Soluble factor-mediated differentiation of CD4+CD8+ thymocytes to single positives in vitro.

Although the thymic microenvironment provides the necessary elements for T-cell differentiation, the precise role of individual components remains to be determined. In this paper, attempts were made to address the possibility that CD4 or CD8 single-positive (SP) thymocytes could be developed from immature CD4+CD8+ (double-positive; DP) thymocytes in a suspension culture in the presence of soluble factors. We observed that IL-4 and IFN-gamma weakly induced DP cells to differentiate to CD4 cells, but not to CD8.

Expression and characterization of beta-1,4-galactosyltransferase from Neisseria meningitidis and Neisseria gonorrhoeae.

The lgtB genes that encode beta-1,4-galactosyltransferases from Neisseria meningitidis ATCC 13102 and gonorrhoeae ATCC 31151 were isolated by a polymerase chain reaction using the pfu DNA polymerase. They were expressed under the control of lac and T7 promoters in Escherichia coli M15 and BL21 (DE3). Although the genes were efficiently expressed in E.

A dipalmitoyl peptide that binds SH3 domain, disturbs intracellular signal transduction, and inhibits tumor growth in vivo.

The Src homology 3 (SH3) domain plays a crucial role in protein-protein interactions during intracellular signal transduction. Blocking the SH3-mediated protein binding may inhibit the corresponding signal transduction, and thus, block the cellular functions. In this study, a peptide that specifically binds to SH3 domain could be introduced into the intracellular region when the peptides were conjugated with dipalmitic acid and appeared to disturb intracellular signaling.

Cloned zebrafish by nuclear transfer from long-term-cultured cells.

Although mammals have been cloned from genetically manipulated cultured cells, a comparable achievement has not been realized in lower vertebrates. Here we report that fertile transgenic zebrafish can be obtained by nuclear transfer using embryonic fibroblast cells from long-term cultures. The donor nuclei, modified by retroviral insertions expressing green fluorescent protein (GFP), were transplanted into manually enucleated eggs.

Characterization of HLA-A2.1-restricted epitopes, conserved in both Hantaan and Sin Nombre viruses, in Hantaan virus-infected patients.

Nine different CTL epitopes, conserved in both Hantaan virus (HTNV) and Sin Nombre virus (SNV), were selected for study. The binding affinity of each peptide with HLA-A2.1 molecules in vitro was determined and antigen-specific responses from seven donors who had a previous field infection with HTNV were examined.

Investigation of antigen delivery route in vivo and imune-boosting effects mediated by pH-sensitive liposomes encapsulated with K(b)-restricted CTL epitope.

Using fluorescein isothiocyanate (FITC)-conjugated H-2K(b) CTL epitope (SIINFEKL) as a model system, we investigated the antigen delivery route by pH-sensitive liposomes in vivo. Fluorescence was initially detected in lymph nodes at 3 h after immunization, and its intensity reached a peak value in superticial inguinal lymph node at 9 h. No trace could be detected in spleen even with prolonged monitoring for up to 24 h.

Nitrous acid, nitrogen dioxide, and ozone concentrations in residential environments.

Nitrous acid (HONO) may be generated by heterogeneous reactions of nitrogen dioxide and direct emission from combustion sources. Interactions among nitrogen oxides and ozone are important for outdoor photochemical reactions. However, little is known of indoor HONO levels or the relationship between residential HONO, NO(2), and O(3) concentrations in occupied houses.

Residual Perchloroethylene in Dry-Cleaned Acetate: The Effect of Pressing and Extent of Inter-Dry-Cleaner Variability.

Measurements of residual perchloroethylene (PCE), a dry-cleaning solvent associated with human health effects, were made in dry-cleaned acetate cloth to enable improved characterizations of both occupational and environmental exposure. A limited sample size (25 acetate cloths) was used to explore the extent of inter-dry-cleaner variability in residual PCE and to characterize the effect of the pressing operation on residual PCE. A new method, which uses carbon-disulfide as the direct extracting agent, proved effective in the analysis of residual PCE, with a recovery-efficiency ≈ 75%.