Aberrant expression of B203.13 antigen in acute lymphoid leukemia of B-cell origin.

The B203.13 monoclonal antibody was developed by immunizing mice with the B/monocyte biphenotypic cell line B1b. During normal hematopoiesis B203.

Efficient platelet delta-granule release induced by [Ca2+]i elevation is modulated by GPIIbIIIa.

Intracellular Ca2+ elevation generates a cascade of events that leads to platelet activation and degranulation. The GPIIbIIIa-ligand molecular complex plays a central role in several aspects of platelet activation. Taking advantage of the flow cytometric simultaneous analysis of surface GPIIbIIIa expression and intracellular serotonin content, we demonstrate here that the functional inhibition of GPIIbIIIa generates an impairment of delta-granule release even upon maximal intracellular Ca2+ elevation.

Engagement of PI-3-kinase mediated protein kinase C zeta activation in protecting Friend cells from ionizing radiation-induced apoptosis.

Murine erythroleukemia cells (Friend) respond to ionizing radiation with the activation and nuclear translocation of p85alpha subunit of phosphatidylinositol-3-kinase (PI-3-kinase) which mediates the downstream activation and nuclear translocation of atypical Protein kinase C zeta (PKC zeta). This event occurs mainly upon high dose of ionizing radiation (15 Gy) and is concomitant to an increase in BrdU incorporation, which probably accounts for a predominant repair DNA synthesis. Following treatment with wortmannin, a relatively specific inhibitor of PI-3-kinase, both an increased number of apoptotic cells and the inhibition of protein kinase C zeta translocation were detected.

Noradrenergic and cholinergic innervation of the bone marrow.

Bone marrow is supplied by sensory and autonomic innervation. Although it is well established that hematopoiesis is regulated by cytokines and cell-to-cell contacts, the role played by neuromediators on the proliferation, differentiation and release of hematopoietic cells is still controversial. We studied the innervation of rat femur bone marrow by means of fluorescence histochemistry and immunohistochemistry.

Electromagnetic stimulation on the bone growth using backscattered electron imaging.

The events at the hydroxyapatite implant material/tissue interface following electromagnetic stimulation were studied in the rabbit. Two kinds of hydroxyapatite were used: natural (NA) and synthetic (HA) both with a grain size of <50 microm. Bone defects, artificially created in rabbit tibiae, were filled with the material examined.