Precise absolute Seebeck coefficient measurement and uncertainty analysis using high-Tc superconductors as a reference.

The intrinsic properties of superconductors enable the direct determination of the absolute Seebeck coefficient at low temperature due to the disappearance of the Seebeck effect to obey the Meissner effect. We report a precision absolute Seebeck coefficient measurement for the fine Pt sample determined using the high-Tc YBa2Cu3O7-x (YBCO) superconductor as a reference and an analysis of the measurement uncertainty. To make a precision measurement and aid in the verification of the uncertainty components, we developed a cryostat system that enables temperature control in a stable manner. The expected performance of the reference superconductor yielded a zero value well below Tc, which was validated by a superconductor-superconductor thermocouple experiment. Uncertainty analysis shows that the main limiting factor for this measurement is the accuracy of the temperature difference measurement using the resistance temperature sensors, along with its analog noise. We obtained values of S = 5.6 ± 0.2 µV/K with a relative expanded uncertainty of 3% at 80 K and precisely compared the Pt value with that determined by the high-Tc Bi2Sr2Ca2Cu3O8+δ (Bi-2223) superconductor, which has a higher Tc. We found that there was no difference between the Seebeck coefficient values obtained from the YBCO and Bi-2223 references up to its Tc within the expanded measurement uncertainties of 0.3 µV/K (2σ). These results provide accurate validation that the high-Tc superconductor is a useful reference up to the liquid nitrogen temperature.

Impaired fracture healing in macrophage migration inhibitory factor-deficient mice.

UNLABELLED: This study investigated the role of macrophage migration inhibitory factor (MIF) in fracture repair using MIF gene-deficient mice (MIF KO). Fracture healing was delayed in MIF KO, and this was mainly due to the delay in the mineralization of osteoid within the fracture callus. INTRODUCTION: We previously reported that the expression of macrophage migration inhibitory factor (MIF) was up-regulated during the fracture healing process in rats. However, its role in the pathophysiology of this process remained unclear. The aim of the present study was to clarify the role of MIF in the fracture healing process using MIF gene-deficient mice (MIF KO). METHODS: Bone repair in wild-type mice (WT) and MIF KO (n = 70, respectively) was investigated using a tibia fracture model. Radiographic, biomechanical, histological, bone histomorphometric, and molecular analyses were performed. RESULTS: Post-fracture biomechanical testing showed that maximum load and stiffness were significantly lower in MIF KO than in WT on day 42. However, similar levels were observed between the two groups on day 84. Bone histomorphometric analysis revealed significantly higher osteoid volume, a lower mineral apposition rate, and smaller numbers of osteoclasts in the MIF KO callus compared to the WT callus. The messenger ribonucleic acid expressions of matrix metalloproteinase (MMP)-2, membranous type 1-MMP, cathepsin K, and tissue nonspecific alkaline phosphatase were found to be significantly suppressed in the MIF KO callus. CONCLUSION: The results of the present study suggest that delayed fracture healing in MIF KO was mainly attributable to a delay in osteoid mineralization.

DNA-binding activity of TNF-alpha inducing protein from Helicobacter pylori.

Tumor necrosis factor-alpha (TNF-alpha) inducing protein (Tipalpha) is a carcinogenic factor secreted from Helicobacter pylori (H. pylori), mediated through both enhanced expression of TNF-alpha and chemokine genes and activation of nuclear factor-kappaB. Since Tipalpha enters gastric cancer cells, the Tipalpha binding molecules in the cells should be investigated. The direct DNA-binding activity of Tipalpha was observed by pull down assay using single- and double-stranded genomic DNA cellulose. The surface plasmon resonance assay, indicating an association between Tipalpha and DNA, revealed that the affinity of Tipalpha for (dGdC)10 is 2400 times stronger than that of del-Tipalpha, an inactive Tipalpha. This suggests a strong correlation between DNA-binding activity and carcinogenic activity of Tipalpha. And the DNA-binding activity of Tipalpha was first demonstrated with a molecule secreted from H. pylori.

Carcinogenic potential of tobacco tar-resistant Staphylococcus aureus in buccal cavity.

PURPOSE: The effects of cigarette smoking on the association between inflammation and cancer were studied, since some bacteria induce the production of tumor necrosis factor-alpha (TNF-alpha), a proinflammatory cytokine and endogenous tumor promoter, in cells. METHODS: Bacteria from a gargled solution from the buccal cavity of 20 individuals were cultured in the presence of 4 mg/ml cigarette-smoke condensates. Although cigarette-smoke condensates inhibited growth of Staphylococcus aureus strongly and that of Staphylococcus warneri weakly, tobacco tar-resistant S. aureus and S. warneri were obtained. RESULTS: One tobacco tar-resistant S. aureus strain (Sa-TA10) induced expression of the TNF-alpha gene in both Bhas 42 cells (v-Ha-ras transfected BALB/3T3 cells) and human lung cancer cell line H226B, while one tobacco tar-resistant S. warneri (Sw-TA75) did not induce it significantly. Moreover, Sa-TA10 induced formation of transformed foci and soft-agar colony in Bhas 42 cells in cooperation with the v-Ha-ras gene. The results suggested that Sa-TA10 has carcinogenic potential, whereas Sw-TA75 does not. CONCLUSION: These data suggest that tobacco tar-resistant S. aureus, with carcinogenic potential, is present in the buccal cavity of some individuals, and that cigarette smoking simultaneously inhibits growth of most of the bacteria and selects carcinogenic bacteria.

Isolation and synthesis of TNF-alpha release inhibitors from Fijian kawa (Piper methysticum).

Two unique evidence that cancer incidence rates in Fiji were unusually low, compared with those of another Pacific islands and that green tea beverage is an acknowledged cancer preventive in Japan, allowed us to study a local beverage in Fiji, kawa (kava kava) or yangona (Piper methysticum) belonging to Piperaceae. We isolated five known kawapyrones (kavapyrones) (1-5) and a new additional kawapyrone, 7,8-epoxyyangonin (6), from kawa MeOH extract and subjected them to TNF-alpha (tumor necrosis factor-alpha) release assay from BALB/3T3 cells treated with okadaic acid, a tumor promoter. 5,6-Dehydrokawain (desmethoxyyangonin)(1) and yangonin (4) significantly inhibited TNF-alpha release with IC50 values of 17 microM and 40 microM; a potency as great as (-)-epigallocatechin gallate (EGCG) isolated from green tea extract. Among the experiments with 1-5, dihydrokawain (2) was unique in showing the strongest inhibitory activity against TNF-alpha release in mice, but the weakest activity in the cells. We synthesized 5,6-dehydrokawain (1) and yangonin (4) via three steps from the dianion of ethyl acetoacetate achieving a good yield and determined their conformations by high resolution NMR and x-ray crystallographic analysis.

Discrete roles of cytokines, TNF-alpha, IL-1, IL-6 in tumor promotion and cell transformation.

Based on our previous results, which pointed to tumor necrosis factor-alpha (TNF-alpha) as the essential cytokine in tumor promotion in mouse skin, we present here three principal findings related to the specific roles of TNF-alpha, interleukin-1 (IL-1) and IL-6 in tumor promotion (using TNF-alpha- and IL-6-deficient mice) and in BALB/3T3 cell transformation: i) The previously reported residual tumor promotion by 12-O-tetradecanoylphorbol-13-acetate (TPA) in TNF-/- mice was confirmed by experiments with TNF+/+ and TNF-/- 129/Svj mice of the same strain, using two-stage carcinogenesis experiments. TPA produced tumors in 100% of TNF+/+ and 78% of TNF-/- mice at 20 weeks, and the average number of tumors per mouse was 11.1 in the former group and 2.1 in the latter. Judging from the expression of various inflammatory cytokine genes in TNF+/+ and TNF-/- mice, the residual tumor promoting activity of TPA in TNF-/- mice may be dependent on expression of IL-1alpha and IL-1beta genes. ii) Tumor promotion by TPA and okadaic acid in IL-6+/+ and IL-6-/- C57/BL6 mice was studied, with TPA producing tumors in 57.1% of IL-6+/+ and 40.0% of IL-6-/- mice at 20 weeks, and okadaic acid in 40.0% of IL-6+/+ and 53.3% of IL-6-/- mice. Thus, there was no significant difference between TPA or okadaic acid tumor promotion in either group. In addition, expression of IL-6 gene in skin of both types of mice suggested that IL-6 is not the essential cytokine in tumor promotion, since it can be replaced by other cytokines. iii) In transformed clones of BALB/3T3 cells induced by TNF-alpha alone, IL-1alpha gene expression was induced after transformation by TNF-alpha had occurred, which did not occur in parental cells. Expression patterns of TNF-alpha, IL-1beta, IL-6 and IL-10, along with TGF-beta, were similar in both parental and transformed cells. Considering all these results, we conclude that various cytokines have discrete roles in tumor promotion and cell transformation.

New TNF-alpha releasing inhibitors, geraniin and corilagin, in leaves of Acer nikoense, Megusurino-ki.

The success of green tea as a cancer preventive is based on evidence that green tea contains tannins and antioxidants, does not show toxicity in humans and has long traditional use in Asia. In the light of this, herbal medicines are now also attracting attention as potential sources of cancer preventive agents. Using the inhibition of TNF-alpha release assay, we studied Acer nikoense (Megusurino-ki in Japanese), one of the herbal medicines. The inhibitory activity of TNF-alpha release was found in the leaf extract rather than the bark extract, and the main active constituents were identified as geraniin and corilagin, which are present in another Japanese traditional herb, Geranium thunbergii (Genno-shoko). The IC50 values of TNF-alpha release inhibition were 43 microM for geraniin and 76 microM for corilagin, whereas that for (-)-epigallocatechin gallate (EGCG) was 26 microM. Treatment with geraniin prior to application of okadaic acid, a tumor promoter on mouse skin initiated with 7,12-dimethylbenz(a)anthracene, reduced the percentage of tumor-bearing mice from 80.0 to 40.0% and the average numbers of tumor per mouse from 3.8 to 1.1 in week 20. Thus, geraniin has slightly weaker inhibitory activity than EGCG. Since geraniin and corilagin have been well investigated as representative tannins, we discuss here the new possibility of classical herbal medicine in the development of preventive agents for cancer and other life-style related diseases.

Modulation of gene expression by (-)-epigallocatechin gallate in PC-9 cells using a cDNA expression array.

Green tea is the most effective cancer preventive beverage. In the light of this, the mechanisms of action of tea polyphenols were investigated on the molecular levels. We present here the effects of (-)-epigallocatechin gallate (EGCG) on expression of 588 genes in human lung cancer cell line PC-9 cells, using a human cancer cDNA expression array. The levels of gene expression in non-treated control cells, and cells treated with EGCG alone, with the tumor promoter okadaic acid alone, and with EGCG plus okadaic acid, were studied, and their expression levels were classified into down-regulation (under 0.5 fold) and up-regulation (over 2.0 fold) by comparing with the levels of control. Non-treated PC-9 cells expressed 163 genes out of 588, and EGCG-treated cells induced down-regulated expression of 12 genes and up-regulated expression of 4 other genes. From a comparison of gene expression in the cells treated with EGCG and in cells treated with EGCG plus okadaic acid, we found the following genes commonly affected by EGCG: down-regulation of four genes, NF-kappaB inducing kinase (NIK), death-associated protein kinase 1 (DAPK 1), rhoB and tyrosine-protein kinase (SKY); up-regulation of one gene, retinoic acid receptor alpha1. Among them, we think down-regulation of NIK gene expression is significant for cancer prevention, based on evidence that inhibition of NF-kappaB activation is a result of inhibition of NIK/IKK signalling complex.

Cancer prevention with green tea and monitoring by a new biomarker, hnRNP B1.

The study of green tea polyphenols as a cancer preventative is approaching a new era, with significant results accumulating rapidly. This paper briefly reviews four topics related to mechanisms of action of tea polyphenols: (I) identification of the genes commonly affected by EGCG, as demonstrated by Clontech's Atlas cDNA Expression Array; (II) the significance of heterogeneous nuclear ribonucleoprotein B1 (hnRNP B1) as a new biomarker for early detection of lung cancer, and inhibition of its expression by EGCG; (III) the synergistic or additive effects of EGCG with the cancer preventive agents, sulindac and tamoxifen, on induction of apoptosis in PC-9 cells and on inhibition of intestinal tumor development in multiple intestinal neoplasia (Min) mice; (IV) the results of a 10 year prospective cohort study demonstrating the effectiveness of daily consumption of green tea in preventing cancer, and a prototype study for developing green tea beverage as cancer preventive.

Primary hepatic Burkitt's lymphoma with chronic hepatitis C.

The liver is an uncommon primary site for malignant lymphoma, and primary hepatic lymphoma has been found to make up 0.4% of all extranodal lymphomas. We report a rare case of a 75-year-old Japanese male with primary hepatic Burkitt's lymphoma, according to both the revised European-American Lymphoma classification and the new World Health Organization classification. As not only histological findings but also immunological features are deemed essential in the diagnosis of Burkitt's lymphoma, the previous 7 cases of primary hepatic Burkitt's lymphoma were not fully evaluated, using these criteria. As far as we know, this is the first case of primary hepatic Burkitt's lymphoma with typical features on histological, immunological and cytogenetical analysis. He had a history of chronic hepatitis C over several decades with subsequent liver cirrhosis. From our review of the literature and our case, the relationship between hepatitis C virus infection and the development of primary hepatic Burkitt's lymphoma remains obscure.

Helicobacter pylori membrane protein 1: a new carcinogenic factor of Helicobacter pylori.

Considering a suspected link between Helicobacter pylori infection and human stomach cancer, a new H. pylori gene for membrane protein 1 (HP-MP1) was recently cloned. Because HP-MP1 induces release of inflammatory cytokines and tumor necrosis factor-alpha acts as both initiator and tumor promoter, we studied the possible involvement of HP-MP1 in carcinogenesis of H. pylori. Two cell lines, BALB/3T3 cells as control and v-Ha-ras-transfected BALB/3T3 cells (Bhas 42 cells) as putative initiated cells, were each transfected with HP-MP1, urease B genes, or vector alone. All of the Bhas/mpl clones showed strong expression of tumor necrosis factor-alpha gene and produced tumors in 100% of nude mice. Two Bhas/ure clones showed weak tumorigenicity; the other Bhas and BALB clones showed none. Results indicate strong carcinogenic activity of HP-MP1 in cooperation with viral Ras protein and weak activity of urease B.

Thermodynamic stability of base pairs between 2-hydroxyadenine and incoming nucleotides as a determinant of nucleotide incorporation specificity during replication.

We investigated the thermodynamic stability of double-stranded DNAs with an oxidative DNA lesion, 2-hydroxyadenine (2-OH-Ade), in two different sequence contexts (5'-GA*C-3' and 5'-TA*A-3', A* represents 2-OH-Ade). When an A*-N pair (N, any nucleotide base) was located in the center of a duplex, the thermodynamic stabilities of the duplexes were similar for all the natural bases except A (N = T, C and G). On the other hand, for the duplexes with the A*-N pair at the end, which mimic the nucleotide incorporation step, the stabilities of the duplexes were dependent on their sequence. The order of stability is T > G > C >> A in the 5'-GA*C-3' sequences and T > A > C > G in the 5'-TA*A-3' sequences. Because T/G/C and T/A are nucleotides incorporated opposite to 2-OH-Ade in the 5'-GA*C-3' and 5'-TA*A-3' sequences, respectively, these results agree with the tendency of mutagenic misincorporation of the nucleotides opposite to 2-OH-Ade in vitro. Thus, the thermodynamic stability of the A*-N base pair may be an important factor for the mutation spectra of 2-OH-Ade.

Heterogeneous nuclear ribonucleoprotein B1 as early cancer biomarker for occult cancer of human lungs and bronchial dysplasia.

Heterogeneous nuclear ribonucleoprotein (hnRNP) B1 is a RNA-binding protein of Mr 37,000. We previously reported that hnRNP B1 was specifically overexpressed in the nuclei of human lung cancer cells, particularly in squamous cell carcinoma (E. Sueoka et al., Cancer Res., 59: 1404-1407, 1999). We extended this study to determine whether hnRNP BL was overexpressed in roentgenographically occult cancers of the lungs and premalignant lesions of squamous cell carcinomas, such as bronchial dysplasia. The additional object of our study was to examine the usefulness of hnRNP B1 as a potential diagnostic marker for squamous cell carcinoma of various organs, such as the oral cavity and esophagus in humans. Surgically resected specimens of bronchial dysplasia, lung cancers, and various human squamous cell carcinomas, collected at two hospitals in Japan, were subjected to immunohistochemical staining with anti-hnRNP B1 antibody. Overexpression of hnRNP B1 protein was observed in 100% of stage I lung cancer tissues, but it was not found in normal bronchial epithelium. Squamous cell carcinoma of the lungs showed stronger staining than other histological types, and elevation of hnRNP B1 was found in both roentgenographically occult lung cancers and bronchial dysplasia. Furthermore, cytological examination with anti-hnRNP B1 antibody detected cancer cells in sputum, suggesting the potential of hnRNP B1 protein as a new biomarker for the very early stage of lung cancer in humans. Because strong staining of hnRNP B1 was also observed in various squamous cell carcinomas of oral and esophageal tissues as shown in our recent reports, overexpression of hnRNP B1 seems to be a common event in the carcinogenic processes of squamous cell carcinoma. These results suggest that hnRNP B1 protein could be a useful diagnostic biomarker for both the very early stages of lung cancer and various squamous cell carcinomas in humans.

Combination cancer chemoprevention with green tea extract and sulindac shown in intestinal tumor formation in Min mice.

Green tea is the most effective beverage for cancer prevention in humans. Looking at the concept of combination cancer chemoprevention, we previously reported the synergistic effects of (-)-epigallocatechin gallate (EGCG) with sulindac, and the additive effects of EGCG with tamoxifen, on cancer-preventive activity in human lung cancer cell line PC-9. This paper reports confirmation of the synergistic effects of EGCG with sulindac on the inhibition of intestinal tumors in multiple intestinal neoplasia (Min) mice. Treatment with both green tea extract and sulindac significantly reduced the number of tumors from 72.3 +/- 28.3 to 32.0 +/- 18.7 tumors per mouse, a decrease of 44.3%, whereas treatment with green tea extract alone or with sulindac alone reduced it to 56.7 +/- 3.5 and 49.0 +/- 12.7, respectively. The results also indicated that green tea extract inhibited tumor growth in Min mice almost as potently as sulindac itself did. The three treated groups did not show any adenocarcinomas, whereas 10.8% of the control group did. Since cancer-preventive agents like sulindac and tamoxifen are associated with adverse effects, we discuss the possibility of non-toxic, combination cancer chemoprevention with green tea, looking at the goal of truly effective cancer prevention.

Vascular relaxant effects of toborinone on the isolated canine internal mammary artery.

This study was conducted to evaluate the vascular relaxant effects of toborinone on canine internal mammary ring preparations. We determined the concentration-contraction curves for various vasoconstrictors, namely norepinephrine, serotonin, U46619, endothelin-1, phenylephrine, and KCl in internal mammary artery (IMA) preparations, then assessed the vascular relaxant effects of the test drugs. As models, preparations with and without functional endothelium were used. As vasorelaxants, we used milrinone, papaverine, and nitroglycerin. Toborinone produced concentration-dependent relaxation in preparations precontracted with norepinephrine and serotonin. However, the vascular relaxant effect of toborinone on KCl-induced contraction was weaker than those on norepinephrine- and serotonin-induced contraction. Toborinone produced concentration-dependent relaxation in preparations with, and those without functional endothelium. There was no difference in the potency between the preparations with, and those without functional endothelium. The relaxing effect of toborinone on norepinephrine-induced contraction (EC50 = 1.3 x 10(-6) M) was significantly weaker than that of nitroglycerin (EC50 = 7.8 x 10(-8) M), equal to that of papaverine (EC50 = 2.2 x 10(-6) M), and significantly stronger than that of milrinone (EC50 = 3.3 x 10(-6) M). These results demonstrate that toborinone produces relaxant effects on canine IMA preparations, and that it may be effective in the treatment of IMA malperfusion syndrome.

A new function of green tea: prevention of lifestyle-related diseases.

In the normal human life span, there occur lifestyle-related diseases that may be preventable with nontoxic agents. This paper deals with the preventive activity of green tea in some lifestyle-related diseases. Green tea is one of the most practical cancer preventives, as we have shown in various in vitro and in vivo experiments, along with epidemiological studies. Among various biological effects of green tea, we have focused on its inhibitory effect on TNF-alpha gene expression mediated through inhibition of NF-kappaB and AP-1 activation. Based on our recent results with TNF-alpha-deficient mice, TNF-alpha is an endogenous tumor promoter. TNF-alpha is also known to be a central mediator in chronic inflammatory diseases such as rheumatoid arthritis and multiple sclerosis. We therefore hypothesized that green tea might be a preventive agent for chronic inflammatory diseases. To test this hypothesis, TNF-alpha transgenic mice, which overexpress TNF-alpha only in the lungs, were examined. The TNF-alpha transgenic mouse is an animal model of human idiopathic pulmonary fibrosis which also frequently develops lung cancer. Expressions of TNF-alpha and IL-6 were inhibited in the lungs of these mice after treatment with green tea in drinking water for 4 months. In addition, judging from the results of a prospective cohort study in Saitama Prefecture, Japan, green tea helps to prevent cardiovascular disease. In this study, a decreased relative risk of death from cardiovascular disease was found for people consuming over 10 cups of green tea a day, and green tea also had life-prolonging effects on cumulative survival. These data suggest that green tea has preventive effects on both chronic inflammatory diseases and lifestyle-related diseases (including cardiovascular disease and cancer), resulting in prolongation of life span.

Signal through gp130 activated by soluble interleukin (IL)-6 receptor (R) and IL-6 or IL-6R/IL-6 fusion protein enhances ex vivo expansion of human peripheral blood-derived hematopoietic progenitors.

This study was designed to investigate the effects of a combination of soluble interleukin (sIL)-6 receptor (R) and IL-6 on the ex vivo expansion of human peripheral blood (PB)-derived hematopoietic progenitor cells in a short-term serum-free liquid suspension culture system, using PB-derived CD34(+)IL-6R(+/-) cells as a target. In combination with stem cell factor (SCF), IL-3, and sIL-6R/IL-6, the expansion efficiency (EE) for granulocyte/macrophage colony-forming unit (CFU-GM) reached a peak level on day 10 of incubation. On the other hand, the EE for erythroid burst (BFU-E) and mixed colony-forming unit (CFU-Mix) reached a peak level on day 7 of incubation. Among the cytokine combinations tested, SCF + IL-3 + sIL-6R/IL-6 + flt3 ligand (FL) most effectively expanded CFU-GM and CFU-Mix. The maximum EEs for CFU-GM and CFU-Mix were 208-fold and 42-fold, respectively. While the EE for BFU-E was 70-90-fold in the presence of SCF + IL-3 + sIL-6R/IL-6, FL significantly augmented the EE for CFU-GM and CFU-Mix. In contrast, thrombopoietin (TPO) significantly augmented the EE for CFU-Mix. Interestingly, in combination with IL-3 and SCF, newly generated IL-6R/IL-6 fusion protein (FP) expanded PB-derived BFU-E and CFU-Mix twice more effectively than a combination of sIL-6R and IL-6. These results demonstrated that human PB-derived committed progenitors were effectively expanded in vitro using sIL-6R/IL-6 or FP, in combination with IL-3, SCF and/or FL or TPO, and that FP may transduce a stronger intracellular signal than a combination of sIL-6R and IL-6.