Macrophages are essential for controlling the majority of infections, and are mediators of natural immunity. During infection, lipopolysaccharide (LPS) stimulates macrophages to produce pro-inflammatory cytokines. Adenosine and ATP released into the extracellular space by immunological stimuli have been shown to regulate various immune functions. We evaluate immunological effects of adenosine and ATP on the production of cytokines related to inflammation and Thl/Th2 balance by rat peritoneal macrophages. Adenosine and ATP respectively increased the produc-tion of IL-10 without affecting the production of IL-1 βand IL-12 by macrophages. In addition, adenosine and ATP prevented the production of IL-1 iS and IL-12 by LPS-stimulated macrophages. In contrast, adenosine inhibited IL-10 production by LPS-stimulated macrophages, whereas ATP potentiated IL-10 production by LPS-stimula-ted macrophages. These results suggest that conditions related to increased adenosine and/or ATP may play an important role in .a wide range of immune reactions including the Thl and Th2 immune response.

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There have been many applications of toothpastes and gargles containing antibiotic ingredients to periodontal treatment. Cetylpyridinium chloride (CPC) is one such anti-plaque ingredient with a content of 0.05%. This study evaluated the effects of interproximal brushes with a prototype low viscid toothpaste containing 0.05% of CPC on slight periodontitis and gingivitis at interproximal areas. The subjects were 60 patients who had not received general and/or local antibiotics or periodontal therapy for at least 3 months prior to this study. They had at least 1 interproximal area where interproximal brushes could be inserted on the maxillar or mandibular incisors to second premolars without prosthesis. Sampling sites were interproximal areas in each subject. The subjects in the experimental group were instructed as to brushing method and used interproximal brushes with the prototype low viscid toothpaste containing 0.05% of CPC. The other subjects in the placebo group used a prototype low viscid toothpaste without CPC and were given the same instructions as the experimental group of subjects. Mondified gingival index (MGI), modified plaque index (MPI), amount of gingival cervical fluid (GCF), probing depth (PD), clinical attachment level (CAL) and ratio of subgingival microflora were measured at baseline, and after 1 month and 2 months. The data from 23 patients in the experimental group and 25 patients in the placebo group were adopted in this study. MGI, MPI, GCF and PD in both groups showed a significant reduction with time. GCF and PD in the experimental group were significantly lower than those of the placebo group at 1 month. CAL in both groups did not change at any period. Ratio of cocci increased with time in both groups, accordingly rods decreased with time. Spirochetes and motile rods were scarcely detected at every period. These results suggested that the use of low viscid toothpaste containing 0.05% of cetypyridinium chloride with interproximal brushes could quickly improve gingivitis.

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Titanium (Ti) and Ti alloys are widely used for dental materials. Recently, an aluminium and vanadium free titanium alloy, Ti-29Nb-13Ta-4.6Zr alloy, was developed. In the present study, we used the demineralized bone matrix (DBM) pellet for evaluating biocompatibility of Ti, Ti-6A1-4V alloy (the most widely used alloy) and Ti-29Nb-13Ta-4.6Zr alloy. The DBM pellet made of mouse long bones was implanted on the dorsal muscle of mice under ether anesthesia. After the DBM pellet had been implanted for 4 weeks, the expression of mRNA for osteoblastic and osteoclastic phenotypes and mineralization were observed, suggesting that the DBM could heterotopically induce bone. The DBM pellet combined with a disk of Ti, Ti-6A1-4V alloy and Ti-29Nb-13Ta-4.6Zr alloy was implanted in the mouse in the same way. Four weeks after the implantation, the calcium contents accumulated in the DBM pellet with Ti, Ti-6A1-4V alloy and Ti-29Nb-13Ta-4.6Zr alloy were 36.6±8.0 μ g, 50.4± 13.3 μ g and 75.6± 16.9 μ g, respectively. A significant difference was observed between Ti and Ti-29Nb-13Ta-4.6Zr alloy (p<0.05) . This result seemed to suggest the increase of the mineralization in DBM-induced heterotopic bone by Ti-29Nb-13Ta-4.6Zr alloy, because Ti particles showed no toxicities in mouse osteoblastic cells, in mouse bone marrow cells, and in isolated rabbit osteoclasts. These findings suggested that Ti-29Nb-13Ta-4.6Zr alloy might be a higher biocompatible material with bone tissue, and showed that the heterotopic bone induced by the DBM pellet in mice could be a simple and useful method for evaluating biocompatibility of titanium alloys.

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Adenosine and ATP have been implicated in the regulation of inflammatory responses. Furthermore, adenosine and ATP affect cell growth, cell differentiation, and apoptosis. The aim of this study was to evaluate differentiation inducing abilities of adenosine and ATP on human monocytic leukemia THP-1 cells. Adenosine at 10^-3 M markedly induced the differentiation in leukemia THP-1 cells as assessed by evaluating the expression of CDllb. Similarly, ATP at 10^-3 M signifi-cantly induced the differentiation in THP-1 cells. Simultaneously, adenosine at 10^-3 M and ATP at 10^-3 M significantly inhibited the cell number in THP-1 cells. Next, we have evaluated abilities of adenosine and ATP on THP-1 cells differentiated by differentiation inducers all-trans retinoic acid (ATRA), 1, 25-dihydroxy-vitamin D₃ (VD₃) and phorbol 12-myristate 13-acetate (PMA) . Interestingly, adenosine at 10^-3 M significantly potentiated ATRA-induced CDllb expression. In addition, ATRA significantly increased adenosine-induced CDllb expression. Similarly, ATP at 10^-3 M significantly potentiated ATRA-induced CDllb expression. In addition, ATRA potentiated ATP-induced CDllb expression. In contrast, VD₃ and PMA further increased the expression of CDllb in the presence of adenosine of ATP, respectively. These results suggest that adenosine and ATP may induce the differentiation in human leukemia THP-1 cells, and may further increase the ATRA-induced differentiation in THP-1 cells.

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De novo protein synthesis in eukaryotes is mainly controlled at the level of gene transcription by transcription factors in the nucleus. In this communication, the expression and nuclear localization of the activator protein-1 (AP1) family member c-Jun in nuclear and cytosolic fractions of brain and retina from streptozotocin (STZ) -injected diabetic rats were determined in order to evaluate the possibility that transportation of AP1 family members from the cytoplasm to the nucleus could play a role in diabetes. Immunoblotting assays with a specific antibody revealed a much higher expression of immunoreactive c-Jun in nuclear fractions than in cytosolic fractions of the cerebral cortex, hippocampus, striatum and cerebellum after diabetes induction by administration of STZ. In contrast, administration of STZ failed to affect the nuclear localization of c-Jun detected in the hypothalamus, midbrain, medulla-pons and retina. These results suggest that the STZ-injected diabetic rat shows differential alterations in nuclear localization of c-Jun protein in the brain and retina.

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De novo protein synthesis in eukaryotes is mainly controlled at the level of gene transcription by transcription factors in the nucleus. In this communication, DNA binding activities of nuclear factor (NF) -κB and activator protein-1 (AP-1) were determined in the brain from streptozotocin (STZ) -injected diabetic rats in order to explore particular proteins related with diabetes. Gel retardation electrophoresis using core consensus elements containing NF-κB or AP-1 probe revealed that STZ significantly potertiated NF-κB binding in the cerebral cortex and medulla-pons. Moreover, STZ markedly decreased NF-κB binding in the striatum and hypothala-mus. However, no significant changes was detected in NF-κB binding in the hippocampus, midbrain and cerebellum. In contrast, STZ significantly potentiated AP-1 binding in the cerebellum and medulla-pons, whereas STZ markedly decreased AP-1 binding in the striatum, hypothalamus and midbrain. However, AP-1 binding was not markedly affected by the injection of STZ in the cerebral cortex and hippocampus. These results suggest that the STZ-injected diabetic rat shows differential alterations in DNA binding activities of transcription factors NF-κB and AP-1 in the brain.

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Prostaglandin D₂ (PGD₂) acts via the adenyl cyclase-coupled receptor for PGD₂ (DP receptor) . Previously, we presented evidence that BW245C, a DP receptor agonist, inhibited chemotaxis, phagocytosis, superoxide anion production and nitrite production, and potentiated TNF-α production by macrophages. To gain information on the mechanism through which agonist of DP receptor potentiated LPS-stimulated TNF-αproduction by macrophages, in this study, we sought to identify downstream effectors of DP receptor-potentiated TNF-αproduction. Both SB203580, a p38 mitogen-activated protein kinase (MAPK) inhibitor, and PD98059, an extracellular signal-related kinase (ERK) 1/2 inhibitor, prevented LPS-induced TNF-αproduction and BW245C-increased TNFαproduction in the presence of LPS, respectively. In contrast, LY294002, a phosphoinositide 3-kinase (PI3K) inhibitor, D609, a phospholipase C (PLC) inhibitor, and suramin, a PLD inhibitor, all did not affect LPS-induced TNF-αproduction, whereas they markedly inhibited BW245C-increased TNFαproduction in the presence of LPS. These results suggest that LPS evidently induced the production of TNF-αthrough p38 MAPK and ERK 1/2 signaling pathways, and that BW245C further increased LPS-induced TNF-αproduction through PI3K, PLC, and PLD.

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15-Deoxy-Δ^{12, 14}-prostaglandin J₂ (15dPGJ₂ ), that is a ligand for peroxisome proliferator-activated receptor γ (PPAR γ), induced apoptosis of human several tumors including gastric, lung, colon, prostate and breast. However, the role of PPAR y signals in other types of cancer cells such as leukemia except solid cancer cells is still unclear. The aim of this study is to evaluate the ability of 15dPGJ₂ on the proliferation of human T acute lymphoblastic leukemia cell line CCRF-CEM. 15dPGJ₂ at 5 M stimulated the proliferation in CCRF-CEM at 1 to 3 days after incubation. In contrast, 15dPGJ₂ at concentrations of above 10 M inhibited the proliferation. PGD₂, PGJ₂ and Δ¹²PGJ₂ (ΔPGJ₂), those are precursors of 15dPGJ₂, had similarly proliferative effects, whereas they showed anti-proliferative effects at high concentrations. Both SB203580, a p38 mitogen-activated protein kinase ( MAPK ) inhibitor, and LY294002, a phosphoinositide 3-kinase ( PI3K) inhibitor, prevented 15dPGJ₂ and three precursors-accelerated proliferation in CCRF-CEM. In contrast, PD98059, an extracellular signal-related kinase 1/2 inhibitor, did not affect 15dPGJ₂ and three precursors-accelerated proliferation. Immunoblotting analysis revealed that PGD₂ at 5 μM, PGJ₂ at 5 μM, ΔPGJ₂ at 1μ M and 15dPGJ₂ at 5 μM potentiated the expression of cyclin A, without affecting the expression of Cdk inhibitors including p18, p21, p27 in CCRF-CEM. These results suggest that PGD₂, PGJ₂, ΔPGJ₂ and 15dPGJ₂ may, through the activation of p38 MAPK and/or PI3K, potentiate the expression of cyclin A, leading to acceleration of proliferation in CCRF-CEM.

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