Biomedical subjects

G Marangoni

Publications and source records attributed to G Marangoni.

10 recordsLinked to original sources

PubMed2000

Morphologic, immunophenotypic and in vitro growth characteristics of blood and bone marrow associated with stem cell mobilisation in patients with lymphoma.

The proportion of CD34+ cells in the bone marrow (BM) is predictive of the size of progenitor cell mobilisation into the blood (PB). To investigate which other PB and BM parameters may be related to mobilisation, we analysed at steady state PB and BM of 23 patients with relapsed or resistant lymphoma before administering high-dose cyclophosphamide and G-CSF Cell morphology, number of CD34+ cells, and growth in clonogenic assay and in long-term cultures (LTC) were determined and then correlated with mobilisation extent (CD34+ and GM-CFC) and quality (growth of harvested cells in LTC). We found that the good mobilising patients (CD34 > 50 x 10(3)/ml, n=10) had several baseline BM characteristics (number of CD34+ MNC, GM-CFC, BFU-E, production of CFCs in LTC) similar to a group of 12 healthy controls, while patients with reduced mobilisation (CD34 < 50 x 10(3)/ml, n=13) had clearly reduced BM progenitors and LTC growth (p< 0.05). In a multivariate analysis including baseline clinical, blood and bone marrow characteristics, the most significant PB and BM factors independently associated with a higher number and/or quality of mobilised cells were a higher number of CD34+ and GM-CFC in the BM and a higher baseline haemoglobin, platelet, and CD34+ blood count. The capacity to release progenitor cells into the circulation is therefore not predicted by the distribution of morphologically distinguishable cells, marginally predicted by the BM content of highly undifferentiated cells (growth in long term culture), while it is proportional to the number of BM progenitors (CD34+, GM-CFC and BFU-E).

Adult↗

PubMed1999

Ornithine decarboxylase in colonic mucosa from patients with moderate or severe Crohn's disease and ulcerative colitis.

Polyamines, as well as ornithine decarboxylase (ODC), the enzyme involved in their synthesis, were reported to be closely related to cell proliferation. In Crohn's disease and ulcerative colitis, cell destruction and proliferation increase in the active stage. The aim of the present study was to determine the ODC in both involved and uninvolved areas of the colonic mucosa of active Crohn's disease and ulcerative colitis patients. The patients were divided in two groups, owing to the different level of activity (severe or moderate), by means of clinical endoscopy, laboratory, and histology evaluations. Subjects with suspected disease, but endoscopically unconfirmed, were used as controls. In all ulcerative colitis and Crohn's disease patients the ODC values both in involved and uninvolved mucosa were significantly lower than in controls. In severe Crohn's disease ODC was significantly reduced versus moderate Crohn's disease only in affected tissues. In all ulcerative colitis patients (moderate or severe) the ODC was significantly decreased in involved mucosa compared with uninvolved mucosa. Severe ulcerative colitis showed the significantly lowest ODC. We suggest that the significant decrease of ODC in the bowel mucosa is closely related to the severity of the disease. The highest decrease of ODC in ulcerative colitis patients would be due both to the enhanced cell destruction, and to the feed-back from exogenous increased polyamine production (bowel bacteria, cell desquamation). Therefore ODC would be considered a sensitive index of the inflammatory derangement of the mucosa, especially in acute ulcerative colitis. We conclude that this behaviour may result in an enhanced risk of neoplasia.

Adult↗

PubMed1998

Distribution of mobilized progenitor cells in the buffy coat of the haemonetics MCS3p cell separator: a study to optimize the collection of progenitors by leukapheresis.

Hematopoietic progenitor and stem cells for transplantation can be mobilized into the circulation and collected by leukapheresis. In this procedure, the leukocytes are distributed in the buffy coat along a density gradient, and the composition of the final product depends on which layer was collected. For the Haemonetics MCS3p Cell Separator, the manufacturer recommended starting the progenitor cell collection at a light transmission of 30%-40% (compared with plasma) and continue it for 40-50 ml. To optimize the use of this machine, the buffy coat it produces was studied in 12 patients by collecting it in fractions of increasing specific weight. Each fraction was analyzed by morphology, immunocytometry, and cell culture. We found that the buffy coat uniformly contains 8 times more leukocytes than blood, but the proportion of each white cell type varies along a gradient. The lymphocyte-predominant lighter layers are richer in CD34+ cells when compared with the granulocyte-predominant denser layers (6-14 times versus 2-4 times more than blood). The majority of CD34+ cells are found at a light transmission of 10%-70% (hematocrit 6-9). We conclude that cells for transplantation should be collected in a lighter fraction of the buffy coat than originally suggested by the manufacturer.

Antigens, CD↗

PubMed1970