Observation of long-distance radial correlation in toroidal plasma turbulence.

This Letter presents the discovery of macroscale electron temperature fluctuations with a long radial correlation length comparable to the plasma minor radius in a toroidal plasma. Their spatiotemporal structure is characterized by a low frequency of ∼1-3 kHz, ballistic radial propagation, a poloidal or toroidal mode number of m/n=1/1 (or 2/1), and an amplitude of ∼2% at maximum. Nonlinear coupling between the long-range fluctuations and the microscopic fluctuations is identified. A change of the amplitude of the long-range fluctuation is transmitted across the plasma radius at the velocity which is of the order of the drift velocity.

Induction of interleukin-23 p19 by serum amyloid A (SAA) in rheumatoid synoviocytes.

In this study, we investigated the roles of serum amyloid A (SAA) in T helper 17 (Th17)-related cytokine induction in rheumatoid arthritis (RA) synoviocytes. Synoviocytes isolated from rheumatoid arthritis (RA) patients were stimulated with recombinant SAA and IL-23 expression was investigated using reverse transcriptase-polymerase chain reaction and Western blot. The involvement of mitogen-activated protein kineases (MAPKs) and nuclear factor (NF)-κB in SAA-induced interleukin (IL)-23 p19 expression was investigated using pharmacological inhibitors. In RA synoviocytes, SAA induced the expression of IL-23 p19 and p40 mRNA expression. The SAA-stimulated expression of p19 was rapid (< 3 h), and insensitive to polymyxin B treatment. This SAA-stimulated expression of IL-23 p19 was inhibited completely by inhibitors of NF-κB, p38MAPK and dexamethasone. Interestingly, the SAA-induced IL-23, p19 and p40 production was accompanied by enhanced expression of IL-1ß, but not transforming growth factor-ß. These results indicate that SAA is a significant inducer of IL-23 and IL-1ß in RA synoviocytes and potentially activates the IL-23/IL-17 pathway in the RA synovium. Our data present a novel interaction between inflammation and autoimmunity by an acute-phase protein.

Observation of reversed-shear Alfvén eigenmodes excited by energetic ions in a helical plasma.

Reversed-shear Alfvén eigenmodes were observed for the first time in a helical plasma having negative q0'' (the curvature of the safety factor q at the zero shear layer). The frequency is swept downward and upward sequentially via the time variation in the maximum of q. The eigenmodes calculated by ideal MHD theory are consistent with the experimental data. The frequency sweeping is mainly determined by the effects of energetic ions and the bulk pressure gradient. Coupling of reversed-shear Alfvén eigenmodes with energetic ion driven geodesic acoustic modes generates a multitude of frequency-sweeping modes.

Potentiation of glucocorticoid receptor (GR)-mediated signaling by the immunosuppressant tacrolimus in rheumatoid synoviocytes.

OBJECTIVE: The immunosuppressant tacrolimus is known to enhance many aspects of glucocorticoid. In this study, we investigated the effects of tacrolimus on glucocorticoid receptor (GR) signaling using rheumatoid fibroblast-like synoviocytes (RA-FLS). METHODS: The nuclear translocation of GR was analyzed by immunocytochemistry. The DNA binding activity of p65 was assayed by a functional ELISA kit using nuclear extracts. GR-associated FK506-binding protein-51 (FKBP-51) was analyzed by Western blotting following immunoprecipitation of glucocorticoid receptor (GR) complexes. RESULTS: High concentrations (10-7M) of Dexamethasone (Dex) induced GR translocation to the nucleus in RA-FLS. However, the nuclear GR translocation did not occur with low concentrations of Dex (10-9M). Tacrolimus treatment of RA-FLS results in potentiation of GR translocation to the nucleus even in the presence of a low concentration of Dex (10-9M). GR-associated FKBP-51 decreased after tacrolimus treatment. Furthermore, tacrolimus also decreased the IL-1Beta-induced DNA binding activity of p65, a subunit of NF-KappaB, in the presence of 10-9 M of Dex. CONCLUSION: These data suggest that tacrolimus exerts anti-inflammatory properties by potentiating the GR signaling through the GR-immunosuppressant-binding proteins (immunophilins) interaction and its nuclear transport in rheumatoid synovium.

MEFV mutations in Japanese rheumatoid arthritis patients.

OBJECTIVE: Familiar Mediterranean Fever (FMF) is common among Mediterranean populations, while other populations are rarely affected. The aim of this study was to assess the involvement of MEFV gene mutations among Japanese rheumatoid arthritis patients with or without amyloid A (AA) amyloidosis. METHODS: The frequency of the MEFV mutations, which were identified in Japanese FMF patients, was determined in 126 Japanese RA patients and 76 Japanese healthy subjects. RESULTS: The M694I mutation was not observed among RA patients and healthy subjects. Allele frequency of R408Q, P369S, E148Q, L110P mutations account respectively for 3.3%, 3.9%, 23.7%, 9.2% in healthy subjects and 5.6%, 6.7%, 24.2%, 9.5% in RA patients. The overall mutation rate was comparable between the RA patients and healthy subjects, as well as between the RA patients with and without amyloidosis. CONCLUSION: This study shows the high prevalence of mutations of the MEFV genes in Japanese RA patients. However, our data suggest that the MEFV gene mutations may not be a genetic factor affecting the susceptibility of RA or the development of amyloidosis in a Japanese population.

Determination of anti-cyclic citrullinated peptide antibodies in the sera of patients with liver diseases.

OBJECTIVE: To determine the frequency of anti-cyclic citrullinated peptide (anti-CCP) antibodies in patients with HCV infection, primary biliary cirrhosis (PBC) and type-I autoimmune hepatitis (AIH) to assess the specificity of anti-CCP antibodies. METHODS: Rheumatoid factor (RF) and anti-CCP antibodies were measured in the sera from patients with HCV infection (n=45), PBC (n=73), AIH (n=55) and rheumatoid arthritis (n=48), and also from the sera of healthy subjects (n=23). Anti-CCP antibodies were measured using a second generation enzyme-linked immunosorbent assay (ELISA). RESULTS: No sera with elevated anti-CCP were found in the patients with HCV infection. Two PBC patients (2.7%) and six AIH patients (10.5%) had anti-CCP antibodies. The seropositivity for anti-CCP in these autoimmune disease patients was associated with a high frequency of RA association [PBC; 100% (2/2), AIH; 86.4% (5/6)]. CONCLUSIONS: Although anti-CCP antibodies may be present in patients with autoimmune liver diseases, almost seropositive patients had concomitant RA. As a result, the measurement of anti-CCP antibodies may therefore be helpful for accurately diagnosing RA in patients with these liver diseases.

Hyperphosphorylation of retinoblastoma protein and p53 by okadaic acid, a tumor promoter.

A potent tumor promoter, okadaic acid, induced hyperphosphorylation of tumor suppressor proteins, retinoblastoma protein and p53, by in vitro incubation with nuclei isolated from rat regenerating liver as well as by incubation with primary human fibroblasts. Most of the retinoblastoma protein migrated to a hyperphosphorylated position in electrophoresis. The phosphorylation of p53 was increased at a rate 8 times that in non-treated primary human fibroblasts. Hyperphosphorylation of tumor suppressor proteins, mediated through inhibition of protein phosphatases 1 and 2A, is involved in tumor promotion by okadaic acid. The significance of hyperphosphorylation of the retinoblastoma protein and p53 is discussed in relation to the regulation of the cell cycle.

Canventol inhibits tumor promotion in CD-1 mouse skin through inhibition of tumor necrosis factor alpha release and of protein isoprenylation.

A synthetic compound named canventol, 2-isopropyl-4-isopropylidencyclohex-2-ene-1-ol, inhibited tumor promotion of okadaic acid on mouse skin initiated with 7,12-dimethylbenz(a)anthracene in two-stage carcinogenesis experiments more strongly than sarcophytol A, isolated from a soft coral, although canventol has a simpler structure than sarcophytol A. Their mechanisms of action were studied based on our recent evidence that tumor necrosis factor alpha release induced by okadaic acid is an essential mechanism of tumor promotion. Canventol inhibited mouse tumor necrosis factor alpha release from BALB/3T3 cells less strongly than sarcophytol A, indicating that canventol has additional activity. Canventol inhibited isoprenylation of proteins with various molecular weights, such as M(r) 22,000, 17,000, and 13,000, whereas sarcophytol A did not show significant inhibition. Thus, a potent anticarcinogenic activity of canventol is mediated through the inhibitory bifunctions of tumor necrosis factor alpha release and of protein isoprenylation. Since canventol is less toxic to cells than sarcophytol A, these bifunctions are useful markers for screening for new cancer chemopreventive agents.

Tumor necrosis factor acts as a tumor promoter in BALB/3T3 cell transformation.

Tumor necrosis factor (TNF), a cytokine, and okadaic acid, a tumor promoter, strongly phosphorylated the same proteins, vimentin and heat shock protein 27, although their time courses were different. Human TNF-alpha at a concentration of 0.6 nM markedly stimulated transformation of BALB/3T3 cells initiated with 3-methylcholanthrene. The human TNF-alpha was about 1000 times more effective than the chemical tumor promoters, okadaic acid and 12-O-tetradecanoylphorbol-13-acetate. TNF induced growth of v-Ha-ras transfected BALB/3T3 cells (Bhas 42 cells), whereas it did not induce growth of nontransfected BALB/3T3 cells. Okadiac acid induced mouse TNF-alpha from Bhas 42 and BALB/3T3 cells. The results suggest that a chemical tumor promoter induces the secretion of TNF-alpha from various cells. The TNF then acts as an endogenous tumor promoter in vivo.

Hyperphosphorylation of cytokeratins by okadaic acid class tumor promoters in primary human keratinocytes.

Okadaic acid, dinophysistoxin-1 (35-methylokadaic acid), and calyculin A are potent tumor promoters on mouse skin (H. Fujiki, M. Suganuma, S. Nishiwaki, S. Yoshizawa, J. Yatsunami, R. Matsushima, H. Furuya, S. Okabe, S. Matsunaga, and T. Sugimura. In: R. D'Amato, T. J. Slaga, W. Farland, and C. Henry (eds.), Relevance of Animal Studies to the Evaluation of Human Cancer Risk, pp. 337-350. New York: John Wiley and Sons, Inc., 1992). These tumor promoters, which are also inhibitors of protein phosphatases 1 and 2A, induced hyperphosphorylation of M(r) 60,000, M(r) 58,000, M(r) 56,000, M(r) 52,000, M(r) 42,000, and M(r) 27,000 proteins in PHK 16-I cells, human keratinocytes immortalized by human papillomavirus type 16. Except for the M(r) 27,000 protein, these hyperphosphorylated proteins were identified to be cytokeratin peptides (CK) CK 5, CK 6, CK 7, CK 16, and CK 19, by anti-cytokeratin antibodies. CK 5 and CK 6 were more strongly phosphorylated than CK 16 and CK 19. The in vitro hyperphosphorylation of these cytokeratins was also found by incubation with an enzyme fraction containing a mixture of protein phosphatase 2A and protein kinases isolated from mouse brain and various concentrations of dinophysistoxin-1. Indirect immunofluorescence microscopy with anti-cytokeratin antibodies revealed that the hyperphosphorylated cytokeratins had retracted to the perinuclear area. The hyperphosphorylated M(r) 27,000 protein was identified as a heat shock protein, HSP27. Hyperphosphorylation of HSP27 and intermediate filaments, such as cytokeratins, is one of the early biochemical changes, or pleiotropic effects, in cells induced by the okadaic acid class of tumor promoters.

A new process of cancer prevention mediated through inhibition of tumor necrosis factor alpha expression.

Mechanisms of cancer prevention were studied using structurally different cancer-preventive agents, sarcophytol A, canventol, (-)-epigallo-catechin gallate, and tamoxifen, based on our evidence that tumor necrosis factor alpha (TNF-alpha) acts as an endogenous tumor promoter relevant to human carcinogenesis. Pretreatment with the four preventive agents commonly inhibited TNF-alpha mRNA expression and TNF-alpha release in BALB/3T3 cells induced by a tumor promoter, okadaic acid, whereas the expression of early response genes (c-jun, junB, c-fos, and fosB) was enhanced. These results strongly suggest that inhibition of TNF-alpha mRNA expression and its release is a new process of cancer prevention.

Nodularin, a potent inhibitor of protein phosphatases 1 and 2A, is a new environmental carcinogen in male F344 rat liver.

Nodularin and microcystin-LR are cyanobacterial toxins and environmental hazards. Nodularin inhibits protein phosphatases 1 and 2A with the same potency as does microcystin-LR, which has recently been identified as a potent tumor promoter in rat liver. Our results suggested that nodularin is also a new tumor promoter in rat liver. A two-stage carcinogenesis experiment in rat liver initiated with diethylnitrosamine and without partial hepatectomy revealed that nodularin stimulated glutathione S-transferase placental form-positive foci in rat liver more effectively than did microcystin-LR, and that nodularin alone induced glutathione S-transferase placental form-positive foci as well as did diethylnitrosamine alone. Thus, nodularin itself is a new liver carcinogen, and microcystin-LR is a tumor promoter rather than a carcinogen. Nodularin induced hyperphosphorylation of cytokeratin peptides 8 and 18 in primary cultured rat hepatocytes 20% more effectively than did microcystin-LR, suggesting that nodularin penetrates more easily into the hepatocytes than does microcystin-LR. Nodularin up-regulated induction of c-jun, jun-B,jun-D,c-fos,fos-B, and fra-1 mRNA transcripts in rat liver after i.p. administration, and the accumulation of the mRNA transcripts was sustained for over 9 h after treatment. The environmental hazards of cyanobacterial toxins are discussed in relation to human primary liver cancer in Qidong county in the People's Republic of China. Our results support this hypothesis and indicate the need for prevention measures against cyanobacterial toxins.

Significance of MTG8 in leukemogenesis.

MTG8 is a counterpart gene of AML1 in acute myeloid leukemia with t(8:21) translocation. Most of the coding region of the MTG8 is fused with AML1 runt domain. In normal tissues, the MTG8 is highly expressed in brain, but not in hematopoietic tissues. MTG8 may be important in leukemogenesis as well as in AML1 truncation. The function of MTG8 is assumed to be as a transcription factor, because it possesses several features common to transcription factors; putative zinc finger motifs, serine/threonine/proline-rich sequences and a region similar to TAF110. In this paper, we report on the protein properties of the MTG8.

In vitro catalytic activities of DNA/RNA chimeric hammerhead ribozymes against AML1-MTG8 mRNA, a fused gene transcript in acute myeloid leukemia with t(8;21).

In order to design the best construct for therapeutic hammerhead ribozymes against AML1-MTG8, the t(8;21)-associated fusion mRNA of acute myeloid leukemia, we synthesized DNA/RNA chimeric ribozymes directed to the area adjacent to the fusion point between AML1 and MTG8. Catalytic efficiency and fusion gene specificity of ribozymes were examined by kinetic studies of the cleavage reactions of AML1-MTG8, AML1, and MTG8 RNAs transcribed in vitro. Ribozyme 2 (Rz2) specifically cleaved AML1-MTG8 RNA at three nucleotides downstream of the fusion junction with high efficiency. The highest cleavage efficiency was achieved by Rz4.3, which targeted non-contiguous sequences and cleaved at 19 nucleotides downstream of the fusion junction. Rz4.3 also cleaved MTG8 RNA but the cleavage efficiency was three orders of magnitude lower than that for AML1-MTG8 RNA. Therefore, Rz4.3 and Rz2 are the proper ribozymes for in vivo application to modulate gene expression of the AML1-MTG8.

Effects of rapamycin in experimental organ allografting.

The immunosuppressive effect of rapamycin (RAPA), a macrolide antibiotic produced by Streptomyces hygroscopicus, was tested using allografts in the rat and dog. It was immunosuppressive at a dose of 3.0 mg/kg/day for 8 days in skin allografts and 0.1 mg/kg/day for 11 days using cardiac allografts in the rat. It prevented rejection of renal allografts in beagle dogs at a dose of 0.3 mg/kg; however, emaciation and gastrointestinal toxicity resulted in some deaths in dogs. Mucosal necrosis and vasculitis in the submucosal layer were the predominant findings at autopsy in dogs receiving RAPA. Serum amylase values rose soon after commencement of RAPA treatment. Combined drug treatment with CsA at a nonimmunosuppressive dose of 3.2 mg/kg in the rat or 2.5 mg/kg in the dog was synergistic, with a low dose of 0.1 mg/kg/week RAPA. Combined therapy of CsA and RAPA also inhibited the frequency of vasculitis and emaciation in dogs. The present data suggest that RAPA is immunosuppressive in organ allografting and that the combination of CsA and RAPA would be effective clinically.

Energy confinement time and heat transport in initial neutral beam heated plasmas on the large helical device

The confinement characteristics of large net-current-free plasmas heated by neutral-beam injection have been investigated in the Large Helical Device (LHD). A systematic enhancement in energy-confinement times from the scaling derived from the medium-sized heliotron/torsatron experiments have been observed, which is attributed to the edge pedestal. The core confinement is scaled with the Bohm term divided by the square root of the gyro radii. The comparative analysis using a dimensionally similar discharge in the Compact Helical System indicates gyro-Bohm dependence in the core and transport improvement in the edge region of LHD plasmas.

Edge thermal transport barrier In LHD discharges

In LHD discharges a significant enhancement of the global energy confinement has been achieved for the first time in a helical device with an edge thermal barrier, which exhibits a sharp gradient at the edge of the temperature profile. Key features associated with the barrier are quite different from those seen in tokamaks: (i) almost no change in particle (including impurity) transport, (ii) a gradual formation of the barrier, (iii) a very high ratio of the edge temperature to the average temperature, and (iv) no edge relaxation phenomenon. These features are very attractive in applying the thermal barrier to future reactor grade devices.

Tautomycin: an inhibitor of protein phosphatases 1 and 2A but not a tumor promoter on mouse skin and in rat glandular stomach.

Tautomycin isolated from Streptomyces spiroverticillatus is an inhibitor of protein phosphatases 1 and 2A. Tautomycin induced hyperphosphorylation of cytokeratin peptides in human keratinocytes (PHK 16-I cells) 30 times less strongly than did okadaic acid. Repeated applications of tautomycin (30 micrograms, 40 nmol/application) did not induce tumor promotion in a two-stage carcinogenesis experiment on mouse skin initiated with 7,12-dimethylbenz[a]anthracene, whereas okadaic acid (1 microgram, 1.2 nmol/application) as a control induced tumor promotion strongly. As for mucosa of rat glandular stomach, tautomycin induced ornithine decarboxylase 4 h after intubation into the stomach. The tumor-promoting activity of tautomycin was next studied in the glandular stomach initiated with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). Administration of tautomycin in the diet (1 mg rat-1 day-1), from week 9 to week 52 of the experiment, inhibited rather than enhanced tumor development in the glandular stomach initiated with MNNG. The percentages of tumor-bearing rats of the groups treated with MNNG plus tautomycin, MNNG alone, and tautomycin alone were 20.0%, 40.6%, and 0% respectively in week 52. The reason for the absence of tumor-promoting activity of tautomycin was studied in relation to tumor necrosis factor alpha (TNF alpha), an endogenous tumor promoter. We found that tautomycin neither enhanced TNF alpha mRNA expression in mouse skin nor induced TNF alpha release in a human stomach cancer cell line (KATO III cells), whereas okadaic acid did both. These results indicate that not all inhibitors of protein phosphatases are tumor promoters, and suggest that tumor promotion of the okadaic acid class of compounds is mediated by TNF alpha.

Designing of chimeric DNA/RNA hammerhead ribozymes to be targeted against AML1/MTG8 mRNA.

For therapeutic purposes, two chimeric DNA/RNA hammerhead ribozymes were synthesized to cleave AML1/MTG8, the t(8;21)-associated fusion mRNA of acute myeloid leukemia. One ribozyme, A/MRZ-1, recognizes the area adjacent to the fusion point between AML1 and MTG8, and cleaves six bases downstream from this point. The other, MRZ-1, recognizes the MTG8 sequence. Both ribozymes cleaved synthetic chimeric DNA/RNA substrates at theoretical sites. Neither cleaved AML1 RNA. A/MRZ-1 cleaved only AML1/MTG8 RNA, and MRZ-1 cleaved both AML1/MTG8 and MTG8 RNAs. The two ribozymes showed growth inhibition of an acute myeloid leukemia cell line carrying t(8;21), SKNO-1 cells. The same extent of growth inhibition was attained by antisense oligonucleotides against AML1/MTG8 RNA. The results suggest that the ribozyme has the potential to be developed as a useful agent for gene therapy, in particular for leukemia with t(8;21).

Expression of the tumor necrosis factor alpha gene and early response genes by nodularin, a liver tumor promoter, in primary cultured rat hepatocytes.

Nodularin is a new liver carcinogen possessing a potent tumor-promoting activity in rat liver, mediated through inhibition of protein phosphatases 1 and 2A, and a weak initiating activity. Since we previously reported evidence that nodularin up-regulated expression of the tumor necrosis factor alpha gene (TNF alpha) and early-response genes in rat liver after its i.p. administration, and since TNF alpha had tumor-promoting activity in vitro, it is possible that TNF alpha itself is involved in liver tumor promotion. We investigated whether hepatocytes themselves induce expression of the TNF alpha gene and early-response genes in primary cultured rat hepatocytes treated with nodularin. Like nodularin, microcystin-LR, which is another liver tumor promoter belonging to the okadaic acid class, strongly induced TNF alpha gene expression in rat hepatocytes, as well as TNF alpha release from those cells into the medium. On the other hand, 12-O-tetradecanoylphorbol-13-acetate, which has been reported to induce no tumor promotion in rat liver, induced no apparent expression of the TNF alpha gene in primary cultured rat hepatocytes. As for the expression of early-response genes, 1 microM nodularin or microcystin-LR induced expression of the c-jun, jun B, jun D, c-fos, fos B and fra-1 genes in the hepatocytes, and the expression of these genes was prolonged up to 24 h, suggesting mRNA stabilization induced by inhibition of protein phosphatases 1 and 2A. This paper presents new evidence that the TNF alpha gene and early-response genes were expressed in hepatocytes treated with a liver tumor promoter.