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S Ono

Publications and source records attributed to S Ono.

At least 685 records · Page 38Linked to original sources
PubMed1987

Optimal positioning for CT examinations of the skull base. Experimental and clinical studies.

To evaluate the most appropriate CT angles for the skull base, four adult phantom skulls of various shapes were examined by CT. 15 osseous sites in each skull base were selected and the optimum angle for their delineation was determined. Using Reid's base line (0 degree), many sites could be imaged best at angles up to +20 degrees, and +10 degrees was found to be optimum. Examinations of patients using OM-line as a reference disclosed imaging rates in excess of 70% for sites other than the hypoglossal canal, the optic canal and foramen rotundum, which are in horizontal planes.

Adolescent↗
PubMed1986

Polyclonal B cell activation by a B cell differentiation factor, B151-TRF2. II. Evidence for interaction of B151-TRF2 with glycoprotein on B cell membrane via recognition of terminal N-acetyl-D-glucosamine residue(s).

We investigated the role of carbohydrates in the interaction of a B cell differentiation factor designated as B151-TRF2 derived from B151K12 T cell hybridoma with the corresponding receptor on B cells. Induction of polyclonal differentiation of unprimed B cells into IgM-secreting cells by B151-TRF2 was specifically inhibited by addition of N-acetyl-D-glucosamine (GlcNAc) but not by structurally unrelated monosaccharides such as D-galactose, D-glucose, and N-acetyl-D-galactosamine (GalNAc). Absorption of B151-TRF2 activity with spleen cells was specifically inhibited by the presence of GlcNAc. These results indicate that GlcNAc residues are involved in the interaction of B151-TRF2 with the receptor on B cells. To gain insight into mechanism by which GlcNAc inhibits B151-TRF2-mediated B cell responses, the existence of GlcNAc residues was examined on the B151-TRF2 molecule and the corresponding receptor on the B cell surface. The results revealed that B151-TRF2 molecule was not bound to various lectin-coupled agarose beads so far tested, suggesting absence of carbohydrate moieties on the B151-TRF2 molecule. By contrast, pretreatment of spleen cells with trypsin or glycosidase mixture abolished their ability to absorb B151-TRF2 activity. Moreover, B151-TRF2-absorbing ability of spleen cells disappeared by the pretreatment with beta-N-acetylglucosaminidase, which cleaves terminal GlcNAc. The fact that pnitrophenyl (PNP)-GlcNAc specifically inhibited such enzyme activity on target cells indicates that terminal GlcNAc on the B cell surface plays a crucial role in the interaction with B151-TRF2 molecule. Interestingly, it was also found that B151-TRF2 activity was trapped and eluted from GlcNAc-coupled agarose beads. Taken collectively, these results strongly suggest that B cell membrane receptors for B151-TRF2 comprise glycoproteins with a terminal GlcNAc residue(s), and that binding of B151-TRF2 with terminal GlcNAc on the receptor is important for the subsequent activation of B cells.

Acetylglucosamine↗
PubMed1986

Polyclonal B cell activation by B cell differentiation factor B151-TRF2. I. Involvement of self-Ia recognition process mediated by B cells.

The present study examined the functional role of Ia antigens on B cells in polyclonal B cell activation induced by a B cell differentiation factor, B151-TRF2. The polyclonal IgM PFC responses by B151-TRF2 were inhibited by monoclonal antibodies specific for class II MHC antigens (Ia antigens) but not class I MHC antigens. Such inhibition by anti-Ia antibodies was haplotype-specific and was observed in the absence of both T cells and accessory cells. Moreover, the anti-Ia antibody-induced inhibition of the B151-TRF2 responses was not due to the blocking of binding of B151-TRF2 to the corresponding B cell receptor. A series of kinetic studies revealed that some Ia-mediated cellular activation process occurs before the resting B cells become responsive to B151-TRF2. Thus, the B151-TRF2-mediated B cell responses consist of at least two distinct phases. The early phase is an Ia-dependent but B151-TRF2-independent process, whereas the late phase is an Ia-independent but B151-TRF2-dependent process. To further characterize the functional role of Ia antigens on B cells, an additional experiment was carried out by using F1 B cells which co-dominantly express both parental Ia antigens on the surface. Interestingly, it was observed that the degree of inhibition of the B151-TRF2-mediated responses of F1 B cells by anti-parental Ia antibody was, at best, one-half that of the parental B cells, suggesting that F1 B cells may be separated into two subpopulations with the restriction specificity for the respective parental Ia antigens. To examine this possibility, (B10 X B10.BR)F1 B cells were separated into adherent and nonadherent cell populations by their ability to bind to either one of the parental B cell monolayers, and the specificity of inhibition of their responses to B151-TRF2 by anti-Ia antibodies was assessed. It was found that the responses of (B10 X B10.BR)F1 B cells adherent to the B10 B cell monolayer or the B10.BR B cell monolayer were almost completely inhibited by anti-I-Ab and anti-I-Ak antibodies, whereas those of nonadherent cells were now selectively inhibited by anti-I-Ak and anti-I-Ab antibodies, respectively. These findings are interpreted as indicating that the B151-TRF2-responsive F1 B cells consist of at least two subpopulations with the restriction specificity for either one of the parental Ia antigens.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1986

Identification of two distinct factors, B151-TRF1 and B151-TRF2, inducing differentiation of activated B cells and small resting B cells into antibody-producing cells.

We demonstrated previously that cellfree supernatant of the B151K12 T cell hybridoma (B151-CFS) contained T cell-replacing factor (here in after referred to as B151-TRF1) capable of inducing growth and differentiation of antigen-activated B cells into antigen-specific plaque-forming cells (PFC). In the present study, we have identified in B151-CFS another unique lymphokine activity (referred to as B151-TRF2), which induces polyclonal differentiation of unstimulated B cells into IgM-secreting cells without concomitant stimulation of antigen, mitogen, or anti-Ig antibody. The B151-TRF2 activity induced polyclonal IgM PFC responses via the action on surface Ig-positive small resting B cells from normal unprimed mice. This activation was effective across an H-2 barrier, and apparently independent of the presence of T cells and accessory cells. Interestingly, the B151-TRF2 activity notably stimulated B cells of neonatal and mutant DBA/2Ha mice, which are nonresponders to B151-TRF1, whereas it failed to activate the xid B cells from CBA/N mice. To substantiate that B151-TRF1 and B151-TRF2 activities are mediated by mutually distinguishable molecules, an absorption experiment of B151-CFS was performed by utilizing DBA/2Ha B cells which are lacking in B151-TRF1 receptor. It was found that DBA/2Ha B cells could absorb B151-TRF2 activity but not B151-TRF1 activity. In contrast, murine chronic B cell leukemia BCL1 cells, which were shown to differentiate into IgM-secreting cells by stimulation with B151-CFS, selectively removed B151-TRF1 activity but not B151-TRF2 activity. Furthermore, biochemical analysis revealed that the B151-TRF2 was a heat (56 degrees C for 30 min)-sensitive protein with an apparent m.w. of 30,000 by gel filtration, whereas B151-TRF1 was a heat-resistant glycoprotein with m.w. of 50,000. In addition, it was shown that prostaglandin E2 selectively inhibited B151-TRF2-mediated B cell responses. These results demonstrate clearly that B151-TRF1 and B151-TRF2 are distinct B cell differentiation factors involved in the different activation pathways of distinct B cell subpopulations. The immunologic implication of B151-TRF2 activity in B cell differentiation is discussed in comparison with other lymphokines so far reported to activate small resting B cells.

Animals↗
PubMed1986

Evidence for existence of two distinct TNP-Ficoll-responsive B cell subpopulations preferentially reactive either to a T cell-replacing factor (B151-TRF) or to a signal from accessory cells.

The ability of B cells to respond to TNP-Ficoll has been shown to correlate with their ability to respond to T cell-replacing factor (TRF). The present study analyzed the relationship of TNP-Ficoll-responsive B cells to a TRF-responsive B cell subpopulation. The B cells from normal, unprimed mice responded to TNP-Ficoll in the presence of accessory cells. Such responses were notably augmented by the addition of TRF derived from a monoclonal T cell hybridoma, B151K12(B151-TRF). Interestingly, B cells of mutant X-linked immunodeficient DBA/2Ha which failed to respond to B151-TRF gave anti-TNP PFC responses to TNP-Ficoll comparable to those of normal mice, depending on the presence of accessory cells. However, under this condition, the addition of B151-TRF did not augment the TNP-Ficoll responses. One explanation of the augmentation of TNP-Ficoll response by TRF for the B cells from nondefective mice was that two distinct B cell subpopulations exist which differ in their respective activation requirement for TRF and accessory cells. To examine this possibility, syngeneic accessory cells were pulsed with TNP-Ficoll and were assayed for their ability to activate normal B cells in the presence or absence of B151-TRF. The results revealed that TNP-Ficoll-pulsed accessory cells were able to induce primary anti-TNP PFC responses in normal B cells to the same magnitude as soluble TNP-Ficoll. However, these B cell responses induced by the TNP-Ficoll-pulsed accessory cells were not augmented by the addition of B151-TRF to the culture. These results support the notion that two distinct TNP-Ficoll-responsive B cell subpopulations exist; one requires accessory cell-B cell interaction to be activated by TNP-Ficoll but fails to respond to TRF, and the other can be activated by TRF in a totally accessory cell-independent manner.

Animals↗