395 research outputs found
Mesenchymal stromal cells, from indifferent spectators to principal actors. Are we going to witness a revolution in the scenario of allograft and immune-mediated disorders?
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PSA-NCAM in the developing and mature thalamus
No full textThe polysialylated form of the neural cell adhesion molecule (PSA-NCAM) is involved in several morphogenetic processes of the central nervous
system. In the present study the expression of PSA-NCAM has been investigated in the rat thalamus during embryonic and postnatal development
using light and electron microscopic immunocytochemical techniques. At all the examined ages, PSA-NCAM staining in the thalamus was mainly
observed along neuronal plasmatic membranes and absent in astrocytes identified by labelling with cytoskeletal (vimentin and glial fibrillary
acidic protein) and membrane (GABA transporter-3) markers. At embryonic day 14 the immunoreactivity was restricted to the dorsal thalamic
mantle and to the region of reticular thalamic migration and subsequently it extended throughout the whole thalamic primordium. PSA-NCAM
labelling remained intense and homogeneously distributed along perinatal period, but from P4 it began to decrease selectively, persisting throughout
adulthood only in the reticular nucleus, ventral lateral geniculate nucleus and midline and intralaminar nuclei. The expression of this adhesion
molecule differed in areas characterized by the presence of neurons containing distinct calcium binding proteins, as PSA-NCAM labelling was
intense around calretinin-positive neurons, whereas it decreased in some calbindin-immunoreactive regions.
These findings show evidence of a selective neuronal expression of PSA-NCAM in developing thalamus, supporting its suggested role in cell
migration and synaptogenesis as it occurs in the cerebral cortex. In adulthood PSA-NCAM could instead be a marker of thalamic nuclei that retain
a potential for synaptic plasticity
Phenotypic and functional heterogeneity of human NK cells developing after umbilical cord blood transplantation: a role for human cytomegalovirus?
No full textNatural killer (NK) cells play a crucial role in early immunity after hematopoietic stem cell transplantation because they are the first lymphocyte subset recovering after the allograft. In this study, we analyzed the development of NK cells after intrabone umbilical cord blood (CB) transplantation in 18 adult patients with hematologic malignancies. Our data indicate that, also in this transplantation setting, NK cells are the first lymphoid population detectable in peripheral blood. However, different patterns of NK-cell development could be identified. Indeed, in a group of patients, a relevant fraction of NK cells expressed a mature phenotype characterized by the KIR+NKG2A- signature 3-6 months after transplantation. In other patients, most NK cells maintained an immature phenotype even after 12 months. A possible role for cytomegalovirus in the promotion of NK-cell development was suggested by the observation that a more rapid NK-cell maturation together with expansion of NKG2C+NK cells was confined to patients experiencing cytomegalovirus reactivation. In a fraction of these patients, an aberrant and hyporesponsive CD56-CD16 +p75/AIRM1-NK-cell subset (mostly KIR +NKG2A-) reminiscent of that described in patients with viremic HIV was detected. Our data support the concept that cytomegalovirus infection may drive NK-cell development after umbilical CB transplantation. © 2012 by The American Society of Hematology
Erythropoiesis in myelofibrosis with myeloid metaplasia: recognition of different classes of patients by erythrokinetics.
No full textA quantitative assessment of erythropoiesis was performed by means of a mathematical model of iron kinetics in 26 patients with myelofibrosis with myeloid metaplasia (MMM). A direct relationship between total erythropoiesis and red cell volume was revealed. This 'inverse' characteristic of erythropoietic control was the best marker of the proliferative nature of the disease. Three classes of patients were singled out by means of a cluster analysis of the erythrokinetic parameters. In class I (11 patients) the red cell volume was above the predicted normal in all but two patients. Erythropoiesis was sustained at 5--10 times the normal levels with a high degree of ineffective erythropoiesis. A fairly constant absence of erythroid activity over the sacral marrow was demonstrated. In class II most of the 12 patients had a decreased red cell volume. Erythropoiesis was sustained at 2--4 times the normal level with a high degree of peripheral haemolysis. Erythroid activity was recognized over the sacral area in all but two patients. The three patients of class III showed a pattern of erythroid failure and had the worst prognosis. It is suggested that these classes represent separate disease forms of MMM
Spontaneous exodus of high numbers of normal early progenitor cells (Ph-negative LTC-IC) in the peripheral blood of patients with chronic myeloid leukaemia at the beginning of the disease.
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