Interleukin 12 and CD86 Regulate Th1 and Th2 Development Induced by a Range of Antigen Doses Presented by Peyer's Patch and Spleen Cells

In this study, we demonstrate the role of interleukin 12 (IL-12), CD80 and CD86 in T helper type 1 (Th1) and Th2 differentiation induced through antigen presentation by Peyer's patch (PP) and spleen (SPL) cells with various doses of antigen. IL-12 was found to be critical for the induction of Th1-type cytokine producing cells, while antigen-dose dependent patterns of differentiation into Th2-type cytokine producing cells were not altered by the blockade of IL-12. Further, the difference in the pattern of Th2-type cytokine producing cell differentiation induced by PP and SPL cells depending on the antigen dosage were preserved in the absence of IL-12. When the function of CD86 was blocked by specific antibody, the induction of Th1-type cytokine producing cells was kept at high levels through every antigen dose, and the difference between PP and SPL cells was abrogated. With regard to Th2 induction, CD86 enhanced the differentiation of Th2-type cytokine producing cells but it was not essential in the case of antigen presentation by SPL cells. These results suggest that antigen-dose dependent changes in Th2 cell induction are regulated by additional factors which cannot induce antigen-dose dependent changes in Th1 cell differentiation by themselves.     

Photochemical energy conversion system using immobilized chloroplasts

Immobilized chloroplasts and Clostridium butyricum were employed for a photochemical energy conversion system. Spinach chloroplasts were immobilized in 2% agar gel. The optimum temperature of immobilized chloroplasts was 30°C. The maximum activity was obtained in the phosphate buffer solution (pH 8.0) containing 8μM of ferredoxin under an N₂ bubbling condition. Hydrogen was evolved under illumination by immobilized chloroplasts and C. butyricum. Hydrogen produced by this system was applied to a hydrogen-oxygen fuel cell. Photoinduced current was obtained from this photochemical energy conversion system. A photocurrent of 0.4?1.5 mA was continuously obtained for 4 h. The conversion ratio from hydrogen to current was 80?100%.     

Effect of temperature on the viability of Bacillus stearothermophilus

One of the obligate thermophilic bacteria, Bacillus stearothermophilus, was unable to grow at temperatures below 35° C. About 80% of the population in the bacterial culture died at the temperatures, and the same extent of loss in either of the activities of oxygen consumption or synthesis of protein or nucleic acid of the organisms was observed. With the progress of death of the organisms, reduced nicotinamide-adenine dinucleotide came to be oxidized by the organisms, enzymes such as fructose-1,6-diphosphate aldolase, when the organisms were washed with phosphate buffer, were leaked out of the organisms, and an increasing amount of ribonucleoprotein was released into the culture medium. The change of the membrane state was then suggested to be one of the possible causes for the death of the organisms at the temperatures.     

Collagen scaffolds for tissue engineering

There are two major approaches to tissue engineering for regeneration of tissues and organs. One involves cell-free materials and/or factors and one involves delivering cells to contribute to the regeneraion process. Of the many scaffold materials being investigated, collagen type I, with selective removal of its telopeptides, has been shown to have many advantageous features for both of these approaches. Highly porous collagen lattice sponges have been used to support in vitro growth of many types of tissues. Use of bioreactors to control in vitro perfusion of medium and to apply hydrostatic fluid pressure has been shown to enhance histogenesis in collagen scaffolds. Collagen sponges have also been developed to contain differentiating-inducing materials like demineralized bone to stimulate differentiation of cartilage tissue both in vitro and in vivo.     

A general route to pendant C-glycosyl 1,2- and 1,3-diamines

Practical and convenient preparations of C-glycosyl 1,2- and 1,3-alkanediamines are described. Two 1,2-ethylenediamine derivatives were synthesized from acetylated allyl alpha-C-glycosyl compounds via dibromination, azidation, carbohydrate deprotection, and azide reduction. Four 1,3-propanediamine derivatives were prepared from acetylated sugar halides via C-glycosylation with sodiomalononitrile, followed by the reduction of the nitrile moieties and the deacetylation of the carbohydrate moiety. These 1,3-propanediamine derivatives have the beta-anomeric configurations. The methods reported here serve as general routes to access carbohydrate-diamine conjugates with C-glycosyl linkages.     

Novel genes involved in canonical Wnt/beta-catenin signaling pathway in early Ciona intestinalis embryos

We report here characterization of five genes for novel components of the canonical Wnt/ β -catenin signaling pathway. These genes were identified in the ascidian Ciona intestinalis through a loss-of-function screening for genes required for embryogenesis with morpholinos, and four of them have counterparts in vertebrates. The five genes we studied are as follows: Ci-PGAP1 , a Ciona orthologue of human PGAP1 , which encodes GPI (glycosylphosphatidylinositol) inositol-deacylase, Ci-ZF278 , a gene encoding a C2H2 zinc-finger protein, Ci-C10orf11 , a Ciona orthologue of human C10orf11 that encodes a protein with leucine-rich repeats, Ci-Spatial/C4orf17 , a single counterpart for two human genes Spatial and C4orf17 , and Ci-FLJ10634 , a Ciona orthologue of human FLJ10634 that encodes a member of the J-protein family. Knockdown of each of the genes mimicked β -catenin knockdown and resulted in suppression of the expression of β -catenin downstream genes ( Ci-FoxD , Ci-Lhx3 , Ci-Otx and Ci-Fgf9/16/20 ) and subsequent endoderm formation. For every gene, defects in knockdown embryos were rescued by overexpression of a constitutively active form, but not wild-type, of Ci- β -catenin. Dosage-sensitive interactions were found between Ci-β-catenin and each of the genes. These results suggest that these five genes act upstream of or parallel to Ci- β -catenin in the Wnt/ β -catenin signaling pathway in early Ciona embryos.     

Early detection of the Limulus amebocyte lysate reaction evoked by endotoxins

The gelation of Limulus amebocyte lysate (LAL) evoked by bacterial endotoxins can be detected earlier than with usual methods by using laser scattering photometry to recognize the formation of small particles of clotted enzyme produced when the reaction mixture is agitated. The appearance of these small particles means that the influence of endotoxins has stimulated activation of the clotting enzyme across the LAL cascade, and the timing of their appearance is related to endotoxin concentration. This new method can be used for quick and sensitive endotoxin assay. The average endotoxin level of healthy volunteers was assayed to be 0.0738 pg/ml [0.0312-0.3445 pg/ml] (n = 11) within 70 min from the start of the assay.     

GABA and synaptic inhibition of mouse cerebellum lacking glutamate decarboxylase 67

γ-Aminobutyric acid (GABA) is a major inhibitory neurotransmitter and also presumed to be a neurotrophic factor. GABA is synthesized by glutamate decarboxylase (GAD). A mouse lacking a 67 kDa isoform of GAD (GAD67) has a reduced GABA level in its brain at birth and does not survive postnatally because of cleft palate. In this study, to investigate the functional and developmental roles of GABA in the postnatal cerebellum, selective GAD67 deletion was achieved using a Cre-loxP strategy. In this mouse, GABA level was reduced to 16-44% in the cerebellum but not in the cerebrum. Inhibitory synaptic transmission to Purkinje cells was seriously impaired. However, the morphology of Purkinje cells and the density of synaptic terminals in the cerebellar cortex appeared unaffected, suggesting that GABA does not participate in cerebellar development substantially.