) patients from an Italian Cooperative Group. In univariate analyses, age and sex of patients, presence of bone marrow (BM; greater than or equal to 50%), and peripheral blood (PB; greater than or equal to 60,000/microL) lymphocytosis, anemia (hemoglobin [Hb] less than 11 g/dL), thrombocytopenia (less than 100,000/microL), direct Coombs' test positivity, hepatomegaly, splenomegaly, and extent of lymph node involvement were shown to be of significant prognostic value. Multivariate analyses, through a stepwise procedure, showed that the most important prognostic variables are Hb, hepatomegaly, lymph node involvement, PB lymphocytosis, and age and sex of patients. Further covariates would produce an improvement having a nonsignificant P value. Based on the results of multivariate analyses, a four-step staging using the significant variables of the Cox model is proposed.

Adult↗
PubMed1985

An intracellular pool of the procoagulant thromboplastin in human monocytes.

Human monocytes cell extracts have been analysed by density gradient centrifugation in Percoll gradients. Two peaks of activity of the plasma membrane marker enzyme 5' nucleotidase were detected. The main peak was at a density of 1.040 and a secondary one at a lower density. Thromboplastin activity was recovered associated with the main peak of 5' nucleotidase activity in control cells. In NH4Cl treated cells, thromboplastin activity is found at both densities. In agreement with this, labelling of the cell surface with 125I shows a reduction in availability of proteins for labelling between control and NH4Cl treatment. The availability of thromboplastin in monocytes for attack by exogenous trypsin or for initiation of coagulation is also reduced by cultivation with amines. We suggest that the low density peak of 5'nucleotidase and thromboplastin represents an intracellular compartment.

5'-Nucleotidase↗
PubMed1985

Effect of additives on liposomes: an electric birefringence study.

Under the influence of an electric field, vesicles in suspension partially deform or orientate, rendering the medium optically birefringent. The amplitudes of the birefringence under fields of variable amplitude lead to evaluation of the anisotropy of the electrical delta alpha and optical delta G polarisabilities of the vesicles. By using pulsed fields, rates of establishment and decay of birefringence enable vesicle sizes d to be measured. Samples of 9:1 phosphatidylcholine-phosphatidylserine liposome suspension in water were studied in the presence of various additives, including sucrose, an antibiotic (streptomycin), a steroid (dexamethasone), an anaesthetic (lignocaine) and a fluidising agent (benzyl alcohol). The changes in the three parameters delta alpha, delta G and d were different for each additive and are thought to be indicative of the mode of interaction of each. Electric birefringence also appears to be a rapid means of detecting structure changes.

Benzyl Alcohol↗
PubMed1984

Cell surface events which may initiate lysosomal enzyme secretion by human monocytes.

Freshly isolated and subsequently matured human monocytes secreted lysosomal hexosaminidase in response to exposure to IgG-Sepharose, but not certain derivatized control Sepharoses. The cells bound selectively to the surface of IgG-Sepharose (and not the control Sepharoses) but because of the large size of the particles, could not ingest them. Since the soluble IgG was covalently linked to the Sepharose and free soluble IgG was not an inducer of secretion, the secretion was thus induced directly at the cell surface. Zymosan, a yeast cell wall particle which contains a mannan, was also able to induce secretion in the various monocyte stages under study. It could even bind to the cell surface of fresh monocytes which lacked the receptor for mannose-terminated glycoproteins, and induce secretion in these cells. The mannose receptor appeared as monocytes matured, and the Ir number on the surface was increased by the action of lymphokines. Although zymosan-induced secretion could be inhibited by mannose and certain other sugars, these seemed to have some complex metabolic effects in human monocytes (which previous work with mouse macrophages has not revealed). Thus, it was not possible to demonstrate whether zymosan could initiate secretion directly by interaction at the monocyte surface mannose glycoprotein receptor.

Cell Membrane↗
PubMed1984

Regulation of procoagulant factors in mononuclear phagocytes.

Mononuclear phagocytes can be activated to develop enhanced expression of a wide range of macromolecules and mediators. Amongst these are several procoagulants, most notably thromboplastin. A variety of stimuli (particles, ligands for cell surface receptors, and some pharmacological agents) enhance procoagulant expression. We indicate that such enhancement may contribute to intra-and extravascular coagulation in several types of infections. We also point to the paucity of knowledge on the biosynthesis and intracellular transport of these procoagulants and speculate on the nature of the mechanisms involved.

Animals↗