Selective diapedesis of Th1 cells induced by endothelial cell RANTES.

Differentiated CD4 T cells can be divided into Th1 and Th2 types based on the cytokines they produce. Differential expression of chemokine receptors on either the Th1-type or the Th2-type cell suggests that Th1-type and Th2-type cells differ not only in cytokine production but also in their migratory capacity. Stimulation of endothelial cells with IFN-gamma selectively enhanced transmigration of Th1-type cells, but not Th2-type cells, in a transendothelial migration assay. Enhanced transmigration of Th1-type cells was dependent on the chemokine RANTES produced by endothelial cells, as indicated by the findings that Ab neutralizing RANTES, or Ab to its receptor CCR5, inhibited transmigration. Neutralizing Ab to chemokines macrophage-inflammatory protein-1alpha or monocyte chemotactic protein-1 did not inhibit Th1 selective migration. Whereas anti-CD18 and anti-CD54 blocked basal levels of Th1-type cell adherence to endothelial cells and also inhibited transmigration, anti-RANTES blocked only transmigration, indicating that RANTES appeared to induce transmigration of adherent T cells. RANTES seemed to promote diapedesis of adherent Th1-type cells by augmenting pseudopod formation in conjunction with actin rearrangement by a pathway that was sensitive to the phosphoinositol 3-kinase inhibitor wortmannin and to the Rho GTP-binding protein inhibitor, epidermal cell differentiation inhibitor. Thus, enhancement of Th1-type selective migration appeared to be responsible for the diapedesis induced by interaction between CCR5 on Th1-type cells and RANTES produced by endothelial cells. Further evidence that CCR5 and RANTES play a modulatory role in Th1-type selective migration derives from the abrogation of this migration by anti-RANTES and anti-CCR5 Abs.     

Synthèse Facile de Pyrazines Disubstituées en 2 et 31)

Corynebacterium equi IFO 3730 was found to oxidize a wide variety of sec-alcohols, including alkanols, substituted alkanols, alkenols and cyclic alcohols, in moderate to high yields. Among them, the sec-alcohols which have longer carbon chains were oxidized more smoothly than those with smaller numbers of carbon. Although both enantiomers of unsymmetrically disubstituted carbinols were oxidized, the S form of 2-dodecanol was converted to the corresponding ketone a little faster than the other enantiomer.     

Localization of carbonic anhydrase in the rat lung

Summary The localization of carbonic anhydrase in the rat lung has been demonstrated, at light and electron microscopic levels, by the cobalt bicarbonate histochemical method of Hansson. Focal deposits of the cobalt sulfide reaction product were found not only in the capillary endothelium of the alveolar walls, but also in the small and large alveolar cells. The histochemical reaction was abolished by two potent inhibitors, acetazolamide (10^–5 to 10^–6 M) and KCNO (5×10^–3 to 10×10^–3 M). Physiological assay with Maren's method indicated that values for carbonic anhydrase activity in rat lung are 4.4±0.8 UA/mg of protein, 25.0±5.5 UA/mg of nitrogen, and 369±86 UA/g of wet weight. In addition, it was calculated that after fixation in glutaraldehyde-formaldehyde-picric acid about 9% activity is retained.     

The calcium-binding property of equine lysozyme

It was found that equine lysozyme binds one Ca2+. It was eluted with equimolar Ca2+ from a Bio-Gel P-4 column. Human lysozyme did not behave similarly. Equine lysozyme is concluded to be a calcium metallo-protein like alpha-lactalbumin, which is a homologue of hen egg white lysozyme.     

Conformational change of bovine serum albumin by heat treatment

The thermal denaturation of bovine serum albumin (BSA) was studied at pH 2.8 and 7.0 in the range of 2–65°C. The relative proportions of -helix, -structure, and disordered structure in the protein conformation were determined as a function of temperature, by the curve-fitting method of circular dichroism spectra. With the rise of temperature at pH 7.0, the proportion of -helix decreased above 30°C and those of -structure and disordered structure increased in the same temperature range. The structural change was reversible in the temperature range below 45°C. However, the structural change was partially reversible upon cooling to room temperature subsequent to heating at 65°C. On the other hand, the structural change of BSA at pH 2.3 was completely reversible in the temperature range of 2–65°C, probably because the interactions between domains and between subdomains might disappear due to the acid expansion. The secondary structure of disulfide bridges-cleaved BSA remained unchanged during the heat treatment up to 65°C at pH 2.8 and 7.0.     

Division and gametophytic tissue formation from protoplasts of young sporophytes in fern Lygodium japonicum

Protoplasts isolated enzymatically from juvenile leaflets of sporophytes in fern Lyqodium japonicum were inoculated in a MS medium containing NAA 2.7 m, BAP 2.2 m, 0.6 M mannitol, and 0.05 M sucrose. Cell division took place within 8 days of culture initiation, and after 30 days cell-clusters with 10–15 cells were observed. When the cell-clusters were transferred into fresh hormone-free medium containing no mannitol, they developed rhizoids and protonema-like regenerants. About 2 months later, cordate prothallia developed bearing both antheridia and archegonia.Abbreviations MS Murashige and Skoog (1962) - NAA naphthalene acetic acid - BAP 6-benzylaminopurine     

C1q,a collagen-like complement subcomponent,in dermatosparactic cattle: its extracellular modification is not affected by lack of procollagen N-terminal proteinase (pN-proteinase)

C1q, a collagen-like complement protein, was purified from the serum of a ddermatosparactic calf which lacks procollagen N-terminal proteinase (pN-proteinase). The specific hemolytic activity of the serum Clq from the dermatosparactic animal was identical to that of C1q from a normal calf. Gel-filtration of serum from dermatosparactic calf, on Sepharose 6B, showed the presence of C1q-antigenic material at only one position which was identical to the elution position of normal bovine C1q. No differdence, under dissociating conditions, could be seen in the size of the chains of C1q in specific immunoprecipitates isolated from the sera of dermatosparactic and normal animals, as judged by polyacrylamidegel electrophoresis (PAGE) in the presence of sodium dodecyl sulfate (SDS). The C1q from the dermatosparactic animal showed the same N-terminal amino acid and typtic-digest peptide pattern on HPLC as C1q from the normal calf. These results strongly suggest that pN-proteinase is not involved in the extracellular processing of C1q.     

Behavior of chloroplasts and chloroplast nuclei during spermatogenesis in the fern,Pteris vittata L.

Summary The fate of the chloroplasts and chloroplast nuclei (cp-nuclei) was followed during spermatogenesis in the fernPteris vittata L. by epifluorescence microscopy after staining with 4-6-diamidino-2-phenylindole (DAPI) and by quantitation of chloroplast DNA (cp-DNA) by fluorimetry using a video intensified microscope photon counting system (VIMPICS). The spores were grown on solid medium that contained antheridiogen (An_ptd), and formed an antheridium initial on the protonema cell. The antheridium initial divided and produced 16 spermatocytes and 3 surrounding cells. The chloroplasts in the spermatocytes decreased in volume as cell division was repeated, until finally the volume of each chloroplast was 1/15 of that of the primary chloroplasts. The DNA content of the chloroplasts was also reduced to 1/5 of the original value and when the sperm matured, the fluorescence of cp-DNA disappeared. In the 16-cell spermatocyte, the recognition of the fluorescence of chlorophyll in the chloroplasts with a green excitation filter became difficult. But, the plastids could be observed until the final stage of the sperm. From these observations, it appears that there are two steps in the metamorphosis of chloroplasts during spermatogenesis in the fern. The first step involves the decrease in the volume of chloroplasts, accompanied by reduction of the DNA content, and the second step involves the change of the physical state of chloroplasts to amyloplasts and the disappearance of the cp-DNA from the amyloplasts.     

Comparative study of embryonic thermoresistance of two inbred strains of the medaka (Oryzias latipes)

Summary By using inbred strains (HO4C and HB32C) of the medaka,Oryzias latipes, the involvement of genetic factor(s) in the determination of thermoresistance of fish was investigated. The thermoresistance of embryos of the medaka was quantitated by the fraction of the embryos surviving 1 day after heat treatment. At early stages of development (st. 13 and st. 20–21), the HO4C strain was more resistant than the HB32C strain. At st. 20–21, the HO4C strain was more resistant than the HB32C strain at all temperatures used (42, 43, and 44°C). At later stages of development (st. 27 and st. 32), however, the HB32C strain was more resistant than the HO4C strain.The results of genetic cross experiments raised the following possibilities; the thermoresistance of embryos at early developmental stages can be lowered by some factor(s) inherited in the HO4C strain and/or increased by those in the HB32C strain. By contrast, the sensitivity of embryos at later stages of development was not affected by factor(s) of their parents, but by their own genetic constitution.