Time-resolved measurements of FT-IR and Raman spectra and X-ray diffraction have been performed to trace the structural changes in the solvent-induced crystallization of syndiotactic polystyrene glass sample. After the exposure of the glassy sample into the atmosphere of such organic solvent as toluene, benzene, or chloroform, the IR and Raman bands characteristic of the regular helical conformation of (T2G2)2 type were found to increase the intensities with time. Some time delay was found for the appearance of the bands with different critical sequence lengths, leading to the concrete description of the growth of regular helical chain from the random coil. The X-ray scattering intensity began to increase largely at the timing of the appearance of the IR and Raman bands of long helical sequences, indicating that the crystal lattice starts to be formed at the timing when the long segments of regular helical form are gathered together. The rate of this crystallization process depends on the kind of the used solvent. The factors governing this difference have been discussed.

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Hemophagocytic lymphohistiocytosis (HLH) is characterized by uncontrolled activation of T cells and macrophages with overproduction of cytokines. Familial HLH type2 (FHL2) is the most common form of primary HLH and is caused by mutations in PRF1. We have recently described a significant increase in the subpopulation of CD8 + T cells with clonal expansion and CD5 down-regulation in Epstein-Barr virus associated-HLH, which represented a valuable tool for its diagnosis. However, this unusual phenotype of CD8 + T cells has not been investigated fully in patients with FHL2. We performed immunophenotypic analysis of peripheral blood and measured serum proinflammatory cytokines in 5 patients with FHL2. All patients showed significantly increased subpopulations of activated CD8 + T cells with down-regulation of CD5, which were negligible among normal controls. Analysis of T-cell receptor Vβ repertoire suggested the reactive and oligoclonal expansion of these cells. The proportion of the subset declined after successful treatment concomitant with reduction in the serum levels of cytokines in all patients except one who continued to have a high proportion of the subset and died. These findings suggest that down-regulation of CD5 on activated CD8 +

Solvent-induced crystallization behaviour has been investigated for the glass sample of syndiotactic polystyrene. The time-resolved measurements of the Fourier-transform infrared and Raman spectra and the X-ray diffraction profile revealed the molecular and crystal structural change during the ordering process of polymer chains. On the basis of the idea of critical sequence length, the structural change in the conformational ordering process could be deduced. The crystallization rate was found to be affected remarkably by the kind of solvent: chloroform gave higher crystallization rate than benzene and toluene. This tendency was in contrast to that observed for the gelation process from the dilute solution: the gelation rate was chloroform << benzene. This high contrast between the crystallization and gelation rates could be interpreted qualitatively in terms of the difference in the solubility of polymer in these solvents.

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