Intraoperative imprint cytology of the thyroid gland with computer-assisted morphometric analysis of cell clusters

Imprint preparations were used in addition to frozen sections in the intraoperative diagnosis of 37 cases of benign and malignant lesions of the thyroid gland, including adenomatous goiter, follicular adenoma, follicular carcinoma and papillary carcinoma. In the imprints, the cytologic features specific for carcinoma, as compared with benign lesions, were (1) the folding of the nuclear contour, (2) the increased density of the cytoplasmic matrix and (3) the frequent appearance of cell clusters of larger size. The size and frequency of cell clusters were morphometrically analyzed by a computer image analyzer. There was an increasing number of large clusters, plus the appearance of clusters of more than 300 micron in diameter, in both follicular and papillary carcinoma. In benign lesions, on the contrary, the majority of cells were isolated or in small clusters, the diameter of which never exceeded 300 micron in diameter. These results demonstrate that (1) the imprint cytology of the thyroid gland is useful in making a rapid intraoperative diagnosis and (2) the introduction of computer-assisted quantitative analysis is of practical value in the diagnosis of malignancy.     

Coenzyme Q10 as a potent compound that inhibits Cdt1–geminin interaction

A human replication initiation protein Cdt1 is a very central player in the cell cycle regulation of DNA replication, and geminin down-regulates Cdt1 function by directly binding to it. It has been demonstrated that Cdt1 hyperfunction resulting from Cdt1–geminin imbalance, for example by geminin silencing with siRNA, induces DNA re-replication and eventual cell death in some cancer-derived cell lines. In the present study, we first established a high throughput screening system based on modified ELISA (enzyme linked immunosorbent assay) to identify compounds that interfere with human Cdt1–geminin binding. Using this system, we found that coenzyme Q₁₀ (CoQ₁₀) can inhibit Cdt1–geminin interaction in vitro. CoQ compound is an isoprenoid quinine that functions as an electron carrier in the mitochondrial respiratory chain in eukaryotes. CoQ₁₀, having a longer isoprenoid chain, was the strongest inhibitor of Cdt1–geminin binding in the tested CoQs, with 50% inhibition observed at concentrations of 16.2 μM. Surface plasmon resonance analysis demonstrated that CoQ₁₀ bound selectively to Cdt1, but did not interact with geminin. Moreover, CoQ₁₀ had no influence on the interaction between Cdt1 and mini-chromosome maintenance (MCM)4/6/7 complexes. These results suggested that CoQ₁₀ inhibits Cdt1–geminin complex formation by binding to Cdt1 and thereby could liberate Cdt1 from inhibition by geminin. Using three-dimensional computer modeling analysis, CoQ₁₀ was considered to interact with the geminin interaction interface on Cdt1, and was assumed to make hydrogen bonds with the residue of Arg243 of Cdt1. CoQ₁₀ could prevent the growth of human cancer cells, although only at high concentrations, and it remains unclear whether such an inhibitory effect is associated with the interference with Cdt1–geminin binding. The application of inhibitors for the formation of Cdt1–geminin complex is discussed.     

Inhibitory effect of dietary carotenoids on dinitrofluorobenzene-induced contact hypersensitivity in mice

We evaluated the effect of carotenoids on the dinitrofluorobenzene (DNFB)-induced contact hypersensitivity in mice. Dietary carotenoids significantly inhibited ear swelling and reduced the contents of TNF-α and histamine in the DNFB-treated mice. Our results suggest that dietary carotenoids exerted an anti-inflammatory effect by suppressing mast cell degranulation in vivo.     

Structural evidence for guanidine-protein side chain interactions: crystal structure of CutA from Pyrococcus horikoshii in 3 M guanidine hydrochloride

This study was carried out to investigate the structural perturbation of the protein's local structure by the denaturants under non-denaturing conditions. Crystal structure of CutA from an archaeon Pyrococcus horikosii (PhoCutA), a heavy-metal binding protein, was determined at 1.6-angstroms resolution in the presence of 3 M guanidine HCl (GdnHCl). Native PhoCutA has a large number of short intramolecular hydrogen bonds and salt bridges on the protein surface, of which greater than 90% of hydrogen bonds and all salt bridges were retained in 3 M GdnHCl. Hydrogen bonds that disappeared in the GdnHCl crystal structure were mainly located on the protein surface, especially around the structurally perturbed loop, suggesting interactions between peptide groups and GdnHCl. Only a few GdnH+ ions were observed in the crystal structure, although none at the surface, of the protein. Two GdnH+ ions were observed in the center of the trimeric structure, replacing water molecules, and were hydrogen bonded with Asp84 and Asp86 of each chain. The exterior loop from Tyr39 to Lys44, including Trp40-Trp41, was perturbed structurally. Decreases in temperature factors were observed in beta strand 5 and the N terminus of helix 3. These results suggest the specific bindings of GdnH+ with some acidic residues and the non-specific bindings around Trp residues and peptide groups on the protein surface and that binding of GdnHCl to the native protein is limited, resulting in local structural perturbation.     

Psychiatrists' Attitudes toward Metabolic Adverse Events in Patients with Schizophrenia

Background

There is growing concern about the metabolic abnormalities in patients with schizophrenia.

Aims

The aim of this study was to assess the attitudes of psychiatrists toward metabolic adverse events in patients with schizophrenia.

Method

A brief questionnaire was constructed to cover the following broad areas: the psychiatrists'' recognition of the metabolic risk of antipsychotic therapy, pattern of monitoring patients for physical risks, practice pattern for physical risks, and knowledge of metabolic disturbance. In March 2012, the questionnaire was mailed to 8,482 psychiatrists who were working at hospitals belonging to the Japan Psychiatric Hospitals Association.

Results

The overall response rate was 2,583/8,482 (30.5%). Of the respondents, 85.2% (2,200/2,581) reported that they were concerned about prescribing antipsychotics that have a risk of elevating blood sugar; 47.6% (1,201/2,524) stated that their frequency of monitoring patients under antipsychotic treatment was based on their own experiences; and only 20.6% (5,22/2,534) of respondents answered that the frequency with which they monitored their patients was sufficient to reduce the metabolic risks.

Conclusions

Psychiatrists practicing in Japan were generally aware and concerned about the metabolic risks for patients being treated with antipsychotics. Although psychiatrists should monitor their patients for metabolic abnormalities to balance these risks, a limited number of psychiatrists answered that the frequency with which they monitored patients to reduce the metabolic risks was sufficient. Promotion of the best practices of pharmacotherapy and monitoring is needed for psychiatrists treating patients with schizophrenia.     

The Saccharomyces cerevisiae Msh2 mismatch repair protein localizes to recombination intermediates in vivo

Mismatch repair proteins act during double-strand break repair (DSBR) to correct mismatches in heteroduplex DNA, to suppress recombination between divergent sequences, and to promote removal of nonhomologous DNA at DSB ends. We investigated yeast Msh2p association with recombination intermediates in vivo using chromatin immunoprecipitation. During DSBR involving nonhomologous ends, Msh2p localized strongly to recipient and donor sequences. Localization required Msh3p and was greatly reduced in rad50delta strains. Minimal localization of Msh2p was observed during fully homologous repair, but this was increased in rad52delta strains. These findings argue that Msh2p-Msh3p associates with intermediates early in DSBR to participate in the rejection of homeologous pairing and to stabilize nonhomologous tails for cleavage by Rad1p-Rad10p endonuclease.     

Total synthesis of aurachins C,D, and L,and a structurally simplified analog of aurachin C

The quinoline antibiotics aurachins C, D, and L, and a structurally simplified analog of aurachin C were synthesized from 1-(2-nitrophenyl)butane-1,3-dione via reductive cyclizations of δ-nitro ketone intermediates, with zinc or iron as key steps. The results of antimicrobial tests indicate that the N-hydroxyquinolone nucleus mimics the electron carrier in the respiratory chain more strongly than the quinoline N-oxide nucleus.     

EGFR T790M Mutation as a Possible Target for Immunotherapy; Identification of HLA-A*0201-Restricted T Cell Epitopes Derived from the EGFR T790M Mutation

Treatment with epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs), such as gefitinib and erlotinib, has achieved high clinical response rates in patients with non–small cell lung cancers (NSCLCs). However, over time, most tumors develop acquired resistance to EGFR-TKIs, which is associated with the secondary EGFR T790M resistance mutation in about half the cases. Currently there are no effective treatment options for patients with this resistance mutation. Here we identified two novel HLA-A*0201 (A2)-restricted T cell epitopes containing the mutated methionine residue of the EGFR T790M mutation, T790M-5 (MQLMPFGCLL) and T790M-7 (LIMQLMPFGCL), as potential targets for EGFR-TKI-resistant patients. When peripheral blood cells were repeatedly stimulated in vitro with these two peptides and assessed by antigen-specific IFN-γ secretion, T cell lines responsive to T790M-5 and T790M-7 were established in 5 of 6 (83%) and 3 of 6 (50%) healthy donors, respectively. Additionally, the T790M-5- and T790M-7-specific T cell lines displayed an MHC class I-restricted reactivity against NSCLC cell lines expressing both HLA-A2 and the T790M mutation. Interestingly, the NSCLC patients with antigen-specific T cell responses to these epitopes showed a significantly less frequency of EGFR-T790M mutation than those without them [1 of 7 (14%) vs 9 of 15 (60%); chi-squared test, p  =  0.0449], indicating the negative correlation between the immune responses to the EGFR-T790M-derived epitopes and the presence of EGFR-T790M mutation in NSCLC patients. This finding could possibly be explained by the hypothesis that immune responses to the mutated neo-antigens derived from T790M might prevent the emergence of tumor cell variants with the T790M resistance mutation in NSCLC patients during EGFR-TKI treatment. Together, our results suggest that the identified T cell epitopes might provide a novel immunotherapeutic approach for prevention and/or treatment of EGFR-TKI resistance with the secondary EGFR T790M resistance mutation in NSCLC patients.     

Electrotransformation of Thiobacillus ferrooxidans with plasmids containing a mer determinant.

The mer operon from a strain of Thiobacillus ferrooxidans (C. Inoue, K. Sugawara, and T. Kusano, Mol. Microbiol. 5:2707-2718, 1991) consists of the regulatory gene merR and an operator-promoter region followed by merC and merA structural genes and differs from other known gram-negative mer operons. We have constructed four potential shuttle plasmids composed of a T. ferrooxidans-borne cryptic plasmid, a pUC18 plasmid, and the above-mentioned mer determinant as a selectable marker. Mercury ion-sensitive T. ferrooxidans strains were electroporated with constructed plasmids, and one strain, Y4-3 (of 30 independent strains tested), was found to have a transformation efficiency of 120 to 200 mercury-resistant colonies per microgram of plasmid DNA. This recipient strain was confirmed to be T. ferrooxidans by physiological, morphological, and chemotaxonomical data. The transformants carried a plasmid with no physical rearrangements through 25 passages under no selective pressure. Cell extracts showed mercury ion-dependent NADPH oxidation activity.