4f-derived Fermi surfaces of CeRu2(Si1-xGex)2 near the quantum critical point: resonant soft-X-ray ARPES study

Angle-resolved photoelectron spectroscopy in the Ce 3d-->4f excitation region was measured for the paramagnetic state of CeRu2Si2, CeRu2(Si0.82Ge0.18)2, and LaRu2Si2 to investigate the changes of the 4f electron Fermi surfaces around the quantum critical point. While the difference of the Fermi surfaces between CeRu2Si2 and LaRu2Si2 was experimentally confirmed, a strong 4f-electron character was observed in the band structures and the Fermi surfaces of CeRu2Si2 and CeRu2(Si0.82Ge0.18)2, consequently indicating a delocalized nature of the 4f electrons in both compounds. The absence of Fermi surface reconstruction across the critical composition suggests that SDW quantum criticality is more appropriate than local quantum criticality in CeRu2(Si1-xGex)2.

LKB1 mutations in mucinous bronchioloalveolar carcinoma occurring in Peutz-Jeghers syndrome patients

11047

Background: Mutations in the gene encoding Liver Kinase B1, LKB1, are common in patients with Peutz-Jeghers syndrome (PJS), which is characterized by mucocutaneous pigmentation, intestinal polyps and a high incidence of cancers at variable sites (colorectal, gynecological, breast, pancreas, and lung). Although tumors occurring in PJS patients are known to contain mucin-rich conmponents, mucinous bronchioloalveolar carcinomas (mBACs) arising from the PJS background have only rarely been reported. Here we report two mBAC patients with PJS. We further explored the LKB1 gene in these two patients and, in addition, eight sporadic mBAC patients. Methods: Frozen tissue specimens were collected from ten mBAC patients who underwent surgery in our department from 2002 to 2008, and high molecular weight genomic DNA was extracted from them and stocked in the bio-bank. Written informed consent was obtained from each patient, and ethical approval was obtained from the IRB. The nucleotide sequence of LKB1 (EX01–09) was determined by genomic PCR-direct sequencing. Loss of heterozygosity (LOH) was analyzed by high resolution fluorescent microsatellite analysis (HRFMA) using two microsatellite markers that encompass the LKB1 locus, D19S886 and D19S565. Results: Among 11 tumors derived from the 10 patients, 9 distinct LKB1 mutations were found in 7 tumors (4 G:C to A:T transitions; 3 G:C to C:G transversions; 2 single nucleotide insetion/deletion). All of three tumors obtained from the two PJS patients harbored a same sequence alteration. Although LOH was not observed in these tumors, independent sequence alterations were found in two of the three tumors, which may suggest biallelic inactivation of LKB1 in tumors occurred in the PJS patients. Conclusions: The relatively high frequency of LKB1 mutation in mBAC patients may suggest its implication in lung carcinogenesis, at least in mBAC, and its potential as a therapeutic target.

[Table: see text]

No significant financial relationships to disclose.

Activation of Wnt/beta-catenin signalling pathway induces chemoresistance to interferon-alpha/5-fluorouracil combination therapy for hepatocellular carcinoma

Type I IFN receptor type 2 (IFNAR2) expression correlates significantly with clinical response to interferon (IFN)-α/5-fluorouracil (5-FU) combination therapy for hepatocellular carcinoma (HCC). However, some IFNAR2-positive patients show no response to the therapy. This result suggests the possibility of other factors, which would be responsible for resistance to IFN-α/5-FU therapy. The aim of this study was to examine the mechanism of anti-proliferative effects of IFN-α/5-FU therapy and search for a biological marker of chemoresistance to such therapy. Gene expression profiling and molecular network analysis were used in the analysis of non-responders and responders with IFNAR2-positive HCC. The Wnt/β-catenin signalling pathway contributed to resistance to IFN-α/5-FU therapy. Immunohistochemical analysis showed positive epithelial cell adhesion molecule (Ep-CAM) expression, the target molecule of Wnt/β-catenin signalling, only in non-responders. In vitro studies showed that activation of Wnt/β-catenin signalling by glycogen synthesis kinase-3 inhibitor (6-bromoindirubin-3′-oxime (BIO)) induced chemoresistance to IFN-α/5-FU. BrdU-based cell proliferation ELISA and cell cycle analysis showed that concurrent addition of BIO and IFN-α/5-FU significantly to hepatoma cell cultures reduced the inhibitory effects of the latter two on DNA synthesis and accumulation of cells in the S-phase. The results indicate that activation of Wnt/β-catenin signalling pathway induces chemoresistance to IFN-α/5-FU therapy and suggest that Ep-CAM is a potentially useful marker for resistance to such therapy, especially in IFNAR2-positive cases.

Economic recession and health inequalities in Japan: analysis with a national sample, 1986-2001

OBJECTIVE

Little is known about whether economic crises widen health inequalities. Japan experienced more than 10 years of economic recession beginning in the 1990s. The question of whether socioeconomic-based inequality in self-rated health widened after the economic crisis was examined.

DESIGN, SETTING AND PARTICIPANTS

Repeated cross-sectional survey design. Two pooled datasets from 1986 and 1989 and from 1998 and 2001 were analysed separately, and temporal change was examined. The study took place in Japan among the working-age population (20-60 years old). The two surveys consisted of 168 801 and 150 016 people, respectively, with about an 80% response rate.

RESULTS

The absolute percentages of people reporting poor health declined across all socioeconomic statuses following the crisis. However, after controlling for confounding factors, the odds ratio (OR) for poor self-rated health (95% confidence intervals) among middle-class non-manual workers (clerical/sales/service workers) compared with the highest class workers (managers/administrators) was 1.02 (0.92 to 1.14) before the crisis but increased to 1.14 (1.02 to 1.29) after the crisis (p for temporal change = 0.02). The association was stronger among males. The adjusted ORs among professional workers and young female homemakers also marginally increased over time. Unemployed people were twice as likely to report poor health compared with the highest class workers throughout the period. Self-rated health of people with middle to higher incomes deteriorated in relative terms following the crisis compared with that of lower income people.

CONCLUSIONS

Self-rated health improved in absolute terms for all occupational groups even after the economic recession. However, the relative disparity increased between the top and middle occupational groups in men.

Exploratory study of clonality determined by expression of tumor markers in intrinsic subtypes of breast cancers

Abstract #5060

[Background] However expression profile-based intrinsic subtypes revealed heterogeneity of breast cancer, several biological issues are not clarified yet, especially in tumor development. [Objectives] In order to clarify the relationship between intrinsic subtypes and positivity of tumor markers (TMs), CEA, CA15-3, BCA225 and NCC-ST439 were measured from sera taken from patients at the relapse retrospectively. In addition to the analysis of positivity of TMs, migration of TMs were analyzed in each intrinsic subtype, especially focused on changes of CA15-3 (equivalent to soluble MUC1) to identify the heterogeneity and development to other subtypes in the meaning of TMs expression. [Methods] Sera were collected from seventy five patients of newly diagnosed metastatic breast cancer. Intrinsic subtypes were simply determined by immunohistochemical staining as Luminal A (LA) ,B (LB), HER2 and TN. The positivity of TM was defined if it elevated 20% higher than normal upper limit. [Results] The positive rate of any TMs were higher in order of LA, LB, HER2 and TN. There was significant difference between Luminal (LA+LB) and TN in positive rate of TMs(p<0.05). If focused on mammary epithelium development marker MUC1 (CA15-3 as a soluble form), it was significantly elevated in Luminal (LA+LB) than HER2 and TN(p<0.05). Interestingly, 18 of 23 (72.3%) TN tumors showed all TMs negative at the relapse, although 4 of 18 (22.2%) TN tumors developed to TMs positive after palliative chemotherapies. [Conclusion] Luminal type showed higher expression of TMs at the relapse. It might be explained by the fact that common TMs were selected as responsive serum proteins to the tumor volume of dominant population of breast cancer by chance. But if we integrate the idea that CA15-3 as a development marker, luminal cancer was developed from ER+ highly developed progenitor and HER2 and TN might be developed from ER- progenitor lineage. The migration of TMs of TN after palliative chemotherapies might be illustrated with clonal selection by chemosensitivity. These phenomenon will be understood by further biological experiments and prospective clinical trials to improve the outcome of metastatic breast cancer.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5060.

Nanogroove formation by ion irradiation on indentation-modified amorphous SiO(2)

Ion beams are widely used for micro/nanostructure fabrication with unique features of the energetic processes. In this work, we present a self-assembled nanostructure fabrication by ion irradiation with a patterned strain/stress field. The patterned strain/stress field is introduced by micro-Vickers indentation to amorphous SiO(2) (load = 100 mN). After irradiation of 60 keV Cu(-) ions, nanogrooves (width from 150 to 250 nm) were created at the indentation edge. Under the ion irradiation of a constant ion flux, the nanogroove size linearly increased with ion fluence from 2 × 10(16) to 1.2 × 10(17) ions cm(-2). Comparison of indented samples after irradiation and thermal annealing suggests that the nanogrooving originates from ion beam interactions with residual stress/strain by indentation and that a non-thermal effect results from the ion irradiation processes. Cross-sectional TEM analysis showed that the grooves extend over 200 nm below the surface, implying that the groove growth is not caused by surface diffusion. It is concluded from the results that the grooving is due to irradiation-induced mass transport accompanied by vacancy aggregation at the interface between the indented and non-indented areas.

Long-term effect of tacrolimus therapy in patients with refractory ulcerative colitis

BACKGROUND

Little is known about long-term outcome of tacrolimus therapy for ulcerative colitis. Aim To evaluate long-term efficacy and safety of tacrolimus in Japanese patients with refractory ulcerative colitis.

METHODS

Twenty-seven patients with UC refractory to conventional therapy were administered tacrolimus with trough whole-blood levels of 10-15 ng/mL to induce remission and 5-10 ng/mL to maintain remission. Median treatment duration was 11 months (1-39 months) and median follow-up duration was 17 months (2-65 months). Evaluation of the clinical response was based on a modified Truelove-Witts severity index (MTWSI).

RESULTS

Tacrolimus produced a clinical response in 21 patients (77.8%), and remission was achieved in 19 of these 21 (70.4%) within 30 days. Overall cumulative colectomy-free survival was estimated as 62.3% at 65 months. In 18 of 19 patients treated with corticosteroids at the initiation of tacrolimus therapy, corticosteroids were discontinued or tapered. Adverse events were tremor (25.9%), renal function impairment (18.5%), infectious disease (14.8%), hot flashes (11.1%), hyperkalaemia (7.4%), headache (7.4%), epigastralgia (7.4%) and nausea (3.7%). No mortality occurred.

CONCLUSION

Long-term administration of tacrolimus appears to be an effective and well-tolerated treatment for Japanese patients with refractory ulcerative colitis.

Nature of magnetic coupling between Mn ions in As-grown Ga1-xMnxAs studied by X-ray magnetic circular dichroism

The magnetic properties of as-grown Ga1-xMnxAs have been investigated by the systematic measurements of temperature and magnetic field dependent soft x-ray magnetic circular dichroism (XMCD). The intrinsic XMCD intensity at high temperatures obeys the Curie-Weiss law, but a residual spin magnetic moment appears already around 100 K, significantly above the Curie temperature (T_{C}), suggesting that short-range ferromagnetic correlations are developed above T_{C}. The present results also suggest that the antiferromagnetic interaction between the substitutional and interstitial Mn (Mn_{int}) ions exists and that the amount of the Mn_{int} affects T_{C}.

[Novel coronary transfer technique for transposition of the great arteries with Planché type II coronary anatomy]

The arterial switch operation has evolved to become the treatment of choice for most of transposition of the great arteries and some types of double outlet right ventricle. Technical improvement in the coronary transfer is the major contribution to the evolution of this procedure. We proposed a novel technique of coronary transfer for the patients with rare but difficult coronary anatomy of Planché type II. We believe it could become one of the options of coronary transfer technique and contribute to the completion of arterial switch operation with uncommon coronary artery patterns.

Amelogenin positive cells scattered in the interstitial component of odontogenic fibromas

BACKGROUND

Odontogenic tumours are often biphasic, consisting of epithelial and interstitial components, with an origin that is not well understood. Odontogenic fibromas are rich in mesenchymal component, but also have many epithelial nests.

AIMS

To investigate the origin of this tumour by immunohistochemistry.

METHODS

The expression of several odontogenic and epithelial markers, including amelogenin, was investigated by immunofluorescent studies.

RESULTS

Immunohistochemical analysis showed that epithelial nests exhibited E-cadherin expression, but not amelogenin. Amelogenin positive cells were scattered in the fibrous tissue, which did not exhibit epithelial marker expression except for epithelial membrane antigen. In one case that had received a test biopsy before whole resection of tumour, amelogenin positive cells were distributed in the regenerating mucosal epithelium or subepithelial tissue.

CONCLUSIONS

Results indicate that amelogenin positive cells of odontogenic fibromas have an epithelial origin and may have the potential for epithelial mesenchymal transition, which has not to date been investigated in benign tumours.