Participation of CD14 in the Phagocytosis of Smooth-Type Salmonella typhimurium by the Macrophage-Like Cell Line,J774.1

The role of CD14 in the phagocytosis and killing of microorganisms was investigated using macrophage-like cell lines, CD14-positive J774.1 cells and CD14-negative mutant J7.DEF3 cells derived from J744.1 cells. The cells were infected with Salmonella typhimurium organisms of the smooth (S)-form LT2, mutant rough (R)-form TV148 or Staphylococcus aureus 248βH. At 30 or 180 min incubation, the cells were washed and disrupted. Colony-forming units (CFUs) liberated from the disrupted cells were determined by quantitative cultivation, and the phagocytic index and killing rate were calculated. Both the phagocytic index and killing rate of J774.1 cells against LT2 organisms were greater than those of J7.DEF.3 cells. However, the index and rate of J774.1 cells against TV148 and 248βH organisms were similar to those of the J7.DEF.3 cells. The phagocytosis of LT2 organisms by J774.1 cells was partially inhibited by S-form LPS (S-LPS) and anti-CD14 antibody, but not by R-chemotype LPS (R-LPS). These results suggest that CD14 participates in the phagocytosis of S-form Salmonella.     

Factors affecting carbohydrate and free amino acid content in overwintering larvae of Enosima leucotaeniella

Amounts of several metabolites were measured in overwintering larvae of Enosima leucotaeniella acclimated to temperatures between -5 and 15 degrees C for 30days. In the diapausing stage, cold hardiness, as shown by the survival rate, began rising below 15 degrees C. Glycogen content decreased as the temperature decreased from 10 to 0 degrees C. Trehalose content rose as the temperature decreased from 15 to 5 degrees C, but remained unchanged as the temperature decreased from 5 and 0 degrees C. Twenty-eight free amino acids were detected in the haemolymph; levels of proline, glutamine and glutamic acid increased at high temperatures, but alanine increased at low temperatures, especially as temperature decreased from 5 to 0 degrees C. Lipid content was unchanged by the different acclimation temperatures. The effects of temperature, diapause and aerobic conditions on the levels of carbohydrates and amino acids in overwintering larvae were analyzed. Alanine levels rose at low temperature only when the larvae were in the diapausing stage. The level of trehalose rose at low temperature in both the diapausing and post-diapausing stages, although it was higher at aerobic conditions in the post-diapausing stage. These results suggest that efficient trehalose synthesis occurs under the combination of low temperature and aerobic conditions of the post-diapausing stage, so that cold hardiness in overwintering E. leucotaeniella larvae may rise to a high level in winter.     

Patterns of wing size variation in seeds of the lily Cardiocrinum cordatum (Liliaceae)

We examined the patterns of variation in wing-loading and its related characteristics in Cardiocrinum cordatum to clarify the factors that determine the variation in seed dispersal ability in this species. The square root of wing-loading of a seed of a plant was not significantly correlated with basal stem diameter of a plant, indicating that large plants did not necessarily produce seeds with high dispersal ability. This result was inconsistent with the hypothesis that large plants produce seeds with high dispersal ability to avoid high mortality of seeds and seedlings in the vicinity of the parents. On the other hand, the square root of wing-loading of a seed of a fruit was negatively dependent on seed number of a fruit. Thus, many-seeded fruits produced seeds with high dispersal ability. This was because the projected surface area per seed was large in large fruits and large fruits contained large numbers of seeds. The cost per seed of producing fruit structures was small for many-seeded fruits. Thus, high dispersal ability of seeds in many-seeded fruits may be a result of an effective resource allocation pattern in which a high proportion of resources are allocated to those many-seeded fruits, enabling seeds to develop large wings and thus reducing the structural cost of fruits per seed.     

Trace element contents in hair of residents from Harbin (China), Medan (Indonesia), and Tokushima (Japan)

The concentrations of 19 trace element in hair samples from 1273 residents of Harbin (China), Medan (Indonesia), and Tokushima (Japan) were measured by inductively coupled plasma emission spectrometry. The mean concentrations of Ba, Ca, and Se were significantly higher in the Harbin hair samples when compared to those from Medan, but Al, B, Cu, Fe, Mn, Na, Pb, Ti, Zn, and K were significantly higher in Medan than in Harbin hair samples. The differences in the mean concentrations of As, Cr, Mg, P, Sn, and Sr between the Medan and Harbin lots were not significant. In the Tokushima hair samples, Na and K were significantly higher, but As, B, Ba, Ca, Cr, Mg, Mn, Pb, Sn, Sr, and Se were significantly lower than in the Harbin hair samples. The differences in the mean concentrations of Al, Cu, Fe, P, Ti, and Zn between Harbin and Tokushima were not significant. In the Medan hair samples, Al, As, B, Ba, Ca, Cr, Cu, Fe, Mg, Mn, Pb, Sn, Sr, Ti, and Zn were significantly higher, but P and Se were significantly lower than in Tokushima hair samples. Differences in mean concentrations of Na and K between Tokushima and Medan were not significant.     

Expression of heat shock protein in host macrophages correlates with a protective potential against infection with Leishmania major in mice

We studied the relationship between the expression of 65-kDa heat shock protein (HSP65) and resistance of mice to infection with Leishmania major (L. major), an obligate intracellular protozoan. C57BL/6 (B6) mice, a strain genetically resistant to L. major infection, expressed high level of HSP65 in their peritoneal and draining lymph node macrophages after infection, whereas susceptible BALB/c mice expressed only slightly at the early stage of infection. This protein was not expressed in the parasite itself and macrophages of non-infected mice. We examined the role of T cells in the expression of HSP65 by using SCID mice grafted with the fetal thymus from B6 or BALB/c mice (B6-TG or BALB-TG mice, respectively). Either BALB-TG or B6-TG mice were reconstituted with T cells derived from each grafted fetal thymus. B6-TG mice were markedly resistant against infection with L. major, compared with BALB-TG mice. Furthermore, the HSP65 expression in macrophages of thymus-grafted mice was similar to that of the thymus-donor type. That is, B6-TG mice expressed a high level of this protein, whereas BALB-TG mice did in lower level than B6-TG mice. These results show that T cells are necessary to express HSP65 and the expression correlates with a protective potential of T cells against infection with L. major.     

Chromosomal Mapping of Genes in theRBCS Family in Arabidopsis thaliana

In Arabidopsis thaliana, four genes have been identified inthe RBCS gene family, one being assigned to subfamily RBCS-Aand the other three to subfamily RBCS-B (1B, 2B and 3B). Todetermine the chromosomal location ofthese genes, hybridizationanalysis with CIC YAC high-density filters was carried out forthe RBCS-A gene, and CAPS analysis for the three RBCS-B genes,based on the finding that restriction fragment length polymorphismis present in the upstream region of the gene RBCS-3B. The RBCS-Agene was mapped at 100.8 cM from the top of chromosome 1 andthe three RBCS-B genes at 62.70 cM from the top of chromosome5.     

Phenological diversity in tropical forests

One of the most intriguing and complex characteristics of reproductive phenology in tropical forests is high diversity within and among forests. To understand such diversity, Newstrom et al. provided a systematic framework for the classification of tropical flowering phenology. They adopted frequency and regularity as criteria with priority, and classified plants in La Selva, Costa Rica, where most plants reproduced more than once a year irregularly. Many other studies have demonstrated annual cycles corresponding to rainfall patterns at the community level in Neotropical forests, including La Selva. On the other hand, supraannual flowering synchronized among various plant species, called general flowering, is known from aseasonal lowland dipterocarp forests in Southeast Asia. Within both forests, a wide spectrum of flowering patterns is found. This range of patterns suggests the great potential of tropical phenological studies to explore the selective pressures on phenology. Various abiotic and biotic factors can be selective agents. The shared pollinators hypothesis suggests that plant species sharing pollinators segregate flowering temporarily to minimize interspecific overlap in flowering times and thus minimize ineffective pollination or competition for pollinators, indicating strong phylogenetic constraints in timing and variation of flowering. Comparison of phenology within and among forests may help our understanding of phenological diversity. Attempts are now being made to develop a common language to communicate concepts and render interpretations of data more compatible among investigators and to create a network to promote comparative studies. Received: September 8, 2000 / Accepted: January 30, 2001     

Identification of intracellular target proteins of the calcium-signaling protein S100A12.

In this report, we have focused our attention on identifying intracellular mammalian proteins that bind S100A12 in a Ca2+-dependent manner. Using S100A12 affinity chromatography, we have identified cytosolic NADP+-dependent isocitrate dehydrogenase (IDH), fructose-1,6-bisphosphate aldolase A (aldolase), glyceraldehyde-3-phosphate dehydrogenese (GAPDH), annexin V, S100A9, and S100A12 itself as S100A12-binding proteins. Immunoprecipitation experiments indicated the formation of stable complexes between S100A12 and IDH, aldolase, GAPDH, annexin V and S100A9 in vivo. Surface plasmon resonance analysis showed that the binding to S100A12, of S100A12, S100A9 and annexin V, was strictly Ca2+-dependent, whereas that of GAPDH and IDH was only weakly Ca2+-dependent. To localize the site of S100A12 interaction, we examined the binding of a series of C-terminal truncation mutants to the S100A12-immobilized sensor chip. The results indicated that the S100A12-binding site on S100A12 itself is located at the C-terminus (residues 87-92). However, cross-linking experiments with the truncation mutants indicated that residues 87-92 were not essential for S100A12 dimerization. Thus, the interaction between S100A12 and S100A9 or immobilized S100A12 should not be viewed as a typical S100 homo- or heterodimerization model. Ca2+-dependent affinity chromatography revealed that C-terminal residues 75-92 are not necessary for the interaction of S100A12 with IDH, aldolase, GAPDH and annexin V. To analyze the functional properties of S100A12, we studied its action in protein folding reactions in vitro. The thermal aggregation of IDH or GAPDH was facilitated by S100A12 in the absence of Ca2+, whereas in the presence of Ca2+ the protein suppressed the aggregation of aldolase to less than 50%. These results suggest that S100A12 may have a chaperone/antichaperone-like function which is Ca2+-dependent.